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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 "config-host.h" | |
25 | #include "qemu-common.h" | |
26 | #include "trace.h" | |
27 | #include "block/block_int.h" | |
28 | #include "block/blockjob.h" | |
29 | #include "qemu/module.h" | |
30 | #include "qapi/qmp/qjson.h" | |
31 | #include "sysemu/sysemu.h" | |
32 | #include "qemu/notify.h" | |
33 | #include "block/coroutine.h" | |
34 | #include "block/qapi.h" | |
35 | #include "qmp-commands.h" | |
36 | #include "qemu/timer.h" | |
37 | #include "qapi-event.h" | |
38 | ||
39 | #ifdef CONFIG_BSD | |
40 | #include <sys/types.h> | |
41 | #include <sys/stat.h> | |
42 | #include <sys/ioctl.h> | |
43 | #include <sys/queue.h> | |
44 | #ifndef __DragonFly__ | |
45 | #include <sys/disk.h> | |
46 | #endif | |
47 | #endif | |
48 | ||
49 | #ifdef _WIN32 | |
50 | #include <windows.h> | |
51 | #endif | |
52 | ||
53 | struct BdrvDirtyBitmap { | |
54 | HBitmap *bitmap; | |
55 | QLIST_ENTRY(BdrvDirtyBitmap) list; | |
56 | }; | |
57 | ||
58 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ | |
59 | ||
60 | #define COROUTINE_POOL_RESERVATION 64 /* number of coroutines to reserve */ | |
61 | ||
62 | static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load); | |
63 | static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, | |
64 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
65 | BlockDriverCompletionFunc *cb, void *opaque); | |
66 | static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, | |
67 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
68 | BlockDriverCompletionFunc *cb, void *opaque); | |
69 | static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, | |
70 | int64_t sector_num, int nb_sectors, | |
71 | QEMUIOVector *iov); | |
72 | static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, | |
73 | int64_t sector_num, int nb_sectors, | |
74 | QEMUIOVector *iov); | |
75 | static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, | |
76 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
77 | BdrvRequestFlags flags); | |
78 | static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, | |
79 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
80 | BdrvRequestFlags flags); | |
81 | static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, | |
82 | int64_t sector_num, | |
83 | QEMUIOVector *qiov, | |
84 | int nb_sectors, | |
85 | BdrvRequestFlags flags, | |
86 | BlockDriverCompletionFunc *cb, | |
87 | void *opaque, | |
88 | bool is_write); | |
89 | static void coroutine_fn bdrv_co_do_rw(void *opaque); | |
90 | static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, | |
91 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); | |
92 | ||
93 | static QTAILQ_HEAD(, BlockDriverState) bdrv_states = | |
94 | QTAILQ_HEAD_INITIALIZER(bdrv_states); | |
95 | ||
96 | static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states = | |
97 | QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); | |
98 | ||
99 | static QLIST_HEAD(, BlockDriver) bdrv_drivers = | |
100 | QLIST_HEAD_INITIALIZER(bdrv_drivers); | |
101 | ||
102 | /* If non-zero, use only whitelisted block drivers */ | |
103 | static int use_bdrv_whitelist; | |
104 | ||
105 | #ifdef _WIN32 | |
106 | static int is_windows_drive_prefix(const char *filename) | |
107 | { | |
108 | return (((filename[0] >= 'a' && filename[0] <= 'z') || | |
109 | (filename[0] >= 'A' && filename[0] <= 'Z')) && | |
110 | filename[1] == ':'); | |
111 | } | |
112 | ||
113 | int is_windows_drive(const char *filename) | |
114 | { | |
115 | if (is_windows_drive_prefix(filename) && | |
116 | filename[2] == '\0') | |
117 | return 1; | |
118 | if (strstart(filename, "\\\\.\\", NULL) || | |
119 | strstart(filename, "//./", NULL)) | |
120 | return 1; | |
121 | return 0; | |
122 | } | |
123 | #endif | |
124 | ||
125 | /* throttling disk I/O limits */ | |
126 | void bdrv_set_io_limits(BlockDriverState *bs, | |
127 | ThrottleConfig *cfg) | |
128 | { | |
129 | int i; | |
130 | ||
131 | throttle_config(&bs->throttle_state, cfg); | |
132 | ||
133 | for (i = 0; i < 2; i++) { | |
134 | qemu_co_enter_next(&bs->throttled_reqs[i]); | |
135 | } | |
136 | } | |
137 | ||
138 | /* this function drain all the throttled IOs */ | |
139 | static bool bdrv_start_throttled_reqs(BlockDriverState *bs) | |
140 | { | |
141 | bool drained = false; | |
142 | bool enabled = bs->io_limits_enabled; | |
143 | int i; | |
144 | ||
145 | bs->io_limits_enabled = false; | |
146 | ||
147 | for (i = 0; i < 2; i++) { | |
148 | while (qemu_co_enter_next(&bs->throttled_reqs[i])) { | |
149 | drained = true; | |
150 | } | |
151 | } | |
152 | ||
153 | bs->io_limits_enabled = enabled; | |
154 | ||
155 | return drained; | |
156 | } | |
157 | ||
158 | void bdrv_io_limits_disable(BlockDriverState *bs) | |
159 | { | |
160 | bs->io_limits_enabled = false; | |
161 | ||
162 | bdrv_start_throttled_reqs(bs); | |
163 | ||
164 | throttle_destroy(&bs->throttle_state); | |
165 | } | |
166 | ||
167 | static void bdrv_throttle_read_timer_cb(void *opaque) | |
168 | { | |
169 | BlockDriverState *bs = opaque; | |
170 | qemu_co_enter_next(&bs->throttled_reqs[0]); | |
171 | } | |
172 | ||
173 | static void bdrv_throttle_write_timer_cb(void *opaque) | |
174 | { | |
175 | BlockDriverState *bs = opaque; | |
176 | qemu_co_enter_next(&bs->throttled_reqs[1]); | |
177 | } | |
178 | ||
179 | /* should be called before bdrv_set_io_limits if a limit is set */ | |
180 | void bdrv_io_limits_enable(BlockDriverState *bs) | |
181 | { | |
182 | assert(!bs->io_limits_enabled); | |
183 | throttle_init(&bs->throttle_state, | |
184 | bdrv_get_aio_context(bs), | |
185 | QEMU_CLOCK_VIRTUAL, | |
186 | bdrv_throttle_read_timer_cb, | |
187 | bdrv_throttle_write_timer_cb, | |
188 | bs); | |
189 | bs->io_limits_enabled = true; | |
190 | } | |
191 | ||
192 | /* This function makes an IO wait if needed | |
193 | * | |
194 | * @nb_sectors: the number of sectors of the IO | |
195 | * @is_write: is the IO a write | |
196 | */ | |
197 | static void bdrv_io_limits_intercept(BlockDriverState *bs, | |
198 | unsigned int bytes, | |
199 | bool is_write) | |
200 | { | |
201 | /* does this io must wait */ | |
202 | bool must_wait = throttle_schedule_timer(&bs->throttle_state, is_write); | |
203 | ||
204 | /* if must wait or any request of this type throttled queue the IO */ | |
205 | if (must_wait || | |
206 | !qemu_co_queue_empty(&bs->throttled_reqs[is_write])) { | |
207 | qemu_co_queue_wait(&bs->throttled_reqs[is_write]); | |
208 | } | |
209 | ||
210 | /* the IO will be executed, do the accounting */ | |
211 | throttle_account(&bs->throttle_state, is_write, bytes); | |
212 | ||
213 | ||
214 | /* if the next request must wait -> do nothing */ | |
215 | if (throttle_schedule_timer(&bs->throttle_state, is_write)) { | |
216 | return; | |
217 | } | |
218 | ||
219 | /* else queue next request for execution */ | |
220 | qemu_co_queue_next(&bs->throttled_reqs[is_write]); | |
221 | } | |
222 | ||
223 | size_t bdrv_opt_mem_align(BlockDriverState *bs) | |
224 | { | |
225 | if (!bs || !bs->drv) { | |
226 | /* 4k should be on the safe side */ | |
227 | return 4096; | |
228 | } | |
229 | ||
230 | return bs->bl.opt_mem_alignment; | |
231 | } | |
232 | ||
233 | /* check if the path starts with "<protocol>:" */ | |
234 | static int path_has_protocol(const char *path) | |
235 | { | |
236 | const char *p; | |
237 | ||
238 | #ifdef _WIN32 | |
239 | if (is_windows_drive(path) || | |
240 | is_windows_drive_prefix(path)) { | |
241 | return 0; | |
242 | } | |
243 | p = path + strcspn(path, ":/\\"); | |
244 | #else | |
245 | p = path + strcspn(path, ":/"); | |
246 | #endif | |
247 | ||
248 | return *p == ':'; | |
249 | } | |
250 | ||
251 | int path_is_absolute(const char *path) | |
252 | { | |
253 | #ifdef _WIN32 | |
254 | /* specific case for names like: "\\.\d:" */ | |
255 | if (is_windows_drive(path) || is_windows_drive_prefix(path)) { | |
256 | return 1; | |
257 | } | |
258 | return (*path == '/' || *path == '\\'); | |
259 | #else | |
260 | return (*path == '/'); | |
261 | #endif | |
262 | } | |
263 | ||
264 | /* if filename is absolute, just copy it to dest. Otherwise, build a | |
265 | path to it by considering it is relative to base_path. URL are | |
266 | supported. */ | |
267 | void path_combine(char *dest, int dest_size, | |
268 | const char *base_path, | |
269 | const char *filename) | |
270 | { | |
271 | const char *p, *p1; | |
272 | int len; | |
273 | ||
274 | if (dest_size <= 0) | |
275 | return; | |
276 | if (path_is_absolute(filename)) { | |
277 | pstrcpy(dest, dest_size, filename); | |
278 | } else { | |
279 | p = strchr(base_path, ':'); | |
280 | if (p) | |
281 | p++; | |
282 | else | |
283 | p = base_path; | |
284 | p1 = strrchr(base_path, '/'); | |
285 | #ifdef _WIN32 | |
286 | { | |
287 | const char *p2; | |
288 | p2 = strrchr(base_path, '\\'); | |
289 | if (!p1 || p2 > p1) | |
290 | p1 = p2; | |
291 | } | |
292 | #endif | |
293 | if (p1) | |
294 | p1++; | |
295 | else | |
296 | p1 = base_path; | |
297 | if (p1 > p) | |
298 | p = p1; | |
299 | len = p - base_path; | |
300 | if (len > dest_size - 1) | |
301 | len = dest_size - 1; | |
302 | memcpy(dest, base_path, len); | |
303 | dest[len] = '\0'; | |
304 | pstrcat(dest, dest_size, filename); | |
305 | } | |
306 | } | |
307 | ||
308 | void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz) | |
309 | { | |
310 | if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) { | |
311 | pstrcpy(dest, sz, bs->backing_file); | |
312 | } else { | |
313 | path_combine(dest, sz, bs->filename, bs->backing_file); | |
314 | } | |
315 | } | |
316 | ||
317 | void bdrv_register(BlockDriver *bdrv) | |
318 | { | |
319 | /* Block drivers without coroutine functions need emulation */ | |
320 | if (!bdrv->bdrv_co_readv) { | |
321 | bdrv->bdrv_co_readv = bdrv_co_readv_em; | |
322 | bdrv->bdrv_co_writev = bdrv_co_writev_em; | |
323 | ||
324 | /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if | |
325 | * the block driver lacks aio we need to emulate that too. | |
326 | */ | |
327 | if (!bdrv->bdrv_aio_readv) { | |
328 | /* add AIO emulation layer */ | |
329 | bdrv->bdrv_aio_readv = bdrv_aio_readv_em; | |
330 | bdrv->bdrv_aio_writev = bdrv_aio_writev_em; | |
331 | } | |
332 | } | |
333 | ||
334 | QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); | |
335 | } | |
336 | ||
337 | /* create a new block device (by default it is empty) */ | |
338 | BlockDriverState *bdrv_new(const char *device_name, Error **errp) | |
339 | { | |
340 | BlockDriverState *bs; | |
341 | int i; | |
342 | ||
343 | if (bdrv_find(device_name)) { | |
344 | error_setg(errp, "Device with id '%s' already exists", | |
345 | device_name); | |
346 | return NULL; | |
347 | } | |
348 | if (bdrv_find_node(device_name)) { | |
349 | error_setg(errp, "Device with node-name '%s' already exists", | |
350 | device_name); | |
351 | return NULL; | |
352 | } | |
353 | ||
354 | bs = g_new0(BlockDriverState, 1); | |
355 | QLIST_INIT(&bs->dirty_bitmaps); | |
356 | pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); | |
357 | if (device_name[0] != '\0') { | |
358 | QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list); | |
359 | } | |
360 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
361 | QLIST_INIT(&bs->op_blockers[i]); | |
362 | } | |
363 | bdrv_iostatus_disable(bs); | |
364 | notifier_list_init(&bs->close_notifiers); | |
365 | notifier_with_return_list_init(&bs->before_write_notifiers); | |
366 | qemu_co_queue_init(&bs->throttled_reqs[0]); | |
367 | qemu_co_queue_init(&bs->throttled_reqs[1]); | |
368 | bs->refcnt = 1; | |
369 | bs->aio_context = qemu_get_aio_context(); | |
370 | ||
371 | return bs; | |
372 | } | |
373 | ||
374 | void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify) | |
375 | { | |
376 | notifier_list_add(&bs->close_notifiers, notify); | |
377 | } | |
378 | ||
379 | BlockDriver *bdrv_find_format(const char *format_name) | |
380 | { | |
381 | BlockDriver *drv1; | |
382 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
383 | if (!strcmp(drv1->format_name, format_name)) { | |
384 | return drv1; | |
385 | } | |
386 | } | |
387 | return NULL; | |
388 | } | |
389 | ||
390 | static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) | |
391 | { | |
392 | static const char *whitelist_rw[] = { | |
393 | CONFIG_BDRV_RW_WHITELIST | |
394 | }; | |
395 | static const char *whitelist_ro[] = { | |
396 | CONFIG_BDRV_RO_WHITELIST | |
397 | }; | |
398 | const char **p; | |
399 | ||
400 | if (!whitelist_rw[0] && !whitelist_ro[0]) { | |
401 | return 1; /* no whitelist, anything goes */ | |
402 | } | |
403 | ||
404 | for (p = whitelist_rw; *p; p++) { | |
405 | if (!strcmp(drv->format_name, *p)) { | |
406 | return 1; | |
407 | } | |
408 | } | |
409 | if (read_only) { | |
410 | for (p = whitelist_ro; *p; p++) { | |
411 | if (!strcmp(drv->format_name, *p)) { | |
412 | return 1; | |
413 | } | |
414 | } | |
415 | } | |
416 | return 0; | |
417 | } | |
418 | ||
419 | BlockDriver *bdrv_find_whitelisted_format(const char *format_name, | |
420 | bool read_only) | |
421 | { | |
422 | BlockDriver *drv = bdrv_find_format(format_name); | |
423 | return drv && bdrv_is_whitelisted(drv, read_only) ? drv : NULL; | |
424 | } | |
425 | ||
426 | typedef struct CreateCo { | |
427 | BlockDriver *drv; | |
428 | char *filename; | |
429 | QemuOpts *opts; | |
430 | int ret; | |
431 | Error *err; | |
432 | } CreateCo; | |
433 | ||
434 | static void coroutine_fn bdrv_create_co_entry(void *opaque) | |
435 | { | |
436 | Error *local_err = NULL; | |
437 | int ret; | |
438 | ||
439 | CreateCo *cco = opaque; | |
440 | assert(cco->drv); | |
441 | ||
442 | ret = cco->drv->bdrv_create(cco->filename, cco->opts, &local_err); | |
443 | if (local_err) { | |
444 | error_propagate(&cco->err, local_err); | |
445 | } | |
446 | cco->ret = ret; | |
447 | } | |
448 | ||
449 | int bdrv_create(BlockDriver *drv, const char* filename, | |
450 | QemuOpts *opts, Error **errp) | |
451 | { | |
452 | int ret; | |
453 | ||
454 | Coroutine *co; | |
455 | CreateCo cco = { | |
456 | .drv = drv, | |
457 | .filename = g_strdup(filename), | |
458 | .opts = opts, | |
459 | .ret = NOT_DONE, | |
460 | .err = NULL, | |
461 | }; | |
462 | ||
463 | if (!drv->bdrv_create) { | |
464 | error_setg(errp, "Driver '%s' does not support image creation", drv->format_name); | |
465 | ret = -ENOTSUP; | |
466 | goto out; | |
467 | } | |
468 | ||
469 | if (qemu_in_coroutine()) { | |
470 | /* Fast-path if already in coroutine context */ | |
471 | bdrv_create_co_entry(&cco); | |
472 | } else { | |
473 | co = qemu_coroutine_create(bdrv_create_co_entry); | |
474 | qemu_coroutine_enter(co, &cco); | |
475 | while (cco.ret == NOT_DONE) { | |
476 | aio_poll(qemu_get_aio_context(), true); | |
477 | } | |
478 | } | |
479 | ||
480 | ret = cco.ret; | |
481 | if (ret < 0) { | |
482 | if (cco.err) { | |
483 | error_propagate(errp, cco.err); | |
484 | } else { | |
485 | error_setg_errno(errp, -ret, "Could not create image"); | |
486 | } | |
487 | } | |
488 | ||
489 | out: | |
490 | g_free(cco.filename); | |
491 | return ret; | |
492 | } | |
493 | ||
494 | int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp) | |
495 | { | |
496 | BlockDriver *drv; | |
497 | Error *local_err = NULL; | |
498 | int ret; | |
499 | ||
500 | drv = bdrv_find_protocol(filename, true); | |
501 | if (drv == NULL) { | |
502 | error_setg(errp, "Could not find protocol for file '%s'", filename); | |
503 | return -ENOENT; | |
504 | } | |
505 | ||
506 | ret = bdrv_create(drv, filename, opts, &local_err); | |
507 | if (local_err) { | |
508 | error_propagate(errp, local_err); | |
509 | } | |
510 | return ret; | |
511 | } | |
512 | ||
513 | void bdrv_refresh_limits(BlockDriverState *bs, Error **errp) | |
514 | { | |
515 | BlockDriver *drv = bs->drv; | |
516 | Error *local_err = NULL; | |
517 | ||
518 | memset(&bs->bl, 0, sizeof(bs->bl)); | |
519 | ||
520 | if (!drv) { | |
521 | return; | |
522 | } | |
523 | ||
524 | /* Take some limits from the children as a default */ | |
525 | if (bs->file) { | |
526 | bdrv_refresh_limits(bs->file, &local_err); | |
527 | if (local_err) { | |
528 | error_propagate(errp, local_err); | |
529 | return; | |
530 | } | |
531 | bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length; | |
532 | bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment; | |
533 | } else { | |
534 | bs->bl.opt_mem_alignment = 512; | |
535 | } | |
536 | ||
537 | if (bs->backing_hd) { | |
538 | bdrv_refresh_limits(bs->backing_hd, &local_err); | |
539 | if (local_err) { | |
540 | error_propagate(errp, local_err); | |
541 | return; | |
542 | } | |
543 | bs->bl.opt_transfer_length = | |
544 | MAX(bs->bl.opt_transfer_length, | |
545 | bs->backing_hd->bl.opt_transfer_length); | |
546 | bs->bl.opt_mem_alignment = | |
547 | MAX(bs->bl.opt_mem_alignment, | |
548 | bs->backing_hd->bl.opt_mem_alignment); | |
549 | } | |
550 | ||
551 | /* Then let the driver override it */ | |
552 | if (drv->bdrv_refresh_limits) { | |
553 | drv->bdrv_refresh_limits(bs, errp); | |
554 | } | |
555 | } | |
556 | ||
557 | /* | |
558 | * Create a uniquely-named empty temporary file. | |
559 | * Return 0 upon success, otherwise a negative errno value. | |
560 | */ | |
561 | int get_tmp_filename(char *filename, int size) | |
562 | { | |
563 | #ifdef _WIN32 | |
564 | char temp_dir[MAX_PATH]; | |
565 | /* GetTempFileName requires that its output buffer (4th param) | |
566 | have length MAX_PATH or greater. */ | |
567 | assert(size >= MAX_PATH); | |
568 | return (GetTempPath(MAX_PATH, temp_dir) | |
569 | && GetTempFileName(temp_dir, "qem", 0, filename) | |
570 | ? 0 : -GetLastError()); | |
571 | #else | |
572 | int fd; | |
573 | const char *tmpdir; | |
574 | tmpdir = getenv("TMPDIR"); | |
575 | if (!tmpdir) { | |
576 | tmpdir = "/var/tmp"; | |
577 | } | |
578 | if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) { | |
579 | return -EOVERFLOW; | |
580 | } | |
581 | fd = mkstemp(filename); | |
582 | if (fd < 0) { | |
583 | return -errno; | |
584 | } | |
585 | if (close(fd) != 0) { | |
586 | unlink(filename); | |
587 | return -errno; | |
588 | } | |
589 | return 0; | |
590 | #endif | |
591 | } | |
592 | ||
593 | /* | |
594 | * Detect host devices. By convention, /dev/cdrom[N] is always | |
595 | * recognized as a host CDROM. | |
596 | */ | |
597 | static BlockDriver *find_hdev_driver(const char *filename) | |
598 | { | |
599 | int score_max = 0, score; | |
600 | BlockDriver *drv = NULL, *d; | |
601 | ||
602 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
603 | if (d->bdrv_probe_device) { | |
604 | score = d->bdrv_probe_device(filename); | |
605 | if (score > score_max) { | |
606 | score_max = score; | |
607 | drv = d; | |
608 | } | |
609 | } | |
610 | } | |
611 | ||
612 | return drv; | |
613 | } | |
614 | ||
615 | BlockDriver *bdrv_find_protocol(const char *filename, | |
616 | bool allow_protocol_prefix) | |
617 | { | |
618 | BlockDriver *drv1; | |
619 | char protocol[128]; | |
620 | int len; | |
621 | const char *p; | |
622 | ||
623 | /* TODO Drivers without bdrv_file_open must be specified explicitly */ | |
624 | ||
625 | /* | |
626 | * XXX(hch): we really should not let host device detection | |
627 | * override an explicit protocol specification, but moving this | |
628 | * later breaks access to device names with colons in them. | |
629 | * Thanks to the brain-dead persistent naming schemes on udev- | |
630 | * based Linux systems those actually are quite common. | |
631 | */ | |
632 | drv1 = find_hdev_driver(filename); | |
633 | if (drv1) { | |
634 | return drv1; | |
635 | } | |
636 | ||
637 | if (!path_has_protocol(filename) || !allow_protocol_prefix) { | |
638 | return bdrv_find_format("file"); | |
639 | } | |
640 | ||
641 | p = strchr(filename, ':'); | |
642 | assert(p != NULL); | |
643 | len = p - filename; | |
644 | if (len > sizeof(protocol) - 1) | |
645 | len = sizeof(protocol) - 1; | |
646 | memcpy(protocol, filename, len); | |
647 | protocol[len] = '\0'; | |
648 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
649 | if (drv1->protocol_name && | |
650 | !strcmp(drv1->protocol_name, protocol)) { | |
651 | return drv1; | |
652 | } | |
653 | } | |
654 | return NULL; | |
655 | } | |
656 | ||
657 | static int find_image_format(BlockDriverState *bs, const char *filename, | |
658 | BlockDriver **pdrv, Error **errp) | |
659 | { | |
660 | int score, score_max; | |
661 | BlockDriver *drv1, *drv; | |
662 | uint8_t buf[2048]; | |
663 | int ret = 0; | |
664 | ||
665 | /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ | |
666 | if (bs->sg || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) { | |
667 | drv = bdrv_find_format("raw"); | |
668 | if (!drv) { | |
669 | error_setg(errp, "Could not find raw image format"); | |
670 | ret = -ENOENT; | |
671 | } | |
672 | *pdrv = drv; | |
673 | return ret; | |
674 | } | |
675 | ||
676 | ret = bdrv_pread(bs, 0, buf, sizeof(buf)); | |
677 | if (ret < 0) { | |
678 | error_setg_errno(errp, -ret, "Could not read image for determining its " | |
679 | "format"); | |
680 | *pdrv = NULL; | |
681 | return ret; | |
682 | } | |
683 | ||
684 | score_max = 0; | |
685 | drv = NULL; | |
686 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
687 | if (drv1->bdrv_probe) { | |
688 | score = drv1->bdrv_probe(buf, ret, filename); | |
689 | if (score > score_max) { | |
690 | score_max = score; | |
691 | drv = drv1; | |
692 | } | |
693 | } | |
694 | } | |
695 | if (!drv) { | |
696 | error_setg(errp, "Could not determine image format: No compatible " | |
697 | "driver found"); | |
698 | ret = -ENOENT; | |
699 | } | |
700 | *pdrv = drv; | |
701 | return ret; | |
702 | } | |
703 | ||
704 | /** | |
705 | * Set the current 'total_sectors' value | |
706 | * Return 0 on success, -errno on error. | |
707 | */ | |
708 | static int refresh_total_sectors(BlockDriverState *bs, int64_t hint) | |
709 | { | |
710 | BlockDriver *drv = bs->drv; | |
711 | ||
712 | /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */ | |
713 | if (bs->sg) | |
714 | return 0; | |
715 | ||
716 | /* query actual device if possible, otherwise just trust the hint */ | |
717 | if (drv->bdrv_getlength) { | |
718 | int64_t length = drv->bdrv_getlength(bs); | |
719 | if (length < 0) { | |
720 | return length; | |
721 | } | |
722 | hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE); | |
723 | } | |
724 | ||
725 | bs->total_sectors = hint; | |
726 | return 0; | |
727 | } | |
728 | ||
729 | /** | |
730 | * Set open flags for a given discard mode | |
731 | * | |
732 | * Return 0 on success, -1 if the discard mode was invalid. | |
733 | */ | |
734 | int bdrv_parse_discard_flags(const char *mode, int *flags) | |
735 | { | |
736 | *flags &= ~BDRV_O_UNMAP; | |
737 | ||
738 | if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) { | |
739 | /* do nothing */ | |
740 | } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) { | |
741 | *flags |= BDRV_O_UNMAP; | |
742 | } else { | |
743 | return -1; | |
744 | } | |
745 | ||
746 | return 0; | |
747 | } | |
748 | ||
749 | /** | |
750 | * Set open flags for a given cache mode | |
751 | * | |
752 | * Return 0 on success, -1 if the cache mode was invalid. | |
753 | */ | |
754 | int bdrv_parse_cache_flags(const char *mode, int *flags) | |
755 | { | |
756 | *flags &= ~BDRV_O_CACHE_MASK; | |
757 | ||
758 | if (!strcmp(mode, "off") || !strcmp(mode, "none")) { | |
759 | *flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; | |
760 | } else if (!strcmp(mode, "directsync")) { | |
761 | *flags |= BDRV_O_NOCACHE; | |
762 | } else if (!strcmp(mode, "writeback")) { | |
763 | *flags |= BDRV_O_CACHE_WB; | |
764 | } else if (!strcmp(mode, "unsafe")) { | |
765 | *flags |= BDRV_O_CACHE_WB; | |
766 | *flags |= BDRV_O_NO_FLUSH; | |
767 | } else if (!strcmp(mode, "writethrough")) { | |
768 | /* this is the default */ | |
769 | } else { | |
770 | return -1; | |
771 | } | |
772 | ||
773 | return 0; | |
774 | } | |
775 | ||
776 | /** | |
777 | * The copy-on-read flag is actually a reference count so multiple users may | |
778 | * use the feature without worrying about clobbering its previous state. | |
779 | * Copy-on-read stays enabled until all users have called to disable it. | |
780 | */ | |
781 | void bdrv_enable_copy_on_read(BlockDriverState *bs) | |
782 | { | |
783 | bs->copy_on_read++; | |
784 | } | |
785 | ||
786 | void bdrv_disable_copy_on_read(BlockDriverState *bs) | |
787 | { | |
788 | assert(bs->copy_on_read > 0); | |
789 | bs->copy_on_read--; | |
790 | } | |
791 | ||
792 | /* | |
793 | * Returns the flags that a temporary snapshot should get, based on the | |
794 | * originally requested flags (the originally requested image will have flags | |
795 | * like a backing file) | |
796 | */ | |
797 | static int bdrv_temp_snapshot_flags(int flags) | |
798 | { | |
799 | return (flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY; | |
800 | } | |
801 | ||
802 | /* | |
803 | * Returns the flags that bs->file should get, based on the given flags for | |
804 | * the parent BDS | |
805 | */ | |
806 | static int bdrv_inherited_flags(int flags) | |
807 | { | |
808 | /* Enable protocol handling, disable format probing for bs->file */ | |
809 | flags |= BDRV_O_PROTOCOL; | |
810 | ||
811 | /* Our block drivers take care to send flushes and respect unmap policy, | |
812 | * so we can enable both unconditionally on lower layers. */ | |
813 | flags |= BDRV_O_CACHE_WB | BDRV_O_UNMAP; | |
814 | ||
815 | /* Clear flags that only apply to the top layer */ | |
816 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ); | |
817 | ||
818 | return flags; | |
819 | } | |
820 | ||
821 | /* | |
822 | * Returns the flags that bs->backing_hd should get, based on the given flags | |
823 | * for the parent BDS | |
824 | */ | |
825 | static int bdrv_backing_flags(int flags) | |
826 | { | |
827 | /* backing files always opened read-only */ | |
828 | flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ); | |
829 | ||
830 | /* snapshot=on is handled on the top layer */ | |
831 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); | |
832 | ||
833 | return flags; | |
834 | } | |
835 | ||
836 | static int bdrv_open_flags(BlockDriverState *bs, int flags) | |
837 | { | |
838 | int open_flags = flags | BDRV_O_CACHE_WB; | |
839 | ||
840 | /* | |
841 | * Clear flags that are internal to the block layer before opening the | |
842 | * image. | |
843 | */ | |
844 | open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL); | |
845 | ||
846 | /* | |
847 | * Snapshots should be writable. | |
848 | */ | |
849 | if (flags & BDRV_O_TEMPORARY) { | |
850 | open_flags |= BDRV_O_RDWR; | |
851 | } | |
852 | ||
853 | return open_flags; | |
854 | } | |
855 | ||
856 | static void bdrv_assign_node_name(BlockDriverState *bs, | |
857 | const char *node_name, | |
858 | Error **errp) | |
859 | { | |
860 | if (!node_name) { | |
861 | return; | |
862 | } | |
863 | ||
864 | /* empty string node name is invalid */ | |
865 | if (node_name[0] == '\0') { | |
866 | error_setg(errp, "Empty node name"); | |
867 | return; | |
868 | } | |
869 | ||
870 | /* takes care of avoiding namespaces collisions */ | |
871 | if (bdrv_find(node_name)) { | |
872 | error_setg(errp, "node-name=%s is conflicting with a device id", | |
873 | node_name); | |
874 | return; | |
875 | } | |
876 | ||
877 | /* takes care of avoiding duplicates node names */ | |
878 | if (bdrv_find_node(node_name)) { | |
879 | error_setg(errp, "Duplicate node name"); | |
880 | return; | |
881 | } | |
882 | ||
883 | /* copy node name into the bs and insert it into the graph list */ | |
884 | pstrcpy(bs->node_name, sizeof(bs->node_name), node_name); | |
885 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list); | |
886 | } | |
887 | ||
888 | /* | |
889 | * Common part for opening disk images and files | |
890 | * | |
891 | * Removes all processed options from *options. | |
892 | */ | |
893 | static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file, | |
894 | QDict *options, int flags, BlockDriver *drv, Error **errp) | |
895 | { | |
896 | int ret, open_flags; | |
897 | const char *filename; | |
898 | const char *node_name = NULL; | |
899 | Error *local_err = NULL; | |
900 | ||
901 | assert(drv != NULL); | |
902 | assert(bs->file == NULL); | |
903 | assert(options != NULL && bs->options != options); | |
904 | ||
905 | if (file != NULL) { | |
906 | filename = file->filename; | |
907 | } else { | |
908 | filename = qdict_get_try_str(options, "filename"); | |
909 | } | |
910 | ||
911 | if (drv->bdrv_needs_filename && !filename) { | |
912 | error_setg(errp, "The '%s' block driver requires a file name", | |
913 | drv->format_name); | |
914 | return -EINVAL; | |
915 | } | |
916 | ||
917 | trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name); | |
918 | ||
919 | node_name = qdict_get_try_str(options, "node-name"); | |
920 | bdrv_assign_node_name(bs, node_name, &local_err); | |
921 | if (local_err) { | |
922 | error_propagate(errp, local_err); | |
923 | return -EINVAL; | |
924 | } | |
925 | qdict_del(options, "node-name"); | |
926 | ||
927 | /* bdrv_open() with directly using a protocol as drv. This layer is already | |
928 | * opened, so assign it to bs (while file becomes a closed BlockDriverState) | |
929 | * and return immediately. */ | |
930 | if (file != NULL && drv->bdrv_file_open) { | |
931 | bdrv_swap(file, bs); | |
932 | return 0; | |
933 | } | |
934 | ||
935 | bs->open_flags = flags; | |
936 | bs->guest_block_size = 512; | |
937 | bs->request_alignment = 512; | |
938 | bs->zero_beyond_eof = true; | |
939 | open_flags = bdrv_open_flags(bs, flags); | |
940 | bs->read_only = !(open_flags & BDRV_O_RDWR); | |
941 | bs->growable = !!(flags & BDRV_O_PROTOCOL); | |
942 | ||
943 | if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) { | |
944 | error_setg(errp, | |
945 | !bs->read_only && bdrv_is_whitelisted(drv, true) | |
946 | ? "Driver '%s' can only be used for read-only devices" | |
947 | : "Driver '%s' is not whitelisted", | |
948 | drv->format_name); | |
949 | return -ENOTSUP; | |
950 | } | |
951 | ||
952 | assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ | |
953 | if (flags & BDRV_O_COPY_ON_READ) { | |
954 | if (!bs->read_only) { | |
955 | bdrv_enable_copy_on_read(bs); | |
956 | } else { | |
957 | error_setg(errp, "Can't use copy-on-read on read-only device"); | |
958 | return -EINVAL; | |
959 | } | |
960 | } | |
961 | ||
962 | if (filename != NULL) { | |
963 | pstrcpy(bs->filename, sizeof(bs->filename), filename); | |
964 | } else { | |
965 | bs->filename[0] = '\0'; | |
966 | } | |
967 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename); | |
968 | ||
969 | bs->drv = drv; | |
970 | bs->opaque = g_malloc0(drv->instance_size); | |
971 | ||
972 | bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB); | |
973 | ||
974 | /* Open the image, either directly or using a protocol */ | |
975 | if (drv->bdrv_file_open) { | |
976 | assert(file == NULL); | |
977 | assert(!drv->bdrv_needs_filename || filename != NULL); | |
978 | ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); | |
979 | } else { | |
980 | if (file == NULL) { | |
981 | error_setg(errp, "Can't use '%s' as a block driver for the " | |
982 | "protocol level", drv->format_name); | |
983 | ret = -EINVAL; | |
984 | goto free_and_fail; | |
985 | } | |
986 | bs->file = file; | |
987 | ret = drv->bdrv_open(bs, options, open_flags, &local_err); | |
988 | } | |
989 | ||
990 | if (ret < 0) { | |
991 | if (local_err) { | |
992 | error_propagate(errp, local_err); | |
993 | } else if (bs->filename[0]) { | |
994 | error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename); | |
995 | } else { | |
996 | error_setg_errno(errp, -ret, "Could not open image"); | |
997 | } | |
998 | goto free_and_fail; | |
999 | } | |
1000 | ||
1001 | ret = refresh_total_sectors(bs, bs->total_sectors); | |
1002 | if (ret < 0) { | |
1003 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
1004 | goto free_and_fail; | |
1005 | } | |
1006 | ||
1007 | bdrv_refresh_limits(bs, &local_err); | |
1008 | if (local_err) { | |
1009 | error_propagate(errp, local_err); | |
1010 | ret = -EINVAL; | |
1011 | goto free_and_fail; | |
1012 | } | |
1013 | ||
1014 | assert(bdrv_opt_mem_align(bs) != 0); | |
1015 | assert((bs->request_alignment != 0) || bs->sg); | |
1016 | return 0; | |
1017 | ||
1018 | free_and_fail: | |
1019 | bs->file = NULL; | |
1020 | g_free(bs->opaque); | |
1021 | bs->opaque = NULL; | |
1022 | bs->drv = NULL; | |
1023 | return ret; | |
1024 | } | |
1025 | ||
1026 | static QDict *parse_json_filename(const char *filename, Error **errp) | |
1027 | { | |
1028 | QObject *options_obj; | |
1029 | QDict *options; | |
1030 | int ret; | |
1031 | ||
1032 | ret = strstart(filename, "json:", &filename); | |
1033 | assert(ret); | |
1034 | ||
1035 | options_obj = qobject_from_json(filename); | |
1036 | if (!options_obj) { | |
1037 | error_setg(errp, "Could not parse the JSON options"); | |
1038 | return NULL; | |
1039 | } | |
1040 | ||
1041 | if (qobject_type(options_obj) != QTYPE_QDICT) { | |
1042 | qobject_decref(options_obj); | |
1043 | error_setg(errp, "Invalid JSON object given"); | |
1044 | return NULL; | |
1045 | } | |
1046 | ||
1047 | options = qobject_to_qdict(options_obj); | |
1048 | qdict_flatten(options); | |
1049 | ||
1050 | return options; | |
1051 | } | |
1052 | ||
1053 | /* | |
1054 | * Fills in default options for opening images and converts the legacy | |
1055 | * filename/flags pair to option QDict entries. | |
1056 | */ | |
1057 | static int bdrv_fill_options(QDict **options, const char **pfilename, int flags, | |
1058 | BlockDriver *drv, Error **errp) | |
1059 | { | |
1060 | const char *filename = *pfilename; | |
1061 | const char *drvname; | |
1062 | bool protocol = flags & BDRV_O_PROTOCOL; | |
1063 | bool parse_filename = false; | |
1064 | Error *local_err = NULL; | |
1065 | ||
1066 | /* Parse json: pseudo-protocol */ | |
1067 | if (filename && g_str_has_prefix(filename, "json:")) { | |
1068 | QDict *json_options = parse_json_filename(filename, &local_err); | |
1069 | if (local_err) { | |
1070 | error_propagate(errp, local_err); | |
1071 | return -EINVAL; | |
1072 | } | |
1073 | ||
1074 | /* Options given in the filename have lower priority than options | |
1075 | * specified directly */ | |
1076 | qdict_join(*options, json_options, false); | |
1077 | QDECREF(json_options); | |
1078 | *pfilename = filename = NULL; | |
1079 | } | |
1080 | ||
1081 | /* Fetch the file name from the options QDict if necessary */ | |
1082 | if (protocol && filename) { | |
1083 | if (!qdict_haskey(*options, "filename")) { | |
1084 | qdict_put(*options, "filename", qstring_from_str(filename)); | |
1085 | parse_filename = true; | |
1086 | } else { | |
1087 | error_setg(errp, "Can't specify 'file' and 'filename' options at " | |
1088 | "the same time"); | |
1089 | return -EINVAL; | |
1090 | } | |
1091 | } | |
1092 | ||
1093 | /* Find the right block driver */ | |
1094 | filename = qdict_get_try_str(*options, "filename"); | |
1095 | drvname = qdict_get_try_str(*options, "driver"); | |
1096 | ||
1097 | if (drv) { | |
1098 | if (drvname) { | |
1099 | error_setg(errp, "Driver specified twice"); | |
1100 | return -EINVAL; | |
1101 | } | |
1102 | drvname = drv->format_name; | |
1103 | qdict_put(*options, "driver", qstring_from_str(drvname)); | |
1104 | } else { | |
1105 | if (!drvname && protocol) { | |
1106 | if (filename) { | |
1107 | drv = bdrv_find_protocol(filename, parse_filename); | |
1108 | if (!drv) { | |
1109 | error_setg(errp, "Unknown protocol"); | |
1110 | return -EINVAL; | |
1111 | } | |
1112 | ||
1113 | drvname = drv->format_name; | |
1114 | qdict_put(*options, "driver", qstring_from_str(drvname)); | |
1115 | } else { | |
1116 | error_setg(errp, "Must specify either driver or file"); | |
1117 | return -EINVAL; | |
1118 | } | |
1119 | } else if (drvname) { | |
1120 | drv = bdrv_find_format(drvname); | |
1121 | if (!drv) { | |
1122 | error_setg(errp, "Unknown driver '%s'", drvname); | |
1123 | return -ENOENT; | |
1124 | } | |
1125 | } | |
1126 | } | |
1127 | ||
1128 | assert(drv || !protocol); | |
1129 | ||
1130 | /* Driver-specific filename parsing */ | |
1131 | if (drv && drv->bdrv_parse_filename && parse_filename) { | |
1132 | drv->bdrv_parse_filename(filename, *options, &local_err); | |
1133 | if (local_err) { | |
1134 | error_propagate(errp, local_err); | |
1135 | return -EINVAL; | |
1136 | } | |
1137 | ||
1138 | if (!drv->bdrv_needs_filename) { | |
1139 | qdict_del(*options, "filename"); | |
1140 | } | |
1141 | } | |
1142 | ||
1143 | return 0; | |
1144 | } | |
1145 | ||
1146 | void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) | |
1147 | { | |
1148 | ||
1149 | if (bs->backing_hd) { | |
1150 | assert(bs->backing_blocker); | |
1151 | bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker); | |
1152 | } else if (backing_hd) { | |
1153 | error_setg(&bs->backing_blocker, | |
1154 | "device is used as backing hd of '%s'", | |
1155 | bs->device_name); | |
1156 | } | |
1157 | ||
1158 | bs->backing_hd = backing_hd; | |
1159 | if (!backing_hd) { | |
1160 | error_free(bs->backing_blocker); | |
1161 | bs->backing_blocker = NULL; | |
1162 | goto out; | |
1163 | } | |
1164 | bs->open_flags &= ~BDRV_O_NO_BACKING; | |
1165 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); | |
1166 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), | |
1167 | backing_hd->drv ? backing_hd->drv->format_name : ""); | |
1168 | ||
1169 | bdrv_op_block_all(bs->backing_hd, bs->backing_blocker); | |
1170 | /* Otherwise we won't be able to commit due to check in bdrv_commit */ | |
1171 | bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, | |
1172 | bs->backing_blocker); | |
1173 | out: | |
1174 | bdrv_refresh_limits(bs, NULL); | |
1175 | } | |
1176 | ||
1177 | /* | |
1178 | * Opens the backing file for a BlockDriverState if not yet open | |
1179 | * | |
1180 | * options is a QDict of options to pass to the block drivers, or NULL for an | |
1181 | * empty set of options. The reference to the QDict is transferred to this | |
1182 | * function (even on failure), so if the caller intends to reuse the dictionary, | |
1183 | * it needs to use QINCREF() before calling bdrv_file_open. | |
1184 | */ | |
1185 | int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) | |
1186 | { | |
1187 | char *backing_filename = g_malloc0(PATH_MAX); | |
1188 | int ret = 0; | |
1189 | BlockDriver *back_drv = NULL; | |
1190 | BlockDriverState *backing_hd; | |
1191 | Error *local_err = NULL; | |
1192 | ||
1193 | if (bs->backing_hd != NULL) { | |
1194 | QDECREF(options); | |
1195 | goto free_exit; | |
1196 | } | |
1197 | ||
1198 | /* NULL means an empty set of options */ | |
1199 | if (options == NULL) { | |
1200 | options = qdict_new(); | |
1201 | } | |
1202 | ||
1203 | bs->open_flags &= ~BDRV_O_NO_BACKING; | |
1204 | if (qdict_haskey(options, "file.filename")) { | |
1205 | backing_filename[0] = '\0'; | |
1206 | } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { | |
1207 | QDECREF(options); | |
1208 | goto free_exit; | |
1209 | } else { | |
1210 | bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX); | |
1211 | } | |
1212 | ||
1213 | if (!bs->drv || !bs->drv->supports_backing) { | |
1214 | ret = -EINVAL; | |
1215 | error_setg(errp, "Driver doesn't support backing files"); | |
1216 | QDECREF(options); | |
1217 | goto free_exit; | |
1218 | } | |
1219 | ||
1220 | backing_hd = bdrv_new("", errp); | |
1221 | ||
1222 | if (bs->backing_format[0] != '\0') { | |
1223 | back_drv = bdrv_find_format(bs->backing_format); | |
1224 | } | |
1225 | ||
1226 | assert(bs->backing_hd == NULL); | |
1227 | ret = bdrv_open(&backing_hd, | |
1228 | *backing_filename ? backing_filename : NULL, NULL, options, | |
1229 | bdrv_backing_flags(bs->open_flags), back_drv, &local_err); | |
1230 | if (ret < 0) { | |
1231 | bdrv_unref(backing_hd); | |
1232 | backing_hd = NULL; | |
1233 | bs->open_flags |= BDRV_O_NO_BACKING; | |
1234 | error_setg(errp, "Could not open backing file: %s", | |
1235 | error_get_pretty(local_err)); | |
1236 | error_free(local_err); | |
1237 | goto free_exit; | |
1238 | } | |
1239 | bdrv_set_backing_hd(bs, backing_hd); | |
1240 | ||
1241 | free_exit: | |
1242 | g_free(backing_filename); | |
1243 | return ret; | |
1244 | } | |
1245 | ||
1246 | /* | |
1247 | * Opens a disk image whose options are given as BlockdevRef in another block | |
1248 | * device's options. | |
1249 | * | |
1250 | * If allow_none is true, no image will be opened if filename is false and no | |
1251 | * BlockdevRef is given. *pbs will remain unchanged and 0 will be returned. | |
1252 | * | |
1253 | * bdrev_key specifies the key for the image's BlockdevRef in the options QDict. | |
1254 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict | |
1255 | * itself, all options starting with "${bdref_key}." are considered part of the | |
1256 | * BlockdevRef. | |
1257 | * | |
1258 | * The BlockdevRef will be removed from the options QDict. | |
1259 | * | |
1260 | * To conform with the behavior of bdrv_open(), *pbs has to be NULL. | |
1261 | */ | |
1262 | int bdrv_open_image(BlockDriverState **pbs, const char *filename, | |
1263 | QDict *options, const char *bdref_key, int flags, | |
1264 | bool allow_none, Error **errp) | |
1265 | { | |
1266 | QDict *image_options; | |
1267 | int ret; | |
1268 | char *bdref_key_dot; | |
1269 | const char *reference; | |
1270 | ||
1271 | assert(pbs); | |
1272 | assert(*pbs == NULL); | |
1273 | ||
1274 | bdref_key_dot = g_strdup_printf("%s.", bdref_key); | |
1275 | qdict_extract_subqdict(options, &image_options, bdref_key_dot); | |
1276 | g_free(bdref_key_dot); | |
1277 | ||
1278 | reference = qdict_get_try_str(options, bdref_key); | |
1279 | if (!filename && !reference && !qdict_size(image_options)) { | |
1280 | if (allow_none) { | |
1281 | ret = 0; | |
1282 | } else { | |
1283 | error_setg(errp, "A block device must be specified for \"%s\"", | |
1284 | bdref_key); | |
1285 | ret = -EINVAL; | |
1286 | } | |
1287 | QDECREF(image_options); | |
1288 | goto done; | |
1289 | } | |
1290 | ||
1291 | ret = bdrv_open(pbs, filename, reference, image_options, flags, NULL, errp); | |
1292 | ||
1293 | done: | |
1294 | qdict_del(options, bdref_key); | |
1295 | return ret; | |
1296 | } | |
1297 | ||
1298 | int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) | |
1299 | { | |
1300 | /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ | |
1301 | char *tmp_filename = g_malloc0(PATH_MAX + 1); | |
1302 | int64_t total_size; | |
1303 | BlockDriver *bdrv_qcow2; | |
1304 | QemuOpts *opts = NULL; | |
1305 | QDict *snapshot_options; | |
1306 | BlockDriverState *bs_snapshot; | |
1307 | Error *local_err; | |
1308 | int ret; | |
1309 | ||
1310 | /* if snapshot, we create a temporary backing file and open it | |
1311 | instead of opening 'filename' directly */ | |
1312 | ||
1313 | /* Get the required size from the image */ | |
1314 | total_size = bdrv_getlength(bs); | |
1315 | if (total_size < 0) { | |
1316 | ret = total_size; | |
1317 | error_setg_errno(errp, -total_size, "Could not get image size"); | |
1318 | goto out; | |
1319 | } | |
1320 | ||
1321 | /* Create the temporary image */ | |
1322 | ret = get_tmp_filename(tmp_filename, PATH_MAX + 1); | |
1323 | if (ret < 0) { | |
1324 | error_setg_errno(errp, -ret, "Could not get temporary filename"); | |
1325 | goto out; | |
1326 | } | |
1327 | ||
1328 | bdrv_qcow2 = bdrv_find_format("qcow2"); | |
1329 | opts = qemu_opts_create(bdrv_qcow2->create_opts, NULL, 0, | |
1330 | &error_abort); | |
1331 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size); | |
1332 | ret = bdrv_create(bdrv_qcow2, tmp_filename, opts, &local_err); | |
1333 | qemu_opts_del(opts); | |
1334 | if (ret < 0) { | |
1335 | error_setg_errno(errp, -ret, "Could not create temporary overlay " | |
1336 | "'%s': %s", tmp_filename, | |
1337 | error_get_pretty(local_err)); | |
1338 | error_free(local_err); | |
1339 | goto out; | |
1340 | } | |
1341 | ||
1342 | /* Prepare a new options QDict for the temporary file */ | |
1343 | snapshot_options = qdict_new(); | |
1344 | qdict_put(snapshot_options, "file.driver", | |
1345 | qstring_from_str("file")); | |
1346 | qdict_put(snapshot_options, "file.filename", | |
1347 | qstring_from_str(tmp_filename)); | |
1348 | ||
1349 | bs_snapshot = bdrv_new("", &error_abort); | |
1350 | ||
1351 | ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options, | |
1352 | flags, bdrv_qcow2, &local_err); | |
1353 | if (ret < 0) { | |
1354 | error_propagate(errp, local_err); | |
1355 | goto out; | |
1356 | } | |
1357 | ||
1358 | bdrv_append(bs_snapshot, bs); | |
1359 | ||
1360 | out: | |
1361 | g_free(tmp_filename); | |
1362 | return ret; | |
1363 | } | |
1364 | ||
1365 | /* | |
1366 | * Opens a disk image (raw, qcow2, vmdk, ...) | |
1367 | * | |
1368 | * options is a QDict of options to pass to the block drivers, or NULL for an | |
1369 | * empty set of options. The reference to the QDict belongs to the block layer | |
1370 | * after the call (even on failure), so if the caller intends to reuse the | |
1371 | * dictionary, it needs to use QINCREF() before calling bdrv_open. | |
1372 | * | |
1373 | * If *pbs is NULL, a new BDS will be created with a pointer to it stored there. | |
1374 | * If it is not NULL, the referenced BDS will be reused. | |
1375 | * | |
1376 | * The reference parameter may be used to specify an existing block device which | |
1377 | * should be opened. If specified, neither options nor a filename may be given, | |
1378 | * nor can an existing BDS be reused (that is, *pbs has to be NULL). | |
1379 | */ | |
1380 | int bdrv_open(BlockDriverState **pbs, const char *filename, | |
1381 | const char *reference, QDict *options, int flags, | |
1382 | BlockDriver *drv, Error **errp) | |
1383 | { | |
1384 | int ret; | |
1385 | BlockDriverState *file = NULL, *bs; | |
1386 | const char *drvname; | |
1387 | Error *local_err = NULL; | |
1388 | int snapshot_flags = 0; | |
1389 | ||
1390 | assert(pbs); | |
1391 | ||
1392 | if (reference) { | |
1393 | bool options_non_empty = options ? qdict_size(options) : false; | |
1394 | QDECREF(options); | |
1395 | ||
1396 | if (*pbs) { | |
1397 | error_setg(errp, "Cannot reuse an existing BDS when referencing " | |
1398 | "another block device"); | |
1399 | return -EINVAL; | |
1400 | } | |
1401 | ||
1402 | if (filename || options_non_empty) { | |
1403 | error_setg(errp, "Cannot reference an existing block device with " | |
1404 | "additional options or a new filename"); | |
1405 | return -EINVAL; | |
1406 | } | |
1407 | ||
1408 | bs = bdrv_lookup_bs(reference, reference, errp); | |
1409 | if (!bs) { | |
1410 | return -ENODEV; | |
1411 | } | |
1412 | bdrv_ref(bs); | |
1413 | *pbs = bs; | |
1414 | return 0; | |
1415 | } | |
1416 | ||
1417 | if (*pbs) { | |
1418 | bs = *pbs; | |
1419 | } else { | |
1420 | bs = bdrv_new("", &error_abort); | |
1421 | } | |
1422 | ||
1423 | /* NULL means an empty set of options */ | |
1424 | if (options == NULL) { | |
1425 | options = qdict_new(); | |
1426 | } | |
1427 | ||
1428 | ret = bdrv_fill_options(&options, &filename, flags, drv, &local_err); | |
1429 | if (local_err) { | |
1430 | goto fail; | |
1431 | } | |
1432 | ||
1433 | /* Find the right image format driver */ | |
1434 | drv = NULL; | |
1435 | drvname = qdict_get_try_str(options, "driver"); | |
1436 | if (drvname) { | |
1437 | drv = bdrv_find_format(drvname); | |
1438 | qdict_del(options, "driver"); | |
1439 | if (!drv) { | |
1440 | error_setg(errp, "Unknown driver: '%s'", drvname); | |
1441 | ret = -EINVAL; | |
1442 | goto fail; | |
1443 | } | |
1444 | } | |
1445 | ||
1446 | assert(drvname || !(flags & BDRV_O_PROTOCOL)); | |
1447 | if (drv && !drv->bdrv_file_open) { | |
1448 | /* If the user explicitly wants a format driver here, we'll need to add | |
1449 | * another layer for the protocol in bs->file */ | |
1450 | flags &= ~BDRV_O_PROTOCOL; | |
1451 | } | |
1452 | ||
1453 | bs->options = options; | |
1454 | options = qdict_clone_shallow(options); | |
1455 | ||
1456 | /* Open image file without format layer */ | |
1457 | if ((flags & BDRV_O_PROTOCOL) == 0) { | |
1458 | if (flags & BDRV_O_RDWR) { | |
1459 | flags |= BDRV_O_ALLOW_RDWR; | |
1460 | } | |
1461 | if (flags & BDRV_O_SNAPSHOT) { | |
1462 | snapshot_flags = bdrv_temp_snapshot_flags(flags); | |
1463 | flags = bdrv_backing_flags(flags); | |
1464 | } | |
1465 | ||
1466 | assert(file == NULL); | |
1467 | ret = bdrv_open_image(&file, filename, options, "file", | |
1468 | bdrv_inherited_flags(flags), | |
1469 | true, &local_err); | |
1470 | if (ret < 0) { | |
1471 | goto fail; | |
1472 | } | |
1473 | } | |
1474 | ||
1475 | /* Image format probing */ | |
1476 | if (!drv && file) { | |
1477 | ret = find_image_format(file, filename, &drv, &local_err); | |
1478 | if (ret < 0) { | |
1479 | goto fail; | |
1480 | } | |
1481 | } else if (!drv) { | |
1482 | error_setg(errp, "Must specify either driver or file"); | |
1483 | ret = -EINVAL; | |
1484 | goto fail; | |
1485 | } | |
1486 | ||
1487 | /* Open the image */ | |
1488 | ret = bdrv_open_common(bs, file, options, flags, drv, &local_err); | |
1489 | if (ret < 0) { | |
1490 | goto fail; | |
1491 | } | |
1492 | ||
1493 | if (file && (bs->file != file)) { | |
1494 | bdrv_unref(file); | |
1495 | file = NULL; | |
1496 | } | |
1497 | ||
1498 | /* If there is a backing file, use it */ | |
1499 | if ((flags & BDRV_O_NO_BACKING) == 0) { | |
1500 | QDict *backing_options; | |
1501 | ||
1502 | qdict_extract_subqdict(options, &backing_options, "backing."); | |
1503 | ret = bdrv_open_backing_file(bs, backing_options, &local_err); | |
1504 | if (ret < 0) { | |
1505 | goto close_and_fail; | |
1506 | } | |
1507 | } | |
1508 | ||
1509 | bdrv_refresh_filename(bs); | |
1510 | ||
1511 | /* For snapshot=on, create a temporary qcow2 overlay. bs points to the | |
1512 | * temporary snapshot afterwards. */ | |
1513 | if (snapshot_flags) { | |
1514 | ret = bdrv_append_temp_snapshot(bs, snapshot_flags, &local_err); | |
1515 | if (local_err) { | |
1516 | goto close_and_fail; | |
1517 | } | |
1518 | } | |
1519 | ||
1520 | /* Check if any unknown options were used */ | |
1521 | if (options && (qdict_size(options) != 0)) { | |
1522 | const QDictEntry *entry = qdict_first(options); | |
1523 | if (flags & BDRV_O_PROTOCOL) { | |
1524 | error_setg(errp, "Block protocol '%s' doesn't support the option " | |
1525 | "'%s'", drv->format_name, entry->key); | |
1526 | } else { | |
1527 | error_setg(errp, "Block format '%s' used by device '%s' doesn't " | |
1528 | "support the option '%s'", drv->format_name, | |
1529 | bs->device_name, entry->key); | |
1530 | } | |
1531 | ||
1532 | ret = -EINVAL; | |
1533 | goto close_and_fail; | |
1534 | } | |
1535 | ||
1536 | if (!bdrv_key_required(bs)) { | |
1537 | bdrv_dev_change_media_cb(bs, true); | |
1538 | } else if (!runstate_check(RUN_STATE_PRELAUNCH) | |
1539 | && !runstate_check(RUN_STATE_INMIGRATE) | |
1540 | && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */ | |
1541 | error_setg(errp, | |
1542 | "Guest must be stopped for opening of encrypted image"); | |
1543 | ret = -EBUSY; | |
1544 | goto close_and_fail; | |
1545 | } | |
1546 | ||
1547 | QDECREF(options); | |
1548 | *pbs = bs; | |
1549 | return 0; | |
1550 | ||
1551 | fail: | |
1552 | if (file != NULL) { | |
1553 | bdrv_unref(file); | |
1554 | } | |
1555 | QDECREF(bs->options); | |
1556 | QDECREF(options); | |
1557 | bs->options = NULL; | |
1558 | if (!*pbs) { | |
1559 | /* If *pbs is NULL, a new BDS has been created in this function and | |
1560 | needs to be freed now. Otherwise, it does not need to be closed, | |
1561 | since it has not really been opened yet. */ | |
1562 | bdrv_unref(bs); | |
1563 | } | |
1564 | if (local_err) { | |
1565 | error_propagate(errp, local_err); | |
1566 | } | |
1567 | return ret; | |
1568 | ||
1569 | close_and_fail: | |
1570 | /* See fail path, but now the BDS has to be always closed */ | |
1571 | if (*pbs) { | |
1572 | bdrv_close(bs); | |
1573 | } else { | |
1574 | bdrv_unref(bs); | |
1575 | } | |
1576 | QDECREF(options); | |
1577 | if (local_err) { | |
1578 | error_propagate(errp, local_err); | |
1579 | } | |
1580 | return ret; | |
1581 | } | |
1582 | ||
1583 | typedef struct BlockReopenQueueEntry { | |
1584 | bool prepared; | |
1585 | BDRVReopenState state; | |
1586 | QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; | |
1587 | } BlockReopenQueueEntry; | |
1588 | ||
1589 | /* | |
1590 | * Adds a BlockDriverState to a simple queue for an atomic, transactional | |
1591 | * reopen of multiple devices. | |
1592 | * | |
1593 | * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT | |
1594 | * already performed, or alternatively may be NULL a new BlockReopenQueue will | |
1595 | * be created and initialized. This newly created BlockReopenQueue should be | |
1596 | * passed back in for subsequent calls that are intended to be of the same | |
1597 | * atomic 'set'. | |
1598 | * | |
1599 | * bs is the BlockDriverState to add to the reopen queue. | |
1600 | * | |
1601 | * flags contains the open flags for the associated bs | |
1602 | * | |
1603 | * returns a pointer to bs_queue, which is either the newly allocated | |
1604 | * bs_queue, or the existing bs_queue being used. | |
1605 | * | |
1606 | */ | |
1607 | BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, | |
1608 | BlockDriverState *bs, int flags) | |
1609 | { | |
1610 | assert(bs != NULL); | |
1611 | ||
1612 | BlockReopenQueueEntry *bs_entry; | |
1613 | if (bs_queue == NULL) { | |
1614 | bs_queue = g_new0(BlockReopenQueue, 1); | |
1615 | QSIMPLEQ_INIT(bs_queue); | |
1616 | } | |
1617 | ||
1618 | /* bdrv_open() masks this flag out */ | |
1619 | flags &= ~BDRV_O_PROTOCOL; | |
1620 | ||
1621 | if (bs->file) { | |
1622 | bdrv_reopen_queue(bs_queue, bs->file, bdrv_inherited_flags(flags)); | |
1623 | } | |
1624 | ||
1625 | bs_entry = g_new0(BlockReopenQueueEntry, 1); | |
1626 | QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); | |
1627 | ||
1628 | bs_entry->state.bs = bs; | |
1629 | bs_entry->state.flags = flags; | |
1630 | ||
1631 | return bs_queue; | |
1632 | } | |
1633 | ||
1634 | /* | |
1635 | * Reopen multiple BlockDriverStates atomically & transactionally. | |
1636 | * | |
1637 | * The queue passed in (bs_queue) must have been built up previous | |
1638 | * via bdrv_reopen_queue(). | |
1639 | * | |
1640 | * Reopens all BDS specified in the queue, with the appropriate | |
1641 | * flags. All devices are prepared for reopen, and failure of any | |
1642 | * device will cause all device changes to be abandonded, and intermediate | |
1643 | * data cleaned up. | |
1644 | * | |
1645 | * If all devices prepare successfully, then the changes are committed | |
1646 | * to all devices. | |
1647 | * | |
1648 | */ | |
1649 | int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) | |
1650 | { | |
1651 | int ret = -1; | |
1652 | BlockReopenQueueEntry *bs_entry, *next; | |
1653 | Error *local_err = NULL; | |
1654 | ||
1655 | assert(bs_queue != NULL); | |
1656 | ||
1657 | bdrv_drain_all(); | |
1658 | ||
1659 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
1660 | if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) { | |
1661 | error_propagate(errp, local_err); | |
1662 | goto cleanup; | |
1663 | } | |
1664 | bs_entry->prepared = true; | |
1665 | } | |
1666 | ||
1667 | /* If we reach this point, we have success and just need to apply the | |
1668 | * changes | |
1669 | */ | |
1670 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
1671 | bdrv_reopen_commit(&bs_entry->state); | |
1672 | } | |
1673 | ||
1674 | ret = 0; | |
1675 | ||
1676 | cleanup: | |
1677 | QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { | |
1678 | if (ret && bs_entry->prepared) { | |
1679 | bdrv_reopen_abort(&bs_entry->state); | |
1680 | } | |
1681 | g_free(bs_entry); | |
1682 | } | |
1683 | g_free(bs_queue); | |
1684 | return ret; | |
1685 | } | |
1686 | ||
1687 | ||
1688 | /* Reopen a single BlockDriverState with the specified flags. */ | |
1689 | int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp) | |
1690 | { | |
1691 | int ret = -1; | |
1692 | Error *local_err = NULL; | |
1693 | BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, bdrv_flags); | |
1694 | ||
1695 | ret = bdrv_reopen_multiple(queue, &local_err); | |
1696 | if (local_err != NULL) { | |
1697 | error_propagate(errp, local_err); | |
1698 | } | |
1699 | return ret; | |
1700 | } | |
1701 | ||
1702 | ||
1703 | /* | |
1704 | * Prepares a BlockDriverState for reopen. All changes are staged in the | |
1705 | * 'opaque' field of the BDRVReopenState, which is used and allocated by | |
1706 | * the block driver layer .bdrv_reopen_prepare() | |
1707 | * | |
1708 | * bs is the BlockDriverState to reopen | |
1709 | * flags are the new open flags | |
1710 | * queue is the reopen queue | |
1711 | * | |
1712 | * Returns 0 on success, non-zero on error. On error errp will be set | |
1713 | * as well. | |
1714 | * | |
1715 | * On failure, bdrv_reopen_abort() will be called to clean up any data. | |
1716 | * It is the responsibility of the caller to then call the abort() or | |
1717 | * commit() for any other BDS that have been left in a prepare() state | |
1718 | * | |
1719 | */ | |
1720 | int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, | |
1721 | Error **errp) | |
1722 | { | |
1723 | int ret = -1; | |
1724 | Error *local_err = NULL; | |
1725 | BlockDriver *drv; | |
1726 | ||
1727 | assert(reopen_state != NULL); | |
1728 | assert(reopen_state->bs->drv != NULL); | |
1729 | drv = reopen_state->bs->drv; | |
1730 | ||
1731 | /* if we are to stay read-only, do not allow permission change | |
1732 | * to r/w */ | |
1733 | if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) && | |
1734 | reopen_state->flags & BDRV_O_RDWR) { | |
1735 | error_set(errp, QERR_DEVICE_IS_READ_ONLY, | |
1736 | reopen_state->bs->device_name); | |
1737 | goto error; | |
1738 | } | |
1739 | ||
1740 | ||
1741 | ret = bdrv_flush(reopen_state->bs); | |
1742 | if (ret) { | |
1743 | error_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive", | |
1744 | strerror(-ret)); | |
1745 | goto error; | |
1746 | } | |
1747 | ||
1748 | if (drv->bdrv_reopen_prepare) { | |
1749 | ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); | |
1750 | if (ret) { | |
1751 | if (local_err != NULL) { | |
1752 | error_propagate(errp, local_err); | |
1753 | } else { | |
1754 | error_setg(errp, "failed while preparing to reopen image '%s'", | |
1755 | reopen_state->bs->filename); | |
1756 | } | |
1757 | goto error; | |
1758 | } | |
1759 | } else { | |
1760 | /* It is currently mandatory to have a bdrv_reopen_prepare() | |
1761 | * handler for each supported drv. */ | |
1762 | error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, | |
1763 | drv->format_name, reopen_state->bs->device_name, | |
1764 | "reopening of file"); | |
1765 | ret = -1; | |
1766 | goto error; | |
1767 | } | |
1768 | ||
1769 | ret = 0; | |
1770 | ||
1771 | error: | |
1772 | return ret; | |
1773 | } | |
1774 | ||
1775 | /* | |
1776 | * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and | |
1777 | * makes them final by swapping the staging BlockDriverState contents into | |
1778 | * the active BlockDriverState contents. | |
1779 | */ | |
1780 | void bdrv_reopen_commit(BDRVReopenState *reopen_state) | |
1781 | { | |
1782 | BlockDriver *drv; | |
1783 | ||
1784 | assert(reopen_state != NULL); | |
1785 | drv = reopen_state->bs->drv; | |
1786 | assert(drv != NULL); | |
1787 | ||
1788 | /* If there are any driver level actions to take */ | |
1789 | if (drv->bdrv_reopen_commit) { | |
1790 | drv->bdrv_reopen_commit(reopen_state); | |
1791 | } | |
1792 | ||
1793 | /* set BDS specific flags now */ | |
1794 | reopen_state->bs->open_flags = reopen_state->flags; | |
1795 | reopen_state->bs->enable_write_cache = !!(reopen_state->flags & | |
1796 | BDRV_O_CACHE_WB); | |
1797 | reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); | |
1798 | ||
1799 | bdrv_refresh_limits(reopen_state->bs, NULL); | |
1800 | } | |
1801 | ||
1802 | /* | |
1803 | * Abort the reopen, and delete and free the staged changes in | |
1804 | * reopen_state | |
1805 | */ | |
1806 | void bdrv_reopen_abort(BDRVReopenState *reopen_state) | |
1807 | { | |
1808 | BlockDriver *drv; | |
1809 | ||
1810 | assert(reopen_state != NULL); | |
1811 | drv = reopen_state->bs->drv; | |
1812 | assert(drv != NULL); | |
1813 | ||
1814 | if (drv->bdrv_reopen_abort) { | |
1815 | drv->bdrv_reopen_abort(reopen_state); | |
1816 | } | |
1817 | } | |
1818 | ||
1819 | ||
1820 | void bdrv_close(BlockDriverState *bs) | |
1821 | { | |
1822 | if (bs->job) { | |
1823 | block_job_cancel_sync(bs->job); | |
1824 | } | |
1825 | bdrv_drain_all(); /* complete I/O */ | |
1826 | bdrv_flush(bs); | |
1827 | bdrv_drain_all(); /* in case flush left pending I/O */ | |
1828 | notifier_list_notify(&bs->close_notifiers, bs); | |
1829 | ||
1830 | if (bs->drv) { | |
1831 | if (bs->backing_hd) { | |
1832 | BlockDriverState *backing_hd = bs->backing_hd; | |
1833 | bdrv_set_backing_hd(bs, NULL); | |
1834 | bdrv_unref(backing_hd); | |
1835 | } | |
1836 | bs->drv->bdrv_close(bs); | |
1837 | g_free(bs->opaque); | |
1838 | bs->opaque = NULL; | |
1839 | bs->drv = NULL; | |
1840 | bs->copy_on_read = 0; | |
1841 | bs->backing_file[0] = '\0'; | |
1842 | bs->backing_format[0] = '\0'; | |
1843 | bs->total_sectors = 0; | |
1844 | bs->encrypted = 0; | |
1845 | bs->valid_key = 0; | |
1846 | bs->sg = 0; | |
1847 | bs->growable = 0; | |
1848 | bs->zero_beyond_eof = false; | |
1849 | QDECREF(bs->options); | |
1850 | bs->options = NULL; | |
1851 | QDECREF(bs->full_open_options); | |
1852 | bs->full_open_options = NULL; | |
1853 | ||
1854 | if (bs->file != NULL) { | |
1855 | bdrv_unref(bs->file); | |
1856 | bs->file = NULL; | |
1857 | } | |
1858 | } | |
1859 | ||
1860 | bdrv_dev_change_media_cb(bs, false); | |
1861 | ||
1862 | /*throttling disk I/O limits*/ | |
1863 | if (bs->io_limits_enabled) { | |
1864 | bdrv_io_limits_disable(bs); | |
1865 | } | |
1866 | } | |
1867 | ||
1868 | void bdrv_close_all(void) | |
1869 | { | |
1870 | BlockDriverState *bs; | |
1871 | ||
1872 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
1873 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
1874 | ||
1875 | aio_context_acquire(aio_context); | |
1876 | bdrv_close(bs); | |
1877 | aio_context_release(aio_context); | |
1878 | } | |
1879 | } | |
1880 | ||
1881 | /* Check if any requests are in-flight (including throttled requests) */ | |
1882 | static bool bdrv_requests_pending(BlockDriverState *bs) | |
1883 | { | |
1884 | if (!QLIST_EMPTY(&bs->tracked_requests)) { | |
1885 | return true; | |
1886 | } | |
1887 | if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) { | |
1888 | return true; | |
1889 | } | |
1890 | if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) { | |
1891 | return true; | |
1892 | } | |
1893 | if (bs->file && bdrv_requests_pending(bs->file)) { | |
1894 | return true; | |
1895 | } | |
1896 | if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) { | |
1897 | return true; | |
1898 | } | |
1899 | return false; | |
1900 | } | |
1901 | ||
1902 | /* | |
1903 | * Wait for pending requests to complete across all BlockDriverStates | |
1904 | * | |
1905 | * This function does not flush data to disk, use bdrv_flush_all() for that | |
1906 | * after calling this function. | |
1907 | * | |
1908 | * Note that completion of an asynchronous I/O operation can trigger any | |
1909 | * number of other I/O operations on other devices---for example a coroutine | |
1910 | * can be arbitrarily complex and a constant flow of I/O can come until the | |
1911 | * coroutine is complete. Because of this, it is not possible to have a | |
1912 | * function to drain a single device's I/O queue. | |
1913 | */ | |
1914 | void bdrv_drain_all(void) | |
1915 | { | |
1916 | /* Always run first iteration so any pending completion BHs run */ | |
1917 | bool busy = true; | |
1918 | BlockDriverState *bs; | |
1919 | ||
1920 | while (busy) { | |
1921 | busy = false; | |
1922 | ||
1923 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
1924 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
1925 | bool bs_busy; | |
1926 | ||
1927 | aio_context_acquire(aio_context); | |
1928 | bdrv_flush_io_queue(bs); | |
1929 | bdrv_start_throttled_reqs(bs); | |
1930 | bs_busy = bdrv_requests_pending(bs); | |
1931 | bs_busy |= aio_poll(aio_context, bs_busy); | |
1932 | aio_context_release(aio_context); | |
1933 | ||
1934 | busy |= bs_busy; | |
1935 | } | |
1936 | } | |
1937 | } | |
1938 | ||
1939 | /* make a BlockDriverState anonymous by removing from bdrv_state and | |
1940 | * graph_bdrv_state list. | |
1941 | Also, NULL terminate the device_name to prevent double remove */ | |
1942 | void bdrv_make_anon(BlockDriverState *bs) | |
1943 | { | |
1944 | if (bs->device_name[0] != '\0') { | |
1945 | QTAILQ_REMOVE(&bdrv_states, bs, device_list); | |
1946 | } | |
1947 | bs->device_name[0] = '\0'; | |
1948 | if (bs->node_name[0] != '\0') { | |
1949 | QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); | |
1950 | } | |
1951 | bs->node_name[0] = '\0'; | |
1952 | } | |
1953 | ||
1954 | static void bdrv_rebind(BlockDriverState *bs) | |
1955 | { | |
1956 | if (bs->drv && bs->drv->bdrv_rebind) { | |
1957 | bs->drv->bdrv_rebind(bs); | |
1958 | } | |
1959 | } | |
1960 | ||
1961 | static void bdrv_move_feature_fields(BlockDriverState *bs_dest, | |
1962 | BlockDriverState *bs_src) | |
1963 | { | |
1964 | /* move some fields that need to stay attached to the device */ | |
1965 | ||
1966 | /* dev info */ | |
1967 | bs_dest->dev_ops = bs_src->dev_ops; | |
1968 | bs_dest->dev_opaque = bs_src->dev_opaque; | |
1969 | bs_dest->dev = bs_src->dev; | |
1970 | bs_dest->guest_block_size = bs_src->guest_block_size; | |
1971 | bs_dest->copy_on_read = bs_src->copy_on_read; | |
1972 | ||
1973 | bs_dest->enable_write_cache = bs_src->enable_write_cache; | |
1974 | ||
1975 | /* i/o throttled req */ | |
1976 | memcpy(&bs_dest->throttle_state, | |
1977 | &bs_src->throttle_state, | |
1978 | sizeof(ThrottleState)); | |
1979 | bs_dest->throttled_reqs[0] = bs_src->throttled_reqs[0]; | |
1980 | bs_dest->throttled_reqs[1] = bs_src->throttled_reqs[1]; | |
1981 | bs_dest->io_limits_enabled = bs_src->io_limits_enabled; | |
1982 | ||
1983 | /* r/w error */ | |
1984 | bs_dest->on_read_error = bs_src->on_read_error; | |
1985 | bs_dest->on_write_error = bs_src->on_write_error; | |
1986 | ||
1987 | /* i/o status */ | |
1988 | bs_dest->iostatus_enabled = bs_src->iostatus_enabled; | |
1989 | bs_dest->iostatus = bs_src->iostatus; | |
1990 | ||
1991 | /* dirty bitmap */ | |
1992 | bs_dest->dirty_bitmaps = bs_src->dirty_bitmaps; | |
1993 | ||
1994 | /* reference count */ | |
1995 | bs_dest->refcnt = bs_src->refcnt; | |
1996 | ||
1997 | /* job */ | |
1998 | bs_dest->job = bs_src->job; | |
1999 | ||
2000 | /* keep the same entry in bdrv_states */ | |
2001 | pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name), | |
2002 | bs_src->device_name); | |
2003 | bs_dest->device_list = bs_src->device_list; | |
2004 | memcpy(bs_dest->op_blockers, bs_src->op_blockers, | |
2005 | sizeof(bs_dest->op_blockers)); | |
2006 | } | |
2007 | ||
2008 | /* | |
2009 | * Swap bs contents for two image chains while they are live, | |
2010 | * while keeping required fields on the BlockDriverState that is | |
2011 | * actually attached to a device. | |
2012 | * | |
2013 | * This will modify the BlockDriverState fields, and swap contents | |
2014 | * between bs_new and bs_old. Both bs_new and bs_old are modified. | |
2015 | * | |
2016 | * bs_new is required to be anonymous. | |
2017 | * | |
2018 | * This function does not create any image files. | |
2019 | */ | |
2020 | void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) | |
2021 | { | |
2022 | BlockDriverState tmp; | |
2023 | ||
2024 | /* The code needs to swap the node_name but simply swapping node_list won't | |
2025 | * work so first remove the nodes from the graph list, do the swap then | |
2026 | * insert them back if needed. | |
2027 | */ | |
2028 | if (bs_new->node_name[0] != '\0') { | |
2029 | QTAILQ_REMOVE(&graph_bdrv_states, bs_new, node_list); | |
2030 | } | |
2031 | if (bs_old->node_name[0] != '\0') { | |
2032 | QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list); | |
2033 | } | |
2034 | ||
2035 | /* bs_new must be anonymous and shouldn't have anything fancy enabled */ | |
2036 | assert(bs_new->device_name[0] == '\0'); | |
2037 | assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); | |
2038 | assert(bs_new->job == NULL); | |
2039 | assert(bs_new->dev == NULL); | |
2040 | assert(bs_new->io_limits_enabled == false); | |
2041 | assert(!throttle_have_timer(&bs_new->throttle_state)); | |
2042 | ||
2043 | tmp = *bs_new; | |
2044 | *bs_new = *bs_old; | |
2045 | *bs_old = tmp; | |
2046 | ||
2047 | /* there are some fields that should not be swapped, move them back */ | |
2048 | bdrv_move_feature_fields(&tmp, bs_old); | |
2049 | bdrv_move_feature_fields(bs_old, bs_new); | |
2050 | bdrv_move_feature_fields(bs_new, &tmp); | |
2051 | ||
2052 | /* bs_new shouldn't be in bdrv_states even after the swap! */ | |
2053 | assert(bs_new->device_name[0] == '\0'); | |
2054 | ||
2055 | /* Check a few fields that should remain attached to the device */ | |
2056 | assert(bs_new->dev == NULL); | |
2057 | assert(bs_new->job == NULL); | |
2058 | assert(bs_new->io_limits_enabled == false); | |
2059 | assert(!throttle_have_timer(&bs_new->throttle_state)); | |
2060 | ||
2061 | /* insert the nodes back into the graph node list if needed */ | |
2062 | if (bs_new->node_name[0] != '\0') { | |
2063 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_new, node_list); | |
2064 | } | |
2065 | if (bs_old->node_name[0] != '\0') { | |
2066 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list); | |
2067 | } | |
2068 | ||
2069 | bdrv_rebind(bs_new); | |
2070 | bdrv_rebind(bs_old); | |
2071 | } | |
2072 | ||
2073 | /* | |
2074 | * Add new bs contents at the top of an image chain while the chain is | |
2075 | * live, while keeping required fields on the top layer. | |
2076 | * | |
2077 | * This will modify the BlockDriverState fields, and swap contents | |
2078 | * between bs_new and bs_top. Both bs_new and bs_top are modified. | |
2079 | * | |
2080 | * bs_new is required to be anonymous. | |
2081 | * | |
2082 | * This function does not create any image files. | |
2083 | */ | |
2084 | void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) | |
2085 | { | |
2086 | bdrv_swap(bs_new, bs_top); | |
2087 | ||
2088 | /* The contents of 'tmp' will become bs_top, as we are | |
2089 | * swapping bs_new and bs_top contents. */ | |
2090 | bdrv_set_backing_hd(bs_top, bs_new); | |
2091 | } | |
2092 | ||
2093 | static void bdrv_delete(BlockDriverState *bs) | |
2094 | { | |
2095 | assert(!bs->dev); | |
2096 | assert(!bs->job); | |
2097 | assert(bdrv_op_blocker_is_empty(bs)); | |
2098 | assert(!bs->refcnt); | |
2099 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); | |
2100 | ||
2101 | bdrv_close(bs); | |
2102 | ||
2103 | /* remove from list, if necessary */ | |
2104 | bdrv_make_anon(bs); | |
2105 | ||
2106 | g_free(bs); | |
2107 | } | |
2108 | ||
2109 | int bdrv_attach_dev(BlockDriverState *bs, void *dev) | |
2110 | /* TODO change to DeviceState *dev when all users are qdevified */ | |
2111 | { | |
2112 | if (bs->dev) { | |
2113 | return -EBUSY; | |
2114 | } | |
2115 | bs->dev = dev; | |
2116 | bdrv_iostatus_reset(bs); | |
2117 | ||
2118 | /* We're expecting I/O from the device so bump up coroutine pool size */ | |
2119 | qemu_coroutine_adjust_pool_size(COROUTINE_POOL_RESERVATION); | |
2120 | return 0; | |
2121 | } | |
2122 | ||
2123 | /* TODO qdevified devices don't use this, remove when devices are qdevified */ | |
2124 | void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev) | |
2125 | { | |
2126 | if (bdrv_attach_dev(bs, dev) < 0) { | |
2127 | abort(); | |
2128 | } | |
2129 | } | |
2130 | ||
2131 | void bdrv_detach_dev(BlockDriverState *bs, void *dev) | |
2132 | /* TODO change to DeviceState *dev when all users are qdevified */ | |
2133 | { | |
2134 | assert(bs->dev == dev); | |
2135 | bs->dev = NULL; | |
2136 | bs->dev_ops = NULL; | |
2137 | bs->dev_opaque = NULL; | |
2138 | bs->guest_block_size = 512; | |
2139 | qemu_coroutine_adjust_pool_size(-COROUTINE_POOL_RESERVATION); | |
2140 | } | |
2141 | ||
2142 | /* TODO change to return DeviceState * when all users are qdevified */ | |
2143 | void *bdrv_get_attached_dev(BlockDriverState *bs) | |
2144 | { | |
2145 | return bs->dev; | |
2146 | } | |
2147 | ||
2148 | void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops, | |
2149 | void *opaque) | |
2150 | { | |
2151 | bs->dev_ops = ops; | |
2152 | bs->dev_opaque = opaque; | |
2153 | } | |
2154 | ||
2155 | static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load) | |
2156 | { | |
2157 | if (bs->dev_ops && bs->dev_ops->change_media_cb) { | |
2158 | bool tray_was_closed = !bdrv_dev_is_tray_open(bs); | |
2159 | bs->dev_ops->change_media_cb(bs->dev_opaque, load); | |
2160 | if (tray_was_closed) { | |
2161 | /* tray open */ | |
2162 | qapi_event_send_device_tray_moved(bdrv_get_device_name(bs), | |
2163 | true, &error_abort); | |
2164 | } | |
2165 | if (load) { | |
2166 | /* tray close */ | |
2167 | qapi_event_send_device_tray_moved(bdrv_get_device_name(bs), | |
2168 | false, &error_abort); | |
2169 | } | |
2170 | } | |
2171 | } | |
2172 | ||
2173 | bool bdrv_dev_has_removable_media(BlockDriverState *bs) | |
2174 | { | |
2175 | return !bs->dev || (bs->dev_ops && bs->dev_ops->change_media_cb); | |
2176 | } | |
2177 | ||
2178 | void bdrv_dev_eject_request(BlockDriverState *bs, bool force) | |
2179 | { | |
2180 | if (bs->dev_ops && bs->dev_ops->eject_request_cb) { | |
2181 | bs->dev_ops->eject_request_cb(bs->dev_opaque, force); | |
2182 | } | |
2183 | } | |
2184 | ||
2185 | bool bdrv_dev_is_tray_open(BlockDriverState *bs) | |
2186 | { | |
2187 | if (bs->dev_ops && bs->dev_ops->is_tray_open) { | |
2188 | return bs->dev_ops->is_tray_open(bs->dev_opaque); | |
2189 | } | |
2190 | return false; | |
2191 | } | |
2192 | ||
2193 | static void bdrv_dev_resize_cb(BlockDriverState *bs) | |
2194 | { | |
2195 | if (bs->dev_ops && bs->dev_ops->resize_cb) { | |
2196 | bs->dev_ops->resize_cb(bs->dev_opaque); | |
2197 | } | |
2198 | } | |
2199 | ||
2200 | bool bdrv_dev_is_medium_locked(BlockDriverState *bs) | |
2201 | { | |
2202 | if (bs->dev_ops && bs->dev_ops->is_medium_locked) { | |
2203 | return bs->dev_ops->is_medium_locked(bs->dev_opaque); | |
2204 | } | |
2205 | return false; | |
2206 | } | |
2207 | ||
2208 | /* | |
2209 | * Run consistency checks on an image | |
2210 | * | |
2211 | * Returns 0 if the check could be completed (it doesn't mean that the image is | |
2212 | * free of errors) or -errno when an internal error occurred. The results of the | |
2213 | * check are stored in res. | |
2214 | */ | |
2215 | int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) | |
2216 | { | |
2217 | if (bs->drv == NULL) { | |
2218 | return -ENOMEDIUM; | |
2219 | } | |
2220 | if (bs->drv->bdrv_check == NULL) { | |
2221 | return -ENOTSUP; | |
2222 | } | |
2223 | ||
2224 | memset(res, 0, sizeof(*res)); | |
2225 | return bs->drv->bdrv_check(bs, res, fix); | |
2226 | } | |
2227 | ||
2228 | #define COMMIT_BUF_SECTORS 2048 | |
2229 | ||
2230 | /* commit COW file into the raw image */ | |
2231 | int bdrv_commit(BlockDriverState *bs) | |
2232 | { | |
2233 | BlockDriver *drv = bs->drv; | |
2234 | int64_t sector, total_sectors, length, backing_length; | |
2235 | int n, ro, open_flags; | |
2236 | int ret = 0; | |
2237 | uint8_t *buf = NULL; | |
2238 | char filename[PATH_MAX]; | |
2239 | ||
2240 | if (!drv) | |
2241 | return -ENOMEDIUM; | |
2242 | ||
2243 | if (!bs->backing_hd) { | |
2244 | return -ENOTSUP; | |
2245 | } | |
2246 | ||
2247 | if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, NULL) || | |
2248 | bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, NULL)) { | |
2249 | return -EBUSY; | |
2250 | } | |
2251 | ||
2252 | ro = bs->backing_hd->read_only; | |
2253 | /* Use pstrcpy (not strncpy): filename must be NUL-terminated. */ | |
2254 | pstrcpy(filename, sizeof(filename), bs->backing_hd->filename); | |
2255 | open_flags = bs->backing_hd->open_flags; | |
2256 | ||
2257 | if (ro) { | |
2258 | if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) { | |
2259 | return -EACCES; | |
2260 | } | |
2261 | } | |
2262 | ||
2263 | length = bdrv_getlength(bs); | |
2264 | if (length < 0) { | |
2265 | ret = length; | |
2266 | goto ro_cleanup; | |
2267 | } | |
2268 | ||
2269 | backing_length = bdrv_getlength(bs->backing_hd); | |
2270 | if (backing_length < 0) { | |
2271 | ret = backing_length; | |
2272 | goto ro_cleanup; | |
2273 | } | |
2274 | ||
2275 | /* If our top snapshot is larger than the backing file image, | |
2276 | * grow the backing file image if possible. If not possible, | |
2277 | * we must return an error */ | |
2278 | if (length > backing_length) { | |
2279 | ret = bdrv_truncate(bs->backing_hd, length); | |
2280 | if (ret < 0) { | |
2281 | goto ro_cleanup; | |
2282 | } | |
2283 | } | |
2284 | ||
2285 | total_sectors = length >> BDRV_SECTOR_BITS; | |
2286 | ||
2287 | /* qemu_try_blockalign() for bs will choose an alignment that works for | |
2288 | * bs->backing_hd as well, so no need to compare the alignment manually. */ | |
2289 | buf = qemu_try_blockalign(bs, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); | |
2290 | if (buf == NULL) { | |
2291 | ret = -ENOMEM; | |
2292 | goto ro_cleanup; | |
2293 | } | |
2294 | ||
2295 | for (sector = 0; sector < total_sectors; sector += n) { | |
2296 | ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n); | |
2297 | if (ret < 0) { | |
2298 | goto ro_cleanup; | |
2299 | } | |
2300 | if (ret) { | |
2301 | ret = bdrv_read(bs, sector, buf, n); | |
2302 | if (ret < 0) { | |
2303 | goto ro_cleanup; | |
2304 | } | |
2305 | ||
2306 | ret = bdrv_write(bs->backing_hd, sector, buf, n); | |
2307 | if (ret < 0) { | |
2308 | goto ro_cleanup; | |
2309 | } | |
2310 | } | |
2311 | } | |
2312 | ||
2313 | if (drv->bdrv_make_empty) { | |
2314 | ret = drv->bdrv_make_empty(bs); | |
2315 | if (ret < 0) { | |
2316 | goto ro_cleanup; | |
2317 | } | |
2318 | bdrv_flush(bs); | |
2319 | } | |
2320 | ||
2321 | /* | |
2322 | * Make sure all data we wrote to the backing device is actually | |
2323 | * stable on disk. | |
2324 | */ | |
2325 | if (bs->backing_hd) { | |
2326 | bdrv_flush(bs->backing_hd); | |
2327 | } | |
2328 | ||
2329 | ret = 0; | |
2330 | ro_cleanup: | |
2331 | qemu_vfree(buf); | |
2332 | ||
2333 | if (ro) { | |
2334 | /* ignoring error return here */ | |
2335 | bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL); | |
2336 | } | |
2337 | ||
2338 | return ret; | |
2339 | } | |
2340 | ||
2341 | int bdrv_commit_all(void) | |
2342 | { | |
2343 | BlockDriverState *bs; | |
2344 | ||
2345 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
2346 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
2347 | ||
2348 | aio_context_acquire(aio_context); | |
2349 | if (bs->drv && bs->backing_hd) { | |
2350 | int ret = bdrv_commit(bs); | |
2351 | if (ret < 0) { | |
2352 | aio_context_release(aio_context); | |
2353 | return ret; | |
2354 | } | |
2355 | } | |
2356 | aio_context_release(aio_context); | |
2357 | } | |
2358 | return 0; | |
2359 | } | |
2360 | ||
2361 | /** | |
2362 | * Remove an active request from the tracked requests list | |
2363 | * | |
2364 | * This function should be called when a tracked request is completing. | |
2365 | */ | |
2366 | static void tracked_request_end(BdrvTrackedRequest *req) | |
2367 | { | |
2368 | if (req->serialising) { | |
2369 | req->bs->serialising_in_flight--; | |
2370 | } | |
2371 | ||
2372 | QLIST_REMOVE(req, list); | |
2373 | qemu_co_queue_restart_all(&req->wait_queue); | |
2374 | } | |
2375 | ||
2376 | /** | |
2377 | * Add an active request to the tracked requests list | |
2378 | */ | |
2379 | static void tracked_request_begin(BdrvTrackedRequest *req, | |
2380 | BlockDriverState *bs, | |
2381 | int64_t offset, | |
2382 | unsigned int bytes, bool is_write) | |
2383 | { | |
2384 | *req = (BdrvTrackedRequest){ | |
2385 | .bs = bs, | |
2386 | .offset = offset, | |
2387 | .bytes = bytes, | |
2388 | .is_write = is_write, | |
2389 | .co = qemu_coroutine_self(), | |
2390 | .serialising = false, | |
2391 | .overlap_offset = offset, | |
2392 | .overlap_bytes = bytes, | |
2393 | }; | |
2394 | ||
2395 | qemu_co_queue_init(&req->wait_queue); | |
2396 | ||
2397 | QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); | |
2398 | } | |
2399 | ||
2400 | static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) | |
2401 | { | |
2402 | int64_t overlap_offset = req->offset & ~(align - 1); | |
2403 | unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align) | |
2404 | - overlap_offset; | |
2405 | ||
2406 | if (!req->serialising) { | |
2407 | req->bs->serialising_in_flight++; | |
2408 | req->serialising = true; | |
2409 | } | |
2410 | ||
2411 | req->overlap_offset = MIN(req->overlap_offset, overlap_offset); | |
2412 | req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes); | |
2413 | } | |
2414 | ||
2415 | /** | |
2416 | * Round a region to cluster boundaries | |
2417 | */ | |
2418 | void bdrv_round_to_clusters(BlockDriverState *bs, | |
2419 | int64_t sector_num, int nb_sectors, | |
2420 | int64_t *cluster_sector_num, | |
2421 | int *cluster_nb_sectors) | |
2422 | { | |
2423 | BlockDriverInfo bdi; | |
2424 | ||
2425 | if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { | |
2426 | *cluster_sector_num = sector_num; | |
2427 | *cluster_nb_sectors = nb_sectors; | |
2428 | } else { | |
2429 | int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; | |
2430 | *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); | |
2431 | *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + | |
2432 | nb_sectors, c); | |
2433 | } | |
2434 | } | |
2435 | ||
2436 | static int bdrv_get_cluster_size(BlockDriverState *bs) | |
2437 | { | |
2438 | BlockDriverInfo bdi; | |
2439 | int ret; | |
2440 | ||
2441 | ret = bdrv_get_info(bs, &bdi); | |
2442 | if (ret < 0 || bdi.cluster_size == 0) { | |
2443 | return bs->request_alignment; | |
2444 | } else { | |
2445 | return bdi.cluster_size; | |
2446 | } | |
2447 | } | |
2448 | ||
2449 | static bool tracked_request_overlaps(BdrvTrackedRequest *req, | |
2450 | int64_t offset, unsigned int bytes) | |
2451 | { | |
2452 | /* aaaa bbbb */ | |
2453 | if (offset >= req->overlap_offset + req->overlap_bytes) { | |
2454 | return false; | |
2455 | } | |
2456 | /* bbbb aaaa */ | |
2457 | if (req->overlap_offset >= offset + bytes) { | |
2458 | return false; | |
2459 | } | |
2460 | return true; | |
2461 | } | |
2462 | ||
2463 | static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) | |
2464 | { | |
2465 | BlockDriverState *bs = self->bs; | |
2466 | BdrvTrackedRequest *req; | |
2467 | bool retry; | |
2468 | bool waited = false; | |
2469 | ||
2470 | if (!bs->serialising_in_flight) { | |
2471 | return false; | |
2472 | } | |
2473 | ||
2474 | do { | |
2475 | retry = false; | |
2476 | QLIST_FOREACH(req, &bs->tracked_requests, list) { | |
2477 | if (req == self || (!req->serialising && !self->serialising)) { | |
2478 | continue; | |
2479 | } | |
2480 | if (tracked_request_overlaps(req, self->overlap_offset, | |
2481 | self->overlap_bytes)) | |
2482 | { | |
2483 | /* Hitting this means there was a reentrant request, for | |
2484 | * example, a block driver issuing nested requests. This must | |
2485 | * never happen since it means deadlock. | |
2486 | */ | |
2487 | assert(qemu_coroutine_self() != req->co); | |
2488 | ||
2489 | /* If the request is already (indirectly) waiting for us, or | |
2490 | * will wait for us as soon as it wakes up, then just go on | |
2491 | * (instead of producing a deadlock in the former case). */ | |
2492 | if (!req->waiting_for) { | |
2493 | self->waiting_for = req; | |
2494 | qemu_co_queue_wait(&req->wait_queue); | |
2495 | self->waiting_for = NULL; | |
2496 | retry = true; | |
2497 | waited = true; | |
2498 | break; | |
2499 | } | |
2500 | } | |
2501 | } | |
2502 | } while (retry); | |
2503 | ||
2504 | return waited; | |
2505 | } | |
2506 | ||
2507 | /* | |
2508 | * Return values: | |
2509 | * 0 - success | |
2510 | * -EINVAL - backing format specified, but no file | |
2511 | * -ENOSPC - can't update the backing file because no space is left in the | |
2512 | * image file header | |
2513 | * -ENOTSUP - format driver doesn't support changing the backing file | |
2514 | */ | |
2515 | int bdrv_change_backing_file(BlockDriverState *bs, | |
2516 | const char *backing_file, const char *backing_fmt) | |
2517 | { | |
2518 | BlockDriver *drv = bs->drv; | |
2519 | int ret; | |
2520 | ||
2521 | /* Backing file format doesn't make sense without a backing file */ | |
2522 | if (backing_fmt && !backing_file) { | |
2523 | return -EINVAL; | |
2524 | } | |
2525 | ||
2526 | if (drv->bdrv_change_backing_file != NULL) { | |
2527 | ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); | |
2528 | } else { | |
2529 | ret = -ENOTSUP; | |
2530 | } | |
2531 | ||
2532 | if (ret == 0) { | |
2533 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); | |
2534 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); | |
2535 | } | |
2536 | return ret; | |
2537 | } | |
2538 | ||
2539 | /* | |
2540 | * Finds the image layer in the chain that has 'bs' as its backing file. | |
2541 | * | |
2542 | * active is the current topmost image. | |
2543 | * | |
2544 | * Returns NULL if bs is not found in active's image chain, | |
2545 | * or if active == bs. | |
2546 | * | |
2547 | * Returns the bottommost base image if bs == NULL. | |
2548 | */ | |
2549 | BlockDriverState *bdrv_find_overlay(BlockDriverState *active, | |
2550 | BlockDriverState *bs) | |
2551 | { | |
2552 | while (active && bs != active->backing_hd) { | |
2553 | active = active->backing_hd; | |
2554 | } | |
2555 | ||
2556 | return active; | |
2557 | } | |
2558 | ||
2559 | /* Given a BDS, searches for the base layer. */ | |
2560 | BlockDriverState *bdrv_find_base(BlockDriverState *bs) | |
2561 | { | |
2562 | return bdrv_find_overlay(bs, NULL); | |
2563 | } | |
2564 | ||
2565 | typedef struct BlkIntermediateStates { | |
2566 | BlockDriverState *bs; | |
2567 | QSIMPLEQ_ENTRY(BlkIntermediateStates) entry; | |
2568 | } BlkIntermediateStates; | |
2569 | ||
2570 | ||
2571 | /* | |
2572 | * Drops images above 'base' up to and including 'top', and sets the image | |
2573 | * above 'top' to have base as its backing file. | |
2574 | * | |
2575 | * Requires that the overlay to 'top' is opened r/w, so that the backing file | |
2576 | * information in 'bs' can be properly updated. | |
2577 | * | |
2578 | * E.g., this will convert the following chain: | |
2579 | * bottom <- base <- intermediate <- top <- active | |
2580 | * | |
2581 | * to | |
2582 | * | |
2583 | * bottom <- base <- active | |
2584 | * | |
2585 | * It is allowed for bottom==base, in which case it converts: | |
2586 | * | |
2587 | * base <- intermediate <- top <- active | |
2588 | * | |
2589 | * to | |
2590 | * | |
2591 | * base <- active | |
2592 | * | |
2593 | * If backing_file_str is non-NULL, it will be used when modifying top's | |
2594 | * overlay image metadata. | |
2595 | * | |
2596 | * Error conditions: | |
2597 | * if active == top, that is considered an error | |
2598 | * | |
2599 | */ | |
2600 | int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, | |
2601 | BlockDriverState *base, const char *backing_file_str) | |
2602 | { | |
2603 | BlockDriverState *intermediate; | |
2604 | BlockDriverState *base_bs = NULL; | |
2605 | BlockDriverState *new_top_bs = NULL; | |
2606 | BlkIntermediateStates *intermediate_state, *next; | |
2607 | int ret = -EIO; | |
2608 | ||
2609 | QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete; | |
2610 | QSIMPLEQ_INIT(&states_to_delete); | |
2611 | ||
2612 | if (!top->drv || !base->drv) { | |
2613 | goto exit; | |
2614 | } | |
2615 | ||
2616 | new_top_bs = bdrv_find_overlay(active, top); | |
2617 | ||
2618 | if (new_top_bs == NULL) { | |
2619 | /* we could not find the image above 'top', this is an error */ | |
2620 | goto exit; | |
2621 | } | |
2622 | ||
2623 | /* special case of new_top_bs->backing_hd already pointing to base - nothing | |
2624 | * to do, no intermediate images */ | |
2625 | if (new_top_bs->backing_hd == base) { | |
2626 | ret = 0; | |
2627 | goto exit; | |
2628 | } | |
2629 | ||
2630 | intermediate = top; | |
2631 | ||
2632 | /* now we will go down through the list, and add each BDS we find | |
2633 | * into our deletion queue, until we hit the 'base' | |
2634 | */ | |
2635 | while (intermediate) { | |
2636 | intermediate_state = g_new0(BlkIntermediateStates, 1); | |
2637 | intermediate_state->bs = intermediate; | |
2638 | QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry); | |
2639 | ||
2640 | if (intermediate->backing_hd == base) { | |
2641 | base_bs = intermediate->backing_hd; | |
2642 | break; | |
2643 | } | |
2644 | intermediate = intermediate->backing_hd; | |
2645 | } | |
2646 | if (base_bs == NULL) { | |
2647 | /* something went wrong, we did not end at the base. safely | |
2648 | * unravel everything, and exit with error */ | |
2649 | goto exit; | |
2650 | } | |
2651 | ||
2652 | /* success - we can delete the intermediate states, and link top->base */ | |
2653 | backing_file_str = backing_file_str ? backing_file_str : base_bs->filename; | |
2654 | ret = bdrv_change_backing_file(new_top_bs, backing_file_str, | |
2655 | base_bs->drv ? base_bs->drv->format_name : ""); | |
2656 | if (ret) { | |
2657 | goto exit; | |
2658 | } | |
2659 | bdrv_set_backing_hd(new_top_bs, base_bs); | |
2660 | ||
2661 | QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { | |
2662 | /* so that bdrv_close() does not recursively close the chain */ | |
2663 | bdrv_set_backing_hd(intermediate_state->bs, NULL); | |
2664 | bdrv_unref(intermediate_state->bs); | |
2665 | } | |
2666 | ret = 0; | |
2667 | ||
2668 | exit: | |
2669 | QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { | |
2670 | g_free(intermediate_state); | |
2671 | } | |
2672 | return ret; | |
2673 | } | |
2674 | ||
2675 | ||
2676 | static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, | |
2677 | size_t size) | |
2678 | { | |
2679 | int64_t len; | |
2680 | ||
2681 | if (size > INT_MAX) { | |
2682 | return -EIO; | |
2683 | } | |
2684 | ||
2685 | if (!bdrv_is_inserted(bs)) | |
2686 | return -ENOMEDIUM; | |
2687 | ||
2688 | if (bs->growable) | |
2689 | return 0; | |
2690 | ||
2691 | len = bdrv_getlength(bs); | |
2692 | ||
2693 | if (offset < 0) | |
2694 | return -EIO; | |
2695 | ||
2696 | if ((offset > len) || (len - offset < size)) | |
2697 | return -EIO; | |
2698 | ||
2699 | return 0; | |
2700 | } | |
2701 | ||
2702 | static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, | |
2703 | int nb_sectors) | |
2704 | { | |
2705 | if (nb_sectors < 0 || nb_sectors > INT_MAX / BDRV_SECTOR_SIZE) { | |
2706 | return -EIO; | |
2707 | } | |
2708 | ||
2709 | return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE, | |
2710 | nb_sectors * BDRV_SECTOR_SIZE); | |
2711 | } | |
2712 | ||
2713 | typedef struct RwCo { | |
2714 | BlockDriverState *bs; | |
2715 | int64_t offset; | |
2716 | QEMUIOVector *qiov; | |
2717 | bool is_write; | |
2718 | int ret; | |
2719 | BdrvRequestFlags flags; | |
2720 | } RwCo; | |
2721 | ||
2722 | static void coroutine_fn bdrv_rw_co_entry(void *opaque) | |
2723 | { | |
2724 | RwCo *rwco = opaque; | |
2725 | ||
2726 | if (!rwco->is_write) { | |
2727 | rwco->ret = bdrv_co_do_preadv(rwco->bs, rwco->offset, | |
2728 | rwco->qiov->size, rwco->qiov, | |
2729 | rwco->flags); | |
2730 | } else { | |
2731 | rwco->ret = bdrv_co_do_pwritev(rwco->bs, rwco->offset, | |
2732 | rwco->qiov->size, rwco->qiov, | |
2733 | rwco->flags); | |
2734 | } | |
2735 | } | |
2736 | ||
2737 | /* | |
2738 | * Process a vectored synchronous request using coroutines | |
2739 | */ | |
2740 | static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset, | |
2741 | QEMUIOVector *qiov, bool is_write, | |
2742 | BdrvRequestFlags flags) | |
2743 | { | |
2744 | Coroutine *co; | |
2745 | RwCo rwco = { | |
2746 | .bs = bs, | |
2747 | .offset = offset, | |
2748 | .qiov = qiov, | |
2749 | .is_write = is_write, | |
2750 | .ret = NOT_DONE, | |
2751 | .flags = flags, | |
2752 | }; | |
2753 | ||
2754 | /** | |
2755 | * In sync call context, when the vcpu is blocked, this throttling timer | |
2756 | * will not fire; so the I/O throttling function has to be disabled here | |
2757 | * if it has been enabled. | |
2758 | */ | |
2759 | if (bs->io_limits_enabled) { | |
2760 | fprintf(stderr, "Disabling I/O throttling on '%s' due " | |
2761 | "to synchronous I/O.\n", bdrv_get_device_name(bs)); | |
2762 | bdrv_io_limits_disable(bs); | |
2763 | } | |
2764 | ||
2765 | if (qemu_in_coroutine()) { | |
2766 | /* Fast-path if already in coroutine context */ | |
2767 | bdrv_rw_co_entry(&rwco); | |
2768 | } else { | |
2769 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
2770 | ||
2771 | co = qemu_coroutine_create(bdrv_rw_co_entry); | |
2772 | qemu_coroutine_enter(co, &rwco); | |
2773 | while (rwco.ret == NOT_DONE) { | |
2774 | aio_poll(aio_context, true); | |
2775 | } | |
2776 | } | |
2777 | return rwco.ret; | |
2778 | } | |
2779 | ||
2780 | /* | |
2781 | * Process a synchronous request using coroutines | |
2782 | */ | |
2783 | static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, | |
2784 | int nb_sectors, bool is_write, BdrvRequestFlags flags) | |
2785 | { | |
2786 | QEMUIOVector qiov; | |
2787 | struct iovec iov = { | |
2788 | .iov_base = (void *)buf, | |
2789 | .iov_len = nb_sectors * BDRV_SECTOR_SIZE, | |
2790 | }; | |
2791 | ||
2792 | if (nb_sectors < 0 || nb_sectors > INT_MAX / BDRV_SECTOR_SIZE) { | |
2793 | return -EINVAL; | |
2794 | } | |
2795 | ||
2796 | qemu_iovec_init_external(&qiov, &iov, 1); | |
2797 | return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS, | |
2798 | &qiov, is_write, flags); | |
2799 | } | |
2800 | ||
2801 | /* return < 0 if error. See bdrv_write() for the return codes */ | |
2802 | int bdrv_read(BlockDriverState *bs, int64_t sector_num, | |
2803 | uint8_t *buf, int nb_sectors) | |
2804 | { | |
2805 | return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0); | |
2806 | } | |
2807 | ||
2808 | /* Just like bdrv_read(), but with I/O throttling temporarily disabled */ | |
2809 | int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num, | |
2810 | uint8_t *buf, int nb_sectors) | |
2811 | { | |
2812 | bool enabled; | |
2813 | int ret; | |
2814 | ||
2815 | enabled = bs->io_limits_enabled; | |
2816 | bs->io_limits_enabled = false; | |
2817 | ret = bdrv_read(bs, sector_num, buf, nb_sectors); | |
2818 | bs->io_limits_enabled = enabled; | |
2819 | return ret; | |
2820 | } | |
2821 | ||
2822 | /* Return < 0 if error. Important errors are: | |
2823 | -EIO generic I/O error (may happen for all errors) | |
2824 | -ENOMEDIUM No media inserted. | |
2825 | -EINVAL Invalid sector number or nb_sectors | |
2826 | -EACCES Trying to write a read-only device | |
2827 | */ | |
2828 | int bdrv_write(BlockDriverState *bs, int64_t sector_num, | |
2829 | const uint8_t *buf, int nb_sectors) | |
2830 | { | |
2831 | return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0); | |
2832 | } | |
2833 | ||
2834 | int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num, | |
2835 | int nb_sectors, BdrvRequestFlags flags) | |
2836 | { | |
2837 | return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true, | |
2838 | BDRV_REQ_ZERO_WRITE | flags); | |
2839 | } | |
2840 | ||
2841 | /* | |
2842 | * Completely zero out a block device with the help of bdrv_write_zeroes. | |
2843 | * The operation is sped up by checking the block status and only writing | |
2844 | * zeroes to the device if they currently do not return zeroes. Optional | |
2845 | * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP). | |
2846 | * | |
2847 | * Returns < 0 on error, 0 on success. For error codes see bdrv_write(). | |
2848 | */ | |
2849 | int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags) | |
2850 | { | |
2851 | int64_t target_sectors, ret, nb_sectors, sector_num = 0; | |
2852 | int n; | |
2853 | ||
2854 | target_sectors = bdrv_nb_sectors(bs); | |
2855 | if (target_sectors < 0) { | |
2856 | return target_sectors; | |
2857 | } | |
2858 | ||
2859 | for (;;) { | |
2860 | nb_sectors = target_sectors - sector_num; | |
2861 | if (nb_sectors <= 0) { | |
2862 | return 0; | |
2863 | } | |
2864 | if (nb_sectors > INT_MAX) { | |
2865 | nb_sectors = INT_MAX; | |
2866 | } | |
2867 | ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n); | |
2868 | if (ret < 0) { | |
2869 | error_report("error getting block status at sector %" PRId64 ": %s", | |
2870 | sector_num, strerror(-ret)); | |
2871 | return ret; | |
2872 | } | |
2873 | if (ret & BDRV_BLOCK_ZERO) { | |
2874 | sector_num += n; | |
2875 | continue; | |
2876 | } | |
2877 | ret = bdrv_write_zeroes(bs, sector_num, n, flags); | |
2878 | if (ret < 0) { | |
2879 | error_report("error writing zeroes at sector %" PRId64 ": %s", | |
2880 | sector_num, strerror(-ret)); | |
2881 | return ret; | |
2882 | } | |
2883 | sector_num += n; | |
2884 | } | |
2885 | } | |
2886 | ||
2887 | int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes) | |
2888 | { | |
2889 | QEMUIOVector qiov; | |
2890 | struct iovec iov = { | |
2891 | .iov_base = (void *)buf, | |
2892 | .iov_len = bytes, | |
2893 | }; | |
2894 | int ret; | |
2895 | ||
2896 | if (bytes < 0) { | |
2897 | return -EINVAL; | |
2898 | } | |
2899 | ||
2900 | qemu_iovec_init_external(&qiov, &iov, 1); | |
2901 | ret = bdrv_prwv_co(bs, offset, &qiov, false, 0); | |
2902 | if (ret < 0) { | |
2903 | return ret; | |
2904 | } | |
2905 | ||
2906 | return bytes; | |
2907 | } | |
2908 | ||
2909 | int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov) | |
2910 | { | |
2911 | int ret; | |
2912 | ||
2913 | ret = bdrv_prwv_co(bs, offset, qiov, true, 0); | |
2914 | if (ret < 0) { | |
2915 | return ret; | |
2916 | } | |
2917 | ||
2918 | return qiov->size; | |
2919 | } | |
2920 | ||
2921 | int bdrv_pwrite(BlockDriverState *bs, int64_t offset, | |
2922 | const void *buf, int bytes) | |
2923 | { | |
2924 | QEMUIOVector qiov; | |
2925 | struct iovec iov = { | |
2926 | .iov_base = (void *) buf, | |
2927 | .iov_len = bytes, | |
2928 | }; | |
2929 | ||
2930 | if (bytes < 0) { | |
2931 | return -EINVAL; | |
2932 | } | |
2933 | ||
2934 | qemu_iovec_init_external(&qiov, &iov, 1); | |
2935 | return bdrv_pwritev(bs, offset, &qiov); | |
2936 | } | |
2937 | ||
2938 | /* | |
2939 | * Writes to the file and ensures that no writes are reordered across this | |
2940 | * request (acts as a barrier) | |
2941 | * | |
2942 | * Returns 0 on success, -errno in error cases. | |
2943 | */ | |
2944 | int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset, | |
2945 | const void *buf, int count) | |
2946 | { | |
2947 | int ret; | |
2948 | ||
2949 | ret = bdrv_pwrite(bs, offset, buf, count); | |
2950 | if (ret < 0) { | |
2951 | return ret; | |
2952 | } | |
2953 | ||
2954 | /* No flush needed for cache modes that already do it */ | |
2955 | if (bs->enable_write_cache) { | |
2956 | bdrv_flush(bs); | |
2957 | } | |
2958 | ||
2959 | return 0; | |
2960 | } | |
2961 | ||
2962 | static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, | |
2963 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) | |
2964 | { | |
2965 | /* Perform I/O through a temporary buffer so that users who scribble over | |
2966 | * their read buffer while the operation is in progress do not end up | |
2967 | * modifying the image file. This is critical for zero-copy guest I/O | |
2968 | * where anything might happen inside guest memory. | |
2969 | */ | |
2970 | void *bounce_buffer; | |
2971 | ||
2972 | BlockDriver *drv = bs->drv; | |
2973 | struct iovec iov; | |
2974 | QEMUIOVector bounce_qiov; | |
2975 | int64_t cluster_sector_num; | |
2976 | int cluster_nb_sectors; | |
2977 | size_t skip_bytes; | |
2978 | int ret; | |
2979 | ||
2980 | /* Cover entire cluster so no additional backing file I/O is required when | |
2981 | * allocating cluster in the image file. | |
2982 | */ | |
2983 | bdrv_round_to_clusters(bs, sector_num, nb_sectors, | |
2984 | &cluster_sector_num, &cluster_nb_sectors); | |
2985 | ||
2986 | trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, | |
2987 | cluster_sector_num, cluster_nb_sectors); | |
2988 | ||
2989 | iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE; | |
2990 | iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len); | |
2991 | if (bounce_buffer == NULL) { | |
2992 | ret = -ENOMEM; | |
2993 | goto err; | |
2994 | } | |
2995 | ||
2996 | qemu_iovec_init_external(&bounce_qiov, &iov, 1); | |
2997 | ||
2998 | ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, | |
2999 | &bounce_qiov); | |
3000 | if (ret < 0) { | |
3001 | goto err; | |
3002 | } | |
3003 | ||
3004 | if (drv->bdrv_co_write_zeroes && | |
3005 | buffer_is_zero(bounce_buffer, iov.iov_len)) { | |
3006 | ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, | |
3007 | cluster_nb_sectors, 0); | |
3008 | } else { | |
3009 | /* This does not change the data on the disk, it is not necessary | |
3010 | * to flush even in cache=writethrough mode. | |
3011 | */ | |
3012 | ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, | |
3013 | &bounce_qiov); | |
3014 | } | |
3015 | ||
3016 | if (ret < 0) { | |
3017 | /* It might be okay to ignore write errors for guest requests. If this | |
3018 | * is a deliberate copy-on-read then we don't want to ignore the error. | |
3019 | * Simply report it in all cases. | |
3020 | */ | |
3021 | goto err; | |
3022 | } | |
3023 | ||
3024 | skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE; | |
3025 | qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, | |
3026 | nb_sectors * BDRV_SECTOR_SIZE); | |
3027 | ||
3028 | err: | |
3029 | qemu_vfree(bounce_buffer); | |
3030 | return ret; | |
3031 | } | |
3032 | ||
3033 | /* | |
3034 | * Forwards an already correctly aligned request to the BlockDriver. This | |
3035 | * handles copy on read and zeroing after EOF; any other features must be | |
3036 | * implemented by the caller. | |
3037 | */ | |
3038 | static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, | |
3039 | BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, | |
3040 | int64_t align, QEMUIOVector *qiov, int flags) | |
3041 | { | |
3042 | BlockDriver *drv = bs->drv; | |
3043 | int ret; | |
3044 | ||
3045 | int64_t sector_num = offset >> BDRV_SECTOR_BITS; | |
3046 | unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
3047 | ||
3048 | assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); | |
3049 | assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); | |
3050 | assert(!qiov || bytes == qiov->size); | |
3051 | ||
3052 | /* Handle Copy on Read and associated serialisation */ | |
3053 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
3054 | /* If we touch the same cluster it counts as an overlap. This | |
3055 | * guarantees that allocating writes will be serialized and not race | |
3056 | * with each other for the same cluster. For example, in copy-on-read | |
3057 | * it ensures that the CoR read and write operations are atomic and | |
3058 | * guest writes cannot interleave between them. */ | |
3059 | mark_request_serialising(req, bdrv_get_cluster_size(bs)); | |
3060 | } | |
3061 | ||
3062 | wait_serialising_requests(req); | |
3063 | ||
3064 | if (flags & BDRV_REQ_COPY_ON_READ) { | |
3065 | int pnum; | |
3066 | ||
3067 | ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum); | |
3068 | if (ret < 0) { | |
3069 | goto out; | |
3070 | } | |
3071 | ||
3072 | if (!ret || pnum != nb_sectors) { | |
3073 | ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov); | |
3074 | goto out; | |
3075 | } | |
3076 | } | |
3077 | ||
3078 | /* Forward the request to the BlockDriver */ | |
3079 | if (!(bs->zero_beyond_eof && bs->growable)) { | |
3080 | ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); | |
3081 | } else { | |
3082 | /* Read zeros after EOF of growable BDSes */ | |
3083 | int64_t total_sectors, max_nb_sectors; | |
3084 | ||
3085 | total_sectors = bdrv_nb_sectors(bs); | |
3086 | if (total_sectors < 0) { | |
3087 | ret = total_sectors; | |
3088 | goto out; | |
3089 | } | |
3090 | ||
3091 | max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num), | |
3092 | align >> BDRV_SECTOR_BITS); | |
3093 | if (max_nb_sectors > 0) { | |
3094 | QEMUIOVector local_qiov; | |
3095 | size_t local_sectors; | |
3096 | ||
3097 | max_nb_sectors = MIN(max_nb_sectors, SIZE_MAX / BDRV_SECTOR_BITS); | |
3098 | local_sectors = MIN(max_nb_sectors, nb_sectors); | |
3099 | ||
3100 | qemu_iovec_init(&local_qiov, qiov->niov); | |
3101 | qemu_iovec_concat(&local_qiov, qiov, 0, | |
3102 | local_sectors * BDRV_SECTOR_SIZE); | |
3103 | ||
3104 | ret = drv->bdrv_co_readv(bs, sector_num, local_sectors, | |
3105 | &local_qiov); | |
3106 | ||
3107 | qemu_iovec_destroy(&local_qiov); | |
3108 | } else { | |
3109 | ret = 0; | |
3110 | } | |
3111 | ||
3112 | /* Reading beyond end of file is supposed to produce zeroes */ | |
3113 | if (ret == 0 && total_sectors < sector_num + nb_sectors) { | |
3114 | uint64_t offset = MAX(0, total_sectors - sector_num); | |
3115 | uint64_t bytes = (sector_num + nb_sectors - offset) * | |
3116 | BDRV_SECTOR_SIZE; | |
3117 | qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes); | |
3118 | } | |
3119 | } | |
3120 | ||
3121 | out: | |
3122 | return ret; | |
3123 | } | |
3124 | ||
3125 | /* | |
3126 | * Handle a read request in coroutine context | |
3127 | */ | |
3128 | static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, | |
3129 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
3130 | BdrvRequestFlags flags) | |
3131 | { | |
3132 | BlockDriver *drv = bs->drv; | |
3133 | BdrvTrackedRequest req; | |
3134 | ||
3135 | /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ | |
3136 | uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); | |
3137 | uint8_t *head_buf = NULL; | |
3138 | uint8_t *tail_buf = NULL; | |
3139 | QEMUIOVector local_qiov; | |
3140 | bool use_local_qiov = false; | |
3141 | int ret; | |
3142 | ||
3143 | if (!drv) { | |
3144 | return -ENOMEDIUM; | |
3145 | } | |
3146 | if (bdrv_check_byte_request(bs, offset, bytes)) { | |
3147 | return -EIO; | |
3148 | } | |
3149 | ||
3150 | if (bs->copy_on_read) { | |
3151 | flags |= BDRV_REQ_COPY_ON_READ; | |
3152 | } | |
3153 | ||
3154 | /* throttling disk I/O */ | |
3155 | if (bs->io_limits_enabled) { | |
3156 | bdrv_io_limits_intercept(bs, bytes, false); | |
3157 | } | |
3158 | ||
3159 | /* Align read if necessary by padding qiov */ | |
3160 | if (offset & (align - 1)) { | |
3161 | head_buf = qemu_blockalign(bs, align); | |
3162 | qemu_iovec_init(&local_qiov, qiov->niov + 2); | |
3163 | qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); | |
3164 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
3165 | use_local_qiov = true; | |
3166 | ||
3167 | bytes += offset & (align - 1); | |
3168 | offset = offset & ~(align - 1); | |
3169 | } | |
3170 | ||
3171 | if ((offset + bytes) & (align - 1)) { | |
3172 | if (!use_local_qiov) { | |
3173 | qemu_iovec_init(&local_qiov, qiov->niov + 1); | |
3174 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
3175 | use_local_qiov = true; | |
3176 | } | |
3177 | tail_buf = qemu_blockalign(bs, align); | |
3178 | qemu_iovec_add(&local_qiov, tail_buf, | |
3179 | align - ((offset + bytes) & (align - 1))); | |
3180 | ||
3181 | bytes = ROUND_UP(bytes, align); | |
3182 | } | |
3183 | ||
3184 | tracked_request_begin(&req, bs, offset, bytes, false); | |
3185 | ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align, | |
3186 | use_local_qiov ? &local_qiov : qiov, | |
3187 | flags); | |
3188 | tracked_request_end(&req); | |
3189 | ||
3190 | if (use_local_qiov) { | |
3191 | qemu_iovec_destroy(&local_qiov); | |
3192 | qemu_vfree(head_buf); | |
3193 | qemu_vfree(tail_buf); | |
3194 | } | |
3195 | ||
3196 | return ret; | |
3197 | } | |
3198 | ||
3199 | static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, | |
3200 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, | |
3201 | BdrvRequestFlags flags) | |
3202 | { | |
3203 | if (nb_sectors < 0 || nb_sectors > (UINT_MAX >> BDRV_SECTOR_BITS)) { | |
3204 | return -EINVAL; | |
3205 | } | |
3206 | ||
3207 | return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS, | |
3208 | nb_sectors << BDRV_SECTOR_BITS, qiov, flags); | |
3209 | } | |
3210 | ||
3211 | int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num, | |
3212 | int nb_sectors, QEMUIOVector *qiov) | |
3213 | { | |
3214 | trace_bdrv_co_readv(bs, sector_num, nb_sectors); | |
3215 | ||
3216 | return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0); | |
3217 | } | |
3218 | ||
3219 | int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, | |
3220 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) | |
3221 | { | |
3222 | trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors); | |
3223 | ||
3224 | return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, | |
3225 | BDRV_REQ_COPY_ON_READ); | |
3226 | } | |
3227 | ||
3228 | /* if no limit is specified in the BlockLimits use a default | |
3229 | * of 32768 512-byte sectors (16 MiB) per request. | |
3230 | */ | |
3231 | #define MAX_WRITE_ZEROES_DEFAULT 32768 | |
3232 | ||
3233 | static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, | |
3234 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) | |
3235 | { | |
3236 | BlockDriver *drv = bs->drv; | |
3237 | QEMUIOVector qiov; | |
3238 | struct iovec iov = {0}; | |
3239 | int ret = 0; | |
3240 | ||
3241 | int max_write_zeroes = bs->bl.max_write_zeroes ? | |
3242 | bs->bl.max_write_zeroes : MAX_WRITE_ZEROES_DEFAULT; | |
3243 | ||
3244 | while (nb_sectors > 0 && !ret) { | |
3245 | int num = nb_sectors; | |
3246 | ||
3247 | /* Align request. Block drivers can expect the "bulk" of the request | |
3248 | * to be aligned. | |
3249 | */ | |
3250 | if (bs->bl.write_zeroes_alignment | |
3251 | && num > bs->bl.write_zeroes_alignment) { | |
3252 | if (sector_num % bs->bl.write_zeroes_alignment != 0) { | |
3253 | /* Make a small request up to the first aligned sector. */ | |
3254 | num = bs->bl.write_zeroes_alignment; | |
3255 | num -= sector_num % bs->bl.write_zeroes_alignment; | |
3256 | } else if ((sector_num + num) % bs->bl.write_zeroes_alignment != 0) { | |
3257 | /* Shorten the request to the last aligned sector. num cannot | |
3258 | * underflow because num > bs->bl.write_zeroes_alignment. | |
3259 | */ | |
3260 | num -= (sector_num + num) % bs->bl.write_zeroes_alignment; | |
3261 | } | |
3262 | } | |
3263 | ||
3264 | /* limit request size */ | |
3265 | if (num > max_write_zeroes) { | |
3266 | num = max_write_zeroes; | |
3267 | } | |
3268 | ||
3269 | ret = -ENOTSUP; | |
3270 | /* First try the efficient write zeroes operation */ | |
3271 | if (drv->bdrv_co_write_zeroes) { | |
3272 | ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags); | |
3273 | } | |
3274 | ||
3275 | if (ret == -ENOTSUP) { | |
3276 | /* Fall back to bounce buffer if write zeroes is unsupported */ | |
3277 | iov.iov_len = num * BDRV_SECTOR_SIZE; | |
3278 | if (iov.iov_base == NULL) { | |
3279 | iov.iov_base = qemu_try_blockalign(bs, num * BDRV_SECTOR_SIZE); | |
3280 | if (iov.iov_base == NULL) { | |
3281 | ret = -ENOMEM; | |
3282 | goto fail; | |
3283 | } | |
3284 | memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE); | |
3285 | } | |
3286 | qemu_iovec_init_external(&qiov, &iov, 1); | |
3287 | ||
3288 | ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov); | |
3289 | ||
3290 | /* Keep bounce buffer around if it is big enough for all | |
3291 | * all future requests. | |
3292 | */ | |
3293 | if (num < max_write_zeroes) { | |
3294 | qemu_vfree(iov.iov_base); | |
3295 | iov.iov_base = NULL; | |
3296 | } | |
3297 | } | |
3298 | ||
3299 | sector_num += num; | |
3300 | nb_sectors -= num; | |
3301 | } | |
3302 | ||
3303 | fail: | |
3304 | qemu_vfree(iov.iov_base); | |
3305 | return ret; | |
3306 | } | |
3307 | ||
3308 | /* | |
3309 | * Forwards an already correctly aligned write request to the BlockDriver. | |
3310 | */ | |
3311 | static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, | |
3312 | BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, | |
3313 | QEMUIOVector *qiov, int flags) | |
3314 | { | |
3315 | BlockDriver *drv = bs->drv; | |
3316 | bool waited; | |
3317 | int ret; | |
3318 | ||
3319 | int64_t sector_num = offset >> BDRV_SECTOR_BITS; | |
3320 | unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; | |
3321 | ||
3322 | assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); | |
3323 | assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); | |
3324 | assert(!qiov || bytes == qiov->size); | |
3325 | ||
3326 | waited = wait_serialising_requests(req); | |
3327 | assert(!waited || !req->serialising); | |
3328 | assert(req->overlap_offset <= offset); | |
3329 | assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); | |
3330 | ||
3331 | ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req); | |
3332 | ||
3333 | if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF && | |
3334 | !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes && | |
3335 | qemu_iovec_is_zero(qiov)) { | |
3336 | flags |= BDRV_REQ_ZERO_WRITE; | |
3337 | if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) { | |
3338 | flags |= BDRV_REQ_MAY_UNMAP; | |
3339 | } | |
3340 | } | |
3341 | ||
3342 | if (ret < 0) { | |
3343 | /* Do nothing, write notifier decided to fail this request */ | |
3344 | } else if (flags & BDRV_REQ_ZERO_WRITE) { | |
3345 | BLKDBG_EVENT(bs, BLKDBG_PWRITEV_ZERO); | |
3346 | ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags); | |
3347 | } else { | |
3348 | BLKDBG_EVENT(bs, BLKDBG_PWRITEV); | |
3349 | ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); | |
3350 | } | |
3351 | BLKDBG_EVENT(bs, BLKDBG_PWRITEV_DONE); | |
3352 | ||
3353 | if (ret == 0 && !bs->enable_write_cache) { | |
3354 | ret = bdrv_co_flush(bs); | |
3355 | } | |
3356 | ||
3357 | bdrv_set_dirty(bs, sector_num, nb_sectors); | |
3358 | ||
3359 | if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { | |
3360 | bs->wr_highest_sector = sector_num + nb_sectors - 1; | |
3361 | } | |
3362 | if (bs->growable && ret >= 0) { | |
3363 | bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors); | |
3364 | } | |
3365 | ||
3366 | return ret; | |
3367 | } | |
3368 | ||
3369 | /* | |
3370 | * Handle a write request in coroutine context | |
3371 | */ | |
3372 | static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, | |
3373 | int64_t offset, unsigned int bytes, QEMUIOVector *qiov, | |
3374 | BdrvRequestFlags flags) | |
3375 | { | |
3376 | BdrvTrackedRequest req; | |
3377 | /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ | |
3378 | uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); | |
3379 | uint8_t *head_buf = NULL; | |
3380 | uint8_t *tail_buf = NULL; | |
3381 | QEMUIOVector local_qiov; | |
3382 | bool use_local_qiov = false; | |
3383 | int ret; | |
3384 | ||
3385 | if (!bs->drv) { | |
3386 | return -ENOMEDIUM; | |
3387 | } | |
3388 | if (bs->read_only) { | |
3389 | return -EACCES; | |
3390 | } | |
3391 | if (bdrv_check_byte_request(bs, offset, bytes)) { | |
3392 | return -EIO; | |
3393 | } | |
3394 | ||
3395 | /* throttling disk I/O */ | |
3396 | if (bs->io_limits_enabled) { | |
3397 | bdrv_io_limits_intercept(bs, bytes, true); | |
3398 | } | |
3399 | ||
3400 | /* | |
3401 | * Align write if necessary by performing a read-modify-write cycle. | |
3402 | * Pad qiov with the read parts and be sure to have a tracked request not | |
3403 | * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle. | |
3404 | */ | |
3405 | tracked_request_begin(&req, bs, offset, bytes, true); | |
3406 | ||
3407 | if (offset & (align - 1)) { | |
3408 | QEMUIOVector head_qiov; | |
3409 | struct iovec head_iov; | |
3410 | ||
3411 | mark_request_serialising(&req, align); | |
3412 | wait_serialising_requests(&req); | |
3413 | ||
3414 | head_buf = qemu_blockalign(bs, align); | |
3415 | head_iov = (struct iovec) { | |
3416 | .iov_base = head_buf, | |
3417 | .iov_len = align, | |
3418 | }; | |
3419 | qemu_iovec_init_external(&head_qiov, &head_iov, 1); | |
3420 | ||
3421 | BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_HEAD); | |
3422 | ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align, | |
3423 | align, &head_qiov, 0); | |
3424 | if (ret < 0) { | |
3425 | goto fail; | |
3426 | } | |
3427 | BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); | |
3428 | ||
3429 | qemu_iovec_init(&local_qiov, qiov->niov + 2); | |
3430 | qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); | |
3431 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
3432 | use_local_qiov = true; | |
3433 | ||
3434 | bytes += offset & (align - 1); | |
3435 | offset = offset & ~(align - 1); | |
3436 | } | |
3437 | ||
3438 | if ((offset + bytes) & (align - 1)) { | |
3439 | QEMUIOVector tail_qiov; | |
3440 | struct iovec tail_iov; | |
3441 | size_t tail_bytes; | |
3442 | bool waited; | |
3443 | ||
3444 | mark_request_serialising(&req, align); | |
3445 | waited = wait_serialising_requests(&req); | |
3446 | assert(!waited || !use_local_qiov); | |
3447 | ||
3448 | tail_buf = qemu_blockalign(bs, align); | |
3449 | tail_iov = (struct iovec) { | |
3450 | .iov_base = tail_buf, | |
3451 | .iov_len = align, | |
3452 | }; | |
3453 | qemu_iovec_init_external(&tail_qiov, &tail_iov, 1); | |
3454 | ||
3455 | BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_TAIL); | |
3456 | ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align, | |
3457 | align, &tail_qiov, 0); | |
3458 | if (ret < 0) { | |
3459 | goto fail; | |
3460 | } | |
3461 | BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); | |
3462 | ||
3463 | if (!use_local_qiov) { | |
3464 | qemu_iovec_init(&local_qiov, qiov->niov + 1); | |
3465 | qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); | |
3466 | use_local_qiov = true; | |
3467 | } | |
3468 | ||
3469 | tail_bytes = (offset + bytes) & (align - 1); | |
3470 | qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes); | |
3471 | ||
3472 | bytes = ROUND_UP(bytes, align); | |
3473 | } | |
3474 | ||
3475 | ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, | |
3476 | use_local_qiov ? &local_qiov : qiov, | |
3477 | flags); | |
3478 | ||
3479 | fail: | |
3480 | tracked_request_end(&req); | |
3481 | ||
3482 | if (use_local_qiov) { | |
3483 | qemu_iovec_destroy(&local_qiov); | |
3484 | } | |
3485 | qemu_vfree(head_buf); | |
3486 | qemu_vfree(tail_buf); | |
3487 | ||
3488 | return ret; | |
3489 | } | |
3490 | ||
3491 | static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, | |
3492 | int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, | |
3493 | BdrvRequestFlags flags) | |
3494 | { | |
3495 | if (nb_sectors < 0 || nb_sectors > (INT_MAX >> BDRV_SECTOR_BITS)) { | |
3496 | return -EINVAL; | |
3497 | } | |
3498 | ||
3499 | return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS, | |
3500 | nb_sectors << BDRV_SECTOR_BITS, qiov, flags); | |
3501 | } | |
3502 | ||
3503 | int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, | |
3504 | int nb_sectors, QEMUIOVector *qiov) | |
3505 | { | |
3506 | trace_bdrv_co_writev(bs, sector_num, nb_sectors); | |
3507 | ||
3508 | return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0); | |
3509 | } | |
3510 | ||
3511 | int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, | |
3512 | int64_t sector_num, int nb_sectors, | |
3513 | BdrvRequestFlags flags) | |
3514 | { | |
3515 | trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags); | |
3516 | ||
3517 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
3518 | flags &= ~BDRV_REQ_MAY_UNMAP; | |
3519 | } | |
3520 | ||
3521 | return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, | |
3522 | BDRV_REQ_ZERO_WRITE | flags); | |
3523 | } | |
3524 | ||
3525 | /** | |
3526 | * Truncate file to 'offset' bytes (needed only for file protocols) | |
3527 | */ | |
3528 | int bdrv_truncate(BlockDriverState *bs, int64_t offset) | |
3529 | { | |
3530 | BlockDriver *drv = bs->drv; | |
3531 | int ret; | |
3532 | if (!drv) | |
3533 | return -ENOMEDIUM; | |
3534 | if (!drv->bdrv_truncate) | |
3535 | return -ENOTSUP; | |
3536 | if (bs->read_only) | |
3537 | return -EACCES; | |
3538 | ||
3539 | ret = drv->bdrv_truncate(bs, offset); | |
3540 | if (ret == 0) { | |
3541 | ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); | |
3542 | bdrv_dev_resize_cb(bs); | |
3543 | } | |
3544 | return ret; | |
3545 | } | |
3546 | ||
3547 | /** | |
3548 | * Length of a allocated file in bytes. Sparse files are counted by actual | |
3549 | * allocated space. Return < 0 if error or unknown. | |
3550 | */ | |
3551 | int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) | |
3552 | { | |
3553 | BlockDriver *drv = bs->drv; | |
3554 | if (!drv) { | |
3555 | return -ENOMEDIUM; | |
3556 | } | |
3557 | if (drv->bdrv_get_allocated_file_size) { | |
3558 | return drv->bdrv_get_allocated_file_size(bs); | |
3559 | } | |
3560 | if (bs->file) { | |
3561 | return bdrv_get_allocated_file_size(bs->file); | |
3562 | } | |
3563 | return -ENOTSUP; | |
3564 | } | |
3565 | ||
3566 | /** | |
3567 | * Return number of sectors on success, -errno on error. | |
3568 | */ | |
3569 | int64_t bdrv_nb_sectors(BlockDriverState *bs) | |
3570 | { | |
3571 | BlockDriver *drv = bs->drv; | |
3572 | ||
3573 | if (!drv) | |
3574 | return -ENOMEDIUM; | |
3575 | ||
3576 | if (drv->has_variable_length) { | |
3577 | int ret = refresh_total_sectors(bs, bs->total_sectors); | |
3578 | if (ret < 0) { | |
3579 | return ret; | |
3580 | } | |
3581 | } | |
3582 | return bs->total_sectors; | |
3583 | } | |
3584 | ||
3585 | /** | |
3586 | * Return length in bytes on success, -errno on error. | |
3587 | * The length is always a multiple of BDRV_SECTOR_SIZE. | |
3588 | */ | |
3589 | int64_t bdrv_getlength(BlockDriverState *bs) | |
3590 | { | |
3591 | int64_t ret = bdrv_nb_sectors(bs); | |
3592 | ||
3593 | return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE; | |
3594 | } | |
3595 | ||
3596 | /* return 0 as number of sectors if no device present or error */ | |
3597 | void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) | |
3598 | { | |
3599 | int64_t nb_sectors = bdrv_nb_sectors(bs); | |
3600 | ||
3601 | *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors; | |
3602 | } | |
3603 | ||
3604 | void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error, | |
3605 | BlockdevOnError on_write_error) | |
3606 | { | |
3607 | bs->on_read_error = on_read_error; | |
3608 | bs->on_write_error = on_write_error; | |
3609 | } | |
3610 | ||
3611 | BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read) | |
3612 | { | |
3613 | return is_read ? bs->on_read_error : bs->on_write_error; | |
3614 | } | |
3615 | ||
3616 | BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error) | |
3617 | { | |
3618 | BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error; | |
3619 | ||
3620 | switch (on_err) { | |
3621 | case BLOCKDEV_ON_ERROR_ENOSPC: | |
3622 | return (error == ENOSPC) ? | |
3623 | BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT; | |
3624 | case BLOCKDEV_ON_ERROR_STOP: | |
3625 | return BLOCK_ERROR_ACTION_STOP; | |
3626 | case BLOCKDEV_ON_ERROR_REPORT: | |
3627 | return BLOCK_ERROR_ACTION_REPORT; | |
3628 | case BLOCKDEV_ON_ERROR_IGNORE: | |
3629 | return BLOCK_ERROR_ACTION_IGNORE; | |
3630 | default: | |
3631 | abort(); | |
3632 | } | |
3633 | } | |
3634 | ||
3635 | /* This is done by device models because, while the block layer knows | |
3636 | * about the error, it does not know whether an operation comes from | |
3637 | * the device or the block layer (from a job, for example). | |
3638 | */ | |
3639 | void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action, | |
3640 | bool is_read, int error) | |
3641 | { | |
3642 | assert(error >= 0); | |
3643 | ||
3644 | if (action == BLOCK_ERROR_ACTION_STOP) { | |
3645 | /* First set the iostatus, so that "info block" returns an iostatus | |
3646 | * that matches the events raised so far (an additional error iostatus | |
3647 | * is fine, but not a lost one). | |
3648 | */ | |
3649 | bdrv_iostatus_set_err(bs, error); | |
3650 | ||
3651 | /* Then raise the request to stop the VM and the event. | |
3652 | * qemu_system_vmstop_request_prepare has two effects. First, | |
3653 | * it ensures that the STOP event always comes after the | |
3654 | * BLOCK_IO_ERROR event. Second, it ensures that even if management | |
3655 | * can observe the STOP event and do a "cont" before the STOP | |
3656 | * event is issued, the VM will not stop. In this case, vm_start() | |
3657 | * also ensures that the STOP/RESUME pair of events is emitted. | |
3658 | */ | |
3659 | qemu_system_vmstop_request_prepare(); | |
3660 | qapi_event_send_block_io_error(bdrv_get_device_name(bs), | |
3661 | is_read ? IO_OPERATION_TYPE_READ : | |
3662 | IO_OPERATION_TYPE_WRITE, | |
3663 | action, &error_abort); | |
3664 | qemu_system_vmstop_request(RUN_STATE_IO_ERROR); | |
3665 | } else { | |
3666 | qapi_event_send_block_io_error(bdrv_get_device_name(bs), | |
3667 | is_read ? IO_OPERATION_TYPE_READ : | |
3668 | IO_OPERATION_TYPE_WRITE, | |
3669 | action, &error_abort); | |
3670 | } | |
3671 | } | |
3672 | ||
3673 | int bdrv_is_read_only(BlockDriverState *bs) | |
3674 | { | |
3675 | return bs->read_only; | |
3676 | } | |
3677 | ||
3678 | int bdrv_is_sg(BlockDriverState *bs) | |
3679 | { | |
3680 | return bs->sg; | |
3681 | } | |
3682 | ||
3683 | int bdrv_enable_write_cache(BlockDriverState *bs) | |
3684 | { | |
3685 | return bs->enable_write_cache; | |
3686 | } | |
3687 | ||
3688 | void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce) | |
3689 | { | |
3690 | bs->enable_write_cache = wce; | |
3691 | ||
3692 | /* so a reopen() will preserve wce */ | |
3693 | if (wce) { | |
3694 | bs->open_flags |= BDRV_O_CACHE_WB; | |
3695 | } else { | |
3696 | bs->open_flags &= ~BDRV_O_CACHE_WB; | |
3697 | } | |
3698 | } | |
3699 | ||
3700 | int bdrv_is_encrypted(BlockDriverState *bs) | |
3701 | { | |
3702 | if (bs->backing_hd && bs->backing_hd->encrypted) | |
3703 | return 1; | |
3704 | return bs->encrypted; | |
3705 | } | |
3706 | ||
3707 | int bdrv_key_required(BlockDriverState *bs) | |
3708 | { | |
3709 | BlockDriverState *backing_hd = bs->backing_hd; | |
3710 | ||
3711 | if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key) | |
3712 | return 1; | |
3713 | return (bs->encrypted && !bs->valid_key); | |
3714 | } | |
3715 | ||
3716 | int bdrv_set_key(BlockDriverState *bs, const char *key) | |
3717 | { | |
3718 | int ret; | |
3719 | if (bs->backing_hd && bs->backing_hd->encrypted) { | |
3720 | ret = bdrv_set_key(bs->backing_hd, key); | |
3721 | if (ret < 0) | |
3722 | return ret; | |
3723 | if (!bs->encrypted) | |
3724 | return 0; | |
3725 | } | |
3726 | if (!bs->encrypted) { | |
3727 | return -EINVAL; | |
3728 | } else if (!bs->drv || !bs->drv->bdrv_set_key) { | |
3729 | return -ENOMEDIUM; | |
3730 | } | |
3731 | ret = bs->drv->bdrv_set_key(bs, key); | |
3732 | if (ret < 0) { | |
3733 | bs->valid_key = 0; | |
3734 | } else if (!bs->valid_key) { | |
3735 | bs->valid_key = 1; | |
3736 | /* call the change callback now, we skipped it on open */ | |
3737 | bdrv_dev_change_media_cb(bs, true); | |
3738 | } | |
3739 | return ret; | |
3740 | } | |
3741 | ||
3742 | const char *bdrv_get_format_name(BlockDriverState *bs) | |
3743 | { | |
3744 | return bs->drv ? bs->drv->format_name : NULL; | |
3745 | } | |
3746 | ||
3747 | void bdrv_iterate_format(void (*it)(void *opaque, const char *name), | |
3748 | void *opaque) | |
3749 | { | |
3750 | BlockDriver *drv; | |
3751 | int count = 0; | |
3752 | const char **formats = NULL; | |
3753 | ||
3754 | QLIST_FOREACH(drv, &bdrv_drivers, list) { | |
3755 | if (drv->format_name) { | |
3756 | bool found = false; | |
3757 | int i = count; | |
3758 | while (formats && i && !found) { | |
3759 | found = !strcmp(formats[--i], drv->format_name); | |
3760 | } | |
3761 | ||
3762 | if (!found) { | |
3763 | formats = g_renew(const char *, formats, count + 1); | |
3764 | formats[count++] = drv->format_name; | |
3765 | it(opaque, drv->format_name); | |
3766 | } | |
3767 | } | |
3768 | } | |
3769 | g_free(formats); | |
3770 | } | |
3771 | ||
3772 | /* This function is to find block backend bs */ | |
3773 | BlockDriverState *bdrv_find(const char *name) | |
3774 | { | |
3775 | BlockDriverState *bs; | |
3776 | ||
3777 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
3778 | if (!strcmp(name, bs->device_name)) { | |
3779 | return bs; | |
3780 | } | |
3781 | } | |
3782 | return NULL; | |
3783 | } | |
3784 | ||
3785 | /* This function is to find a node in the bs graph */ | |
3786 | BlockDriverState *bdrv_find_node(const char *node_name) | |
3787 | { | |
3788 | BlockDriverState *bs; | |
3789 | ||
3790 | assert(node_name); | |
3791 | ||
3792 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
3793 | if (!strcmp(node_name, bs->node_name)) { | |
3794 | return bs; | |
3795 | } | |
3796 | } | |
3797 | return NULL; | |
3798 | } | |
3799 | ||
3800 | /* Put this QMP function here so it can access the static graph_bdrv_states. */ | |
3801 | BlockDeviceInfoList *bdrv_named_nodes_list(void) | |
3802 | { | |
3803 | BlockDeviceInfoList *list, *entry; | |
3804 | BlockDriverState *bs; | |
3805 | ||
3806 | list = NULL; | |
3807 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
3808 | entry = g_malloc0(sizeof(*entry)); | |
3809 | entry->value = bdrv_block_device_info(bs); | |
3810 | entry->next = list; | |
3811 | list = entry; | |
3812 | } | |
3813 | ||
3814 | return list; | |
3815 | } | |
3816 | ||
3817 | BlockDriverState *bdrv_lookup_bs(const char *device, | |
3818 | const char *node_name, | |
3819 | Error **errp) | |
3820 | { | |
3821 | BlockDriverState *bs = NULL; | |
3822 | ||
3823 | if (device) { | |
3824 | bs = bdrv_find(device); | |
3825 | ||
3826 | if (bs) { | |
3827 | return bs; | |
3828 | } | |
3829 | } | |
3830 | ||
3831 | if (node_name) { | |
3832 | bs = bdrv_find_node(node_name); | |
3833 | ||
3834 | if (bs) { | |
3835 | return bs; | |
3836 | } | |
3837 | } | |
3838 | ||
3839 | error_setg(errp, "Cannot find device=%s nor node_name=%s", | |
3840 | device ? device : "", | |
3841 | node_name ? node_name : ""); | |
3842 | return NULL; | |
3843 | } | |
3844 | ||
3845 | /* If 'base' is in the same chain as 'top', return true. Otherwise, | |
3846 | * return false. If either argument is NULL, return false. */ | |
3847 | bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) | |
3848 | { | |
3849 | while (top && top != base) { | |
3850 | top = top->backing_hd; | |
3851 | } | |
3852 | ||
3853 | return top != NULL; | |
3854 | } | |
3855 | ||
3856 | BlockDriverState *bdrv_next(BlockDriverState *bs) | |
3857 | { | |
3858 | if (!bs) { | |
3859 | return QTAILQ_FIRST(&bdrv_states); | |
3860 | } | |
3861 | return QTAILQ_NEXT(bs, device_list); | |
3862 | } | |
3863 | ||
3864 | void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque) | |
3865 | { | |
3866 | BlockDriverState *bs; | |
3867 | ||
3868 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
3869 | it(opaque, bs); | |
3870 | } | |
3871 | } | |
3872 | ||
3873 | const char *bdrv_get_device_name(BlockDriverState *bs) | |
3874 | { | |
3875 | return bs->device_name; | |
3876 | } | |
3877 | ||
3878 | int bdrv_get_flags(BlockDriverState *bs) | |
3879 | { | |
3880 | return bs->open_flags; | |
3881 | } | |
3882 | ||
3883 | int bdrv_flush_all(void) | |
3884 | { | |
3885 | BlockDriverState *bs; | |
3886 | int result = 0; | |
3887 | ||
3888 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
3889 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
3890 | int ret; | |
3891 | ||
3892 | aio_context_acquire(aio_context); | |
3893 | ret = bdrv_flush(bs); | |
3894 | if (ret < 0 && !result) { | |
3895 | result = ret; | |
3896 | } | |
3897 | aio_context_release(aio_context); | |
3898 | } | |
3899 | ||
3900 | return result; | |
3901 | } | |
3902 | ||
3903 | int bdrv_has_zero_init_1(BlockDriverState *bs) | |
3904 | { | |
3905 | return 1; | |
3906 | } | |
3907 | ||
3908 | int bdrv_has_zero_init(BlockDriverState *bs) | |
3909 | { | |
3910 | assert(bs->drv); | |
3911 | ||
3912 | /* If BS is a copy on write image, it is initialized to | |
3913 | the contents of the base image, which may not be zeroes. */ | |
3914 | if (bs->backing_hd) { | |
3915 | return 0; | |
3916 | } | |
3917 | if (bs->drv->bdrv_has_zero_init) { | |
3918 | return bs->drv->bdrv_has_zero_init(bs); | |
3919 | } | |
3920 | ||
3921 | /* safe default */ | |
3922 | return 0; | |
3923 | } | |
3924 | ||
3925 | bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs) | |
3926 | { | |
3927 | BlockDriverInfo bdi; | |
3928 | ||
3929 | if (bs->backing_hd) { | |
3930 | return false; | |
3931 | } | |
3932 | ||
3933 | if (bdrv_get_info(bs, &bdi) == 0) { | |
3934 | return bdi.unallocated_blocks_are_zero; | |
3935 | } | |
3936 | ||
3937 | return false; | |
3938 | } | |
3939 | ||
3940 | bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) | |
3941 | { | |
3942 | BlockDriverInfo bdi; | |
3943 | ||
3944 | if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) { | |
3945 | return false; | |
3946 | } | |
3947 | ||
3948 | if (bdrv_get_info(bs, &bdi) == 0) { | |
3949 | return bdi.can_write_zeroes_with_unmap; | |
3950 | } | |
3951 | ||
3952 | return false; | |
3953 | } | |
3954 | ||
3955 | typedef struct BdrvCoGetBlockStatusData { | |
3956 | BlockDriverState *bs; | |
3957 | BlockDriverState *base; | |
3958 | int64_t sector_num; | |
3959 | int nb_sectors; | |
3960 | int *pnum; | |
3961 | int64_t ret; | |
3962 | bool done; | |
3963 | } BdrvCoGetBlockStatusData; | |
3964 | ||
3965 | /* | |
3966 | * Returns true iff the specified sector is present in the disk image. Drivers | |
3967 | * not implementing the functionality are assumed to not support backing files, | |
3968 | * hence all their sectors are reported as allocated. | |
3969 | * | |
3970 | * If 'sector_num' is beyond the end of the disk image the return value is 0 | |
3971 | * and 'pnum' is set to 0. | |
3972 | * | |
3973 | * 'pnum' is set to the number of sectors (including and immediately following | |
3974 | * the specified sector) that are known to be in the same | |
3975 | * allocated/unallocated state. | |
3976 | * | |
3977 | * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes | |
3978 | * beyond the end of the disk image it will be clamped. | |
3979 | */ | |
3980 | static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, | |
3981 | int64_t sector_num, | |
3982 | int nb_sectors, int *pnum) | |
3983 | { | |
3984 | int64_t total_sectors; | |
3985 | int64_t n; | |
3986 | int64_t ret, ret2; | |
3987 | ||
3988 | total_sectors = bdrv_nb_sectors(bs); | |
3989 | if (total_sectors < 0) { | |
3990 | return total_sectors; | |
3991 | } | |
3992 | ||
3993 | if (sector_num >= total_sectors) { | |
3994 | *pnum = 0; | |
3995 | return 0; | |
3996 | } | |
3997 | ||
3998 | n = total_sectors - sector_num; | |
3999 | if (n < nb_sectors) { | |
4000 | nb_sectors = n; | |
4001 | } | |
4002 | ||
4003 | if (!bs->drv->bdrv_co_get_block_status) { | |
4004 | *pnum = nb_sectors; | |
4005 | ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED; | |
4006 | if (bs->drv->protocol_name) { | |
4007 | ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE); | |
4008 | } | |
4009 | return ret; | |
4010 | } | |
4011 | ||
4012 | ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum); | |
4013 | if (ret < 0) { | |
4014 | *pnum = 0; | |
4015 | return ret; | |
4016 | } | |
4017 | ||
4018 | if (ret & BDRV_BLOCK_RAW) { | |
4019 | assert(ret & BDRV_BLOCK_OFFSET_VALID); | |
4020 | return bdrv_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS, | |
4021 | *pnum, pnum); | |
4022 | } | |
4023 | ||
4024 | if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { | |
4025 | ret |= BDRV_BLOCK_ALLOCATED; | |
4026 | } | |
4027 | ||
4028 | if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) { | |
4029 | if (bdrv_unallocated_blocks_are_zero(bs)) { | |
4030 | ret |= BDRV_BLOCK_ZERO; | |
4031 | } else if (bs->backing_hd) { | |
4032 | BlockDriverState *bs2 = bs->backing_hd; | |
4033 | int64_t nb_sectors2 = bdrv_nb_sectors(bs2); | |
4034 | if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) { | |
4035 | ret |= BDRV_BLOCK_ZERO; | |
4036 | } | |
4037 | } | |
4038 | } | |
4039 | ||
4040 | if (bs->file && | |
4041 | (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && | |
4042 | (ret & BDRV_BLOCK_OFFSET_VALID)) { | |
4043 | ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS, | |
4044 | *pnum, pnum); | |
4045 | if (ret2 >= 0) { | |
4046 | /* Ignore errors. This is just providing extra information, it | |
4047 | * is useful but not necessary. | |
4048 | */ | |
4049 | ret |= (ret2 & BDRV_BLOCK_ZERO); | |
4050 | } | |
4051 | } | |
4052 | ||
4053 | return ret; | |
4054 | } | |
4055 | ||
4056 | /* Coroutine wrapper for bdrv_get_block_status() */ | |
4057 | static void coroutine_fn bdrv_get_block_status_co_entry(void *opaque) | |
4058 | { | |
4059 | BdrvCoGetBlockStatusData *data = opaque; | |
4060 | BlockDriverState *bs = data->bs; | |
4061 | ||
4062 | data->ret = bdrv_co_get_block_status(bs, data->sector_num, data->nb_sectors, | |
4063 | data->pnum); | |
4064 | data->done = true; | |
4065 | } | |
4066 | ||
4067 | /* | |
4068 | * Synchronous wrapper around bdrv_co_get_block_status(). | |
4069 | * | |
4070 | * See bdrv_co_get_block_status() for details. | |
4071 | */ | |
4072 | int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num, | |
4073 | int nb_sectors, int *pnum) | |
4074 | { | |
4075 | Coroutine *co; | |
4076 | BdrvCoGetBlockStatusData data = { | |
4077 | .bs = bs, | |
4078 | .sector_num = sector_num, | |
4079 | .nb_sectors = nb_sectors, | |
4080 | .pnum = pnum, | |
4081 | .done = false, | |
4082 | }; | |
4083 | ||
4084 | if (qemu_in_coroutine()) { | |
4085 | /* Fast-path if already in coroutine context */ | |
4086 | bdrv_get_block_status_co_entry(&data); | |
4087 | } else { | |
4088 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
4089 | ||
4090 | co = qemu_coroutine_create(bdrv_get_block_status_co_entry); | |
4091 | qemu_coroutine_enter(co, &data); | |
4092 | while (!data.done) { | |
4093 | aio_poll(aio_context, true); | |
4094 | } | |
4095 | } | |
4096 | return data.ret; | |
4097 | } | |
4098 | ||
4099 | int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, | |
4100 | int nb_sectors, int *pnum) | |
4101 | { | |
4102 | int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum); | |
4103 | if (ret < 0) { | |
4104 | return ret; | |
4105 | } | |
4106 | return !!(ret & BDRV_BLOCK_ALLOCATED); | |
4107 | } | |
4108 | ||
4109 | /* | |
4110 | * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] | |
4111 | * | |
4112 | * Return true if the given sector is allocated in any image between | |
4113 | * BASE and TOP (inclusive). BASE can be NULL to check if the given | |
4114 | * sector is allocated in any image of the chain. Return false otherwise. | |
4115 | * | |
4116 | * 'pnum' is set to the number of sectors (including and immediately following | |
4117 | * the specified sector) that are known to be in the same | |
4118 | * allocated/unallocated state. | |
4119 | * | |
4120 | */ | |
4121 | int bdrv_is_allocated_above(BlockDriverState *top, | |
4122 | BlockDriverState *base, | |
4123 | int64_t sector_num, | |
4124 | int nb_sectors, int *pnum) | |
4125 | { | |
4126 | BlockDriverState *intermediate; | |
4127 | int ret, n = nb_sectors; | |
4128 | ||
4129 | intermediate = top; | |
4130 | while (intermediate && intermediate != base) { | |
4131 | int pnum_inter; | |
4132 | ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors, | |
4133 | &pnum_inter); | |
4134 | if (ret < 0) { | |
4135 | return ret; | |
4136 | } else if (ret) { | |
4137 | *pnum = pnum_inter; | |
4138 | return 1; | |
4139 | } | |
4140 | ||
4141 | /* | |
4142 | * [sector_num, nb_sectors] is unallocated on top but intermediate | |
4143 | * might have | |
4144 | * | |
4145 | * [sector_num+x, nr_sectors] allocated. | |
4146 | */ | |
4147 | if (n > pnum_inter && | |
4148 | (intermediate == top || | |
4149 | sector_num + pnum_inter < intermediate->total_sectors)) { | |
4150 | n = pnum_inter; | |
4151 | } | |
4152 | ||
4153 | intermediate = intermediate->backing_hd; | |
4154 | } | |
4155 | ||
4156 | *pnum = n; | |
4157 | return 0; | |
4158 | } | |
4159 | ||
4160 | const char *bdrv_get_encrypted_filename(BlockDriverState *bs) | |
4161 | { | |
4162 | if (bs->backing_hd && bs->backing_hd->encrypted) | |
4163 | return bs->backing_file; | |
4164 | else if (bs->encrypted) | |
4165 | return bs->filename; | |
4166 | else | |
4167 | return NULL; | |
4168 | } | |
4169 | ||
4170 | void bdrv_get_backing_filename(BlockDriverState *bs, | |
4171 | char *filename, int filename_size) | |
4172 | { | |
4173 | pstrcpy(filename, filename_size, bs->backing_file); | |
4174 | } | |
4175 | ||
4176 | int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num, | |
4177 | const uint8_t *buf, int nb_sectors) | |
4178 | { | |
4179 | BlockDriver *drv = bs->drv; | |
4180 | if (!drv) | |
4181 | return -ENOMEDIUM; | |
4182 | if (!drv->bdrv_write_compressed) | |
4183 | return -ENOTSUP; | |
4184 | if (bdrv_check_request(bs, sector_num, nb_sectors)) | |
4185 | return -EIO; | |
4186 | ||
4187 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); | |
4188 | ||
4189 | return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); | |
4190 | } | |
4191 | ||
4192 | int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) | |
4193 | { | |
4194 | BlockDriver *drv = bs->drv; | |
4195 | if (!drv) | |
4196 | return -ENOMEDIUM; | |
4197 | if (!drv->bdrv_get_info) | |
4198 | return -ENOTSUP; | |
4199 | memset(bdi, 0, sizeof(*bdi)); | |
4200 | return drv->bdrv_get_info(bs, bdi); | |
4201 | } | |
4202 | ||
4203 | ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs) | |
4204 | { | |
4205 | BlockDriver *drv = bs->drv; | |
4206 | if (drv && drv->bdrv_get_specific_info) { | |
4207 | return drv->bdrv_get_specific_info(bs); | |
4208 | } | |
4209 | return NULL; | |
4210 | } | |
4211 | ||
4212 | int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, | |
4213 | int64_t pos, int size) | |
4214 | { | |
4215 | QEMUIOVector qiov; | |
4216 | struct iovec iov = { | |
4217 | .iov_base = (void *) buf, | |
4218 | .iov_len = size, | |
4219 | }; | |
4220 | ||
4221 | qemu_iovec_init_external(&qiov, &iov, 1); | |
4222 | return bdrv_writev_vmstate(bs, &qiov, pos); | |
4223 | } | |
4224 | ||
4225 | int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) | |
4226 | { | |
4227 | BlockDriver *drv = bs->drv; | |
4228 | ||
4229 | if (!drv) { | |
4230 | return -ENOMEDIUM; | |
4231 | } else if (drv->bdrv_save_vmstate) { | |
4232 | return drv->bdrv_save_vmstate(bs, qiov, pos); | |
4233 | } else if (bs->file) { | |
4234 | return bdrv_writev_vmstate(bs->file, qiov, pos); | |
4235 | } | |
4236 | ||
4237 | return -ENOTSUP; | |
4238 | } | |
4239 | ||
4240 | int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, | |
4241 | int64_t pos, int size) | |
4242 | { | |
4243 | BlockDriver *drv = bs->drv; | |
4244 | if (!drv) | |
4245 | return -ENOMEDIUM; | |
4246 | if (drv->bdrv_load_vmstate) | |
4247 | return drv->bdrv_load_vmstate(bs, buf, pos, size); | |
4248 | if (bs->file) | |
4249 | return bdrv_load_vmstate(bs->file, buf, pos, size); | |
4250 | return -ENOTSUP; | |
4251 | } | |
4252 | ||
4253 | void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event) | |
4254 | { | |
4255 | if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) { | |
4256 | return; | |
4257 | } | |
4258 | ||
4259 | bs->drv->bdrv_debug_event(bs, event); | |
4260 | } | |
4261 | ||
4262 | int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, | |
4263 | const char *tag) | |
4264 | { | |
4265 | while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { | |
4266 | bs = bs->file; | |
4267 | } | |
4268 | ||
4269 | if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) { | |
4270 | return bs->drv->bdrv_debug_breakpoint(bs, event, tag); | |
4271 | } | |
4272 | ||
4273 | return -ENOTSUP; | |
4274 | } | |
4275 | ||
4276 | int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) | |
4277 | { | |
4278 | while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) { | |
4279 | bs = bs->file; | |
4280 | } | |
4281 | ||
4282 | if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) { | |
4283 | return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); | |
4284 | } | |
4285 | ||
4286 | return -ENOTSUP; | |
4287 | } | |
4288 | ||
4289 | int bdrv_debug_resume(BlockDriverState *bs, const char *tag) | |
4290 | { | |
4291 | while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { | |
4292 | bs = bs->file; | |
4293 | } | |
4294 | ||
4295 | if (bs && bs->drv && bs->drv->bdrv_debug_resume) { | |
4296 | return bs->drv->bdrv_debug_resume(bs, tag); | |
4297 | } | |
4298 | ||
4299 | return -ENOTSUP; | |
4300 | } | |
4301 | ||
4302 | bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) | |
4303 | { | |
4304 | while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { | |
4305 | bs = bs->file; | |
4306 | } | |
4307 | ||
4308 | if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { | |
4309 | return bs->drv->bdrv_debug_is_suspended(bs, tag); | |
4310 | } | |
4311 | ||
4312 | return false; | |
4313 | } | |
4314 | ||
4315 | int bdrv_is_snapshot(BlockDriverState *bs) | |
4316 | { | |
4317 | return !!(bs->open_flags & BDRV_O_SNAPSHOT); | |
4318 | } | |
4319 | ||
4320 | /* backing_file can either be relative, or absolute, or a protocol. If it is | |
4321 | * relative, it must be relative to the chain. So, passing in bs->filename | |
4322 | * from a BDS as backing_file should not be done, as that may be relative to | |
4323 | * the CWD rather than the chain. */ | |
4324 | BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, | |
4325 | const char *backing_file) | |
4326 | { | |
4327 | char *filename_full = NULL; | |
4328 | char *backing_file_full = NULL; | |
4329 | char *filename_tmp = NULL; | |
4330 | int is_protocol = 0; | |
4331 | BlockDriverState *curr_bs = NULL; | |
4332 | BlockDriverState *retval = NULL; | |
4333 | ||
4334 | if (!bs || !bs->drv || !backing_file) { | |
4335 | return NULL; | |
4336 | } | |
4337 | ||
4338 | filename_full = g_malloc(PATH_MAX); | |
4339 | backing_file_full = g_malloc(PATH_MAX); | |
4340 | filename_tmp = g_malloc(PATH_MAX); | |
4341 | ||
4342 | is_protocol = path_has_protocol(backing_file); | |
4343 | ||
4344 | for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) { | |
4345 | ||
4346 | /* If either of the filename paths is actually a protocol, then | |
4347 | * compare unmodified paths; otherwise make paths relative */ | |
4348 | if (is_protocol || path_has_protocol(curr_bs->backing_file)) { | |
4349 | if (strcmp(backing_file, curr_bs->backing_file) == 0) { | |
4350 | retval = curr_bs->backing_hd; | |
4351 | break; | |
4352 | } | |
4353 | } else { | |
4354 | /* If not an absolute filename path, make it relative to the current | |
4355 | * image's filename path */ | |
4356 | path_combine(filename_tmp, PATH_MAX, curr_bs->filename, | |
4357 | backing_file); | |
4358 | ||
4359 | /* We are going to compare absolute pathnames */ | |
4360 | if (!realpath(filename_tmp, filename_full)) { | |
4361 | continue; | |
4362 | } | |
4363 | ||
4364 | /* We need to make sure the backing filename we are comparing against | |
4365 | * is relative to the current image filename (or absolute) */ | |
4366 | path_combine(filename_tmp, PATH_MAX, curr_bs->filename, | |
4367 | curr_bs->backing_file); | |
4368 | ||
4369 | if (!realpath(filename_tmp, backing_file_full)) { | |
4370 | continue; | |
4371 | } | |
4372 | ||
4373 | if (strcmp(backing_file_full, filename_full) == 0) { | |
4374 | retval = curr_bs->backing_hd; | |
4375 | break; | |
4376 | } | |
4377 | } | |
4378 | } | |
4379 | ||
4380 | g_free(filename_full); | |
4381 | g_free(backing_file_full); | |
4382 | g_free(filename_tmp); | |
4383 | return retval; | |
4384 | } | |
4385 | ||
4386 | int bdrv_get_backing_file_depth(BlockDriverState *bs) | |
4387 | { | |
4388 | if (!bs->drv) { | |
4389 | return 0; | |
4390 | } | |
4391 | ||
4392 | if (!bs->backing_hd) { | |
4393 | return 0; | |
4394 | } | |
4395 | ||
4396 | return 1 + bdrv_get_backing_file_depth(bs->backing_hd); | |
4397 | } | |
4398 | ||
4399 | /**************************************************************/ | |
4400 | /* async I/Os */ | |
4401 | ||
4402 | BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, | |
4403 | QEMUIOVector *qiov, int nb_sectors, | |
4404 | BlockDriverCompletionFunc *cb, void *opaque) | |
4405 | { | |
4406 | trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); | |
4407 | ||
4408 | return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, | |
4409 | cb, opaque, false); | |
4410 | } | |
4411 | ||
4412 | BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, | |
4413 | QEMUIOVector *qiov, int nb_sectors, | |
4414 | BlockDriverCompletionFunc *cb, void *opaque) | |
4415 | { | |
4416 | trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); | |
4417 | ||
4418 | return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, | |
4419 | cb, opaque, true); | |
4420 | } | |
4421 | ||
4422 | BlockDriverAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, | |
4423 | int64_t sector_num, int nb_sectors, BdrvRequestFlags flags, | |
4424 | BlockDriverCompletionFunc *cb, void *opaque) | |
4425 | { | |
4426 | trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque); | |
4427 | ||
4428 | return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors, | |
4429 | BDRV_REQ_ZERO_WRITE | flags, | |
4430 | cb, opaque, true); | |
4431 | } | |
4432 | ||
4433 | ||
4434 | typedef struct MultiwriteCB { | |
4435 | int error; | |
4436 | int num_requests; | |
4437 | int num_callbacks; | |
4438 | struct { | |
4439 | BlockDriverCompletionFunc *cb; | |
4440 | void *opaque; | |
4441 | QEMUIOVector *free_qiov; | |
4442 | } callbacks[]; | |
4443 | } MultiwriteCB; | |
4444 | ||
4445 | static void multiwrite_user_cb(MultiwriteCB *mcb) | |
4446 | { | |
4447 | int i; | |
4448 | ||
4449 | for (i = 0; i < mcb->num_callbacks; i++) { | |
4450 | mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); | |
4451 | if (mcb->callbacks[i].free_qiov) { | |
4452 | qemu_iovec_destroy(mcb->callbacks[i].free_qiov); | |
4453 | } | |
4454 | g_free(mcb->callbacks[i].free_qiov); | |
4455 | } | |
4456 | } | |
4457 | ||
4458 | static void multiwrite_cb(void *opaque, int ret) | |
4459 | { | |
4460 | MultiwriteCB *mcb = opaque; | |
4461 | ||
4462 | trace_multiwrite_cb(mcb, ret); | |
4463 | ||
4464 | if (ret < 0 && !mcb->error) { | |
4465 | mcb->error = ret; | |
4466 | } | |
4467 | ||
4468 | mcb->num_requests--; | |
4469 | if (mcb->num_requests == 0) { | |
4470 | multiwrite_user_cb(mcb); | |
4471 | g_free(mcb); | |
4472 | } | |
4473 | } | |
4474 | ||
4475 | static int multiwrite_req_compare(const void *a, const void *b) | |
4476 | { | |
4477 | const BlockRequest *req1 = a, *req2 = b; | |
4478 | ||
4479 | /* | |
4480 | * Note that we can't simply subtract req2->sector from req1->sector | |
4481 | * here as that could overflow the return value. | |
4482 | */ | |
4483 | if (req1->sector > req2->sector) { | |
4484 | return 1; | |
4485 | } else if (req1->sector < req2->sector) { | |
4486 | return -1; | |
4487 | } else { | |
4488 | return 0; | |
4489 | } | |
4490 | } | |
4491 | ||
4492 | /* | |
4493 | * Takes a bunch of requests and tries to merge them. Returns the number of | |
4494 | * requests that remain after merging. | |
4495 | */ | |
4496 | static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, | |
4497 | int num_reqs, MultiwriteCB *mcb) | |
4498 | { | |
4499 | int i, outidx; | |
4500 | ||
4501 | // Sort requests by start sector | |
4502 | qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare); | |
4503 | ||
4504 | // Check if adjacent requests touch the same clusters. If so, combine them, | |
4505 | // filling up gaps with zero sectors. | |
4506 | outidx = 0; | |
4507 | for (i = 1; i < num_reqs; i++) { | |
4508 | int merge = 0; | |
4509 | int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; | |
4510 | ||
4511 | // Handle exactly sequential writes and overlapping writes. | |
4512 | if (reqs[i].sector <= oldreq_last) { | |
4513 | merge = 1; | |
4514 | } | |
4515 | ||
4516 | if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) { | |
4517 | merge = 0; | |
4518 | } | |
4519 | ||
4520 | if (merge) { | |
4521 | size_t size; | |
4522 | QEMUIOVector *qiov = g_malloc0(sizeof(*qiov)); | |
4523 | qemu_iovec_init(qiov, | |
4524 | reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1); | |
4525 | ||
4526 | // Add the first request to the merged one. If the requests are | |
4527 | // overlapping, drop the last sectors of the first request. | |
4528 | size = (reqs[i].sector - reqs[outidx].sector) << 9; | |
4529 | qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size); | |
4530 | ||
4531 | // We should need to add any zeros between the two requests | |
4532 | assert (reqs[i].sector <= oldreq_last); | |
4533 | ||
4534 | // Add the second request | |
4535 | qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size); | |
4536 | ||
4537 | reqs[outidx].nb_sectors = qiov->size >> 9; | |
4538 | reqs[outidx].qiov = qiov; | |
4539 | ||
4540 | mcb->callbacks[i].free_qiov = reqs[outidx].qiov; | |
4541 | } else { | |
4542 | outidx++; | |
4543 | reqs[outidx].sector = reqs[i].sector; | |
4544 | reqs[outidx].nb_sectors = reqs[i].nb_sectors; | |
4545 | reqs[outidx].qiov = reqs[i].qiov; | |
4546 | } | |
4547 | } | |
4548 | ||
4549 | return outidx + 1; | |
4550 | } | |
4551 | ||
4552 | /* | |
4553 | * Submit multiple AIO write requests at once. | |
4554 | * | |
4555 | * On success, the function returns 0 and all requests in the reqs array have | |
4556 | * been submitted. In error case this function returns -1, and any of the | |
4557 | * requests may or may not be submitted yet. In particular, this means that the | |
4558 | * callback will be called for some of the requests, for others it won't. The | |
4559 | * caller must check the error field of the BlockRequest to wait for the right | |
4560 | * callbacks (if error != 0, no callback will be called). | |
4561 | * | |
4562 | * The implementation may modify the contents of the reqs array, e.g. to merge | |
4563 | * requests. However, the fields opaque and error are left unmodified as they | |
4564 | * are used to signal failure for a single request to the caller. | |
4565 | */ | |
4566 | int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) | |
4567 | { | |
4568 | MultiwriteCB *mcb; | |
4569 | int i; | |
4570 | ||
4571 | /* don't submit writes if we don't have a medium */ | |
4572 | if (bs->drv == NULL) { | |
4573 | for (i = 0; i < num_reqs; i++) { | |
4574 | reqs[i].error = -ENOMEDIUM; | |
4575 | } | |
4576 | return -1; | |
4577 | } | |
4578 | ||
4579 | if (num_reqs == 0) { | |
4580 | return 0; | |
4581 | } | |
4582 | ||
4583 | // Create MultiwriteCB structure | |
4584 | mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); | |
4585 | mcb->num_requests = 0; | |
4586 | mcb->num_callbacks = num_reqs; | |
4587 | ||
4588 | for (i = 0; i < num_reqs; i++) { | |
4589 | mcb->callbacks[i].cb = reqs[i].cb; | |
4590 | mcb->callbacks[i].opaque = reqs[i].opaque; | |
4591 | } | |
4592 | ||
4593 | // Check for mergable requests | |
4594 | num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); | |
4595 | ||
4596 | trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); | |
4597 | ||
4598 | /* Run the aio requests. */ | |
4599 | mcb->num_requests = num_reqs; | |
4600 | for (i = 0; i < num_reqs; i++) { | |
4601 | bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov, | |
4602 | reqs[i].nb_sectors, reqs[i].flags, | |
4603 | multiwrite_cb, mcb, | |
4604 | true); | |
4605 | } | |
4606 | ||
4607 | return 0; | |
4608 | } | |
4609 | ||
4610 | void bdrv_aio_cancel(BlockDriverAIOCB *acb) | |
4611 | { | |
4612 | acb->aiocb_info->cancel(acb); | |
4613 | } | |
4614 | ||
4615 | /**************************************************************/ | |
4616 | /* async block device emulation */ | |
4617 | ||
4618 | typedef struct BlockDriverAIOCBSync { | |
4619 | BlockDriverAIOCB common; | |
4620 | QEMUBH *bh; | |
4621 | int ret; | |
4622 | /* vector translation state */ | |
4623 | QEMUIOVector *qiov; | |
4624 | uint8_t *bounce; | |
4625 | int is_write; | |
4626 | } BlockDriverAIOCBSync; | |
4627 | ||
4628 | static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb) | |
4629 | { | |
4630 | BlockDriverAIOCBSync *acb = | |
4631 | container_of(blockacb, BlockDriverAIOCBSync, common); | |
4632 | qemu_bh_delete(acb->bh); | |
4633 | acb->bh = NULL; | |
4634 | qemu_aio_release(acb); | |
4635 | } | |
4636 | ||
4637 | static const AIOCBInfo bdrv_em_aiocb_info = { | |
4638 | .aiocb_size = sizeof(BlockDriverAIOCBSync), | |
4639 | .cancel = bdrv_aio_cancel_em, | |
4640 | }; | |
4641 | ||
4642 | static void bdrv_aio_bh_cb(void *opaque) | |
4643 | { | |
4644 | BlockDriverAIOCBSync *acb = opaque; | |
4645 | ||
4646 | if (!acb->is_write && acb->ret >= 0) { | |
4647 | qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); | |
4648 | } | |
4649 | qemu_vfree(acb->bounce); | |
4650 | acb->common.cb(acb->common.opaque, acb->ret); | |
4651 | qemu_bh_delete(acb->bh); | |
4652 | acb->bh = NULL; | |
4653 | qemu_aio_release(acb); | |
4654 | } | |
4655 | ||
4656 | static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs, | |
4657 | int64_t sector_num, | |
4658 | QEMUIOVector *qiov, | |
4659 | int nb_sectors, | |
4660 | BlockDriverCompletionFunc *cb, | |
4661 | void *opaque, | |
4662 | int is_write) | |
4663 | ||
4664 | { | |
4665 | BlockDriverAIOCBSync *acb; | |
4666 | ||
4667 | acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque); | |
4668 | acb->is_write = is_write; | |
4669 | acb->qiov = qiov; | |
4670 | acb->bounce = qemu_try_blockalign(bs, qiov->size); | |
4671 | acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_aio_bh_cb, acb); | |
4672 | ||
4673 | if (acb->bounce == NULL) { | |
4674 | acb->ret = -ENOMEM; | |
4675 | } else if (is_write) { | |
4676 | qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); | |
4677 | acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors); | |
4678 | } else { | |
4679 | acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors); | |
4680 | } | |
4681 | ||
4682 | qemu_bh_schedule(acb->bh); | |
4683 | ||
4684 | return &acb->common; | |
4685 | } | |
4686 | ||
4687 | static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, | |
4688 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
4689 | BlockDriverCompletionFunc *cb, void *opaque) | |
4690 | { | |
4691 | return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); | |
4692 | } | |
4693 | ||
4694 | static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, | |
4695 | int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, | |
4696 | BlockDriverCompletionFunc *cb, void *opaque) | |
4697 | { | |
4698 | return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); | |
4699 | } | |
4700 | ||
4701 | ||
4702 | typedef struct BlockDriverAIOCBCoroutine { | |
4703 | BlockDriverAIOCB common; | |
4704 | BlockRequest req; | |
4705 | bool is_write; | |
4706 | bool *done; | |
4707 | QEMUBH* bh; | |
4708 | } BlockDriverAIOCBCoroutine; | |
4709 | ||
4710 | static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb) | |
4711 | { | |
4712 | AioContext *aio_context = bdrv_get_aio_context(blockacb->bs); | |
4713 | BlockDriverAIOCBCoroutine *acb = | |
4714 | container_of(blockacb, BlockDriverAIOCBCoroutine, common); | |
4715 | bool done = false; | |
4716 | ||
4717 | acb->done = &done; | |
4718 | while (!done) { | |
4719 | aio_poll(aio_context, true); | |
4720 | } | |
4721 | } | |
4722 | ||
4723 | static const AIOCBInfo bdrv_em_co_aiocb_info = { | |
4724 | .aiocb_size = sizeof(BlockDriverAIOCBCoroutine), | |
4725 | .cancel = bdrv_aio_co_cancel_em, | |
4726 | }; | |
4727 | ||
4728 | static void bdrv_co_em_bh(void *opaque) | |
4729 | { | |
4730 | BlockDriverAIOCBCoroutine *acb = opaque; | |
4731 | ||
4732 | acb->common.cb(acb->common.opaque, acb->req.error); | |
4733 | ||
4734 | if (acb->done) { | |
4735 | *acb->done = true; | |
4736 | } | |
4737 | ||
4738 | qemu_bh_delete(acb->bh); | |
4739 | qemu_aio_release(acb); | |
4740 | } | |
4741 | ||
4742 | /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */ | |
4743 | static void coroutine_fn bdrv_co_do_rw(void *opaque) | |
4744 | { | |
4745 | BlockDriverAIOCBCoroutine *acb = opaque; | |
4746 | BlockDriverState *bs = acb->common.bs; | |
4747 | ||
4748 | if (!acb->is_write) { | |
4749 | acb->req.error = bdrv_co_do_readv(bs, acb->req.sector, | |
4750 | acb->req.nb_sectors, acb->req.qiov, acb->req.flags); | |
4751 | } else { | |
4752 | acb->req.error = bdrv_co_do_writev(bs, acb->req.sector, | |
4753 | acb->req.nb_sectors, acb->req.qiov, acb->req.flags); | |
4754 | } | |
4755 | ||
4756 | acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb); | |
4757 | qemu_bh_schedule(acb->bh); | |
4758 | } | |
4759 | ||
4760 | static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, | |
4761 | int64_t sector_num, | |
4762 | QEMUIOVector *qiov, | |
4763 | int nb_sectors, | |
4764 | BdrvRequestFlags flags, | |
4765 | BlockDriverCompletionFunc *cb, | |
4766 | void *opaque, | |
4767 | bool is_write) | |
4768 | { | |
4769 | Coroutine *co; | |
4770 | BlockDriverAIOCBCoroutine *acb; | |
4771 | ||
4772 | acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); | |
4773 | acb->req.sector = sector_num; | |
4774 | acb->req.nb_sectors = nb_sectors; | |
4775 | acb->req.qiov = qiov; | |
4776 | acb->req.flags = flags; | |
4777 | acb->is_write = is_write; | |
4778 | acb->done = NULL; | |
4779 | ||
4780 | co = qemu_coroutine_create(bdrv_co_do_rw); | |
4781 | qemu_coroutine_enter(co, acb); | |
4782 | ||
4783 | return &acb->common; | |
4784 | } | |
4785 | ||
4786 | static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque) | |
4787 | { | |
4788 | BlockDriverAIOCBCoroutine *acb = opaque; | |
4789 | BlockDriverState *bs = acb->common.bs; | |
4790 | ||
4791 | acb->req.error = bdrv_co_flush(bs); | |
4792 | acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb); | |
4793 | qemu_bh_schedule(acb->bh); | |
4794 | } | |
4795 | ||
4796 | BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, | |
4797 | BlockDriverCompletionFunc *cb, void *opaque) | |
4798 | { | |
4799 | trace_bdrv_aio_flush(bs, opaque); | |
4800 | ||
4801 | Coroutine *co; | |
4802 | BlockDriverAIOCBCoroutine *acb; | |
4803 | ||
4804 | acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); | |
4805 | acb->done = NULL; | |
4806 | ||
4807 | co = qemu_coroutine_create(bdrv_aio_flush_co_entry); | |
4808 | qemu_coroutine_enter(co, acb); | |
4809 | ||
4810 | return &acb->common; | |
4811 | } | |
4812 | ||
4813 | static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) | |
4814 | { | |
4815 | BlockDriverAIOCBCoroutine *acb = opaque; | |
4816 | BlockDriverState *bs = acb->common.bs; | |
4817 | ||
4818 | acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); | |
4819 | acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb); | |
4820 | qemu_bh_schedule(acb->bh); | |
4821 | } | |
4822 | ||
4823 | BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs, | |
4824 | int64_t sector_num, int nb_sectors, | |
4825 | BlockDriverCompletionFunc *cb, void *opaque) | |
4826 | { | |
4827 | Coroutine *co; | |
4828 | BlockDriverAIOCBCoroutine *acb; | |
4829 | ||
4830 | trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque); | |
4831 | ||
4832 | acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); | |
4833 | acb->req.sector = sector_num; | |
4834 | acb->req.nb_sectors = nb_sectors; | |
4835 | acb->done = NULL; | |
4836 | co = qemu_coroutine_create(bdrv_aio_discard_co_entry); | |
4837 | qemu_coroutine_enter(co, acb); | |
4838 | ||
4839 | return &acb->common; | |
4840 | } | |
4841 | ||
4842 | void bdrv_init(void) | |
4843 | { | |
4844 | module_call_init(MODULE_INIT_BLOCK); | |
4845 | } | |
4846 | ||
4847 | void bdrv_init_with_whitelist(void) | |
4848 | { | |
4849 | use_bdrv_whitelist = 1; | |
4850 | bdrv_init(); | |
4851 | } | |
4852 | ||
4853 | void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs, | |
4854 | BlockDriverCompletionFunc *cb, void *opaque) | |
4855 | { | |
4856 | BlockDriverAIOCB *acb; | |
4857 | ||
4858 | acb = g_slice_alloc(aiocb_info->aiocb_size); | |
4859 | acb->aiocb_info = aiocb_info; | |
4860 | acb->bs = bs; | |
4861 | acb->cb = cb; | |
4862 | acb->opaque = opaque; | |
4863 | return acb; | |
4864 | } | |
4865 | ||
4866 | void qemu_aio_release(void *p) | |
4867 | { | |
4868 | BlockDriverAIOCB *acb = p; | |
4869 | g_slice_free1(acb->aiocb_info->aiocb_size, acb); | |
4870 | } | |
4871 | ||
4872 | /**************************************************************/ | |
4873 | /* Coroutine block device emulation */ | |
4874 | ||
4875 | typedef struct CoroutineIOCompletion { | |
4876 | Coroutine *coroutine; | |
4877 | int ret; | |
4878 | } CoroutineIOCompletion; | |
4879 | ||
4880 | static void bdrv_co_io_em_complete(void *opaque, int ret) | |
4881 | { | |
4882 | CoroutineIOCompletion *co = opaque; | |
4883 | ||
4884 | co->ret = ret; | |
4885 | qemu_coroutine_enter(co->coroutine, NULL); | |
4886 | } | |
4887 | ||
4888 | static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num, | |
4889 | int nb_sectors, QEMUIOVector *iov, | |
4890 | bool is_write) | |
4891 | { | |
4892 | CoroutineIOCompletion co = { | |
4893 | .coroutine = qemu_coroutine_self(), | |
4894 | }; | |
4895 | BlockDriverAIOCB *acb; | |
4896 | ||
4897 | if (is_write) { | |
4898 | acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors, | |
4899 | bdrv_co_io_em_complete, &co); | |
4900 | } else { | |
4901 | acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors, | |
4902 | bdrv_co_io_em_complete, &co); | |
4903 | } | |
4904 | ||
4905 | trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb); | |
4906 | if (!acb) { | |
4907 | return -EIO; | |
4908 | } | |
4909 | qemu_coroutine_yield(); | |
4910 | ||
4911 | return co.ret; | |
4912 | } | |
4913 | ||
4914 | static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, | |
4915 | int64_t sector_num, int nb_sectors, | |
4916 | QEMUIOVector *iov) | |
4917 | { | |
4918 | return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false); | |
4919 | } | |
4920 | ||
4921 | static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, | |
4922 | int64_t sector_num, int nb_sectors, | |
4923 | QEMUIOVector *iov) | |
4924 | { | |
4925 | return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true); | |
4926 | } | |
4927 | ||
4928 | static void coroutine_fn bdrv_flush_co_entry(void *opaque) | |
4929 | { | |
4930 | RwCo *rwco = opaque; | |
4931 | ||
4932 | rwco->ret = bdrv_co_flush(rwco->bs); | |
4933 | } | |
4934 | ||
4935 | int coroutine_fn bdrv_co_flush(BlockDriverState *bs) | |
4936 | { | |
4937 | int ret; | |
4938 | ||
4939 | if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { | |
4940 | return 0; | |
4941 | } | |
4942 | ||
4943 | /* Write back cached data to the OS even with cache=unsafe */ | |
4944 | BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); | |
4945 | if (bs->drv->bdrv_co_flush_to_os) { | |
4946 | ret = bs->drv->bdrv_co_flush_to_os(bs); | |
4947 | if (ret < 0) { | |
4948 | return ret; | |
4949 | } | |
4950 | } | |
4951 | ||
4952 | /* But don't actually force it to the disk with cache=unsafe */ | |
4953 | if (bs->open_flags & BDRV_O_NO_FLUSH) { | |
4954 | goto flush_parent; | |
4955 | } | |
4956 | ||
4957 | BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); | |
4958 | if (bs->drv->bdrv_co_flush_to_disk) { | |
4959 | ret = bs->drv->bdrv_co_flush_to_disk(bs); | |
4960 | } else if (bs->drv->bdrv_aio_flush) { | |
4961 | BlockDriverAIOCB *acb; | |
4962 | CoroutineIOCompletion co = { | |
4963 | .coroutine = qemu_coroutine_self(), | |
4964 | }; | |
4965 | ||
4966 | acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); | |
4967 | if (acb == NULL) { | |
4968 | ret = -EIO; | |
4969 | } else { | |
4970 | qemu_coroutine_yield(); | |
4971 | ret = co.ret; | |
4972 | } | |
4973 | } else { | |
4974 | /* | |
4975 | * Some block drivers always operate in either writethrough or unsafe | |
4976 | * mode and don't support bdrv_flush therefore. Usually qemu doesn't | |
4977 | * know how the server works (because the behaviour is hardcoded or | |
4978 | * depends on server-side configuration), so we can't ensure that | |
4979 | * everything is safe on disk. Returning an error doesn't work because | |
4980 | * that would break guests even if the server operates in writethrough | |
4981 | * mode. | |
4982 | * | |
4983 | * Let's hope the user knows what he's doing. | |
4984 | */ | |
4985 | ret = 0; | |
4986 | } | |
4987 | if (ret < 0) { | |
4988 | return ret; | |
4989 | } | |
4990 | ||
4991 | /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH | |
4992 | * in the case of cache=unsafe, so there are no useless flushes. | |
4993 | */ | |
4994 | flush_parent: | |
4995 | return bdrv_co_flush(bs->file); | |
4996 | } | |
4997 | ||
4998 | void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) | |
4999 | { | |
5000 | Error *local_err = NULL; | |
5001 | int ret; | |
5002 | ||
5003 | if (!bs->drv) { | |
5004 | return; | |
5005 | } | |
5006 | ||
5007 | if (bs->drv->bdrv_invalidate_cache) { | |
5008 | bs->drv->bdrv_invalidate_cache(bs, &local_err); | |
5009 | } else if (bs->file) { | |
5010 | bdrv_invalidate_cache(bs->file, &local_err); | |
5011 | } | |
5012 | if (local_err) { | |
5013 | error_propagate(errp, local_err); | |
5014 | return; | |
5015 | } | |
5016 | ||
5017 | ret = refresh_total_sectors(bs, bs->total_sectors); | |
5018 | if (ret < 0) { | |
5019 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
5020 | return; | |
5021 | } | |
5022 | } | |
5023 | ||
5024 | void bdrv_invalidate_cache_all(Error **errp) | |
5025 | { | |
5026 | BlockDriverState *bs; | |
5027 | Error *local_err = NULL; | |
5028 | ||
5029 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
5030 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
5031 | ||
5032 | aio_context_acquire(aio_context); | |
5033 | bdrv_invalidate_cache(bs, &local_err); | |
5034 | aio_context_release(aio_context); | |
5035 | if (local_err) { | |
5036 | error_propagate(errp, local_err); | |
5037 | return; | |
5038 | } | |
5039 | } | |
5040 | } | |
5041 | ||
5042 | void bdrv_clear_incoming_migration_all(void) | |
5043 | { | |
5044 | BlockDriverState *bs; | |
5045 | ||
5046 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
5047 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
5048 | ||
5049 | aio_context_acquire(aio_context); | |
5050 | bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING); | |
5051 | aio_context_release(aio_context); | |
5052 | } | |
5053 | } | |
5054 | ||
5055 | int bdrv_flush(BlockDriverState *bs) | |
5056 | { | |
5057 | Coroutine *co; | |
5058 | RwCo rwco = { | |
5059 | .bs = bs, | |
5060 | .ret = NOT_DONE, | |
5061 | }; | |
5062 | ||
5063 | if (qemu_in_coroutine()) { | |
5064 | /* Fast-path if already in coroutine context */ | |
5065 | bdrv_flush_co_entry(&rwco); | |
5066 | } else { | |
5067 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
5068 | ||
5069 | co = qemu_coroutine_create(bdrv_flush_co_entry); | |
5070 | qemu_coroutine_enter(co, &rwco); | |
5071 | while (rwco.ret == NOT_DONE) { | |
5072 | aio_poll(aio_context, true); | |
5073 | } | |
5074 | } | |
5075 | ||
5076 | return rwco.ret; | |
5077 | } | |
5078 | ||
5079 | typedef struct DiscardCo { | |
5080 | BlockDriverState *bs; | |
5081 | int64_t sector_num; | |
5082 | int nb_sectors; | |
5083 | int ret; | |
5084 | } DiscardCo; | |
5085 | static void coroutine_fn bdrv_discard_co_entry(void *opaque) | |
5086 | { | |
5087 | DiscardCo *rwco = opaque; | |
5088 | ||
5089 | rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); | |
5090 | } | |
5091 | ||
5092 | /* if no limit is specified in the BlockLimits use a default | |
5093 | * of 32768 512-byte sectors (16 MiB) per request. | |
5094 | */ | |
5095 | #define MAX_DISCARD_DEFAULT 32768 | |
5096 | ||
5097 | int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, | |
5098 | int nb_sectors) | |
5099 | { | |
5100 | int max_discard; | |
5101 | ||
5102 | if (!bs->drv) { | |
5103 | return -ENOMEDIUM; | |
5104 | } else if (bdrv_check_request(bs, sector_num, nb_sectors)) { | |
5105 | return -EIO; | |
5106 | } else if (bs->read_only) { | |
5107 | return -EROFS; | |
5108 | } | |
5109 | ||
5110 | bdrv_reset_dirty(bs, sector_num, nb_sectors); | |
5111 | ||
5112 | /* Do nothing if disabled. */ | |
5113 | if (!(bs->open_flags & BDRV_O_UNMAP)) { | |
5114 | return 0; | |
5115 | } | |
5116 | ||
5117 | if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) { | |
5118 | return 0; | |
5119 | } | |
5120 | ||
5121 | max_discard = bs->bl.max_discard ? bs->bl.max_discard : MAX_DISCARD_DEFAULT; | |
5122 | while (nb_sectors > 0) { | |
5123 | int ret; | |
5124 | int num = nb_sectors; | |
5125 | ||
5126 | /* align request */ | |
5127 | if (bs->bl.discard_alignment && | |
5128 | num >= bs->bl.discard_alignment && | |
5129 | sector_num % bs->bl.discard_alignment) { | |
5130 | if (num > bs->bl.discard_alignment) { | |
5131 | num = bs->bl.discard_alignment; | |
5132 | } | |
5133 | num -= sector_num % bs->bl.discard_alignment; | |
5134 | } | |
5135 | ||
5136 | /* limit request size */ | |
5137 | if (num > max_discard) { | |
5138 | num = max_discard; | |
5139 | } | |
5140 | ||
5141 | if (bs->drv->bdrv_co_discard) { | |
5142 | ret = bs->drv->bdrv_co_discard(bs, sector_num, num); | |
5143 | } else { | |
5144 | BlockDriverAIOCB *acb; | |
5145 | CoroutineIOCompletion co = { | |
5146 | .coroutine = qemu_coroutine_self(), | |
5147 | }; | |
5148 | ||
5149 | acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, | |
5150 | bdrv_co_io_em_complete, &co); | |
5151 | if (acb == NULL) { | |
5152 | return -EIO; | |
5153 | } else { | |
5154 | qemu_coroutine_yield(); | |
5155 | ret = co.ret; | |
5156 | } | |
5157 | } | |
5158 | if (ret && ret != -ENOTSUP) { | |
5159 | return ret; | |
5160 | } | |
5161 | ||
5162 | sector_num += num; | |
5163 | nb_sectors -= num; | |
5164 | } | |
5165 | return 0; | |
5166 | } | |
5167 | ||
5168 | int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) | |
5169 | { | |
5170 | Coroutine *co; | |
5171 | DiscardCo rwco = { | |
5172 | .bs = bs, | |
5173 | .sector_num = sector_num, | |
5174 | .nb_sectors = nb_sectors, | |
5175 | .ret = NOT_DONE, | |
5176 | }; | |
5177 | ||
5178 | if (qemu_in_coroutine()) { | |
5179 | /* Fast-path if already in coroutine context */ | |
5180 | bdrv_discard_co_entry(&rwco); | |
5181 | } else { | |
5182 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
5183 | ||
5184 | co = qemu_coroutine_create(bdrv_discard_co_entry); | |
5185 | qemu_coroutine_enter(co, &rwco); | |
5186 | while (rwco.ret == NOT_DONE) { | |
5187 | aio_poll(aio_context, true); | |
5188 | } | |
5189 | } | |
5190 | ||
5191 | return rwco.ret; | |
5192 | } | |
5193 | ||
5194 | /**************************************************************/ | |
5195 | /* removable device support */ | |
5196 | ||
5197 | /** | |
5198 | * Return TRUE if the media is present | |
5199 | */ | |
5200 | int bdrv_is_inserted(BlockDriverState *bs) | |
5201 | { | |
5202 | BlockDriver *drv = bs->drv; | |
5203 | ||
5204 | if (!drv) | |
5205 | return 0; | |
5206 | if (!drv->bdrv_is_inserted) | |
5207 | return 1; | |
5208 | return drv->bdrv_is_inserted(bs); | |
5209 | } | |
5210 | ||
5211 | /** | |
5212 | * Return whether the media changed since the last call to this | |
5213 | * function, or -ENOTSUP if we don't know. Most drivers don't know. | |
5214 | */ | |
5215 | int bdrv_media_changed(BlockDriverState *bs) | |
5216 | { | |
5217 | BlockDriver *drv = bs->drv; | |
5218 | ||
5219 | if (drv && drv->bdrv_media_changed) { | |
5220 | return drv->bdrv_media_changed(bs); | |
5221 | } | |
5222 | return -ENOTSUP; | |
5223 | } | |
5224 | ||
5225 | /** | |
5226 | * If eject_flag is TRUE, eject the media. Otherwise, close the tray | |
5227 | */ | |
5228 | void bdrv_eject(BlockDriverState *bs, bool eject_flag) | |
5229 | { | |
5230 | BlockDriver *drv = bs->drv; | |
5231 | ||
5232 | if (drv && drv->bdrv_eject) { | |
5233 | drv->bdrv_eject(bs, eject_flag); | |
5234 | } | |
5235 | ||
5236 | if (bs->device_name[0] != '\0') { | |
5237 | qapi_event_send_device_tray_moved(bdrv_get_device_name(bs), | |
5238 | eject_flag, &error_abort); | |
5239 | } | |
5240 | } | |
5241 | ||
5242 | /** | |
5243 | * Lock or unlock the media (if it is locked, the user won't be able | |
5244 | * to eject it manually). | |
5245 | */ | |
5246 | void bdrv_lock_medium(BlockDriverState *bs, bool locked) | |
5247 | { | |
5248 | BlockDriver *drv = bs->drv; | |
5249 | ||
5250 | trace_bdrv_lock_medium(bs, locked); | |
5251 | ||
5252 | if (drv && drv->bdrv_lock_medium) { | |
5253 | drv->bdrv_lock_medium(bs, locked); | |
5254 | } | |
5255 | } | |
5256 | ||
5257 | /* needed for generic scsi interface */ | |
5258 | ||
5259 | int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) | |
5260 | { | |
5261 | BlockDriver *drv = bs->drv; | |
5262 | ||
5263 | if (drv && drv->bdrv_ioctl) | |
5264 | return drv->bdrv_ioctl(bs, req, buf); | |
5265 | return -ENOTSUP; | |
5266 | } | |
5267 | ||
5268 | BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, | |
5269 | unsigned long int req, void *buf, | |
5270 | BlockDriverCompletionFunc *cb, void *opaque) | |
5271 | { | |
5272 | BlockDriver *drv = bs->drv; | |
5273 | ||
5274 | if (drv && drv->bdrv_aio_ioctl) | |
5275 | return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque); | |
5276 | return NULL; | |
5277 | } | |
5278 | ||
5279 | void bdrv_set_guest_block_size(BlockDriverState *bs, int align) | |
5280 | { | |
5281 | bs->guest_block_size = align; | |
5282 | } | |
5283 | ||
5284 | void *qemu_blockalign(BlockDriverState *bs, size_t size) | |
5285 | { | |
5286 | return qemu_memalign(bdrv_opt_mem_align(bs), size); | |
5287 | } | |
5288 | ||
5289 | void *qemu_try_blockalign(BlockDriverState *bs, size_t size) | |
5290 | { | |
5291 | size_t align = bdrv_opt_mem_align(bs); | |
5292 | ||
5293 | /* Ensure that NULL is never returned on success */ | |
5294 | assert(align > 0); | |
5295 | if (size == 0) { | |
5296 | size = align; | |
5297 | } | |
5298 | ||
5299 | return qemu_try_memalign(align, size); | |
5300 | } | |
5301 | ||
5302 | /* | |
5303 | * Check if all memory in this vector is sector aligned. | |
5304 | */ | |
5305 | bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) | |
5306 | { | |
5307 | int i; | |
5308 | size_t alignment = bdrv_opt_mem_align(bs); | |
5309 | ||
5310 | for (i = 0; i < qiov->niov; i++) { | |
5311 | if ((uintptr_t) qiov->iov[i].iov_base % alignment) { | |
5312 | return false; | |
5313 | } | |
5314 | if (qiov->iov[i].iov_len % alignment) { | |
5315 | return false; | |
5316 | } | |
5317 | } | |
5318 | ||
5319 | return true; | |
5320 | } | |
5321 | ||
5322 | BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity, | |
5323 | Error **errp) | |
5324 | { | |
5325 | int64_t bitmap_size; | |
5326 | BdrvDirtyBitmap *bitmap; | |
5327 | ||
5328 | assert((granularity & (granularity - 1)) == 0); | |
5329 | ||
5330 | granularity >>= BDRV_SECTOR_BITS; | |
5331 | assert(granularity); | |
5332 | bitmap_size = bdrv_nb_sectors(bs); | |
5333 | if (bitmap_size < 0) { | |
5334 | error_setg_errno(errp, -bitmap_size, "could not get length of device"); | |
5335 | errno = -bitmap_size; | |
5336 | return NULL; | |
5337 | } | |
5338 | bitmap = g_new0(BdrvDirtyBitmap, 1); | |
5339 | bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1); | |
5340 | QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list); | |
5341 | return bitmap; | |
5342 | } | |
5343 | ||
5344 | void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) | |
5345 | { | |
5346 | BdrvDirtyBitmap *bm, *next; | |
5347 | QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) { | |
5348 | if (bm == bitmap) { | |
5349 | QLIST_REMOVE(bitmap, list); | |
5350 | hbitmap_free(bitmap->bitmap); | |
5351 | g_free(bitmap); | |
5352 | return; | |
5353 | } | |
5354 | } | |
5355 | } | |
5356 | ||
5357 | BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs) | |
5358 | { | |
5359 | BdrvDirtyBitmap *bm; | |
5360 | BlockDirtyInfoList *list = NULL; | |
5361 | BlockDirtyInfoList **plist = &list; | |
5362 | ||
5363 | QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { | |
5364 | BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1); | |
5365 | BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1); | |
5366 | info->count = bdrv_get_dirty_count(bs, bm); | |
5367 | info->granularity = | |
5368 | ((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap)); | |
5369 | entry->value = info; | |
5370 | *plist = entry; | |
5371 | plist = &entry->next; | |
5372 | } | |
5373 | ||
5374 | return list; | |
5375 | } | |
5376 | ||
5377 | int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector) | |
5378 | { | |
5379 | if (bitmap) { | |
5380 | return hbitmap_get(bitmap->bitmap, sector); | |
5381 | } else { | |
5382 | return 0; | |
5383 | } | |
5384 | } | |
5385 | ||
5386 | void bdrv_dirty_iter_init(BlockDriverState *bs, | |
5387 | BdrvDirtyBitmap *bitmap, HBitmapIter *hbi) | |
5388 | { | |
5389 | hbitmap_iter_init(hbi, bitmap->bitmap, 0); | |
5390 | } | |
5391 | ||
5392 | void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, | |
5393 | int nr_sectors) | |
5394 | { | |
5395 | BdrvDirtyBitmap *bitmap; | |
5396 | QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { | |
5397 | hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); | |
5398 | } | |
5399 | } | |
5400 | ||
5401 | void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors) | |
5402 | { | |
5403 | BdrvDirtyBitmap *bitmap; | |
5404 | QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { | |
5405 | hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); | |
5406 | } | |
5407 | } | |
5408 | ||
5409 | int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) | |
5410 | { | |
5411 | return hbitmap_count(bitmap->bitmap); | |
5412 | } | |
5413 | ||
5414 | /* Get a reference to bs */ | |
5415 | void bdrv_ref(BlockDriverState *bs) | |
5416 | { | |
5417 | bs->refcnt++; | |
5418 | } | |
5419 | ||
5420 | /* Release a previously grabbed reference to bs. | |
5421 | * If after releasing, reference count is zero, the BlockDriverState is | |
5422 | * deleted. */ | |
5423 | void bdrv_unref(BlockDriverState *bs) | |
5424 | { | |
5425 | if (!bs) { | |
5426 | return; | |
5427 | } | |
5428 | assert(bs->refcnt > 0); | |
5429 | if (--bs->refcnt == 0) { | |
5430 | bdrv_delete(bs); | |
5431 | } | |
5432 | } | |
5433 | ||
5434 | struct BdrvOpBlocker { | |
5435 | Error *reason; | |
5436 | QLIST_ENTRY(BdrvOpBlocker) list; | |
5437 | }; | |
5438 | ||
5439 | bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) | |
5440 | { | |
5441 | BdrvOpBlocker *blocker; | |
5442 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
5443 | if (!QLIST_EMPTY(&bs->op_blockers[op])) { | |
5444 | blocker = QLIST_FIRST(&bs->op_blockers[op]); | |
5445 | if (errp) { | |
5446 | error_setg(errp, "Device '%s' is busy: %s", | |
5447 | bs->device_name, error_get_pretty(blocker->reason)); | |
5448 | } | |
5449 | return true; | |
5450 | } | |
5451 | return false; | |
5452 | } | |
5453 | ||
5454 | void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason) | |
5455 | { | |
5456 | BdrvOpBlocker *blocker; | |
5457 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
5458 | ||
5459 | blocker = g_new0(BdrvOpBlocker, 1); | |
5460 | blocker->reason = reason; | |
5461 | QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list); | |
5462 | } | |
5463 | ||
5464 | void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason) | |
5465 | { | |
5466 | BdrvOpBlocker *blocker, *next; | |
5467 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
5468 | QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) { | |
5469 | if (blocker->reason == reason) { | |
5470 | QLIST_REMOVE(blocker, list); | |
5471 | g_free(blocker); | |
5472 | } | |
5473 | } | |
5474 | } | |
5475 | ||
5476 | void bdrv_op_block_all(BlockDriverState *bs, Error *reason) | |
5477 | { | |
5478 | int i; | |
5479 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
5480 | bdrv_op_block(bs, i, reason); | |
5481 | } | |
5482 | } | |
5483 | ||
5484 | void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason) | |
5485 | { | |
5486 | int i; | |
5487 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
5488 | bdrv_op_unblock(bs, i, reason); | |
5489 | } | |
5490 | } | |
5491 | ||
5492 | bool bdrv_op_blocker_is_empty(BlockDriverState *bs) | |
5493 | { | |
5494 | int i; | |
5495 | ||
5496 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
5497 | if (!QLIST_EMPTY(&bs->op_blockers[i])) { | |
5498 | return false; | |
5499 | } | |
5500 | } | |
5501 | return true; | |
5502 | } | |
5503 | ||
5504 | void bdrv_iostatus_enable(BlockDriverState *bs) | |
5505 | { | |
5506 | bs->iostatus_enabled = true; | |
5507 | bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; | |
5508 | } | |
5509 | ||
5510 | /* The I/O status is only enabled if the drive explicitly | |
5511 | * enables it _and_ the VM is configured to stop on errors */ | |
5512 | bool bdrv_iostatus_is_enabled(const BlockDriverState *bs) | |
5513 | { | |
5514 | return (bs->iostatus_enabled && | |
5515 | (bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC || | |
5516 | bs->on_write_error == BLOCKDEV_ON_ERROR_STOP || | |
5517 | bs->on_read_error == BLOCKDEV_ON_ERROR_STOP)); | |
5518 | } | |
5519 | ||
5520 | void bdrv_iostatus_disable(BlockDriverState *bs) | |
5521 | { | |
5522 | bs->iostatus_enabled = false; | |
5523 | } | |
5524 | ||
5525 | void bdrv_iostatus_reset(BlockDriverState *bs) | |
5526 | { | |
5527 | if (bdrv_iostatus_is_enabled(bs)) { | |
5528 | bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; | |
5529 | if (bs->job) { | |
5530 | block_job_iostatus_reset(bs->job); | |
5531 | } | |
5532 | } | |
5533 | } | |
5534 | ||
5535 | void bdrv_iostatus_set_err(BlockDriverState *bs, int error) | |
5536 | { | |
5537 | assert(bdrv_iostatus_is_enabled(bs)); | |
5538 | if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { | |
5539 | bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : | |
5540 | BLOCK_DEVICE_IO_STATUS_FAILED; | |
5541 | } | |
5542 | } | |
5543 | ||
5544 | void | |
5545 | bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes, | |
5546 | enum BlockAcctType type) | |
5547 | { | |
5548 | assert(type < BDRV_MAX_IOTYPE); | |
5549 | ||
5550 | cookie->bytes = bytes; | |
5551 | cookie->start_time_ns = get_clock(); | |
5552 | cookie->type = type; | |
5553 | } | |
5554 | ||
5555 | void | |
5556 | bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie) | |
5557 | { | |
5558 | assert(cookie->type < BDRV_MAX_IOTYPE); | |
5559 | ||
5560 | bs->nr_bytes[cookie->type] += cookie->bytes; | |
5561 | bs->nr_ops[cookie->type]++; | |
5562 | bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns; | |
5563 | } | |
5564 | ||
5565 | void bdrv_img_create(const char *filename, const char *fmt, | |
5566 | const char *base_filename, const char *base_fmt, | |
5567 | char *options, uint64_t img_size, int flags, | |
5568 | Error **errp, bool quiet) | |
5569 | { | |
5570 | QemuOptsList *create_opts = NULL; | |
5571 | QemuOpts *opts = NULL; | |
5572 | const char *backing_fmt, *backing_file; | |
5573 | int64_t size; | |
5574 | BlockDriver *drv, *proto_drv; | |
5575 | BlockDriver *backing_drv = NULL; | |
5576 | Error *local_err = NULL; | |
5577 | int ret = 0; | |
5578 | ||
5579 | /* Find driver and parse its options */ | |
5580 | drv = bdrv_find_format(fmt); | |
5581 | if (!drv) { | |
5582 | error_setg(errp, "Unknown file format '%s'", fmt); | |
5583 | return; | |
5584 | } | |
5585 | ||
5586 | proto_drv = bdrv_find_protocol(filename, true); | |
5587 | if (!proto_drv) { | |
5588 | error_setg(errp, "Unknown protocol '%s'", filename); | |
5589 | return; | |
5590 | } | |
5591 | ||
5592 | create_opts = qemu_opts_append(create_opts, drv->create_opts); | |
5593 | create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); | |
5594 | ||
5595 | /* Create parameter list with default values */ | |
5596 | opts = qemu_opts_create(create_opts, NULL, 0, &error_abort); | |
5597 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size); | |
5598 | ||
5599 | /* Parse -o options */ | |
5600 | if (options) { | |
5601 | if (qemu_opts_do_parse(opts, options, NULL) != 0) { | |
5602 | error_setg(errp, "Invalid options for file format '%s'", fmt); | |
5603 | goto out; | |
5604 | } | |
5605 | } | |
5606 | ||
5607 | if (base_filename) { | |
5608 | if (qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename)) { | |
5609 | error_setg(errp, "Backing file not supported for file format '%s'", | |
5610 | fmt); | |
5611 | goto out; | |
5612 | } | |
5613 | } | |
5614 | ||
5615 | if (base_fmt) { | |
5616 | if (qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt)) { | |
5617 | error_setg(errp, "Backing file format not supported for file " | |
5618 | "format '%s'", fmt); | |
5619 | goto out; | |
5620 | } | |
5621 | } | |
5622 | ||
5623 | backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); | |
5624 | if (backing_file) { | |
5625 | if (!strcmp(filename, backing_file)) { | |
5626 | error_setg(errp, "Error: Trying to create an image with the " | |
5627 | "same filename as the backing file"); | |
5628 | goto out; | |
5629 | } | |
5630 | } | |
5631 | ||
5632 | backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); | |
5633 | if (backing_fmt) { | |
5634 | backing_drv = bdrv_find_format(backing_fmt); | |
5635 | if (!backing_drv) { | |
5636 | error_setg(errp, "Unknown backing file format '%s'", | |
5637 | backing_fmt); | |
5638 | goto out; | |
5639 | } | |
5640 | } | |
5641 | ||
5642 | // The size for the image must always be specified, with one exception: | |
5643 | // If we are using a backing file, we can obtain the size from there | |
5644 | size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); | |
5645 | if (size == -1) { | |
5646 | if (backing_file) { | |
5647 | BlockDriverState *bs; | |
5648 | int64_t size; | |
5649 | int back_flags; | |
5650 | ||
5651 | /* backing files always opened read-only */ | |
5652 | back_flags = | |
5653 | flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); | |
5654 | ||
5655 | bs = NULL; | |
5656 | ret = bdrv_open(&bs, backing_file, NULL, NULL, back_flags, | |
5657 | backing_drv, &local_err); | |
5658 | if (ret < 0) { | |
5659 | error_setg_errno(errp, -ret, "Could not open '%s': %s", | |
5660 | backing_file, | |
5661 | error_get_pretty(local_err)); | |
5662 | error_free(local_err); | |
5663 | local_err = NULL; | |
5664 | goto out; | |
5665 | } | |
5666 | size = bdrv_getlength(bs); | |
5667 | if (size < 0) { | |
5668 | error_setg_errno(errp, -size, "Could not get size of '%s'", | |
5669 | backing_file); | |
5670 | bdrv_unref(bs); | |
5671 | goto out; | |
5672 | } | |
5673 | ||
5674 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size); | |
5675 | ||
5676 | bdrv_unref(bs); | |
5677 | } else { | |
5678 | error_setg(errp, "Image creation needs a size parameter"); | |
5679 | goto out; | |
5680 | } | |
5681 | } | |
5682 | ||
5683 | if (!quiet) { | |
5684 | printf("Formatting '%s', fmt=%s ", filename, fmt); | |
5685 | qemu_opts_print(opts); | |
5686 | puts(""); | |
5687 | } | |
5688 | ||
5689 | ret = bdrv_create(drv, filename, opts, &local_err); | |
5690 | ||
5691 | if (ret == -EFBIG) { | |
5692 | /* This is generally a better message than whatever the driver would | |
5693 | * deliver (especially because of the cluster_size_hint), since that | |
5694 | * is most probably not much different from "image too large". */ | |
5695 | const char *cluster_size_hint = ""; | |
5696 | if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) { | |
5697 | cluster_size_hint = " (try using a larger cluster size)"; | |
5698 | } | |
5699 | error_setg(errp, "The image size is too large for file format '%s'" | |
5700 | "%s", fmt, cluster_size_hint); | |
5701 | error_free(local_err); | |
5702 | local_err = NULL; | |
5703 | } | |
5704 | ||
5705 | out: | |
5706 | qemu_opts_del(opts); | |
5707 | qemu_opts_free(create_opts); | |
5708 | if (local_err) { | |
5709 | error_propagate(errp, local_err); | |
5710 | } | |
5711 | } | |
5712 | ||
5713 | AioContext *bdrv_get_aio_context(BlockDriverState *bs) | |
5714 | { | |
5715 | return bs->aio_context; | |
5716 | } | |
5717 | ||
5718 | void bdrv_detach_aio_context(BlockDriverState *bs) | |
5719 | { | |
5720 | if (!bs->drv) { | |
5721 | return; | |
5722 | } | |
5723 | ||
5724 | if (bs->io_limits_enabled) { | |
5725 | throttle_detach_aio_context(&bs->throttle_state); | |
5726 | } | |
5727 | if (bs->drv->bdrv_detach_aio_context) { | |
5728 | bs->drv->bdrv_detach_aio_context(bs); | |
5729 | } | |
5730 | if (bs->file) { | |
5731 | bdrv_detach_aio_context(bs->file); | |
5732 | } | |
5733 | if (bs->backing_hd) { | |
5734 | bdrv_detach_aio_context(bs->backing_hd); | |
5735 | } | |
5736 | ||
5737 | bs->aio_context = NULL; | |
5738 | } | |
5739 | ||
5740 | void bdrv_attach_aio_context(BlockDriverState *bs, | |
5741 | AioContext *new_context) | |
5742 | { | |
5743 | if (!bs->drv) { | |
5744 | return; | |
5745 | } | |
5746 | ||
5747 | bs->aio_context = new_context; | |
5748 | ||
5749 | if (bs->backing_hd) { | |
5750 | bdrv_attach_aio_context(bs->backing_hd, new_context); | |
5751 | } | |
5752 | if (bs->file) { | |
5753 | bdrv_attach_aio_context(bs->file, new_context); | |
5754 | } | |
5755 | if (bs->drv->bdrv_attach_aio_context) { | |
5756 | bs->drv->bdrv_attach_aio_context(bs, new_context); | |
5757 | } | |
5758 | if (bs->io_limits_enabled) { | |
5759 | throttle_attach_aio_context(&bs->throttle_state, new_context); | |
5760 | } | |
5761 | } | |
5762 | ||
5763 | void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) | |
5764 | { | |
5765 | bdrv_drain_all(); /* ensure there are no in-flight requests */ | |
5766 | ||
5767 | bdrv_detach_aio_context(bs); | |
5768 | ||
5769 | /* This function executes in the old AioContext so acquire the new one in | |
5770 | * case it runs in a different thread. | |
5771 | */ | |
5772 | aio_context_acquire(new_context); | |
5773 | bdrv_attach_aio_context(bs, new_context); | |
5774 | aio_context_release(new_context); | |
5775 | } | |
5776 | ||
5777 | void bdrv_add_before_write_notifier(BlockDriverState *bs, | |
5778 | NotifierWithReturn *notifier) | |
5779 | { | |
5780 | notifier_with_return_list_add(&bs->before_write_notifiers, notifier); | |
5781 | } | |
5782 | ||
5783 | int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts) | |
5784 | { | |
5785 | if (!bs->drv->bdrv_amend_options) { | |
5786 | return -ENOTSUP; | |
5787 | } | |
5788 | return bs->drv->bdrv_amend_options(bs, opts); | |
5789 | } | |
5790 | ||
5791 | /* This function will be called by the bdrv_recurse_is_first_non_filter method | |
5792 | * of block filter and by bdrv_is_first_non_filter. | |
5793 | * It is used to test if the given bs is the candidate or recurse more in the | |
5794 | * node graph. | |
5795 | */ | |
5796 | bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, | |
5797 | BlockDriverState *candidate) | |
5798 | { | |
5799 | /* return false if basic checks fails */ | |
5800 | if (!bs || !bs->drv) { | |
5801 | return false; | |
5802 | } | |
5803 | ||
5804 | /* the code reached a non block filter driver -> check if the bs is | |
5805 | * the same as the candidate. It's the recursion termination condition. | |
5806 | */ | |
5807 | if (!bs->drv->is_filter) { | |
5808 | return bs == candidate; | |
5809 | } | |
5810 | /* Down this path the driver is a block filter driver */ | |
5811 | ||
5812 | /* If the block filter recursion method is defined use it to recurse down | |
5813 | * the node graph. | |
5814 | */ | |
5815 | if (bs->drv->bdrv_recurse_is_first_non_filter) { | |
5816 | return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate); | |
5817 | } | |
5818 | ||
5819 | /* the driver is a block filter but don't allow to recurse -> return false | |
5820 | */ | |
5821 | return false; | |
5822 | } | |
5823 | ||
5824 | /* This function checks if the candidate is the first non filter bs down it's | |
5825 | * bs chain. Since we don't have pointers to parents it explore all bs chains | |
5826 | * from the top. Some filters can choose not to pass down the recursion. | |
5827 | */ | |
5828 | bool bdrv_is_first_non_filter(BlockDriverState *candidate) | |
5829 | { | |
5830 | BlockDriverState *bs; | |
5831 | ||
5832 | /* walk down the bs forest recursively */ | |
5833 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
5834 | bool perm; | |
5835 | ||
5836 | /* try to recurse in this top level bs */ | |
5837 | perm = bdrv_recurse_is_first_non_filter(bs, candidate); | |
5838 | ||
5839 | /* candidate is the first non filter */ | |
5840 | if (perm) { | |
5841 | return true; | |
5842 | } | |
5843 | } | |
5844 | ||
5845 | return false; | |
5846 | } | |
5847 | ||
5848 | BlockDriverState *check_to_replace_node(const char *node_name, Error **errp) | |
5849 | { | |
5850 | BlockDriverState *to_replace_bs = bdrv_find_node(node_name); | |
5851 | if (!to_replace_bs) { | |
5852 | error_setg(errp, "Node name '%s' not found", node_name); | |
5853 | return NULL; | |
5854 | } | |
5855 | ||
5856 | if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) { | |
5857 | return NULL; | |
5858 | } | |
5859 | ||
5860 | /* We don't want arbitrary node of the BDS chain to be replaced only the top | |
5861 | * most non filter in order to prevent data corruption. | |
5862 | * Another benefit is that this tests exclude backing files which are | |
5863 | * blocked by the backing blockers. | |
5864 | */ | |
5865 | if (!bdrv_is_first_non_filter(to_replace_bs)) { | |
5866 | error_setg(errp, "Only top most non filter can be replaced"); | |
5867 | return NULL; | |
5868 | } | |
5869 | ||
5870 | return to_replace_bs; | |
5871 | } | |
5872 | ||
5873 | void bdrv_io_plug(BlockDriverState *bs) | |
5874 | { | |
5875 | BlockDriver *drv = bs->drv; | |
5876 | if (drv && drv->bdrv_io_plug) { | |
5877 | drv->bdrv_io_plug(bs); | |
5878 | } else if (bs->file) { | |
5879 | bdrv_io_plug(bs->file); | |
5880 | } | |
5881 | } | |
5882 | ||
5883 | void bdrv_io_unplug(BlockDriverState *bs) | |
5884 | { | |
5885 | BlockDriver *drv = bs->drv; | |
5886 | if (drv && drv->bdrv_io_unplug) { | |
5887 | drv->bdrv_io_unplug(bs); | |
5888 | } else if (bs->file) { | |
5889 | bdrv_io_unplug(bs->file); | |
5890 | } | |
5891 | } | |
5892 | ||
5893 | void bdrv_flush_io_queue(BlockDriverState *bs) | |
5894 | { | |
5895 | BlockDriver *drv = bs->drv; | |
5896 | if (drv && drv->bdrv_flush_io_queue) { | |
5897 | drv->bdrv_flush_io_queue(bs); | |
5898 | } else if (bs->file) { | |
5899 | bdrv_flush_io_queue(bs->file); | |
5900 | } | |
5901 | } | |
5902 | ||
5903 | static bool append_open_options(QDict *d, BlockDriverState *bs) | |
5904 | { | |
5905 | const QDictEntry *entry; | |
5906 | bool found_any = false; | |
5907 | ||
5908 | for (entry = qdict_first(bs->options); entry; | |
5909 | entry = qdict_next(bs->options, entry)) | |
5910 | { | |
5911 | /* Only take options for this level and exclude all non-driver-specific | |
5912 | * options */ | |
5913 | if (!strchr(qdict_entry_key(entry), '.') && | |
5914 | strcmp(qdict_entry_key(entry), "node-name")) | |
5915 | { | |
5916 | qobject_incref(qdict_entry_value(entry)); | |
5917 | qdict_put_obj(d, qdict_entry_key(entry), qdict_entry_value(entry)); | |
5918 | found_any = true; | |
5919 | } | |
5920 | } | |
5921 | ||
5922 | return found_any; | |
5923 | } | |
5924 | ||
5925 | /* Updates the following BDS fields: | |
5926 | * - exact_filename: A filename which may be used for opening a block device | |
5927 | * which (mostly) equals the given BDS (even without any | |
5928 | * other options; so reading and writing must return the same | |
5929 | * results, but caching etc. may be different) | |
5930 | * - full_open_options: Options which, when given when opening a block device | |
5931 | * (without a filename), result in a BDS (mostly) | |
5932 | * equalling the given one | |
5933 | * - filename: If exact_filename is set, it is copied here. Otherwise, | |
5934 | * full_open_options is converted to a JSON object, prefixed with | |
5935 | * "json:" (for use through the JSON pseudo protocol) and put here. | |
5936 | */ | |
5937 | void bdrv_refresh_filename(BlockDriverState *bs) | |
5938 | { | |
5939 | BlockDriver *drv = bs->drv; | |
5940 | QDict *opts; | |
5941 | ||
5942 | if (!drv) { | |
5943 | return; | |
5944 | } | |
5945 | ||
5946 | /* This BDS's file name will most probably depend on its file's name, so | |
5947 | * refresh that first */ | |
5948 | if (bs->file) { | |
5949 | bdrv_refresh_filename(bs->file); | |
5950 | } | |
5951 | ||
5952 | if (drv->bdrv_refresh_filename) { | |
5953 | /* Obsolete information is of no use here, so drop the old file name | |
5954 | * information before refreshing it */ | |
5955 | bs->exact_filename[0] = '\0'; | |
5956 | if (bs->full_open_options) { | |
5957 | QDECREF(bs->full_open_options); | |
5958 | bs->full_open_options = NULL; | |
5959 | } | |
5960 | ||
5961 | drv->bdrv_refresh_filename(bs); | |
5962 | } else if (bs->file) { | |
5963 | /* Try to reconstruct valid information from the underlying file */ | |
5964 | bool has_open_options; | |
5965 | ||
5966 | bs->exact_filename[0] = '\0'; | |
5967 | if (bs->full_open_options) { | |
5968 | QDECREF(bs->full_open_options); | |
5969 | bs->full_open_options = NULL; | |
5970 | } | |
5971 | ||
5972 | opts = qdict_new(); | |
5973 | has_open_options = append_open_options(opts, bs); | |
5974 | ||
5975 | /* If no specific options have been given for this BDS, the filename of | |
5976 | * the underlying file should suffice for this one as well */ | |
5977 | if (bs->file->exact_filename[0] && !has_open_options) { | |
5978 | strcpy(bs->exact_filename, bs->file->exact_filename); | |
5979 | } | |
5980 | /* Reconstructing the full options QDict is simple for most format block | |
5981 | * drivers, as long as the full options are known for the underlying | |
5982 | * file BDS. The full options QDict of that file BDS should somehow | |
5983 | * contain a representation of the filename, therefore the following | |
5984 | * suffices without querying the (exact_)filename of this BDS. */ | |
5985 | if (bs->file->full_open_options) { | |
5986 | qdict_put_obj(opts, "driver", | |
5987 | QOBJECT(qstring_from_str(drv->format_name))); | |
5988 | QINCREF(bs->file->full_open_options); | |
5989 | qdict_put_obj(opts, "file", QOBJECT(bs->file->full_open_options)); | |
5990 | ||
5991 | bs->full_open_options = opts; | |
5992 | } else { | |
5993 | QDECREF(opts); | |
5994 | } | |
5995 | } else if (!bs->full_open_options && qdict_size(bs->options)) { | |
5996 | /* There is no underlying file BDS (at least referenced by BDS.file), | |
5997 | * so the full options QDict should be equal to the options given | |
5998 | * specifically for this block device when it was opened (plus the | |
5999 | * driver specification). | |
6000 | * Because those options don't change, there is no need to update | |
6001 | * full_open_options when it's already set. */ | |
6002 | ||
6003 | opts = qdict_new(); | |
6004 | append_open_options(opts, bs); | |
6005 | qdict_put_obj(opts, "driver", | |
6006 | QOBJECT(qstring_from_str(drv->format_name))); | |
6007 | ||
6008 | if (bs->exact_filename[0]) { | |
6009 | /* This may not work for all block protocol drivers (some may | |
6010 | * require this filename to be parsed), but we have to find some | |
6011 | * default solution here, so just include it. If some block driver | |
6012 | * does not support pure options without any filename at all or | |
6013 | * needs some special format of the options QDict, it needs to | |
6014 | * implement the driver-specific bdrv_refresh_filename() function. | |
6015 | */ | |
6016 | qdict_put_obj(opts, "filename", | |
6017 | QOBJECT(qstring_from_str(bs->exact_filename))); | |
6018 | } | |
6019 | ||
6020 | bs->full_open_options = opts; | |
6021 | } | |
6022 | ||
6023 | if (bs->exact_filename[0]) { | |
6024 | pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); | |
6025 | } else if (bs->full_open_options) { | |
6026 | QString *json = qobject_to_json(QOBJECT(bs->full_open_options)); | |
6027 | snprintf(bs->filename, sizeof(bs->filename), "json:%s", | |
6028 | qstring_get_str(json)); | |
6029 | QDECREF(json); | |
6030 | } | |
6031 | } |