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 | |
25 | #include "qemu/osdep.h" |
26 | #include "block/trace.h" |
27 | #include "block/block_int.h" |
28 | #include "block/blockjob.h" |
29 | #include "block/nbd.h" |
30 | #include "block/qdict.h" |
31 | #include "qemu/error-report.h" |
32 | #include "module_block.h" |
33 | #include "qemu/main-loop.h" |
34 | #include "qemu/module.h" |
35 | #include "qapi/error.h" |
36 | #include "qapi/qmp/qdict.h" |
37 | #include "qapi/qmp/qjson.h" |
38 | #include "qapi/qmp/qnull.h" |
39 | #include "qapi/qmp/qstring.h" |
40 | #include "qapi/qobject-output-visitor.h" |
41 | #include "qapi/qapi-visit-block-core.h" |
42 | #include "sysemu/block-backend.h" |
43 | #include "sysemu/sysemu.h" |
44 | #include "qemu/notify.h" |
45 | #include "qemu/option.h" |
46 | #include "qemu/coroutine.h" |
47 | #include "block/qapi.h" |
48 | #include "qemu/timer.h" |
49 | #include "qemu/cutils.h" |
50 | #include "qemu/id.h" |
51 | |
52 | #ifdef CONFIG_BSD |
53 | #include <sys/ioctl.h> |
54 | #include <sys/queue.h> |
55 | #ifndef __DragonFly__ |
56 | #include <sys/disk.h> |
57 | #endif |
58 | #endif |
59 | |
60 | #ifdef _WIN32 |
61 | #include <windows.h> |
62 | #endif |
63 | |
64 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ |
65 | |
66 | static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states = |
67 | QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); |
68 | |
69 | static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states = |
70 | QTAILQ_HEAD_INITIALIZER(all_bdrv_states); |
71 | |
72 | static QLIST_HEAD(, BlockDriver) bdrv_drivers = |
73 | QLIST_HEAD_INITIALIZER(bdrv_drivers); |
74 | |
75 | static BlockDriverState *bdrv_open_inherit(const char *filename, |
76 | const char *reference, |
77 | QDict *options, int flags, |
78 | BlockDriverState *parent, |
79 | const BdrvChildRole *child_role, |
80 | Error **errp); |
81 | |
82 | /* If non-zero, use only whitelisted block drivers */ |
83 | static int use_bdrv_whitelist; |
84 | |
85 | #ifdef _WIN32 |
86 | static int is_windows_drive_prefix(const char *filename) |
87 | { |
88 | return (((filename[0] >= 'a' && filename[0] <= 'z') || |
89 | (filename[0] >= 'A' && filename[0] <= 'Z')) && |
90 | filename[1] == ':'); |
91 | } |
92 | |
93 | int is_windows_drive(const char *filename) |
94 | { |
95 | if (is_windows_drive_prefix(filename) && |
96 | filename[2] == '\0') |
97 | return 1; |
98 | if (strstart(filename, "\\\\.\\" , NULL) || |
99 | strstart(filename, "//./" , NULL)) |
100 | return 1; |
101 | return 0; |
102 | } |
103 | #endif |
104 | |
105 | size_t bdrv_opt_mem_align(BlockDriverState *bs) |
106 | { |
107 | if (!bs || !bs->drv) { |
108 | /* page size or 4k (hdd sector size) should be on the safe side */ |
109 | return MAX(4096, getpagesize()); |
110 | } |
111 | |
112 | return bs->bl.opt_mem_alignment; |
113 | } |
114 | |
115 | size_t bdrv_min_mem_align(BlockDriverState *bs) |
116 | { |
117 | if (!bs || !bs->drv) { |
118 | /* page size or 4k (hdd sector size) should be on the safe side */ |
119 | return MAX(4096, getpagesize()); |
120 | } |
121 | |
122 | return bs->bl.min_mem_alignment; |
123 | } |
124 | |
125 | /* check if the path starts with "<protocol>:" */ |
126 | int path_has_protocol(const char *path) |
127 | { |
128 | const char *p; |
129 | |
130 | #ifdef _WIN32 |
131 | if (is_windows_drive(path) || |
132 | is_windows_drive_prefix(path)) { |
133 | return 0; |
134 | } |
135 | p = path + strcspn(path, ":/\\" ); |
136 | #else |
137 | p = path + strcspn(path, ":/" ); |
138 | #endif |
139 | |
140 | return *p == ':'; |
141 | } |
142 | |
143 | int path_is_absolute(const char *path) |
144 | { |
145 | #ifdef _WIN32 |
146 | /* specific case for names like: "\\.\d:" */ |
147 | if (is_windows_drive(path) || is_windows_drive_prefix(path)) { |
148 | return 1; |
149 | } |
150 | return (*path == '/' || *path == '\\'); |
151 | #else |
152 | return (*path == '/'); |
153 | #endif |
154 | } |
155 | |
156 | /* if filename is absolute, just return its duplicate. Otherwise, build a |
157 | path to it by considering it is relative to base_path. URL are |
158 | supported. */ |
159 | char *path_combine(const char *base_path, const char *filename) |
160 | { |
161 | const char *protocol_stripped = NULL; |
162 | const char *p, *p1; |
163 | char *result; |
164 | int len; |
165 | |
166 | if (path_is_absolute(filename)) { |
167 | return g_strdup(filename); |
168 | } |
169 | |
170 | if (path_has_protocol(base_path)) { |
171 | protocol_stripped = strchr(base_path, ':'); |
172 | if (protocol_stripped) { |
173 | protocol_stripped++; |
174 | } |
175 | } |
176 | p = protocol_stripped ?: base_path; |
177 | |
178 | p1 = strrchr(base_path, '/'); |
179 | #ifdef _WIN32 |
180 | { |
181 | const char *p2; |
182 | p2 = strrchr(base_path, '\\'); |
183 | if (!p1 || p2 > p1) { |
184 | p1 = p2; |
185 | } |
186 | } |
187 | #endif |
188 | if (p1) { |
189 | p1++; |
190 | } else { |
191 | p1 = base_path; |
192 | } |
193 | if (p1 > p) { |
194 | p = p1; |
195 | } |
196 | len = p - base_path; |
197 | |
198 | result = g_malloc(len + strlen(filename) + 1); |
199 | memcpy(result, base_path, len); |
200 | strcpy(result + len, filename); |
201 | |
202 | return result; |
203 | } |
204 | |
205 | /* |
206 | * Helper function for bdrv_parse_filename() implementations to remove optional |
207 | * protocol prefixes (especially "file:") from a filename and for putting the |
208 | * stripped filename into the options QDict if there is such a prefix. |
209 | */ |
210 | void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix, |
211 | QDict *options) |
212 | { |
213 | if (strstart(filename, prefix, &filename)) { |
214 | /* Stripping the explicit protocol prefix may result in a protocol |
215 | * prefix being (wrongly) detected (if the filename contains a colon) */ |
216 | if (path_has_protocol(filename)) { |
217 | QString *fat_filename; |
218 | |
219 | /* This means there is some colon before the first slash; therefore, |
220 | * this cannot be an absolute path */ |
221 | assert(!path_is_absolute(filename)); |
222 | |
223 | /* And we can thus fix the protocol detection issue by prefixing it |
224 | * by "./" */ |
225 | fat_filename = qstring_from_str("./" ); |
226 | qstring_append(fat_filename, filename); |
227 | |
228 | assert(!path_has_protocol(qstring_get_str(fat_filename))); |
229 | |
230 | qdict_put(options, "filename" , fat_filename); |
231 | } else { |
232 | /* If no protocol prefix was detected, we can use the shortened |
233 | * filename as-is */ |
234 | qdict_put_str(options, "filename" , filename); |
235 | } |
236 | } |
237 | } |
238 | |
239 | |
240 | /* Returns whether the image file is opened as read-only. Note that this can |
241 | * return false and writing to the image file is still not possible because the |
242 | * image is inactivated. */ |
243 | bool bdrv_is_read_only(BlockDriverState *bs) |
244 | { |
245 | return bs->read_only; |
246 | } |
247 | |
248 | int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, |
249 | bool ignore_allow_rdw, Error **errp) |
250 | { |
251 | /* Do not set read_only if copy_on_read is enabled */ |
252 | if (bs->copy_on_read && read_only) { |
253 | error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled" , |
254 | bdrv_get_device_or_node_name(bs)); |
255 | return -EINVAL; |
256 | } |
257 | |
258 | /* Do not clear read_only if it is prohibited */ |
259 | if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) && |
260 | !ignore_allow_rdw) |
261 | { |
262 | error_setg(errp, "Node '%s' is read only" , |
263 | bdrv_get_device_or_node_name(bs)); |
264 | return -EPERM; |
265 | } |
266 | |
267 | return 0; |
268 | } |
269 | |
270 | /* |
271 | * Called by a driver that can only provide a read-only image. |
272 | * |
273 | * Returns 0 if the node is already read-only or it could switch the node to |
274 | * read-only because BDRV_O_AUTO_RDONLY is set. |
275 | * |
276 | * Returns -EACCES if the node is read-write and BDRV_O_AUTO_RDONLY is not set |
277 | * or bdrv_can_set_read_only() forbids making the node read-only. If @errmsg |
278 | * is not NULL, it is used as the error message for the Error object. |
279 | */ |
280 | int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg, |
281 | Error **errp) |
282 | { |
283 | int ret = 0; |
284 | |
285 | if (!(bs->open_flags & BDRV_O_RDWR)) { |
286 | return 0; |
287 | } |
288 | if (!(bs->open_flags & BDRV_O_AUTO_RDONLY)) { |
289 | goto fail; |
290 | } |
291 | |
292 | ret = bdrv_can_set_read_only(bs, true, false, NULL); |
293 | if (ret < 0) { |
294 | goto fail; |
295 | } |
296 | |
297 | bs->read_only = true; |
298 | bs->open_flags &= ~BDRV_O_RDWR; |
299 | |
300 | return 0; |
301 | |
302 | fail: |
303 | error_setg(errp, "%s" , errmsg ?: "Image is read-only" ); |
304 | return -EACCES; |
305 | } |
306 | |
307 | /* |
308 | * If @backing is empty, this function returns NULL without setting |
309 | * @errp. In all other cases, NULL will only be returned with @errp |
310 | * set. |
311 | * |
312 | * Therefore, a return value of NULL without @errp set means that |
313 | * there is no backing file; if @errp is set, there is one but its |
314 | * absolute filename cannot be generated. |
315 | */ |
316 | char *bdrv_get_full_backing_filename_from_filename(const char *backed, |
317 | const char *backing, |
318 | Error **errp) |
319 | { |
320 | if (backing[0] == '\0') { |
321 | return NULL; |
322 | } else if (path_has_protocol(backing) || path_is_absolute(backing)) { |
323 | return g_strdup(backing); |
324 | } else if (backed[0] == '\0' || strstart(backed, "json:" , NULL)) { |
325 | error_setg(errp, "Cannot use relative backing file names for '%s'" , |
326 | backed); |
327 | return NULL; |
328 | } else { |
329 | return path_combine(backed, backing); |
330 | } |
331 | } |
332 | |
333 | /* |
334 | * If @filename is empty or NULL, this function returns NULL without |
335 | * setting @errp. In all other cases, NULL will only be returned with |
336 | * @errp set. |
337 | */ |
338 | static char *bdrv_make_absolute_filename(BlockDriverState *relative_to, |
339 | const char *filename, Error **errp) |
340 | { |
341 | char *dir, *full_name; |
342 | |
343 | if (!filename || filename[0] == '\0') { |
344 | return NULL; |
345 | } else if (path_has_protocol(filename) || path_is_absolute(filename)) { |
346 | return g_strdup(filename); |
347 | } |
348 | |
349 | dir = bdrv_dirname(relative_to, errp); |
350 | if (!dir) { |
351 | return NULL; |
352 | } |
353 | |
354 | full_name = g_strconcat(dir, filename, NULL); |
355 | g_free(dir); |
356 | return full_name; |
357 | } |
358 | |
359 | char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp) |
360 | { |
361 | return bdrv_make_absolute_filename(bs, bs->backing_file, errp); |
362 | } |
363 | |
364 | void bdrv_register(BlockDriver *bdrv) |
365 | { |
366 | QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); |
367 | } |
368 | |
369 | BlockDriverState *bdrv_new(void) |
370 | { |
371 | BlockDriverState *bs; |
372 | int i; |
373 | |
374 | bs = g_new0(BlockDriverState, 1); |
375 | QLIST_INIT(&bs->dirty_bitmaps); |
376 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
377 | QLIST_INIT(&bs->op_blockers[i]); |
378 | } |
379 | notifier_with_return_list_init(&bs->before_write_notifiers); |
380 | qemu_co_mutex_init(&bs->reqs_lock); |
381 | qemu_mutex_init(&bs->dirty_bitmap_mutex); |
382 | bs->refcnt = 1; |
383 | bs->aio_context = qemu_get_aio_context(); |
384 | |
385 | qemu_co_queue_init(&bs->flush_queue); |
386 | |
387 | for (i = 0; i < bdrv_drain_all_count; i++) { |
388 | bdrv_drained_begin(bs); |
389 | } |
390 | |
391 | QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list); |
392 | |
393 | return bs; |
394 | } |
395 | |
396 | static BlockDriver *bdrv_do_find_format(const char *format_name) |
397 | { |
398 | BlockDriver *drv1; |
399 | |
400 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
401 | if (!strcmp(drv1->format_name, format_name)) { |
402 | return drv1; |
403 | } |
404 | } |
405 | |
406 | return NULL; |
407 | } |
408 | |
409 | BlockDriver *bdrv_find_format(const char *format_name) |
410 | { |
411 | BlockDriver *drv1; |
412 | int i; |
413 | |
414 | drv1 = bdrv_do_find_format(format_name); |
415 | if (drv1) { |
416 | return drv1; |
417 | } |
418 | |
419 | /* The driver isn't registered, maybe we need to load a module */ |
420 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { |
421 | if (!strcmp(block_driver_modules[i].format_name, format_name)) { |
422 | block_module_load_one(block_driver_modules[i].library_name); |
423 | break; |
424 | } |
425 | } |
426 | |
427 | return bdrv_do_find_format(format_name); |
428 | } |
429 | |
430 | static int bdrv_format_is_whitelisted(const char *format_name, bool read_only) |
431 | { |
432 | static const char *whitelist_rw[] = { |
433 | CONFIG_BDRV_RW_WHITELIST |
434 | }; |
435 | static const char *whitelist_ro[] = { |
436 | CONFIG_BDRV_RO_WHITELIST |
437 | }; |
438 | const char **p; |
439 | |
440 | if (!whitelist_rw[0] && !whitelist_ro[0]) { |
441 | return 1; /* no whitelist, anything goes */ |
442 | } |
443 | |
444 | for (p = whitelist_rw; *p; p++) { |
445 | if (!strcmp(format_name, *p)) { |
446 | return 1; |
447 | } |
448 | } |
449 | if (read_only) { |
450 | for (p = whitelist_ro; *p; p++) { |
451 | if (!strcmp(format_name, *p)) { |
452 | return 1; |
453 | } |
454 | } |
455 | } |
456 | return 0; |
457 | } |
458 | |
459 | int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) |
460 | { |
461 | return bdrv_format_is_whitelisted(drv->format_name, read_only); |
462 | } |
463 | |
464 | bool bdrv_uses_whitelist(void) |
465 | { |
466 | return use_bdrv_whitelist; |
467 | } |
468 | |
469 | typedef struct CreateCo { |
470 | BlockDriver *drv; |
471 | char *filename; |
472 | QemuOpts *opts; |
473 | int ret; |
474 | Error *err; |
475 | } CreateCo; |
476 | |
477 | static void coroutine_fn bdrv_create_co_entry(void *opaque) |
478 | { |
479 | Error *local_err = NULL; |
480 | int ret; |
481 | |
482 | CreateCo *cco = opaque; |
483 | assert(cco->drv); |
484 | |
485 | ret = cco->drv->bdrv_co_create_opts(cco->filename, cco->opts, &local_err); |
486 | error_propagate(&cco->err, local_err); |
487 | cco->ret = ret; |
488 | } |
489 | |
490 | int bdrv_create(BlockDriver *drv, const char* filename, |
491 | QemuOpts *opts, Error **errp) |
492 | { |
493 | int ret; |
494 | |
495 | Coroutine *co; |
496 | CreateCo cco = { |
497 | .drv = drv, |
498 | .filename = g_strdup(filename), |
499 | .opts = opts, |
500 | .ret = NOT_DONE, |
501 | .err = NULL, |
502 | }; |
503 | |
504 | if (!drv->bdrv_co_create_opts) { |
505 | error_setg(errp, "Driver '%s' does not support image creation" , drv->format_name); |
506 | ret = -ENOTSUP; |
507 | goto out; |
508 | } |
509 | |
510 | if (qemu_in_coroutine()) { |
511 | /* Fast-path if already in coroutine context */ |
512 | bdrv_create_co_entry(&cco); |
513 | } else { |
514 | co = qemu_coroutine_create(bdrv_create_co_entry, &cco); |
515 | qemu_coroutine_enter(co); |
516 | while (cco.ret == NOT_DONE) { |
517 | aio_poll(qemu_get_aio_context(), true); |
518 | } |
519 | } |
520 | |
521 | ret = cco.ret; |
522 | if (ret < 0) { |
523 | if (cco.err) { |
524 | error_propagate(errp, cco.err); |
525 | } else { |
526 | error_setg_errno(errp, -ret, "Could not create image" ); |
527 | } |
528 | } |
529 | |
530 | out: |
531 | g_free(cco.filename); |
532 | return ret; |
533 | } |
534 | |
535 | int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp) |
536 | { |
537 | BlockDriver *drv; |
538 | Error *local_err = NULL; |
539 | int ret; |
540 | |
541 | drv = bdrv_find_protocol(filename, true, errp); |
542 | if (drv == NULL) { |
543 | return -ENOENT; |
544 | } |
545 | |
546 | ret = bdrv_create(drv, filename, opts, &local_err); |
547 | error_propagate(errp, local_err); |
548 | return ret; |
549 | } |
550 | |
551 | /** |
552 | * Try to get @bs's logical and physical block size. |
553 | * On success, store them in @bsz struct and return 0. |
554 | * On failure return -errno. |
555 | * @bs must not be empty. |
556 | */ |
557 | int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) |
558 | { |
559 | BlockDriver *drv = bs->drv; |
560 | |
561 | if (drv && drv->bdrv_probe_blocksizes) { |
562 | return drv->bdrv_probe_blocksizes(bs, bsz); |
563 | } else if (drv && drv->is_filter && bs->file) { |
564 | return bdrv_probe_blocksizes(bs->file->bs, bsz); |
565 | } |
566 | |
567 | return -ENOTSUP; |
568 | } |
569 | |
570 | /** |
571 | * Try to get @bs's geometry (cyls, heads, sectors). |
572 | * On success, store them in @geo struct and return 0. |
573 | * On failure return -errno. |
574 | * @bs must not be empty. |
575 | */ |
576 | int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo) |
577 | { |
578 | BlockDriver *drv = bs->drv; |
579 | |
580 | if (drv && drv->bdrv_probe_geometry) { |
581 | return drv->bdrv_probe_geometry(bs, geo); |
582 | } else if (drv && drv->is_filter && bs->file) { |
583 | return bdrv_probe_geometry(bs->file->bs, geo); |
584 | } |
585 | |
586 | return -ENOTSUP; |
587 | } |
588 | |
589 | /* |
590 | * Create a uniquely-named empty temporary file. |
591 | * Return 0 upon success, otherwise a negative errno value. |
592 | */ |
593 | int get_tmp_filename(char *filename, int size) |
594 | { |
595 | #ifdef _WIN32 |
596 | char temp_dir[MAX_PATH]; |
597 | /* GetTempFileName requires that its output buffer (4th param) |
598 | have length MAX_PATH or greater. */ |
599 | assert(size >= MAX_PATH); |
600 | return (GetTempPath(MAX_PATH, temp_dir) |
601 | && GetTempFileName(temp_dir, "qem" , 0, filename) |
602 | ? 0 : -GetLastError()); |
603 | #else |
604 | int fd; |
605 | const char *tmpdir; |
606 | tmpdir = getenv("TMPDIR" ); |
607 | if (!tmpdir) { |
608 | tmpdir = "/var/tmp" ; |
609 | } |
610 | if (snprintf(filename, size, "%s/vl.XXXXXX" , tmpdir) >= size) { |
611 | return -EOVERFLOW; |
612 | } |
613 | fd = mkstemp(filename); |
614 | if (fd < 0) { |
615 | return -errno; |
616 | } |
617 | if (close(fd) != 0) { |
618 | unlink(filename); |
619 | return -errno; |
620 | } |
621 | return 0; |
622 | #endif |
623 | } |
624 | |
625 | /* |
626 | * Detect host devices. By convention, /dev/cdrom[N] is always |
627 | * recognized as a host CDROM. |
628 | */ |
629 | static BlockDriver *find_hdev_driver(const char *filename) |
630 | { |
631 | int score_max = 0, score; |
632 | BlockDriver *drv = NULL, *d; |
633 | |
634 | QLIST_FOREACH(d, &bdrv_drivers, list) { |
635 | if (d->bdrv_probe_device) { |
636 | score = d->bdrv_probe_device(filename); |
637 | if (score > score_max) { |
638 | score_max = score; |
639 | drv = d; |
640 | } |
641 | } |
642 | } |
643 | |
644 | return drv; |
645 | } |
646 | |
647 | static BlockDriver *bdrv_do_find_protocol(const char *protocol) |
648 | { |
649 | BlockDriver *drv1; |
650 | |
651 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
652 | if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) { |
653 | return drv1; |
654 | } |
655 | } |
656 | |
657 | return NULL; |
658 | } |
659 | |
660 | BlockDriver *bdrv_find_protocol(const char *filename, |
661 | bool allow_protocol_prefix, |
662 | Error **errp) |
663 | { |
664 | BlockDriver *drv1; |
665 | char protocol[128]; |
666 | int len; |
667 | const char *p; |
668 | int i; |
669 | |
670 | /* TODO Drivers without bdrv_file_open must be specified explicitly */ |
671 | |
672 | /* |
673 | * XXX(hch): we really should not let host device detection |
674 | * override an explicit protocol specification, but moving this |
675 | * later breaks access to device names with colons in them. |
676 | * Thanks to the brain-dead persistent naming schemes on udev- |
677 | * based Linux systems those actually are quite common. |
678 | */ |
679 | drv1 = find_hdev_driver(filename); |
680 | if (drv1) { |
681 | return drv1; |
682 | } |
683 | |
684 | if (!path_has_protocol(filename) || !allow_protocol_prefix) { |
685 | return &bdrv_file; |
686 | } |
687 | |
688 | p = strchr(filename, ':'); |
689 | assert(p != NULL); |
690 | len = p - filename; |
691 | if (len > sizeof(protocol) - 1) |
692 | len = sizeof(protocol) - 1; |
693 | memcpy(protocol, filename, len); |
694 | protocol[len] = '\0'; |
695 | |
696 | drv1 = bdrv_do_find_protocol(protocol); |
697 | if (drv1) { |
698 | return drv1; |
699 | } |
700 | |
701 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { |
702 | if (block_driver_modules[i].protocol_name && |
703 | !strcmp(block_driver_modules[i].protocol_name, protocol)) { |
704 | block_module_load_one(block_driver_modules[i].library_name); |
705 | break; |
706 | } |
707 | } |
708 | |
709 | drv1 = bdrv_do_find_protocol(protocol); |
710 | if (!drv1) { |
711 | error_setg(errp, "Unknown protocol '%s'" , protocol); |
712 | } |
713 | return drv1; |
714 | } |
715 | |
716 | /* |
717 | * Guess image format by probing its contents. |
718 | * This is not a good idea when your image is raw (CVE-2008-2004), but |
719 | * we do it anyway for backward compatibility. |
720 | * |
721 | * @buf contains the image's first @buf_size bytes. |
722 | * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE, |
723 | * but can be smaller if the image file is smaller) |
724 | * @filename is its filename. |
725 | * |
726 | * For all block drivers, call the bdrv_probe() method to get its |
727 | * probing score. |
728 | * Return the first block driver with the highest probing score. |
729 | */ |
730 | BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, |
731 | const char *filename) |
732 | { |
733 | int score_max = 0, score; |
734 | BlockDriver *drv = NULL, *d; |
735 | |
736 | QLIST_FOREACH(d, &bdrv_drivers, list) { |
737 | if (d->bdrv_probe) { |
738 | score = d->bdrv_probe(buf, buf_size, filename); |
739 | if (score > score_max) { |
740 | score_max = score; |
741 | drv = d; |
742 | } |
743 | } |
744 | } |
745 | |
746 | return drv; |
747 | } |
748 | |
749 | static int find_image_format(BlockBackend *file, const char *filename, |
750 | BlockDriver **pdrv, Error **errp) |
751 | { |
752 | BlockDriver *drv; |
753 | uint8_t buf[BLOCK_PROBE_BUF_SIZE]; |
754 | int ret = 0; |
755 | |
756 | /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ |
757 | if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) { |
758 | *pdrv = &bdrv_raw; |
759 | return ret; |
760 | } |
761 | |
762 | ret = blk_pread(file, 0, buf, sizeof(buf)); |
763 | if (ret < 0) { |
764 | error_setg_errno(errp, -ret, "Could not read image for determining its " |
765 | "format" ); |
766 | *pdrv = NULL; |
767 | return ret; |
768 | } |
769 | |
770 | drv = bdrv_probe_all(buf, ret, filename); |
771 | if (!drv) { |
772 | error_setg(errp, "Could not determine image format: No compatible " |
773 | "driver found" ); |
774 | ret = -ENOENT; |
775 | } |
776 | *pdrv = drv; |
777 | return ret; |
778 | } |
779 | |
780 | /** |
781 | * Set the current 'total_sectors' value |
782 | * Return 0 on success, -errno on error. |
783 | */ |
784 | int refresh_total_sectors(BlockDriverState *bs, int64_t hint) |
785 | { |
786 | BlockDriver *drv = bs->drv; |
787 | |
788 | if (!drv) { |
789 | return -ENOMEDIUM; |
790 | } |
791 | |
792 | /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */ |
793 | if (bdrv_is_sg(bs)) |
794 | return 0; |
795 | |
796 | /* query actual device if possible, otherwise just trust the hint */ |
797 | if (drv->bdrv_getlength) { |
798 | int64_t length = drv->bdrv_getlength(bs); |
799 | if (length < 0) { |
800 | return length; |
801 | } |
802 | hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE); |
803 | } |
804 | |
805 | bs->total_sectors = hint; |
806 | return 0; |
807 | } |
808 | |
809 | /** |
810 | * Combines a QDict of new block driver @options with any missing options taken |
811 | * from @old_options, so that leaving out an option defaults to its old value. |
812 | */ |
813 | static void bdrv_join_options(BlockDriverState *bs, QDict *options, |
814 | QDict *old_options) |
815 | { |
816 | if (bs->drv && bs->drv->bdrv_join_options) { |
817 | bs->drv->bdrv_join_options(options, old_options); |
818 | } else { |
819 | qdict_join(options, old_options, false); |
820 | } |
821 | } |
822 | |
823 | static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts, |
824 | int open_flags, |
825 | Error **errp) |
826 | { |
827 | Error *local_err = NULL; |
828 | char *value = qemu_opt_get_del(opts, "detect-zeroes" ); |
829 | BlockdevDetectZeroesOptions detect_zeroes = |
830 | qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, value, |
831 | BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err); |
832 | g_free(value); |
833 | if (local_err) { |
834 | error_propagate(errp, local_err); |
835 | return detect_zeroes; |
836 | } |
837 | |
838 | if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && |
839 | !(open_flags & BDRV_O_UNMAP)) |
840 | { |
841 | error_setg(errp, "setting detect-zeroes to unmap is not allowed " |
842 | "without setting discard operation to unmap" ); |
843 | } |
844 | |
845 | return detect_zeroes; |
846 | } |
847 | |
848 | /** |
849 | * Set open flags for a given discard mode |
850 | * |
851 | * Return 0 on success, -1 if the discard mode was invalid. |
852 | */ |
853 | int bdrv_parse_discard_flags(const char *mode, int *flags) |
854 | { |
855 | *flags &= ~BDRV_O_UNMAP; |
856 | |
857 | if (!strcmp(mode, "off" ) || !strcmp(mode, "ignore" )) { |
858 | /* do nothing */ |
859 | } else if (!strcmp(mode, "on" ) || !strcmp(mode, "unmap" )) { |
860 | *flags |= BDRV_O_UNMAP; |
861 | } else { |
862 | return -1; |
863 | } |
864 | |
865 | return 0; |
866 | } |
867 | |
868 | /** |
869 | * Set open flags for a given cache mode |
870 | * |
871 | * Return 0 on success, -1 if the cache mode was invalid. |
872 | */ |
873 | int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough) |
874 | { |
875 | *flags &= ~BDRV_O_CACHE_MASK; |
876 | |
877 | if (!strcmp(mode, "off" ) || !strcmp(mode, "none" )) { |
878 | *writethrough = false; |
879 | *flags |= BDRV_O_NOCACHE; |
880 | } else if (!strcmp(mode, "directsync" )) { |
881 | *writethrough = true; |
882 | *flags |= BDRV_O_NOCACHE; |
883 | } else if (!strcmp(mode, "writeback" )) { |
884 | *writethrough = false; |
885 | } else if (!strcmp(mode, "unsafe" )) { |
886 | *writethrough = false; |
887 | *flags |= BDRV_O_NO_FLUSH; |
888 | } else if (!strcmp(mode, "writethrough" )) { |
889 | *writethrough = true; |
890 | } else { |
891 | return -1; |
892 | } |
893 | |
894 | return 0; |
895 | } |
896 | |
897 | static char *bdrv_child_get_parent_desc(BdrvChild *c) |
898 | { |
899 | BlockDriverState *parent = c->opaque; |
900 | return g_strdup(bdrv_get_device_or_node_name(parent)); |
901 | } |
902 | |
903 | static void bdrv_child_cb_drained_begin(BdrvChild *child) |
904 | { |
905 | BlockDriverState *bs = child->opaque; |
906 | bdrv_do_drained_begin_quiesce(bs, NULL, false); |
907 | } |
908 | |
909 | static bool bdrv_child_cb_drained_poll(BdrvChild *child) |
910 | { |
911 | BlockDriverState *bs = child->opaque; |
912 | return bdrv_drain_poll(bs, false, NULL, false); |
913 | } |
914 | |
915 | static void bdrv_child_cb_drained_end(BdrvChild *child, |
916 | int *drained_end_counter) |
917 | { |
918 | BlockDriverState *bs = child->opaque; |
919 | bdrv_drained_end_no_poll(bs, drained_end_counter); |
920 | } |
921 | |
922 | static void bdrv_child_cb_attach(BdrvChild *child) |
923 | { |
924 | BlockDriverState *bs = child->opaque; |
925 | bdrv_apply_subtree_drain(child, bs); |
926 | } |
927 | |
928 | static void bdrv_child_cb_detach(BdrvChild *child) |
929 | { |
930 | BlockDriverState *bs = child->opaque; |
931 | bdrv_unapply_subtree_drain(child, bs); |
932 | } |
933 | |
934 | static int bdrv_child_cb_inactivate(BdrvChild *child) |
935 | { |
936 | BlockDriverState *bs = child->opaque; |
937 | assert(bs->open_flags & BDRV_O_INACTIVE); |
938 | return 0; |
939 | } |
940 | |
941 | static bool bdrv_child_cb_can_set_aio_ctx(BdrvChild *child, AioContext *ctx, |
942 | GSList **ignore, Error **errp) |
943 | { |
944 | BlockDriverState *bs = child->opaque; |
945 | return bdrv_can_set_aio_context(bs, ctx, ignore, errp); |
946 | } |
947 | |
948 | static void bdrv_child_cb_set_aio_ctx(BdrvChild *child, AioContext *ctx, |
949 | GSList **ignore) |
950 | { |
951 | BlockDriverState *bs = child->opaque; |
952 | return bdrv_set_aio_context_ignore(bs, ctx, ignore); |
953 | } |
954 | |
955 | /* |
956 | * Returns the options and flags that a temporary snapshot should get, based on |
957 | * the originally requested flags (the originally requested image will have |
958 | * flags like a backing file) |
959 | */ |
960 | static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options, |
961 | int parent_flags, QDict *parent_options) |
962 | { |
963 | *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY; |
964 | |
965 | /* For temporary files, unconditional cache=unsafe is fine */ |
966 | qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off" ); |
967 | qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on" ); |
968 | |
969 | /* Copy the read-only and discard options from the parent */ |
970 | qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); |
971 | qdict_copy_default(child_options, parent_options, BDRV_OPT_DISCARD); |
972 | |
973 | /* aio=native doesn't work for cache.direct=off, so disable it for the |
974 | * temporary snapshot */ |
975 | *child_flags &= ~BDRV_O_NATIVE_AIO; |
976 | } |
977 | |
978 | /* |
979 | * Returns the options and flags that bs->file should get if a protocol driver |
980 | * is expected, based on the given options and flags for the parent BDS |
981 | */ |
982 | static void bdrv_inherited_options(int *child_flags, QDict *child_options, |
983 | int parent_flags, QDict *parent_options) |
984 | { |
985 | int flags = parent_flags; |
986 | |
987 | /* Enable protocol handling, disable format probing for bs->file */ |
988 | flags |= BDRV_O_PROTOCOL; |
989 | |
990 | /* If the cache mode isn't explicitly set, inherit direct and no-flush from |
991 | * the parent. */ |
992 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); |
993 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); |
994 | qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE); |
995 | |
996 | /* Inherit the read-only option from the parent if it's not set */ |
997 | qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); |
998 | qdict_copy_default(child_options, parent_options, BDRV_OPT_AUTO_READ_ONLY); |
999 | |
1000 | /* Our block drivers take care to send flushes and respect unmap policy, |
1001 | * so we can default to enable both on lower layers regardless of the |
1002 | * corresponding parent options. */ |
1003 | qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap" ); |
1004 | |
1005 | /* Clear flags that only apply to the top layer */ |
1006 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ | |
1007 | BDRV_O_NO_IO); |
1008 | |
1009 | *child_flags = flags; |
1010 | } |
1011 | |
1012 | const BdrvChildRole child_file = { |
1013 | .parent_is_bds = true, |
1014 | .get_parent_desc = bdrv_child_get_parent_desc, |
1015 | .inherit_options = bdrv_inherited_options, |
1016 | .drained_begin = bdrv_child_cb_drained_begin, |
1017 | .drained_poll = bdrv_child_cb_drained_poll, |
1018 | .drained_end = bdrv_child_cb_drained_end, |
1019 | .attach = bdrv_child_cb_attach, |
1020 | .detach = bdrv_child_cb_detach, |
1021 | .inactivate = bdrv_child_cb_inactivate, |
1022 | .can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx, |
1023 | .set_aio_ctx = bdrv_child_cb_set_aio_ctx, |
1024 | }; |
1025 | |
1026 | /* |
1027 | * Returns the options and flags that bs->file should get if the use of formats |
1028 | * (and not only protocols) is permitted for it, based on the given options and |
1029 | * flags for the parent BDS |
1030 | */ |
1031 | static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options, |
1032 | int parent_flags, QDict *parent_options) |
1033 | { |
1034 | child_file.inherit_options(child_flags, child_options, |
1035 | parent_flags, parent_options); |
1036 | |
1037 | *child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO); |
1038 | } |
1039 | |
1040 | const BdrvChildRole child_format = { |
1041 | .parent_is_bds = true, |
1042 | .get_parent_desc = bdrv_child_get_parent_desc, |
1043 | .inherit_options = bdrv_inherited_fmt_options, |
1044 | .drained_begin = bdrv_child_cb_drained_begin, |
1045 | .drained_poll = bdrv_child_cb_drained_poll, |
1046 | .drained_end = bdrv_child_cb_drained_end, |
1047 | .attach = bdrv_child_cb_attach, |
1048 | .detach = bdrv_child_cb_detach, |
1049 | .inactivate = bdrv_child_cb_inactivate, |
1050 | .can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx, |
1051 | .set_aio_ctx = bdrv_child_cb_set_aio_ctx, |
1052 | }; |
1053 | |
1054 | static void bdrv_backing_attach(BdrvChild *c) |
1055 | { |
1056 | BlockDriverState *parent = c->opaque; |
1057 | BlockDriverState *backing_hd = c->bs; |
1058 | |
1059 | assert(!parent->backing_blocker); |
1060 | error_setg(&parent->backing_blocker, |
1061 | "node is used as backing hd of '%s'" , |
1062 | bdrv_get_device_or_node_name(parent)); |
1063 | |
1064 | bdrv_refresh_filename(backing_hd); |
1065 | |
1066 | parent->open_flags &= ~BDRV_O_NO_BACKING; |
1067 | pstrcpy(parent->backing_file, sizeof(parent->backing_file), |
1068 | backing_hd->filename); |
1069 | pstrcpy(parent->backing_format, sizeof(parent->backing_format), |
1070 | backing_hd->drv ? backing_hd->drv->format_name : "" ); |
1071 | |
1072 | bdrv_op_block_all(backing_hd, parent->backing_blocker); |
1073 | /* Otherwise we won't be able to commit or stream */ |
1074 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, |
1075 | parent->backing_blocker); |
1076 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM, |
1077 | parent->backing_blocker); |
1078 | /* |
1079 | * We do backup in 3 ways: |
1080 | * 1. drive backup |
1081 | * The target bs is new opened, and the source is top BDS |
1082 | * 2. blockdev backup |
1083 | * Both the source and the target are top BDSes. |
1084 | * 3. internal backup(used for block replication) |
1085 | * Both the source and the target are backing file |
1086 | * |
1087 | * In case 1 and 2, neither the source nor the target is the backing file. |
1088 | * In case 3, we will block the top BDS, so there is only one block job |
1089 | * for the top BDS and its backing chain. |
1090 | */ |
1091 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE, |
1092 | parent->backing_blocker); |
1093 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET, |
1094 | parent->backing_blocker); |
1095 | |
1096 | bdrv_child_cb_attach(c); |
1097 | } |
1098 | |
1099 | static void bdrv_backing_detach(BdrvChild *c) |
1100 | { |
1101 | BlockDriverState *parent = c->opaque; |
1102 | |
1103 | assert(parent->backing_blocker); |
1104 | bdrv_op_unblock_all(c->bs, parent->backing_blocker); |
1105 | error_free(parent->backing_blocker); |
1106 | parent->backing_blocker = NULL; |
1107 | |
1108 | bdrv_child_cb_detach(c); |
1109 | } |
1110 | |
1111 | /* |
1112 | * Returns the options and flags that bs->backing should get, based on the |
1113 | * given options and flags for the parent BDS |
1114 | */ |
1115 | static void bdrv_backing_options(int *child_flags, QDict *child_options, |
1116 | int parent_flags, QDict *parent_options) |
1117 | { |
1118 | int flags = parent_flags; |
1119 | |
1120 | /* The cache mode is inherited unmodified for backing files; except WCE, |
1121 | * which is only applied on the top level (BlockBackend) */ |
1122 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); |
1123 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); |
1124 | qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE); |
1125 | |
1126 | /* backing files always opened read-only */ |
1127 | qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on" ); |
1128 | qdict_set_default_str(child_options, BDRV_OPT_AUTO_READ_ONLY, "off" ); |
1129 | flags &= ~BDRV_O_COPY_ON_READ; |
1130 | |
1131 | /* snapshot=on is handled on the top layer */ |
1132 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); |
1133 | |
1134 | *child_flags = flags; |
1135 | } |
1136 | |
1137 | static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base, |
1138 | const char *filename, Error **errp) |
1139 | { |
1140 | BlockDriverState *parent = c->opaque; |
1141 | bool read_only = bdrv_is_read_only(parent); |
1142 | int ret; |
1143 | |
1144 | if (read_only) { |
1145 | ret = bdrv_reopen_set_read_only(parent, false, errp); |
1146 | if (ret < 0) { |
1147 | return ret; |
1148 | } |
1149 | } |
1150 | |
1151 | ret = bdrv_change_backing_file(parent, filename, |
1152 | base->drv ? base->drv->format_name : "" ); |
1153 | if (ret < 0) { |
1154 | error_setg_errno(errp, -ret, "Could not update backing file link" ); |
1155 | } |
1156 | |
1157 | if (read_only) { |
1158 | bdrv_reopen_set_read_only(parent, true, NULL); |
1159 | } |
1160 | |
1161 | return ret; |
1162 | } |
1163 | |
1164 | const BdrvChildRole child_backing = { |
1165 | .parent_is_bds = true, |
1166 | .get_parent_desc = bdrv_child_get_parent_desc, |
1167 | .attach = bdrv_backing_attach, |
1168 | .detach = bdrv_backing_detach, |
1169 | .inherit_options = bdrv_backing_options, |
1170 | .drained_begin = bdrv_child_cb_drained_begin, |
1171 | .drained_poll = bdrv_child_cb_drained_poll, |
1172 | .drained_end = bdrv_child_cb_drained_end, |
1173 | .inactivate = bdrv_child_cb_inactivate, |
1174 | .update_filename = bdrv_backing_update_filename, |
1175 | .can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx, |
1176 | .set_aio_ctx = bdrv_child_cb_set_aio_ctx, |
1177 | }; |
1178 | |
1179 | static int bdrv_open_flags(BlockDriverState *bs, int flags) |
1180 | { |
1181 | int open_flags = flags; |
1182 | |
1183 | /* |
1184 | * Clear flags that are internal to the block layer before opening the |
1185 | * image. |
1186 | */ |
1187 | open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL); |
1188 | |
1189 | return open_flags; |
1190 | } |
1191 | |
1192 | static void update_flags_from_options(int *flags, QemuOpts *opts) |
1193 | { |
1194 | *flags &= ~(BDRV_O_CACHE_MASK | BDRV_O_RDWR | BDRV_O_AUTO_RDONLY); |
1195 | |
1196 | if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) { |
1197 | *flags |= BDRV_O_NO_FLUSH; |
1198 | } |
1199 | |
1200 | if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_DIRECT, false)) { |
1201 | *flags |= BDRV_O_NOCACHE; |
1202 | } |
1203 | |
1204 | if (!qemu_opt_get_bool_del(opts, BDRV_OPT_READ_ONLY, false)) { |
1205 | *flags |= BDRV_O_RDWR; |
1206 | } |
1207 | |
1208 | if (qemu_opt_get_bool_del(opts, BDRV_OPT_AUTO_READ_ONLY, false)) { |
1209 | *flags |= BDRV_O_AUTO_RDONLY; |
1210 | } |
1211 | } |
1212 | |
1213 | static void update_options_from_flags(QDict *options, int flags) |
1214 | { |
1215 | if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) { |
1216 | qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE); |
1217 | } |
1218 | if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) { |
1219 | qdict_put_bool(options, BDRV_OPT_CACHE_NO_FLUSH, |
1220 | flags & BDRV_O_NO_FLUSH); |
1221 | } |
1222 | if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) { |
1223 | qdict_put_bool(options, BDRV_OPT_READ_ONLY, !(flags & BDRV_O_RDWR)); |
1224 | } |
1225 | if (!qdict_haskey(options, BDRV_OPT_AUTO_READ_ONLY)) { |
1226 | qdict_put_bool(options, BDRV_OPT_AUTO_READ_ONLY, |
1227 | flags & BDRV_O_AUTO_RDONLY); |
1228 | } |
1229 | } |
1230 | |
1231 | static void bdrv_assign_node_name(BlockDriverState *bs, |
1232 | const char *node_name, |
1233 | Error **errp) |
1234 | { |
1235 | char *gen_node_name = NULL; |
1236 | |
1237 | if (!node_name) { |
1238 | node_name = gen_node_name = id_generate(ID_BLOCK); |
1239 | } else if (!id_wellformed(node_name)) { |
1240 | /* |
1241 | * Check for empty string or invalid characters, but not if it is |
1242 | * generated (generated names use characters not available to the user) |
1243 | */ |
1244 | error_setg(errp, "Invalid node name" ); |
1245 | return; |
1246 | } |
1247 | |
1248 | /* takes care of avoiding namespaces collisions */ |
1249 | if (blk_by_name(node_name)) { |
1250 | error_setg(errp, "node-name=%s is conflicting with a device id" , |
1251 | node_name); |
1252 | goto out; |
1253 | } |
1254 | |
1255 | /* takes care of avoiding duplicates node names */ |
1256 | if (bdrv_find_node(node_name)) { |
1257 | error_setg(errp, "Duplicate node name" ); |
1258 | goto out; |
1259 | } |
1260 | |
1261 | /* Make sure that the node name isn't truncated */ |
1262 | if (strlen(node_name) >= sizeof(bs->node_name)) { |
1263 | error_setg(errp, "Node name too long" ); |
1264 | goto out; |
1265 | } |
1266 | |
1267 | /* copy node name into the bs and insert it into the graph list */ |
1268 | pstrcpy(bs->node_name, sizeof(bs->node_name), node_name); |
1269 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list); |
1270 | out: |
1271 | g_free(gen_node_name); |
1272 | } |
1273 | |
1274 | static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv, |
1275 | const char *node_name, QDict *options, |
1276 | int open_flags, Error **errp) |
1277 | { |
1278 | Error *local_err = NULL; |
1279 | int i, ret; |
1280 | |
1281 | bdrv_assign_node_name(bs, node_name, &local_err); |
1282 | if (local_err) { |
1283 | error_propagate(errp, local_err); |
1284 | return -EINVAL; |
1285 | } |
1286 | |
1287 | bs->drv = drv; |
1288 | bs->read_only = !(bs->open_flags & BDRV_O_RDWR); |
1289 | bs->opaque = g_malloc0(drv->instance_size); |
1290 | |
1291 | if (drv->bdrv_file_open) { |
1292 | assert(!drv->bdrv_needs_filename || bs->filename[0]); |
1293 | ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); |
1294 | } else if (drv->bdrv_open) { |
1295 | ret = drv->bdrv_open(bs, options, open_flags, &local_err); |
1296 | } else { |
1297 | ret = 0; |
1298 | } |
1299 | |
1300 | if (ret < 0) { |
1301 | if (local_err) { |
1302 | error_propagate(errp, local_err); |
1303 | } else if (bs->filename[0]) { |
1304 | error_setg_errno(errp, -ret, "Could not open '%s'" , bs->filename); |
1305 | } else { |
1306 | error_setg_errno(errp, -ret, "Could not open image" ); |
1307 | } |
1308 | goto open_failed; |
1309 | } |
1310 | |
1311 | ret = refresh_total_sectors(bs, bs->total_sectors); |
1312 | if (ret < 0) { |
1313 | error_setg_errno(errp, -ret, "Could not refresh total sector count" ); |
1314 | return ret; |
1315 | } |
1316 | |
1317 | bdrv_refresh_limits(bs, &local_err); |
1318 | if (local_err) { |
1319 | error_propagate(errp, local_err); |
1320 | return -EINVAL; |
1321 | } |
1322 | |
1323 | assert(bdrv_opt_mem_align(bs) != 0); |
1324 | assert(bdrv_min_mem_align(bs) != 0); |
1325 | assert(is_power_of_2(bs->bl.request_alignment)); |
1326 | |
1327 | for (i = 0; i < bs->quiesce_counter; i++) { |
1328 | if (drv->bdrv_co_drain_begin) { |
1329 | drv->bdrv_co_drain_begin(bs); |
1330 | } |
1331 | } |
1332 | |
1333 | return 0; |
1334 | open_failed: |
1335 | bs->drv = NULL; |
1336 | if (bs->file != NULL) { |
1337 | bdrv_unref_child(bs, bs->file); |
1338 | bs->file = NULL; |
1339 | } |
1340 | g_free(bs->opaque); |
1341 | bs->opaque = NULL; |
1342 | return ret; |
1343 | } |
1344 | |
1345 | BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, |
1346 | int flags, Error **errp) |
1347 | { |
1348 | BlockDriverState *bs; |
1349 | int ret; |
1350 | |
1351 | bs = bdrv_new(); |
1352 | bs->open_flags = flags; |
1353 | bs->explicit_options = qdict_new(); |
1354 | bs->options = qdict_new(); |
1355 | bs->opaque = NULL; |
1356 | |
1357 | update_options_from_flags(bs->options, flags); |
1358 | |
1359 | ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp); |
1360 | if (ret < 0) { |
1361 | qobject_unref(bs->explicit_options); |
1362 | bs->explicit_options = NULL; |
1363 | qobject_unref(bs->options); |
1364 | bs->options = NULL; |
1365 | bdrv_unref(bs); |
1366 | return NULL; |
1367 | } |
1368 | |
1369 | return bs; |
1370 | } |
1371 | |
1372 | QemuOptsList bdrv_runtime_opts = { |
1373 | .name = "bdrv_common" , |
1374 | .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head), |
1375 | .desc = { |
1376 | { |
1377 | .name = "node-name" , |
1378 | .type = QEMU_OPT_STRING, |
1379 | .help = "Node name of the block device node" , |
1380 | }, |
1381 | { |
1382 | .name = "driver" , |
1383 | .type = QEMU_OPT_STRING, |
1384 | .help = "Block driver to use for the node" , |
1385 | }, |
1386 | { |
1387 | .name = BDRV_OPT_CACHE_DIRECT, |
1388 | .type = QEMU_OPT_BOOL, |
1389 | .help = "Bypass software writeback cache on the host" , |
1390 | }, |
1391 | { |
1392 | .name = BDRV_OPT_CACHE_NO_FLUSH, |
1393 | .type = QEMU_OPT_BOOL, |
1394 | .help = "Ignore flush requests" , |
1395 | }, |
1396 | { |
1397 | .name = BDRV_OPT_READ_ONLY, |
1398 | .type = QEMU_OPT_BOOL, |
1399 | .help = "Node is opened in read-only mode" , |
1400 | }, |
1401 | { |
1402 | .name = BDRV_OPT_AUTO_READ_ONLY, |
1403 | .type = QEMU_OPT_BOOL, |
1404 | .help = "Node can become read-only if opening read-write fails" , |
1405 | }, |
1406 | { |
1407 | .name = "detect-zeroes" , |
1408 | .type = QEMU_OPT_STRING, |
1409 | .help = "try to optimize zero writes (off, on, unmap)" , |
1410 | }, |
1411 | { |
1412 | .name = BDRV_OPT_DISCARD, |
1413 | .type = QEMU_OPT_STRING, |
1414 | .help = "discard operation (ignore/off, unmap/on)" , |
1415 | }, |
1416 | { |
1417 | .name = BDRV_OPT_FORCE_SHARE, |
1418 | .type = QEMU_OPT_BOOL, |
1419 | .help = "always accept other writers (default: off)" , |
1420 | }, |
1421 | { /* end of list */ } |
1422 | }, |
1423 | }; |
1424 | |
1425 | /* |
1426 | * Common part for opening disk images and files |
1427 | * |
1428 | * Removes all processed options from *options. |
1429 | */ |
1430 | static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, |
1431 | QDict *options, Error **errp) |
1432 | { |
1433 | int ret, open_flags; |
1434 | const char *filename; |
1435 | const char *driver_name = NULL; |
1436 | const char *node_name = NULL; |
1437 | const char *discard; |
1438 | QemuOpts *opts; |
1439 | BlockDriver *drv; |
1440 | Error *local_err = NULL; |
1441 | |
1442 | assert(bs->file == NULL); |
1443 | assert(options != NULL && bs->options != options); |
1444 | |
1445 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); |
1446 | qemu_opts_absorb_qdict(opts, options, &local_err); |
1447 | if (local_err) { |
1448 | error_propagate(errp, local_err); |
1449 | ret = -EINVAL; |
1450 | goto fail_opts; |
1451 | } |
1452 | |
1453 | update_flags_from_options(&bs->open_flags, opts); |
1454 | |
1455 | driver_name = qemu_opt_get(opts, "driver" ); |
1456 | drv = bdrv_find_format(driver_name); |
1457 | assert(drv != NULL); |
1458 | |
1459 | bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false); |
1460 | |
1461 | if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) { |
1462 | error_setg(errp, |
1463 | BDRV_OPT_FORCE_SHARE |
1464 | "=on can only be used with read-only images" ); |
1465 | ret = -EINVAL; |
1466 | goto fail_opts; |
1467 | } |
1468 | |
1469 | if (file != NULL) { |
1470 | bdrv_refresh_filename(blk_bs(file)); |
1471 | filename = blk_bs(file)->filename; |
1472 | } else { |
1473 | /* |
1474 | * Caution: while qdict_get_try_str() is fine, getting |
1475 | * non-string types would require more care. When @options |
1476 | * come from -blockdev or blockdev_add, its members are typed |
1477 | * according to the QAPI schema, but when they come from |
1478 | * -drive, they're all QString. |
1479 | */ |
1480 | filename = qdict_get_try_str(options, "filename" ); |
1481 | } |
1482 | |
1483 | if (drv->bdrv_needs_filename && (!filename || !filename[0])) { |
1484 | error_setg(errp, "The '%s' block driver requires a file name" , |
1485 | drv->format_name); |
1486 | ret = -EINVAL; |
1487 | goto fail_opts; |
1488 | } |
1489 | |
1490 | trace_bdrv_open_common(bs, filename ?: "" , bs->open_flags, |
1491 | drv->format_name); |
1492 | |
1493 | bs->read_only = !(bs->open_flags & BDRV_O_RDWR); |
1494 | |
1495 | if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) { |
1496 | if (!bs->read_only && bdrv_is_whitelisted(drv, true)) { |
1497 | ret = bdrv_apply_auto_read_only(bs, NULL, NULL); |
1498 | } else { |
1499 | ret = -ENOTSUP; |
1500 | } |
1501 | if (ret < 0) { |
1502 | error_setg(errp, |
1503 | !bs->read_only && bdrv_is_whitelisted(drv, true) |
1504 | ? "Driver '%s' can only be used for read-only devices" |
1505 | : "Driver '%s' is not whitelisted" , |
1506 | drv->format_name); |
1507 | goto fail_opts; |
1508 | } |
1509 | } |
1510 | |
1511 | /* bdrv_new() and bdrv_close() make it so */ |
1512 | assert(atomic_read(&bs->copy_on_read) == 0); |
1513 | |
1514 | if (bs->open_flags & BDRV_O_COPY_ON_READ) { |
1515 | if (!bs->read_only) { |
1516 | bdrv_enable_copy_on_read(bs); |
1517 | } else { |
1518 | error_setg(errp, "Can't use copy-on-read on read-only device" ); |
1519 | ret = -EINVAL; |
1520 | goto fail_opts; |
1521 | } |
1522 | } |
1523 | |
1524 | discard = qemu_opt_get(opts, BDRV_OPT_DISCARD); |
1525 | if (discard != NULL) { |
1526 | if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) { |
1527 | error_setg(errp, "Invalid discard option" ); |
1528 | ret = -EINVAL; |
1529 | goto fail_opts; |
1530 | } |
1531 | } |
1532 | |
1533 | bs->detect_zeroes = |
1534 | bdrv_parse_detect_zeroes(opts, bs->open_flags, &local_err); |
1535 | if (local_err) { |
1536 | error_propagate(errp, local_err); |
1537 | ret = -EINVAL; |
1538 | goto fail_opts; |
1539 | } |
1540 | |
1541 | if (filename != NULL) { |
1542 | pstrcpy(bs->filename, sizeof(bs->filename), filename); |
1543 | } else { |
1544 | bs->filename[0] = '\0'; |
1545 | } |
1546 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename); |
1547 | |
1548 | /* Open the image, either directly or using a protocol */ |
1549 | open_flags = bdrv_open_flags(bs, bs->open_flags); |
1550 | node_name = qemu_opt_get(opts, "node-name" ); |
1551 | |
1552 | assert(!drv->bdrv_file_open || file == NULL); |
1553 | ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp); |
1554 | if (ret < 0) { |
1555 | goto fail_opts; |
1556 | } |
1557 | |
1558 | qemu_opts_del(opts); |
1559 | return 0; |
1560 | |
1561 | fail_opts: |
1562 | qemu_opts_del(opts); |
1563 | return ret; |
1564 | } |
1565 | |
1566 | static QDict *parse_json_filename(const char *filename, Error **errp) |
1567 | { |
1568 | QObject *options_obj; |
1569 | QDict *options; |
1570 | int ret; |
1571 | |
1572 | ret = strstart(filename, "json:" , &filename); |
1573 | assert(ret); |
1574 | |
1575 | options_obj = qobject_from_json(filename, errp); |
1576 | if (!options_obj) { |
1577 | error_prepend(errp, "Could not parse the JSON options: " ); |
1578 | return NULL; |
1579 | } |
1580 | |
1581 | options = qobject_to(QDict, options_obj); |
1582 | if (!options) { |
1583 | qobject_unref(options_obj); |
1584 | error_setg(errp, "Invalid JSON object given" ); |
1585 | return NULL; |
1586 | } |
1587 | |
1588 | qdict_flatten(options); |
1589 | |
1590 | return options; |
1591 | } |
1592 | |
1593 | static void parse_json_protocol(QDict *options, const char **pfilename, |
1594 | Error **errp) |
1595 | { |
1596 | QDict *json_options; |
1597 | Error *local_err = NULL; |
1598 | |
1599 | /* Parse json: pseudo-protocol */ |
1600 | if (!*pfilename || !g_str_has_prefix(*pfilename, "json:" )) { |
1601 | return; |
1602 | } |
1603 | |
1604 | json_options = parse_json_filename(*pfilename, &local_err); |
1605 | if (local_err) { |
1606 | error_propagate(errp, local_err); |
1607 | return; |
1608 | } |
1609 | |
1610 | /* Options given in the filename have lower priority than options |
1611 | * specified directly */ |
1612 | qdict_join(options, json_options, false); |
1613 | qobject_unref(json_options); |
1614 | *pfilename = NULL; |
1615 | } |
1616 | |
1617 | /* |
1618 | * Fills in default options for opening images and converts the legacy |
1619 | * filename/flags pair to option QDict entries. |
1620 | * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a |
1621 | * block driver has been specified explicitly. |
1622 | */ |
1623 | static int bdrv_fill_options(QDict **options, const char *filename, |
1624 | int *flags, Error **errp) |
1625 | { |
1626 | const char *drvname; |
1627 | bool protocol = *flags & BDRV_O_PROTOCOL; |
1628 | bool parse_filename = false; |
1629 | BlockDriver *drv = NULL; |
1630 | Error *local_err = NULL; |
1631 | |
1632 | /* |
1633 | * Caution: while qdict_get_try_str() is fine, getting non-string |
1634 | * types would require more care. When @options come from |
1635 | * -blockdev or blockdev_add, its members are typed according to |
1636 | * the QAPI schema, but when they come from -drive, they're all |
1637 | * QString. |
1638 | */ |
1639 | drvname = qdict_get_try_str(*options, "driver" ); |
1640 | if (drvname) { |
1641 | drv = bdrv_find_format(drvname); |
1642 | if (!drv) { |
1643 | error_setg(errp, "Unknown driver '%s'" , drvname); |
1644 | return -ENOENT; |
1645 | } |
1646 | /* If the user has explicitly specified the driver, this choice should |
1647 | * override the BDRV_O_PROTOCOL flag */ |
1648 | protocol = drv->bdrv_file_open; |
1649 | } |
1650 | |
1651 | if (protocol) { |
1652 | *flags |= BDRV_O_PROTOCOL; |
1653 | } else { |
1654 | *flags &= ~BDRV_O_PROTOCOL; |
1655 | } |
1656 | |
1657 | /* Translate cache options from flags into options */ |
1658 | update_options_from_flags(*options, *flags); |
1659 | |
1660 | /* Fetch the file name from the options QDict if necessary */ |
1661 | if (protocol && filename) { |
1662 | if (!qdict_haskey(*options, "filename" )) { |
1663 | qdict_put_str(*options, "filename" , filename); |
1664 | parse_filename = true; |
1665 | } else { |
1666 | error_setg(errp, "Can't specify 'file' and 'filename' options at " |
1667 | "the same time" ); |
1668 | return -EINVAL; |
1669 | } |
1670 | } |
1671 | |
1672 | /* Find the right block driver */ |
1673 | /* See cautionary note on accessing @options above */ |
1674 | filename = qdict_get_try_str(*options, "filename" ); |
1675 | |
1676 | if (!drvname && protocol) { |
1677 | if (filename) { |
1678 | drv = bdrv_find_protocol(filename, parse_filename, errp); |
1679 | if (!drv) { |
1680 | return -EINVAL; |
1681 | } |
1682 | |
1683 | drvname = drv->format_name; |
1684 | qdict_put_str(*options, "driver" , drvname); |
1685 | } else { |
1686 | error_setg(errp, "Must specify either driver or file" ); |
1687 | return -EINVAL; |
1688 | } |
1689 | } |
1690 | |
1691 | assert(drv || !protocol); |
1692 | |
1693 | /* Driver-specific filename parsing */ |
1694 | if (drv && drv->bdrv_parse_filename && parse_filename) { |
1695 | drv->bdrv_parse_filename(filename, *options, &local_err); |
1696 | if (local_err) { |
1697 | error_propagate(errp, local_err); |
1698 | return -EINVAL; |
1699 | } |
1700 | |
1701 | if (!drv->bdrv_needs_filename) { |
1702 | qdict_del(*options, "filename" ); |
1703 | } |
1704 | } |
1705 | |
1706 | return 0; |
1707 | } |
1708 | |
1709 | static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, |
1710 | uint64_t perm, uint64_t shared, |
1711 | GSList *ignore_children, |
1712 | bool *tighten_restrictions, Error **errp); |
1713 | static void bdrv_child_abort_perm_update(BdrvChild *c); |
1714 | static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared); |
1715 | static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, |
1716 | uint64_t *shared_perm); |
1717 | |
1718 | typedef struct BlockReopenQueueEntry { |
1719 | bool prepared; |
1720 | bool perms_checked; |
1721 | BDRVReopenState state; |
1722 | QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; |
1723 | } BlockReopenQueueEntry; |
1724 | |
1725 | /* |
1726 | * Return the flags that @bs will have after the reopens in @q have |
1727 | * successfully completed. If @q is NULL (or @bs is not contained in @q), |
1728 | * return the current flags. |
1729 | */ |
1730 | static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs) |
1731 | { |
1732 | BlockReopenQueueEntry *entry; |
1733 | |
1734 | if (q != NULL) { |
1735 | QSIMPLEQ_FOREACH(entry, q, entry) { |
1736 | if (entry->state.bs == bs) { |
1737 | return entry->state.flags; |
1738 | } |
1739 | } |
1740 | } |
1741 | |
1742 | return bs->open_flags; |
1743 | } |
1744 | |
1745 | /* Returns whether the image file can be written to after the reopen queue @q |
1746 | * has been successfully applied, or right now if @q is NULL. */ |
1747 | static bool bdrv_is_writable_after_reopen(BlockDriverState *bs, |
1748 | BlockReopenQueue *q) |
1749 | { |
1750 | int flags = bdrv_reopen_get_flags(q, bs); |
1751 | |
1752 | return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR; |
1753 | } |
1754 | |
1755 | /* |
1756 | * Return whether the BDS can be written to. This is not necessarily |
1757 | * the same as !bdrv_is_read_only(bs), as inactivated images may not |
1758 | * be written to but do not count as read-only images. |
1759 | */ |
1760 | bool bdrv_is_writable(BlockDriverState *bs) |
1761 | { |
1762 | return bdrv_is_writable_after_reopen(bs, NULL); |
1763 | } |
1764 | |
1765 | static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs, |
1766 | BdrvChild *c, const BdrvChildRole *role, |
1767 | BlockReopenQueue *reopen_queue, |
1768 | uint64_t parent_perm, uint64_t parent_shared, |
1769 | uint64_t *nperm, uint64_t *nshared) |
1770 | { |
1771 | assert(bs->drv && bs->drv->bdrv_child_perm); |
1772 | bs->drv->bdrv_child_perm(bs, c, role, reopen_queue, |
1773 | parent_perm, parent_shared, |
1774 | nperm, nshared); |
1775 | /* TODO Take force_share from reopen_queue */ |
1776 | if (child_bs && child_bs->force_share) { |
1777 | *nshared = BLK_PERM_ALL; |
1778 | } |
1779 | } |
1780 | |
1781 | /* |
1782 | * Check whether permissions on this node can be changed in a way that |
1783 | * @cumulative_perms and @cumulative_shared_perms are the new cumulative |
1784 | * permissions of all its parents. This involves checking whether all necessary |
1785 | * permission changes to child nodes can be performed. |
1786 | * |
1787 | * Will set *tighten_restrictions to true if and only if new permissions have to |
1788 | * be taken or currently shared permissions are to be unshared. Otherwise, |
1789 | * errors are not fatal as long as the caller accepts that the restrictions |
1790 | * remain tighter than they need to be. The caller still has to abort the |
1791 | * transaction. |
1792 | * @tighten_restrictions cannot be used together with @q: When reopening, we may |
1793 | * encounter fatal errors even though no restrictions are to be tightened. For |
1794 | * example, changing a node from RW to RO will fail if the WRITE permission is |
1795 | * to be kept. |
1796 | * |
1797 | * A call to this function must always be followed by a call to bdrv_set_perm() |
1798 | * or bdrv_abort_perm_update(). |
1799 | */ |
1800 | static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q, |
1801 | uint64_t cumulative_perms, |
1802 | uint64_t cumulative_shared_perms, |
1803 | GSList *ignore_children, |
1804 | bool *tighten_restrictions, Error **errp) |
1805 | { |
1806 | BlockDriver *drv = bs->drv; |
1807 | BdrvChild *c; |
1808 | int ret; |
1809 | |
1810 | assert(!q || !tighten_restrictions); |
1811 | |
1812 | if (tighten_restrictions) { |
1813 | uint64_t current_perms, current_shared; |
1814 | uint64_t added_perms, removed_shared_perms; |
1815 | |
1816 | bdrv_get_cumulative_perm(bs, ¤t_perms, ¤t_shared); |
1817 | |
1818 | added_perms = cumulative_perms & ~current_perms; |
1819 | removed_shared_perms = current_shared & ~cumulative_shared_perms; |
1820 | |
1821 | *tighten_restrictions = added_perms || removed_shared_perms; |
1822 | } |
1823 | |
1824 | /* Write permissions never work with read-only images */ |
1825 | if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) && |
1826 | !bdrv_is_writable_after_reopen(bs, q)) |
1827 | { |
1828 | if (!bdrv_is_writable_after_reopen(bs, NULL)) { |
1829 | error_setg(errp, "Block node is read-only" ); |
1830 | } else { |
1831 | uint64_t current_perms, current_shared; |
1832 | bdrv_get_cumulative_perm(bs, ¤t_perms, ¤t_shared); |
1833 | if (current_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) { |
1834 | error_setg(errp, "Cannot make block node read-only, there is " |
1835 | "a writer on it" ); |
1836 | } else { |
1837 | error_setg(errp, "Cannot make block node read-only and create " |
1838 | "a writer on it" ); |
1839 | } |
1840 | } |
1841 | |
1842 | return -EPERM; |
1843 | } |
1844 | |
1845 | /* Check this node */ |
1846 | if (!drv) { |
1847 | return 0; |
1848 | } |
1849 | |
1850 | if (drv->bdrv_check_perm) { |
1851 | return drv->bdrv_check_perm(bs, cumulative_perms, |
1852 | cumulative_shared_perms, errp); |
1853 | } |
1854 | |
1855 | /* Drivers that never have children can omit .bdrv_child_perm() */ |
1856 | if (!drv->bdrv_child_perm) { |
1857 | assert(QLIST_EMPTY(&bs->children)); |
1858 | return 0; |
1859 | } |
1860 | |
1861 | /* Check all children */ |
1862 | QLIST_FOREACH(c, &bs->children, next) { |
1863 | uint64_t cur_perm, cur_shared; |
1864 | bool child_tighten_restr; |
1865 | |
1866 | bdrv_child_perm(bs, c->bs, c, c->role, q, |
1867 | cumulative_perms, cumulative_shared_perms, |
1868 | &cur_perm, &cur_shared); |
1869 | ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared, ignore_children, |
1870 | tighten_restrictions ? &child_tighten_restr |
1871 | : NULL, |
1872 | errp); |
1873 | if (tighten_restrictions) { |
1874 | *tighten_restrictions |= child_tighten_restr; |
1875 | } |
1876 | if (ret < 0) { |
1877 | return ret; |
1878 | } |
1879 | } |
1880 | |
1881 | return 0; |
1882 | } |
1883 | |
1884 | /* |
1885 | * Notifies drivers that after a previous bdrv_check_perm() call, the |
1886 | * permission update is not performed and any preparations made for it (e.g. |
1887 | * taken file locks) need to be undone. |
1888 | * |
1889 | * This function recursively notifies all child nodes. |
1890 | */ |
1891 | static void bdrv_abort_perm_update(BlockDriverState *bs) |
1892 | { |
1893 | BlockDriver *drv = bs->drv; |
1894 | BdrvChild *c; |
1895 | |
1896 | if (!drv) { |
1897 | return; |
1898 | } |
1899 | |
1900 | if (drv->bdrv_abort_perm_update) { |
1901 | drv->bdrv_abort_perm_update(bs); |
1902 | } |
1903 | |
1904 | QLIST_FOREACH(c, &bs->children, next) { |
1905 | bdrv_child_abort_perm_update(c); |
1906 | } |
1907 | } |
1908 | |
1909 | static void bdrv_set_perm(BlockDriverState *bs, uint64_t cumulative_perms, |
1910 | uint64_t cumulative_shared_perms) |
1911 | { |
1912 | BlockDriver *drv = bs->drv; |
1913 | BdrvChild *c; |
1914 | |
1915 | if (!drv) { |
1916 | return; |
1917 | } |
1918 | |
1919 | /* Update this node */ |
1920 | if (drv->bdrv_set_perm) { |
1921 | drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms); |
1922 | } |
1923 | |
1924 | /* Drivers that never have children can omit .bdrv_child_perm() */ |
1925 | if (!drv->bdrv_child_perm) { |
1926 | assert(QLIST_EMPTY(&bs->children)); |
1927 | return; |
1928 | } |
1929 | |
1930 | /* Update all children */ |
1931 | QLIST_FOREACH(c, &bs->children, next) { |
1932 | uint64_t cur_perm, cur_shared; |
1933 | bdrv_child_perm(bs, c->bs, c, c->role, NULL, |
1934 | cumulative_perms, cumulative_shared_perms, |
1935 | &cur_perm, &cur_shared); |
1936 | bdrv_child_set_perm(c, cur_perm, cur_shared); |
1937 | } |
1938 | } |
1939 | |
1940 | static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, |
1941 | uint64_t *shared_perm) |
1942 | { |
1943 | BdrvChild *c; |
1944 | uint64_t cumulative_perms = 0; |
1945 | uint64_t cumulative_shared_perms = BLK_PERM_ALL; |
1946 | |
1947 | QLIST_FOREACH(c, &bs->parents, next_parent) { |
1948 | cumulative_perms |= c->perm; |
1949 | cumulative_shared_perms &= c->shared_perm; |
1950 | } |
1951 | |
1952 | *perm = cumulative_perms; |
1953 | *shared_perm = cumulative_shared_perms; |
1954 | } |
1955 | |
1956 | static char *bdrv_child_user_desc(BdrvChild *c) |
1957 | { |
1958 | if (c->role->get_parent_desc) { |
1959 | return c->role->get_parent_desc(c); |
1960 | } |
1961 | |
1962 | return g_strdup("another user" ); |
1963 | } |
1964 | |
1965 | char *bdrv_perm_names(uint64_t perm) |
1966 | { |
1967 | struct perm_name { |
1968 | uint64_t perm; |
1969 | const char *name; |
1970 | } permissions[] = { |
1971 | { BLK_PERM_CONSISTENT_READ, "consistent read" }, |
1972 | { BLK_PERM_WRITE, "write" }, |
1973 | { BLK_PERM_WRITE_UNCHANGED, "write unchanged" }, |
1974 | { BLK_PERM_RESIZE, "resize" }, |
1975 | { BLK_PERM_GRAPH_MOD, "change children" }, |
1976 | { 0, NULL } |
1977 | }; |
1978 | |
1979 | char *result = g_strdup("" ); |
1980 | struct perm_name *p; |
1981 | |
1982 | for (p = permissions; p->name; p++) { |
1983 | if (perm & p->perm) { |
1984 | char *old = result; |
1985 | result = g_strdup_printf("%s%s%s" , old, *old ? ", " : "" , p->name); |
1986 | g_free(old); |
1987 | } |
1988 | } |
1989 | |
1990 | return result; |
1991 | } |
1992 | |
1993 | /* |
1994 | * Checks whether a new reference to @bs can be added if the new user requires |
1995 | * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is |
1996 | * set, the BdrvChild objects in this list are ignored in the calculations; |
1997 | * this allows checking permission updates for an existing reference. |
1998 | * |
1999 | * See bdrv_check_perm() for the semantics of @tighten_restrictions. |
2000 | * |
2001 | * Needs to be followed by a call to either bdrv_set_perm() or |
2002 | * bdrv_abort_perm_update(). */ |
2003 | static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q, |
2004 | uint64_t new_used_perm, |
2005 | uint64_t new_shared_perm, |
2006 | GSList *ignore_children, |
2007 | bool *tighten_restrictions, |
2008 | Error **errp) |
2009 | { |
2010 | BdrvChild *c; |
2011 | uint64_t cumulative_perms = new_used_perm; |
2012 | uint64_t cumulative_shared_perms = new_shared_perm; |
2013 | |
2014 | assert(!q || !tighten_restrictions); |
2015 | |
2016 | /* There is no reason why anyone couldn't tolerate write_unchanged */ |
2017 | assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED); |
2018 | |
2019 | QLIST_FOREACH(c, &bs->parents, next_parent) { |
2020 | if (g_slist_find(ignore_children, c)) { |
2021 | continue; |
2022 | } |
2023 | |
2024 | if ((new_used_perm & c->shared_perm) != new_used_perm) { |
2025 | char *user = bdrv_child_user_desc(c); |
2026 | char *perm_names = bdrv_perm_names(new_used_perm & ~c->shared_perm); |
2027 | |
2028 | if (tighten_restrictions) { |
2029 | *tighten_restrictions = true; |
2030 | } |
2031 | |
2032 | error_setg(errp, "Conflicts with use by %s as '%s', which does not " |
2033 | "allow '%s' on %s" , |
2034 | user, c->name, perm_names, bdrv_get_node_name(c->bs)); |
2035 | g_free(user); |
2036 | g_free(perm_names); |
2037 | return -EPERM; |
2038 | } |
2039 | |
2040 | if ((c->perm & new_shared_perm) != c->perm) { |
2041 | char *user = bdrv_child_user_desc(c); |
2042 | char *perm_names = bdrv_perm_names(c->perm & ~new_shared_perm); |
2043 | |
2044 | if (tighten_restrictions) { |
2045 | *tighten_restrictions = true; |
2046 | } |
2047 | |
2048 | error_setg(errp, "Conflicts with use by %s as '%s', which uses " |
2049 | "'%s' on %s" , |
2050 | user, c->name, perm_names, bdrv_get_node_name(c->bs)); |
2051 | g_free(user); |
2052 | g_free(perm_names); |
2053 | return -EPERM; |
2054 | } |
2055 | |
2056 | cumulative_perms |= c->perm; |
2057 | cumulative_shared_perms &= c->shared_perm; |
2058 | } |
2059 | |
2060 | return bdrv_check_perm(bs, q, cumulative_perms, cumulative_shared_perms, |
2061 | ignore_children, tighten_restrictions, errp); |
2062 | } |
2063 | |
2064 | /* Needs to be followed by a call to either bdrv_child_set_perm() or |
2065 | * bdrv_child_abort_perm_update(). */ |
2066 | static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q, |
2067 | uint64_t perm, uint64_t shared, |
2068 | GSList *ignore_children, |
2069 | bool *tighten_restrictions, Error **errp) |
2070 | { |
2071 | int ret; |
2072 | |
2073 | ignore_children = g_slist_prepend(g_slist_copy(ignore_children), c); |
2074 | ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, |
2075 | tighten_restrictions, errp); |
2076 | g_slist_free(ignore_children); |
2077 | |
2078 | if (ret < 0) { |
2079 | return ret; |
2080 | } |
2081 | |
2082 | if (!c->has_backup_perm) { |
2083 | c->has_backup_perm = true; |
2084 | c->backup_perm = c->perm; |
2085 | c->backup_shared_perm = c->shared_perm; |
2086 | } |
2087 | /* |
2088 | * Note: it's OK if c->has_backup_perm was already set, as we can find the |
2089 | * same child twice during check_perm procedure |
2090 | */ |
2091 | |
2092 | c->perm = perm; |
2093 | c->shared_perm = shared; |
2094 | |
2095 | return 0; |
2096 | } |
2097 | |
2098 | static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared) |
2099 | { |
2100 | uint64_t cumulative_perms, cumulative_shared_perms; |
2101 | |
2102 | c->has_backup_perm = false; |
2103 | |
2104 | c->perm = perm; |
2105 | c->shared_perm = shared; |
2106 | |
2107 | bdrv_get_cumulative_perm(c->bs, &cumulative_perms, |
2108 | &cumulative_shared_perms); |
2109 | bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms); |
2110 | } |
2111 | |
2112 | static void bdrv_child_abort_perm_update(BdrvChild *c) |
2113 | { |
2114 | if (c->has_backup_perm) { |
2115 | c->perm = c->backup_perm; |
2116 | c->shared_perm = c->backup_shared_perm; |
2117 | c->has_backup_perm = false; |
2118 | } |
2119 | |
2120 | bdrv_abort_perm_update(c->bs); |
2121 | } |
2122 | |
2123 | int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, |
2124 | Error **errp) |
2125 | { |
2126 | Error *local_err = NULL; |
2127 | int ret; |
2128 | bool tighten_restrictions; |
2129 | |
2130 | ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL, |
2131 | &tighten_restrictions, &local_err); |
2132 | if (ret < 0) { |
2133 | bdrv_child_abort_perm_update(c); |
2134 | if (tighten_restrictions) { |
2135 | error_propagate(errp, local_err); |
2136 | } else { |
2137 | /* |
2138 | * Our caller may intend to only loosen restrictions and |
2139 | * does not expect this function to fail. Errors are not |
2140 | * fatal in such a case, so we can just hide them from our |
2141 | * caller. |
2142 | */ |
2143 | error_free(local_err); |
2144 | ret = 0; |
2145 | } |
2146 | return ret; |
2147 | } |
2148 | |
2149 | bdrv_child_set_perm(c, perm, shared); |
2150 | |
2151 | return 0; |
2152 | } |
2153 | |
2154 | int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp) |
2155 | { |
2156 | uint64_t parent_perms, parent_shared; |
2157 | uint64_t perms, shared; |
2158 | |
2159 | bdrv_get_cumulative_perm(bs, &parent_perms, &parent_shared); |
2160 | bdrv_child_perm(bs, c->bs, c, c->role, NULL, parent_perms, parent_shared, |
2161 | &perms, &shared); |
2162 | |
2163 | return bdrv_child_try_set_perm(c, perms, shared, errp); |
2164 | } |
2165 | |
2166 | void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, |
2167 | const BdrvChildRole *role, |
2168 | BlockReopenQueue *reopen_queue, |
2169 | uint64_t perm, uint64_t shared, |
2170 | uint64_t *nperm, uint64_t *nshared) |
2171 | { |
2172 | *nperm = perm & DEFAULT_PERM_PASSTHROUGH; |
2173 | *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED; |
2174 | } |
2175 | |
2176 | void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, |
2177 | const BdrvChildRole *role, |
2178 | BlockReopenQueue *reopen_queue, |
2179 | uint64_t perm, uint64_t shared, |
2180 | uint64_t *nperm, uint64_t *nshared) |
2181 | { |
2182 | bool backing = (role == &child_backing); |
2183 | assert(role == &child_backing || role == &child_file); |
2184 | |
2185 | if (!backing) { |
2186 | int flags = bdrv_reopen_get_flags(reopen_queue, bs); |
2187 | |
2188 | /* Apart from the modifications below, the same permissions are |
2189 | * forwarded and left alone as for filters */ |
2190 | bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared, |
2191 | &perm, &shared); |
2192 | |
2193 | /* Format drivers may touch metadata even if the guest doesn't write */ |
2194 | if (bdrv_is_writable_after_reopen(bs, reopen_queue)) { |
2195 | perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; |
2196 | } |
2197 | |
2198 | /* bs->file always needs to be consistent because of the metadata. We |
2199 | * can never allow other users to resize or write to it. */ |
2200 | if (!(flags & BDRV_O_NO_IO)) { |
2201 | perm |= BLK_PERM_CONSISTENT_READ; |
2202 | } |
2203 | shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); |
2204 | } else { |
2205 | /* We want consistent read from backing files if the parent needs it. |
2206 | * No other operations are performed on backing files. */ |
2207 | perm &= BLK_PERM_CONSISTENT_READ; |
2208 | |
2209 | /* If the parent can deal with changing data, we're okay with a |
2210 | * writable and resizable backing file. */ |
2211 | /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */ |
2212 | if (shared & BLK_PERM_WRITE) { |
2213 | shared = BLK_PERM_WRITE | BLK_PERM_RESIZE; |
2214 | } else { |
2215 | shared = 0; |
2216 | } |
2217 | |
2218 | shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD | |
2219 | BLK_PERM_WRITE_UNCHANGED; |
2220 | } |
2221 | |
2222 | if (bs->open_flags & BDRV_O_INACTIVE) { |
2223 | shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE; |
2224 | } |
2225 | |
2226 | *nperm = perm; |
2227 | *nshared = shared; |
2228 | } |
2229 | |
2230 | static void bdrv_replace_child_noperm(BdrvChild *child, |
2231 | BlockDriverState *new_bs) |
2232 | { |
2233 | BlockDriverState *old_bs = child->bs; |
2234 | int new_bs_quiesce_counter; |
2235 | int drain_saldo; |
2236 | |
2237 | assert(!child->frozen); |
2238 | |
2239 | if (old_bs && new_bs) { |
2240 | assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)); |
2241 | } |
2242 | |
2243 | new_bs_quiesce_counter = (new_bs ? new_bs->quiesce_counter : 0); |
2244 | drain_saldo = new_bs_quiesce_counter - child->parent_quiesce_counter; |
2245 | |
2246 | /* |
2247 | * If the new child node is drained but the old one was not, flush |
2248 | * all outstanding requests to the old child node. |
2249 | */ |
2250 | while (drain_saldo > 0 && child->role->drained_begin) { |
2251 | bdrv_parent_drained_begin_single(child, true); |
2252 | drain_saldo--; |
2253 | } |
2254 | |
2255 | if (old_bs) { |
2256 | /* Detach first so that the recursive drain sections coming from @child |
2257 | * are already gone and we only end the drain sections that came from |
2258 | * elsewhere. */ |
2259 | if (child->role->detach) { |
2260 | child->role->detach(child); |
2261 | } |
2262 | QLIST_REMOVE(child, next_parent); |
2263 | } |
2264 | |
2265 | child->bs = new_bs; |
2266 | |
2267 | if (new_bs) { |
2268 | QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent); |
2269 | |
2270 | /* |
2271 | * Detaching the old node may have led to the new node's |
2272 | * quiesce_counter having been decreased. Not a problem, we |
2273 | * just need to recognize this here and then invoke |
2274 | * drained_end appropriately more often. |
2275 | */ |
2276 | assert(new_bs->quiesce_counter <= new_bs_quiesce_counter); |
2277 | drain_saldo += new_bs->quiesce_counter - new_bs_quiesce_counter; |
2278 | |
2279 | /* Attach only after starting new drained sections, so that recursive |
2280 | * drain sections coming from @child don't get an extra .drained_begin |
2281 | * callback. */ |
2282 | if (child->role->attach) { |
2283 | child->role->attach(child); |
2284 | } |
2285 | } |
2286 | |
2287 | /* |
2288 | * If the old child node was drained but the new one is not, allow |
2289 | * requests to come in only after the new node has been attached. |
2290 | */ |
2291 | while (drain_saldo < 0 && child->role->drained_end) { |
2292 | bdrv_parent_drained_end_single(child); |
2293 | drain_saldo++; |
2294 | } |
2295 | } |
2296 | |
2297 | /* |
2298 | * Updates @child to change its reference to point to @new_bs, including |
2299 | * checking and applying the necessary permisson updates both to the old node |
2300 | * and to @new_bs. |
2301 | * |
2302 | * NULL is passed as @new_bs for removing the reference before freeing @child. |
2303 | * |
2304 | * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this |
2305 | * function uses bdrv_set_perm() to update the permissions according to the new |
2306 | * reference that @new_bs gets. |
2307 | */ |
2308 | static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) |
2309 | { |
2310 | BlockDriverState *old_bs = child->bs; |
2311 | uint64_t perm, shared_perm; |
2312 | |
2313 | bdrv_replace_child_noperm(child, new_bs); |
2314 | |
2315 | /* |
2316 | * Start with the new node's permissions. If @new_bs is a (direct |
2317 | * or indirect) child of @old_bs, we must complete the permission |
2318 | * update on @new_bs before we loosen the restrictions on @old_bs. |
2319 | * Otherwise, bdrv_check_perm() on @old_bs would re-initiate |
2320 | * updating the permissions of @new_bs, and thus not purely loosen |
2321 | * restrictions. |
2322 | */ |
2323 | if (new_bs) { |
2324 | bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm); |
2325 | bdrv_set_perm(new_bs, perm, shared_perm); |
2326 | } |
2327 | |
2328 | if (old_bs) { |
2329 | /* Update permissions for old node. This is guaranteed to succeed |
2330 | * because we're just taking a parent away, so we're loosening |
2331 | * restrictions. */ |
2332 | bool tighten_restrictions; |
2333 | int ret; |
2334 | |
2335 | bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm); |
2336 | ret = bdrv_check_perm(old_bs, NULL, perm, shared_perm, NULL, |
2337 | &tighten_restrictions, NULL); |
2338 | assert(tighten_restrictions == false); |
2339 | if (ret < 0) { |
2340 | /* We only tried to loosen restrictions, so errors are not fatal */ |
2341 | bdrv_abort_perm_update(old_bs); |
2342 | } else { |
2343 | bdrv_set_perm(old_bs, perm, shared_perm); |
2344 | } |
2345 | |
2346 | /* When the parent requiring a non-default AioContext is removed, the |
2347 | * node moves back to the main AioContext */ |
2348 | bdrv_try_set_aio_context(old_bs, qemu_get_aio_context(), NULL); |
2349 | } |
2350 | } |
2351 | |
2352 | /* |
2353 | * This function steals the reference to child_bs from the caller. |
2354 | * That reference is later dropped by bdrv_root_unref_child(). |
2355 | * |
2356 | * On failure NULL is returned, errp is set and the reference to |
2357 | * child_bs is also dropped. |
2358 | * |
2359 | * The caller must hold the AioContext lock @child_bs, but not that of @ctx |
2360 | * (unless @child_bs is already in @ctx). |
2361 | */ |
2362 | BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, |
2363 | const char *child_name, |
2364 | const BdrvChildRole *child_role, |
2365 | AioContext *ctx, |
2366 | uint64_t perm, uint64_t shared_perm, |
2367 | void *opaque, Error **errp) |
2368 | { |
2369 | BdrvChild *child; |
2370 | Error *local_err = NULL; |
2371 | int ret; |
2372 | |
2373 | ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, NULL, |
2374 | errp); |
2375 | if (ret < 0) { |
2376 | bdrv_abort_perm_update(child_bs); |
2377 | bdrv_unref(child_bs); |
2378 | return NULL; |
2379 | } |
2380 | |
2381 | child = g_new(BdrvChild, 1); |
2382 | *child = (BdrvChild) { |
2383 | .bs = NULL, |
2384 | .name = g_strdup(child_name), |
2385 | .role = child_role, |
2386 | .perm = perm, |
2387 | .shared_perm = shared_perm, |
2388 | .opaque = opaque, |
2389 | }; |
2390 | |
2391 | /* If the AioContexts don't match, first try to move the subtree of |
2392 | * child_bs into the AioContext of the new parent. If this doesn't work, |
2393 | * try moving the parent into the AioContext of child_bs instead. */ |
2394 | if (bdrv_get_aio_context(child_bs) != ctx) { |
2395 | ret = bdrv_try_set_aio_context(child_bs, ctx, &local_err); |
2396 | if (ret < 0 && child_role->can_set_aio_ctx) { |
2397 | GSList *ignore = g_slist_prepend(NULL, child);; |
2398 | ctx = bdrv_get_aio_context(child_bs); |
2399 | if (child_role->can_set_aio_ctx(child, ctx, &ignore, NULL)) { |
2400 | error_free(local_err); |
2401 | ret = 0; |
2402 | g_slist_free(ignore); |
2403 | ignore = g_slist_prepend(NULL, child);; |
2404 | child_role->set_aio_ctx(child, ctx, &ignore); |
2405 | } |
2406 | g_slist_free(ignore); |
2407 | } |
2408 | if (ret < 0) { |
2409 | error_propagate(errp, local_err); |
2410 | g_free(child); |
2411 | bdrv_abort_perm_update(child_bs); |
2412 | return NULL; |
2413 | } |
2414 | } |
2415 | |
2416 | /* This performs the matching bdrv_set_perm() for the above check. */ |
2417 | bdrv_replace_child(child, child_bs); |
2418 | |
2419 | return child; |
2420 | } |
2421 | |
2422 | /* |
2423 | * This function transfers the reference to child_bs from the caller |
2424 | * to parent_bs. That reference is later dropped by parent_bs on |
2425 | * bdrv_close() or if someone calls bdrv_unref_child(). |
2426 | * |
2427 | * On failure NULL is returned, errp is set and the reference to |
2428 | * child_bs is also dropped. |
2429 | * |
2430 | * If @parent_bs and @child_bs are in different AioContexts, the caller must |
2431 | * hold the AioContext lock for @child_bs, but not for @parent_bs. |
2432 | */ |
2433 | BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, |
2434 | BlockDriverState *child_bs, |
2435 | const char *child_name, |
2436 | const BdrvChildRole *child_role, |
2437 | Error **errp) |
2438 | { |
2439 | BdrvChild *child; |
2440 | uint64_t perm, shared_perm; |
2441 | |
2442 | bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm); |
2443 | |
2444 | assert(parent_bs->drv); |
2445 | bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL, |
2446 | perm, shared_perm, &perm, &shared_perm); |
2447 | |
2448 | child = bdrv_root_attach_child(child_bs, child_name, child_role, |
2449 | bdrv_get_aio_context(parent_bs), |
2450 | perm, shared_perm, parent_bs, errp); |
2451 | if (child == NULL) { |
2452 | return NULL; |
2453 | } |
2454 | |
2455 | QLIST_INSERT_HEAD(&parent_bs->children, child, next); |
2456 | return child; |
2457 | } |
2458 | |
2459 | static void bdrv_detach_child(BdrvChild *child) |
2460 | { |
2461 | if (child->next.le_prev) { |
2462 | QLIST_REMOVE(child, next); |
2463 | child->next.le_prev = NULL; |
2464 | } |
2465 | |
2466 | bdrv_replace_child(child, NULL); |
2467 | |
2468 | g_free(child->name); |
2469 | g_free(child); |
2470 | } |
2471 | |
2472 | void bdrv_root_unref_child(BdrvChild *child) |
2473 | { |
2474 | BlockDriverState *child_bs; |
2475 | |
2476 | child_bs = child->bs; |
2477 | bdrv_detach_child(child); |
2478 | bdrv_unref(child_bs); |
2479 | } |
2480 | |
2481 | /** |
2482 | * Clear all inherits_from pointers from children and grandchildren of |
2483 | * @root that point to @root, where necessary. |
2484 | */ |
2485 | static void bdrv_unset_inherits_from(BlockDriverState *root, BdrvChild *child) |
2486 | { |
2487 | BdrvChild *c; |
2488 | |
2489 | if (child->bs->inherits_from == root) { |
2490 | /* |
2491 | * Remove inherits_from only when the last reference between root and |
2492 | * child->bs goes away. |
2493 | */ |
2494 | QLIST_FOREACH(c, &root->children, next) { |
2495 | if (c != child && c->bs == child->bs) { |
2496 | break; |
2497 | } |
2498 | } |
2499 | if (c == NULL) { |
2500 | child->bs->inherits_from = NULL; |
2501 | } |
2502 | } |
2503 | |
2504 | QLIST_FOREACH(c, &child->bs->children, next) { |
2505 | bdrv_unset_inherits_from(root, c); |
2506 | } |
2507 | } |
2508 | |
2509 | void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) |
2510 | { |
2511 | if (child == NULL) { |
2512 | return; |
2513 | } |
2514 | |
2515 | bdrv_unset_inherits_from(parent, child); |
2516 | bdrv_root_unref_child(child); |
2517 | } |
2518 | |
2519 | |
2520 | static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load) |
2521 | { |
2522 | BdrvChild *c; |
2523 | QLIST_FOREACH(c, &bs->parents, next_parent) { |
2524 | if (c->role->change_media) { |
2525 | c->role->change_media(c, load); |
2526 | } |
2527 | } |
2528 | } |
2529 | |
2530 | /* Return true if you can reach parent going through child->inherits_from |
2531 | * recursively. If parent or child are NULL, return false */ |
2532 | static bool bdrv_inherits_from_recursive(BlockDriverState *child, |
2533 | BlockDriverState *parent) |
2534 | { |
2535 | while (child && child != parent) { |
2536 | child = child->inherits_from; |
2537 | } |
2538 | |
2539 | return child != NULL; |
2540 | } |
2541 | |
2542 | /* |
2543 | * Sets the backing file link of a BDS. A new reference is created; callers |
2544 | * which don't need their own reference any more must call bdrv_unref(). |
2545 | */ |
2546 | void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, |
2547 | Error **errp) |
2548 | { |
2549 | bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) && |
2550 | bdrv_inherits_from_recursive(backing_hd, bs); |
2551 | |
2552 | if (bdrv_is_backing_chain_frozen(bs, backing_bs(bs), errp)) { |
2553 | return; |
2554 | } |
2555 | |
2556 | if (backing_hd) { |
2557 | bdrv_ref(backing_hd); |
2558 | } |
2559 | |
2560 | if (bs->backing) { |
2561 | bdrv_unref_child(bs, bs->backing); |
2562 | } |
2563 | |
2564 | if (!backing_hd) { |
2565 | bs->backing = NULL; |
2566 | goto out; |
2567 | } |
2568 | |
2569 | bs->backing = bdrv_attach_child(bs, backing_hd, "backing" , &child_backing, |
2570 | errp); |
2571 | /* If backing_hd was already part of bs's backing chain, and |
2572 | * inherits_from pointed recursively to bs then let's update it to |
2573 | * point directly to bs (else it will become NULL). */ |
2574 | if (bs->backing && update_inherits_from) { |
2575 | backing_hd->inherits_from = bs; |
2576 | } |
2577 | |
2578 | out: |
2579 | bdrv_refresh_limits(bs, NULL); |
2580 | } |
2581 | |
2582 | /* |
2583 | * Opens the backing file for a BlockDriverState if not yet open |
2584 | * |
2585 | * bdref_key specifies the key for the image's BlockdevRef in the options QDict. |
2586 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict |
2587 | * itself, all options starting with "${bdref_key}." are considered part of the |
2588 | * BlockdevRef. |
2589 | * |
2590 | * TODO Can this be unified with bdrv_open_image()? |
2591 | */ |
2592 | int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, |
2593 | const char *bdref_key, Error **errp) |
2594 | { |
2595 | char *backing_filename = NULL; |
2596 | char *bdref_key_dot; |
2597 | const char *reference = NULL; |
2598 | int ret = 0; |
2599 | bool implicit_backing = false; |
2600 | BlockDriverState *backing_hd; |
2601 | QDict *options; |
2602 | QDict *tmp_parent_options = NULL; |
2603 | Error *local_err = NULL; |
2604 | |
2605 | if (bs->backing != NULL) { |
2606 | goto free_exit; |
2607 | } |
2608 | |
2609 | /* NULL means an empty set of options */ |
2610 | if (parent_options == NULL) { |
2611 | tmp_parent_options = qdict_new(); |
2612 | parent_options = tmp_parent_options; |
2613 | } |
2614 | |
2615 | bs->open_flags &= ~BDRV_O_NO_BACKING; |
2616 | |
2617 | bdref_key_dot = g_strdup_printf("%s." , bdref_key); |
2618 | qdict_extract_subqdict(parent_options, &options, bdref_key_dot); |
2619 | g_free(bdref_key_dot); |
2620 | |
2621 | /* |
2622 | * Caution: while qdict_get_try_str() is fine, getting non-string |
2623 | * types would require more care. When @parent_options come from |
2624 | * -blockdev or blockdev_add, its members are typed according to |
2625 | * the QAPI schema, but when they come from -drive, they're all |
2626 | * QString. |
2627 | */ |
2628 | reference = qdict_get_try_str(parent_options, bdref_key); |
2629 | if (reference || qdict_haskey(options, "file.filename" )) { |
2630 | /* keep backing_filename NULL */ |
2631 | } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { |
2632 | qobject_unref(options); |
2633 | goto free_exit; |
2634 | } else { |
2635 | if (qdict_size(options) == 0) { |
2636 | /* If the user specifies options that do not modify the |
2637 | * backing file's behavior, we might still consider it the |
2638 | * implicit backing file. But it's easier this way, and |
2639 | * just specifying some of the backing BDS's options is |
2640 | * only possible with -drive anyway (otherwise the QAPI |
2641 | * schema forces the user to specify everything). */ |
2642 | implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file); |
2643 | } |
2644 | |
2645 | backing_filename = bdrv_get_full_backing_filename(bs, &local_err); |
2646 | if (local_err) { |
2647 | ret = -EINVAL; |
2648 | error_propagate(errp, local_err); |
2649 | qobject_unref(options); |
2650 | goto free_exit; |
2651 | } |
2652 | } |
2653 | |
2654 | if (!bs->drv || !bs->drv->supports_backing) { |
2655 | ret = -EINVAL; |
2656 | error_setg(errp, "Driver doesn't support backing files" ); |
2657 | qobject_unref(options); |
2658 | goto free_exit; |
2659 | } |
2660 | |
2661 | if (!reference && |
2662 | bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver" )) { |
2663 | qdict_put_str(options, "driver" , bs->backing_format); |
2664 | } |
2665 | |
2666 | backing_hd = bdrv_open_inherit(backing_filename, reference, options, 0, bs, |
2667 | &child_backing, errp); |
2668 | if (!backing_hd) { |
2669 | bs->open_flags |= BDRV_O_NO_BACKING; |
2670 | error_prepend(errp, "Could not open backing file: " ); |
2671 | ret = -EINVAL; |
2672 | goto free_exit; |
2673 | } |
2674 | |
2675 | if (implicit_backing) { |
2676 | bdrv_refresh_filename(backing_hd); |
2677 | pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), |
2678 | backing_hd->filename); |
2679 | } |
2680 | |
2681 | /* Hook up the backing file link; drop our reference, bs owns the |
2682 | * backing_hd reference now */ |
2683 | bdrv_set_backing_hd(bs, backing_hd, &local_err); |
2684 | bdrv_unref(backing_hd); |
2685 | if (local_err) { |
2686 | error_propagate(errp, local_err); |
2687 | ret = -EINVAL; |
2688 | goto free_exit; |
2689 | } |
2690 | |
2691 | qdict_del(parent_options, bdref_key); |
2692 | |
2693 | free_exit: |
2694 | g_free(backing_filename); |
2695 | qobject_unref(tmp_parent_options); |
2696 | return ret; |
2697 | } |
2698 | |
2699 | static BlockDriverState * |
2700 | bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key, |
2701 | BlockDriverState *parent, const BdrvChildRole *child_role, |
2702 | bool allow_none, Error **errp) |
2703 | { |
2704 | BlockDriverState *bs = NULL; |
2705 | QDict *image_options; |
2706 | char *bdref_key_dot; |
2707 | const char *reference; |
2708 | |
2709 | assert(child_role != NULL); |
2710 | |
2711 | bdref_key_dot = g_strdup_printf("%s." , bdref_key); |
2712 | qdict_extract_subqdict(options, &image_options, bdref_key_dot); |
2713 | g_free(bdref_key_dot); |
2714 | |
2715 | /* |
2716 | * Caution: while qdict_get_try_str() is fine, getting non-string |
2717 | * types would require more care. When @options come from |
2718 | * -blockdev or blockdev_add, its members are typed according to |
2719 | * the QAPI schema, but when they come from -drive, they're all |
2720 | * QString. |
2721 | */ |
2722 | reference = qdict_get_try_str(options, bdref_key); |
2723 | if (!filename && !reference && !qdict_size(image_options)) { |
2724 | if (!allow_none) { |
2725 | error_setg(errp, "A block device must be specified for \"%s\"" , |
2726 | bdref_key); |
2727 | } |
2728 | qobject_unref(image_options); |
2729 | goto done; |
2730 | } |
2731 | |
2732 | bs = bdrv_open_inherit(filename, reference, image_options, 0, |
2733 | parent, child_role, errp); |
2734 | if (!bs) { |
2735 | goto done; |
2736 | } |
2737 | |
2738 | done: |
2739 | qdict_del(options, bdref_key); |
2740 | return bs; |
2741 | } |
2742 | |
2743 | /* |
2744 | * Opens a disk image whose options are given as BlockdevRef in another block |
2745 | * device's options. |
2746 | * |
2747 | * If allow_none is true, no image will be opened if filename is false and no |
2748 | * BlockdevRef is given. NULL will be returned, but errp remains unset. |
2749 | * |
2750 | * bdrev_key specifies the key for the image's BlockdevRef in the options QDict. |
2751 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict |
2752 | * itself, all options starting with "${bdref_key}." are considered part of the |
2753 | * BlockdevRef. |
2754 | * |
2755 | * The BlockdevRef will be removed from the options QDict. |
2756 | */ |
2757 | BdrvChild *bdrv_open_child(const char *filename, |
2758 | QDict *options, const char *bdref_key, |
2759 | BlockDriverState *parent, |
2760 | const BdrvChildRole *child_role, |
2761 | bool allow_none, Error **errp) |
2762 | { |
2763 | BlockDriverState *bs; |
2764 | |
2765 | bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_role, |
2766 | allow_none, errp); |
2767 | if (bs == NULL) { |
2768 | return NULL; |
2769 | } |
2770 | |
2771 | return bdrv_attach_child(parent, bs, bdref_key, child_role, errp); |
2772 | } |
2773 | |
2774 | /* TODO Future callers may need to specify parent/child_role in order for |
2775 | * option inheritance to work. Existing callers use it for the root node. */ |
2776 | BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp) |
2777 | { |
2778 | BlockDriverState *bs = NULL; |
2779 | Error *local_err = NULL; |
2780 | QObject *obj = NULL; |
2781 | QDict *qdict = NULL; |
2782 | const char *reference = NULL; |
2783 | Visitor *v = NULL; |
2784 | |
2785 | if (ref->type == QTYPE_QSTRING) { |
2786 | reference = ref->u.reference; |
2787 | } else { |
2788 | BlockdevOptions *options = &ref->u.definition; |
2789 | assert(ref->type == QTYPE_QDICT); |
2790 | |
2791 | v = qobject_output_visitor_new(&obj); |
2792 | visit_type_BlockdevOptions(v, NULL, &options, &local_err); |
2793 | if (local_err) { |
2794 | error_propagate(errp, local_err); |
2795 | goto fail; |
2796 | } |
2797 | visit_complete(v, &obj); |
2798 | |
2799 | qdict = qobject_to(QDict, obj); |
2800 | qdict_flatten(qdict); |
2801 | |
2802 | /* bdrv_open_inherit() defaults to the values in bdrv_flags (for |
2803 | * compatibility with other callers) rather than what we want as the |
2804 | * real defaults. Apply the defaults here instead. */ |
2805 | qdict_set_default_str(qdict, BDRV_OPT_CACHE_DIRECT, "off" ); |
2806 | qdict_set_default_str(qdict, BDRV_OPT_CACHE_NO_FLUSH, "off" ); |
2807 | qdict_set_default_str(qdict, BDRV_OPT_READ_ONLY, "off" ); |
2808 | qdict_set_default_str(qdict, BDRV_OPT_AUTO_READ_ONLY, "off" ); |
2809 | |
2810 | } |
2811 | |
2812 | bs = bdrv_open_inherit(NULL, reference, qdict, 0, NULL, NULL, errp); |
2813 | obj = NULL; |
2814 | |
2815 | fail: |
2816 | qobject_unref(obj); |
2817 | visit_free(v); |
2818 | return bs; |
2819 | } |
2820 | |
2821 | static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs, |
2822 | int flags, |
2823 | QDict *snapshot_options, |
2824 | Error **errp) |
2825 | { |
2826 | /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ |
2827 | char *tmp_filename = g_malloc0(PATH_MAX + 1); |
2828 | int64_t total_size; |
2829 | QemuOpts *opts = NULL; |
2830 | BlockDriverState *bs_snapshot = NULL; |
2831 | Error *local_err = NULL; |
2832 | int ret; |
2833 | |
2834 | /* if snapshot, we create a temporary backing file and open it |
2835 | instead of opening 'filename' directly */ |
2836 | |
2837 | /* Get the required size from the image */ |
2838 | total_size = bdrv_getlength(bs); |
2839 | if (total_size < 0) { |
2840 | error_setg_errno(errp, -total_size, "Could not get image size" ); |
2841 | goto out; |
2842 | } |
2843 | |
2844 | /* Create the temporary image */ |
2845 | ret = get_tmp_filename(tmp_filename, PATH_MAX + 1); |
2846 | if (ret < 0) { |
2847 | error_setg_errno(errp, -ret, "Could not get temporary filename" ); |
2848 | goto out; |
2849 | } |
2850 | |
2851 | opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, |
2852 | &error_abort); |
2853 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort); |
2854 | ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp); |
2855 | qemu_opts_del(opts); |
2856 | if (ret < 0) { |
2857 | error_prepend(errp, "Could not create temporary overlay '%s': " , |
2858 | tmp_filename); |
2859 | goto out; |
2860 | } |
2861 | |
2862 | /* Prepare options QDict for the temporary file */ |
2863 | qdict_put_str(snapshot_options, "file.driver" , "file" ); |
2864 | qdict_put_str(snapshot_options, "file.filename" , tmp_filename); |
2865 | qdict_put_str(snapshot_options, "driver" , "qcow2" ); |
2866 | |
2867 | bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp); |
2868 | snapshot_options = NULL; |
2869 | if (!bs_snapshot) { |
2870 | goto out; |
2871 | } |
2872 | |
2873 | /* bdrv_append() consumes a strong reference to bs_snapshot |
2874 | * (i.e. it will call bdrv_unref() on it) even on error, so in |
2875 | * order to be able to return one, we have to increase |
2876 | * bs_snapshot's refcount here */ |
2877 | bdrv_ref(bs_snapshot); |
2878 | bdrv_append(bs_snapshot, bs, &local_err); |
2879 | if (local_err) { |
2880 | error_propagate(errp, local_err); |
2881 | bs_snapshot = NULL; |
2882 | goto out; |
2883 | } |
2884 | |
2885 | out: |
2886 | qobject_unref(snapshot_options); |
2887 | g_free(tmp_filename); |
2888 | return bs_snapshot; |
2889 | } |
2890 | |
2891 | /* |
2892 | * Opens a disk image (raw, qcow2, vmdk, ...) |
2893 | * |
2894 | * options is a QDict of options to pass to the block drivers, or NULL for an |
2895 | * empty set of options. The reference to the QDict belongs to the block layer |
2896 | * after the call (even on failure), so if the caller intends to reuse the |
2897 | * dictionary, it needs to use qobject_ref() before calling bdrv_open. |
2898 | * |
2899 | * If *pbs is NULL, a new BDS will be created with a pointer to it stored there. |
2900 | * If it is not NULL, the referenced BDS will be reused. |
2901 | * |
2902 | * The reference parameter may be used to specify an existing block device which |
2903 | * should be opened. If specified, neither options nor a filename may be given, |
2904 | * nor can an existing BDS be reused (that is, *pbs has to be NULL). |
2905 | */ |
2906 | static BlockDriverState *bdrv_open_inherit(const char *filename, |
2907 | const char *reference, |
2908 | QDict *options, int flags, |
2909 | BlockDriverState *parent, |
2910 | const BdrvChildRole *child_role, |
2911 | Error **errp) |
2912 | { |
2913 | int ret; |
2914 | BlockBackend *file = NULL; |
2915 | BlockDriverState *bs; |
2916 | BlockDriver *drv = NULL; |
2917 | BdrvChild *child; |
2918 | const char *drvname; |
2919 | const char *backing; |
2920 | Error *local_err = NULL; |
2921 | QDict *snapshot_options = NULL; |
2922 | int snapshot_flags = 0; |
2923 | |
2924 | assert(!child_role || !flags); |
2925 | assert(!child_role == !parent); |
2926 | |
2927 | if (reference) { |
2928 | bool options_non_empty = options ? qdict_size(options) : false; |
2929 | qobject_unref(options); |
2930 | |
2931 | if (filename || options_non_empty) { |
2932 | error_setg(errp, "Cannot reference an existing block device with " |
2933 | "additional options or a new filename" ); |
2934 | return NULL; |
2935 | } |
2936 | |
2937 | bs = bdrv_lookup_bs(reference, reference, errp); |
2938 | if (!bs) { |
2939 | return NULL; |
2940 | } |
2941 | |
2942 | bdrv_ref(bs); |
2943 | return bs; |
2944 | } |
2945 | |
2946 | bs = bdrv_new(); |
2947 | |
2948 | /* NULL means an empty set of options */ |
2949 | if (options == NULL) { |
2950 | options = qdict_new(); |
2951 | } |
2952 | |
2953 | /* json: syntax counts as explicit options, as if in the QDict */ |
2954 | parse_json_protocol(options, &filename, &local_err); |
2955 | if (local_err) { |
2956 | goto fail; |
2957 | } |
2958 | |
2959 | bs->explicit_options = qdict_clone_shallow(options); |
2960 | |
2961 | if (child_role) { |
2962 | bs->inherits_from = parent; |
2963 | child_role->inherit_options(&flags, options, |
2964 | parent->open_flags, parent->options); |
2965 | } |
2966 | |
2967 | ret = bdrv_fill_options(&options, filename, &flags, &local_err); |
2968 | if (local_err) { |
2969 | goto fail; |
2970 | } |
2971 | |
2972 | /* |
2973 | * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags. |
2974 | * Caution: getting a boolean member of @options requires care. |
2975 | * When @options come from -blockdev or blockdev_add, members are |
2976 | * typed according to the QAPI schema, but when they come from |
2977 | * -drive, they're all QString. |
2978 | */ |
2979 | if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on" ) && |
2980 | !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) { |
2981 | flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR); |
2982 | } else { |
2983 | flags &= ~BDRV_O_RDWR; |
2984 | } |
2985 | |
2986 | if (flags & BDRV_O_SNAPSHOT) { |
2987 | snapshot_options = qdict_new(); |
2988 | bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options, |
2989 | flags, options); |
2990 | /* Let bdrv_backing_options() override "read-only" */ |
2991 | qdict_del(options, BDRV_OPT_READ_ONLY); |
2992 | bdrv_backing_options(&flags, options, flags, options); |
2993 | } |
2994 | |
2995 | bs->open_flags = flags; |
2996 | bs->options = options; |
2997 | options = qdict_clone_shallow(options); |
2998 | |
2999 | /* Find the right image format driver */ |
3000 | /* See cautionary note on accessing @options above */ |
3001 | drvname = qdict_get_try_str(options, "driver" ); |
3002 | if (drvname) { |
3003 | drv = bdrv_find_format(drvname); |
3004 | if (!drv) { |
3005 | error_setg(errp, "Unknown driver: '%s'" , drvname); |
3006 | goto fail; |
3007 | } |
3008 | } |
3009 | |
3010 | assert(drvname || !(flags & BDRV_O_PROTOCOL)); |
3011 | |
3012 | /* See cautionary note on accessing @options above */ |
3013 | backing = qdict_get_try_str(options, "backing" ); |
3014 | if (qobject_to(QNull, qdict_get(options, "backing" )) != NULL || |
3015 | (backing && *backing == '\0')) |
3016 | { |
3017 | if (backing) { |
3018 | warn_report("Use of \"backing\": \"\" is deprecated; " |
3019 | "use \"backing\": null instead" ); |
3020 | } |
3021 | flags |= BDRV_O_NO_BACKING; |
3022 | qdict_del(options, "backing" ); |
3023 | } |
3024 | |
3025 | /* Open image file without format layer. This BlockBackend is only used for |
3026 | * probing, the block drivers will do their own bdrv_open_child() for the |
3027 | * same BDS, which is why we put the node name back into options. */ |
3028 | if ((flags & BDRV_O_PROTOCOL) == 0) { |
3029 | BlockDriverState *file_bs; |
3030 | |
3031 | file_bs = bdrv_open_child_bs(filename, options, "file" , bs, |
3032 | &child_file, true, &local_err); |
3033 | if (local_err) { |
3034 | goto fail; |
3035 | } |
3036 | if (file_bs != NULL) { |
3037 | /* Not requesting BLK_PERM_CONSISTENT_READ because we're only |
3038 | * looking at the header to guess the image format. This works even |
3039 | * in cases where a guest would not see a consistent state. */ |
3040 | file = blk_new(bdrv_get_aio_context(file_bs), 0, BLK_PERM_ALL); |
3041 | blk_insert_bs(file, file_bs, &local_err); |
3042 | bdrv_unref(file_bs); |
3043 | if (local_err) { |
3044 | goto fail; |
3045 | } |
3046 | |
3047 | qdict_put_str(options, "file" , bdrv_get_node_name(file_bs)); |
3048 | } |
3049 | } |
3050 | |
3051 | /* Image format probing */ |
3052 | bs->probed = !drv; |
3053 | if (!drv && file) { |
3054 | ret = find_image_format(file, filename, &drv, &local_err); |
3055 | if (ret < 0) { |
3056 | goto fail; |
3057 | } |
3058 | /* |
3059 | * This option update would logically belong in bdrv_fill_options(), |
3060 | * but we first need to open bs->file for the probing to work, while |
3061 | * opening bs->file already requires the (mostly) final set of options |
3062 | * so that cache mode etc. can be inherited. |
3063 | * |
3064 | * Adding the driver later is somewhat ugly, but it's not an option |
3065 | * that would ever be inherited, so it's correct. We just need to make |
3066 | * sure to update both bs->options (which has the full effective |
3067 | * options for bs) and options (which has file.* already removed). |
3068 | */ |
3069 | qdict_put_str(bs->options, "driver" , drv->format_name); |
3070 | qdict_put_str(options, "driver" , drv->format_name); |
3071 | } else if (!drv) { |
3072 | error_setg(errp, "Must specify either driver or file" ); |
3073 | goto fail; |
3074 | } |
3075 | |
3076 | /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */ |
3077 | assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open); |
3078 | /* file must be NULL if a protocol BDS is about to be created |
3079 | * (the inverse results in an error message from bdrv_open_common()) */ |
3080 | assert(!(flags & BDRV_O_PROTOCOL) || !file); |
3081 | |
3082 | /* Open the image */ |
3083 | ret = bdrv_open_common(bs, file, options, &local_err); |
3084 | if (ret < 0) { |
3085 | goto fail; |
3086 | } |
3087 | |
3088 | if (file) { |
3089 | blk_unref(file); |
3090 | file = NULL; |
3091 | } |
3092 | |
3093 | /* If there is a backing file, use it */ |
3094 | if ((flags & BDRV_O_NO_BACKING) == 0) { |
3095 | ret = bdrv_open_backing_file(bs, options, "backing" , &local_err); |
3096 | if (ret < 0) { |
3097 | goto close_and_fail; |
3098 | } |
3099 | } |
3100 | |
3101 | /* Remove all children options and references |
3102 | * from bs->options and bs->explicit_options */ |
3103 | QLIST_FOREACH(child, &bs->children, next) { |
3104 | char *child_key_dot; |
3105 | child_key_dot = g_strdup_printf("%s." , child->name); |
3106 | qdict_extract_subqdict(bs->explicit_options, NULL, child_key_dot); |
3107 | qdict_extract_subqdict(bs->options, NULL, child_key_dot); |
3108 | qdict_del(bs->explicit_options, child->name); |
3109 | qdict_del(bs->options, child->name); |
3110 | g_free(child_key_dot); |
3111 | } |
3112 | |
3113 | /* Check if any unknown options were used */ |
3114 | if (qdict_size(options) != 0) { |
3115 | const QDictEntry *entry = qdict_first(options); |
3116 | if (flags & BDRV_O_PROTOCOL) { |
3117 | error_setg(errp, "Block protocol '%s' doesn't support the option " |
3118 | "'%s'" , drv->format_name, entry->key); |
3119 | } else { |
3120 | error_setg(errp, |
3121 | "Block format '%s' does not support the option '%s'" , |
3122 | drv->format_name, entry->key); |
3123 | } |
3124 | |
3125 | goto close_and_fail; |
3126 | } |
3127 | |
3128 | bdrv_parent_cb_change_media(bs, true); |
3129 | |
3130 | qobject_unref(options); |
3131 | options = NULL; |
3132 | |
3133 | /* For snapshot=on, create a temporary qcow2 overlay. bs points to the |
3134 | * temporary snapshot afterwards. */ |
3135 | if (snapshot_flags) { |
3136 | BlockDriverState *snapshot_bs; |
3137 | snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags, |
3138 | snapshot_options, &local_err); |
3139 | snapshot_options = NULL; |
3140 | if (local_err) { |
3141 | goto close_and_fail; |
3142 | } |
3143 | /* We are not going to return bs but the overlay on top of it |
3144 | * (snapshot_bs); thus, we have to drop the strong reference to bs |
3145 | * (which we obtained by calling bdrv_new()). bs will not be deleted, |
3146 | * though, because the overlay still has a reference to it. */ |
3147 | bdrv_unref(bs); |
3148 | bs = snapshot_bs; |
3149 | } |
3150 | |
3151 | return bs; |
3152 | |
3153 | fail: |
3154 | blk_unref(file); |
3155 | qobject_unref(snapshot_options); |
3156 | qobject_unref(bs->explicit_options); |
3157 | qobject_unref(bs->options); |
3158 | qobject_unref(options); |
3159 | bs->options = NULL; |
3160 | bs->explicit_options = NULL; |
3161 | bdrv_unref(bs); |
3162 | error_propagate(errp, local_err); |
3163 | return NULL; |
3164 | |
3165 | close_and_fail: |
3166 | bdrv_unref(bs); |
3167 | qobject_unref(snapshot_options); |
3168 | qobject_unref(options); |
3169 | error_propagate(errp, local_err); |
3170 | return NULL; |
3171 | } |
3172 | |
3173 | BlockDriverState *bdrv_open(const char *filename, const char *reference, |
3174 | QDict *options, int flags, Error **errp) |
3175 | { |
3176 | return bdrv_open_inherit(filename, reference, options, flags, NULL, |
3177 | NULL, errp); |
3178 | } |
3179 | |
3180 | /* Return true if the NULL-terminated @list contains @str */ |
3181 | static bool is_str_in_list(const char *str, const char *const *list) |
3182 | { |
3183 | if (str && list) { |
3184 | int i; |
3185 | for (i = 0; list[i] != NULL; i++) { |
3186 | if (!strcmp(str, list[i])) { |
3187 | return true; |
3188 | } |
3189 | } |
3190 | } |
3191 | return false; |
3192 | } |
3193 | |
3194 | /* |
3195 | * Check that every option set in @bs->options is also set in |
3196 | * @new_opts. |
3197 | * |
3198 | * Options listed in the common_options list and in |
3199 | * @bs->drv->mutable_opts are skipped. |
3200 | * |
3201 | * Return 0 on success, otherwise return -EINVAL and set @errp. |
3202 | */ |
3203 | static int bdrv_reset_options_allowed(BlockDriverState *bs, |
3204 | const QDict *new_opts, Error **errp) |
3205 | { |
3206 | const QDictEntry *e; |
3207 | /* These options are common to all block drivers and are handled |
3208 | * in bdrv_reopen_prepare() so they can be left out of @new_opts */ |
3209 | const char *const common_options[] = { |
3210 | "node-name" , "discard" , "cache.direct" , "cache.no-flush" , |
3211 | "read-only" , "auto-read-only" , "detect-zeroes" , NULL |
3212 | }; |
3213 | |
3214 | for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) { |
3215 | if (!qdict_haskey(new_opts, e->key) && |
3216 | !is_str_in_list(e->key, common_options) && |
3217 | !is_str_in_list(e->key, bs->drv->mutable_opts)) { |
3218 | error_setg(errp, "Option '%s' cannot be reset " |
3219 | "to its default value" , e->key); |
3220 | return -EINVAL; |
3221 | } |
3222 | } |
3223 | |
3224 | return 0; |
3225 | } |
3226 | |
3227 | /* |
3228 | * Returns true if @child can be reached recursively from @bs |
3229 | */ |
3230 | static bool bdrv_recurse_has_child(BlockDriverState *bs, |
3231 | BlockDriverState *child) |
3232 | { |
3233 | BdrvChild *c; |
3234 | |
3235 | if (bs == child) { |
3236 | return true; |
3237 | } |
3238 | |
3239 | QLIST_FOREACH(c, &bs->children, next) { |
3240 | if (bdrv_recurse_has_child(c->bs, child)) { |
3241 | return true; |
3242 | } |
3243 | } |
3244 | |
3245 | return false; |
3246 | } |
3247 | |
3248 | /* |
3249 | * Adds a BlockDriverState to a simple queue for an atomic, transactional |
3250 | * reopen of multiple devices. |
3251 | * |
3252 | * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT |
3253 | * already performed, or alternatively may be NULL a new BlockReopenQueue will |
3254 | * be created and initialized. This newly created BlockReopenQueue should be |
3255 | * passed back in for subsequent calls that are intended to be of the same |
3256 | * atomic 'set'. |
3257 | * |
3258 | * bs is the BlockDriverState to add to the reopen queue. |
3259 | * |
3260 | * options contains the changed options for the associated bs |
3261 | * (the BlockReopenQueue takes ownership) |
3262 | * |
3263 | * flags contains the open flags for the associated bs |
3264 | * |
3265 | * returns a pointer to bs_queue, which is either the newly allocated |
3266 | * bs_queue, or the existing bs_queue being used. |
3267 | * |
3268 | * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple(). |
3269 | */ |
3270 | static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, |
3271 | BlockDriverState *bs, |
3272 | QDict *options, |
3273 | const BdrvChildRole *role, |
3274 | QDict *parent_options, |
3275 | int parent_flags, |
3276 | bool keep_old_opts) |
3277 | { |
3278 | assert(bs != NULL); |
3279 | |
3280 | BlockReopenQueueEntry *bs_entry; |
3281 | BdrvChild *child; |
3282 | QDict *old_options, *explicit_options, *options_copy; |
3283 | int flags; |
3284 | QemuOpts *opts; |
3285 | |
3286 | /* Make sure that the caller remembered to use a drained section. This is |
3287 | * important to avoid graph changes between the recursive queuing here and |
3288 | * bdrv_reopen_multiple(). */ |
3289 | assert(bs->quiesce_counter > 0); |
3290 | |
3291 | if (bs_queue == NULL) { |
3292 | bs_queue = g_new0(BlockReopenQueue, 1); |
3293 | QSIMPLEQ_INIT(bs_queue); |
3294 | } |
3295 | |
3296 | if (!options) { |
3297 | options = qdict_new(); |
3298 | } |
3299 | |
3300 | /* Check if this BlockDriverState is already in the queue */ |
3301 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
3302 | if (bs == bs_entry->state.bs) { |
3303 | break; |
3304 | } |
3305 | } |
3306 | |
3307 | /* |
3308 | * Precedence of options: |
3309 | * 1. Explicitly passed in options (highest) |
3310 | * 2. Retained from explicitly set options of bs |
3311 | * 3. Inherited from parent node |
3312 | * 4. Retained from effective options of bs |
3313 | */ |
3314 | |
3315 | /* Old explicitly set values (don't overwrite by inherited value) */ |
3316 | if (bs_entry || keep_old_opts) { |
3317 | old_options = qdict_clone_shallow(bs_entry ? |
3318 | bs_entry->state.explicit_options : |
3319 | bs->explicit_options); |
3320 | bdrv_join_options(bs, options, old_options); |
3321 | qobject_unref(old_options); |
3322 | } |
3323 | |
3324 | explicit_options = qdict_clone_shallow(options); |
3325 | |
3326 | /* Inherit from parent node */ |
3327 | if (parent_options) { |
3328 | flags = 0; |
3329 | role->inherit_options(&flags, options, parent_flags, parent_options); |
3330 | } else { |
3331 | flags = bdrv_get_flags(bs); |
3332 | } |
3333 | |
3334 | if (keep_old_opts) { |
3335 | /* Old values are used for options that aren't set yet */ |
3336 | old_options = qdict_clone_shallow(bs->options); |
3337 | bdrv_join_options(bs, options, old_options); |
3338 | qobject_unref(old_options); |
3339 | } |
3340 | |
3341 | /* We have the final set of options so let's update the flags */ |
3342 | options_copy = qdict_clone_shallow(options); |
3343 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); |
3344 | qemu_opts_absorb_qdict(opts, options_copy, NULL); |
3345 | update_flags_from_options(&flags, opts); |
3346 | qemu_opts_del(opts); |
3347 | qobject_unref(options_copy); |
3348 | |
3349 | /* bdrv_open_inherit() sets and clears some additional flags internally */ |
3350 | flags &= ~BDRV_O_PROTOCOL; |
3351 | if (flags & BDRV_O_RDWR) { |
3352 | flags |= BDRV_O_ALLOW_RDWR; |
3353 | } |
3354 | |
3355 | if (!bs_entry) { |
3356 | bs_entry = g_new0(BlockReopenQueueEntry, 1); |
3357 | QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); |
3358 | } else { |
3359 | qobject_unref(bs_entry->state.options); |
3360 | qobject_unref(bs_entry->state.explicit_options); |
3361 | } |
3362 | |
3363 | bs_entry->state.bs = bs; |
3364 | bs_entry->state.options = options; |
3365 | bs_entry->state.explicit_options = explicit_options; |
3366 | bs_entry->state.flags = flags; |
3367 | |
3368 | /* This needs to be overwritten in bdrv_reopen_prepare() */ |
3369 | bs_entry->state.perm = UINT64_MAX; |
3370 | bs_entry->state.shared_perm = 0; |
3371 | |
3372 | /* |
3373 | * If keep_old_opts is false then it means that unspecified |
3374 | * options must be reset to their original value. We don't allow |
3375 | * resetting 'backing' but we need to know if the option is |
3376 | * missing in order to decide if we have to return an error. |
3377 | */ |
3378 | if (!keep_old_opts) { |
3379 | bs_entry->state.backing_missing = |
3380 | !qdict_haskey(options, "backing" ) && |
3381 | !qdict_haskey(options, "backing.driver" ); |
3382 | } |
3383 | |
3384 | QLIST_FOREACH(child, &bs->children, next) { |
3385 | QDict *new_child_options = NULL; |
3386 | bool child_keep_old = keep_old_opts; |
3387 | |
3388 | /* reopen can only change the options of block devices that were |
3389 | * implicitly created and inherited options. For other (referenced) |
3390 | * block devices, a syntax like "backing.foo" results in an error. */ |
3391 | if (child->bs->inherits_from != bs) { |
3392 | continue; |
3393 | } |
3394 | |
3395 | /* Check if the options contain a child reference */ |
3396 | if (qdict_haskey(options, child->name)) { |
3397 | const char *childref = qdict_get_try_str(options, child->name); |
3398 | /* |
3399 | * The current child must not be reopened if the child |
3400 | * reference is null or points to a different node. |
3401 | */ |
3402 | if (g_strcmp0(childref, child->bs->node_name)) { |
3403 | continue; |
3404 | } |
3405 | /* |
3406 | * If the child reference points to the current child then |
3407 | * reopen it with its existing set of options (note that |
3408 | * it can still inherit new options from the parent). |
3409 | */ |
3410 | child_keep_old = true; |
3411 | } else { |
3412 | /* Extract child options ("child-name.*") */ |
3413 | char *child_key_dot = g_strdup_printf("%s." , child->name); |
3414 | qdict_extract_subqdict(explicit_options, NULL, child_key_dot); |
3415 | qdict_extract_subqdict(options, &new_child_options, child_key_dot); |
3416 | g_free(child_key_dot); |
3417 | } |
3418 | |
3419 | bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options, |
3420 | child->role, options, flags, child_keep_old); |
3421 | } |
3422 | |
3423 | return bs_queue; |
3424 | } |
3425 | |
3426 | BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, |
3427 | BlockDriverState *bs, |
3428 | QDict *options, bool keep_old_opts) |
3429 | { |
3430 | return bdrv_reopen_queue_child(bs_queue, bs, options, NULL, NULL, 0, |
3431 | keep_old_opts); |
3432 | } |
3433 | |
3434 | /* |
3435 | * Reopen multiple BlockDriverStates atomically & transactionally. |
3436 | * |
3437 | * The queue passed in (bs_queue) must have been built up previous |
3438 | * via bdrv_reopen_queue(). |
3439 | * |
3440 | * Reopens all BDS specified in the queue, with the appropriate |
3441 | * flags. All devices are prepared for reopen, and failure of any |
3442 | * device will cause all device changes to be abandoned, and intermediate |
3443 | * data cleaned up. |
3444 | * |
3445 | * If all devices prepare successfully, then the changes are committed |
3446 | * to all devices. |
3447 | * |
3448 | * All affected nodes must be drained between bdrv_reopen_queue() and |
3449 | * bdrv_reopen_multiple(). |
3450 | */ |
3451 | int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) |
3452 | { |
3453 | int ret = -1; |
3454 | BlockReopenQueueEntry *bs_entry, *next; |
3455 | |
3456 | assert(bs_queue != NULL); |
3457 | |
3458 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
3459 | assert(bs_entry->state.bs->quiesce_counter > 0); |
3460 | if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, errp)) { |
3461 | goto cleanup; |
3462 | } |
3463 | bs_entry->prepared = true; |
3464 | } |
3465 | |
3466 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
3467 | BDRVReopenState *state = &bs_entry->state; |
3468 | ret = bdrv_check_perm(state->bs, bs_queue, state->perm, |
3469 | state->shared_perm, NULL, NULL, errp); |
3470 | if (ret < 0) { |
3471 | goto cleanup_perm; |
3472 | } |
3473 | /* Check if new_backing_bs would accept the new permissions */ |
3474 | if (state->replace_backing_bs && state->new_backing_bs) { |
3475 | uint64_t nperm, nshared; |
3476 | bdrv_child_perm(state->bs, state->new_backing_bs, |
3477 | NULL, &child_backing, bs_queue, |
3478 | state->perm, state->shared_perm, |
3479 | &nperm, &nshared); |
3480 | ret = bdrv_check_update_perm(state->new_backing_bs, NULL, |
3481 | nperm, nshared, NULL, NULL, errp); |
3482 | if (ret < 0) { |
3483 | goto cleanup_perm; |
3484 | } |
3485 | } |
3486 | bs_entry->perms_checked = true; |
3487 | } |
3488 | |
3489 | /* If we reach this point, we have success and just need to apply the |
3490 | * changes |
3491 | */ |
3492 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
3493 | bdrv_reopen_commit(&bs_entry->state); |
3494 | } |
3495 | |
3496 | ret = 0; |
3497 | cleanup_perm: |
3498 | QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { |
3499 | BDRVReopenState *state = &bs_entry->state; |
3500 | |
3501 | if (!bs_entry->perms_checked) { |
3502 | continue; |
3503 | } |
3504 | |
3505 | if (ret == 0) { |
3506 | bdrv_set_perm(state->bs, state->perm, state->shared_perm); |
3507 | } else { |
3508 | bdrv_abort_perm_update(state->bs); |
3509 | if (state->replace_backing_bs && state->new_backing_bs) { |
3510 | bdrv_abort_perm_update(state->new_backing_bs); |
3511 | } |
3512 | } |
3513 | } |
3514 | cleanup: |
3515 | QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { |
3516 | if (ret) { |
3517 | if (bs_entry->prepared) { |
3518 | bdrv_reopen_abort(&bs_entry->state); |
3519 | } |
3520 | qobject_unref(bs_entry->state.explicit_options); |
3521 | qobject_unref(bs_entry->state.options); |
3522 | } |
3523 | if (bs_entry->state.new_backing_bs) { |
3524 | bdrv_unref(bs_entry->state.new_backing_bs); |
3525 | } |
3526 | g_free(bs_entry); |
3527 | } |
3528 | g_free(bs_queue); |
3529 | |
3530 | return ret; |
3531 | } |
3532 | |
3533 | int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only, |
3534 | Error **errp) |
3535 | { |
3536 | int ret; |
3537 | BlockReopenQueue *queue; |
3538 | QDict *opts = qdict_new(); |
3539 | |
3540 | qdict_put_bool(opts, BDRV_OPT_READ_ONLY, read_only); |
3541 | |
3542 | bdrv_subtree_drained_begin(bs); |
3543 | queue = bdrv_reopen_queue(NULL, bs, opts, true); |
3544 | ret = bdrv_reopen_multiple(queue, errp); |
3545 | bdrv_subtree_drained_end(bs); |
3546 | |
3547 | return ret; |
3548 | } |
3549 | |
3550 | static BlockReopenQueueEntry *find_parent_in_reopen_queue(BlockReopenQueue *q, |
3551 | BdrvChild *c) |
3552 | { |
3553 | BlockReopenQueueEntry *entry; |
3554 | |
3555 | QSIMPLEQ_FOREACH(entry, q, entry) { |
3556 | BlockDriverState *bs = entry->state.bs; |
3557 | BdrvChild *child; |
3558 | |
3559 | QLIST_FOREACH(child, &bs->children, next) { |
3560 | if (child == c) { |
3561 | return entry; |
3562 | } |
3563 | } |
3564 | } |
3565 | |
3566 | return NULL; |
3567 | } |
3568 | |
3569 | static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs, |
3570 | uint64_t *perm, uint64_t *shared) |
3571 | { |
3572 | BdrvChild *c; |
3573 | BlockReopenQueueEntry *parent; |
3574 | uint64_t cumulative_perms = 0; |
3575 | uint64_t cumulative_shared_perms = BLK_PERM_ALL; |
3576 | |
3577 | QLIST_FOREACH(c, &bs->parents, next_parent) { |
3578 | parent = find_parent_in_reopen_queue(q, c); |
3579 | if (!parent) { |
3580 | cumulative_perms |= c->perm; |
3581 | cumulative_shared_perms &= c->shared_perm; |
3582 | } else { |
3583 | uint64_t nperm, nshared; |
3584 | |
3585 | bdrv_child_perm(parent->state.bs, bs, c, c->role, q, |
3586 | parent->state.perm, parent->state.shared_perm, |
3587 | &nperm, &nshared); |
3588 | |
3589 | cumulative_perms |= nperm; |
3590 | cumulative_shared_perms &= nshared; |
3591 | } |
3592 | } |
3593 | *perm = cumulative_perms; |
3594 | *shared = cumulative_shared_perms; |
3595 | } |
3596 | |
3597 | /* |
3598 | * Take a BDRVReopenState and check if the value of 'backing' in the |
3599 | * reopen_state->options QDict is valid or not. |
3600 | * |
3601 | * If 'backing' is missing from the QDict then return 0. |
3602 | * |
3603 | * If 'backing' contains the node name of the backing file of |
3604 | * reopen_state->bs then return 0. |
3605 | * |
3606 | * If 'backing' contains a different node name (or is null) then check |
3607 | * whether the current backing file can be replaced with the new one. |
3608 | * If that's the case then reopen_state->replace_backing_bs is set to |
3609 | * true and reopen_state->new_backing_bs contains a pointer to the new |
3610 | * backing BlockDriverState (or NULL). |
3611 | * |
3612 | * Return 0 on success, otherwise return < 0 and set @errp. |
3613 | */ |
3614 | static int bdrv_reopen_parse_backing(BDRVReopenState *reopen_state, |
3615 | Error **errp) |
3616 | { |
3617 | BlockDriverState *bs = reopen_state->bs; |
3618 | BlockDriverState *overlay_bs, *new_backing_bs; |
3619 | QObject *value; |
3620 | const char *str; |
3621 | |
3622 | value = qdict_get(reopen_state->options, "backing" ); |
3623 | if (value == NULL) { |
3624 | return 0; |
3625 | } |
3626 | |
3627 | switch (qobject_type(value)) { |
3628 | case QTYPE_QNULL: |
3629 | new_backing_bs = NULL; |
3630 | break; |
3631 | case QTYPE_QSTRING: |
3632 | str = qobject_get_try_str(value); |
3633 | new_backing_bs = bdrv_lookup_bs(NULL, str, errp); |
3634 | if (new_backing_bs == NULL) { |
3635 | return -EINVAL; |
3636 | } else if (bdrv_recurse_has_child(new_backing_bs, bs)) { |
3637 | error_setg(errp, "Making '%s' a backing file of '%s' " |
3638 | "would create a cycle" , str, bs->node_name); |
3639 | return -EINVAL; |
3640 | } |
3641 | break; |
3642 | default: |
3643 | /* 'backing' does not allow any other data type */ |
3644 | g_assert_not_reached(); |
3645 | } |
3646 | |
3647 | /* |
3648 | * TODO: before removing the x- prefix from x-blockdev-reopen we |
3649 | * should move the new backing file into the right AioContext |
3650 | * instead of returning an error. |
3651 | */ |
3652 | if (new_backing_bs) { |
3653 | if (bdrv_get_aio_context(new_backing_bs) != bdrv_get_aio_context(bs)) { |
3654 | error_setg(errp, "Cannot use a new backing file " |
3655 | "with a different AioContext" ); |
3656 | return -EINVAL; |
3657 | } |
3658 | } |
3659 | |
3660 | /* |
3661 | * Find the "actual" backing file by skipping all links that point |
3662 | * to an implicit node, if any (e.g. a commit filter node). |
3663 | */ |
3664 | overlay_bs = bs; |
3665 | while (backing_bs(overlay_bs) && backing_bs(overlay_bs)->implicit) { |
3666 | overlay_bs = backing_bs(overlay_bs); |
3667 | } |
3668 | |
3669 | /* If we want to replace the backing file we need some extra checks */ |
3670 | if (new_backing_bs != backing_bs(overlay_bs)) { |
3671 | /* Check for implicit nodes between bs and its backing file */ |
3672 | if (bs != overlay_bs) { |
3673 | error_setg(errp, "Cannot change backing link if '%s' has " |
3674 | "an implicit backing file" , bs->node_name); |
3675 | return -EPERM; |
3676 | } |
3677 | /* Check if the backing link that we want to replace is frozen */ |
3678 | if (bdrv_is_backing_chain_frozen(overlay_bs, backing_bs(overlay_bs), |
3679 | errp)) { |
3680 | return -EPERM; |
3681 | } |
3682 | reopen_state->replace_backing_bs = true; |
3683 | if (new_backing_bs) { |
3684 | bdrv_ref(new_backing_bs); |
3685 | reopen_state->new_backing_bs = new_backing_bs; |
3686 | } |
3687 | } |
3688 | |
3689 | return 0; |
3690 | } |
3691 | |
3692 | /* |
3693 | * Prepares a BlockDriverState for reopen. All changes are staged in the |
3694 | * 'opaque' field of the BDRVReopenState, which is used and allocated by |
3695 | * the block driver layer .bdrv_reopen_prepare() |
3696 | * |
3697 | * bs is the BlockDriverState to reopen |
3698 | * flags are the new open flags |
3699 | * queue is the reopen queue |
3700 | * |
3701 | * Returns 0 on success, non-zero on error. On error errp will be set |
3702 | * as well. |
3703 | * |
3704 | * On failure, bdrv_reopen_abort() will be called to clean up any data. |
3705 | * It is the responsibility of the caller to then call the abort() or |
3706 | * commit() for any other BDS that have been left in a prepare() state |
3707 | * |
3708 | */ |
3709 | int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, |
3710 | Error **errp) |
3711 | { |
3712 | int ret = -1; |
3713 | int old_flags; |
3714 | Error *local_err = NULL; |
3715 | BlockDriver *drv; |
3716 | QemuOpts *opts; |
3717 | QDict *orig_reopen_opts; |
3718 | char *discard = NULL; |
3719 | bool read_only; |
3720 | bool drv_prepared = false; |
3721 | |
3722 | assert(reopen_state != NULL); |
3723 | assert(reopen_state->bs->drv != NULL); |
3724 | drv = reopen_state->bs->drv; |
3725 | |
3726 | /* This function and each driver's bdrv_reopen_prepare() remove |
3727 | * entries from reopen_state->options as they are processed, so |
3728 | * we need to make a copy of the original QDict. */ |
3729 | orig_reopen_opts = qdict_clone_shallow(reopen_state->options); |
3730 | |
3731 | /* Process generic block layer options */ |
3732 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); |
3733 | qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err); |
3734 | if (local_err) { |
3735 | error_propagate(errp, local_err); |
3736 | ret = -EINVAL; |
3737 | goto error; |
3738 | } |
3739 | |
3740 | /* This was already called in bdrv_reopen_queue_child() so the flags |
3741 | * are up-to-date. This time we simply want to remove the options from |
3742 | * QemuOpts in order to indicate that they have been processed. */ |
3743 | old_flags = reopen_state->flags; |
3744 | update_flags_from_options(&reopen_state->flags, opts); |
3745 | assert(old_flags == reopen_state->flags); |
3746 | |
3747 | discard = qemu_opt_get_del(opts, BDRV_OPT_DISCARD); |
3748 | if (discard != NULL) { |
3749 | if (bdrv_parse_discard_flags(discard, &reopen_state->flags) != 0) { |
3750 | error_setg(errp, "Invalid discard option" ); |
3751 | ret = -EINVAL; |
3752 | goto error; |
3753 | } |
3754 | } |
3755 | |
3756 | reopen_state->detect_zeroes = |
3757 | bdrv_parse_detect_zeroes(opts, reopen_state->flags, &local_err); |
3758 | if (local_err) { |
3759 | error_propagate(errp, local_err); |
3760 | ret = -EINVAL; |
3761 | goto error; |
3762 | } |
3763 | |
3764 | /* All other options (including node-name and driver) must be unchanged. |
3765 | * Put them back into the QDict, so that they are checked at the end |
3766 | * of this function. */ |
3767 | qemu_opts_to_qdict(opts, reopen_state->options); |
3768 | |
3769 | /* If we are to stay read-only, do not allow permission change |
3770 | * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is |
3771 | * not set, or if the BDS still has copy_on_read enabled */ |
3772 | read_only = !(reopen_state->flags & BDRV_O_RDWR); |
3773 | ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err); |
3774 | if (local_err) { |
3775 | error_propagate(errp, local_err); |
3776 | goto error; |
3777 | } |
3778 | |
3779 | /* Calculate required permissions after reopening */ |
3780 | bdrv_reopen_perm(queue, reopen_state->bs, |
3781 | &reopen_state->perm, &reopen_state->shared_perm); |
3782 | |
3783 | ret = bdrv_flush(reopen_state->bs); |
3784 | if (ret) { |
3785 | error_setg_errno(errp, -ret, "Error flushing drive" ); |
3786 | goto error; |
3787 | } |
3788 | |
3789 | if (drv->bdrv_reopen_prepare) { |
3790 | /* |
3791 | * If a driver-specific option is missing, it means that we |
3792 | * should reset it to its default value. |
3793 | * But not all options allow that, so we need to check it first. |
3794 | */ |
3795 | ret = bdrv_reset_options_allowed(reopen_state->bs, |
3796 | reopen_state->options, errp); |
3797 | if (ret) { |
3798 | goto error; |
3799 | } |
3800 | |
3801 | ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); |
3802 | if (ret) { |
3803 | if (local_err != NULL) { |
3804 | error_propagate(errp, local_err); |
3805 | } else { |
3806 | bdrv_refresh_filename(reopen_state->bs); |
3807 | error_setg(errp, "failed while preparing to reopen image '%s'" , |
3808 | reopen_state->bs->filename); |
3809 | } |
3810 | goto error; |
3811 | } |
3812 | } else { |
3813 | /* It is currently mandatory to have a bdrv_reopen_prepare() |
3814 | * handler for each supported drv. */ |
3815 | error_setg(errp, "Block format '%s' used by node '%s' " |
3816 | "does not support reopening files" , drv->format_name, |
3817 | bdrv_get_device_or_node_name(reopen_state->bs)); |
3818 | ret = -1; |
3819 | goto error; |
3820 | } |
3821 | |
3822 | drv_prepared = true; |
3823 | |
3824 | /* |
3825 | * We must provide the 'backing' option if the BDS has a backing |
3826 | * file or if the image file has a backing file name as part of |
3827 | * its metadata. Otherwise the 'backing' option can be omitted. |
3828 | */ |
3829 | if (drv->supports_backing && reopen_state->backing_missing && |
3830 | (backing_bs(reopen_state->bs) || reopen_state->bs->backing_file[0])) { |
3831 | error_setg(errp, "backing is missing for '%s'" , |
3832 | reopen_state->bs->node_name); |
3833 | ret = -EINVAL; |
3834 | goto error; |
3835 | } |
3836 | |
3837 | /* |
3838 | * Allow changing the 'backing' option. The new value can be |
3839 | * either a reference to an existing node (using its node name) |
3840 | * or NULL to simply detach the current backing file. |
3841 | */ |
3842 | ret = bdrv_reopen_parse_backing(reopen_state, errp); |
3843 | if (ret < 0) { |
3844 | goto error; |
3845 | } |
3846 | qdict_del(reopen_state->options, "backing" ); |
3847 | |
3848 | /* Options that are not handled are only okay if they are unchanged |
3849 | * compared to the old state. It is expected that some options are only |
3850 | * used for the initial open, but not reopen (e.g. filename) */ |
3851 | if (qdict_size(reopen_state->options)) { |
3852 | const QDictEntry *entry = qdict_first(reopen_state->options); |
3853 | |
3854 | do { |
3855 | QObject *new = entry->value; |
3856 | QObject *old = qdict_get(reopen_state->bs->options, entry->key); |
3857 | |
3858 | /* Allow child references (child_name=node_name) as long as they |
3859 | * point to the current child (i.e. everything stays the same). */ |
3860 | if (qobject_type(new) == QTYPE_QSTRING) { |
3861 | BdrvChild *child; |
3862 | QLIST_FOREACH(child, &reopen_state->bs->children, next) { |
3863 | if (!strcmp(child->name, entry->key)) { |
3864 | break; |
3865 | } |
3866 | } |
3867 | |
3868 | if (child) { |
3869 | const char *str = qobject_get_try_str(new); |
3870 | if (!strcmp(child->bs->node_name, str)) { |
3871 | continue; /* Found child with this name, skip option */ |
3872 | } |
3873 | } |
3874 | } |
3875 | |
3876 | /* |
3877 | * TODO: When using -drive to specify blockdev options, all values |
3878 | * will be strings; however, when using -blockdev, blockdev-add or |
3879 | * filenames using the json:{} pseudo-protocol, they will be |
3880 | * correctly typed. |
3881 | * In contrast, reopening options are (currently) always strings |
3882 | * (because you can only specify them through qemu-io; all other |
3883 | * callers do not specify any options). |
3884 | * Therefore, when using anything other than -drive to create a BDS, |
3885 | * this cannot detect non-string options as unchanged, because |
3886 | * qobject_is_equal() always returns false for objects of different |
3887 | * type. In the future, this should be remedied by correctly typing |
3888 | * all options. For now, this is not too big of an issue because |
3889 | * the user can simply omit options which cannot be changed anyway, |
3890 | * so they will stay unchanged. |
3891 | */ |
3892 | if (!qobject_is_equal(new, old)) { |
3893 | error_setg(errp, "Cannot change the option '%s'" , entry->key); |
3894 | ret = -EINVAL; |
3895 | goto error; |
3896 | } |
3897 | } while ((entry = qdict_next(reopen_state->options, entry))); |
3898 | } |
3899 | |
3900 | ret = 0; |
3901 | |
3902 | /* Restore the original reopen_state->options QDict */ |
3903 | qobject_unref(reopen_state->options); |
3904 | reopen_state->options = qobject_ref(orig_reopen_opts); |
3905 | |
3906 | error: |
3907 | if (ret < 0 && drv_prepared) { |
3908 | /* drv->bdrv_reopen_prepare() has succeeded, so we need to |
3909 | * call drv->bdrv_reopen_abort() before signaling an error |
3910 | * (bdrv_reopen_multiple() will not call bdrv_reopen_abort() |
3911 | * when the respective bdrv_reopen_prepare() has failed) */ |
3912 | if (drv->bdrv_reopen_abort) { |
3913 | drv->bdrv_reopen_abort(reopen_state); |
3914 | } |
3915 | } |
3916 | qemu_opts_del(opts); |
3917 | qobject_unref(orig_reopen_opts); |
3918 | g_free(discard); |
3919 | return ret; |
3920 | } |
3921 | |
3922 | /* |
3923 | * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and |
3924 | * makes them final by swapping the staging BlockDriverState contents into |
3925 | * the active BlockDriverState contents. |
3926 | */ |
3927 | void bdrv_reopen_commit(BDRVReopenState *reopen_state) |
3928 | { |
3929 | BlockDriver *drv; |
3930 | BlockDriverState *bs; |
3931 | BdrvChild *child; |
3932 | bool old_can_write, new_can_write; |
3933 | |
3934 | assert(reopen_state != NULL); |
3935 | bs = reopen_state->bs; |
3936 | drv = bs->drv; |
3937 | assert(drv != NULL); |
3938 | |
3939 | old_can_write = |
3940 | !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE); |
3941 | |
3942 | /* If there are any driver level actions to take */ |
3943 | if (drv->bdrv_reopen_commit) { |
3944 | drv->bdrv_reopen_commit(reopen_state); |
3945 | } |
3946 | |
3947 | /* set BDS specific flags now */ |
3948 | qobject_unref(bs->explicit_options); |
3949 | qobject_unref(bs->options); |
3950 | |
3951 | bs->explicit_options = reopen_state->explicit_options; |
3952 | bs->options = reopen_state->options; |
3953 | bs->open_flags = reopen_state->flags; |
3954 | bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); |
3955 | bs->detect_zeroes = reopen_state->detect_zeroes; |
3956 | |
3957 | if (reopen_state->replace_backing_bs) { |
3958 | qdict_del(bs->explicit_options, "backing" ); |
3959 | qdict_del(bs->options, "backing" ); |
3960 | } |
3961 | |
3962 | /* Remove child references from bs->options and bs->explicit_options. |
3963 | * Child options were already removed in bdrv_reopen_queue_child() */ |
3964 | QLIST_FOREACH(child, &bs->children, next) { |
3965 | qdict_del(bs->explicit_options, child->name); |
3966 | qdict_del(bs->options, child->name); |
3967 | } |
3968 | |
3969 | /* |
3970 | * Change the backing file if a new one was specified. We do this |
3971 | * after updating bs->options, so bdrv_refresh_filename() (called |
3972 | * from bdrv_set_backing_hd()) has the new values. |
3973 | */ |
3974 | if (reopen_state->replace_backing_bs) { |
3975 | BlockDriverState *old_backing_bs = backing_bs(bs); |
3976 | assert(!old_backing_bs || !old_backing_bs->implicit); |
3977 | /* Abort the permission update on the backing bs we're detaching */ |
3978 | if (old_backing_bs) { |
3979 | bdrv_abort_perm_update(old_backing_bs); |
3980 | } |
3981 | bdrv_set_backing_hd(bs, reopen_state->new_backing_bs, &error_abort); |
3982 | } |
3983 | |
3984 | bdrv_refresh_limits(bs, NULL); |
3985 | |
3986 | new_can_write = |
3987 | !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE); |
3988 | if (!old_can_write && new_can_write && drv->bdrv_reopen_bitmaps_rw) { |
3989 | Error *local_err = NULL; |
3990 | if (drv->bdrv_reopen_bitmaps_rw(bs, &local_err) < 0) { |
3991 | /* This is not fatal, bitmaps just left read-only, so all following |
3992 | * writes will fail. User can remove read-only bitmaps to unblock |
3993 | * writes. |
3994 | */ |
3995 | error_reportf_err(local_err, |
3996 | "%s: Failed to make dirty bitmaps writable: " , |
3997 | bdrv_get_node_name(bs)); |
3998 | } |
3999 | } |
4000 | } |
4001 | |
4002 | /* |
4003 | * Abort the reopen, and delete and free the staged changes in |
4004 | * reopen_state |
4005 | */ |
4006 | void bdrv_reopen_abort(BDRVReopenState *reopen_state) |
4007 | { |
4008 | BlockDriver *drv; |
4009 | |
4010 | assert(reopen_state != NULL); |
4011 | drv = reopen_state->bs->drv; |
4012 | assert(drv != NULL); |
4013 | |
4014 | if (drv->bdrv_reopen_abort) { |
4015 | drv->bdrv_reopen_abort(reopen_state); |
4016 | } |
4017 | } |
4018 | |
4019 | |
4020 | static void bdrv_close(BlockDriverState *bs) |
4021 | { |
4022 | BdrvAioNotifier *ban, *ban_next; |
4023 | BdrvChild *child, *next; |
4024 | |
4025 | assert(!bs->refcnt); |
4026 | |
4027 | bdrv_drained_begin(bs); /* complete I/O */ |
4028 | bdrv_flush(bs); |
4029 | bdrv_drain(bs); /* in case flush left pending I/O */ |
4030 | |
4031 | if (bs->drv) { |
4032 | if (bs->drv->bdrv_close) { |
4033 | bs->drv->bdrv_close(bs); |
4034 | } |
4035 | bs->drv = NULL; |
4036 | } |
4037 | |
4038 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { |
4039 | bdrv_unref_child(bs, child); |
4040 | } |
4041 | |
4042 | bs->backing = NULL; |
4043 | bs->file = NULL; |
4044 | g_free(bs->opaque); |
4045 | bs->opaque = NULL; |
4046 | atomic_set(&bs->copy_on_read, 0); |
4047 | bs->backing_file[0] = '\0'; |
4048 | bs->backing_format[0] = '\0'; |
4049 | bs->total_sectors = 0; |
4050 | bs->encrypted = false; |
4051 | bs->sg = false; |
4052 | qobject_unref(bs->options); |
4053 | qobject_unref(bs->explicit_options); |
4054 | bs->options = NULL; |
4055 | bs->explicit_options = NULL; |
4056 | qobject_unref(bs->full_open_options); |
4057 | bs->full_open_options = NULL; |
4058 | |
4059 | bdrv_release_named_dirty_bitmaps(bs); |
4060 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); |
4061 | |
4062 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { |
4063 | g_free(ban); |
4064 | } |
4065 | QLIST_INIT(&bs->aio_notifiers); |
4066 | bdrv_drained_end(bs); |
4067 | } |
4068 | |
4069 | void bdrv_close_all(void) |
4070 | { |
4071 | assert(job_next(NULL) == NULL); |
4072 | nbd_export_close_all(); |
4073 | |
4074 | /* Drop references from requests still in flight, such as canceled block |
4075 | * jobs whose AIO context has not been polled yet */ |
4076 | bdrv_drain_all(); |
4077 | |
4078 | blk_remove_all_bs(); |
4079 | blockdev_close_all_bdrv_states(); |
4080 | |
4081 | assert(QTAILQ_EMPTY(&all_bdrv_states)); |
4082 | } |
4083 | |
4084 | static bool should_update_child(BdrvChild *c, BlockDriverState *to) |
4085 | { |
4086 | GQueue *queue; |
4087 | GHashTable *found; |
4088 | bool ret; |
4089 | |
4090 | if (c->role->stay_at_node) { |
4091 | return false; |
4092 | } |
4093 | |
4094 | /* If the child @c belongs to the BDS @to, replacing the current |
4095 | * c->bs by @to would mean to create a loop. |
4096 | * |
4097 | * Such a case occurs when appending a BDS to a backing chain. |
4098 | * For instance, imagine the following chain: |
4099 | * |
4100 | * guest device -> node A -> further backing chain... |
4101 | * |
4102 | * Now we create a new BDS B which we want to put on top of this |
4103 | * chain, so we first attach A as its backing node: |
4104 | * |
4105 | * node B |
4106 | * | |
4107 | * v |
4108 | * guest device -> node A -> further backing chain... |
4109 | * |
4110 | * Finally we want to replace A by B. When doing that, we want to |
4111 | * replace all pointers to A by pointers to B -- except for the |
4112 | * pointer from B because (1) that would create a loop, and (2) |
4113 | * that pointer should simply stay intact: |
4114 | * |
4115 | * guest device -> node B |
4116 | * | |
4117 | * v |
4118 | * node A -> further backing chain... |
4119 | * |
4120 | * In general, when replacing a node A (c->bs) by a node B (@to), |
4121 | * if A is a child of B, that means we cannot replace A by B there |
4122 | * because that would create a loop. Silently detaching A from B |
4123 | * is also not really an option. So overall just leaving A in |
4124 | * place there is the most sensible choice. |
4125 | * |
4126 | * We would also create a loop in any cases where @c is only |
4127 | * indirectly referenced by @to. Prevent this by returning false |
4128 | * if @c is found (by breadth-first search) anywhere in the whole |
4129 | * subtree of @to. |
4130 | */ |
4131 | |
4132 | ret = true; |
4133 | found = g_hash_table_new(NULL, NULL); |
4134 | g_hash_table_add(found, to); |
4135 | queue = g_queue_new(); |
4136 | g_queue_push_tail(queue, to); |
4137 | |
4138 | while (!g_queue_is_empty(queue)) { |
4139 | BlockDriverState *v = g_queue_pop_head(queue); |
4140 | BdrvChild *c2; |
4141 | |
4142 | QLIST_FOREACH(c2, &v->children, next) { |
4143 | if (c2 == c) { |
4144 | ret = false; |
4145 | break; |
4146 | } |
4147 | |
4148 | if (g_hash_table_contains(found, c2->bs)) { |
4149 | continue; |
4150 | } |
4151 | |
4152 | g_queue_push_tail(queue, c2->bs); |
4153 | g_hash_table_add(found, c2->bs); |
4154 | } |
4155 | } |
4156 | |
4157 | g_queue_free(queue); |
4158 | g_hash_table_destroy(found); |
4159 | |
4160 | return ret; |
4161 | } |
4162 | |
4163 | void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to, |
4164 | Error **errp) |
4165 | { |
4166 | BdrvChild *c, *next; |
4167 | GSList *list = NULL, *p; |
4168 | uint64_t perm = 0, shared = BLK_PERM_ALL; |
4169 | int ret; |
4170 | |
4171 | /* Make sure that @from doesn't go away until we have successfully attached |
4172 | * all of its parents to @to. */ |
4173 | bdrv_ref(from); |
4174 | |
4175 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
4176 | bdrv_drained_begin(from); |
4177 | |
4178 | /* Put all parents into @list and calculate their cumulative permissions */ |
4179 | QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { |
4180 | assert(c->bs == from); |
4181 | if (!should_update_child(c, to)) { |
4182 | continue; |
4183 | } |
4184 | if (c->frozen) { |
4185 | error_setg(errp, "Cannot change '%s' link to '%s'" , |
4186 | c->name, from->node_name); |
4187 | goto out; |
4188 | } |
4189 | list = g_slist_prepend(list, c); |
4190 | perm |= c->perm; |
4191 | shared &= c->shared_perm; |
4192 | } |
4193 | |
4194 | /* Check whether the required permissions can be granted on @to, ignoring |
4195 | * all BdrvChild in @list so that they can't block themselves. */ |
4196 | ret = bdrv_check_update_perm(to, NULL, perm, shared, list, NULL, errp); |
4197 | if (ret < 0) { |
4198 | bdrv_abort_perm_update(to); |
4199 | goto out; |
4200 | } |
4201 | |
4202 | /* Now actually perform the change. We performed the permission check for |
4203 | * all elements of @list at once, so set the permissions all at once at the |
4204 | * very end. */ |
4205 | for (p = list; p != NULL; p = p->next) { |
4206 | c = p->data; |
4207 | |
4208 | bdrv_ref(to); |
4209 | bdrv_replace_child_noperm(c, to); |
4210 | bdrv_unref(from); |
4211 | } |
4212 | |
4213 | bdrv_get_cumulative_perm(to, &perm, &shared); |
4214 | bdrv_set_perm(to, perm, shared); |
4215 | |
4216 | out: |
4217 | g_slist_free(list); |
4218 | bdrv_drained_end(from); |
4219 | bdrv_unref(from); |
4220 | } |
4221 | |
4222 | /* |
4223 | * Add new bs contents at the top of an image chain while the chain is |
4224 | * live, while keeping required fields on the top layer. |
4225 | * |
4226 | * This will modify the BlockDriverState fields, and swap contents |
4227 | * between bs_new and bs_top. Both bs_new and bs_top are modified. |
4228 | * |
4229 | * bs_new must not be attached to a BlockBackend. |
4230 | * |
4231 | * This function does not create any image files. |
4232 | * |
4233 | * bdrv_append() takes ownership of a bs_new reference and unrefs it because |
4234 | * that's what the callers commonly need. bs_new will be referenced by the old |
4235 | * parents of bs_top after bdrv_append() returns. If the caller needs to keep a |
4236 | * reference of its own, it must call bdrv_ref(). |
4237 | */ |
4238 | void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, |
4239 | Error **errp) |
4240 | { |
4241 | Error *local_err = NULL; |
4242 | |
4243 | bdrv_set_backing_hd(bs_new, bs_top, &local_err); |
4244 | if (local_err) { |
4245 | error_propagate(errp, local_err); |
4246 | goto out; |
4247 | } |
4248 | |
4249 | bdrv_replace_node(bs_top, bs_new, &local_err); |
4250 | if (local_err) { |
4251 | error_propagate(errp, local_err); |
4252 | bdrv_set_backing_hd(bs_new, NULL, &error_abort); |
4253 | goto out; |
4254 | } |
4255 | |
4256 | /* bs_new is now referenced by its new parents, we don't need the |
4257 | * additional reference any more. */ |
4258 | out: |
4259 | bdrv_unref(bs_new); |
4260 | } |
4261 | |
4262 | static void bdrv_delete(BlockDriverState *bs) |
4263 | { |
4264 | assert(bdrv_op_blocker_is_empty(bs)); |
4265 | assert(!bs->refcnt); |
4266 | |
4267 | /* remove from list, if necessary */ |
4268 | if (bs->node_name[0] != '\0') { |
4269 | QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); |
4270 | } |
4271 | QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list); |
4272 | |
4273 | bdrv_close(bs); |
4274 | |
4275 | g_free(bs); |
4276 | } |
4277 | |
4278 | /* |
4279 | * Run consistency checks on an image |
4280 | * |
4281 | * Returns 0 if the check could be completed (it doesn't mean that the image is |
4282 | * free of errors) or -errno when an internal error occurred. The results of the |
4283 | * check are stored in res. |
4284 | */ |
4285 | static int coroutine_fn bdrv_co_check(BlockDriverState *bs, |
4286 | BdrvCheckResult *res, BdrvCheckMode fix) |
4287 | { |
4288 | if (bs->drv == NULL) { |
4289 | return -ENOMEDIUM; |
4290 | } |
4291 | if (bs->drv->bdrv_co_check == NULL) { |
4292 | return -ENOTSUP; |
4293 | } |
4294 | |
4295 | memset(res, 0, sizeof(*res)); |
4296 | return bs->drv->bdrv_co_check(bs, res, fix); |
4297 | } |
4298 | |
4299 | typedef struct CheckCo { |
4300 | BlockDriverState *bs; |
4301 | BdrvCheckResult *res; |
4302 | BdrvCheckMode fix; |
4303 | int ret; |
4304 | } CheckCo; |
4305 | |
4306 | static void coroutine_fn bdrv_check_co_entry(void *opaque) |
4307 | { |
4308 | CheckCo *cco = opaque; |
4309 | cco->ret = bdrv_co_check(cco->bs, cco->res, cco->fix); |
4310 | aio_wait_kick(); |
4311 | } |
4312 | |
4313 | int bdrv_check(BlockDriverState *bs, |
4314 | BdrvCheckResult *res, BdrvCheckMode fix) |
4315 | { |
4316 | Coroutine *co; |
4317 | CheckCo cco = { |
4318 | .bs = bs, |
4319 | .res = res, |
4320 | .ret = -EINPROGRESS, |
4321 | .fix = fix, |
4322 | }; |
4323 | |
4324 | if (qemu_in_coroutine()) { |
4325 | /* Fast-path if already in coroutine context */ |
4326 | bdrv_check_co_entry(&cco); |
4327 | } else { |
4328 | co = qemu_coroutine_create(bdrv_check_co_entry, &cco); |
4329 | bdrv_coroutine_enter(bs, co); |
4330 | BDRV_POLL_WHILE(bs, cco.ret == -EINPROGRESS); |
4331 | } |
4332 | |
4333 | return cco.ret; |
4334 | } |
4335 | |
4336 | /* |
4337 | * Return values: |
4338 | * 0 - success |
4339 | * -EINVAL - backing format specified, but no file |
4340 | * -ENOSPC - can't update the backing file because no space is left in the |
4341 | * image file header |
4342 | * -ENOTSUP - format driver doesn't support changing the backing file |
4343 | */ |
4344 | int bdrv_change_backing_file(BlockDriverState *bs, |
4345 | const char *backing_file, const char *backing_fmt) |
4346 | { |
4347 | BlockDriver *drv = bs->drv; |
4348 | int ret; |
4349 | |
4350 | if (!drv) { |
4351 | return -ENOMEDIUM; |
4352 | } |
4353 | |
4354 | /* Backing file format doesn't make sense without a backing file */ |
4355 | if (backing_fmt && !backing_file) { |
4356 | return -EINVAL; |
4357 | } |
4358 | |
4359 | if (drv->bdrv_change_backing_file != NULL) { |
4360 | ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); |
4361 | } else { |
4362 | ret = -ENOTSUP; |
4363 | } |
4364 | |
4365 | if (ret == 0) { |
4366 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "" ); |
4367 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "" ); |
4368 | pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), |
4369 | backing_file ?: "" ); |
4370 | } |
4371 | return ret; |
4372 | } |
4373 | |
4374 | /* |
4375 | * Finds the image layer in the chain that has 'bs' as its backing file. |
4376 | * |
4377 | * active is the current topmost image. |
4378 | * |
4379 | * Returns NULL if bs is not found in active's image chain, |
4380 | * or if active == bs. |
4381 | * |
4382 | * Returns the bottommost base image if bs == NULL. |
4383 | */ |
4384 | BlockDriverState *bdrv_find_overlay(BlockDriverState *active, |
4385 | BlockDriverState *bs) |
4386 | { |
4387 | while (active && bs != backing_bs(active)) { |
4388 | active = backing_bs(active); |
4389 | } |
4390 | |
4391 | return active; |
4392 | } |
4393 | |
4394 | /* Given a BDS, searches for the base layer. */ |
4395 | BlockDriverState *bdrv_find_base(BlockDriverState *bs) |
4396 | { |
4397 | return bdrv_find_overlay(bs, NULL); |
4398 | } |
4399 | |
4400 | /* |
4401 | * Return true if at least one of the backing links between @bs and |
4402 | * @base is frozen. @errp is set if that's the case. |
4403 | * @base must be reachable from @bs, or NULL. |
4404 | */ |
4405 | bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base, |
4406 | Error **errp) |
4407 | { |
4408 | BlockDriverState *i; |
4409 | |
4410 | for (i = bs; i != base; i = backing_bs(i)) { |
4411 | if (i->backing && i->backing->frozen) { |
4412 | error_setg(errp, "Cannot change '%s' link from '%s' to '%s'" , |
4413 | i->backing->name, i->node_name, |
4414 | backing_bs(i)->node_name); |
4415 | return true; |
4416 | } |
4417 | } |
4418 | |
4419 | return false; |
4420 | } |
4421 | |
4422 | /* |
4423 | * Freeze all backing links between @bs and @base. |
4424 | * If any of the links is already frozen the operation is aborted and |
4425 | * none of the links are modified. |
4426 | * @base must be reachable from @bs, or NULL. |
4427 | * Returns 0 on success. On failure returns < 0 and sets @errp. |
4428 | */ |
4429 | int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base, |
4430 | Error **errp) |
4431 | { |
4432 | BlockDriverState *i; |
4433 | |
4434 | if (bdrv_is_backing_chain_frozen(bs, base, errp)) { |
4435 | return -EPERM; |
4436 | } |
4437 | |
4438 | for (i = bs; i != base; i = backing_bs(i)) { |
4439 | if (i->backing && backing_bs(i)->never_freeze) { |
4440 | error_setg(errp, "Cannot freeze '%s' link to '%s'" , |
4441 | i->backing->name, backing_bs(i)->node_name); |
4442 | return -EPERM; |
4443 | } |
4444 | } |
4445 | |
4446 | for (i = bs; i != base; i = backing_bs(i)) { |
4447 | if (i->backing) { |
4448 | i->backing->frozen = true; |
4449 | } |
4450 | } |
4451 | |
4452 | return 0; |
4453 | } |
4454 | |
4455 | /* |
4456 | * Unfreeze all backing links between @bs and @base. The caller must |
4457 | * ensure that all links are frozen before using this function. |
4458 | * @base must be reachable from @bs, or NULL. |
4459 | */ |
4460 | void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base) |
4461 | { |
4462 | BlockDriverState *i; |
4463 | |
4464 | for (i = bs; i != base; i = backing_bs(i)) { |
4465 | if (i->backing) { |
4466 | assert(i->backing->frozen); |
4467 | i->backing->frozen = false; |
4468 | } |
4469 | } |
4470 | } |
4471 | |
4472 | /* |
4473 | * Drops images above 'base' up to and including 'top', and sets the image |
4474 | * above 'top' to have base as its backing file. |
4475 | * |
4476 | * Requires that the overlay to 'top' is opened r/w, so that the backing file |
4477 | * information in 'bs' can be properly updated. |
4478 | * |
4479 | * E.g., this will convert the following chain: |
4480 | * bottom <- base <- intermediate <- top <- active |
4481 | * |
4482 | * to |
4483 | * |
4484 | * bottom <- base <- active |
4485 | * |
4486 | * It is allowed for bottom==base, in which case it converts: |
4487 | * |
4488 | * base <- intermediate <- top <- active |
4489 | * |
4490 | * to |
4491 | * |
4492 | * base <- active |
4493 | * |
4494 | * If backing_file_str is non-NULL, it will be used when modifying top's |
4495 | * overlay image metadata. |
4496 | * |
4497 | * Error conditions: |
4498 | * if active == top, that is considered an error |
4499 | * |
4500 | */ |
4501 | int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base, |
4502 | const char *backing_file_str) |
4503 | { |
4504 | BlockDriverState *explicit_top = top; |
4505 | bool update_inherits_from; |
4506 | BdrvChild *c, *next; |
4507 | Error *local_err = NULL; |
4508 | int ret = -EIO; |
4509 | |
4510 | bdrv_ref(top); |
4511 | bdrv_subtree_drained_begin(top); |
4512 | |
4513 | if (!top->drv || !base->drv) { |
4514 | goto exit; |
4515 | } |
4516 | |
4517 | /* Make sure that base is in the backing chain of top */ |
4518 | if (!bdrv_chain_contains(top, base)) { |
4519 | goto exit; |
4520 | } |
4521 | |
4522 | /* This function changes all links that point to top and makes |
4523 | * them point to base. Check that none of them is frozen. */ |
4524 | QLIST_FOREACH(c, &top->parents, next_parent) { |
4525 | if (c->frozen) { |
4526 | goto exit; |
4527 | } |
4528 | } |
4529 | |
4530 | /* If 'base' recursively inherits from 'top' then we should set |
4531 | * base->inherits_from to top->inherits_from after 'top' and all |
4532 | * other intermediate nodes have been dropped. |
4533 | * If 'top' is an implicit node (e.g. "commit_top") we should skip |
4534 | * it because no one inherits from it. We use explicit_top for that. */ |
4535 | while (explicit_top && explicit_top->implicit) { |
4536 | explicit_top = backing_bs(explicit_top); |
4537 | } |
4538 | update_inherits_from = bdrv_inherits_from_recursive(base, explicit_top); |
4539 | |
4540 | /* success - we can delete the intermediate states, and link top->base */ |
4541 | /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once |
4542 | * we've figured out how they should work. */ |
4543 | if (!backing_file_str) { |
4544 | bdrv_refresh_filename(base); |
4545 | backing_file_str = base->filename; |
4546 | } |
4547 | |
4548 | QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) { |
4549 | /* Check whether we are allowed to switch c from top to base */ |
4550 | GSList *ignore_children = g_slist_prepend(NULL, c); |
4551 | ret = bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm, |
4552 | ignore_children, NULL, &local_err); |
4553 | g_slist_free(ignore_children); |
4554 | if (ret < 0) { |
4555 | error_report_err(local_err); |
4556 | goto exit; |
4557 | } |
4558 | |
4559 | /* If so, update the backing file path in the image file */ |
4560 | if (c->role->update_filename) { |
4561 | ret = c->role->update_filename(c, base, backing_file_str, |
4562 | &local_err); |
4563 | if (ret < 0) { |
4564 | bdrv_abort_perm_update(base); |
4565 | error_report_err(local_err); |
4566 | goto exit; |
4567 | } |
4568 | } |
4569 | |
4570 | /* Do the actual switch in the in-memory graph. |
4571 | * Completes bdrv_check_update_perm() transaction internally. */ |
4572 | bdrv_ref(base); |
4573 | bdrv_replace_child(c, base); |
4574 | bdrv_unref(top); |
4575 | } |
4576 | |
4577 | if (update_inherits_from) { |
4578 | base->inherits_from = explicit_top->inherits_from; |
4579 | } |
4580 | |
4581 | ret = 0; |
4582 | exit: |
4583 | bdrv_subtree_drained_end(top); |
4584 | bdrv_unref(top); |
4585 | return ret; |
4586 | } |
4587 | |
4588 | /** |
4589 | * Length of a allocated file in bytes. Sparse files are counted by actual |
4590 | * allocated space. Return < 0 if error or unknown. |
4591 | */ |
4592 | int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) |
4593 | { |
4594 | BlockDriver *drv = bs->drv; |
4595 | if (!drv) { |
4596 | return -ENOMEDIUM; |
4597 | } |
4598 | if (drv->bdrv_get_allocated_file_size) { |
4599 | return drv->bdrv_get_allocated_file_size(bs); |
4600 | } |
4601 | if (bs->file) { |
4602 | return bdrv_get_allocated_file_size(bs->file->bs); |
4603 | } |
4604 | return -ENOTSUP; |
4605 | } |
4606 | |
4607 | /* |
4608 | * bdrv_measure: |
4609 | * @drv: Format driver |
4610 | * @opts: Creation options for new image |
4611 | * @in_bs: Existing image containing data for new image (may be NULL) |
4612 | * @errp: Error object |
4613 | * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo()) |
4614 | * or NULL on error |
4615 | * |
4616 | * Calculate file size required to create a new image. |
4617 | * |
4618 | * If @in_bs is given then space for allocated clusters and zero clusters |
4619 | * from that image are included in the calculation. If @opts contains a |
4620 | * backing file that is shared by @in_bs then backing clusters may be omitted |
4621 | * from the calculation. |
4622 | * |
4623 | * If @in_bs is NULL then the calculation includes no allocated clusters |
4624 | * unless a preallocation option is given in @opts. |
4625 | * |
4626 | * Note that @in_bs may use a different BlockDriver from @drv. |
4627 | * |
4628 | * If an error occurs the @errp pointer is set. |
4629 | */ |
4630 | BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, |
4631 | BlockDriverState *in_bs, Error **errp) |
4632 | { |
4633 | if (!drv->bdrv_measure) { |
4634 | error_setg(errp, "Block driver '%s' does not support size measurement" , |
4635 | drv->format_name); |
4636 | return NULL; |
4637 | } |
4638 | |
4639 | return drv->bdrv_measure(opts, in_bs, errp); |
4640 | } |
4641 | |
4642 | /** |
4643 | * Return number of sectors on success, -errno on error. |
4644 | */ |
4645 | int64_t bdrv_nb_sectors(BlockDriverState *bs) |
4646 | { |
4647 | BlockDriver *drv = bs->drv; |
4648 | |
4649 | if (!drv) |
4650 | return -ENOMEDIUM; |
4651 | |
4652 | if (drv->has_variable_length) { |
4653 | int ret = refresh_total_sectors(bs, bs->total_sectors); |
4654 | if (ret < 0) { |
4655 | return ret; |
4656 | } |
4657 | } |
4658 | return bs->total_sectors; |
4659 | } |
4660 | |
4661 | /** |
4662 | * Return length in bytes on success, -errno on error. |
4663 | * The length is always a multiple of BDRV_SECTOR_SIZE. |
4664 | */ |
4665 | int64_t bdrv_getlength(BlockDriverState *bs) |
4666 | { |
4667 | int64_t ret = bdrv_nb_sectors(bs); |
4668 | |
4669 | ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret; |
4670 | return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE; |
4671 | } |
4672 | |
4673 | /* return 0 as number of sectors if no device present or error */ |
4674 | void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) |
4675 | { |
4676 | int64_t nb_sectors = bdrv_nb_sectors(bs); |
4677 | |
4678 | *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors; |
4679 | } |
4680 | |
4681 | bool bdrv_is_sg(BlockDriverState *bs) |
4682 | { |
4683 | return bs->sg; |
4684 | } |
4685 | |
4686 | bool bdrv_is_encrypted(BlockDriverState *bs) |
4687 | { |
4688 | if (bs->backing && bs->backing->bs->encrypted) { |
4689 | return true; |
4690 | } |
4691 | return bs->encrypted; |
4692 | } |
4693 | |
4694 | const char *bdrv_get_format_name(BlockDriverState *bs) |
4695 | { |
4696 | return bs->drv ? bs->drv->format_name : NULL; |
4697 | } |
4698 | |
4699 | static int qsort_strcmp(const void *a, const void *b) |
4700 | { |
4701 | return strcmp(*(char *const *)a, *(char *const *)b); |
4702 | } |
4703 | |
4704 | void bdrv_iterate_format(void (*it)(void *opaque, const char *name), |
4705 | void *opaque, bool read_only) |
4706 | { |
4707 | BlockDriver *drv; |
4708 | int count = 0; |
4709 | int i; |
4710 | const char **formats = NULL; |
4711 | |
4712 | QLIST_FOREACH(drv, &bdrv_drivers, list) { |
4713 | if (drv->format_name) { |
4714 | bool found = false; |
4715 | int i = count; |
4716 | |
4717 | if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, read_only)) { |
4718 | continue; |
4719 | } |
4720 | |
4721 | while (formats && i && !found) { |
4722 | found = !strcmp(formats[--i], drv->format_name); |
4723 | } |
4724 | |
4725 | if (!found) { |
4726 | formats = g_renew(const char *, formats, count + 1); |
4727 | formats[count++] = drv->format_name; |
4728 | } |
4729 | } |
4730 | } |
4731 | |
4732 | for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) { |
4733 | const char *format_name = block_driver_modules[i].format_name; |
4734 | |
4735 | if (format_name) { |
4736 | bool found = false; |
4737 | int j = count; |
4738 | |
4739 | if (use_bdrv_whitelist && |
4740 | !bdrv_format_is_whitelisted(format_name, read_only)) { |
4741 | continue; |
4742 | } |
4743 | |
4744 | while (formats && j && !found) { |
4745 | found = !strcmp(formats[--j], format_name); |
4746 | } |
4747 | |
4748 | if (!found) { |
4749 | formats = g_renew(const char *, formats, count + 1); |
4750 | formats[count++] = format_name; |
4751 | } |
4752 | } |
4753 | } |
4754 | |
4755 | qsort(formats, count, sizeof(formats[0]), qsort_strcmp); |
4756 | |
4757 | for (i = 0; i < count; i++) { |
4758 | it(opaque, formats[i]); |
4759 | } |
4760 | |
4761 | g_free(formats); |
4762 | } |
4763 | |
4764 | /* This function is to find a node in the bs graph */ |
4765 | BlockDriverState *bdrv_find_node(const char *node_name) |
4766 | { |
4767 | BlockDriverState *bs; |
4768 | |
4769 | assert(node_name); |
4770 | |
4771 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { |
4772 | if (!strcmp(node_name, bs->node_name)) { |
4773 | return bs; |
4774 | } |
4775 | } |
4776 | return NULL; |
4777 | } |
4778 | |
4779 | /* Put this QMP function here so it can access the static graph_bdrv_states. */ |
4780 | BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp) |
4781 | { |
4782 | BlockDeviceInfoList *list, *entry; |
4783 | BlockDriverState *bs; |
4784 | |
4785 | list = NULL; |
4786 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { |
4787 | BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp); |
4788 | if (!info) { |
4789 | qapi_free_BlockDeviceInfoList(list); |
4790 | return NULL; |
4791 | } |
4792 | entry = g_malloc0(sizeof(*entry)); |
4793 | entry->value = info; |
4794 | entry->next = list; |
4795 | list = entry; |
4796 | } |
4797 | |
4798 | return list; |
4799 | } |
4800 | |
4801 | #define QAPI_LIST_ADD(list, element) do { \ |
4802 | typeof(list) _tmp = g_new(typeof(*(list)), 1); \ |
4803 | _tmp->value = (element); \ |
4804 | _tmp->next = (list); \ |
4805 | (list) = _tmp; \ |
4806 | } while (0) |
4807 | |
4808 | typedef struct XDbgBlockGraphConstructor { |
4809 | XDbgBlockGraph *graph; |
4810 | GHashTable *graph_nodes; |
4811 | } XDbgBlockGraphConstructor; |
4812 | |
4813 | static XDbgBlockGraphConstructor *xdbg_graph_new(void) |
4814 | { |
4815 | XDbgBlockGraphConstructor *gr = g_new(XDbgBlockGraphConstructor, 1); |
4816 | |
4817 | gr->graph = g_new0(XDbgBlockGraph, 1); |
4818 | gr->graph_nodes = g_hash_table_new(NULL, NULL); |
4819 | |
4820 | return gr; |
4821 | } |
4822 | |
4823 | static XDbgBlockGraph *xdbg_graph_finalize(XDbgBlockGraphConstructor *gr) |
4824 | { |
4825 | XDbgBlockGraph *graph = gr->graph; |
4826 | |
4827 | g_hash_table_destroy(gr->graph_nodes); |
4828 | g_free(gr); |
4829 | |
4830 | return graph; |
4831 | } |
4832 | |
4833 | static uintptr_t xdbg_graph_node_num(XDbgBlockGraphConstructor *gr, void *node) |
4834 | { |
4835 | uintptr_t ret = (uintptr_t)g_hash_table_lookup(gr->graph_nodes, node); |
4836 | |
4837 | if (ret != 0) { |
4838 | return ret; |
4839 | } |
4840 | |
4841 | /* |
4842 | * Start counting from 1, not 0, because 0 interferes with not-found (NULL) |
4843 | * answer of g_hash_table_lookup. |
4844 | */ |
4845 | ret = g_hash_table_size(gr->graph_nodes) + 1; |
4846 | g_hash_table_insert(gr->graph_nodes, node, (void *)ret); |
4847 | |
4848 | return ret; |
4849 | } |
4850 | |
4851 | static void xdbg_graph_add_node(XDbgBlockGraphConstructor *gr, void *node, |
4852 | XDbgBlockGraphNodeType type, const char *name) |
4853 | { |
4854 | XDbgBlockGraphNode *n; |
4855 | |
4856 | n = g_new0(XDbgBlockGraphNode, 1); |
4857 | |
4858 | n->id = xdbg_graph_node_num(gr, node); |
4859 | n->type = type; |
4860 | n->name = g_strdup(name); |
4861 | |
4862 | QAPI_LIST_ADD(gr->graph->nodes, n); |
4863 | } |
4864 | |
4865 | static void xdbg_graph_add_edge(XDbgBlockGraphConstructor *gr, void *parent, |
4866 | const BdrvChild *child) |
4867 | { |
4868 | typedef struct { |
4869 | unsigned int flag; |
4870 | BlockPermission num; |
4871 | } PermissionMap; |
4872 | |
4873 | static const PermissionMap permissions[] = { |
4874 | { BLK_PERM_CONSISTENT_READ, BLOCK_PERMISSION_CONSISTENT_READ }, |
4875 | { BLK_PERM_WRITE, BLOCK_PERMISSION_WRITE }, |
4876 | { BLK_PERM_WRITE_UNCHANGED, BLOCK_PERMISSION_WRITE_UNCHANGED }, |
4877 | { BLK_PERM_RESIZE, BLOCK_PERMISSION_RESIZE }, |
4878 | { BLK_PERM_GRAPH_MOD, BLOCK_PERMISSION_GRAPH_MOD }, |
4879 | { 0, 0 } |
4880 | }; |
4881 | const PermissionMap *p; |
4882 | XDbgBlockGraphEdge *edge; |
4883 | |
4884 | QEMU_BUILD_BUG_ON(1UL << (ARRAY_SIZE(permissions) - 1) != BLK_PERM_ALL + 1); |
4885 | |
4886 | edge = g_new0(XDbgBlockGraphEdge, 1); |
4887 | |
4888 | edge->parent = xdbg_graph_node_num(gr, parent); |
4889 | edge->child = xdbg_graph_node_num(gr, child->bs); |
4890 | edge->name = g_strdup(child->name); |
4891 | |
4892 | for (p = permissions; p->flag; p++) { |
4893 | if (p->flag & child->perm) { |
4894 | QAPI_LIST_ADD(edge->perm, p->num); |
4895 | } |
4896 | if (p->flag & child->shared_perm) { |
4897 | QAPI_LIST_ADD(edge->shared_perm, p->num); |
4898 | } |
4899 | } |
4900 | |
4901 | QAPI_LIST_ADD(gr->graph->edges, edge); |
4902 | } |
4903 | |
4904 | |
4905 | XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp) |
4906 | { |
4907 | BlockBackend *blk; |
4908 | BlockJob *job; |
4909 | BlockDriverState *bs; |
4910 | BdrvChild *child; |
4911 | XDbgBlockGraphConstructor *gr = xdbg_graph_new(); |
4912 | |
4913 | for (blk = blk_all_next(NULL); blk; blk = blk_all_next(blk)) { |
4914 | char *allocated_name = NULL; |
4915 | const char *name = blk_name(blk); |
4916 | |
4917 | if (!*name) { |
4918 | name = allocated_name = blk_get_attached_dev_id(blk); |
4919 | } |
4920 | xdbg_graph_add_node(gr, blk, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND, |
4921 | name); |
4922 | g_free(allocated_name); |
4923 | if (blk_root(blk)) { |
4924 | xdbg_graph_add_edge(gr, blk, blk_root(blk)); |
4925 | } |
4926 | } |
4927 | |
4928 | for (job = block_job_next(NULL); job; job = block_job_next(job)) { |
4929 | GSList *el; |
4930 | |
4931 | xdbg_graph_add_node(gr, job, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB, |
4932 | job->job.id); |
4933 | for (el = job->nodes; el; el = el->next) { |
4934 | xdbg_graph_add_edge(gr, job, (BdrvChild *)el->data); |
4935 | } |
4936 | } |
4937 | |
4938 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { |
4939 | xdbg_graph_add_node(gr, bs, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER, |
4940 | bs->node_name); |
4941 | QLIST_FOREACH(child, &bs->children, next) { |
4942 | xdbg_graph_add_edge(gr, bs, child); |
4943 | } |
4944 | } |
4945 | |
4946 | return xdbg_graph_finalize(gr); |
4947 | } |
4948 | |
4949 | BlockDriverState *bdrv_lookup_bs(const char *device, |
4950 | const char *node_name, |
4951 | Error **errp) |
4952 | { |
4953 | BlockBackend *blk; |
4954 | BlockDriverState *bs; |
4955 | |
4956 | if (device) { |
4957 | blk = blk_by_name(device); |
4958 | |
4959 | if (blk) { |
4960 | bs = blk_bs(blk); |
4961 | if (!bs) { |
4962 | error_setg(errp, "Device '%s' has no medium" , device); |
4963 | } |
4964 | |
4965 | return bs; |
4966 | } |
4967 | } |
4968 | |
4969 | if (node_name) { |
4970 | bs = bdrv_find_node(node_name); |
4971 | |
4972 | if (bs) { |
4973 | return bs; |
4974 | } |
4975 | } |
4976 | |
4977 | error_setg(errp, "Cannot find device=%s nor node_name=%s" , |
4978 | device ? device : "" , |
4979 | node_name ? node_name : "" ); |
4980 | return NULL; |
4981 | } |
4982 | |
4983 | /* If 'base' is in the same chain as 'top', return true. Otherwise, |
4984 | * return false. If either argument is NULL, return false. */ |
4985 | bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) |
4986 | { |
4987 | while (top && top != base) { |
4988 | top = backing_bs(top); |
4989 | } |
4990 | |
4991 | return top != NULL; |
4992 | } |
4993 | |
4994 | BlockDriverState *bdrv_next_node(BlockDriverState *bs) |
4995 | { |
4996 | if (!bs) { |
4997 | return QTAILQ_FIRST(&graph_bdrv_states); |
4998 | } |
4999 | return QTAILQ_NEXT(bs, node_list); |
5000 | } |
5001 | |
5002 | BlockDriverState *bdrv_next_all_states(BlockDriverState *bs) |
5003 | { |
5004 | if (!bs) { |
5005 | return QTAILQ_FIRST(&all_bdrv_states); |
5006 | } |
5007 | return QTAILQ_NEXT(bs, bs_list); |
5008 | } |
5009 | |
5010 | const char *bdrv_get_node_name(const BlockDriverState *bs) |
5011 | { |
5012 | return bs->node_name; |
5013 | } |
5014 | |
5015 | const char *bdrv_get_parent_name(const BlockDriverState *bs) |
5016 | { |
5017 | BdrvChild *c; |
5018 | const char *name; |
5019 | |
5020 | /* If multiple parents have a name, just pick the first one. */ |
5021 | QLIST_FOREACH(c, &bs->parents, next_parent) { |
5022 | if (c->role->get_name) { |
5023 | name = c->role->get_name(c); |
5024 | if (name && *name) { |
5025 | return name; |
5026 | } |
5027 | } |
5028 | } |
5029 | |
5030 | return NULL; |
5031 | } |
5032 | |
5033 | /* TODO check what callers really want: bs->node_name or blk_name() */ |
5034 | const char *bdrv_get_device_name(const BlockDriverState *bs) |
5035 | { |
5036 | return bdrv_get_parent_name(bs) ?: "" ; |
5037 | } |
5038 | |
5039 | /* This can be used to identify nodes that might not have a device |
5040 | * name associated. Since node and device names live in the same |
5041 | * namespace, the result is unambiguous. The exception is if both are |
5042 | * absent, then this returns an empty (non-null) string. */ |
5043 | const char *bdrv_get_device_or_node_name(const BlockDriverState *bs) |
5044 | { |
5045 | return bdrv_get_parent_name(bs) ?: bs->node_name; |
5046 | } |
5047 | |
5048 | int bdrv_get_flags(BlockDriverState *bs) |
5049 | { |
5050 | return bs->open_flags; |
5051 | } |
5052 | |
5053 | int bdrv_has_zero_init_1(BlockDriverState *bs) |
5054 | { |
5055 | return 1; |
5056 | } |
5057 | |
5058 | int bdrv_has_zero_init(BlockDriverState *bs) |
5059 | { |
5060 | if (!bs->drv) { |
5061 | return 0; |
5062 | } |
5063 | |
5064 | /* If BS is a copy on write image, it is initialized to |
5065 | the contents of the base image, which may not be zeroes. */ |
5066 | if (bs->backing) { |
5067 | return 0; |
5068 | } |
5069 | if (bs->drv->bdrv_has_zero_init) { |
5070 | return bs->drv->bdrv_has_zero_init(bs); |
5071 | } |
5072 | if (bs->file && bs->drv->is_filter) { |
5073 | return bdrv_has_zero_init(bs->file->bs); |
5074 | } |
5075 | |
5076 | /* safe default */ |
5077 | return 0; |
5078 | } |
5079 | |
5080 | int bdrv_has_zero_init_truncate(BlockDriverState *bs) |
5081 | { |
5082 | if (!bs->drv) { |
5083 | return 0; |
5084 | } |
5085 | |
5086 | if (bs->backing) { |
5087 | /* Depends on the backing image length, but better safe than sorry */ |
5088 | return 0; |
5089 | } |
5090 | if (bs->drv->bdrv_has_zero_init_truncate) { |
5091 | return bs->drv->bdrv_has_zero_init_truncate(bs); |
5092 | } |
5093 | if (bs->file && bs->drv->is_filter) { |
5094 | return bdrv_has_zero_init_truncate(bs->file->bs); |
5095 | } |
5096 | |
5097 | /* safe default */ |
5098 | return 0; |
5099 | } |
5100 | |
5101 | bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs) |
5102 | { |
5103 | BlockDriverInfo bdi; |
5104 | |
5105 | if (bs->backing) { |
5106 | return false; |
5107 | } |
5108 | |
5109 | if (bdrv_get_info(bs, &bdi) == 0) { |
5110 | return bdi.unallocated_blocks_are_zero; |
5111 | } |
5112 | |
5113 | return false; |
5114 | } |
5115 | |
5116 | bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) |
5117 | { |
5118 | if (!(bs->open_flags & BDRV_O_UNMAP)) { |
5119 | return false; |
5120 | } |
5121 | |
5122 | return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP; |
5123 | } |
5124 | |
5125 | void bdrv_get_backing_filename(BlockDriverState *bs, |
5126 | char *filename, int filename_size) |
5127 | { |
5128 | pstrcpy(filename, filename_size, bs->backing_file); |
5129 | } |
5130 | |
5131 | int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
5132 | { |
5133 | BlockDriver *drv = bs->drv; |
5134 | /* if bs->drv == NULL, bs is closed, so there's nothing to do here */ |
5135 | if (!drv) { |
5136 | return -ENOMEDIUM; |
5137 | } |
5138 | if (!drv->bdrv_get_info) { |
5139 | if (bs->file && drv->is_filter) { |
5140 | return bdrv_get_info(bs->file->bs, bdi); |
5141 | } |
5142 | return -ENOTSUP; |
5143 | } |
5144 | memset(bdi, 0, sizeof(*bdi)); |
5145 | return drv->bdrv_get_info(bs, bdi); |
5146 | } |
5147 | |
5148 | ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs, |
5149 | Error **errp) |
5150 | { |
5151 | BlockDriver *drv = bs->drv; |
5152 | if (drv && drv->bdrv_get_specific_info) { |
5153 | return drv->bdrv_get_specific_info(bs, errp); |
5154 | } |
5155 | return NULL; |
5156 | } |
5157 | |
5158 | void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event) |
5159 | { |
5160 | if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) { |
5161 | return; |
5162 | } |
5163 | |
5164 | bs->drv->bdrv_debug_event(bs, event); |
5165 | } |
5166 | |
5167 | int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, |
5168 | const char *tag) |
5169 | { |
5170 | while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { |
5171 | bs = bs->file ? bs->file->bs : NULL; |
5172 | } |
5173 | |
5174 | if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) { |
5175 | return bs->drv->bdrv_debug_breakpoint(bs, event, tag); |
5176 | } |
5177 | |
5178 | return -ENOTSUP; |
5179 | } |
5180 | |
5181 | int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) |
5182 | { |
5183 | while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) { |
5184 | bs = bs->file ? bs->file->bs : NULL; |
5185 | } |
5186 | |
5187 | if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) { |
5188 | return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); |
5189 | } |
5190 | |
5191 | return -ENOTSUP; |
5192 | } |
5193 | |
5194 | int bdrv_debug_resume(BlockDriverState *bs, const char *tag) |
5195 | { |
5196 | while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { |
5197 | bs = bs->file ? bs->file->bs : NULL; |
5198 | } |
5199 | |
5200 | if (bs && bs->drv && bs->drv->bdrv_debug_resume) { |
5201 | return bs->drv->bdrv_debug_resume(bs, tag); |
5202 | } |
5203 | |
5204 | return -ENOTSUP; |
5205 | } |
5206 | |
5207 | bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) |
5208 | { |
5209 | while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { |
5210 | bs = bs->file ? bs->file->bs : NULL; |
5211 | } |
5212 | |
5213 | if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { |
5214 | return bs->drv->bdrv_debug_is_suspended(bs, tag); |
5215 | } |
5216 | |
5217 | return false; |
5218 | } |
5219 | |
5220 | /* backing_file can either be relative, or absolute, or a protocol. If it is |
5221 | * relative, it must be relative to the chain. So, passing in bs->filename |
5222 | * from a BDS as backing_file should not be done, as that may be relative to |
5223 | * the CWD rather than the chain. */ |
5224 | BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, |
5225 | const char *backing_file) |
5226 | { |
5227 | char *filename_full = NULL; |
5228 | char *backing_file_full = NULL; |
5229 | char *filename_tmp = NULL; |
5230 | int is_protocol = 0; |
5231 | BlockDriverState *curr_bs = NULL; |
5232 | BlockDriverState *retval = NULL; |
5233 | |
5234 | if (!bs || !bs->drv || !backing_file) { |
5235 | return NULL; |
5236 | } |
5237 | |
5238 | filename_full = g_malloc(PATH_MAX); |
5239 | backing_file_full = g_malloc(PATH_MAX); |
5240 | |
5241 | is_protocol = path_has_protocol(backing_file); |
5242 | |
5243 | for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) { |
5244 | |
5245 | /* If either of the filename paths is actually a protocol, then |
5246 | * compare unmodified paths; otherwise make paths relative */ |
5247 | if (is_protocol || path_has_protocol(curr_bs->backing_file)) { |
5248 | char *backing_file_full_ret; |
5249 | |
5250 | if (strcmp(backing_file, curr_bs->backing_file) == 0) { |
5251 | retval = curr_bs->backing->bs; |
5252 | break; |
5253 | } |
5254 | /* Also check against the full backing filename for the image */ |
5255 | backing_file_full_ret = bdrv_get_full_backing_filename(curr_bs, |
5256 | NULL); |
5257 | if (backing_file_full_ret) { |
5258 | bool equal = strcmp(backing_file, backing_file_full_ret) == 0; |
5259 | g_free(backing_file_full_ret); |
5260 | if (equal) { |
5261 | retval = curr_bs->backing->bs; |
5262 | break; |
5263 | } |
5264 | } |
5265 | } else { |
5266 | /* If not an absolute filename path, make it relative to the current |
5267 | * image's filename path */ |
5268 | filename_tmp = bdrv_make_absolute_filename(curr_bs, backing_file, |
5269 | NULL); |
5270 | /* We are going to compare canonicalized absolute pathnames */ |
5271 | if (!filename_tmp || !realpath(filename_tmp, filename_full)) { |
5272 | g_free(filename_tmp); |
5273 | continue; |
5274 | } |
5275 | g_free(filename_tmp); |
5276 | |
5277 | /* We need to make sure the backing filename we are comparing against |
5278 | * is relative to the current image filename (or absolute) */ |
5279 | filename_tmp = bdrv_get_full_backing_filename(curr_bs, NULL); |
5280 | if (!filename_tmp || !realpath(filename_tmp, backing_file_full)) { |
5281 | g_free(filename_tmp); |
5282 | continue; |
5283 | } |
5284 | g_free(filename_tmp); |
5285 | |
5286 | if (strcmp(backing_file_full, filename_full) == 0) { |
5287 | retval = curr_bs->backing->bs; |
5288 | break; |
5289 | } |
5290 | } |
5291 | } |
5292 | |
5293 | g_free(filename_full); |
5294 | g_free(backing_file_full); |
5295 | return retval; |
5296 | } |
5297 | |
5298 | void bdrv_init(void) |
5299 | { |
5300 | module_call_init(MODULE_INIT_BLOCK); |
5301 | } |
5302 | |
5303 | void bdrv_init_with_whitelist(void) |
5304 | { |
5305 | use_bdrv_whitelist = 1; |
5306 | bdrv_init(); |
5307 | } |
5308 | |
5309 | static void coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, |
5310 | Error **errp) |
5311 | { |
5312 | BdrvChild *child, *parent; |
5313 | uint64_t perm, shared_perm; |
5314 | Error *local_err = NULL; |
5315 | int ret; |
5316 | BdrvDirtyBitmap *bm; |
5317 | |
5318 | if (!bs->drv) { |
5319 | return; |
5320 | } |
5321 | |
5322 | if (!(bs->open_flags & BDRV_O_INACTIVE)) { |
5323 | return; |
5324 | } |
5325 | |
5326 | QLIST_FOREACH(child, &bs->children, next) { |
5327 | bdrv_co_invalidate_cache(child->bs, &local_err); |
5328 | if (local_err) { |
5329 | error_propagate(errp, local_err); |
5330 | return; |
5331 | } |
5332 | } |
5333 | |
5334 | /* |
5335 | * Update permissions, they may differ for inactive nodes. |
5336 | * |
5337 | * Note that the required permissions of inactive images are always a |
5338 | * subset of the permissions required after activating the image. This |
5339 | * allows us to just get the permissions upfront without restricting |
5340 | * drv->bdrv_invalidate_cache(). |
5341 | * |
5342 | * It also means that in error cases, we don't have to try and revert to |
5343 | * the old permissions (which is an operation that could fail, too). We can |
5344 | * just keep the extended permissions for the next time that an activation |
5345 | * of the image is tried. |
5346 | */ |
5347 | bs->open_flags &= ~BDRV_O_INACTIVE; |
5348 | bdrv_get_cumulative_perm(bs, &perm, &shared_perm); |
5349 | ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, NULL, &local_err); |
5350 | if (ret < 0) { |
5351 | bs->open_flags |= BDRV_O_INACTIVE; |
5352 | error_propagate(errp, local_err); |
5353 | return; |
5354 | } |
5355 | bdrv_set_perm(bs, perm, shared_perm); |
5356 | |
5357 | if (bs->drv->bdrv_co_invalidate_cache) { |
5358 | bs->drv->bdrv_co_invalidate_cache(bs, &local_err); |
5359 | if (local_err) { |
5360 | bs->open_flags |= BDRV_O_INACTIVE; |
5361 | error_propagate(errp, local_err); |
5362 | return; |
5363 | } |
5364 | } |
5365 | |
5366 | for (bm = bdrv_dirty_bitmap_next(bs, NULL); bm; |
5367 | bm = bdrv_dirty_bitmap_next(bs, bm)) |
5368 | { |
5369 | bdrv_dirty_bitmap_skip_store(bm, false); |
5370 | } |
5371 | |
5372 | ret = refresh_total_sectors(bs, bs->total_sectors); |
5373 | if (ret < 0) { |
5374 | bs->open_flags |= BDRV_O_INACTIVE; |
5375 | error_setg_errno(errp, -ret, "Could not refresh total sector count" ); |
5376 | return; |
5377 | } |
5378 | |
5379 | QLIST_FOREACH(parent, &bs->parents, next_parent) { |
5380 | if (parent->role->activate) { |
5381 | parent->role->activate(parent, &local_err); |
5382 | if (local_err) { |
5383 | bs->open_flags |= BDRV_O_INACTIVE; |
5384 | error_propagate(errp, local_err); |
5385 | return; |
5386 | } |
5387 | } |
5388 | } |
5389 | } |
5390 | |
5391 | typedef struct InvalidateCacheCo { |
5392 | BlockDriverState *bs; |
5393 | Error **errp; |
5394 | bool done; |
5395 | } InvalidateCacheCo; |
5396 | |
5397 | static void coroutine_fn bdrv_invalidate_cache_co_entry(void *opaque) |
5398 | { |
5399 | InvalidateCacheCo *ico = opaque; |
5400 | bdrv_co_invalidate_cache(ico->bs, ico->errp); |
5401 | ico->done = true; |
5402 | aio_wait_kick(); |
5403 | } |
5404 | |
5405 | void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) |
5406 | { |
5407 | Coroutine *co; |
5408 | InvalidateCacheCo ico = { |
5409 | .bs = bs, |
5410 | .done = false, |
5411 | .errp = errp |
5412 | }; |
5413 | |
5414 | if (qemu_in_coroutine()) { |
5415 | /* Fast-path if already in coroutine context */ |
5416 | bdrv_invalidate_cache_co_entry(&ico); |
5417 | } else { |
5418 | co = qemu_coroutine_create(bdrv_invalidate_cache_co_entry, &ico); |
5419 | bdrv_coroutine_enter(bs, co); |
5420 | BDRV_POLL_WHILE(bs, !ico.done); |
5421 | } |
5422 | } |
5423 | |
5424 | void bdrv_invalidate_cache_all(Error **errp) |
5425 | { |
5426 | BlockDriverState *bs; |
5427 | Error *local_err = NULL; |
5428 | BdrvNextIterator it; |
5429 | |
5430 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
5431 | AioContext *aio_context = bdrv_get_aio_context(bs); |
5432 | |
5433 | aio_context_acquire(aio_context); |
5434 | bdrv_invalidate_cache(bs, &local_err); |
5435 | aio_context_release(aio_context); |
5436 | if (local_err) { |
5437 | error_propagate(errp, local_err); |
5438 | bdrv_next_cleanup(&it); |
5439 | return; |
5440 | } |
5441 | } |
5442 | } |
5443 | |
5444 | static bool bdrv_has_bds_parent(BlockDriverState *bs, bool only_active) |
5445 | { |
5446 | BdrvChild *parent; |
5447 | |
5448 | QLIST_FOREACH(parent, &bs->parents, next_parent) { |
5449 | if (parent->role->parent_is_bds) { |
5450 | BlockDriverState *parent_bs = parent->opaque; |
5451 | if (!only_active || !(parent_bs->open_flags & BDRV_O_INACTIVE)) { |
5452 | return true; |
5453 | } |
5454 | } |
5455 | } |
5456 | |
5457 | return false; |
5458 | } |
5459 | |
5460 | static int bdrv_inactivate_recurse(BlockDriverState *bs) |
5461 | { |
5462 | BdrvChild *child, *parent; |
5463 | bool tighten_restrictions; |
5464 | uint64_t perm, shared_perm; |
5465 | int ret; |
5466 | |
5467 | if (!bs->drv) { |
5468 | return -ENOMEDIUM; |
5469 | } |
5470 | |
5471 | /* Make sure that we don't inactivate a child before its parent. |
5472 | * It will be covered by recursion from the yet active parent. */ |
5473 | if (bdrv_has_bds_parent(bs, true)) { |
5474 | return 0; |
5475 | } |
5476 | |
5477 | assert(!(bs->open_flags & BDRV_O_INACTIVE)); |
5478 | |
5479 | /* Inactivate this node */ |
5480 | if (bs->drv->bdrv_inactivate) { |
5481 | ret = bs->drv->bdrv_inactivate(bs); |
5482 | if (ret < 0) { |
5483 | return ret; |
5484 | } |
5485 | } |
5486 | |
5487 | QLIST_FOREACH(parent, &bs->parents, next_parent) { |
5488 | if (parent->role->inactivate) { |
5489 | ret = parent->role->inactivate(parent); |
5490 | if (ret < 0) { |
5491 | return ret; |
5492 | } |
5493 | } |
5494 | } |
5495 | |
5496 | bs->open_flags |= BDRV_O_INACTIVE; |
5497 | |
5498 | /* Update permissions, they may differ for inactive nodes */ |
5499 | bdrv_get_cumulative_perm(bs, &perm, &shared_perm); |
5500 | ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, |
5501 | &tighten_restrictions, NULL); |
5502 | assert(tighten_restrictions == false); |
5503 | if (ret < 0) { |
5504 | /* We only tried to loosen restrictions, so errors are not fatal */ |
5505 | bdrv_abort_perm_update(bs); |
5506 | } else { |
5507 | bdrv_set_perm(bs, perm, shared_perm); |
5508 | } |
5509 | |
5510 | |
5511 | /* Recursively inactivate children */ |
5512 | QLIST_FOREACH(child, &bs->children, next) { |
5513 | ret = bdrv_inactivate_recurse(child->bs); |
5514 | if (ret < 0) { |
5515 | return ret; |
5516 | } |
5517 | } |
5518 | |
5519 | return 0; |
5520 | } |
5521 | |
5522 | int bdrv_inactivate_all(void) |
5523 | { |
5524 | BlockDriverState *bs = NULL; |
5525 | BdrvNextIterator it; |
5526 | int ret = 0; |
5527 | GSList *aio_ctxs = NULL, *ctx; |
5528 | |
5529 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
5530 | AioContext *aio_context = bdrv_get_aio_context(bs); |
5531 | |
5532 | if (!g_slist_find(aio_ctxs, aio_context)) { |
5533 | aio_ctxs = g_slist_prepend(aio_ctxs, aio_context); |
5534 | aio_context_acquire(aio_context); |
5535 | } |
5536 | } |
5537 | |
5538 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
5539 | /* Nodes with BDS parents are covered by recursion from the last |
5540 | * parent that gets inactivated. Don't inactivate them a second |
5541 | * time if that has already happened. */ |
5542 | if (bdrv_has_bds_parent(bs, false)) { |
5543 | continue; |
5544 | } |
5545 | ret = bdrv_inactivate_recurse(bs); |
5546 | if (ret < 0) { |
5547 | bdrv_next_cleanup(&it); |
5548 | goto out; |
5549 | } |
5550 | } |
5551 | |
5552 | out: |
5553 | for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) { |
5554 | AioContext *aio_context = ctx->data; |
5555 | aio_context_release(aio_context); |
5556 | } |
5557 | g_slist_free(aio_ctxs); |
5558 | |
5559 | return ret; |
5560 | } |
5561 | |
5562 | /**************************************************************/ |
5563 | /* removable device support */ |
5564 | |
5565 | /** |
5566 | * Return TRUE if the media is present |
5567 | */ |
5568 | bool bdrv_is_inserted(BlockDriverState *bs) |
5569 | { |
5570 | BlockDriver *drv = bs->drv; |
5571 | BdrvChild *child; |
5572 | |
5573 | if (!drv) { |
5574 | return false; |
5575 | } |
5576 | if (drv->bdrv_is_inserted) { |
5577 | return drv->bdrv_is_inserted(bs); |
5578 | } |
5579 | QLIST_FOREACH(child, &bs->children, next) { |
5580 | if (!bdrv_is_inserted(child->bs)) { |
5581 | return false; |
5582 | } |
5583 | } |
5584 | return true; |
5585 | } |
5586 | |
5587 | /** |
5588 | * If eject_flag is TRUE, eject the media. Otherwise, close the tray |
5589 | */ |
5590 | void bdrv_eject(BlockDriverState *bs, bool eject_flag) |
5591 | { |
5592 | BlockDriver *drv = bs->drv; |
5593 | |
5594 | if (drv && drv->bdrv_eject) { |
5595 | drv->bdrv_eject(bs, eject_flag); |
5596 | } |
5597 | } |
5598 | |
5599 | /** |
5600 | * Lock or unlock the media (if it is locked, the user won't be able |
5601 | * to eject it manually). |
5602 | */ |
5603 | void bdrv_lock_medium(BlockDriverState *bs, bool locked) |
5604 | { |
5605 | BlockDriver *drv = bs->drv; |
5606 | |
5607 | trace_bdrv_lock_medium(bs, locked); |
5608 | |
5609 | if (drv && drv->bdrv_lock_medium) { |
5610 | drv->bdrv_lock_medium(bs, locked); |
5611 | } |
5612 | } |
5613 | |
5614 | /* Get a reference to bs */ |
5615 | void bdrv_ref(BlockDriverState *bs) |
5616 | { |
5617 | bs->refcnt++; |
5618 | } |
5619 | |
5620 | /* Release a previously grabbed reference to bs. |
5621 | * If after releasing, reference count is zero, the BlockDriverState is |
5622 | * deleted. */ |
5623 | void bdrv_unref(BlockDriverState *bs) |
5624 | { |
5625 | if (!bs) { |
5626 | return; |
5627 | } |
5628 | assert(bs->refcnt > 0); |
5629 | if (--bs->refcnt == 0) { |
5630 | bdrv_delete(bs); |
5631 | } |
5632 | } |
5633 | |
5634 | struct BdrvOpBlocker { |
5635 | Error *reason; |
5636 | QLIST_ENTRY(BdrvOpBlocker) list; |
5637 | }; |
5638 | |
5639 | bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) |
5640 | { |
5641 | BdrvOpBlocker *blocker; |
5642 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); |
5643 | if (!QLIST_EMPTY(&bs->op_blockers[op])) { |
5644 | blocker = QLIST_FIRST(&bs->op_blockers[op]); |
5645 | error_propagate_prepend(errp, error_copy(blocker->reason), |
5646 | "Node '%s' is busy: " , |
5647 | bdrv_get_device_or_node_name(bs)); |
5648 | return true; |
5649 | } |
5650 | return false; |
5651 | } |
5652 | |
5653 | void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason) |
5654 | { |
5655 | BdrvOpBlocker *blocker; |
5656 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); |
5657 | |
5658 | blocker = g_new0(BdrvOpBlocker, 1); |
5659 | blocker->reason = reason; |
5660 | QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list); |
5661 | } |
5662 | |
5663 | void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason) |
5664 | { |
5665 | BdrvOpBlocker *blocker, *next; |
5666 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); |
5667 | QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) { |
5668 | if (blocker->reason == reason) { |
5669 | QLIST_REMOVE(blocker, list); |
5670 | g_free(blocker); |
5671 | } |
5672 | } |
5673 | } |
5674 | |
5675 | void bdrv_op_block_all(BlockDriverState *bs, Error *reason) |
5676 | { |
5677 | int i; |
5678 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
5679 | bdrv_op_block(bs, i, reason); |
5680 | } |
5681 | } |
5682 | |
5683 | void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason) |
5684 | { |
5685 | int i; |
5686 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
5687 | bdrv_op_unblock(bs, i, reason); |
5688 | } |
5689 | } |
5690 | |
5691 | bool bdrv_op_blocker_is_empty(BlockDriverState *bs) |
5692 | { |
5693 | int i; |
5694 | |
5695 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
5696 | if (!QLIST_EMPTY(&bs->op_blockers[i])) { |
5697 | return false; |
5698 | } |
5699 | } |
5700 | return true; |
5701 | } |
5702 | |
5703 | void bdrv_img_create(const char *filename, const char *fmt, |
5704 | const char *base_filename, const char *base_fmt, |
5705 | char *options, uint64_t img_size, int flags, bool quiet, |
5706 | Error **errp) |
5707 | { |
5708 | QemuOptsList *create_opts = NULL; |
5709 | QemuOpts *opts = NULL; |
5710 | const char *backing_fmt, *backing_file; |
5711 | int64_t size; |
5712 | BlockDriver *drv, *proto_drv; |
5713 | Error *local_err = NULL; |
5714 | int ret = 0; |
5715 | |
5716 | /* Find driver and parse its options */ |
5717 | drv = bdrv_find_format(fmt); |
5718 | if (!drv) { |
5719 | error_setg(errp, "Unknown file format '%s'" , fmt); |
5720 | return; |
5721 | } |
5722 | |
5723 | proto_drv = bdrv_find_protocol(filename, true, errp); |
5724 | if (!proto_drv) { |
5725 | return; |
5726 | } |
5727 | |
5728 | if (!drv->create_opts) { |
5729 | error_setg(errp, "Format driver '%s' does not support image creation" , |
5730 | drv->format_name); |
5731 | return; |
5732 | } |
5733 | |
5734 | if (!proto_drv->create_opts) { |
5735 | error_setg(errp, "Protocol driver '%s' does not support image creation" , |
5736 | proto_drv->format_name); |
5737 | return; |
5738 | } |
5739 | |
5740 | create_opts = qemu_opts_append(create_opts, drv->create_opts); |
5741 | create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); |
5742 | |
5743 | /* Create parameter list with default values */ |
5744 | opts = qemu_opts_create(create_opts, NULL, 0, &error_abort); |
5745 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort); |
5746 | |
5747 | /* Parse -o options */ |
5748 | if (options) { |
5749 | qemu_opts_do_parse(opts, options, NULL, &local_err); |
5750 | if (local_err) { |
5751 | goto out; |
5752 | } |
5753 | } |
5754 | |
5755 | if (base_filename) { |
5756 | qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err); |
5757 | if (local_err) { |
5758 | error_setg(errp, "Backing file not supported for file format '%s'" , |
5759 | fmt); |
5760 | goto out; |
5761 | } |
5762 | } |
5763 | |
5764 | if (base_fmt) { |
5765 | qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err); |
5766 | if (local_err) { |
5767 | error_setg(errp, "Backing file format not supported for file " |
5768 | "format '%s'" , fmt); |
5769 | goto out; |
5770 | } |
5771 | } |
5772 | |
5773 | backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); |
5774 | if (backing_file) { |
5775 | if (!strcmp(filename, backing_file)) { |
5776 | error_setg(errp, "Error: Trying to create an image with the " |
5777 | "same filename as the backing file" ); |
5778 | goto out; |
5779 | } |
5780 | } |
5781 | |
5782 | backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); |
5783 | |
5784 | /* The size for the image must always be specified, unless we have a backing |
5785 | * file and we have not been forbidden from opening it. */ |
5786 | size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size); |
5787 | if (backing_file && !(flags & BDRV_O_NO_BACKING)) { |
5788 | BlockDriverState *bs; |
5789 | char *full_backing; |
5790 | int back_flags; |
5791 | QDict *backing_options = NULL; |
5792 | |
5793 | full_backing = |
5794 | bdrv_get_full_backing_filename_from_filename(filename, backing_file, |
5795 | &local_err); |
5796 | if (local_err) { |
5797 | goto out; |
5798 | } |
5799 | assert(full_backing); |
5800 | |
5801 | /* backing files always opened read-only */ |
5802 | back_flags = flags; |
5803 | back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
5804 | |
5805 | backing_options = qdict_new(); |
5806 | if (backing_fmt) { |
5807 | qdict_put_str(backing_options, "driver" , backing_fmt); |
5808 | } |
5809 | qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true); |
5810 | |
5811 | bs = bdrv_open(full_backing, NULL, backing_options, back_flags, |
5812 | &local_err); |
5813 | g_free(full_backing); |
5814 | if (!bs && size != -1) { |
5815 | /* Couldn't open BS, but we have a size, so it's nonfatal */ |
5816 | warn_reportf_err(local_err, |
5817 | "Could not verify backing image. " |
5818 | "This may become an error in future versions.\n" ); |
5819 | local_err = NULL; |
5820 | } else if (!bs) { |
5821 | /* Couldn't open bs, do not have size */ |
5822 | error_append_hint(&local_err, |
5823 | "Could not open backing image to determine size.\n" ); |
5824 | goto out; |
5825 | } else { |
5826 | if (size == -1) { |
5827 | /* Opened BS, have no size */ |
5828 | size = bdrv_getlength(bs); |
5829 | if (size < 0) { |
5830 | error_setg_errno(errp, -size, "Could not get size of '%s'" , |
5831 | backing_file); |
5832 | bdrv_unref(bs); |
5833 | goto out; |
5834 | } |
5835 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort); |
5836 | } |
5837 | bdrv_unref(bs); |
5838 | } |
5839 | } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */ |
5840 | |
5841 | if (size == -1) { |
5842 | error_setg(errp, "Image creation needs a size parameter" ); |
5843 | goto out; |
5844 | } |
5845 | |
5846 | if (!quiet) { |
5847 | printf("Formatting '%s', fmt=%s " , filename, fmt); |
5848 | qemu_opts_print(opts, " " ); |
5849 | puts("" ); |
5850 | } |
5851 | |
5852 | ret = bdrv_create(drv, filename, opts, &local_err); |
5853 | |
5854 | if (ret == -EFBIG) { |
5855 | /* This is generally a better message than whatever the driver would |
5856 | * deliver (especially because of the cluster_size_hint), since that |
5857 | * is most probably not much different from "image too large". */ |
5858 | const char *cluster_size_hint = "" ; |
5859 | if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) { |
5860 | cluster_size_hint = " (try using a larger cluster size)" ; |
5861 | } |
5862 | error_setg(errp, "The image size is too large for file format '%s'" |
5863 | "%s" , fmt, cluster_size_hint); |
5864 | error_free(local_err); |
5865 | local_err = NULL; |
5866 | } |
5867 | |
5868 | out: |
5869 | qemu_opts_del(opts); |
5870 | qemu_opts_free(create_opts); |
5871 | error_propagate(errp, local_err); |
5872 | } |
5873 | |
5874 | AioContext *bdrv_get_aio_context(BlockDriverState *bs) |
5875 | { |
5876 | return bs ? bs->aio_context : qemu_get_aio_context(); |
5877 | } |
5878 | |
5879 | void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co) |
5880 | { |
5881 | aio_co_enter(bdrv_get_aio_context(bs), co); |
5882 | } |
5883 | |
5884 | static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban) |
5885 | { |
5886 | QLIST_REMOVE(ban, list); |
5887 | g_free(ban); |
5888 | } |
5889 | |
5890 | static void bdrv_detach_aio_context(BlockDriverState *bs) |
5891 | { |
5892 | BdrvAioNotifier *baf, *baf_tmp; |
5893 | |
5894 | assert(!bs->walking_aio_notifiers); |
5895 | bs->walking_aio_notifiers = true; |
5896 | QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) { |
5897 | if (baf->deleted) { |
5898 | bdrv_do_remove_aio_context_notifier(baf); |
5899 | } else { |
5900 | baf->detach_aio_context(baf->opaque); |
5901 | } |
5902 | } |
5903 | /* Never mind iterating again to check for ->deleted. bdrv_close() will |
5904 | * remove remaining aio notifiers if we aren't called again. |
5905 | */ |
5906 | bs->walking_aio_notifiers = false; |
5907 | |
5908 | if (bs->drv && bs->drv->bdrv_detach_aio_context) { |
5909 | bs->drv->bdrv_detach_aio_context(bs); |
5910 | } |
5911 | |
5912 | if (bs->quiesce_counter) { |
5913 | aio_enable_external(bs->aio_context); |
5914 | } |
5915 | bs->aio_context = NULL; |
5916 | } |
5917 | |
5918 | static void bdrv_attach_aio_context(BlockDriverState *bs, |
5919 | AioContext *new_context) |
5920 | { |
5921 | BdrvAioNotifier *ban, *ban_tmp; |
5922 | |
5923 | if (bs->quiesce_counter) { |
5924 | aio_disable_external(new_context); |
5925 | } |
5926 | |
5927 | bs->aio_context = new_context; |
5928 | |
5929 | if (bs->drv && bs->drv->bdrv_attach_aio_context) { |
5930 | bs->drv->bdrv_attach_aio_context(bs, new_context); |
5931 | } |
5932 | |
5933 | assert(!bs->walking_aio_notifiers); |
5934 | bs->walking_aio_notifiers = true; |
5935 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) { |
5936 | if (ban->deleted) { |
5937 | bdrv_do_remove_aio_context_notifier(ban); |
5938 | } else { |
5939 | ban->attached_aio_context(new_context, ban->opaque); |
5940 | } |
5941 | } |
5942 | bs->walking_aio_notifiers = false; |
5943 | } |
5944 | |
5945 | /* |
5946 | * Changes the AioContext used for fd handlers, timers, and BHs by this |
5947 | * BlockDriverState and all its children and parents. |
5948 | * |
5949 | * Must be called from the main AioContext. |
5950 | * |
5951 | * The caller must own the AioContext lock for the old AioContext of bs, but it |
5952 | * must not own the AioContext lock for new_context (unless new_context is the |
5953 | * same as the current context of bs). |
5954 | * |
5955 | * @ignore will accumulate all visited BdrvChild object. The caller is |
5956 | * responsible for freeing the list afterwards. |
5957 | */ |
5958 | void bdrv_set_aio_context_ignore(BlockDriverState *bs, |
5959 | AioContext *new_context, GSList **ignore) |
5960 | { |
5961 | AioContext *old_context = bdrv_get_aio_context(bs); |
5962 | BdrvChild *child; |
5963 | |
5964 | g_assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
5965 | |
5966 | if (old_context == new_context) { |
5967 | return; |
5968 | } |
5969 | |
5970 | bdrv_drained_begin(bs); |
5971 | |
5972 | QLIST_FOREACH(child, &bs->children, next) { |
5973 | if (g_slist_find(*ignore, child)) { |
5974 | continue; |
5975 | } |
5976 | *ignore = g_slist_prepend(*ignore, child); |
5977 | bdrv_set_aio_context_ignore(child->bs, new_context, ignore); |
5978 | } |
5979 | QLIST_FOREACH(child, &bs->parents, next_parent) { |
5980 | if (g_slist_find(*ignore, child)) { |
5981 | continue; |
5982 | } |
5983 | assert(child->role->set_aio_ctx); |
5984 | *ignore = g_slist_prepend(*ignore, child); |
5985 | child->role->set_aio_ctx(child, new_context, ignore); |
5986 | } |
5987 | |
5988 | bdrv_detach_aio_context(bs); |
5989 | |
5990 | /* Acquire the new context, if necessary */ |
5991 | if (qemu_get_aio_context() != new_context) { |
5992 | aio_context_acquire(new_context); |
5993 | } |
5994 | |
5995 | bdrv_attach_aio_context(bs, new_context); |
5996 | |
5997 | /* |
5998 | * If this function was recursively called from |
5999 | * bdrv_set_aio_context_ignore(), there may be nodes in the |
6000 | * subtree that have not yet been moved to the new AioContext. |
6001 | * Release the old one so bdrv_drained_end() can poll them. |
6002 | */ |
6003 | if (qemu_get_aio_context() != old_context) { |
6004 | aio_context_release(old_context); |
6005 | } |
6006 | |
6007 | bdrv_drained_end(bs); |
6008 | |
6009 | if (qemu_get_aio_context() != old_context) { |
6010 | aio_context_acquire(old_context); |
6011 | } |
6012 | if (qemu_get_aio_context() != new_context) { |
6013 | aio_context_release(new_context); |
6014 | } |
6015 | } |
6016 | |
6017 | static bool bdrv_parent_can_set_aio_context(BdrvChild *c, AioContext *ctx, |
6018 | GSList **ignore, Error **errp) |
6019 | { |
6020 | if (g_slist_find(*ignore, c)) { |
6021 | return true; |
6022 | } |
6023 | *ignore = g_slist_prepend(*ignore, c); |
6024 | |
6025 | /* A BdrvChildRole that doesn't handle AioContext changes cannot |
6026 | * tolerate any AioContext changes */ |
6027 | if (!c->role->can_set_aio_ctx) { |
6028 | char *user = bdrv_child_user_desc(c); |
6029 | error_setg(errp, "Changing iothreads is not supported by %s" , user); |
6030 | g_free(user); |
6031 | return false; |
6032 | } |
6033 | if (!c->role->can_set_aio_ctx(c, ctx, ignore, errp)) { |
6034 | assert(!errp || *errp); |
6035 | return false; |
6036 | } |
6037 | return true; |
6038 | } |
6039 | |
6040 | bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx, |
6041 | GSList **ignore, Error **errp) |
6042 | { |
6043 | if (g_slist_find(*ignore, c)) { |
6044 | return true; |
6045 | } |
6046 | *ignore = g_slist_prepend(*ignore, c); |
6047 | return bdrv_can_set_aio_context(c->bs, ctx, ignore, errp); |
6048 | } |
6049 | |
6050 | /* @ignore will accumulate all visited BdrvChild object. The caller is |
6051 | * responsible for freeing the list afterwards. */ |
6052 | bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx, |
6053 | GSList **ignore, Error **errp) |
6054 | { |
6055 | BdrvChild *c; |
6056 | |
6057 | if (bdrv_get_aio_context(bs) == ctx) { |
6058 | return true; |
6059 | } |
6060 | |
6061 | QLIST_FOREACH(c, &bs->parents, next_parent) { |
6062 | if (!bdrv_parent_can_set_aio_context(c, ctx, ignore, errp)) { |
6063 | return false; |
6064 | } |
6065 | } |
6066 | QLIST_FOREACH(c, &bs->children, next) { |
6067 | if (!bdrv_child_can_set_aio_context(c, ctx, ignore, errp)) { |
6068 | return false; |
6069 | } |
6070 | } |
6071 | |
6072 | return true; |
6073 | } |
6074 | |
6075 | int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx, |
6076 | BdrvChild *ignore_child, Error **errp) |
6077 | { |
6078 | GSList *ignore; |
6079 | bool ret; |
6080 | |
6081 | ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL; |
6082 | ret = bdrv_can_set_aio_context(bs, ctx, &ignore, errp); |
6083 | g_slist_free(ignore); |
6084 | |
6085 | if (!ret) { |
6086 | return -EPERM; |
6087 | } |
6088 | |
6089 | ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL; |
6090 | bdrv_set_aio_context_ignore(bs, ctx, &ignore); |
6091 | g_slist_free(ignore); |
6092 | |
6093 | return 0; |
6094 | } |
6095 | |
6096 | int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx, |
6097 | Error **errp) |
6098 | { |
6099 | return bdrv_child_try_set_aio_context(bs, ctx, NULL, errp); |
6100 | } |
6101 | |
6102 | void bdrv_add_aio_context_notifier(BlockDriverState *bs, |
6103 | void (*attached_aio_context)(AioContext *new_context, void *opaque), |
6104 | void (*detach_aio_context)(void *opaque), void *opaque) |
6105 | { |
6106 | BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1); |
6107 | *ban = (BdrvAioNotifier){ |
6108 | .attached_aio_context = attached_aio_context, |
6109 | .detach_aio_context = detach_aio_context, |
6110 | .opaque = opaque |
6111 | }; |
6112 | |
6113 | QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list); |
6114 | } |
6115 | |
6116 | void bdrv_remove_aio_context_notifier(BlockDriverState *bs, |
6117 | void (*attached_aio_context)(AioContext *, |
6118 | void *), |
6119 | void (*detach_aio_context)(void *), |
6120 | void *opaque) |
6121 | { |
6122 | BdrvAioNotifier *ban, *ban_next; |
6123 | |
6124 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { |
6125 | if (ban->attached_aio_context == attached_aio_context && |
6126 | ban->detach_aio_context == detach_aio_context && |
6127 | ban->opaque == opaque && |
6128 | ban->deleted == false) |
6129 | { |
6130 | if (bs->walking_aio_notifiers) { |
6131 | ban->deleted = true; |
6132 | } else { |
6133 | bdrv_do_remove_aio_context_notifier(ban); |
6134 | } |
6135 | return; |
6136 | } |
6137 | } |
6138 | |
6139 | abort(); |
6140 | } |
6141 | |
6142 | int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts, |
6143 | BlockDriverAmendStatusCB *status_cb, void *cb_opaque, |
6144 | Error **errp) |
6145 | { |
6146 | if (!bs->drv) { |
6147 | error_setg(errp, "Node is ejected" ); |
6148 | return -ENOMEDIUM; |
6149 | } |
6150 | if (!bs->drv->bdrv_amend_options) { |
6151 | error_setg(errp, "Block driver '%s' does not support option amendment" , |
6152 | bs->drv->format_name); |
6153 | return -ENOTSUP; |
6154 | } |
6155 | return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque, errp); |
6156 | } |
6157 | |
6158 | /* This function will be called by the bdrv_recurse_is_first_non_filter method |
6159 | * of block filter and by bdrv_is_first_non_filter. |
6160 | * It is used to test if the given bs is the candidate or recurse more in the |
6161 | * node graph. |
6162 | */ |
6163 | bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, |
6164 | BlockDriverState *candidate) |
6165 | { |
6166 | /* return false if basic checks fails */ |
6167 | if (!bs || !bs->drv) { |
6168 | return false; |
6169 | } |
6170 | |
6171 | /* the code reached a non block filter driver -> check if the bs is |
6172 | * the same as the candidate. It's the recursion termination condition. |
6173 | */ |
6174 | if (!bs->drv->is_filter) { |
6175 | return bs == candidate; |
6176 | } |
6177 | /* Down this path the driver is a block filter driver */ |
6178 | |
6179 | /* If the block filter recursion method is defined use it to recurse down |
6180 | * the node graph. |
6181 | */ |
6182 | if (bs->drv->bdrv_recurse_is_first_non_filter) { |
6183 | return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate); |
6184 | } |
6185 | |
6186 | /* the driver is a block filter but don't allow to recurse -> return false |
6187 | */ |
6188 | return false; |
6189 | } |
6190 | |
6191 | /* This function checks if the candidate is the first non filter bs down it's |
6192 | * bs chain. Since we don't have pointers to parents it explore all bs chains |
6193 | * from the top. Some filters can choose not to pass down the recursion. |
6194 | */ |
6195 | bool bdrv_is_first_non_filter(BlockDriverState *candidate) |
6196 | { |
6197 | BlockDriverState *bs; |
6198 | BdrvNextIterator it; |
6199 | |
6200 | /* walk down the bs forest recursively */ |
6201 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
6202 | bool perm; |
6203 | |
6204 | /* try to recurse in this top level bs */ |
6205 | perm = bdrv_recurse_is_first_non_filter(bs, candidate); |
6206 | |
6207 | /* candidate is the first non filter */ |
6208 | if (perm) { |
6209 | bdrv_next_cleanup(&it); |
6210 | return true; |
6211 | } |
6212 | } |
6213 | |
6214 | return false; |
6215 | } |
6216 | |
6217 | BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, |
6218 | const char *node_name, Error **errp) |
6219 | { |
6220 | BlockDriverState *to_replace_bs = bdrv_find_node(node_name); |
6221 | AioContext *aio_context; |
6222 | |
6223 | if (!to_replace_bs) { |
6224 | error_setg(errp, "Node name '%s' not found" , node_name); |
6225 | return NULL; |
6226 | } |
6227 | |
6228 | aio_context = bdrv_get_aio_context(to_replace_bs); |
6229 | aio_context_acquire(aio_context); |
6230 | |
6231 | if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) { |
6232 | to_replace_bs = NULL; |
6233 | goto out; |
6234 | } |
6235 | |
6236 | /* We don't want arbitrary node of the BDS chain to be replaced only the top |
6237 | * most non filter in order to prevent data corruption. |
6238 | * Another benefit is that this tests exclude backing files which are |
6239 | * blocked by the backing blockers. |
6240 | */ |
6241 | if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) { |
6242 | error_setg(errp, "Only top most non filter can be replaced" ); |
6243 | to_replace_bs = NULL; |
6244 | goto out; |
6245 | } |
6246 | |
6247 | out: |
6248 | aio_context_release(aio_context); |
6249 | return to_replace_bs; |
6250 | } |
6251 | |
6252 | /** |
6253 | * Iterates through the list of runtime option keys that are said to |
6254 | * be "strong" for a BDS. An option is called "strong" if it changes |
6255 | * a BDS's data. For example, the null block driver's "size" and |
6256 | * "read-zeroes" options are strong, but its "latency-ns" option is |
6257 | * not. |
6258 | * |
6259 | * If a key returned by this function ends with a dot, all options |
6260 | * starting with that prefix are strong. |
6261 | */ |
6262 | static const char *const *strong_options(BlockDriverState *bs, |
6263 | const char *const *curopt) |
6264 | { |
6265 | static const char *const global_options[] = { |
6266 | "driver" , "filename" , NULL |
6267 | }; |
6268 | |
6269 | if (!curopt) { |
6270 | return &global_options[0]; |
6271 | } |
6272 | |
6273 | curopt++; |
6274 | if (curopt == &global_options[ARRAY_SIZE(global_options) - 1] && bs->drv) { |
6275 | curopt = bs->drv->strong_runtime_opts; |
6276 | } |
6277 | |
6278 | return (curopt && *curopt) ? curopt : NULL; |
6279 | } |
6280 | |
6281 | /** |
6282 | * Copies all strong runtime options from bs->options to the given |
6283 | * QDict. The set of strong option keys is determined by invoking |
6284 | * strong_options(). |
6285 | * |
6286 | * Returns true iff any strong option was present in bs->options (and |
6287 | * thus copied to the target QDict) with the exception of "filename" |
6288 | * and "driver". The caller is expected to use this value to decide |
6289 | * whether the existence of strong options prevents the generation of |
6290 | * a plain filename. |
6291 | */ |
6292 | static bool append_strong_runtime_options(QDict *d, BlockDriverState *bs) |
6293 | { |
6294 | bool found_any = false; |
6295 | const char *const *option_name = NULL; |
6296 | |
6297 | if (!bs->drv) { |
6298 | return false; |
6299 | } |
6300 | |
6301 | while ((option_name = strong_options(bs, option_name))) { |
6302 | bool option_given = false; |
6303 | |
6304 | assert(strlen(*option_name) > 0); |
6305 | if ((*option_name)[strlen(*option_name) - 1] != '.') { |
6306 | QObject *entry = qdict_get(bs->options, *option_name); |
6307 | if (!entry) { |
6308 | continue; |
6309 | } |
6310 | |
6311 | qdict_put_obj(d, *option_name, qobject_ref(entry)); |
6312 | option_given = true; |
6313 | } else { |
6314 | const QDictEntry *entry; |
6315 | for (entry = qdict_first(bs->options); entry; |
6316 | entry = qdict_next(bs->options, entry)) |
6317 | { |
6318 | if (strstart(qdict_entry_key(entry), *option_name, NULL)) { |
6319 | qdict_put_obj(d, qdict_entry_key(entry), |
6320 | qobject_ref(qdict_entry_value(entry))); |
6321 | option_given = true; |
6322 | } |
6323 | } |
6324 | } |
6325 | |
6326 | /* While "driver" and "filename" need to be included in a JSON filename, |
6327 | * their existence does not prohibit generation of a plain filename. */ |
6328 | if (!found_any && option_given && |
6329 | strcmp(*option_name, "driver" ) && strcmp(*option_name, "filename" )) |
6330 | { |
6331 | found_any = true; |
6332 | } |
6333 | } |
6334 | |
6335 | if (!qdict_haskey(d, "driver" )) { |
6336 | /* Drivers created with bdrv_new_open_driver() may not have a |
6337 | * @driver option. Add it here. */ |
6338 | qdict_put_str(d, "driver" , bs->drv->format_name); |
6339 | } |
6340 | |
6341 | return found_any; |
6342 | } |
6343 | |
6344 | /* Note: This function may return false positives; it may return true |
6345 | * even if opening the backing file specified by bs's image header |
6346 | * would result in exactly bs->backing. */ |
6347 | static bool bdrv_backing_overridden(BlockDriverState *bs) |
6348 | { |
6349 | if (bs->backing) { |
6350 | return strcmp(bs->auto_backing_file, |
6351 | bs->backing->bs->filename); |
6352 | } else { |
6353 | /* No backing BDS, so if the image header reports any backing |
6354 | * file, it must have been suppressed */ |
6355 | return bs->auto_backing_file[0] != '\0'; |
6356 | } |
6357 | } |
6358 | |
6359 | /* Updates the following BDS fields: |
6360 | * - exact_filename: A filename which may be used for opening a block device |
6361 | * which (mostly) equals the given BDS (even without any |
6362 | * other options; so reading and writing must return the same |
6363 | * results, but caching etc. may be different) |
6364 | * - full_open_options: Options which, when given when opening a block device |
6365 | * (without a filename), result in a BDS (mostly) |
6366 | * equalling the given one |
6367 | * - filename: If exact_filename is set, it is copied here. Otherwise, |
6368 | * full_open_options is converted to a JSON object, prefixed with |
6369 | * "json:" (for use through the JSON pseudo protocol) and put here. |
6370 | */ |
6371 | void bdrv_refresh_filename(BlockDriverState *bs) |
6372 | { |
6373 | BlockDriver *drv = bs->drv; |
6374 | BdrvChild *child; |
6375 | QDict *opts; |
6376 | bool backing_overridden; |
6377 | bool generate_json_filename; /* Whether our default implementation should |
6378 | fill exact_filename (false) or not (true) */ |
6379 | |
6380 | if (!drv) { |
6381 | return; |
6382 | } |
6383 | |
6384 | /* This BDS's file name may depend on any of its children's file names, so |
6385 | * refresh those first */ |
6386 | QLIST_FOREACH(child, &bs->children, next) { |
6387 | bdrv_refresh_filename(child->bs); |
6388 | } |
6389 | |
6390 | if (bs->implicit) { |
6391 | /* For implicit nodes, just copy everything from the single child */ |
6392 | child = QLIST_FIRST(&bs->children); |
6393 | assert(QLIST_NEXT(child, next) == NULL); |
6394 | |
6395 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), |
6396 | child->bs->exact_filename); |
6397 | pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename); |
6398 | |
6399 | bs->full_open_options = qobject_ref(child->bs->full_open_options); |
6400 | |
6401 | return; |
6402 | } |
6403 | |
6404 | backing_overridden = bdrv_backing_overridden(bs); |
6405 | |
6406 | if (bs->open_flags & BDRV_O_NO_IO) { |
6407 | /* Without I/O, the backing file does not change anything. |
6408 | * Therefore, in such a case (primarily qemu-img), we can |
6409 | * pretend the backing file has not been overridden even if |
6410 | * it technically has been. */ |
6411 | backing_overridden = false; |
6412 | } |
6413 | |
6414 | /* Gather the options QDict */ |
6415 | opts = qdict_new(); |
6416 | generate_json_filename = append_strong_runtime_options(opts, bs); |
6417 | generate_json_filename |= backing_overridden; |
6418 | |
6419 | if (drv->bdrv_gather_child_options) { |
6420 | /* Some block drivers may not want to present all of their children's |
6421 | * options, or name them differently from BdrvChild.name */ |
6422 | drv->bdrv_gather_child_options(bs, opts, backing_overridden); |
6423 | } else { |
6424 | QLIST_FOREACH(child, &bs->children, next) { |
6425 | if (child->role == &child_backing && !backing_overridden) { |
6426 | /* We can skip the backing BDS if it has not been overridden */ |
6427 | continue; |
6428 | } |
6429 | |
6430 | qdict_put(opts, child->name, |
6431 | qobject_ref(child->bs->full_open_options)); |
6432 | } |
6433 | |
6434 | if (backing_overridden && !bs->backing) { |
6435 | /* Force no backing file */ |
6436 | qdict_put_null(opts, "backing" ); |
6437 | } |
6438 | } |
6439 | |
6440 | qobject_unref(bs->full_open_options); |
6441 | bs->full_open_options = opts; |
6442 | |
6443 | if (drv->bdrv_refresh_filename) { |
6444 | /* Obsolete information is of no use here, so drop the old file name |
6445 | * information before refreshing it */ |
6446 | bs->exact_filename[0] = '\0'; |
6447 | |
6448 | drv->bdrv_refresh_filename(bs); |
6449 | } else if (bs->file) { |
6450 | /* Try to reconstruct valid information from the underlying file */ |
6451 | |
6452 | bs->exact_filename[0] = '\0'; |
6453 | |
6454 | /* |
6455 | * We can use the underlying file's filename if: |
6456 | * - it has a filename, |
6457 | * - the file is a protocol BDS, and |
6458 | * - opening that file (as this BDS's format) will automatically create |
6459 | * the BDS tree we have right now, that is: |
6460 | * - the user did not significantly change this BDS's behavior with |
6461 | * some explicit (strong) options |
6462 | * - no non-file child of this BDS has been overridden by the user |
6463 | * Both of these conditions are represented by generate_json_filename. |
6464 | */ |
6465 | if (bs->file->bs->exact_filename[0] && |
6466 | bs->file->bs->drv->bdrv_file_open && |
6467 | !generate_json_filename) |
6468 | { |
6469 | strcpy(bs->exact_filename, bs->file->bs->exact_filename); |
6470 | } |
6471 | } |
6472 | |
6473 | if (bs->exact_filename[0]) { |
6474 | pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); |
6475 | } else { |
6476 | QString *json = qobject_to_json(QOBJECT(bs->full_open_options)); |
6477 | snprintf(bs->filename, sizeof(bs->filename), "json:%s" , |
6478 | qstring_get_str(json)); |
6479 | qobject_unref(json); |
6480 | } |
6481 | } |
6482 | |
6483 | char *bdrv_dirname(BlockDriverState *bs, Error **errp) |
6484 | { |
6485 | BlockDriver *drv = bs->drv; |
6486 | |
6487 | if (!drv) { |
6488 | error_setg(errp, "Node '%s' is ejected" , bs->node_name); |
6489 | return NULL; |
6490 | } |
6491 | |
6492 | if (drv->bdrv_dirname) { |
6493 | return drv->bdrv_dirname(bs, errp); |
6494 | } |
6495 | |
6496 | if (bs->file) { |
6497 | return bdrv_dirname(bs->file->bs, errp); |
6498 | } |
6499 | |
6500 | bdrv_refresh_filename(bs); |
6501 | if (bs->exact_filename[0] != '\0') { |
6502 | return path_combine(bs->exact_filename, "" ); |
6503 | } |
6504 | |
6505 | error_setg(errp, "Cannot generate a base directory for %s nodes" , |
6506 | drv->format_name); |
6507 | return NULL; |
6508 | } |
6509 | |
6510 | /* |
6511 | * Hot add/remove a BDS's child. So the user can take a child offline when |
6512 | * it is broken and take a new child online |
6513 | */ |
6514 | void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, |
6515 | Error **errp) |
6516 | { |
6517 | |
6518 | if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) { |
6519 | error_setg(errp, "The node %s does not support adding a child" , |
6520 | bdrv_get_device_or_node_name(parent_bs)); |
6521 | return; |
6522 | } |
6523 | |
6524 | if (!QLIST_EMPTY(&child_bs->parents)) { |
6525 | error_setg(errp, "The node %s already has a parent" , |
6526 | child_bs->node_name); |
6527 | return; |
6528 | } |
6529 | |
6530 | parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp); |
6531 | } |
6532 | |
6533 | void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp) |
6534 | { |
6535 | BdrvChild *tmp; |
6536 | |
6537 | if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) { |
6538 | error_setg(errp, "The node %s does not support removing a child" , |
6539 | bdrv_get_device_or_node_name(parent_bs)); |
6540 | return; |
6541 | } |
6542 | |
6543 | QLIST_FOREACH(tmp, &parent_bs->children, next) { |
6544 | if (tmp == child) { |
6545 | break; |
6546 | } |
6547 | } |
6548 | |
6549 | if (!tmp) { |
6550 | error_setg(errp, "The node %s does not have a child named %s" , |
6551 | bdrv_get_device_or_node_name(parent_bs), |
6552 | bdrv_get_device_or_node_name(child->bs)); |
6553 | return; |
6554 | } |
6555 | |
6556 | parent_bs->drv->bdrv_del_child(parent_bs, child, errp); |
6557 | } |
6558 | |
6559 | bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, |
6560 | uint32_t granularity, Error **errp) |
6561 | { |
6562 | BlockDriver *drv = bs->drv; |
6563 | |
6564 | if (!drv) { |
6565 | error_setg_errno(errp, ENOMEDIUM, |
6566 | "Can't store persistent bitmaps to %s" , |
6567 | bdrv_get_device_or_node_name(bs)); |
6568 | return false; |
6569 | } |
6570 | |
6571 | if (!drv->bdrv_can_store_new_dirty_bitmap) { |
6572 | error_setg_errno(errp, ENOTSUP, |
6573 | "Can't store persistent bitmaps to %s" , |
6574 | bdrv_get_device_or_node_name(bs)); |
6575 | return false; |
6576 | } |
6577 | |
6578 | return drv->bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp); |
6579 | } |
6580 | |