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1 | /* | |
2 | * QEMU System Emulator block driver | |
3 | * | |
4 | * Copyright (c) 2003 Fabrice Bellard | |
5 | * Copyright (c) 2020 Virtuozzo International GmbH. | |
6 | * | |
7 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
8 | * of this software and associated documentation files (the "Software"), to deal | |
9 | * in the Software without restriction, including without limitation the rights | |
10 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
11 | * copies of the Software, and to permit persons to whom the Software is | |
12 | * furnished to do so, subject to the following conditions: | |
13 | * | |
14 | * The above copyright notice and this permission notice shall be included in | |
15 | * all copies or substantial portions of the Software. | |
16 | * | |
17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
18 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
19 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
20 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
21 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
22 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
23 | * THE SOFTWARE. | |
24 | */ | |
25 | ||
26 | #include "qemu/osdep.h" | |
27 | #include "block/trace.h" | |
28 | #include "block/block_int.h" | |
29 | #include "block/blockjob.h" | |
30 | #include "block/dirty-bitmap.h" | |
31 | #include "block/fuse.h" | |
32 | #include "block/nbd.h" | |
33 | #include "block/qdict.h" | |
34 | #include "qemu/error-report.h" | |
35 | #include "block/module_block.h" | |
36 | #include "qemu/main-loop.h" | |
37 | #include "qemu/module.h" | |
38 | #include "qapi/error.h" | |
39 | #include "qapi/qmp/qdict.h" | |
40 | #include "qapi/qmp/qjson.h" | |
41 | #include "qapi/qmp/qnull.h" | |
42 | #include "qapi/qmp/qstring.h" | |
43 | #include "qapi/qobject-output-visitor.h" | |
44 | #include "qapi/qapi-visit-block-core.h" | |
45 | #include "sysemu/block-backend.h" | |
46 | #include "qemu/notify.h" | |
47 | #include "qemu/option.h" | |
48 | #include "qemu/coroutine.h" | |
49 | #include "block/qapi.h" | |
50 | #include "qemu/timer.h" | |
51 | #include "qemu/cutils.h" | |
52 | #include "qemu/id.h" | |
53 | #include "qemu/range.h" | |
54 | #include "qemu/rcu.h" | |
55 | #include "block/coroutines.h" | |
56 | ||
57 | #ifdef CONFIG_BSD | |
58 | #include <sys/ioctl.h> | |
59 | #include <sys/queue.h> | |
60 | #if defined(HAVE_SYS_DISK_H) | |
61 | #include <sys/disk.h> | |
62 | #endif | |
63 | #endif | |
64 | ||
65 | #ifdef _WIN32 | |
66 | #include <windows.h> | |
67 | #endif | |
68 | ||
69 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ | |
70 | ||
71 | /* Protected by BQL */ | |
72 | static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states = | |
73 | QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); | |
74 | ||
75 | /* Protected by BQL */ | |
76 | static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states = | |
77 | QTAILQ_HEAD_INITIALIZER(all_bdrv_states); | |
78 | ||
79 | /* Protected by BQL */ | |
80 | static QLIST_HEAD(, BlockDriver) bdrv_drivers = | |
81 | QLIST_HEAD_INITIALIZER(bdrv_drivers); | |
82 | ||
83 | static BlockDriverState *bdrv_open_inherit(const char *filename, | |
84 | const char *reference, | |
85 | QDict *options, int flags, | |
86 | BlockDriverState *parent, | |
87 | const BdrvChildClass *child_class, | |
88 | BdrvChildRole child_role, | |
89 | Error **errp); | |
90 | ||
91 | static bool bdrv_recurse_has_child(BlockDriverState *bs, | |
92 | BlockDriverState *child); | |
93 | ||
94 | static void bdrv_replace_child_noperm(BdrvChild *child, | |
95 | BlockDriverState *new_bs); | |
96 | static void bdrv_remove_child(BdrvChild *child, Transaction *tran); | |
97 | ||
98 | static int bdrv_reopen_prepare(BDRVReopenState *reopen_state, | |
99 | BlockReopenQueue *queue, | |
100 | Transaction *change_child_tran, Error **errp); | |
101 | static void bdrv_reopen_commit(BDRVReopenState *reopen_state); | |
102 | static void bdrv_reopen_abort(BDRVReopenState *reopen_state); | |
103 | ||
104 | static bool bdrv_backing_overridden(BlockDriverState *bs); | |
105 | ||
106 | static bool bdrv_change_aio_context(BlockDriverState *bs, AioContext *ctx, | |
107 | GHashTable *visited, Transaction *tran, | |
108 | Error **errp); | |
109 | ||
110 | /* If non-zero, use only whitelisted block drivers */ | |
111 | static int use_bdrv_whitelist; | |
112 | ||
113 | #ifdef _WIN32 | |
114 | static int is_windows_drive_prefix(const char *filename) | |
115 | { | |
116 | return (((filename[0] >= 'a' && filename[0] <= 'z') || | |
117 | (filename[0] >= 'A' && filename[0] <= 'Z')) && | |
118 | filename[1] == ':'); | |
119 | } | |
120 | ||
121 | int is_windows_drive(const char *filename) | |
122 | { | |
123 | if (is_windows_drive_prefix(filename) && | |
124 | filename[2] == '\0') | |
125 | return 1; | |
126 | if (strstart(filename, "\\\\.\\", NULL) || | |
127 | strstart(filename, "//./", NULL)) | |
128 | return 1; | |
129 | return 0; | |
130 | } | |
131 | #endif | |
132 | ||
133 | size_t bdrv_opt_mem_align(BlockDriverState *bs) | |
134 | { | |
135 | if (!bs || !bs->drv) { | |
136 | /* page size or 4k (hdd sector size) should be on the safe side */ | |
137 | return MAX(4096, qemu_real_host_page_size()); | |
138 | } | |
139 | IO_CODE(); | |
140 | ||
141 | return bs->bl.opt_mem_alignment; | |
142 | } | |
143 | ||
144 | size_t bdrv_min_mem_align(BlockDriverState *bs) | |
145 | { | |
146 | if (!bs || !bs->drv) { | |
147 | /* page size or 4k (hdd sector size) should be on the safe side */ | |
148 | return MAX(4096, qemu_real_host_page_size()); | |
149 | } | |
150 | IO_CODE(); | |
151 | ||
152 | return bs->bl.min_mem_alignment; | |
153 | } | |
154 | ||
155 | /* check if the path starts with "<protocol>:" */ | |
156 | int path_has_protocol(const char *path) | |
157 | { | |
158 | const char *p; | |
159 | ||
160 | #ifdef _WIN32 | |
161 | if (is_windows_drive(path) || | |
162 | is_windows_drive_prefix(path)) { | |
163 | return 0; | |
164 | } | |
165 | p = path + strcspn(path, ":/\\"); | |
166 | #else | |
167 | p = path + strcspn(path, ":/"); | |
168 | #endif | |
169 | ||
170 | return *p == ':'; | |
171 | } | |
172 | ||
173 | int path_is_absolute(const char *path) | |
174 | { | |
175 | #ifdef _WIN32 | |
176 | /* specific case for names like: "\\.\d:" */ | |
177 | if (is_windows_drive(path) || is_windows_drive_prefix(path)) { | |
178 | return 1; | |
179 | } | |
180 | return (*path == '/' || *path == '\\'); | |
181 | #else | |
182 | return (*path == '/'); | |
183 | #endif | |
184 | } | |
185 | ||
186 | /* if filename is absolute, just return its duplicate. Otherwise, build a | |
187 | path to it by considering it is relative to base_path. URL are | |
188 | supported. */ | |
189 | char *path_combine(const char *base_path, const char *filename) | |
190 | { | |
191 | const char *protocol_stripped = NULL; | |
192 | const char *p, *p1; | |
193 | char *result; | |
194 | int len; | |
195 | ||
196 | if (path_is_absolute(filename)) { | |
197 | return g_strdup(filename); | |
198 | } | |
199 | ||
200 | if (path_has_protocol(base_path)) { | |
201 | protocol_stripped = strchr(base_path, ':'); | |
202 | if (protocol_stripped) { | |
203 | protocol_stripped++; | |
204 | } | |
205 | } | |
206 | p = protocol_stripped ?: base_path; | |
207 | ||
208 | p1 = strrchr(base_path, '/'); | |
209 | #ifdef _WIN32 | |
210 | { | |
211 | const char *p2; | |
212 | p2 = strrchr(base_path, '\\'); | |
213 | if (!p1 || p2 > p1) { | |
214 | p1 = p2; | |
215 | } | |
216 | } | |
217 | #endif | |
218 | if (p1) { | |
219 | p1++; | |
220 | } else { | |
221 | p1 = base_path; | |
222 | } | |
223 | if (p1 > p) { | |
224 | p = p1; | |
225 | } | |
226 | len = p - base_path; | |
227 | ||
228 | result = g_malloc(len + strlen(filename) + 1); | |
229 | memcpy(result, base_path, len); | |
230 | strcpy(result + len, filename); | |
231 | ||
232 | return result; | |
233 | } | |
234 | ||
235 | /* | |
236 | * Helper function for bdrv_parse_filename() implementations to remove optional | |
237 | * protocol prefixes (especially "file:") from a filename and for putting the | |
238 | * stripped filename into the options QDict if there is such a prefix. | |
239 | */ | |
240 | void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix, | |
241 | QDict *options) | |
242 | { | |
243 | if (strstart(filename, prefix, &filename)) { | |
244 | /* Stripping the explicit protocol prefix may result in a protocol | |
245 | * prefix being (wrongly) detected (if the filename contains a colon) */ | |
246 | if (path_has_protocol(filename)) { | |
247 | GString *fat_filename; | |
248 | ||
249 | /* This means there is some colon before the first slash; therefore, | |
250 | * this cannot be an absolute path */ | |
251 | assert(!path_is_absolute(filename)); | |
252 | ||
253 | /* And we can thus fix the protocol detection issue by prefixing it | |
254 | * by "./" */ | |
255 | fat_filename = g_string_new("./"); | |
256 | g_string_append(fat_filename, filename); | |
257 | ||
258 | assert(!path_has_protocol(fat_filename->str)); | |
259 | ||
260 | qdict_put(options, "filename", | |
261 | qstring_from_gstring(fat_filename)); | |
262 | } else { | |
263 | /* If no protocol prefix was detected, we can use the shortened | |
264 | * filename as-is */ | |
265 | qdict_put_str(options, "filename", filename); | |
266 | } | |
267 | } | |
268 | } | |
269 | ||
270 | ||
271 | /* Returns whether the image file is opened as read-only. Note that this can | |
272 | * return false and writing to the image file is still not possible because the | |
273 | * image is inactivated. */ | |
274 | bool bdrv_is_read_only(BlockDriverState *bs) | |
275 | { | |
276 | IO_CODE(); | |
277 | return !(bs->open_flags & BDRV_O_RDWR); | |
278 | } | |
279 | ||
280 | static int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, | |
281 | bool ignore_allow_rdw, Error **errp) | |
282 | { | |
283 | IO_CODE(); | |
284 | ||
285 | /* Do not set read_only if copy_on_read is enabled */ | |
286 | if (bs->copy_on_read && read_only) { | |
287 | error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled", | |
288 | bdrv_get_device_or_node_name(bs)); | |
289 | return -EINVAL; | |
290 | } | |
291 | ||
292 | /* Do not clear read_only if it is prohibited */ | |
293 | if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) && | |
294 | !ignore_allow_rdw) | |
295 | { | |
296 | error_setg(errp, "Node '%s' is read only", | |
297 | bdrv_get_device_or_node_name(bs)); | |
298 | return -EPERM; | |
299 | } | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
304 | /* | |
305 | * Called by a driver that can only provide a read-only image. | |
306 | * | |
307 | * Returns 0 if the node is already read-only or it could switch the node to | |
308 | * read-only because BDRV_O_AUTO_RDONLY is set. | |
309 | * | |
310 | * Returns -EACCES if the node is read-write and BDRV_O_AUTO_RDONLY is not set | |
311 | * or bdrv_can_set_read_only() forbids making the node read-only. If @errmsg | |
312 | * is not NULL, it is used as the error message for the Error object. | |
313 | */ | |
314 | int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg, | |
315 | Error **errp) | |
316 | { | |
317 | int ret = 0; | |
318 | IO_CODE(); | |
319 | ||
320 | if (!(bs->open_flags & BDRV_O_RDWR)) { | |
321 | return 0; | |
322 | } | |
323 | if (!(bs->open_flags & BDRV_O_AUTO_RDONLY)) { | |
324 | goto fail; | |
325 | } | |
326 | ||
327 | ret = bdrv_can_set_read_only(bs, true, false, NULL); | |
328 | if (ret < 0) { | |
329 | goto fail; | |
330 | } | |
331 | ||
332 | bs->open_flags &= ~BDRV_O_RDWR; | |
333 | ||
334 | return 0; | |
335 | ||
336 | fail: | |
337 | error_setg(errp, "%s", errmsg ?: "Image is read-only"); | |
338 | return -EACCES; | |
339 | } | |
340 | ||
341 | /* | |
342 | * If @backing is empty, this function returns NULL without setting | |
343 | * @errp. In all other cases, NULL will only be returned with @errp | |
344 | * set. | |
345 | * | |
346 | * Therefore, a return value of NULL without @errp set means that | |
347 | * there is no backing file; if @errp is set, there is one but its | |
348 | * absolute filename cannot be generated. | |
349 | */ | |
350 | char *bdrv_get_full_backing_filename_from_filename(const char *backed, | |
351 | const char *backing, | |
352 | Error **errp) | |
353 | { | |
354 | if (backing[0] == '\0') { | |
355 | return NULL; | |
356 | } else if (path_has_protocol(backing) || path_is_absolute(backing)) { | |
357 | return g_strdup(backing); | |
358 | } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) { | |
359 | error_setg(errp, "Cannot use relative backing file names for '%s'", | |
360 | backed); | |
361 | return NULL; | |
362 | } else { | |
363 | return path_combine(backed, backing); | |
364 | } | |
365 | } | |
366 | ||
367 | /* | |
368 | * If @filename is empty or NULL, this function returns NULL without | |
369 | * setting @errp. In all other cases, NULL will only be returned with | |
370 | * @errp set. | |
371 | */ | |
372 | static char *bdrv_make_absolute_filename(BlockDriverState *relative_to, | |
373 | const char *filename, Error **errp) | |
374 | { | |
375 | char *dir, *full_name; | |
376 | ||
377 | if (!filename || filename[0] == '\0') { | |
378 | return NULL; | |
379 | } else if (path_has_protocol(filename) || path_is_absolute(filename)) { | |
380 | return g_strdup(filename); | |
381 | } | |
382 | ||
383 | dir = bdrv_dirname(relative_to, errp); | |
384 | if (!dir) { | |
385 | return NULL; | |
386 | } | |
387 | ||
388 | full_name = g_strconcat(dir, filename, NULL); | |
389 | g_free(dir); | |
390 | return full_name; | |
391 | } | |
392 | ||
393 | char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp) | |
394 | { | |
395 | GLOBAL_STATE_CODE(); | |
396 | return bdrv_make_absolute_filename(bs, bs->backing_file, errp); | |
397 | } | |
398 | ||
399 | void bdrv_register(BlockDriver *bdrv) | |
400 | { | |
401 | assert(bdrv->format_name); | |
402 | GLOBAL_STATE_CODE(); | |
403 | QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); | |
404 | } | |
405 | ||
406 | BlockDriverState *bdrv_new(void) | |
407 | { | |
408 | BlockDriverState *bs; | |
409 | int i; | |
410 | ||
411 | GLOBAL_STATE_CODE(); | |
412 | ||
413 | bs = g_new0(BlockDriverState, 1); | |
414 | QLIST_INIT(&bs->dirty_bitmaps); | |
415 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
416 | QLIST_INIT(&bs->op_blockers[i]); | |
417 | } | |
418 | qemu_co_mutex_init(&bs->reqs_lock); | |
419 | qemu_mutex_init(&bs->dirty_bitmap_mutex); | |
420 | bs->refcnt = 1; | |
421 | bs->aio_context = qemu_get_aio_context(); | |
422 | ||
423 | qemu_co_queue_init(&bs->flush_queue); | |
424 | ||
425 | qemu_co_mutex_init(&bs->bsc_modify_lock); | |
426 | bs->block_status_cache = g_new0(BdrvBlockStatusCache, 1); | |
427 | ||
428 | for (i = 0; i < bdrv_drain_all_count; i++) { | |
429 | bdrv_drained_begin(bs); | |
430 | } | |
431 | ||
432 | QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list); | |
433 | ||
434 | return bs; | |
435 | } | |
436 | ||
437 | static BlockDriver *bdrv_do_find_format(const char *format_name) | |
438 | { | |
439 | BlockDriver *drv1; | |
440 | GLOBAL_STATE_CODE(); | |
441 | ||
442 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
443 | if (!strcmp(drv1->format_name, format_name)) { | |
444 | return drv1; | |
445 | } | |
446 | } | |
447 | ||
448 | return NULL; | |
449 | } | |
450 | ||
451 | BlockDriver *bdrv_find_format(const char *format_name) | |
452 | { | |
453 | BlockDriver *drv1; | |
454 | int i; | |
455 | ||
456 | GLOBAL_STATE_CODE(); | |
457 | ||
458 | drv1 = bdrv_do_find_format(format_name); | |
459 | if (drv1) { | |
460 | return drv1; | |
461 | } | |
462 | ||
463 | /* The driver isn't registered, maybe we need to load a module */ | |
464 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { | |
465 | if (!strcmp(block_driver_modules[i].format_name, format_name)) { | |
466 | Error *local_err = NULL; | |
467 | int rv = block_module_load(block_driver_modules[i].library_name, | |
468 | &local_err); | |
469 | if (rv > 0) { | |
470 | return bdrv_do_find_format(format_name); | |
471 | } else if (rv < 0) { | |
472 | error_report_err(local_err); | |
473 | } | |
474 | break; | |
475 | } | |
476 | } | |
477 | return NULL; | |
478 | } | |
479 | ||
480 | static int bdrv_format_is_whitelisted(const char *format_name, bool read_only) | |
481 | { | |
482 | static const char *whitelist_rw[] = { | |
483 | CONFIG_BDRV_RW_WHITELIST | |
484 | NULL | |
485 | }; | |
486 | static const char *whitelist_ro[] = { | |
487 | CONFIG_BDRV_RO_WHITELIST | |
488 | NULL | |
489 | }; | |
490 | const char **p; | |
491 | ||
492 | if (!whitelist_rw[0] && !whitelist_ro[0]) { | |
493 | return 1; /* no whitelist, anything goes */ | |
494 | } | |
495 | ||
496 | for (p = whitelist_rw; *p; p++) { | |
497 | if (!strcmp(format_name, *p)) { | |
498 | return 1; | |
499 | } | |
500 | } | |
501 | if (read_only) { | |
502 | for (p = whitelist_ro; *p; p++) { | |
503 | if (!strcmp(format_name, *p)) { | |
504 | return 1; | |
505 | } | |
506 | } | |
507 | } | |
508 | return 0; | |
509 | } | |
510 | ||
511 | int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) | |
512 | { | |
513 | GLOBAL_STATE_CODE(); | |
514 | return bdrv_format_is_whitelisted(drv->format_name, read_only); | |
515 | } | |
516 | ||
517 | bool bdrv_uses_whitelist(void) | |
518 | { | |
519 | return use_bdrv_whitelist; | |
520 | } | |
521 | ||
522 | typedef struct CreateCo { | |
523 | BlockDriver *drv; | |
524 | char *filename; | |
525 | QemuOpts *opts; | |
526 | int ret; | |
527 | Error *err; | |
528 | } CreateCo; | |
529 | ||
530 | int coroutine_fn bdrv_co_create(BlockDriver *drv, const char *filename, | |
531 | QemuOpts *opts, Error **errp) | |
532 | { | |
533 | int ret; | |
534 | GLOBAL_STATE_CODE(); | |
535 | ERRP_GUARD(); | |
536 | assert_bdrv_graph_readable(); | |
537 | ||
538 | if (!drv->bdrv_co_create_opts) { | |
539 | error_setg(errp, "Driver '%s' does not support image creation", | |
540 | drv->format_name); | |
541 | return -ENOTSUP; | |
542 | } | |
543 | ||
544 | ret = drv->bdrv_co_create_opts(drv, filename, opts, errp); | |
545 | if (ret < 0 && !*errp) { | |
546 | error_setg_errno(errp, -ret, "Could not create image"); | |
547 | } | |
548 | ||
549 | return ret; | |
550 | } | |
551 | ||
552 | /** | |
553 | * Helper function for bdrv_create_file_fallback(): Resize @blk to at | |
554 | * least the given @minimum_size. | |
555 | * | |
556 | * On success, return @blk's actual length. | |
557 | * Otherwise, return -errno. | |
558 | */ | |
559 | static int64_t create_file_fallback_truncate(BlockBackend *blk, | |
560 | int64_t minimum_size, Error **errp) | |
561 | { | |
562 | Error *local_err = NULL; | |
563 | int64_t size; | |
564 | int ret; | |
565 | ||
566 | GLOBAL_STATE_CODE(); | |
567 | ||
568 | ret = blk_truncate(blk, minimum_size, false, PREALLOC_MODE_OFF, 0, | |
569 | &local_err); | |
570 | if (ret < 0 && ret != -ENOTSUP) { | |
571 | error_propagate(errp, local_err); | |
572 | return ret; | |
573 | } | |
574 | ||
575 | size = blk_getlength(blk); | |
576 | if (size < 0) { | |
577 | error_free(local_err); | |
578 | error_setg_errno(errp, -size, | |
579 | "Failed to inquire the new image file's length"); | |
580 | return size; | |
581 | } | |
582 | ||
583 | if (size < minimum_size) { | |
584 | /* Need to grow the image, but we failed to do that */ | |
585 | error_propagate(errp, local_err); | |
586 | return -ENOTSUP; | |
587 | } | |
588 | ||
589 | error_free(local_err); | |
590 | local_err = NULL; | |
591 | ||
592 | return size; | |
593 | } | |
594 | ||
595 | /** | |
596 | * Helper function for bdrv_create_file_fallback(): Zero the first | |
597 | * sector to remove any potentially pre-existing image header. | |
598 | */ | |
599 | static int coroutine_fn | |
600 | create_file_fallback_zero_first_sector(BlockBackend *blk, | |
601 | int64_t current_size, | |
602 | Error **errp) | |
603 | { | |
604 | int64_t bytes_to_clear; | |
605 | int ret; | |
606 | ||
607 | GLOBAL_STATE_CODE(); | |
608 | ||
609 | bytes_to_clear = MIN(current_size, BDRV_SECTOR_SIZE); | |
610 | if (bytes_to_clear) { | |
611 | ret = blk_co_pwrite_zeroes(blk, 0, bytes_to_clear, BDRV_REQ_MAY_UNMAP); | |
612 | if (ret < 0) { | |
613 | error_setg_errno(errp, -ret, | |
614 | "Failed to clear the new image's first sector"); | |
615 | return ret; | |
616 | } | |
617 | } | |
618 | ||
619 | return 0; | |
620 | } | |
621 | ||
622 | /** | |
623 | * Simple implementation of bdrv_co_create_opts for protocol drivers | |
624 | * which only support creation via opening a file | |
625 | * (usually existing raw storage device) | |
626 | */ | |
627 | int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv, | |
628 | const char *filename, | |
629 | QemuOpts *opts, | |
630 | Error **errp) | |
631 | { | |
632 | BlockBackend *blk; | |
633 | QDict *options; | |
634 | int64_t size = 0; | |
635 | char *buf = NULL; | |
636 | PreallocMode prealloc; | |
637 | Error *local_err = NULL; | |
638 | int ret; | |
639 | ||
640 | GLOBAL_STATE_CODE(); | |
641 | ||
642 | size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); | |
643 | buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); | |
644 | prealloc = qapi_enum_parse(&PreallocMode_lookup, buf, | |
645 | PREALLOC_MODE_OFF, &local_err); | |
646 | g_free(buf); | |
647 | if (local_err) { | |
648 | error_propagate(errp, local_err); | |
649 | return -EINVAL; | |
650 | } | |
651 | ||
652 | if (prealloc != PREALLOC_MODE_OFF) { | |
653 | error_setg(errp, "Unsupported preallocation mode '%s'", | |
654 | PreallocMode_str(prealloc)); | |
655 | return -ENOTSUP; | |
656 | } | |
657 | ||
658 | options = qdict_new(); | |
659 | qdict_put_str(options, "driver", drv->format_name); | |
660 | ||
661 | blk = blk_co_new_open(filename, NULL, options, | |
662 | BDRV_O_RDWR | BDRV_O_RESIZE, errp); | |
663 | if (!blk) { | |
664 | error_prepend(errp, "Protocol driver '%s' does not support image " | |
665 | "creation, and opening the image failed: ", | |
666 | drv->format_name); | |
667 | return -EINVAL; | |
668 | } | |
669 | ||
670 | size = create_file_fallback_truncate(blk, size, errp); | |
671 | if (size < 0) { | |
672 | ret = size; | |
673 | goto out; | |
674 | } | |
675 | ||
676 | ret = create_file_fallback_zero_first_sector(blk, size, errp); | |
677 | if (ret < 0) { | |
678 | goto out; | |
679 | } | |
680 | ||
681 | ret = 0; | |
682 | out: | |
683 | blk_unref(blk); | |
684 | return ret; | |
685 | } | |
686 | ||
687 | int coroutine_fn bdrv_co_create_file(const char *filename, QemuOpts *opts, | |
688 | Error **errp) | |
689 | { | |
690 | QemuOpts *protocol_opts; | |
691 | BlockDriver *drv; | |
692 | QDict *qdict; | |
693 | int ret; | |
694 | ||
695 | GLOBAL_STATE_CODE(); | |
696 | ||
697 | drv = bdrv_find_protocol(filename, true, errp); | |
698 | if (drv == NULL) { | |
699 | return -ENOENT; | |
700 | } | |
701 | ||
702 | if (!drv->create_opts) { | |
703 | error_setg(errp, "Driver '%s' does not support image creation", | |
704 | drv->format_name); | |
705 | return -ENOTSUP; | |
706 | } | |
707 | ||
708 | /* | |
709 | * 'opts' contains a QemuOptsList with a combination of format and protocol | |
710 | * default values. | |
711 | * | |
712 | * The format properly removes its options, but the default values remain | |
713 | * in 'opts->list'. So if the protocol has options with the same name | |
714 | * (e.g. rbd has 'cluster_size' as qcow2), it will see the default values | |
715 | * of the format, since for overlapping options, the format wins. | |
716 | * | |
717 | * To avoid this issue, lets convert QemuOpts to QDict, in this way we take | |
718 | * only the set options, and then convert it back to QemuOpts, using the | |
719 | * create_opts of the protocol. So the new QemuOpts, will contain only the | |
720 | * protocol defaults. | |
721 | */ | |
722 | qdict = qemu_opts_to_qdict(opts, NULL); | |
723 | protocol_opts = qemu_opts_from_qdict(drv->create_opts, qdict, errp); | |
724 | if (protocol_opts == NULL) { | |
725 | ret = -EINVAL; | |
726 | goto out; | |
727 | } | |
728 | ||
729 | ret = bdrv_co_create(drv, filename, protocol_opts, errp); | |
730 | out: | |
731 | qemu_opts_del(protocol_opts); | |
732 | qobject_unref(qdict); | |
733 | return ret; | |
734 | } | |
735 | ||
736 | int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp) | |
737 | { | |
738 | Error *local_err = NULL; | |
739 | int ret; | |
740 | ||
741 | IO_CODE(); | |
742 | assert(bs != NULL); | |
743 | assert_bdrv_graph_readable(); | |
744 | ||
745 | if (!bs->drv) { | |
746 | error_setg(errp, "Block node '%s' is not opened", bs->filename); | |
747 | return -ENOMEDIUM; | |
748 | } | |
749 | ||
750 | if (!bs->drv->bdrv_co_delete_file) { | |
751 | error_setg(errp, "Driver '%s' does not support image deletion", | |
752 | bs->drv->format_name); | |
753 | return -ENOTSUP; | |
754 | } | |
755 | ||
756 | ret = bs->drv->bdrv_co_delete_file(bs, &local_err); | |
757 | if (ret < 0) { | |
758 | error_propagate(errp, local_err); | |
759 | } | |
760 | ||
761 | return ret; | |
762 | } | |
763 | ||
764 | void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs) | |
765 | { | |
766 | Error *local_err = NULL; | |
767 | int ret; | |
768 | IO_CODE(); | |
769 | ||
770 | if (!bs) { | |
771 | return; | |
772 | } | |
773 | ||
774 | ret = bdrv_co_delete_file(bs, &local_err); | |
775 | /* | |
776 | * ENOTSUP will happen if the block driver doesn't support | |
777 | * the 'bdrv_co_delete_file' interface. This is a predictable | |
778 | * scenario and shouldn't be reported back to the user. | |
779 | */ | |
780 | if (ret == -ENOTSUP) { | |
781 | error_free(local_err); | |
782 | } else if (ret < 0) { | |
783 | error_report_err(local_err); | |
784 | } | |
785 | } | |
786 | ||
787 | /** | |
788 | * Try to get @bs's logical and physical block size. | |
789 | * On success, store them in @bsz struct and return 0. | |
790 | * On failure return -errno. | |
791 | * @bs must not be empty. | |
792 | */ | |
793 | int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) | |
794 | { | |
795 | BlockDriver *drv = bs->drv; | |
796 | BlockDriverState *filtered = bdrv_filter_bs(bs); | |
797 | GLOBAL_STATE_CODE(); | |
798 | ||
799 | if (drv && drv->bdrv_probe_blocksizes) { | |
800 | return drv->bdrv_probe_blocksizes(bs, bsz); | |
801 | } else if (filtered) { | |
802 | return bdrv_probe_blocksizes(filtered, bsz); | |
803 | } | |
804 | ||
805 | return -ENOTSUP; | |
806 | } | |
807 | ||
808 | /** | |
809 | * Try to get @bs's geometry (cyls, heads, sectors). | |
810 | * On success, store them in @geo struct and return 0. | |
811 | * On failure return -errno. | |
812 | * @bs must not be empty. | |
813 | */ | |
814 | int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo) | |
815 | { | |
816 | BlockDriver *drv = bs->drv; | |
817 | BlockDriverState *filtered = bdrv_filter_bs(bs); | |
818 | GLOBAL_STATE_CODE(); | |
819 | ||
820 | if (drv && drv->bdrv_probe_geometry) { | |
821 | return drv->bdrv_probe_geometry(bs, geo); | |
822 | } else if (filtered) { | |
823 | return bdrv_probe_geometry(filtered, geo); | |
824 | } | |
825 | ||
826 | return -ENOTSUP; | |
827 | } | |
828 | ||
829 | /* | |
830 | * Create a uniquely-named empty temporary file. | |
831 | * Return the actual file name used upon success, otherwise NULL. | |
832 | * This string should be freed with g_free() when not needed any longer. | |
833 | * | |
834 | * Note: creating a temporary file for the caller to (re)open is | |
835 | * inherently racy. Use g_file_open_tmp() instead whenever practical. | |
836 | */ | |
837 | char *create_tmp_file(Error **errp) | |
838 | { | |
839 | int fd; | |
840 | const char *tmpdir; | |
841 | g_autofree char *filename = NULL; | |
842 | ||
843 | tmpdir = g_get_tmp_dir(); | |
844 | #ifndef _WIN32 | |
845 | /* | |
846 | * See commit 69bef79 ("block: use /var/tmp instead of /tmp for -snapshot") | |
847 | * | |
848 | * This function is used to create temporary disk images (like -snapshot), | |
849 | * so the files can become very large. /tmp is often a tmpfs where as | |
850 | * /var/tmp is usually on a disk, so more appropriate for disk images. | |
851 | */ | |
852 | if (!g_strcmp0(tmpdir, "/tmp")) { | |
853 | tmpdir = "/var/tmp"; | |
854 | } | |
855 | #endif | |
856 | ||
857 | filename = g_strdup_printf("%s/vl.XXXXXX", tmpdir); | |
858 | fd = g_mkstemp(filename); | |
859 | if (fd < 0) { | |
860 | error_setg_errno(errp, errno, "Could not open temporary file '%s'", | |
861 | filename); | |
862 | return NULL; | |
863 | } | |
864 | close(fd); | |
865 | ||
866 | return g_steal_pointer(&filename); | |
867 | } | |
868 | ||
869 | /* | |
870 | * Detect host devices. By convention, /dev/cdrom[N] is always | |
871 | * recognized as a host CDROM. | |
872 | */ | |
873 | static BlockDriver *find_hdev_driver(const char *filename) | |
874 | { | |
875 | int score_max = 0, score; | |
876 | BlockDriver *drv = NULL, *d; | |
877 | GLOBAL_STATE_CODE(); | |
878 | ||
879 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
880 | if (d->bdrv_probe_device) { | |
881 | score = d->bdrv_probe_device(filename); | |
882 | if (score > score_max) { | |
883 | score_max = score; | |
884 | drv = d; | |
885 | } | |
886 | } | |
887 | } | |
888 | ||
889 | return drv; | |
890 | } | |
891 | ||
892 | static BlockDriver *bdrv_do_find_protocol(const char *protocol) | |
893 | { | |
894 | BlockDriver *drv1; | |
895 | GLOBAL_STATE_CODE(); | |
896 | ||
897 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
898 | if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) { | |
899 | return drv1; | |
900 | } | |
901 | } | |
902 | ||
903 | return NULL; | |
904 | } | |
905 | ||
906 | BlockDriver *bdrv_find_protocol(const char *filename, | |
907 | bool allow_protocol_prefix, | |
908 | Error **errp) | |
909 | { | |
910 | BlockDriver *drv1; | |
911 | char protocol[128]; | |
912 | int len; | |
913 | const char *p; | |
914 | int i; | |
915 | ||
916 | GLOBAL_STATE_CODE(); | |
917 | /* TODO Drivers without bdrv_file_open must be specified explicitly */ | |
918 | ||
919 | /* | |
920 | * XXX(hch): we really should not let host device detection | |
921 | * override an explicit protocol specification, but moving this | |
922 | * later breaks access to device names with colons in them. | |
923 | * Thanks to the brain-dead persistent naming schemes on udev- | |
924 | * based Linux systems those actually are quite common. | |
925 | */ | |
926 | drv1 = find_hdev_driver(filename); | |
927 | if (drv1) { | |
928 | return drv1; | |
929 | } | |
930 | ||
931 | if (!path_has_protocol(filename) || !allow_protocol_prefix) { | |
932 | return &bdrv_file; | |
933 | } | |
934 | ||
935 | p = strchr(filename, ':'); | |
936 | assert(p != NULL); | |
937 | len = p - filename; | |
938 | if (len > sizeof(protocol) - 1) | |
939 | len = sizeof(protocol) - 1; | |
940 | memcpy(protocol, filename, len); | |
941 | protocol[len] = '\0'; | |
942 | ||
943 | drv1 = bdrv_do_find_protocol(protocol); | |
944 | if (drv1) { | |
945 | return drv1; | |
946 | } | |
947 | ||
948 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { | |
949 | if (block_driver_modules[i].protocol_name && | |
950 | !strcmp(block_driver_modules[i].protocol_name, protocol)) { | |
951 | int rv = block_module_load(block_driver_modules[i].library_name, errp); | |
952 | if (rv > 0) { | |
953 | drv1 = bdrv_do_find_protocol(protocol); | |
954 | } else if (rv < 0) { | |
955 | return NULL; | |
956 | } | |
957 | break; | |
958 | } | |
959 | } | |
960 | ||
961 | if (!drv1) { | |
962 | error_setg(errp, "Unknown protocol '%s'", protocol); | |
963 | } | |
964 | return drv1; | |
965 | } | |
966 | ||
967 | /* | |
968 | * Guess image format by probing its contents. | |
969 | * This is not a good idea when your image is raw (CVE-2008-2004), but | |
970 | * we do it anyway for backward compatibility. | |
971 | * | |
972 | * @buf contains the image's first @buf_size bytes. | |
973 | * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE, | |
974 | * but can be smaller if the image file is smaller) | |
975 | * @filename is its filename. | |
976 | * | |
977 | * For all block drivers, call the bdrv_probe() method to get its | |
978 | * probing score. | |
979 | * Return the first block driver with the highest probing score. | |
980 | */ | |
981 | BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, | |
982 | const char *filename) | |
983 | { | |
984 | int score_max = 0, score; | |
985 | BlockDriver *drv = NULL, *d; | |
986 | IO_CODE(); | |
987 | ||
988 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
989 | if (d->bdrv_probe) { | |
990 | score = d->bdrv_probe(buf, buf_size, filename); | |
991 | if (score > score_max) { | |
992 | score_max = score; | |
993 | drv = d; | |
994 | } | |
995 | } | |
996 | } | |
997 | ||
998 | return drv; | |
999 | } | |
1000 | ||
1001 | static int find_image_format(BlockBackend *file, const char *filename, | |
1002 | BlockDriver **pdrv, Error **errp) | |
1003 | { | |
1004 | BlockDriver *drv; | |
1005 | uint8_t buf[BLOCK_PROBE_BUF_SIZE]; | |
1006 | int ret = 0; | |
1007 | ||
1008 | GLOBAL_STATE_CODE(); | |
1009 | ||
1010 | /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ | |
1011 | if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) { | |
1012 | *pdrv = &bdrv_raw; | |
1013 | return ret; | |
1014 | } | |
1015 | ||
1016 | ret = blk_pread(file, 0, sizeof(buf), buf, 0); | |
1017 | if (ret < 0) { | |
1018 | error_setg_errno(errp, -ret, "Could not read image for determining its " | |
1019 | "format"); | |
1020 | *pdrv = NULL; | |
1021 | return ret; | |
1022 | } | |
1023 | ||
1024 | drv = bdrv_probe_all(buf, sizeof(buf), filename); | |
1025 | if (!drv) { | |
1026 | error_setg(errp, "Could not determine image format: No compatible " | |
1027 | "driver found"); | |
1028 | *pdrv = NULL; | |
1029 | return -ENOENT; | |
1030 | } | |
1031 | ||
1032 | *pdrv = drv; | |
1033 | return 0; | |
1034 | } | |
1035 | ||
1036 | /** | |
1037 | * Set the current 'total_sectors' value | |
1038 | * Return 0 on success, -errno on error. | |
1039 | */ | |
1040 | int coroutine_fn bdrv_co_refresh_total_sectors(BlockDriverState *bs, | |
1041 | int64_t hint) | |
1042 | { | |
1043 | BlockDriver *drv = bs->drv; | |
1044 | IO_CODE(); | |
1045 | assert_bdrv_graph_readable(); | |
1046 | ||
1047 | if (!drv) { | |
1048 | return -ENOMEDIUM; | |
1049 | } | |
1050 | ||
1051 | /* Do not attempt drv->bdrv_co_getlength() on scsi-generic devices */ | |
1052 | if (bdrv_is_sg(bs)) | |
1053 | return 0; | |
1054 | ||
1055 | /* query actual device if possible, otherwise just trust the hint */ | |
1056 | if (drv->bdrv_co_getlength) { | |
1057 | int64_t length = drv->bdrv_co_getlength(bs); | |
1058 | if (length < 0) { | |
1059 | return length; | |
1060 | } | |
1061 | hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE); | |
1062 | } | |
1063 | ||
1064 | bs->total_sectors = hint; | |
1065 | ||
1066 | if (bs->total_sectors * BDRV_SECTOR_SIZE > BDRV_MAX_LENGTH) { | |
1067 | return -EFBIG; | |
1068 | } | |
1069 | ||
1070 | return 0; | |
1071 | } | |
1072 | ||
1073 | /** | |
1074 | * Combines a QDict of new block driver @options with any missing options taken | |
1075 | * from @old_options, so that leaving out an option defaults to its old value. | |
1076 | */ | |
1077 | static void bdrv_join_options(BlockDriverState *bs, QDict *options, | |
1078 | QDict *old_options) | |
1079 | { | |
1080 | GLOBAL_STATE_CODE(); | |
1081 | if (bs->drv && bs->drv->bdrv_join_options) { | |
1082 | bs->drv->bdrv_join_options(options, old_options); | |
1083 | } else { | |
1084 | qdict_join(options, old_options, false); | |
1085 | } | |
1086 | } | |
1087 | ||
1088 | static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts, | |
1089 | int open_flags, | |
1090 | Error **errp) | |
1091 | { | |
1092 | Error *local_err = NULL; | |
1093 | char *value = qemu_opt_get_del(opts, "detect-zeroes"); | |
1094 | BlockdevDetectZeroesOptions detect_zeroes = | |
1095 | qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, value, | |
1096 | BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err); | |
1097 | GLOBAL_STATE_CODE(); | |
1098 | g_free(value); | |
1099 | if (local_err) { | |
1100 | error_propagate(errp, local_err); | |
1101 | return detect_zeroes; | |
1102 | } | |
1103 | ||
1104 | if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && | |
1105 | !(open_flags & BDRV_O_UNMAP)) | |
1106 | { | |
1107 | error_setg(errp, "setting detect-zeroes to unmap is not allowed " | |
1108 | "without setting discard operation to unmap"); | |
1109 | } | |
1110 | ||
1111 | return detect_zeroes; | |
1112 | } | |
1113 | ||
1114 | /** | |
1115 | * Set open flags for aio engine | |
1116 | * | |
1117 | * Return 0 on success, -1 if the engine specified is invalid | |
1118 | */ | |
1119 | int bdrv_parse_aio(const char *mode, int *flags) | |
1120 | { | |
1121 | if (!strcmp(mode, "threads")) { | |
1122 | /* do nothing, default */ | |
1123 | } else if (!strcmp(mode, "native")) { | |
1124 | *flags |= BDRV_O_NATIVE_AIO; | |
1125 | #ifdef CONFIG_LINUX_IO_URING | |
1126 | } else if (!strcmp(mode, "io_uring")) { | |
1127 | *flags |= BDRV_O_IO_URING; | |
1128 | #endif | |
1129 | } else { | |
1130 | return -1; | |
1131 | } | |
1132 | ||
1133 | return 0; | |
1134 | } | |
1135 | ||
1136 | /** | |
1137 | * Set open flags for a given discard mode | |
1138 | * | |
1139 | * Return 0 on success, -1 if the discard mode was invalid. | |
1140 | */ | |
1141 | int bdrv_parse_discard_flags(const char *mode, int *flags) | |
1142 | { | |
1143 | *flags &= ~BDRV_O_UNMAP; | |
1144 | ||
1145 | if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) { | |
1146 | /* do nothing */ | |
1147 | } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) { | |
1148 | *flags |= BDRV_O_UNMAP; | |
1149 | } else { | |
1150 | return -1; | |
1151 | } | |
1152 | ||
1153 | return 0; | |
1154 | } | |
1155 | ||
1156 | /** | |
1157 | * Set open flags for a given cache mode | |
1158 | * | |
1159 | * Return 0 on success, -1 if the cache mode was invalid. | |
1160 | */ | |
1161 | int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough) | |
1162 | { | |
1163 | *flags &= ~BDRV_O_CACHE_MASK; | |
1164 | ||
1165 | if (!strcmp(mode, "off") || !strcmp(mode, "none")) { | |
1166 | *writethrough = false; | |
1167 | *flags |= BDRV_O_NOCACHE; | |
1168 | } else if (!strcmp(mode, "directsync")) { | |
1169 | *writethrough = true; | |
1170 | *flags |= BDRV_O_NOCACHE; | |
1171 | } else if (!strcmp(mode, "writeback")) { | |
1172 | *writethrough = false; | |
1173 | } else if (!strcmp(mode, "unsafe")) { | |
1174 | *writethrough = false; | |
1175 | *flags |= BDRV_O_NO_FLUSH; | |
1176 | } else if (!strcmp(mode, "writethrough")) { | |
1177 | *writethrough = true; | |
1178 | } else { | |
1179 | return -1; | |
1180 | } | |
1181 | ||
1182 | return 0; | |
1183 | } | |
1184 | ||
1185 | static char *bdrv_child_get_parent_desc(BdrvChild *c) | |
1186 | { | |
1187 | BlockDriverState *parent = c->opaque; | |
1188 | return g_strdup_printf("node '%s'", bdrv_get_node_name(parent)); | |
1189 | } | |
1190 | ||
1191 | static void bdrv_child_cb_drained_begin(BdrvChild *child) | |
1192 | { | |
1193 | BlockDriverState *bs = child->opaque; | |
1194 | bdrv_do_drained_begin_quiesce(bs, NULL); | |
1195 | } | |
1196 | ||
1197 | static bool bdrv_child_cb_drained_poll(BdrvChild *child) | |
1198 | { | |
1199 | BlockDriverState *bs = child->opaque; | |
1200 | return bdrv_drain_poll(bs, NULL, false); | |
1201 | } | |
1202 | ||
1203 | static void bdrv_child_cb_drained_end(BdrvChild *child) | |
1204 | { | |
1205 | BlockDriverState *bs = child->opaque; | |
1206 | bdrv_drained_end(bs); | |
1207 | } | |
1208 | ||
1209 | static int bdrv_child_cb_inactivate(BdrvChild *child) | |
1210 | { | |
1211 | BlockDriverState *bs = child->opaque; | |
1212 | GLOBAL_STATE_CODE(); | |
1213 | assert(bs->open_flags & BDRV_O_INACTIVE); | |
1214 | return 0; | |
1215 | } | |
1216 | ||
1217 | static bool bdrv_child_cb_change_aio_ctx(BdrvChild *child, AioContext *ctx, | |
1218 | GHashTable *visited, Transaction *tran, | |
1219 | Error **errp) | |
1220 | { | |
1221 | BlockDriverState *bs = child->opaque; | |
1222 | return bdrv_change_aio_context(bs, ctx, visited, tran, errp); | |
1223 | } | |
1224 | ||
1225 | /* | |
1226 | * Returns the options and flags that a temporary snapshot should get, based on | |
1227 | * the originally requested flags (the originally requested image will have | |
1228 | * flags like a backing file) | |
1229 | */ | |
1230 | static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options, | |
1231 | int parent_flags, QDict *parent_options) | |
1232 | { | |
1233 | GLOBAL_STATE_CODE(); | |
1234 | *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY; | |
1235 | ||
1236 | /* For temporary files, unconditional cache=unsafe is fine */ | |
1237 | qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off"); | |
1238 | qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on"); | |
1239 | ||
1240 | /* Copy the read-only and discard options from the parent */ | |
1241 | qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); | |
1242 | qdict_copy_default(child_options, parent_options, BDRV_OPT_DISCARD); | |
1243 | ||
1244 | /* aio=native doesn't work for cache.direct=off, so disable it for the | |
1245 | * temporary snapshot */ | |
1246 | *child_flags &= ~BDRV_O_NATIVE_AIO; | |
1247 | } | |
1248 | ||
1249 | static void bdrv_backing_attach(BdrvChild *c) | |
1250 | { | |
1251 | BlockDriverState *parent = c->opaque; | |
1252 | BlockDriverState *backing_hd = c->bs; | |
1253 | ||
1254 | GLOBAL_STATE_CODE(); | |
1255 | assert(!parent->backing_blocker); | |
1256 | error_setg(&parent->backing_blocker, | |
1257 | "node is used as backing hd of '%s'", | |
1258 | bdrv_get_device_or_node_name(parent)); | |
1259 | ||
1260 | bdrv_refresh_filename(backing_hd); | |
1261 | ||
1262 | parent->open_flags &= ~BDRV_O_NO_BACKING; | |
1263 | ||
1264 | bdrv_op_block_all(backing_hd, parent->backing_blocker); | |
1265 | /* Otherwise we won't be able to commit or stream */ | |
1266 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, | |
1267 | parent->backing_blocker); | |
1268 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM, | |
1269 | parent->backing_blocker); | |
1270 | /* | |
1271 | * We do backup in 3 ways: | |
1272 | * 1. drive backup | |
1273 | * The target bs is new opened, and the source is top BDS | |
1274 | * 2. blockdev backup | |
1275 | * Both the source and the target are top BDSes. | |
1276 | * 3. internal backup(used for block replication) | |
1277 | * Both the source and the target are backing file | |
1278 | * | |
1279 | * In case 1 and 2, neither the source nor the target is the backing file. | |
1280 | * In case 3, we will block the top BDS, so there is only one block job | |
1281 | * for the top BDS and its backing chain. | |
1282 | */ | |
1283 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE, | |
1284 | parent->backing_blocker); | |
1285 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET, | |
1286 | parent->backing_blocker); | |
1287 | } | |
1288 | ||
1289 | static void bdrv_backing_detach(BdrvChild *c) | |
1290 | { | |
1291 | BlockDriverState *parent = c->opaque; | |
1292 | ||
1293 | GLOBAL_STATE_CODE(); | |
1294 | assert(parent->backing_blocker); | |
1295 | bdrv_op_unblock_all(c->bs, parent->backing_blocker); | |
1296 | error_free(parent->backing_blocker); | |
1297 | parent->backing_blocker = NULL; | |
1298 | } | |
1299 | ||
1300 | static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base, | |
1301 | const char *filename, Error **errp) | |
1302 | { | |
1303 | BlockDriverState *parent = c->opaque; | |
1304 | bool read_only = bdrv_is_read_only(parent); | |
1305 | int ret; | |
1306 | GLOBAL_STATE_CODE(); | |
1307 | ||
1308 | if (read_only) { | |
1309 | ret = bdrv_reopen_set_read_only(parent, false, errp); | |
1310 | if (ret < 0) { | |
1311 | return ret; | |
1312 | } | |
1313 | } | |
1314 | ||
1315 | ret = bdrv_change_backing_file(parent, filename, | |
1316 | base->drv ? base->drv->format_name : "", | |
1317 | false); | |
1318 | if (ret < 0) { | |
1319 | error_setg_errno(errp, -ret, "Could not update backing file link"); | |
1320 | } | |
1321 | ||
1322 | if (read_only) { | |
1323 | bdrv_reopen_set_read_only(parent, true, NULL); | |
1324 | } | |
1325 | ||
1326 | return ret; | |
1327 | } | |
1328 | ||
1329 | /* | |
1330 | * Returns the options and flags that a generic child of a BDS should | |
1331 | * get, based on the given options and flags for the parent BDS. | |
1332 | */ | |
1333 | static void bdrv_inherited_options(BdrvChildRole role, bool parent_is_format, | |
1334 | int *child_flags, QDict *child_options, | |
1335 | int parent_flags, QDict *parent_options) | |
1336 | { | |
1337 | int flags = parent_flags; | |
1338 | GLOBAL_STATE_CODE(); | |
1339 | ||
1340 | /* | |
1341 | * First, decide whether to set, clear, or leave BDRV_O_PROTOCOL. | |
1342 | * Generally, the question to answer is: Should this child be | |
1343 | * format-probed by default? | |
1344 | */ | |
1345 | ||
1346 | /* | |
1347 | * Pure and non-filtered data children of non-format nodes should | |
1348 | * be probed by default (even when the node itself has BDRV_O_PROTOCOL | |
1349 | * set). This only affects a very limited set of drivers (namely | |
1350 | * quorum and blkverify when this comment was written). | |
1351 | * Force-clear BDRV_O_PROTOCOL then. | |
1352 | */ | |
1353 | if (!parent_is_format && | |
1354 | (role & BDRV_CHILD_DATA) && | |
1355 | !(role & (BDRV_CHILD_METADATA | BDRV_CHILD_FILTERED))) | |
1356 | { | |
1357 | flags &= ~BDRV_O_PROTOCOL; | |
1358 | } | |
1359 | ||
1360 | /* | |
1361 | * All children of format nodes (except for COW children) and all | |
1362 | * metadata children in general should never be format-probed. | |
1363 | * Force-set BDRV_O_PROTOCOL then. | |
1364 | */ | |
1365 | if ((parent_is_format && !(role & BDRV_CHILD_COW)) || | |
1366 | (role & BDRV_CHILD_METADATA)) | |
1367 | { | |
1368 | flags |= BDRV_O_PROTOCOL; | |
1369 | } | |
1370 | ||
1371 | /* | |
1372 | * If the cache mode isn't explicitly set, inherit direct and no-flush from | |
1373 | * the parent. | |
1374 | */ | |
1375 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); | |
1376 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); | |
1377 | qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE); | |
1378 | ||
1379 | if (role & BDRV_CHILD_COW) { | |
1380 | /* backing files are opened read-only by default */ | |
1381 | qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on"); | |
1382 | qdict_set_default_str(child_options, BDRV_OPT_AUTO_READ_ONLY, "off"); | |
1383 | } else { | |
1384 | /* Inherit the read-only option from the parent if it's not set */ | |
1385 | qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); | |
1386 | qdict_copy_default(child_options, parent_options, | |
1387 | BDRV_OPT_AUTO_READ_ONLY); | |
1388 | } | |
1389 | ||
1390 | /* | |
1391 | * bdrv_co_pdiscard() respects unmap policy for the parent, so we | |
1392 | * can default to enable it on lower layers regardless of the | |
1393 | * parent option. | |
1394 | */ | |
1395 | qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap"); | |
1396 | ||
1397 | /* Clear flags that only apply to the top layer */ | |
1398 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ); | |
1399 | ||
1400 | if (role & BDRV_CHILD_METADATA) { | |
1401 | flags &= ~BDRV_O_NO_IO; | |
1402 | } | |
1403 | if (role & BDRV_CHILD_COW) { | |
1404 | flags &= ~BDRV_O_TEMPORARY; | |
1405 | } | |
1406 | ||
1407 | *child_flags = flags; | |
1408 | } | |
1409 | ||
1410 | static void GRAPH_WRLOCK bdrv_child_cb_attach(BdrvChild *child) | |
1411 | { | |
1412 | BlockDriverState *bs = child->opaque; | |
1413 | ||
1414 | assert_bdrv_graph_writable(); | |
1415 | QLIST_INSERT_HEAD(&bs->children, child, next); | |
1416 | if (bs->drv->is_filter || (child->role & BDRV_CHILD_FILTERED)) { | |
1417 | /* | |
1418 | * Here we handle filters and block/raw-format.c when it behave like | |
1419 | * filter. They generally have a single PRIMARY child, which is also the | |
1420 | * FILTERED child, and that they may have multiple more children, which | |
1421 | * are neither PRIMARY nor FILTERED. And never we have a COW child here. | |
1422 | * So bs->file will be the PRIMARY child, unless the PRIMARY child goes | |
1423 | * into bs->backing on exceptional cases; and bs->backing will be | |
1424 | * nothing else. | |
1425 | */ | |
1426 | assert(!(child->role & BDRV_CHILD_COW)); | |
1427 | if (child->role & BDRV_CHILD_PRIMARY) { | |
1428 | assert(child->role & BDRV_CHILD_FILTERED); | |
1429 | assert(!bs->backing); | |
1430 | assert(!bs->file); | |
1431 | ||
1432 | if (bs->drv->filtered_child_is_backing) { | |
1433 | bs->backing = child; | |
1434 | } else { | |
1435 | bs->file = child; | |
1436 | } | |
1437 | } else { | |
1438 | assert(!(child->role & BDRV_CHILD_FILTERED)); | |
1439 | } | |
1440 | } else if (child->role & BDRV_CHILD_COW) { | |
1441 | assert(bs->drv->supports_backing); | |
1442 | assert(!(child->role & BDRV_CHILD_PRIMARY)); | |
1443 | assert(!bs->backing); | |
1444 | bs->backing = child; | |
1445 | bdrv_backing_attach(child); | |
1446 | } else if (child->role & BDRV_CHILD_PRIMARY) { | |
1447 | assert(!bs->file); | |
1448 | bs->file = child; | |
1449 | } | |
1450 | } | |
1451 | ||
1452 | static void GRAPH_WRLOCK bdrv_child_cb_detach(BdrvChild *child) | |
1453 | { | |
1454 | BlockDriverState *bs = child->opaque; | |
1455 | ||
1456 | if (child->role & BDRV_CHILD_COW) { | |
1457 | bdrv_backing_detach(child); | |
1458 | } | |
1459 | ||
1460 | assert_bdrv_graph_writable(); | |
1461 | QLIST_REMOVE(child, next); | |
1462 | if (child == bs->backing) { | |
1463 | assert(child != bs->file); | |
1464 | bs->backing = NULL; | |
1465 | } else if (child == bs->file) { | |
1466 | bs->file = NULL; | |
1467 | } | |
1468 | } | |
1469 | ||
1470 | static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *base, | |
1471 | const char *filename, Error **errp) | |
1472 | { | |
1473 | if (c->role & BDRV_CHILD_COW) { | |
1474 | return bdrv_backing_update_filename(c, base, filename, errp); | |
1475 | } | |
1476 | return 0; | |
1477 | } | |
1478 | ||
1479 | AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c) | |
1480 | { | |
1481 | BlockDriverState *bs = c->opaque; | |
1482 | IO_CODE(); | |
1483 | ||
1484 | return bdrv_get_aio_context(bs); | |
1485 | } | |
1486 | ||
1487 | const BdrvChildClass child_of_bds = { | |
1488 | .parent_is_bds = true, | |
1489 | .get_parent_desc = bdrv_child_get_parent_desc, | |
1490 | .inherit_options = bdrv_inherited_options, | |
1491 | .drained_begin = bdrv_child_cb_drained_begin, | |
1492 | .drained_poll = bdrv_child_cb_drained_poll, | |
1493 | .drained_end = bdrv_child_cb_drained_end, | |
1494 | .attach = bdrv_child_cb_attach, | |
1495 | .detach = bdrv_child_cb_detach, | |
1496 | .inactivate = bdrv_child_cb_inactivate, | |
1497 | .change_aio_ctx = bdrv_child_cb_change_aio_ctx, | |
1498 | .update_filename = bdrv_child_cb_update_filename, | |
1499 | .get_parent_aio_context = child_of_bds_get_parent_aio_context, | |
1500 | }; | |
1501 | ||
1502 | AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c) | |
1503 | { | |
1504 | IO_CODE(); | |
1505 | return c->klass->get_parent_aio_context(c); | |
1506 | } | |
1507 | ||
1508 | static int bdrv_open_flags(BlockDriverState *bs, int flags) | |
1509 | { | |
1510 | int open_flags = flags; | |
1511 | GLOBAL_STATE_CODE(); | |
1512 | ||
1513 | /* | |
1514 | * Clear flags that are internal to the block layer before opening the | |
1515 | * image. | |
1516 | */ | |
1517 | open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL); | |
1518 | ||
1519 | return open_flags; | |
1520 | } | |
1521 | ||
1522 | static void update_flags_from_options(int *flags, QemuOpts *opts) | |
1523 | { | |
1524 | GLOBAL_STATE_CODE(); | |
1525 | ||
1526 | *flags &= ~(BDRV_O_CACHE_MASK | BDRV_O_RDWR | BDRV_O_AUTO_RDONLY); | |
1527 | ||
1528 | if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) { | |
1529 | *flags |= BDRV_O_NO_FLUSH; | |
1530 | } | |
1531 | ||
1532 | if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_DIRECT, false)) { | |
1533 | *flags |= BDRV_O_NOCACHE; | |
1534 | } | |
1535 | ||
1536 | if (!qemu_opt_get_bool_del(opts, BDRV_OPT_READ_ONLY, false)) { | |
1537 | *flags |= BDRV_O_RDWR; | |
1538 | } | |
1539 | ||
1540 | if (qemu_opt_get_bool_del(opts, BDRV_OPT_AUTO_READ_ONLY, false)) { | |
1541 | *flags |= BDRV_O_AUTO_RDONLY; | |
1542 | } | |
1543 | } | |
1544 | ||
1545 | static void update_options_from_flags(QDict *options, int flags) | |
1546 | { | |
1547 | GLOBAL_STATE_CODE(); | |
1548 | if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) { | |
1549 | qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE); | |
1550 | } | |
1551 | if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) { | |
1552 | qdict_put_bool(options, BDRV_OPT_CACHE_NO_FLUSH, | |
1553 | flags & BDRV_O_NO_FLUSH); | |
1554 | } | |
1555 | if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) { | |
1556 | qdict_put_bool(options, BDRV_OPT_READ_ONLY, !(flags & BDRV_O_RDWR)); | |
1557 | } | |
1558 | if (!qdict_haskey(options, BDRV_OPT_AUTO_READ_ONLY)) { | |
1559 | qdict_put_bool(options, BDRV_OPT_AUTO_READ_ONLY, | |
1560 | flags & BDRV_O_AUTO_RDONLY); | |
1561 | } | |
1562 | } | |
1563 | ||
1564 | static void bdrv_assign_node_name(BlockDriverState *bs, | |
1565 | const char *node_name, | |
1566 | Error **errp) | |
1567 | { | |
1568 | char *gen_node_name = NULL; | |
1569 | GLOBAL_STATE_CODE(); | |
1570 | ||
1571 | if (!node_name) { | |
1572 | node_name = gen_node_name = id_generate(ID_BLOCK); | |
1573 | } else if (!id_wellformed(node_name)) { | |
1574 | /* | |
1575 | * Check for empty string or invalid characters, but not if it is | |
1576 | * generated (generated names use characters not available to the user) | |
1577 | */ | |
1578 | error_setg(errp, "Invalid node-name: '%s'", node_name); | |
1579 | return; | |
1580 | } | |
1581 | ||
1582 | /* takes care of avoiding namespaces collisions */ | |
1583 | if (blk_by_name(node_name)) { | |
1584 | error_setg(errp, "node-name=%s is conflicting with a device id", | |
1585 | node_name); | |
1586 | goto out; | |
1587 | } | |
1588 | ||
1589 | /* takes care of avoiding duplicates node names */ | |
1590 | if (bdrv_find_node(node_name)) { | |
1591 | error_setg(errp, "Duplicate nodes with node-name='%s'", node_name); | |
1592 | goto out; | |
1593 | } | |
1594 | ||
1595 | /* Make sure that the node name isn't truncated */ | |
1596 | if (strlen(node_name) >= sizeof(bs->node_name)) { | |
1597 | error_setg(errp, "Node name too long"); | |
1598 | goto out; | |
1599 | } | |
1600 | ||
1601 | /* copy node name into the bs and insert it into the graph list */ | |
1602 | pstrcpy(bs->node_name, sizeof(bs->node_name), node_name); | |
1603 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list); | |
1604 | out: | |
1605 | g_free(gen_node_name); | |
1606 | } | |
1607 | ||
1608 | /* | |
1609 | * The caller must always hold @bs AioContext lock, because this function calls | |
1610 | * bdrv_refresh_total_sectors() which polls when called from non-coroutine | |
1611 | * context. | |
1612 | */ | |
1613 | static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv, | |
1614 | const char *node_name, QDict *options, | |
1615 | int open_flags, Error **errp) | |
1616 | { | |
1617 | Error *local_err = NULL; | |
1618 | int i, ret; | |
1619 | GLOBAL_STATE_CODE(); | |
1620 | ||
1621 | bdrv_assign_node_name(bs, node_name, &local_err); | |
1622 | if (local_err) { | |
1623 | error_propagate(errp, local_err); | |
1624 | return -EINVAL; | |
1625 | } | |
1626 | ||
1627 | bs->drv = drv; | |
1628 | bs->opaque = g_malloc0(drv->instance_size); | |
1629 | ||
1630 | if (drv->bdrv_file_open) { | |
1631 | assert(!drv->bdrv_needs_filename || bs->filename[0]); | |
1632 | ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); | |
1633 | } else if (drv->bdrv_open) { | |
1634 | ret = drv->bdrv_open(bs, options, open_flags, &local_err); | |
1635 | } else { | |
1636 | ret = 0; | |
1637 | } | |
1638 | ||
1639 | if (ret < 0) { | |
1640 | if (local_err) { | |
1641 | error_propagate(errp, local_err); | |
1642 | } else if (bs->filename[0]) { | |
1643 | error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename); | |
1644 | } else { | |
1645 | error_setg_errno(errp, -ret, "Could not open image"); | |
1646 | } | |
1647 | goto open_failed; | |
1648 | } | |
1649 | ||
1650 | assert(!(bs->supported_read_flags & ~BDRV_REQ_MASK)); | |
1651 | assert(!(bs->supported_write_flags & ~BDRV_REQ_MASK)); | |
1652 | ||
1653 | /* | |
1654 | * Always allow the BDRV_REQ_REGISTERED_BUF optimization hint. This saves | |
1655 | * drivers that pass read/write requests through to a child the trouble of | |
1656 | * declaring support explicitly. | |
1657 | * | |
1658 | * Drivers must not propagate this flag accidentally when they initiate I/O | |
1659 | * to a bounce buffer. That case should be rare though. | |
1660 | */ | |
1661 | bs->supported_read_flags |= BDRV_REQ_REGISTERED_BUF; | |
1662 | bs->supported_write_flags |= BDRV_REQ_REGISTERED_BUF; | |
1663 | ||
1664 | ret = bdrv_refresh_total_sectors(bs, bs->total_sectors); | |
1665 | if (ret < 0) { | |
1666 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
1667 | return ret; | |
1668 | } | |
1669 | ||
1670 | bdrv_refresh_limits(bs, NULL, &local_err); | |
1671 | if (local_err) { | |
1672 | error_propagate(errp, local_err); | |
1673 | return -EINVAL; | |
1674 | } | |
1675 | ||
1676 | assert(bdrv_opt_mem_align(bs) != 0); | |
1677 | assert(bdrv_min_mem_align(bs) != 0); | |
1678 | assert(is_power_of_2(bs->bl.request_alignment)); | |
1679 | ||
1680 | for (i = 0; i < bs->quiesce_counter; i++) { | |
1681 | if (drv->bdrv_drain_begin) { | |
1682 | drv->bdrv_drain_begin(bs); | |
1683 | } | |
1684 | } | |
1685 | ||
1686 | return 0; | |
1687 | open_failed: | |
1688 | bs->drv = NULL; | |
1689 | if (bs->file != NULL) { | |
1690 | bdrv_unref_child(bs, bs->file); | |
1691 | assert(!bs->file); | |
1692 | } | |
1693 | g_free(bs->opaque); | |
1694 | bs->opaque = NULL; | |
1695 | return ret; | |
1696 | } | |
1697 | ||
1698 | /* | |
1699 | * Create and open a block node. | |
1700 | * | |
1701 | * @options is a QDict of options to pass to the block drivers, or NULL for an | |
1702 | * empty set of options. The reference to the QDict belongs to the block layer | |
1703 | * after the call (even on failure), so if the caller intends to reuse the | |
1704 | * dictionary, it needs to use qobject_ref() before calling bdrv_open. | |
1705 | */ | |
1706 | BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv, | |
1707 | const char *node_name, | |
1708 | QDict *options, int flags, | |
1709 | Error **errp) | |
1710 | { | |
1711 | BlockDriverState *bs; | |
1712 | int ret; | |
1713 | ||
1714 | GLOBAL_STATE_CODE(); | |
1715 | ||
1716 | bs = bdrv_new(); | |
1717 | bs->open_flags = flags; | |
1718 | bs->options = options ?: qdict_new(); | |
1719 | bs->explicit_options = qdict_clone_shallow(bs->options); | |
1720 | bs->opaque = NULL; | |
1721 | ||
1722 | update_options_from_flags(bs->options, flags); | |
1723 | ||
1724 | ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp); | |
1725 | if (ret < 0) { | |
1726 | qobject_unref(bs->explicit_options); | |
1727 | bs->explicit_options = NULL; | |
1728 | qobject_unref(bs->options); | |
1729 | bs->options = NULL; | |
1730 | bdrv_unref(bs); | |
1731 | return NULL; | |
1732 | } | |
1733 | ||
1734 | return bs; | |
1735 | } | |
1736 | ||
1737 | /* Create and open a block node. */ | |
1738 | BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, | |
1739 | int flags, Error **errp) | |
1740 | { | |
1741 | GLOBAL_STATE_CODE(); | |
1742 | return bdrv_new_open_driver_opts(drv, node_name, NULL, flags, errp); | |
1743 | } | |
1744 | ||
1745 | QemuOptsList bdrv_runtime_opts = { | |
1746 | .name = "bdrv_common", | |
1747 | .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head), | |
1748 | .desc = { | |
1749 | { | |
1750 | .name = "node-name", | |
1751 | .type = QEMU_OPT_STRING, | |
1752 | .help = "Node name of the block device node", | |
1753 | }, | |
1754 | { | |
1755 | .name = "driver", | |
1756 | .type = QEMU_OPT_STRING, | |
1757 | .help = "Block driver to use for the node", | |
1758 | }, | |
1759 | { | |
1760 | .name = BDRV_OPT_CACHE_DIRECT, | |
1761 | .type = QEMU_OPT_BOOL, | |
1762 | .help = "Bypass software writeback cache on the host", | |
1763 | }, | |
1764 | { | |
1765 | .name = BDRV_OPT_CACHE_NO_FLUSH, | |
1766 | .type = QEMU_OPT_BOOL, | |
1767 | .help = "Ignore flush requests", | |
1768 | }, | |
1769 | { | |
1770 | .name = BDRV_OPT_READ_ONLY, | |
1771 | .type = QEMU_OPT_BOOL, | |
1772 | .help = "Node is opened in read-only mode", | |
1773 | }, | |
1774 | { | |
1775 | .name = BDRV_OPT_AUTO_READ_ONLY, | |
1776 | .type = QEMU_OPT_BOOL, | |
1777 | .help = "Node can become read-only if opening read-write fails", | |
1778 | }, | |
1779 | { | |
1780 | .name = "detect-zeroes", | |
1781 | .type = QEMU_OPT_STRING, | |
1782 | .help = "try to optimize zero writes (off, on, unmap)", | |
1783 | }, | |
1784 | { | |
1785 | .name = BDRV_OPT_DISCARD, | |
1786 | .type = QEMU_OPT_STRING, | |
1787 | .help = "discard operation (ignore/off, unmap/on)", | |
1788 | }, | |
1789 | { | |
1790 | .name = BDRV_OPT_FORCE_SHARE, | |
1791 | .type = QEMU_OPT_BOOL, | |
1792 | .help = "always accept other writers (default: off)", | |
1793 | }, | |
1794 | { /* end of list */ } | |
1795 | }, | |
1796 | }; | |
1797 | ||
1798 | QemuOptsList bdrv_create_opts_simple = { | |
1799 | .name = "simple-create-opts", | |
1800 | .head = QTAILQ_HEAD_INITIALIZER(bdrv_create_opts_simple.head), | |
1801 | .desc = { | |
1802 | { | |
1803 | .name = BLOCK_OPT_SIZE, | |
1804 | .type = QEMU_OPT_SIZE, | |
1805 | .help = "Virtual disk size" | |
1806 | }, | |
1807 | { | |
1808 | .name = BLOCK_OPT_PREALLOC, | |
1809 | .type = QEMU_OPT_STRING, | |
1810 | .help = "Preallocation mode (allowed values: off)" | |
1811 | }, | |
1812 | { /* end of list */ } | |
1813 | } | |
1814 | }; | |
1815 | ||
1816 | /* | |
1817 | * Common part for opening disk images and files | |
1818 | * | |
1819 | * Removes all processed options from *options. | |
1820 | */ | |
1821 | static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, | |
1822 | QDict *options, Error **errp) | |
1823 | { | |
1824 | int ret, open_flags; | |
1825 | const char *filename; | |
1826 | const char *driver_name = NULL; | |
1827 | const char *node_name = NULL; | |
1828 | const char *discard; | |
1829 | QemuOpts *opts; | |
1830 | BlockDriver *drv; | |
1831 | Error *local_err = NULL; | |
1832 | bool ro; | |
1833 | ||
1834 | assert(bs->file == NULL); | |
1835 | assert(options != NULL && bs->options != options); | |
1836 | GLOBAL_STATE_CODE(); | |
1837 | ||
1838 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); | |
1839 | if (!qemu_opts_absorb_qdict(opts, options, errp)) { | |
1840 | ret = -EINVAL; | |
1841 | goto fail_opts; | |
1842 | } | |
1843 | ||
1844 | update_flags_from_options(&bs->open_flags, opts); | |
1845 | ||
1846 | driver_name = qemu_opt_get(opts, "driver"); | |
1847 | drv = bdrv_find_format(driver_name); | |
1848 | assert(drv != NULL); | |
1849 | ||
1850 | bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false); | |
1851 | ||
1852 | if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) { | |
1853 | error_setg(errp, | |
1854 | BDRV_OPT_FORCE_SHARE | |
1855 | "=on can only be used with read-only images"); | |
1856 | ret = -EINVAL; | |
1857 | goto fail_opts; | |
1858 | } | |
1859 | ||
1860 | if (file != NULL) { | |
1861 | bdrv_refresh_filename(blk_bs(file)); | |
1862 | filename = blk_bs(file)->filename; | |
1863 | } else { | |
1864 | /* | |
1865 | * Caution: while qdict_get_try_str() is fine, getting | |
1866 | * non-string types would require more care. When @options | |
1867 | * come from -blockdev or blockdev_add, its members are typed | |
1868 | * according to the QAPI schema, but when they come from | |
1869 | * -drive, they're all QString. | |
1870 | */ | |
1871 | filename = qdict_get_try_str(options, "filename"); | |
1872 | } | |
1873 | ||
1874 | if (drv->bdrv_needs_filename && (!filename || !filename[0])) { | |
1875 | error_setg(errp, "The '%s' block driver requires a file name", | |
1876 | drv->format_name); | |
1877 | ret = -EINVAL; | |
1878 | goto fail_opts; | |
1879 | } | |
1880 | ||
1881 | trace_bdrv_open_common(bs, filename ?: "", bs->open_flags, | |
1882 | drv->format_name); | |
1883 | ||
1884 | ro = bdrv_is_read_only(bs); | |
1885 | ||
1886 | if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, ro)) { | |
1887 | if (!ro && bdrv_is_whitelisted(drv, true)) { | |
1888 | ret = bdrv_apply_auto_read_only(bs, NULL, NULL); | |
1889 | } else { | |
1890 | ret = -ENOTSUP; | |
1891 | } | |
1892 | if (ret < 0) { | |
1893 | error_setg(errp, | |
1894 | !ro && bdrv_is_whitelisted(drv, true) | |
1895 | ? "Driver '%s' can only be used for read-only devices" | |
1896 | : "Driver '%s' is not whitelisted", | |
1897 | drv->format_name); | |
1898 | goto fail_opts; | |
1899 | } | |
1900 | } | |
1901 | ||
1902 | /* bdrv_new() and bdrv_close() make it so */ | |
1903 | assert(qatomic_read(&bs->copy_on_read) == 0); | |
1904 | ||
1905 | if (bs->open_flags & BDRV_O_COPY_ON_READ) { | |
1906 | if (!ro) { | |
1907 | bdrv_enable_copy_on_read(bs); | |
1908 | } else { | |
1909 | error_setg(errp, "Can't use copy-on-read on read-only device"); | |
1910 | ret = -EINVAL; | |
1911 | goto fail_opts; | |
1912 | } | |
1913 | } | |
1914 | ||
1915 | discard = qemu_opt_get(opts, BDRV_OPT_DISCARD); | |
1916 | if (discard != NULL) { | |
1917 | if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) { | |
1918 | error_setg(errp, "Invalid discard option"); | |
1919 | ret = -EINVAL; | |
1920 | goto fail_opts; | |
1921 | } | |
1922 | } | |
1923 | ||
1924 | bs->detect_zeroes = | |
1925 | bdrv_parse_detect_zeroes(opts, bs->open_flags, &local_err); | |
1926 | if (local_err) { | |
1927 | error_propagate(errp, local_err); | |
1928 | ret = -EINVAL; | |
1929 | goto fail_opts; | |
1930 | } | |
1931 | ||
1932 | if (filename != NULL) { | |
1933 | pstrcpy(bs->filename, sizeof(bs->filename), filename); | |
1934 | } else { | |
1935 | bs->filename[0] = '\0'; | |
1936 | } | |
1937 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename); | |
1938 | ||
1939 | /* Open the image, either directly or using a protocol */ | |
1940 | open_flags = bdrv_open_flags(bs, bs->open_flags); | |
1941 | node_name = qemu_opt_get(opts, "node-name"); | |
1942 | ||
1943 | assert(!drv->bdrv_file_open || file == NULL); | |
1944 | ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp); | |
1945 | if (ret < 0) { | |
1946 | goto fail_opts; | |
1947 | } | |
1948 | ||
1949 | qemu_opts_del(opts); | |
1950 | return 0; | |
1951 | ||
1952 | fail_opts: | |
1953 | qemu_opts_del(opts); | |
1954 | return ret; | |
1955 | } | |
1956 | ||
1957 | static QDict *parse_json_filename(const char *filename, Error **errp) | |
1958 | { | |
1959 | QObject *options_obj; | |
1960 | QDict *options; | |
1961 | int ret; | |
1962 | GLOBAL_STATE_CODE(); | |
1963 | ||
1964 | ret = strstart(filename, "json:", &filename); | |
1965 | assert(ret); | |
1966 | ||
1967 | options_obj = qobject_from_json(filename, errp); | |
1968 | if (!options_obj) { | |
1969 | error_prepend(errp, "Could not parse the JSON options: "); | |
1970 | return NULL; | |
1971 | } | |
1972 | ||
1973 | options = qobject_to(QDict, options_obj); | |
1974 | if (!options) { | |
1975 | qobject_unref(options_obj); | |
1976 | error_setg(errp, "Invalid JSON object given"); | |
1977 | return NULL; | |
1978 | } | |
1979 | ||
1980 | qdict_flatten(options); | |
1981 | ||
1982 | return options; | |
1983 | } | |
1984 | ||
1985 | static void parse_json_protocol(QDict *options, const char **pfilename, | |
1986 | Error **errp) | |
1987 | { | |
1988 | QDict *json_options; | |
1989 | Error *local_err = NULL; | |
1990 | GLOBAL_STATE_CODE(); | |
1991 | ||
1992 | /* Parse json: pseudo-protocol */ | |
1993 | if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) { | |
1994 | return; | |
1995 | } | |
1996 | ||
1997 | json_options = parse_json_filename(*pfilename, &local_err); | |
1998 | if (local_err) { | |
1999 | error_propagate(errp, local_err); | |
2000 | return; | |
2001 | } | |
2002 | ||
2003 | /* Options given in the filename have lower priority than options | |
2004 | * specified directly */ | |
2005 | qdict_join(options, json_options, false); | |
2006 | qobject_unref(json_options); | |
2007 | *pfilename = NULL; | |
2008 | } | |
2009 | ||
2010 | /* | |
2011 | * Fills in default options for opening images and converts the legacy | |
2012 | * filename/flags pair to option QDict entries. | |
2013 | * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a | |
2014 | * block driver has been specified explicitly. | |
2015 | */ | |
2016 | static int bdrv_fill_options(QDict **options, const char *filename, | |
2017 | int *flags, Error **errp) | |
2018 | { | |
2019 | const char *drvname; | |
2020 | bool protocol = *flags & BDRV_O_PROTOCOL; | |
2021 | bool parse_filename = false; | |
2022 | BlockDriver *drv = NULL; | |
2023 | Error *local_err = NULL; | |
2024 | ||
2025 | GLOBAL_STATE_CODE(); | |
2026 | ||
2027 | /* | |
2028 | * Caution: while qdict_get_try_str() is fine, getting non-string | |
2029 | * types would require more care. When @options come from | |
2030 | * -blockdev or blockdev_add, its members are typed according to | |
2031 | * the QAPI schema, but when they come from -drive, they're all | |
2032 | * QString. | |
2033 | */ | |
2034 | drvname = qdict_get_try_str(*options, "driver"); | |
2035 | if (drvname) { | |
2036 | drv = bdrv_find_format(drvname); | |
2037 | if (!drv) { | |
2038 | error_setg(errp, "Unknown driver '%s'", drvname); | |
2039 | return -ENOENT; | |
2040 | } | |
2041 | /* If the user has explicitly specified the driver, this choice should | |
2042 | * override the BDRV_O_PROTOCOL flag */ | |
2043 | protocol = drv->bdrv_file_open; | |
2044 | } | |
2045 | ||
2046 | if (protocol) { | |
2047 | *flags |= BDRV_O_PROTOCOL; | |
2048 | } else { | |
2049 | *flags &= ~BDRV_O_PROTOCOL; | |
2050 | } | |
2051 | ||
2052 | /* Translate cache options from flags into options */ | |
2053 | update_options_from_flags(*options, *flags); | |
2054 | ||
2055 | /* Fetch the file name from the options QDict if necessary */ | |
2056 | if (protocol && filename) { | |
2057 | if (!qdict_haskey(*options, "filename")) { | |
2058 | qdict_put_str(*options, "filename", filename); | |
2059 | parse_filename = true; | |
2060 | } else { | |
2061 | error_setg(errp, "Can't specify 'file' and 'filename' options at " | |
2062 | "the same time"); | |
2063 | return -EINVAL; | |
2064 | } | |
2065 | } | |
2066 | ||
2067 | /* Find the right block driver */ | |
2068 | /* See cautionary note on accessing @options above */ | |
2069 | filename = qdict_get_try_str(*options, "filename"); | |
2070 | ||
2071 | if (!drvname && protocol) { | |
2072 | if (filename) { | |
2073 | drv = bdrv_find_protocol(filename, parse_filename, errp); | |
2074 | if (!drv) { | |
2075 | return -EINVAL; | |
2076 | } | |
2077 | ||
2078 | drvname = drv->format_name; | |
2079 | qdict_put_str(*options, "driver", drvname); | |
2080 | } else { | |
2081 | error_setg(errp, "Must specify either driver or file"); | |
2082 | return -EINVAL; | |
2083 | } | |
2084 | } | |
2085 | ||
2086 | assert(drv || !protocol); | |
2087 | ||
2088 | /* Driver-specific filename parsing */ | |
2089 | if (drv && drv->bdrv_parse_filename && parse_filename) { | |
2090 | drv->bdrv_parse_filename(filename, *options, &local_err); | |
2091 | if (local_err) { | |
2092 | error_propagate(errp, local_err); | |
2093 | return -EINVAL; | |
2094 | } | |
2095 | ||
2096 | if (!drv->bdrv_needs_filename) { | |
2097 | qdict_del(*options, "filename"); | |
2098 | } | |
2099 | } | |
2100 | ||
2101 | return 0; | |
2102 | } | |
2103 | ||
2104 | typedef struct BlockReopenQueueEntry { | |
2105 | bool prepared; | |
2106 | bool perms_checked; | |
2107 | BDRVReopenState state; | |
2108 | QTAILQ_ENTRY(BlockReopenQueueEntry) entry; | |
2109 | } BlockReopenQueueEntry; | |
2110 | ||
2111 | /* | |
2112 | * Return the flags that @bs will have after the reopens in @q have | |
2113 | * successfully completed. If @q is NULL (or @bs is not contained in @q), | |
2114 | * return the current flags. | |
2115 | */ | |
2116 | static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs) | |
2117 | { | |
2118 | BlockReopenQueueEntry *entry; | |
2119 | ||
2120 | if (q != NULL) { | |
2121 | QTAILQ_FOREACH(entry, q, entry) { | |
2122 | if (entry->state.bs == bs) { | |
2123 | return entry->state.flags; | |
2124 | } | |
2125 | } | |
2126 | } | |
2127 | ||
2128 | return bs->open_flags; | |
2129 | } | |
2130 | ||
2131 | /* Returns whether the image file can be written to after the reopen queue @q | |
2132 | * has been successfully applied, or right now if @q is NULL. */ | |
2133 | static bool bdrv_is_writable_after_reopen(BlockDriverState *bs, | |
2134 | BlockReopenQueue *q) | |
2135 | { | |
2136 | int flags = bdrv_reopen_get_flags(q, bs); | |
2137 | ||
2138 | return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR; | |
2139 | } | |
2140 | ||
2141 | /* | |
2142 | * Return whether the BDS can be written to. This is not necessarily | |
2143 | * the same as !bdrv_is_read_only(bs), as inactivated images may not | |
2144 | * be written to but do not count as read-only images. | |
2145 | */ | |
2146 | bool bdrv_is_writable(BlockDriverState *bs) | |
2147 | { | |
2148 | IO_CODE(); | |
2149 | return bdrv_is_writable_after_reopen(bs, NULL); | |
2150 | } | |
2151 | ||
2152 | static char *bdrv_child_user_desc(BdrvChild *c) | |
2153 | { | |
2154 | GLOBAL_STATE_CODE(); | |
2155 | return c->klass->get_parent_desc(c); | |
2156 | } | |
2157 | ||
2158 | /* | |
2159 | * Check that @a allows everything that @b needs. @a and @b must reference same | |
2160 | * child node. | |
2161 | */ | |
2162 | static bool bdrv_a_allow_b(BdrvChild *a, BdrvChild *b, Error **errp) | |
2163 | { | |
2164 | const char *child_bs_name; | |
2165 | g_autofree char *a_user = NULL; | |
2166 | g_autofree char *b_user = NULL; | |
2167 | g_autofree char *perms = NULL; | |
2168 | ||
2169 | assert(a->bs); | |
2170 | assert(a->bs == b->bs); | |
2171 | GLOBAL_STATE_CODE(); | |
2172 | ||
2173 | if ((b->perm & a->shared_perm) == b->perm) { | |
2174 | return true; | |
2175 | } | |
2176 | ||
2177 | child_bs_name = bdrv_get_node_name(b->bs); | |
2178 | a_user = bdrv_child_user_desc(a); | |
2179 | b_user = bdrv_child_user_desc(b); | |
2180 | perms = bdrv_perm_names(b->perm & ~a->shared_perm); | |
2181 | ||
2182 | error_setg(errp, "Permission conflict on node '%s': permissions '%s' are " | |
2183 | "both required by %s (uses node '%s' as '%s' child) and " | |
2184 | "unshared by %s (uses node '%s' as '%s' child).", | |
2185 | child_bs_name, perms, | |
2186 | b_user, child_bs_name, b->name, | |
2187 | a_user, child_bs_name, a->name); | |
2188 | ||
2189 | return false; | |
2190 | } | |
2191 | ||
2192 | static bool bdrv_parent_perms_conflict(BlockDriverState *bs, Error **errp) | |
2193 | { | |
2194 | BdrvChild *a, *b; | |
2195 | GLOBAL_STATE_CODE(); | |
2196 | ||
2197 | /* | |
2198 | * During the loop we'll look at each pair twice. That's correct because | |
2199 | * bdrv_a_allow_b() is asymmetric and we should check each pair in both | |
2200 | * directions. | |
2201 | */ | |
2202 | QLIST_FOREACH(a, &bs->parents, next_parent) { | |
2203 | QLIST_FOREACH(b, &bs->parents, next_parent) { | |
2204 | if (a == b) { | |
2205 | continue; | |
2206 | } | |
2207 | ||
2208 | if (!bdrv_a_allow_b(a, b, errp)) { | |
2209 | return true; | |
2210 | } | |
2211 | } | |
2212 | } | |
2213 | ||
2214 | return false; | |
2215 | } | |
2216 | ||
2217 | static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs, | |
2218 | BdrvChild *c, BdrvChildRole role, | |
2219 | BlockReopenQueue *reopen_queue, | |
2220 | uint64_t parent_perm, uint64_t parent_shared, | |
2221 | uint64_t *nperm, uint64_t *nshared) | |
2222 | { | |
2223 | assert(bs->drv && bs->drv->bdrv_child_perm); | |
2224 | GLOBAL_STATE_CODE(); | |
2225 | bs->drv->bdrv_child_perm(bs, c, role, reopen_queue, | |
2226 | parent_perm, parent_shared, | |
2227 | nperm, nshared); | |
2228 | /* TODO Take force_share from reopen_queue */ | |
2229 | if (child_bs && child_bs->force_share) { | |
2230 | *nshared = BLK_PERM_ALL; | |
2231 | } | |
2232 | } | |
2233 | ||
2234 | /* | |
2235 | * Adds the whole subtree of @bs (including @bs itself) to the @list (except for | |
2236 | * nodes that are already in the @list, of course) so that final list is | |
2237 | * topologically sorted. Return the result (GSList @list object is updated, so | |
2238 | * don't use old reference after function call). | |
2239 | * | |
2240 | * On function start @list must be already topologically sorted and for any node | |
2241 | * in the @list the whole subtree of the node must be in the @list as well. The | |
2242 | * simplest way to satisfy this criteria: use only result of | |
2243 | * bdrv_topological_dfs() or NULL as @list parameter. | |
2244 | */ | |
2245 | static GSList *bdrv_topological_dfs(GSList *list, GHashTable *found, | |
2246 | BlockDriverState *bs) | |
2247 | { | |
2248 | BdrvChild *child; | |
2249 | g_autoptr(GHashTable) local_found = NULL; | |
2250 | ||
2251 | GLOBAL_STATE_CODE(); | |
2252 | ||
2253 | if (!found) { | |
2254 | assert(!list); | |
2255 | found = local_found = g_hash_table_new(NULL, NULL); | |
2256 | } | |
2257 | ||
2258 | if (g_hash_table_contains(found, bs)) { | |
2259 | return list; | |
2260 | } | |
2261 | g_hash_table_add(found, bs); | |
2262 | ||
2263 | QLIST_FOREACH(child, &bs->children, next) { | |
2264 | list = bdrv_topological_dfs(list, found, child->bs); | |
2265 | } | |
2266 | ||
2267 | return g_slist_prepend(list, bs); | |
2268 | } | |
2269 | ||
2270 | typedef struct BdrvChildSetPermState { | |
2271 | BdrvChild *child; | |
2272 | uint64_t old_perm; | |
2273 | uint64_t old_shared_perm; | |
2274 | } BdrvChildSetPermState; | |
2275 | ||
2276 | static void bdrv_child_set_perm_abort(void *opaque) | |
2277 | { | |
2278 | BdrvChildSetPermState *s = opaque; | |
2279 | ||
2280 | GLOBAL_STATE_CODE(); | |
2281 | ||
2282 | s->child->perm = s->old_perm; | |
2283 | s->child->shared_perm = s->old_shared_perm; | |
2284 | } | |
2285 | ||
2286 | static TransactionActionDrv bdrv_child_set_pem_drv = { | |
2287 | .abort = bdrv_child_set_perm_abort, | |
2288 | .clean = g_free, | |
2289 | }; | |
2290 | ||
2291 | static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, | |
2292 | uint64_t shared, Transaction *tran) | |
2293 | { | |
2294 | BdrvChildSetPermState *s = g_new(BdrvChildSetPermState, 1); | |
2295 | GLOBAL_STATE_CODE(); | |
2296 | ||
2297 | *s = (BdrvChildSetPermState) { | |
2298 | .child = c, | |
2299 | .old_perm = c->perm, | |
2300 | .old_shared_perm = c->shared_perm, | |
2301 | }; | |
2302 | ||
2303 | c->perm = perm; | |
2304 | c->shared_perm = shared; | |
2305 | ||
2306 | tran_add(tran, &bdrv_child_set_pem_drv, s); | |
2307 | } | |
2308 | ||
2309 | static void bdrv_drv_set_perm_commit(void *opaque) | |
2310 | { | |
2311 | BlockDriverState *bs = opaque; | |
2312 | uint64_t cumulative_perms, cumulative_shared_perms; | |
2313 | GLOBAL_STATE_CODE(); | |
2314 | ||
2315 | if (bs->drv->bdrv_set_perm) { | |
2316 | bdrv_get_cumulative_perm(bs, &cumulative_perms, | |
2317 | &cumulative_shared_perms); | |
2318 | bs->drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms); | |
2319 | } | |
2320 | } | |
2321 | ||
2322 | static void bdrv_drv_set_perm_abort(void *opaque) | |
2323 | { | |
2324 | BlockDriverState *bs = opaque; | |
2325 | GLOBAL_STATE_CODE(); | |
2326 | ||
2327 | if (bs->drv->bdrv_abort_perm_update) { | |
2328 | bs->drv->bdrv_abort_perm_update(bs); | |
2329 | } | |
2330 | } | |
2331 | ||
2332 | TransactionActionDrv bdrv_drv_set_perm_drv = { | |
2333 | .abort = bdrv_drv_set_perm_abort, | |
2334 | .commit = bdrv_drv_set_perm_commit, | |
2335 | }; | |
2336 | ||
2337 | static int bdrv_drv_set_perm(BlockDriverState *bs, uint64_t perm, | |
2338 | uint64_t shared_perm, Transaction *tran, | |
2339 | Error **errp) | |
2340 | { | |
2341 | GLOBAL_STATE_CODE(); | |
2342 | if (!bs->drv) { | |
2343 | return 0; | |
2344 | } | |
2345 | ||
2346 | if (bs->drv->bdrv_check_perm) { | |
2347 | int ret = bs->drv->bdrv_check_perm(bs, perm, shared_perm, errp); | |
2348 | if (ret < 0) { | |
2349 | return ret; | |
2350 | } | |
2351 | } | |
2352 | ||
2353 | if (tran) { | |
2354 | tran_add(tran, &bdrv_drv_set_perm_drv, bs); | |
2355 | } | |
2356 | ||
2357 | return 0; | |
2358 | } | |
2359 | ||
2360 | typedef struct BdrvReplaceChildState { | |
2361 | BdrvChild *child; | |
2362 | BlockDriverState *old_bs; | |
2363 | } BdrvReplaceChildState; | |
2364 | ||
2365 | static void bdrv_replace_child_commit(void *opaque) | |
2366 | { | |
2367 | BdrvReplaceChildState *s = opaque; | |
2368 | GLOBAL_STATE_CODE(); | |
2369 | ||
2370 | bdrv_unref(s->old_bs); | |
2371 | } | |
2372 | ||
2373 | static void bdrv_replace_child_abort(void *opaque) | |
2374 | { | |
2375 | BdrvReplaceChildState *s = opaque; | |
2376 | BlockDriverState *new_bs = s->child->bs; | |
2377 | ||
2378 | GLOBAL_STATE_CODE(); | |
2379 | /* old_bs reference is transparently moved from @s to @s->child */ | |
2380 | if (!s->child->bs) { | |
2381 | /* | |
2382 | * The parents were undrained when removing old_bs from the child. New | |
2383 | * requests can't have been made, though, because the child was empty. | |
2384 | * | |
2385 | * TODO Make bdrv_replace_child_noperm() transactionable to avoid | |
2386 | * undraining the parent in the first place. Once this is done, having | |
2387 | * new_bs drained when calling bdrv_replace_child_tran() is not a | |
2388 | * requirement any more. | |
2389 | */ | |
2390 | bdrv_parent_drained_begin_single(s->child); | |
2391 | assert(!bdrv_parent_drained_poll_single(s->child)); | |
2392 | } | |
2393 | assert(s->child->quiesced_parent); | |
2394 | bdrv_replace_child_noperm(s->child, s->old_bs); | |
2395 | bdrv_unref(new_bs); | |
2396 | } | |
2397 | ||
2398 | static TransactionActionDrv bdrv_replace_child_drv = { | |
2399 | .commit = bdrv_replace_child_commit, | |
2400 | .abort = bdrv_replace_child_abort, | |
2401 | .clean = g_free, | |
2402 | }; | |
2403 | ||
2404 | /* | |
2405 | * bdrv_replace_child_tran | |
2406 | * | |
2407 | * Note: real unref of old_bs is done only on commit. | |
2408 | * | |
2409 | * Both @child->bs and @new_bs (if non-NULL) must be drained. @new_bs must be | |
2410 | * kept drained until the transaction is completed. | |
2411 | * | |
2412 | * The function doesn't update permissions, caller is responsible for this. | |
2413 | */ | |
2414 | static void bdrv_replace_child_tran(BdrvChild *child, BlockDriverState *new_bs, | |
2415 | Transaction *tran) | |
2416 | { | |
2417 | BdrvReplaceChildState *s = g_new(BdrvReplaceChildState, 1); | |
2418 | ||
2419 | assert(child->quiesced_parent); | |
2420 | assert(!new_bs || new_bs->quiesce_counter); | |
2421 | ||
2422 | *s = (BdrvReplaceChildState) { | |
2423 | .child = child, | |
2424 | .old_bs = child->bs, | |
2425 | }; | |
2426 | tran_add(tran, &bdrv_replace_child_drv, s); | |
2427 | ||
2428 | if (new_bs) { | |
2429 | bdrv_ref(new_bs); | |
2430 | } | |
2431 | bdrv_replace_child_noperm(child, new_bs); | |
2432 | /* old_bs reference is transparently moved from @child to @s */ | |
2433 | } | |
2434 | ||
2435 | /* | |
2436 | * Refresh permissions in @bs subtree. The function is intended to be called | |
2437 | * after some graph modification that was done without permission update. | |
2438 | */ | |
2439 | static int bdrv_node_refresh_perm(BlockDriverState *bs, BlockReopenQueue *q, | |
2440 | Transaction *tran, Error **errp) | |
2441 | { | |
2442 | BlockDriver *drv = bs->drv; | |
2443 | BdrvChild *c; | |
2444 | int ret; | |
2445 | uint64_t cumulative_perms, cumulative_shared_perms; | |
2446 | GLOBAL_STATE_CODE(); | |
2447 | ||
2448 | bdrv_get_cumulative_perm(bs, &cumulative_perms, &cumulative_shared_perms); | |
2449 | ||
2450 | /* Write permissions never work with read-only images */ | |
2451 | if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) && | |
2452 | !bdrv_is_writable_after_reopen(bs, q)) | |
2453 | { | |
2454 | if (!bdrv_is_writable_after_reopen(bs, NULL)) { | |
2455 | error_setg(errp, "Block node is read-only"); | |
2456 | } else { | |
2457 | error_setg(errp, "Read-only block node '%s' cannot support " | |
2458 | "read-write users", bdrv_get_node_name(bs)); | |
2459 | } | |
2460 | ||
2461 | return -EPERM; | |
2462 | } | |
2463 | ||
2464 | /* | |
2465 | * Unaligned requests will automatically be aligned to bl.request_alignment | |
2466 | * and without RESIZE we can't extend requests to write to space beyond the | |
2467 | * end of the image, so it's required that the image size is aligned. | |
2468 | */ | |
2469 | if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) && | |
2470 | !(cumulative_perms & BLK_PERM_RESIZE)) | |
2471 | { | |
2472 | if ((bs->total_sectors * BDRV_SECTOR_SIZE) % bs->bl.request_alignment) { | |
2473 | error_setg(errp, "Cannot get 'write' permission without 'resize': " | |
2474 | "Image size is not a multiple of request " | |
2475 | "alignment"); | |
2476 | return -EPERM; | |
2477 | } | |
2478 | } | |
2479 | ||
2480 | /* Check this node */ | |
2481 | if (!drv) { | |
2482 | return 0; | |
2483 | } | |
2484 | ||
2485 | ret = bdrv_drv_set_perm(bs, cumulative_perms, cumulative_shared_perms, tran, | |
2486 | errp); | |
2487 | if (ret < 0) { | |
2488 | return ret; | |
2489 | } | |
2490 | ||
2491 | /* Drivers that never have children can omit .bdrv_child_perm() */ | |
2492 | if (!drv->bdrv_child_perm) { | |
2493 | assert(QLIST_EMPTY(&bs->children)); | |
2494 | return 0; | |
2495 | } | |
2496 | ||
2497 | /* Check all children */ | |
2498 | QLIST_FOREACH(c, &bs->children, next) { | |
2499 | uint64_t cur_perm, cur_shared; | |
2500 | ||
2501 | bdrv_child_perm(bs, c->bs, c, c->role, q, | |
2502 | cumulative_perms, cumulative_shared_perms, | |
2503 | &cur_perm, &cur_shared); | |
2504 | bdrv_child_set_perm(c, cur_perm, cur_shared, tran); | |
2505 | } | |
2506 | ||
2507 | return 0; | |
2508 | } | |
2509 | ||
2510 | /* | |
2511 | * @list is a product of bdrv_topological_dfs() (may be called several times) - | |
2512 | * a topologically sorted subgraph. | |
2513 | */ | |
2514 | static int bdrv_do_refresh_perms(GSList *list, BlockReopenQueue *q, | |
2515 | Transaction *tran, Error **errp) | |
2516 | { | |
2517 | int ret; | |
2518 | BlockDriverState *bs; | |
2519 | GLOBAL_STATE_CODE(); | |
2520 | ||
2521 | for ( ; list; list = list->next) { | |
2522 | bs = list->data; | |
2523 | ||
2524 | if (bdrv_parent_perms_conflict(bs, errp)) { | |
2525 | return -EINVAL; | |
2526 | } | |
2527 | ||
2528 | ret = bdrv_node_refresh_perm(bs, q, tran, errp); | |
2529 | if (ret < 0) { | |
2530 | return ret; | |
2531 | } | |
2532 | } | |
2533 | ||
2534 | return 0; | |
2535 | } | |
2536 | ||
2537 | /* | |
2538 | * @list is any list of nodes. List is completed by all subtrees and | |
2539 | * topologically sorted. It's not a problem if some node occurs in the @list | |
2540 | * several times. | |
2541 | */ | |
2542 | static int bdrv_list_refresh_perms(GSList *list, BlockReopenQueue *q, | |
2543 | Transaction *tran, Error **errp) | |
2544 | { | |
2545 | g_autoptr(GHashTable) found = g_hash_table_new(NULL, NULL); | |
2546 | g_autoptr(GSList) refresh_list = NULL; | |
2547 | ||
2548 | for ( ; list; list = list->next) { | |
2549 | refresh_list = bdrv_topological_dfs(refresh_list, found, list->data); | |
2550 | } | |
2551 | ||
2552 | return bdrv_do_refresh_perms(refresh_list, q, tran, errp); | |
2553 | } | |
2554 | ||
2555 | void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, | |
2556 | uint64_t *shared_perm) | |
2557 | { | |
2558 | BdrvChild *c; | |
2559 | uint64_t cumulative_perms = 0; | |
2560 | uint64_t cumulative_shared_perms = BLK_PERM_ALL; | |
2561 | ||
2562 | GLOBAL_STATE_CODE(); | |
2563 | ||
2564 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
2565 | cumulative_perms |= c->perm; | |
2566 | cumulative_shared_perms &= c->shared_perm; | |
2567 | } | |
2568 | ||
2569 | *perm = cumulative_perms; | |
2570 | *shared_perm = cumulative_shared_perms; | |
2571 | } | |
2572 | ||
2573 | char *bdrv_perm_names(uint64_t perm) | |
2574 | { | |
2575 | struct perm_name { | |
2576 | uint64_t perm; | |
2577 | const char *name; | |
2578 | } permissions[] = { | |
2579 | { BLK_PERM_CONSISTENT_READ, "consistent read" }, | |
2580 | { BLK_PERM_WRITE, "write" }, | |
2581 | { BLK_PERM_WRITE_UNCHANGED, "write unchanged" }, | |
2582 | { BLK_PERM_RESIZE, "resize" }, | |
2583 | { 0, NULL } | |
2584 | }; | |
2585 | ||
2586 | GString *result = g_string_sized_new(30); | |
2587 | struct perm_name *p; | |
2588 | ||
2589 | for (p = permissions; p->name; p++) { | |
2590 | if (perm & p->perm) { | |
2591 | if (result->len > 0) { | |
2592 | g_string_append(result, ", "); | |
2593 | } | |
2594 | g_string_append(result, p->name); | |
2595 | } | |
2596 | } | |
2597 | ||
2598 | return g_string_free(result, FALSE); | |
2599 | } | |
2600 | ||
2601 | ||
2602 | /* @tran is allowed to be NULL. In this case no rollback is possible */ | |
2603 | static int bdrv_refresh_perms(BlockDriverState *bs, Transaction *tran, | |
2604 | Error **errp) | |
2605 | { | |
2606 | int ret; | |
2607 | Transaction *local_tran = NULL; | |
2608 | g_autoptr(GSList) list = bdrv_topological_dfs(NULL, NULL, bs); | |
2609 | GLOBAL_STATE_CODE(); | |
2610 | ||
2611 | if (!tran) { | |
2612 | tran = local_tran = tran_new(); | |
2613 | } | |
2614 | ||
2615 | ret = bdrv_do_refresh_perms(list, NULL, tran, errp); | |
2616 | ||
2617 | if (local_tran) { | |
2618 | tran_finalize(local_tran, ret); | |
2619 | } | |
2620 | ||
2621 | return ret; | |
2622 | } | |
2623 | ||
2624 | int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, | |
2625 | Error **errp) | |
2626 | { | |
2627 | Error *local_err = NULL; | |
2628 | Transaction *tran = tran_new(); | |
2629 | int ret; | |
2630 | ||
2631 | GLOBAL_STATE_CODE(); | |
2632 | ||
2633 | bdrv_child_set_perm(c, perm, shared, tran); | |
2634 | ||
2635 | ret = bdrv_refresh_perms(c->bs, tran, &local_err); | |
2636 | ||
2637 | tran_finalize(tran, ret); | |
2638 | ||
2639 | if (ret < 0) { | |
2640 | if ((perm & ~c->perm) || (c->shared_perm & ~shared)) { | |
2641 | /* tighten permissions */ | |
2642 | error_propagate(errp, local_err); | |
2643 | } else { | |
2644 | /* | |
2645 | * Our caller may intend to only loosen restrictions and | |
2646 | * does not expect this function to fail. Errors are not | |
2647 | * fatal in such a case, so we can just hide them from our | |
2648 | * caller. | |
2649 | */ | |
2650 | error_free(local_err); | |
2651 | ret = 0; | |
2652 | } | |
2653 | } | |
2654 | ||
2655 | return ret; | |
2656 | } | |
2657 | ||
2658 | int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp) | |
2659 | { | |
2660 | uint64_t parent_perms, parent_shared; | |
2661 | uint64_t perms, shared; | |
2662 | ||
2663 | GLOBAL_STATE_CODE(); | |
2664 | ||
2665 | bdrv_get_cumulative_perm(bs, &parent_perms, &parent_shared); | |
2666 | bdrv_child_perm(bs, c->bs, c, c->role, NULL, | |
2667 | parent_perms, parent_shared, &perms, &shared); | |
2668 | ||
2669 | return bdrv_child_try_set_perm(c, perms, shared, errp); | |
2670 | } | |
2671 | ||
2672 | /* | |
2673 | * Default implementation for .bdrv_child_perm() for block filters: | |
2674 | * Forward CONSISTENT_READ, WRITE, WRITE_UNCHANGED, and RESIZE to the | |
2675 | * filtered child. | |
2676 | */ | |
2677 | static void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, | |
2678 | BdrvChildRole role, | |
2679 | BlockReopenQueue *reopen_queue, | |
2680 | uint64_t perm, uint64_t shared, | |
2681 | uint64_t *nperm, uint64_t *nshared) | |
2682 | { | |
2683 | GLOBAL_STATE_CODE(); | |
2684 | *nperm = perm & DEFAULT_PERM_PASSTHROUGH; | |
2685 | *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED; | |
2686 | } | |
2687 | ||
2688 | static void bdrv_default_perms_for_cow(BlockDriverState *bs, BdrvChild *c, | |
2689 | BdrvChildRole role, | |
2690 | BlockReopenQueue *reopen_queue, | |
2691 | uint64_t perm, uint64_t shared, | |
2692 | uint64_t *nperm, uint64_t *nshared) | |
2693 | { | |
2694 | assert(role & BDRV_CHILD_COW); | |
2695 | GLOBAL_STATE_CODE(); | |
2696 | ||
2697 | /* | |
2698 | * We want consistent read from backing files if the parent needs it. | |
2699 | * No other operations are performed on backing files. | |
2700 | */ | |
2701 | perm &= BLK_PERM_CONSISTENT_READ; | |
2702 | ||
2703 | /* | |
2704 | * If the parent can deal with changing data, we're okay with a | |
2705 | * writable and resizable backing file. | |
2706 | * TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? | |
2707 | */ | |
2708 | if (shared & BLK_PERM_WRITE) { | |
2709 | shared = BLK_PERM_WRITE | BLK_PERM_RESIZE; | |
2710 | } else { | |
2711 | shared = 0; | |
2712 | } | |
2713 | ||
2714 | shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED; | |
2715 | ||
2716 | if (bs->open_flags & BDRV_O_INACTIVE) { | |
2717 | shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; | |
2718 | } | |
2719 | ||
2720 | *nperm = perm; | |
2721 | *nshared = shared; | |
2722 | } | |
2723 | ||
2724 | static void bdrv_default_perms_for_storage(BlockDriverState *bs, BdrvChild *c, | |
2725 | BdrvChildRole role, | |
2726 | BlockReopenQueue *reopen_queue, | |
2727 | uint64_t perm, uint64_t shared, | |
2728 | uint64_t *nperm, uint64_t *nshared) | |
2729 | { | |
2730 | int flags; | |
2731 | ||
2732 | GLOBAL_STATE_CODE(); | |
2733 | assert(role & (BDRV_CHILD_METADATA | BDRV_CHILD_DATA)); | |
2734 | ||
2735 | flags = bdrv_reopen_get_flags(reopen_queue, bs); | |
2736 | ||
2737 | /* | |
2738 | * Apart from the modifications below, the same permissions are | |
2739 | * forwarded and left alone as for filters | |
2740 | */ | |
2741 | bdrv_filter_default_perms(bs, c, role, reopen_queue, | |
2742 | perm, shared, &perm, &shared); | |
2743 | ||
2744 | if (role & BDRV_CHILD_METADATA) { | |
2745 | /* Format drivers may touch metadata even if the guest doesn't write */ | |
2746 | if (bdrv_is_writable_after_reopen(bs, reopen_queue)) { | |
2747 | perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; | |
2748 | } | |
2749 | ||
2750 | /* | |
2751 | * bs->file always needs to be consistent because of the | |
2752 | * metadata. We can never allow other users to resize or write | |
2753 | * to it. | |
2754 | */ | |
2755 | if (!(flags & BDRV_O_NO_IO)) { | |
2756 | perm |= BLK_PERM_CONSISTENT_READ; | |
2757 | } | |
2758 | shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); | |
2759 | } | |
2760 | ||
2761 | if (role & BDRV_CHILD_DATA) { | |
2762 | /* | |
2763 | * Technically, everything in this block is a subset of the | |
2764 | * BDRV_CHILD_METADATA path taken above, and so this could | |
2765 | * be an "else if" branch. However, that is not obvious, and | |
2766 | * this function is not performance critical, therefore we let | |
2767 | * this be an independent "if". | |
2768 | */ | |
2769 | ||
2770 | /* | |
2771 | * We cannot allow other users to resize the file because the | |
2772 | * format driver might have some assumptions about the size | |
2773 | * (e.g. because it is stored in metadata, or because the file | |
2774 | * is split into fixed-size data files). | |
2775 | */ | |
2776 | shared &= ~BLK_PERM_RESIZE; | |
2777 | ||
2778 | /* | |
2779 | * WRITE_UNCHANGED often cannot be performed as such on the | |
2780 | * data file. For example, the qcow2 driver may still need to | |
2781 | * write copied clusters on copy-on-read. | |
2782 | */ | |
2783 | if (perm & BLK_PERM_WRITE_UNCHANGED) { | |
2784 | perm |= BLK_PERM_WRITE; | |
2785 | } | |
2786 | ||
2787 | /* | |
2788 | * If the data file is written to, the format driver may | |
2789 | * expect to be able to resize it by writing beyond the EOF. | |
2790 | */ | |
2791 | if (perm & BLK_PERM_WRITE) { | |
2792 | perm |= BLK_PERM_RESIZE; | |
2793 | } | |
2794 | } | |
2795 | ||
2796 | if (bs->open_flags & BDRV_O_INACTIVE) { | |
2797 | shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; | |
2798 | } | |
2799 | ||
2800 | *nperm = perm; | |
2801 | *nshared = shared; | |
2802 | } | |
2803 | ||
2804 | void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c, | |
2805 | BdrvChildRole role, BlockReopenQueue *reopen_queue, | |
2806 | uint64_t perm, uint64_t shared, | |
2807 | uint64_t *nperm, uint64_t *nshared) | |
2808 | { | |
2809 | GLOBAL_STATE_CODE(); | |
2810 | if (role & BDRV_CHILD_FILTERED) { | |
2811 | assert(!(role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA | | |
2812 | BDRV_CHILD_COW))); | |
2813 | bdrv_filter_default_perms(bs, c, role, reopen_queue, | |
2814 | perm, shared, nperm, nshared); | |
2815 | } else if (role & BDRV_CHILD_COW) { | |
2816 | assert(!(role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA))); | |
2817 | bdrv_default_perms_for_cow(bs, c, role, reopen_queue, | |
2818 | perm, shared, nperm, nshared); | |
2819 | } else if (role & (BDRV_CHILD_METADATA | BDRV_CHILD_DATA)) { | |
2820 | bdrv_default_perms_for_storage(bs, c, role, reopen_queue, | |
2821 | perm, shared, nperm, nshared); | |
2822 | } else { | |
2823 | g_assert_not_reached(); | |
2824 | } | |
2825 | } | |
2826 | ||
2827 | uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm) | |
2828 | { | |
2829 | static const uint64_t permissions[] = { | |
2830 | [BLOCK_PERMISSION_CONSISTENT_READ] = BLK_PERM_CONSISTENT_READ, | |
2831 | [BLOCK_PERMISSION_WRITE] = BLK_PERM_WRITE, | |
2832 | [BLOCK_PERMISSION_WRITE_UNCHANGED] = BLK_PERM_WRITE_UNCHANGED, | |
2833 | [BLOCK_PERMISSION_RESIZE] = BLK_PERM_RESIZE, | |
2834 | }; | |
2835 | ||
2836 | QEMU_BUILD_BUG_ON(ARRAY_SIZE(permissions) != BLOCK_PERMISSION__MAX); | |
2837 | QEMU_BUILD_BUG_ON(1UL << ARRAY_SIZE(permissions) != BLK_PERM_ALL + 1); | |
2838 | ||
2839 | assert(qapi_perm < BLOCK_PERMISSION__MAX); | |
2840 | ||
2841 | return permissions[qapi_perm]; | |
2842 | } | |
2843 | ||
2844 | /* | |
2845 | * Replaces the node that a BdrvChild points to without updating permissions. | |
2846 | * | |
2847 | * If @new_bs is non-NULL, the parent of @child must already be drained through | |
2848 | * @child. | |
2849 | */ | |
2850 | static void bdrv_replace_child_noperm(BdrvChild *child, | |
2851 | BlockDriverState *new_bs) | |
2852 | { | |
2853 | BlockDriverState *old_bs = child->bs; | |
2854 | int new_bs_quiesce_counter; | |
2855 | ||
2856 | assert(!child->frozen); | |
2857 | ||
2858 | /* | |
2859 | * If we want to change the BdrvChild to point to a drained node as its new | |
2860 | * child->bs, we need to make sure that its new parent is drained, too. In | |
2861 | * other words, either child->quiesce_parent must already be true or we must | |
2862 | * be able to set it and keep the parent's quiesce_counter consistent with | |
2863 | * that, but without polling or starting new requests (this function | |
2864 | * guarantees that it doesn't poll, and starting new requests would be | |
2865 | * against the invariants of drain sections). | |
2866 | * | |
2867 | * To keep things simple, we pick the first option (child->quiesce_parent | |
2868 | * must already be true). We also generalise the rule a bit to make it | |
2869 | * easier to verify in callers and more likely to be covered in test cases: | |
2870 | * The parent must be quiesced through this child even if new_bs isn't | |
2871 | * currently drained. | |
2872 | * | |
2873 | * The only exception is for callers that always pass new_bs == NULL. In | |
2874 | * this case, we obviously never need to consider the case of a drained | |
2875 | * new_bs, so we can keep the callers simpler by allowing them not to drain | |
2876 | * the parent. | |
2877 | */ | |
2878 | assert(!new_bs || child->quiesced_parent); | |
2879 | assert(old_bs != new_bs); | |
2880 | GLOBAL_STATE_CODE(); | |
2881 | ||
2882 | if (old_bs && new_bs) { | |
2883 | assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)); | |
2884 | } | |
2885 | ||
2886 | /* TODO Pull this up into the callers to avoid polling here */ | |
2887 | bdrv_graph_wrlock(); | |
2888 | if (old_bs) { | |
2889 | if (child->klass->detach) { | |
2890 | child->klass->detach(child); | |
2891 | } | |
2892 | QLIST_REMOVE(child, next_parent); | |
2893 | } | |
2894 | ||
2895 | child->bs = new_bs; | |
2896 | ||
2897 | if (new_bs) { | |
2898 | QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent); | |
2899 | if (child->klass->attach) { | |
2900 | child->klass->attach(child); | |
2901 | } | |
2902 | } | |
2903 | bdrv_graph_wrunlock(); | |
2904 | ||
2905 | /* | |
2906 | * If the parent was drained through this BdrvChild previously, but new_bs | |
2907 | * is not drained, allow requests to come in only after the new node has | |
2908 | * been attached. | |
2909 | */ | |
2910 | new_bs_quiesce_counter = (new_bs ? new_bs->quiesce_counter : 0); | |
2911 | if (!new_bs_quiesce_counter && child->quiesced_parent) { | |
2912 | bdrv_parent_drained_end_single(child); | |
2913 | } | |
2914 | } | |
2915 | ||
2916 | /** | |
2917 | * Free the given @child. | |
2918 | * | |
2919 | * The child must be empty (i.e. `child->bs == NULL`) and it must be | |
2920 | * unused (i.e. not in a children list). | |
2921 | */ | |
2922 | static void bdrv_child_free(BdrvChild *child) | |
2923 | { | |
2924 | assert(!child->bs); | |
2925 | GLOBAL_STATE_CODE(); | |
2926 | assert(!child->next.le_prev); /* not in children list */ | |
2927 | ||
2928 | g_free(child->name); | |
2929 | g_free(child); | |
2930 | } | |
2931 | ||
2932 | typedef struct BdrvAttachChildCommonState { | |
2933 | BdrvChild *child; | |
2934 | AioContext *old_parent_ctx; | |
2935 | AioContext *old_child_ctx; | |
2936 | } BdrvAttachChildCommonState; | |
2937 | ||
2938 | static void bdrv_attach_child_common_abort(void *opaque) | |
2939 | { | |
2940 | BdrvAttachChildCommonState *s = opaque; | |
2941 | BlockDriverState *bs = s->child->bs; | |
2942 | ||
2943 | GLOBAL_STATE_CODE(); | |
2944 | bdrv_replace_child_noperm(s->child, NULL); | |
2945 | ||
2946 | if (bdrv_get_aio_context(bs) != s->old_child_ctx) { | |
2947 | bdrv_try_change_aio_context(bs, s->old_child_ctx, NULL, &error_abort); | |
2948 | } | |
2949 | ||
2950 | if (bdrv_child_get_parent_aio_context(s->child) != s->old_parent_ctx) { | |
2951 | Transaction *tran; | |
2952 | GHashTable *visited; | |
2953 | bool ret; | |
2954 | ||
2955 | tran = tran_new(); | |
2956 | ||
2957 | /* No need to visit `child`, because it has been detached already */ | |
2958 | visited = g_hash_table_new(NULL, NULL); | |
2959 | ret = s->child->klass->change_aio_ctx(s->child, s->old_parent_ctx, | |
2960 | visited, tran, &error_abort); | |
2961 | g_hash_table_destroy(visited); | |
2962 | ||
2963 | /* transaction is supposed to always succeed */ | |
2964 | assert(ret == true); | |
2965 | tran_commit(tran); | |
2966 | } | |
2967 | ||
2968 | bdrv_unref(bs); | |
2969 | bdrv_child_free(s->child); | |
2970 | } | |
2971 | ||
2972 | static TransactionActionDrv bdrv_attach_child_common_drv = { | |
2973 | .abort = bdrv_attach_child_common_abort, | |
2974 | .clean = g_free, | |
2975 | }; | |
2976 | ||
2977 | /* | |
2978 | * Common part of attaching bdrv child to bs or to blk or to job | |
2979 | * | |
2980 | * Function doesn't update permissions, caller is responsible for this. | |
2981 | * | |
2982 | * Returns new created child. | |
2983 | */ | |
2984 | static BdrvChild *bdrv_attach_child_common(BlockDriverState *child_bs, | |
2985 | const char *child_name, | |
2986 | const BdrvChildClass *child_class, | |
2987 | BdrvChildRole child_role, | |
2988 | uint64_t perm, uint64_t shared_perm, | |
2989 | void *opaque, | |
2990 | Transaction *tran, Error **errp) | |
2991 | { | |
2992 | BdrvChild *new_child; | |
2993 | AioContext *parent_ctx; | |
2994 | AioContext *child_ctx = bdrv_get_aio_context(child_bs); | |
2995 | ||
2996 | assert(child_class->get_parent_desc); | |
2997 | GLOBAL_STATE_CODE(); | |
2998 | ||
2999 | new_child = g_new(BdrvChild, 1); | |
3000 | *new_child = (BdrvChild) { | |
3001 | .bs = NULL, | |
3002 | .name = g_strdup(child_name), | |
3003 | .klass = child_class, | |
3004 | .role = child_role, | |
3005 | .perm = perm, | |
3006 | .shared_perm = shared_perm, | |
3007 | .opaque = opaque, | |
3008 | }; | |
3009 | ||
3010 | /* | |
3011 | * If the AioContexts don't match, first try to move the subtree of | |
3012 | * child_bs into the AioContext of the new parent. If this doesn't work, | |
3013 | * try moving the parent into the AioContext of child_bs instead. | |
3014 | */ | |
3015 | parent_ctx = bdrv_child_get_parent_aio_context(new_child); | |
3016 | if (child_ctx != parent_ctx) { | |
3017 | Error *local_err = NULL; | |
3018 | int ret = bdrv_try_change_aio_context(child_bs, parent_ctx, NULL, | |
3019 | &local_err); | |
3020 | ||
3021 | if (ret < 0 && child_class->change_aio_ctx) { | |
3022 | Transaction *tran = tran_new(); | |
3023 | GHashTable *visited = g_hash_table_new(NULL, NULL); | |
3024 | bool ret_child; | |
3025 | ||
3026 | g_hash_table_add(visited, new_child); | |
3027 | ret_child = child_class->change_aio_ctx(new_child, child_ctx, | |
3028 | visited, tran, NULL); | |
3029 | if (ret_child == true) { | |
3030 | error_free(local_err); | |
3031 | ret = 0; | |
3032 | } | |
3033 | tran_finalize(tran, ret_child == true ? 0 : -1); | |
3034 | g_hash_table_destroy(visited); | |
3035 | } | |
3036 | ||
3037 | if (ret < 0) { | |
3038 | error_propagate(errp, local_err); | |
3039 | bdrv_child_free(new_child); | |
3040 | return NULL; | |
3041 | } | |
3042 | } | |
3043 | ||
3044 | bdrv_ref(child_bs); | |
3045 | /* | |
3046 | * Let every new BdrvChild start with a drained parent. Inserting the child | |
3047 | * in the graph with bdrv_replace_child_noperm() will undrain it if | |
3048 | * @child_bs is not drained. | |
3049 | * | |
3050 | * The child was only just created and is not yet visible in global state | |
3051 | * until bdrv_replace_child_noperm() inserts it into the graph, so nobody | |
3052 | * could have sent requests and polling is not necessary. | |
3053 | * | |
3054 | * Note that this means that the parent isn't fully drained yet, we only | |
3055 | * stop new requests from coming in. This is fine, we don't care about the | |
3056 | * old requests here, they are not for this child. If another place enters a | |
3057 | * drain section for the same parent, but wants it to be fully quiesced, it | |
3058 | * will not run most of the the code in .drained_begin() again (which is not | |
3059 | * a problem, we already did this), but it will still poll until the parent | |
3060 | * is fully quiesced, so it will not be negatively affected either. | |
3061 | */ | |
3062 | bdrv_parent_drained_begin_single(new_child); | |
3063 | bdrv_replace_child_noperm(new_child, child_bs); | |
3064 | ||
3065 | BdrvAttachChildCommonState *s = g_new(BdrvAttachChildCommonState, 1); | |
3066 | *s = (BdrvAttachChildCommonState) { | |
3067 | .child = new_child, | |
3068 | .old_parent_ctx = parent_ctx, | |
3069 | .old_child_ctx = child_ctx, | |
3070 | }; | |
3071 | tran_add(tran, &bdrv_attach_child_common_drv, s); | |
3072 | ||
3073 | return new_child; | |
3074 | } | |
3075 | ||
3076 | /* | |
3077 | * Function doesn't update permissions, caller is responsible for this. | |
3078 | */ | |
3079 | static BdrvChild *bdrv_attach_child_noperm(BlockDriverState *parent_bs, | |
3080 | BlockDriverState *child_bs, | |
3081 | const char *child_name, | |
3082 | const BdrvChildClass *child_class, | |
3083 | BdrvChildRole child_role, | |
3084 | Transaction *tran, | |
3085 | Error **errp) | |
3086 | { | |
3087 | uint64_t perm, shared_perm; | |
3088 | ||
3089 | assert(parent_bs->drv); | |
3090 | GLOBAL_STATE_CODE(); | |
3091 | ||
3092 | if (bdrv_recurse_has_child(child_bs, parent_bs)) { | |
3093 | error_setg(errp, "Making '%s' a %s child of '%s' would create a cycle", | |
3094 | child_bs->node_name, child_name, parent_bs->node_name); | |
3095 | return NULL; | |
3096 | } | |
3097 | ||
3098 | bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm); | |
3099 | bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL, | |
3100 | perm, shared_perm, &perm, &shared_perm); | |
3101 | ||
3102 | return bdrv_attach_child_common(child_bs, child_name, child_class, | |
3103 | child_role, perm, shared_perm, parent_bs, | |
3104 | tran, errp); | |
3105 | } | |
3106 | ||
3107 | /* | |
3108 | * This function steals the reference to child_bs from the caller. | |
3109 | * That reference is later dropped by bdrv_root_unref_child(). | |
3110 | * | |
3111 | * On failure NULL is returned, errp is set and the reference to | |
3112 | * child_bs is also dropped. | |
3113 | * | |
3114 | * The caller must hold the AioContext lock @child_bs, but not that of @ctx | |
3115 | * (unless @child_bs is already in @ctx). | |
3116 | */ | |
3117 | BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, | |
3118 | const char *child_name, | |
3119 | const BdrvChildClass *child_class, | |
3120 | BdrvChildRole child_role, | |
3121 | uint64_t perm, uint64_t shared_perm, | |
3122 | void *opaque, Error **errp) | |
3123 | { | |
3124 | int ret; | |
3125 | BdrvChild *child; | |
3126 | Transaction *tran = tran_new(); | |
3127 | ||
3128 | GLOBAL_STATE_CODE(); | |
3129 | ||
3130 | child = bdrv_attach_child_common(child_bs, child_name, child_class, | |
3131 | child_role, perm, shared_perm, opaque, | |
3132 | tran, errp); | |
3133 | if (!child) { | |
3134 | ret = -EINVAL; | |
3135 | goto out; | |
3136 | } | |
3137 | ||
3138 | ret = bdrv_refresh_perms(child_bs, tran, errp); | |
3139 | ||
3140 | out: | |
3141 | tran_finalize(tran, ret); | |
3142 | ||
3143 | bdrv_unref(child_bs); | |
3144 | ||
3145 | return ret < 0 ? NULL : child; | |
3146 | } | |
3147 | ||
3148 | /* | |
3149 | * This function transfers the reference to child_bs from the caller | |
3150 | * to parent_bs. That reference is later dropped by parent_bs on | |
3151 | * bdrv_close() or if someone calls bdrv_unref_child(). | |
3152 | * | |
3153 | * On failure NULL is returned, errp is set and the reference to | |
3154 | * child_bs is also dropped. | |
3155 | * | |
3156 | * If @parent_bs and @child_bs are in different AioContexts, the caller must | |
3157 | * hold the AioContext lock for @child_bs, but not for @parent_bs. | |
3158 | */ | |
3159 | BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, | |
3160 | BlockDriverState *child_bs, | |
3161 | const char *child_name, | |
3162 | const BdrvChildClass *child_class, | |
3163 | BdrvChildRole child_role, | |
3164 | Error **errp) | |
3165 | { | |
3166 | int ret; | |
3167 | BdrvChild *child; | |
3168 | Transaction *tran = tran_new(); | |
3169 | ||
3170 | GLOBAL_STATE_CODE(); | |
3171 | ||
3172 | child = bdrv_attach_child_noperm(parent_bs, child_bs, child_name, | |
3173 | child_class, child_role, tran, errp); | |
3174 | if (!child) { | |
3175 | ret = -EINVAL; | |
3176 | goto out; | |
3177 | } | |
3178 | ||
3179 | ret = bdrv_refresh_perms(parent_bs, tran, errp); | |
3180 | if (ret < 0) { | |
3181 | goto out; | |
3182 | } | |
3183 | ||
3184 | out: | |
3185 | tran_finalize(tran, ret); | |
3186 | ||
3187 | bdrv_unref(child_bs); | |
3188 | ||
3189 | return ret < 0 ? NULL : child; | |
3190 | } | |
3191 | ||
3192 | /* Callers must ensure that child->frozen is false. */ | |
3193 | void bdrv_root_unref_child(BdrvChild *child) | |
3194 | { | |
3195 | BlockDriverState *child_bs = child->bs; | |
3196 | ||
3197 | GLOBAL_STATE_CODE(); | |
3198 | bdrv_replace_child_noperm(child, NULL); | |
3199 | bdrv_child_free(child); | |
3200 | ||
3201 | if (child_bs) { | |
3202 | /* | |
3203 | * Update permissions for old node. We're just taking a parent away, so | |
3204 | * we're loosening restrictions. Errors of permission update are not | |
3205 | * fatal in this case, ignore them. | |
3206 | */ | |
3207 | bdrv_refresh_perms(child_bs, NULL, NULL); | |
3208 | ||
3209 | /* | |
3210 | * When the parent requiring a non-default AioContext is removed, the | |
3211 | * node moves back to the main AioContext | |
3212 | */ | |
3213 | bdrv_try_change_aio_context(child_bs, qemu_get_aio_context(), NULL, | |
3214 | NULL); | |
3215 | } | |
3216 | ||
3217 | bdrv_unref(child_bs); | |
3218 | } | |
3219 | ||
3220 | typedef struct BdrvSetInheritsFrom { | |
3221 | BlockDriverState *bs; | |
3222 | BlockDriverState *old_inherits_from; | |
3223 | } BdrvSetInheritsFrom; | |
3224 | ||
3225 | static void bdrv_set_inherits_from_abort(void *opaque) | |
3226 | { | |
3227 | BdrvSetInheritsFrom *s = opaque; | |
3228 | ||
3229 | s->bs->inherits_from = s->old_inherits_from; | |
3230 | } | |
3231 | ||
3232 | static TransactionActionDrv bdrv_set_inherits_from_drv = { | |
3233 | .abort = bdrv_set_inherits_from_abort, | |
3234 | .clean = g_free, | |
3235 | }; | |
3236 | ||
3237 | /* @tran is allowed to be NULL. In this case no rollback is possible */ | |
3238 | static void bdrv_set_inherits_from(BlockDriverState *bs, | |
3239 | BlockDriverState *new_inherits_from, | |
3240 | Transaction *tran) | |
3241 | { | |
3242 | if (tran) { | |
3243 | BdrvSetInheritsFrom *s = g_new(BdrvSetInheritsFrom, 1); | |
3244 | ||
3245 | *s = (BdrvSetInheritsFrom) { | |
3246 | .bs = bs, | |
3247 | .old_inherits_from = bs->inherits_from, | |
3248 | }; | |
3249 | ||
3250 | tran_add(tran, &bdrv_set_inherits_from_drv, s); | |
3251 | } | |
3252 | ||
3253 | bs->inherits_from = new_inherits_from; | |
3254 | } | |
3255 | ||
3256 | /** | |
3257 | * Clear all inherits_from pointers from children and grandchildren of | |
3258 | * @root that point to @root, where necessary. | |
3259 | * @tran is allowed to be NULL. In this case no rollback is possible | |
3260 | */ | |
3261 | static void bdrv_unset_inherits_from(BlockDriverState *root, BdrvChild *child, | |
3262 | Transaction *tran) | |
3263 | { | |
3264 | BdrvChild *c; | |
3265 | ||
3266 | if (child->bs->inherits_from == root) { | |
3267 | /* | |
3268 | * Remove inherits_from only when the last reference between root and | |
3269 | * child->bs goes away. | |
3270 | */ | |
3271 | QLIST_FOREACH(c, &root->children, next) { | |
3272 | if (c != child && c->bs == child->bs) { | |
3273 | break; | |
3274 | } | |
3275 | } | |
3276 | if (c == NULL) { | |
3277 | bdrv_set_inherits_from(child->bs, NULL, tran); | |
3278 | } | |
3279 | } | |
3280 | ||
3281 | QLIST_FOREACH(c, &child->bs->children, next) { | |
3282 | bdrv_unset_inherits_from(root, c, tran); | |
3283 | } | |
3284 | } | |
3285 | ||
3286 | /* Callers must ensure that child->frozen is false. */ | |
3287 | void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) | |
3288 | { | |
3289 | GLOBAL_STATE_CODE(); | |
3290 | if (child == NULL) { | |
3291 | return; | |
3292 | } | |
3293 | ||
3294 | bdrv_unset_inherits_from(parent, child, NULL); | |
3295 | bdrv_root_unref_child(child); | |
3296 | } | |
3297 | ||
3298 | ||
3299 | static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load) | |
3300 | { | |
3301 | BdrvChild *c; | |
3302 | GLOBAL_STATE_CODE(); | |
3303 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
3304 | if (c->klass->change_media) { | |
3305 | c->klass->change_media(c, load); | |
3306 | } | |
3307 | } | |
3308 | } | |
3309 | ||
3310 | /* Return true if you can reach parent going through child->inherits_from | |
3311 | * recursively. If parent or child are NULL, return false */ | |
3312 | static bool bdrv_inherits_from_recursive(BlockDriverState *child, | |
3313 | BlockDriverState *parent) | |
3314 | { | |
3315 | while (child && child != parent) { | |
3316 | child = child->inherits_from; | |
3317 | } | |
3318 | ||
3319 | return child != NULL; | |
3320 | } | |
3321 | ||
3322 | /* | |
3323 | * Return the BdrvChildRole for @bs's backing child. bs->backing is | |
3324 | * mostly used for COW backing children (role = COW), but also for | |
3325 | * filtered children (role = FILTERED | PRIMARY). | |
3326 | */ | |
3327 | static BdrvChildRole bdrv_backing_role(BlockDriverState *bs) | |
3328 | { | |
3329 | if (bs->drv && bs->drv->is_filter) { | |
3330 | return BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY; | |
3331 | } else { | |
3332 | return BDRV_CHILD_COW; | |
3333 | } | |
3334 | } | |
3335 | ||
3336 | /* | |
3337 | * Sets the bs->backing or bs->file link of a BDS. A new reference is created; | |
3338 | * callers which don't need their own reference any more must call bdrv_unref(). | |
3339 | * | |
3340 | * Function doesn't update permissions, caller is responsible for this. | |
3341 | */ | |
3342 | static int bdrv_set_file_or_backing_noperm(BlockDriverState *parent_bs, | |
3343 | BlockDriverState *child_bs, | |
3344 | bool is_backing, | |
3345 | Transaction *tran, Error **errp) | |
3346 | { | |
3347 | bool update_inherits_from = | |
3348 | bdrv_inherits_from_recursive(child_bs, parent_bs); | |
3349 | BdrvChild *child = is_backing ? parent_bs->backing : parent_bs->file; | |
3350 | BdrvChildRole role; | |
3351 | ||
3352 | GLOBAL_STATE_CODE(); | |
3353 | ||
3354 | if (!parent_bs->drv) { | |
3355 | /* | |
3356 | * Node without drv is an object without a class :/. TODO: finally fix | |
3357 | * qcow2 driver to never clear bs->drv and implement format corruption | |
3358 | * handling in other way. | |
3359 | */ | |
3360 | error_setg(errp, "Node corrupted"); | |
3361 | return -EINVAL; | |
3362 | } | |
3363 | ||
3364 | if (child && child->frozen) { | |
3365 | error_setg(errp, "Cannot change frozen '%s' link from '%s' to '%s'", | |
3366 | child->name, parent_bs->node_name, child->bs->node_name); | |
3367 | return -EPERM; | |
3368 | } | |
3369 | ||
3370 | if (is_backing && !parent_bs->drv->is_filter && | |
3371 | !parent_bs->drv->supports_backing) | |
3372 | { | |
3373 | error_setg(errp, "Driver '%s' of node '%s' does not support backing " | |
3374 | "files", parent_bs->drv->format_name, parent_bs->node_name); | |
3375 | return -EINVAL; | |
3376 | } | |
3377 | ||
3378 | if (parent_bs->drv->is_filter) { | |
3379 | role = BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY; | |
3380 | } else if (is_backing) { | |
3381 | role = BDRV_CHILD_COW; | |
3382 | } else { | |
3383 | /* | |
3384 | * We only can use same role as it is in existing child. We don't have | |
3385 | * infrastructure to determine role of file child in generic way | |
3386 | */ | |
3387 | if (!child) { | |
3388 | error_setg(errp, "Cannot set file child to format node without " | |
3389 | "file child"); | |
3390 | return -EINVAL; | |
3391 | } | |
3392 | role = child->role; | |
3393 | } | |
3394 | ||
3395 | if (child) { | |
3396 | bdrv_unset_inherits_from(parent_bs, child, tran); | |
3397 | bdrv_remove_child(child, tran); | |
3398 | } | |
3399 | ||
3400 | if (!child_bs) { | |
3401 | goto out; | |
3402 | } | |
3403 | ||
3404 | child = bdrv_attach_child_noperm(parent_bs, child_bs, | |
3405 | is_backing ? "backing" : "file", | |
3406 | &child_of_bds, role, | |
3407 | tran, errp); | |
3408 | if (!child) { | |
3409 | return -EINVAL; | |
3410 | } | |
3411 | ||
3412 | ||
3413 | /* | |
3414 | * If inherits_from pointed recursively to bs then let's update it to | |
3415 | * point directly to bs (else it will become NULL). | |
3416 | */ | |
3417 | if (update_inherits_from) { | |
3418 | bdrv_set_inherits_from(child_bs, parent_bs, tran); | |
3419 | } | |
3420 | ||
3421 | out: | |
3422 | bdrv_refresh_limits(parent_bs, tran, NULL); | |
3423 | ||
3424 | return 0; | |
3425 | } | |
3426 | ||
3427 | static int bdrv_set_backing_noperm(BlockDriverState *bs, | |
3428 | BlockDriverState *backing_hd, | |
3429 | Transaction *tran, Error **errp) | |
3430 | { | |
3431 | GLOBAL_STATE_CODE(); | |
3432 | return bdrv_set_file_or_backing_noperm(bs, backing_hd, true, tran, errp); | |
3433 | } | |
3434 | ||
3435 | int bdrv_set_backing_hd_drained(BlockDriverState *bs, | |
3436 | BlockDriverState *backing_hd, | |
3437 | Error **errp) | |
3438 | { | |
3439 | int ret; | |
3440 | Transaction *tran = tran_new(); | |
3441 | ||
3442 | GLOBAL_STATE_CODE(); | |
3443 | assert(bs->quiesce_counter > 0); | |
3444 | ||
3445 | ret = bdrv_set_backing_noperm(bs, backing_hd, tran, errp); | |
3446 | if (ret < 0) { | |
3447 | goto out; | |
3448 | } | |
3449 | ||
3450 | ret = bdrv_refresh_perms(bs, tran, errp); | |
3451 | out: | |
3452 | tran_finalize(tran, ret); | |
3453 | return ret; | |
3454 | } | |
3455 | ||
3456 | int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, | |
3457 | Error **errp) | |
3458 | { | |
3459 | int ret; | |
3460 | GLOBAL_STATE_CODE(); | |
3461 | ||
3462 | bdrv_drained_begin(bs); | |
3463 | ret = bdrv_set_backing_hd_drained(bs, backing_hd, errp); | |
3464 | bdrv_drained_end(bs); | |
3465 | ||
3466 | return ret; | |
3467 | } | |
3468 | ||
3469 | /* | |
3470 | * Opens the backing file for a BlockDriverState if not yet open | |
3471 | * | |
3472 | * bdref_key specifies the key for the image's BlockdevRef in the options QDict. | |
3473 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict | |
3474 | * itself, all options starting with "${bdref_key}." are considered part of the | |
3475 | * BlockdevRef. | |
3476 | * | |
3477 | * TODO Can this be unified with bdrv_open_image()? | |
3478 | */ | |
3479 | int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, | |
3480 | const char *bdref_key, Error **errp) | |
3481 | { | |
3482 | char *backing_filename = NULL; | |
3483 | char *bdref_key_dot; | |
3484 | const char *reference = NULL; | |
3485 | int ret = 0; | |
3486 | bool implicit_backing = false; | |
3487 | BlockDriverState *backing_hd; | |
3488 | QDict *options; | |
3489 | QDict *tmp_parent_options = NULL; | |
3490 | Error *local_err = NULL; | |
3491 | ||
3492 | GLOBAL_STATE_CODE(); | |
3493 | ||
3494 | if (bs->backing != NULL) { | |
3495 | goto free_exit; | |
3496 | } | |
3497 | ||
3498 | /* NULL means an empty set of options */ | |
3499 | if (parent_options == NULL) { | |
3500 | tmp_parent_options = qdict_new(); | |
3501 | parent_options = tmp_parent_options; | |
3502 | } | |
3503 | ||
3504 | bs->open_flags &= ~BDRV_O_NO_BACKING; | |
3505 | ||
3506 | bdref_key_dot = g_strdup_printf("%s.", bdref_key); | |
3507 | qdict_extract_subqdict(parent_options, &options, bdref_key_dot); | |
3508 | g_free(bdref_key_dot); | |
3509 | ||
3510 | /* | |
3511 | * Caution: while qdict_get_try_str() is fine, getting non-string | |
3512 | * types would require more care. When @parent_options come from | |
3513 | * -blockdev or blockdev_add, its members are typed according to | |
3514 | * the QAPI schema, but when they come from -drive, they're all | |
3515 | * QString. | |
3516 | */ | |
3517 | reference = qdict_get_try_str(parent_options, bdref_key); | |
3518 | if (reference || qdict_haskey(options, "file.filename")) { | |
3519 | /* keep backing_filename NULL */ | |
3520 | } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { | |
3521 | qobject_unref(options); | |
3522 | goto free_exit; | |
3523 | } else { | |
3524 | if (qdict_size(options) == 0) { | |
3525 | /* If the user specifies options that do not modify the | |
3526 | * backing file's behavior, we might still consider it the | |
3527 | * implicit backing file. But it's easier this way, and | |
3528 | * just specifying some of the backing BDS's options is | |
3529 | * only possible with -drive anyway (otherwise the QAPI | |
3530 | * schema forces the user to specify everything). */ | |
3531 | implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file); | |
3532 | } | |
3533 | ||
3534 | backing_filename = bdrv_get_full_backing_filename(bs, &local_err); | |
3535 | if (local_err) { | |
3536 | ret = -EINVAL; | |
3537 | error_propagate(errp, local_err); | |
3538 | qobject_unref(options); | |
3539 | goto free_exit; | |
3540 | } | |
3541 | } | |
3542 | ||
3543 | if (!bs->drv || !bs->drv->supports_backing) { | |
3544 | ret = -EINVAL; | |
3545 | error_setg(errp, "Driver doesn't support backing files"); | |
3546 | qobject_unref(options); | |
3547 | goto free_exit; | |
3548 | } | |
3549 | ||
3550 | if (!reference && | |
3551 | bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { | |
3552 | qdict_put_str(options, "driver", bs->backing_format); | |
3553 | } | |
3554 | ||
3555 | backing_hd = bdrv_open_inherit(backing_filename, reference, options, 0, bs, | |
3556 | &child_of_bds, bdrv_backing_role(bs), errp); | |
3557 | if (!backing_hd) { | |
3558 | bs->open_flags |= BDRV_O_NO_BACKING; | |
3559 | error_prepend(errp, "Could not open backing file: "); | |
3560 | ret = -EINVAL; | |
3561 | goto free_exit; | |
3562 | } | |
3563 | ||
3564 | if (implicit_backing) { | |
3565 | bdrv_refresh_filename(backing_hd); | |
3566 | pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), | |
3567 | backing_hd->filename); | |
3568 | } | |
3569 | ||
3570 | /* Hook up the backing file link; drop our reference, bs owns the | |
3571 | * backing_hd reference now */ | |
3572 | ret = bdrv_set_backing_hd(bs, backing_hd, errp); | |
3573 | bdrv_unref(backing_hd); | |
3574 | if (ret < 0) { | |
3575 | goto free_exit; | |
3576 | } | |
3577 | ||
3578 | qdict_del(parent_options, bdref_key); | |
3579 | ||
3580 | free_exit: | |
3581 | g_free(backing_filename); | |
3582 | qobject_unref(tmp_parent_options); | |
3583 | return ret; | |
3584 | } | |
3585 | ||
3586 | static BlockDriverState * | |
3587 | bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key, | |
3588 | BlockDriverState *parent, const BdrvChildClass *child_class, | |
3589 | BdrvChildRole child_role, bool allow_none, Error **errp) | |
3590 | { | |
3591 | BlockDriverState *bs = NULL; | |
3592 | QDict *image_options; | |
3593 | char *bdref_key_dot; | |
3594 | const char *reference; | |
3595 | ||
3596 | assert(child_class != NULL); | |
3597 | ||
3598 | bdref_key_dot = g_strdup_printf("%s.", bdref_key); | |
3599 | qdict_extract_subqdict(options, &image_options, bdref_key_dot); | |
3600 | g_free(bdref_key_dot); | |
3601 | ||
3602 | /* | |
3603 | * Caution: while qdict_get_try_str() is fine, getting non-string | |
3604 | * types would require more care. When @options come from | |
3605 | * -blockdev or blockdev_add, its members are typed according to | |
3606 | * the QAPI schema, but when they come from -drive, they're all | |
3607 | * QString. | |
3608 | */ | |
3609 | reference = qdict_get_try_str(options, bdref_key); | |
3610 | if (!filename && !reference && !qdict_size(image_options)) { | |
3611 | if (!allow_none) { | |
3612 | error_setg(errp, "A block device must be specified for \"%s\"", | |
3613 | bdref_key); | |
3614 | } | |
3615 | qobject_unref(image_options); | |
3616 | goto done; | |
3617 | } | |
3618 | ||
3619 | bs = bdrv_open_inherit(filename, reference, image_options, 0, | |
3620 | parent, child_class, child_role, errp); | |
3621 | if (!bs) { | |
3622 | goto done; | |
3623 | } | |
3624 | ||
3625 | done: | |
3626 | qdict_del(options, bdref_key); | |
3627 | return bs; | |
3628 | } | |
3629 | ||
3630 | /* | |
3631 | * Opens a disk image whose options are given as BlockdevRef in another block | |
3632 | * device's options. | |
3633 | * | |
3634 | * If allow_none is true, no image will be opened if filename is false and no | |
3635 | * BlockdevRef is given. NULL will be returned, but errp remains unset. | |
3636 | * | |
3637 | * bdrev_key specifies the key for the image's BlockdevRef in the options QDict. | |
3638 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict | |
3639 | * itself, all options starting with "${bdref_key}." are considered part of the | |
3640 | * BlockdevRef. | |
3641 | * | |
3642 | * The BlockdevRef will be removed from the options QDict. | |
3643 | */ | |
3644 | BdrvChild *bdrv_open_child(const char *filename, | |
3645 | QDict *options, const char *bdref_key, | |
3646 | BlockDriverState *parent, | |
3647 | const BdrvChildClass *child_class, | |
3648 | BdrvChildRole child_role, | |
3649 | bool allow_none, Error **errp) | |
3650 | { | |
3651 | BlockDriverState *bs; | |
3652 | ||
3653 | GLOBAL_STATE_CODE(); | |
3654 | ||
3655 | bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_class, | |
3656 | child_role, allow_none, errp); | |
3657 | if (bs == NULL) { | |
3658 | return NULL; | |
3659 | } | |
3660 | ||
3661 | return bdrv_attach_child(parent, bs, bdref_key, child_class, child_role, | |
3662 | errp); | |
3663 | } | |
3664 | ||
3665 | /* | |
3666 | * Wrapper on bdrv_open_child() for most popular case: open primary child of bs. | |
3667 | */ | |
3668 | int bdrv_open_file_child(const char *filename, | |
3669 | QDict *options, const char *bdref_key, | |
3670 | BlockDriverState *parent, Error **errp) | |
3671 | { | |
3672 | BdrvChildRole role; | |
3673 | ||
3674 | /* commit_top and mirror_top don't use this function */ | |
3675 | assert(!parent->drv->filtered_child_is_backing); | |
3676 | role = parent->drv->is_filter ? | |
3677 | (BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY) : BDRV_CHILD_IMAGE; | |
3678 | ||
3679 | if (!bdrv_open_child(filename, options, bdref_key, parent, | |
3680 | &child_of_bds, role, false, errp)) | |
3681 | { | |
3682 | return -EINVAL; | |
3683 | } | |
3684 | ||
3685 | return 0; | |
3686 | } | |
3687 | ||
3688 | /* | |
3689 | * TODO Future callers may need to specify parent/child_class in order for | |
3690 | * option inheritance to work. Existing callers use it for the root node. | |
3691 | */ | |
3692 | BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp) | |
3693 | { | |
3694 | BlockDriverState *bs = NULL; | |
3695 | QObject *obj = NULL; | |
3696 | QDict *qdict = NULL; | |
3697 | const char *reference = NULL; | |
3698 | Visitor *v = NULL; | |
3699 | ||
3700 | GLOBAL_STATE_CODE(); | |
3701 | ||
3702 | if (ref->type == QTYPE_QSTRING) { | |
3703 | reference = ref->u.reference; | |
3704 | } else { | |
3705 | BlockdevOptions *options = &ref->u.definition; | |
3706 | assert(ref->type == QTYPE_QDICT); | |
3707 | ||
3708 | v = qobject_output_visitor_new(&obj); | |
3709 | visit_type_BlockdevOptions(v, NULL, &options, &error_abort); | |
3710 | visit_complete(v, &obj); | |
3711 | ||
3712 | qdict = qobject_to(QDict, obj); | |
3713 | qdict_flatten(qdict); | |
3714 | ||
3715 | /* bdrv_open_inherit() defaults to the values in bdrv_flags (for | |
3716 | * compatibility with other callers) rather than what we want as the | |
3717 | * real defaults. Apply the defaults here instead. */ | |
3718 | qdict_set_default_str(qdict, BDRV_OPT_CACHE_DIRECT, "off"); | |
3719 | qdict_set_default_str(qdict, BDRV_OPT_CACHE_NO_FLUSH, "off"); | |
3720 | qdict_set_default_str(qdict, BDRV_OPT_READ_ONLY, "off"); | |
3721 | qdict_set_default_str(qdict, BDRV_OPT_AUTO_READ_ONLY, "off"); | |
3722 | ||
3723 | } | |
3724 | ||
3725 | bs = bdrv_open_inherit(NULL, reference, qdict, 0, NULL, NULL, 0, errp); | |
3726 | obj = NULL; | |
3727 | qobject_unref(obj); | |
3728 | visit_free(v); | |
3729 | return bs; | |
3730 | } | |
3731 | ||
3732 | static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs, | |
3733 | int flags, | |
3734 | QDict *snapshot_options, | |
3735 | Error **errp) | |
3736 | { | |
3737 | g_autofree char *tmp_filename = NULL; | |
3738 | int64_t total_size; | |
3739 | QemuOpts *opts = NULL; | |
3740 | BlockDriverState *bs_snapshot = NULL; | |
3741 | int ret; | |
3742 | ||
3743 | GLOBAL_STATE_CODE(); | |
3744 | ||
3745 | /* if snapshot, we create a temporary backing file and open it | |
3746 | instead of opening 'filename' directly */ | |
3747 | ||
3748 | /* Get the required size from the image */ | |
3749 | total_size = bdrv_getlength(bs); | |
3750 | if (total_size < 0) { | |
3751 | error_setg_errno(errp, -total_size, "Could not get image size"); | |
3752 | goto out; | |
3753 | } | |
3754 | ||
3755 | /* Create the temporary image */ | |
3756 | tmp_filename = create_tmp_file(errp); | |
3757 | if (!tmp_filename) { | |
3758 | goto out; | |
3759 | } | |
3760 | ||
3761 | opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, | |
3762 | &error_abort); | |
3763 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort); | |
3764 | ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp); | |
3765 | qemu_opts_del(opts); | |
3766 | if (ret < 0) { | |
3767 | error_prepend(errp, "Could not create temporary overlay '%s': ", | |
3768 | tmp_filename); | |
3769 | goto out; | |
3770 | } | |
3771 | ||
3772 | /* Prepare options QDict for the temporary file */ | |
3773 | qdict_put_str(snapshot_options, "file.driver", "file"); | |
3774 | qdict_put_str(snapshot_options, "file.filename", tmp_filename); | |
3775 | qdict_put_str(snapshot_options, "driver", "qcow2"); | |
3776 | ||
3777 | bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp); | |
3778 | snapshot_options = NULL; | |
3779 | if (!bs_snapshot) { | |
3780 | goto out; | |
3781 | } | |
3782 | ||
3783 | ret = bdrv_append(bs_snapshot, bs, errp); | |
3784 | if (ret < 0) { | |
3785 | bs_snapshot = NULL; | |
3786 | goto out; | |
3787 | } | |
3788 | ||
3789 | out: | |
3790 | qobject_unref(snapshot_options); | |
3791 | return bs_snapshot; | |
3792 | } | |
3793 | ||
3794 | /* | |
3795 | * Opens a disk image (raw, qcow2, vmdk, ...) | |
3796 | * | |
3797 | * options is a QDict of options to pass to the block drivers, or NULL for an | |
3798 | * empty set of options. The reference to the QDict belongs to the block layer | |
3799 | * after the call (even on failure), so if the caller intends to reuse the | |
3800 | * dictionary, it needs to use qobject_ref() before calling bdrv_open. | |
3801 | * | |
3802 | * If *pbs is NULL, a new BDS will be created with a pointer to it stored there. | |
3803 | * If it is not NULL, the referenced BDS will be reused. | |
3804 | * | |
3805 | * The reference parameter may be used to specify an existing block device which | |
3806 | * should be opened. If specified, neither options nor a filename may be given, | |
3807 | * nor can an existing BDS be reused (that is, *pbs has to be NULL). | |
3808 | * | |
3809 | * The caller must always hold @filename AioContext lock, because this | |
3810 | * function eventually calls bdrv_refresh_total_sectors() which polls | |
3811 | * when called from non-coroutine context. | |
3812 | */ | |
3813 | static BlockDriverState * no_coroutine_fn | |
3814 | bdrv_open_inherit(const char *filename, const char *reference, QDict *options, | |
3815 | int flags, BlockDriverState *parent, | |
3816 | const BdrvChildClass *child_class, BdrvChildRole child_role, | |
3817 | Error **errp) | |
3818 | { | |
3819 | int ret; | |
3820 | BlockBackend *file = NULL; | |
3821 | BlockDriverState *bs; | |
3822 | BlockDriver *drv = NULL; | |
3823 | BdrvChild *child; | |
3824 | const char *drvname; | |
3825 | const char *backing; | |
3826 | Error *local_err = NULL; | |
3827 | QDict *snapshot_options = NULL; | |
3828 | int snapshot_flags = 0; | |
3829 | ||
3830 | assert(!child_class || !flags); | |
3831 | assert(!child_class == !parent); | |
3832 | GLOBAL_STATE_CODE(); | |
3833 | assert(!qemu_in_coroutine()); | |
3834 | ||
3835 | if (reference) { | |
3836 | bool options_non_empty = options ? qdict_size(options) : false; | |
3837 | qobject_unref(options); | |
3838 | ||
3839 | if (filename || options_non_empty) { | |
3840 | error_setg(errp, "Cannot reference an existing block device with " | |
3841 | "additional options or a new filename"); | |
3842 | return NULL; | |
3843 | } | |
3844 | ||
3845 | bs = bdrv_lookup_bs(reference, reference, errp); | |
3846 | if (!bs) { | |
3847 | return NULL; | |
3848 | } | |
3849 | ||
3850 | bdrv_ref(bs); | |
3851 | return bs; | |
3852 | } | |
3853 | ||
3854 | bs = bdrv_new(); | |
3855 | ||
3856 | /* NULL means an empty set of options */ | |
3857 | if (options == NULL) { | |
3858 | options = qdict_new(); | |
3859 | } | |
3860 | ||
3861 | /* json: syntax counts as explicit options, as if in the QDict */ | |
3862 | parse_json_protocol(options, &filename, &local_err); | |
3863 | if (local_err) { | |
3864 | goto fail; | |
3865 | } | |
3866 | ||
3867 | bs->explicit_options = qdict_clone_shallow(options); | |
3868 | ||
3869 | if (child_class) { | |
3870 | bool parent_is_format; | |
3871 | ||
3872 | if (parent->drv) { | |
3873 | parent_is_format = parent->drv->is_format; | |
3874 | } else { | |
3875 | /* | |
3876 | * parent->drv is not set yet because this node is opened for | |
3877 | * (potential) format probing. That means that @parent is going | |
3878 | * to be a format node. | |
3879 | */ | |
3880 | parent_is_format = true; | |
3881 | } | |
3882 | ||
3883 | bs->inherits_from = parent; | |
3884 | child_class->inherit_options(child_role, parent_is_format, | |
3885 | &flags, options, | |
3886 | parent->open_flags, parent->options); | |
3887 | } | |
3888 | ||
3889 | ret = bdrv_fill_options(&options, filename, &flags, &local_err); | |
3890 | if (ret < 0) { | |
3891 | goto fail; | |
3892 | } | |
3893 | ||
3894 | /* | |
3895 | * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags. | |
3896 | * Caution: getting a boolean member of @options requires care. | |
3897 | * When @options come from -blockdev or blockdev_add, members are | |
3898 | * typed according to the QAPI schema, but when they come from | |
3899 | * -drive, they're all QString. | |
3900 | */ | |
3901 | if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") && | |
3902 | !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) { | |
3903 | flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR); | |
3904 | } else { | |
3905 | flags &= ~BDRV_O_RDWR; | |
3906 | } | |
3907 | ||
3908 | if (flags & BDRV_O_SNAPSHOT) { | |
3909 | snapshot_options = qdict_new(); | |
3910 | bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options, | |
3911 | flags, options); | |
3912 | /* Let bdrv_backing_options() override "read-only" */ | |
3913 | qdict_del(options, BDRV_OPT_READ_ONLY); | |
3914 | bdrv_inherited_options(BDRV_CHILD_COW, true, | |
3915 | &flags, options, flags, options); | |
3916 | } | |
3917 | ||
3918 | bs->open_flags = flags; | |
3919 | bs->options = options; | |
3920 | options = qdict_clone_shallow(options); | |
3921 | ||
3922 | /* Find the right image format driver */ | |
3923 | /* See cautionary note on accessing @options above */ | |
3924 | drvname = qdict_get_try_str(options, "driver"); | |
3925 | if (drvname) { | |
3926 | drv = bdrv_find_format(drvname); | |
3927 | if (!drv) { | |
3928 | error_setg(errp, "Unknown driver: '%s'", drvname); | |
3929 | goto fail; | |
3930 | } | |
3931 | } | |
3932 | ||
3933 | assert(drvname || !(flags & BDRV_O_PROTOCOL)); | |
3934 | ||
3935 | /* See cautionary note on accessing @options above */ | |
3936 | backing = qdict_get_try_str(options, "backing"); | |
3937 | if (qobject_to(QNull, qdict_get(options, "backing")) != NULL || | |
3938 | (backing && *backing == '\0')) | |
3939 | { | |
3940 | if (backing) { | |
3941 | warn_report("Use of \"backing\": \"\" is deprecated; " | |
3942 | "use \"backing\": null instead"); | |
3943 | } | |
3944 | flags |= BDRV_O_NO_BACKING; | |
3945 | qdict_del(bs->explicit_options, "backing"); | |
3946 | qdict_del(bs->options, "backing"); | |
3947 | qdict_del(options, "backing"); | |
3948 | } | |
3949 | ||
3950 | /* Open image file without format layer. This BlockBackend is only used for | |
3951 | * probing, the block drivers will do their own bdrv_open_child() for the | |
3952 | * same BDS, which is why we put the node name back into options. */ | |
3953 | if ((flags & BDRV_O_PROTOCOL) == 0) { | |
3954 | BlockDriverState *file_bs; | |
3955 | ||
3956 | file_bs = bdrv_open_child_bs(filename, options, "file", bs, | |
3957 | &child_of_bds, BDRV_CHILD_IMAGE, | |
3958 | true, &local_err); | |
3959 | if (local_err) { | |
3960 | goto fail; | |
3961 | } | |
3962 | if (file_bs != NULL) { | |
3963 | /* Not requesting BLK_PERM_CONSISTENT_READ because we're only | |
3964 | * looking at the header to guess the image format. This works even | |
3965 | * in cases where a guest would not see a consistent state. */ | |
3966 | file = blk_new(bdrv_get_aio_context(file_bs), 0, BLK_PERM_ALL); | |
3967 | blk_insert_bs(file, file_bs, &local_err); | |
3968 | bdrv_unref(file_bs); | |
3969 | if (local_err) { | |
3970 | goto fail; | |
3971 | } | |
3972 | ||
3973 | qdict_put_str(options, "file", bdrv_get_node_name(file_bs)); | |
3974 | } | |
3975 | } | |
3976 | ||
3977 | /* Image format probing */ | |
3978 | bs->probed = !drv; | |
3979 | if (!drv && file) { | |
3980 | ret = find_image_format(file, filename, &drv, &local_err); | |
3981 | if (ret < 0) { | |
3982 | goto fail; | |
3983 | } | |
3984 | /* | |
3985 | * This option update would logically belong in bdrv_fill_options(), | |
3986 | * but we first need to open bs->file for the probing to work, while | |
3987 | * opening bs->file already requires the (mostly) final set of options | |
3988 | * so that cache mode etc. can be inherited. | |
3989 | * | |
3990 | * Adding the driver later is somewhat ugly, but it's not an option | |
3991 | * that would ever be inherited, so it's correct. We just need to make | |
3992 | * sure to update both bs->options (which has the full effective | |
3993 | * options for bs) and options (which has file.* already removed). | |
3994 | */ | |
3995 | qdict_put_str(bs->options, "driver", drv->format_name); | |
3996 | qdict_put_str(options, "driver", drv->format_name); | |
3997 | } else if (!drv) { | |
3998 | error_setg(errp, "Must specify either driver or file"); | |
3999 | goto fail; | |
4000 | } | |
4001 | ||
4002 | /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */ | |
4003 | assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open); | |
4004 | /* file must be NULL if a protocol BDS is about to be created | |
4005 | * (the inverse results in an error message from bdrv_open_common()) */ | |
4006 | assert(!(flags & BDRV_O_PROTOCOL) || !file); | |
4007 | ||
4008 | /* Open the image */ | |
4009 | ret = bdrv_open_common(bs, file, options, &local_err); | |
4010 | if (ret < 0) { | |
4011 | goto fail; | |
4012 | } | |
4013 | ||
4014 | if (file) { | |
4015 | blk_unref(file); | |
4016 | file = NULL; | |
4017 | } | |
4018 | ||
4019 | /* If there is a backing file, use it */ | |
4020 | if ((flags & BDRV_O_NO_BACKING) == 0) { | |
4021 | ret = bdrv_open_backing_file(bs, options, "backing", &local_err); | |
4022 | if (ret < 0) { | |
4023 | goto close_and_fail; | |
4024 | } | |
4025 | } | |
4026 | ||
4027 | /* Remove all children options and references | |
4028 | * from bs->options and bs->explicit_options */ | |
4029 | QLIST_FOREACH(child, &bs->children, next) { | |
4030 | char *child_key_dot; | |
4031 | child_key_dot = g_strdup_printf("%s.", child->name); | |
4032 | qdict_extract_subqdict(bs->explicit_options, NULL, child_key_dot); | |
4033 | qdict_extract_subqdict(bs->options, NULL, child_key_dot); | |
4034 | qdict_del(bs->explicit_options, child->name); | |
4035 | qdict_del(bs->options, child->name); | |
4036 | g_free(child_key_dot); | |
4037 | } | |
4038 | ||
4039 | /* Check if any unknown options were used */ | |
4040 | if (qdict_size(options) != 0) { | |
4041 | const QDictEntry *entry = qdict_first(options); | |
4042 | if (flags & BDRV_O_PROTOCOL) { | |
4043 | error_setg(errp, "Block protocol '%s' doesn't support the option " | |
4044 | "'%s'", drv->format_name, entry->key); | |
4045 | } else { | |
4046 | error_setg(errp, | |
4047 | "Block format '%s' does not support the option '%s'", | |
4048 | drv->format_name, entry->key); | |
4049 | } | |
4050 | ||
4051 | goto close_and_fail; | |
4052 | } | |
4053 | ||
4054 | bdrv_parent_cb_change_media(bs, true); | |
4055 | ||
4056 | qobject_unref(options); | |
4057 | options = NULL; | |
4058 | ||
4059 | /* For snapshot=on, create a temporary qcow2 overlay. bs points to the | |
4060 | * temporary snapshot afterwards. */ | |
4061 | if (snapshot_flags) { | |
4062 | BlockDriverState *snapshot_bs; | |
4063 | snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags, | |
4064 | snapshot_options, &local_err); | |
4065 | snapshot_options = NULL; | |
4066 | if (local_err) { | |
4067 | goto close_and_fail; | |
4068 | } | |
4069 | /* We are not going to return bs but the overlay on top of it | |
4070 | * (snapshot_bs); thus, we have to drop the strong reference to bs | |
4071 | * (which we obtained by calling bdrv_new()). bs will not be deleted, | |
4072 | * though, because the overlay still has a reference to it. */ | |
4073 | bdrv_unref(bs); | |
4074 | bs = snapshot_bs; | |
4075 | } | |
4076 | ||
4077 | return bs; | |
4078 | ||
4079 | fail: | |
4080 | blk_unref(file); | |
4081 | qobject_unref(snapshot_options); | |
4082 | qobject_unref(bs->explicit_options); | |
4083 | qobject_unref(bs->options); | |
4084 | qobject_unref(options); | |
4085 | bs->options = NULL; | |
4086 | bs->explicit_options = NULL; | |
4087 | bdrv_unref(bs); | |
4088 | error_propagate(errp, local_err); | |
4089 | return NULL; | |
4090 | ||
4091 | close_and_fail: | |
4092 | bdrv_unref(bs); | |
4093 | qobject_unref(snapshot_options); | |
4094 | qobject_unref(options); | |
4095 | error_propagate(errp, local_err); | |
4096 | return NULL; | |
4097 | } | |
4098 | ||
4099 | /* | |
4100 | * The caller must always hold @filename AioContext lock, because this | |
4101 | * function eventually calls bdrv_refresh_total_sectors() which polls | |
4102 | * when called from non-coroutine context. | |
4103 | */ | |
4104 | BlockDriverState *bdrv_open(const char *filename, const char *reference, | |
4105 | QDict *options, int flags, Error **errp) | |
4106 | { | |
4107 | GLOBAL_STATE_CODE(); | |
4108 | ||
4109 | return bdrv_open_inherit(filename, reference, options, flags, NULL, | |
4110 | NULL, 0, errp); | |
4111 | } | |
4112 | ||
4113 | /* Return true if the NULL-terminated @list contains @str */ | |
4114 | static bool is_str_in_list(const char *str, const char *const *list) | |
4115 | { | |
4116 | if (str && list) { | |
4117 | int i; | |
4118 | for (i = 0; list[i] != NULL; i++) { | |
4119 | if (!strcmp(str, list[i])) { | |
4120 | return true; | |
4121 | } | |
4122 | } | |
4123 | } | |
4124 | return false; | |
4125 | } | |
4126 | ||
4127 | /* | |
4128 | * Check that every option set in @bs->options is also set in | |
4129 | * @new_opts. | |
4130 | * | |
4131 | * Options listed in the common_options list and in | |
4132 | * @bs->drv->mutable_opts are skipped. | |
4133 | * | |
4134 | * Return 0 on success, otherwise return -EINVAL and set @errp. | |
4135 | */ | |
4136 | static int bdrv_reset_options_allowed(BlockDriverState *bs, | |
4137 | const QDict *new_opts, Error **errp) | |
4138 | { | |
4139 | const QDictEntry *e; | |
4140 | /* These options are common to all block drivers and are handled | |
4141 | * in bdrv_reopen_prepare() so they can be left out of @new_opts */ | |
4142 | const char *const common_options[] = { | |
4143 | "node-name", "discard", "cache.direct", "cache.no-flush", | |
4144 | "read-only", "auto-read-only", "detect-zeroes", NULL | |
4145 | }; | |
4146 | ||
4147 | for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) { | |
4148 | if (!qdict_haskey(new_opts, e->key) && | |
4149 | !is_str_in_list(e->key, common_options) && | |
4150 | !is_str_in_list(e->key, bs->drv->mutable_opts)) { | |
4151 | error_setg(errp, "Option '%s' cannot be reset " | |
4152 | "to its default value", e->key); | |
4153 | return -EINVAL; | |
4154 | } | |
4155 | } | |
4156 | ||
4157 | return 0; | |
4158 | } | |
4159 | ||
4160 | /* | |
4161 | * Returns true if @child can be reached recursively from @bs | |
4162 | */ | |
4163 | static bool bdrv_recurse_has_child(BlockDriverState *bs, | |
4164 | BlockDriverState *child) | |
4165 | { | |
4166 | BdrvChild *c; | |
4167 | ||
4168 | if (bs == child) { | |
4169 | return true; | |
4170 | } | |
4171 | ||
4172 | QLIST_FOREACH(c, &bs->children, next) { | |
4173 | if (bdrv_recurse_has_child(c->bs, child)) { | |
4174 | return true; | |
4175 | } | |
4176 | } | |
4177 | ||
4178 | return false; | |
4179 | } | |
4180 | ||
4181 | /* | |
4182 | * Adds a BlockDriverState to a simple queue for an atomic, transactional | |
4183 | * reopen of multiple devices. | |
4184 | * | |
4185 | * bs_queue can either be an existing BlockReopenQueue that has had QTAILQ_INIT | |
4186 | * already performed, or alternatively may be NULL a new BlockReopenQueue will | |
4187 | * be created and initialized. This newly created BlockReopenQueue should be | |
4188 | * passed back in for subsequent calls that are intended to be of the same | |
4189 | * atomic 'set'. | |
4190 | * | |
4191 | * bs is the BlockDriverState to add to the reopen queue. | |
4192 | * | |
4193 | * options contains the changed options for the associated bs | |
4194 | * (the BlockReopenQueue takes ownership) | |
4195 | * | |
4196 | * flags contains the open flags for the associated bs | |
4197 | * | |
4198 | * returns a pointer to bs_queue, which is either the newly allocated | |
4199 | * bs_queue, or the existing bs_queue being used. | |
4200 | * | |
4201 | * bs is drained here and undrained by bdrv_reopen_queue_free(). | |
4202 | * | |
4203 | * To be called with bs->aio_context locked. | |
4204 | */ | |
4205 | static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, | |
4206 | BlockDriverState *bs, | |
4207 | QDict *options, | |
4208 | const BdrvChildClass *klass, | |
4209 | BdrvChildRole role, | |
4210 | bool parent_is_format, | |
4211 | QDict *parent_options, | |
4212 | int parent_flags, | |
4213 | bool keep_old_opts) | |
4214 | { | |
4215 | assert(bs != NULL); | |
4216 | ||
4217 | BlockReopenQueueEntry *bs_entry; | |
4218 | BdrvChild *child; | |
4219 | QDict *old_options, *explicit_options, *options_copy; | |
4220 | int flags; | |
4221 | QemuOpts *opts; | |
4222 | ||
4223 | GLOBAL_STATE_CODE(); | |
4224 | ||
4225 | bdrv_drained_begin(bs); | |
4226 | ||
4227 | if (bs_queue == NULL) { | |
4228 | bs_queue = g_new0(BlockReopenQueue, 1); | |
4229 | QTAILQ_INIT(bs_queue); | |
4230 | } | |
4231 | ||
4232 | if (!options) { | |
4233 | options = qdict_new(); | |
4234 | } | |
4235 | ||
4236 | /* Check if this BlockDriverState is already in the queue */ | |
4237 | QTAILQ_FOREACH(bs_entry, bs_queue, entry) { | |
4238 | if (bs == bs_entry->state.bs) { | |
4239 | break; | |
4240 | } | |
4241 | } | |
4242 | ||
4243 | /* | |
4244 | * Precedence of options: | |
4245 | * 1. Explicitly passed in options (highest) | |
4246 | * 2. Retained from explicitly set options of bs | |
4247 | * 3. Inherited from parent node | |
4248 | * 4. Retained from effective options of bs | |
4249 | */ | |
4250 | ||
4251 | /* Old explicitly set values (don't overwrite by inherited value) */ | |
4252 | if (bs_entry || keep_old_opts) { | |
4253 | old_options = qdict_clone_shallow(bs_entry ? | |
4254 | bs_entry->state.explicit_options : | |
4255 | bs->explicit_options); | |
4256 | bdrv_join_options(bs, options, old_options); | |
4257 | qobject_unref(old_options); | |
4258 | } | |
4259 | ||
4260 | explicit_options = qdict_clone_shallow(options); | |
4261 | ||
4262 | /* Inherit from parent node */ | |
4263 | if (parent_options) { | |
4264 | flags = 0; | |
4265 | klass->inherit_options(role, parent_is_format, &flags, options, | |
4266 | parent_flags, parent_options); | |
4267 | } else { | |
4268 | flags = bdrv_get_flags(bs); | |
4269 | } | |
4270 | ||
4271 | if (keep_old_opts) { | |
4272 | /* Old values are used for options that aren't set yet */ | |
4273 | old_options = qdict_clone_shallow(bs->options); | |
4274 | bdrv_join_options(bs, options, old_options); | |
4275 | qobject_unref(old_options); | |
4276 | } | |
4277 | ||
4278 | /* We have the final set of options so let's update the flags */ | |
4279 | options_copy = qdict_clone_shallow(options); | |
4280 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); | |
4281 | qemu_opts_absorb_qdict(opts, options_copy, NULL); | |
4282 | update_flags_from_options(&flags, opts); | |
4283 | qemu_opts_del(opts); | |
4284 | qobject_unref(options_copy); | |
4285 | ||
4286 | /* bdrv_open_inherit() sets and clears some additional flags internally */ | |
4287 | flags &= ~BDRV_O_PROTOCOL; | |
4288 | if (flags & BDRV_O_RDWR) { | |
4289 | flags |= BDRV_O_ALLOW_RDWR; | |
4290 | } | |
4291 | ||
4292 | if (!bs_entry) { | |
4293 | bs_entry = g_new0(BlockReopenQueueEntry, 1); | |
4294 | QTAILQ_INSERT_TAIL(bs_queue, bs_entry, entry); | |
4295 | } else { | |
4296 | qobject_unref(bs_entry->state.options); | |
4297 | qobject_unref(bs_entry->state.explicit_options); | |
4298 | } | |
4299 | ||
4300 | bs_entry->state.bs = bs; | |
4301 | bs_entry->state.options = options; | |
4302 | bs_entry->state.explicit_options = explicit_options; | |
4303 | bs_entry->state.flags = flags; | |
4304 | ||
4305 | /* | |
4306 | * If keep_old_opts is false then it means that unspecified | |
4307 | * options must be reset to their original value. We don't allow | |
4308 | * resetting 'backing' but we need to know if the option is | |
4309 | * missing in order to decide if we have to return an error. | |
4310 | */ | |
4311 | if (!keep_old_opts) { | |
4312 | bs_entry->state.backing_missing = | |
4313 | !qdict_haskey(options, "backing") && | |
4314 | !qdict_haskey(options, "backing.driver"); | |
4315 | } | |
4316 | ||
4317 | QLIST_FOREACH(child, &bs->children, next) { | |
4318 | QDict *new_child_options = NULL; | |
4319 | bool child_keep_old = keep_old_opts; | |
4320 | ||
4321 | /* reopen can only change the options of block devices that were | |
4322 | * implicitly created and inherited options. For other (referenced) | |
4323 | * block devices, a syntax like "backing.foo" results in an error. */ | |
4324 | if (child->bs->inherits_from != bs) { | |
4325 | continue; | |
4326 | } | |
4327 | ||
4328 | /* Check if the options contain a child reference */ | |
4329 | if (qdict_haskey(options, child->name)) { | |
4330 | const char *childref = qdict_get_try_str(options, child->name); | |
4331 | /* | |
4332 | * The current child must not be reopened if the child | |
4333 | * reference is null or points to a different node. | |
4334 | */ | |
4335 | if (g_strcmp0(childref, child->bs->node_name)) { | |
4336 | continue; | |
4337 | } | |
4338 | /* | |
4339 | * If the child reference points to the current child then | |
4340 | * reopen it with its existing set of options (note that | |
4341 | * it can still inherit new options from the parent). | |
4342 | */ | |
4343 | child_keep_old = true; | |
4344 | } else { | |
4345 | /* Extract child options ("child-name.*") */ | |
4346 | char *child_key_dot = g_strdup_printf("%s.", child->name); | |
4347 | qdict_extract_subqdict(explicit_options, NULL, child_key_dot); | |
4348 | qdict_extract_subqdict(options, &new_child_options, child_key_dot); | |
4349 | g_free(child_key_dot); | |
4350 | } | |
4351 | ||
4352 | bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options, | |
4353 | child->klass, child->role, bs->drv->is_format, | |
4354 | options, flags, child_keep_old); | |
4355 | } | |
4356 | ||
4357 | return bs_queue; | |
4358 | } | |
4359 | ||
4360 | /* To be called with bs->aio_context locked */ | |
4361 | BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, | |
4362 | BlockDriverState *bs, | |
4363 | QDict *options, bool keep_old_opts) | |
4364 | { | |
4365 | GLOBAL_STATE_CODE(); | |
4366 | ||
4367 | return bdrv_reopen_queue_child(bs_queue, bs, options, NULL, 0, false, | |
4368 | NULL, 0, keep_old_opts); | |
4369 | } | |
4370 | ||
4371 | void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue) | |
4372 | { | |
4373 | GLOBAL_STATE_CODE(); | |
4374 | if (bs_queue) { | |
4375 | BlockReopenQueueEntry *bs_entry, *next; | |
4376 | QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { | |
4377 | AioContext *ctx = bdrv_get_aio_context(bs_entry->state.bs); | |
4378 | ||
4379 | aio_context_acquire(ctx); | |
4380 | bdrv_drained_end(bs_entry->state.bs); | |
4381 | aio_context_release(ctx); | |
4382 | ||
4383 | qobject_unref(bs_entry->state.explicit_options); | |
4384 | qobject_unref(bs_entry->state.options); | |
4385 | g_free(bs_entry); | |
4386 | } | |
4387 | g_free(bs_queue); | |
4388 | } | |
4389 | } | |
4390 | ||
4391 | /* | |
4392 | * Reopen multiple BlockDriverStates atomically & transactionally. | |
4393 | * | |
4394 | * The queue passed in (bs_queue) must have been built up previous | |
4395 | * via bdrv_reopen_queue(). | |
4396 | * | |
4397 | * Reopens all BDS specified in the queue, with the appropriate | |
4398 | * flags. All devices are prepared for reopen, and failure of any | |
4399 | * device will cause all device changes to be abandoned, and intermediate | |
4400 | * data cleaned up. | |
4401 | * | |
4402 | * If all devices prepare successfully, then the changes are committed | |
4403 | * to all devices. | |
4404 | * | |
4405 | * All affected nodes must be drained between bdrv_reopen_queue() and | |
4406 | * bdrv_reopen_multiple(). | |
4407 | * | |
4408 | * To be called from the main thread, with all other AioContexts unlocked. | |
4409 | */ | |
4410 | int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) | |
4411 | { | |
4412 | int ret = -1; | |
4413 | BlockReopenQueueEntry *bs_entry, *next; | |
4414 | AioContext *ctx; | |
4415 | Transaction *tran = tran_new(); | |
4416 | g_autoptr(GSList) refresh_list = NULL; | |
4417 | ||
4418 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); | |
4419 | assert(bs_queue != NULL); | |
4420 | GLOBAL_STATE_CODE(); | |
4421 | ||
4422 | QTAILQ_FOREACH(bs_entry, bs_queue, entry) { | |
4423 | ctx = bdrv_get_aio_context(bs_entry->state.bs); | |
4424 | aio_context_acquire(ctx); | |
4425 | ret = bdrv_flush(bs_entry->state.bs); | |
4426 | aio_context_release(ctx); | |
4427 | if (ret < 0) { | |
4428 | error_setg_errno(errp, -ret, "Error flushing drive"); | |
4429 | goto abort; | |
4430 | } | |
4431 | } | |
4432 | ||
4433 | QTAILQ_FOREACH(bs_entry, bs_queue, entry) { | |
4434 | assert(bs_entry->state.bs->quiesce_counter > 0); | |
4435 | ctx = bdrv_get_aio_context(bs_entry->state.bs); | |
4436 | aio_context_acquire(ctx); | |
4437 | ret = bdrv_reopen_prepare(&bs_entry->state, bs_queue, tran, errp); | |
4438 | aio_context_release(ctx); | |
4439 | if (ret < 0) { | |
4440 | goto abort; | |
4441 | } | |
4442 | bs_entry->prepared = true; | |
4443 | } | |
4444 | ||
4445 | QTAILQ_FOREACH(bs_entry, bs_queue, entry) { | |
4446 | BDRVReopenState *state = &bs_entry->state; | |
4447 | ||
4448 | refresh_list = g_slist_prepend(refresh_list, state->bs); | |
4449 | if (state->old_backing_bs) { | |
4450 | refresh_list = g_slist_prepend(refresh_list, state->old_backing_bs); | |
4451 | } | |
4452 | if (state->old_file_bs) { | |
4453 | refresh_list = g_slist_prepend(refresh_list, state->old_file_bs); | |
4454 | } | |
4455 | } | |
4456 | ||
4457 | /* | |
4458 | * Note that file-posix driver rely on permission update done during reopen | |
4459 | * (even if no permission changed), because it wants "new" permissions for | |
4460 | * reconfiguring the fd and that's why it does it in raw_check_perm(), not | |
4461 | * in raw_reopen_prepare() which is called with "old" permissions. | |
4462 | */ | |
4463 | ret = bdrv_list_refresh_perms(refresh_list, bs_queue, tran, errp); | |
4464 | if (ret < 0) { | |
4465 | goto abort; | |
4466 | } | |
4467 | ||
4468 | /* | |
4469 | * If we reach this point, we have success and just need to apply the | |
4470 | * changes. | |
4471 | * | |
4472 | * Reverse order is used to comfort qcow2 driver: on commit it need to write | |
4473 | * IN_USE flag to the image, to mark bitmaps in the image as invalid. But | |
4474 | * children are usually goes after parents in reopen-queue, so go from last | |
4475 | * to first element. | |
4476 | */ | |
4477 | QTAILQ_FOREACH_REVERSE(bs_entry, bs_queue, entry) { | |
4478 | ctx = bdrv_get_aio_context(bs_entry->state.bs); | |
4479 | aio_context_acquire(ctx); | |
4480 | bdrv_reopen_commit(&bs_entry->state); | |
4481 | aio_context_release(ctx); | |
4482 | } | |
4483 | ||
4484 | tran_commit(tran); | |
4485 | ||
4486 | QTAILQ_FOREACH_REVERSE(bs_entry, bs_queue, entry) { | |
4487 | BlockDriverState *bs = bs_entry->state.bs; | |
4488 | ||
4489 | if (bs->drv->bdrv_reopen_commit_post) { | |
4490 | ctx = bdrv_get_aio_context(bs); | |
4491 | aio_context_acquire(ctx); | |
4492 | bs->drv->bdrv_reopen_commit_post(&bs_entry->state); | |
4493 | aio_context_release(ctx); | |
4494 | } | |
4495 | } | |
4496 | ||
4497 | ret = 0; | |
4498 | goto cleanup; | |
4499 | ||
4500 | abort: | |
4501 | tran_abort(tran); | |
4502 | QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { | |
4503 | if (bs_entry->prepared) { | |
4504 | ctx = bdrv_get_aio_context(bs_entry->state.bs); | |
4505 | aio_context_acquire(ctx); | |
4506 | bdrv_reopen_abort(&bs_entry->state); | |
4507 | aio_context_release(ctx); | |
4508 | } | |
4509 | } | |
4510 | ||
4511 | cleanup: | |
4512 | bdrv_reopen_queue_free(bs_queue); | |
4513 | ||
4514 | return ret; | |
4515 | } | |
4516 | ||
4517 | int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts, | |
4518 | Error **errp) | |
4519 | { | |
4520 | AioContext *ctx = bdrv_get_aio_context(bs); | |
4521 | BlockReopenQueue *queue; | |
4522 | int ret; | |
4523 | ||
4524 | GLOBAL_STATE_CODE(); | |
4525 | ||
4526 | queue = bdrv_reopen_queue(NULL, bs, opts, keep_old_opts); | |
4527 | ||
4528 | if (ctx != qemu_get_aio_context()) { | |
4529 | aio_context_release(ctx); | |
4530 | } | |
4531 | ret = bdrv_reopen_multiple(queue, errp); | |
4532 | ||
4533 | if (ctx != qemu_get_aio_context()) { | |
4534 | aio_context_acquire(ctx); | |
4535 | } | |
4536 | ||
4537 | return ret; | |
4538 | } | |
4539 | ||
4540 | int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only, | |
4541 | Error **errp) | |
4542 | { | |
4543 | QDict *opts = qdict_new(); | |
4544 | ||
4545 | GLOBAL_STATE_CODE(); | |
4546 | ||
4547 | qdict_put_bool(opts, BDRV_OPT_READ_ONLY, read_only); | |
4548 | ||
4549 | return bdrv_reopen(bs, opts, true, errp); | |
4550 | } | |
4551 | ||
4552 | /* | |
4553 | * Take a BDRVReopenState and check if the value of 'backing' in the | |
4554 | * reopen_state->options QDict is valid or not. | |
4555 | * | |
4556 | * If 'backing' is missing from the QDict then return 0. | |
4557 | * | |
4558 | * If 'backing' contains the node name of the backing file of | |
4559 | * reopen_state->bs then return 0. | |
4560 | * | |
4561 | * If 'backing' contains a different node name (or is null) then check | |
4562 | * whether the current backing file can be replaced with the new one. | |
4563 | * If that's the case then reopen_state->replace_backing_bs is set to | |
4564 | * true and reopen_state->new_backing_bs contains a pointer to the new | |
4565 | * backing BlockDriverState (or NULL). | |
4566 | * | |
4567 | * Return 0 on success, otherwise return < 0 and set @errp. | |
4568 | */ | |
4569 | static int bdrv_reopen_parse_file_or_backing(BDRVReopenState *reopen_state, | |
4570 | bool is_backing, Transaction *tran, | |
4571 | Error **errp) | |
4572 | { | |
4573 | BlockDriverState *bs = reopen_state->bs; | |
4574 | BlockDriverState *new_child_bs; | |
4575 | BlockDriverState *old_child_bs = is_backing ? child_bs(bs->backing) : | |
4576 | child_bs(bs->file); | |
4577 | const char *child_name = is_backing ? "backing" : "file"; | |
4578 | QObject *value; | |
4579 | const char *str; | |
4580 | ||
4581 | GLOBAL_STATE_CODE(); | |
4582 | ||
4583 | value = qdict_get(reopen_state->options, child_name); | |
4584 | if (value == NULL) { | |
4585 | return 0; | |
4586 | } | |
4587 | ||
4588 | switch (qobject_type(value)) { | |
4589 | case QTYPE_QNULL: | |
4590 | assert(is_backing); /* The 'file' option does not allow a null value */ | |
4591 | new_child_bs = NULL; | |
4592 | break; | |
4593 | case QTYPE_QSTRING: | |
4594 | str = qstring_get_str(qobject_to(QString, value)); | |
4595 | new_child_bs = bdrv_lookup_bs(NULL, str, errp); | |
4596 | if (new_child_bs == NULL) { | |
4597 | return -EINVAL; | |
4598 | } else if (bdrv_recurse_has_child(new_child_bs, bs)) { | |
4599 | error_setg(errp, "Making '%s' a %s child of '%s' would create a " | |
4600 | "cycle", str, child_name, bs->node_name); | |
4601 | return -EINVAL; | |
4602 | } | |
4603 | break; | |
4604 | default: | |
4605 | /* | |
4606 | * The options QDict has been flattened, so 'backing' and 'file' | |
4607 | * do not allow any other data type here. | |
4608 | */ | |
4609 | g_assert_not_reached(); | |
4610 | } | |
4611 | ||
4612 | if (old_child_bs == new_child_bs) { | |
4613 | return 0; | |
4614 | } | |
4615 | ||
4616 | if (old_child_bs) { | |
4617 | if (bdrv_skip_implicit_filters(old_child_bs) == new_child_bs) { | |
4618 | return 0; | |
4619 | } | |
4620 | ||
4621 | if (old_child_bs->implicit) { | |
4622 | error_setg(errp, "Cannot replace implicit %s child of %s", | |
4623 | child_name, bs->node_name); | |
4624 | return -EPERM; | |
4625 | } | |
4626 | } | |
4627 | ||
4628 | if (bs->drv->is_filter && !old_child_bs) { | |
4629 | /* | |
4630 | * Filters always have a file or a backing child, so we are trying to | |
4631 | * change wrong child | |
4632 | */ | |
4633 | error_setg(errp, "'%s' is a %s filter node that does not support a " | |
4634 | "%s child", bs->node_name, bs->drv->format_name, child_name); | |
4635 | return -EINVAL; | |
4636 | } | |
4637 | ||
4638 | if (is_backing) { | |
4639 | reopen_state->old_backing_bs = old_child_bs; | |
4640 | } else { | |
4641 | reopen_state->old_file_bs = old_child_bs; | |
4642 | } | |
4643 | ||
4644 | return bdrv_set_file_or_backing_noperm(bs, new_child_bs, is_backing, | |
4645 | tran, errp); | |
4646 | } | |
4647 | ||
4648 | /* | |
4649 | * Prepares a BlockDriverState for reopen. All changes are staged in the | |
4650 | * 'opaque' field of the BDRVReopenState, which is used and allocated by | |
4651 | * the block driver layer .bdrv_reopen_prepare() | |
4652 | * | |
4653 | * bs is the BlockDriverState to reopen | |
4654 | * flags are the new open flags | |
4655 | * queue is the reopen queue | |
4656 | * | |
4657 | * Returns 0 on success, non-zero on error. On error errp will be set | |
4658 | * as well. | |
4659 | * | |
4660 | * On failure, bdrv_reopen_abort() will be called to clean up any data. | |
4661 | * It is the responsibility of the caller to then call the abort() or | |
4662 | * commit() for any other BDS that have been left in a prepare() state | |
4663 | * | |
4664 | */ | |
4665 | static int bdrv_reopen_prepare(BDRVReopenState *reopen_state, | |
4666 | BlockReopenQueue *queue, | |
4667 | Transaction *change_child_tran, Error **errp) | |
4668 | { | |
4669 | int ret = -1; | |
4670 | int old_flags; | |
4671 | Error *local_err = NULL; | |
4672 | BlockDriver *drv; | |
4673 | QemuOpts *opts; | |
4674 | QDict *orig_reopen_opts; | |
4675 | char *discard = NULL; | |
4676 | bool read_only; | |
4677 | bool drv_prepared = false; | |
4678 | ||
4679 | assert(reopen_state != NULL); | |
4680 | assert(reopen_state->bs->drv != NULL); | |
4681 | GLOBAL_STATE_CODE(); | |
4682 | drv = reopen_state->bs->drv; | |
4683 | ||
4684 | /* This function and each driver's bdrv_reopen_prepare() remove | |
4685 | * entries from reopen_state->options as they are processed, so | |
4686 | * we need to make a copy of the original QDict. */ | |
4687 | orig_reopen_opts = qdict_clone_shallow(reopen_state->options); | |
4688 | ||
4689 | /* Process generic block layer options */ | |
4690 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); | |
4691 | if (!qemu_opts_absorb_qdict(opts, reopen_state->options, errp)) { | |
4692 | ret = -EINVAL; | |
4693 | goto error; | |
4694 | } | |
4695 | ||
4696 | /* This was already called in bdrv_reopen_queue_child() so the flags | |
4697 | * are up-to-date. This time we simply want to remove the options from | |
4698 | * QemuOpts in order to indicate that they have been processed. */ | |
4699 | old_flags = reopen_state->flags; | |
4700 | update_flags_from_options(&reopen_state->flags, opts); | |
4701 | assert(old_flags == reopen_state->flags); | |
4702 | ||
4703 | discard = qemu_opt_get_del(opts, BDRV_OPT_DISCARD); | |
4704 | if (discard != NULL) { | |
4705 | if (bdrv_parse_discard_flags(discard, &reopen_state->flags) != 0) { | |
4706 | error_setg(errp, "Invalid discard option"); | |
4707 | ret = -EINVAL; | |
4708 | goto error; | |
4709 | } | |
4710 | } | |
4711 | ||
4712 | reopen_state->detect_zeroes = | |
4713 | bdrv_parse_detect_zeroes(opts, reopen_state->flags, &local_err); | |
4714 | if (local_err) { | |
4715 | error_propagate(errp, local_err); | |
4716 | ret = -EINVAL; | |
4717 | goto error; | |
4718 | } | |
4719 | ||
4720 | /* All other options (including node-name and driver) must be unchanged. | |
4721 | * Put them back into the QDict, so that they are checked at the end | |
4722 | * of this function. */ | |
4723 | qemu_opts_to_qdict(opts, reopen_state->options); | |
4724 | ||
4725 | /* If we are to stay read-only, do not allow permission change | |
4726 | * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is | |
4727 | * not set, or if the BDS still has copy_on_read enabled */ | |
4728 | read_only = !(reopen_state->flags & BDRV_O_RDWR); | |
4729 | ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err); | |
4730 | if (local_err) { | |
4731 | error_propagate(errp, local_err); | |
4732 | goto error; | |
4733 | } | |
4734 | ||
4735 | if (drv->bdrv_reopen_prepare) { | |
4736 | /* | |
4737 | * If a driver-specific option is missing, it means that we | |
4738 | * should reset it to its default value. | |
4739 | * But not all options allow that, so we need to check it first. | |
4740 | */ | |
4741 | ret = bdrv_reset_options_allowed(reopen_state->bs, | |
4742 | reopen_state->options, errp); | |
4743 | if (ret) { | |
4744 | goto error; | |
4745 | } | |
4746 | ||
4747 | ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); | |
4748 | if (ret) { | |
4749 | if (local_err != NULL) { | |
4750 | error_propagate(errp, local_err); | |
4751 | } else { | |
4752 | bdrv_refresh_filename(reopen_state->bs); | |
4753 | error_setg(errp, "failed while preparing to reopen image '%s'", | |
4754 | reopen_state->bs->filename); | |
4755 | } | |
4756 | goto error; | |
4757 | } | |
4758 | } else { | |
4759 | /* It is currently mandatory to have a bdrv_reopen_prepare() | |
4760 | * handler for each supported drv. */ | |
4761 | error_setg(errp, "Block format '%s' used by node '%s' " | |
4762 | "does not support reopening files", drv->format_name, | |
4763 | bdrv_get_device_or_node_name(reopen_state->bs)); | |
4764 | ret = -1; | |
4765 | goto error; | |
4766 | } | |
4767 | ||
4768 | drv_prepared = true; | |
4769 | ||
4770 | /* | |
4771 | * We must provide the 'backing' option if the BDS has a backing | |
4772 | * file or if the image file has a backing file name as part of | |
4773 | * its metadata. Otherwise the 'backing' option can be omitted. | |
4774 | */ | |
4775 | if (drv->supports_backing && reopen_state->backing_missing && | |
4776 | (reopen_state->bs->backing || reopen_state->bs->backing_file[0])) { | |
4777 | error_setg(errp, "backing is missing for '%s'", | |
4778 | reopen_state->bs->node_name); | |
4779 | ret = -EINVAL; | |
4780 | goto error; | |
4781 | } | |
4782 | ||
4783 | /* | |
4784 | * Allow changing the 'backing' option. The new value can be | |
4785 | * either a reference to an existing node (using its node name) | |
4786 | * or NULL to simply detach the current backing file. | |
4787 | */ | |
4788 | ret = bdrv_reopen_parse_file_or_backing(reopen_state, true, | |
4789 | change_child_tran, errp); | |
4790 | if (ret < 0) { | |
4791 | goto error; | |
4792 | } | |
4793 | qdict_del(reopen_state->options, "backing"); | |
4794 | ||
4795 | /* Allow changing the 'file' option. In this case NULL is not allowed */ | |
4796 | ret = bdrv_reopen_parse_file_or_backing(reopen_state, false, | |
4797 | change_child_tran, errp); | |
4798 | if (ret < 0) { | |
4799 | goto error; | |
4800 | } | |
4801 | qdict_del(reopen_state->options, "file"); | |
4802 | ||
4803 | /* Options that are not handled are only okay if they are unchanged | |
4804 | * compared to the old state. It is expected that some options are only | |
4805 | * used for the initial open, but not reopen (e.g. filename) */ | |
4806 | if (qdict_size(reopen_state->options)) { | |
4807 | const QDictEntry *entry = qdict_first(reopen_state->options); | |
4808 | ||
4809 | do { | |
4810 | QObject *new = entry->value; | |
4811 | QObject *old = qdict_get(reopen_state->bs->options, entry->key); | |
4812 | ||
4813 | /* Allow child references (child_name=node_name) as long as they | |
4814 | * point to the current child (i.e. everything stays the same). */ | |
4815 | if (qobject_type(new) == QTYPE_QSTRING) { | |
4816 | BdrvChild *child; | |
4817 | QLIST_FOREACH(child, &reopen_state->bs->children, next) { | |
4818 | if (!strcmp(child->name, entry->key)) { | |
4819 | break; | |
4820 | } | |
4821 | } | |
4822 | ||
4823 | if (child) { | |
4824 | if (!strcmp(child->bs->node_name, | |
4825 | qstring_get_str(qobject_to(QString, new)))) { | |
4826 | continue; /* Found child with this name, skip option */ | |
4827 | } | |
4828 | } | |
4829 | } | |
4830 | ||
4831 | /* | |
4832 | * TODO: When using -drive to specify blockdev options, all values | |
4833 | * will be strings; however, when using -blockdev, blockdev-add or | |
4834 | * filenames using the json:{} pseudo-protocol, they will be | |
4835 | * correctly typed. | |
4836 | * In contrast, reopening options are (currently) always strings | |
4837 | * (because you can only specify them through qemu-io; all other | |
4838 | * callers do not specify any options). | |
4839 | * Therefore, when using anything other than -drive to create a BDS, | |
4840 | * this cannot detect non-string options as unchanged, because | |
4841 | * qobject_is_equal() always returns false for objects of different | |
4842 | * type. In the future, this should be remedied by correctly typing | |
4843 | * all options. For now, this is not too big of an issue because | |
4844 | * the user can simply omit options which cannot be changed anyway, | |
4845 | * so they will stay unchanged. | |
4846 | */ | |
4847 | if (!qobject_is_equal(new, old)) { | |
4848 | error_setg(errp, "Cannot change the option '%s'", entry->key); | |
4849 | ret = -EINVAL; | |
4850 | goto error; | |
4851 | } | |
4852 | } while ((entry = qdict_next(reopen_state->options, entry))); | |
4853 | } | |
4854 | ||
4855 | ret = 0; | |
4856 | ||
4857 | /* Restore the original reopen_state->options QDict */ | |
4858 | qobject_unref(reopen_state->options); | |
4859 | reopen_state->options = qobject_ref(orig_reopen_opts); | |
4860 | ||
4861 | error: | |
4862 | if (ret < 0 && drv_prepared) { | |
4863 | /* drv->bdrv_reopen_prepare() has succeeded, so we need to | |
4864 | * call drv->bdrv_reopen_abort() before signaling an error | |
4865 | * (bdrv_reopen_multiple() will not call bdrv_reopen_abort() | |
4866 | * when the respective bdrv_reopen_prepare() has failed) */ | |
4867 | if (drv->bdrv_reopen_abort) { | |
4868 | drv->bdrv_reopen_abort(reopen_state); | |
4869 | } | |
4870 | } | |
4871 | qemu_opts_del(opts); | |
4872 | qobject_unref(orig_reopen_opts); | |
4873 | g_free(discard); | |
4874 | return ret; | |
4875 | } | |
4876 | ||
4877 | /* | |
4878 | * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and | |
4879 | * makes them final by swapping the staging BlockDriverState contents into | |
4880 | * the active BlockDriverState contents. | |
4881 | */ | |
4882 | static void bdrv_reopen_commit(BDRVReopenState *reopen_state) | |
4883 | { | |
4884 | BlockDriver *drv; | |
4885 | BlockDriverState *bs; | |
4886 | BdrvChild *child; | |
4887 | ||
4888 | assert(reopen_state != NULL); | |
4889 | bs = reopen_state->bs; | |
4890 | drv = bs->drv; | |
4891 | assert(drv != NULL); | |
4892 | GLOBAL_STATE_CODE(); | |
4893 | ||
4894 | /* If there are any driver level actions to take */ | |
4895 | if (drv->bdrv_reopen_commit) { | |
4896 | drv->bdrv_reopen_commit(reopen_state); | |
4897 | } | |
4898 | ||
4899 | /* set BDS specific flags now */ | |
4900 | qobject_unref(bs->explicit_options); | |
4901 | qobject_unref(bs->options); | |
4902 | qobject_ref(reopen_state->explicit_options); | |
4903 | qobject_ref(reopen_state->options); | |
4904 | ||
4905 | bs->explicit_options = reopen_state->explicit_options; | |
4906 | bs->options = reopen_state->options; | |
4907 | bs->open_flags = reopen_state->flags; | |
4908 | bs->detect_zeroes = reopen_state->detect_zeroes; | |
4909 | ||
4910 | /* Remove child references from bs->options and bs->explicit_options. | |
4911 | * Child options were already removed in bdrv_reopen_queue_child() */ | |
4912 | QLIST_FOREACH(child, &bs->children, next) { | |
4913 | qdict_del(bs->explicit_options, child->name); | |
4914 | qdict_del(bs->options, child->name); | |
4915 | } | |
4916 | /* backing is probably removed, so it's not handled by previous loop */ | |
4917 | qdict_del(bs->explicit_options, "backing"); | |
4918 | qdict_del(bs->options, "backing"); | |
4919 | ||
4920 | bdrv_refresh_limits(bs, NULL, NULL); | |
4921 | } | |
4922 | ||
4923 | /* | |
4924 | * Abort the reopen, and delete and free the staged changes in | |
4925 | * reopen_state | |
4926 | */ | |
4927 | static void bdrv_reopen_abort(BDRVReopenState *reopen_state) | |
4928 | { | |
4929 | BlockDriver *drv; | |
4930 | ||
4931 | assert(reopen_state != NULL); | |
4932 | drv = reopen_state->bs->drv; | |
4933 | assert(drv != NULL); | |
4934 | GLOBAL_STATE_CODE(); | |
4935 | ||
4936 | if (drv->bdrv_reopen_abort) { | |
4937 | drv->bdrv_reopen_abort(reopen_state); | |
4938 | } | |
4939 | } | |
4940 | ||
4941 | ||
4942 | static void bdrv_close(BlockDriverState *bs) | |
4943 | { | |
4944 | BdrvAioNotifier *ban, *ban_next; | |
4945 | BdrvChild *child, *next; | |
4946 | ||
4947 | GLOBAL_STATE_CODE(); | |
4948 | assert(!bs->refcnt); | |
4949 | ||
4950 | bdrv_drained_begin(bs); /* complete I/O */ | |
4951 | bdrv_flush(bs); | |
4952 | bdrv_drain(bs); /* in case flush left pending I/O */ | |
4953 | ||
4954 | if (bs->drv) { | |
4955 | if (bs->drv->bdrv_close) { | |
4956 | /* Must unfreeze all children, so bdrv_unref_child() works */ | |
4957 | bs->drv->bdrv_close(bs); | |
4958 | } | |
4959 | bs->drv = NULL; | |
4960 | } | |
4961 | ||
4962 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { | |
4963 | bdrv_unref_child(bs, child); | |
4964 | } | |
4965 | ||
4966 | assert(!bs->backing); | |
4967 | assert(!bs->file); | |
4968 | g_free(bs->opaque); | |
4969 | bs->opaque = NULL; | |
4970 | qatomic_set(&bs->copy_on_read, 0); | |
4971 | bs->backing_file[0] = '\0'; | |
4972 | bs->backing_format[0] = '\0'; | |
4973 | bs->total_sectors = 0; | |
4974 | bs->encrypted = false; | |
4975 | bs->sg = false; | |
4976 | qobject_unref(bs->options); | |
4977 | qobject_unref(bs->explicit_options); | |
4978 | bs->options = NULL; | |
4979 | bs->explicit_options = NULL; | |
4980 | qobject_unref(bs->full_open_options); | |
4981 | bs->full_open_options = NULL; | |
4982 | g_free(bs->block_status_cache); | |
4983 | bs->block_status_cache = NULL; | |
4984 | ||
4985 | bdrv_release_named_dirty_bitmaps(bs); | |
4986 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); | |
4987 | ||
4988 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { | |
4989 | g_free(ban); | |
4990 | } | |
4991 | QLIST_INIT(&bs->aio_notifiers); | |
4992 | bdrv_drained_end(bs); | |
4993 | ||
4994 | /* | |
4995 | * If we're still inside some bdrv_drain_all_begin()/end() sections, end | |
4996 | * them now since this BDS won't exist anymore when bdrv_drain_all_end() | |
4997 | * gets called. | |
4998 | */ | |
4999 | if (bs->quiesce_counter) { | |
5000 | bdrv_drain_all_end_quiesce(bs); | |
5001 | } | |
5002 | } | |
5003 | ||
5004 | void bdrv_close_all(void) | |
5005 | { | |
5006 | GLOBAL_STATE_CODE(); | |
5007 | assert(job_next(NULL) == NULL); | |
5008 | ||
5009 | /* Drop references from requests still in flight, such as canceled block | |
5010 | * jobs whose AIO context has not been polled yet */ | |
5011 | bdrv_drain_all(); | |
5012 | ||
5013 | blk_remove_all_bs(); | |
5014 | blockdev_close_all_bdrv_states(); | |
5015 | ||
5016 | assert(QTAILQ_EMPTY(&all_bdrv_states)); | |
5017 | } | |
5018 | ||
5019 | static bool should_update_child(BdrvChild *c, BlockDriverState *to) | |
5020 | { | |
5021 | GQueue *queue; | |
5022 | GHashTable *found; | |
5023 | bool ret; | |
5024 | ||
5025 | if (c->klass->stay_at_node) { | |
5026 | return false; | |
5027 | } | |
5028 | ||
5029 | /* If the child @c belongs to the BDS @to, replacing the current | |
5030 | * c->bs by @to would mean to create a loop. | |
5031 | * | |
5032 | * Such a case occurs when appending a BDS to a backing chain. | |
5033 | * For instance, imagine the following chain: | |
5034 | * | |
5035 | * guest device -> node A -> further backing chain... | |
5036 | * | |
5037 | * Now we create a new BDS B which we want to put on top of this | |
5038 | * chain, so we first attach A as its backing node: | |
5039 | * | |
5040 | * node B | |
5041 | * | | |
5042 | * v | |
5043 | * guest device -> node A -> further backing chain... | |
5044 | * | |
5045 | * Finally we want to replace A by B. When doing that, we want to | |
5046 | * replace all pointers to A by pointers to B -- except for the | |
5047 | * pointer from B because (1) that would create a loop, and (2) | |
5048 | * that pointer should simply stay intact: | |
5049 | * | |
5050 | * guest device -> node B | |
5051 | * | | |
5052 | * v | |
5053 | * node A -> further backing chain... | |
5054 | * | |
5055 | * In general, when replacing a node A (c->bs) by a node B (@to), | |
5056 | * if A is a child of B, that means we cannot replace A by B there | |
5057 | * because that would create a loop. Silently detaching A from B | |
5058 | * is also not really an option. So overall just leaving A in | |
5059 | * place there is the most sensible choice. | |
5060 | * | |
5061 | * We would also create a loop in any cases where @c is only | |
5062 | * indirectly referenced by @to. Prevent this by returning false | |
5063 | * if @c is found (by breadth-first search) anywhere in the whole | |
5064 | * subtree of @to. | |
5065 | */ | |
5066 | ||
5067 | ret = true; | |
5068 | found = g_hash_table_new(NULL, NULL); | |
5069 | g_hash_table_add(found, to); | |
5070 | queue = g_queue_new(); | |
5071 | g_queue_push_tail(queue, to); | |
5072 | ||
5073 | while (!g_queue_is_empty(queue)) { | |
5074 | BlockDriverState *v = g_queue_pop_head(queue); | |
5075 | BdrvChild *c2; | |
5076 | ||
5077 | QLIST_FOREACH(c2, &v->children, next) { | |
5078 | if (c2 == c) { | |
5079 | ret = false; | |
5080 | break; | |
5081 | } | |
5082 | ||
5083 | if (g_hash_table_contains(found, c2->bs)) { | |
5084 | continue; | |
5085 | } | |
5086 | ||
5087 | g_queue_push_tail(queue, c2->bs); | |
5088 | g_hash_table_add(found, c2->bs); | |
5089 | } | |
5090 | } | |
5091 | ||
5092 | g_queue_free(queue); | |
5093 | g_hash_table_destroy(found); | |
5094 | ||
5095 | return ret; | |
5096 | } | |
5097 | ||
5098 | static void bdrv_remove_child_commit(void *opaque) | |
5099 | { | |
5100 | GLOBAL_STATE_CODE(); | |
5101 | bdrv_child_free(opaque); | |
5102 | } | |
5103 | ||
5104 | static TransactionActionDrv bdrv_remove_child_drv = { | |
5105 | .commit = bdrv_remove_child_commit, | |
5106 | }; | |
5107 | ||
5108 | /* Function doesn't update permissions, caller is responsible for this. */ | |
5109 | static void bdrv_remove_child(BdrvChild *child, Transaction *tran) | |
5110 | { | |
5111 | if (!child) { | |
5112 | return; | |
5113 | } | |
5114 | ||
5115 | if (child->bs) { | |
5116 | BlockDriverState *bs = child->bs; | |
5117 | bdrv_drained_begin(bs); | |
5118 | bdrv_replace_child_tran(child, NULL, tran); | |
5119 | bdrv_drained_end(bs); | |
5120 | } | |
5121 | ||
5122 | tran_add(tran, &bdrv_remove_child_drv, child); | |
5123 | } | |
5124 | ||
5125 | static void undrain_on_clean_cb(void *opaque) | |
5126 | { | |
5127 | bdrv_drained_end(opaque); | |
5128 | } | |
5129 | ||
5130 | static TransactionActionDrv undrain_on_clean = { | |
5131 | .clean = undrain_on_clean_cb, | |
5132 | }; | |
5133 | ||
5134 | static int bdrv_replace_node_noperm(BlockDriverState *from, | |
5135 | BlockDriverState *to, | |
5136 | bool auto_skip, Transaction *tran, | |
5137 | Error **errp) | |
5138 | { | |
5139 | BdrvChild *c, *next; | |
5140 | ||
5141 | GLOBAL_STATE_CODE(); | |
5142 | ||
5143 | bdrv_drained_begin(from); | |
5144 | bdrv_drained_begin(to); | |
5145 | tran_add(tran, &undrain_on_clean, from); | |
5146 | tran_add(tran, &undrain_on_clean, to); | |
5147 | ||
5148 | QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { | |
5149 | assert(c->bs == from); | |
5150 | if (!should_update_child(c, to)) { | |
5151 | if (auto_skip) { | |
5152 | continue; | |
5153 | } | |
5154 | error_setg(errp, "Should not change '%s' link to '%s'", | |
5155 | c->name, from->node_name); | |
5156 | return -EINVAL; | |
5157 | } | |
5158 | if (c->frozen) { | |
5159 | error_setg(errp, "Cannot change '%s' link to '%s'", | |
5160 | c->name, from->node_name); | |
5161 | return -EPERM; | |
5162 | } | |
5163 | bdrv_replace_child_tran(c, to, tran); | |
5164 | } | |
5165 | ||
5166 | return 0; | |
5167 | } | |
5168 | ||
5169 | /* | |
5170 | * With auto_skip=true bdrv_replace_node_common skips updating from parents | |
5171 | * if it creates a parent-child relation loop or if parent is block-job. | |
5172 | * | |
5173 | * With auto_skip=false the error is returned if from has a parent which should | |
5174 | * not be updated. | |
5175 | * | |
5176 | * With @detach_subchain=true @to must be in a backing chain of @from. In this | |
5177 | * case backing link of the cow-parent of @to is removed. | |
5178 | */ | |
5179 | static int bdrv_replace_node_common(BlockDriverState *from, | |
5180 | BlockDriverState *to, | |
5181 | bool auto_skip, bool detach_subchain, | |
5182 | Error **errp) | |
5183 | { | |
5184 | Transaction *tran = tran_new(); | |
5185 | g_autoptr(GSList) refresh_list = NULL; | |
5186 | BlockDriverState *to_cow_parent = NULL; | |
5187 | int ret; | |
5188 | ||
5189 | GLOBAL_STATE_CODE(); | |
5190 | ||
5191 | if (detach_subchain) { | |
5192 | assert(bdrv_chain_contains(from, to)); | |
5193 | assert(from != to); | |
5194 | for (to_cow_parent = from; | |
5195 | bdrv_filter_or_cow_bs(to_cow_parent) != to; | |
5196 | to_cow_parent = bdrv_filter_or_cow_bs(to_cow_parent)) | |
5197 | { | |
5198 | ; | |
5199 | } | |
5200 | } | |
5201 | ||
5202 | /* Make sure that @from doesn't go away until we have successfully attached | |
5203 | * all of its parents to @to. */ | |
5204 | bdrv_ref(from); | |
5205 | ||
5206 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); | |
5207 | assert(bdrv_get_aio_context(from) == bdrv_get_aio_context(to)); | |
5208 | bdrv_drained_begin(from); | |
5209 | ||
5210 | /* | |
5211 | * Do the replacement without permission update. | |
5212 | * Replacement may influence the permissions, we should calculate new | |
5213 | * permissions based on new graph. If we fail, we'll roll-back the | |
5214 | * replacement. | |
5215 | */ | |
5216 | ret = bdrv_replace_node_noperm(from, to, auto_skip, tran, errp); | |
5217 | if (ret < 0) { | |
5218 | goto out; | |
5219 | } | |
5220 | ||
5221 | if (detach_subchain) { | |
5222 | bdrv_remove_child(bdrv_filter_or_cow_child(to_cow_parent), tran); | |
5223 | } | |
5224 | ||
5225 | refresh_list = g_slist_prepend(refresh_list, to); | |
5226 | refresh_list = g_slist_prepend(refresh_list, from); | |
5227 | ||
5228 | ret = bdrv_list_refresh_perms(refresh_list, NULL, tran, errp); | |
5229 | if (ret < 0) { | |
5230 | goto out; | |
5231 | } | |
5232 | ||
5233 | ret = 0; | |
5234 | ||
5235 | out: | |
5236 | tran_finalize(tran, ret); | |
5237 | ||
5238 | bdrv_drained_end(from); | |
5239 | bdrv_unref(from); | |
5240 | ||
5241 | return ret; | |
5242 | } | |
5243 | ||
5244 | int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, | |
5245 | Error **errp) | |
5246 | { | |
5247 | GLOBAL_STATE_CODE(); | |
5248 | ||
5249 | return bdrv_replace_node_common(from, to, true, false, errp); | |
5250 | } | |
5251 | ||
5252 | int bdrv_drop_filter(BlockDriverState *bs, Error **errp) | |
5253 | { | |
5254 | GLOBAL_STATE_CODE(); | |
5255 | ||
5256 | return bdrv_replace_node_common(bs, bdrv_filter_or_cow_bs(bs), true, true, | |
5257 | errp); | |
5258 | } | |
5259 | ||
5260 | /* | |
5261 | * Add new bs contents at the top of an image chain while the chain is | |
5262 | * live, while keeping required fields on the top layer. | |
5263 | * | |
5264 | * This will modify the BlockDriverState fields, and swap contents | |
5265 | * between bs_new and bs_top. Both bs_new and bs_top are modified. | |
5266 | * | |
5267 | * bs_new must not be attached to a BlockBackend and must not have backing | |
5268 | * child. | |
5269 | * | |
5270 | * This function does not create any image files. | |
5271 | * | |
5272 | * The caller must hold the AioContext lock for @bs_top. | |
5273 | */ | |
5274 | int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, | |
5275 | Error **errp) | |
5276 | { | |
5277 | int ret; | |
5278 | BdrvChild *child; | |
5279 | Transaction *tran = tran_new(); | |
5280 | AioContext *old_context, *new_context = NULL; | |
5281 | ||
5282 | GLOBAL_STATE_CODE(); | |
5283 | ||
5284 | assert(!bs_new->backing); | |
5285 | ||
5286 | old_context = bdrv_get_aio_context(bs_top); | |
5287 | ||
5288 | child = bdrv_attach_child_noperm(bs_new, bs_top, "backing", | |
5289 | &child_of_bds, bdrv_backing_role(bs_new), | |
5290 | tran, errp); | |
5291 | if (!child) { | |
5292 | ret = -EINVAL; | |
5293 | goto out; | |
5294 | } | |
5295 | ||
5296 | /* | |
5297 | * bdrv_attach_child_noperm could change the AioContext of bs_top. | |
5298 | * bdrv_replace_node_noperm calls bdrv_drained_begin, so let's temporarily | |
5299 | * hold the new AioContext, since bdrv_drained_begin calls BDRV_POLL_WHILE | |
5300 | * that assumes the new lock is taken. | |
5301 | */ | |
5302 | new_context = bdrv_get_aio_context(bs_top); | |
5303 | ||
5304 | if (old_context != new_context) { | |
5305 | aio_context_release(old_context); | |
5306 | aio_context_acquire(new_context); | |
5307 | } | |
5308 | ||
5309 | ret = bdrv_replace_node_noperm(bs_top, bs_new, true, tran, errp); | |
5310 | if (ret < 0) { | |
5311 | goto out; | |
5312 | } | |
5313 | ||
5314 | ret = bdrv_refresh_perms(bs_new, tran, errp); | |
5315 | out: | |
5316 | tran_finalize(tran, ret); | |
5317 | ||
5318 | bdrv_refresh_limits(bs_top, NULL, NULL); | |
5319 | ||
5320 | if (new_context && old_context != new_context) { | |
5321 | aio_context_release(new_context); | |
5322 | aio_context_acquire(old_context); | |
5323 | } | |
5324 | ||
5325 | return ret; | |
5326 | } | |
5327 | ||
5328 | /* Not for empty child */ | |
5329 | int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs, | |
5330 | Error **errp) | |
5331 | { | |
5332 | int ret; | |
5333 | Transaction *tran = tran_new(); | |
5334 | g_autoptr(GSList) refresh_list = NULL; | |
5335 | BlockDriverState *old_bs = child->bs; | |
5336 | ||
5337 | GLOBAL_STATE_CODE(); | |
5338 | ||
5339 | bdrv_ref(old_bs); | |
5340 | bdrv_drained_begin(old_bs); | |
5341 | bdrv_drained_begin(new_bs); | |
5342 | ||
5343 | bdrv_replace_child_tran(child, new_bs, tran); | |
5344 | ||
5345 | refresh_list = g_slist_prepend(refresh_list, old_bs); | |
5346 | refresh_list = g_slist_prepend(refresh_list, new_bs); | |
5347 | ||
5348 | ret = bdrv_list_refresh_perms(refresh_list, NULL, tran, errp); | |
5349 | ||
5350 | tran_finalize(tran, ret); | |
5351 | ||
5352 | bdrv_drained_end(old_bs); | |
5353 | bdrv_drained_end(new_bs); | |
5354 | bdrv_unref(old_bs); | |
5355 | ||
5356 | return ret; | |
5357 | } | |
5358 | ||
5359 | static void bdrv_delete(BlockDriverState *bs) | |
5360 | { | |
5361 | assert(bdrv_op_blocker_is_empty(bs)); | |
5362 | assert(!bs->refcnt); | |
5363 | GLOBAL_STATE_CODE(); | |
5364 | ||
5365 | /* remove from list, if necessary */ | |
5366 | if (bs->node_name[0] != '\0') { | |
5367 | QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); | |
5368 | } | |
5369 | QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list); | |
5370 | ||
5371 | bdrv_close(bs); | |
5372 | ||
5373 | g_free(bs); | |
5374 | } | |
5375 | ||
5376 | ||
5377 | /* | |
5378 | * Replace @bs by newly created block node. | |
5379 | * | |
5380 | * @options is a QDict of options to pass to the block drivers, or NULL for an | |
5381 | * empty set of options. The reference to the QDict belongs to the block layer | |
5382 | * after the call (even on failure), so if the caller intends to reuse the | |
5383 | * dictionary, it needs to use qobject_ref() before calling bdrv_open. | |
5384 | */ | |
5385 | BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *options, | |
5386 | int flags, Error **errp) | |
5387 | { | |
5388 | ERRP_GUARD(); | |
5389 | int ret; | |
5390 | BlockDriverState *new_node_bs = NULL; | |
5391 | const char *drvname, *node_name; | |
5392 | BlockDriver *drv; | |
5393 | ||
5394 | drvname = qdict_get_try_str(options, "driver"); | |
5395 | if (!drvname) { | |
5396 | error_setg(errp, "driver is not specified"); | |
5397 | goto fail; | |
5398 | } | |
5399 | ||
5400 | drv = bdrv_find_format(drvname); | |
5401 | if (!drv) { | |
5402 | error_setg(errp, "Unknown driver: '%s'", drvname); | |
5403 | goto fail; | |
5404 | } | |
5405 | ||
5406 | node_name = qdict_get_try_str(options, "node-name"); | |
5407 | ||
5408 | GLOBAL_STATE_CODE(); | |
5409 | ||
5410 | new_node_bs = bdrv_new_open_driver_opts(drv, node_name, options, flags, | |
5411 | errp); | |
5412 | options = NULL; /* bdrv_new_open_driver() eats options */ | |
5413 | if (!new_node_bs) { | |
5414 | error_prepend(errp, "Could not create node: "); | |
5415 | goto fail; | |
5416 | } | |
5417 | ||
5418 | bdrv_drained_begin(bs); | |
5419 | ret = bdrv_replace_node(bs, new_node_bs, errp); | |
5420 | bdrv_drained_end(bs); | |
5421 | ||
5422 | if (ret < 0) { | |
5423 | error_prepend(errp, "Could not replace node: "); | |
5424 | goto fail; | |
5425 | } | |
5426 | ||
5427 | return new_node_bs; | |
5428 | ||
5429 | fail: | |
5430 | qobject_unref(options); | |
5431 | bdrv_unref(new_node_bs); | |
5432 | return NULL; | |
5433 | } | |
5434 | ||
5435 | /* | |
5436 | * Run consistency checks on an image | |
5437 | * | |
5438 | * Returns 0 if the check could be completed (it doesn't mean that the image is | |
5439 | * free of errors) or -errno when an internal error occurred. The results of the | |
5440 | * check are stored in res. | |
5441 | */ | |
5442 | int coroutine_fn bdrv_co_check(BlockDriverState *bs, | |
5443 | BdrvCheckResult *res, BdrvCheckMode fix) | |
5444 | { | |
5445 | IO_CODE(); | |
5446 | assert_bdrv_graph_readable(); | |
5447 | if (bs->drv == NULL) { | |
5448 | return -ENOMEDIUM; | |
5449 | } | |
5450 | if (bs->drv->bdrv_co_check == NULL) { | |
5451 | return -ENOTSUP; | |
5452 | } | |
5453 | ||
5454 | memset(res, 0, sizeof(*res)); | |
5455 | return bs->drv->bdrv_co_check(bs, res, fix); | |
5456 | } | |
5457 | ||
5458 | /* | |
5459 | * Return values: | |
5460 | * 0 - success | |
5461 | * -EINVAL - backing format specified, but no file | |
5462 | * -ENOSPC - can't update the backing file because no space is left in the | |
5463 | * image file header | |
5464 | * -ENOTSUP - format driver doesn't support changing the backing file | |
5465 | */ | |
5466 | int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file, | |
5467 | const char *backing_fmt, bool require) | |
5468 | { | |
5469 | BlockDriver *drv = bs->drv; | |
5470 | int ret; | |
5471 | ||
5472 | GLOBAL_STATE_CODE(); | |
5473 | ||
5474 | if (!drv) { | |
5475 | return -ENOMEDIUM; | |
5476 | } | |
5477 | ||
5478 | /* Backing file format doesn't make sense without a backing file */ | |
5479 | if (backing_fmt && !backing_file) { | |
5480 | return -EINVAL; | |
5481 | } | |
5482 | ||
5483 | if (require && backing_file && !backing_fmt) { | |
5484 | return -EINVAL; | |
5485 | } | |
5486 | ||
5487 | if (drv->bdrv_change_backing_file != NULL) { | |
5488 | ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); | |
5489 | } else { | |
5490 | ret = -ENOTSUP; | |
5491 | } | |
5492 | ||
5493 | if (ret == 0) { | |
5494 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); | |
5495 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); | |
5496 | pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), | |
5497 | backing_file ?: ""); | |
5498 | } | |
5499 | return ret; | |
5500 | } | |
5501 | ||
5502 | /* | |
5503 | * Finds the first non-filter node above bs in the chain between | |
5504 | * active and bs. The returned node is either an immediate parent of | |
5505 | * bs, or there are only filter nodes between the two. | |
5506 | * | |
5507 | * Returns NULL if bs is not found in active's image chain, | |
5508 | * or if active == bs. | |
5509 | * | |
5510 | * Returns the bottommost base image if bs == NULL. | |
5511 | */ | |
5512 | BlockDriverState *bdrv_find_overlay(BlockDriverState *active, | |
5513 | BlockDriverState *bs) | |
5514 | { | |
5515 | ||
5516 | GLOBAL_STATE_CODE(); | |
5517 | ||
5518 | bs = bdrv_skip_filters(bs); | |
5519 | active = bdrv_skip_filters(active); | |
5520 | ||
5521 | while (active) { | |
5522 | BlockDriverState *next = bdrv_backing_chain_next(active); | |
5523 | if (bs == next) { | |
5524 | return active; | |
5525 | } | |
5526 | active = next; | |
5527 | } | |
5528 | ||
5529 | return NULL; | |
5530 | } | |
5531 | ||
5532 | /* Given a BDS, searches for the base layer. */ | |
5533 | BlockDriverState *bdrv_find_base(BlockDriverState *bs) | |
5534 | { | |
5535 | GLOBAL_STATE_CODE(); | |
5536 | ||
5537 | return bdrv_find_overlay(bs, NULL); | |
5538 | } | |
5539 | ||
5540 | /* | |
5541 | * Return true if at least one of the COW (backing) and filter links | |
5542 | * between @bs and @base is frozen. @errp is set if that's the case. | |
5543 | * @base must be reachable from @bs, or NULL. | |
5544 | */ | |
5545 | bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base, | |
5546 | Error **errp) | |
5547 | { | |
5548 | BlockDriverState *i; | |
5549 | BdrvChild *child; | |
5550 | ||
5551 | GLOBAL_STATE_CODE(); | |
5552 | ||
5553 | for (i = bs; i != base; i = child_bs(child)) { | |
5554 | child = bdrv_filter_or_cow_child(i); | |
5555 | ||
5556 | if (child && child->frozen) { | |
5557 | error_setg(errp, "Cannot change '%s' link from '%s' to '%s'", | |
5558 | child->name, i->node_name, child->bs->node_name); | |
5559 | return true; | |
5560 | } | |
5561 | } | |
5562 | ||
5563 | return false; | |
5564 | } | |
5565 | ||
5566 | /* | |
5567 | * Freeze all COW (backing) and filter links between @bs and @base. | |
5568 | * If any of the links is already frozen the operation is aborted and | |
5569 | * none of the links are modified. | |
5570 | * @base must be reachable from @bs, or NULL. | |
5571 | * Returns 0 on success. On failure returns < 0 and sets @errp. | |
5572 | */ | |
5573 | int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, | |
5574 | Error **errp) | |
5575 | { | |
5576 | BlockDriverState *i; | |
5577 | BdrvChild *child; | |
5578 | ||
5579 | GLOBAL_STATE_CODE(); | |
5580 | ||
5581 | if (bdrv_is_backing_chain_frozen(bs, base, errp)) { | |
5582 | return -EPERM; | |
5583 | } | |
5584 | ||
5585 | for (i = bs; i != base; i = child_bs(child)) { | |
5586 | child = bdrv_filter_or_cow_child(i); | |
5587 | if (child && child->bs->never_freeze) { | |
5588 | error_setg(errp, "Cannot freeze '%s' link to '%s'", | |
5589 | child->name, child->bs->node_name); | |
5590 | return -EPERM; | |
5591 | } | |
5592 | } | |
5593 | ||
5594 | for (i = bs; i != base; i = child_bs(child)) { | |
5595 | child = bdrv_filter_or_cow_child(i); | |
5596 | if (child) { | |
5597 | child->frozen = true; | |
5598 | } | |
5599 | } | |
5600 | ||
5601 | return 0; | |
5602 | } | |
5603 | ||
5604 | /* | |
5605 | * Unfreeze all COW (backing) and filter links between @bs and @base. | |
5606 | * The caller must ensure that all links are frozen before using this | |
5607 | * function. | |
5608 | * @base must be reachable from @bs, or NULL. | |
5609 | */ | |
5610 | void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base) | |
5611 | { | |
5612 | BlockDriverState *i; | |
5613 | BdrvChild *child; | |
5614 | ||
5615 | GLOBAL_STATE_CODE(); | |
5616 | ||
5617 | for (i = bs; i != base; i = child_bs(child)) { | |
5618 | child = bdrv_filter_or_cow_child(i); | |
5619 | if (child) { | |
5620 | assert(child->frozen); | |
5621 | child->frozen = false; | |
5622 | } | |
5623 | } | |
5624 | } | |
5625 | ||
5626 | /* | |
5627 | * Drops images above 'base' up to and including 'top', and sets the image | |
5628 | * above 'top' to have base as its backing file. | |
5629 | * | |
5630 | * Requires that the overlay to 'top' is opened r/w, so that the backing file | |
5631 | * information in 'bs' can be properly updated. | |
5632 | * | |
5633 | * E.g., this will convert the following chain: | |
5634 | * bottom <- base <- intermediate <- top <- active | |
5635 | * | |
5636 | * to | |
5637 | * | |
5638 | * bottom <- base <- active | |
5639 | * | |
5640 | * It is allowed for bottom==base, in which case it converts: | |
5641 | * | |
5642 | * base <- intermediate <- top <- active | |
5643 | * | |
5644 | * to | |
5645 | * | |
5646 | * base <- active | |
5647 | * | |
5648 | * If backing_file_str is non-NULL, it will be used when modifying top's | |
5649 | * overlay image metadata. | |
5650 | * | |
5651 | * Error conditions: | |
5652 | * if active == top, that is considered an error | |
5653 | * | |
5654 | */ | |
5655 | int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, | |
5656 | const char *backing_file_str) | |
5657 | { | |
5658 | BlockDriverState *explicit_top = top; | |
5659 | bool update_inherits_from; | |
5660 | BdrvChild *c; | |
5661 | Error *local_err = NULL; | |
5662 | int ret = -EIO; | |
5663 | g_autoptr(GSList) updated_children = NULL; | |
5664 | GSList *p; | |
5665 | ||
5666 | GLOBAL_STATE_CODE(); | |
5667 | ||
5668 | bdrv_ref(top); | |
5669 | bdrv_drained_begin(base); | |
5670 | ||
5671 | if (!top->drv || !base->drv) { | |
5672 | goto exit; | |
5673 | } | |
5674 | ||
5675 | /* Make sure that base is in the backing chain of top */ | |
5676 | if (!bdrv_chain_contains(top, base)) { | |
5677 | goto exit; | |
5678 | } | |
5679 | ||
5680 | /* If 'base' recursively inherits from 'top' then we should set | |
5681 | * base->inherits_from to top->inherits_from after 'top' and all | |
5682 | * other intermediate nodes have been dropped. | |
5683 | * If 'top' is an implicit node (e.g. "commit_top") we should skip | |
5684 | * it because no one inherits from it. We use explicit_top for that. */ | |
5685 | explicit_top = bdrv_skip_implicit_filters(explicit_top); | |
5686 | update_inherits_from = bdrv_inherits_from_recursive(base, explicit_top); | |
5687 | ||
5688 | /* success - we can delete the intermediate states, and link top->base */ | |
5689 | if (!backing_file_str) { | |
5690 | bdrv_refresh_filename(base); | |
5691 | backing_file_str = base->filename; | |
5692 | } | |
5693 | ||
5694 | QLIST_FOREACH(c, &top->parents, next_parent) { | |
5695 | updated_children = g_slist_prepend(updated_children, c); | |
5696 | } | |
5697 | ||
5698 | /* | |
5699 | * It seems correct to pass detach_subchain=true here, but it triggers | |
5700 | * one more yet not fixed bug, when due to nested aio_poll loop we switch to | |
5701 | * another drained section, which modify the graph (for example, removing | |
5702 | * the child, which we keep in updated_children list). So, it's a TODO. | |
5703 | * | |
5704 | * Note, bug triggered if pass detach_subchain=true here and run | |
5705 | * test-bdrv-drain. test_drop_intermediate_poll() test-case will crash. | |
5706 | * That's a FIXME. | |
5707 | */ | |
5708 | bdrv_replace_node_common(top, base, false, false, &local_err); | |
5709 | if (local_err) { | |
5710 | error_report_err(local_err); | |
5711 | goto exit; | |
5712 | } | |
5713 | ||
5714 | for (p = updated_children; p; p = p->next) { | |
5715 | c = p->data; | |
5716 | ||
5717 | if (c->klass->update_filename) { | |
5718 | ret = c->klass->update_filename(c, base, backing_file_str, | |
5719 | &local_err); | |
5720 | if (ret < 0) { | |
5721 | /* | |
5722 | * TODO: Actually, we want to rollback all previous iterations | |
5723 | * of this loop, and (which is almost impossible) previous | |
5724 | * bdrv_replace_node()... | |
5725 | * | |
5726 | * Note, that c->klass->update_filename may lead to permission | |
5727 | * update, so it's a bad idea to call it inside permission | |
5728 | * update transaction of bdrv_replace_node. | |
5729 | */ | |
5730 | error_report_err(local_err); | |
5731 | goto exit; | |
5732 | } | |
5733 | } | |
5734 | } | |
5735 | ||
5736 | if (update_inherits_from) { | |
5737 | base->inherits_from = explicit_top->inherits_from; | |
5738 | } | |
5739 | ||
5740 | ret = 0; | |
5741 | exit: | |
5742 | bdrv_drained_end(base); | |
5743 | bdrv_unref(top); | |
5744 | return ret; | |
5745 | } | |
5746 | ||
5747 | /** | |
5748 | * Implementation of BlockDriver.bdrv_co_get_allocated_file_size() that | |
5749 | * sums the size of all data-bearing children. (This excludes backing | |
5750 | * children.) | |
5751 | */ | |
5752 | static int64_t bdrv_sum_allocated_file_size(BlockDriverState *bs) | |
5753 | { | |
5754 | BdrvChild *child; | |
5755 | int64_t child_size, sum = 0; | |
5756 | ||
5757 | QLIST_FOREACH(child, &bs->children, next) { | |
5758 | if (child->role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA | | |
5759 | BDRV_CHILD_FILTERED)) | |
5760 | { | |
5761 | child_size = bdrv_co_get_allocated_file_size(child->bs); | |
5762 | if (child_size < 0) { | |
5763 | return child_size; | |
5764 | } | |
5765 | sum += child_size; | |
5766 | } | |
5767 | } | |
5768 | ||
5769 | return sum; | |
5770 | } | |
5771 | ||
5772 | /** | |
5773 | * Length of a allocated file in bytes. Sparse files are counted by actual | |
5774 | * allocated space. Return < 0 if error or unknown. | |
5775 | */ | |
5776 | int64_t coroutine_fn bdrv_co_get_allocated_file_size(BlockDriverState *bs) | |
5777 | { | |
5778 | BlockDriver *drv = bs->drv; | |
5779 | IO_CODE(); | |
5780 | ||
5781 | if (!drv) { | |
5782 | return -ENOMEDIUM; | |
5783 | } | |
5784 | if (drv->bdrv_co_get_allocated_file_size) { | |
5785 | return drv->bdrv_co_get_allocated_file_size(bs); | |
5786 | } | |
5787 | ||
5788 | if (drv->bdrv_file_open) { | |
5789 | /* | |
5790 | * Protocol drivers default to -ENOTSUP (most of their data is | |
5791 | * not stored in any of their children (if they even have any), | |
5792 | * so there is no generic way to figure it out). | |
5793 | */ | |
5794 | return -ENOTSUP; | |
5795 | } else if (drv->is_filter) { | |
5796 | /* Filter drivers default to the size of their filtered child */ | |
5797 | return bdrv_co_get_allocated_file_size(bdrv_filter_bs(bs)); | |
5798 | } else { | |
5799 | /* Other drivers default to summing their children's sizes */ | |
5800 | return bdrv_sum_allocated_file_size(bs); | |
5801 | } | |
5802 | } | |
5803 | ||
5804 | /* | |
5805 | * bdrv_measure: | |
5806 | * @drv: Format driver | |
5807 | * @opts: Creation options for new image | |
5808 | * @in_bs: Existing image containing data for new image (may be NULL) | |
5809 | * @errp: Error object | |
5810 | * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo()) | |
5811 | * or NULL on error | |
5812 | * | |
5813 | * Calculate file size required to create a new image. | |
5814 | * | |
5815 | * If @in_bs is given then space for allocated clusters and zero clusters | |
5816 | * from that image are included in the calculation. If @opts contains a | |
5817 | * backing file that is shared by @in_bs then backing clusters may be omitted | |
5818 | * from the calculation. | |
5819 | * | |
5820 | * If @in_bs is NULL then the calculation includes no allocated clusters | |
5821 | * unless a preallocation option is given in @opts. | |
5822 | * | |
5823 | * Note that @in_bs may use a different BlockDriver from @drv. | |
5824 | * | |
5825 | * If an error occurs the @errp pointer is set. | |
5826 | */ | |
5827 | BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, | |
5828 | BlockDriverState *in_bs, Error **errp) | |
5829 | { | |
5830 | IO_CODE(); | |
5831 | if (!drv->bdrv_measure) { | |
5832 | error_setg(errp, "Block driver '%s' does not support size measurement", | |
5833 | drv->format_name); | |
5834 | return NULL; | |
5835 | } | |
5836 | ||
5837 | return drv->bdrv_measure(opts, in_bs, errp); | |
5838 | } | |
5839 | ||
5840 | /** | |
5841 | * Return number of sectors on success, -errno on error. | |
5842 | */ | |
5843 | int64_t coroutine_fn bdrv_co_nb_sectors(BlockDriverState *bs) | |
5844 | { | |
5845 | BlockDriver *drv = bs->drv; | |
5846 | IO_CODE(); | |
5847 | assert_bdrv_graph_readable(); | |
5848 | ||
5849 | if (!drv) | |
5850 | return -ENOMEDIUM; | |
5851 | ||
5852 | if (drv->has_variable_length) { | |
5853 | int ret = bdrv_co_refresh_total_sectors(bs, bs->total_sectors); | |
5854 | if (ret < 0) { | |
5855 | return ret; | |
5856 | } | |
5857 | } | |
5858 | return bs->total_sectors; | |
5859 | } | |
5860 | ||
5861 | /** | |
5862 | * Return length in bytes on success, -errno on error. | |
5863 | * The length is always a multiple of BDRV_SECTOR_SIZE. | |
5864 | */ | |
5865 | int64_t coroutine_fn bdrv_co_getlength(BlockDriverState *bs) | |
5866 | { | |
5867 | int64_t ret; | |
5868 | IO_CODE(); | |
5869 | assert_bdrv_graph_readable(); | |
5870 | ||
5871 | ret = bdrv_co_nb_sectors(bs); | |
5872 | if (ret < 0) { | |
5873 | return ret; | |
5874 | } | |
5875 | if (ret > INT64_MAX / BDRV_SECTOR_SIZE) { | |
5876 | return -EFBIG; | |
5877 | } | |
5878 | return ret * BDRV_SECTOR_SIZE; | |
5879 | } | |
5880 | ||
5881 | /* return 0 as number of sectors if no device present or error */ | |
5882 | void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) | |
5883 | { | |
5884 | int64_t nb_sectors = bdrv_nb_sectors(bs); | |
5885 | IO_CODE(); | |
5886 | ||
5887 | *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors; | |
5888 | } | |
5889 | ||
5890 | bool bdrv_is_sg(BlockDriverState *bs) | |
5891 | { | |
5892 | IO_CODE(); | |
5893 | return bs->sg; | |
5894 | } | |
5895 | ||
5896 | /** | |
5897 | * Return whether the given node supports compressed writes. | |
5898 | */ | |
5899 | bool bdrv_supports_compressed_writes(BlockDriverState *bs) | |
5900 | { | |
5901 | BlockDriverState *filtered; | |
5902 | IO_CODE(); | |
5903 | ||
5904 | if (!bs->drv || !block_driver_can_compress(bs->drv)) { | |
5905 | return false; | |
5906 | } | |
5907 | ||
5908 | filtered = bdrv_filter_bs(bs); | |
5909 | if (filtered) { | |
5910 | /* | |
5911 | * Filters can only forward compressed writes, so we have to | |
5912 | * check the child. | |
5913 | */ | |
5914 | return bdrv_supports_compressed_writes(filtered); | |
5915 | } | |
5916 | ||
5917 | return true; | |
5918 | } | |
5919 | ||
5920 | const char *bdrv_get_format_name(BlockDriverState *bs) | |
5921 | { | |
5922 | IO_CODE(); | |
5923 | return bs->drv ? bs->drv->format_name : NULL; | |
5924 | } | |
5925 | ||
5926 | static int qsort_strcmp(const void *a, const void *b) | |
5927 | { | |
5928 | return strcmp(*(char *const *)a, *(char *const *)b); | |
5929 | } | |
5930 | ||
5931 | void bdrv_iterate_format(void (*it)(void *opaque, const char *name), | |
5932 | void *opaque, bool read_only) | |
5933 | { | |
5934 | BlockDriver *drv; | |
5935 | int count = 0; | |
5936 | int i; | |
5937 | const char **formats = NULL; | |
5938 | ||
5939 | GLOBAL_STATE_CODE(); | |
5940 | ||
5941 | QLIST_FOREACH(drv, &bdrv_drivers, list) { | |
5942 | if (drv->format_name) { | |
5943 | bool found = false; | |
5944 | int i = count; | |
5945 | ||
5946 | if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, read_only)) { | |
5947 | continue; | |
5948 | } | |
5949 | ||
5950 | while (formats && i && !found) { | |
5951 | found = !strcmp(formats[--i], drv->format_name); | |
5952 | } | |
5953 | ||
5954 | if (!found) { | |
5955 | formats = g_renew(const char *, formats, count + 1); | |
5956 | formats[count++] = drv->format_name; | |
5957 | } | |
5958 | } | |
5959 | } | |
5960 | ||
5961 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) { | |
5962 | const char *format_name = block_driver_modules[i].format_name; | |
5963 | ||
5964 | if (format_name) { | |
5965 | bool found = false; | |
5966 | int j = count; | |
5967 | ||
5968 | if (use_bdrv_whitelist && | |
5969 | !bdrv_format_is_whitelisted(format_name, read_only)) { | |
5970 | continue; | |
5971 | } | |
5972 | ||
5973 | while (formats && j && !found) { | |
5974 | found = !strcmp(formats[--j], format_name); | |
5975 | } | |
5976 | ||
5977 | if (!found) { | |
5978 | formats = g_renew(const char *, formats, count + 1); | |
5979 | formats[count++] = format_name; | |
5980 | } | |
5981 | } | |
5982 | } | |
5983 | ||
5984 | qsort(formats, count, sizeof(formats[0]), qsort_strcmp); | |
5985 | ||
5986 | for (i = 0; i < count; i++) { | |
5987 | it(opaque, formats[i]); | |
5988 | } | |
5989 | ||
5990 | g_free(formats); | |
5991 | } | |
5992 | ||
5993 | /* This function is to find a node in the bs graph */ | |
5994 | BlockDriverState *bdrv_find_node(const char *node_name) | |
5995 | { | |
5996 | BlockDriverState *bs; | |
5997 | ||
5998 | assert(node_name); | |
5999 | GLOBAL_STATE_CODE(); | |
6000 | ||
6001 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
6002 | if (!strcmp(node_name, bs->node_name)) { | |
6003 | return bs; | |
6004 | } | |
6005 | } | |
6006 | return NULL; | |
6007 | } | |
6008 | ||
6009 | /* Put this QMP function here so it can access the static graph_bdrv_states. */ | |
6010 | BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, | |
6011 | Error **errp) | |
6012 | { | |
6013 | BlockDeviceInfoList *list; | |
6014 | BlockDriverState *bs; | |
6015 | ||
6016 | GLOBAL_STATE_CODE(); | |
6017 | ||
6018 | list = NULL; | |
6019 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
6020 | BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, flat, errp); | |
6021 | if (!info) { | |
6022 | qapi_free_BlockDeviceInfoList(list); | |
6023 | return NULL; | |
6024 | } | |
6025 | QAPI_LIST_PREPEND(list, info); | |
6026 | } | |
6027 | ||
6028 | return list; | |
6029 | } | |
6030 | ||
6031 | typedef struct XDbgBlockGraphConstructor { | |
6032 | XDbgBlockGraph *graph; | |
6033 | GHashTable *graph_nodes; | |
6034 | } XDbgBlockGraphConstructor; | |
6035 | ||
6036 | static XDbgBlockGraphConstructor *xdbg_graph_new(void) | |
6037 | { | |
6038 | XDbgBlockGraphConstructor *gr = g_new(XDbgBlockGraphConstructor, 1); | |
6039 | ||
6040 | gr->graph = g_new0(XDbgBlockGraph, 1); | |
6041 | gr->graph_nodes = g_hash_table_new(NULL, NULL); | |
6042 | ||
6043 | return gr; | |
6044 | } | |
6045 | ||
6046 | static XDbgBlockGraph *xdbg_graph_finalize(XDbgBlockGraphConstructor *gr) | |
6047 | { | |
6048 | XDbgBlockGraph *graph = gr->graph; | |
6049 | ||
6050 | g_hash_table_destroy(gr->graph_nodes); | |
6051 | g_free(gr); | |
6052 | ||
6053 | return graph; | |
6054 | } | |
6055 | ||
6056 | static uintptr_t xdbg_graph_node_num(XDbgBlockGraphConstructor *gr, void *node) | |
6057 | { | |
6058 | uintptr_t ret = (uintptr_t)g_hash_table_lookup(gr->graph_nodes, node); | |
6059 | ||
6060 | if (ret != 0) { | |
6061 | return ret; | |
6062 | } | |
6063 | ||
6064 | /* | |
6065 | * Start counting from 1, not 0, because 0 interferes with not-found (NULL) | |
6066 | * answer of g_hash_table_lookup. | |
6067 | */ | |
6068 | ret = g_hash_table_size(gr->graph_nodes) + 1; | |
6069 | g_hash_table_insert(gr->graph_nodes, node, (void *)ret); | |
6070 | ||
6071 | return ret; | |
6072 | } | |
6073 | ||
6074 | static void xdbg_graph_add_node(XDbgBlockGraphConstructor *gr, void *node, | |
6075 | XDbgBlockGraphNodeType type, const char *name) | |
6076 | { | |
6077 | XDbgBlockGraphNode *n; | |
6078 | ||
6079 | n = g_new0(XDbgBlockGraphNode, 1); | |
6080 | ||
6081 | n->id = xdbg_graph_node_num(gr, node); | |
6082 | n->type = type; | |
6083 | n->name = g_strdup(name); | |
6084 | ||
6085 | QAPI_LIST_PREPEND(gr->graph->nodes, n); | |
6086 | } | |
6087 | ||
6088 | static void xdbg_graph_add_edge(XDbgBlockGraphConstructor *gr, void *parent, | |
6089 | const BdrvChild *child) | |
6090 | { | |
6091 | BlockPermission qapi_perm; | |
6092 | XDbgBlockGraphEdge *edge; | |
6093 | GLOBAL_STATE_CODE(); | |
6094 | ||
6095 | edge = g_new0(XDbgBlockGraphEdge, 1); | |
6096 | ||
6097 | edge->parent = xdbg_graph_node_num(gr, parent); | |
6098 | edge->child = xdbg_graph_node_num(gr, child->bs); | |
6099 | edge->name = g_strdup(child->name); | |
6100 | ||
6101 | for (qapi_perm = 0; qapi_perm < BLOCK_PERMISSION__MAX; qapi_perm++) { | |
6102 | uint64_t flag = bdrv_qapi_perm_to_blk_perm(qapi_perm); | |
6103 | ||
6104 | if (flag & child->perm) { | |
6105 | QAPI_LIST_PREPEND(edge->perm, qapi_perm); | |
6106 | } | |
6107 | if (flag & child->shared_perm) { | |
6108 | QAPI_LIST_PREPEND(edge->shared_perm, qapi_perm); | |
6109 | } | |
6110 | } | |
6111 | ||
6112 | QAPI_LIST_PREPEND(gr->graph->edges, edge); | |
6113 | } | |
6114 | ||
6115 | ||
6116 | XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp) | |
6117 | { | |
6118 | BlockBackend *blk; | |
6119 | BlockJob *job; | |
6120 | BlockDriverState *bs; | |
6121 | BdrvChild *child; | |
6122 | XDbgBlockGraphConstructor *gr = xdbg_graph_new(); | |
6123 | ||
6124 | GLOBAL_STATE_CODE(); | |
6125 | ||
6126 | for (blk = blk_all_next(NULL); blk; blk = blk_all_next(blk)) { | |
6127 | char *allocated_name = NULL; | |
6128 | const char *name = blk_name(blk); | |
6129 | ||
6130 | if (!*name) { | |
6131 | name = allocated_name = blk_get_attached_dev_id(blk); | |
6132 | } | |
6133 | xdbg_graph_add_node(gr, blk, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND, | |
6134 | name); | |
6135 | g_free(allocated_name); | |
6136 | if (blk_root(blk)) { | |
6137 | xdbg_graph_add_edge(gr, blk, blk_root(blk)); | |
6138 | } | |
6139 | } | |
6140 | ||
6141 | WITH_JOB_LOCK_GUARD() { | |
6142 | for (job = block_job_next_locked(NULL); job; | |
6143 | job = block_job_next_locked(job)) { | |
6144 | GSList *el; | |
6145 | ||
6146 | xdbg_graph_add_node(gr, job, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB, | |
6147 | job->job.id); | |
6148 | for (el = job->nodes; el; el = el->next) { | |
6149 | xdbg_graph_add_edge(gr, job, (BdrvChild *)el->data); | |
6150 | } | |
6151 | } | |
6152 | } | |
6153 | ||
6154 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
6155 | xdbg_graph_add_node(gr, bs, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER, | |
6156 | bs->node_name); | |
6157 | QLIST_FOREACH(child, &bs->children, next) { | |
6158 | xdbg_graph_add_edge(gr, bs, child); | |
6159 | } | |
6160 | } | |
6161 | ||
6162 | return xdbg_graph_finalize(gr); | |
6163 | } | |
6164 | ||
6165 | BlockDriverState *bdrv_lookup_bs(const char *device, | |
6166 | const char *node_name, | |
6167 | Error **errp) | |
6168 | { | |
6169 | BlockBackend *blk; | |
6170 | BlockDriverState *bs; | |
6171 | ||
6172 | GLOBAL_STATE_CODE(); | |
6173 | ||
6174 | if (device) { | |
6175 | blk = blk_by_name(device); | |
6176 | ||
6177 | if (blk) { | |
6178 | bs = blk_bs(blk); | |
6179 | if (!bs) { | |
6180 | error_setg(errp, "Device '%s' has no medium", device); | |
6181 | } | |
6182 | ||
6183 | return bs; | |
6184 | } | |
6185 | } | |
6186 | ||
6187 | if (node_name) { | |
6188 | bs = bdrv_find_node(node_name); | |
6189 | ||
6190 | if (bs) { | |
6191 | return bs; | |
6192 | } | |
6193 | } | |
6194 | ||
6195 | error_setg(errp, "Cannot find device=\'%s\' nor node-name=\'%s\'", | |
6196 | device ? device : "", | |
6197 | node_name ? node_name : ""); | |
6198 | return NULL; | |
6199 | } | |
6200 | ||
6201 | /* If 'base' is in the same chain as 'top', return true. Otherwise, | |
6202 | * return false. If either argument is NULL, return false. */ | |
6203 | bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) | |
6204 | { | |
6205 | ||
6206 | GLOBAL_STATE_CODE(); | |
6207 | ||
6208 | while (top && top != base) { | |
6209 | top = bdrv_filter_or_cow_bs(top); | |
6210 | } | |
6211 | ||
6212 | return top != NULL; | |
6213 | } | |
6214 | ||
6215 | BlockDriverState *bdrv_next_node(BlockDriverState *bs) | |
6216 | { | |
6217 | GLOBAL_STATE_CODE(); | |
6218 | if (!bs) { | |
6219 | return QTAILQ_FIRST(&graph_bdrv_states); | |
6220 | } | |
6221 | return QTAILQ_NEXT(bs, node_list); | |
6222 | } | |
6223 | ||
6224 | BlockDriverState *bdrv_next_all_states(BlockDriverState *bs) | |
6225 | { | |
6226 | GLOBAL_STATE_CODE(); | |
6227 | if (!bs) { | |
6228 | return QTAILQ_FIRST(&all_bdrv_states); | |
6229 | } | |
6230 | return QTAILQ_NEXT(bs, bs_list); | |
6231 | } | |
6232 | ||
6233 | const char *bdrv_get_node_name(const BlockDriverState *bs) | |
6234 | { | |
6235 | IO_CODE(); | |
6236 | return bs->node_name; | |
6237 | } | |
6238 | ||
6239 | const char *bdrv_get_parent_name(const BlockDriverState *bs) | |
6240 | { | |
6241 | BdrvChild *c; | |
6242 | const char *name; | |
6243 | IO_CODE(); | |
6244 | ||
6245 | /* If multiple parents have a name, just pick the first one. */ | |
6246 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
6247 | if (c->klass->get_name) { | |
6248 | name = c->klass->get_name(c); | |
6249 | if (name && *name) { | |
6250 | return name; | |
6251 | } | |
6252 | } | |
6253 | } | |
6254 | ||
6255 | return NULL; | |
6256 | } | |
6257 | ||
6258 | /* TODO check what callers really want: bs->node_name or blk_name() */ | |
6259 | const char *bdrv_get_device_name(const BlockDriverState *bs) | |
6260 | { | |
6261 | IO_CODE(); | |
6262 | return bdrv_get_parent_name(bs) ?: ""; | |
6263 | } | |
6264 | ||
6265 | /* This can be used to identify nodes that might not have a device | |
6266 | * name associated. Since node and device names live in the same | |
6267 | * namespace, the result is unambiguous. The exception is if both are | |
6268 | * absent, then this returns an empty (non-null) string. */ | |
6269 | const char *bdrv_get_device_or_node_name(const BlockDriverState *bs) | |
6270 | { | |
6271 | IO_CODE(); | |
6272 | return bdrv_get_parent_name(bs) ?: bs->node_name; | |
6273 | } | |
6274 | ||
6275 | int bdrv_get_flags(BlockDriverState *bs) | |
6276 | { | |
6277 | IO_CODE(); | |
6278 | return bs->open_flags; | |
6279 | } | |
6280 | ||
6281 | int bdrv_has_zero_init_1(BlockDriverState *bs) | |
6282 | { | |
6283 | GLOBAL_STATE_CODE(); | |
6284 | return 1; | |
6285 | } | |
6286 | ||
6287 | int bdrv_has_zero_init(BlockDriverState *bs) | |
6288 | { | |
6289 | BlockDriverState *filtered; | |
6290 | GLOBAL_STATE_CODE(); | |
6291 | ||
6292 | if (!bs->drv) { | |
6293 | return 0; | |
6294 | } | |
6295 | ||
6296 | /* If BS is a copy on write image, it is initialized to | |
6297 | the contents of the base image, which may not be zeroes. */ | |
6298 | if (bdrv_cow_child(bs)) { | |
6299 | return 0; | |
6300 | } | |
6301 | if (bs->drv->bdrv_has_zero_init) { | |
6302 | return bs->drv->bdrv_has_zero_init(bs); | |
6303 | } | |
6304 | ||
6305 | filtered = bdrv_filter_bs(bs); | |
6306 | if (filtered) { | |
6307 | return bdrv_has_zero_init(filtered); | |
6308 | } | |
6309 | ||
6310 | /* safe default */ | |
6311 | return 0; | |
6312 | } | |
6313 | ||
6314 | bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) | |
6315 | { | |
6316 | IO_CODE(); | |
6317 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
6318 | return false; | |
6319 | } | |
6320 | ||
6321 | return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP; | |
6322 | } | |
6323 | ||
6324 | void bdrv_get_backing_filename(BlockDriverState *bs, | |
6325 | char *filename, int filename_size) | |
6326 | { | |
6327 | IO_CODE(); | |
6328 | pstrcpy(filename, filename_size, bs->backing_file); | |
6329 | } | |
6330 | ||
6331 | int coroutine_fn bdrv_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) | |
6332 | { | |
6333 | int ret; | |
6334 | BlockDriver *drv = bs->drv; | |
6335 | IO_CODE(); | |
6336 | /* if bs->drv == NULL, bs is closed, so there's nothing to do here */ | |
6337 | if (!drv) { | |
6338 | return -ENOMEDIUM; | |
6339 | } | |
6340 | if (!drv->bdrv_co_get_info) { | |
6341 | BlockDriverState *filtered = bdrv_filter_bs(bs); | |
6342 | if (filtered) { | |
6343 | return bdrv_co_get_info(filtered, bdi); | |
6344 | } | |
6345 | return -ENOTSUP; | |
6346 | } | |
6347 | memset(bdi, 0, sizeof(*bdi)); | |
6348 | ret = drv->bdrv_co_get_info(bs, bdi); | |
6349 | if (ret < 0) { | |
6350 | return ret; | |
6351 | } | |
6352 | ||
6353 | if (bdi->cluster_size > BDRV_MAX_ALIGNMENT) { | |
6354 | return -EINVAL; | |
6355 | } | |
6356 | ||
6357 | return 0; | |
6358 | } | |
6359 | ||
6360 | ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs, | |
6361 | Error **errp) | |
6362 | { | |
6363 | BlockDriver *drv = bs->drv; | |
6364 | IO_CODE(); | |
6365 | if (drv && drv->bdrv_get_specific_info) { | |
6366 | return drv->bdrv_get_specific_info(bs, errp); | |
6367 | } | |
6368 | return NULL; | |
6369 | } | |
6370 | ||
6371 | BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs) | |
6372 | { | |
6373 | BlockDriver *drv = bs->drv; | |
6374 | IO_CODE(); | |
6375 | if (!drv || !drv->bdrv_get_specific_stats) { | |
6376 | return NULL; | |
6377 | } | |
6378 | return drv->bdrv_get_specific_stats(bs); | |
6379 | } | |
6380 | ||
6381 | void coroutine_fn bdrv_co_debug_event(BlockDriverState *bs, BlkdebugEvent event) | |
6382 | { | |
6383 | IO_CODE(); | |
6384 | if (!bs || !bs->drv || !bs->drv->bdrv_co_debug_event) { | |
6385 | return; | |
6386 | } | |
6387 | ||
6388 | bs->drv->bdrv_co_debug_event(bs, event); | |
6389 | } | |
6390 | ||
6391 | static BlockDriverState *bdrv_find_debug_node(BlockDriverState *bs) | |
6392 | { | |
6393 | GLOBAL_STATE_CODE(); | |
6394 | while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { | |
6395 | bs = bdrv_primary_bs(bs); | |
6396 | } | |
6397 | ||
6398 | if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) { | |
6399 | assert(bs->drv->bdrv_debug_remove_breakpoint); | |
6400 | return bs; | |
6401 | } | |
6402 | ||
6403 | return NULL; | |
6404 | } | |
6405 | ||
6406 | int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, | |
6407 | const char *tag) | |
6408 | { | |
6409 | GLOBAL_STATE_CODE(); | |
6410 | bs = bdrv_find_debug_node(bs); | |
6411 | if (bs) { | |
6412 | return bs->drv->bdrv_debug_breakpoint(bs, event, tag); | |
6413 | } | |
6414 | ||
6415 | return -ENOTSUP; | |
6416 | } | |
6417 | ||
6418 | int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) | |
6419 | { | |
6420 | GLOBAL_STATE_CODE(); | |
6421 | bs = bdrv_find_debug_node(bs); | |
6422 | if (bs) { | |
6423 | return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); | |
6424 | } | |
6425 | ||
6426 | return -ENOTSUP; | |
6427 | } | |
6428 | ||
6429 | int bdrv_debug_resume(BlockDriverState *bs, const char *tag) | |
6430 | { | |
6431 | GLOBAL_STATE_CODE(); | |
6432 | while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { | |
6433 | bs = bdrv_primary_bs(bs); | |
6434 | } | |
6435 | ||
6436 | if (bs && bs->drv && bs->drv->bdrv_debug_resume) { | |
6437 | return bs->drv->bdrv_debug_resume(bs, tag); | |
6438 | } | |
6439 | ||
6440 | return -ENOTSUP; | |
6441 | } | |
6442 | ||
6443 | bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) | |
6444 | { | |
6445 | GLOBAL_STATE_CODE(); | |
6446 | while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { | |
6447 | bs = bdrv_primary_bs(bs); | |
6448 | } | |
6449 | ||
6450 | if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { | |
6451 | return bs->drv->bdrv_debug_is_suspended(bs, tag); | |
6452 | } | |
6453 | ||
6454 | return false; | |
6455 | } | |
6456 | ||
6457 | /* backing_file can either be relative, or absolute, or a protocol. If it is | |
6458 | * relative, it must be relative to the chain. So, passing in bs->filename | |
6459 | * from a BDS as backing_file should not be done, as that may be relative to | |
6460 | * the CWD rather than the chain. */ | |
6461 | BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, | |
6462 | const char *backing_file) | |
6463 | { | |
6464 | char *filename_full = NULL; | |
6465 | char *backing_file_full = NULL; | |
6466 | char *filename_tmp = NULL; | |
6467 | int is_protocol = 0; | |
6468 | bool filenames_refreshed = false; | |
6469 | BlockDriverState *curr_bs = NULL; | |
6470 | BlockDriverState *retval = NULL; | |
6471 | BlockDriverState *bs_below; | |
6472 | ||
6473 | GLOBAL_STATE_CODE(); | |
6474 | ||
6475 | if (!bs || !bs->drv || !backing_file) { | |
6476 | return NULL; | |
6477 | } | |
6478 | ||
6479 | filename_full = g_malloc(PATH_MAX); | |
6480 | backing_file_full = g_malloc(PATH_MAX); | |
6481 | ||
6482 | is_protocol = path_has_protocol(backing_file); | |
6483 | ||
6484 | /* | |
6485 | * Being largely a legacy function, skip any filters here | |
6486 | * (because filters do not have normal filenames, so they cannot | |
6487 | * match anyway; and allowing json:{} filenames is a bit out of | |
6488 | * scope). | |
6489 | */ | |
6490 | for (curr_bs = bdrv_skip_filters(bs); | |
6491 | bdrv_cow_child(curr_bs) != NULL; | |
6492 | curr_bs = bs_below) | |
6493 | { | |
6494 | bs_below = bdrv_backing_chain_next(curr_bs); | |
6495 | ||
6496 | if (bdrv_backing_overridden(curr_bs)) { | |
6497 | /* | |
6498 | * If the backing file was overridden, we can only compare | |
6499 | * directly against the backing node's filename. | |
6500 | */ | |
6501 | ||
6502 | if (!filenames_refreshed) { | |
6503 | /* | |
6504 | * This will automatically refresh all of the | |
6505 | * filenames in the rest of the backing chain, so we | |
6506 | * only need to do this once. | |
6507 | */ | |
6508 | bdrv_refresh_filename(bs_below); | |
6509 | filenames_refreshed = true; | |
6510 | } | |
6511 | ||
6512 | if (strcmp(backing_file, bs_below->filename) == 0) { | |
6513 | retval = bs_below; | |
6514 | break; | |
6515 | } | |
6516 | } else if (is_protocol || path_has_protocol(curr_bs->backing_file)) { | |
6517 | /* | |
6518 | * If either of the filename paths is actually a protocol, then | |
6519 | * compare unmodified paths; otherwise make paths relative. | |
6520 | */ | |
6521 | char *backing_file_full_ret; | |
6522 | ||
6523 | if (strcmp(backing_file, curr_bs->backing_file) == 0) { | |
6524 | retval = bs_below; | |
6525 | break; | |
6526 | } | |
6527 | /* Also check against the full backing filename for the image */ | |
6528 | backing_file_full_ret = bdrv_get_full_backing_filename(curr_bs, | |
6529 | NULL); | |
6530 | if (backing_file_full_ret) { | |
6531 | bool equal = strcmp(backing_file, backing_file_full_ret) == 0; | |
6532 | g_free(backing_file_full_ret); | |
6533 | if (equal) { | |
6534 | retval = bs_below; | |
6535 | break; | |
6536 | } | |
6537 | } | |
6538 | } else { | |
6539 | /* If not an absolute filename path, make it relative to the current | |
6540 | * image's filename path */ | |
6541 | filename_tmp = bdrv_make_absolute_filename(curr_bs, backing_file, | |
6542 | NULL); | |
6543 | /* We are going to compare canonicalized absolute pathnames */ | |
6544 | if (!filename_tmp || !realpath(filename_tmp, filename_full)) { | |
6545 | g_free(filename_tmp); | |
6546 | continue; | |
6547 | } | |
6548 | g_free(filename_tmp); | |
6549 | ||
6550 | /* We need to make sure the backing filename we are comparing against | |
6551 | * is relative to the current image filename (or absolute) */ | |
6552 | filename_tmp = bdrv_get_full_backing_filename(curr_bs, NULL); | |
6553 | if (!filename_tmp || !realpath(filename_tmp, backing_file_full)) { | |
6554 | g_free(filename_tmp); | |
6555 | continue; | |
6556 | } | |
6557 | g_free(filename_tmp); | |
6558 | ||
6559 | if (strcmp(backing_file_full, filename_full) == 0) { | |
6560 | retval = bs_below; | |
6561 | break; | |
6562 | } | |
6563 | } | |
6564 | } | |
6565 | ||
6566 | g_free(filename_full); | |
6567 | g_free(backing_file_full); | |
6568 | return retval; | |
6569 | } | |
6570 | ||
6571 | void bdrv_init(void) | |
6572 | { | |
6573 | #ifdef CONFIG_BDRV_WHITELIST_TOOLS | |
6574 | use_bdrv_whitelist = 1; | |
6575 | #endif | |
6576 | module_call_init(MODULE_INIT_BLOCK); | |
6577 | } | |
6578 | ||
6579 | void bdrv_init_with_whitelist(void) | |
6580 | { | |
6581 | use_bdrv_whitelist = 1; | |
6582 | bdrv_init(); | |
6583 | } | |
6584 | ||
6585 | int bdrv_activate(BlockDriverState *bs, Error **errp) | |
6586 | { | |
6587 | BdrvChild *child, *parent; | |
6588 | Error *local_err = NULL; | |
6589 | int ret; | |
6590 | BdrvDirtyBitmap *bm; | |
6591 | ||
6592 | GLOBAL_STATE_CODE(); | |
6593 | ||
6594 | if (!bs->drv) { | |
6595 | return -ENOMEDIUM; | |
6596 | } | |
6597 | ||
6598 | QLIST_FOREACH(child, &bs->children, next) { | |
6599 | bdrv_activate(child->bs, &local_err); | |
6600 | if (local_err) { | |
6601 | error_propagate(errp, local_err); | |
6602 | return -EINVAL; | |
6603 | } | |
6604 | } | |
6605 | ||
6606 | /* | |
6607 | * Update permissions, they may differ for inactive nodes. | |
6608 | * | |
6609 | * Note that the required permissions of inactive images are always a | |
6610 | * subset of the permissions required after activating the image. This | |
6611 | * allows us to just get the permissions upfront without restricting | |
6612 | * bdrv_co_invalidate_cache(). | |
6613 | * | |
6614 | * It also means that in error cases, we don't have to try and revert to | |
6615 | * the old permissions (which is an operation that could fail, too). We can | |
6616 | * just keep the extended permissions for the next time that an activation | |
6617 | * of the image is tried. | |
6618 | */ | |
6619 | if (bs->open_flags & BDRV_O_INACTIVE) { | |
6620 | bs->open_flags &= ~BDRV_O_INACTIVE; | |
6621 | ret = bdrv_refresh_perms(bs, NULL, errp); | |
6622 | if (ret < 0) { | |
6623 | bs->open_flags |= BDRV_O_INACTIVE; | |
6624 | return ret; | |
6625 | } | |
6626 | ||
6627 | ret = bdrv_invalidate_cache(bs, errp); | |
6628 | if (ret < 0) { | |
6629 | bs->open_flags |= BDRV_O_INACTIVE; | |
6630 | return ret; | |
6631 | } | |
6632 | ||
6633 | FOR_EACH_DIRTY_BITMAP(bs, bm) { | |
6634 | bdrv_dirty_bitmap_skip_store(bm, false); | |
6635 | } | |
6636 | ||
6637 | ret = bdrv_refresh_total_sectors(bs, bs->total_sectors); | |
6638 | if (ret < 0) { | |
6639 | bs->open_flags |= BDRV_O_INACTIVE; | |
6640 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
6641 | return ret; | |
6642 | } | |
6643 | } | |
6644 | ||
6645 | QLIST_FOREACH(parent, &bs->parents, next_parent) { | |
6646 | if (parent->klass->activate) { | |
6647 | parent->klass->activate(parent, &local_err); | |
6648 | if (local_err) { | |
6649 | bs->open_flags |= BDRV_O_INACTIVE; | |
6650 | error_propagate(errp, local_err); | |
6651 | return -EINVAL; | |
6652 | } | |
6653 | } | |
6654 | } | |
6655 | ||
6656 | return 0; | |
6657 | } | |
6658 | ||
6659 | int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp) | |
6660 | { | |
6661 | Error *local_err = NULL; | |
6662 | IO_CODE(); | |
6663 | ||
6664 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); | |
6665 | assert_bdrv_graph_readable(); | |
6666 | ||
6667 | if (bs->drv->bdrv_co_invalidate_cache) { | |
6668 | bs->drv->bdrv_co_invalidate_cache(bs, &local_err); | |
6669 | if (local_err) { | |
6670 | error_propagate(errp, local_err); | |
6671 | return -EINVAL; | |
6672 | } | |
6673 | } | |
6674 | ||
6675 | return 0; | |
6676 | } | |
6677 | ||
6678 | void bdrv_activate_all(Error **errp) | |
6679 | { | |
6680 | BlockDriverState *bs; | |
6681 | BdrvNextIterator it; | |
6682 | ||
6683 | GLOBAL_STATE_CODE(); | |
6684 | ||
6685 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
6686 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
6687 | int ret; | |
6688 | ||
6689 | aio_context_acquire(aio_context); | |
6690 | ret = bdrv_activate(bs, errp); | |
6691 | aio_context_release(aio_context); | |
6692 | if (ret < 0) { | |
6693 | bdrv_next_cleanup(&it); | |
6694 | return; | |
6695 | } | |
6696 | } | |
6697 | } | |
6698 | ||
6699 | static bool bdrv_has_bds_parent(BlockDriverState *bs, bool only_active) | |
6700 | { | |
6701 | BdrvChild *parent; | |
6702 | GLOBAL_STATE_CODE(); | |
6703 | ||
6704 | QLIST_FOREACH(parent, &bs->parents, next_parent) { | |
6705 | if (parent->klass->parent_is_bds) { | |
6706 | BlockDriverState *parent_bs = parent->opaque; | |
6707 | if (!only_active || !(parent_bs->open_flags & BDRV_O_INACTIVE)) { | |
6708 | return true; | |
6709 | } | |
6710 | } | |
6711 | } | |
6712 | ||
6713 | return false; | |
6714 | } | |
6715 | ||
6716 | static int bdrv_inactivate_recurse(BlockDriverState *bs) | |
6717 | { | |
6718 | BdrvChild *child, *parent; | |
6719 | int ret; | |
6720 | uint64_t cumulative_perms, cumulative_shared_perms; | |
6721 | ||
6722 | GLOBAL_STATE_CODE(); | |
6723 | ||
6724 | if (!bs->drv) { | |
6725 | return -ENOMEDIUM; | |
6726 | } | |
6727 | ||
6728 | /* Make sure that we don't inactivate a child before its parent. | |
6729 | * It will be covered by recursion from the yet active parent. */ | |
6730 | if (bdrv_has_bds_parent(bs, true)) { | |
6731 | return 0; | |
6732 | } | |
6733 | ||
6734 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); | |
6735 | ||
6736 | /* Inactivate this node */ | |
6737 | if (bs->drv->bdrv_inactivate) { | |
6738 | ret = bs->drv->bdrv_inactivate(bs); | |
6739 | if (ret < 0) { | |
6740 | return ret; | |
6741 | } | |
6742 | } | |
6743 | ||
6744 | QLIST_FOREACH(parent, &bs->parents, next_parent) { | |
6745 | if (parent->klass->inactivate) { | |
6746 | ret = parent->klass->inactivate(parent); | |
6747 | if (ret < 0) { | |
6748 | return ret; | |
6749 | } | |
6750 | } | |
6751 | } | |
6752 | ||
6753 | bdrv_get_cumulative_perm(bs, &cumulative_perms, | |
6754 | &cumulative_shared_perms); | |
6755 | if (cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) { | |
6756 | /* Our inactive parents still need write access. Inactivation failed. */ | |
6757 | return -EPERM; | |
6758 | } | |
6759 | ||
6760 | bs->open_flags |= BDRV_O_INACTIVE; | |
6761 | ||
6762 | /* | |
6763 | * Update permissions, they may differ for inactive nodes. | |
6764 | * We only tried to loosen restrictions, so errors are not fatal, ignore | |
6765 | * them. | |
6766 | */ | |
6767 | bdrv_refresh_perms(bs, NULL, NULL); | |
6768 | ||
6769 | /* Recursively inactivate children */ | |
6770 | QLIST_FOREACH(child, &bs->children, next) { | |
6771 | ret = bdrv_inactivate_recurse(child->bs); | |
6772 | if (ret < 0) { | |
6773 | return ret; | |
6774 | } | |
6775 | } | |
6776 | ||
6777 | return 0; | |
6778 | } | |
6779 | ||
6780 | int bdrv_inactivate_all(void) | |
6781 | { | |
6782 | BlockDriverState *bs = NULL; | |
6783 | BdrvNextIterator it; | |
6784 | int ret = 0; | |
6785 | GSList *aio_ctxs = NULL, *ctx; | |
6786 | ||
6787 | GLOBAL_STATE_CODE(); | |
6788 | ||
6789 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
6790 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
6791 | ||
6792 | if (!g_slist_find(aio_ctxs, aio_context)) { | |
6793 | aio_ctxs = g_slist_prepend(aio_ctxs, aio_context); | |
6794 | aio_context_acquire(aio_context); | |
6795 | } | |
6796 | } | |
6797 | ||
6798 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
6799 | /* Nodes with BDS parents are covered by recursion from the last | |
6800 | * parent that gets inactivated. Don't inactivate them a second | |
6801 | * time if that has already happened. */ | |
6802 | if (bdrv_has_bds_parent(bs, false)) { | |
6803 | continue; | |
6804 | } | |
6805 | ret = bdrv_inactivate_recurse(bs); | |
6806 | if (ret < 0) { | |
6807 | bdrv_next_cleanup(&it); | |
6808 | goto out; | |
6809 | } | |
6810 | } | |
6811 | ||
6812 | out: | |
6813 | for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) { | |
6814 | AioContext *aio_context = ctx->data; | |
6815 | aio_context_release(aio_context); | |
6816 | } | |
6817 | g_slist_free(aio_ctxs); | |
6818 | ||
6819 | return ret; | |
6820 | } | |
6821 | ||
6822 | /**************************************************************/ | |
6823 | /* removable device support */ | |
6824 | ||
6825 | /** | |
6826 | * Return TRUE if the media is present | |
6827 | */ | |
6828 | bool coroutine_fn bdrv_co_is_inserted(BlockDriverState *bs) | |
6829 | { | |
6830 | BlockDriver *drv = bs->drv; | |
6831 | BdrvChild *child; | |
6832 | IO_CODE(); | |
6833 | assert_bdrv_graph_readable(); | |
6834 | ||
6835 | if (!drv) { | |
6836 | return false; | |
6837 | } | |
6838 | if (drv->bdrv_co_is_inserted) { | |
6839 | return drv->bdrv_co_is_inserted(bs); | |
6840 | } | |
6841 | QLIST_FOREACH(child, &bs->children, next) { | |
6842 | if (!bdrv_co_is_inserted(child->bs)) { | |
6843 | return false; | |
6844 | } | |
6845 | } | |
6846 | return true; | |
6847 | } | |
6848 | ||
6849 | /** | |
6850 | * If eject_flag is TRUE, eject the media. Otherwise, close the tray | |
6851 | */ | |
6852 | void coroutine_fn bdrv_co_eject(BlockDriverState *bs, bool eject_flag) | |
6853 | { | |
6854 | BlockDriver *drv = bs->drv; | |
6855 | IO_CODE(); | |
6856 | assert_bdrv_graph_readable(); | |
6857 | ||
6858 | if (drv && drv->bdrv_co_eject) { | |
6859 | drv->bdrv_co_eject(bs, eject_flag); | |
6860 | } | |
6861 | } | |
6862 | ||
6863 | /** | |
6864 | * Lock or unlock the media (if it is locked, the user won't be able | |
6865 | * to eject it manually). | |
6866 | */ | |
6867 | void coroutine_fn bdrv_co_lock_medium(BlockDriverState *bs, bool locked) | |
6868 | { | |
6869 | BlockDriver *drv = bs->drv; | |
6870 | IO_CODE(); | |
6871 | assert_bdrv_graph_readable(); | |
6872 | trace_bdrv_lock_medium(bs, locked); | |
6873 | ||
6874 | if (drv && drv->bdrv_co_lock_medium) { | |
6875 | drv->bdrv_co_lock_medium(bs, locked); | |
6876 | } | |
6877 | } | |
6878 | ||
6879 | /* Get a reference to bs */ | |
6880 | void bdrv_ref(BlockDriverState *bs) | |
6881 | { | |
6882 | GLOBAL_STATE_CODE(); | |
6883 | bs->refcnt++; | |
6884 | } | |
6885 | ||
6886 | /* Release a previously grabbed reference to bs. | |
6887 | * If after releasing, reference count is zero, the BlockDriverState is | |
6888 | * deleted. */ | |
6889 | void bdrv_unref(BlockDriverState *bs) | |
6890 | { | |
6891 | GLOBAL_STATE_CODE(); | |
6892 | if (!bs) { | |
6893 | return; | |
6894 | } | |
6895 | assert(bs->refcnt > 0); | |
6896 | if (--bs->refcnt == 0) { | |
6897 | bdrv_delete(bs); | |
6898 | } | |
6899 | } | |
6900 | ||
6901 | struct BdrvOpBlocker { | |
6902 | Error *reason; | |
6903 | QLIST_ENTRY(BdrvOpBlocker) list; | |
6904 | }; | |
6905 | ||
6906 | bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) | |
6907 | { | |
6908 | BdrvOpBlocker *blocker; | |
6909 | GLOBAL_STATE_CODE(); | |
6910 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
6911 | if (!QLIST_EMPTY(&bs->op_blockers[op])) { | |
6912 | blocker = QLIST_FIRST(&bs->op_blockers[op]); | |
6913 | error_propagate_prepend(errp, error_copy(blocker->reason), | |
6914 | "Node '%s' is busy: ", | |
6915 | bdrv_get_device_or_node_name(bs)); | |
6916 | return true; | |
6917 | } | |
6918 | return false; | |
6919 | } | |
6920 | ||
6921 | void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason) | |
6922 | { | |
6923 | BdrvOpBlocker *blocker; | |
6924 | GLOBAL_STATE_CODE(); | |
6925 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
6926 | ||
6927 | blocker = g_new0(BdrvOpBlocker, 1); | |
6928 | blocker->reason = reason; | |
6929 | QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list); | |
6930 | } | |
6931 | ||
6932 | void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason) | |
6933 | { | |
6934 | BdrvOpBlocker *blocker, *next; | |
6935 | GLOBAL_STATE_CODE(); | |
6936 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
6937 | QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) { | |
6938 | if (blocker->reason == reason) { | |
6939 | QLIST_REMOVE(blocker, list); | |
6940 | g_free(blocker); | |
6941 | } | |
6942 | } | |
6943 | } | |
6944 | ||
6945 | void bdrv_op_block_all(BlockDriverState *bs, Error *reason) | |
6946 | { | |
6947 | int i; | |
6948 | GLOBAL_STATE_CODE(); | |
6949 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
6950 | bdrv_op_block(bs, i, reason); | |
6951 | } | |
6952 | } | |
6953 | ||
6954 | void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason) | |
6955 | { | |
6956 | int i; | |
6957 | GLOBAL_STATE_CODE(); | |
6958 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
6959 | bdrv_op_unblock(bs, i, reason); | |
6960 | } | |
6961 | } | |
6962 | ||
6963 | bool bdrv_op_blocker_is_empty(BlockDriverState *bs) | |
6964 | { | |
6965 | int i; | |
6966 | GLOBAL_STATE_CODE(); | |
6967 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
6968 | if (!QLIST_EMPTY(&bs->op_blockers[i])) { | |
6969 | return false; | |
6970 | } | |
6971 | } | |
6972 | return true; | |
6973 | } | |
6974 | ||
6975 | /* | |
6976 | * Must not be called while holding the lock of an AioContext other than the | |
6977 | * current one. | |
6978 | */ | |
6979 | void bdrv_img_create(const char *filename, const char *fmt, | |
6980 | const char *base_filename, const char *base_fmt, | |
6981 | char *options, uint64_t img_size, int flags, bool quiet, | |
6982 | Error **errp) | |
6983 | { | |
6984 | QemuOptsList *create_opts = NULL; | |
6985 | QemuOpts *opts = NULL; | |
6986 | const char *backing_fmt, *backing_file; | |
6987 | int64_t size; | |
6988 | BlockDriver *drv, *proto_drv; | |
6989 | Error *local_err = NULL; | |
6990 | int ret = 0; | |
6991 | ||
6992 | GLOBAL_STATE_CODE(); | |
6993 | ||
6994 | /* Find driver and parse its options */ | |
6995 | drv = bdrv_find_format(fmt); | |
6996 | if (!drv) { | |
6997 | error_setg(errp, "Unknown file format '%s'", fmt); | |
6998 | return; | |
6999 | } | |
7000 | ||
7001 | proto_drv = bdrv_find_protocol(filename, true, errp); | |
7002 | if (!proto_drv) { | |
7003 | return; | |
7004 | } | |
7005 | ||
7006 | if (!drv->create_opts) { | |
7007 | error_setg(errp, "Format driver '%s' does not support image creation", | |
7008 | drv->format_name); | |
7009 | return; | |
7010 | } | |
7011 | ||
7012 | if (!proto_drv->create_opts) { | |
7013 | error_setg(errp, "Protocol driver '%s' does not support image creation", | |
7014 | proto_drv->format_name); | |
7015 | return; | |
7016 | } | |
7017 | ||
7018 | /* Create parameter list */ | |
7019 | create_opts = qemu_opts_append(create_opts, drv->create_opts); | |
7020 | create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); | |
7021 | ||
7022 | opts = qemu_opts_create(create_opts, NULL, 0, &error_abort); | |
7023 | ||
7024 | /* Parse -o options */ | |
7025 | if (options) { | |
7026 | if (!qemu_opts_do_parse(opts, options, NULL, errp)) { | |
7027 | goto out; | |
7028 | } | |
7029 | } | |
7030 | ||
7031 | if (!qemu_opt_get(opts, BLOCK_OPT_SIZE)) { | |
7032 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort); | |
7033 | } else if (img_size != UINT64_C(-1)) { | |
7034 | error_setg(errp, "The image size must be specified only once"); | |
7035 | goto out; | |
7036 | } | |
7037 | ||
7038 | if (base_filename) { | |
7039 | if (!qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, | |
7040 | NULL)) { | |
7041 | error_setg(errp, "Backing file not supported for file format '%s'", | |
7042 | fmt); | |
7043 | goto out; | |
7044 | } | |
7045 | } | |
7046 | ||
7047 | if (base_fmt) { | |
7048 | if (!qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, NULL)) { | |
7049 | error_setg(errp, "Backing file format not supported for file " | |
7050 | "format '%s'", fmt); | |
7051 | goto out; | |
7052 | } | |
7053 | } | |
7054 | ||
7055 | backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); | |
7056 | if (backing_file) { | |
7057 | if (!strcmp(filename, backing_file)) { | |
7058 | error_setg(errp, "Error: Trying to create an image with the " | |
7059 | "same filename as the backing file"); | |
7060 | goto out; | |
7061 | } | |
7062 | if (backing_file[0] == '\0') { | |
7063 | error_setg(errp, "Expected backing file name, got empty string"); | |
7064 | goto out; | |
7065 | } | |
7066 | } | |
7067 | ||
7068 | backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); | |
7069 | ||
7070 | /* The size for the image must always be specified, unless we have a backing | |
7071 | * file and we have not been forbidden from opening it. */ | |
7072 | size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size); | |
7073 | if (backing_file && !(flags & BDRV_O_NO_BACKING)) { | |
7074 | BlockDriverState *bs; | |
7075 | char *full_backing; | |
7076 | int back_flags; | |
7077 | QDict *backing_options = NULL; | |
7078 | ||
7079 | full_backing = | |
7080 | bdrv_get_full_backing_filename_from_filename(filename, backing_file, | |
7081 | &local_err); | |
7082 | if (local_err) { | |
7083 | goto out; | |
7084 | } | |
7085 | assert(full_backing); | |
7086 | ||
7087 | /* | |
7088 | * No need to do I/O here, which allows us to open encrypted | |
7089 | * backing images without needing the secret | |
7090 | */ | |
7091 | back_flags = flags; | |
7092 | back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); | |
7093 | back_flags |= BDRV_O_NO_IO; | |
7094 | ||
7095 | backing_options = qdict_new(); | |
7096 | if (backing_fmt) { | |
7097 | qdict_put_str(backing_options, "driver", backing_fmt); | |
7098 | } | |
7099 | qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true); | |
7100 | ||
7101 | bs = bdrv_open(full_backing, NULL, backing_options, back_flags, | |
7102 | &local_err); | |
7103 | g_free(full_backing); | |
7104 | if (!bs) { | |
7105 | error_append_hint(&local_err, "Could not open backing image.\n"); | |
7106 | goto out; | |
7107 | } else { | |
7108 | if (!backing_fmt) { | |
7109 | error_setg(&local_err, | |
7110 | "Backing file specified without backing format"); | |
7111 | error_append_hint(&local_err, "Detected format of %s.", | |
7112 | bs->drv->format_name); | |
7113 | goto out; | |
7114 | } | |
7115 | if (size == -1) { | |
7116 | /* Opened BS, have no size */ | |
7117 | size = bdrv_getlength(bs); | |
7118 | if (size < 0) { | |
7119 | error_setg_errno(errp, -size, "Could not get size of '%s'", | |
7120 | backing_file); | |
7121 | bdrv_unref(bs); | |
7122 | goto out; | |
7123 | } | |
7124 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort); | |
7125 | } | |
7126 | bdrv_unref(bs); | |
7127 | } | |
7128 | /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */ | |
7129 | } else if (backing_file && !backing_fmt) { | |
7130 | error_setg(&local_err, | |
7131 | "Backing file specified without backing format"); | |
7132 | goto out; | |
7133 | } | |
7134 | ||
7135 | if (size == -1) { | |
7136 | error_setg(errp, "Image creation needs a size parameter"); | |
7137 | goto out; | |
7138 | } | |
7139 | ||
7140 | if (!quiet) { | |
7141 | printf("Formatting '%s', fmt=%s ", filename, fmt); | |
7142 | qemu_opts_print(opts, " "); | |
7143 | puts(""); | |
7144 | fflush(stdout); | |
7145 | } | |
7146 | ||
7147 | ret = bdrv_create(drv, filename, opts, &local_err); | |
7148 | ||
7149 | if (ret == -EFBIG) { | |
7150 | /* This is generally a better message than whatever the driver would | |
7151 | * deliver (especially because of the cluster_size_hint), since that | |
7152 | * is most probably not much different from "image too large". */ | |
7153 | const char *cluster_size_hint = ""; | |
7154 | if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) { | |
7155 | cluster_size_hint = " (try using a larger cluster size)"; | |
7156 | } | |
7157 | error_setg(errp, "The image size is too large for file format '%s'" | |
7158 | "%s", fmt, cluster_size_hint); | |
7159 | error_free(local_err); | |
7160 | local_err = NULL; | |
7161 | } | |
7162 | ||
7163 | out: | |
7164 | qemu_opts_del(opts); | |
7165 | qemu_opts_free(create_opts); | |
7166 | error_propagate(errp, local_err); | |
7167 | } | |
7168 | ||
7169 | AioContext *bdrv_get_aio_context(BlockDriverState *bs) | |
7170 | { | |
7171 | IO_CODE(); | |
7172 | return bs ? bs->aio_context : qemu_get_aio_context(); | |
7173 | } | |
7174 | ||
7175 | AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs) | |
7176 | { | |
7177 | Coroutine *self = qemu_coroutine_self(); | |
7178 | AioContext *old_ctx = qemu_coroutine_get_aio_context(self); | |
7179 | AioContext *new_ctx; | |
7180 | IO_CODE(); | |
7181 | ||
7182 | /* | |
7183 | * Increase bs->in_flight to ensure that this operation is completed before | |
7184 | * moving the node to a different AioContext. Read new_ctx only afterwards. | |
7185 | */ | |
7186 | bdrv_inc_in_flight(bs); | |
7187 | ||
7188 | new_ctx = bdrv_get_aio_context(bs); | |
7189 | aio_co_reschedule_self(new_ctx); | |
7190 | return old_ctx; | |
7191 | } | |
7192 | ||
7193 | void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx) | |
7194 | { | |
7195 | IO_CODE(); | |
7196 | aio_co_reschedule_self(old_ctx); | |
7197 | bdrv_dec_in_flight(bs); | |
7198 | } | |
7199 | ||
7200 | void coroutine_fn bdrv_co_lock(BlockDriverState *bs) | |
7201 | { | |
7202 | AioContext *ctx = bdrv_get_aio_context(bs); | |
7203 | ||
7204 | /* In the main thread, bs->aio_context won't change concurrently */ | |
7205 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); | |
7206 | ||
7207 | /* | |
7208 | * We're in coroutine context, so we already hold the lock of the main | |
7209 | * loop AioContext. Don't lock it twice to avoid deadlocks. | |
7210 | */ | |
7211 | assert(qemu_in_coroutine()); | |
7212 | if (ctx != qemu_get_aio_context()) { | |
7213 | aio_context_acquire(ctx); | |
7214 | } | |
7215 | } | |
7216 | ||
7217 | void coroutine_fn bdrv_co_unlock(BlockDriverState *bs) | |
7218 | { | |
7219 | AioContext *ctx = bdrv_get_aio_context(bs); | |
7220 | ||
7221 | assert(qemu_in_coroutine()); | |
7222 | if (ctx != qemu_get_aio_context()) { | |
7223 | aio_context_release(ctx); | |
7224 | } | |
7225 | } | |
7226 | ||
7227 | static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban) | |
7228 | { | |
7229 | GLOBAL_STATE_CODE(); | |
7230 | QLIST_REMOVE(ban, list); | |
7231 | g_free(ban); | |
7232 | } | |
7233 | ||
7234 | static void bdrv_detach_aio_context(BlockDriverState *bs) | |
7235 | { | |
7236 | BdrvAioNotifier *baf, *baf_tmp; | |
7237 | ||
7238 | assert(!bs->walking_aio_notifiers); | |
7239 | GLOBAL_STATE_CODE(); | |
7240 | bs->walking_aio_notifiers = true; | |
7241 | QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) { | |
7242 | if (baf->deleted) { | |
7243 | bdrv_do_remove_aio_context_notifier(baf); | |
7244 | } else { | |
7245 | baf->detach_aio_context(baf->opaque); | |
7246 | } | |
7247 | } | |
7248 | /* Never mind iterating again to check for ->deleted. bdrv_close() will | |
7249 | * remove remaining aio notifiers if we aren't called again. | |
7250 | */ | |
7251 | bs->walking_aio_notifiers = false; | |
7252 | ||
7253 | if (bs->drv && bs->drv->bdrv_detach_aio_context) { | |
7254 | bs->drv->bdrv_detach_aio_context(bs); | |
7255 | } | |
7256 | ||
7257 | if (bs->quiesce_counter) { | |
7258 | aio_enable_external(bs->aio_context); | |
7259 | } | |
7260 | bs->aio_context = NULL; | |
7261 | } | |
7262 | ||
7263 | static void bdrv_attach_aio_context(BlockDriverState *bs, | |
7264 | AioContext *new_context) | |
7265 | { | |
7266 | BdrvAioNotifier *ban, *ban_tmp; | |
7267 | GLOBAL_STATE_CODE(); | |
7268 | ||
7269 | if (bs->quiesce_counter) { | |
7270 | aio_disable_external(new_context); | |
7271 | } | |
7272 | ||
7273 | bs->aio_context = new_context; | |
7274 | ||
7275 | if (bs->drv && bs->drv->bdrv_attach_aio_context) { | |
7276 | bs->drv->bdrv_attach_aio_context(bs, new_context); | |
7277 | } | |
7278 | ||
7279 | assert(!bs->walking_aio_notifiers); | |
7280 | bs->walking_aio_notifiers = true; | |
7281 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) { | |
7282 | if (ban->deleted) { | |
7283 | bdrv_do_remove_aio_context_notifier(ban); | |
7284 | } else { | |
7285 | ban->attached_aio_context(new_context, ban->opaque); | |
7286 | } | |
7287 | } | |
7288 | bs->walking_aio_notifiers = false; | |
7289 | } | |
7290 | ||
7291 | typedef struct BdrvStateSetAioContext { | |
7292 | AioContext *new_ctx; | |
7293 | BlockDriverState *bs; | |
7294 | } BdrvStateSetAioContext; | |
7295 | ||
7296 | static bool bdrv_parent_change_aio_context(BdrvChild *c, AioContext *ctx, | |
7297 | GHashTable *visited, | |
7298 | Transaction *tran, | |
7299 | Error **errp) | |
7300 | { | |
7301 | GLOBAL_STATE_CODE(); | |
7302 | if (g_hash_table_contains(visited, c)) { | |
7303 | return true; | |
7304 | } | |
7305 | g_hash_table_add(visited, c); | |
7306 | ||
7307 | /* | |
7308 | * A BdrvChildClass that doesn't handle AioContext changes cannot | |
7309 | * tolerate any AioContext changes | |
7310 | */ | |
7311 | if (!c->klass->change_aio_ctx) { | |
7312 | char *user = bdrv_child_user_desc(c); | |
7313 | error_setg(errp, "Changing iothreads is not supported by %s", user); | |
7314 | g_free(user); | |
7315 | return false; | |
7316 | } | |
7317 | if (!c->klass->change_aio_ctx(c, ctx, visited, tran, errp)) { | |
7318 | assert(!errp || *errp); | |
7319 | return false; | |
7320 | } | |
7321 | return true; | |
7322 | } | |
7323 | ||
7324 | bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx, | |
7325 | GHashTable *visited, Transaction *tran, | |
7326 | Error **errp) | |
7327 | { | |
7328 | GLOBAL_STATE_CODE(); | |
7329 | if (g_hash_table_contains(visited, c)) { | |
7330 | return true; | |
7331 | } | |
7332 | g_hash_table_add(visited, c); | |
7333 | return bdrv_change_aio_context(c->bs, ctx, visited, tran, errp); | |
7334 | } | |
7335 | ||
7336 | static void bdrv_set_aio_context_clean(void *opaque) | |
7337 | { | |
7338 | BdrvStateSetAioContext *state = (BdrvStateSetAioContext *) opaque; | |
7339 | BlockDriverState *bs = (BlockDriverState *) state->bs; | |
7340 | ||
7341 | /* Paired with bdrv_drained_begin in bdrv_change_aio_context() */ | |
7342 | bdrv_drained_end(bs); | |
7343 | ||
7344 | g_free(state); | |
7345 | } | |
7346 | ||
7347 | static void bdrv_set_aio_context_commit(void *opaque) | |
7348 | { | |
7349 | BdrvStateSetAioContext *state = (BdrvStateSetAioContext *) opaque; | |
7350 | BlockDriverState *bs = (BlockDriverState *) state->bs; | |
7351 | AioContext *new_context = state->new_ctx; | |
7352 | AioContext *old_context = bdrv_get_aio_context(bs); | |
7353 | ||
7354 | /* | |
7355 | * Take the old AioContex when detaching it from bs. | |
7356 | * At this point, new_context lock is already acquired, and we are now | |
7357 | * also taking old_context. This is safe as long as bdrv_detach_aio_context | |
7358 | * does not call AIO_POLL_WHILE(). | |
7359 | */ | |
7360 | if (old_context != qemu_get_aio_context()) { | |
7361 | aio_context_acquire(old_context); | |
7362 | } | |
7363 | bdrv_detach_aio_context(bs); | |
7364 | if (old_context != qemu_get_aio_context()) { | |
7365 | aio_context_release(old_context); | |
7366 | } | |
7367 | bdrv_attach_aio_context(bs, new_context); | |
7368 | } | |
7369 | ||
7370 | static TransactionActionDrv set_aio_context = { | |
7371 | .commit = bdrv_set_aio_context_commit, | |
7372 | .clean = bdrv_set_aio_context_clean, | |
7373 | }; | |
7374 | ||
7375 | /* | |
7376 | * Changes the AioContext used for fd handlers, timers, and BHs by this | |
7377 | * BlockDriverState and all its children and parents. | |
7378 | * | |
7379 | * Must be called from the main AioContext. | |
7380 | * | |
7381 | * The caller must own the AioContext lock for the old AioContext of bs, but it | |
7382 | * must not own the AioContext lock for new_context (unless new_context is the | |
7383 | * same as the current context of bs). | |
7384 | * | |
7385 | * @visited will accumulate all visited BdrvChild objects. The caller is | |
7386 | * responsible for freeing the list afterwards. | |
7387 | */ | |
7388 | static bool bdrv_change_aio_context(BlockDriverState *bs, AioContext *ctx, | |
7389 | GHashTable *visited, Transaction *tran, | |
7390 | Error **errp) | |
7391 | { | |
7392 | BdrvChild *c; | |
7393 | BdrvStateSetAioContext *state; | |
7394 | ||
7395 | GLOBAL_STATE_CODE(); | |
7396 | ||
7397 | if (bdrv_get_aio_context(bs) == ctx) { | |
7398 | return true; | |
7399 | } | |
7400 | ||
7401 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
7402 | if (!bdrv_parent_change_aio_context(c, ctx, visited, tran, errp)) { | |
7403 | return false; | |
7404 | } | |
7405 | } | |
7406 | ||
7407 | QLIST_FOREACH(c, &bs->children, next) { | |
7408 | if (!bdrv_child_change_aio_context(c, ctx, visited, tran, errp)) { | |
7409 | return false; | |
7410 | } | |
7411 | } | |
7412 | ||
7413 | state = g_new(BdrvStateSetAioContext, 1); | |
7414 | *state = (BdrvStateSetAioContext) { | |
7415 | .new_ctx = ctx, | |
7416 | .bs = bs, | |
7417 | }; | |
7418 | ||
7419 | /* Paired with bdrv_drained_end in bdrv_set_aio_context_clean() */ | |
7420 | bdrv_drained_begin(bs); | |
7421 | ||
7422 | tran_add(tran, &set_aio_context, state); | |
7423 | ||
7424 | return true; | |
7425 | } | |
7426 | ||
7427 | /* | |
7428 | * Change bs's and recursively all of its parents' and children's AioContext | |
7429 | * to the given new context, returning an error if that isn't possible. | |
7430 | * | |
7431 | * If ignore_child is not NULL, that child (and its subgraph) will not | |
7432 | * be touched. | |
7433 | * | |
7434 | * This function still requires the caller to take the bs current | |
7435 | * AioContext lock, otherwise draining will fail since AIO_WAIT_WHILE | |
7436 | * assumes the lock is always held if bs is in another AioContext. | |
7437 | * For the same reason, it temporarily also holds the new AioContext, since | |
7438 | * bdrv_drained_end calls BDRV_POLL_WHILE that assumes the lock is taken too. | |
7439 | * Therefore the new AioContext lock must not be taken by the caller. | |
7440 | */ | |
7441 | int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx, | |
7442 | BdrvChild *ignore_child, Error **errp) | |
7443 | { | |
7444 | Transaction *tran; | |
7445 | GHashTable *visited; | |
7446 | int ret; | |
7447 | AioContext *old_context = bdrv_get_aio_context(bs); | |
7448 | GLOBAL_STATE_CODE(); | |
7449 | ||
7450 | /* | |
7451 | * Recursion phase: go through all nodes of the graph. | |
7452 | * Take care of checking that all nodes support changing AioContext | |
7453 | * and drain them, builing a linear list of callbacks to run if everything | |
7454 | * is successful (the transaction itself). | |
7455 | */ | |
7456 | tran = tran_new(); | |
7457 | visited = g_hash_table_new(NULL, NULL); | |
7458 | if (ignore_child) { | |
7459 | g_hash_table_add(visited, ignore_child); | |
7460 | } | |
7461 | ret = bdrv_change_aio_context(bs, ctx, visited, tran, errp); | |
7462 | g_hash_table_destroy(visited); | |
7463 | ||
7464 | /* | |
7465 | * Linear phase: go through all callbacks collected in the transaction. | |
7466 | * Run all callbacks collected in the recursion to switch all nodes | |
7467 | * AioContext lock (transaction commit), or undo all changes done in the | |
7468 | * recursion (transaction abort). | |
7469 | */ | |
7470 | ||
7471 | if (!ret) { | |
7472 | /* Just run clean() callbacks. No AioContext changed. */ | |
7473 | tran_abort(tran); | |
7474 | return -EPERM; | |
7475 | } | |
7476 | ||
7477 | /* | |
7478 | * Release old AioContext, it won't be needed anymore, as all | |
7479 | * bdrv_drained_begin() have been called already. | |
7480 | */ | |
7481 | if (qemu_get_aio_context() != old_context) { | |
7482 | aio_context_release(old_context); | |
7483 | } | |
7484 | ||
7485 | /* | |
7486 | * Acquire new AioContext since bdrv_drained_end() is going to be called | |
7487 | * after we switched all nodes in the new AioContext, and the function | |
7488 | * assumes that the lock of the bs is always taken. | |
7489 | */ | |
7490 | if (qemu_get_aio_context() != ctx) { | |
7491 | aio_context_acquire(ctx); | |
7492 | } | |
7493 | ||
7494 | tran_commit(tran); | |
7495 | ||
7496 | if (qemu_get_aio_context() != ctx) { | |
7497 | aio_context_release(ctx); | |
7498 | } | |
7499 | ||
7500 | /* Re-acquire the old AioContext, since the caller takes and releases it. */ | |
7501 | if (qemu_get_aio_context() != old_context) { | |
7502 | aio_context_acquire(old_context); | |
7503 | } | |
7504 | ||
7505 | return 0; | |
7506 | } | |
7507 | ||
7508 | void bdrv_add_aio_context_notifier(BlockDriverState *bs, | |
7509 | void (*attached_aio_context)(AioContext *new_context, void *opaque), | |
7510 | void (*detach_aio_context)(void *opaque), void *opaque) | |
7511 | { | |
7512 | BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1); | |
7513 | *ban = (BdrvAioNotifier){ | |
7514 | .attached_aio_context = attached_aio_context, | |
7515 | .detach_aio_context = detach_aio_context, | |
7516 | .opaque = opaque | |
7517 | }; | |
7518 | GLOBAL_STATE_CODE(); | |
7519 | ||
7520 | QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list); | |
7521 | } | |
7522 | ||
7523 | void bdrv_remove_aio_context_notifier(BlockDriverState *bs, | |
7524 | void (*attached_aio_context)(AioContext *, | |
7525 | void *), | |
7526 | void (*detach_aio_context)(void *), | |
7527 | void *opaque) | |
7528 | { | |
7529 | BdrvAioNotifier *ban, *ban_next; | |
7530 | GLOBAL_STATE_CODE(); | |
7531 | ||
7532 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { | |
7533 | if (ban->attached_aio_context == attached_aio_context && | |
7534 | ban->detach_aio_context == detach_aio_context && | |
7535 | ban->opaque == opaque && | |
7536 | ban->deleted == false) | |
7537 | { | |
7538 | if (bs->walking_aio_notifiers) { | |
7539 | ban->deleted = true; | |
7540 | } else { | |
7541 | bdrv_do_remove_aio_context_notifier(ban); | |
7542 | } | |
7543 | return; | |
7544 | } | |
7545 | } | |
7546 | ||
7547 | abort(); | |
7548 | } | |
7549 | ||
7550 | int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts, | |
7551 | BlockDriverAmendStatusCB *status_cb, void *cb_opaque, | |
7552 | bool force, | |
7553 | Error **errp) | |
7554 | { | |
7555 | GLOBAL_STATE_CODE(); | |
7556 | if (!bs->drv) { | |
7557 | error_setg(errp, "Node is ejected"); | |
7558 | return -ENOMEDIUM; | |
7559 | } | |
7560 | if (!bs->drv->bdrv_amend_options) { | |
7561 | error_setg(errp, "Block driver '%s' does not support option amendment", | |
7562 | bs->drv->format_name); | |
7563 | return -ENOTSUP; | |
7564 | } | |
7565 | return bs->drv->bdrv_amend_options(bs, opts, status_cb, | |
7566 | cb_opaque, force, errp); | |
7567 | } | |
7568 | ||
7569 | /* | |
7570 | * This function checks whether the given @to_replace is allowed to be | |
7571 | * replaced by a node that always shows the same data as @bs. This is | |
7572 | * used for example to verify whether the mirror job can replace | |
7573 | * @to_replace by the target mirrored from @bs. | |
7574 | * To be replaceable, @bs and @to_replace may either be guaranteed to | |
7575 | * always show the same data (because they are only connected through | |
7576 | * filters), or some driver may allow replacing one of its children | |
7577 | * because it can guarantee that this child's data is not visible at | |
7578 | * all (for example, for dissenting quorum children that have no other | |
7579 | * parents). | |
7580 | */ | |
7581 | bool bdrv_recurse_can_replace(BlockDriverState *bs, | |
7582 | BlockDriverState *to_replace) | |
7583 | { | |
7584 | BlockDriverState *filtered; | |
7585 | ||
7586 | GLOBAL_STATE_CODE(); | |
7587 | ||
7588 | if (!bs || !bs->drv) { | |
7589 | return false; | |
7590 | } | |
7591 | ||
7592 | if (bs == to_replace) { | |
7593 | return true; | |
7594 | } | |
7595 | ||
7596 | /* See what the driver can do */ | |
7597 | if (bs->drv->bdrv_recurse_can_replace) { | |
7598 | return bs->drv->bdrv_recurse_can_replace(bs, to_replace); | |
7599 | } | |
7600 | ||
7601 | /* For filters without an own implementation, we can recurse on our own */ | |
7602 | filtered = bdrv_filter_bs(bs); | |
7603 | if (filtered) { | |
7604 | return bdrv_recurse_can_replace(filtered, to_replace); | |
7605 | } | |
7606 | ||
7607 | /* Safe default */ | |
7608 | return false; | |
7609 | } | |
7610 | ||
7611 | /* | |
7612 | * Check whether the given @node_name can be replaced by a node that | |
7613 | * has the same data as @parent_bs. If so, return @node_name's BDS; | |
7614 | * NULL otherwise. | |
7615 | * | |
7616 | * @node_name must be a (recursive) *child of @parent_bs (or this | |
7617 | * function will return NULL). | |
7618 | * | |
7619 | * The result (whether the node can be replaced or not) is only valid | |
7620 | * for as long as no graph or permission changes occur. | |
7621 | */ | |
7622 | BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, | |
7623 | const char *node_name, Error **errp) | |
7624 | { | |
7625 | BlockDriverState *to_replace_bs = bdrv_find_node(node_name); | |
7626 | AioContext *aio_context; | |
7627 | ||
7628 | GLOBAL_STATE_CODE(); | |
7629 | ||
7630 | if (!to_replace_bs) { | |
7631 | error_setg(errp, "Failed to find node with node-name='%s'", node_name); | |
7632 | return NULL; | |
7633 | } | |
7634 | ||
7635 | aio_context = bdrv_get_aio_context(to_replace_bs); | |
7636 | aio_context_acquire(aio_context); | |
7637 | ||
7638 | if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) { | |
7639 | to_replace_bs = NULL; | |
7640 | goto out; | |
7641 | } | |
7642 | ||
7643 | /* We don't want arbitrary node of the BDS chain to be replaced only the top | |
7644 | * most non filter in order to prevent data corruption. | |
7645 | * Another benefit is that this tests exclude backing files which are | |
7646 | * blocked by the backing blockers. | |
7647 | */ | |
7648 | if (!bdrv_recurse_can_replace(parent_bs, to_replace_bs)) { | |
7649 | error_setg(errp, "Cannot replace '%s' by a node mirrored from '%s', " | |
7650 | "because it cannot be guaranteed that doing so would not " | |
7651 | "lead to an abrupt change of visible data", | |
7652 | node_name, parent_bs->node_name); | |
7653 | to_replace_bs = NULL; | |
7654 | goto out; | |
7655 | } | |
7656 | ||
7657 | out: | |
7658 | aio_context_release(aio_context); | |
7659 | return to_replace_bs; | |
7660 | } | |
7661 | ||
7662 | /** | |
7663 | * Iterates through the list of runtime option keys that are said to | |
7664 | * be "strong" for a BDS. An option is called "strong" if it changes | |
7665 | * a BDS's data. For example, the null block driver's "size" and | |
7666 | * "read-zeroes" options are strong, but its "latency-ns" option is | |
7667 | * not. | |
7668 | * | |
7669 | * If a key returned by this function ends with a dot, all options | |
7670 | * starting with that prefix are strong. | |
7671 | */ | |
7672 | static const char *const *strong_options(BlockDriverState *bs, | |
7673 | const char *const *curopt) | |
7674 | { | |
7675 | static const char *const global_options[] = { | |
7676 | "driver", "filename", NULL | |
7677 | }; | |
7678 | ||
7679 | if (!curopt) { | |
7680 | return &global_options[0]; | |
7681 | } | |
7682 | ||
7683 | curopt++; | |
7684 | if (curopt == &global_options[ARRAY_SIZE(global_options) - 1] && bs->drv) { | |
7685 | curopt = bs->drv->strong_runtime_opts; | |
7686 | } | |
7687 | ||
7688 | return (curopt && *curopt) ? curopt : NULL; | |
7689 | } | |
7690 | ||
7691 | /** | |
7692 | * Copies all strong runtime options from bs->options to the given | |
7693 | * QDict. The set of strong option keys is determined by invoking | |
7694 | * strong_options(). | |
7695 | * | |
7696 | * Returns true iff any strong option was present in bs->options (and | |
7697 | * thus copied to the target QDict) with the exception of "filename" | |
7698 | * and "driver". The caller is expected to use this value to decide | |
7699 | * whether the existence of strong options prevents the generation of | |
7700 | * a plain filename. | |
7701 | */ | |
7702 | static bool append_strong_runtime_options(QDict *d, BlockDriverState *bs) | |
7703 | { | |
7704 | bool found_any = false; | |
7705 | const char *const *option_name = NULL; | |
7706 | ||
7707 | if (!bs->drv) { | |
7708 | return false; | |
7709 | } | |
7710 | ||
7711 | while ((option_name = strong_options(bs, option_name))) { | |
7712 | bool option_given = false; | |
7713 | ||
7714 | assert(strlen(*option_name) > 0); | |
7715 | if ((*option_name)[strlen(*option_name) - 1] != '.') { | |
7716 | QObject *entry = qdict_get(bs->options, *option_name); | |
7717 | if (!entry) { | |
7718 | continue; | |
7719 | } | |
7720 | ||
7721 | qdict_put_obj(d, *option_name, qobject_ref(entry)); | |
7722 | option_given = true; | |
7723 | } else { | |
7724 | const QDictEntry *entry; | |
7725 | for (entry = qdict_first(bs->options); entry; | |
7726 | entry = qdict_next(bs->options, entry)) | |
7727 | { | |
7728 | if (strstart(qdict_entry_key(entry), *option_name, NULL)) { | |
7729 | qdict_put_obj(d, qdict_entry_key(entry), | |
7730 | qobject_ref(qdict_entry_value(entry))); | |
7731 | option_given = true; | |
7732 | } | |
7733 | } | |
7734 | } | |
7735 | ||
7736 | /* While "driver" and "filename" need to be included in a JSON filename, | |
7737 | * their existence does not prohibit generation of a plain filename. */ | |
7738 | if (!found_any && option_given && | |
7739 | strcmp(*option_name, "driver") && strcmp(*option_name, "filename")) | |
7740 | { | |
7741 | found_any = true; | |
7742 | } | |
7743 | } | |
7744 | ||
7745 | if (!qdict_haskey(d, "driver")) { | |
7746 | /* Drivers created with bdrv_new_open_driver() may not have a | |
7747 | * @driver option. Add it here. */ | |
7748 | qdict_put_str(d, "driver", bs->drv->format_name); | |
7749 | } | |
7750 | ||
7751 | return found_any; | |
7752 | } | |
7753 | ||
7754 | /* Note: This function may return false positives; it may return true | |
7755 | * even if opening the backing file specified by bs's image header | |
7756 | * would result in exactly bs->backing. */ | |
7757 | static bool bdrv_backing_overridden(BlockDriverState *bs) | |
7758 | { | |
7759 | GLOBAL_STATE_CODE(); | |
7760 | if (bs->backing) { | |
7761 | return strcmp(bs->auto_backing_file, | |
7762 | bs->backing->bs->filename); | |
7763 | } else { | |
7764 | /* No backing BDS, so if the image header reports any backing | |
7765 | * file, it must have been suppressed */ | |
7766 | return bs->auto_backing_file[0] != '\0'; | |
7767 | } | |
7768 | } | |
7769 | ||
7770 | /* Updates the following BDS fields: | |
7771 | * - exact_filename: A filename which may be used for opening a block device | |
7772 | * which (mostly) equals the given BDS (even without any | |
7773 | * other options; so reading and writing must return the same | |
7774 | * results, but caching etc. may be different) | |
7775 | * - full_open_options: Options which, when given when opening a block device | |
7776 | * (without a filename), result in a BDS (mostly) | |
7777 | * equalling the given one | |
7778 | * - filename: If exact_filename is set, it is copied here. Otherwise, | |
7779 | * full_open_options is converted to a JSON object, prefixed with | |
7780 | * "json:" (for use through the JSON pseudo protocol) and put here. | |
7781 | */ | |
7782 | void bdrv_refresh_filename(BlockDriverState *bs) | |
7783 | { | |
7784 | BlockDriver *drv = bs->drv; | |
7785 | BdrvChild *child; | |
7786 | BlockDriverState *primary_child_bs; | |
7787 | QDict *opts; | |
7788 | bool backing_overridden; | |
7789 | bool generate_json_filename; /* Whether our default implementation should | |
7790 | fill exact_filename (false) or not (true) */ | |
7791 | ||
7792 | GLOBAL_STATE_CODE(); | |
7793 | ||
7794 | if (!drv) { | |
7795 | return; | |
7796 | } | |
7797 | ||
7798 | /* This BDS's file name may depend on any of its children's file names, so | |
7799 | * refresh those first */ | |
7800 | QLIST_FOREACH(child, &bs->children, next) { | |
7801 | bdrv_refresh_filename(child->bs); | |
7802 | } | |
7803 | ||
7804 | if (bs->implicit) { | |
7805 | /* For implicit nodes, just copy everything from the single child */ | |
7806 | child = QLIST_FIRST(&bs->children); | |
7807 | assert(QLIST_NEXT(child, next) == NULL); | |
7808 | ||
7809 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), | |
7810 | child->bs->exact_filename); | |
7811 | pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename); | |
7812 | ||
7813 | qobject_unref(bs->full_open_options); | |
7814 | bs->full_open_options = qobject_ref(child->bs->full_open_options); | |
7815 | ||
7816 | return; | |
7817 | } | |
7818 | ||
7819 | backing_overridden = bdrv_backing_overridden(bs); | |
7820 | ||
7821 | if (bs->open_flags & BDRV_O_NO_IO) { | |
7822 | /* Without I/O, the backing file does not change anything. | |
7823 | * Therefore, in such a case (primarily qemu-img), we can | |
7824 | * pretend the backing file has not been overridden even if | |
7825 | * it technically has been. */ | |
7826 | backing_overridden = false; | |
7827 | } | |
7828 | ||
7829 | /* Gather the options QDict */ | |
7830 | opts = qdict_new(); | |
7831 | generate_json_filename = append_strong_runtime_options(opts, bs); | |
7832 | generate_json_filename |= backing_overridden; | |
7833 | ||
7834 | if (drv->bdrv_gather_child_options) { | |
7835 | /* Some block drivers may not want to present all of their children's | |
7836 | * options, or name them differently from BdrvChild.name */ | |
7837 | drv->bdrv_gather_child_options(bs, opts, backing_overridden); | |
7838 | } else { | |
7839 | QLIST_FOREACH(child, &bs->children, next) { | |
7840 | if (child == bs->backing && !backing_overridden) { | |
7841 | /* We can skip the backing BDS if it has not been overridden */ | |
7842 | continue; | |
7843 | } | |
7844 | ||
7845 | qdict_put(opts, child->name, | |
7846 | qobject_ref(child->bs->full_open_options)); | |
7847 | } | |
7848 | ||
7849 | if (backing_overridden && !bs->backing) { | |
7850 | /* Force no backing file */ | |
7851 | qdict_put_null(opts, "backing"); | |
7852 | } | |
7853 | } | |
7854 | ||
7855 | qobject_unref(bs->full_open_options); | |
7856 | bs->full_open_options = opts; | |
7857 | ||
7858 | primary_child_bs = bdrv_primary_bs(bs); | |
7859 | ||
7860 | if (drv->bdrv_refresh_filename) { | |
7861 | /* Obsolete information is of no use here, so drop the old file name | |
7862 | * information before refreshing it */ | |
7863 | bs->exact_filename[0] = '\0'; | |
7864 | ||
7865 | drv->bdrv_refresh_filename(bs); | |
7866 | } else if (primary_child_bs) { | |
7867 | /* | |
7868 | * Try to reconstruct valid information from the underlying | |
7869 | * file -- this only works for format nodes (filter nodes | |
7870 | * cannot be probed and as such must be selected by the user | |
7871 | * either through an options dict, or through a special | |
7872 | * filename which the filter driver must construct in its | |
7873 | * .bdrv_refresh_filename() implementation). | |
7874 | */ | |
7875 | ||
7876 | bs->exact_filename[0] = '\0'; | |
7877 | ||
7878 | /* | |
7879 | * We can use the underlying file's filename if: | |
7880 | * - it has a filename, | |
7881 | * - the current BDS is not a filter, | |
7882 | * - the file is a protocol BDS, and | |
7883 | * - opening that file (as this BDS's format) will automatically create | |
7884 | * the BDS tree we have right now, that is: | |
7885 | * - the user did not significantly change this BDS's behavior with | |
7886 | * some explicit (strong) options | |
7887 | * - no non-file child of this BDS has been overridden by the user | |
7888 | * Both of these conditions are represented by generate_json_filename. | |
7889 | */ | |
7890 | if (primary_child_bs->exact_filename[0] && | |
7891 | primary_child_bs->drv->bdrv_file_open && | |
7892 | !drv->is_filter && !generate_json_filename) | |
7893 | { | |
7894 | strcpy(bs->exact_filename, primary_child_bs->exact_filename); | |
7895 | } | |
7896 | } | |
7897 | ||
7898 | if (bs->exact_filename[0]) { | |
7899 | pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); | |
7900 | } else { | |
7901 | GString *json = qobject_to_json(QOBJECT(bs->full_open_options)); | |
7902 | if (snprintf(bs->filename, sizeof(bs->filename), "json:%s", | |
7903 | json->str) >= sizeof(bs->filename)) { | |
7904 | /* Give user a hint if we truncated things. */ | |
7905 | strcpy(bs->filename + sizeof(bs->filename) - 4, "..."); | |
7906 | } | |
7907 | g_string_free(json, true); | |
7908 | } | |
7909 | } | |
7910 | ||
7911 | char *bdrv_dirname(BlockDriverState *bs, Error **errp) | |
7912 | { | |
7913 | BlockDriver *drv = bs->drv; | |
7914 | BlockDriverState *child_bs; | |
7915 | ||
7916 | GLOBAL_STATE_CODE(); | |
7917 | ||
7918 | if (!drv) { | |
7919 | error_setg(errp, "Node '%s' is ejected", bs->node_name); | |
7920 | return NULL; | |
7921 | } | |
7922 | ||
7923 | if (drv->bdrv_dirname) { | |
7924 | return drv->bdrv_dirname(bs, errp); | |
7925 | } | |
7926 | ||
7927 | child_bs = bdrv_primary_bs(bs); | |
7928 | if (child_bs) { | |
7929 | return bdrv_dirname(child_bs, errp); | |
7930 | } | |
7931 | ||
7932 | bdrv_refresh_filename(bs); | |
7933 | if (bs->exact_filename[0] != '\0') { | |
7934 | return path_combine(bs->exact_filename, ""); | |
7935 | } | |
7936 | ||
7937 | error_setg(errp, "Cannot generate a base directory for %s nodes", | |
7938 | drv->format_name); | |
7939 | return NULL; | |
7940 | } | |
7941 | ||
7942 | /* | |
7943 | * Hot add/remove a BDS's child. So the user can take a child offline when | |
7944 | * it is broken and take a new child online | |
7945 | */ | |
7946 | void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, | |
7947 | Error **errp) | |
7948 | { | |
7949 | GLOBAL_STATE_CODE(); | |
7950 | if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) { | |
7951 | error_setg(errp, "The node %s does not support adding a child", | |
7952 | bdrv_get_device_or_node_name(parent_bs)); | |
7953 | return; | |
7954 | } | |
7955 | ||
7956 | if (!QLIST_EMPTY(&child_bs->parents)) { | |
7957 | error_setg(errp, "The node %s already has a parent", | |
7958 | child_bs->node_name); | |
7959 | return; | |
7960 | } | |
7961 | ||
7962 | parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp); | |
7963 | } | |
7964 | ||
7965 | void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp) | |
7966 | { | |
7967 | BdrvChild *tmp; | |
7968 | ||
7969 | GLOBAL_STATE_CODE(); | |
7970 | if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) { | |
7971 | error_setg(errp, "The node %s does not support removing a child", | |
7972 | bdrv_get_device_or_node_name(parent_bs)); | |
7973 | return; | |
7974 | } | |
7975 | ||
7976 | QLIST_FOREACH(tmp, &parent_bs->children, next) { | |
7977 | if (tmp == child) { | |
7978 | break; | |
7979 | } | |
7980 | } | |
7981 | ||
7982 | if (!tmp) { | |
7983 | error_setg(errp, "The node %s does not have a child named %s", | |
7984 | bdrv_get_device_or_node_name(parent_bs), | |
7985 | bdrv_get_device_or_node_name(child->bs)); | |
7986 | return; | |
7987 | } | |
7988 | ||
7989 | parent_bs->drv->bdrv_del_child(parent_bs, child, errp); | |
7990 | } | |
7991 | ||
7992 | int bdrv_make_empty(BdrvChild *c, Error **errp) | |
7993 | { | |
7994 | BlockDriver *drv = c->bs->drv; | |
7995 | int ret; | |
7996 | ||
7997 | GLOBAL_STATE_CODE(); | |
7998 | assert(c->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)); | |
7999 | ||
8000 | if (!drv->bdrv_make_empty) { | |
8001 | error_setg(errp, "%s does not support emptying nodes", | |
8002 | drv->format_name); | |
8003 | return -ENOTSUP; | |
8004 | } | |
8005 | ||
8006 | ret = drv->bdrv_make_empty(c->bs); | |
8007 | if (ret < 0) { | |
8008 | error_setg_errno(errp, -ret, "Failed to empty %s", | |
8009 | c->bs->filename); | |
8010 | return ret; | |
8011 | } | |
8012 | ||
8013 | return 0; | |
8014 | } | |
8015 | ||
8016 | /* | |
8017 | * Return the child that @bs acts as an overlay for, and from which data may be | |
8018 | * copied in COW or COR operations. Usually this is the backing file. | |
8019 | */ | |
8020 | BdrvChild *bdrv_cow_child(BlockDriverState *bs) | |
8021 | { | |
8022 | IO_CODE(); | |
8023 | ||
8024 | if (!bs || !bs->drv) { | |
8025 | return NULL; | |
8026 | } | |
8027 | ||
8028 | if (bs->drv->is_filter) { | |
8029 | return NULL; | |
8030 | } | |
8031 | ||
8032 | if (!bs->backing) { | |
8033 | return NULL; | |
8034 | } | |
8035 | ||
8036 | assert(bs->backing->role & BDRV_CHILD_COW); | |
8037 | return bs->backing; | |
8038 | } | |
8039 | ||
8040 | /* | |
8041 | * If @bs acts as a filter for exactly one of its children, return | |
8042 | * that child. | |
8043 | */ | |
8044 | BdrvChild *bdrv_filter_child(BlockDriverState *bs) | |
8045 | { | |
8046 | BdrvChild *c; | |
8047 | IO_CODE(); | |
8048 | ||
8049 | if (!bs || !bs->drv) { | |
8050 | return NULL; | |
8051 | } | |
8052 | ||
8053 | if (!bs->drv->is_filter) { | |
8054 | return NULL; | |
8055 | } | |
8056 | ||
8057 | /* Only one of @backing or @file may be used */ | |
8058 | assert(!(bs->backing && bs->file)); | |
8059 | ||
8060 | c = bs->backing ?: bs->file; | |
8061 | if (!c) { | |
8062 | return NULL; | |
8063 | } | |
8064 | ||
8065 | assert(c->role & BDRV_CHILD_FILTERED); | |
8066 | return c; | |
8067 | } | |
8068 | ||
8069 | /* | |
8070 | * Return either the result of bdrv_cow_child() or bdrv_filter_child(), | |
8071 | * whichever is non-NULL. | |
8072 | * | |
8073 | * Return NULL if both are NULL. | |
8074 | */ | |
8075 | BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs) | |
8076 | { | |
8077 | BdrvChild *cow_child = bdrv_cow_child(bs); | |
8078 | BdrvChild *filter_child = bdrv_filter_child(bs); | |
8079 | IO_CODE(); | |
8080 | ||
8081 | /* Filter nodes cannot have COW backing files */ | |
8082 | assert(!(cow_child && filter_child)); | |
8083 | ||
8084 | return cow_child ?: filter_child; | |
8085 | } | |
8086 | ||
8087 | /* | |
8088 | * Return the primary child of this node: For filters, that is the | |
8089 | * filtered child. For other nodes, that is usually the child storing | |
8090 | * metadata. | |
8091 | * (A generally more helpful description is that this is (usually) the | |
8092 | * child that has the same filename as @bs.) | |
8093 | * | |
8094 | * Drivers do not necessarily have a primary child; for example quorum | |
8095 | * does not. | |
8096 | */ | |
8097 | BdrvChild *bdrv_primary_child(BlockDriverState *bs) | |
8098 | { | |
8099 | BdrvChild *c, *found = NULL; | |
8100 | IO_CODE(); | |
8101 | ||
8102 | QLIST_FOREACH(c, &bs->children, next) { | |
8103 | if (c->role & BDRV_CHILD_PRIMARY) { | |
8104 | assert(!found); | |
8105 | found = c; | |
8106 | } | |
8107 | } | |
8108 | ||
8109 | return found; | |
8110 | } | |
8111 | ||
8112 | static BlockDriverState *bdrv_do_skip_filters(BlockDriverState *bs, | |
8113 | bool stop_on_explicit_filter) | |
8114 | { | |
8115 | BdrvChild *c; | |
8116 | ||
8117 | if (!bs) { | |
8118 | return NULL; | |
8119 | } | |
8120 | ||
8121 | while (!(stop_on_explicit_filter && !bs->implicit)) { | |
8122 | c = bdrv_filter_child(bs); | |
8123 | if (!c) { | |
8124 | /* | |
8125 | * A filter that is embedded in a working block graph must | |
8126 | * have a child. Assert this here so this function does | |
8127 | * not return a filter node that is not expected by the | |
8128 | * caller. | |
8129 | */ | |
8130 | assert(!bs->drv || !bs->drv->is_filter); | |
8131 | break; | |
8132 | } | |
8133 | bs = c->bs; | |
8134 | } | |
8135 | /* | |
8136 | * Note that this treats nodes with bs->drv == NULL as not being | |
8137 | * filters (bs->drv == NULL should be replaced by something else | |
8138 | * anyway). | |
8139 | * The advantage of this behavior is that this function will thus | |
8140 | * always return a non-NULL value (given a non-NULL @bs). | |
8141 | */ | |
8142 | ||
8143 | return bs; | |
8144 | } | |
8145 | ||
8146 | /* | |
8147 | * Return the first BDS that has not been added implicitly or that | |
8148 | * does not have a filtered child down the chain starting from @bs | |
8149 | * (including @bs itself). | |
8150 | */ | |
8151 | BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs) | |
8152 | { | |
8153 | GLOBAL_STATE_CODE(); | |
8154 | return bdrv_do_skip_filters(bs, true); | |
8155 | } | |
8156 | ||
8157 | /* | |
8158 | * Return the first BDS that does not have a filtered child down the | |
8159 | * chain starting from @bs (including @bs itself). | |
8160 | */ | |
8161 | BlockDriverState *bdrv_skip_filters(BlockDriverState *bs) | |
8162 | { | |
8163 | IO_CODE(); | |
8164 | return bdrv_do_skip_filters(bs, false); | |
8165 | } | |
8166 | ||
8167 | /* | |
8168 | * For a backing chain, return the first non-filter backing image of | |
8169 | * the first non-filter image. | |
8170 | */ | |
8171 | BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs) | |
8172 | { | |
8173 | IO_CODE(); | |
8174 | return bdrv_skip_filters(bdrv_cow_bs(bdrv_skip_filters(bs))); | |
8175 | } | |
8176 | ||
8177 | /** | |
8178 | * Check whether [offset, offset + bytes) overlaps with the cached | |
8179 | * block-status data region. | |
8180 | * | |
8181 | * If so, and @pnum is not NULL, set *pnum to `bsc.data_end - offset`, | |
8182 | * which is what bdrv_bsc_is_data()'s interface needs. | |
8183 | * Otherwise, *pnum is not touched. | |
8184 | */ | |
8185 | static bool bdrv_bsc_range_overlaps_locked(BlockDriverState *bs, | |
8186 | int64_t offset, int64_t bytes, | |
8187 | int64_t *pnum) | |
8188 | { | |
8189 | BdrvBlockStatusCache *bsc = qatomic_rcu_read(&bs->block_status_cache); | |
8190 | bool overlaps; | |
8191 | ||
8192 | overlaps = | |
8193 | qatomic_read(&bsc->valid) && | |
8194 | ranges_overlap(offset, bytes, bsc->data_start, | |
8195 | bsc->data_end - bsc->data_start); | |
8196 | ||
8197 | if (overlaps && pnum) { | |
8198 | *pnum = bsc->data_end - offset; | |
8199 | } | |
8200 | ||
8201 | return overlaps; | |
8202 | } | |
8203 | ||
8204 | /** | |
8205 | * See block_int.h for this function's documentation. | |
8206 | */ | |
8207 | bool bdrv_bsc_is_data(BlockDriverState *bs, int64_t offset, int64_t *pnum) | |
8208 | { | |
8209 | IO_CODE(); | |
8210 | RCU_READ_LOCK_GUARD(); | |
8211 | return bdrv_bsc_range_overlaps_locked(bs, offset, 1, pnum); | |
8212 | } | |
8213 | ||
8214 | /** | |
8215 | * See block_int.h for this function's documentation. | |
8216 | */ | |
8217 | void bdrv_bsc_invalidate_range(BlockDriverState *bs, | |
8218 | int64_t offset, int64_t bytes) | |
8219 | { | |
8220 | IO_CODE(); | |
8221 | RCU_READ_LOCK_GUARD(); | |
8222 | ||
8223 | if (bdrv_bsc_range_overlaps_locked(bs, offset, bytes, NULL)) { | |
8224 | qatomic_set(&bs->block_status_cache->valid, false); | |
8225 | } | |
8226 | } | |
8227 | ||
8228 | /** | |
8229 | * See block_int.h for this function's documentation. | |
8230 | */ | |
8231 | void bdrv_bsc_fill(BlockDriverState *bs, int64_t offset, int64_t bytes) | |
8232 | { | |
8233 | BdrvBlockStatusCache *new_bsc = g_new(BdrvBlockStatusCache, 1); | |
8234 | BdrvBlockStatusCache *old_bsc; | |
8235 | IO_CODE(); | |
8236 | ||
8237 | *new_bsc = (BdrvBlockStatusCache) { | |
8238 | .valid = true, | |
8239 | .data_start = offset, | |
8240 | .data_end = offset + bytes, | |
8241 | }; | |
8242 | ||
8243 | QEMU_LOCK_GUARD(&bs->bsc_modify_lock); | |
8244 | ||
8245 | old_bsc = qatomic_rcu_read(&bs->block_status_cache); | |
8246 | qatomic_rcu_set(&bs->block_status_cache, new_bsc); | |
8247 | if (old_bsc) { | |
8248 | g_free_rcu(old_bsc, rcu); | |
8249 | } | |
8250 | } |