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1 | /* | |
2 | * QEMU System Emulator block driver | |
3 | * | |
4 | * Copyright (c) 2003 Fabrice Bellard | |
5 | * | |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | * THE SOFTWARE. | |
23 | */ | |
24 | #include "config-host.h" | |
25 | #include "qemu-common.h" | |
26 | #include "trace.h" | |
27 | #include "block/block_int.h" | |
28 | #include "block/blockjob.h" | |
29 | #include "qemu/error-report.h" | |
30 | #include "qemu/module.h" | |
31 | #include "qapi/qmp/qerror.h" | |
32 | #include "qapi/qmp/qjson.h" | |
33 | #include "sysemu/block-backend.h" | |
34 | #include "sysemu/sysemu.h" | |
35 | #include "qemu/notify.h" | |
36 | #include "block/coroutine.h" | |
37 | #include "block/qapi.h" | |
38 | #include "qmp-commands.h" | |
39 | #include "qemu/timer.h" | |
40 | #include "qapi-event.h" | |
41 | #include "block/throttle-groups.h" | |
42 | ||
43 | #ifdef CONFIG_BSD | |
44 | #include <sys/types.h> | |
45 | #include <sys/stat.h> | |
46 | #include <sys/ioctl.h> | |
47 | #include <sys/queue.h> | |
48 | #ifndef __DragonFly__ | |
49 | #include <sys/disk.h> | |
50 | #endif | |
51 | #endif | |
52 | ||
53 | #ifdef _WIN32 | |
54 | #include <windows.h> | |
55 | #endif | |
56 | ||
57 | /** | |
58 | * A BdrvDirtyBitmap can be in three possible states: | |
59 | * (1) successor is NULL and disabled is false: full r/w mode | |
60 | * (2) successor is NULL and disabled is true: read only mode ("disabled") | |
61 | * (3) successor is set: frozen mode. | |
62 | * A frozen bitmap cannot be renamed, deleted, anonymized, cleared, set, | |
63 | * or enabled. A frozen bitmap can only abdicate() or reclaim(). | |
64 | */ | |
65 | struct BdrvDirtyBitmap { | |
66 | HBitmap *bitmap; /* Dirty sector bitmap implementation */ | |
67 | BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */ | |
68 | char *name; /* Optional non-empty unique ID */ | |
69 | int64_t size; /* Size of the bitmap (Number of sectors) */ | |
70 | bool disabled; /* Bitmap is read-only */ | |
71 | QLIST_ENTRY(BdrvDirtyBitmap) list; | |
72 | }; | |
73 | ||
74 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ | |
75 | ||
76 | static QTAILQ_HEAD(, BlockDriverState) bdrv_states = | |
77 | QTAILQ_HEAD_INITIALIZER(bdrv_states); | |
78 | ||
79 | static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states = | |
80 | QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); | |
81 | ||
82 | static QLIST_HEAD(, BlockDriver) bdrv_drivers = | |
83 | QLIST_HEAD_INITIALIZER(bdrv_drivers); | |
84 | ||
85 | static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, | |
86 | const char *reference, QDict *options, int flags, | |
87 | BlockDriverState *parent, | |
88 | const BdrvChildRole *child_role, | |
89 | BlockDriver *drv, Error **errp); | |
90 | ||
91 | static void bdrv_dirty_bitmap_truncate(BlockDriverState *bs); | |
92 | /* If non-zero, use only whitelisted block drivers */ | |
93 | static int use_bdrv_whitelist; | |
94 | ||
95 | #ifdef _WIN32 | |
96 | static int is_windows_drive_prefix(const char *filename) | |
97 | { | |
98 | return (((filename[0] >= 'a' && filename[0] <= 'z') || | |
99 | (filename[0] >= 'A' && filename[0] <= 'Z')) && | |
100 | filename[1] == ':'); | |
101 | } | |
102 | ||
103 | int is_windows_drive(const char *filename) | |
104 | { | |
105 | if (is_windows_drive_prefix(filename) && | |
106 | filename[2] == '\0') | |
107 | return 1; | |
108 | if (strstart(filename, "\\\\.\\", NULL) || | |
109 | strstart(filename, "//./", NULL)) | |
110 | return 1; | |
111 | return 0; | |
112 | } | |
113 | #endif | |
114 | ||
115 | size_t bdrv_opt_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.opt_mem_alignment; | |
123 | } | |
124 | ||
125 | size_t bdrv_min_mem_align(BlockDriverState *bs) | |
126 | { | |
127 | if (!bs || !bs->drv) { | |
128 | /* page size or 4k (hdd sector size) should be on the safe side */ | |
129 | return MAX(4096, getpagesize()); | |
130 | } | |
131 | ||
132 | return bs->bl.min_mem_alignment; | |
133 | } | |
134 | ||
135 | /* check if the path starts with "<protocol>:" */ | |
136 | int path_has_protocol(const char *path) | |
137 | { | |
138 | const char *p; | |
139 | ||
140 | #ifdef _WIN32 | |
141 | if (is_windows_drive(path) || | |
142 | is_windows_drive_prefix(path)) { | |
143 | return 0; | |
144 | } | |
145 | p = path + strcspn(path, ":/\\"); | |
146 | #else | |
147 | p = path + strcspn(path, ":/"); | |
148 | #endif | |
149 | ||
150 | return *p == ':'; | |
151 | } | |
152 | ||
153 | int path_is_absolute(const char *path) | |
154 | { | |
155 | #ifdef _WIN32 | |
156 | /* specific case for names like: "\\.\d:" */ | |
157 | if (is_windows_drive(path) || is_windows_drive_prefix(path)) { | |
158 | return 1; | |
159 | } | |
160 | return (*path == '/' || *path == '\\'); | |
161 | #else | |
162 | return (*path == '/'); | |
163 | #endif | |
164 | } | |
165 | ||
166 | /* if filename is absolute, just copy it to dest. Otherwise, build a | |
167 | path to it by considering it is relative to base_path. URL are | |
168 | supported. */ | |
169 | void path_combine(char *dest, int dest_size, | |
170 | const char *base_path, | |
171 | const char *filename) | |
172 | { | |
173 | const char *p, *p1; | |
174 | int len; | |
175 | ||
176 | if (dest_size <= 0) | |
177 | return; | |
178 | if (path_is_absolute(filename)) { | |
179 | pstrcpy(dest, dest_size, filename); | |
180 | } else { | |
181 | p = strchr(base_path, ':'); | |
182 | if (p) | |
183 | p++; | |
184 | else | |
185 | p = base_path; | |
186 | p1 = strrchr(base_path, '/'); | |
187 | #ifdef _WIN32 | |
188 | { | |
189 | const char *p2; | |
190 | p2 = strrchr(base_path, '\\'); | |
191 | if (!p1 || p2 > p1) | |
192 | p1 = p2; | |
193 | } | |
194 | #endif | |
195 | if (p1) | |
196 | p1++; | |
197 | else | |
198 | p1 = base_path; | |
199 | if (p1 > p) | |
200 | p = p1; | |
201 | len = p - base_path; | |
202 | if (len > dest_size - 1) | |
203 | len = dest_size - 1; | |
204 | memcpy(dest, base_path, len); | |
205 | dest[len] = '\0'; | |
206 | pstrcat(dest, dest_size, filename); | |
207 | } | |
208 | } | |
209 | ||
210 | void bdrv_get_full_backing_filename_from_filename(const char *backed, | |
211 | const char *backing, | |
212 | char *dest, size_t sz, | |
213 | Error **errp) | |
214 | { | |
215 | if (backing[0] == '\0' || path_has_protocol(backing) || | |
216 | path_is_absolute(backing)) | |
217 | { | |
218 | pstrcpy(dest, sz, backing); | |
219 | } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) { | |
220 | error_setg(errp, "Cannot use relative backing file names for '%s'", | |
221 | backed); | |
222 | } else { | |
223 | path_combine(dest, sz, backed, backing); | |
224 | } | |
225 | } | |
226 | ||
227 | void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz, | |
228 | Error **errp) | |
229 | { | |
230 | char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename; | |
231 | ||
232 | bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file, | |
233 | dest, sz, errp); | |
234 | } | |
235 | ||
236 | void bdrv_register(BlockDriver *bdrv) | |
237 | { | |
238 | bdrv_setup_io_funcs(bdrv); | |
239 | ||
240 | QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); | |
241 | } | |
242 | ||
243 | BlockDriverState *bdrv_new_root(void) | |
244 | { | |
245 | BlockDriverState *bs = bdrv_new(); | |
246 | ||
247 | QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list); | |
248 | return bs; | |
249 | } | |
250 | ||
251 | BlockDriverState *bdrv_new(void) | |
252 | { | |
253 | BlockDriverState *bs; | |
254 | int i; | |
255 | ||
256 | bs = g_new0(BlockDriverState, 1); | |
257 | QLIST_INIT(&bs->dirty_bitmaps); | |
258 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
259 | QLIST_INIT(&bs->op_blockers[i]); | |
260 | } | |
261 | bdrv_iostatus_disable(bs); | |
262 | notifier_list_init(&bs->close_notifiers); | |
263 | notifier_with_return_list_init(&bs->before_write_notifiers); | |
264 | qemu_co_queue_init(&bs->throttled_reqs[0]); | |
265 | qemu_co_queue_init(&bs->throttled_reqs[1]); | |
266 | bs->refcnt = 1; | |
267 | bs->aio_context = qemu_get_aio_context(); | |
268 | ||
269 | return bs; | |
270 | } | |
271 | ||
272 | void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify) | |
273 | { | |
274 | notifier_list_add(&bs->close_notifiers, notify); | |
275 | } | |
276 | ||
277 | BlockDriver *bdrv_find_format(const char *format_name) | |
278 | { | |
279 | BlockDriver *drv1; | |
280 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
281 | if (!strcmp(drv1->format_name, format_name)) { | |
282 | return drv1; | |
283 | } | |
284 | } | |
285 | return NULL; | |
286 | } | |
287 | ||
288 | static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) | |
289 | { | |
290 | static const char *whitelist_rw[] = { | |
291 | CONFIG_BDRV_RW_WHITELIST | |
292 | }; | |
293 | static const char *whitelist_ro[] = { | |
294 | CONFIG_BDRV_RO_WHITELIST | |
295 | }; | |
296 | const char **p; | |
297 | ||
298 | if (!whitelist_rw[0] && !whitelist_ro[0]) { | |
299 | return 1; /* no whitelist, anything goes */ | |
300 | } | |
301 | ||
302 | for (p = whitelist_rw; *p; p++) { | |
303 | if (!strcmp(drv->format_name, *p)) { | |
304 | return 1; | |
305 | } | |
306 | } | |
307 | if (read_only) { | |
308 | for (p = whitelist_ro; *p; p++) { | |
309 | if (!strcmp(drv->format_name, *p)) { | |
310 | return 1; | |
311 | } | |
312 | } | |
313 | } | |
314 | return 0; | |
315 | } | |
316 | ||
317 | BlockDriver *bdrv_find_whitelisted_format(const char *format_name, | |
318 | bool read_only) | |
319 | { | |
320 | BlockDriver *drv = bdrv_find_format(format_name); | |
321 | return drv && bdrv_is_whitelisted(drv, read_only) ? drv : NULL; | |
322 | } | |
323 | ||
324 | typedef struct CreateCo { | |
325 | BlockDriver *drv; | |
326 | char *filename; | |
327 | QemuOpts *opts; | |
328 | int ret; | |
329 | Error *err; | |
330 | } CreateCo; | |
331 | ||
332 | static void coroutine_fn bdrv_create_co_entry(void *opaque) | |
333 | { | |
334 | Error *local_err = NULL; | |
335 | int ret; | |
336 | ||
337 | CreateCo *cco = opaque; | |
338 | assert(cco->drv); | |
339 | ||
340 | ret = cco->drv->bdrv_create(cco->filename, cco->opts, &local_err); | |
341 | if (local_err) { | |
342 | error_propagate(&cco->err, local_err); | |
343 | } | |
344 | cco->ret = ret; | |
345 | } | |
346 | ||
347 | int bdrv_create(BlockDriver *drv, const char* filename, | |
348 | QemuOpts *opts, Error **errp) | |
349 | { | |
350 | int ret; | |
351 | ||
352 | Coroutine *co; | |
353 | CreateCo cco = { | |
354 | .drv = drv, | |
355 | .filename = g_strdup(filename), | |
356 | .opts = opts, | |
357 | .ret = NOT_DONE, | |
358 | .err = NULL, | |
359 | }; | |
360 | ||
361 | if (!drv->bdrv_create) { | |
362 | error_setg(errp, "Driver '%s' does not support image creation", drv->format_name); | |
363 | ret = -ENOTSUP; | |
364 | goto out; | |
365 | } | |
366 | ||
367 | if (qemu_in_coroutine()) { | |
368 | /* Fast-path if already in coroutine context */ | |
369 | bdrv_create_co_entry(&cco); | |
370 | } else { | |
371 | co = qemu_coroutine_create(bdrv_create_co_entry); | |
372 | qemu_coroutine_enter(co, &cco); | |
373 | while (cco.ret == NOT_DONE) { | |
374 | aio_poll(qemu_get_aio_context(), true); | |
375 | } | |
376 | } | |
377 | ||
378 | ret = cco.ret; | |
379 | if (ret < 0) { | |
380 | if (cco.err) { | |
381 | error_propagate(errp, cco.err); | |
382 | } else { | |
383 | error_setg_errno(errp, -ret, "Could not create image"); | |
384 | } | |
385 | } | |
386 | ||
387 | out: | |
388 | g_free(cco.filename); | |
389 | return ret; | |
390 | } | |
391 | ||
392 | int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp) | |
393 | { | |
394 | BlockDriver *drv; | |
395 | Error *local_err = NULL; | |
396 | int ret; | |
397 | ||
398 | drv = bdrv_find_protocol(filename, true, errp); | |
399 | if (drv == NULL) { | |
400 | return -ENOENT; | |
401 | } | |
402 | ||
403 | ret = bdrv_create(drv, filename, opts, &local_err); | |
404 | if (local_err) { | |
405 | error_propagate(errp, local_err); | |
406 | } | |
407 | return ret; | |
408 | } | |
409 | ||
410 | /** | |
411 | * Try to get @bs's logical and physical block size. | |
412 | * On success, store them in @bsz struct and return 0. | |
413 | * On failure return -errno. | |
414 | * @bs must not be empty. | |
415 | */ | |
416 | int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) | |
417 | { | |
418 | BlockDriver *drv = bs->drv; | |
419 | ||
420 | if (drv && drv->bdrv_probe_blocksizes) { | |
421 | return drv->bdrv_probe_blocksizes(bs, bsz); | |
422 | } | |
423 | ||
424 | return -ENOTSUP; | |
425 | } | |
426 | ||
427 | /** | |
428 | * Try to get @bs's geometry (cyls, heads, sectors). | |
429 | * On success, store them in @geo struct and return 0. | |
430 | * On failure return -errno. | |
431 | * @bs must not be empty. | |
432 | */ | |
433 | int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo) | |
434 | { | |
435 | BlockDriver *drv = bs->drv; | |
436 | ||
437 | if (drv && drv->bdrv_probe_geometry) { | |
438 | return drv->bdrv_probe_geometry(bs, geo); | |
439 | } | |
440 | ||
441 | return -ENOTSUP; | |
442 | } | |
443 | ||
444 | /* | |
445 | * Create a uniquely-named empty temporary file. | |
446 | * Return 0 upon success, otherwise a negative errno value. | |
447 | */ | |
448 | int get_tmp_filename(char *filename, int size) | |
449 | { | |
450 | #ifdef _WIN32 | |
451 | char temp_dir[MAX_PATH]; | |
452 | /* GetTempFileName requires that its output buffer (4th param) | |
453 | have length MAX_PATH or greater. */ | |
454 | assert(size >= MAX_PATH); | |
455 | return (GetTempPath(MAX_PATH, temp_dir) | |
456 | && GetTempFileName(temp_dir, "qem", 0, filename) | |
457 | ? 0 : -GetLastError()); | |
458 | #else | |
459 | int fd; | |
460 | const char *tmpdir; | |
461 | tmpdir = getenv("TMPDIR"); | |
462 | if (!tmpdir) { | |
463 | tmpdir = "/var/tmp"; | |
464 | } | |
465 | if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) { | |
466 | return -EOVERFLOW; | |
467 | } | |
468 | fd = mkstemp(filename); | |
469 | if (fd < 0) { | |
470 | return -errno; | |
471 | } | |
472 | if (close(fd) != 0) { | |
473 | unlink(filename); | |
474 | return -errno; | |
475 | } | |
476 | return 0; | |
477 | #endif | |
478 | } | |
479 | ||
480 | /* | |
481 | * Detect host devices. By convention, /dev/cdrom[N] is always | |
482 | * recognized as a host CDROM. | |
483 | */ | |
484 | static BlockDriver *find_hdev_driver(const char *filename) | |
485 | { | |
486 | int score_max = 0, score; | |
487 | BlockDriver *drv = NULL, *d; | |
488 | ||
489 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
490 | if (d->bdrv_probe_device) { | |
491 | score = d->bdrv_probe_device(filename); | |
492 | if (score > score_max) { | |
493 | score_max = score; | |
494 | drv = d; | |
495 | } | |
496 | } | |
497 | } | |
498 | ||
499 | return drv; | |
500 | } | |
501 | ||
502 | BlockDriver *bdrv_find_protocol(const char *filename, | |
503 | bool allow_protocol_prefix, | |
504 | Error **errp) | |
505 | { | |
506 | BlockDriver *drv1; | |
507 | char protocol[128]; | |
508 | int len; | |
509 | const char *p; | |
510 | ||
511 | /* TODO Drivers without bdrv_file_open must be specified explicitly */ | |
512 | ||
513 | /* | |
514 | * XXX(hch): we really should not let host device detection | |
515 | * override an explicit protocol specification, but moving this | |
516 | * later breaks access to device names with colons in them. | |
517 | * Thanks to the brain-dead persistent naming schemes on udev- | |
518 | * based Linux systems those actually are quite common. | |
519 | */ | |
520 | drv1 = find_hdev_driver(filename); | |
521 | if (drv1) { | |
522 | return drv1; | |
523 | } | |
524 | ||
525 | if (!path_has_protocol(filename) || !allow_protocol_prefix) { | |
526 | return &bdrv_file; | |
527 | } | |
528 | ||
529 | p = strchr(filename, ':'); | |
530 | assert(p != NULL); | |
531 | len = p - filename; | |
532 | if (len > sizeof(protocol) - 1) | |
533 | len = sizeof(protocol) - 1; | |
534 | memcpy(protocol, filename, len); | |
535 | protocol[len] = '\0'; | |
536 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
537 | if (drv1->protocol_name && | |
538 | !strcmp(drv1->protocol_name, protocol)) { | |
539 | return drv1; | |
540 | } | |
541 | } | |
542 | ||
543 | error_setg(errp, "Unknown protocol '%s'", protocol); | |
544 | return NULL; | |
545 | } | |
546 | ||
547 | /* | |
548 | * Guess image format by probing its contents. | |
549 | * This is not a good idea when your image is raw (CVE-2008-2004), but | |
550 | * we do it anyway for backward compatibility. | |
551 | * | |
552 | * @buf contains the image's first @buf_size bytes. | |
553 | * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE, | |
554 | * but can be smaller if the image file is smaller) | |
555 | * @filename is its filename. | |
556 | * | |
557 | * For all block drivers, call the bdrv_probe() method to get its | |
558 | * probing score. | |
559 | * Return the first block driver with the highest probing score. | |
560 | */ | |
561 | BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, | |
562 | const char *filename) | |
563 | { | |
564 | int score_max = 0, score; | |
565 | BlockDriver *drv = NULL, *d; | |
566 | ||
567 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
568 | if (d->bdrv_probe) { | |
569 | score = d->bdrv_probe(buf, buf_size, filename); | |
570 | if (score > score_max) { | |
571 | score_max = score; | |
572 | drv = d; | |
573 | } | |
574 | } | |
575 | } | |
576 | ||
577 | return drv; | |
578 | } | |
579 | ||
580 | static int find_image_format(BlockDriverState *bs, const char *filename, | |
581 | BlockDriver **pdrv, Error **errp) | |
582 | { | |
583 | BlockDriver *drv; | |
584 | uint8_t buf[BLOCK_PROBE_BUF_SIZE]; | |
585 | int ret = 0; | |
586 | ||
587 | /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ | |
588 | if (bdrv_is_sg(bs) || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) { | |
589 | *pdrv = &bdrv_raw; | |
590 | return ret; | |
591 | } | |
592 | ||
593 | ret = bdrv_pread(bs, 0, buf, sizeof(buf)); | |
594 | if (ret < 0) { | |
595 | error_setg_errno(errp, -ret, "Could not read image for determining its " | |
596 | "format"); | |
597 | *pdrv = NULL; | |
598 | return ret; | |
599 | } | |
600 | ||
601 | drv = bdrv_probe_all(buf, ret, filename); | |
602 | if (!drv) { | |
603 | error_setg(errp, "Could not determine image format: No compatible " | |
604 | "driver found"); | |
605 | ret = -ENOENT; | |
606 | } | |
607 | *pdrv = drv; | |
608 | return ret; | |
609 | } | |
610 | ||
611 | /** | |
612 | * Set the current 'total_sectors' value | |
613 | * Return 0 on success, -errno on error. | |
614 | */ | |
615 | static int refresh_total_sectors(BlockDriverState *bs, int64_t hint) | |
616 | { | |
617 | BlockDriver *drv = bs->drv; | |
618 | ||
619 | /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */ | |
620 | if (bdrv_is_sg(bs)) | |
621 | return 0; | |
622 | ||
623 | /* query actual device if possible, otherwise just trust the hint */ | |
624 | if (drv->bdrv_getlength) { | |
625 | int64_t length = drv->bdrv_getlength(bs); | |
626 | if (length < 0) { | |
627 | return length; | |
628 | } | |
629 | hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE); | |
630 | } | |
631 | ||
632 | bs->total_sectors = hint; | |
633 | return 0; | |
634 | } | |
635 | ||
636 | /** | |
637 | * Set open flags for a given discard mode | |
638 | * | |
639 | * Return 0 on success, -1 if the discard mode was invalid. | |
640 | */ | |
641 | int bdrv_parse_discard_flags(const char *mode, int *flags) | |
642 | { | |
643 | *flags &= ~BDRV_O_UNMAP; | |
644 | ||
645 | if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) { | |
646 | /* do nothing */ | |
647 | } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) { | |
648 | *flags |= BDRV_O_UNMAP; | |
649 | } else { | |
650 | return -1; | |
651 | } | |
652 | ||
653 | return 0; | |
654 | } | |
655 | ||
656 | /** | |
657 | * Set open flags for a given cache mode | |
658 | * | |
659 | * Return 0 on success, -1 if the cache mode was invalid. | |
660 | */ | |
661 | int bdrv_parse_cache_flags(const char *mode, int *flags) | |
662 | { | |
663 | *flags &= ~BDRV_O_CACHE_MASK; | |
664 | ||
665 | if (!strcmp(mode, "off") || !strcmp(mode, "none")) { | |
666 | *flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; | |
667 | } else if (!strcmp(mode, "directsync")) { | |
668 | *flags |= BDRV_O_NOCACHE; | |
669 | } else if (!strcmp(mode, "writeback")) { | |
670 | *flags |= BDRV_O_CACHE_WB; | |
671 | } else if (!strcmp(mode, "unsafe")) { | |
672 | *flags |= BDRV_O_CACHE_WB; | |
673 | *flags |= BDRV_O_NO_FLUSH; | |
674 | } else if (!strcmp(mode, "writethrough")) { | |
675 | /* this is the default */ | |
676 | } else { | |
677 | return -1; | |
678 | } | |
679 | ||
680 | return 0; | |
681 | } | |
682 | ||
683 | /* | |
684 | * Returns the flags that a temporary snapshot should get, based on the | |
685 | * originally requested flags (the originally requested image will have flags | |
686 | * like a backing file) | |
687 | */ | |
688 | static int bdrv_temp_snapshot_flags(int flags) | |
689 | { | |
690 | return (flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY; | |
691 | } | |
692 | ||
693 | /* | |
694 | * Returns the flags that bs->file should get if a protocol driver is expected, | |
695 | * based on the given flags for the parent BDS | |
696 | */ | |
697 | static int bdrv_inherited_flags(int flags) | |
698 | { | |
699 | /* Enable protocol handling, disable format probing for bs->file */ | |
700 | flags |= BDRV_O_PROTOCOL; | |
701 | ||
702 | /* Our block drivers take care to send flushes and respect unmap policy, | |
703 | * so we can enable both unconditionally on lower layers. */ | |
704 | flags |= BDRV_O_CACHE_WB | BDRV_O_UNMAP; | |
705 | ||
706 | /* Clear flags that only apply to the top layer */ | |
707 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ); | |
708 | ||
709 | return flags; | |
710 | } | |
711 | ||
712 | const BdrvChildRole child_file = { | |
713 | .inherit_flags = bdrv_inherited_flags, | |
714 | }; | |
715 | ||
716 | /* | |
717 | * Returns the flags that bs->file should get if the use of formats (and not | |
718 | * only protocols) is permitted for it, based on the given flags for the parent | |
719 | * BDS | |
720 | */ | |
721 | static int bdrv_inherited_fmt_flags(int parent_flags) | |
722 | { | |
723 | int flags = child_file.inherit_flags(parent_flags); | |
724 | return flags & ~BDRV_O_PROTOCOL; | |
725 | } | |
726 | ||
727 | const BdrvChildRole child_format = { | |
728 | .inherit_flags = bdrv_inherited_fmt_flags, | |
729 | }; | |
730 | ||
731 | /* | |
732 | * Returns the flags that bs->backing_hd should get, based on the given flags | |
733 | * for the parent BDS | |
734 | */ | |
735 | static int bdrv_backing_flags(int flags) | |
736 | { | |
737 | /* backing files always opened read-only */ | |
738 | flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ); | |
739 | ||
740 | /* snapshot=on is handled on the top layer */ | |
741 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); | |
742 | ||
743 | return flags; | |
744 | } | |
745 | ||
746 | static const BdrvChildRole child_backing = { | |
747 | .inherit_flags = bdrv_backing_flags, | |
748 | }; | |
749 | ||
750 | static int bdrv_open_flags(BlockDriverState *bs, int flags) | |
751 | { | |
752 | int open_flags = flags | BDRV_O_CACHE_WB; | |
753 | ||
754 | /* | |
755 | * Clear flags that are internal to the block layer before opening the | |
756 | * image. | |
757 | */ | |
758 | open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL); | |
759 | ||
760 | /* | |
761 | * Snapshots should be writable. | |
762 | */ | |
763 | if (flags & BDRV_O_TEMPORARY) { | |
764 | open_flags |= BDRV_O_RDWR; | |
765 | } | |
766 | ||
767 | return open_flags; | |
768 | } | |
769 | ||
770 | static void bdrv_assign_node_name(BlockDriverState *bs, | |
771 | const char *node_name, | |
772 | Error **errp) | |
773 | { | |
774 | if (!node_name) { | |
775 | return; | |
776 | } | |
777 | ||
778 | /* Check for empty string or invalid characters */ | |
779 | if (!id_wellformed(node_name)) { | |
780 | error_setg(errp, "Invalid node name"); | |
781 | return; | |
782 | } | |
783 | ||
784 | /* takes care of avoiding namespaces collisions */ | |
785 | if (blk_by_name(node_name)) { | |
786 | error_setg(errp, "node-name=%s is conflicting with a device id", | |
787 | node_name); | |
788 | return; | |
789 | } | |
790 | ||
791 | /* takes care of avoiding duplicates node names */ | |
792 | if (bdrv_find_node(node_name)) { | |
793 | error_setg(errp, "Duplicate node name"); | |
794 | return; | |
795 | } | |
796 | ||
797 | /* copy node name into the bs and insert it into the graph list */ | |
798 | pstrcpy(bs->node_name, sizeof(bs->node_name), node_name); | |
799 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list); | |
800 | } | |
801 | ||
802 | static QemuOptsList bdrv_runtime_opts = { | |
803 | .name = "bdrv_common", | |
804 | .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head), | |
805 | .desc = { | |
806 | { | |
807 | .name = "node-name", | |
808 | .type = QEMU_OPT_STRING, | |
809 | .help = "Node name of the block device node", | |
810 | }, | |
811 | { /* end of list */ } | |
812 | }, | |
813 | }; | |
814 | ||
815 | /* | |
816 | * Common part for opening disk images and files | |
817 | * | |
818 | * Removes all processed options from *options. | |
819 | */ | |
820 | static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file, | |
821 | QDict *options, int flags, BlockDriver *drv, Error **errp) | |
822 | { | |
823 | int ret, open_flags; | |
824 | const char *filename; | |
825 | const char *node_name = NULL; | |
826 | QemuOpts *opts; | |
827 | Error *local_err = NULL; | |
828 | ||
829 | assert(drv != NULL); | |
830 | assert(bs->file == NULL); | |
831 | assert(options != NULL && bs->options != options); | |
832 | ||
833 | if (file != NULL) { | |
834 | filename = file->filename; | |
835 | } else { | |
836 | filename = qdict_get_try_str(options, "filename"); | |
837 | } | |
838 | ||
839 | if (drv->bdrv_needs_filename && !filename) { | |
840 | error_setg(errp, "The '%s' block driver requires a file name", | |
841 | drv->format_name); | |
842 | return -EINVAL; | |
843 | } | |
844 | ||
845 | trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name); | |
846 | ||
847 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); | |
848 | qemu_opts_absorb_qdict(opts, options, &local_err); | |
849 | if (local_err) { | |
850 | error_propagate(errp, local_err); | |
851 | ret = -EINVAL; | |
852 | goto fail_opts; | |
853 | } | |
854 | ||
855 | node_name = qemu_opt_get(opts, "node-name"); | |
856 | bdrv_assign_node_name(bs, node_name, &local_err); | |
857 | if (local_err) { | |
858 | error_propagate(errp, local_err); | |
859 | ret = -EINVAL; | |
860 | goto fail_opts; | |
861 | } | |
862 | ||
863 | bs->guest_block_size = 512; | |
864 | bs->request_alignment = 512; | |
865 | bs->zero_beyond_eof = true; | |
866 | open_flags = bdrv_open_flags(bs, flags); | |
867 | bs->read_only = !(open_flags & BDRV_O_RDWR); | |
868 | ||
869 | if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) { | |
870 | error_setg(errp, | |
871 | !bs->read_only && bdrv_is_whitelisted(drv, true) | |
872 | ? "Driver '%s' can only be used for read-only devices" | |
873 | : "Driver '%s' is not whitelisted", | |
874 | drv->format_name); | |
875 | ret = -ENOTSUP; | |
876 | goto fail_opts; | |
877 | } | |
878 | ||
879 | assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ | |
880 | if (flags & BDRV_O_COPY_ON_READ) { | |
881 | if (!bs->read_only) { | |
882 | bdrv_enable_copy_on_read(bs); | |
883 | } else { | |
884 | error_setg(errp, "Can't use copy-on-read on read-only device"); | |
885 | ret = -EINVAL; | |
886 | goto fail_opts; | |
887 | } | |
888 | } | |
889 | ||
890 | if (filename != NULL) { | |
891 | pstrcpy(bs->filename, sizeof(bs->filename), filename); | |
892 | } else { | |
893 | bs->filename[0] = '\0'; | |
894 | } | |
895 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename); | |
896 | ||
897 | bs->drv = drv; | |
898 | bs->opaque = g_malloc0(drv->instance_size); | |
899 | ||
900 | bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB); | |
901 | ||
902 | /* Open the image, either directly or using a protocol */ | |
903 | if (drv->bdrv_file_open) { | |
904 | assert(file == NULL); | |
905 | assert(!drv->bdrv_needs_filename || filename != NULL); | |
906 | ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); | |
907 | } else { | |
908 | if (file == NULL) { | |
909 | error_setg(errp, "Can't use '%s' as a block driver for the " | |
910 | "protocol level", drv->format_name); | |
911 | ret = -EINVAL; | |
912 | goto free_and_fail; | |
913 | } | |
914 | bs->file = file; | |
915 | ret = drv->bdrv_open(bs, options, open_flags, &local_err); | |
916 | } | |
917 | ||
918 | if (ret < 0) { | |
919 | if (local_err) { | |
920 | error_propagate(errp, local_err); | |
921 | } else if (bs->filename[0]) { | |
922 | error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename); | |
923 | } else { | |
924 | error_setg_errno(errp, -ret, "Could not open image"); | |
925 | } | |
926 | goto free_and_fail; | |
927 | } | |
928 | ||
929 | if (bs->encrypted) { | |
930 | error_report("Encrypted images are deprecated"); | |
931 | error_printf("Support for them will be removed in a future release.\n" | |
932 | "You can use 'qemu-img convert' to convert your image" | |
933 | " to an unencrypted one.\n"); | |
934 | } | |
935 | ||
936 | ret = refresh_total_sectors(bs, bs->total_sectors); | |
937 | if (ret < 0) { | |
938 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
939 | goto free_and_fail; | |
940 | } | |
941 | ||
942 | bdrv_refresh_limits(bs, &local_err); | |
943 | if (local_err) { | |
944 | error_propagate(errp, local_err); | |
945 | ret = -EINVAL; | |
946 | goto free_and_fail; | |
947 | } | |
948 | ||
949 | assert(bdrv_opt_mem_align(bs) != 0); | |
950 | assert(bdrv_min_mem_align(bs) != 0); | |
951 | assert((bs->request_alignment != 0) || bdrv_is_sg(bs)); | |
952 | ||
953 | qemu_opts_del(opts); | |
954 | return 0; | |
955 | ||
956 | free_and_fail: | |
957 | bs->file = NULL; | |
958 | g_free(bs->opaque); | |
959 | bs->opaque = NULL; | |
960 | bs->drv = NULL; | |
961 | fail_opts: | |
962 | qemu_opts_del(opts); | |
963 | return ret; | |
964 | } | |
965 | ||
966 | static QDict *parse_json_filename(const char *filename, Error **errp) | |
967 | { | |
968 | QObject *options_obj; | |
969 | QDict *options; | |
970 | int ret; | |
971 | ||
972 | ret = strstart(filename, "json:", &filename); | |
973 | assert(ret); | |
974 | ||
975 | options_obj = qobject_from_json(filename); | |
976 | if (!options_obj) { | |
977 | error_setg(errp, "Could not parse the JSON options"); | |
978 | return NULL; | |
979 | } | |
980 | ||
981 | if (qobject_type(options_obj) != QTYPE_QDICT) { | |
982 | qobject_decref(options_obj); | |
983 | error_setg(errp, "Invalid JSON object given"); | |
984 | return NULL; | |
985 | } | |
986 | ||
987 | options = qobject_to_qdict(options_obj); | |
988 | qdict_flatten(options); | |
989 | ||
990 | return options; | |
991 | } | |
992 | ||
993 | /* | |
994 | * Fills in default options for opening images and converts the legacy | |
995 | * filename/flags pair to option QDict entries. | |
996 | * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a | |
997 | * block driver has been specified explicitly. | |
998 | */ | |
999 | static int bdrv_fill_options(QDict **options, const char **pfilename, | |
1000 | int *flags, BlockDriver *drv, Error **errp) | |
1001 | { | |
1002 | const char *filename = *pfilename; | |
1003 | const char *drvname; | |
1004 | bool protocol = *flags & BDRV_O_PROTOCOL; | |
1005 | bool parse_filename = false; | |
1006 | BlockDriver *tmp_drv; | |
1007 | Error *local_err = NULL; | |
1008 | ||
1009 | /* Parse json: pseudo-protocol */ | |
1010 | if (filename && g_str_has_prefix(filename, "json:")) { | |
1011 | QDict *json_options = parse_json_filename(filename, &local_err); | |
1012 | if (local_err) { | |
1013 | error_propagate(errp, local_err); | |
1014 | return -EINVAL; | |
1015 | } | |
1016 | ||
1017 | /* Options given in the filename have lower priority than options | |
1018 | * specified directly */ | |
1019 | qdict_join(*options, json_options, false); | |
1020 | QDECREF(json_options); | |
1021 | *pfilename = filename = NULL; | |
1022 | } | |
1023 | ||
1024 | drvname = qdict_get_try_str(*options, "driver"); | |
1025 | ||
1026 | /* If the user has explicitly specified the driver, this choice should | |
1027 | * override the BDRV_O_PROTOCOL flag */ | |
1028 | tmp_drv = drv; | |
1029 | if (!tmp_drv && drvname) { | |
1030 | tmp_drv = bdrv_find_format(drvname); | |
1031 | } | |
1032 | if (tmp_drv) { | |
1033 | protocol = tmp_drv->bdrv_file_open; | |
1034 | } | |
1035 | ||
1036 | if (protocol) { | |
1037 | *flags |= BDRV_O_PROTOCOL; | |
1038 | } else { | |
1039 | *flags &= ~BDRV_O_PROTOCOL; | |
1040 | } | |
1041 | ||
1042 | /* Fetch the file name from the options QDict if necessary */ | |
1043 | if (protocol && filename) { | |
1044 | if (!qdict_haskey(*options, "filename")) { | |
1045 | qdict_put(*options, "filename", qstring_from_str(filename)); | |
1046 | parse_filename = true; | |
1047 | } else { | |
1048 | error_setg(errp, "Can't specify 'file' and 'filename' options at " | |
1049 | "the same time"); | |
1050 | return -EINVAL; | |
1051 | } | |
1052 | } | |
1053 | ||
1054 | /* Find the right block driver */ | |
1055 | filename = qdict_get_try_str(*options, "filename"); | |
1056 | ||
1057 | if (drv) { | |
1058 | if (drvname) { | |
1059 | error_setg(errp, "Driver specified twice"); | |
1060 | return -EINVAL; | |
1061 | } | |
1062 | drvname = drv->format_name; | |
1063 | qdict_put(*options, "driver", qstring_from_str(drvname)); | |
1064 | } else { | |
1065 | if (!drvname && protocol) { | |
1066 | if (filename) { | |
1067 | drv = bdrv_find_protocol(filename, parse_filename, errp); | |
1068 | if (!drv) { | |
1069 | return -EINVAL; | |
1070 | } | |
1071 | ||
1072 | drvname = drv->format_name; | |
1073 | qdict_put(*options, "driver", qstring_from_str(drvname)); | |
1074 | } else { | |
1075 | error_setg(errp, "Must specify either driver or file"); | |
1076 | return -EINVAL; | |
1077 | } | |
1078 | } else if (drvname) { | |
1079 | drv = bdrv_find_format(drvname); | |
1080 | if (!drv) { | |
1081 | error_setg(errp, "Unknown driver '%s'", drvname); | |
1082 | return -ENOENT; | |
1083 | } | |
1084 | } | |
1085 | } | |
1086 | ||
1087 | assert(drv || !protocol); | |
1088 | ||
1089 | /* Driver-specific filename parsing */ | |
1090 | if (drv && drv->bdrv_parse_filename && parse_filename) { | |
1091 | drv->bdrv_parse_filename(filename, *options, &local_err); | |
1092 | if (local_err) { | |
1093 | error_propagate(errp, local_err); | |
1094 | return -EINVAL; | |
1095 | } | |
1096 | ||
1097 | if (!drv->bdrv_needs_filename) { | |
1098 | qdict_del(*options, "filename"); | |
1099 | } | |
1100 | } | |
1101 | ||
1102 | return 0; | |
1103 | } | |
1104 | ||
1105 | static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, | |
1106 | BlockDriverState *child_bs, | |
1107 | const BdrvChildRole *child_role) | |
1108 | { | |
1109 | BdrvChild *child = g_new(BdrvChild, 1); | |
1110 | *child = (BdrvChild) { | |
1111 | .bs = child_bs, | |
1112 | .role = child_role, | |
1113 | }; | |
1114 | ||
1115 | QLIST_INSERT_HEAD(&parent_bs->children, child, next); | |
1116 | ||
1117 | return child; | |
1118 | } | |
1119 | ||
1120 | static void bdrv_detach_child(BdrvChild *child) | |
1121 | { | |
1122 | QLIST_REMOVE(child, next); | |
1123 | g_free(child); | |
1124 | } | |
1125 | ||
1126 | void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) | |
1127 | { | |
1128 | BlockDriverState *child_bs = child->bs; | |
1129 | ||
1130 | if (child->bs->inherits_from == parent) { | |
1131 | child->bs->inherits_from = NULL; | |
1132 | } | |
1133 | ||
1134 | bdrv_detach_child(child); | |
1135 | bdrv_unref(child_bs); | |
1136 | } | |
1137 | ||
1138 | void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) | |
1139 | { | |
1140 | ||
1141 | if (bs->backing_hd) { | |
1142 | assert(bs->backing_blocker); | |
1143 | bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker); | |
1144 | bdrv_detach_child(bs->backing_child); | |
1145 | } else if (backing_hd) { | |
1146 | error_setg(&bs->backing_blocker, | |
1147 | "node is used as backing hd of '%s'", | |
1148 | bdrv_get_device_or_node_name(bs)); | |
1149 | } | |
1150 | ||
1151 | bs->backing_hd = backing_hd; | |
1152 | if (!backing_hd) { | |
1153 | error_free(bs->backing_blocker); | |
1154 | bs->backing_blocker = NULL; | |
1155 | bs->backing_child = NULL; | |
1156 | goto out; | |
1157 | } | |
1158 | bs->backing_child = bdrv_attach_child(bs, backing_hd, &child_backing); | |
1159 | bs->open_flags &= ~BDRV_O_NO_BACKING; | |
1160 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); | |
1161 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), | |
1162 | backing_hd->drv ? backing_hd->drv->format_name : ""); | |
1163 | ||
1164 | bdrv_op_block_all(bs->backing_hd, bs->backing_blocker); | |
1165 | /* Otherwise we won't be able to commit due to check in bdrv_commit */ | |
1166 | bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, | |
1167 | bs->backing_blocker); | |
1168 | out: | |
1169 | bdrv_refresh_limits(bs, NULL); | |
1170 | } | |
1171 | ||
1172 | /* | |
1173 | * Opens the backing file for a BlockDriverState if not yet open | |
1174 | * | |
1175 | * options is a QDict of options to pass to the block drivers, or NULL for an | |
1176 | * empty set of options. The reference to the QDict is transferred to this | |
1177 | * function (even on failure), so if the caller intends to reuse the dictionary, | |
1178 | * it needs to use QINCREF() before calling bdrv_file_open. | |
1179 | */ | |
1180 | int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) | |
1181 | { | |
1182 | char *backing_filename = g_malloc0(PATH_MAX); | |
1183 | int ret = 0; | |
1184 | BlockDriverState *backing_hd; | |
1185 | Error *local_err = NULL; | |
1186 | ||
1187 | if (bs->backing_hd != NULL) { | |
1188 | QDECREF(options); | |
1189 | goto free_exit; | |
1190 | } | |
1191 | ||
1192 | /* NULL means an empty set of options */ | |
1193 | if (options == NULL) { | |
1194 | options = qdict_new(); | |
1195 | } | |
1196 | ||
1197 | bs->open_flags &= ~BDRV_O_NO_BACKING; | |
1198 | if (qdict_haskey(options, "file.filename")) { | |
1199 | backing_filename[0] = '\0'; | |
1200 | } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { | |
1201 | QDECREF(options); | |
1202 | goto free_exit; | |
1203 | } else { | |
1204 | bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX, | |
1205 | &local_err); | |
1206 | if (local_err) { | |
1207 | ret = -EINVAL; | |
1208 | error_propagate(errp, local_err); | |
1209 | QDECREF(options); | |
1210 | goto free_exit; | |
1211 | } | |
1212 | } | |
1213 | ||
1214 | if (!bs->drv || !bs->drv->supports_backing) { | |
1215 | ret = -EINVAL; | |
1216 | error_setg(errp, "Driver doesn't support backing files"); | |
1217 | QDECREF(options); | |
1218 | goto free_exit; | |
1219 | } | |
1220 | ||
1221 | backing_hd = bdrv_new(); | |
1222 | ||
1223 | if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { | |
1224 | qdict_put(options, "driver", qstring_from_str(bs->backing_format)); | |
1225 | } | |
1226 | ||
1227 | assert(bs->backing_hd == NULL); | |
1228 | ret = bdrv_open_inherit(&backing_hd, | |
1229 | *backing_filename ? backing_filename : NULL, | |
1230 | NULL, options, 0, bs, &child_backing, | |
1231 | NULL, &local_err); | |
1232 | if (ret < 0) { | |
1233 | bdrv_unref(backing_hd); | |
1234 | backing_hd = NULL; | |
1235 | bs->open_flags |= BDRV_O_NO_BACKING; | |
1236 | error_setg(errp, "Could not open backing file: %s", | |
1237 | error_get_pretty(local_err)); | |
1238 | error_free(local_err); | |
1239 | goto free_exit; | |
1240 | } | |
1241 | ||
1242 | bdrv_set_backing_hd(bs, backing_hd); | |
1243 | ||
1244 | free_exit: | |
1245 | g_free(backing_filename); | |
1246 | return ret; | |
1247 | } | |
1248 | ||
1249 | /* | |
1250 | * Opens a disk image whose options are given as BlockdevRef in another block | |
1251 | * device's options. | |
1252 | * | |
1253 | * If allow_none is true, no image will be opened if filename is false and no | |
1254 | * BlockdevRef is given. NULL will be returned, but errp remains unset. | |
1255 | * | |
1256 | * bdrev_key specifies the key for the image's BlockdevRef in the options QDict. | |
1257 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict | |
1258 | * itself, all options starting with "${bdref_key}." are considered part of the | |
1259 | * BlockdevRef. | |
1260 | * | |
1261 | * The BlockdevRef will be removed from the options QDict. | |
1262 | */ | |
1263 | BdrvChild *bdrv_open_child(const char *filename, | |
1264 | QDict *options, const char *bdref_key, | |
1265 | BlockDriverState* parent, | |
1266 | const BdrvChildRole *child_role, | |
1267 | bool allow_none, Error **errp) | |
1268 | { | |
1269 | BdrvChild *c = NULL; | |
1270 | BlockDriverState *bs; | |
1271 | QDict *image_options; | |
1272 | int ret; | |
1273 | char *bdref_key_dot; | |
1274 | const char *reference; | |
1275 | ||
1276 | assert(child_role != NULL); | |
1277 | ||
1278 | bdref_key_dot = g_strdup_printf("%s.", bdref_key); | |
1279 | qdict_extract_subqdict(options, &image_options, bdref_key_dot); | |
1280 | g_free(bdref_key_dot); | |
1281 | ||
1282 | reference = qdict_get_try_str(options, bdref_key); | |
1283 | if (!filename && !reference && !qdict_size(image_options)) { | |
1284 | if (!allow_none) { | |
1285 | error_setg(errp, "A block device must be specified for \"%s\"", | |
1286 | bdref_key); | |
1287 | } | |
1288 | QDECREF(image_options); | |
1289 | goto done; | |
1290 | } | |
1291 | ||
1292 | bs = NULL; | |
1293 | ret = bdrv_open_inherit(&bs, filename, reference, image_options, 0, | |
1294 | parent, child_role, NULL, errp); | |
1295 | if (ret < 0) { | |
1296 | goto done; | |
1297 | } | |
1298 | ||
1299 | c = bdrv_attach_child(parent, bs, child_role); | |
1300 | ||
1301 | done: | |
1302 | qdict_del(options, bdref_key); | |
1303 | return c; | |
1304 | } | |
1305 | ||
1306 | /* | |
1307 | * This is a version of bdrv_open_child() that returns 0/-EINVAL instead of | |
1308 | * a BdrvChild object. | |
1309 | * | |
1310 | * If allow_none is true, no image will be opened if filename is false and no | |
1311 | * BlockdevRef is given. *pbs will remain unchanged and 0 will be returned. | |
1312 | * | |
1313 | * To conform with the behavior of bdrv_open(), *pbs has to be NULL. | |
1314 | */ | |
1315 | int bdrv_open_image(BlockDriverState **pbs, const char *filename, | |
1316 | QDict *options, const char *bdref_key, | |
1317 | BlockDriverState* parent, const BdrvChildRole *child_role, | |
1318 | bool allow_none, Error **errp) | |
1319 | { | |
1320 | Error *local_err = NULL; | |
1321 | BdrvChild *c; | |
1322 | ||
1323 | assert(pbs); | |
1324 | assert(*pbs == NULL); | |
1325 | ||
1326 | c = bdrv_open_child(filename, options, bdref_key, parent, child_role, | |
1327 | allow_none, &local_err); | |
1328 | if (local_err) { | |
1329 | error_propagate(errp, local_err); | |
1330 | return -EINVAL; | |
1331 | } | |
1332 | ||
1333 | if (c != NULL) { | |
1334 | *pbs = c->bs; | |
1335 | } | |
1336 | ||
1337 | return 0; | |
1338 | } | |
1339 | ||
1340 | int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) | |
1341 | { | |
1342 | /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ | |
1343 | char *tmp_filename = g_malloc0(PATH_MAX + 1); | |
1344 | int64_t total_size; | |
1345 | QemuOpts *opts = NULL; | |
1346 | QDict *snapshot_options; | |
1347 | BlockDriverState *bs_snapshot; | |
1348 | Error *local_err = NULL; | |
1349 | int ret; | |
1350 | ||
1351 | /* if snapshot, we create a temporary backing file and open it | |
1352 | instead of opening 'filename' directly */ | |
1353 | ||
1354 | /* Get the required size from the image */ | |
1355 | total_size = bdrv_getlength(bs); | |
1356 | if (total_size < 0) { | |
1357 | ret = total_size; | |
1358 | error_setg_errno(errp, -total_size, "Could not get image size"); | |
1359 | goto out; | |
1360 | } | |
1361 | ||
1362 | /* Create the temporary image */ | |
1363 | ret = get_tmp_filename(tmp_filename, PATH_MAX + 1); | |
1364 | if (ret < 0) { | |
1365 | error_setg_errno(errp, -ret, "Could not get temporary filename"); | |
1366 | goto out; | |
1367 | } | |
1368 | ||
1369 | opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, | |
1370 | &error_abort); | |
1371 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort); | |
1372 | ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, &local_err); | |
1373 | qemu_opts_del(opts); | |
1374 | if (ret < 0) { | |
1375 | error_setg_errno(errp, -ret, "Could not create temporary overlay " | |
1376 | "'%s': %s", tmp_filename, | |
1377 | error_get_pretty(local_err)); | |
1378 | error_free(local_err); | |
1379 | goto out; | |
1380 | } | |
1381 | ||
1382 | /* Prepare a new options QDict for the temporary file */ | |
1383 | snapshot_options = qdict_new(); | |
1384 | qdict_put(snapshot_options, "file.driver", | |
1385 | qstring_from_str("file")); | |
1386 | qdict_put(snapshot_options, "file.filename", | |
1387 | qstring_from_str(tmp_filename)); | |
1388 | ||
1389 | bs_snapshot = bdrv_new(); | |
1390 | ||
1391 | ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options, | |
1392 | flags, &bdrv_qcow2, &local_err); | |
1393 | if (ret < 0) { | |
1394 | error_propagate(errp, local_err); | |
1395 | goto out; | |
1396 | } | |
1397 | ||
1398 | bdrv_append(bs_snapshot, bs); | |
1399 | ||
1400 | out: | |
1401 | g_free(tmp_filename); | |
1402 | return ret; | |
1403 | } | |
1404 | ||
1405 | /* | |
1406 | * Opens a disk image (raw, qcow2, vmdk, ...) | |
1407 | * | |
1408 | * options is a QDict of options to pass to the block drivers, or NULL for an | |
1409 | * empty set of options. The reference to the QDict belongs to the block layer | |
1410 | * after the call (even on failure), so if the caller intends to reuse the | |
1411 | * dictionary, it needs to use QINCREF() before calling bdrv_open. | |
1412 | * | |
1413 | * If *pbs is NULL, a new BDS will be created with a pointer to it stored there. | |
1414 | * If it is not NULL, the referenced BDS will be reused. | |
1415 | * | |
1416 | * The reference parameter may be used to specify an existing block device which | |
1417 | * should be opened. If specified, neither options nor a filename may be given, | |
1418 | * nor can an existing BDS be reused (that is, *pbs has to be NULL). | |
1419 | */ | |
1420 | static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, | |
1421 | const char *reference, QDict *options, int flags, | |
1422 | BlockDriverState *parent, | |
1423 | const BdrvChildRole *child_role, | |
1424 | BlockDriver *drv, Error **errp) | |
1425 | { | |
1426 | int ret; | |
1427 | BlockDriverState *file = NULL, *bs; | |
1428 | const char *drvname; | |
1429 | Error *local_err = NULL; | |
1430 | int snapshot_flags = 0; | |
1431 | ||
1432 | assert(pbs); | |
1433 | assert(!child_role || !flags); | |
1434 | assert(!child_role == !parent); | |
1435 | ||
1436 | if (reference) { | |
1437 | bool options_non_empty = options ? qdict_size(options) : false; | |
1438 | QDECREF(options); | |
1439 | ||
1440 | if (*pbs) { | |
1441 | error_setg(errp, "Cannot reuse an existing BDS when referencing " | |
1442 | "another block device"); | |
1443 | return -EINVAL; | |
1444 | } | |
1445 | ||
1446 | if (filename || options_non_empty) { | |
1447 | error_setg(errp, "Cannot reference an existing block device with " | |
1448 | "additional options or a new filename"); | |
1449 | return -EINVAL; | |
1450 | } | |
1451 | ||
1452 | bs = bdrv_lookup_bs(reference, reference, errp); | |
1453 | if (!bs) { | |
1454 | return -ENODEV; | |
1455 | } | |
1456 | bdrv_ref(bs); | |
1457 | *pbs = bs; | |
1458 | return 0; | |
1459 | } | |
1460 | ||
1461 | if (*pbs) { | |
1462 | bs = *pbs; | |
1463 | } else { | |
1464 | bs = bdrv_new(); | |
1465 | } | |
1466 | ||
1467 | /* NULL means an empty set of options */ | |
1468 | if (options == NULL) { | |
1469 | options = qdict_new(); | |
1470 | } | |
1471 | ||
1472 | if (child_role) { | |
1473 | bs->inherits_from = parent; | |
1474 | flags = child_role->inherit_flags(parent->open_flags); | |
1475 | } | |
1476 | ||
1477 | ret = bdrv_fill_options(&options, &filename, &flags, drv, &local_err); | |
1478 | if (local_err) { | |
1479 | goto fail; | |
1480 | } | |
1481 | ||
1482 | /* Find the right image format driver */ | |
1483 | drv = NULL; | |
1484 | drvname = qdict_get_try_str(options, "driver"); | |
1485 | if (drvname) { | |
1486 | drv = bdrv_find_format(drvname); | |
1487 | qdict_del(options, "driver"); | |
1488 | if (!drv) { | |
1489 | error_setg(errp, "Unknown driver: '%s'", drvname); | |
1490 | ret = -EINVAL; | |
1491 | goto fail; | |
1492 | } | |
1493 | } | |
1494 | ||
1495 | assert(drvname || !(flags & BDRV_O_PROTOCOL)); | |
1496 | ||
1497 | bs->open_flags = flags; | |
1498 | bs->options = options; | |
1499 | options = qdict_clone_shallow(options); | |
1500 | ||
1501 | /* Open image file without format layer */ | |
1502 | if ((flags & BDRV_O_PROTOCOL) == 0) { | |
1503 | if (flags & BDRV_O_RDWR) { | |
1504 | flags |= BDRV_O_ALLOW_RDWR; | |
1505 | } | |
1506 | if (flags & BDRV_O_SNAPSHOT) { | |
1507 | snapshot_flags = bdrv_temp_snapshot_flags(flags); | |
1508 | flags = bdrv_backing_flags(flags); | |
1509 | } | |
1510 | ||
1511 | assert(file == NULL); | |
1512 | bs->open_flags = flags; | |
1513 | ret = bdrv_open_image(&file, filename, options, "file", | |
1514 | bs, &child_file, true, &local_err); | |
1515 | if (ret < 0) { | |
1516 | goto fail; | |
1517 | } | |
1518 | } | |
1519 | ||
1520 | /* Image format probing */ | |
1521 | bs->probed = !drv; | |
1522 | if (!drv && file) { | |
1523 | ret = find_image_format(file, filename, &drv, &local_err); | |
1524 | if (ret < 0) { | |
1525 | goto fail; | |
1526 | } | |
1527 | } else if (!drv) { | |
1528 | error_setg(errp, "Must specify either driver or file"); | |
1529 | ret = -EINVAL; | |
1530 | goto fail; | |
1531 | } | |
1532 | ||
1533 | /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */ | |
1534 | assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open); | |
1535 | /* file must be NULL if a protocol BDS is about to be created | |
1536 | * (the inverse results in an error message from bdrv_open_common()) */ | |
1537 | assert(!(flags & BDRV_O_PROTOCOL) || !file); | |
1538 | ||
1539 | /* Open the image */ | |
1540 | ret = bdrv_open_common(bs, file, options, flags, drv, &local_err); | |
1541 | if (ret < 0) { | |
1542 | goto fail; | |
1543 | } | |
1544 | ||
1545 | if (file && (bs->file != file)) { | |
1546 | bdrv_unref(file); | |
1547 | file = NULL; | |
1548 | } | |
1549 | ||
1550 | /* If there is a backing file, use it */ | |
1551 | if ((flags & BDRV_O_NO_BACKING) == 0) { | |
1552 | QDict *backing_options; | |
1553 | ||
1554 | qdict_extract_subqdict(options, &backing_options, "backing."); | |
1555 | ret = bdrv_open_backing_file(bs, backing_options, &local_err); | |
1556 | if (ret < 0) { | |
1557 | goto close_and_fail; | |
1558 | } | |
1559 | } | |
1560 | ||
1561 | bdrv_refresh_filename(bs); | |
1562 | ||
1563 | /* For snapshot=on, create a temporary qcow2 overlay. bs points to the | |
1564 | * temporary snapshot afterwards. */ | |
1565 | if (snapshot_flags) { | |
1566 | ret = bdrv_append_temp_snapshot(bs, snapshot_flags, &local_err); | |
1567 | if (local_err) { | |
1568 | goto close_and_fail; | |
1569 | } | |
1570 | } | |
1571 | ||
1572 | /* Check if any unknown options were used */ | |
1573 | if (options && (qdict_size(options) != 0)) { | |
1574 | const QDictEntry *entry = qdict_first(options); | |
1575 | if (flags & BDRV_O_PROTOCOL) { | |
1576 | error_setg(errp, "Block protocol '%s' doesn't support the option " | |
1577 | "'%s'", drv->format_name, entry->key); | |
1578 | } else { | |
1579 | error_setg(errp, "Block format '%s' used by device '%s' doesn't " | |
1580 | "support the option '%s'", drv->format_name, | |
1581 | bdrv_get_device_name(bs), entry->key); | |
1582 | } | |
1583 | ||
1584 | ret = -EINVAL; | |
1585 | goto close_and_fail; | |
1586 | } | |
1587 | ||
1588 | if (!bdrv_key_required(bs)) { | |
1589 | if (bs->blk) { | |
1590 | blk_dev_change_media_cb(bs->blk, true); | |
1591 | } | |
1592 | } else if (!runstate_check(RUN_STATE_PRELAUNCH) | |
1593 | && !runstate_check(RUN_STATE_INMIGRATE) | |
1594 | && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */ | |
1595 | error_setg(errp, | |
1596 | "Guest must be stopped for opening of encrypted image"); | |
1597 | ret = -EBUSY; | |
1598 | goto close_and_fail; | |
1599 | } | |
1600 | ||
1601 | QDECREF(options); | |
1602 | *pbs = bs; | |
1603 | return 0; | |
1604 | ||
1605 | fail: | |
1606 | if (file != NULL) { | |
1607 | bdrv_unref(file); | |
1608 | } | |
1609 | QDECREF(bs->options); | |
1610 | QDECREF(options); | |
1611 | bs->options = NULL; | |
1612 | if (!*pbs) { | |
1613 | /* If *pbs is NULL, a new BDS has been created in this function and | |
1614 | needs to be freed now. Otherwise, it does not need to be closed, | |
1615 | since it has not really been opened yet. */ | |
1616 | bdrv_unref(bs); | |
1617 | } | |
1618 | if (local_err) { | |
1619 | error_propagate(errp, local_err); | |
1620 | } | |
1621 | return ret; | |
1622 | ||
1623 | close_and_fail: | |
1624 | /* See fail path, but now the BDS has to be always closed */ | |
1625 | if (*pbs) { | |
1626 | bdrv_close(bs); | |
1627 | } else { | |
1628 | bdrv_unref(bs); | |
1629 | } | |
1630 | QDECREF(options); | |
1631 | if (local_err) { | |
1632 | error_propagate(errp, local_err); | |
1633 | } | |
1634 | return ret; | |
1635 | } | |
1636 | ||
1637 | int bdrv_open(BlockDriverState **pbs, const char *filename, | |
1638 | const char *reference, QDict *options, int flags, | |
1639 | BlockDriver *drv, Error **errp) | |
1640 | { | |
1641 | return bdrv_open_inherit(pbs, filename, reference, options, flags, NULL, | |
1642 | NULL, drv, errp); | |
1643 | } | |
1644 | ||
1645 | typedef struct BlockReopenQueueEntry { | |
1646 | bool prepared; | |
1647 | BDRVReopenState state; | |
1648 | QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; | |
1649 | } BlockReopenQueueEntry; | |
1650 | ||
1651 | /* | |
1652 | * Adds a BlockDriverState to a simple queue for an atomic, transactional | |
1653 | * reopen of multiple devices. | |
1654 | * | |
1655 | * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT | |
1656 | * already performed, or alternatively may be NULL a new BlockReopenQueue will | |
1657 | * be created and initialized. This newly created BlockReopenQueue should be | |
1658 | * passed back in for subsequent calls that are intended to be of the same | |
1659 | * atomic 'set'. | |
1660 | * | |
1661 | * bs is the BlockDriverState to add to the reopen queue. | |
1662 | * | |
1663 | * flags contains the open flags for the associated bs | |
1664 | * | |
1665 | * returns a pointer to bs_queue, which is either the newly allocated | |
1666 | * bs_queue, or the existing bs_queue being used. | |
1667 | * | |
1668 | */ | |
1669 | BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, | |
1670 | BlockDriverState *bs, int flags) | |
1671 | { | |
1672 | assert(bs != NULL); | |
1673 | ||
1674 | BlockReopenQueueEntry *bs_entry; | |
1675 | BdrvChild *child; | |
1676 | ||
1677 | if (bs_queue == NULL) { | |
1678 | bs_queue = g_new0(BlockReopenQueue, 1); | |
1679 | QSIMPLEQ_INIT(bs_queue); | |
1680 | } | |
1681 | ||
1682 | /* bdrv_open() masks this flag out */ | |
1683 | flags &= ~BDRV_O_PROTOCOL; | |
1684 | ||
1685 | QLIST_FOREACH(child, &bs->children, next) { | |
1686 | int child_flags; | |
1687 | ||
1688 | if (child->bs->inherits_from != bs) { | |
1689 | continue; | |
1690 | } | |
1691 | ||
1692 | child_flags = child->role->inherit_flags(flags); | |
1693 | bdrv_reopen_queue(bs_queue, child->bs, child_flags); | |
1694 | } | |
1695 | ||
1696 | bs_entry = g_new0(BlockReopenQueueEntry, 1); | |
1697 | QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); | |
1698 | ||
1699 | bs_entry->state.bs = bs; | |
1700 | bs_entry->state.flags = flags; | |
1701 | ||
1702 | return bs_queue; | |
1703 | } | |
1704 | ||
1705 | /* | |
1706 | * Reopen multiple BlockDriverStates atomically & transactionally. | |
1707 | * | |
1708 | * The queue passed in (bs_queue) must have been built up previous | |
1709 | * via bdrv_reopen_queue(). | |
1710 | * | |
1711 | * Reopens all BDS specified in the queue, with the appropriate | |
1712 | * flags. All devices are prepared for reopen, and failure of any | |
1713 | * device will cause all device changes to be abandonded, and intermediate | |
1714 | * data cleaned up. | |
1715 | * | |
1716 | * If all devices prepare successfully, then the changes are committed | |
1717 | * to all devices. | |
1718 | * | |
1719 | */ | |
1720 | int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) | |
1721 | { | |
1722 | int ret = -1; | |
1723 | BlockReopenQueueEntry *bs_entry, *next; | |
1724 | Error *local_err = NULL; | |
1725 | ||
1726 | assert(bs_queue != NULL); | |
1727 | ||
1728 | bdrv_drain_all(); | |
1729 | ||
1730 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
1731 | if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) { | |
1732 | error_propagate(errp, local_err); | |
1733 | goto cleanup; | |
1734 | } | |
1735 | bs_entry->prepared = true; | |
1736 | } | |
1737 | ||
1738 | /* If we reach this point, we have success and just need to apply the | |
1739 | * changes | |
1740 | */ | |
1741 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
1742 | bdrv_reopen_commit(&bs_entry->state); | |
1743 | } | |
1744 | ||
1745 | ret = 0; | |
1746 | ||
1747 | cleanup: | |
1748 | QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { | |
1749 | if (ret && bs_entry->prepared) { | |
1750 | bdrv_reopen_abort(&bs_entry->state); | |
1751 | } | |
1752 | g_free(bs_entry); | |
1753 | } | |
1754 | g_free(bs_queue); | |
1755 | return ret; | |
1756 | } | |
1757 | ||
1758 | ||
1759 | /* Reopen a single BlockDriverState with the specified flags. */ | |
1760 | int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp) | |
1761 | { | |
1762 | int ret = -1; | |
1763 | Error *local_err = NULL; | |
1764 | BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, bdrv_flags); | |
1765 | ||
1766 | ret = bdrv_reopen_multiple(queue, &local_err); | |
1767 | if (local_err != NULL) { | |
1768 | error_propagate(errp, local_err); | |
1769 | } | |
1770 | return ret; | |
1771 | } | |
1772 | ||
1773 | ||
1774 | /* | |
1775 | * Prepares a BlockDriverState for reopen. All changes are staged in the | |
1776 | * 'opaque' field of the BDRVReopenState, which is used and allocated by | |
1777 | * the block driver layer .bdrv_reopen_prepare() | |
1778 | * | |
1779 | * bs is the BlockDriverState to reopen | |
1780 | * flags are the new open flags | |
1781 | * queue is the reopen queue | |
1782 | * | |
1783 | * Returns 0 on success, non-zero on error. On error errp will be set | |
1784 | * as well. | |
1785 | * | |
1786 | * On failure, bdrv_reopen_abort() will be called to clean up any data. | |
1787 | * It is the responsibility of the caller to then call the abort() or | |
1788 | * commit() for any other BDS that have been left in a prepare() state | |
1789 | * | |
1790 | */ | |
1791 | int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, | |
1792 | Error **errp) | |
1793 | { | |
1794 | int ret = -1; | |
1795 | Error *local_err = NULL; | |
1796 | BlockDriver *drv; | |
1797 | ||
1798 | assert(reopen_state != NULL); | |
1799 | assert(reopen_state->bs->drv != NULL); | |
1800 | drv = reopen_state->bs->drv; | |
1801 | ||
1802 | /* if we are to stay read-only, do not allow permission change | |
1803 | * to r/w */ | |
1804 | if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) && | |
1805 | reopen_state->flags & BDRV_O_RDWR) { | |
1806 | error_setg(errp, "Node '%s' is read only", | |
1807 | bdrv_get_device_or_node_name(reopen_state->bs)); | |
1808 | goto error; | |
1809 | } | |
1810 | ||
1811 | ||
1812 | ret = bdrv_flush(reopen_state->bs); | |
1813 | if (ret) { | |
1814 | error_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive", | |
1815 | strerror(-ret)); | |
1816 | goto error; | |
1817 | } | |
1818 | ||
1819 | if (drv->bdrv_reopen_prepare) { | |
1820 | ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); | |
1821 | if (ret) { | |
1822 | if (local_err != NULL) { | |
1823 | error_propagate(errp, local_err); | |
1824 | } else { | |
1825 | error_setg(errp, "failed while preparing to reopen image '%s'", | |
1826 | reopen_state->bs->filename); | |
1827 | } | |
1828 | goto error; | |
1829 | } | |
1830 | } else { | |
1831 | /* It is currently mandatory to have a bdrv_reopen_prepare() | |
1832 | * handler for each supported drv. */ | |
1833 | error_setg(errp, "Block format '%s' used by node '%s' " | |
1834 | "does not support reopening files", drv->format_name, | |
1835 | bdrv_get_device_or_node_name(reopen_state->bs)); | |
1836 | ret = -1; | |
1837 | goto error; | |
1838 | } | |
1839 | ||
1840 | ret = 0; | |
1841 | ||
1842 | error: | |
1843 | return ret; | |
1844 | } | |
1845 | ||
1846 | /* | |
1847 | * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and | |
1848 | * makes them final by swapping the staging BlockDriverState contents into | |
1849 | * the active BlockDriverState contents. | |
1850 | */ | |
1851 | void bdrv_reopen_commit(BDRVReopenState *reopen_state) | |
1852 | { | |
1853 | BlockDriver *drv; | |
1854 | ||
1855 | assert(reopen_state != NULL); | |
1856 | drv = reopen_state->bs->drv; | |
1857 | assert(drv != NULL); | |
1858 | ||
1859 | /* If there are any driver level actions to take */ | |
1860 | if (drv->bdrv_reopen_commit) { | |
1861 | drv->bdrv_reopen_commit(reopen_state); | |
1862 | } | |
1863 | ||
1864 | /* set BDS specific flags now */ | |
1865 | reopen_state->bs->open_flags = reopen_state->flags; | |
1866 | reopen_state->bs->enable_write_cache = !!(reopen_state->flags & | |
1867 | BDRV_O_CACHE_WB); | |
1868 | reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); | |
1869 | ||
1870 | bdrv_refresh_limits(reopen_state->bs, NULL); | |
1871 | } | |
1872 | ||
1873 | /* | |
1874 | * Abort the reopen, and delete and free the staged changes in | |
1875 | * reopen_state | |
1876 | */ | |
1877 | void bdrv_reopen_abort(BDRVReopenState *reopen_state) | |
1878 | { | |
1879 | BlockDriver *drv; | |
1880 | ||
1881 | assert(reopen_state != NULL); | |
1882 | drv = reopen_state->bs->drv; | |
1883 | assert(drv != NULL); | |
1884 | ||
1885 | if (drv->bdrv_reopen_abort) { | |
1886 | drv->bdrv_reopen_abort(reopen_state); | |
1887 | } | |
1888 | } | |
1889 | ||
1890 | ||
1891 | void bdrv_close(BlockDriverState *bs) | |
1892 | { | |
1893 | BdrvAioNotifier *ban, *ban_next; | |
1894 | ||
1895 | if (bs->job) { | |
1896 | block_job_cancel_sync(bs->job); | |
1897 | } | |
1898 | bdrv_drain(bs); /* complete I/O */ | |
1899 | bdrv_flush(bs); | |
1900 | bdrv_drain(bs); /* in case flush left pending I/O */ | |
1901 | notifier_list_notify(&bs->close_notifiers, bs); | |
1902 | ||
1903 | if (bs->drv) { | |
1904 | BdrvChild *child, *next; | |
1905 | ||
1906 | bs->drv->bdrv_close(bs); | |
1907 | ||
1908 | if (bs->backing_hd) { | |
1909 | BlockDriverState *backing_hd = bs->backing_hd; | |
1910 | bdrv_set_backing_hd(bs, NULL); | |
1911 | bdrv_unref(backing_hd); | |
1912 | } | |
1913 | ||
1914 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { | |
1915 | /* TODO Remove bdrv_unref() from drivers' close function and use | |
1916 | * bdrv_unref_child() here */ | |
1917 | if (child->bs->inherits_from == bs) { | |
1918 | child->bs->inherits_from = NULL; | |
1919 | } | |
1920 | bdrv_detach_child(child); | |
1921 | } | |
1922 | ||
1923 | g_free(bs->opaque); | |
1924 | bs->opaque = NULL; | |
1925 | bs->drv = NULL; | |
1926 | bs->copy_on_read = 0; | |
1927 | bs->backing_file[0] = '\0'; | |
1928 | bs->backing_format[0] = '\0'; | |
1929 | bs->total_sectors = 0; | |
1930 | bs->encrypted = 0; | |
1931 | bs->valid_key = 0; | |
1932 | bs->sg = 0; | |
1933 | bs->zero_beyond_eof = false; | |
1934 | QDECREF(bs->options); | |
1935 | bs->options = NULL; | |
1936 | QDECREF(bs->full_open_options); | |
1937 | bs->full_open_options = NULL; | |
1938 | ||
1939 | if (bs->file != NULL) { | |
1940 | bdrv_unref(bs->file); | |
1941 | bs->file = NULL; | |
1942 | } | |
1943 | } | |
1944 | ||
1945 | if (bs->blk) { | |
1946 | blk_dev_change_media_cb(bs->blk, false); | |
1947 | } | |
1948 | ||
1949 | /*throttling disk I/O limits*/ | |
1950 | if (bs->io_limits_enabled) { | |
1951 | bdrv_io_limits_disable(bs); | |
1952 | } | |
1953 | ||
1954 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { | |
1955 | g_free(ban); | |
1956 | } | |
1957 | QLIST_INIT(&bs->aio_notifiers); | |
1958 | } | |
1959 | ||
1960 | void bdrv_close_all(void) | |
1961 | { | |
1962 | BlockDriverState *bs; | |
1963 | ||
1964 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
1965 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
1966 | ||
1967 | aio_context_acquire(aio_context); | |
1968 | bdrv_close(bs); | |
1969 | aio_context_release(aio_context); | |
1970 | } | |
1971 | } | |
1972 | ||
1973 | /* make a BlockDriverState anonymous by removing from bdrv_state and | |
1974 | * graph_bdrv_state list. | |
1975 | Also, NULL terminate the device_name to prevent double remove */ | |
1976 | void bdrv_make_anon(BlockDriverState *bs) | |
1977 | { | |
1978 | /* | |
1979 | * Take care to remove bs from bdrv_states only when it's actually | |
1980 | * in it. Note that bs->device_list.tqe_prev is initially null, | |
1981 | * and gets set to non-null by QTAILQ_INSERT_TAIL(). Establish | |
1982 | * the useful invariant "bs in bdrv_states iff bs->tqe_prev" by | |
1983 | * resetting it to null on remove. | |
1984 | */ | |
1985 | if (bs->device_list.tqe_prev) { | |
1986 | QTAILQ_REMOVE(&bdrv_states, bs, device_list); | |
1987 | bs->device_list.tqe_prev = NULL; | |
1988 | } | |
1989 | if (bs->node_name[0] != '\0') { | |
1990 | QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); | |
1991 | } | |
1992 | bs->node_name[0] = '\0'; | |
1993 | } | |
1994 | ||
1995 | static void bdrv_rebind(BlockDriverState *bs) | |
1996 | { | |
1997 | if (bs->drv && bs->drv->bdrv_rebind) { | |
1998 | bs->drv->bdrv_rebind(bs); | |
1999 | } | |
2000 | } | |
2001 | ||
2002 | static void bdrv_move_feature_fields(BlockDriverState *bs_dest, | |
2003 | BlockDriverState *bs_src) | |
2004 | { | |
2005 | /* move some fields that need to stay attached to the device */ | |
2006 | ||
2007 | /* dev info */ | |
2008 | bs_dest->guest_block_size = bs_src->guest_block_size; | |
2009 | bs_dest->copy_on_read = bs_src->copy_on_read; | |
2010 | ||
2011 | bs_dest->enable_write_cache = bs_src->enable_write_cache; | |
2012 | ||
2013 | /* i/o throttled req */ | |
2014 | bs_dest->throttle_state = bs_src->throttle_state, | |
2015 | bs_dest->io_limits_enabled = bs_src->io_limits_enabled; | |
2016 | bs_dest->pending_reqs[0] = bs_src->pending_reqs[0]; | |
2017 | bs_dest->pending_reqs[1] = bs_src->pending_reqs[1]; | |
2018 | bs_dest->throttled_reqs[0] = bs_src->throttled_reqs[0]; | |
2019 | bs_dest->throttled_reqs[1] = bs_src->throttled_reqs[1]; | |
2020 | memcpy(&bs_dest->round_robin, | |
2021 | &bs_src->round_robin, | |
2022 | sizeof(bs_dest->round_robin)); | |
2023 | memcpy(&bs_dest->throttle_timers, | |
2024 | &bs_src->throttle_timers, | |
2025 | sizeof(ThrottleTimers)); | |
2026 | ||
2027 | /* r/w error */ | |
2028 | bs_dest->on_read_error = bs_src->on_read_error; | |
2029 | bs_dest->on_write_error = bs_src->on_write_error; | |
2030 | ||
2031 | /* i/o status */ | |
2032 | bs_dest->iostatus_enabled = bs_src->iostatus_enabled; | |
2033 | bs_dest->iostatus = bs_src->iostatus; | |
2034 | ||
2035 | /* dirty bitmap */ | |
2036 | bs_dest->dirty_bitmaps = bs_src->dirty_bitmaps; | |
2037 | ||
2038 | /* reference count */ | |
2039 | bs_dest->refcnt = bs_src->refcnt; | |
2040 | ||
2041 | /* job */ | |
2042 | bs_dest->job = bs_src->job; | |
2043 | ||
2044 | /* keep the same entry in bdrv_states */ | |
2045 | bs_dest->device_list = bs_src->device_list; | |
2046 | bs_dest->blk = bs_src->blk; | |
2047 | ||
2048 | memcpy(bs_dest->op_blockers, bs_src->op_blockers, | |
2049 | sizeof(bs_dest->op_blockers)); | |
2050 | } | |
2051 | ||
2052 | /* | |
2053 | * Swap bs contents for two image chains while they are live, | |
2054 | * while keeping required fields on the BlockDriverState that is | |
2055 | * actually attached to a device. | |
2056 | * | |
2057 | * This will modify the BlockDriverState fields, and swap contents | |
2058 | * between bs_new and bs_old. Both bs_new and bs_old are modified. | |
2059 | * | |
2060 | * bs_new must not be attached to a BlockBackend. | |
2061 | * | |
2062 | * This function does not create any image files. | |
2063 | */ | |
2064 | void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) | |
2065 | { | |
2066 | BlockDriverState tmp; | |
2067 | BdrvChild *child; | |
2068 | ||
2069 | bdrv_drain(bs_new); | |
2070 | bdrv_drain(bs_old); | |
2071 | ||
2072 | /* The code needs to swap the node_name but simply swapping node_list won't | |
2073 | * work so first remove the nodes from the graph list, do the swap then | |
2074 | * insert them back if needed. | |
2075 | */ | |
2076 | if (bs_new->node_name[0] != '\0') { | |
2077 | QTAILQ_REMOVE(&graph_bdrv_states, bs_new, node_list); | |
2078 | } | |
2079 | if (bs_old->node_name[0] != '\0') { | |
2080 | QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list); | |
2081 | } | |
2082 | ||
2083 | /* If the BlockDriverState is part of a throttling group acquire | |
2084 | * its lock since we're going to mess with the protected fields. | |
2085 | * Otherwise there's no need to worry since no one else can touch | |
2086 | * them. */ | |
2087 | if (bs_old->throttle_state) { | |
2088 | throttle_group_lock(bs_old); | |
2089 | } | |
2090 | ||
2091 | /* bs_new must be unattached and shouldn't have anything fancy enabled */ | |
2092 | assert(!bs_new->blk); | |
2093 | assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); | |
2094 | assert(bs_new->job == NULL); | |
2095 | assert(bs_new->io_limits_enabled == false); | |
2096 | assert(bs_new->throttle_state == NULL); | |
2097 | assert(!throttle_timers_are_initialized(&bs_new->throttle_timers)); | |
2098 | ||
2099 | tmp = *bs_new; | |
2100 | *bs_new = *bs_old; | |
2101 | *bs_old = tmp; | |
2102 | ||
2103 | /* there are some fields that should not be swapped, move them back */ | |
2104 | bdrv_move_feature_fields(&tmp, bs_old); | |
2105 | bdrv_move_feature_fields(bs_old, bs_new); | |
2106 | bdrv_move_feature_fields(bs_new, &tmp); | |
2107 | ||
2108 | /* bs_new must remain unattached */ | |
2109 | assert(!bs_new->blk); | |
2110 | ||
2111 | /* Check a few fields that should remain attached to the device */ | |
2112 | assert(bs_new->job == NULL); | |
2113 | assert(bs_new->io_limits_enabled == false); | |
2114 | assert(bs_new->throttle_state == NULL); | |
2115 | assert(!throttle_timers_are_initialized(&bs_new->throttle_timers)); | |
2116 | ||
2117 | /* Release the ThrottleGroup lock */ | |
2118 | if (bs_old->throttle_state) { | |
2119 | throttle_group_unlock(bs_old); | |
2120 | } | |
2121 | ||
2122 | /* insert the nodes back into the graph node list if needed */ | |
2123 | if (bs_new->node_name[0] != '\0') { | |
2124 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_new, node_list); | |
2125 | } | |
2126 | if (bs_old->node_name[0] != '\0') { | |
2127 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list); | |
2128 | } | |
2129 | ||
2130 | /* | |
2131 | * Update lh_first.le_prev for non-empty lists. | |
2132 | * | |
2133 | * The head of the op blocker list doesn't change because it is moved back | |
2134 | * in bdrv_move_feature_fields(). | |
2135 | */ | |
2136 | assert(QLIST_EMPTY(&bs_old->tracked_requests)); | |
2137 | assert(QLIST_EMPTY(&bs_new->tracked_requests)); | |
2138 | ||
2139 | QLIST_FIX_HEAD_PTR(&bs_new->children, next); | |
2140 | QLIST_FIX_HEAD_PTR(&bs_old->children, next); | |
2141 | ||
2142 | /* Update references in bs->opaque and children */ | |
2143 | QLIST_FOREACH(child, &bs_old->children, next) { | |
2144 | if (child->bs->inherits_from == bs_new) { | |
2145 | child->bs->inherits_from = bs_old; | |
2146 | } | |
2147 | } | |
2148 | QLIST_FOREACH(child, &bs_new->children, next) { | |
2149 | if (child->bs->inherits_from == bs_old) { | |
2150 | child->bs->inherits_from = bs_new; | |
2151 | } | |
2152 | } | |
2153 | ||
2154 | bdrv_rebind(bs_new); | |
2155 | bdrv_rebind(bs_old); | |
2156 | } | |
2157 | ||
2158 | /* | |
2159 | * Add new bs contents at the top of an image chain while the chain is | |
2160 | * live, while keeping required fields on the top layer. | |
2161 | * | |
2162 | * This will modify the BlockDriverState fields, and swap contents | |
2163 | * between bs_new and bs_top. Both bs_new and bs_top are modified. | |
2164 | * | |
2165 | * bs_new must not be attached to a BlockBackend. | |
2166 | * | |
2167 | * This function does not create any image files. | |
2168 | */ | |
2169 | void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) | |
2170 | { | |
2171 | bdrv_swap(bs_new, bs_top); | |
2172 | ||
2173 | /* The contents of 'tmp' will become bs_top, as we are | |
2174 | * swapping bs_new and bs_top contents. */ | |
2175 | bdrv_set_backing_hd(bs_top, bs_new); | |
2176 | } | |
2177 | ||
2178 | static void bdrv_delete(BlockDriverState *bs) | |
2179 | { | |
2180 | assert(!bs->job); | |
2181 | assert(bdrv_op_blocker_is_empty(bs)); | |
2182 | assert(!bs->refcnt); | |
2183 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); | |
2184 | ||
2185 | bdrv_close(bs); | |
2186 | ||
2187 | /* remove from list, if necessary */ | |
2188 | bdrv_make_anon(bs); | |
2189 | ||
2190 | g_free(bs); | |
2191 | } | |
2192 | ||
2193 | /* | |
2194 | * Run consistency checks on an image | |
2195 | * | |
2196 | * Returns 0 if the check could be completed (it doesn't mean that the image is | |
2197 | * free of errors) or -errno when an internal error occurred. The results of the | |
2198 | * check are stored in res. | |
2199 | */ | |
2200 | int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) | |
2201 | { | |
2202 | if (bs->drv == NULL) { | |
2203 | return -ENOMEDIUM; | |
2204 | } | |
2205 | if (bs->drv->bdrv_check == NULL) { | |
2206 | return -ENOTSUP; | |
2207 | } | |
2208 | ||
2209 | memset(res, 0, sizeof(*res)); | |
2210 | return bs->drv->bdrv_check(bs, res, fix); | |
2211 | } | |
2212 | ||
2213 | #define COMMIT_BUF_SECTORS 2048 | |
2214 | ||
2215 | /* commit COW file into the raw image */ | |
2216 | int bdrv_commit(BlockDriverState *bs) | |
2217 | { | |
2218 | BlockDriver *drv = bs->drv; | |
2219 | int64_t sector, total_sectors, length, backing_length; | |
2220 | int n, ro, open_flags; | |
2221 | int ret = 0; | |
2222 | uint8_t *buf = NULL; | |
2223 | ||
2224 | if (!drv) | |
2225 | return -ENOMEDIUM; | |
2226 | ||
2227 | if (!bs->backing_hd) { | |
2228 | return -ENOTSUP; | |
2229 | } | |
2230 | ||
2231 | if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, NULL) || | |
2232 | bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) { | |
2233 | return -EBUSY; | |
2234 | } | |
2235 | ||
2236 | ro = bs->backing_hd->read_only; | |
2237 | open_flags = bs->backing_hd->open_flags; | |
2238 | ||
2239 | if (ro) { | |
2240 | if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) { | |
2241 | return -EACCES; | |
2242 | } | |
2243 | } | |
2244 | ||
2245 | length = bdrv_getlength(bs); | |
2246 | if (length < 0) { | |
2247 | ret = length; | |
2248 | goto ro_cleanup; | |
2249 | } | |
2250 | ||
2251 | backing_length = bdrv_getlength(bs->backing_hd); | |
2252 | if (backing_length < 0) { | |
2253 | ret = backing_length; | |
2254 | goto ro_cleanup; | |
2255 | } | |
2256 | ||
2257 | /* If our top snapshot is larger than the backing file image, | |
2258 | * grow the backing file image if possible. If not possible, | |
2259 | * we must return an error */ | |
2260 | if (length > backing_length) { | |
2261 | ret = bdrv_truncate(bs->backing_hd, length); | |
2262 | if (ret < 0) { | |
2263 | goto ro_cleanup; | |
2264 | } | |
2265 | } | |
2266 | ||
2267 | total_sectors = length >> BDRV_SECTOR_BITS; | |
2268 | ||
2269 | /* qemu_try_blockalign() for bs will choose an alignment that works for | |
2270 | * bs->backing_hd as well, so no need to compare the alignment manually. */ | |
2271 | buf = qemu_try_blockalign(bs, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); | |
2272 | if (buf == NULL) { | |
2273 | ret = -ENOMEM; | |
2274 | goto ro_cleanup; | |
2275 | } | |
2276 | ||
2277 | for (sector = 0; sector < total_sectors; sector += n) { | |
2278 | ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n); | |
2279 | if (ret < 0) { | |
2280 | goto ro_cleanup; | |
2281 | } | |
2282 | if (ret) { | |
2283 | ret = bdrv_read(bs, sector, buf, n); | |
2284 | if (ret < 0) { | |
2285 | goto ro_cleanup; | |
2286 | } | |
2287 | ||
2288 | ret = bdrv_write(bs->backing_hd, sector, buf, n); | |
2289 | if (ret < 0) { | |
2290 | goto ro_cleanup; | |
2291 | } | |
2292 | } | |
2293 | } | |
2294 | ||
2295 | if (drv->bdrv_make_empty) { | |
2296 | ret = drv->bdrv_make_empty(bs); | |
2297 | if (ret < 0) { | |
2298 | goto ro_cleanup; | |
2299 | } | |
2300 | bdrv_flush(bs); | |
2301 | } | |
2302 | ||
2303 | /* | |
2304 | * Make sure all data we wrote to the backing device is actually | |
2305 | * stable on disk. | |
2306 | */ | |
2307 | if (bs->backing_hd) { | |
2308 | bdrv_flush(bs->backing_hd); | |
2309 | } | |
2310 | ||
2311 | ret = 0; | |
2312 | ro_cleanup: | |
2313 | qemu_vfree(buf); | |
2314 | ||
2315 | if (ro) { | |
2316 | /* ignoring error return here */ | |
2317 | bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL); | |
2318 | } | |
2319 | ||
2320 | return ret; | |
2321 | } | |
2322 | ||
2323 | int bdrv_commit_all(void) | |
2324 | { | |
2325 | BlockDriverState *bs; | |
2326 | ||
2327 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
2328 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
2329 | ||
2330 | aio_context_acquire(aio_context); | |
2331 | if (bs->drv && bs->backing_hd) { | |
2332 | int ret = bdrv_commit(bs); | |
2333 | if (ret < 0) { | |
2334 | aio_context_release(aio_context); | |
2335 | return ret; | |
2336 | } | |
2337 | } | |
2338 | aio_context_release(aio_context); | |
2339 | } | |
2340 | return 0; | |
2341 | } | |
2342 | ||
2343 | /* | |
2344 | * Return values: | |
2345 | * 0 - success | |
2346 | * -EINVAL - backing format specified, but no file | |
2347 | * -ENOSPC - can't update the backing file because no space is left in the | |
2348 | * image file header | |
2349 | * -ENOTSUP - format driver doesn't support changing the backing file | |
2350 | */ | |
2351 | int bdrv_change_backing_file(BlockDriverState *bs, | |
2352 | const char *backing_file, const char *backing_fmt) | |
2353 | { | |
2354 | BlockDriver *drv = bs->drv; | |
2355 | int ret; | |
2356 | ||
2357 | /* Backing file format doesn't make sense without a backing file */ | |
2358 | if (backing_fmt && !backing_file) { | |
2359 | return -EINVAL; | |
2360 | } | |
2361 | ||
2362 | if (drv->bdrv_change_backing_file != NULL) { | |
2363 | ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); | |
2364 | } else { | |
2365 | ret = -ENOTSUP; | |
2366 | } | |
2367 | ||
2368 | if (ret == 0) { | |
2369 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); | |
2370 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); | |
2371 | } | |
2372 | return ret; | |
2373 | } | |
2374 | ||
2375 | /* | |
2376 | * Finds the image layer in the chain that has 'bs' as its backing file. | |
2377 | * | |
2378 | * active is the current topmost image. | |
2379 | * | |
2380 | * Returns NULL if bs is not found in active's image chain, | |
2381 | * or if active == bs. | |
2382 | * | |
2383 | * Returns the bottommost base image if bs == NULL. | |
2384 | */ | |
2385 | BlockDriverState *bdrv_find_overlay(BlockDriverState *active, | |
2386 | BlockDriverState *bs) | |
2387 | { | |
2388 | while (active && bs != active->backing_hd) { | |
2389 | active = active->backing_hd; | |
2390 | } | |
2391 | ||
2392 | return active; | |
2393 | } | |
2394 | ||
2395 | /* Given a BDS, searches for the base layer. */ | |
2396 | BlockDriverState *bdrv_find_base(BlockDriverState *bs) | |
2397 | { | |
2398 | return bdrv_find_overlay(bs, NULL); | |
2399 | } | |
2400 | ||
2401 | typedef struct BlkIntermediateStates { | |
2402 | BlockDriverState *bs; | |
2403 | QSIMPLEQ_ENTRY(BlkIntermediateStates) entry; | |
2404 | } BlkIntermediateStates; | |
2405 | ||
2406 | ||
2407 | /* | |
2408 | * Drops images above 'base' up to and including 'top', and sets the image | |
2409 | * above 'top' to have base as its backing file. | |
2410 | * | |
2411 | * Requires that the overlay to 'top' is opened r/w, so that the backing file | |
2412 | * information in 'bs' can be properly updated. | |
2413 | * | |
2414 | * E.g., this will convert the following chain: | |
2415 | * bottom <- base <- intermediate <- top <- active | |
2416 | * | |
2417 | * to | |
2418 | * | |
2419 | * bottom <- base <- active | |
2420 | * | |
2421 | * It is allowed for bottom==base, in which case it converts: | |
2422 | * | |
2423 | * base <- intermediate <- top <- active | |
2424 | * | |
2425 | * to | |
2426 | * | |
2427 | * base <- active | |
2428 | * | |
2429 | * If backing_file_str is non-NULL, it will be used when modifying top's | |
2430 | * overlay image metadata. | |
2431 | * | |
2432 | * Error conditions: | |
2433 | * if active == top, that is considered an error | |
2434 | * | |
2435 | */ | |
2436 | int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, | |
2437 | BlockDriverState *base, const char *backing_file_str) | |
2438 | { | |
2439 | BlockDriverState *intermediate; | |
2440 | BlockDriverState *base_bs = NULL; | |
2441 | BlockDriverState *new_top_bs = NULL; | |
2442 | BlkIntermediateStates *intermediate_state, *next; | |
2443 | int ret = -EIO; | |
2444 | ||
2445 | QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete; | |
2446 | QSIMPLEQ_INIT(&states_to_delete); | |
2447 | ||
2448 | if (!top->drv || !base->drv) { | |
2449 | goto exit; | |
2450 | } | |
2451 | ||
2452 | new_top_bs = bdrv_find_overlay(active, top); | |
2453 | ||
2454 | if (new_top_bs == NULL) { | |
2455 | /* we could not find the image above 'top', this is an error */ | |
2456 | goto exit; | |
2457 | } | |
2458 | ||
2459 | /* special case of new_top_bs->backing_hd already pointing to base - nothing | |
2460 | * to do, no intermediate images */ | |
2461 | if (new_top_bs->backing_hd == base) { | |
2462 | ret = 0; | |
2463 | goto exit; | |
2464 | } | |
2465 | ||
2466 | intermediate = top; | |
2467 | ||
2468 | /* now we will go down through the list, and add each BDS we find | |
2469 | * into our deletion queue, until we hit the 'base' | |
2470 | */ | |
2471 | while (intermediate) { | |
2472 | intermediate_state = g_new0(BlkIntermediateStates, 1); | |
2473 | intermediate_state->bs = intermediate; | |
2474 | QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry); | |
2475 | ||
2476 | if (intermediate->backing_hd == base) { | |
2477 | base_bs = intermediate->backing_hd; | |
2478 | break; | |
2479 | } | |
2480 | intermediate = intermediate->backing_hd; | |
2481 | } | |
2482 | if (base_bs == NULL) { | |
2483 | /* something went wrong, we did not end at the base. safely | |
2484 | * unravel everything, and exit with error */ | |
2485 | goto exit; | |
2486 | } | |
2487 | ||
2488 | /* success - we can delete the intermediate states, and link top->base */ | |
2489 | backing_file_str = backing_file_str ? backing_file_str : base_bs->filename; | |
2490 | ret = bdrv_change_backing_file(new_top_bs, backing_file_str, | |
2491 | base_bs->drv ? base_bs->drv->format_name : ""); | |
2492 | if (ret) { | |
2493 | goto exit; | |
2494 | } | |
2495 | bdrv_set_backing_hd(new_top_bs, base_bs); | |
2496 | ||
2497 | QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { | |
2498 | /* so that bdrv_close() does not recursively close the chain */ | |
2499 | bdrv_set_backing_hd(intermediate_state->bs, NULL); | |
2500 | bdrv_unref(intermediate_state->bs); | |
2501 | } | |
2502 | ret = 0; | |
2503 | ||
2504 | exit: | |
2505 | QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { | |
2506 | g_free(intermediate_state); | |
2507 | } | |
2508 | return ret; | |
2509 | } | |
2510 | ||
2511 | /** | |
2512 | * Truncate file to 'offset' bytes (needed only for file protocols) | |
2513 | */ | |
2514 | int bdrv_truncate(BlockDriverState *bs, int64_t offset) | |
2515 | { | |
2516 | BlockDriver *drv = bs->drv; | |
2517 | int ret; | |
2518 | if (!drv) | |
2519 | return -ENOMEDIUM; | |
2520 | if (!drv->bdrv_truncate) | |
2521 | return -ENOTSUP; | |
2522 | if (bs->read_only) | |
2523 | return -EACCES; | |
2524 | ||
2525 | ret = drv->bdrv_truncate(bs, offset); | |
2526 | if (ret == 0) { | |
2527 | ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); | |
2528 | bdrv_dirty_bitmap_truncate(bs); | |
2529 | if (bs->blk) { | |
2530 | blk_dev_resize_cb(bs->blk); | |
2531 | } | |
2532 | } | |
2533 | return ret; | |
2534 | } | |
2535 | ||
2536 | /** | |
2537 | * Length of a allocated file in bytes. Sparse files are counted by actual | |
2538 | * allocated space. Return < 0 if error or unknown. | |
2539 | */ | |
2540 | int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) | |
2541 | { | |
2542 | BlockDriver *drv = bs->drv; | |
2543 | if (!drv) { | |
2544 | return -ENOMEDIUM; | |
2545 | } | |
2546 | if (drv->bdrv_get_allocated_file_size) { | |
2547 | return drv->bdrv_get_allocated_file_size(bs); | |
2548 | } | |
2549 | if (bs->file) { | |
2550 | return bdrv_get_allocated_file_size(bs->file); | |
2551 | } | |
2552 | return -ENOTSUP; | |
2553 | } | |
2554 | ||
2555 | /** | |
2556 | * Return number of sectors on success, -errno on error. | |
2557 | */ | |
2558 | int64_t bdrv_nb_sectors(BlockDriverState *bs) | |
2559 | { | |
2560 | BlockDriver *drv = bs->drv; | |
2561 | ||
2562 | if (!drv) | |
2563 | return -ENOMEDIUM; | |
2564 | ||
2565 | if (drv->has_variable_length) { | |
2566 | int ret = refresh_total_sectors(bs, bs->total_sectors); | |
2567 | if (ret < 0) { | |
2568 | return ret; | |
2569 | } | |
2570 | } | |
2571 | return bs->total_sectors; | |
2572 | } | |
2573 | ||
2574 | /** | |
2575 | * Return length in bytes on success, -errno on error. | |
2576 | * The length is always a multiple of BDRV_SECTOR_SIZE. | |
2577 | */ | |
2578 | int64_t bdrv_getlength(BlockDriverState *bs) | |
2579 | { | |
2580 | int64_t ret = bdrv_nb_sectors(bs); | |
2581 | ||
2582 | ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret; | |
2583 | return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE; | |
2584 | } | |
2585 | ||
2586 | /* return 0 as number of sectors if no device present or error */ | |
2587 | void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) | |
2588 | { | |
2589 | int64_t nb_sectors = bdrv_nb_sectors(bs); | |
2590 | ||
2591 | *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors; | |
2592 | } | |
2593 | ||
2594 | void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error, | |
2595 | BlockdevOnError on_write_error) | |
2596 | { | |
2597 | bs->on_read_error = on_read_error; | |
2598 | bs->on_write_error = on_write_error; | |
2599 | } | |
2600 | ||
2601 | BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read) | |
2602 | { | |
2603 | return is_read ? bs->on_read_error : bs->on_write_error; | |
2604 | } | |
2605 | ||
2606 | BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error) | |
2607 | { | |
2608 | BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error; | |
2609 | ||
2610 | switch (on_err) { | |
2611 | case BLOCKDEV_ON_ERROR_ENOSPC: | |
2612 | return (error == ENOSPC) ? | |
2613 | BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT; | |
2614 | case BLOCKDEV_ON_ERROR_STOP: | |
2615 | return BLOCK_ERROR_ACTION_STOP; | |
2616 | case BLOCKDEV_ON_ERROR_REPORT: | |
2617 | return BLOCK_ERROR_ACTION_REPORT; | |
2618 | case BLOCKDEV_ON_ERROR_IGNORE: | |
2619 | return BLOCK_ERROR_ACTION_IGNORE; | |
2620 | default: | |
2621 | abort(); | |
2622 | } | |
2623 | } | |
2624 | ||
2625 | static void send_qmp_error_event(BlockDriverState *bs, | |
2626 | BlockErrorAction action, | |
2627 | bool is_read, int error) | |
2628 | { | |
2629 | IoOperationType optype; | |
2630 | ||
2631 | optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE; | |
2632 | qapi_event_send_block_io_error(bdrv_get_device_name(bs), optype, action, | |
2633 | bdrv_iostatus_is_enabled(bs), | |
2634 | error == ENOSPC, strerror(error), | |
2635 | &error_abort); | |
2636 | } | |
2637 | ||
2638 | /* This is done by device models because, while the block layer knows | |
2639 | * about the error, it does not know whether an operation comes from | |
2640 | * the device or the block layer (from a job, for example). | |
2641 | */ | |
2642 | void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action, | |
2643 | bool is_read, int error) | |
2644 | { | |
2645 | assert(error >= 0); | |
2646 | ||
2647 | if (action == BLOCK_ERROR_ACTION_STOP) { | |
2648 | /* First set the iostatus, so that "info block" returns an iostatus | |
2649 | * that matches the events raised so far (an additional error iostatus | |
2650 | * is fine, but not a lost one). | |
2651 | */ | |
2652 | bdrv_iostatus_set_err(bs, error); | |
2653 | ||
2654 | /* Then raise the request to stop the VM and the event. | |
2655 | * qemu_system_vmstop_request_prepare has two effects. First, | |
2656 | * it ensures that the STOP event always comes after the | |
2657 | * BLOCK_IO_ERROR event. Second, it ensures that even if management | |
2658 | * can observe the STOP event and do a "cont" before the STOP | |
2659 | * event is issued, the VM will not stop. In this case, vm_start() | |
2660 | * also ensures that the STOP/RESUME pair of events is emitted. | |
2661 | */ | |
2662 | qemu_system_vmstop_request_prepare(); | |
2663 | send_qmp_error_event(bs, action, is_read, error); | |
2664 | qemu_system_vmstop_request(RUN_STATE_IO_ERROR); | |
2665 | } else { | |
2666 | send_qmp_error_event(bs, action, is_read, error); | |
2667 | } | |
2668 | } | |
2669 | ||
2670 | int bdrv_is_read_only(BlockDriverState *bs) | |
2671 | { | |
2672 | return bs->read_only; | |
2673 | } | |
2674 | ||
2675 | int bdrv_is_sg(BlockDriverState *bs) | |
2676 | { | |
2677 | return bs->sg; | |
2678 | } | |
2679 | ||
2680 | int bdrv_enable_write_cache(BlockDriverState *bs) | |
2681 | { | |
2682 | return bs->enable_write_cache; | |
2683 | } | |
2684 | ||
2685 | void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce) | |
2686 | { | |
2687 | bs->enable_write_cache = wce; | |
2688 | ||
2689 | /* so a reopen() will preserve wce */ | |
2690 | if (wce) { | |
2691 | bs->open_flags |= BDRV_O_CACHE_WB; | |
2692 | } else { | |
2693 | bs->open_flags &= ~BDRV_O_CACHE_WB; | |
2694 | } | |
2695 | } | |
2696 | ||
2697 | int bdrv_is_encrypted(BlockDriverState *bs) | |
2698 | { | |
2699 | if (bs->backing_hd && bs->backing_hd->encrypted) | |
2700 | return 1; | |
2701 | return bs->encrypted; | |
2702 | } | |
2703 | ||
2704 | int bdrv_key_required(BlockDriverState *bs) | |
2705 | { | |
2706 | BlockDriverState *backing_hd = bs->backing_hd; | |
2707 | ||
2708 | if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key) | |
2709 | return 1; | |
2710 | return (bs->encrypted && !bs->valid_key); | |
2711 | } | |
2712 | ||
2713 | int bdrv_set_key(BlockDriverState *bs, const char *key) | |
2714 | { | |
2715 | int ret; | |
2716 | if (bs->backing_hd && bs->backing_hd->encrypted) { | |
2717 | ret = bdrv_set_key(bs->backing_hd, key); | |
2718 | if (ret < 0) | |
2719 | return ret; | |
2720 | if (!bs->encrypted) | |
2721 | return 0; | |
2722 | } | |
2723 | if (!bs->encrypted) { | |
2724 | return -EINVAL; | |
2725 | } else if (!bs->drv || !bs->drv->bdrv_set_key) { | |
2726 | return -ENOMEDIUM; | |
2727 | } | |
2728 | ret = bs->drv->bdrv_set_key(bs, key); | |
2729 | if (ret < 0) { | |
2730 | bs->valid_key = 0; | |
2731 | } else if (!bs->valid_key) { | |
2732 | bs->valid_key = 1; | |
2733 | if (bs->blk) { | |
2734 | /* call the change callback now, we skipped it on open */ | |
2735 | blk_dev_change_media_cb(bs->blk, true); | |
2736 | } | |
2737 | } | |
2738 | return ret; | |
2739 | } | |
2740 | ||
2741 | /* | |
2742 | * Provide an encryption key for @bs. | |
2743 | * If @key is non-null: | |
2744 | * If @bs is not encrypted, fail. | |
2745 | * Else if the key is invalid, fail. | |
2746 | * Else set @bs's key to @key, replacing the existing key, if any. | |
2747 | * If @key is null: | |
2748 | * If @bs is encrypted and still lacks a key, fail. | |
2749 | * Else do nothing. | |
2750 | * On failure, store an error object through @errp if non-null. | |
2751 | */ | |
2752 | void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp) | |
2753 | { | |
2754 | if (key) { | |
2755 | if (!bdrv_is_encrypted(bs)) { | |
2756 | error_setg(errp, "Node '%s' is not encrypted", | |
2757 | bdrv_get_device_or_node_name(bs)); | |
2758 | } else if (bdrv_set_key(bs, key) < 0) { | |
2759 | error_setg(errp, QERR_INVALID_PASSWORD); | |
2760 | } | |
2761 | } else { | |
2762 | if (bdrv_key_required(bs)) { | |
2763 | error_set(errp, ERROR_CLASS_DEVICE_ENCRYPTED, | |
2764 | "'%s' (%s) is encrypted", | |
2765 | bdrv_get_device_or_node_name(bs), | |
2766 | bdrv_get_encrypted_filename(bs)); | |
2767 | } | |
2768 | } | |
2769 | } | |
2770 | ||
2771 | const char *bdrv_get_format_name(BlockDriverState *bs) | |
2772 | { | |
2773 | return bs->drv ? bs->drv->format_name : NULL; | |
2774 | } | |
2775 | ||
2776 | static int qsort_strcmp(const void *a, const void *b) | |
2777 | { | |
2778 | return strcmp(a, b); | |
2779 | } | |
2780 | ||
2781 | void bdrv_iterate_format(void (*it)(void *opaque, const char *name), | |
2782 | void *opaque) | |
2783 | { | |
2784 | BlockDriver *drv; | |
2785 | int count = 0; | |
2786 | int i; | |
2787 | const char **formats = NULL; | |
2788 | ||
2789 | QLIST_FOREACH(drv, &bdrv_drivers, list) { | |
2790 | if (drv->format_name) { | |
2791 | bool found = false; | |
2792 | int i = count; | |
2793 | while (formats && i && !found) { | |
2794 | found = !strcmp(formats[--i], drv->format_name); | |
2795 | } | |
2796 | ||
2797 | if (!found) { | |
2798 | formats = g_renew(const char *, formats, count + 1); | |
2799 | formats[count++] = drv->format_name; | |
2800 | } | |
2801 | } | |
2802 | } | |
2803 | ||
2804 | qsort(formats, count, sizeof(formats[0]), qsort_strcmp); | |
2805 | ||
2806 | for (i = 0; i < count; i++) { | |
2807 | it(opaque, formats[i]); | |
2808 | } | |
2809 | ||
2810 | g_free(formats); | |
2811 | } | |
2812 | ||
2813 | /* This function is to find a node in the bs graph */ | |
2814 | BlockDriverState *bdrv_find_node(const char *node_name) | |
2815 | { | |
2816 | BlockDriverState *bs; | |
2817 | ||
2818 | assert(node_name); | |
2819 | ||
2820 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
2821 | if (!strcmp(node_name, bs->node_name)) { | |
2822 | return bs; | |
2823 | } | |
2824 | } | |
2825 | return NULL; | |
2826 | } | |
2827 | ||
2828 | /* Put this QMP function here so it can access the static graph_bdrv_states. */ | |
2829 | BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp) | |
2830 | { | |
2831 | BlockDeviceInfoList *list, *entry; | |
2832 | BlockDriverState *bs; | |
2833 | ||
2834 | list = NULL; | |
2835 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
2836 | BlockDeviceInfo *info = bdrv_block_device_info(bs, errp); | |
2837 | if (!info) { | |
2838 | qapi_free_BlockDeviceInfoList(list); | |
2839 | return NULL; | |
2840 | } | |
2841 | entry = g_malloc0(sizeof(*entry)); | |
2842 | entry->value = info; | |
2843 | entry->next = list; | |
2844 | list = entry; | |
2845 | } | |
2846 | ||
2847 | return list; | |
2848 | } | |
2849 | ||
2850 | BlockDriverState *bdrv_lookup_bs(const char *device, | |
2851 | const char *node_name, | |
2852 | Error **errp) | |
2853 | { | |
2854 | BlockBackend *blk; | |
2855 | BlockDriverState *bs; | |
2856 | ||
2857 | if (device) { | |
2858 | blk = blk_by_name(device); | |
2859 | ||
2860 | if (blk) { | |
2861 | return blk_bs(blk); | |
2862 | } | |
2863 | } | |
2864 | ||
2865 | if (node_name) { | |
2866 | bs = bdrv_find_node(node_name); | |
2867 | ||
2868 | if (bs) { | |
2869 | return bs; | |
2870 | } | |
2871 | } | |
2872 | ||
2873 | error_setg(errp, "Cannot find device=%s nor node_name=%s", | |
2874 | device ? device : "", | |
2875 | node_name ? node_name : ""); | |
2876 | return NULL; | |
2877 | } | |
2878 | ||
2879 | /* If 'base' is in the same chain as 'top', return true. Otherwise, | |
2880 | * return false. If either argument is NULL, return false. */ | |
2881 | bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) | |
2882 | { | |
2883 | while (top && top != base) { | |
2884 | top = top->backing_hd; | |
2885 | } | |
2886 | ||
2887 | return top != NULL; | |
2888 | } | |
2889 | ||
2890 | BlockDriverState *bdrv_next_node(BlockDriverState *bs) | |
2891 | { | |
2892 | if (!bs) { | |
2893 | return QTAILQ_FIRST(&graph_bdrv_states); | |
2894 | } | |
2895 | return QTAILQ_NEXT(bs, node_list); | |
2896 | } | |
2897 | ||
2898 | BlockDriverState *bdrv_next(BlockDriverState *bs) | |
2899 | { | |
2900 | if (!bs) { | |
2901 | return QTAILQ_FIRST(&bdrv_states); | |
2902 | } | |
2903 | return QTAILQ_NEXT(bs, device_list); | |
2904 | } | |
2905 | ||
2906 | const char *bdrv_get_node_name(const BlockDriverState *bs) | |
2907 | { | |
2908 | return bs->node_name; | |
2909 | } | |
2910 | ||
2911 | /* TODO check what callers really want: bs->node_name or blk_name() */ | |
2912 | const char *bdrv_get_device_name(const BlockDriverState *bs) | |
2913 | { | |
2914 | return bs->blk ? blk_name(bs->blk) : ""; | |
2915 | } | |
2916 | ||
2917 | /* This can be used to identify nodes that might not have a device | |
2918 | * name associated. Since node and device names live in the same | |
2919 | * namespace, the result is unambiguous. The exception is if both are | |
2920 | * absent, then this returns an empty (non-null) string. */ | |
2921 | const char *bdrv_get_device_or_node_name(const BlockDriverState *bs) | |
2922 | { | |
2923 | return bs->blk ? blk_name(bs->blk) : bs->node_name; | |
2924 | } | |
2925 | ||
2926 | int bdrv_get_flags(BlockDriverState *bs) | |
2927 | { | |
2928 | return bs->open_flags; | |
2929 | } | |
2930 | ||
2931 | int bdrv_has_zero_init_1(BlockDriverState *bs) | |
2932 | { | |
2933 | return 1; | |
2934 | } | |
2935 | ||
2936 | int bdrv_has_zero_init(BlockDriverState *bs) | |
2937 | { | |
2938 | assert(bs->drv); | |
2939 | ||
2940 | /* If BS is a copy on write image, it is initialized to | |
2941 | the contents of the base image, which may not be zeroes. */ | |
2942 | if (bs->backing_hd) { | |
2943 | return 0; | |
2944 | } | |
2945 | if (bs->drv->bdrv_has_zero_init) { | |
2946 | return bs->drv->bdrv_has_zero_init(bs); | |
2947 | } | |
2948 | ||
2949 | /* safe default */ | |
2950 | return 0; | |
2951 | } | |
2952 | ||
2953 | bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs) | |
2954 | { | |
2955 | BlockDriverInfo bdi; | |
2956 | ||
2957 | if (bs->backing_hd) { | |
2958 | return false; | |
2959 | } | |
2960 | ||
2961 | if (bdrv_get_info(bs, &bdi) == 0) { | |
2962 | return bdi.unallocated_blocks_are_zero; | |
2963 | } | |
2964 | ||
2965 | return false; | |
2966 | } | |
2967 | ||
2968 | bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) | |
2969 | { | |
2970 | BlockDriverInfo bdi; | |
2971 | ||
2972 | if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) { | |
2973 | return false; | |
2974 | } | |
2975 | ||
2976 | if (bdrv_get_info(bs, &bdi) == 0) { | |
2977 | return bdi.can_write_zeroes_with_unmap; | |
2978 | } | |
2979 | ||
2980 | return false; | |
2981 | } | |
2982 | ||
2983 | const char *bdrv_get_encrypted_filename(BlockDriverState *bs) | |
2984 | { | |
2985 | if (bs->backing_hd && bs->backing_hd->encrypted) | |
2986 | return bs->backing_file; | |
2987 | else if (bs->encrypted) | |
2988 | return bs->filename; | |
2989 | else | |
2990 | return NULL; | |
2991 | } | |
2992 | ||
2993 | void bdrv_get_backing_filename(BlockDriverState *bs, | |
2994 | char *filename, int filename_size) | |
2995 | { | |
2996 | pstrcpy(filename, filename_size, bs->backing_file); | |
2997 | } | |
2998 | ||
2999 | int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) | |
3000 | { | |
3001 | BlockDriver *drv = bs->drv; | |
3002 | if (!drv) | |
3003 | return -ENOMEDIUM; | |
3004 | if (!drv->bdrv_get_info) | |
3005 | return -ENOTSUP; | |
3006 | memset(bdi, 0, sizeof(*bdi)); | |
3007 | return drv->bdrv_get_info(bs, bdi); | |
3008 | } | |
3009 | ||
3010 | ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs) | |
3011 | { | |
3012 | BlockDriver *drv = bs->drv; | |
3013 | if (drv && drv->bdrv_get_specific_info) { | |
3014 | return drv->bdrv_get_specific_info(bs); | |
3015 | } | |
3016 | return NULL; | |
3017 | } | |
3018 | ||
3019 | void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event) | |
3020 | { | |
3021 | if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) { | |
3022 | return; | |
3023 | } | |
3024 | ||
3025 | bs->drv->bdrv_debug_event(bs, event); | |
3026 | } | |
3027 | ||
3028 | int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, | |
3029 | const char *tag) | |
3030 | { | |
3031 | while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { | |
3032 | bs = bs->file; | |
3033 | } | |
3034 | ||
3035 | if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) { | |
3036 | return bs->drv->bdrv_debug_breakpoint(bs, event, tag); | |
3037 | } | |
3038 | ||
3039 | return -ENOTSUP; | |
3040 | } | |
3041 | ||
3042 | int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) | |
3043 | { | |
3044 | while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) { | |
3045 | bs = bs->file; | |
3046 | } | |
3047 | ||
3048 | if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) { | |
3049 | return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); | |
3050 | } | |
3051 | ||
3052 | return -ENOTSUP; | |
3053 | } | |
3054 | ||
3055 | int bdrv_debug_resume(BlockDriverState *bs, const char *tag) | |
3056 | { | |
3057 | while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { | |
3058 | bs = bs->file; | |
3059 | } | |
3060 | ||
3061 | if (bs && bs->drv && bs->drv->bdrv_debug_resume) { | |
3062 | return bs->drv->bdrv_debug_resume(bs, tag); | |
3063 | } | |
3064 | ||
3065 | return -ENOTSUP; | |
3066 | } | |
3067 | ||
3068 | bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) | |
3069 | { | |
3070 | while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { | |
3071 | bs = bs->file; | |
3072 | } | |
3073 | ||
3074 | if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { | |
3075 | return bs->drv->bdrv_debug_is_suspended(bs, tag); | |
3076 | } | |
3077 | ||
3078 | return false; | |
3079 | } | |
3080 | ||
3081 | int bdrv_is_snapshot(BlockDriverState *bs) | |
3082 | { | |
3083 | return !!(bs->open_flags & BDRV_O_SNAPSHOT); | |
3084 | } | |
3085 | ||
3086 | /* backing_file can either be relative, or absolute, or a protocol. If it is | |
3087 | * relative, it must be relative to the chain. So, passing in bs->filename | |
3088 | * from a BDS as backing_file should not be done, as that may be relative to | |
3089 | * the CWD rather than the chain. */ | |
3090 | BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, | |
3091 | const char *backing_file) | |
3092 | { | |
3093 | char *filename_full = NULL; | |
3094 | char *backing_file_full = NULL; | |
3095 | char *filename_tmp = NULL; | |
3096 | int is_protocol = 0; | |
3097 | BlockDriverState *curr_bs = NULL; | |
3098 | BlockDriverState *retval = NULL; | |
3099 | ||
3100 | if (!bs || !bs->drv || !backing_file) { | |
3101 | return NULL; | |
3102 | } | |
3103 | ||
3104 | filename_full = g_malloc(PATH_MAX); | |
3105 | backing_file_full = g_malloc(PATH_MAX); | |
3106 | filename_tmp = g_malloc(PATH_MAX); | |
3107 | ||
3108 | is_protocol = path_has_protocol(backing_file); | |
3109 | ||
3110 | for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) { | |
3111 | ||
3112 | /* If either of the filename paths is actually a protocol, then | |
3113 | * compare unmodified paths; otherwise make paths relative */ | |
3114 | if (is_protocol || path_has_protocol(curr_bs->backing_file)) { | |
3115 | if (strcmp(backing_file, curr_bs->backing_file) == 0) { | |
3116 | retval = curr_bs->backing_hd; | |
3117 | break; | |
3118 | } | |
3119 | } else { | |
3120 | /* If not an absolute filename path, make it relative to the current | |
3121 | * image's filename path */ | |
3122 | path_combine(filename_tmp, PATH_MAX, curr_bs->filename, | |
3123 | backing_file); | |
3124 | ||
3125 | /* We are going to compare absolute pathnames */ | |
3126 | if (!realpath(filename_tmp, filename_full)) { | |
3127 | continue; | |
3128 | } | |
3129 | ||
3130 | /* We need to make sure the backing filename we are comparing against | |
3131 | * is relative to the current image filename (or absolute) */ | |
3132 | path_combine(filename_tmp, PATH_MAX, curr_bs->filename, | |
3133 | curr_bs->backing_file); | |
3134 | ||
3135 | if (!realpath(filename_tmp, backing_file_full)) { | |
3136 | continue; | |
3137 | } | |
3138 | ||
3139 | if (strcmp(backing_file_full, filename_full) == 0) { | |
3140 | retval = curr_bs->backing_hd; | |
3141 | break; | |
3142 | } | |
3143 | } | |
3144 | } | |
3145 | ||
3146 | g_free(filename_full); | |
3147 | g_free(backing_file_full); | |
3148 | g_free(filename_tmp); | |
3149 | return retval; | |
3150 | } | |
3151 | ||
3152 | int bdrv_get_backing_file_depth(BlockDriverState *bs) | |
3153 | { | |
3154 | if (!bs->drv) { | |
3155 | return 0; | |
3156 | } | |
3157 | ||
3158 | if (!bs->backing_hd) { | |
3159 | return 0; | |
3160 | } | |
3161 | ||
3162 | return 1 + bdrv_get_backing_file_depth(bs->backing_hd); | |
3163 | } | |
3164 | ||
3165 | void bdrv_init(void) | |
3166 | { | |
3167 | module_call_init(MODULE_INIT_BLOCK); | |
3168 | } | |
3169 | ||
3170 | void bdrv_init_with_whitelist(void) | |
3171 | { | |
3172 | use_bdrv_whitelist = 1; | |
3173 | bdrv_init(); | |
3174 | } | |
3175 | ||
3176 | void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) | |
3177 | { | |
3178 | Error *local_err = NULL; | |
3179 | int ret; | |
3180 | ||
3181 | if (!bs->drv) { | |
3182 | return; | |
3183 | } | |
3184 | ||
3185 | if (!(bs->open_flags & BDRV_O_INCOMING)) { | |
3186 | return; | |
3187 | } | |
3188 | bs->open_flags &= ~BDRV_O_INCOMING; | |
3189 | ||
3190 | if (bs->drv->bdrv_invalidate_cache) { | |
3191 | bs->drv->bdrv_invalidate_cache(bs, &local_err); | |
3192 | } else if (bs->file) { | |
3193 | bdrv_invalidate_cache(bs->file, &local_err); | |
3194 | } | |
3195 | if (local_err) { | |
3196 | error_propagate(errp, local_err); | |
3197 | return; | |
3198 | } | |
3199 | ||
3200 | ret = refresh_total_sectors(bs, bs->total_sectors); | |
3201 | if (ret < 0) { | |
3202 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
3203 | return; | |
3204 | } | |
3205 | } | |
3206 | ||
3207 | void bdrv_invalidate_cache_all(Error **errp) | |
3208 | { | |
3209 | BlockDriverState *bs; | |
3210 | Error *local_err = NULL; | |
3211 | ||
3212 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
3213 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
3214 | ||
3215 | aio_context_acquire(aio_context); | |
3216 | bdrv_invalidate_cache(bs, &local_err); | |
3217 | aio_context_release(aio_context); | |
3218 | if (local_err) { | |
3219 | error_propagate(errp, local_err); | |
3220 | return; | |
3221 | } | |
3222 | } | |
3223 | } | |
3224 | ||
3225 | /**************************************************************/ | |
3226 | /* removable device support */ | |
3227 | ||
3228 | /** | |
3229 | * Return TRUE if the media is present | |
3230 | */ | |
3231 | int bdrv_is_inserted(BlockDriverState *bs) | |
3232 | { | |
3233 | BlockDriver *drv = bs->drv; | |
3234 | ||
3235 | if (!drv) | |
3236 | return 0; | |
3237 | if (!drv->bdrv_is_inserted) | |
3238 | return 1; | |
3239 | return drv->bdrv_is_inserted(bs); | |
3240 | } | |
3241 | ||
3242 | /** | |
3243 | * Return whether the media changed since the last call to this | |
3244 | * function, or -ENOTSUP if we don't know. Most drivers don't know. | |
3245 | */ | |
3246 | int bdrv_media_changed(BlockDriverState *bs) | |
3247 | { | |
3248 | BlockDriver *drv = bs->drv; | |
3249 | ||
3250 | if (drv && drv->bdrv_media_changed) { | |
3251 | return drv->bdrv_media_changed(bs); | |
3252 | } | |
3253 | return -ENOTSUP; | |
3254 | } | |
3255 | ||
3256 | /** | |
3257 | * If eject_flag is TRUE, eject the media. Otherwise, close the tray | |
3258 | */ | |
3259 | void bdrv_eject(BlockDriverState *bs, bool eject_flag) | |
3260 | { | |
3261 | BlockDriver *drv = bs->drv; | |
3262 | const char *device_name; | |
3263 | ||
3264 | if (drv && drv->bdrv_eject) { | |
3265 | drv->bdrv_eject(bs, eject_flag); | |
3266 | } | |
3267 | ||
3268 | device_name = bdrv_get_device_name(bs); | |
3269 | if (device_name[0] != '\0') { | |
3270 | qapi_event_send_device_tray_moved(device_name, | |
3271 | eject_flag, &error_abort); | |
3272 | } | |
3273 | } | |
3274 | ||
3275 | /** | |
3276 | * Lock or unlock the media (if it is locked, the user won't be able | |
3277 | * to eject it manually). | |
3278 | */ | |
3279 | void bdrv_lock_medium(BlockDriverState *bs, bool locked) | |
3280 | { | |
3281 | BlockDriver *drv = bs->drv; | |
3282 | ||
3283 | trace_bdrv_lock_medium(bs, locked); | |
3284 | ||
3285 | if (drv && drv->bdrv_lock_medium) { | |
3286 | drv->bdrv_lock_medium(bs, locked); | |
3287 | } | |
3288 | } | |
3289 | ||
3290 | void bdrv_set_guest_block_size(BlockDriverState *bs, int align) | |
3291 | { | |
3292 | bs->guest_block_size = align; | |
3293 | } | |
3294 | ||
3295 | BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name) | |
3296 | { | |
3297 | BdrvDirtyBitmap *bm; | |
3298 | ||
3299 | assert(name); | |
3300 | QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { | |
3301 | if (bm->name && !strcmp(name, bm->name)) { | |
3302 | return bm; | |
3303 | } | |
3304 | } | |
3305 | return NULL; | |
3306 | } | |
3307 | ||
3308 | void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap) | |
3309 | { | |
3310 | assert(!bdrv_dirty_bitmap_frozen(bitmap)); | |
3311 | g_free(bitmap->name); | |
3312 | bitmap->name = NULL; | |
3313 | } | |
3314 | ||
3315 | BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, | |
3316 | uint32_t granularity, | |
3317 | const char *name, | |
3318 | Error **errp) | |
3319 | { | |
3320 | int64_t bitmap_size; | |
3321 | BdrvDirtyBitmap *bitmap; | |
3322 | uint32_t sector_granularity; | |
3323 | ||
3324 | assert((granularity & (granularity - 1)) == 0); | |
3325 | ||
3326 | if (name && bdrv_find_dirty_bitmap(bs, name)) { | |
3327 | error_setg(errp, "Bitmap already exists: %s", name); | |
3328 | return NULL; | |
3329 | } | |
3330 | sector_granularity = granularity >> BDRV_SECTOR_BITS; | |
3331 | assert(sector_granularity); | |
3332 | bitmap_size = bdrv_nb_sectors(bs); | |
3333 | if (bitmap_size < 0) { | |
3334 | error_setg_errno(errp, -bitmap_size, "could not get length of device"); | |
3335 | errno = -bitmap_size; | |
3336 | return NULL; | |
3337 | } | |
3338 | bitmap = g_new0(BdrvDirtyBitmap, 1); | |
3339 | bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity)); | |
3340 | bitmap->size = bitmap_size; | |
3341 | bitmap->name = g_strdup(name); | |
3342 | bitmap->disabled = false; | |
3343 | QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list); | |
3344 | return bitmap; | |
3345 | } | |
3346 | ||
3347 | bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap) | |
3348 | { | |
3349 | return bitmap->successor; | |
3350 | } | |
3351 | ||
3352 | bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap) | |
3353 | { | |
3354 | return !(bitmap->disabled || bitmap->successor); | |
3355 | } | |
3356 | ||
3357 | DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap) | |
3358 | { | |
3359 | if (bdrv_dirty_bitmap_frozen(bitmap)) { | |
3360 | return DIRTY_BITMAP_STATUS_FROZEN; | |
3361 | } else if (!bdrv_dirty_bitmap_enabled(bitmap)) { | |
3362 | return DIRTY_BITMAP_STATUS_DISABLED; | |
3363 | } else { | |
3364 | return DIRTY_BITMAP_STATUS_ACTIVE; | |
3365 | } | |
3366 | } | |
3367 | ||
3368 | /** | |
3369 | * Create a successor bitmap destined to replace this bitmap after an operation. | |
3370 | * Requires that the bitmap is not frozen and has no successor. | |
3371 | */ | |
3372 | int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs, | |
3373 | BdrvDirtyBitmap *bitmap, Error **errp) | |
3374 | { | |
3375 | uint64_t granularity; | |
3376 | BdrvDirtyBitmap *child; | |
3377 | ||
3378 | if (bdrv_dirty_bitmap_frozen(bitmap)) { | |
3379 | error_setg(errp, "Cannot create a successor for a bitmap that is " | |
3380 | "currently frozen"); | |
3381 | return -1; | |
3382 | } | |
3383 | assert(!bitmap->successor); | |
3384 | ||
3385 | /* Create an anonymous successor */ | |
3386 | granularity = bdrv_dirty_bitmap_granularity(bitmap); | |
3387 | child = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); | |
3388 | if (!child) { | |
3389 | return -1; | |
3390 | } | |
3391 | ||
3392 | /* Successor will be on or off based on our current state. */ | |
3393 | child->disabled = bitmap->disabled; | |
3394 | ||
3395 | /* Install the successor and freeze the parent */ | |
3396 | bitmap->successor = child; | |
3397 | return 0; | |
3398 | } | |
3399 | ||
3400 | /** | |
3401 | * For a bitmap with a successor, yield our name to the successor, | |
3402 | * delete the old bitmap, and return a handle to the new bitmap. | |
3403 | */ | |
3404 | BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs, | |
3405 | BdrvDirtyBitmap *bitmap, | |
3406 | Error **errp) | |
3407 | { | |
3408 | char *name; | |
3409 | BdrvDirtyBitmap *successor = bitmap->successor; | |
3410 | ||
3411 | if (successor == NULL) { | |
3412 | error_setg(errp, "Cannot relinquish control if " | |
3413 | "there's no successor present"); | |
3414 | return NULL; | |
3415 | } | |
3416 | ||
3417 | name = bitmap->name; | |
3418 | bitmap->name = NULL; | |
3419 | successor->name = name; | |
3420 | bitmap->successor = NULL; | |
3421 | bdrv_release_dirty_bitmap(bs, bitmap); | |
3422 | ||
3423 | return successor; | |
3424 | } | |
3425 | ||
3426 | /** | |
3427 | * In cases of failure where we can no longer safely delete the parent, | |
3428 | * we may wish to re-join the parent and child/successor. | |
3429 | * The merged parent will be un-frozen, but not explicitly re-enabled. | |
3430 | */ | |
3431 | BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs, | |
3432 | BdrvDirtyBitmap *parent, | |
3433 | Error **errp) | |
3434 | { | |
3435 | BdrvDirtyBitmap *successor = parent->successor; | |
3436 | ||
3437 | if (!successor) { | |
3438 | error_setg(errp, "Cannot reclaim a successor when none is present"); | |
3439 | return NULL; | |
3440 | } | |
3441 | ||
3442 | if (!hbitmap_merge(parent->bitmap, successor->bitmap)) { | |
3443 | error_setg(errp, "Merging of parent and successor bitmap failed"); | |
3444 | return NULL; | |
3445 | } | |
3446 | bdrv_release_dirty_bitmap(bs, successor); | |
3447 | parent->successor = NULL; | |
3448 | ||
3449 | return parent; | |
3450 | } | |
3451 | ||
3452 | /** | |
3453 | * Truncates _all_ bitmaps attached to a BDS. | |
3454 | */ | |
3455 | static void bdrv_dirty_bitmap_truncate(BlockDriverState *bs) | |
3456 | { | |
3457 | BdrvDirtyBitmap *bitmap; | |
3458 | uint64_t size = bdrv_nb_sectors(bs); | |
3459 | ||
3460 | QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { | |
3461 | assert(!bdrv_dirty_bitmap_frozen(bitmap)); | |
3462 | hbitmap_truncate(bitmap->bitmap, size); | |
3463 | bitmap->size = size; | |
3464 | } | |
3465 | } | |
3466 | ||
3467 | void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) | |
3468 | { | |
3469 | BdrvDirtyBitmap *bm, *next; | |
3470 | QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) { | |
3471 | if (bm == bitmap) { | |
3472 | assert(!bdrv_dirty_bitmap_frozen(bm)); | |
3473 | QLIST_REMOVE(bitmap, list); | |
3474 | hbitmap_free(bitmap->bitmap); | |
3475 | g_free(bitmap->name); | |
3476 | g_free(bitmap); | |
3477 | return; | |
3478 | } | |
3479 | } | |
3480 | } | |
3481 | ||
3482 | void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap) | |
3483 | { | |
3484 | assert(!bdrv_dirty_bitmap_frozen(bitmap)); | |
3485 | bitmap->disabled = true; | |
3486 | } | |
3487 | ||
3488 | void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap) | |
3489 | { | |
3490 | assert(!bdrv_dirty_bitmap_frozen(bitmap)); | |
3491 | bitmap->disabled = false; | |
3492 | } | |
3493 | ||
3494 | BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs) | |
3495 | { | |
3496 | BdrvDirtyBitmap *bm; | |
3497 | BlockDirtyInfoList *list = NULL; | |
3498 | BlockDirtyInfoList **plist = &list; | |
3499 | ||
3500 | QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { | |
3501 | BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1); | |
3502 | BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1); | |
3503 | info->count = bdrv_get_dirty_count(bm); | |
3504 | info->granularity = bdrv_dirty_bitmap_granularity(bm); | |
3505 | info->has_name = !!bm->name; | |
3506 | info->name = g_strdup(bm->name); | |
3507 | info->status = bdrv_dirty_bitmap_status(bm); | |
3508 | entry->value = info; | |
3509 | *plist = entry; | |
3510 | plist = &entry->next; | |
3511 | } | |
3512 | ||
3513 | return list; | |
3514 | } | |
3515 | ||
3516 | int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector) | |
3517 | { | |
3518 | if (bitmap) { | |
3519 | return hbitmap_get(bitmap->bitmap, sector); | |
3520 | } else { | |
3521 | return 0; | |
3522 | } | |
3523 | } | |
3524 | ||
3525 | /** | |
3526 | * Chooses a default granularity based on the existing cluster size, | |
3527 | * but clamped between [4K, 64K]. Defaults to 64K in the case that there | |
3528 | * is no cluster size information available. | |
3529 | */ | |
3530 | uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs) | |
3531 | { | |
3532 | BlockDriverInfo bdi; | |
3533 | uint32_t granularity; | |
3534 | ||
3535 | if (bdrv_get_info(bs, &bdi) >= 0 && bdi.cluster_size > 0) { | |
3536 | granularity = MAX(4096, bdi.cluster_size); | |
3537 | granularity = MIN(65536, granularity); | |
3538 | } else { | |
3539 | granularity = 65536; | |
3540 | } | |
3541 | ||
3542 | return granularity; | |
3543 | } | |
3544 | ||
3545 | uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap) | |
3546 | { | |
3547 | return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap); | |
3548 | } | |
3549 | ||
3550 | void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, HBitmapIter *hbi) | |
3551 | { | |
3552 | hbitmap_iter_init(hbi, bitmap->bitmap, 0); | |
3553 | } | |
3554 | ||
3555 | void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap, | |
3556 | int64_t cur_sector, int nr_sectors) | |
3557 | { | |
3558 | assert(bdrv_dirty_bitmap_enabled(bitmap)); | |
3559 | hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); | |
3560 | } | |
3561 | ||
3562 | void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap, | |
3563 | int64_t cur_sector, int nr_sectors) | |
3564 | { | |
3565 | assert(bdrv_dirty_bitmap_enabled(bitmap)); | |
3566 | hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); | |
3567 | } | |
3568 | ||
3569 | void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap) | |
3570 | { | |
3571 | assert(bdrv_dirty_bitmap_enabled(bitmap)); | |
3572 | hbitmap_reset_all(bitmap->bitmap); | |
3573 | } | |
3574 | ||
3575 | void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, | |
3576 | int nr_sectors) | |
3577 | { | |
3578 | BdrvDirtyBitmap *bitmap; | |
3579 | QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { | |
3580 | if (!bdrv_dirty_bitmap_enabled(bitmap)) { | |
3581 | continue; | |
3582 | } | |
3583 | hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); | |
3584 | } | |
3585 | } | |
3586 | ||
3587 | /** | |
3588 | * Advance an HBitmapIter to an arbitrary offset. | |
3589 | */ | |
3590 | void bdrv_set_dirty_iter(HBitmapIter *hbi, int64_t offset) | |
3591 | { | |
3592 | assert(hbi->hb); | |
3593 | hbitmap_iter_init(hbi, hbi->hb, offset); | |
3594 | } | |
3595 | ||
3596 | int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap) | |
3597 | { | |
3598 | return hbitmap_count(bitmap->bitmap); | |
3599 | } | |
3600 | ||
3601 | /* Get a reference to bs */ | |
3602 | void bdrv_ref(BlockDriverState *bs) | |
3603 | { | |
3604 | bs->refcnt++; | |
3605 | } | |
3606 | ||
3607 | /* Release a previously grabbed reference to bs. | |
3608 | * If after releasing, reference count is zero, the BlockDriverState is | |
3609 | * deleted. */ | |
3610 | void bdrv_unref(BlockDriverState *bs) | |
3611 | { | |
3612 | if (!bs) { | |
3613 | return; | |
3614 | } | |
3615 | assert(bs->refcnt > 0); | |
3616 | if (--bs->refcnt == 0) { | |
3617 | bdrv_delete(bs); | |
3618 | } | |
3619 | } | |
3620 | ||
3621 | struct BdrvOpBlocker { | |
3622 | Error *reason; | |
3623 | QLIST_ENTRY(BdrvOpBlocker) list; | |
3624 | }; | |
3625 | ||
3626 | bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) | |
3627 | { | |
3628 | BdrvOpBlocker *blocker; | |
3629 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
3630 | if (!QLIST_EMPTY(&bs->op_blockers[op])) { | |
3631 | blocker = QLIST_FIRST(&bs->op_blockers[op]); | |
3632 | if (errp) { | |
3633 | error_setg(errp, "Node '%s' is busy: %s", | |
3634 | bdrv_get_device_or_node_name(bs), | |
3635 | error_get_pretty(blocker->reason)); | |
3636 | } | |
3637 | return true; | |
3638 | } | |
3639 | return false; | |
3640 | } | |
3641 | ||
3642 | void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason) | |
3643 | { | |
3644 | BdrvOpBlocker *blocker; | |
3645 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
3646 | ||
3647 | blocker = g_new0(BdrvOpBlocker, 1); | |
3648 | blocker->reason = reason; | |
3649 | QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list); | |
3650 | } | |
3651 | ||
3652 | void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason) | |
3653 | { | |
3654 | BdrvOpBlocker *blocker, *next; | |
3655 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
3656 | QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) { | |
3657 | if (blocker->reason == reason) { | |
3658 | QLIST_REMOVE(blocker, list); | |
3659 | g_free(blocker); | |
3660 | } | |
3661 | } | |
3662 | } | |
3663 | ||
3664 | void bdrv_op_block_all(BlockDriverState *bs, Error *reason) | |
3665 | { | |
3666 | int i; | |
3667 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
3668 | bdrv_op_block(bs, i, reason); | |
3669 | } | |
3670 | } | |
3671 | ||
3672 | void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason) | |
3673 | { | |
3674 | int i; | |
3675 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
3676 | bdrv_op_unblock(bs, i, reason); | |
3677 | } | |
3678 | } | |
3679 | ||
3680 | bool bdrv_op_blocker_is_empty(BlockDriverState *bs) | |
3681 | { | |
3682 | int i; | |
3683 | ||
3684 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
3685 | if (!QLIST_EMPTY(&bs->op_blockers[i])) { | |
3686 | return false; | |
3687 | } | |
3688 | } | |
3689 | return true; | |
3690 | } | |
3691 | ||
3692 | void bdrv_iostatus_enable(BlockDriverState *bs) | |
3693 | { | |
3694 | bs->iostatus_enabled = true; | |
3695 | bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; | |
3696 | } | |
3697 | ||
3698 | /* The I/O status is only enabled if the drive explicitly | |
3699 | * enables it _and_ the VM is configured to stop on errors */ | |
3700 | bool bdrv_iostatus_is_enabled(const BlockDriverState *bs) | |
3701 | { | |
3702 | return (bs->iostatus_enabled && | |
3703 | (bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC || | |
3704 | bs->on_write_error == BLOCKDEV_ON_ERROR_STOP || | |
3705 | bs->on_read_error == BLOCKDEV_ON_ERROR_STOP)); | |
3706 | } | |
3707 | ||
3708 | void bdrv_iostatus_disable(BlockDriverState *bs) | |
3709 | { | |
3710 | bs->iostatus_enabled = false; | |
3711 | } | |
3712 | ||
3713 | void bdrv_iostatus_reset(BlockDriverState *bs) | |
3714 | { | |
3715 | if (bdrv_iostatus_is_enabled(bs)) { | |
3716 | bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; | |
3717 | if (bs->job) { | |
3718 | block_job_iostatus_reset(bs->job); | |
3719 | } | |
3720 | } | |
3721 | } | |
3722 | ||
3723 | void bdrv_iostatus_set_err(BlockDriverState *bs, int error) | |
3724 | { | |
3725 | assert(bdrv_iostatus_is_enabled(bs)); | |
3726 | if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { | |
3727 | bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : | |
3728 | BLOCK_DEVICE_IO_STATUS_FAILED; | |
3729 | } | |
3730 | } | |
3731 | ||
3732 | void bdrv_img_create(const char *filename, const char *fmt, | |
3733 | const char *base_filename, const char *base_fmt, | |
3734 | char *options, uint64_t img_size, int flags, | |
3735 | Error **errp, bool quiet) | |
3736 | { | |
3737 | QemuOptsList *create_opts = NULL; | |
3738 | QemuOpts *opts = NULL; | |
3739 | const char *backing_fmt, *backing_file; | |
3740 | int64_t size; | |
3741 | BlockDriver *drv, *proto_drv; | |
3742 | BlockDriver *backing_drv = NULL; | |
3743 | Error *local_err = NULL; | |
3744 | int ret = 0; | |
3745 | ||
3746 | /* Find driver and parse its options */ | |
3747 | drv = bdrv_find_format(fmt); | |
3748 | if (!drv) { | |
3749 | error_setg(errp, "Unknown file format '%s'", fmt); | |
3750 | return; | |
3751 | } | |
3752 | ||
3753 | proto_drv = bdrv_find_protocol(filename, true, errp); | |
3754 | if (!proto_drv) { | |
3755 | return; | |
3756 | } | |
3757 | ||
3758 | if (!drv->create_opts) { | |
3759 | error_setg(errp, "Format driver '%s' does not support image creation", | |
3760 | drv->format_name); | |
3761 | return; | |
3762 | } | |
3763 | ||
3764 | if (!proto_drv->create_opts) { | |
3765 | error_setg(errp, "Protocol driver '%s' does not support image creation", | |
3766 | proto_drv->format_name); | |
3767 | return; | |
3768 | } | |
3769 | ||
3770 | create_opts = qemu_opts_append(create_opts, drv->create_opts); | |
3771 | create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); | |
3772 | ||
3773 | /* Create parameter list with default values */ | |
3774 | opts = qemu_opts_create(create_opts, NULL, 0, &error_abort); | |
3775 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort); | |
3776 | ||
3777 | /* Parse -o options */ | |
3778 | if (options) { | |
3779 | qemu_opts_do_parse(opts, options, NULL, &local_err); | |
3780 | if (local_err) { | |
3781 | error_report_err(local_err); | |
3782 | local_err = NULL; | |
3783 | error_setg(errp, "Invalid options for file format '%s'", fmt); | |
3784 | goto out; | |
3785 | } | |
3786 | } | |
3787 | ||
3788 | if (base_filename) { | |
3789 | qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err); | |
3790 | if (local_err) { | |
3791 | error_setg(errp, "Backing file not supported for file format '%s'", | |
3792 | fmt); | |
3793 | goto out; | |
3794 | } | |
3795 | } | |
3796 | ||
3797 | if (base_fmt) { | |
3798 | qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err); | |
3799 | if (local_err) { | |
3800 | error_setg(errp, "Backing file format not supported for file " | |
3801 | "format '%s'", fmt); | |
3802 | goto out; | |
3803 | } | |
3804 | } | |
3805 | ||
3806 | backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); | |
3807 | if (backing_file) { | |
3808 | if (!strcmp(filename, backing_file)) { | |
3809 | error_setg(errp, "Error: Trying to create an image with the " | |
3810 | "same filename as the backing file"); | |
3811 | goto out; | |
3812 | } | |
3813 | } | |
3814 | ||
3815 | backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); | |
3816 | if (backing_fmt) { | |
3817 | backing_drv = bdrv_find_format(backing_fmt); | |
3818 | if (!backing_drv) { | |
3819 | error_setg(errp, "Unknown backing file format '%s'", | |
3820 | backing_fmt); | |
3821 | goto out; | |
3822 | } | |
3823 | } | |
3824 | ||
3825 | // The size for the image must always be specified, with one exception: | |
3826 | // If we are using a backing file, we can obtain the size from there | |
3827 | size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); | |
3828 | if (size == -1) { | |
3829 | if (backing_file) { | |
3830 | BlockDriverState *bs; | |
3831 | char *full_backing = g_new0(char, PATH_MAX); | |
3832 | int64_t size; | |
3833 | int back_flags; | |
3834 | ||
3835 | bdrv_get_full_backing_filename_from_filename(filename, backing_file, | |
3836 | full_backing, PATH_MAX, | |
3837 | &local_err); | |
3838 | if (local_err) { | |
3839 | g_free(full_backing); | |
3840 | goto out; | |
3841 | } | |
3842 | ||
3843 | /* backing files always opened read-only */ | |
3844 | back_flags = | |
3845 | flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); | |
3846 | ||
3847 | bs = NULL; | |
3848 | ret = bdrv_open(&bs, full_backing, NULL, NULL, back_flags, | |
3849 | backing_drv, &local_err); | |
3850 | g_free(full_backing); | |
3851 | if (ret < 0) { | |
3852 | goto out; | |
3853 | } | |
3854 | size = bdrv_getlength(bs); | |
3855 | if (size < 0) { | |
3856 | error_setg_errno(errp, -size, "Could not get size of '%s'", | |
3857 | backing_file); | |
3858 | bdrv_unref(bs); | |
3859 | goto out; | |
3860 | } | |
3861 | ||
3862 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort); | |
3863 | ||
3864 | bdrv_unref(bs); | |
3865 | } else { | |
3866 | error_setg(errp, "Image creation needs a size parameter"); | |
3867 | goto out; | |
3868 | } | |
3869 | } | |
3870 | ||
3871 | if (!quiet) { | |
3872 | printf("Formatting '%s', fmt=%s ", filename, fmt); | |
3873 | qemu_opts_print(opts, " "); | |
3874 | puts(""); | |
3875 | } | |
3876 | ||
3877 | ret = bdrv_create(drv, filename, opts, &local_err); | |
3878 | ||
3879 | if (ret == -EFBIG) { | |
3880 | /* This is generally a better message than whatever the driver would | |
3881 | * deliver (especially because of the cluster_size_hint), since that | |
3882 | * is most probably not much different from "image too large". */ | |
3883 | const char *cluster_size_hint = ""; | |
3884 | if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) { | |
3885 | cluster_size_hint = " (try using a larger cluster size)"; | |
3886 | } | |
3887 | error_setg(errp, "The image size is too large for file format '%s'" | |
3888 | "%s", fmt, cluster_size_hint); | |
3889 | error_free(local_err); | |
3890 | local_err = NULL; | |
3891 | } | |
3892 | ||
3893 | out: | |
3894 | qemu_opts_del(opts); | |
3895 | qemu_opts_free(create_opts); | |
3896 | if (local_err) { | |
3897 | error_propagate(errp, local_err); | |
3898 | } | |
3899 | } | |
3900 | ||
3901 | AioContext *bdrv_get_aio_context(BlockDriverState *bs) | |
3902 | { | |
3903 | return bs->aio_context; | |
3904 | } | |
3905 | ||
3906 | void bdrv_detach_aio_context(BlockDriverState *bs) | |
3907 | { | |
3908 | BdrvAioNotifier *baf; | |
3909 | ||
3910 | if (!bs->drv) { | |
3911 | return; | |
3912 | } | |
3913 | ||
3914 | QLIST_FOREACH(baf, &bs->aio_notifiers, list) { | |
3915 | baf->detach_aio_context(baf->opaque); | |
3916 | } | |
3917 | ||
3918 | if (bs->io_limits_enabled) { | |
3919 | throttle_timers_detach_aio_context(&bs->throttle_timers); | |
3920 | } | |
3921 | if (bs->drv->bdrv_detach_aio_context) { | |
3922 | bs->drv->bdrv_detach_aio_context(bs); | |
3923 | } | |
3924 | if (bs->file) { | |
3925 | bdrv_detach_aio_context(bs->file); | |
3926 | } | |
3927 | if (bs->backing_hd) { | |
3928 | bdrv_detach_aio_context(bs->backing_hd); | |
3929 | } | |
3930 | ||
3931 | bs->aio_context = NULL; | |
3932 | } | |
3933 | ||
3934 | void bdrv_attach_aio_context(BlockDriverState *bs, | |
3935 | AioContext *new_context) | |
3936 | { | |
3937 | BdrvAioNotifier *ban; | |
3938 | ||
3939 | if (!bs->drv) { | |
3940 | return; | |
3941 | } | |
3942 | ||
3943 | bs->aio_context = new_context; | |
3944 | ||
3945 | if (bs->backing_hd) { | |
3946 | bdrv_attach_aio_context(bs->backing_hd, new_context); | |
3947 | } | |
3948 | if (bs->file) { | |
3949 | bdrv_attach_aio_context(bs->file, new_context); | |
3950 | } | |
3951 | if (bs->drv->bdrv_attach_aio_context) { | |
3952 | bs->drv->bdrv_attach_aio_context(bs, new_context); | |
3953 | } | |
3954 | if (bs->io_limits_enabled) { | |
3955 | throttle_timers_attach_aio_context(&bs->throttle_timers, new_context); | |
3956 | } | |
3957 | ||
3958 | QLIST_FOREACH(ban, &bs->aio_notifiers, list) { | |
3959 | ban->attached_aio_context(new_context, ban->opaque); | |
3960 | } | |
3961 | } | |
3962 | ||
3963 | void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) | |
3964 | { | |
3965 | bdrv_drain(bs); /* ensure there are no in-flight requests */ | |
3966 | ||
3967 | bdrv_detach_aio_context(bs); | |
3968 | ||
3969 | /* This function executes in the old AioContext so acquire the new one in | |
3970 | * case it runs in a different thread. | |
3971 | */ | |
3972 | aio_context_acquire(new_context); | |
3973 | bdrv_attach_aio_context(bs, new_context); | |
3974 | aio_context_release(new_context); | |
3975 | } | |
3976 | ||
3977 | void bdrv_add_aio_context_notifier(BlockDriverState *bs, | |
3978 | void (*attached_aio_context)(AioContext *new_context, void *opaque), | |
3979 | void (*detach_aio_context)(void *opaque), void *opaque) | |
3980 | { | |
3981 | BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1); | |
3982 | *ban = (BdrvAioNotifier){ | |
3983 | .attached_aio_context = attached_aio_context, | |
3984 | .detach_aio_context = detach_aio_context, | |
3985 | .opaque = opaque | |
3986 | }; | |
3987 | ||
3988 | QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list); | |
3989 | } | |
3990 | ||
3991 | void bdrv_remove_aio_context_notifier(BlockDriverState *bs, | |
3992 | void (*attached_aio_context)(AioContext *, | |
3993 | void *), | |
3994 | void (*detach_aio_context)(void *), | |
3995 | void *opaque) | |
3996 | { | |
3997 | BdrvAioNotifier *ban, *ban_next; | |
3998 | ||
3999 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { | |
4000 | if (ban->attached_aio_context == attached_aio_context && | |
4001 | ban->detach_aio_context == detach_aio_context && | |
4002 | ban->opaque == opaque) | |
4003 | { | |
4004 | QLIST_REMOVE(ban, list); | |
4005 | g_free(ban); | |
4006 | ||
4007 | return; | |
4008 | } | |
4009 | } | |
4010 | ||
4011 | abort(); | |
4012 | } | |
4013 | ||
4014 | int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts, | |
4015 | BlockDriverAmendStatusCB *status_cb) | |
4016 | { | |
4017 | if (!bs->drv->bdrv_amend_options) { | |
4018 | return -ENOTSUP; | |
4019 | } | |
4020 | return bs->drv->bdrv_amend_options(bs, opts, status_cb); | |
4021 | } | |
4022 | ||
4023 | /* This function will be called by the bdrv_recurse_is_first_non_filter method | |
4024 | * of block filter and by bdrv_is_first_non_filter. | |
4025 | * It is used to test if the given bs is the candidate or recurse more in the | |
4026 | * node graph. | |
4027 | */ | |
4028 | bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, | |
4029 | BlockDriverState *candidate) | |
4030 | { | |
4031 | /* return false if basic checks fails */ | |
4032 | if (!bs || !bs->drv) { | |
4033 | return false; | |
4034 | } | |
4035 | ||
4036 | /* the code reached a non block filter driver -> check if the bs is | |
4037 | * the same as the candidate. It's the recursion termination condition. | |
4038 | */ | |
4039 | if (!bs->drv->is_filter) { | |
4040 | return bs == candidate; | |
4041 | } | |
4042 | /* Down this path the driver is a block filter driver */ | |
4043 | ||
4044 | /* If the block filter recursion method is defined use it to recurse down | |
4045 | * the node graph. | |
4046 | */ | |
4047 | if (bs->drv->bdrv_recurse_is_first_non_filter) { | |
4048 | return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate); | |
4049 | } | |
4050 | ||
4051 | /* the driver is a block filter but don't allow to recurse -> return false | |
4052 | */ | |
4053 | return false; | |
4054 | } | |
4055 | ||
4056 | /* This function checks if the candidate is the first non filter bs down it's | |
4057 | * bs chain. Since we don't have pointers to parents it explore all bs chains | |
4058 | * from the top. Some filters can choose not to pass down the recursion. | |
4059 | */ | |
4060 | bool bdrv_is_first_non_filter(BlockDriverState *candidate) | |
4061 | { | |
4062 | BlockDriverState *bs; | |
4063 | ||
4064 | /* walk down the bs forest recursively */ | |
4065 | QTAILQ_FOREACH(bs, &bdrv_states, device_list) { | |
4066 | bool perm; | |
4067 | ||
4068 | /* try to recurse in this top level bs */ | |
4069 | perm = bdrv_recurse_is_first_non_filter(bs, candidate); | |
4070 | ||
4071 | /* candidate is the first non filter */ | |
4072 | if (perm) { | |
4073 | return true; | |
4074 | } | |
4075 | } | |
4076 | ||
4077 | return false; | |
4078 | } | |
4079 | ||
4080 | BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, | |
4081 | const char *node_name, Error **errp) | |
4082 | { | |
4083 | BlockDriverState *to_replace_bs = bdrv_find_node(node_name); | |
4084 | AioContext *aio_context; | |
4085 | ||
4086 | if (!to_replace_bs) { | |
4087 | error_setg(errp, "Node name '%s' not found", node_name); | |
4088 | return NULL; | |
4089 | } | |
4090 | ||
4091 | aio_context = bdrv_get_aio_context(to_replace_bs); | |
4092 | aio_context_acquire(aio_context); | |
4093 | ||
4094 | if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) { | |
4095 | to_replace_bs = NULL; | |
4096 | goto out; | |
4097 | } | |
4098 | ||
4099 | /* We don't want arbitrary node of the BDS chain to be replaced only the top | |
4100 | * most non filter in order to prevent data corruption. | |
4101 | * Another benefit is that this tests exclude backing files which are | |
4102 | * blocked by the backing blockers. | |
4103 | */ | |
4104 | if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) { | |
4105 | error_setg(errp, "Only top most non filter can be replaced"); | |
4106 | to_replace_bs = NULL; | |
4107 | goto out; | |
4108 | } | |
4109 | ||
4110 | out: | |
4111 | aio_context_release(aio_context); | |
4112 | return to_replace_bs; | |
4113 | } | |
4114 | ||
4115 | static bool append_open_options(QDict *d, BlockDriverState *bs) | |
4116 | { | |
4117 | const QDictEntry *entry; | |
4118 | bool found_any = false; | |
4119 | ||
4120 | for (entry = qdict_first(bs->options); entry; | |
4121 | entry = qdict_next(bs->options, entry)) | |
4122 | { | |
4123 | /* Only take options for this level and exclude all non-driver-specific | |
4124 | * options */ | |
4125 | if (!strchr(qdict_entry_key(entry), '.') && | |
4126 | strcmp(qdict_entry_key(entry), "node-name")) | |
4127 | { | |
4128 | qobject_incref(qdict_entry_value(entry)); | |
4129 | qdict_put_obj(d, qdict_entry_key(entry), qdict_entry_value(entry)); | |
4130 | found_any = true; | |
4131 | } | |
4132 | } | |
4133 | ||
4134 | return found_any; | |
4135 | } | |
4136 | ||
4137 | /* Updates the following BDS fields: | |
4138 | * - exact_filename: A filename which may be used for opening a block device | |
4139 | * which (mostly) equals the given BDS (even without any | |
4140 | * other options; so reading and writing must return the same | |
4141 | * results, but caching etc. may be different) | |
4142 | * - full_open_options: Options which, when given when opening a block device | |
4143 | * (without a filename), result in a BDS (mostly) | |
4144 | * equalling the given one | |
4145 | * - filename: If exact_filename is set, it is copied here. Otherwise, | |
4146 | * full_open_options is converted to a JSON object, prefixed with | |
4147 | * "json:" (for use through the JSON pseudo protocol) and put here. | |
4148 | */ | |
4149 | void bdrv_refresh_filename(BlockDriverState *bs) | |
4150 | { | |
4151 | BlockDriver *drv = bs->drv; | |
4152 | QDict *opts; | |
4153 | ||
4154 | if (!drv) { | |
4155 | return; | |
4156 | } | |
4157 | ||
4158 | /* This BDS's file name will most probably depend on its file's name, so | |
4159 | * refresh that first */ | |
4160 | if (bs->file) { | |
4161 | bdrv_refresh_filename(bs->file); | |
4162 | } | |
4163 | ||
4164 | if (drv->bdrv_refresh_filename) { | |
4165 | /* Obsolete information is of no use here, so drop the old file name | |
4166 | * information before refreshing it */ | |
4167 | bs->exact_filename[0] = '\0'; | |
4168 | if (bs->full_open_options) { | |
4169 | QDECREF(bs->full_open_options); | |
4170 | bs->full_open_options = NULL; | |
4171 | } | |
4172 | ||
4173 | drv->bdrv_refresh_filename(bs); | |
4174 | } else if (bs->file) { | |
4175 | /* Try to reconstruct valid information from the underlying file */ | |
4176 | bool has_open_options; | |
4177 | ||
4178 | bs->exact_filename[0] = '\0'; | |
4179 | if (bs->full_open_options) { | |
4180 | QDECREF(bs->full_open_options); | |
4181 | bs->full_open_options = NULL; | |
4182 | } | |
4183 | ||
4184 | opts = qdict_new(); | |
4185 | has_open_options = append_open_options(opts, bs); | |
4186 | ||
4187 | /* If no specific options have been given for this BDS, the filename of | |
4188 | * the underlying file should suffice for this one as well */ | |
4189 | if (bs->file->exact_filename[0] && !has_open_options) { | |
4190 | strcpy(bs->exact_filename, bs->file->exact_filename); | |
4191 | } | |
4192 | /* Reconstructing the full options QDict is simple for most format block | |
4193 | * drivers, as long as the full options are known for the underlying | |
4194 | * file BDS. The full options QDict of that file BDS should somehow | |
4195 | * contain a representation of the filename, therefore the following | |
4196 | * suffices without querying the (exact_)filename of this BDS. */ | |
4197 | if (bs->file->full_open_options) { | |
4198 | qdict_put_obj(opts, "driver", | |
4199 | QOBJECT(qstring_from_str(drv->format_name))); | |
4200 | QINCREF(bs->file->full_open_options); | |
4201 | qdict_put_obj(opts, "file", QOBJECT(bs->file->full_open_options)); | |
4202 | ||
4203 | bs->full_open_options = opts; | |
4204 | } else { | |
4205 | QDECREF(opts); | |
4206 | } | |
4207 | } else if (!bs->full_open_options && qdict_size(bs->options)) { | |
4208 | /* There is no underlying file BDS (at least referenced by BDS.file), | |
4209 | * so the full options QDict should be equal to the options given | |
4210 | * specifically for this block device when it was opened (plus the | |
4211 | * driver specification). | |
4212 | * Because those options don't change, there is no need to update | |
4213 | * full_open_options when it's already set. */ | |
4214 | ||
4215 | opts = qdict_new(); | |
4216 | append_open_options(opts, bs); | |
4217 | qdict_put_obj(opts, "driver", | |
4218 | QOBJECT(qstring_from_str(drv->format_name))); | |
4219 | ||
4220 | if (bs->exact_filename[0]) { | |
4221 | /* This may not work for all block protocol drivers (some may | |
4222 | * require this filename to be parsed), but we have to find some | |
4223 | * default solution here, so just include it. If some block driver | |
4224 | * does not support pure options without any filename at all or | |
4225 | * needs some special format of the options QDict, it needs to | |
4226 | * implement the driver-specific bdrv_refresh_filename() function. | |
4227 | */ | |
4228 | qdict_put_obj(opts, "filename", | |
4229 | QOBJECT(qstring_from_str(bs->exact_filename))); | |
4230 | } | |
4231 | ||
4232 | bs->full_open_options = opts; | |
4233 | } | |
4234 | ||
4235 | if (bs->exact_filename[0]) { | |
4236 | pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); | |
4237 | } else if (bs->full_open_options) { | |
4238 | QString *json = qobject_to_json(QOBJECT(bs->full_open_options)); | |
4239 | snprintf(bs->filename, sizeof(bs->filename), "json:%s", | |
4240 | qstring_get_str(json)); | |
4241 | QDECREF(json); | |
4242 | } | |
4243 | } | |
4244 | ||
4245 | /* This accessor function purpose is to allow the device models to access the | |
4246 | * BlockAcctStats structure embedded inside a BlockDriverState without being | |
4247 | * aware of the BlockDriverState structure layout. | |
4248 | * It will go away when the BlockAcctStats structure will be moved inside | |
4249 | * the device models. | |
4250 | */ | |
4251 | BlockAcctStats *bdrv_get_stats(BlockDriverState *bs) | |
4252 | { | |
4253 | return &bs->stats; | |
4254 | } |