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1 | /* | |
2 | * QEMU System Emulator block driver | |
3 | * | |
4 | * Copyright (c) 2003 Fabrice Bellard | |
5 | * | |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | * THE SOFTWARE. | |
23 | */ | |
24 | #include "qemu/osdep.h" | |
25 | #include "block/trace.h" | |
26 | #include "block/block_int.h" | |
27 | #include "block/blockjob.h" | |
28 | #include "block/nbd.h" | |
29 | #include "qemu/error-report.h" | |
30 | #include "module_block.h" | |
31 | #include "qemu/module.h" | |
32 | #include "qapi/qmp/qerror.h" | |
33 | #include "qapi/qmp/qbool.h" | |
34 | #include "qapi/qmp/qjson.h" | |
35 | #include "sysemu/block-backend.h" | |
36 | #include "sysemu/sysemu.h" | |
37 | #include "qemu/notify.h" | |
38 | #include "qemu/coroutine.h" | |
39 | #include "block/qapi.h" | |
40 | #include "qmp-commands.h" | |
41 | #include "qemu/timer.h" | |
42 | #include "qapi-event.h" | |
43 | #include "qemu/cutils.h" | |
44 | #include "qemu/id.h" | |
45 | ||
46 | #ifdef CONFIG_BSD | |
47 | #include <sys/ioctl.h> | |
48 | #include <sys/queue.h> | |
49 | #ifndef __DragonFly__ | |
50 | #include <sys/disk.h> | |
51 | #endif | |
52 | #endif | |
53 | ||
54 | #ifdef _WIN32 | |
55 | #include <windows.h> | |
56 | #endif | |
57 | ||
58 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ | |
59 | ||
60 | static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states = | |
61 | QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); | |
62 | ||
63 | static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states = | |
64 | QTAILQ_HEAD_INITIALIZER(all_bdrv_states); | |
65 | ||
66 | static QLIST_HEAD(, BlockDriver) bdrv_drivers = | |
67 | QLIST_HEAD_INITIALIZER(bdrv_drivers); | |
68 | ||
69 | static BlockDriverState *bdrv_open_inherit(const char *filename, | |
70 | const char *reference, | |
71 | QDict *options, int flags, | |
72 | BlockDriverState *parent, | |
73 | const BdrvChildRole *child_role, | |
74 | Error **errp); | |
75 | ||
76 | /* If non-zero, use only whitelisted block drivers */ | |
77 | static int use_bdrv_whitelist; | |
78 | ||
79 | #ifdef _WIN32 | |
80 | static int is_windows_drive_prefix(const char *filename) | |
81 | { | |
82 | return (((filename[0] >= 'a' && filename[0] <= 'z') || | |
83 | (filename[0] >= 'A' && filename[0] <= 'Z')) && | |
84 | filename[1] == ':'); | |
85 | } | |
86 | ||
87 | int is_windows_drive(const char *filename) | |
88 | { | |
89 | if (is_windows_drive_prefix(filename) && | |
90 | filename[2] == '\0') | |
91 | return 1; | |
92 | if (strstart(filename, "\\\\.\\", NULL) || | |
93 | strstart(filename, "//./", NULL)) | |
94 | return 1; | |
95 | return 0; | |
96 | } | |
97 | #endif | |
98 | ||
99 | size_t bdrv_opt_mem_align(BlockDriverState *bs) | |
100 | { | |
101 | if (!bs || !bs->drv) { | |
102 | /* page size or 4k (hdd sector size) should be on the safe side */ | |
103 | return MAX(4096, getpagesize()); | |
104 | } | |
105 | ||
106 | return bs->bl.opt_mem_alignment; | |
107 | } | |
108 | ||
109 | size_t bdrv_min_mem_align(BlockDriverState *bs) | |
110 | { | |
111 | if (!bs || !bs->drv) { | |
112 | /* page size or 4k (hdd sector size) should be on the safe side */ | |
113 | return MAX(4096, getpagesize()); | |
114 | } | |
115 | ||
116 | return bs->bl.min_mem_alignment; | |
117 | } | |
118 | ||
119 | /* check if the path starts with "<protocol>:" */ | |
120 | int path_has_protocol(const char *path) | |
121 | { | |
122 | const char *p; | |
123 | ||
124 | #ifdef _WIN32 | |
125 | if (is_windows_drive(path) || | |
126 | is_windows_drive_prefix(path)) { | |
127 | return 0; | |
128 | } | |
129 | p = path + strcspn(path, ":/\\"); | |
130 | #else | |
131 | p = path + strcspn(path, ":/"); | |
132 | #endif | |
133 | ||
134 | return *p == ':'; | |
135 | } | |
136 | ||
137 | int path_is_absolute(const char *path) | |
138 | { | |
139 | #ifdef _WIN32 | |
140 | /* specific case for names like: "\\.\d:" */ | |
141 | if (is_windows_drive(path) || is_windows_drive_prefix(path)) { | |
142 | return 1; | |
143 | } | |
144 | return (*path == '/' || *path == '\\'); | |
145 | #else | |
146 | return (*path == '/'); | |
147 | #endif | |
148 | } | |
149 | ||
150 | /* if filename is absolute, just copy it to dest. Otherwise, build a | |
151 | path to it by considering it is relative to base_path. URL are | |
152 | supported. */ | |
153 | void path_combine(char *dest, int dest_size, | |
154 | const char *base_path, | |
155 | const char *filename) | |
156 | { | |
157 | const char *p, *p1; | |
158 | int len; | |
159 | ||
160 | if (dest_size <= 0) | |
161 | return; | |
162 | if (path_is_absolute(filename)) { | |
163 | pstrcpy(dest, dest_size, filename); | |
164 | } else { | |
165 | const char *protocol_stripped = NULL; | |
166 | ||
167 | if (path_has_protocol(base_path)) { | |
168 | protocol_stripped = strchr(base_path, ':'); | |
169 | if (protocol_stripped) { | |
170 | protocol_stripped++; | |
171 | } | |
172 | } | |
173 | p = protocol_stripped ?: base_path; | |
174 | ||
175 | p1 = strrchr(base_path, '/'); | |
176 | #ifdef _WIN32 | |
177 | { | |
178 | const char *p2; | |
179 | p2 = strrchr(base_path, '\\'); | |
180 | if (!p1 || p2 > p1) | |
181 | p1 = p2; | |
182 | } | |
183 | #endif | |
184 | if (p1) | |
185 | p1++; | |
186 | else | |
187 | p1 = base_path; | |
188 | if (p1 > p) | |
189 | p = p1; | |
190 | len = p - base_path; | |
191 | if (len > dest_size - 1) | |
192 | len = dest_size - 1; | |
193 | memcpy(dest, base_path, len); | |
194 | dest[len] = '\0'; | |
195 | pstrcat(dest, dest_size, filename); | |
196 | } | |
197 | } | |
198 | ||
199 | /* | |
200 | * Helper function for bdrv_parse_filename() implementations to remove optional | |
201 | * protocol prefixes (especially "file:") from a filename and for putting the | |
202 | * stripped filename into the options QDict if there is such a prefix. | |
203 | */ | |
204 | void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix, | |
205 | QDict *options) | |
206 | { | |
207 | if (strstart(filename, prefix, &filename)) { | |
208 | /* Stripping the explicit protocol prefix may result in a protocol | |
209 | * prefix being (wrongly) detected (if the filename contains a colon) */ | |
210 | if (path_has_protocol(filename)) { | |
211 | QString *fat_filename; | |
212 | ||
213 | /* This means there is some colon before the first slash; therefore, | |
214 | * this cannot be an absolute path */ | |
215 | assert(!path_is_absolute(filename)); | |
216 | ||
217 | /* And we can thus fix the protocol detection issue by prefixing it | |
218 | * by "./" */ | |
219 | fat_filename = qstring_from_str("./"); | |
220 | qstring_append(fat_filename, filename); | |
221 | ||
222 | assert(!path_has_protocol(qstring_get_str(fat_filename))); | |
223 | ||
224 | qdict_put(options, "filename", fat_filename); | |
225 | } else { | |
226 | /* If no protocol prefix was detected, we can use the shortened | |
227 | * filename as-is */ | |
228 | qdict_put_str(options, "filename", filename); | |
229 | } | |
230 | } | |
231 | } | |
232 | ||
233 | ||
234 | /* Returns whether the image file is opened as read-only. Note that this can | |
235 | * return false and writing to the image file is still not possible because the | |
236 | * image is inactivated. */ | |
237 | bool bdrv_is_read_only(BlockDriverState *bs) | |
238 | { | |
239 | return bs->read_only; | |
240 | } | |
241 | ||
242 | int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, | |
243 | bool ignore_allow_rdw, Error **errp) | |
244 | { | |
245 | /* Do not set read_only if copy_on_read is enabled */ | |
246 | if (bs->copy_on_read && read_only) { | |
247 | error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled", | |
248 | bdrv_get_device_or_node_name(bs)); | |
249 | return -EINVAL; | |
250 | } | |
251 | ||
252 | /* Do not clear read_only if it is prohibited */ | |
253 | if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) && | |
254 | !ignore_allow_rdw) | |
255 | { | |
256 | error_setg(errp, "Node '%s' is read only", | |
257 | bdrv_get_device_or_node_name(bs)); | |
258 | return -EPERM; | |
259 | } | |
260 | ||
261 | return 0; | |
262 | } | |
263 | ||
264 | /* TODO Remove (deprecated since 2.11) | |
265 | * Block drivers are not supposed to automatically change bs->read_only. | |
266 | * Instead, they should just check whether they can provide what the user | |
267 | * explicitly requested and error out if read-write is requested, but they can | |
268 | * only provide read-only access. */ | |
269 | int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp) | |
270 | { | |
271 | int ret = 0; | |
272 | ||
273 | ret = bdrv_can_set_read_only(bs, read_only, false, errp); | |
274 | if (ret < 0) { | |
275 | return ret; | |
276 | } | |
277 | ||
278 | bs->read_only = read_only; | |
279 | return 0; | |
280 | } | |
281 | ||
282 | void bdrv_get_full_backing_filename_from_filename(const char *backed, | |
283 | const char *backing, | |
284 | char *dest, size_t sz, | |
285 | Error **errp) | |
286 | { | |
287 | if (backing[0] == '\0' || path_has_protocol(backing) || | |
288 | path_is_absolute(backing)) | |
289 | { | |
290 | pstrcpy(dest, sz, backing); | |
291 | } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) { | |
292 | error_setg(errp, "Cannot use relative backing file names for '%s'", | |
293 | backed); | |
294 | } else { | |
295 | path_combine(dest, sz, backed, backing); | |
296 | } | |
297 | } | |
298 | ||
299 | void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz, | |
300 | Error **errp) | |
301 | { | |
302 | char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename; | |
303 | ||
304 | bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file, | |
305 | dest, sz, errp); | |
306 | } | |
307 | ||
308 | void bdrv_register(BlockDriver *bdrv) | |
309 | { | |
310 | QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); | |
311 | } | |
312 | ||
313 | BlockDriverState *bdrv_new(void) | |
314 | { | |
315 | BlockDriverState *bs; | |
316 | int i; | |
317 | ||
318 | bs = g_new0(BlockDriverState, 1); | |
319 | QLIST_INIT(&bs->dirty_bitmaps); | |
320 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
321 | QLIST_INIT(&bs->op_blockers[i]); | |
322 | } | |
323 | notifier_with_return_list_init(&bs->before_write_notifiers); | |
324 | qemu_co_mutex_init(&bs->reqs_lock); | |
325 | qemu_mutex_init(&bs->dirty_bitmap_mutex); | |
326 | bs->refcnt = 1; | |
327 | bs->aio_context = qemu_get_aio_context(); | |
328 | ||
329 | qemu_co_queue_init(&bs->flush_queue); | |
330 | ||
331 | QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list); | |
332 | ||
333 | return bs; | |
334 | } | |
335 | ||
336 | static BlockDriver *bdrv_do_find_format(const char *format_name) | |
337 | { | |
338 | BlockDriver *drv1; | |
339 | ||
340 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
341 | if (!strcmp(drv1->format_name, format_name)) { | |
342 | return drv1; | |
343 | } | |
344 | } | |
345 | ||
346 | return NULL; | |
347 | } | |
348 | ||
349 | BlockDriver *bdrv_find_format(const char *format_name) | |
350 | { | |
351 | BlockDriver *drv1; | |
352 | int i; | |
353 | ||
354 | drv1 = bdrv_do_find_format(format_name); | |
355 | if (drv1) { | |
356 | return drv1; | |
357 | } | |
358 | ||
359 | /* The driver isn't registered, maybe we need to load a module */ | |
360 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { | |
361 | if (!strcmp(block_driver_modules[i].format_name, format_name)) { | |
362 | block_module_load_one(block_driver_modules[i].library_name); | |
363 | break; | |
364 | } | |
365 | } | |
366 | ||
367 | return bdrv_do_find_format(format_name); | |
368 | } | |
369 | ||
370 | static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) | |
371 | { | |
372 | static const char *whitelist_rw[] = { | |
373 | CONFIG_BDRV_RW_WHITELIST | |
374 | }; | |
375 | static const char *whitelist_ro[] = { | |
376 | CONFIG_BDRV_RO_WHITELIST | |
377 | }; | |
378 | const char **p; | |
379 | ||
380 | if (!whitelist_rw[0] && !whitelist_ro[0]) { | |
381 | return 1; /* no whitelist, anything goes */ | |
382 | } | |
383 | ||
384 | for (p = whitelist_rw; *p; p++) { | |
385 | if (!strcmp(drv->format_name, *p)) { | |
386 | return 1; | |
387 | } | |
388 | } | |
389 | if (read_only) { | |
390 | for (p = whitelist_ro; *p; p++) { | |
391 | if (!strcmp(drv->format_name, *p)) { | |
392 | return 1; | |
393 | } | |
394 | } | |
395 | } | |
396 | return 0; | |
397 | } | |
398 | ||
399 | bool bdrv_uses_whitelist(void) | |
400 | { | |
401 | return use_bdrv_whitelist; | |
402 | } | |
403 | ||
404 | typedef struct CreateCo { | |
405 | BlockDriver *drv; | |
406 | char *filename; | |
407 | QemuOpts *opts; | |
408 | int ret; | |
409 | Error *err; | |
410 | } CreateCo; | |
411 | ||
412 | static void coroutine_fn bdrv_create_co_entry(void *opaque) | |
413 | { | |
414 | Error *local_err = NULL; | |
415 | int ret; | |
416 | ||
417 | CreateCo *cco = opaque; | |
418 | assert(cco->drv); | |
419 | ||
420 | ret = cco->drv->bdrv_create(cco->filename, cco->opts, &local_err); | |
421 | error_propagate(&cco->err, local_err); | |
422 | cco->ret = ret; | |
423 | } | |
424 | ||
425 | int bdrv_create(BlockDriver *drv, const char* filename, | |
426 | QemuOpts *opts, Error **errp) | |
427 | { | |
428 | int ret; | |
429 | ||
430 | Coroutine *co; | |
431 | CreateCo cco = { | |
432 | .drv = drv, | |
433 | .filename = g_strdup(filename), | |
434 | .opts = opts, | |
435 | .ret = NOT_DONE, | |
436 | .err = NULL, | |
437 | }; | |
438 | ||
439 | if (!drv->bdrv_create) { | |
440 | error_setg(errp, "Driver '%s' does not support image creation", drv->format_name); | |
441 | ret = -ENOTSUP; | |
442 | goto out; | |
443 | } | |
444 | ||
445 | if (qemu_in_coroutine()) { | |
446 | /* Fast-path if already in coroutine context */ | |
447 | bdrv_create_co_entry(&cco); | |
448 | } else { | |
449 | co = qemu_coroutine_create(bdrv_create_co_entry, &cco); | |
450 | qemu_coroutine_enter(co); | |
451 | while (cco.ret == NOT_DONE) { | |
452 | aio_poll(qemu_get_aio_context(), true); | |
453 | } | |
454 | } | |
455 | ||
456 | ret = cco.ret; | |
457 | if (ret < 0) { | |
458 | if (cco.err) { | |
459 | error_propagate(errp, cco.err); | |
460 | } else { | |
461 | error_setg_errno(errp, -ret, "Could not create image"); | |
462 | } | |
463 | } | |
464 | ||
465 | out: | |
466 | g_free(cco.filename); | |
467 | return ret; | |
468 | } | |
469 | ||
470 | int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp) | |
471 | { | |
472 | BlockDriver *drv; | |
473 | Error *local_err = NULL; | |
474 | int ret; | |
475 | ||
476 | drv = bdrv_find_protocol(filename, true, errp); | |
477 | if (drv == NULL) { | |
478 | return -ENOENT; | |
479 | } | |
480 | ||
481 | ret = bdrv_create(drv, filename, opts, &local_err); | |
482 | error_propagate(errp, local_err); | |
483 | return ret; | |
484 | } | |
485 | ||
486 | /** | |
487 | * Try to get @bs's logical and physical block size. | |
488 | * On success, store them in @bsz struct and return 0. | |
489 | * On failure return -errno. | |
490 | * @bs must not be empty. | |
491 | */ | |
492 | int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) | |
493 | { | |
494 | BlockDriver *drv = bs->drv; | |
495 | ||
496 | if (drv && drv->bdrv_probe_blocksizes) { | |
497 | return drv->bdrv_probe_blocksizes(bs, bsz); | |
498 | } else if (drv && drv->is_filter && bs->file) { | |
499 | return bdrv_probe_blocksizes(bs->file->bs, bsz); | |
500 | } | |
501 | ||
502 | return -ENOTSUP; | |
503 | } | |
504 | ||
505 | /** | |
506 | * Try to get @bs's geometry (cyls, heads, sectors). | |
507 | * On success, store them in @geo struct and return 0. | |
508 | * On failure return -errno. | |
509 | * @bs must not be empty. | |
510 | */ | |
511 | int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo) | |
512 | { | |
513 | BlockDriver *drv = bs->drv; | |
514 | ||
515 | if (drv && drv->bdrv_probe_geometry) { | |
516 | return drv->bdrv_probe_geometry(bs, geo); | |
517 | } else if (drv && drv->is_filter && bs->file) { | |
518 | return bdrv_probe_geometry(bs->file->bs, geo); | |
519 | } | |
520 | ||
521 | return -ENOTSUP; | |
522 | } | |
523 | ||
524 | /* | |
525 | * Create a uniquely-named empty temporary file. | |
526 | * Return 0 upon success, otherwise a negative errno value. | |
527 | */ | |
528 | int get_tmp_filename(char *filename, int size) | |
529 | { | |
530 | #ifdef _WIN32 | |
531 | char temp_dir[MAX_PATH]; | |
532 | /* GetTempFileName requires that its output buffer (4th param) | |
533 | have length MAX_PATH or greater. */ | |
534 | assert(size >= MAX_PATH); | |
535 | return (GetTempPath(MAX_PATH, temp_dir) | |
536 | && GetTempFileName(temp_dir, "qem", 0, filename) | |
537 | ? 0 : -GetLastError()); | |
538 | #else | |
539 | int fd; | |
540 | const char *tmpdir; | |
541 | tmpdir = getenv("TMPDIR"); | |
542 | if (!tmpdir) { | |
543 | tmpdir = "/var/tmp"; | |
544 | } | |
545 | if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) { | |
546 | return -EOVERFLOW; | |
547 | } | |
548 | fd = mkstemp(filename); | |
549 | if (fd < 0) { | |
550 | return -errno; | |
551 | } | |
552 | if (close(fd) != 0) { | |
553 | unlink(filename); | |
554 | return -errno; | |
555 | } | |
556 | return 0; | |
557 | #endif | |
558 | } | |
559 | ||
560 | /* | |
561 | * Detect host devices. By convention, /dev/cdrom[N] is always | |
562 | * recognized as a host CDROM. | |
563 | */ | |
564 | static BlockDriver *find_hdev_driver(const char *filename) | |
565 | { | |
566 | int score_max = 0, score; | |
567 | BlockDriver *drv = NULL, *d; | |
568 | ||
569 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
570 | if (d->bdrv_probe_device) { | |
571 | score = d->bdrv_probe_device(filename); | |
572 | if (score > score_max) { | |
573 | score_max = score; | |
574 | drv = d; | |
575 | } | |
576 | } | |
577 | } | |
578 | ||
579 | return drv; | |
580 | } | |
581 | ||
582 | static BlockDriver *bdrv_do_find_protocol(const char *protocol) | |
583 | { | |
584 | BlockDriver *drv1; | |
585 | ||
586 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
587 | if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) { | |
588 | return drv1; | |
589 | } | |
590 | } | |
591 | ||
592 | return NULL; | |
593 | } | |
594 | ||
595 | BlockDriver *bdrv_find_protocol(const char *filename, | |
596 | bool allow_protocol_prefix, | |
597 | Error **errp) | |
598 | { | |
599 | BlockDriver *drv1; | |
600 | char protocol[128]; | |
601 | int len; | |
602 | const char *p; | |
603 | int i; | |
604 | ||
605 | /* TODO Drivers without bdrv_file_open must be specified explicitly */ | |
606 | ||
607 | /* | |
608 | * XXX(hch): we really should not let host device detection | |
609 | * override an explicit protocol specification, but moving this | |
610 | * later breaks access to device names with colons in them. | |
611 | * Thanks to the brain-dead persistent naming schemes on udev- | |
612 | * based Linux systems those actually are quite common. | |
613 | */ | |
614 | drv1 = find_hdev_driver(filename); | |
615 | if (drv1) { | |
616 | return drv1; | |
617 | } | |
618 | ||
619 | if (!path_has_protocol(filename) || !allow_protocol_prefix) { | |
620 | return &bdrv_file; | |
621 | } | |
622 | ||
623 | p = strchr(filename, ':'); | |
624 | assert(p != NULL); | |
625 | len = p - filename; | |
626 | if (len > sizeof(protocol) - 1) | |
627 | len = sizeof(protocol) - 1; | |
628 | memcpy(protocol, filename, len); | |
629 | protocol[len] = '\0'; | |
630 | ||
631 | drv1 = bdrv_do_find_protocol(protocol); | |
632 | if (drv1) { | |
633 | return drv1; | |
634 | } | |
635 | ||
636 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { | |
637 | if (block_driver_modules[i].protocol_name && | |
638 | !strcmp(block_driver_modules[i].protocol_name, protocol)) { | |
639 | block_module_load_one(block_driver_modules[i].library_name); | |
640 | break; | |
641 | } | |
642 | } | |
643 | ||
644 | drv1 = bdrv_do_find_protocol(protocol); | |
645 | if (!drv1) { | |
646 | error_setg(errp, "Unknown protocol '%s'", protocol); | |
647 | } | |
648 | return drv1; | |
649 | } | |
650 | ||
651 | /* | |
652 | * Guess image format by probing its contents. | |
653 | * This is not a good idea when your image is raw (CVE-2008-2004), but | |
654 | * we do it anyway for backward compatibility. | |
655 | * | |
656 | * @buf contains the image's first @buf_size bytes. | |
657 | * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE, | |
658 | * but can be smaller if the image file is smaller) | |
659 | * @filename is its filename. | |
660 | * | |
661 | * For all block drivers, call the bdrv_probe() method to get its | |
662 | * probing score. | |
663 | * Return the first block driver with the highest probing score. | |
664 | */ | |
665 | BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, | |
666 | const char *filename) | |
667 | { | |
668 | int score_max = 0, score; | |
669 | BlockDriver *drv = NULL, *d; | |
670 | ||
671 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
672 | if (d->bdrv_probe) { | |
673 | score = d->bdrv_probe(buf, buf_size, filename); | |
674 | if (score > score_max) { | |
675 | score_max = score; | |
676 | drv = d; | |
677 | } | |
678 | } | |
679 | } | |
680 | ||
681 | return drv; | |
682 | } | |
683 | ||
684 | static int find_image_format(BlockBackend *file, const char *filename, | |
685 | BlockDriver **pdrv, Error **errp) | |
686 | { | |
687 | BlockDriver *drv; | |
688 | uint8_t buf[BLOCK_PROBE_BUF_SIZE]; | |
689 | int ret = 0; | |
690 | ||
691 | /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ | |
692 | if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) { | |
693 | *pdrv = &bdrv_raw; | |
694 | return ret; | |
695 | } | |
696 | ||
697 | ret = blk_pread(file, 0, buf, sizeof(buf)); | |
698 | if (ret < 0) { | |
699 | error_setg_errno(errp, -ret, "Could not read image for determining its " | |
700 | "format"); | |
701 | *pdrv = NULL; | |
702 | return ret; | |
703 | } | |
704 | ||
705 | drv = bdrv_probe_all(buf, ret, filename); | |
706 | if (!drv) { | |
707 | error_setg(errp, "Could not determine image format: No compatible " | |
708 | "driver found"); | |
709 | ret = -ENOENT; | |
710 | } | |
711 | *pdrv = drv; | |
712 | return ret; | |
713 | } | |
714 | ||
715 | /** | |
716 | * Set the current 'total_sectors' value | |
717 | * Return 0 on success, -errno on error. | |
718 | */ | |
719 | static int refresh_total_sectors(BlockDriverState *bs, int64_t hint) | |
720 | { | |
721 | BlockDriver *drv = bs->drv; | |
722 | ||
723 | if (!drv) { | |
724 | return -ENOMEDIUM; | |
725 | } | |
726 | ||
727 | /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */ | |
728 | if (bdrv_is_sg(bs)) | |
729 | return 0; | |
730 | ||
731 | /* query actual device if possible, otherwise just trust the hint */ | |
732 | if (drv->bdrv_getlength) { | |
733 | int64_t length = drv->bdrv_getlength(bs); | |
734 | if (length < 0) { | |
735 | return length; | |
736 | } | |
737 | hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE); | |
738 | } | |
739 | ||
740 | bs->total_sectors = hint; | |
741 | return 0; | |
742 | } | |
743 | ||
744 | /** | |
745 | * Combines a QDict of new block driver @options with any missing options taken | |
746 | * from @old_options, so that leaving out an option defaults to its old value. | |
747 | */ | |
748 | static void bdrv_join_options(BlockDriverState *bs, QDict *options, | |
749 | QDict *old_options) | |
750 | { | |
751 | if (bs->drv && bs->drv->bdrv_join_options) { | |
752 | bs->drv->bdrv_join_options(options, old_options); | |
753 | } else { | |
754 | qdict_join(options, old_options, false); | |
755 | } | |
756 | } | |
757 | ||
758 | /** | |
759 | * Set open flags for a given discard mode | |
760 | * | |
761 | * Return 0 on success, -1 if the discard mode was invalid. | |
762 | */ | |
763 | int bdrv_parse_discard_flags(const char *mode, int *flags) | |
764 | { | |
765 | *flags &= ~BDRV_O_UNMAP; | |
766 | ||
767 | if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) { | |
768 | /* do nothing */ | |
769 | } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) { | |
770 | *flags |= BDRV_O_UNMAP; | |
771 | } else { | |
772 | return -1; | |
773 | } | |
774 | ||
775 | return 0; | |
776 | } | |
777 | ||
778 | /** | |
779 | * Set open flags for a given cache mode | |
780 | * | |
781 | * Return 0 on success, -1 if the cache mode was invalid. | |
782 | */ | |
783 | int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough) | |
784 | { | |
785 | *flags &= ~BDRV_O_CACHE_MASK; | |
786 | ||
787 | if (!strcmp(mode, "off") || !strcmp(mode, "none")) { | |
788 | *writethrough = false; | |
789 | *flags |= BDRV_O_NOCACHE; | |
790 | } else if (!strcmp(mode, "directsync")) { | |
791 | *writethrough = true; | |
792 | *flags |= BDRV_O_NOCACHE; | |
793 | } else if (!strcmp(mode, "writeback")) { | |
794 | *writethrough = false; | |
795 | } else if (!strcmp(mode, "unsafe")) { | |
796 | *writethrough = false; | |
797 | *flags |= BDRV_O_NO_FLUSH; | |
798 | } else if (!strcmp(mode, "writethrough")) { | |
799 | *writethrough = true; | |
800 | } else { | |
801 | return -1; | |
802 | } | |
803 | ||
804 | return 0; | |
805 | } | |
806 | ||
807 | static char *bdrv_child_get_parent_desc(BdrvChild *c) | |
808 | { | |
809 | BlockDriverState *parent = c->opaque; | |
810 | return g_strdup(bdrv_get_device_or_node_name(parent)); | |
811 | } | |
812 | ||
813 | static void bdrv_child_cb_drained_begin(BdrvChild *child) | |
814 | { | |
815 | BlockDriverState *bs = child->opaque; | |
816 | bdrv_drained_begin(bs); | |
817 | } | |
818 | ||
819 | static void bdrv_child_cb_drained_end(BdrvChild *child) | |
820 | { | |
821 | BlockDriverState *bs = child->opaque; | |
822 | bdrv_drained_end(bs); | |
823 | } | |
824 | ||
825 | static int bdrv_child_cb_inactivate(BdrvChild *child) | |
826 | { | |
827 | BlockDriverState *bs = child->opaque; | |
828 | assert(bs->open_flags & BDRV_O_INACTIVE); | |
829 | return 0; | |
830 | } | |
831 | ||
832 | /* | |
833 | * Returns the options and flags that a temporary snapshot should get, based on | |
834 | * the originally requested flags (the originally requested image will have | |
835 | * flags like a backing file) | |
836 | */ | |
837 | static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options, | |
838 | int parent_flags, QDict *parent_options) | |
839 | { | |
840 | *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY; | |
841 | ||
842 | /* For temporary files, unconditional cache=unsafe is fine */ | |
843 | qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off"); | |
844 | qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on"); | |
845 | ||
846 | /* Copy the read-only option from the parent */ | |
847 | qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); | |
848 | ||
849 | /* aio=native doesn't work for cache.direct=off, so disable it for the | |
850 | * temporary snapshot */ | |
851 | *child_flags &= ~BDRV_O_NATIVE_AIO; | |
852 | } | |
853 | ||
854 | /* | |
855 | * Returns the options and flags that bs->file should get if a protocol driver | |
856 | * is expected, based on the given options and flags for the parent BDS | |
857 | */ | |
858 | static void bdrv_inherited_options(int *child_flags, QDict *child_options, | |
859 | int parent_flags, QDict *parent_options) | |
860 | { | |
861 | int flags = parent_flags; | |
862 | ||
863 | /* Enable protocol handling, disable format probing for bs->file */ | |
864 | flags |= BDRV_O_PROTOCOL; | |
865 | ||
866 | /* If the cache mode isn't explicitly set, inherit direct and no-flush from | |
867 | * the parent. */ | |
868 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); | |
869 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); | |
870 | qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE); | |
871 | ||
872 | /* Inherit the read-only option from the parent if it's not set */ | |
873 | qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); | |
874 | ||
875 | /* Our block drivers take care to send flushes and respect unmap policy, | |
876 | * so we can default to enable both on lower layers regardless of the | |
877 | * corresponding parent options. */ | |
878 | qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap"); | |
879 | ||
880 | /* Clear flags that only apply to the top layer */ | |
881 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ | | |
882 | BDRV_O_NO_IO); | |
883 | ||
884 | *child_flags = flags; | |
885 | } | |
886 | ||
887 | const BdrvChildRole child_file = { | |
888 | .get_parent_desc = bdrv_child_get_parent_desc, | |
889 | .inherit_options = bdrv_inherited_options, | |
890 | .drained_begin = bdrv_child_cb_drained_begin, | |
891 | .drained_end = bdrv_child_cb_drained_end, | |
892 | .inactivate = bdrv_child_cb_inactivate, | |
893 | }; | |
894 | ||
895 | /* | |
896 | * Returns the options and flags that bs->file should get if the use of formats | |
897 | * (and not only protocols) is permitted for it, based on the given options and | |
898 | * flags for the parent BDS | |
899 | */ | |
900 | static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options, | |
901 | int parent_flags, QDict *parent_options) | |
902 | { | |
903 | child_file.inherit_options(child_flags, child_options, | |
904 | parent_flags, parent_options); | |
905 | ||
906 | *child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO); | |
907 | } | |
908 | ||
909 | const BdrvChildRole child_format = { | |
910 | .get_parent_desc = bdrv_child_get_parent_desc, | |
911 | .inherit_options = bdrv_inherited_fmt_options, | |
912 | .drained_begin = bdrv_child_cb_drained_begin, | |
913 | .drained_end = bdrv_child_cb_drained_end, | |
914 | .inactivate = bdrv_child_cb_inactivate, | |
915 | }; | |
916 | ||
917 | static void bdrv_backing_attach(BdrvChild *c) | |
918 | { | |
919 | BlockDriverState *parent = c->opaque; | |
920 | BlockDriverState *backing_hd = c->bs; | |
921 | ||
922 | assert(!parent->backing_blocker); | |
923 | error_setg(&parent->backing_blocker, | |
924 | "node is used as backing hd of '%s'", | |
925 | bdrv_get_device_or_node_name(parent)); | |
926 | ||
927 | parent->open_flags &= ~BDRV_O_NO_BACKING; | |
928 | pstrcpy(parent->backing_file, sizeof(parent->backing_file), | |
929 | backing_hd->filename); | |
930 | pstrcpy(parent->backing_format, sizeof(parent->backing_format), | |
931 | backing_hd->drv ? backing_hd->drv->format_name : ""); | |
932 | ||
933 | bdrv_op_block_all(backing_hd, parent->backing_blocker); | |
934 | /* Otherwise we won't be able to commit or stream */ | |
935 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, | |
936 | parent->backing_blocker); | |
937 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM, | |
938 | parent->backing_blocker); | |
939 | /* | |
940 | * We do backup in 3 ways: | |
941 | * 1. drive backup | |
942 | * The target bs is new opened, and the source is top BDS | |
943 | * 2. blockdev backup | |
944 | * Both the source and the target are top BDSes. | |
945 | * 3. internal backup(used for block replication) | |
946 | * Both the source and the target are backing file | |
947 | * | |
948 | * In case 1 and 2, neither the source nor the target is the backing file. | |
949 | * In case 3, we will block the top BDS, so there is only one block job | |
950 | * for the top BDS and its backing chain. | |
951 | */ | |
952 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE, | |
953 | parent->backing_blocker); | |
954 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET, | |
955 | parent->backing_blocker); | |
956 | } | |
957 | ||
958 | static void bdrv_backing_detach(BdrvChild *c) | |
959 | { | |
960 | BlockDriverState *parent = c->opaque; | |
961 | ||
962 | assert(parent->backing_blocker); | |
963 | bdrv_op_unblock_all(c->bs, parent->backing_blocker); | |
964 | error_free(parent->backing_blocker); | |
965 | parent->backing_blocker = NULL; | |
966 | } | |
967 | ||
968 | /* | |
969 | * Returns the options and flags that bs->backing should get, based on the | |
970 | * given options and flags for the parent BDS | |
971 | */ | |
972 | static void bdrv_backing_options(int *child_flags, QDict *child_options, | |
973 | int parent_flags, QDict *parent_options) | |
974 | { | |
975 | int flags = parent_flags; | |
976 | ||
977 | /* The cache mode is inherited unmodified for backing files; except WCE, | |
978 | * which is only applied on the top level (BlockBackend) */ | |
979 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); | |
980 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); | |
981 | qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE); | |
982 | ||
983 | /* backing files always opened read-only */ | |
984 | qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on"); | |
985 | flags &= ~BDRV_O_COPY_ON_READ; | |
986 | ||
987 | /* snapshot=on is handled on the top layer */ | |
988 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); | |
989 | ||
990 | *child_flags = flags; | |
991 | } | |
992 | ||
993 | static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base, | |
994 | const char *filename, Error **errp) | |
995 | { | |
996 | BlockDriverState *parent = c->opaque; | |
997 | int orig_flags = bdrv_get_flags(parent); | |
998 | int ret; | |
999 | ||
1000 | if (!(orig_flags & BDRV_O_RDWR)) { | |
1001 | ret = bdrv_reopen(parent, orig_flags | BDRV_O_RDWR, errp); | |
1002 | if (ret < 0) { | |
1003 | return ret; | |
1004 | } | |
1005 | } | |
1006 | ||
1007 | ret = bdrv_change_backing_file(parent, filename, | |
1008 | base->drv ? base->drv->format_name : ""); | |
1009 | if (ret < 0) { | |
1010 | error_setg_errno(errp, -ret, "Could not update backing file link"); | |
1011 | } | |
1012 | ||
1013 | if (!(orig_flags & BDRV_O_RDWR)) { | |
1014 | bdrv_reopen(parent, orig_flags, NULL); | |
1015 | } | |
1016 | ||
1017 | return ret; | |
1018 | } | |
1019 | ||
1020 | const BdrvChildRole child_backing = { | |
1021 | .get_parent_desc = bdrv_child_get_parent_desc, | |
1022 | .attach = bdrv_backing_attach, | |
1023 | .detach = bdrv_backing_detach, | |
1024 | .inherit_options = bdrv_backing_options, | |
1025 | .drained_begin = bdrv_child_cb_drained_begin, | |
1026 | .drained_end = bdrv_child_cb_drained_end, | |
1027 | .inactivate = bdrv_child_cb_inactivate, | |
1028 | .update_filename = bdrv_backing_update_filename, | |
1029 | }; | |
1030 | ||
1031 | static int bdrv_open_flags(BlockDriverState *bs, int flags) | |
1032 | { | |
1033 | int open_flags = flags; | |
1034 | ||
1035 | /* | |
1036 | * Clear flags that are internal to the block layer before opening the | |
1037 | * image. | |
1038 | */ | |
1039 | open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL); | |
1040 | ||
1041 | /* | |
1042 | * Snapshots should be writable. | |
1043 | */ | |
1044 | if (flags & BDRV_O_TEMPORARY) { | |
1045 | open_flags |= BDRV_O_RDWR; | |
1046 | } | |
1047 | ||
1048 | return open_flags; | |
1049 | } | |
1050 | ||
1051 | static void update_flags_from_options(int *flags, QemuOpts *opts) | |
1052 | { | |
1053 | *flags &= ~BDRV_O_CACHE_MASK; | |
1054 | ||
1055 | assert(qemu_opt_find(opts, BDRV_OPT_CACHE_NO_FLUSH)); | |
1056 | if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) { | |
1057 | *flags |= BDRV_O_NO_FLUSH; | |
1058 | } | |
1059 | ||
1060 | assert(qemu_opt_find(opts, BDRV_OPT_CACHE_DIRECT)); | |
1061 | if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) { | |
1062 | *flags |= BDRV_O_NOCACHE; | |
1063 | } | |
1064 | ||
1065 | *flags &= ~BDRV_O_RDWR; | |
1066 | ||
1067 | assert(qemu_opt_find(opts, BDRV_OPT_READ_ONLY)); | |
1068 | if (!qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false)) { | |
1069 | *flags |= BDRV_O_RDWR; | |
1070 | } | |
1071 | ||
1072 | } | |
1073 | ||
1074 | static void update_options_from_flags(QDict *options, int flags) | |
1075 | { | |
1076 | if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) { | |
1077 | qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE); | |
1078 | } | |
1079 | if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) { | |
1080 | qdict_put_bool(options, BDRV_OPT_CACHE_NO_FLUSH, | |
1081 | flags & BDRV_O_NO_FLUSH); | |
1082 | } | |
1083 | if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) { | |
1084 | qdict_put_bool(options, BDRV_OPT_READ_ONLY, !(flags & BDRV_O_RDWR)); | |
1085 | } | |
1086 | } | |
1087 | ||
1088 | static void bdrv_assign_node_name(BlockDriverState *bs, | |
1089 | const char *node_name, | |
1090 | Error **errp) | |
1091 | { | |
1092 | char *gen_node_name = NULL; | |
1093 | ||
1094 | if (!node_name) { | |
1095 | node_name = gen_node_name = id_generate(ID_BLOCK); | |
1096 | } else if (!id_wellformed(node_name)) { | |
1097 | /* | |
1098 | * Check for empty string or invalid characters, but not if it is | |
1099 | * generated (generated names use characters not available to the user) | |
1100 | */ | |
1101 | error_setg(errp, "Invalid node name"); | |
1102 | return; | |
1103 | } | |
1104 | ||
1105 | /* takes care of avoiding namespaces collisions */ | |
1106 | if (blk_by_name(node_name)) { | |
1107 | error_setg(errp, "node-name=%s is conflicting with a device id", | |
1108 | node_name); | |
1109 | goto out; | |
1110 | } | |
1111 | ||
1112 | /* takes care of avoiding duplicates node names */ | |
1113 | if (bdrv_find_node(node_name)) { | |
1114 | error_setg(errp, "Duplicate node name"); | |
1115 | goto out; | |
1116 | } | |
1117 | ||
1118 | /* copy node name into the bs and insert it into the graph list */ | |
1119 | pstrcpy(bs->node_name, sizeof(bs->node_name), node_name); | |
1120 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list); | |
1121 | out: | |
1122 | g_free(gen_node_name); | |
1123 | } | |
1124 | ||
1125 | static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv, | |
1126 | const char *node_name, QDict *options, | |
1127 | int open_flags, Error **errp) | |
1128 | { | |
1129 | Error *local_err = NULL; | |
1130 | int ret; | |
1131 | ||
1132 | bdrv_assign_node_name(bs, node_name, &local_err); | |
1133 | if (local_err) { | |
1134 | error_propagate(errp, local_err); | |
1135 | return -EINVAL; | |
1136 | } | |
1137 | ||
1138 | bs->drv = drv; | |
1139 | bs->read_only = !(bs->open_flags & BDRV_O_RDWR); | |
1140 | bs->opaque = g_malloc0(drv->instance_size); | |
1141 | ||
1142 | if (drv->bdrv_file_open) { | |
1143 | assert(!drv->bdrv_needs_filename || bs->filename[0]); | |
1144 | ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); | |
1145 | } else if (drv->bdrv_open) { | |
1146 | ret = drv->bdrv_open(bs, options, open_flags, &local_err); | |
1147 | } else { | |
1148 | ret = 0; | |
1149 | } | |
1150 | ||
1151 | if (ret < 0) { | |
1152 | if (local_err) { | |
1153 | error_propagate(errp, local_err); | |
1154 | } else if (bs->filename[0]) { | |
1155 | error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename); | |
1156 | } else { | |
1157 | error_setg_errno(errp, -ret, "Could not open image"); | |
1158 | } | |
1159 | goto open_failed; | |
1160 | } | |
1161 | ||
1162 | ret = refresh_total_sectors(bs, bs->total_sectors); | |
1163 | if (ret < 0) { | |
1164 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
1165 | return ret; | |
1166 | } | |
1167 | ||
1168 | bdrv_refresh_limits(bs, &local_err); | |
1169 | if (local_err) { | |
1170 | error_propagate(errp, local_err); | |
1171 | return -EINVAL; | |
1172 | } | |
1173 | ||
1174 | assert(bdrv_opt_mem_align(bs) != 0); | |
1175 | assert(bdrv_min_mem_align(bs) != 0); | |
1176 | assert(is_power_of_2(bs->bl.request_alignment)); | |
1177 | ||
1178 | return 0; | |
1179 | open_failed: | |
1180 | bs->drv = NULL; | |
1181 | if (bs->file != NULL) { | |
1182 | bdrv_unref_child(bs, bs->file); | |
1183 | bs->file = NULL; | |
1184 | } | |
1185 | g_free(bs->opaque); | |
1186 | bs->opaque = NULL; | |
1187 | return ret; | |
1188 | } | |
1189 | ||
1190 | BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, | |
1191 | int flags, Error **errp) | |
1192 | { | |
1193 | BlockDriverState *bs; | |
1194 | int ret; | |
1195 | ||
1196 | bs = bdrv_new(); | |
1197 | bs->open_flags = flags; | |
1198 | bs->explicit_options = qdict_new(); | |
1199 | bs->options = qdict_new(); | |
1200 | bs->opaque = NULL; | |
1201 | ||
1202 | update_options_from_flags(bs->options, flags); | |
1203 | ||
1204 | ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp); | |
1205 | if (ret < 0) { | |
1206 | QDECREF(bs->explicit_options); | |
1207 | bs->explicit_options = NULL; | |
1208 | QDECREF(bs->options); | |
1209 | bs->options = NULL; | |
1210 | bdrv_unref(bs); | |
1211 | return NULL; | |
1212 | } | |
1213 | ||
1214 | return bs; | |
1215 | } | |
1216 | ||
1217 | QemuOptsList bdrv_runtime_opts = { | |
1218 | .name = "bdrv_common", | |
1219 | .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head), | |
1220 | .desc = { | |
1221 | { | |
1222 | .name = "node-name", | |
1223 | .type = QEMU_OPT_STRING, | |
1224 | .help = "Node name of the block device node", | |
1225 | }, | |
1226 | { | |
1227 | .name = "driver", | |
1228 | .type = QEMU_OPT_STRING, | |
1229 | .help = "Block driver to use for the node", | |
1230 | }, | |
1231 | { | |
1232 | .name = BDRV_OPT_CACHE_DIRECT, | |
1233 | .type = QEMU_OPT_BOOL, | |
1234 | .help = "Bypass software writeback cache on the host", | |
1235 | }, | |
1236 | { | |
1237 | .name = BDRV_OPT_CACHE_NO_FLUSH, | |
1238 | .type = QEMU_OPT_BOOL, | |
1239 | .help = "Ignore flush requests", | |
1240 | }, | |
1241 | { | |
1242 | .name = BDRV_OPT_READ_ONLY, | |
1243 | .type = QEMU_OPT_BOOL, | |
1244 | .help = "Node is opened in read-only mode", | |
1245 | }, | |
1246 | { | |
1247 | .name = "detect-zeroes", | |
1248 | .type = QEMU_OPT_STRING, | |
1249 | .help = "try to optimize zero writes (off, on, unmap)", | |
1250 | }, | |
1251 | { | |
1252 | .name = "discard", | |
1253 | .type = QEMU_OPT_STRING, | |
1254 | .help = "discard operation (ignore/off, unmap/on)", | |
1255 | }, | |
1256 | { | |
1257 | .name = BDRV_OPT_FORCE_SHARE, | |
1258 | .type = QEMU_OPT_BOOL, | |
1259 | .help = "always accept other writers (default: off)", | |
1260 | }, | |
1261 | { /* end of list */ } | |
1262 | }, | |
1263 | }; | |
1264 | ||
1265 | /* | |
1266 | * Common part for opening disk images and files | |
1267 | * | |
1268 | * Removes all processed options from *options. | |
1269 | */ | |
1270 | static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, | |
1271 | QDict *options, Error **errp) | |
1272 | { | |
1273 | int ret, open_flags; | |
1274 | const char *filename; | |
1275 | const char *driver_name = NULL; | |
1276 | const char *node_name = NULL; | |
1277 | const char *discard; | |
1278 | const char *detect_zeroes; | |
1279 | QemuOpts *opts; | |
1280 | BlockDriver *drv; | |
1281 | Error *local_err = NULL; | |
1282 | ||
1283 | assert(bs->file == NULL); | |
1284 | assert(options != NULL && bs->options != options); | |
1285 | ||
1286 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); | |
1287 | qemu_opts_absorb_qdict(opts, options, &local_err); | |
1288 | if (local_err) { | |
1289 | error_propagate(errp, local_err); | |
1290 | ret = -EINVAL; | |
1291 | goto fail_opts; | |
1292 | } | |
1293 | ||
1294 | update_flags_from_options(&bs->open_flags, opts); | |
1295 | ||
1296 | driver_name = qemu_opt_get(opts, "driver"); | |
1297 | drv = bdrv_find_format(driver_name); | |
1298 | assert(drv != NULL); | |
1299 | ||
1300 | bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false); | |
1301 | ||
1302 | if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) { | |
1303 | error_setg(errp, | |
1304 | BDRV_OPT_FORCE_SHARE | |
1305 | "=on can only be used with read-only images"); | |
1306 | ret = -EINVAL; | |
1307 | goto fail_opts; | |
1308 | } | |
1309 | ||
1310 | if (file != NULL) { | |
1311 | filename = blk_bs(file)->filename; | |
1312 | } else { | |
1313 | /* | |
1314 | * Caution: while qdict_get_try_str() is fine, getting | |
1315 | * non-string types would require more care. When @options | |
1316 | * come from -blockdev or blockdev_add, its members are typed | |
1317 | * according to the QAPI schema, but when they come from | |
1318 | * -drive, they're all QString. | |
1319 | */ | |
1320 | filename = qdict_get_try_str(options, "filename"); | |
1321 | } | |
1322 | ||
1323 | if (drv->bdrv_needs_filename && (!filename || !filename[0])) { | |
1324 | error_setg(errp, "The '%s' block driver requires a file name", | |
1325 | drv->format_name); | |
1326 | ret = -EINVAL; | |
1327 | goto fail_opts; | |
1328 | } | |
1329 | ||
1330 | trace_bdrv_open_common(bs, filename ?: "", bs->open_flags, | |
1331 | drv->format_name); | |
1332 | ||
1333 | bs->read_only = !(bs->open_flags & BDRV_O_RDWR); | |
1334 | ||
1335 | if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) { | |
1336 | error_setg(errp, | |
1337 | !bs->read_only && bdrv_is_whitelisted(drv, true) | |
1338 | ? "Driver '%s' can only be used for read-only devices" | |
1339 | : "Driver '%s' is not whitelisted", | |
1340 | drv->format_name); | |
1341 | ret = -ENOTSUP; | |
1342 | goto fail_opts; | |
1343 | } | |
1344 | ||
1345 | /* bdrv_new() and bdrv_close() make it so */ | |
1346 | assert(atomic_read(&bs->copy_on_read) == 0); | |
1347 | ||
1348 | if (bs->open_flags & BDRV_O_COPY_ON_READ) { | |
1349 | if (!bs->read_only) { | |
1350 | bdrv_enable_copy_on_read(bs); | |
1351 | } else { | |
1352 | error_setg(errp, "Can't use copy-on-read on read-only device"); | |
1353 | ret = -EINVAL; | |
1354 | goto fail_opts; | |
1355 | } | |
1356 | } | |
1357 | ||
1358 | discard = qemu_opt_get(opts, "discard"); | |
1359 | if (discard != NULL) { | |
1360 | if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) { | |
1361 | error_setg(errp, "Invalid discard option"); | |
1362 | ret = -EINVAL; | |
1363 | goto fail_opts; | |
1364 | } | |
1365 | } | |
1366 | ||
1367 | detect_zeroes = qemu_opt_get(opts, "detect-zeroes"); | |
1368 | if (detect_zeroes) { | |
1369 | BlockdevDetectZeroesOptions value = | |
1370 | qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, | |
1371 | detect_zeroes, | |
1372 | BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, | |
1373 | &local_err); | |
1374 | if (local_err) { | |
1375 | error_propagate(errp, local_err); | |
1376 | ret = -EINVAL; | |
1377 | goto fail_opts; | |
1378 | } | |
1379 | ||
1380 | if (value == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && | |
1381 | !(bs->open_flags & BDRV_O_UNMAP)) | |
1382 | { | |
1383 | error_setg(errp, "setting detect-zeroes to unmap is not allowed " | |
1384 | "without setting discard operation to unmap"); | |
1385 | ret = -EINVAL; | |
1386 | goto fail_opts; | |
1387 | } | |
1388 | ||
1389 | bs->detect_zeroes = value; | |
1390 | } | |
1391 | ||
1392 | if (filename != NULL) { | |
1393 | pstrcpy(bs->filename, sizeof(bs->filename), filename); | |
1394 | } else { | |
1395 | bs->filename[0] = '\0'; | |
1396 | } | |
1397 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename); | |
1398 | ||
1399 | /* Open the image, either directly or using a protocol */ | |
1400 | open_flags = bdrv_open_flags(bs, bs->open_flags); | |
1401 | node_name = qemu_opt_get(opts, "node-name"); | |
1402 | ||
1403 | assert(!drv->bdrv_file_open || file == NULL); | |
1404 | ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp); | |
1405 | if (ret < 0) { | |
1406 | goto fail_opts; | |
1407 | } | |
1408 | ||
1409 | qemu_opts_del(opts); | |
1410 | return 0; | |
1411 | ||
1412 | fail_opts: | |
1413 | qemu_opts_del(opts); | |
1414 | return ret; | |
1415 | } | |
1416 | ||
1417 | static QDict *parse_json_filename(const char *filename, Error **errp) | |
1418 | { | |
1419 | QObject *options_obj; | |
1420 | QDict *options; | |
1421 | int ret; | |
1422 | ||
1423 | ret = strstart(filename, "json:", &filename); | |
1424 | assert(ret); | |
1425 | ||
1426 | options_obj = qobject_from_json(filename, errp); | |
1427 | if (!options_obj) { | |
1428 | /* Work around qobject_from_json() lossage TODO fix that */ | |
1429 | if (errp && !*errp) { | |
1430 | error_setg(errp, "Could not parse the JSON options"); | |
1431 | return NULL; | |
1432 | } | |
1433 | error_prepend(errp, "Could not parse the JSON options: "); | |
1434 | return NULL; | |
1435 | } | |
1436 | ||
1437 | options = qobject_to_qdict(options_obj); | |
1438 | if (!options) { | |
1439 | qobject_decref(options_obj); | |
1440 | error_setg(errp, "Invalid JSON object given"); | |
1441 | return NULL; | |
1442 | } | |
1443 | ||
1444 | qdict_flatten(options); | |
1445 | ||
1446 | return options; | |
1447 | } | |
1448 | ||
1449 | static void parse_json_protocol(QDict *options, const char **pfilename, | |
1450 | Error **errp) | |
1451 | { | |
1452 | QDict *json_options; | |
1453 | Error *local_err = NULL; | |
1454 | ||
1455 | /* Parse json: pseudo-protocol */ | |
1456 | if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) { | |
1457 | return; | |
1458 | } | |
1459 | ||
1460 | json_options = parse_json_filename(*pfilename, &local_err); | |
1461 | if (local_err) { | |
1462 | error_propagate(errp, local_err); | |
1463 | return; | |
1464 | } | |
1465 | ||
1466 | /* Options given in the filename have lower priority than options | |
1467 | * specified directly */ | |
1468 | qdict_join(options, json_options, false); | |
1469 | QDECREF(json_options); | |
1470 | *pfilename = NULL; | |
1471 | } | |
1472 | ||
1473 | /* | |
1474 | * Fills in default options for opening images and converts the legacy | |
1475 | * filename/flags pair to option QDict entries. | |
1476 | * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a | |
1477 | * block driver has been specified explicitly. | |
1478 | */ | |
1479 | static int bdrv_fill_options(QDict **options, const char *filename, | |
1480 | int *flags, Error **errp) | |
1481 | { | |
1482 | const char *drvname; | |
1483 | bool protocol = *flags & BDRV_O_PROTOCOL; | |
1484 | bool parse_filename = false; | |
1485 | BlockDriver *drv = NULL; | |
1486 | Error *local_err = NULL; | |
1487 | ||
1488 | /* | |
1489 | * Caution: while qdict_get_try_str() is fine, getting non-string | |
1490 | * types would require more care. When @options come from | |
1491 | * -blockdev or blockdev_add, its members are typed according to | |
1492 | * the QAPI schema, but when they come from -drive, they're all | |
1493 | * QString. | |
1494 | */ | |
1495 | drvname = qdict_get_try_str(*options, "driver"); | |
1496 | if (drvname) { | |
1497 | drv = bdrv_find_format(drvname); | |
1498 | if (!drv) { | |
1499 | error_setg(errp, "Unknown driver '%s'", drvname); | |
1500 | return -ENOENT; | |
1501 | } | |
1502 | /* If the user has explicitly specified the driver, this choice should | |
1503 | * override the BDRV_O_PROTOCOL flag */ | |
1504 | protocol = drv->bdrv_file_open; | |
1505 | } | |
1506 | ||
1507 | if (protocol) { | |
1508 | *flags |= BDRV_O_PROTOCOL; | |
1509 | } else { | |
1510 | *flags &= ~BDRV_O_PROTOCOL; | |
1511 | } | |
1512 | ||
1513 | /* Translate cache options from flags into options */ | |
1514 | update_options_from_flags(*options, *flags); | |
1515 | ||
1516 | /* Fetch the file name from the options QDict if necessary */ | |
1517 | if (protocol && filename) { | |
1518 | if (!qdict_haskey(*options, "filename")) { | |
1519 | qdict_put_str(*options, "filename", filename); | |
1520 | parse_filename = true; | |
1521 | } else { | |
1522 | error_setg(errp, "Can't specify 'file' and 'filename' options at " | |
1523 | "the same time"); | |
1524 | return -EINVAL; | |
1525 | } | |
1526 | } | |
1527 | ||
1528 | /* Find the right block driver */ | |
1529 | /* See cautionary note on accessing @options above */ | |
1530 | filename = qdict_get_try_str(*options, "filename"); | |
1531 | ||
1532 | if (!drvname && protocol) { | |
1533 | if (filename) { | |
1534 | drv = bdrv_find_protocol(filename, parse_filename, errp); | |
1535 | if (!drv) { | |
1536 | return -EINVAL; | |
1537 | } | |
1538 | ||
1539 | drvname = drv->format_name; | |
1540 | qdict_put_str(*options, "driver", drvname); | |
1541 | } else { | |
1542 | error_setg(errp, "Must specify either driver or file"); | |
1543 | return -EINVAL; | |
1544 | } | |
1545 | } | |
1546 | ||
1547 | assert(drv || !protocol); | |
1548 | ||
1549 | /* Driver-specific filename parsing */ | |
1550 | if (drv && drv->bdrv_parse_filename && parse_filename) { | |
1551 | drv->bdrv_parse_filename(filename, *options, &local_err); | |
1552 | if (local_err) { | |
1553 | error_propagate(errp, local_err); | |
1554 | return -EINVAL; | |
1555 | } | |
1556 | ||
1557 | if (!drv->bdrv_needs_filename) { | |
1558 | qdict_del(*options, "filename"); | |
1559 | } | |
1560 | } | |
1561 | ||
1562 | return 0; | |
1563 | } | |
1564 | ||
1565 | static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, | |
1566 | uint64_t perm, uint64_t shared, | |
1567 | GSList *ignore_children, Error **errp); | |
1568 | static void bdrv_child_abort_perm_update(BdrvChild *c); | |
1569 | static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared); | |
1570 | ||
1571 | typedef struct BlockReopenQueueEntry { | |
1572 | bool prepared; | |
1573 | BDRVReopenState state; | |
1574 | QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; | |
1575 | } BlockReopenQueueEntry; | |
1576 | ||
1577 | /* | |
1578 | * Return the flags that @bs will have after the reopens in @q have | |
1579 | * successfully completed. If @q is NULL (or @bs is not contained in @q), | |
1580 | * return the current flags. | |
1581 | */ | |
1582 | static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs) | |
1583 | { | |
1584 | BlockReopenQueueEntry *entry; | |
1585 | ||
1586 | if (q != NULL) { | |
1587 | QSIMPLEQ_FOREACH(entry, q, entry) { | |
1588 | if (entry->state.bs == bs) { | |
1589 | return entry->state.flags; | |
1590 | } | |
1591 | } | |
1592 | } | |
1593 | ||
1594 | return bs->open_flags; | |
1595 | } | |
1596 | ||
1597 | /* Returns whether the image file can be written to after the reopen queue @q | |
1598 | * has been successfully applied, or right now if @q is NULL. */ | |
1599 | static bool bdrv_is_writable(BlockDriverState *bs, BlockReopenQueue *q) | |
1600 | { | |
1601 | int flags = bdrv_reopen_get_flags(q, bs); | |
1602 | ||
1603 | return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR; | |
1604 | } | |
1605 | ||
1606 | static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs, | |
1607 | BdrvChild *c, const BdrvChildRole *role, | |
1608 | BlockReopenQueue *reopen_queue, | |
1609 | uint64_t parent_perm, uint64_t parent_shared, | |
1610 | uint64_t *nperm, uint64_t *nshared) | |
1611 | { | |
1612 | if (bs->drv && bs->drv->bdrv_child_perm) { | |
1613 | bs->drv->bdrv_child_perm(bs, c, role, reopen_queue, | |
1614 | parent_perm, parent_shared, | |
1615 | nperm, nshared); | |
1616 | } | |
1617 | /* TODO Take force_share from reopen_queue */ | |
1618 | if (child_bs && child_bs->force_share) { | |
1619 | *nshared = BLK_PERM_ALL; | |
1620 | } | |
1621 | } | |
1622 | ||
1623 | /* | |
1624 | * Check whether permissions on this node can be changed in a way that | |
1625 | * @cumulative_perms and @cumulative_shared_perms are the new cumulative | |
1626 | * permissions of all its parents. This involves checking whether all necessary | |
1627 | * permission changes to child nodes can be performed. | |
1628 | * | |
1629 | * A call to this function must always be followed by a call to bdrv_set_perm() | |
1630 | * or bdrv_abort_perm_update(). | |
1631 | */ | |
1632 | static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q, | |
1633 | uint64_t cumulative_perms, | |
1634 | uint64_t cumulative_shared_perms, | |
1635 | GSList *ignore_children, Error **errp) | |
1636 | { | |
1637 | BlockDriver *drv = bs->drv; | |
1638 | BdrvChild *c; | |
1639 | int ret; | |
1640 | ||
1641 | /* Write permissions never work with read-only images */ | |
1642 | if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) && | |
1643 | !bdrv_is_writable(bs, q)) | |
1644 | { | |
1645 | error_setg(errp, "Block node is read-only"); | |
1646 | return -EPERM; | |
1647 | } | |
1648 | ||
1649 | /* Check this node */ | |
1650 | if (!drv) { | |
1651 | return 0; | |
1652 | } | |
1653 | ||
1654 | if (drv->bdrv_check_perm) { | |
1655 | return drv->bdrv_check_perm(bs, cumulative_perms, | |
1656 | cumulative_shared_perms, errp); | |
1657 | } | |
1658 | ||
1659 | /* Drivers that never have children can omit .bdrv_child_perm() */ | |
1660 | if (!drv->bdrv_child_perm) { | |
1661 | assert(QLIST_EMPTY(&bs->children)); | |
1662 | return 0; | |
1663 | } | |
1664 | ||
1665 | /* Check all children */ | |
1666 | QLIST_FOREACH(c, &bs->children, next) { | |
1667 | uint64_t cur_perm, cur_shared; | |
1668 | bdrv_child_perm(bs, c->bs, c, c->role, q, | |
1669 | cumulative_perms, cumulative_shared_perms, | |
1670 | &cur_perm, &cur_shared); | |
1671 | ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared, | |
1672 | ignore_children, errp); | |
1673 | if (ret < 0) { | |
1674 | return ret; | |
1675 | } | |
1676 | } | |
1677 | ||
1678 | return 0; | |
1679 | } | |
1680 | ||
1681 | /* | |
1682 | * Notifies drivers that after a previous bdrv_check_perm() call, the | |
1683 | * permission update is not performed and any preparations made for it (e.g. | |
1684 | * taken file locks) need to be undone. | |
1685 | * | |
1686 | * This function recursively notifies all child nodes. | |
1687 | */ | |
1688 | static void bdrv_abort_perm_update(BlockDriverState *bs) | |
1689 | { | |
1690 | BlockDriver *drv = bs->drv; | |
1691 | BdrvChild *c; | |
1692 | ||
1693 | if (!drv) { | |
1694 | return; | |
1695 | } | |
1696 | ||
1697 | if (drv->bdrv_abort_perm_update) { | |
1698 | drv->bdrv_abort_perm_update(bs); | |
1699 | } | |
1700 | ||
1701 | QLIST_FOREACH(c, &bs->children, next) { | |
1702 | bdrv_child_abort_perm_update(c); | |
1703 | } | |
1704 | } | |
1705 | ||
1706 | static void bdrv_set_perm(BlockDriverState *bs, uint64_t cumulative_perms, | |
1707 | uint64_t cumulative_shared_perms) | |
1708 | { | |
1709 | BlockDriver *drv = bs->drv; | |
1710 | BdrvChild *c; | |
1711 | ||
1712 | if (!drv) { | |
1713 | return; | |
1714 | } | |
1715 | ||
1716 | /* Update this node */ | |
1717 | if (drv->bdrv_set_perm) { | |
1718 | drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms); | |
1719 | } | |
1720 | ||
1721 | /* Drivers that never have children can omit .bdrv_child_perm() */ | |
1722 | if (!drv->bdrv_child_perm) { | |
1723 | assert(QLIST_EMPTY(&bs->children)); | |
1724 | return; | |
1725 | } | |
1726 | ||
1727 | /* Update all children */ | |
1728 | QLIST_FOREACH(c, &bs->children, next) { | |
1729 | uint64_t cur_perm, cur_shared; | |
1730 | bdrv_child_perm(bs, c->bs, c, c->role, NULL, | |
1731 | cumulative_perms, cumulative_shared_perms, | |
1732 | &cur_perm, &cur_shared); | |
1733 | bdrv_child_set_perm(c, cur_perm, cur_shared); | |
1734 | } | |
1735 | } | |
1736 | ||
1737 | static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, | |
1738 | uint64_t *shared_perm) | |
1739 | { | |
1740 | BdrvChild *c; | |
1741 | uint64_t cumulative_perms = 0; | |
1742 | uint64_t cumulative_shared_perms = BLK_PERM_ALL; | |
1743 | ||
1744 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
1745 | cumulative_perms |= c->perm; | |
1746 | cumulative_shared_perms &= c->shared_perm; | |
1747 | } | |
1748 | ||
1749 | *perm = cumulative_perms; | |
1750 | *shared_perm = cumulative_shared_perms; | |
1751 | } | |
1752 | ||
1753 | static char *bdrv_child_user_desc(BdrvChild *c) | |
1754 | { | |
1755 | if (c->role->get_parent_desc) { | |
1756 | return c->role->get_parent_desc(c); | |
1757 | } | |
1758 | ||
1759 | return g_strdup("another user"); | |
1760 | } | |
1761 | ||
1762 | char *bdrv_perm_names(uint64_t perm) | |
1763 | { | |
1764 | struct perm_name { | |
1765 | uint64_t perm; | |
1766 | const char *name; | |
1767 | } permissions[] = { | |
1768 | { BLK_PERM_CONSISTENT_READ, "consistent read" }, | |
1769 | { BLK_PERM_WRITE, "write" }, | |
1770 | { BLK_PERM_WRITE_UNCHANGED, "write unchanged" }, | |
1771 | { BLK_PERM_RESIZE, "resize" }, | |
1772 | { BLK_PERM_GRAPH_MOD, "change children" }, | |
1773 | { 0, NULL } | |
1774 | }; | |
1775 | ||
1776 | char *result = g_strdup(""); | |
1777 | struct perm_name *p; | |
1778 | ||
1779 | for (p = permissions; p->name; p++) { | |
1780 | if (perm & p->perm) { | |
1781 | char *old = result; | |
1782 | result = g_strdup_printf("%s%s%s", old, *old ? ", " : "", p->name); | |
1783 | g_free(old); | |
1784 | } | |
1785 | } | |
1786 | ||
1787 | return result; | |
1788 | } | |
1789 | ||
1790 | /* | |
1791 | * Checks whether a new reference to @bs can be added if the new user requires | |
1792 | * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is | |
1793 | * set, the BdrvChild objects in this list are ignored in the calculations; | |
1794 | * this allows checking permission updates for an existing reference. | |
1795 | * | |
1796 | * Needs to be followed by a call to either bdrv_set_perm() or | |
1797 | * bdrv_abort_perm_update(). */ | |
1798 | static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q, | |
1799 | uint64_t new_used_perm, | |
1800 | uint64_t new_shared_perm, | |
1801 | GSList *ignore_children, Error **errp) | |
1802 | { | |
1803 | BdrvChild *c; | |
1804 | uint64_t cumulative_perms = new_used_perm; | |
1805 | uint64_t cumulative_shared_perms = new_shared_perm; | |
1806 | ||
1807 | /* There is no reason why anyone couldn't tolerate write_unchanged */ | |
1808 | assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED); | |
1809 | ||
1810 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
1811 | if (g_slist_find(ignore_children, c)) { | |
1812 | continue; | |
1813 | } | |
1814 | ||
1815 | if ((new_used_perm & c->shared_perm) != new_used_perm) { | |
1816 | char *user = bdrv_child_user_desc(c); | |
1817 | char *perm_names = bdrv_perm_names(new_used_perm & ~c->shared_perm); | |
1818 | error_setg(errp, "Conflicts with use by %s as '%s', which does not " | |
1819 | "allow '%s' on %s", | |
1820 | user, c->name, perm_names, bdrv_get_node_name(c->bs)); | |
1821 | g_free(user); | |
1822 | g_free(perm_names); | |
1823 | return -EPERM; | |
1824 | } | |
1825 | ||
1826 | if ((c->perm & new_shared_perm) != c->perm) { | |
1827 | char *user = bdrv_child_user_desc(c); | |
1828 | char *perm_names = bdrv_perm_names(c->perm & ~new_shared_perm); | |
1829 | error_setg(errp, "Conflicts with use by %s as '%s', which uses " | |
1830 | "'%s' on %s", | |
1831 | user, c->name, perm_names, bdrv_get_node_name(c->bs)); | |
1832 | g_free(user); | |
1833 | g_free(perm_names); | |
1834 | return -EPERM; | |
1835 | } | |
1836 | ||
1837 | cumulative_perms |= c->perm; | |
1838 | cumulative_shared_perms &= c->shared_perm; | |
1839 | } | |
1840 | ||
1841 | return bdrv_check_perm(bs, q, cumulative_perms, cumulative_shared_perms, | |
1842 | ignore_children, errp); | |
1843 | } | |
1844 | ||
1845 | /* Needs to be followed by a call to either bdrv_child_set_perm() or | |
1846 | * bdrv_child_abort_perm_update(). */ | |
1847 | static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, | |
1848 | uint64_t perm, uint64_t shared, | |
1849 | GSList *ignore_children, Error **errp) | |
1850 | { | |
1851 | int ret; | |
1852 | ||
1853 | ignore_children = g_slist_prepend(g_slist_copy(ignore_children), c); | |
1854 | ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, errp); | |
1855 | g_slist_free(ignore_children); | |
1856 | ||
1857 | return ret; | |
1858 | } | |
1859 | ||
1860 | static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared) | |
1861 | { | |
1862 | uint64_t cumulative_perms, cumulative_shared_perms; | |
1863 | ||
1864 | c->perm = perm; | |
1865 | c->shared_perm = shared; | |
1866 | ||
1867 | bdrv_get_cumulative_perm(c->bs, &cumulative_perms, | |
1868 | &cumulative_shared_perms); | |
1869 | bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms); | |
1870 | } | |
1871 | ||
1872 | static void bdrv_child_abort_perm_update(BdrvChild *c) | |
1873 | { | |
1874 | bdrv_abort_perm_update(c->bs); | |
1875 | } | |
1876 | ||
1877 | int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, | |
1878 | Error **errp) | |
1879 | { | |
1880 | int ret; | |
1881 | ||
1882 | ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL, errp); | |
1883 | if (ret < 0) { | |
1884 | bdrv_child_abort_perm_update(c); | |
1885 | return ret; | |
1886 | } | |
1887 | ||
1888 | bdrv_child_set_perm(c, perm, shared); | |
1889 | ||
1890 | return 0; | |
1891 | } | |
1892 | ||
1893 | #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \ | |
1894 | | BLK_PERM_WRITE \ | |
1895 | | BLK_PERM_WRITE_UNCHANGED \ | |
1896 | | BLK_PERM_RESIZE) | |
1897 | #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH) | |
1898 | ||
1899 | void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, | |
1900 | const BdrvChildRole *role, | |
1901 | BlockReopenQueue *reopen_queue, | |
1902 | uint64_t perm, uint64_t shared, | |
1903 | uint64_t *nperm, uint64_t *nshared) | |
1904 | { | |
1905 | if (c == NULL) { | |
1906 | *nperm = perm & DEFAULT_PERM_PASSTHROUGH; | |
1907 | *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED; | |
1908 | return; | |
1909 | } | |
1910 | ||
1911 | *nperm = (perm & DEFAULT_PERM_PASSTHROUGH) | | |
1912 | (c->perm & DEFAULT_PERM_UNCHANGED); | |
1913 | *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | | |
1914 | (c->shared_perm & DEFAULT_PERM_UNCHANGED); | |
1915 | } | |
1916 | ||
1917 | void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, | |
1918 | const BdrvChildRole *role, | |
1919 | BlockReopenQueue *reopen_queue, | |
1920 | uint64_t perm, uint64_t shared, | |
1921 | uint64_t *nperm, uint64_t *nshared) | |
1922 | { | |
1923 | bool backing = (role == &child_backing); | |
1924 | assert(role == &child_backing || role == &child_file); | |
1925 | ||
1926 | if (!backing) { | |
1927 | /* Apart from the modifications below, the same permissions are | |
1928 | * forwarded and left alone as for filters */ | |
1929 | bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared, | |
1930 | &perm, &shared); | |
1931 | ||
1932 | /* Format drivers may touch metadata even if the guest doesn't write */ | |
1933 | if (bdrv_is_writable(bs, reopen_queue)) { | |
1934 | perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; | |
1935 | } | |
1936 | ||
1937 | /* bs->file always needs to be consistent because of the metadata. We | |
1938 | * can never allow other users to resize or write to it. */ | |
1939 | perm |= BLK_PERM_CONSISTENT_READ; | |
1940 | shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); | |
1941 | } else { | |
1942 | /* We want consistent read from backing files if the parent needs it. | |
1943 | * No other operations are performed on backing files. */ | |
1944 | perm &= BLK_PERM_CONSISTENT_READ; | |
1945 | ||
1946 | /* If the parent can deal with changing data, we're okay with a | |
1947 | * writable and resizable backing file. */ | |
1948 | /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */ | |
1949 | if (shared & BLK_PERM_WRITE) { | |
1950 | shared = BLK_PERM_WRITE | BLK_PERM_RESIZE; | |
1951 | } else { | |
1952 | shared = 0; | |
1953 | } | |
1954 | ||
1955 | shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD | | |
1956 | BLK_PERM_WRITE_UNCHANGED; | |
1957 | } | |
1958 | ||
1959 | if (bs->open_flags & BDRV_O_INACTIVE) { | |
1960 | shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; | |
1961 | } | |
1962 | ||
1963 | *nperm = perm; | |
1964 | *nshared = shared; | |
1965 | } | |
1966 | ||
1967 | static void bdrv_replace_child_noperm(BdrvChild *child, | |
1968 | BlockDriverState *new_bs) | |
1969 | { | |
1970 | BlockDriverState *old_bs = child->bs; | |
1971 | ||
1972 | if (old_bs && new_bs) { | |
1973 | assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)); | |
1974 | } | |
1975 | if (old_bs) { | |
1976 | if (old_bs->quiesce_counter && child->role->drained_end) { | |
1977 | child->role->drained_end(child); | |
1978 | } | |
1979 | if (child->role->detach) { | |
1980 | child->role->detach(child); | |
1981 | } | |
1982 | QLIST_REMOVE(child, next_parent); | |
1983 | } | |
1984 | ||
1985 | child->bs = new_bs; | |
1986 | ||
1987 | if (new_bs) { | |
1988 | QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent); | |
1989 | if (new_bs->quiesce_counter && child->role->drained_begin) { | |
1990 | child->role->drained_begin(child); | |
1991 | } | |
1992 | ||
1993 | if (child->role->attach) { | |
1994 | child->role->attach(child); | |
1995 | } | |
1996 | } | |
1997 | } | |
1998 | ||
1999 | /* | |
2000 | * Updates @child to change its reference to point to @new_bs, including | |
2001 | * checking and applying the necessary permisson updates both to the old node | |
2002 | * and to @new_bs. | |
2003 | * | |
2004 | * NULL is passed as @new_bs for removing the reference before freeing @child. | |
2005 | * | |
2006 | * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this | |
2007 | * function uses bdrv_set_perm() to update the permissions according to the new | |
2008 | * reference that @new_bs gets. | |
2009 | */ | |
2010 | static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) | |
2011 | { | |
2012 | BlockDriverState *old_bs = child->bs; | |
2013 | uint64_t perm, shared_perm; | |
2014 | ||
2015 | bdrv_replace_child_noperm(child, new_bs); | |
2016 | ||
2017 | if (old_bs) { | |
2018 | /* Update permissions for old node. This is guaranteed to succeed | |
2019 | * because we're just taking a parent away, so we're loosening | |
2020 | * restrictions. */ | |
2021 | bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm); | |
2022 | bdrv_check_perm(old_bs, NULL, perm, shared_perm, NULL, &error_abort); | |
2023 | bdrv_set_perm(old_bs, perm, shared_perm); | |
2024 | } | |
2025 | ||
2026 | if (new_bs) { | |
2027 | bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm); | |
2028 | bdrv_set_perm(new_bs, perm, shared_perm); | |
2029 | } | |
2030 | } | |
2031 | ||
2032 | BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, | |
2033 | const char *child_name, | |
2034 | const BdrvChildRole *child_role, | |
2035 | uint64_t perm, uint64_t shared_perm, | |
2036 | void *opaque, Error **errp) | |
2037 | { | |
2038 | BdrvChild *child; | |
2039 | int ret; | |
2040 | ||
2041 | ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, errp); | |
2042 | if (ret < 0) { | |
2043 | bdrv_abort_perm_update(child_bs); | |
2044 | return NULL; | |
2045 | } | |
2046 | ||
2047 | child = g_new(BdrvChild, 1); | |
2048 | *child = (BdrvChild) { | |
2049 | .bs = NULL, | |
2050 | .name = g_strdup(child_name), | |
2051 | .role = child_role, | |
2052 | .perm = perm, | |
2053 | .shared_perm = shared_perm, | |
2054 | .opaque = opaque, | |
2055 | }; | |
2056 | ||
2057 | /* This performs the matching bdrv_set_perm() for the above check. */ | |
2058 | bdrv_replace_child(child, child_bs); | |
2059 | ||
2060 | return child; | |
2061 | } | |
2062 | ||
2063 | BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, | |
2064 | BlockDriverState *child_bs, | |
2065 | const char *child_name, | |
2066 | const BdrvChildRole *child_role, | |
2067 | Error **errp) | |
2068 | { | |
2069 | BdrvChild *child; | |
2070 | uint64_t perm, shared_perm; | |
2071 | ||
2072 | bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm); | |
2073 | ||
2074 | assert(parent_bs->drv); | |
2075 | assert(bdrv_get_aio_context(parent_bs) == bdrv_get_aio_context(child_bs)); | |
2076 | bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL, | |
2077 | perm, shared_perm, &perm, &shared_perm); | |
2078 | ||
2079 | child = bdrv_root_attach_child(child_bs, child_name, child_role, | |
2080 | perm, shared_perm, parent_bs, errp); | |
2081 | if (child == NULL) { | |
2082 | return NULL; | |
2083 | } | |
2084 | ||
2085 | QLIST_INSERT_HEAD(&parent_bs->children, child, next); | |
2086 | return child; | |
2087 | } | |
2088 | ||
2089 | static void bdrv_detach_child(BdrvChild *child) | |
2090 | { | |
2091 | if (child->next.le_prev) { | |
2092 | QLIST_REMOVE(child, next); | |
2093 | child->next.le_prev = NULL; | |
2094 | } | |
2095 | ||
2096 | bdrv_replace_child(child, NULL); | |
2097 | ||
2098 | g_free(child->name); | |
2099 | g_free(child); | |
2100 | } | |
2101 | ||
2102 | void bdrv_root_unref_child(BdrvChild *child) | |
2103 | { | |
2104 | BlockDriverState *child_bs; | |
2105 | ||
2106 | child_bs = child->bs; | |
2107 | bdrv_detach_child(child); | |
2108 | bdrv_unref(child_bs); | |
2109 | } | |
2110 | ||
2111 | void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) | |
2112 | { | |
2113 | if (child == NULL) { | |
2114 | return; | |
2115 | } | |
2116 | ||
2117 | if (child->bs->inherits_from == parent) { | |
2118 | BdrvChild *c; | |
2119 | ||
2120 | /* Remove inherits_from only when the last reference between parent and | |
2121 | * child->bs goes away. */ | |
2122 | QLIST_FOREACH(c, &parent->children, next) { | |
2123 | if (c != child && c->bs == child->bs) { | |
2124 | break; | |
2125 | } | |
2126 | } | |
2127 | if (c == NULL) { | |
2128 | child->bs->inherits_from = NULL; | |
2129 | } | |
2130 | } | |
2131 | ||
2132 | bdrv_root_unref_child(child); | |
2133 | } | |
2134 | ||
2135 | ||
2136 | static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load) | |
2137 | { | |
2138 | BdrvChild *c; | |
2139 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
2140 | if (c->role->change_media) { | |
2141 | c->role->change_media(c, load); | |
2142 | } | |
2143 | } | |
2144 | } | |
2145 | ||
2146 | static void bdrv_parent_cb_resize(BlockDriverState *bs) | |
2147 | { | |
2148 | BdrvChild *c; | |
2149 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
2150 | if (c->role->resize) { | |
2151 | c->role->resize(c); | |
2152 | } | |
2153 | } | |
2154 | } | |
2155 | ||
2156 | /* | |
2157 | * Sets the backing file link of a BDS. A new reference is created; callers | |
2158 | * which don't need their own reference any more must call bdrv_unref(). | |
2159 | */ | |
2160 | void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, | |
2161 | Error **errp) | |
2162 | { | |
2163 | if (backing_hd) { | |
2164 | bdrv_ref(backing_hd); | |
2165 | } | |
2166 | ||
2167 | if (bs->backing) { | |
2168 | bdrv_unref_child(bs, bs->backing); | |
2169 | } | |
2170 | ||
2171 | if (!backing_hd) { | |
2172 | bs->backing = NULL; | |
2173 | goto out; | |
2174 | } | |
2175 | ||
2176 | bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing, | |
2177 | errp); | |
2178 | if (!bs->backing) { | |
2179 | bdrv_unref(backing_hd); | |
2180 | } | |
2181 | ||
2182 | bdrv_refresh_filename(bs); | |
2183 | ||
2184 | out: | |
2185 | bdrv_refresh_limits(bs, NULL); | |
2186 | } | |
2187 | ||
2188 | /* | |
2189 | * Opens the backing file for a BlockDriverState if not yet open | |
2190 | * | |
2191 | * bdref_key specifies the key for the image's BlockdevRef in the options QDict. | |
2192 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict | |
2193 | * itself, all options starting with "${bdref_key}." are considered part of the | |
2194 | * BlockdevRef. | |
2195 | * | |
2196 | * TODO Can this be unified with bdrv_open_image()? | |
2197 | */ | |
2198 | int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, | |
2199 | const char *bdref_key, Error **errp) | |
2200 | { | |
2201 | char *backing_filename = g_malloc0(PATH_MAX); | |
2202 | char *bdref_key_dot; | |
2203 | const char *reference = NULL; | |
2204 | int ret = 0; | |
2205 | BlockDriverState *backing_hd; | |
2206 | QDict *options; | |
2207 | QDict *tmp_parent_options = NULL; | |
2208 | Error *local_err = NULL; | |
2209 | ||
2210 | if (bs->backing != NULL) { | |
2211 | goto free_exit; | |
2212 | } | |
2213 | ||
2214 | /* NULL means an empty set of options */ | |
2215 | if (parent_options == NULL) { | |
2216 | tmp_parent_options = qdict_new(); | |
2217 | parent_options = tmp_parent_options; | |
2218 | } | |
2219 | ||
2220 | bs->open_flags &= ~BDRV_O_NO_BACKING; | |
2221 | ||
2222 | bdref_key_dot = g_strdup_printf("%s.", bdref_key); | |
2223 | qdict_extract_subqdict(parent_options, &options, bdref_key_dot); | |
2224 | g_free(bdref_key_dot); | |
2225 | ||
2226 | /* | |
2227 | * Caution: while qdict_get_try_str() is fine, getting non-string | |
2228 | * types would require more care. When @parent_options come from | |
2229 | * -blockdev or blockdev_add, its members are typed according to | |
2230 | * the QAPI schema, but when they come from -drive, they're all | |
2231 | * QString. | |
2232 | */ | |
2233 | reference = qdict_get_try_str(parent_options, bdref_key); | |
2234 | if (reference || qdict_haskey(options, "file.filename")) { | |
2235 | backing_filename[0] = '\0'; | |
2236 | } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { | |
2237 | QDECREF(options); | |
2238 | goto free_exit; | |
2239 | } else { | |
2240 | bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX, | |
2241 | &local_err); | |
2242 | if (local_err) { | |
2243 | ret = -EINVAL; | |
2244 | error_propagate(errp, local_err); | |
2245 | QDECREF(options); | |
2246 | goto free_exit; | |
2247 | } | |
2248 | } | |
2249 | ||
2250 | if (!bs->drv || !bs->drv->supports_backing) { | |
2251 | ret = -EINVAL; | |
2252 | error_setg(errp, "Driver doesn't support backing files"); | |
2253 | QDECREF(options); | |
2254 | goto free_exit; | |
2255 | } | |
2256 | ||
2257 | if (!reference && | |
2258 | bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { | |
2259 | qdict_put_str(options, "driver", bs->backing_format); | |
2260 | } | |
2261 | ||
2262 | backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL, | |
2263 | reference, options, 0, bs, &child_backing, | |
2264 | errp); | |
2265 | if (!backing_hd) { | |
2266 | bs->open_flags |= BDRV_O_NO_BACKING; | |
2267 | error_prepend(errp, "Could not open backing file: "); | |
2268 | ret = -EINVAL; | |
2269 | goto free_exit; | |
2270 | } | |
2271 | bdrv_set_aio_context(backing_hd, bdrv_get_aio_context(bs)); | |
2272 | ||
2273 | /* Hook up the backing file link; drop our reference, bs owns the | |
2274 | * backing_hd reference now */ | |
2275 | bdrv_set_backing_hd(bs, backing_hd, &local_err); | |
2276 | bdrv_unref(backing_hd); | |
2277 | if (local_err) { | |
2278 | error_propagate(errp, local_err); | |
2279 | ret = -EINVAL; | |
2280 | goto free_exit; | |
2281 | } | |
2282 | ||
2283 | qdict_del(parent_options, bdref_key); | |
2284 | ||
2285 | free_exit: | |
2286 | g_free(backing_filename); | |
2287 | QDECREF(tmp_parent_options); | |
2288 | return ret; | |
2289 | } | |
2290 | ||
2291 | static BlockDriverState * | |
2292 | bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key, | |
2293 | BlockDriverState *parent, const BdrvChildRole *child_role, | |
2294 | bool allow_none, Error **errp) | |
2295 | { | |
2296 | BlockDriverState *bs = NULL; | |
2297 | QDict *image_options; | |
2298 | char *bdref_key_dot; | |
2299 | const char *reference; | |
2300 | ||
2301 | assert(child_role != NULL); | |
2302 | ||
2303 | bdref_key_dot = g_strdup_printf("%s.", bdref_key); | |
2304 | qdict_extract_subqdict(options, &image_options, bdref_key_dot); | |
2305 | g_free(bdref_key_dot); | |
2306 | ||
2307 | /* | |
2308 | * Caution: while qdict_get_try_str() is fine, getting non-string | |
2309 | * types would require more care. When @options come from | |
2310 | * -blockdev or blockdev_add, its members are typed according to | |
2311 | * the QAPI schema, but when they come from -drive, they're all | |
2312 | * QString. | |
2313 | */ | |
2314 | reference = qdict_get_try_str(options, bdref_key); | |
2315 | if (!filename && !reference && !qdict_size(image_options)) { | |
2316 | if (!allow_none) { | |
2317 | error_setg(errp, "A block device must be specified for \"%s\"", | |
2318 | bdref_key); | |
2319 | } | |
2320 | QDECREF(image_options); | |
2321 | goto done; | |
2322 | } | |
2323 | ||
2324 | bs = bdrv_open_inherit(filename, reference, image_options, 0, | |
2325 | parent, child_role, errp); | |
2326 | if (!bs) { | |
2327 | goto done; | |
2328 | } | |
2329 | ||
2330 | done: | |
2331 | qdict_del(options, bdref_key); | |
2332 | return bs; | |
2333 | } | |
2334 | ||
2335 | /* | |
2336 | * Opens a disk image whose options are given as BlockdevRef in another block | |
2337 | * device's options. | |
2338 | * | |
2339 | * If allow_none is true, no image will be opened if filename is false and no | |
2340 | * BlockdevRef is given. NULL will be returned, but errp remains unset. | |
2341 | * | |
2342 | * bdrev_key specifies the key for the image's BlockdevRef in the options QDict. | |
2343 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict | |
2344 | * itself, all options starting with "${bdref_key}." are considered part of the | |
2345 | * BlockdevRef. | |
2346 | * | |
2347 | * The BlockdevRef will be removed from the options QDict. | |
2348 | */ | |
2349 | BdrvChild *bdrv_open_child(const char *filename, | |
2350 | QDict *options, const char *bdref_key, | |
2351 | BlockDriverState *parent, | |
2352 | const BdrvChildRole *child_role, | |
2353 | bool allow_none, Error **errp) | |
2354 | { | |
2355 | BdrvChild *c; | |
2356 | BlockDriverState *bs; | |
2357 | ||
2358 | bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_role, | |
2359 | allow_none, errp); | |
2360 | if (bs == NULL) { | |
2361 | return NULL; | |
2362 | } | |
2363 | ||
2364 | c = bdrv_attach_child(parent, bs, bdref_key, child_role, errp); | |
2365 | if (!c) { | |
2366 | bdrv_unref(bs); | |
2367 | return NULL; | |
2368 | } | |
2369 | ||
2370 | return c; | |
2371 | } | |
2372 | ||
2373 | static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs, | |
2374 | int flags, | |
2375 | QDict *snapshot_options, | |
2376 | Error **errp) | |
2377 | { | |
2378 | /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ | |
2379 | char *tmp_filename = g_malloc0(PATH_MAX + 1); | |
2380 | int64_t total_size; | |
2381 | QemuOpts *opts = NULL; | |
2382 | BlockDriverState *bs_snapshot = NULL; | |
2383 | Error *local_err = NULL; | |
2384 | int ret; | |
2385 | ||
2386 | /* if snapshot, we create a temporary backing file and open it | |
2387 | instead of opening 'filename' directly */ | |
2388 | ||
2389 | /* Get the required size from the image */ | |
2390 | total_size = bdrv_getlength(bs); | |
2391 | if (total_size < 0) { | |
2392 | error_setg_errno(errp, -total_size, "Could not get image size"); | |
2393 | goto out; | |
2394 | } | |
2395 | ||
2396 | /* Create the temporary image */ | |
2397 | ret = get_tmp_filename(tmp_filename, PATH_MAX + 1); | |
2398 | if (ret < 0) { | |
2399 | error_setg_errno(errp, -ret, "Could not get temporary filename"); | |
2400 | goto out; | |
2401 | } | |
2402 | ||
2403 | opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, | |
2404 | &error_abort); | |
2405 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort); | |
2406 | ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp); | |
2407 | qemu_opts_del(opts); | |
2408 | if (ret < 0) { | |
2409 | error_prepend(errp, "Could not create temporary overlay '%s': ", | |
2410 | tmp_filename); | |
2411 | goto out; | |
2412 | } | |
2413 | ||
2414 | /* Prepare options QDict for the temporary file */ | |
2415 | qdict_put_str(snapshot_options, "file.driver", "file"); | |
2416 | qdict_put_str(snapshot_options, "file.filename", tmp_filename); | |
2417 | qdict_put_str(snapshot_options, "driver", "qcow2"); | |
2418 | ||
2419 | bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp); | |
2420 | snapshot_options = NULL; | |
2421 | if (!bs_snapshot) { | |
2422 | goto out; | |
2423 | } | |
2424 | ||
2425 | /* bdrv_append() consumes a strong reference to bs_snapshot | |
2426 | * (i.e. it will call bdrv_unref() on it) even on error, so in | |
2427 | * order to be able to return one, we have to increase | |
2428 | * bs_snapshot's refcount here */ | |
2429 | bdrv_ref(bs_snapshot); | |
2430 | bdrv_append(bs_snapshot, bs, &local_err); | |
2431 | if (local_err) { | |
2432 | error_propagate(errp, local_err); | |
2433 | bs_snapshot = NULL; | |
2434 | goto out; | |
2435 | } | |
2436 | ||
2437 | out: | |
2438 | QDECREF(snapshot_options); | |
2439 | g_free(tmp_filename); | |
2440 | return bs_snapshot; | |
2441 | } | |
2442 | ||
2443 | /* | |
2444 | * Opens a disk image (raw, qcow2, vmdk, ...) | |
2445 | * | |
2446 | * options is a QDict of options to pass to the block drivers, or NULL for an | |
2447 | * empty set of options. The reference to the QDict belongs to the block layer | |
2448 | * after the call (even on failure), so if the caller intends to reuse the | |
2449 | * dictionary, it needs to use QINCREF() before calling bdrv_open. | |
2450 | * | |
2451 | * If *pbs is NULL, a new BDS will be created with a pointer to it stored there. | |
2452 | * If it is not NULL, the referenced BDS will be reused. | |
2453 | * | |
2454 | * The reference parameter may be used to specify an existing block device which | |
2455 | * should be opened. If specified, neither options nor a filename may be given, | |
2456 | * nor can an existing BDS be reused (that is, *pbs has to be NULL). | |
2457 | */ | |
2458 | static BlockDriverState *bdrv_open_inherit(const char *filename, | |
2459 | const char *reference, | |
2460 | QDict *options, int flags, | |
2461 | BlockDriverState *parent, | |
2462 | const BdrvChildRole *child_role, | |
2463 | Error **errp) | |
2464 | { | |
2465 | int ret; | |
2466 | BlockBackend *file = NULL; | |
2467 | BlockDriverState *bs; | |
2468 | BlockDriver *drv = NULL; | |
2469 | const char *drvname; | |
2470 | const char *backing; | |
2471 | Error *local_err = NULL; | |
2472 | QDict *snapshot_options = NULL; | |
2473 | int snapshot_flags = 0; | |
2474 | ||
2475 | assert(!child_role || !flags); | |
2476 | assert(!child_role == !parent); | |
2477 | ||
2478 | if (reference) { | |
2479 | bool options_non_empty = options ? qdict_size(options) : false; | |
2480 | QDECREF(options); | |
2481 | ||
2482 | if (filename || options_non_empty) { | |
2483 | error_setg(errp, "Cannot reference an existing block device with " | |
2484 | "additional options or a new filename"); | |
2485 | return NULL; | |
2486 | } | |
2487 | ||
2488 | bs = bdrv_lookup_bs(reference, reference, errp); | |
2489 | if (!bs) { | |
2490 | return NULL; | |
2491 | } | |
2492 | ||
2493 | bdrv_ref(bs); | |
2494 | return bs; | |
2495 | } | |
2496 | ||
2497 | bs = bdrv_new(); | |
2498 | ||
2499 | /* NULL means an empty set of options */ | |
2500 | if (options == NULL) { | |
2501 | options = qdict_new(); | |
2502 | } | |
2503 | ||
2504 | /* json: syntax counts as explicit options, as if in the QDict */ | |
2505 | parse_json_protocol(options, &filename, &local_err); | |
2506 | if (local_err) { | |
2507 | goto fail; | |
2508 | } | |
2509 | ||
2510 | bs->explicit_options = qdict_clone_shallow(options); | |
2511 | ||
2512 | if (child_role) { | |
2513 | bs->inherits_from = parent; | |
2514 | child_role->inherit_options(&flags, options, | |
2515 | parent->open_flags, parent->options); | |
2516 | } | |
2517 | ||
2518 | ret = bdrv_fill_options(&options, filename, &flags, &local_err); | |
2519 | if (local_err) { | |
2520 | goto fail; | |
2521 | } | |
2522 | ||
2523 | /* | |
2524 | * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags. | |
2525 | * Caution: getting a boolean member of @options requires care. | |
2526 | * When @options come from -blockdev or blockdev_add, members are | |
2527 | * typed according to the QAPI schema, but when they come from | |
2528 | * -drive, they're all QString. | |
2529 | */ | |
2530 | if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") && | |
2531 | !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) { | |
2532 | flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR); | |
2533 | } else { | |
2534 | flags &= ~BDRV_O_RDWR; | |
2535 | } | |
2536 | ||
2537 | if (flags & BDRV_O_SNAPSHOT) { | |
2538 | snapshot_options = qdict_new(); | |
2539 | bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options, | |
2540 | flags, options); | |
2541 | /* Let bdrv_backing_options() override "read-only" */ | |
2542 | qdict_del(options, BDRV_OPT_READ_ONLY); | |
2543 | bdrv_backing_options(&flags, options, flags, options); | |
2544 | } | |
2545 | ||
2546 | bs->open_flags = flags; | |
2547 | bs->options = options; | |
2548 | options = qdict_clone_shallow(options); | |
2549 | ||
2550 | /* Find the right image format driver */ | |
2551 | /* See cautionary note on accessing @options above */ | |
2552 | drvname = qdict_get_try_str(options, "driver"); | |
2553 | if (drvname) { | |
2554 | drv = bdrv_find_format(drvname); | |
2555 | if (!drv) { | |
2556 | error_setg(errp, "Unknown driver: '%s'", drvname); | |
2557 | goto fail; | |
2558 | } | |
2559 | } | |
2560 | ||
2561 | assert(drvname || !(flags & BDRV_O_PROTOCOL)); | |
2562 | ||
2563 | /* See cautionary note on accessing @options above */ | |
2564 | backing = qdict_get_try_str(options, "backing"); | |
2565 | if (backing && *backing == '\0') { | |
2566 | flags |= BDRV_O_NO_BACKING; | |
2567 | qdict_del(options, "backing"); | |
2568 | } | |
2569 | ||
2570 | /* Open image file without format layer. This BlockBackend is only used for | |
2571 | * probing, the block drivers will do their own bdrv_open_child() for the | |
2572 | * same BDS, which is why we put the node name back into options. */ | |
2573 | if ((flags & BDRV_O_PROTOCOL) == 0) { | |
2574 | BlockDriverState *file_bs; | |
2575 | ||
2576 | file_bs = bdrv_open_child_bs(filename, options, "file", bs, | |
2577 | &child_file, true, &local_err); | |
2578 | if (local_err) { | |
2579 | goto fail; | |
2580 | } | |
2581 | if (file_bs != NULL) { | |
2582 | /* Not requesting BLK_PERM_CONSISTENT_READ because we're only | |
2583 | * looking at the header to guess the image format. This works even | |
2584 | * in cases where a guest would not see a consistent state. */ | |
2585 | file = blk_new(0, BLK_PERM_ALL); | |
2586 | blk_insert_bs(file, file_bs, &local_err); | |
2587 | bdrv_unref(file_bs); | |
2588 | if (local_err) { | |
2589 | goto fail; | |
2590 | } | |
2591 | ||
2592 | qdict_put_str(options, "file", bdrv_get_node_name(file_bs)); | |
2593 | } | |
2594 | } | |
2595 | ||
2596 | /* Image format probing */ | |
2597 | bs->probed = !drv; | |
2598 | if (!drv && file) { | |
2599 | ret = find_image_format(file, filename, &drv, &local_err); | |
2600 | if (ret < 0) { | |
2601 | goto fail; | |
2602 | } | |
2603 | /* | |
2604 | * This option update would logically belong in bdrv_fill_options(), | |
2605 | * but we first need to open bs->file for the probing to work, while | |
2606 | * opening bs->file already requires the (mostly) final set of options | |
2607 | * so that cache mode etc. can be inherited. | |
2608 | * | |
2609 | * Adding the driver later is somewhat ugly, but it's not an option | |
2610 | * that would ever be inherited, so it's correct. We just need to make | |
2611 | * sure to update both bs->options (which has the full effective | |
2612 | * options for bs) and options (which has file.* already removed). | |
2613 | */ | |
2614 | qdict_put_str(bs->options, "driver", drv->format_name); | |
2615 | qdict_put_str(options, "driver", drv->format_name); | |
2616 | } else if (!drv) { | |
2617 | error_setg(errp, "Must specify either driver or file"); | |
2618 | goto fail; | |
2619 | } | |
2620 | ||
2621 | /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */ | |
2622 | assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open); | |
2623 | /* file must be NULL if a protocol BDS is about to be created | |
2624 | * (the inverse results in an error message from bdrv_open_common()) */ | |
2625 | assert(!(flags & BDRV_O_PROTOCOL) || !file); | |
2626 | ||
2627 | /* Open the image */ | |
2628 | ret = bdrv_open_common(bs, file, options, &local_err); | |
2629 | if (ret < 0) { | |
2630 | goto fail; | |
2631 | } | |
2632 | ||
2633 | if (file) { | |
2634 | blk_unref(file); | |
2635 | file = NULL; | |
2636 | } | |
2637 | ||
2638 | /* If there is a backing file, use it */ | |
2639 | if ((flags & BDRV_O_NO_BACKING) == 0) { | |
2640 | ret = bdrv_open_backing_file(bs, options, "backing", &local_err); | |
2641 | if (ret < 0) { | |
2642 | goto close_and_fail; | |
2643 | } | |
2644 | } | |
2645 | ||
2646 | bdrv_refresh_filename(bs); | |
2647 | ||
2648 | /* Check if any unknown options were used */ | |
2649 | if (qdict_size(options) != 0) { | |
2650 | const QDictEntry *entry = qdict_first(options); | |
2651 | if (flags & BDRV_O_PROTOCOL) { | |
2652 | error_setg(errp, "Block protocol '%s' doesn't support the option " | |
2653 | "'%s'", drv->format_name, entry->key); | |
2654 | } else { | |
2655 | error_setg(errp, | |
2656 | "Block format '%s' does not support the option '%s'", | |
2657 | drv->format_name, entry->key); | |
2658 | } | |
2659 | ||
2660 | goto close_and_fail; | |
2661 | } | |
2662 | ||
2663 | bdrv_parent_cb_change_media(bs, true); | |
2664 | ||
2665 | QDECREF(options); | |
2666 | ||
2667 | /* For snapshot=on, create a temporary qcow2 overlay. bs points to the | |
2668 | * temporary snapshot afterwards. */ | |
2669 | if (snapshot_flags) { | |
2670 | BlockDriverState *snapshot_bs; | |
2671 | snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags, | |
2672 | snapshot_options, &local_err); | |
2673 | snapshot_options = NULL; | |
2674 | if (local_err) { | |
2675 | goto close_and_fail; | |
2676 | } | |
2677 | /* We are not going to return bs but the overlay on top of it | |
2678 | * (snapshot_bs); thus, we have to drop the strong reference to bs | |
2679 | * (which we obtained by calling bdrv_new()). bs will not be deleted, | |
2680 | * though, because the overlay still has a reference to it. */ | |
2681 | bdrv_unref(bs); | |
2682 | bs = snapshot_bs; | |
2683 | } | |
2684 | ||
2685 | return bs; | |
2686 | ||
2687 | fail: | |
2688 | blk_unref(file); | |
2689 | QDECREF(snapshot_options); | |
2690 | QDECREF(bs->explicit_options); | |
2691 | QDECREF(bs->options); | |
2692 | QDECREF(options); | |
2693 | bs->options = NULL; | |
2694 | bs->explicit_options = NULL; | |
2695 | bdrv_unref(bs); | |
2696 | error_propagate(errp, local_err); | |
2697 | return NULL; | |
2698 | ||
2699 | close_and_fail: | |
2700 | bdrv_unref(bs); | |
2701 | QDECREF(snapshot_options); | |
2702 | QDECREF(options); | |
2703 | error_propagate(errp, local_err); | |
2704 | return NULL; | |
2705 | } | |
2706 | ||
2707 | BlockDriverState *bdrv_open(const char *filename, const char *reference, | |
2708 | QDict *options, int flags, Error **errp) | |
2709 | { | |
2710 | return bdrv_open_inherit(filename, reference, options, flags, NULL, | |
2711 | NULL, errp); | |
2712 | } | |
2713 | ||
2714 | /* | |
2715 | * Adds a BlockDriverState to a simple queue for an atomic, transactional | |
2716 | * reopen of multiple devices. | |
2717 | * | |
2718 | * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT | |
2719 | * already performed, or alternatively may be NULL a new BlockReopenQueue will | |
2720 | * be created and initialized. This newly created BlockReopenQueue should be | |
2721 | * passed back in for subsequent calls that are intended to be of the same | |
2722 | * atomic 'set'. | |
2723 | * | |
2724 | * bs is the BlockDriverState to add to the reopen queue. | |
2725 | * | |
2726 | * options contains the changed options for the associated bs | |
2727 | * (the BlockReopenQueue takes ownership) | |
2728 | * | |
2729 | * flags contains the open flags for the associated bs | |
2730 | * | |
2731 | * returns a pointer to bs_queue, which is either the newly allocated | |
2732 | * bs_queue, or the existing bs_queue being used. | |
2733 | * | |
2734 | */ | |
2735 | static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, | |
2736 | BlockDriverState *bs, | |
2737 | QDict *options, | |
2738 | int flags, | |
2739 | const BdrvChildRole *role, | |
2740 | QDict *parent_options, | |
2741 | int parent_flags) | |
2742 | { | |
2743 | assert(bs != NULL); | |
2744 | ||
2745 | BlockReopenQueueEntry *bs_entry; | |
2746 | BdrvChild *child; | |
2747 | QDict *old_options, *explicit_options; | |
2748 | ||
2749 | if (bs_queue == NULL) { | |
2750 | bs_queue = g_new0(BlockReopenQueue, 1); | |
2751 | QSIMPLEQ_INIT(bs_queue); | |
2752 | } | |
2753 | ||
2754 | if (!options) { | |
2755 | options = qdict_new(); | |
2756 | } | |
2757 | ||
2758 | /* Check if this BlockDriverState is already in the queue */ | |
2759 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
2760 | if (bs == bs_entry->state.bs) { | |
2761 | break; | |
2762 | } | |
2763 | } | |
2764 | ||
2765 | /* | |
2766 | * Precedence of options: | |
2767 | * 1. Explicitly passed in options (highest) | |
2768 | * 2. Set in flags (only for top level) | |
2769 | * 3. Retained from explicitly set options of bs | |
2770 | * 4. Inherited from parent node | |
2771 | * 5. Retained from effective options of bs | |
2772 | */ | |
2773 | ||
2774 | if (!parent_options) { | |
2775 | /* | |
2776 | * Any setting represented by flags is always updated. If the | |
2777 | * corresponding QDict option is set, it takes precedence. Otherwise | |
2778 | * the flag is translated into a QDict option. The old setting of bs is | |
2779 | * not considered. | |
2780 | */ | |
2781 | update_options_from_flags(options, flags); | |
2782 | } | |
2783 | ||
2784 | /* Old explicitly set values (don't overwrite by inherited value) */ | |
2785 | if (bs_entry) { | |
2786 | old_options = qdict_clone_shallow(bs_entry->state.explicit_options); | |
2787 | } else { | |
2788 | old_options = qdict_clone_shallow(bs->explicit_options); | |
2789 | } | |
2790 | bdrv_join_options(bs, options, old_options); | |
2791 | QDECREF(old_options); | |
2792 | ||
2793 | explicit_options = qdict_clone_shallow(options); | |
2794 | ||
2795 | /* Inherit from parent node */ | |
2796 | if (parent_options) { | |
2797 | assert(!flags); | |
2798 | role->inherit_options(&flags, options, parent_flags, parent_options); | |
2799 | } | |
2800 | ||
2801 | /* Old values are used for options that aren't set yet */ | |
2802 | old_options = qdict_clone_shallow(bs->options); | |
2803 | bdrv_join_options(bs, options, old_options); | |
2804 | QDECREF(old_options); | |
2805 | ||
2806 | /* bdrv_open_inherit() sets and clears some additional flags internally */ | |
2807 | flags &= ~BDRV_O_PROTOCOL; | |
2808 | if (flags & BDRV_O_RDWR) { | |
2809 | flags |= BDRV_O_ALLOW_RDWR; | |
2810 | } | |
2811 | ||
2812 | if (!bs_entry) { | |
2813 | bs_entry = g_new0(BlockReopenQueueEntry, 1); | |
2814 | QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); | |
2815 | } else { | |
2816 | QDECREF(bs_entry->state.options); | |
2817 | QDECREF(bs_entry->state.explicit_options); | |
2818 | } | |
2819 | ||
2820 | bs_entry->state.bs = bs; | |
2821 | bs_entry->state.options = options; | |
2822 | bs_entry->state.explicit_options = explicit_options; | |
2823 | bs_entry->state.flags = flags; | |
2824 | ||
2825 | /* This needs to be overwritten in bdrv_reopen_prepare() */ | |
2826 | bs_entry->state.perm = UINT64_MAX; | |
2827 | bs_entry->state.shared_perm = 0; | |
2828 | ||
2829 | QLIST_FOREACH(child, &bs->children, next) { | |
2830 | QDict *new_child_options; | |
2831 | char *child_key_dot; | |
2832 | ||
2833 | /* reopen can only change the options of block devices that were | |
2834 | * implicitly created and inherited options. For other (referenced) | |
2835 | * block devices, a syntax like "backing.foo" results in an error. */ | |
2836 | if (child->bs->inherits_from != bs) { | |
2837 | continue; | |
2838 | } | |
2839 | ||
2840 | child_key_dot = g_strdup_printf("%s.", child->name); | |
2841 | qdict_extract_subqdict(options, &new_child_options, child_key_dot); | |
2842 | g_free(child_key_dot); | |
2843 | ||
2844 | bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options, 0, | |
2845 | child->role, options, flags); | |
2846 | } | |
2847 | ||
2848 | return bs_queue; | |
2849 | } | |
2850 | ||
2851 | BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, | |
2852 | BlockDriverState *bs, | |
2853 | QDict *options, int flags) | |
2854 | { | |
2855 | return bdrv_reopen_queue_child(bs_queue, bs, options, flags, | |
2856 | NULL, NULL, 0); | |
2857 | } | |
2858 | ||
2859 | /* | |
2860 | * Reopen multiple BlockDriverStates atomically & transactionally. | |
2861 | * | |
2862 | * The queue passed in (bs_queue) must have been built up previous | |
2863 | * via bdrv_reopen_queue(). | |
2864 | * | |
2865 | * Reopens all BDS specified in the queue, with the appropriate | |
2866 | * flags. All devices are prepared for reopen, and failure of any | |
2867 | * device will cause all device changes to be abandonded, and intermediate | |
2868 | * data cleaned up. | |
2869 | * | |
2870 | * If all devices prepare successfully, then the changes are committed | |
2871 | * to all devices. | |
2872 | * | |
2873 | */ | |
2874 | int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp) | |
2875 | { | |
2876 | int ret = -1; | |
2877 | BlockReopenQueueEntry *bs_entry, *next; | |
2878 | Error *local_err = NULL; | |
2879 | ||
2880 | assert(bs_queue != NULL); | |
2881 | ||
2882 | aio_context_release(ctx); | |
2883 | bdrv_drain_all_begin(); | |
2884 | aio_context_acquire(ctx); | |
2885 | ||
2886 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
2887 | if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) { | |
2888 | error_propagate(errp, local_err); | |
2889 | goto cleanup; | |
2890 | } | |
2891 | bs_entry->prepared = true; | |
2892 | } | |
2893 | ||
2894 | /* If we reach this point, we have success and just need to apply the | |
2895 | * changes | |
2896 | */ | |
2897 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
2898 | bdrv_reopen_commit(&bs_entry->state); | |
2899 | } | |
2900 | ||
2901 | ret = 0; | |
2902 | ||
2903 | cleanup: | |
2904 | QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { | |
2905 | if (ret && bs_entry->prepared) { | |
2906 | bdrv_reopen_abort(&bs_entry->state); | |
2907 | } else if (ret) { | |
2908 | QDECREF(bs_entry->state.explicit_options); | |
2909 | } | |
2910 | QDECREF(bs_entry->state.options); | |
2911 | g_free(bs_entry); | |
2912 | } | |
2913 | g_free(bs_queue); | |
2914 | ||
2915 | bdrv_drain_all_end(); | |
2916 | ||
2917 | return ret; | |
2918 | } | |
2919 | ||
2920 | ||
2921 | /* Reopen a single BlockDriverState with the specified flags. */ | |
2922 | int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp) | |
2923 | { | |
2924 | int ret = -1; | |
2925 | Error *local_err = NULL; | |
2926 | BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags); | |
2927 | ||
2928 | ret = bdrv_reopen_multiple(bdrv_get_aio_context(bs), queue, &local_err); | |
2929 | if (local_err != NULL) { | |
2930 | error_propagate(errp, local_err); | |
2931 | } | |
2932 | return ret; | |
2933 | } | |
2934 | ||
2935 | static BlockReopenQueueEntry *find_parent_in_reopen_queue(BlockReopenQueue *q, | |
2936 | BdrvChild *c) | |
2937 | { | |
2938 | BlockReopenQueueEntry *entry; | |
2939 | ||
2940 | QSIMPLEQ_FOREACH(entry, q, entry) { | |
2941 | BlockDriverState *bs = entry->state.bs; | |
2942 | BdrvChild *child; | |
2943 | ||
2944 | QLIST_FOREACH(child, &bs->children, next) { | |
2945 | if (child == c) { | |
2946 | return entry; | |
2947 | } | |
2948 | } | |
2949 | } | |
2950 | ||
2951 | return NULL; | |
2952 | } | |
2953 | ||
2954 | static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs, | |
2955 | uint64_t *perm, uint64_t *shared) | |
2956 | { | |
2957 | BdrvChild *c; | |
2958 | BlockReopenQueueEntry *parent; | |
2959 | uint64_t cumulative_perms = 0; | |
2960 | uint64_t cumulative_shared_perms = BLK_PERM_ALL; | |
2961 | ||
2962 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
2963 | parent = find_parent_in_reopen_queue(q, c); | |
2964 | if (!parent) { | |
2965 | cumulative_perms |= c->perm; | |
2966 | cumulative_shared_perms &= c->shared_perm; | |
2967 | } else { | |
2968 | uint64_t nperm, nshared; | |
2969 | ||
2970 | bdrv_child_perm(parent->state.bs, bs, c, c->role, q, | |
2971 | parent->state.perm, parent->state.shared_perm, | |
2972 | &nperm, &nshared); | |
2973 | ||
2974 | cumulative_perms |= nperm; | |
2975 | cumulative_shared_perms &= nshared; | |
2976 | } | |
2977 | } | |
2978 | *perm = cumulative_perms; | |
2979 | *shared = cumulative_shared_perms; | |
2980 | } | |
2981 | ||
2982 | /* | |
2983 | * Prepares a BlockDriverState for reopen. All changes are staged in the | |
2984 | * 'opaque' field of the BDRVReopenState, which is used and allocated by | |
2985 | * the block driver layer .bdrv_reopen_prepare() | |
2986 | * | |
2987 | * bs is the BlockDriverState to reopen | |
2988 | * flags are the new open flags | |
2989 | * queue is the reopen queue | |
2990 | * | |
2991 | * Returns 0 on success, non-zero on error. On error errp will be set | |
2992 | * as well. | |
2993 | * | |
2994 | * On failure, bdrv_reopen_abort() will be called to clean up any data. | |
2995 | * It is the responsibility of the caller to then call the abort() or | |
2996 | * commit() for any other BDS that have been left in a prepare() state | |
2997 | * | |
2998 | */ | |
2999 | int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, | |
3000 | Error **errp) | |
3001 | { | |
3002 | int ret = -1; | |
3003 | Error *local_err = NULL; | |
3004 | BlockDriver *drv; | |
3005 | QemuOpts *opts; | |
3006 | const char *value; | |
3007 | bool read_only; | |
3008 | ||
3009 | assert(reopen_state != NULL); | |
3010 | assert(reopen_state->bs->drv != NULL); | |
3011 | drv = reopen_state->bs->drv; | |
3012 | ||
3013 | /* Process generic block layer options */ | |
3014 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); | |
3015 | qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err); | |
3016 | if (local_err) { | |
3017 | error_propagate(errp, local_err); | |
3018 | ret = -EINVAL; | |
3019 | goto error; | |
3020 | } | |
3021 | ||
3022 | update_flags_from_options(&reopen_state->flags, opts); | |
3023 | ||
3024 | /* node-name and driver must be unchanged. Put them back into the QDict, so | |
3025 | * that they are checked at the end of this function. */ | |
3026 | value = qemu_opt_get(opts, "node-name"); | |
3027 | if (value) { | |
3028 | qdict_put_str(reopen_state->options, "node-name", value); | |
3029 | } | |
3030 | ||
3031 | value = qemu_opt_get(opts, "driver"); | |
3032 | if (value) { | |
3033 | qdict_put_str(reopen_state->options, "driver", value); | |
3034 | } | |
3035 | ||
3036 | /* If we are to stay read-only, do not allow permission change | |
3037 | * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is | |
3038 | * not set, or if the BDS still has copy_on_read enabled */ | |
3039 | read_only = !(reopen_state->flags & BDRV_O_RDWR); | |
3040 | ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err); | |
3041 | if (local_err) { | |
3042 | error_propagate(errp, local_err); | |
3043 | goto error; | |
3044 | } | |
3045 | ||
3046 | /* Calculate required permissions after reopening */ | |
3047 | bdrv_reopen_perm(queue, reopen_state->bs, | |
3048 | &reopen_state->perm, &reopen_state->shared_perm); | |
3049 | ||
3050 | ret = bdrv_flush(reopen_state->bs); | |
3051 | if (ret) { | |
3052 | error_setg_errno(errp, -ret, "Error flushing drive"); | |
3053 | goto error; | |
3054 | } | |
3055 | ||
3056 | if (drv->bdrv_reopen_prepare) { | |
3057 | ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); | |
3058 | if (ret) { | |
3059 | if (local_err != NULL) { | |
3060 | error_propagate(errp, local_err); | |
3061 | } else { | |
3062 | error_setg(errp, "failed while preparing to reopen image '%s'", | |
3063 | reopen_state->bs->filename); | |
3064 | } | |
3065 | goto error; | |
3066 | } | |
3067 | } else { | |
3068 | /* It is currently mandatory to have a bdrv_reopen_prepare() | |
3069 | * handler for each supported drv. */ | |
3070 | error_setg(errp, "Block format '%s' used by node '%s' " | |
3071 | "does not support reopening files", drv->format_name, | |
3072 | bdrv_get_device_or_node_name(reopen_state->bs)); | |
3073 | ret = -1; | |
3074 | goto error; | |
3075 | } | |
3076 | ||
3077 | /* Options that are not handled are only okay if they are unchanged | |
3078 | * compared to the old state. It is expected that some options are only | |
3079 | * used for the initial open, but not reopen (e.g. filename) */ | |
3080 | if (qdict_size(reopen_state->options)) { | |
3081 | const QDictEntry *entry = qdict_first(reopen_state->options); | |
3082 | ||
3083 | do { | |
3084 | QObject *new = entry->value; | |
3085 | QObject *old = qdict_get(reopen_state->bs->options, entry->key); | |
3086 | ||
3087 | /* | |
3088 | * TODO: When using -drive to specify blockdev options, all values | |
3089 | * will be strings; however, when using -blockdev, blockdev-add or | |
3090 | * filenames using the json:{} pseudo-protocol, they will be | |
3091 | * correctly typed. | |
3092 | * In contrast, reopening options are (currently) always strings | |
3093 | * (because you can only specify them through qemu-io; all other | |
3094 | * callers do not specify any options). | |
3095 | * Therefore, when using anything other than -drive to create a BDS, | |
3096 | * this cannot detect non-string options as unchanged, because | |
3097 | * qobject_is_equal() always returns false for objects of different | |
3098 | * type. In the future, this should be remedied by correctly typing | |
3099 | * all options. For now, this is not too big of an issue because | |
3100 | * the user can simply omit options which cannot be changed anyway, | |
3101 | * so they will stay unchanged. | |
3102 | */ | |
3103 | if (!qobject_is_equal(new, old)) { | |
3104 | error_setg(errp, "Cannot change the option '%s'", entry->key); | |
3105 | ret = -EINVAL; | |
3106 | goto error; | |
3107 | } | |
3108 | } while ((entry = qdict_next(reopen_state->options, entry))); | |
3109 | } | |
3110 | ||
3111 | ret = bdrv_check_perm(reopen_state->bs, queue, reopen_state->perm, | |
3112 | reopen_state->shared_perm, NULL, errp); | |
3113 | if (ret < 0) { | |
3114 | goto error; | |
3115 | } | |
3116 | ||
3117 | ret = 0; | |
3118 | ||
3119 | error: | |
3120 | qemu_opts_del(opts); | |
3121 | return ret; | |
3122 | } | |
3123 | ||
3124 | /* | |
3125 | * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and | |
3126 | * makes them final by swapping the staging BlockDriverState contents into | |
3127 | * the active BlockDriverState contents. | |
3128 | */ | |
3129 | void bdrv_reopen_commit(BDRVReopenState *reopen_state) | |
3130 | { | |
3131 | BlockDriver *drv; | |
3132 | BlockDriverState *bs; | |
3133 | bool old_can_write, new_can_write; | |
3134 | ||
3135 | assert(reopen_state != NULL); | |
3136 | bs = reopen_state->bs; | |
3137 | drv = bs->drv; | |
3138 | assert(drv != NULL); | |
3139 | ||
3140 | old_can_write = | |
3141 | !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE); | |
3142 | ||
3143 | /* If there are any driver level actions to take */ | |
3144 | if (drv->bdrv_reopen_commit) { | |
3145 | drv->bdrv_reopen_commit(reopen_state); | |
3146 | } | |
3147 | ||
3148 | /* set BDS specific flags now */ | |
3149 | QDECREF(bs->explicit_options); | |
3150 | ||
3151 | bs->explicit_options = reopen_state->explicit_options; | |
3152 | bs->open_flags = reopen_state->flags; | |
3153 | bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); | |
3154 | ||
3155 | bdrv_refresh_limits(bs, NULL); | |
3156 | ||
3157 | bdrv_set_perm(reopen_state->bs, reopen_state->perm, | |
3158 | reopen_state->shared_perm); | |
3159 | ||
3160 | new_can_write = | |
3161 | !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE); | |
3162 | if (!old_can_write && new_can_write && drv->bdrv_reopen_bitmaps_rw) { | |
3163 | Error *local_err = NULL; | |
3164 | if (drv->bdrv_reopen_bitmaps_rw(bs, &local_err) < 0) { | |
3165 | /* This is not fatal, bitmaps just left read-only, so all following | |
3166 | * writes will fail. User can remove read-only bitmaps to unblock | |
3167 | * writes. | |
3168 | */ | |
3169 | error_reportf_err(local_err, | |
3170 | "%s: Failed to make dirty bitmaps writable: ", | |
3171 | bdrv_get_node_name(bs)); | |
3172 | } | |
3173 | } | |
3174 | } | |
3175 | ||
3176 | /* | |
3177 | * Abort the reopen, and delete and free the staged changes in | |
3178 | * reopen_state | |
3179 | */ | |
3180 | void bdrv_reopen_abort(BDRVReopenState *reopen_state) | |
3181 | { | |
3182 | BlockDriver *drv; | |
3183 | ||
3184 | assert(reopen_state != NULL); | |
3185 | drv = reopen_state->bs->drv; | |
3186 | assert(drv != NULL); | |
3187 | ||
3188 | if (drv->bdrv_reopen_abort) { | |
3189 | drv->bdrv_reopen_abort(reopen_state); | |
3190 | } | |
3191 | ||
3192 | QDECREF(reopen_state->explicit_options); | |
3193 | ||
3194 | bdrv_abort_perm_update(reopen_state->bs); | |
3195 | } | |
3196 | ||
3197 | ||
3198 | static void bdrv_close(BlockDriverState *bs) | |
3199 | { | |
3200 | BdrvAioNotifier *ban, *ban_next; | |
3201 | BdrvChild *child, *next; | |
3202 | ||
3203 | assert(!bs->job); | |
3204 | assert(!bs->refcnt); | |
3205 | ||
3206 | bdrv_drained_begin(bs); /* complete I/O */ | |
3207 | bdrv_flush(bs); | |
3208 | bdrv_drain(bs); /* in case flush left pending I/O */ | |
3209 | ||
3210 | if (bs->drv) { | |
3211 | bs->drv->bdrv_close(bs); | |
3212 | bs->drv = NULL; | |
3213 | } | |
3214 | ||
3215 | bdrv_set_backing_hd(bs, NULL, &error_abort); | |
3216 | ||
3217 | if (bs->file != NULL) { | |
3218 | bdrv_unref_child(bs, bs->file); | |
3219 | bs->file = NULL; | |
3220 | } | |
3221 | ||
3222 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { | |
3223 | /* TODO Remove bdrv_unref() from drivers' close function and use | |
3224 | * bdrv_unref_child() here */ | |
3225 | if (child->bs->inherits_from == bs) { | |
3226 | child->bs->inherits_from = NULL; | |
3227 | } | |
3228 | bdrv_detach_child(child); | |
3229 | } | |
3230 | ||
3231 | g_free(bs->opaque); | |
3232 | bs->opaque = NULL; | |
3233 | atomic_set(&bs->copy_on_read, 0); | |
3234 | bs->backing_file[0] = '\0'; | |
3235 | bs->backing_format[0] = '\0'; | |
3236 | bs->total_sectors = 0; | |
3237 | bs->encrypted = false; | |
3238 | bs->sg = false; | |
3239 | QDECREF(bs->options); | |
3240 | QDECREF(bs->explicit_options); | |
3241 | bs->options = NULL; | |
3242 | bs->explicit_options = NULL; | |
3243 | QDECREF(bs->full_open_options); | |
3244 | bs->full_open_options = NULL; | |
3245 | ||
3246 | bdrv_release_named_dirty_bitmaps(bs); | |
3247 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); | |
3248 | ||
3249 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { | |
3250 | g_free(ban); | |
3251 | } | |
3252 | QLIST_INIT(&bs->aio_notifiers); | |
3253 | bdrv_drained_end(bs); | |
3254 | } | |
3255 | ||
3256 | void bdrv_close_all(void) | |
3257 | { | |
3258 | block_job_cancel_sync_all(); | |
3259 | nbd_export_close_all(); | |
3260 | ||
3261 | /* Drop references from requests still in flight, such as canceled block | |
3262 | * jobs whose AIO context has not been polled yet */ | |
3263 | bdrv_drain_all(); | |
3264 | ||
3265 | blk_remove_all_bs(); | |
3266 | blockdev_close_all_bdrv_states(); | |
3267 | ||
3268 | assert(QTAILQ_EMPTY(&all_bdrv_states)); | |
3269 | } | |
3270 | ||
3271 | static bool should_update_child(BdrvChild *c, BlockDriverState *to) | |
3272 | { | |
3273 | BdrvChild *to_c; | |
3274 | ||
3275 | if (c->role->stay_at_node) { | |
3276 | return false; | |
3277 | } | |
3278 | ||
3279 | if (c->role == &child_backing) { | |
3280 | /* If @from is a backing file of @to, ignore the child to avoid | |
3281 | * creating a loop. We only want to change the pointer of other | |
3282 | * parents. */ | |
3283 | QLIST_FOREACH(to_c, &to->children, next) { | |
3284 | if (to_c == c) { | |
3285 | break; | |
3286 | } | |
3287 | } | |
3288 | if (to_c) { | |
3289 | return false; | |
3290 | } | |
3291 | } | |
3292 | ||
3293 | return true; | |
3294 | } | |
3295 | ||
3296 | void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, | |
3297 | Error **errp) | |
3298 | { | |
3299 | BdrvChild *c, *next; | |
3300 | GSList *list = NULL, *p; | |
3301 | uint64_t old_perm, old_shared; | |
3302 | uint64_t perm = 0, shared = BLK_PERM_ALL; | |
3303 | int ret; | |
3304 | ||
3305 | assert(!atomic_read(&from->in_flight)); | |
3306 | assert(!atomic_read(&to->in_flight)); | |
3307 | ||
3308 | /* Make sure that @from doesn't go away until we have successfully attached | |
3309 | * all of its parents to @to. */ | |
3310 | bdrv_ref(from); | |
3311 | ||
3312 | /* Put all parents into @list and calculate their cumulative permissions */ | |
3313 | QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { | |
3314 | if (!should_update_child(c, to)) { | |
3315 | continue; | |
3316 | } | |
3317 | list = g_slist_prepend(list, c); | |
3318 | perm |= c->perm; | |
3319 | shared &= c->shared_perm; | |
3320 | } | |
3321 | ||
3322 | /* Check whether the required permissions can be granted on @to, ignoring | |
3323 | * all BdrvChild in @list so that they can't block themselves. */ | |
3324 | ret = bdrv_check_update_perm(to, NULL, perm, shared, list, errp); | |
3325 | if (ret < 0) { | |
3326 | bdrv_abort_perm_update(to); | |
3327 | goto out; | |
3328 | } | |
3329 | ||
3330 | /* Now actually perform the change. We performed the permission check for | |
3331 | * all elements of @list at once, so set the permissions all at once at the | |
3332 | * very end. */ | |
3333 | for (p = list; p != NULL; p = p->next) { | |
3334 | c = p->data; | |
3335 | ||
3336 | bdrv_ref(to); | |
3337 | bdrv_replace_child_noperm(c, to); | |
3338 | bdrv_unref(from); | |
3339 | } | |
3340 | ||
3341 | bdrv_get_cumulative_perm(to, &old_perm, &old_shared); | |
3342 | bdrv_set_perm(to, old_perm | perm, old_shared | shared); | |
3343 | ||
3344 | out: | |
3345 | g_slist_free(list); | |
3346 | bdrv_unref(from); | |
3347 | } | |
3348 | ||
3349 | /* | |
3350 | * Add new bs contents at the top of an image chain while the chain is | |
3351 | * live, while keeping required fields on the top layer. | |
3352 | * | |
3353 | * This will modify the BlockDriverState fields, and swap contents | |
3354 | * between bs_new and bs_top. Both bs_new and bs_top are modified. | |
3355 | * | |
3356 | * bs_new must not be attached to a BlockBackend. | |
3357 | * | |
3358 | * This function does not create any image files. | |
3359 | * | |
3360 | * bdrv_append() takes ownership of a bs_new reference and unrefs it because | |
3361 | * that's what the callers commonly need. bs_new will be referenced by the old | |
3362 | * parents of bs_top after bdrv_append() returns. If the caller needs to keep a | |
3363 | * reference of its own, it must call bdrv_ref(). | |
3364 | */ | |
3365 | void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, | |
3366 | Error **errp) | |
3367 | { | |
3368 | Error *local_err = NULL; | |
3369 | ||
3370 | bdrv_set_backing_hd(bs_new, bs_top, &local_err); | |
3371 | if (local_err) { | |
3372 | error_propagate(errp, local_err); | |
3373 | goto out; | |
3374 | } | |
3375 | ||
3376 | bdrv_replace_node(bs_top, bs_new, &local_err); | |
3377 | if (local_err) { | |
3378 | error_propagate(errp, local_err); | |
3379 | bdrv_set_backing_hd(bs_new, NULL, &error_abort); | |
3380 | goto out; | |
3381 | } | |
3382 | ||
3383 | /* bs_new is now referenced by its new parents, we don't need the | |
3384 | * additional reference any more. */ | |
3385 | out: | |
3386 | bdrv_unref(bs_new); | |
3387 | } | |
3388 | ||
3389 | static void bdrv_delete(BlockDriverState *bs) | |
3390 | { | |
3391 | assert(!bs->job); | |
3392 | assert(bdrv_op_blocker_is_empty(bs)); | |
3393 | assert(!bs->refcnt); | |
3394 | ||
3395 | bdrv_close(bs); | |
3396 | ||
3397 | /* remove from list, if necessary */ | |
3398 | if (bs->node_name[0] != '\0') { | |
3399 | QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); | |
3400 | } | |
3401 | QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list); | |
3402 | ||
3403 | g_free(bs); | |
3404 | } | |
3405 | ||
3406 | /* | |
3407 | * Run consistency checks on an image | |
3408 | * | |
3409 | * Returns 0 if the check could be completed (it doesn't mean that the image is | |
3410 | * free of errors) or -errno when an internal error occurred. The results of the | |
3411 | * check are stored in res. | |
3412 | */ | |
3413 | int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) | |
3414 | { | |
3415 | if (bs->drv == NULL) { | |
3416 | return -ENOMEDIUM; | |
3417 | } | |
3418 | if (bs->drv->bdrv_check == NULL) { | |
3419 | return -ENOTSUP; | |
3420 | } | |
3421 | ||
3422 | memset(res, 0, sizeof(*res)); | |
3423 | return bs->drv->bdrv_check(bs, res, fix); | |
3424 | } | |
3425 | ||
3426 | /* | |
3427 | * Return values: | |
3428 | * 0 - success | |
3429 | * -EINVAL - backing format specified, but no file | |
3430 | * -ENOSPC - can't update the backing file because no space is left in the | |
3431 | * image file header | |
3432 | * -ENOTSUP - format driver doesn't support changing the backing file | |
3433 | */ | |
3434 | int bdrv_change_backing_file(BlockDriverState *bs, | |
3435 | const char *backing_file, const char *backing_fmt) | |
3436 | { | |
3437 | BlockDriver *drv = bs->drv; | |
3438 | int ret; | |
3439 | ||
3440 | if (!drv) { | |
3441 | return -ENOMEDIUM; | |
3442 | } | |
3443 | ||
3444 | /* Backing file format doesn't make sense without a backing file */ | |
3445 | if (backing_fmt && !backing_file) { | |
3446 | return -EINVAL; | |
3447 | } | |
3448 | ||
3449 | if (drv->bdrv_change_backing_file != NULL) { | |
3450 | ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); | |
3451 | } else { | |
3452 | ret = -ENOTSUP; | |
3453 | } | |
3454 | ||
3455 | if (ret == 0) { | |
3456 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); | |
3457 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); | |
3458 | } | |
3459 | return ret; | |
3460 | } | |
3461 | ||
3462 | /* | |
3463 | * Finds the image layer in the chain that has 'bs' as its backing file. | |
3464 | * | |
3465 | * active is the current topmost image. | |
3466 | * | |
3467 | * Returns NULL if bs is not found in active's image chain, | |
3468 | * or if active == bs. | |
3469 | * | |
3470 | * Returns the bottommost base image if bs == NULL. | |
3471 | */ | |
3472 | BlockDriverState *bdrv_find_overlay(BlockDriverState *active, | |
3473 | BlockDriverState *bs) | |
3474 | { | |
3475 | while (active && bs != backing_bs(active)) { | |
3476 | active = backing_bs(active); | |
3477 | } | |
3478 | ||
3479 | return active; | |
3480 | } | |
3481 | ||
3482 | /* Given a BDS, searches for the base layer. */ | |
3483 | BlockDriverState *bdrv_find_base(BlockDriverState *bs) | |
3484 | { | |
3485 | return bdrv_find_overlay(bs, NULL); | |
3486 | } | |
3487 | ||
3488 | /* | |
3489 | * Drops images above 'base' up to and including 'top', and sets the image | |
3490 | * above 'top' to have base as its backing file. | |
3491 | * | |
3492 | * Requires that the overlay to 'top' is opened r/w, so that the backing file | |
3493 | * information in 'bs' can be properly updated. | |
3494 | * | |
3495 | * E.g., this will convert the following chain: | |
3496 | * bottom <- base <- intermediate <- top <- active | |
3497 | * | |
3498 | * to | |
3499 | * | |
3500 | * bottom <- base <- active | |
3501 | * | |
3502 | * It is allowed for bottom==base, in which case it converts: | |
3503 | * | |
3504 | * base <- intermediate <- top <- active | |
3505 | * | |
3506 | * to | |
3507 | * | |
3508 | * base <- active | |
3509 | * | |
3510 | * If backing_file_str is non-NULL, it will be used when modifying top's | |
3511 | * overlay image metadata. | |
3512 | * | |
3513 | * Error conditions: | |
3514 | * if active == top, that is considered an error | |
3515 | * | |
3516 | */ | |
3517 | int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, | |
3518 | const char *backing_file_str) | |
3519 | { | |
3520 | BdrvChild *c, *next; | |
3521 | Error *local_err = NULL; | |
3522 | int ret = -EIO; | |
3523 | ||
3524 | bdrv_ref(top); | |
3525 | ||
3526 | if (!top->drv || !base->drv) { | |
3527 | goto exit; | |
3528 | } | |
3529 | ||
3530 | /* Make sure that base is in the backing chain of top */ | |
3531 | if (!bdrv_chain_contains(top, base)) { | |
3532 | goto exit; | |
3533 | } | |
3534 | ||
3535 | /* success - we can delete the intermediate states, and link top->base */ | |
3536 | /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once | |
3537 | * we've figured out how they should work. */ | |
3538 | backing_file_str = backing_file_str ? backing_file_str : base->filename; | |
3539 | ||
3540 | QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) { | |
3541 | /* Check whether we are allowed to switch c from top to base */ | |
3542 | GSList *ignore_children = g_slist_prepend(NULL, c); | |
3543 | bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm, | |
3544 | ignore_children, &local_err); | |
3545 | if (local_err) { | |
3546 | ret = -EPERM; | |
3547 | error_report_err(local_err); | |
3548 | goto exit; | |
3549 | } | |
3550 | g_slist_free(ignore_children); | |
3551 | ||
3552 | /* If so, update the backing file path in the image file */ | |
3553 | if (c->role->update_filename) { | |
3554 | ret = c->role->update_filename(c, base, backing_file_str, | |
3555 | &local_err); | |
3556 | if (ret < 0) { | |
3557 | bdrv_abort_perm_update(base); | |
3558 | error_report_err(local_err); | |
3559 | goto exit; | |
3560 | } | |
3561 | } | |
3562 | ||
3563 | /* Do the actual switch in the in-memory graph. | |
3564 | * Completes bdrv_check_update_perm() transaction internally. */ | |
3565 | bdrv_ref(base); | |
3566 | bdrv_replace_child(c, base); | |
3567 | bdrv_unref(top); | |
3568 | } | |
3569 | ||
3570 | ret = 0; | |
3571 | exit: | |
3572 | bdrv_unref(top); | |
3573 | return ret; | |
3574 | } | |
3575 | ||
3576 | /** | |
3577 | * Truncate file to 'offset' bytes (needed only for file protocols) | |
3578 | */ | |
3579 | int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc, | |
3580 | Error **errp) | |
3581 | { | |
3582 | BlockDriverState *bs = child->bs; | |
3583 | BlockDriver *drv = bs->drv; | |
3584 | int ret; | |
3585 | ||
3586 | assert(child->perm & BLK_PERM_RESIZE); | |
3587 | ||
3588 | /* if bs->drv == NULL, bs is closed, so there's nothing to do here */ | |
3589 | if (!drv) { | |
3590 | error_setg(errp, "No medium inserted"); | |
3591 | return -ENOMEDIUM; | |
3592 | } | |
3593 | if (!drv->bdrv_truncate) { | |
3594 | if (bs->file && drv->is_filter) { | |
3595 | return bdrv_truncate(bs->file, offset, prealloc, errp); | |
3596 | } | |
3597 | error_setg(errp, "Image format driver does not support resize"); | |
3598 | return -ENOTSUP; | |
3599 | } | |
3600 | if (bs->read_only) { | |
3601 | error_setg(errp, "Image is read-only"); | |
3602 | return -EACCES; | |
3603 | } | |
3604 | ||
3605 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); | |
3606 | ||
3607 | ret = drv->bdrv_truncate(bs, offset, prealloc, errp); | |
3608 | if (ret < 0) { | |
3609 | return ret; | |
3610 | } | |
3611 | ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); | |
3612 | if (ret < 0) { | |
3613 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
3614 | } else { | |
3615 | offset = bs->total_sectors * BDRV_SECTOR_SIZE; | |
3616 | } | |
3617 | bdrv_dirty_bitmap_truncate(bs, offset); | |
3618 | bdrv_parent_cb_resize(bs); | |
3619 | atomic_inc(&bs->write_gen); | |
3620 | return ret; | |
3621 | } | |
3622 | ||
3623 | /** | |
3624 | * Length of a allocated file in bytes. Sparse files are counted by actual | |
3625 | * allocated space. Return < 0 if error or unknown. | |
3626 | */ | |
3627 | int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) | |
3628 | { | |
3629 | BlockDriver *drv = bs->drv; | |
3630 | if (!drv) { | |
3631 | return -ENOMEDIUM; | |
3632 | } | |
3633 | if (drv->bdrv_get_allocated_file_size) { | |
3634 | return drv->bdrv_get_allocated_file_size(bs); | |
3635 | } | |
3636 | if (bs->file) { | |
3637 | return bdrv_get_allocated_file_size(bs->file->bs); | |
3638 | } | |
3639 | return -ENOTSUP; | |
3640 | } | |
3641 | ||
3642 | /* | |
3643 | * bdrv_measure: | |
3644 | * @drv: Format driver | |
3645 | * @opts: Creation options for new image | |
3646 | * @in_bs: Existing image containing data for new image (may be NULL) | |
3647 | * @errp: Error object | |
3648 | * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo()) | |
3649 | * or NULL on error | |
3650 | * | |
3651 | * Calculate file size required to create a new image. | |
3652 | * | |
3653 | * If @in_bs is given then space for allocated clusters and zero clusters | |
3654 | * from that image are included in the calculation. If @opts contains a | |
3655 | * backing file that is shared by @in_bs then backing clusters may be omitted | |
3656 | * from the calculation. | |
3657 | * | |
3658 | * If @in_bs is NULL then the calculation includes no allocated clusters | |
3659 | * unless a preallocation option is given in @opts. | |
3660 | * | |
3661 | * Note that @in_bs may use a different BlockDriver from @drv. | |
3662 | * | |
3663 | * If an error occurs the @errp pointer is set. | |
3664 | */ | |
3665 | BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, | |
3666 | BlockDriverState *in_bs, Error **errp) | |
3667 | { | |
3668 | if (!drv->bdrv_measure) { | |
3669 | error_setg(errp, "Block driver '%s' does not support size measurement", | |
3670 | drv->format_name); | |
3671 | return NULL; | |
3672 | } | |
3673 | ||
3674 | return drv->bdrv_measure(opts, in_bs, errp); | |
3675 | } | |
3676 | ||
3677 | /** | |
3678 | * Return number of sectors on success, -errno on error. | |
3679 | */ | |
3680 | int64_t bdrv_nb_sectors(BlockDriverState *bs) | |
3681 | { | |
3682 | BlockDriver *drv = bs->drv; | |
3683 | ||
3684 | if (!drv) | |
3685 | return -ENOMEDIUM; | |
3686 | ||
3687 | if (drv->has_variable_length) { | |
3688 | int ret = refresh_total_sectors(bs, bs->total_sectors); | |
3689 | if (ret < 0) { | |
3690 | return ret; | |
3691 | } | |
3692 | } | |
3693 | return bs->total_sectors; | |
3694 | } | |
3695 | ||
3696 | /** | |
3697 | * Return length in bytes on success, -errno on error. | |
3698 | * The length is always a multiple of BDRV_SECTOR_SIZE. | |
3699 | */ | |
3700 | int64_t bdrv_getlength(BlockDriverState *bs) | |
3701 | { | |
3702 | int64_t ret = bdrv_nb_sectors(bs); | |
3703 | ||
3704 | ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret; | |
3705 | return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE; | |
3706 | } | |
3707 | ||
3708 | /* return 0 as number of sectors if no device present or error */ | |
3709 | void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) | |
3710 | { | |
3711 | int64_t nb_sectors = bdrv_nb_sectors(bs); | |
3712 | ||
3713 | *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors; | |
3714 | } | |
3715 | ||
3716 | bool bdrv_is_sg(BlockDriverState *bs) | |
3717 | { | |
3718 | return bs->sg; | |
3719 | } | |
3720 | ||
3721 | bool bdrv_is_encrypted(BlockDriverState *bs) | |
3722 | { | |
3723 | if (bs->backing && bs->backing->bs->encrypted) { | |
3724 | return true; | |
3725 | } | |
3726 | return bs->encrypted; | |
3727 | } | |
3728 | ||
3729 | const char *bdrv_get_format_name(BlockDriverState *bs) | |
3730 | { | |
3731 | return bs->drv ? bs->drv->format_name : NULL; | |
3732 | } | |
3733 | ||
3734 | static int qsort_strcmp(const void *a, const void *b) | |
3735 | { | |
3736 | return strcmp(*(char *const *)a, *(char *const *)b); | |
3737 | } | |
3738 | ||
3739 | void bdrv_iterate_format(void (*it)(void *opaque, const char *name), | |
3740 | void *opaque) | |
3741 | { | |
3742 | BlockDriver *drv; | |
3743 | int count = 0; | |
3744 | int i; | |
3745 | const char **formats = NULL; | |
3746 | ||
3747 | QLIST_FOREACH(drv, &bdrv_drivers, list) { | |
3748 | if (drv->format_name) { | |
3749 | bool found = false; | |
3750 | int i = count; | |
3751 | while (formats && i && !found) { | |
3752 | found = !strcmp(formats[--i], drv->format_name); | |
3753 | } | |
3754 | ||
3755 | if (!found) { | |
3756 | formats = g_renew(const char *, formats, count + 1); | |
3757 | formats[count++] = drv->format_name; | |
3758 | } | |
3759 | } | |
3760 | } | |
3761 | ||
3762 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) { | |
3763 | const char *format_name = block_driver_modules[i].format_name; | |
3764 | ||
3765 | if (format_name) { | |
3766 | bool found = false; | |
3767 | int j = count; | |
3768 | ||
3769 | while (formats && j && !found) { | |
3770 | found = !strcmp(formats[--j], format_name); | |
3771 | } | |
3772 | ||
3773 | if (!found) { | |
3774 | formats = g_renew(const char *, formats, count + 1); | |
3775 | formats[count++] = format_name; | |
3776 | } | |
3777 | } | |
3778 | } | |
3779 | ||
3780 | qsort(formats, count, sizeof(formats[0]), qsort_strcmp); | |
3781 | ||
3782 | for (i = 0; i < count; i++) { | |
3783 | it(opaque, formats[i]); | |
3784 | } | |
3785 | ||
3786 | g_free(formats); | |
3787 | } | |
3788 | ||
3789 | /* This function is to find a node in the bs graph */ | |
3790 | BlockDriverState *bdrv_find_node(const char *node_name) | |
3791 | { | |
3792 | BlockDriverState *bs; | |
3793 | ||
3794 | assert(node_name); | |
3795 | ||
3796 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
3797 | if (!strcmp(node_name, bs->node_name)) { | |
3798 | return bs; | |
3799 | } | |
3800 | } | |
3801 | return NULL; | |
3802 | } | |
3803 | ||
3804 | /* Put this QMP function here so it can access the static graph_bdrv_states. */ | |
3805 | BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp) | |
3806 | { | |
3807 | BlockDeviceInfoList *list, *entry; | |
3808 | BlockDriverState *bs; | |
3809 | ||
3810 | list = NULL; | |
3811 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
3812 | BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp); | |
3813 | if (!info) { | |
3814 | qapi_free_BlockDeviceInfoList(list); | |
3815 | return NULL; | |
3816 | } | |
3817 | entry = g_malloc0(sizeof(*entry)); | |
3818 | entry->value = info; | |
3819 | entry->next = list; | |
3820 | list = entry; | |
3821 | } | |
3822 | ||
3823 | return list; | |
3824 | } | |
3825 | ||
3826 | BlockDriverState *bdrv_lookup_bs(const char *device, | |
3827 | const char *node_name, | |
3828 | Error **errp) | |
3829 | { | |
3830 | BlockBackend *blk; | |
3831 | BlockDriverState *bs; | |
3832 | ||
3833 | if (device) { | |
3834 | blk = blk_by_name(device); | |
3835 | ||
3836 | if (blk) { | |
3837 | bs = blk_bs(blk); | |
3838 | if (!bs) { | |
3839 | error_setg(errp, "Device '%s' has no medium", device); | |
3840 | } | |
3841 | ||
3842 | return bs; | |
3843 | } | |
3844 | } | |
3845 | ||
3846 | if (node_name) { | |
3847 | bs = bdrv_find_node(node_name); | |
3848 | ||
3849 | if (bs) { | |
3850 | return bs; | |
3851 | } | |
3852 | } | |
3853 | ||
3854 | error_setg(errp, "Cannot find device=%s nor node_name=%s", | |
3855 | device ? device : "", | |
3856 | node_name ? node_name : ""); | |
3857 | return NULL; | |
3858 | } | |
3859 | ||
3860 | /* If 'base' is in the same chain as 'top', return true. Otherwise, | |
3861 | * return false. If either argument is NULL, return false. */ | |
3862 | bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) | |
3863 | { | |
3864 | while (top && top != base) { | |
3865 | top = backing_bs(top); | |
3866 | } | |
3867 | ||
3868 | return top != NULL; | |
3869 | } | |
3870 | ||
3871 | BlockDriverState *bdrv_next_node(BlockDriverState *bs) | |
3872 | { | |
3873 | if (!bs) { | |
3874 | return QTAILQ_FIRST(&graph_bdrv_states); | |
3875 | } | |
3876 | return QTAILQ_NEXT(bs, node_list); | |
3877 | } | |
3878 | ||
3879 | const char *bdrv_get_node_name(const BlockDriverState *bs) | |
3880 | { | |
3881 | return bs->node_name; | |
3882 | } | |
3883 | ||
3884 | const char *bdrv_get_parent_name(const BlockDriverState *bs) | |
3885 | { | |
3886 | BdrvChild *c; | |
3887 | const char *name; | |
3888 | ||
3889 | /* If multiple parents have a name, just pick the first one. */ | |
3890 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
3891 | if (c->role->get_name) { | |
3892 | name = c->role->get_name(c); | |
3893 | if (name && *name) { | |
3894 | return name; | |
3895 | } | |
3896 | } | |
3897 | } | |
3898 | ||
3899 | return NULL; | |
3900 | } | |
3901 | ||
3902 | /* TODO check what callers really want: bs->node_name or blk_name() */ | |
3903 | const char *bdrv_get_device_name(const BlockDriverState *bs) | |
3904 | { | |
3905 | return bdrv_get_parent_name(bs) ?: ""; | |
3906 | } | |
3907 | ||
3908 | /* This can be used to identify nodes that might not have a device | |
3909 | * name associated. Since node and device names live in the same | |
3910 | * namespace, the result is unambiguous. The exception is if both are | |
3911 | * absent, then this returns an empty (non-null) string. */ | |
3912 | const char *bdrv_get_device_or_node_name(const BlockDriverState *bs) | |
3913 | { | |
3914 | return bdrv_get_parent_name(bs) ?: bs->node_name; | |
3915 | } | |
3916 | ||
3917 | int bdrv_get_flags(BlockDriverState *bs) | |
3918 | { | |
3919 | return bs->open_flags; | |
3920 | } | |
3921 | ||
3922 | int bdrv_has_zero_init_1(BlockDriverState *bs) | |
3923 | { | |
3924 | return 1; | |
3925 | } | |
3926 | ||
3927 | int bdrv_has_zero_init(BlockDriverState *bs) | |
3928 | { | |
3929 | if (!bs->drv) { | |
3930 | return 0; | |
3931 | } | |
3932 | ||
3933 | /* If BS is a copy on write image, it is initialized to | |
3934 | the contents of the base image, which may not be zeroes. */ | |
3935 | if (bs->backing) { | |
3936 | return 0; | |
3937 | } | |
3938 | if (bs->drv->bdrv_has_zero_init) { | |
3939 | return bs->drv->bdrv_has_zero_init(bs); | |
3940 | } | |
3941 | if (bs->file && bs->drv->is_filter) { | |
3942 | return bdrv_has_zero_init(bs->file->bs); | |
3943 | } | |
3944 | ||
3945 | /* safe default */ | |
3946 | return 0; | |
3947 | } | |
3948 | ||
3949 | bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs) | |
3950 | { | |
3951 | BlockDriverInfo bdi; | |
3952 | ||
3953 | if (bs->backing) { | |
3954 | return false; | |
3955 | } | |
3956 | ||
3957 | if (bdrv_get_info(bs, &bdi) == 0) { | |
3958 | return bdi.unallocated_blocks_are_zero; | |
3959 | } | |
3960 | ||
3961 | return false; | |
3962 | } | |
3963 | ||
3964 | bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) | |
3965 | { | |
3966 | BlockDriverInfo bdi; | |
3967 | ||
3968 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
3969 | return false; | |
3970 | } | |
3971 | ||
3972 | if (bdrv_get_info(bs, &bdi) == 0) { | |
3973 | return bdi.can_write_zeroes_with_unmap; | |
3974 | } | |
3975 | ||
3976 | return false; | |
3977 | } | |
3978 | ||
3979 | const char *bdrv_get_encrypted_filename(BlockDriverState *bs) | |
3980 | { | |
3981 | if (bs->backing && bs->backing->bs->encrypted) | |
3982 | return bs->backing_file; | |
3983 | else if (bs->encrypted) | |
3984 | return bs->filename; | |
3985 | else | |
3986 | return NULL; | |
3987 | } | |
3988 | ||
3989 | void bdrv_get_backing_filename(BlockDriverState *bs, | |
3990 | char *filename, int filename_size) | |
3991 | { | |
3992 | pstrcpy(filename, filename_size, bs->backing_file); | |
3993 | } | |
3994 | ||
3995 | int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) | |
3996 | { | |
3997 | BlockDriver *drv = bs->drv; | |
3998 | /* if bs->drv == NULL, bs is closed, so there's nothing to do here */ | |
3999 | if (!drv) { | |
4000 | return -ENOMEDIUM; | |
4001 | } | |
4002 | if (!drv->bdrv_get_info) { | |
4003 | if (bs->file && drv->is_filter) { | |
4004 | return bdrv_get_info(bs->file->bs, bdi); | |
4005 | } | |
4006 | return -ENOTSUP; | |
4007 | } | |
4008 | memset(bdi, 0, sizeof(*bdi)); | |
4009 | return drv->bdrv_get_info(bs, bdi); | |
4010 | } | |
4011 | ||
4012 | ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs) | |
4013 | { | |
4014 | BlockDriver *drv = bs->drv; | |
4015 | if (drv && drv->bdrv_get_specific_info) { | |
4016 | return drv->bdrv_get_specific_info(bs); | |
4017 | } | |
4018 | return NULL; | |
4019 | } | |
4020 | ||
4021 | void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event) | |
4022 | { | |
4023 | if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) { | |
4024 | return; | |
4025 | } | |
4026 | ||
4027 | bs->drv->bdrv_debug_event(bs, event); | |
4028 | } | |
4029 | ||
4030 | int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, | |
4031 | const char *tag) | |
4032 | { | |
4033 | while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { | |
4034 | bs = bs->file ? bs->file->bs : NULL; | |
4035 | } | |
4036 | ||
4037 | if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) { | |
4038 | return bs->drv->bdrv_debug_breakpoint(bs, event, tag); | |
4039 | } | |
4040 | ||
4041 | return -ENOTSUP; | |
4042 | } | |
4043 | ||
4044 | int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) | |
4045 | { | |
4046 | while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) { | |
4047 | bs = bs->file ? bs->file->bs : NULL; | |
4048 | } | |
4049 | ||
4050 | if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) { | |
4051 | return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); | |
4052 | } | |
4053 | ||
4054 | return -ENOTSUP; | |
4055 | } | |
4056 | ||
4057 | int bdrv_debug_resume(BlockDriverState *bs, const char *tag) | |
4058 | { | |
4059 | while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { | |
4060 | bs = bs->file ? bs->file->bs : NULL; | |
4061 | } | |
4062 | ||
4063 | if (bs && bs->drv && bs->drv->bdrv_debug_resume) { | |
4064 | return bs->drv->bdrv_debug_resume(bs, tag); | |
4065 | } | |
4066 | ||
4067 | return -ENOTSUP; | |
4068 | } | |
4069 | ||
4070 | bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) | |
4071 | { | |
4072 | while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { | |
4073 | bs = bs->file ? bs->file->bs : NULL; | |
4074 | } | |
4075 | ||
4076 | if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { | |
4077 | return bs->drv->bdrv_debug_is_suspended(bs, tag); | |
4078 | } | |
4079 | ||
4080 | return false; | |
4081 | } | |
4082 | ||
4083 | /* backing_file can either be relative, or absolute, or a protocol. If it is | |
4084 | * relative, it must be relative to the chain. So, passing in bs->filename | |
4085 | * from a BDS as backing_file should not be done, as that may be relative to | |
4086 | * the CWD rather than the chain. */ | |
4087 | BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, | |
4088 | const char *backing_file) | |
4089 | { | |
4090 | char *filename_full = NULL; | |
4091 | char *backing_file_full = NULL; | |
4092 | char *filename_tmp = NULL; | |
4093 | int is_protocol = 0; | |
4094 | BlockDriverState *curr_bs = NULL; | |
4095 | BlockDriverState *retval = NULL; | |
4096 | Error *local_error = NULL; | |
4097 | ||
4098 | if (!bs || !bs->drv || !backing_file) { | |
4099 | return NULL; | |
4100 | } | |
4101 | ||
4102 | filename_full = g_malloc(PATH_MAX); | |
4103 | backing_file_full = g_malloc(PATH_MAX); | |
4104 | filename_tmp = g_malloc(PATH_MAX); | |
4105 | ||
4106 | is_protocol = path_has_protocol(backing_file); | |
4107 | ||
4108 | for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) { | |
4109 | ||
4110 | /* If either of the filename paths is actually a protocol, then | |
4111 | * compare unmodified paths; otherwise make paths relative */ | |
4112 | if (is_protocol || path_has_protocol(curr_bs->backing_file)) { | |
4113 | if (strcmp(backing_file, curr_bs->backing_file) == 0) { | |
4114 | retval = curr_bs->backing->bs; | |
4115 | break; | |
4116 | } | |
4117 | /* Also check against the full backing filename for the image */ | |
4118 | bdrv_get_full_backing_filename(curr_bs, backing_file_full, PATH_MAX, | |
4119 | &local_error); | |
4120 | if (local_error == NULL) { | |
4121 | if (strcmp(backing_file, backing_file_full) == 0) { | |
4122 | retval = curr_bs->backing->bs; | |
4123 | break; | |
4124 | } | |
4125 | } else { | |
4126 | error_free(local_error); | |
4127 | local_error = NULL; | |
4128 | } | |
4129 | } else { | |
4130 | /* If not an absolute filename path, make it relative to the current | |
4131 | * image's filename path */ | |
4132 | path_combine(filename_tmp, PATH_MAX, curr_bs->filename, | |
4133 | backing_file); | |
4134 | ||
4135 | /* We are going to compare absolute pathnames */ | |
4136 | if (!realpath(filename_tmp, filename_full)) { | |
4137 | continue; | |
4138 | } | |
4139 | ||
4140 | /* We need to make sure the backing filename we are comparing against | |
4141 | * is relative to the current image filename (or absolute) */ | |
4142 | path_combine(filename_tmp, PATH_MAX, curr_bs->filename, | |
4143 | curr_bs->backing_file); | |
4144 | ||
4145 | if (!realpath(filename_tmp, backing_file_full)) { | |
4146 | continue; | |
4147 | } | |
4148 | ||
4149 | if (strcmp(backing_file_full, filename_full) == 0) { | |
4150 | retval = curr_bs->backing->bs; | |
4151 | break; | |
4152 | } | |
4153 | } | |
4154 | } | |
4155 | ||
4156 | g_free(filename_full); | |
4157 | g_free(backing_file_full); | |
4158 | g_free(filename_tmp); | |
4159 | return retval; | |
4160 | } | |
4161 | ||
4162 | void bdrv_init(void) | |
4163 | { | |
4164 | module_call_init(MODULE_INIT_BLOCK); | |
4165 | } | |
4166 | ||
4167 | void bdrv_init_with_whitelist(void) | |
4168 | { | |
4169 | use_bdrv_whitelist = 1; | |
4170 | bdrv_init(); | |
4171 | } | |
4172 | ||
4173 | void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) | |
4174 | { | |
4175 | BdrvChild *child, *parent; | |
4176 | uint64_t perm, shared_perm; | |
4177 | Error *local_err = NULL; | |
4178 | int ret; | |
4179 | ||
4180 | if (!bs->drv) { | |
4181 | return; | |
4182 | } | |
4183 | ||
4184 | if (!(bs->open_flags & BDRV_O_INACTIVE)) { | |
4185 | return; | |
4186 | } | |
4187 | ||
4188 | QLIST_FOREACH(child, &bs->children, next) { | |
4189 | bdrv_invalidate_cache(child->bs, &local_err); | |
4190 | if (local_err) { | |
4191 | error_propagate(errp, local_err); | |
4192 | return; | |
4193 | } | |
4194 | } | |
4195 | ||
4196 | /* | |
4197 | * Update permissions, they may differ for inactive nodes. | |
4198 | * | |
4199 | * Note that the required permissions of inactive images are always a | |
4200 | * subset of the permissions required after activating the image. This | |
4201 | * allows us to just get the permissions upfront without restricting | |
4202 | * drv->bdrv_invalidate_cache(). | |
4203 | * | |
4204 | * It also means that in error cases, we don't have to try and revert to | |
4205 | * the old permissions (which is an operation that could fail, too). We can | |
4206 | * just keep the extended permissions for the next time that an activation | |
4207 | * of the image is tried. | |
4208 | */ | |
4209 | bs->open_flags &= ~BDRV_O_INACTIVE; | |
4210 | bdrv_get_cumulative_perm(bs, &perm, &shared_perm); | |
4211 | ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &local_err); | |
4212 | if (ret < 0) { | |
4213 | bs->open_flags |= BDRV_O_INACTIVE; | |
4214 | error_propagate(errp, local_err); | |
4215 | return; | |
4216 | } | |
4217 | bdrv_set_perm(bs, perm, shared_perm); | |
4218 | ||
4219 | if (bs->drv->bdrv_invalidate_cache) { | |
4220 | bs->drv->bdrv_invalidate_cache(bs, &local_err); | |
4221 | if (local_err) { | |
4222 | bs->open_flags |= BDRV_O_INACTIVE; | |
4223 | error_propagate(errp, local_err); | |
4224 | return; | |
4225 | } | |
4226 | } | |
4227 | ||
4228 | ret = refresh_total_sectors(bs, bs->total_sectors); | |
4229 | if (ret < 0) { | |
4230 | bs->open_flags |= BDRV_O_INACTIVE; | |
4231 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
4232 | return; | |
4233 | } | |
4234 | ||
4235 | QLIST_FOREACH(parent, &bs->parents, next_parent) { | |
4236 | if (parent->role->activate) { | |
4237 | parent->role->activate(parent, &local_err); | |
4238 | if (local_err) { | |
4239 | error_propagate(errp, local_err); | |
4240 | return; | |
4241 | } | |
4242 | } | |
4243 | } | |
4244 | } | |
4245 | ||
4246 | void bdrv_invalidate_cache_all(Error **errp) | |
4247 | { | |
4248 | BlockDriverState *bs; | |
4249 | Error *local_err = NULL; | |
4250 | BdrvNextIterator it; | |
4251 | ||
4252 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
4253 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
4254 | ||
4255 | aio_context_acquire(aio_context); | |
4256 | bdrv_invalidate_cache(bs, &local_err); | |
4257 | aio_context_release(aio_context); | |
4258 | if (local_err) { | |
4259 | error_propagate(errp, local_err); | |
4260 | bdrv_next_cleanup(&it); | |
4261 | return; | |
4262 | } | |
4263 | } | |
4264 | } | |
4265 | ||
4266 | static int bdrv_inactivate_recurse(BlockDriverState *bs, | |
4267 | bool setting_flag) | |
4268 | { | |
4269 | BdrvChild *child, *parent; | |
4270 | int ret; | |
4271 | ||
4272 | if (!bs->drv) { | |
4273 | return -ENOMEDIUM; | |
4274 | } | |
4275 | ||
4276 | if (!setting_flag && bs->drv->bdrv_inactivate) { | |
4277 | ret = bs->drv->bdrv_inactivate(bs); | |
4278 | if (ret < 0) { | |
4279 | return ret; | |
4280 | } | |
4281 | } | |
4282 | ||
4283 | if (setting_flag && !(bs->open_flags & BDRV_O_INACTIVE)) { | |
4284 | uint64_t perm, shared_perm; | |
4285 | ||
4286 | QLIST_FOREACH(parent, &bs->parents, next_parent) { | |
4287 | if (parent->role->inactivate) { | |
4288 | ret = parent->role->inactivate(parent); | |
4289 | if (ret < 0) { | |
4290 | return ret; | |
4291 | } | |
4292 | } | |
4293 | } | |
4294 | ||
4295 | bs->open_flags |= BDRV_O_INACTIVE; | |
4296 | ||
4297 | /* Update permissions, they may differ for inactive nodes */ | |
4298 | bdrv_get_cumulative_perm(bs, &perm, &shared_perm); | |
4299 | bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &error_abort); | |
4300 | bdrv_set_perm(bs, perm, shared_perm); | |
4301 | } | |
4302 | ||
4303 | QLIST_FOREACH(child, &bs->children, next) { | |
4304 | ret = bdrv_inactivate_recurse(child->bs, setting_flag); | |
4305 | if (ret < 0) { | |
4306 | return ret; | |
4307 | } | |
4308 | } | |
4309 | ||
4310 | /* At this point persistent bitmaps should be already stored by the format | |
4311 | * driver */ | |
4312 | bdrv_release_persistent_dirty_bitmaps(bs); | |
4313 | ||
4314 | return 0; | |
4315 | } | |
4316 | ||
4317 | int bdrv_inactivate_all(void) | |
4318 | { | |
4319 | BlockDriverState *bs = NULL; | |
4320 | BdrvNextIterator it; | |
4321 | int ret = 0; | |
4322 | int pass; | |
4323 | ||
4324 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
4325 | aio_context_acquire(bdrv_get_aio_context(bs)); | |
4326 | } | |
4327 | ||
4328 | /* We do two passes of inactivation. The first pass calls to drivers' | |
4329 | * .bdrv_inactivate callbacks recursively so all cache is flushed to disk; | |
4330 | * the second pass sets the BDRV_O_INACTIVE flag so that no further write | |
4331 | * is allowed. */ | |
4332 | for (pass = 0; pass < 2; pass++) { | |
4333 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
4334 | ret = bdrv_inactivate_recurse(bs, pass); | |
4335 | if (ret < 0) { | |
4336 | bdrv_next_cleanup(&it); | |
4337 | goto out; | |
4338 | } | |
4339 | } | |
4340 | } | |
4341 | ||
4342 | out: | |
4343 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
4344 | aio_context_release(bdrv_get_aio_context(bs)); | |
4345 | } | |
4346 | ||
4347 | return ret; | |
4348 | } | |
4349 | ||
4350 | /**************************************************************/ | |
4351 | /* removable device support */ | |
4352 | ||
4353 | /** | |
4354 | * Return TRUE if the media is present | |
4355 | */ | |
4356 | bool bdrv_is_inserted(BlockDriverState *bs) | |
4357 | { | |
4358 | BlockDriver *drv = bs->drv; | |
4359 | BdrvChild *child; | |
4360 | ||
4361 | if (!drv) { | |
4362 | return false; | |
4363 | } | |
4364 | if (drv->bdrv_is_inserted) { | |
4365 | return drv->bdrv_is_inserted(bs); | |
4366 | } | |
4367 | QLIST_FOREACH(child, &bs->children, next) { | |
4368 | if (!bdrv_is_inserted(child->bs)) { | |
4369 | return false; | |
4370 | } | |
4371 | } | |
4372 | return true; | |
4373 | } | |
4374 | ||
4375 | /** | |
4376 | * If eject_flag is TRUE, eject the media. Otherwise, close the tray | |
4377 | */ | |
4378 | void bdrv_eject(BlockDriverState *bs, bool eject_flag) | |
4379 | { | |
4380 | BlockDriver *drv = bs->drv; | |
4381 | ||
4382 | if (drv && drv->bdrv_eject) { | |
4383 | drv->bdrv_eject(bs, eject_flag); | |
4384 | } | |
4385 | } | |
4386 | ||
4387 | /** | |
4388 | * Lock or unlock the media (if it is locked, the user won't be able | |
4389 | * to eject it manually). | |
4390 | */ | |
4391 | void bdrv_lock_medium(BlockDriverState *bs, bool locked) | |
4392 | { | |
4393 | BlockDriver *drv = bs->drv; | |
4394 | ||
4395 | trace_bdrv_lock_medium(bs, locked); | |
4396 | ||
4397 | if (drv && drv->bdrv_lock_medium) { | |
4398 | drv->bdrv_lock_medium(bs, locked); | |
4399 | } | |
4400 | } | |
4401 | ||
4402 | /* Get a reference to bs */ | |
4403 | void bdrv_ref(BlockDriverState *bs) | |
4404 | { | |
4405 | bs->refcnt++; | |
4406 | } | |
4407 | ||
4408 | /* Release a previously grabbed reference to bs. | |
4409 | * If after releasing, reference count is zero, the BlockDriverState is | |
4410 | * deleted. */ | |
4411 | void bdrv_unref(BlockDriverState *bs) | |
4412 | { | |
4413 | if (!bs) { | |
4414 | return; | |
4415 | } | |
4416 | assert(bs->refcnt > 0); | |
4417 | if (--bs->refcnt == 0) { | |
4418 | bdrv_delete(bs); | |
4419 | } | |
4420 | } | |
4421 | ||
4422 | struct BdrvOpBlocker { | |
4423 | Error *reason; | |
4424 | QLIST_ENTRY(BdrvOpBlocker) list; | |
4425 | }; | |
4426 | ||
4427 | bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) | |
4428 | { | |
4429 | BdrvOpBlocker *blocker; | |
4430 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
4431 | if (!QLIST_EMPTY(&bs->op_blockers[op])) { | |
4432 | blocker = QLIST_FIRST(&bs->op_blockers[op]); | |
4433 | error_propagate(errp, error_copy(blocker->reason)); | |
4434 | error_prepend(errp, "Node '%s' is busy: ", | |
4435 | bdrv_get_device_or_node_name(bs)); | |
4436 | return true; | |
4437 | } | |
4438 | return false; | |
4439 | } | |
4440 | ||
4441 | void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason) | |
4442 | { | |
4443 | BdrvOpBlocker *blocker; | |
4444 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
4445 | ||
4446 | blocker = g_new0(BdrvOpBlocker, 1); | |
4447 | blocker->reason = reason; | |
4448 | QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list); | |
4449 | } | |
4450 | ||
4451 | void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason) | |
4452 | { | |
4453 | BdrvOpBlocker *blocker, *next; | |
4454 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
4455 | QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) { | |
4456 | if (blocker->reason == reason) { | |
4457 | QLIST_REMOVE(blocker, list); | |
4458 | g_free(blocker); | |
4459 | } | |
4460 | } | |
4461 | } | |
4462 | ||
4463 | void bdrv_op_block_all(BlockDriverState *bs, Error *reason) | |
4464 | { | |
4465 | int i; | |
4466 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
4467 | bdrv_op_block(bs, i, reason); | |
4468 | } | |
4469 | } | |
4470 | ||
4471 | void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason) | |
4472 | { | |
4473 | int i; | |
4474 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
4475 | bdrv_op_unblock(bs, i, reason); | |
4476 | } | |
4477 | } | |
4478 | ||
4479 | bool bdrv_op_blocker_is_empty(BlockDriverState *bs) | |
4480 | { | |
4481 | int i; | |
4482 | ||
4483 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
4484 | if (!QLIST_EMPTY(&bs->op_blockers[i])) { | |
4485 | return false; | |
4486 | } | |
4487 | } | |
4488 | return true; | |
4489 | } | |
4490 | ||
4491 | void bdrv_img_create(const char *filename, const char *fmt, | |
4492 | const char *base_filename, const char *base_fmt, | |
4493 | char *options, uint64_t img_size, int flags, bool quiet, | |
4494 | Error **errp) | |
4495 | { | |
4496 | QemuOptsList *create_opts = NULL; | |
4497 | QemuOpts *opts = NULL; | |
4498 | const char *backing_fmt, *backing_file; | |
4499 | int64_t size; | |
4500 | BlockDriver *drv, *proto_drv; | |
4501 | Error *local_err = NULL; | |
4502 | int ret = 0; | |
4503 | ||
4504 | /* Find driver and parse its options */ | |
4505 | drv = bdrv_find_format(fmt); | |
4506 | if (!drv) { | |
4507 | error_setg(errp, "Unknown file format '%s'", fmt); | |
4508 | return; | |
4509 | } | |
4510 | ||
4511 | proto_drv = bdrv_find_protocol(filename, true, errp); | |
4512 | if (!proto_drv) { | |
4513 | return; | |
4514 | } | |
4515 | ||
4516 | if (!drv->create_opts) { | |
4517 | error_setg(errp, "Format driver '%s' does not support image creation", | |
4518 | drv->format_name); | |
4519 | return; | |
4520 | } | |
4521 | ||
4522 | if (!proto_drv->create_opts) { | |
4523 | error_setg(errp, "Protocol driver '%s' does not support image creation", | |
4524 | proto_drv->format_name); | |
4525 | return; | |
4526 | } | |
4527 | ||
4528 | create_opts = qemu_opts_append(create_opts, drv->create_opts); | |
4529 | create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); | |
4530 | ||
4531 | /* Create parameter list with default values */ | |
4532 | opts = qemu_opts_create(create_opts, NULL, 0, &error_abort); | |
4533 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort); | |
4534 | ||
4535 | /* Parse -o options */ | |
4536 | if (options) { | |
4537 | qemu_opts_do_parse(opts, options, NULL, &local_err); | |
4538 | if (local_err) { | |
4539 | error_report_err(local_err); | |
4540 | local_err = NULL; | |
4541 | error_setg(errp, "Invalid options for file format '%s'", fmt); | |
4542 | goto out; | |
4543 | } | |
4544 | } | |
4545 | ||
4546 | if (base_filename) { | |
4547 | qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err); | |
4548 | if (local_err) { | |
4549 | error_setg(errp, "Backing file not supported for file format '%s'", | |
4550 | fmt); | |
4551 | goto out; | |
4552 | } | |
4553 | } | |
4554 | ||
4555 | if (base_fmt) { | |
4556 | qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err); | |
4557 | if (local_err) { | |
4558 | error_setg(errp, "Backing file format not supported for file " | |
4559 | "format '%s'", fmt); | |
4560 | goto out; | |
4561 | } | |
4562 | } | |
4563 | ||
4564 | backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); | |
4565 | if (backing_file) { | |
4566 | if (!strcmp(filename, backing_file)) { | |
4567 | error_setg(errp, "Error: Trying to create an image with the " | |
4568 | "same filename as the backing file"); | |
4569 | goto out; | |
4570 | } | |
4571 | } | |
4572 | ||
4573 | backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); | |
4574 | ||
4575 | /* The size for the image must always be specified, unless we have a backing | |
4576 | * file and we have not been forbidden from opening it. */ | |
4577 | size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size); | |
4578 | if (backing_file && !(flags & BDRV_O_NO_BACKING)) { | |
4579 | BlockDriverState *bs; | |
4580 | char *full_backing = g_new0(char, PATH_MAX); | |
4581 | int back_flags; | |
4582 | QDict *backing_options = NULL; | |
4583 | ||
4584 | bdrv_get_full_backing_filename_from_filename(filename, backing_file, | |
4585 | full_backing, PATH_MAX, | |
4586 | &local_err); | |
4587 | if (local_err) { | |
4588 | g_free(full_backing); | |
4589 | goto out; | |
4590 | } | |
4591 | ||
4592 | /* backing files always opened read-only */ | |
4593 | back_flags = flags; | |
4594 | back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); | |
4595 | ||
4596 | if (backing_fmt) { | |
4597 | backing_options = qdict_new(); | |
4598 | qdict_put_str(backing_options, "driver", backing_fmt); | |
4599 | } | |
4600 | ||
4601 | bs = bdrv_open(full_backing, NULL, backing_options, back_flags, | |
4602 | &local_err); | |
4603 | g_free(full_backing); | |
4604 | if (!bs && size != -1) { | |
4605 | /* Couldn't open BS, but we have a size, so it's nonfatal */ | |
4606 | warn_reportf_err(local_err, | |
4607 | "Could not verify backing image. " | |
4608 | "This may become an error in future versions.\n"); | |
4609 | local_err = NULL; | |
4610 | } else if (!bs) { | |
4611 | /* Couldn't open bs, do not have size */ | |
4612 | error_append_hint(&local_err, | |
4613 | "Could not open backing image to determine size.\n"); | |
4614 | goto out; | |
4615 | } else { | |
4616 | if (size == -1) { | |
4617 | /* Opened BS, have no size */ | |
4618 | size = bdrv_getlength(bs); | |
4619 | if (size < 0) { | |
4620 | error_setg_errno(errp, -size, "Could not get size of '%s'", | |
4621 | backing_file); | |
4622 | bdrv_unref(bs); | |
4623 | goto out; | |
4624 | } | |
4625 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort); | |
4626 | } | |
4627 | bdrv_unref(bs); | |
4628 | } | |
4629 | } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */ | |
4630 | ||
4631 | if (size == -1) { | |
4632 | error_setg(errp, "Image creation needs a size parameter"); | |
4633 | goto out; | |
4634 | } | |
4635 | ||
4636 | if (!quiet) { | |
4637 | printf("Formatting '%s', fmt=%s ", filename, fmt); | |
4638 | qemu_opts_print(opts, " "); | |
4639 | puts(""); | |
4640 | } | |
4641 | ||
4642 | ret = bdrv_create(drv, filename, opts, &local_err); | |
4643 | ||
4644 | if (ret == -EFBIG) { | |
4645 | /* This is generally a better message than whatever the driver would | |
4646 | * deliver (especially because of the cluster_size_hint), since that | |
4647 | * is most probably not much different from "image too large". */ | |
4648 | const char *cluster_size_hint = ""; | |
4649 | if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) { | |
4650 | cluster_size_hint = " (try using a larger cluster size)"; | |
4651 | } | |
4652 | error_setg(errp, "The image size is too large for file format '%s'" | |
4653 | "%s", fmt, cluster_size_hint); | |
4654 | error_free(local_err); | |
4655 | local_err = NULL; | |
4656 | } | |
4657 | ||
4658 | out: | |
4659 | qemu_opts_del(opts); | |
4660 | qemu_opts_free(create_opts); | |
4661 | error_propagate(errp, local_err); | |
4662 | } | |
4663 | ||
4664 | AioContext *bdrv_get_aio_context(BlockDriverState *bs) | |
4665 | { | |
4666 | return bs->aio_context; | |
4667 | } | |
4668 | ||
4669 | void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co) | |
4670 | { | |
4671 | aio_co_enter(bdrv_get_aio_context(bs), co); | |
4672 | } | |
4673 | ||
4674 | static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban) | |
4675 | { | |
4676 | QLIST_REMOVE(ban, list); | |
4677 | g_free(ban); | |
4678 | } | |
4679 | ||
4680 | void bdrv_detach_aio_context(BlockDriverState *bs) | |
4681 | { | |
4682 | BdrvAioNotifier *baf, *baf_tmp; | |
4683 | BdrvChild *child; | |
4684 | ||
4685 | if (!bs->drv) { | |
4686 | return; | |
4687 | } | |
4688 | ||
4689 | assert(!bs->walking_aio_notifiers); | |
4690 | bs->walking_aio_notifiers = true; | |
4691 | QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) { | |
4692 | if (baf->deleted) { | |
4693 | bdrv_do_remove_aio_context_notifier(baf); | |
4694 | } else { | |
4695 | baf->detach_aio_context(baf->opaque); | |
4696 | } | |
4697 | } | |
4698 | /* Never mind iterating again to check for ->deleted. bdrv_close() will | |
4699 | * remove remaining aio notifiers if we aren't called again. | |
4700 | */ | |
4701 | bs->walking_aio_notifiers = false; | |
4702 | ||
4703 | if (bs->drv->bdrv_detach_aio_context) { | |
4704 | bs->drv->bdrv_detach_aio_context(bs); | |
4705 | } | |
4706 | QLIST_FOREACH(child, &bs->children, next) { | |
4707 | bdrv_detach_aio_context(child->bs); | |
4708 | } | |
4709 | ||
4710 | bs->aio_context = NULL; | |
4711 | } | |
4712 | ||
4713 | void bdrv_attach_aio_context(BlockDriverState *bs, | |
4714 | AioContext *new_context) | |
4715 | { | |
4716 | BdrvAioNotifier *ban, *ban_tmp; | |
4717 | BdrvChild *child; | |
4718 | ||
4719 | if (!bs->drv) { | |
4720 | return; | |
4721 | } | |
4722 | ||
4723 | bs->aio_context = new_context; | |
4724 | ||
4725 | QLIST_FOREACH(child, &bs->children, next) { | |
4726 | bdrv_attach_aio_context(child->bs, new_context); | |
4727 | } | |
4728 | if (bs->drv->bdrv_attach_aio_context) { | |
4729 | bs->drv->bdrv_attach_aio_context(bs, new_context); | |
4730 | } | |
4731 | ||
4732 | assert(!bs->walking_aio_notifiers); | |
4733 | bs->walking_aio_notifiers = true; | |
4734 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) { | |
4735 | if (ban->deleted) { | |
4736 | bdrv_do_remove_aio_context_notifier(ban); | |
4737 | } else { | |
4738 | ban->attached_aio_context(new_context, ban->opaque); | |
4739 | } | |
4740 | } | |
4741 | bs->walking_aio_notifiers = false; | |
4742 | } | |
4743 | ||
4744 | void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) | |
4745 | { | |
4746 | AioContext *ctx = bdrv_get_aio_context(bs); | |
4747 | ||
4748 | aio_disable_external(ctx); | |
4749 | bdrv_parent_drained_begin(bs); | |
4750 | bdrv_drain(bs); /* ensure there are no in-flight requests */ | |
4751 | ||
4752 | while (aio_poll(ctx, false)) { | |
4753 | /* wait for all bottom halves to execute */ | |
4754 | } | |
4755 | ||
4756 | bdrv_detach_aio_context(bs); | |
4757 | ||
4758 | /* This function executes in the old AioContext so acquire the new one in | |
4759 | * case it runs in a different thread. | |
4760 | */ | |
4761 | aio_context_acquire(new_context); | |
4762 | bdrv_attach_aio_context(bs, new_context); | |
4763 | bdrv_parent_drained_end(bs); | |
4764 | aio_enable_external(ctx); | |
4765 | aio_context_release(new_context); | |
4766 | } | |
4767 | ||
4768 | void bdrv_add_aio_context_notifier(BlockDriverState *bs, | |
4769 | void (*attached_aio_context)(AioContext *new_context, void *opaque), | |
4770 | void (*detach_aio_context)(void *opaque), void *opaque) | |
4771 | { | |
4772 | BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1); | |
4773 | *ban = (BdrvAioNotifier){ | |
4774 | .attached_aio_context = attached_aio_context, | |
4775 | .detach_aio_context = detach_aio_context, | |
4776 | .opaque = opaque | |
4777 | }; | |
4778 | ||
4779 | QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list); | |
4780 | } | |
4781 | ||
4782 | void bdrv_remove_aio_context_notifier(BlockDriverState *bs, | |
4783 | void (*attached_aio_context)(AioContext *, | |
4784 | void *), | |
4785 | void (*detach_aio_context)(void *), | |
4786 | void *opaque) | |
4787 | { | |
4788 | BdrvAioNotifier *ban, *ban_next; | |
4789 | ||
4790 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { | |
4791 | if (ban->attached_aio_context == attached_aio_context && | |
4792 | ban->detach_aio_context == detach_aio_context && | |
4793 | ban->opaque == opaque && | |
4794 | ban->deleted == false) | |
4795 | { | |
4796 | if (bs->walking_aio_notifiers) { | |
4797 | ban->deleted = true; | |
4798 | } else { | |
4799 | bdrv_do_remove_aio_context_notifier(ban); | |
4800 | } | |
4801 | return; | |
4802 | } | |
4803 | } | |
4804 | ||
4805 | abort(); | |
4806 | } | |
4807 | ||
4808 | int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts, | |
4809 | BlockDriverAmendStatusCB *status_cb, void *cb_opaque) | |
4810 | { | |
4811 | if (!bs->drv) { | |
4812 | return -ENOMEDIUM; | |
4813 | } | |
4814 | if (!bs->drv->bdrv_amend_options) { | |
4815 | return -ENOTSUP; | |
4816 | } | |
4817 | return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque); | |
4818 | } | |
4819 | ||
4820 | /* This function will be called by the bdrv_recurse_is_first_non_filter method | |
4821 | * of block filter and by bdrv_is_first_non_filter. | |
4822 | * It is used to test if the given bs is the candidate or recurse more in the | |
4823 | * node graph. | |
4824 | */ | |
4825 | bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, | |
4826 | BlockDriverState *candidate) | |
4827 | { | |
4828 | /* return false if basic checks fails */ | |
4829 | if (!bs || !bs->drv) { | |
4830 | return false; | |
4831 | } | |
4832 | ||
4833 | /* the code reached a non block filter driver -> check if the bs is | |
4834 | * the same as the candidate. It's the recursion termination condition. | |
4835 | */ | |
4836 | if (!bs->drv->is_filter) { | |
4837 | return bs == candidate; | |
4838 | } | |
4839 | /* Down this path the driver is a block filter driver */ | |
4840 | ||
4841 | /* If the block filter recursion method is defined use it to recurse down | |
4842 | * the node graph. | |
4843 | */ | |
4844 | if (bs->drv->bdrv_recurse_is_first_non_filter) { | |
4845 | return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate); | |
4846 | } | |
4847 | ||
4848 | /* the driver is a block filter but don't allow to recurse -> return false | |
4849 | */ | |
4850 | return false; | |
4851 | } | |
4852 | ||
4853 | /* This function checks if the candidate is the first non filter bs down it's | |
4854 | * bs chain. Since we don't have pointers to parents it explore all bs chains | |
4855 | * from the top. Some filters can choose not to pass down the recursion. | |
4856 | */ | |
4857 | bool bdrv_is_first_non_filter(BlockDriverState *candidate) | |
4858 | { | |
4859 | BlockDriverState *bs; | |
4860 | BdrvNextIterator it; | |
4861 | ||
4862 | /* walk down the bs forest recursively */ | |
4863 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
4864 | bool perm; | |
4865 | ||
4866 | /* try to recurse in this top level bs */ | |
4867 | perm = bdrv_recurse_is_first_non_filter(bs, candidate); | |
4868 | ||
4869 | /* candidate is the first non filter */ | |
4870 | if (perm) { | |
4871 | bdrv_next_cleanup(&it); | |
4872 | return true; | |
4873 | } | |
4874 | } | |
4875 | ||
4876 | return false; | |
4877 | } | |
4878 | ||
4879 | BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, | |
4880 | const char *node_name, Error **errp) | |
4881 | { | |
4882 | BlockDriverState *to_replace_bs = bdrv_find_node(node_name); | |
4883 | AioContext *aio_context; | |
4884 | ||
4885 | if (!to_replace_bs) { | |
4886 | error_setg(errp, "Node name '%s' not found", node_name); | |
4887 | return NULL; | |
4888 | } | |
4889 | ||
4890 | aio_context = bdrv_get_aio_context(to_replace_bs); | |
4891 | aio_context_acquire(aio_context); | |
4892 | ||
4893 | if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) { | |
4894 | to_replace_bs = NULL; | |
4895 | goto out; | |
4896 | } | |
4897 | ||
4898 | /* We don't want arbitrary node of the BDS chain to be replaced only the top | |
4899 | * most non filter in order to prevent data corruption. | |
4900 | * Another benefit is that this tests exclude backing files which are | |
4901 | * blocked by the backing blockers. | |
4902 | */ | |
4903 | if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) { | |
4904 | error_setg(errp, "Only top most non filter can be replaced"); | |
4905 | to_replace_bs = NULL; | |
4906 | goto out; | |
4907 | } | |
4908 | ||
4909 | out: | |
4910 | aio_context_release(aio_context); | |
4911 | return to_replace_bs; | |
4912 | } | |
4913 | ||
4914 | static bool append_open_options(QDict *d, BlockDriverState *bs) | |
4915 | { | |
4916 | const QDictEntry *entry; | |
4917 | QemuOptDesc *desc; | |
4918 | BdrvChild *child; | |
4919 | bool found_any = false; | |
4920 | const char *p; | |
4921 | ||
4922 | for (entry = qdict_first(bs->options); entry; | |
4923 | entry = qdict_next(bs->options, entry)) | |
4924 | { | |
4925 | /* Exclude options for children */ | |
4926 | QLIST_FOREACH(child, &bs->children, next) { | |
4927 | if (strstart(qdict_entry_key(entry), child->name, &p) | |
4928 | && (!*p || *p == '.')) | |
4929 | { | |
4930 | break; | |
4931 | } | |
4932 | } | |
4933 | if (child) { | |
4934 | continue; | |
4935 | } | |
4936 | ||
4937 | /* And exclude all non-driver-specific options */ | |
4938 | for (desc = bdrv_runtime_opts.desc; desc->name; desc++) { | |
4939 | if (!strcmp(qdict_entry_key(entry), desc->name)) { | |
4940 | break; | |
4941 | } | |
4942 | } | |
4943 | if (desc->name) { | |
4944 | continue; | |
4945 | } | |
4946 | ||
4947 | qobject_incref(qdict_entry_value(entry)); | |
4948 | qdict_put_obj(d, qdict_entry_key(entry), qdict_entry_value(entry)); | |
4949 | found_any = true; | |
4950 | } | |
4951 | ||
4952 | return found_any; | |
4953 | } | |
4954 | ||
4955 | /* Updates the following BDS fields: | |
4956 | * - exact_filename: A filename which may be used for opening a block device | |
4957 | * which (mostly) equals the given BDS (even without any | |
4958 | * other options; so reading and writing must return the same | |
4959 | * results, but caching etc. may be different) | |
4960 | * - full_open_options: Options which, when given when opening a block device | |
4961 | * (without a filename), result in a BDS (mostly) | |
4962 | * equalling the given one | |
4963 | * - filename: If exact_filename is set, it is copied here. Otherwise, | |
4964 | * full_open_options is converted to a JSON object, prefixed with | |
4965 | * "json:" (for use through the JSON pseudo protocol) and put here. | |
4966 | */ | |
4967 | void bdrv_refresh_filename(BlockDriverState *bs) | |
4968 | { | |
4969 | BlockDriver *drv = bs->drv; | |
4970 | QDict *opts; | |
4971 | ||
4972 | if (!drv) { | |
4973 | return; | |
4974 | } | |
4975 | ||
4976 | /* This BDS's file name will most probably depend on its file's name, so | |
4977 | * refresh that first */ | |
4978 | if (bs->file) { | |
4979 | bdrv_refresh_filename(bs->file->bs); | |
4980 | } | |
4981 | ||
4982 | if (drv->bdrv_refresh_filename) { | |
4983 | /* Obsolete information is of no use here, so drop the old file name | |
4984 | * information before refreshing it */ | |
4985 | bs->exact_filename[0] = '\0'; | |
4986 | if (bs->full_open_options) { | |
4987 | QDECREF(bs->full_open_options); | |
4988 | bs->full_open_options = NULL; | |
4989 | } | |
4990 | ||
4991 | opts = qdict_new(); | |
4992 | append_open_options(opts, bs); | |
4993 | drv->bdrv_refresh_filename(bs, opts); | |
4994 | QDECREF(opts); | |
4995 | } else if (bs->file) { | |
4996 | /* Try to reconstruct valid information from the underlying file */ | |
4997 | bool has_open_options; | |
4998 | ||
4999 | bs->exact_filename[0] = '\0'; | |
5000 | if (bs->full_open_options) { | |
5001 | QDECREF(bs->full_open_options); | |
5002 | bs->full_open_options = NULL; | |
5003 | } | |
5004 | ||
5005 | opts = qdict_new(); | |
5006 | has_open_options = append_open_options(opts, bs); | |
5007 | ||
5008 | /* If no specific options have been given for this BDS, the filename of | |
5009 | * the underlying file should suffice for this one as well */ | |
5010 | if (bs->file->bs->exact_filename[0] && !has_open_options) { | |
5011 | strcpy(bs->exact_filename, bs->file->bs->exact_filename); | |
5012 | } | |
5013 | /* Reconstructing the full options QDict is simple for most format block | |
5014 | * drivers, as long as the full options are known for the underlying | |
5015 | * file BDS. The full options QDict of that file BDS should somehow | |
5016 | * contain a representation of the filename, therefore the following | |
5017 | * suffices without querying the (exact_)filename of this BDS. */ | |
5018 | if (bs->file->bs->full_open_options) { | |
5019 | qdict_put_str(opts, "driver", drv->format_name); | |
5020 | QINCREF(bs->file->bs->full_open_options); | |
5021 | qdict_put(opts, "file", bs->file->bs->full_open_options); | |
5022 | ||
5023 | bs->full_open_options = opts; | |
5024 | } else { | |
5025 | QDECREF(opts); | |
5026 | } | |
5027 | } else if (!bs->full_open_options && qdict_size(bs->options)) { | |
5028 | /* There is no underlying file BDS (at least referenced by BDS.file), | |
5029 | * so the full options QDict should be equal to the options given | |
5030 | * specifically for this block device when it was opened (plus the | |
5031 | * driver specification). | |
5032 | * Because those options don't change, there is no need to update | |
5033 | * full_open_options when it's already set. */ | |
5034 | ||
5035 | opts = qdict_new(); | |
5036 | append_open_options(opts, bs); | |
5037 | qdict_put_str(opts, "driver", drv->format_name); | |
5038 | ||
5039 | if (bs->exact_filename[0]) { | |
5040 | /* This may not work for all block protocol drivers (some may | |
5041 | * require this filename to be parsed), but we have to find some | |
5042 | * default solution here, so just include it. If some block driver | |
5043 | * does not support pure options without any filename at all or | |
5044 | * needs some special format of the options QDict, it needs to | |
5045 | * implement the driver-specific bdrv_refresh_filename() function. | |
5046 | */ | |
5047 | qdict_put_str(opts, "filename", bs->exact_filename); | |
5048 | } | |
5049 | ||
5050 | bs->full_open_options = opts; | |
5051 | } | |
5052 | ||
5053 | if (bs->exact_filename[0]) { | |
5054 | pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); | |
5055 | } else if (bs->full_open_options) { | |
5056 | QString *json = qobject_to_json(QOBJECT(bs->full_open_options)); | |
5057 | snprintf(bs->filename, sizeof(bs->filename), "json:%s", | |
5058 | qstring_get_str(json)); | |
5059 | QDECREF(json); | |
5060 | } | |
5061 | } | |
5062 | ||
5063 | /* | |
5064 | * Hot add/remove a BDS's child. So the user can take a child offline when | |
5065 | * it is broken and take a new child online | |
5066 | */ | |
5067 | void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, | |
5068 | Error **errp) | |
5069 | { | |
5070 | ||
5071 | if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) { | |
5072 | error_setg(errp, "The node %s does not support adding a child", | |
5073 | bdrv_get_device_or_node_name(parent_bs)); | |
5074 | return; | |
5075 | } | |
5076 | ||
5077 | if (!QLIST_EMPTY(&child_bs->parents)) { | |
5078 | error_setg(errp, "The node %s already has a parent", | |
5079 | child_bs->node_name); | |
5080 | return; | |
5081 | } | |
5082 | ||
5083 | parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp); | |
5084 | } | |
5085 | ||
5086 | void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp) | |
5087 | { | |
5088 | BdrvChild *tmp; | |
5089 | ||
5090 | if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) { | |
5091 | error_setg(errp, "The node %s does not support removing a child", | |
5092 | bdrv_get_device_or_node_name(parent_bs)); | |
5093 | return; | |
5094 | } | |
5095 | ||
5096 | QLIST_FOREACH(tmp, &parent_bs->children, next) { | |
5097 | if (tmp == child) { | |
5098 | break; | |
5099 | } | |
5100 | } | |
5101 | ||
5102 | if (!tmp) { | |
5103 | error_setg(errp, "The node %s does not have a child named %s", | |
5104 | bdrv_get_device_or_node_name(parent_bs), | |
5105 | bdrv_get_device_or_node_name(child->bs)); | |
5106 | return; | |
5107 | } | |
5108 | ||
5109 | parent_bs->drv->bdrv_del_child(parent_bs, child, errp); | |
5110 | } | |
5111 | ||
5112 | bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, | |
5113 | uint32_t granularity, Error **errp) | |
5114 | { | |
5115 | BlockDriver *drv = bs->drv; | |
5116 | ||
5117 | if (!drv) { | |
5118 | error_setg_errno(errp, ENOMEDIUM, | |
5119 | "Can't store persistent bitmaps to %s", | |
5120 | bdrv_get_device_or_node_name(bs)); | |
5121 | return false; | |
5122 | } | |
5123 | ||
5124 | if (!drv->bdrv_can_store_new_dirty_bitmap) { | |
5125 | error_setg_errno(errp, ENOTSUP, | |
5126 | "Can't store persistent bitmaps to %s", | |
5127 | bdrv_get_device_or_node_name(bs)); | |
5128 | return false; | |
5129 | } | |
5130 | ||
5131 | return drv->bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp); | |
5132 | } |