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1 | /* | |
2 | * QEMU System Emulator block driver | |
3 | * | |
4 | * Copyright (c) 2003 Fabrice Bellard | |
5 | * | |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | * THE SOFTWARE. | |
23 | */ | |
24 | #include "qemu/osdep.h" | |
25 | #include "trace.h" | |
26 | #include "block/block_int.h" | |
27 | #include "block/blockjob.h" | |
28 | #include "qemu/error-report.h" | |
29 | #include "qemu/module.h" | |
30 | #include "qapi/qmp/qerror.h" | |
31 | #include "qapi/qmp/qbool.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 "qemu/coroutine.h" | |
37 | #include "block/qapi.h" | |
38 | #include "qmp-commands.h" | |
39 | #include "qemu/timer.h" | |
40 | #include "qapi-event.h" | |
41 | #include "qemu/cutils.h" | |
42 | #include "qemu/id.h" | |
43 | ||
44 | #ifdef CONFIG_BSD | |
45 | #include <sys/ioctl.h> | |
46 | #include <sys/queue.h> | |
47 | #ifndef __DragonFly__ | |
48 | #include <sys/disk.h> | |
49 | #endif | |
50 | #endif | |
51 | ||
52 | #ifdef _WIN32 | |
53 | #include <windows.h> | |
54 | #endif | |
55 | ||
56 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ | |
57 | ||
58 | static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states = | |
59 | QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); | |
60 | ||
61 | static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states = | |
62 | QTAILQ_HEAD_INITIALIZER(all_bdrv_states); | |
63 | ||
64 | static QLIST_HEAD(, BlockDriver) bdrv_drivers = | |
65 | QLIST_HEAD_INITIALIZER(bdrv_drivers); | |
66 | ||
67 | static BlockDriverState *bdrv_open_inherit(const char *filename, | |
68 | const char *reference, | |
69 | QDict *options, int flags, | |
70 | BlockDriverState *parent, | |
71 | const BdrvChildRole *child_role, | |
72 | Error **errp); | |
73 | ||
74 | /* If non-zero, use only whitelisted block drivers */ | |
75 | static int use_bdrv_whitelist; | |
76 | ||
77 | #ifdef _WIN32 | |
78 | static int is_windows_drive_prefix(const char *filename) | |
79 | { | |
80 | return (((filename[0] >= 'a' && filename[0] <= 'z') || | |
81 | (filename[0] >= 'A' && filename[0] <= 'Z')) && | |
82 | filename[1] == ':'); | |
83 | } | |
84 | ||
85 | int is_windows_drive(const char *filename) | |
86 | { | |
87 | if (is_windows_drive_prefix(filename) && | |
88 | filename[2] == '\0') | |
89 | return 1; | |
90 | if (strstart(filename, "\\\\.\\", NULL) || | |
91 | strstart(filename, "//./", NULL)) | |
92 | return 1; | |
93 | return 0; | |
94 | } | |
95 | #endif | |
96 | ||
97 | size_t bdrv_opt_mem_align(BlockDriverState *bs) | |
98 | { | |
99 | if (!bs || !bs->drv) { | |
100 | /* page size or 4k (hdd sector size) should be on the safe side */ | |
101 | return MAX(4096, getpagesize()); | |
102 | } | |
103 | ||
104 | return bs->bl.opt_mem_alignment; | |
105 | } | |
106 | ||
107 | size_t bdrv_min_mem_align(BlockDriverState *bs) | |
108 | { | |
109 | if (!bs || !bs->drv) { | |
110 | /* page size or 4k (hdd sector size) should be on the safe side */ | |
111 | return MAX(4096, getpagesize()); | |
112 | } | |
113 | ||
114 | return bs->bl.min_mem_alignment; | |
115 | } | |
116 | ||
117 | /* check if the path starts with "<protocol>:" */ | |
118 | int path_has_protocol(const char *path) | |
119 | { | |
120 | const char *p; | |
121 | ||
122 | #ifdef _WIN32 | |
123 | if (is_windows_drive(path) || | |
124 | is_windows_drive_prefix(path)) { | |
125 | return 0; | |
126 | } | |
127 | p = path + strcspn(path, ":/\\"); | |
128 | #else | |
129 | p = path + strcspn(path, ":/"); | |
130 | #endif | |
131 | ||
132 | return *p == ':'; | |
133 | } | |
134 | ||
135 | int path_is_absolute(const char *path) | |
136 | { | |
137 | #ifdef _WIN32 | |
138 | /* specific case for names like: "\\.\d:" */ | |
139 | if (is_windows_drive(path) || is_windows_drive_prefix(path)) { | |
140 | return 1; | |
141 | } | |
142 | return (*path == '/' || *path == '\\'); | |
143 | #else | |
144 | return (*path == '/'); | |
145 | #endif | |
146 | } | |
147 | ||
148 | /* if filename is absolute, just copy it to dest. Otherwise, build a | |
149 | path to it by considering it is relative to base_path. URL are | |
150 | supported. */ | |
151 | void path_combine(char *dest, int dest_size, | |
152 | const char *base_path, | |
153 | const char *filename) | |
154 | { | |
155 | const char *p, *p1; | |
156 | int len; | |
157 | ||
158 | if (dest_size <= 0) | |
159 | return; | |
160 | if (path_is_absolute(filename)) { | |
161 | pstrcpy(dest, dest_size, filename); | |
162 | } else { | |
163 | p = strchr(base_path, ':'); | |
164 | if (p) | |
165 | p++; | |
166 | else | |
167 | p = base_path; | |
168 | p1 = strrchr(base_path, '/'); | |
169 | #ifdef _WIN32 | |
170 | { | |
171 | const char *p2; | |
172 | p2 = strrchr(base_path, '\\'); | |
173 | if (!p1 || p2 > p1) | |
174 | p1 = p2; | |
175 | } | |
176 | #endif | |
177 | if (p1) | |
178 | p1++; | |
179 | else | |
180 | p1 = base_path; | |
181 | if (p1 > p) | |
182 | p = p1; | |
183 | len = p - base_path; | |
184 | if (len > dest_size - 1) | |
185 | len = dest_size - 1; | |
186 | memcpy(dest, base_path, len); | |
187 | dest[len] = '\0'; | |
188 | pstrcat(dest, dest_size, filename); | |
189 | } | |
190 | } | |
191 | ||
192 | void bdrv_get_full_backing_filename_from_filename(const char *backed, | |
193 | const char *backing, | |
194 | char *dest, size_t sz, | |
195 | Error **errp) | |
196 | { | |
197 | if (backing[0] == '\0' || path_has_protocol(backing) || | |
198 | path_is_absolute(backing)) | |
199 | { | |
200 | pstrcpy(dest, sz, backing); | |
201 | } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) { | |
202 | error_setg(errp, "Cannot use relative backing file names for '%s'", | |
203 | backed); | |
204 | } else { | |
205 | path_combine(dest, sz, backed, backing); | |
206 | } | |
207 | } | |
208 | ||
209 | void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz, | |
210 | Error **errp) | |
211 | { | |
212 | char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename; | |
213 | ||
214 | bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file, | |
215 | dest, sz, errp); | |
216 | } | |
217 | ||
218 | void bdrv_register(BlockDriver *bdrv) | |
219 | { | |
220 | QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); | |
221 | } | |
222 | ||
223 | BlockDriverState *bdrv_new(void) | |
224 | { | |
225 | BlockDriverState *bs; | |
226 | int i; | |
227 | ||
228 | bs = g_new0(BlockDriverState, 1); | |
229 | QLIST_INIT(&bs->dirty_bitmaps); | |
230 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
231 | QLIST_INIT(&bs->op_blockers[i]); | |
232 | } | |
233 | notifier_with_return_list_init(&bs->before_write_notifiers); | |
234 | bs->refcnt = 1; | |
235 | bs->aio_context = qemu_get_aio_context(); | |
236 | ||
237 | QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list); | |
238 | ||
239 | return bs; | |
240 | } | |
241 | ||
242 | BlockDriver *bdrv_find_format(const char *format_name) | |
243 | { | |
244 | BlockDriver *drv1; | |
245 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
246 | if (!strcmp(drv1->format_name, format_name)) { | |
247 | return drv1; | |
248 | } | |
249 | } | |
250 | return NULL; | |
251 | } | |
252 | ||
253 | static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) | |
254 | { | |
255 | static const char *whitelist_rw[] = { | |
256 | CONFIG_BDRV_RW_WHITELIST | |
257 | }; | |
258 | static const char *whitelist_ro[] = { | |
259 | CONFIG_BDRV_RO_WHITELIST | |
260 | }; | |
261 | const char **p; | |
262 | ||
263 | if (!whitelist_rw[0] && !whitelist_ro[0]) { | |
264 | return 1; /* no whitelist, anything goes */ | |
265 | } | |
266 | ||
267 | for (p = whitelist_rw; *p; p++) { | |
268 | if (!strcmp(drv->format_name, *p)) { | |
269 | return 1; | |
270 | } | |
271 | } | |
272 | if (read_only) { | |
273 | for (p = whitelist_ro; *p; p++) { | |
274 | if (!strcmp(drv->format_name, *p)) { | |
275 | return 1; | |
276 | } | |
277 | } | |
278 | } | |
279 | return 0; | |
280 | } | |
281 | ||
282 | bool bdrv_uses_whitelist(void) | |
283 | { | |
284 | return use_bdrv_whitelist; | |
285 | } | |
286 | ||
287 | typedef struct CreateCo { | |
288 | BlockDriver *drv; | |
289 | char *filename; | |
290 | QemuOpts *opts; | |
291 | int ret; | |
292 | Error *err; | |
293 | } CreateCo; | |
294 | ||
295 | static void coroutine_fn bdrv_create_co_entry(void *opaque) | |
296 | { | |
297 | Error *local_err = NULL; | |
298 | int ret; | |
299 | ||
300 | CreateCo *cco = opaque; | |
301 | assert(cco->drv); | |
302 | ||
303 | ret = cco->drv->bdrv_create(cco->filename, cco->opts, &local_err); | |
304 | if (local_err) { | |
305 | error_propagate(&cco->err, local_err); | |
306 | } | |
307 | cco->ret = ret; | |
308 | } | |
309 | ||
310 | int bdrv_create(BlockDriver *drv, const char* filename, | |
311 | QemuOpts *opts, Error **errp) | |
312 | { | |
313 | int ret; | |
314 | ||
315 | Coroutine *co; | |
316 | CreateCo cco = { | |
317 | .drv = drv, | |
318 | .filename = g_strdup(filename), | |
319 | .opts = opts, | |
320 | .ret = NOT_DONE, | |
321 | .err = NULL, | |
322 | }; | |
323 | ||
324 | if (!drv->bdrv_create) { | |
325 | error_setg(errp, "Driver '%s' does not support image creation", drv->format_name); | |
326 | ret = -ENOTSUP; | |
327 | goto out; | |
328 | } | |
329 | ||
330 | if (qemu_in_coroutine()) { | |
331 | /* Fast-path if already in coroutine context */ | |
332 | bdrv_create_co_entry(&cco); | |
333 | } else { | |
334 | co = qemu_coroutine_create(bdrv_create_co_entry); | |
335 | qemu_coroutine_enter(co, &cco); | |
336 | while (cco.ret == NOT_DONE) { | |
337 | aio_poll(qemu_get_aio_context(), true); | |
338 | } | |
339 | } | |
340 | ||
341 | ret = cco.ret; | |
342 | if (ret < 0) { | |
343 | if (cco.err) { | |
344 | error_propagate(errp, cco.err); | |
345 | } else { | |
346 | error_setg_errno(errp, -ret, "Could not create image"); | |
347 | } | |
348 | } | |
349 | ||
350 | out: | |
351 | g_free(cco.filename); | |
352 | return ret; | |
353 | } | |
354 | ||
355 | int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp) | |
356 | { | |
357 | BlockDriver *drv; | |
358 | Error *local_err = NULL; | |
359 | int ret; | |
360 | ||
361 | drv = bdrv_find_protocol(filename, true, errp); | |
362 | if (drv == NULL) { | |
363 | return -ENOENT; | |
364 | } | |
365 | ||
366 | ret = bdrv_create(drv, filename, opts, &local_err); | |
367 | if (local_err) { | |
368 | error_propagate(errp, local_err); | |
369 | } | |
370 | return ret; | |
371 | } | |
372 | ||
373 | /** | |
374 | * Try to get @bs's logical and physical block size. | |
375 | * On success, store them in @bsz struct and return 0. | |
376 | * On failure return -errno. | |
377 | * @bs must not be empty. | |
378 | */ | |
379 | int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) | |
380 | { | |
381 | BlockDriver *drv = bs->drv; | |
382 | ||
383 | if (drv && drv->bdrv_probe_blocksizes) { | |
384 | return drv->bdrv_probe_blocksizes(bs, bsz); | |
385 | } | |
386 | ||
387 | return -ENOTSUP; | |
388 | } | |
389 | ||
390 | /** | |
391 | * Try to get @bs's geometry (cyls, heads, sectors). | |
392 | * On success, store them in @geo struct and return 0. | |
393 | * On failure return -errno. | |
394 | * @bs must not be empty. | |
395 | */ | |
396 | int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo) | |
397 | { | |
398 | BlockDriver *drv = bs->drv; | |
399 | ||
400 | if (drv && drv->bdrv_probe_geometry) { | |
401 | return drv->bdrv_probe_geometry(bs, geo); | |
402 | } | |
403 | ||
404 | return -ENOTSUP; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Create a uniquely-named empty temporary file. | |
409 | * Return 0 upon success, otherwise a negative errno value. | |
410 | */ | |
411 | int get_tmp_filename(char *filename, int size) | |
412 | { | |
413 | #ifdef _WIN32 | |
414 | char temp_dir[MAX_PATH]; | |
415 | /* GetTempFileName requires that its output buffer (4th param) | |
416 | have length MAX_PATH or greater. */ | |
417 | assert(size >= MAX_PATH); | |
418 | return (GetTempPath(MAX_PATH, temp_dir) | |
419 | && GetTempFileName(temp_dir, "qem", 0, filename) | |
420 | ? 0 : -GetLastError()); | |
421 | #else | |
422 | int fd; | |
423 | const char *tmpdir; | |
424 | tmpdir = getenv("TMPDIR"); | |
425 | if (!tmpdir) { | |
426 | tmpdir = "/var/tmp"; | |
427 | } | |
428 | if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) { | |
429 | return -EOVERFLOW; | |
430 | } | |
431 | fd = mkstemp(filename); | |
432 | if (fd < 0) { | |
433 | return -errno; | |
434 | } | |
435 | if (close(fd) != 0) { | |
436 | unlink(filename); | |
437 | return -errno; | |
438 | } | |
439 | return 0; | |
440 | #endif | |
441 | } | |
442 | ||
443 | /* | |
444 | * Detect host devices. By convention, /dev/cdrom[N] is always | |
445 | * recognized as a host CDROM. | |
446 | */ | |
447 | static BlockDriver *find_hdev_driver(const char *filename) | |
448 | { | |
449 | int score_max = 0, score; | |
450 | BlockDriver *drv = NULL, *d; | |
451 | ||
452 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
453 | if (d->bdrv_probe_device) { | |
454 | score = d->bdrv_probe_device(filename); | |
455 | if (score > score_max) { | |
456 | score_max = score; | |
457 | drv = d; | |
458 | } | |
459 | } | |
460 | } | |
461 | ||
462 | return drv; | |
463 | } | |
464 | ||
465 | BlockDriver *bdrv_find_protocol(const char *filename, | |
466 | bool allow_protocol_prefix, | |
467 | Error **errp) | |
468 | { | |
469 | BlockDriver *drv1; | |
470 | char protocol[128]; | |
471 | int len; | |
472 | const char *p; | |
473 | ||
474 | /* TODO Drivers without bdrv_file_open must be specified explicitly */ | |
475 | ||
476 | /* | |
477 | * XXX(hch): we really should not let host device detection | |
478 | * override an explicit protocol specification, but moving this | |
479 | * later breaks access to device names with colons in them. | |
480 | * Thanks to the brain-dead persistent naming schemes on udev- | |
481 | * based Linux systems those actually are quite common. | |
482 | */ | |
483 | drv1 = find_hdev_driver(filename); | |
484 | if (drv1) { | |
485 | return drv1; | |
486 | } | |
487 | ||
488 | if (!path_has_protocol(filename) || !allow_protocol_prefix) { | |
489 | return &bdrv_file; | |
490 | } | |
491 | ||
492 | p = strchr(filename, ':'); | |
493 | assert(p != NULL); | |
494 | len = p - filename; | |
495 | if (len > sizeof(protocol) - 1) | |
496 | len = sizeof(protocol) - 1; | |
497 | memcpy(protocol, filename, len); | |
498 | protocol[len] = '\0'; | |
499 | QLIST_FOREACH(drv1, &bdrv_drivers, list) { | |
500 | if (drv1->protocol_name && | |
501 | !strcmp(drv1->protocol_name, protocol)) { | |
502 | return drv1; | |
503 | } | |
504 | } | |
505 | ||
506 | error_setg(errp, "Unknown protocol '%s'", protocol); | |
507 | return NULL; | |
508 | } | |
509 | ||
510 | /* | |
511 | * Guess image format by probing its contents. | |
512 | * This is not a good idea when your image is raw (CVE-2008-2004), but | |
513 | * we do it anyway for backward compatibility. | |
514 | * | |
515 | * @buf contains the image's first @buf_size bytes. | |
516 | * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE, | |
517 | * but can be smaller if the image file is smaller) | |
518 | * @filename is its filename. | |
519 | * | |
520 | * For all block drivers, call the bdrv_probe() method to get its | |
521 | * probing score. | |
522 | * Return the first block driver with the highest probing score. | |
523 | */ | |
524 | BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, | |
525 | const char *filename) | |
526 | { | |
527 | int score_max = 0, score; | |
528 | BlockDriver *drv = NULL, *d; | |
529 | ||
530 | QLIST_FOREACH(d, &bdrv_drivers, list) { | |
531 | if (d->bdrv_probe) { | |
532 | score = d->bdrv_probe(buf, buf_size, filename); | |
533 | if (score > score_max) { | |
534 | score_max = score; | |
535 | drv = d; | |
536 | } | |
537 | } | |
538 | } | |
539 | ||
540 | return drv; | |
541 | } | |
542 | ||
543 | static int find_image_format(BlockDriverState *bs, const char *filename, | |
544 | BlockDriver **pdrv, Error **errp) | |
545 | { | |
546 | BlockDriver *drv; | |
547 | uint8_t buf[BLOCK_PROBE_BUF_SIZE]; | |
548 | int ret = 0; | |
549 | ||
550 | /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ | |
551 | if (bdrv_is_sg(bs) || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) { | |
552 | *pdrv = &bdrv_raw; | |
553 | return ret; | |
554 | } | |
555 | ||
556 | ret = bdrv_pread(bs, 0, buf, sizeof(buf)); | |
557 | if (ret < 0) { | |
558 | error_setg_errno(errp, -ret, "Could not read image for determining its " | |
559 | "format"); | |
560 | *pdrv = NULL; | |
561 | return ret; | |
562 | } | |
563 | ||
564 | drv = bdrv_probe_all(buf, ret, filename); | |
565 | if (!drv) { | |
566 | error_setg(errp, "Could not determine image format: No compatible " | |
567 | "driver found"); | |
568 | ret = -ENOENT; | |
569 | } | |
570 | *pdrv = drv; | |
571 | return ret; | |
572 | } | |
573 | ||
574 | /** | |
575 | * Set the current 'total_sectors' value | |
576 | * Return 0 on success, -errno on error. | |
577 | */ | |
578 | static int refresh_total_sectors(BlockDriverState *bs, int64_t hint) | |
579 | { | |
580 | BlockDriver *drv = bs->drv; | |
581 | ||
582 | /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */ | |
583 | if (bdrv_is_sg(bs)) | |
584 | return 0; | |
585 | ||
586 | /* query actual device if possible, otherwise just trust the hint */ | |
587 | if (drv->bdrv_getlength) { | |
588 | int64_t length = drv->bdrv_getlength(bs); | |
589 | if (length < 0) { | |
590 | return length; | |
591 | } | |
592 | hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE); | |
593 | } | |
594 | ||
595 | bs->total_sectors = hint; | |
596 | return 0; | |
597 | } | |
598 | ||
599 | /** | |
600 | * Combines a QDict of new block driver @options with any missing options taken | |
601 | * from @old_options, so that leaving out an option defaults to its old value. | |
602 | */ | |
603 | static void bdrv_join_options(BlockDriverState *bs, QDict *options, | |
604 | QDict *old_options) | |
605 | { | |
606 | if (bs->drv && bs->drv->bdrv_join_options) { | |
607 | bs->drv->bdrv_join_options(options, old_options); | |
608 | } else { | |
609 | qdict_join(options, old_options, false); | |
610 | } | |
611 | } | |
612 | ||
613 | /** | |
614 | * Set open flags for a given discard mode | |
615 | * | |
616 | * Return 0 on success, -1 if the discard mode was invalid. | |
617 | */ | |
618 | int bdrv_parse_discard_flags(const char *mode, int *flags) | |
619 | { | |
620 | *flags &= ~BDRV_O_UNMAP; | |
621 | ||
622 | if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) { | |
623 | /* do nothing */ | |
624 | } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) { | |
625 | *flags |= BDRV_O_UNMAP; | |
626 | } else { | |
627 | return -1; | |
628 | } | |
629 | ||
630 | return 0; | |
631 | } | |
632 | ||
633 | /** | |
634 | * Set open flags for a given cache mode | |
635 | * | |
636 | * Return 0 on success, -1 if the cache mode was invalid. | |
637 | */ | |
638 | int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough) | |
639 | { | |
640 | *flags &= ~BDRV_O_CACHE_MASK; | |
641 | ||
642 | if (!strcmp(mode, "off") || !strcmp(mode, "none")) { | |
643 | *writethrough = false; | |
644 | *flags |= BDRV_O_NOCACHE; | |
645 | } else if (!strcmp(mode, "directsync")) { | |
646 | *writethrough = true; | |
647 | *flags |= BDRV_O_NOCACHE; | |
648 | } else if (!strcmp(mode, "writeback")) { | |
649 | *writethrough = false; | |
650 | } else if (!strcmp(mode, "unsafe")) { | |
651 | *writethrough = false; | |
652 | *flags |= BDRV_O_NO_FLUSH; | |
653 | } else if (!strcmp(mode, "writethrough")) { | |
654 | *writethrough = true; | |
655 | } else { | |
656 | return -1; | |
657 | } | |
658 | ||
659 | return 0; | |
660 | } | |
661 | ||
662 | static void bdrv_child_cb_drained_begin(BdrvChild *child) | |
663 | { | |
664 | BlockDriverState *bs = child->opaque; | |
665 | bdrv_drained_begin(bs); | |
666 | } | |
667 | ||
668 | static void bdrv_child_cb_drained_end(BdrvChild *child) | |
669 | { | |
670 | BlockDriverState *bs = child->opaque; | |
671 | bdrv_drained_end(bs); | |
672 | } | |
673 | ||
674 | /* | |
675 | * Returns the options and flags that a temporary snapshot should get, based on | |
676 | * the originally requested flags (the originally requested image will have | |
677 | * flags like a backing file) | |
678 | */ | |
679 | static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options, | |
680 | int parent_flags, QDict *parent_options) | |
681 | { | |
682 | *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY; | |
683 | ||
684 | /* For temporary files, unconditional cache=unsafe is fine */ | |
685 | qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off"); | |
686 | qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on"); | |
687 | ||
688 | /* aio=native doesn't work for cache.direct=off, so disable it for the | |
689 | * temporary snapshot */ | |
690 | *child_flags &= ~BDRV_O_NATIVE_AIO; | |
691 | } | |
692 | ||
693 | /* | |
694 | * Returns the options and flags that bs->file should get if a protocol driver | |
695 | * is expected, based on the given options and flags for the parent BDS | |
696 | */ | |
697 | static void bdrv_inherited_options(int *child_flags, QDict *child_options, | |
698 | int parent_flags, QDict *parent_options) | |
699 | { | |
700 | int flags = parent_flags; | |
701 | ||
702 | /* Enable protocol handling, disable format probing for bs->file */ | |
703 | flags |= BDRV_O_PROTOCOL; | |
704 | ||
705 | /* If the cache mode isn't explicitly set, inherit direct and no-flush from | |
706 | * the parent. */ | |
707 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); | |
708 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); | |
709 | ||
710 | /* Our block drivers take care to send flushes and respect unmap policy, | |
711 | * so we can default to enable both on lower layers regardless of the | |
712 | * corresponding parent options. */ | |
713 | flags |= BDRV_O_UNMAP; | |
714 | ||
715 | /* Clear flags that only apply to the top layer */ | |
716 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ | | |
717 | BDRV_O_NO_IO); | |
718 | ||
719 | *child_flags = flags; | |
720 | } | |
721 | ||
722 | const BdrvChildRole child_file = { | |
723 | .inherit_options = bdrv_inherited_options, | |
724 | .drained_begin = bdrv_child_cb_drained_begin, | |
725 | .drained_end = bdrv_child_cb_drained_end, | |
726 | }; | |
727 | ||
728 | /* | |
729 | * Returns the options and flags that bs->file should get if the use of formats | |
730 | * (and not only protocols) is permitted for it, based on the given options and | |
731 | * flags for the parent BDS | |
732 | */ | |
733 | static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options, | |
734 | int parent_flags, QDict *parent_options) | |
735 | { | |
736 | child_file.inherit_options(child_flags, child_options, | |
737 | parent_flags, parent_options); | |
738 | ||
739 | *child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO); | |
740 | } | |
741 | ||
742 | const BdrvChildRole child_format = { | |
743 | .inherit_options = bdrv_inherited_fmt_options, | |
744 | .drained_begin = bdrv_child_cb_drained_begin, | |
745 | .drained_end = bdrv_child_cb_drained_end, | |
746 | }; | |
747 | ||
748 | /* | |
749 | * Returns the options and flags that bs->backing should get, based on the | |
750 | * given options and flags for the parent BDS | |
751 | */ | |
752 | static void bdrv_backing_options(int *child_flags, QDict *child_options, | |
753 | int parent_flags, QDict *parent_options) | |
754 | { | |
755 | int flags = parent_flags; | |
756 | ||
757 | /* The cache mode is inherited unmodified for backing files; except WCE, | |
758 | * which is only applied on the top level (BlockBackend) */ | |
759 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); | |
760 | qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); | |
761 | ||
762 | /* backing files always opened read-only */ | |
763 | flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ); | |
764 | ||
765 | /* snapshot=on is handled on the top layer */ | |
766 | flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); | |
767 | ||
768 | *child_flags = flags; | |
769 | } | |
770 | ||
771 | static const BdrvChildRole child_backing = { | |
772 | .inherit_options = bdrv_backing_options, | |
773 | .drained_begin = bdrv_child_cb_drained_begin, | |
774 | .drained_end = bdrv_child_cb_drained_end, | |
775 | }; | |
776 | ||
777 | static int bdrv_open_flags(BlockDriverState *bs, int flags) | |
778 | { | |
779 | int open_flags = flags; | |
780 | ||
781 | /* | |
782 | * Clear flags that are internal to the block layer before opening the | |
783 | * image. | |
784 | */ | |
785 | open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL); | |
786 | ||
787 | /* | |
788 | * Snapshots should be writable. | |
789 | */ | |
790 | if (flags & BDRV_O_TEMPORARY) { | |
791 | open_flags |= BDRV_O_RDWR; | |
792 | } | |
793 | ||
794 | return open_flags; | |
795 | } | |
796 | ||
797 | static void update_flags_from_options(int *flags, QemuOpts *opts) | |
798 | { | |
799 | *flags &= ~BDRV_O_CACHE_MASK; | |
800 | ||
801 | assert(qemu_opt_find(opts, BDRV_OPT_CACHE_NO_FLUSH)); | |
802 | if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) { | |
803 | *flags |= BDRV_O_NO_FLUSH; | |
804 | } | |
805 | ||
806 | assert(qemu_opt_find(opts, BDRV_OPT_CACHE_DIRECT)); | |
807 | if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) { | |
808 | *flags |= BDRV_O_NOCACHE; | |
809 | } | |
810 | } | |
811 | ||
812 | static void update_options_from_flags(QDict *options, int flags) | |
813 | { | |
814 | if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) { | |
815 | qdict_put(options, BDRV_OPT_CACHE_DIRECT, | |
816 | qbool_from_bool(flags & BDRV_O_NOCACHE)); | |
817 | } | |
818 | if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) { | |
819 | qdict_put(options, BDRV_OPT_CACHE_NO_FLUSH, | |
820 | qbool_from_bool(flags & BDRV_O_NO_FLUSH)); | |
821 | } | |
822 | } | |
823 | ||
824 | static void bdrv_assign_node_name(BlockDriverState *bs, | |
825 | const char *node_name, | |
826 | Error **errp) | |
827 | { | |
828 | char *gen_node_name = NULL; | |
829 | ||
830 | if (!node_name) { | |
831 | node_name = gen_node_name = id_generate(ID_BLOCK); | |
832 | } else if (!id_wellformed(node_name)) { | |
833 | /* | |
834 | * Check for empty string or invalid characters, but not if it is | |
835 | * generated (generated names use characters not available to the user) | |
836 | */ | |
837 | error_setg(errp, "Invalid node name"); | |
838 | return; | |
839 | } | |
840 | ||
841 | /* takes care of avoiding namespaces collisions */ | |
842 | if (blk_by_name(node_name)) { | |
843 | error_setg(errp, "node-name=%s is conflicting with a device id", | |
844 | node_name); | |
845 | goto out; | |
846 | } | |
847 | ||
848 | /* takes care of avoiding duplicates node names */ | |
849 | if (bdrv_find_node(node_name)) { | |
850 | error_setg(errp, "Duplicate node name"); | |
851 | goto out; | |
852 | } | |
853 | ||
854 | /* copy node name into the bs and insert it into the graph list */ | |
855 | pstrcpy(bs->node_name, sizeof(bs->node_name), node_name); | |
856 | QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list); | |
857 | out: | |
858 | g_free(gen_node_name); | |
859 | } | |
860 | ||
861 | static QemuOptsList bdrv_runtime_opts = { | |
862 | .name = "bdrv_common", | |
863 | .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head), | |
864 | .desc = { | |
865 | { | |
866 | .name = "node-name", | |
867 | .type = QEMU_OPT_STRING, | |
868 | .help = "Node name of the block device node", | |
869 | }, | |
870 | { | |
871 | .name = "driver", | |
872 | .type = QEMU_OPT_STRING, | |
873 | .help = "Block driver to use for the node", | |
874 | }, | |
875 | { | |
876 | .name = BDRV_OPT_CACHE_DIRECT, | |
877 | .type = QEMU_OPT_BOOL, | |
878 | .help = "Bypass software writeback cache on the host", | |
879 | }, | |
880 | { | |
881 | .name = BDRV_OPT_CACHE_NO_FLUSH, | |
882 | .type = QEMU_OPT_BOOL, | |
883 | .help = "Ignore flush requests", | |
884 | }, | |
885 | { /* end of list */ } | |
886 | }, | |
887 | }; | |
888 | ||
889 | /* | |
890 | * Common part for opening disk images and files | |
891 | * | |
892 | * Removes all processed options from *options. | |
893 | */ | |
894 | static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file, | |
895 | QDict *options, Error **errp) | |
896 | { | |
897 | int ret, open_flags; | |
898 | const char *filename; | |
899 | const char *driver_name = NULL; | |
900 | const char *node_name = NULL; | |
901 | QemuOpts *opts; | |
902 | BlockDriver *drv; | |
903 | Error *local_err = NULL; | |
904 | ||
905 | assert(bs->file == NULL); | |
906 | assert(options != NULL && bs->options != options); | |
907 | ||
908 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); | |
909 | qemu_opts_absorb_qdict(opts, options, &local_err); | |
910 | if (local_err) { | |
911 | error_propagate(errp, local_err); | |
912 | ret = -EINVAL; | |
913 | goto fail_opts; | |
914 | } | |
915 | ||
916 | driver_name = qemu_opt_get(opts, "driver"); | |
917 | drv = bdrv_find_format(driver_name); | |
918 | assert(drv != NULL); | |
919 | ||
920 | if (file != NULL) { | |
921 | filename = file->bs->filename; | |
922 | } else { | |
923 | filename = qdict_get_try_str(options, "filename"); | |
924 | } | |
925 | ||
926 | if (drv->bdrv_needs_filename && !filename) { | |
927 | error_setg(errp, "The '%s' block driver requires a file name", | |
928 | drv->format_name); | |
929 | ret = -EINVAL; | |
930 | goto fail_opts; | |
931 | } | |
932 | ||
933 | trace_bdrv_open_common(bs, filename ?: "", bs->open_flags, | |
934 | drv->format_name); | |
935 | ||
936 | node_name = qemu_opt_get(opts, "node-name"); | |
937 | bdrv_assign_node_name(bs, node_name, &local_err); | |
938 | if (local_err) { | |
939 | error_propagate(errp, local_err); | |
940 | ret = -EINVAL; | |
941 | goto fail_opts; | |
942 | } | |
943 | ||
944 | bs->request_alignment = drv->bdrv_co_preadv ? 1 : 512; | |
945 | bs->read_only = !(bs->open_flags & BDRV_O_RDWR); | |
946 | ||
947 | if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) { | |
948 | error_setg(errp, | |
949 | !bs->read_only && bdrv_is_whitelisted(drv, true) | |
950 | ? "Driver '%s' can only be used for read-only devices" | |
951 | : "Driver '%s' is not whitelisted", | |
952 | drv->format_name); | |
953 | ret = -ENOTSUP; | |
954 | goto fail_opts; | |
955 | } | |
956 | ||
957 | assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ | |
958 | if (bs->open_flags & BDRV_O_COPY_ON_READ) { | |
959 | if (!bs->read_only) { | |
960 | bdrv_enable_copy_on_read(bs); | |
961 | } else { | |
962 | error_setg(errp, "Can't use copy-on-read on read-only device"); | |
963 | ret = -EINVAL; | |
964 | goto fail_opts; | |
965 | } | |
966 | } | |
967 | ||
968 | if (filename != NULL) { | |
969 | pstrcpy(bs->filename, sizeof(bs->filename), filename); | |
970 | } else { | |
971 | bs->filename[0] = '\0'; | |
972 | } | |
973 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename); | |
974 | ||
975 | bs->drv = drv; | |
976 | bs->opaque = g_malloc0(drv->instance_size); | |
977 | ||
978 | /* Apply cache mode options */ | |
979 | update_flags_from_options(&bs->open_flags, opts); | |
980 | ||
981 | /* Open the image, either directly or using a protocol */ | |
982 | open_flags = bdrv_open_flags(bs, bs->open_flags); | |
983 | if (drv->bdrv_file_open) { | |
984 | assert(file == NULL); | |
985 | assert(!drv->bdrv_needs_filename || filename != NULL); | |
986 | ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); | |
987 | } else { | |
988 | if (file == NULL) { | |
989 | error_setg(errp, "Can't use '%s' as a block driver for the " | |
990 | "protocol level", drv->format_name); | |
991 | ret = -EINVAL; | |
992 | goto free_and_fail; | |
993 | } | |
994 | bs->file = file; | |
995 | ret = drv->bdrv_open(bs, options, open_flags, &local_err); | |
996 | } | |
997 | ||
998 | if (ret < 0) { | |
999 | if (local_err) { | |
1000 | error_propagate(errp, local_err); | |
1001 | } else if (bs->filename[0]) { | |
1002 | error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename); | |
1003 | } else { | |
1004 | error_setg_errno(errp, -ret, "Could not open image"); | |
1005 | } | |
1006 | goto free_and_fail; | |
1007 | } | |
1008 | ||
1009 | ret = refresh_total_sectors(bs, bs->total_sectors); | |
1010 | if (ret < 0) { | |
1011 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
1012 | goto free_and_fail; | |
1013 | } | |
1014 | ||
1015 | bdrv_refresh_limits(bs, &local_err); | |
1016 | if (local_err) { | |
1017 | error_propagate(errp, local_err); | |
1018 | ret = -EINVAL; | |
1019 | goto free_and_fail; | |
1020 | } | |
1021 | ||
1022 | assert(bdrv_opt_mem_align(bs) != 0); | |
1023 | assert(bdrv_min_mem_align(bs) != 0); | |
1024 | assert(is_power_of_2(bs->request_alignment) || bdrv_is_sg(bs)); | |
1025 | ||
1026 | qemu_opts_del(opts); | |
1027 | return 0; | |
1028 | ||
1029 | free_and_fail: | |
1030 | bs->file = NULL; | |
1031 | g_free(bs->opaque); | |
1032 | bs->opaque = NULL; | |
1033 | bs->drv = NULL; | |
1034 | fail_opts: | |
1035 | qemu_opts_del(opts); | |
1036 | return ret; | |
1037 | } | |
1038 | ||
1039 | static QDict *parse_json_filename(const char *filename, Error **errp) | |
1040 | { | |
1041 | QObject *options_obj; | |
1042 | QDict *options; | |
1043 | int ret; | |
1044 | ||
1045 | ret = strstart(filename, "json:", &filename); | |
1046 | assert(ret); | |
1047 | ||
1048 | options_obj = qobject_from_json(filename); | |
1049 | if (!options_obj) { | |
1050 | error_setg(errp, "Could not parse the JSON options"); | |
1051 | return NULL; | |
1052 | } | |
1053 | ||
1054 | if (qobject_type(options_obj) != QTYPE_QDICT) { | |
1055 | qobject_decref(options_obj); | |
1056 | error_setg(errp, "Invalid JSON object given"); | |
1057 | return NULL; | |
1058 | } | |
1059 | ||
1060 | options = qobject_to_qdict(options_obj); | |
1061 | qdict_flatten(options); | |
1062 | ||
1063 | return options; | |
1064 | } | |
1065 | ||
1066 | static void parse_json_protocol(QDict *options, const char **pfilename, | |
1067 | Error **errp) | |
1068 | { | |
1069 | QDict *json_options; | |
1070 | Error *local_err = NULL; | |
1071 | ||
1072 | /* Parse json: pseudo-protocol */ | |
1073 | if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) { | |
1074 | return; | |
1075 | } | |
1076 | ||
1077 | json_options = parse_json_filename(*pfilename, &local_err); | |
1078 | if (local_err) { | |
1079 | error_propagate(errp, local_err); | |
1080 | return; | |
1081 | } | |
1082 | ||
1083 | /* Options given in the filename have lower priority than options | |
1084 | * specified directly */ | |
1085 | qdict_join(options, json_options, false); | |
1086 | QDECREF(json_options); | |
1087 | *pfilename = NULL; | |
1088 | } | |
1089 | ||
1090 | /* | |
1091 | * Fills in default options for opening images and converts the legacy | |
1092 | * filename/flags pair to option QDict entries. | |
1093 | * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a | |
1094 | * block driver has been specified explicitly. | |
1095 | */ | |
1096 | static int bdrv_fill_options(QDict **options, const char *filename, | |
1097 | int *flags, Error **errp) | |
1098 | { | |
1099 | const char *drvname; | |
1100 | bool protocol = *flags & BDRV_O_PROTOCOL; | |
1101 | bool parse_filename = false; | |
1102 | BlockDriver *drv = NULL; | |
1103 | Error *local_err = NULL; | |
1104 | ||
1105 | drvname = qdict_get_try_str(*options, "driver"); | |
1106 | if (drvname) { | |
1107 | drv = bdrv_find_format(drvname); | |
1108 | if (!drv) { | |
1109 | error_setg(errp, "Unknown driver '%s'", drvname); | |
1110 | return -ENOENT; | |
1111 | } | |
1112 | /* If the user has explicitly specified the driver, this choice should | |
1113 | * override the BDRV_O_PROTOCOL flag */ | |
1114 | protocol = drv->bdrv_file_open; | |
1115 | } | |
1116 | ||
1117 | if (protocol) { | |
1118 | *flags |= BDRV_O_PROTOCOL; | |
1119 | } else { | |
1120 | *flags &= ~BDRV_O_PROTOCOL; | |
1121 | } | |
1122 | ||
1123 | /* Translate cache options from flags into options */ | |
1124 | update_options_from_flags(*options, *flags); | |
1125 | ||
1126 | /* Fetch the file name from the options QDict if necessary */ | |
1127 | if (protocol && filename) { | |
1128 | if (!qdict_haskey(*options, "filename")) { | |
1129 | qdict_put(*options, "filename", qstring_from_str(filename)); | |
1130 | parse_filename = true; | |
1131 | } else { | |
1132 | error_setg(errp, "Can't specify 'file' and 'filename' options at " | |
1133 | "the same time"); | |
1134 | return -EINVAL; | |
1135 | } | |
1136 | } | |
1137 | ||
1138 | /* Find the right block driver */ | |
1139 | filename = qdict_get_try_str(*options, "filename"); | |
1140 | ||
1141 | if (!drvname && protocol) { | |
1142 | if (filename) { | |
1143 | drv = bdrv_find_protocol(filename, parse_filename, errp); | |
1144 | if (!drv) { | |
1145 | return -EINVAL; | |
1146 | } | |
1147 | ||
1148 | drvname = drv->format_name; | |
1149 | qdict_put(*options, "driver", qstring_from_str(drvname)); | |
1150 | } else { | |
1151 | error_setg(errp, "Must specify either driver or file"); | |
1152 | return -EINVAL; | |
1153 | } | |
1154 | } | |
1155 | ||
1156 | assert(drv || !protocol); | |
1157 | ||
1158 | /* Driver-specific filename parsing */ | |
1159 | if (drv && drv->bdrv_parse_filename && parse_filename) { | |
1160 | drv->bdrv_parse_filename(filename, *options, &local_err); | |
1161 | if (local_err) { | |
1162 | error_propagate(errp, local_err); | |
1163 | return -EINVAL; | |
1164 | } | |
1165 | ||
1166 | if (!drv->bdrv_needs_filename) { | |
1167 | qdict_del(*options, "filename"); | |
1168 | } | |
1169 | } | |
1170 | ||
1171 | return 0; | |
1172 | } | |
1173 | ||
1174 | static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) | |
1175 | { | |
1176 | BlockDriverState *old_bs = child->bs; | |
1177 | ||
1178 | if (old_bs) { | |
1179 | if (old_bs->quiesce_counter && child->role->drained_end) { | |
1180 | child->role->drained_end(child); | |
1181 | } | |
1182 | QLIST_REMOVE(child, next_parent); | |
1183 | } | |
1184 | ||
1185 | child->bs = new_bs; | |
1186 | ||
1187 | if (new_bs) { | |
1188 | QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent); | |
1189 | if (new_bs->quiesce_counter && child->role->drained_begin) { | |
1190 | child->role->drained_begin(child); | |
1191 | } | |
1192 | } | |
1193 | } | |
1194 | ||
1195 | BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, | |
1196 | const char *child_name, | |
1197 | const BdrvChildRole *child_role, | |
1198 | void *opaque) | |
1199 | { | |
1200 | BdrvChild *child = g_new(BdrvChild, 1); | |
1201 | *child = (BdrvChild) { | |
1202 | .bs = NULL, | |
1203 | .name = g_strdup(child_name), | |
1204 | .role = child_role, | |
1205 | .opaque = opaque, | |
1206 | }; | |
1207 | ||
1208 | bdrv_replace_child(child, child_bs); | |
1209 | ||
1210 | return child; | |
1211 | } | |
1212 | ||
1213 | BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, | |
1214 | BlockDriverState *child_bs, | |
1215 | const char *child_name, | |
1216 | const BdrvChildRole *child_role) | |
1217 | { | |
1218 | BdrvChild *child = bdrv_root_attach_child(child_bs, child_name, child_role, | |
1219 | parent_bs); | |
1220 | QLIST_INSERT_HEAD(&parent_bs->children, child, next); | |
1221 | return child; | |
1222 | } | |
1223 | ||
1224 | static void bdrv_detach_child(BdrvChild *child) | |
1225 | { | |
1226 | if (child->next.le_prev) { | |
1227 | QLIST_REMOVE(child, next); | |
1228 | child->next.le_prev = NULL; | |
1229 | } | |
1230 | ||
1231 | bdrv_replace_child(child, NULL); | |
1232 | ||
1233 | g_free(child->name); | |
1234 | g_free(child); | |
1235 | } | |
1236 | ||
1237 | void bdrv_root_unref_child(BdrvChild *child) | |
1238 | { | |
1239 | BlockDriverState *child_bs; | |
1240 | ||
1241 | child_bs = child->bs; | |
1242 | bdrv_detach_child(child); | |
1243 | bdrv_unref(child_bs); | |
1244 | } | |
1245 | ||
1246 | void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) | |
1247 | { | |
1248 | if (child == NULL) { | |
1249 | return; | |
1250 | } | |
1251 | ||
1252 | if (child->bs->inherits_from == parent) { | |
1253 | child->bs->inherits_from = NULL; | |
1254 | } | |
1255 | ||
1256 | bdrv_root_unref_child(child); | |
1257 | } | |
1258 | ||
1259 | ||
1260 | static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load) | |
1261 | { | |
1262 | BdrvChild *c; | |
1263 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
1264 | if (c->role->change_media) { | |
1265 | c->role->change_media(c, load); | |
1266 | } | |
1267 | } | |
1268 | } | |
1269 | ||
1270 | static void bdrv_parent_cb_resize(BlockDriverState *bs) | |
1271 | { | |
1272 | BdrvChild *c; | |
1273 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
1274 | if (c->role->resize) { | |
1275 | c->role->resize(c); | |
1276 | } | |
1277 | } | |
1278 | } | |
1279 | ||
1280 | /* | |
1281 | * Sets the backing file link of a BDS. A new reference is created; callers | |
1282 | * which don't need their own reference any more must call bdrv_unref(). | |
1283 | */ | |
1284 | void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) | |
1285 | { | |
1286 | if (backing_hd) { | |
1287 | bdrv_ref(backing_hd); | |
1288 | } | |
1289 | ||
1290 | if (bs->backing) { | |
1291 | assert(bs->backing_blocker); | |
1292 | bdrv_op_unblock_all(bs->backing->bs, bs->backing_blocker); | |
1293 | bdrv_unref_child(bs, bs->backing); | |
1294 | } else if (backing_hd) { | |
1295 | error_setg(&bs->backing_blocker, | |
1296 | "node is used as backing hd of '%s'", | |
1297 | bdrv_get_device_or_node_name(bs)); | |
1298 | } | |
1299 | ||
1300 | if (!backing_hd) { | |
1301 | error_free(bs->backing_blocker); | |
1302 | bs->backing_blocker = NULL; | |
1303 | bs->backing = NULL; | |
1304 | goto out; | |
1305 | } | |
1306 | bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing); | |
1307 | bs->open_flags &= ~BDRV_O_NO_BACKING; | |
1308 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); | |
1309 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), | |
1310 | backing_hd->drv ? backing_hd->drv->format_name : ""); | |
1311 | ||
1312 | bdrv_op_block_all(backing_hd, bs->backing_blocker); | |
1313 | /* Otherwise we won't be able to commit due to check in bdrv_commit */ | |
1314 | bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, | |
1315 | bs->backing_blocker); | |
1316 | out: | |
1317 | bdrv_refresh_limits(bs, NULL); | |
1318 | } | |
1319 | ||
1320 | /* | |
1321 | * Opens the backing file for a BlockDriverState if not yet open | |
1322 | * | |
1323 | * bdref_key specifies the key for the image's BlockdevRef in the options QDict. | |
1324 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict | |
1325 | * itself, all options starting with "${bdref_key}." are considered part of the | |
1326 | * BlockdevRef. | |
1327 | * | |
1328 | * TODO Can this be unified with bdrv_open_image()? | |
1329 | */ | |
1330 | int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, | |
1331 | const char *bdref_key, Error **errp) | |
1332 | { | |
1333 | char *backing_filename = g_malloc0(PATH_MAX); | |
1334 | char *bdref_key_dot; | |
1335 | const char *reference = NULL; | |
1336 | int ret = 0; | |
1337 | BlockDriverState *backing_hd; | |
1338 | QDict *options; | |
1339 | QDict *tmp_parent_options = NULL; | |
1340 | Error *local_err = NULL; | |
1341 | ||
1342 | if (bs->backing != NULL) { | |
1343 | goto free_exit; | |
1344 | } | |
1345 | ||
1346 | /* NULL means an empty set of options */ | |
1347 | if (parent_options == NULL) { | |
1348 | tmp_parent_options = qdict_new(); | |
1349 | parent_options = tmp_parent_options; | |
1350 | } | |
1351 | ||
1352 | bs->open_flags &= ~BDRV_O_NO_BACKING; | |
1353 | ||
1354 | bdref_key_dot = g_strdup_printf("%s.", bdref_key); | |
1355 | qdict_extract_subqdict(parent_options, &options, bdref_key_dot); | |
1356 | g_free(bdref_key_dot); | |
1357 | ||
1358 | reference = qdict_get_try_str(parent_options, bdref_key); | |
1359 | if (reference || qdict_haskey(options, "file.filename")) { | |
1360 | backing_filename[0] = '\0'; | |
1361 | } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { | |
1362 | QDECREF(options); | |
1363 | goto free_exit; | |
1364 | } else { | |
1365 | bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX, | |
1366 | &local_err); | |
1367 | if (local_err) { | |
1368 | ret = -EINVAL; | |
1369 | error_propagate(errp, local_err); | |
1370 | QDECREF(options); | |
1371 | goto free_exit; | |
1372 | } | |
1373 | } | |
1374 | ||
1375 | if (!bs->drv || !bs->drv->supports_backing) { | |
1376 | ret = -EINVAL; | |
1377 | error_setg(errp, "Driver doesn't support backing files"); | |
1378 | QDECREF(options); | |
1379 | goto free_exit; | |
1380 | } | |
1381 | ||
1382 | if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { | |
1383 | qdict_put(options, "driver", qstring_from_str(bs->backing_format)); | |
1384 | } | |
1385 | ||
1386 | backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL, | |
1387 | reference, options, 0, bs, &child_backing, | |
1388 | errp); | |
1389 | if (!backing_hd) { | |
1390 | bs->open_flags |= BDRV_O_NO_BACKING; | |
1391 | error_prepend(errp, "Could not open backing file: "); | |
1392 | ret = -EINVAL; | |
1393 | goto free_exit; | |
1394 | } | |
1395 | ||
1396 | /* Hook up the backing file link; drop our reference, bs owns the | |
1397 | * backing_hd reference now */ | |
1398 | bdrv_set_backing_hd(bs, backing_hd); | |
1399 | bdrv_unref(backing_hd); | |
1400 | ||
1401 | qdict_del(parent_options, bdref_key); | |
1402 | ||
1403 | free_exit: | |
1404 | g_free(backing_filename); | |
1405 | QDECREF(tmp_parent_options); | |
1406 | return ret; | |
1407 | } | |
1408 | ||
1409 | /* | |
1410 | * Opens a disk image whose options are given as BlockdevRef in another block | |
1411 | * device's options. | |
1412 | * | |
1413 | * If allow_none is true, no image will be opened if filename is false and no | |
1414 | * BlockdevRef is given. NULL will be returned, but errp remains unset. | |
1415 | * | |
1416 | * bdrev_key specifies the key for the image's BlockdevRef in the options QDict. | |
1417 | * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict | |
1418 | * itself, all options starting with "${bdref_key}." are considered part of the | |
1419 | * BlockdevRef. | |
1420 | * | |
1421 | * The BlockdevRef will be removed from the options QDict. | |
1422 | */ | |
1423 | BdrvChild *bdrv_open_child(const char *filename, | |
1424 | QDict *options, const char *bdref_key, | |
1425 | BlockDriverState* parent, | |
1426 | const BdrvChildRole *child_role, | |
1427 | bool allow_none, Error **errp) | |
1428 | { | |
1429 | BdrvChild *c = NULL; | |
1430 | BlockDriverState *bs; | |
1431 | QDict *image_options; | |
1432 | char *bdref_key_dot; | |
1433 | const char *reference; | |
1434 | ||
1435 | assert(child_role != NULL); | |
1436 | ||
1437 | bdref_key_dot = g_strdup_printf("%s.", bdref_key); | |
1438 | qdict_extract_subqdict(options, &image_options, bdref_key_dot); | |
1439 | g_free(bdref_key_dot); | |
1440 | ||
1441 | reference = qdict_get_try_str(options, bdref_key); | |
1442 | if (!filename && !reference && !qdict_size(image_options)) { | |
1443 | if (!allow_none) { | |
1444 | error_setg(errp, "A block device must be specified for \"%s\"", | |
1445 | bdref_key); | |
1446 | } | |
1447 | QDECREF(image_options); | |
1448 | goto done; | |
1449 | } | |
1450 | ||
1451 | bs = bdrv_open_inherit(filename, reference, image_options, 0, | |
1452 | parent, child_role, errp); | |
1453 | if (!bs) { | |
1454 | goto done; | |
1455 | } | |
1456 | ||
1457 | c = bdrv_attach_child(parent, bs, bdref_key, child_role); | |
1458 | ||
1459 | done: | |
1460 | qdict_del(options, bdref_key); | |
1461 | return c; | |
1462 | } | |
1463 | ||
1464 | static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs, | |
1465 | int flags, | |
1466 | QDict *snapshot_options, | |
1467 | Error **errp) | |
1468 | { | |
1469 | /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ | |
1470 | char *tmp_filename = g_malloc0(PATH_MAX + 1); | |
1471 | int64_t total_size; | |
1472 | QemuOpts *opts = NULL; | |
1473 | BlockDriverState *bs_snapshot; | |
1474 | int ret; | |
1475 | ||
1476 | /* if snapshot, we create a temporary backing file and open it | |
1477 | instead of opening 'filename' directly */ | |
1478 | ||
1479 | /* Get the required size from the image */ | |
1480 | total_size = bdrv_getlength(bs); | |
1481 | if (total_size < 0) { | |
1482 | error_setg_errno(errp, -total_size, "Could not get image size"); | |
1483 | goto out; | |
1484 | } | |
1485 | ||
1486 | /* Create the temporary image */ | |
1487 | ret = get_tmp_filename(tmp_filename, PATH_MAX + 1); | |
1488 | if (ret < 0) { | |
1489 | error_setg_errno(errp, -ret, "Could not get temporary filename"); | |
1490 | goto out; | |
1491 | } | |
1492 | ||
1493 | opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, | |
1494 | &error_abort); | |
1495 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort); | |
1496 | ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp); | |
1497 | qemu_opts_del(opts); | |
1498 | if (ret < 0) { | |
1499 | error_prepend(errp, "Could not create temporary overlay '%s': ", | |
1500 | tmp_filename); | |
1501 | goto out; | |
1502 | } | |
1503 | ||
1504 | /* Prepare options QDict for the temporary file */ | |
1505 | qdict_put(snapshot_options, "file.driver", | |
1506 | qstring_from_str("file")); | |
1507 | qdict_put(snapshot_options, "file.filename", | |
1508 | qstring_from_str(tmp_filename)); | |
1509 | qdict_put(snapshot_options, "driver", | |
1510 | qstring_from_str("qcow2")); | |
1511 | ||
1512 | bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp); | |
1513 | snapshot_options = NULL; | |
1514 | if (!bs_snapshot) { | |
1515 | ret = -EINVAL; | |
1516 | goto out; | |
1517 | } | |
1518 | ||
1519 | /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will | |
1520 | * call bdrv_unref() on it), so in order to be able to return one, we have | |
1521 | * to increase bs_snapshot's refcount here */ | |
1522 | bdrv_ref(bs_snapshot); | |
1523 | bdrv_append(bs_snapshot, bs); | |
1524 | ||
1525 | g_free(tmp_filename); | |
1526 | return bs_snapshot; | |
1527 | ||
1528 | out: | |
1529 | QDECREF(snapshot_options); | |
1530 | g_free(tmp_filename); | |
1531 | return NULL; | |
1532 | } | |
1533 | ||
1534 | /* | |
1535 | * Opens a disk image (raw, qcow2, vmdk, ...) | |
1536 | * | |
1537 | * options is a QDict of options to pass to the block drivers, or NULL for an | |
1538 | * empty set of options. The reference to the QDict belongs to the block layer | |
1539 | * after the call (even on failure), so if the caller intends to reuse the | |
1540 | * dictionary, it needs to use QINCREF() before calling bdrv_open. | |
1541 | * | |
1542 | * If *pbs is NULL, a new BDS will be created with a pointer to it stored there. | |
1543 | * If it is not NULL, the referenced BDS will be reused. | |
1544 | * | |
1545 | * The reference parameter may be used to specify an existing block device which | |
1546 | * should be opened. If specified, neither options nor a filename may be given, | |
1547 | * nor can an existing BDS be reused (that is, *pbs has to be NULL). | |
1548 | */ | |
1549 | static BlockDriverState *bdrv_open_inherit(const char *filename, | |
1550 | const char *reference, | |
1551 | QDict *options, int flags, | |
1552 | BlockDriverState *parent, | |
1553 | const BdrvChildRole *child_role, | |
1554 | Error **errp) | |
1555 | { | |
1556 | int ret; | |
1557 | BdrvChild *file = NULL; | |
1558 | BlockDriverState *bs; | |
1559 | BlockDriver *drv = NULL; | |
1560 | const char *drvname; | |
1561 | const char *backing; | |
1562 | Error *local_err = NULL; | |
1563 | QDict *snapshot_options = NULL; | |
1564 | int snapshot_flags = 0; | |
1565 | ||
1566 | assert(!child_role || !flags); | |
1567 | assert(!child_role == !parent); | |
1568 | ||
1569 | if (reference) { | |
1570 | bool options_non_empty = options ? qdict_size(options) : false; | |
1571 | QDECREF(options); | |
1572 | ||
1573 | if (filename || options_non_empty) { | |
1574 | error_setg(errp, "Cannot reference an existing block device with " | |
1575 | "additional options or a new filename"); | |
1576 | return NULL; | |
1577 | } | |
1578 | ||
1579 | bs = bdrv_lookup_bs(reference, reference, errp); | |
1580 | if (!bs) { | |
1581 | return NULL; | |
1582 | } | |
1583 | ||
1584 | bdrv_ref(bs); | |
1585 | return bs; | |
1586 | } | |
1587 | ||
1588 | bs = bdrv_new(); | |
1589 | ||
1590 | /* NULL means an empty set of options */ | |
1591 | if (options == NULL) { | |
1592 | options = qdict_new(); | |
1593 | } | |
1594 | ||
1595 | /* json: syntax counts as explicit options, as if in the QDict */ | |
1596 | parse_json_protocol(options, &filename, &local_err); | |
1597 | if (local_err) { | |
1598 | goto fail; | |
1599 | } | |
1600 | ||
1601 | bs->explicit_options = qdict_clone_shallow(options); | |
1602 | ||
1603 | if (child_role) { | |
1604 | bs->inherits_from = parent; | |
1605 | child_role->inherit_options(&flags, options, | |
1606 | parent->open_flags, parent->options); | |
1607 | } | |
1608 | ||
1609 | ret = bdrv_fill_options(&options, filename, &flags, &local_err); | |
1610 | if (local_err) { | |
1611 | goto fail; | |
1612 | } | |
1613 | ||
1614 | bs->open_flags = flags; | |
1615 | bs->options = options; | |
1616 | options = qdict_clone_shallow(options); | |
1617 | ||
1618 | /* Find the right image format driver */ | |
1619 | drvname = qdict_get_try_str(options, "driver"); | |
1620 | if (drvname) { | |
1621 | drv = bdrv_find_format(drvname); | |
1622 | if (!drv) { | |
1623 | error_setg(errp, "Unknown driver: '%s'", drvname); | |
1624 | goto fail; | |
1625 | } | |
1626 | } | |
1627 | ||
1628 | assert(drvname || !(flags & BDRV_O_PROTOCOL)); | |
1629 | ||
1630 | backing = qdict_get_try_str(options, "backing"); | |
1631 | if (backing && *backing == '\0') { | |
1632 | flags |= BDRV_O_NO_BACKING; | |
1633 | qdict_del(options, "backing"); | |
1634 | } | |
1635 | ||
1636 | /* Open image file without format layer */ | |
1637 | if ((flags & BDRV_O_PROTOCOL) == 0) { | |
1638 | if (flags & BDRV_O_RDWR) { | |
1639 | flags |= BDRV_O_ALLOW_RDWR; | |
1640 | } | |
1641 | if (flags & BDRV_O_SNAPSHOT) { | |
1642 | snapshot_options = qdict_new(); | |
1643 | bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options, | |
1644 | flags, options); | |
1645 | bdrv_backing_options(&flags, options, flags, options); | |
1646 | } | |
1647 | ||
1648 | bs->open_flags = flags; | |
1649 | ||
1650 | file = bdrv_open_child(filename, options, "file", bs, | |
1651 | &child_file, true, &local_err); | |
1652 | if (local_err) { | |
1653 | goto fail; | |
1654 | } | |
1655 | } | |
1656 | ||
1657 | /* Image format probing */ | |
1658 | bs->probed = !drv; | |
1659 | if (!drv && file) { | |
1660 | ret = find_image_format(file->bs, filename, &drv, &local_err); | |
1661 | if (ret < 0) { | |
1662 | goto fail; | |
1663 | } | |
1664 | /* | |
1665 | * This option update would logically belong in bdrv_fill_options(), | |
1666 | * but we first need to open bs->file for the probing to work, while | |
1667 | * opening bs->file already requires the (mostly) final set of options | |
1668 | * so that cache mode etc. can be inherited. | |
1669 | * | |
1670 | * Adding the driver later is somewhat ugly, but it's not an option | |
1671 | * that would ever be inherited, so it's correct. We just need to make | |
1672 | * sure to update both bs->options (which has the full effective | |
1673 | * options for bs) and options (which has file.* already removed). | |
1674 | */ | |
1675 | qdict_put(bs->options, "driver", qstring_from_str(drv->format_name)); | |
1676 | qdict_put(options, "driver", qstring_from_str(drv->format_name)); | |
1677 | } else if (!drv) { | |
1678 | error_setg(errp, "Must specify either driver or file"); | |
1679 | goto fail; | |
1680 | } | |
1681 | ||
1682 | /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */ | |
1683 | assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open); | |
1684 | /* file must be NULL if a protocol BDS is about to be created | |
1685 | * (the inverse results in an error message from bdrv_open_common()) */ | |
1686 | assert(!(flags & BDRV_O_PROTOCOL) || !file); | |
1687 | ||
1688 | /* Open the image */ | |
1689 | ret = bdrv_open_common(bs, file, options, &local_err); | |
1690 | if (ret < 0) { | |
1691 | goto fail; | |
1692 | } | |
1693 | ||
1694 | if (file && (bs->file != file)) { | |
1695 | bdrv_unref_child(bs, file); | |
1696 | file = NULL; | |
1697 | } | |
1698 | ||
1699 | /* If there is a backing file, use it */ | |
1700 | if ((flags & BDRV_O_NO_BACKING) == 0) { | |
1701 | ret = bdrv_open_backing_file(bs, options, "backing", &local_err); | |
1702 | if (ret < 0) { | |
1703 | goto close_and_fail; | |
1704 | } | |
1705 | } | |
1706 | ||
1707 | bdrv_refresh_filename(bs); | |
1708 | ||
1709 | /* Check if any unknown options were used */ | |
1710 | if (options && (qdict_size(options) != 0)) { | |
1711 | const QDictEntry *entry = qdict_first(options); | |
1712 | if (flags & BDRV_O_PROTOCOL) { | |
1713 | error_setg(errp, "Block protocol '%s' doesn't support the option " | |
1714 | "'%s'", drv->format_name, entry->key); | |
1715 | } else { | |
1716 | error_setg(errp, | |
1717 | "Block format '%s' does not support the option '%s'", | |
1718 | drv->format_name, entry->key); | |
1719 | } | |
1720 | ||
1721 | goto close_and_fail; | |
1722 | } | |
1723 | ||
1724 | if (!bdrv_key_required(bs)) { | |
1725 | bdrv_parent_cb_change_media(bs, true); | |
1726 | } else if (!runstate_check(RUN_STATE_PRELAUNCH) | |
1727 | && !runstate_check(RUN_STATE_INMIGRATE) | |
1728 | && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */ | |
1729 | error_setg(errp, | |
1730 | "Guest must be stopped for opening of encrypted image"); | |
1731 | goto close_and_fail; | |
1732 | } | |
1733 | ||
1734 | QDECREF(options); | |
1735 | ||
1736 | /* For snapshot=on, create a temporary qcow2 overlay. bs points to the | |
1737 | * temporary snapshot afterwards. */ | |
1738 | if (snapshot_flags) { | |
1739 | BlockDriverState *snapshot_bs; | |
1740 | snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags, | |
1741 | snapshot_options, &local_err); | |
1742 | snapshot_options = NULL; | |
1743 | if (local_err) { | |
1744 | goto close_and_fail; | |
1745 | } | |
1746 | /* We are not going to return bs but the overlay on top of it | |
1747 | * (snapshot_bs); thus, we have to drop the strong reference to bs | |
1748 | * (which we obtained by calling bdrv_new()). bs will not be deleted, | |
1749 | * though, because the overlay still has a reference to it. */ | |
1750 | bdrv_unref(bs); | |
1751 | bs = snapshot_bs; | |
1752 | } | |
1753 | ||
1754 | return bs; | |
1755 | ||
1756 | fail: | |
1757 | if (file != NULL) { | |
1758 | bdrv_unref_child(bs, file); | |
1759 | } | |
1760 | QDECREF(snapshot_options); | |
1761 | QDECREF(bs->explicit_options); | |
1762 | QDECREF(bs->options); | |
1763 | QDECREF(options); | |
1764 | bs->options = NULL; | |
1765 | bdrv_unref(bs); | |
1766 | if (local_err) { | |
1767 | error_propagate(errp, local_err); | |
1768 | } | |
1769 | return NULL; | |
1770 | ||
1771 | close_and_fail: | |
1772 | bdrv_unref(bs); | |
1773 | QDECREF(snapshot_options); | |
1774 | QDECREF(options); | |
1775 | if (local_err) { | |
1776 | error_propagate(errp, local_err); | |
1777 | } | |
1778 | return NULL; | |
1779 | } | |
1780 | ||
1781 | BlockDriverState *bdrv_open(const char *filename, const char *reference, | |
1782 | QDict *options, int flags, Error **errp) | |
1783 | { | |
1784 | return bdrv_open_inherit(filename, reference, options, flags, NULL, | |
1785 | NULL, errp); | |
1786 | } | |
1787 | ||
1788 | typedef struct BlockReopenQueueEntry { | |
1789 | bool prepared; | |
1790 | BDRVReopenState state; | |
1791 | QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; | |
1792 | } BlockReopenQueueEntry; | |
1793 | ||
1794 | /* | |
1795 | * Adds a BlockDriverState to a simple queue for an atomic, transactional | |
1796 | * reopen of multiple devices. | |
1797 | * | |
1798 | * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT | |
1799 | * already performed, or alternatively may be NULL a new BlockReopenQueue will | |
1800 | * be created and initialized. This newly created BlockReopenQueue should be | |
1801 | * passed back in for subsequent calls that are intended to be of the same | |
1802 | * atomic 'set'. | |
1803 | * | |
1804 | * bs is the BlockDriverState to add to the reopen queue. | |
1805 | * | |
1806 | * options contains the changed options for the associated bs | |
1807 | * (the BlockReopenQueue takes ownership) | |
1808 | * | |
1809 | * flags contains the open flags for the associated bs | |
1810 | * | |
1811 | * returns a pointer to bs_queue, which is either the newly allocated | |
1812 | * bs_queue, or the existing bs_queue being used. | |
1813 | * | |
1814 | */ | |
1815 | static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, | |
1816 | BlockDriverState *bs, | |
1817 | QDict *options, | |
1818 | int flags, | |
1819 | const BdrvChildRole *role, | |
1820 | QDict *parent_options, | |
1821 | int parent_flags) | |
1822 | { | |
1823 | assert(bs != NULL); | |
1824 | ||
1825 | BlockReopenQueueEntry *bs_entry; | |
1826 | BdrvChild *child; | |
1827 | QDict *old_options, *explicit_options; | |
1828 | ||
1829 | if (bs_queue == NULL) { | |
1830 | bs_queue = g_new0(BlockReopenQueue, 1); | |
1831 | QSIMPLEQ_INIT(bs_queue); | |
1832 | } | |
1833 | ||
1834 | if (!options) { | |
1835 | options = qdict_new(); | |
1836 | } | |
1837 | ||
1838 | /* | |
1839 | * Precedence of options: | |
1840 | * 1. Explicitly passed in options (highest) | |
1841 | * 2. Set in flags (only for top level) | |
1842 | * 3. Retained from explicitly set options of bs | |
1843 | * 4. Inherited from parent node | |
1844 | * 5. Retained from effective options of bs | |
1845 | */ | |
1846 | ||
1847 | if (!parent_options) { | |
1848 | /* | |
1849 | * Any setting represented by flags is always updated. If the | |
1850 | * corresponding QDict option is set, it takes precedence. Otherwise | |
1851 | * the flag is translated into a QDict option. The old setting of bs is | |
1852 | * not considered. | |
1853 | */ | |
1854 | update_options_from_flags(options, flags); | |
1855 | } | |
1856 | ||
1857 | /* Old explicitly set values (don't overwrite by inherited value) */ | |
1858 | old_options = qdict_clone_shallow(bs->explicit_options); | |
1859 | bdrv_join_options(bs, options, old_options); | |
1860 | QDECREF(old_options); | |
1861 | ||
1862 | explicit_options = qdict_clone_shallow(options); | |
1863 | ||
1864 | /* Inherit from parent node */ | |
1865 | if (parent_options) { | |
1866 | assert(!flags); | |
1867 | role->inherit_options(&flags, options, parent_flags, parent_options); | |
1868 | } | |
1869 | ||
1870 | /* Old values are used for options that aren't set yet */ | |
1871 | old_options = qdict_clone_shallow(bs->options); | |
1872 | bdrv_join_options(bs, options, old_options); | |
1873 | QDECREF(old_options); | |
1874 | ||
1875 | /* bdrv_open() masks this flag out */ | |
1876 | flags &= ~BDRV_O_PROTOCOL; | |
1877 | ||
1878 | QLIST_FOREACH(child, &bs->children, next) { | |
1879 | QDict *new_child_options; | |
1880 | char *child_key_dot; | |
1881 | ||
1882 | /* reopen can only change the options of block devices that were | |
1883 | * implicitly created and inherited options. For other (referenced) | |
1884 | * block devices, a syntax like "backing.foo" results in an error. */ | |
1885 | if (child->bs->inherits_from != bs) { | |
1886 | continue; | |
1887 | } | |
1888 | ||
1889 | child_key_dot = g_strdup_printf("%s.", child->name); | |
1890 | qdict_extract_subqdict(options, &new_child_options, child_key_dot); | |
1891 | g_free(child_key_dot); | |
1892 | ||
1893 | bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options, 0, | |
1894 | child->role, options, flags); | |
1895 | } | |
1896 | ||
1897 | bs_entry = g_new0(BlockReopenQueueEntry, 1); | |
1898 | QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); | |
1899 | ||
1900 | bs_entry->state.bs = bs; | |
1901 | bs_entry->state.options = options; | |
1902 | bs_entry->state.explicit_options = explicit_options; | |
1903 | bs_entry->state.flags = flags; | |
1904 | ||
1905 | return bs_queue; | |
1906 | } | |
1907 | ||
1908 | BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, | |
1909 | BlockDriverState *bs, | |
1910 | QDict *options, int flags) | |
1911 | { | |
1912 | return bdrv_reopen_queue_child(bs_queue, bs, options, flags, | |
1913 | NULL, NULL, 0); | |
1914 | } | |
1915 | ||
1916 | /* | |
1917 | * Reopen multiple BlockDriverStates atomically & transactionally. | |
1918 | * | |
1919 | * The queue passed in (bs_queue) must have been built up previous | |
1920 | * via bdrv_reopen_queue(). | |
1921 | * | |
1922 | * Reopens all BDS specified in the queue, with the appropriate | |
1923 | * flags. All devices are prepared for reopen, and failure of any | |
1924 | * device will cause all device changes to be abandonded, and intermediate | |
1925 | * data cleaned up. | |
1926 | * | |
1927 | * If all devices prepare successfully, then the changes are committed | |
1928 | * to all devices. | |
1929 | * | |
1930 | */ | |
1931 | int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) | |
1932 | { | |
1933 | int ret = -1; | |
1934 | BlockReopenQueueEntry *bs_entry, *next; | |
1935 | Error *local_err = NULL; | |
1936 | ||
1937 | assert(bs_queue != NULL); | |
1938 | ||
1939 | bdrv_drain_all(); | |
1940 | ||
1941 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
1942 | if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) { | |
1943 | error_propagate(errp, local_err); | |
1944 | goto cleanup; | |
1945 | } | |
1946 | bs_entry->prepared = true; | |
1947 | } | |
1948 | ||
1949 | /* If we reach this point, we have success and just need to apply the | |
1950 | * changes | |
1951 | */ | |
1952 | QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { | |
1953 | bdrv_reopen_commit(&bs_entry->state); | |
1954 | } | |
1955 | ||
1956 | ret = 0; | |
1957 | ||
1958 | cleanup: | |
1959 | QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { | |
1960 | if (ret && bs_entry->prepared) { | |
1961 | bdrv_reopen_abort(&bs_entry->state); | |
1962 | } else if (ret) { | |
1963 | QDECREF(bs_entry->state.explicit_options); | |
1964 | } | |
1965 | QDECREF(bs_entry->state.options); | |
1966 | g_free(bs_entry); | |
1967 | } | |
1968 | g_free(bs_queue); | |
1969 | return ret; | |
1970 | } | |
1971 | ||
1972 | ||
1973 | /* Reopen a single BlockDriverState with the specified flags. */ | |
1974 | int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp) | |
1975 | { | |
1976 | int ret = -1; | |
1977 | Error *local_err = NULL; | |
1978 | BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags); | |
1979 | ||
1980 | ret = bdrv_reopen_multiple(queue, &local_err); | |
1981 | if (local_err != NULL) { | |
1982 | error_propagate(errp, local_err); | |
1983 | } | |
1984 | return ret; | |
1985 | } | |
1986 | ||
1987 | ||
1988 | /* | |
1989 | * Prepares a BlockDriverState for reopen. All changes are staged in the | |
1990 | * 'opaque' field of the BDRVReopenState, which is used and allocated by | |
1991 | * the block driver layer .bdrv_reopen_prepare() | |
1992 | * | |
1993 | * bs is the BlockDriverState to reopen | |
1994 | * flags are the new open flags | |
1995 | * queue is the reopen queue | |
1996 | * | |
1997 | * Returns 0 on success, non-zero on error. On error errp will be set | |
1998 | * as well. | |
1999 | * | |
2000 | * On failure, bdrv_reopen_abort() will be called to clean up any data. | |
2001 | * It is the responsibility of the caller to then call the abort() or | |
2002 | * commit() for any other BDS that have been left in a prepare() state | |
2003 | * | |
2004 | */ | |
2005 | int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, | |
2006 | Error **errp) | |
2007 | { | |
2008 | int ret = -1; | |
2009 | Error *local_err = NULL; | |
2010 | BlockDriver *drv; | |
2011 | QemuOpts *opts; | |
2012 | const char *value; | |
2013 | ||
2014 | assert(reopen_state != NULL); | |
2015 | assert(reopen_state->bs->drv != NULL); | |
2016 | drv = reopen_state->bs->drv; | |
2017 | ||
2018 | /* Process generic block layer options */ | |
2019 | opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); | |
2020 | qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err); | |
2021 | if (local_err) { | |
2022 | error_propagate(errp, local_err); | |
2023 | ret = -EINVAL; | |
2024 | goto error; | |
2025 | } | |
2026 | ||
2027 | update_flags_from_options(&reopen_state->flags, opts); | |
2028 | ||
2029 | /* node-name and driver must be unchanged. Put them back into the QDict, so | |
2030 | * that they are checked at the end of this function. */ | |
2031 | value = qemu_opt_get(opts, "node-name"); | |
2032 | if (value) { | |
2033 | qdict_put(reopen_state->options, "node-name", qstring_from_str(value)); | |
2034 | } | |
2035 | ||
2036 | value = qemu_opt_get(opts, "driver"); | |
2037 | if (value) { | |
2038 | qdict_put(reopen_state->options, "driver", qstring_from_str(value)); | |
2039 | } | |
2040 | ||
2041 | /* if we are to stay read-only, do not allow permission change | |
2042 | * to r/w */ | |
2043 | if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) && | |
2044 | reopen_state->flags & BDRV_O_RDWR) { | |
2045 | error_setg(errp, "Node '%s' is read only", | |
2046 | bdrv_get_device_or_node_name(reopen_state->bs)); | |
2047 | goto error; | |
2048 | } | |
2049 | ||
2050 | ||
2051 | ret = bdrv_flush(reopen_state->bs); | |
2052 | if (ret) { | |
2053 | error_setg_errno(errp, -ret, "Error flushing drive"); | |
2054 | goto error; | |
2055 | } | |
2056 | ||
2057 | if (drv->bdrv_reopen_prepare) { | |
2058 | ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); | |
2059 | if (ret) { | |
2060 | if (local_err != NULL) { | |
2061 | error_propagate(errp, local_err); | |
2062 | } else { | |
2063 | error_setg(errp, "failed while preparing to reopen image '%s'", | |
2064 | reopen_state->bs->filename); | |
2065 | } | |
2066 | goto error; | |
2067 | } | |
2068 | } else { | |
2069 | /* It is currently mandatory to have a bdrv_reopen_prepare() | |
2070 | * handler for each supported drv. */ | |
2071 | error_setg(errp, "Block format '%s' used by node '%s' " | |
2072 | "does not support reopening files", drv->format_name, | |
2073 | bdrv_get_device_or_node_name(reopen_state->bs)); | |
2074 | ret = -1; | |
2075 | goto error; | |
2076 | } | |
2077 | ||
2078 | /* Options that are not handled are only okay if they are unchanged | |
2079 | * compared to the old state. It is expected that some options are only | |
2080 | * used for the initial open, but not reopen (e.g. filename) */ | |
2081 | if (qdict_size(reopen_state->options)) { | |
2082 | const QDictEntry *entry = qdict_first(reopen_state->options); | |
2083 | ||
2084 | do { | |
2085 | QString *new_obj = qobject_to_qstring(entry->value); | |
2086 | const char *new = qstring_get_str(new_obj); | |
2087 | const char *old = qdict_get_try_str(reopen_state->bs->options, | |
2088 | entry->key); | |
2089 | ||
2090 | if (!old || strcmp(new, old)) { | |
2091 | error_setg(errp, "Cannot change the option '%s'", entry->key); | |
2092 | ret = -EINVAL; | |
2093 | goto error; | |
2094 | } | |
2095 | } while ((entry = qdict_next(reopen_state->options, entry))); | |
2096 | } | |
2097 | ||
2098 | ret = 0; | |
2099 | ||
2100 | error: | |
2101 | qemu_opts_del(opts); | |
2102 | return ret; | |
2103 | } | |
2104 | ||
2105 | /* | |
2106 | * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and | |
2107 | * makes them final by swapping the staging BlockDriverState contents into | |
2108 | * the active BlockDriverState contents. | |
2109 | */ | |
2110 | void bdrv_reopen_commit(BDRVReopenState *reopen_state) | |
2111 | { | |
2112 | BlockDriver *drv; | |
2113 | ||
2114 | assert(reopen_state != NULL); | |
2115 | drv = reopen_state->bs->drv; | |
2116 | assert(drv != NULL); | |
2117 | ||
2118 | /* If there are any driver level actions to take */ | |
2119 | if (drv->bdrv_reopen_commit) { | |
2120 | drv->bdrv_reopen_commit(reopen_state); | |
2121 | } | |
2122 | ||
2123 | /* set BDS specific flags now */ | |
2124 | QDECREF(reopen_state->bs->explicit_options); | |
2125 | ||
2126 | reopen_state->bs->explicit_options = reopen_state->explicit_options; | |
2127 | reopen_state->bs->open_flags = reopen_state->flags; | |
2128 | reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); | |
2129 | ||
2130 | bdrv_refresh_limits(reopen_state->bs, NULL); | |
2131 | } | |
2132 | ||
2133 | /* | |
2134 | * Abort the reopen, and delete and free the staged changes in | |
2135 | * reopen_state | |
2136 | */ | |
2137 | void bdrv_reopen_abort(BDRVReopenState *reopen_state) | |
2138 | { | |
2139 | BlockDriver *drv; | |
2140 | ||
2141 | assert(reopen_state != NULL); | |
2142 | drv = reopen_state->bs->drv; | |
2143 | assert(drv != NULL); | |
2144 | ||
2145 | if (drv->bdrv_reopen_abort) { | |
2146 | drv->bdrv_reopen_abort(reopen_state); | |
2147 | } | |
2148 | ||
2149 | QDECREF(reopen_state->explicit_options); | |
2150 | } | |
2151 | ||
2152 | ||
2153 | static void bdrv_close(BlockDriverState *bs) | |
2154 | { | |
2155 | BdrvAioNotifier *ban, *ban_next; | |
2156 | ||
2157 | assert(!bs->job); | |
2158 | assert(!bs->refcnt); | |
2159 | ||
2160 | bdrv_drained_begin(bs); /* complete I/O */ | |
2161 | bdrv_flush(bs); | |
2162 | bdrv_drain(bs); /* in case flush left pending I/O */ | |
2163 | ||
2164 | bdrv_release_named_dirty_bitmaps(bs); | |
2165 | assert(QLIST_EMPTY(&bs->dirty_bitmaps)); | |
2166 | ||
2167 | if (bs->drv) { | |
2168 | BdrvChild *child, *next; | |
2169 | ||
2170 | bs->drv->bdrv_close(bs); | |
2171 | bs->drv = NULL; | |
2172 | ||
2173 | bdrv_set_backing_hd(bs, NULL); | |
2174 | ||
2175 | if (bs->file != NULL) { | |
2176 | bdrv_unref_child(bs, bs->file); | |
2177 | bs->file = NULL; | |
2178 | } | |
2179 | ||
2180 | QLIST_FOREACH_SAFE(child, &bs->children, next, next) { | |
2181 | /* TODO Remove bdrv_unref() from drivers' close function and use | |
2182 | * bdrv_unref_child() here */ | |
2183 | if (child->bs->inherits_from == bs) { | |
2184 | child->bs->inherits_from = NULL; | |
2185 | } | |
2186 | bdrv_detach_child(child); | |
2187 | } | |
2188 | ||
2189 | g_free(bs->opaque); | |
2190 | bs->opaque = NULL; | |
2191 | bs->copy_on_read = 0; | |
2192 | bs->backing_file[0] = '\0'; | |
2193 | bs->backing_format[0] = '\0'; | |
2194 | bs->total_sectors = 0; | |
2195 | bs->encrypted = 0; | |
2196 | bs->valid_key = 0; | |
2197 | bs->sg = 0; | |
2198 | QDECREF(bs->options); | |
2199 | QDECREF(bs->explicit_options); | |
2200 | bs->options = NULL; | |
2201 | QDECREF(bs->full_open_options); | |
2202 | bs->full_open_options = NULL; | |
2203 | } | |
2204 | ||
2205 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { | |
2206 | g_free(ban); | |
2207 | } | |
2208 | QLIST_INIT(&bs->aio_notifiers); | |
2209 | bdrv_drained_end(bs); | |
2210 | } | |
2211 | ||
2212 | void bdrv_close_all(void) | |
2213 | { | |
2214 | block_job_cancel_sync_all(); | |
2215 | ||
2216 | /* Drop references from requests still in flight, such as canceled block | |
2217 | * jobs whose AIO context has not been polled yet */ | |
2218 | bdrv_drain_all(); | |
2219 | ||
2220 | blk_remove_all_bs(); | |
2221 | blockdev_close_all_bdrv_states(); | |
2222 | ||
2223 | assert(QTAILQ_EMPTY(&all_bdrv_states)); | |
2224 | } | |
2225 | ||
2226 | static void change_parent_backing_link(BlockDriverState *from, | |
2227 | BlockDriverState *to) | |
2228 | { | |
2229 | BdrvChild *c, *next, *to_c; | |
2230 | ||
2231 | QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { | |
2232 | if (c->role == &child_backing) { | |
2233 | /* @from is generally not allowed to be a backing file, except for | |
2234 | * when @to is the overlay. In that case, @from may not be replaced | |
2235 | * by @to as @to's backing node. */ | |
2236 | QLIST_FOREACH(to_c, &to->children, next) { | |
2237 | if (to_c == c) { | |
2238 | break; | |
2239 | } | |
2240 | } | |
2241 | if (to_c) { | |
2242 | continue; | |
2243 | } | |
2244 | } | |
2245 | ||
2246 | assert(c->role != &child_backing); | |
2247 | bdrv_ref(to); | |
2248 | bdrv_replace_child(c, to); | |
2249 | bdrv_unref(from); | |
2250 | } | |
2251 | } | |
2252 | ||
2253 | /* | |
2254 | * Add new bs contents at the top of an image chain while the chain is | |
2255 | * live, while keeping required fields on the top layer. | |
2256 | * | |
2257 | * This will modify the BlockDriverState fields, and swap contents | |
2258 | * between bs_new and bs_top. Both bs_new and bs_top are modified. | |
2259 | * | |
2260 | * bs_new must not be attached to a BlockBackend. | |
2261 | * | |
2262 | * This function does not create any image files. | |
2263 | * | |
2264 | * bdrv_append() takes ownership of a bs_new reference and unrefs it because | |
2265 | * that's what the callers commonly need. bs_new will be referenced by the old | |
2266 | * parents of bs_top after bdrv_append() returns. If the caller needs to keep a | |
2267 | * reference of its own, it must call bdrv_ref(). | |
2268 | */ | |
2269 | void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) | |
2270 | { | |
2271 | assert(!bdrv_requests_pending(bs_top)); | |
2272 | assert(!bdrv_requests_pending(bs_new)); | |
2273 | ||
2274 | bdrv_ref(bs_top); | |
2275 | ||
2276 | change_parent_backing_link(bs_top, bs_new); | |
2277 | bdrv_set_backing_hd(bs_new, bs_top); | |
2278 | bdrv_unref(bs_top); | |
2279 | ||
2280 | /* bs_new is now referenced by its new parents, we don't need the | |
2281 | * additional reference any more. */ | |
2282 | bdrv_unref(bs_new); | |
2283 | } | |
2284 | ||
2285 | void bdrv_replace_in_backing_chain(BlockDriverState *old, BlockDriverState *new) | |
2286 | { | |
2287 | assert(!bdrv_requests_pending(old)); | |
2288 | assert(!bdrv_requests_pending(new)); | |
2289 | ||
2290 | bdrv_ref(old); | |
2291 | ||
2292 | change_parent_backing_link(old, new); | |
2293 | ||
2294 | bdrv_unref(old); | |
2295 | } | |
2296 | ||
2297 | static void bdrv_delete(BlockDriverState *bs) | |
2298 | { | |
2299 | assert(!bs->job); | |
2300 | assert(bdrv_op_blocker_is_empty(bs)); | |
2301 | assert(!bs->refcnt); | |
2302 | ||
2303 | bdrv_close(bs); | |
2304 | ||
2305 | /* remove from list, if necessary */ | |
2306 | if (bs->node_name[0] != '\0') { | |
2307 | QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); | |
2308 | } | |
2309 | QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list); | |
2310 | ||
2311 | g_free(bs); | |
2312 | } | |
2313 | ||
2314 | /* | |
2315 | * Run consistency checks on an image | |
2316 | * | |
2317 | * Returns 0 if the check could be completed (it doesn't mean that the image is | |
2318 | * free of errors) or -errno when an internal error occurred. The results of the | |
2319 | * check are stored in res. | |
2320 | */ | |
2321 | int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) | |
2322 | { | |
2323 | if (bs->drv == NULL) { | |
2324 | return -ENOMEDIUM; | |
2325 | } | |
2326 | if (bs->drv->bdrv_check == NULL) { | |
2327 | return -ENOTSUP; | |
2328 | } | |
2329 | ||
2330 | memset(res, 0, sizeof(*res)); | |
2331 | return bs->drv->bdrv_check(bs, res, fix); | |
2332 | } | |
2333 | ||
2334 | #define COMMIT_BUF_SECTORS 2048 | |
2335 | ||
2336 | /* commit COW file into the raw image */ | |
2337 | int bdrv_commit(BlockDriverState *bs) | |
2338 | { | |
2339 | BlockDriver *drv = bs->drv; | |
2340 | int64_t sector, total_sectors, length, backing_length; | |
2341 | int n, ro, open_flags; | |
2342 | int ret = 0; | |
2343 | uint8_t *buf = NULL; | |
2344 | ||
2345 | if (!drv) | |
2346 | return -ENOMEDIUM; | |
2347 | ||
2348 | if (!bs->backing) { | |
2349 | return -ENOTSUP; | |
2350 | } | |
2351 | ||
2352 | if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, NULL) || | |
2353 | bdrv_op_is_blocked(bs->backing->bs, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) { | |
2354 | return -EBUSY; | |
2355 | } | |
2356 | ||
2357 | ro = bs->backing->bs->read_only; | |
2358 | open_flags = bs->backing->bs->open_flags; | |
2359 | ||
2360 | if (ro) { | |
2361 | if (bdrv_reopen(bs->backing->bs, open_flags | BDRV_O_RDWR, NULL)) { | |
2362 | return -EACCES; | |
2363 | } | |
2364 | } | |
2365 | ||
2366 | length = bdrv_getlength(bs); | |
2367 | if (length < 0) { | |
2368 | ret = length; | |
2369 | goto ro_cleanup; | |
2370 | } | |
2371 | ||
2372 | backing_length = bdrv_getlength(bs->backing->bs); | |
2373 | if (backing_length < 0) { | |
2374 | ret = backing_length; | |
2375 | goto ro_cleanup; | |
2376 | } | |
2377 | ||
2378 | /* If our top snapshot is larger than the backing file image, | |
2379 | * grow the backing file image if possible. If not possible, | |
2380 | * we must return an error */ | |
2381 | if (length > backing_length) { | |
2382 | ret = bdrv_truncate(bs->backing->bs, length); | |
2383 | if (ret < 0) { | |
2384 | goto ro_cleanup; | |
2385 | } | |
2386 | } | |
2387 | ||
2388 | total_sectors = length >> BDRV_SECTOR_BITS; | |
2389 | ||
2390 | /* qemu_try_blockalign() for bs will choose an alignment that works for | |
2391 | * bs->backing->bs as well, so no need to compare the alignment manually. */ | |
2392 | buf = qemu_try_blockalign(bs, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); | |
2393 | if (buf == NULL) { | |
2394 | ret = -ENOMEM; | |
2395 | goto ro_cleanup; | |
2396 | } | |
2397 | ||
2398 | for (sector = 0; sector < total_sectors; sector += n) { | |
2399 | ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n); | |
2400 | if (ret < 0) { | |
2401 | goto ro_cleanup; | |
2402 | } | |
2403 | if (ret) { | |
2404 | ret = bdrv_read(bs, sector, buf, n); | |
2405 | if (ret < 0) { | |
2406 | goto ro_cleanup; | |
2407 | } | |
2408 | ||
2409 | ret = bdrv_write(bs->backing->bs, sector, buf, n); | |
2410 | if (ret < 0) { | |
2411 | goto ro_cleanup; | |
2412 | } | |
2413 | } | |
2414 | } | |
2415 | ||
2416 | if (drv->bdrv_make_empty) { | |
2417 | ret = drv->bdrv_make_empty(bs); | |
2418 | if (ret < 0) { | |
2419 | goto ro_cleanup; | |
2420 | } | |
2421 | bdrv_flush(bs); | |
2422 | } | |
2423 | ||
2424 | /* | |
2425 | * Make sure all data we wrote to the backing device is actually | |
2426 | * stable on disk. | |
2427 | */ | |
2428 | if (bs->backing) { | |
2429 | bdrv_flush(bs->backing->bs); | |
2430 | } | |
2431 | ||
2432 | ret = 0; | |
2433 | ro_cleanup: | |
2434 | qemu_vfree(buf); | |
2435 | ||
2436 | if (ro) { | |
2437 | /* ignoring error return here */ | |
2438 | bdrv_reopen(bs->backing->bs, open_flags & ~BDRV_O_RDWR, NULL); | |
2439 | } | |
2440 | ||
2441 | return ret; | |
2442 | } | |
2443 | ||
2444 | /* | |
2445 | * Return values: | |
2446 | * 0 - success | |
2447 | * -EINVAL - backing format specified, but no file | |
2448 | * -ENOSPC - can't update the backing file because no space is left in the | |
2449 | * image file header | |
2450 | * -ENOTSUP - format driver doesn't support changing the backing file | |
2451 | */ | |
2452 | int bdrv_change_backing_file(BlockDriverState *bs, | |
2453 | const char *backing_file, const char *backing_fmt) | |
2454 | { | |
2455 | BlockDriver *drv = bs->drv; | |
2456 | int ret; | |
2457 | ||
2458 | /* Backing file format doesn't make sense without a backing file */ | |
2459 | if (backing_fmt && !backing_file) { | |
2460 | return -EINVAL; | |
2461 | } | |
2462 | ||
2463 | if (drv->bdrv_change_backing_file != NULL) { | |
2464 | ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); | |
2465 | } else { | |
2466 | ret = -ENOTSUP; | |
2467 | } | |
2468 | ||
2469 | if (ret == 0) { | |
2470 | pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); | |
2471 | pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); | |
2472 | } | |
2473 | return ret; | |
2474 | } | |
2475 | ||
2476 | /* | |
2477 | * Finds the image layer in the chain that has 'bs' as its backing file. | |
2478 | * | |
2479 | * active is the current topmost image. | |
2480 | * | |
2481 | * Returns NULL if bs is not found in active's image chain, | |
2482 | * or if active == bs. | |
2483 | * | |
2484 | * Returns the bottommost base image if bs == NULL. | |
2485 | */ | |
2486 | BlockDriverState *bdrv_find_overlay(BlockDriverState *active, | |
2487 | BlockDriverState *bs) | |
2488 | { | |
2489 | while (active && bs != backing_bs(active)) { | |
2490 | active = backing_bs(active); | |
2491 | } | |
2492 | ||
2493 | return active; | |
2494 | } | |
2495 | ||
2496 | /* Given a BDS, searches for the base layer. */ | |
2497 | BlockDriverState *bdrv_find_base(BlockDriverState *bs) | |
2498 | { | |
2499 | return bdrv_find_overlay(bs, NULL); | |
2500 | } | |
2501 | ||
2502 | /* | |
2503 | * Drops images above 'base' up to and including 'top', and sets the image | |
2504 | * above 'top' to have base as its backing file. | |
2505 | * | |
2506 | * Requires that the overlay to 'top' is opened r/w, so that the backing file | |
2507 | * information in 'bs' can be properly updated. | |
2508 | * | |
2509 | * E.g., this will convert the following chain: | |
2510 | * bottom <- base <- intermediate <- top <- active | |
2511 | * | |
2512 | * to | |
2513 | * | |
2514 | * bottom <- base <- active | |
2515 | * | |
2516 | * It is allowed for bottom==base, in which case it converts: | |
2517 | * | |
2518 | * base <- intermediate <- top <- active | |
2519 | * | |
2520 | * to | |
2521 | * | |
2522 | * base <- active | |
2523 | * | |
2524 | * If backing_file_str is non-NULL, it will be used when modifying top's | |
2525 | * overlay image metadata. | |
2526 | * | |
2527 | * Error conditions: | |
2528 | * if active == top, that is considered an error | |
2529 | * | |
2530 | */ | |
2531 | int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, | |
2532 | BlockDriverState *base, const char *backing_file_str) | |
2533 | { | |
2534 | BlockDriverState *new_top_bs = NULL; | |
2535 | int ret = -EIO; | |
2536 | ||
2537 | if (!top->drv || !base->drv) { | |
2538 | goto exit; | |
2539 | } | |
2540 | ||
2541 | new_top_bs = bdrv_find_overlay(active, top); | |
2542 | ||
2543 | if (new_top_bs == NULL) { | |
2544 | /* we could not find the image above 'top', this is an error */ | |
2545 | goto exit; | |
2546 | } | |
2547 | ||
2548 | /* special case of new_top_bs->backing->bs already pointing to base - nothing | |
2549 | * to do, no intermediate images */ | |
2550 | if (backing_bs(new_top_bs) == base) { | |
2551 | ret = 0; | |
2552 | goto exit; | |
2553 | } | |
2554 | ||
2555 | /* Make sure that base is in the backing chain of top */ | |
2556 | if (!bdrv_chain_contains(top, base)) { | |
2557 | goto exit; | |
2558 | } | |
2559 | ||
2560 | /* success - we can delete the intermediate states, and link top->base */ | |
2561 | backing_file_str = backing_file_str ? backing_file_str : base->filename; | |
2562 | ret = bdrv_change_backing_file(new_top_bs, backing_file_str, | |
2563 | base->drv ? base->drv->format_name : ""); | |
2564 | if (ret) { | |
2565 | goto exit; | |
2566 | } | |
2567 | bdrv_set_backing_hd(new_top_bs, base); | |
2568 | ||
2569 | ret = 0; | |
2570 | exit: | |
2571 | return ret; | |
2572 | } | |
2573 | ||
2574 | /** | |
2575 | * Truncate file to 'offset' bytes (needed only for file protocols) | |
2576 | */ | |
2577 | int bdrv_truncate(BlockDriverState *bs, int64_t offset) | |
2578 | { | |
2579 | BlockDriver *drv = bs->drv; | |
2580 | int ret; | |
2581 | if (!drv) | |
2582 | return -ENOMEDIUM; | |
2583 | if (!drv->bdrv_truncate) | |
2584 | return -ENOTSUP; | |
2585 | if (bs->read_only) | |
2586 | return -EACCES; | |
2587 | ||
2588 | ret = drv->bdrv_truncate(bs, offset); | |
2589 | if (ret == 0) { | |
2590 | ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); | |
2591 | bdrv_dirty_bitmap_truncate(bs); | |
2592 | bdrv_parent_cb_resize(bs); | |
2593 | } | |
2594 | return ret; | |
2595 | } | |
2596 | ||
2597 | /** | |
2598 | * Length of a allocated file in bytes. Sparse files are counted by actual | |
2599 | * allocated space. Return < 0 if error or unknown. | |
2600 | */ | |
2601 | int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) | |
2602 | { | |
2603 | BlockDriver *drv = bs->drv; | |
2604 | if (!drv) { | |
2605 | return -ENOMEDIUM; | |
2606 | } | |
2607 | if (drv->bdrv_get_allocated_file_size) { | |
2608 | return drv->bdrv_get_allocated_file_size(bs); | |
2609 | } | |
2610 | if (bs->file) { | |
2611 | return bdrv_get_allocated_file_size(bs->file->bs); | |
2612 | } | |
2613 | return -ENOTSUP; | |
2614 | } | |
2615 | ||
2616 | /** | |
2617 | * Return number of sectors on success, -errno on error. | |
2618 | */ | |
2619 | int64_t bdrv_nb_sectors(BlockDriverState *bs) | |
2620 | { | |
2621 | BlockDriver *drv = bs->drv; | |
2622 | ||
2623 | if (!drv) | |
2624 | return -ENOMEDIUM; | |
2625 | ||
2626 | if (drv->has_variable_length) { | |
2627 | int ret = refresh_total_sectors(bs, bs->total_sectors); | |
2628 | if (ret < 0) { | |
2629 | return ret; | |
2630 | } | |
2631 | } | |
2632 | return bs->total_sectors; | |
2633 | } | |
2634 | ||
2635 | /** | |
2636 | * Return length in bytes on success, -errno on error. | |
2637 | * The length is always a multiple of BDRV_SECTOR_SIZE. | |
2638 | */ | |
2639 | int64_t bdrv_getlength(BlockDriverState *bs) | |
2640 | { | |
2641 | int64_t ret = bdrv_nb_sectors(bs); | |
2642 | ||
2643 | ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret; | |
2644 | return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE; | |
2645 | } | |
2646 | ||
2647 | /* return 0 as number of sectors if no device present or error */ | |
2648 | void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) | |
2649 | { | |
2650 | int64_t nb_sectors = bdrv_nb_sectors(bs); | |
2651 | ||
2652 | *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors; | |
2653 | } | |
2654 | ||
2655 | int bdrv_is_read_only(BlockDriverState *bs) | |
2656 | { | |
2657 | return bs->read_only; | |
2658 | } | |
2659 | ||
2660 | int bdrv_is_sg(BlockDriverState *bs) | |
2661 | { | |
2662 | return bs->sg; | |
2663 | } | |
2664 | ||
2665 | int bdrv_is_encrypted(BlockDriverState *bs) | |
2666 | { | |
2667 | if (bs->backing && bs->backing->bs->encrypted) { | |
2668 | return 1; | |
2669 | } | |
2670 | return bs->encrypted; | |
2671 | } | |
2672 | ||
2673 | int bdrv_key_required(BlockDriverState *bs) | |
2674 | { | |
2675 | BdrvChild *backing = bs->backing; | |
2676 | ||
2677 | if (backing && backing->bs->encrypted && !backing->bs->valid_key) { | |
2678 | return 1; | |
2679 | } | |
2680 | return (bs->encrypted && !bs->valid_key); | |
2681 | } | |
2682 | ||
2683 | int bdrv_set_key(BlockDriverState *bs, const char *key) | |
2684 | { | |
2685 | int ret; | |
2686 | if (bs->backing && bs->backing->bs->encrypted) { | |
2687 | ret = bdrv_set_key(bs->backing->bs, key); | |
2688 | if (ret < 0) | |
2689 | return ret; | |
2690 | if (!bs->encrypted) | |
2691 | return 0; | |
2692 | } | |
2693 | if (!bs->encrypted) { | |
2694 | return -EINVAL; | |
2695 | } else if (!bs->drv || !bs->drv->bdrv_set_key) { | |
2696 | return -ENOMEDIUM; | |
2697 | } | |
2698 | ret = bs->drv->bdrv_set_key(bs, key); | |
2699 | if (ret < 0) { | |
2700 | bs->valid_key = 0; | |
2701 | } else if (!bs->valid_key) { | |
2702 | /* call the change callback now, we skipped it on open */ | |
2703 | bs->valid_key = 1; | |
2704 | bdrv_parent_cb_change_media(bs, true); | |
2705 | } | |
2706 | return ret; | |
2707 | } | |
2708 | ||
2709 | /* | |
2710 | * Provide an encryption key for @bs. | |
2711 | * If @key is non-null: | |
2712 | * If @bs is not encrypted, fail. | |
2713 | * Else if the key is invalid, fail. | |
2714 | * Else set @bs's key to @key, replacing the existing key, if any. | |
2715 | * If @key is null: | |
2716 | * If @bs is encrypted and still lacks a key, fail. | |
2717 | * Else do nothing. | |
2718 | * On failure, store an error object through @errp if non-null. | |
2719 | */ | |
2720 | void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp) | |
2721 | { | |
2722 | if (key) { | |
2723 | if (!bdrv_is_encrypted(bs)) { | |
2724 | error_setg(errp, "Node '%s' is not encrypted", | |
2725 | bdrv_get_device_or_node_name(bs)); | |
2726 | } else if (bdrv_set_key(bs, key) < 0) { | |
2727 | error_setg(errp, QERR_INVALID_PASSWORD); | |
2728 | } | |
2729 | } else { | |
2730 | if (bdrv_key_required(bs)) { | |
2731 | error_set(errp, ERROR_CLASS_DEVICE_ENCRYPTED, | |
2732 | "'%s' (%s) is encrypted", | |
2733 | bdrv_get_device_or_node_name(bs), | |
2734 | bdrv_get_encrypted_filename(bs)); | |
2735 | } | |
2736 | } | |
2737 | } | |
2738 | ||
2739 | const char *bdrv_get_format_name(BlockDriverState *bs) | |
2740 | { | |
2741 | return bs->drv ? bs->drv->format_name : NULL; | |
2742 | } | |
2743 | ||
2744 | static int qsort_strcmp(const void *a, const void *b) | |
2745 | { | |
2746 | return strcmp(a, b); | |
2747 | } | |
2748 | ||
2749 | void bdrv_iterate_format(void (*it)(void *opaque, const char *name), | |
2750 | void *opaque) | |
2751 | { | |
2752 | BlockDriver *drv; | |
2753 | int count = 0; | |
2754 | int i; | |
2755 | const char **formats = NULL; | |
2756 | ||
2757 | QLIST_FOREACH(drv, &bdrv_drivers, list) { | |
2758 | if (drv->format_name) { | |
2759 | bool found = false; | |
2760 | int i = count; | |
2761 | while (formats && i && !found) { | |
2762 | found = !strcmp(formats[--i], drv->format_name); | |
2763 | } | |
2764 | ||
2765 | if (!found) { | |
2766 | formats = g_renew(const char *, formats, count + 1); | |
2767 | formats[count++] = drv->format_name; | |
2768 | } | |
2769 | } | |
2770 | } | |
2771 | ||
2772 | qsort(formats, count, sizeof(formats[0]), qsort_strcmp); | |
2773 | ||
2774 | for (i = 0; i < count; i++) { | |
2775 | it(opaque, formats[i]); | |
2776 | } | |
2777 | ||
2778 | g_free(formats); | |
2779 | } | |
2780 | ||
2781 | /* This function is to find a node in the bs graph */ | |
2782 | BlockDriverState *bdrv_find_node(const char *node_name) | |
2783 | { | |
2784 | BlockDriverState *bs; | |
2785 | ||
2786 | assert(node_name); | |
2787 | ||
2788 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
2789 | if (!strcmp(node_name, bs->node_name)) { | |
2790 | return bs; | |
2791 | } | |
2792 | } | |
2793 | return NULL; | |
2794 | } | |
2795 | ||
2796 | /* Put this QMP function here so it can access the static graph_bdrv_states. */ | |
2797 | BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp) | |
2798 | { | |
2799 | BlockDeviceInfoList *list, *entry; | |
2800 | BlockDriverState *bs; | |
2801 | ||
2802 | list = NULL; | |
2803 | QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { | |
2804 | BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp); | |
2805 | if (!info) { | |
2806 | qapi_free_BlockDeviceInfoList(list); | |
2807 | return NULL; | |
2808 | } | |
2809 | entry = g_malloc0(sizeof(*entry)); | |
2810 | entry->value = info; | |
2811 | entry->next = list; | |
2812 | list = entry; | |
2813 | } | |
2814 | ||
2815 | return list; | |
2816 | } | |
2817 | ||
2818 | BlockDriverState *bdrv_lookup_bs(const char *device, | |
2819 | const char *node_name, | |
2820 | Error **errp) | |
2821 | { | |
2822 | BlockBackend *blk; | |
2823 | BlockDriverState *bs; | |
2824 | ||
2825 | if (device) { | |
2826 | blk = blk_by_name(device); | |
2827 | ||
2828 | if (blk) { | |
2829 | bs = blk_bs(blk); | |
2830 | if (!bs) { | |
2831 | error_setg(errp, "Device '%s' has no medium", device); | |
2832 | } | |
2833 | ||
2834 | return bs; | |
2835 | } | |
2836 | } | |
2837 | ||
2838 | if (node_name) { | |
2839 | bs = bdrv_find_node(node_name); | |
2840 | ||
2841 | if (bs) { | |
2842 | return bs; | |
2843 | } | |
2844 | } | |
2845 | ||
2846 | error_setg(errp, "Cannot find device=%s nor node_name=%s", | |
2847 | device ? device : "", | |
2848 | node_name ? node_name : ""); | |
2849 | return NULL; | |
2850 | } | |
2851 | ||
2852 | /* If 'base' is in the same chain as 'top', return true. Otherwise, | |
2853 | * return false. If either argument is NULL, return false. */ | |
2854 | bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) | |
2855 | { | |
2856 | while (top && top != base) { | |
2857 | top = backing_bs(top); | |
2858 | } | |
2859 | ||
2860 | return top != NULL; | |
2861 | } | |
2862 | ||
2863 | BlockDriverState *bdrv_next_node(BlockDriverState *bs) | |
2864 | { | |
2865 | if (!bs) { | |
2866 | return QTAILQ_FIRST(&graph_bdrv_states); | |
2867 | } | |
2868 | return QTAILQ_NEXT(bs, node_list); | |
2869 | } | |
2870 | ||
2871 | const char *bdrv_get_node_name(const BlockDriverState *bs) | |
2872 | { | |
2873 | return bs->node_name; | |
2874 | } | |
2875 | ||
2876 | const char *bdrv_get_parent_name(const BlockDriverState *bs) | |
2877 | { | |
2878 | BdrvChild *c; | |
2879 | const char *name; | |
2880 | ||
2881 | /* If multiple parents have a name, just pick the first one. */ | |
2882 | QLIST_FOREACH(c, &bs->parents, next_parent) { | |
2883 | if (c->role->get_name) { | |
2884 | name = c->role->get_name(c); | |
2885 | if (name && *name) { | |
2886 | return name; | |
2887 | } | |
2888 | } | |
2889 | } | |
2890 | ||
2891 | return NULL; | |
2892 | } | |
2893 | ||
2894 | /* TODO check what callers really want: bs->node_name or blk_name() */ | |
2895 | const char *bdrv_get_device_name(const BlockDriverState *bs) | |
2896 | { | |
2897 | return bdrv_get_parent_name(bs) ?: ""; | |
2898 | } | |
2899 | ||
2900 | /* This can be used to identify nodes that might not have a device | |
2901 | * name associated. Since node and device names live in the same | |
2902 | * namespace, the result is unambiguous. The exception is if both are | |
2903 | * absent, then this returns an empty (non-null) string. */ | |
2904 | const char *bdrv_get_device_or_node_name(const BlockDriverState *bs) | |
2905 | { | |
2906 | return bdrv_get_parent_name(bs) ?: bs->node_name; | |
2907 | } | |
2908 | ||
2909 | int bdrv_get_flags(BlockDriverState *bs) | |
2910 | { | |
2911 | return bs->open_flags; | |
2912 | } | |
2913 | ||
2914 | int bdrv_has_zero_init_1(BlockDriverState *bs) | |
2915 | { | |
2916 | return 1; | |
2917 | } | |
2918 | ||
2919 | int bdrv_has_zero_init(BlockDriverState *bs) | |
2920 | { | |
2921 | assert(bs->drv); | |
2922 | ||
2923 | /* If BS is a copy on write image, it is initialized to | |
2924 | the contents of the base image, which may not be zeroes. */ | |
2925 | if (bs->backing) { | |
2926 | return 0; | |
2927 | } | |
2928 | if (bs->drv->bdrv_has_zero_init) { | |
2929 | return bs->drv->bdrv_has_zero_init(bs); | |
2930 | } | |
2931 | ||
2932 | /* safe default */ | |
2933 | return 0; | |
2934 | } | |
2935 | ||
2936 | bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs) | |
2937 | { | |
2938 | BlockDriverInfo bdi; | |
2939 | ||
2940 | if (bs->backing) { | |
2941 | return false; | |
2942 | } | |
2943 | ||
2944 | if (bdrv_get_info(bs, &bdi) == 0) { | |
2945 | return bdi.unallocated_blocks_are_zero; | |
2946 | } | |
2947 | ||
2948 | return false; | |
2949 | } | |
2950 | ||
2951 | bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) | |
2952 | { | |
2953 | BlockDriverInfo bdi; | |
2954 | ||
2955 | if (bs->backing || !(bs->open_flags & BDRV_O_UNMAP)) { | |
2956 | return false; | |
2957 | } | |
2958 | ||
2959 | if (bdrv_get_info(bs, &bdi) == 0) { | |
2960 | return bdi.can_write_zeroes_with_unmap; | |
2961 | } | |
2962 | ||
2963 | return false; | |
2964 | } | |
2965 | ||
2966 | const char *bdrv_get_encrypted_filename(BlockDriverState *bs) | |
2967 | { | |
2968 | if (bs->backing && bs->backing->bs->encrypted) | |
2969 | return bs->backing_file; | |
2970 | else if (bs->encrypted) | |
2971 | return bs->filename; | |
2972 | else | |
2973 | return NULL; | |
2974 | } | |
2975 | ||
2976 | void bdrv_get_backing_filename(BlockDriverState *bs, | |
2977 | char *filename, int filename_size) | |
2978 | { | |
2979 | pstrcpy(filename, filename_size, bs->backing_file); | |
2980 | } | |
2981 | ||
2982 | int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) | |
2983 | { | |
2984 | BlockDriver *drv = bs->drv; | |
2985 | if (!drv) | |
2986 | return -ENOMEDIUM; | |
2987 | if (!drv->bdrv_get_info) | |
2988 | return -ENOTSUP; | |
2989 | memset(bdi, 0, sizeof(*bdi)); | |
2990 | return drv->bdrv_get_info(bs, bdi); | |
2991 | } | |
2992 | ||
2993 | ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs) | |
2994 | { | |
2995 | BlockDriver *drv = bs->drv; | |
2996 | if (drv && drv->bdrv_get_specific_info) { | |
2997 | return drv->bdrv_get_specific_info(bs); | |
2998 | } | |
2999 | return NULL; | |
3000 | } | |
3001 | ||
3002 | void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event) | |
3003 | { | |
3004 | if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) { | |
3005 | return; | |
3006 | } | |
3007 | ||
3008 | bs->drv->bdrv_debug_event(bs, event); | |
3009 | } | |
3010 | ||
3011 | int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, | |
3012 | const char *tag) | |
3013 | { | |
3014 | while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { | |
3015 | bs = bs->file ? bs->file->bs : NULL; | |
3016 | } | |
3017 | ||
3018 | if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) { | |
3019 | return bs->drv->bdrv_debug_breakpoint(bs, event, tag); | |
3020 | } | |
3021 | ||
3022 | return -ENOTSUP; | |
3023 | } | |
3024 | ||
3025 | int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) | |
3026 | { | |
3027 | while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) { | |
3028 | bs = bs->file ? bs->file->bs : NULL; | |
3029 | } | |
3030 | ||
3031 | if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) { | |
3032 | return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); | |
3033 | } | |
3034 | ||
3035 | return -ENOTSUP; | |
3036 | } | |
3037 | ||
3038 | int bdrv_debug_resume(BlockDriverState *bs, const char *tag) | |
3039 | { | |
3040 | while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { | |
3041 | bs = bs->file ? bs->file->bs : NULL; | |
3042 | } | |
3043 | ||
3044 | if (bs && bs->drv && bs->drv->bdrv_debug_resume) { | |
3045 | return bs->drv->bdrv_debug_resume(bs, tag); | |
3046 | } | |
3047 | ||
3048 | return -ENOTSUP; | |
3049 | } | |
3050 | ||
3051 | bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) | |
3052 | { | |
3053 | while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { | |
3054 | bs = bs->file ? bs->file->bs : NULL; | |
3055 | } | |
3056 | ||
3057 | if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { | |
3058 | return bs->drv->bdrv_debug_is_suspended(bs, tag); | |
3059 | } | |
3060 | ||
3061 | return false; | |
3062 | } | |
3063 | ||
3064 | int bdrv_is_snapshot(BlockDriverState *bs) | |
3065 | { | |
3066 | return !!(bs->open_flags & BDRV_O_SNAPSHOT); | |
3067 | } | |
3068 | ||
3069 | /* backing_file can either be relative, or absolute, or a protocol. If it is | |
3070 | * relative, it must be relative to the chain. So, passing in bs->filename | |
3071 | * from a BDS as backing_file should not be done, as that may be relative to | |
3072 | * the CWD rather than the chain. */ | |
3073 | BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, | |
3074 | const char *backing_file) | |
3075 | { | |
3076 | char *filename_full = NULL; | |
3077 | char *backing_file_full = NULL; | |
3078 | char *filename_tmp = NULL; | |
3079 | int is_protocol = 0; | |
3080 | BlockDriverState *curr_bs = NULL; | |
3081 | BlockDriverState *retval = NULL; | |
3082 | ||
3083 | if (!bs || !bs->drv || !backing_file) { | |
3084 | return NULL; | |
3085 | } | |
3086 | ||
3087 | filename_full = g_malloc(PATH_MAX); | |
3088 | backing_file_full = g_malloc(PATH_MAX); | |
3089 | filename_tmp = g_malloc(PATH_MAX); | |
3090 | ||
3091 | is_protocol = path_has_protocol(backing_file); | |
3092 | ||
3093 | for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) { | |
3094 | ||
3095 | /* If either of the filename paths is actually a protocol, then | |
3096 | * compare unmodified paths; otherwise make paths relative */ | |
3097 | if (is_protocol || path_has_protocol(curr_bs->backing_file)) { | |
3098 | if (strcmp(backing_file, curr_bs->backing_file) == 0) { | |
3099 | retval = curr_bs->backing->bs; | |
3100 | break; | |
3101 | } | |
3102 | } else { | |
3103 | /* If not an absolute filename path, make it relative to the current | |
3104 | * image's filename path */ | |
3105 | path_combine(filename_tmp, PATH_MAX, curr_bs->filename, | |
3106 | backing_file); | |
3107 | ||
3108 | /* We are going to compare absolute pathnames */ | |
3109 | if (!realpath(filename_tmp, filename_full)) { | |
3110 | continue; | |
3111 | } | |
3112 | ||
3113 | /* We need to make sure the backing filename we are comparing against | |
3114 | * is relative to the current image filename (or absolute) */ | |
3115 | path_combine(filename_tmp, PATH_MAX, curr_bs->filename, | |
3116 | curr_bs->backing_file); | |
3117 | ||
3118 | if (!realpath(filename_tmp, backing_file_full)) { | |
3119 | continue; | |
3120 | } | |
3121 | ||
3122 | if (strcmp(backing_file_full, filename_full) == 0) { | |
3123 | retval = curr_bs->backing->bs; | |
3124 | break; | |
3125 | } | |
3126 | } | |
3127 | } | |
3128 | ||
3129 | g_free(filename_full); | |
3130 | g_free(backing_file_full); | |
3131 | g_free(filename_tmp); | |
3132 | return retval; | |
3133 | } | |
3134 | ||
3135 | int bdrv_get_backing_file_depth(BlockDriverState *bs) | |
3136 | { | |
3137 | if (!bs->drv) { | |
3138 | return 0; | |
3139 | } | |
3140 | ||
3141 | if (!bs->backing) { | |
3142 | return 0; | |
3143 | } | |
3144 | ||
3145 | return 1 + bdrv_get_backing_file_depth(bs->backing->bs); | |
3146 | } | |
3147 | ||
3148 | void bdrv_init(void) | |
3149 | { | |
3150 | module_call_init(MODULE_INIT_BLOCK); | |
3151 | } | |
3152 | ||
3153 | void bdrv_init_with_whitelist(void) | |
3154 | { | |
3155 | use_bdrv_whitelist = 1; | |
3156 | bdrv_init(); | |
3157 | } | |
3158 | ||
3159 | void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) | |
3160 | { | |
3161 | BdrvChild *child; | |
3162 | Error *local_err = NULL; | |
3163 | int ret; | |
3164 | ||
3165 | if (!bs->drv) { | |
3166 | return; | |
3167 | } | |
3168 | ||
3169 | if (!(bs->open_flags & BDRV_O_INACTIVE)) { | |
3170 | return; | |
3171 | } | |
3172 | bs->open_flags &= ~BDRV_O_INACTIVE; | |
3173 | ||
3174 | if (bs->drv->bdrv_invalidate_cache) { | |
3175 | bs->drv->bdrv_invalidate_cache(bs, &local_err); | |
3176 | if (local_err) { | |
3177 | bs->open_flags |= BDRV_O_INACTIVE; | |
3178 | error_propagate(errp, local_err); | |
3179 | return; | |
3180 | } | |
3181 | } | |
3182 | ||
3183 | QLIST_FOREACH(child, &bs->children, next) { | |
3184 | bdrv_invalidate_cache(child->bs, &local_err); | |
3185 | if (local_err) { | |
3186 | bs->open_flags |= BDRV_O_INACTIVE; | |
3187 | error_propagate(errp, local_err); | |
3188 | return; | |
3189 | } | |
3190 | } | |
3191 | ||
3192 | ret = refresh_total_sectors(bs, bs->total_sectors); | |
3193 | if (ret < 0) { | |
3194 | bs->open_flags |= BDRV_O_INACTIVE; | |
3195 | error_setg_errno(errp, -ret, "Could not refresh total sector count"); | |
3196 | return; | |
3197 | } | |
3198 | } | |
3199 | ||
3200 | void bdrv_invalidate_cache_all(Error **errp) | |
3201 | { | |
3202 | BlockDriverState *bs; | |
3203 | Error *local_err = NULL; | |
3204 | BdrvNextIterator it; | |
3205 | ||
3206 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
3207 | AioContext *aio_context = bdrv_get_aio_context(bs); | |
3208 | ||
3209 | aio_context_acquire(aio_context); | |
3210 | bdrv_invalidate_cache(bs, &local_err); | |
3211 | aio_context_release(aio_context); | |
3212 | if (local_err) { | |
3213 | error_propagate(errp, local_err); | |
3214 | return; | |
3215 | } | |
3216 | } | |
3217 | } | |
3218 | ||
3219 | static int bdrv_inactivate_recurse(BlockDriverState *bs, | |
3220 | bool setting_flag) | |
3221 | { | |
3222 | BdrvChild *child; | |
3223 | int ret; | |
3224 | ||
3225 | if (!setting_flag && bs->drv->bdrv_inactivate) { | |
3226 | ret = bs->drv->bdrv_inactivate(bs); | |
3227 | if (ret < 0) { | |
3228 | return ret; | |
3229 | } | |
3230 | } | |
3231 | ||
3232 | QLIST_FOREACH(child, &bs->children, next) { | |
3233 | ret = bdrv_inactivate_recurse(child->bs, setting_flag); | |
3234 | if (ret < 0) { | |
3235 | return ret; | |
3236 | } | |
3237 | } | |
3238 | ||
3239 | if (setting_flag) { | |
3240 | bs->open_flags |= BDRV_O_INACTIVE; | |
3241 | } | |
3242 | return 0; | |
3243 | } | |
3244 | ||
3245 | int bdrv_inactivate_all(void) | |
3246 | { | |
3247 | BlockDriverState *bs = NULL; | |
3248 | BdrvNextIterator it; | |
3249 | int ret = 0; | |
3250 | int pass; | |
3251 | ||
3252 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
3253 | aio_context_acquire(bdrv_get_aio_context(bs)); | |
3254 | } | |
3255 | ||
3256 | /* We do two passes of inactivation. The first pass calls to drivers' | |
3257 | * .bdrv_inactivate callbacks recursively so all cache is flushed to disk; | |
3258 | * the second pass sets the BDRV_O_INACTIVE flag so that no further write | |
3259 | * is allowed. */ | |
3260 | for (pass = 0; pass < 2; pass++) { | |
3261 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
3262 | ret = bdrv_inactivate_recurse(bs, pass); | |
3263 | if (ret < 0) { | |
3264 | goto out; | |
3265 | } | |
3266 | } | |
3267 | } | |
3268 | ||
3269 | out: | |
3270 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
3271 | aio_context_release(bdrv_get_aio_context(bs)); | |
3272 | } | |
3273 | ||
3274 | return ret; | |
3275 | } | |
3276 | ||
3277 | /**************************************************************/ | |
3278 | /* removable device support */ | |
3279 | ||
3280 | /** | |
3281 | * Return TRUE if the media is present | |
3282 | */ | |
3283 | bool bdrv_is_inserted(BlockDriverState *bs) | |
3284 | { | |
3285 | BlockDriver *drv = bs->drv; | |
3286 | BdrvChild *child; | |
3287 | ||
3288 | if (!drv) { | |
3289 | return false; | |
3290 | } | |
3291 | if (drv->bdrv_is_inserted) { | |
3292 | return drv->bdrv_is_inserted(bs); | |
3293 | } | |
3294 | QLIST_FOREACH(child, &bs->children, next) { | |
3295 | if (!bdrv_is_inserted(child->bs)) { | |
3296 | return false; | |
3297 | } | |
3298 | } | |
3299 | return true; | |
3300 | } | |
3301 | ||
3302 | /** | |
3303 | * Return whether the media changed since the last call to this | |
3304 | * function, or -ENOTSUP if we don't know. Most drivers don't know. | |
3305 | */ | |
3306 | int bdrv_media_changed(BlockDriverState *bs) | |
3307 | { | |
3308 | BlockDriver *drv = bs->drv; | |
3309 | ||
3310 | if (drv && drv->bdrv_media_changed) { | |
3311 | return drv->bdrv_media_changed(bs); | |
3312 | } | |
3313 | return -ENOTSUP; | |
3314 | } | |
3315 | ||
3316 | /** | |
3317 | * If eject_flag is TRUE, eject the media. Otherwise, close the tray | |
3318 | */ | |
3319 | void bdrv_eject(BlockDriverState *bs, bool eject_flag) | |
3320 | { | |
3321 | BlockDriver *drv = bs->drv; | |
3322 | const char *device_name; | |
3323 | ||
3324 | if (drv && drv->bdrv_eject) { | |
3325 | drv->bdrv_eject(bs, eject_flag); | |
3326 | } | |
3327 | ||
3328 | device_name = bdrv_get_device_name(bs); | |
3329 | if (device_name[0] != '\0') { | |
3330 | qapi_event_send_device_tray_moved(device_name, | |
3331 | eject_flag, &error_abort); | |
3332 | } | |
3333 | } | |
3334 | ||
3335 | /** | |
3336 | * Lock or unlock the media (if it is locked, the user won't be able | |
3337 | * to eject it manually). | |
3338 | */ | |
3339 | void bdrv_lock_medium(BlockDriverState *bs, bool locked) | |
3340 | { | |
3341 | BlockDriver *drv = bs->drv; | |
3342 | ||
3343 | trace_bdrv_lock_medium(bs, locked); | |
3344 | ||
3345 | if (drv && drv->bdrv_lock_medium) { | |
3346 | drv->bdrv_lock_medium(bs, locked); | |
3347 | } | |
3348 | } | |
3349 | ||
3350 | /* Get a reference to bs */ | |
3351 | void bdrv_ref(BlockDriverState *bs) | |
3352 | { | |
3353 | bs->refcnt++; | |
3354 | } | |
3355 | ||
3356 | /* Release a previously grabbed reference to bs. | |
3357 | * If after releasing, reference count is zero, the BlockDriverState is | |
3358 | * deleted. */ | |
3359 | void bdrv_unref(BlockDriverState *bs) | |
3360 | { | |
3361 | if (!bs) { | |
3362 | return; | |
3363 | } | |
3364 | assert(bs->refcnt > 0); | |
3365 | if (--bs->refcnt == 0) { | |
3366 | bdrv_delete(bs); | |
3367 | } | |
3368 | } | |
3369 | ||
3370 | struct BdrvOpBlocker { | |
3371 | Error *reason; | |
3372 | QLIST_ENTRY(BdrvOpBlocker) list; | |
3373 | }; | |
3374 | ||
3375 | bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) | |
3376 | { | |
3377 | BdrvOpBlocker *blocker; | |
3378 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
3379 | if (!QLIST_EMPTY(&bs->op_blockers[op])) { | |
3380 | blocker = QLIST_FIRST(&bs->op_blockers[op]); | |
3381 | if (errp) { | |
3382 | *errp = error_copy(blocker->reason); | |
3383 | error_prepend(errp, "Node '%s' is busy: ", | |
3384 | bdrv_get_device_or_node_name(bs)); | |
3385 | } | |
3386 | return true; | |
3387 | } | |
3388 | return false; | |
3389 | } | |
3390 | ||
3391 | void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason) | |
3392 | { | |
3393 | BdrvOpBlocker *blocker; | |
3394 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
3395 | ||
3396 | blocker = g_new0(BdrvOpBlocker, 1); | |
3397 | blocker->reason = reason; | |
3398 | QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list); | |
3399 | } | |
3400 | ||
3401 | void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason) | |
3402 | { | |
3403 | BdrvOpBlocker *blocker, *next; | |
3404 | assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); | |
3405 | QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) { | |
3406 | if (blocker->reason == reason) { | |
3407 | QLIST_REMOVE(blocker, list); | |
3408 | g_free(blocker); | |
3409 | } | |
3410 | } | |
3411 | } | |
3412 | ||
3413 | void bdrv_op_block_all(BlockDriverState *bs, Error *reason) | |
3414 | { | |
3415 | int i; | |
3416 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
3417 | bdrv_op_block(bs, i, reason); | |
3418 | } | |
3419 | } | |
3420 | ||
3421 | void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason) | |
3422 | { | |
3423 | int i; | |
3424 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
3425 | bdrv_op_unblock(bs, i, reason); | |
3426 | } | |
3427 | } | |
3428 | ||
3429 | bool bdrv_op_blocker_is_empty(BlockDriverState *bs) | |
3430 | { | |
3431 | int i; | |
3432 | ||
3433 | for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { | |
3434 | if (!QLIST_EMPTY(&bs->op_blockers[i])) { | |
3435 | return false; | |
3436 | } | |
3437 | } | |
3438 | return true; | |
3439 | } | |
3440 | ||
3441 | void bdrv_img_create(const char *filename, const char *fmt, | |
3442 | const char *base_filename, const char *base_fmt, | |
3443 | char *options, uint64_t img_size, int flags, | |
3444 | Error **errp, bool quiet) | |
3445 | { | |
3446 | QemuOptsList *create_opts = NULL; | |
3447 | QemuOpts *opts = NULL; | |
3448 | const char *backing_fmt, *backing_file; | |
3449 | int64_t size; | |
3450 | BlockDriver *drv, *proto_drv; | |
3451 | Error *local_err = NULL; | |
3452 | int ret = 0; | |
3453 | ||
3454 | /* Find driver and parse its options */ | |
3455 | drv = bdrv_find_format(fmt); | |
3456 | if (!drv) { | |
3457 | error_setg(errp, "Unknown file format '%s'", fmt); | |
3458 | return; | |
3459 | } | |
3460 | ||
3461 | proto_drv = bdrv_find_protocol(filename, true, errp); | |
3462 | if (!proto_drv) { | |
3463 | return; | |
3464 | } | |
3465 | ||
3466 | if (!drv->create_opts) { | |
3467 | error_setg(errp, "Format driver '%s' does not support image creation", | |
3468 | drv->format_name); | |
3469 | return; | |
3470 | } | |
3471 | ||
3472 | if (!proto_drv->create_opts) { | |
3473 | error_setg(errp, "Protocol driver '%s' does not support image creation", | |
3474 | proto_drv->format_name); | |
3475 | return; | |
3476 | } | |
3477 | ||
3478 | create_opts = qemu_opts_append(create_opts, drv->create_opts); | |
3479 | create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); | |
3480 | ||
3481 | /* Create parameter list with default values */ | |
3482 | opts = qemu_opts_create(create_opts, NULL, 0, &error_abort); | |
3483 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort); | |
3484 | ||
3485 | /* Parse -o options */ | |
3486 | if (options) { | |
3487 | qemu_opts_do_parse(opts, options, NULL, &local_err); | |
3488 | if (local_err) { | |
3489 | error_report_err(local_err); | |
3490 | local_err = NULL; | |
3491 | error_setg(errp, "Invalid options for file format '%s'", fmt); | |
3492 | goto out; | |
3493 | } | |
3494 | } | |
3495 | ||
3496 | if (base_filename) { | |
3497 | qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err); | |
3498 | if (local_err) { | |
3499 | error_setg(errp, "Backing file not supported for file format '%s'", | |
3500 | fmt); | |
3501 | goto out; | |
3502 | } | |
3503 | } | |
3504 | ||
3505 | if (base_fmt) { | |
3506 | qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err); | |
3507 | if (local_err) { | |
3508 | error_setg(errp, "Backing file format not supported for file " | |
3509 | "format '%s'", fmt); | |
3510 | goto out; | |
3511 | } | |
3512 | } | |
3513 | ||
3514 | backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); | |
3515 | if (backing_file) { | |
3516 | if (!strcmp(filename, backing_file)) { | |
3517 | error_setg(errp, "Error: Trying to create an image with the " | |
3518 | "same filename as the backing file"); | |
3519 | goto out; | |
3520 | } | |
3521 | } | |
3522 | ||
3523 | backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); | |
3524 | ||
3525 | // The size for the image must always be specified, with one exception: | |
3526 | // If we are using a backing file, we can obtain the size from there | |
3527 | size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); | |
3528 | if (size == -1) { | |
3529 | if (backing_file) { | |
3530 | BlockDriverState *bs; | |
3531 | char *full_backing = g_new0(char, PATH_MAX); | |
3532 | int64_t size; | |
3533 | int back_flags; | |
3534 | QDict *backing_options = NULL; | |
3535 | ||
3536 | bdrv_get_full_backing_filename_from_filename(filename, backing_file, | |
3537 | full_backing, PATH_MAX, | |
3538 | &local_err); | |
3539 | if (local_err) { | |
3540 | g_free(full_backing); | |
3541 | goto out; | |
3542 | } | |
3543 | ||
3544 | /* backing files always opened read-only */ | |
3545 | back_flags = flags; | |
3546 | back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); | |
3547 | ||
3548 | if (backing_fmt) { | |
3549 | backing_options = qdict_new(); | |
3550 | qdict_put(backing_options, "driver", | |
3551 | qstring_from_str(backing_fmt)); | |
3552 | } | |
3553 | ||
3554 | bs = bdrv_open(full_backing, NULL, backing_options, back_flags, | |
3555 | &local_err); | |
3556 | g_free(full_backing); | |
3557 | if (!bs) { | |
3558 | goto out; | |
3559 | } | |
3560 | size = bdrv_getlength(bs); | |
3561 | if (size < 0) { | |
3562 | error_setg_errno(errp, -size, "Could not get size of '%s'", | |
3563 | backing_file); | |
3564 | bdrv_unref(bs); | |
3565 | goto out; | |
3566 | } | |
3567 | ||
3568 | qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort); | |
3569 | ||
3570 | bdrv_unref(bs); | |
3571 | } else { | |
3572 | error_setg(errp, "Image creation needs a size parameter"); | |
3573 | goto out; | |
3574 | } | |
3575 | } | |
3576 | ||
3577 | if (!quiet) { | |
3578 | printf("Formatting '%s', fmt=%s ", filename, fmt); | |
3579 | qemu_opts_print(opts, " "); | |
3580 | puts(""); | |
3581 | } | |
3582 | ||
3583 | ret = bdrv_create(drv, filename, opts, &local_err); | |
3584 | ||
3585 | if (ret == -EFBIG) { | |
3586 | /* This is generally a better message than whatever the driver would | |
3587 | * deliver (especially because of the cluster_size_hint), since that | |
3588 | * is most probably not much different from "image too large". */ | |
3589 | const char *cluster_size_hint = ""; | |
3590 | if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) { | |
3591 | cluster_size_hint = " (try using a larger cluster size)"; | |
3592 | } | |
3593 | error_setg(errp, "The image size is too large for file format '%s'" | |
3594 | "%s", fmt, cluster_size_hint); | |
3595 | error_free(local_err); | |
3596 | local_err = NULL; | |
3597 | } | |
3598 | ||
3599 | out: | |
3600 | qemu_opts_del(opts); | |
3601 | qemu_opts_free(create_opts); | |
3602 | if (local_err) { | |
3603 | error_propagate(errp, local_err); | |
3604 | } | |
3605 | } | |
3606 | ||
3607 | AioContext *bdrv_get_aio_context(BlockDriverState *bs) | |
3608 | { | |
3609 | return bs->aio_context; | |
3610 | } | |
3611 | ||
3612 | void bdrv_detach_aio_context(BlockDriverState *bs) | |
3613 | { | |
3614 | BdrvAioNotifier *baf; | |
3615 | BdrvChild *child; | |
3616 | ||
3617 | if (!bs->drv) { | |
3618 | return; | |
3619 | } | |
3620 | ||
3621 | QLIST_FOREACH(baf, &bs->aio_notifiers, list) { | |
3622 | baf->detach_aio_context(baf->opaque); | |
3623 | } | |
3624 | ||
3625 | if (bs->drv->bdrv_detach_aio_context) { | |
3626 | bs->drv->bdrv_detach_aio_context(bs); | |
3627 | } | |
3628 | QLIST_FOREACH(child, &bs->children, next) { | |
3629 | bdrv_detach_aio_context(child->bs); | |
3630 | } | |
3631 | ||
3632 | bs->aio_context = NULL; | |
3633 | } | |
3634 | ||
3635 | void bdrv_attach_aio_context(BlockDriverState *bs, | |
3636 | AioContext *new_context) | |
3637 | { | |
3638 | BdrvAioNotifier *ban; | |
3639 | BdrvChild *child; | |
3640 | ||
3641 | if (!bs->drv) { | |
3642 | return; | |
3643 | } | |
3644 | ||
3645 | bs->aio_context = new_context; | |
3646 | ||
3647 | QLIST_FOREACH(child, &bs->children, next) { | |
3648 | bdrv_attach_aio_context(child->bs, new_context); | |
3649 | } | |
3650 | if (bs->drv->bdrv_attach_aio_context) { | |
3651 | bs->drv->bdrv_attach_aio_context(bs, new_context); | |
3652 | } | |
3653 | ||
3654 | QLIST_FOREACH(ban, &bs->aio_notifiers, list) { | |
3655 | ban->attached_aio_context(new_context, ban->opaque); | |
3656 | } | |
3657 | } | |
3658 | ||
3659 | void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) | |
3660 | { | |
3661 | bdrv_drain(bs); /* ensure there are no in-flight requests */ | |
3662 | ||
3663 | bdrv_detach_aio_context(bs); | |
3664 | ||
3665 | /* This function executes in the old AioContext so acquire the new one in | |
3666 | * case it runs in a different thread. | |
3667 | */ | |
3668 | aio_context_acquire(new_context); | |
3669 | bdrv_attach_aio_context(bs, new_context); | |
3670 | aio_context_release(new_context); | |
3671 | } | |
3672 | ||
3673 | void bdrv_add_aio_context_notifier(BlockDriverState *bs, | |
3674 | void (*attached_aio_context)(AioContext *new_context, void *opaque), | |
3675 | void (*detach_aio_context)(void *opaque), void *opaque) | |
3676 | { | |
3677 | BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1); | |
3678 | *ban = (BdrvAioNotifier){ | |
3679 | .attached_aio_context = attached_aio_context, | |
3680 | .detach_aio_context = detach_aio_context, | |
3681 | .opaque = opaque | |
3682 | }; | |
3683 | ||
3684 | QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list); | |
3685 | } | |
3686 | ||
3687 | void bdrv_remove_aio_context_notifier(BlockDriverState *bs, | |
3688 | void (*attached_aio_context)(AioContext *, | |
3689 | void *), | |
3690 | void (*detach_aio_context)(void *), | |
3691 | void *opaque) | |
3692 | { | |
3693 | BdrvAioNotifier *ban, *ban_next; | |
3694 | ||
3695 | QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { | |
3696 | if (ban->attached_aio_context == attached_aio_context && | |
3697 | ban->detach_aio_context == detach_aio_context && | |
3698 | ban->opaque == opaque) | |
3699 | { | |
3700 | QLIST_REMOVE(ban, list); | |
3701 | g_free(ban); | |
3702 | ||
3703 | return; | |
3704 | } | |
3705 | } | |
3706 | ||
3707 | abort(); | |
3708 | } | |
3709 | ||
3710 | int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts, | |
3711 | BlockDriverAmendStatusCB *status_cb, void *cb_opaque) | |
3712 | { | |
3713 | if (!bs->drv->bdrv_amend_options) { | |
3714 | return -ENOTSUP; | |
3715 | } | |
3716 | return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque); | |
3717 | } | |
3718 | ||
3719 | /* This function will be called by the bdrv_recurse_is_first_non_filter method | |
3720 | * of block filter and by bdrv_is_first_non_filter. | |
3721 | * It is used to test if the given bs is the candidate or recurse more in the | |
3722 | * node graph. | |
3723 | */ | |
3724 | bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, | |
3725 | BlockDriverState *candidate) | |
3726 | { | |
3727 | /* return false if basic checks fails */ | |
3728 | if (!bs || !bs->drv) { | |
3729 | return false; | |
3730 | } | |
3731 | ||
3732 | /* the code reached a non block filter driver -> check if the bs is | |
3733 | * the same as the candidate. It's the recursion termination condition. | |
3734 | */ | |
3735 | if (!bs->drv->is_filter) { | |
3736 | return bs == candidate; | |
3737 | } | |
3738 | /* Down this path the driver is a block filter driver */ | |
3739 | ||
3740 | /* If the block filter recursion method is defined use it to recurse down | |
3741 | * the node graph. | |
3742 | */ | |
3743 | if (bs->drv->bdrv_recurse_is_first_non_filter) { | |
3744 | return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate); | |
3745 | } | |
3746 | ||
3747 | /* the driver is a block filter but don't allow to recurse -> return false | |
3748 | */ | |
3749 | return false; | |
3750 | } | |
3751 | ||
3752 | /* This function checks if the candidate is the first non filter bs down it's | |
3753 | * bs chain. Since we don't have pointers to parents it explore all bs chains | |
3754 | * from the top. Some filters can choose not to pass down the recursion. | |
3755 | */ | |
3756 | bool bdrv_is_first_non_filter(BlockDriverState *candidate) | |
3757 | { | |
3758 | BlockDriverState *bs; | |
3759 | BdrvNextIterator it; | |
3760 | ||
3761 | /* walk down the bs forest recursively */ | |
3762 | for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { | |
3763 | bool perm; | |
3764 | ||
3765 | /* try to recurse in this top level bs */ | |
3766 | perm = bdrv_recurse_is_first_non_filter(bs, candidate); | |
3767 | ||
3768 | /* candidate is the first non filter */ | |
3769 | if (perm) { | |
3770 | return true; | |
3771 | } | |
3772 | } | |
3773 | ||
3774 | return false; | |
3775 | } | |
3776 | ||
3777 | BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, | |
3778 | const char *node_name, Error **errp) | |
3779 | { | |
3780 | BlockDriverState *to_replace_bs = bdrv_find_node(node_name); | |
3781 | AioContext *aio_context; | |
3782 | ||
3783 | if (!to_replace_bs) { | |
3784 | error_setg(errp, "Node name '%s' not found", node_name); | |
3785 | return NULL; | |
3786 | } | |
3787 | ||
3788 | aio_context = bdrv_get_aio_context(to_replace_bs); | |
3789 | aio_context_acquire(aio_context); | |
3790 | ||
3791 | if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) { | |
3792 | to_replace_bs = NULL; | |
3793 | goto out; | |
3794 | } | |
3795 | ||
3796 | /* We don't want arbitrary node of the BDS chain to be replaced only the top | |
3797 | * most non filter in order to prevent data corruption. | |
3798 | * Another benefit is that this tests exclude backing files which are | |
3799 | * blocked by the backing blockers. | |
3800 | */ | |
3801 | if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) { | |
3802 | error_setg(errp, "Only top most non filter can be replaced"); | |
3803 | to_replace_bs = NULL; | |
3804 | goto out; | |
3805 | } | |
3806 | ||
3807 | out: | |
3808 | aio_context_release(aio_context); | |
3809 | return to_replace_bs; | |
3810 | } | |
3811 | ||
3812 | static bool append_open_options(QDict *d, BlockDriverState *bs) | |
3813 | { | |
3814 | const QDictEntry *entry; | |
3815 | QemuOptDesc *desc; | |
3816 | BdrvChild *child; | |
3817 | bool found_any = false; | |
3818 | const char *p; | |
3819 | ||
3820 | for (entry = qdict_first(bs->options); entry; | |
3821 | entry = qdict_next(bs->options, entry)) | |
3822 | { | |
3823 | /* Exclude options for children */ | |
3824 | QLIST_FOREACH(child, &bs->children, next) { | |
3825 | if (strstart(qdict_entry_key(entry), child->name, &p) | |
3826 | && (!*p || *p == '.')) | |
3827 | { | |
3828 | break; | |
3829 | } | |
3830 | } | |
3831 | if (child) { | |
3832 | continue; | |
3833 | } | |
3834 | ||
3835 | /* And exclude all non-driver-specific options */ | |
3836 | for (desc = bdrv_runtime_opts.desc; desc->name; desc++) { | |
3837 | if (!strcmp(qdict_entry_key(entry), desc->name)) { | |
3838 | break; | |
3839 | } | |
3840 | } | |
3841 | if (desc->name) { | |
3842 | continue; | |
3843 | } | |
3844 | ||
3845 | qobject_incref(qdict_entry_value(entry)); | |
3846 | qdict_put_obj(d, qdict_entry_key(entry), qdict_entry_value(entry)); | |
3847 | found_any = true; | |
3848 | } | |
3849 | ||
3850 | return found_any; | |
3851 | } | |
3852 | ||
3853 | /* Updates the following BDS fields: | |
3854 | * - exact_filename: A filename which may be used for opening a block device | |
3855 | * which (mostly) equals the given BDS (even without any | |
3856 | * other options; so reading and writing must return the same | |
3857 | * results, but caching etc. may be different) | |
3858 | * - full_open_options: Options which, when given when opening a block device | |
3859 | * (without a filename), result in a BDS (mostly) | |
3860 | * equalling the given one | |
3861 | * - filename: If exact_filename is set, it is copied here. Otherwise, | |
3862 | * full_open_options is converted to a JSON object, prefixed with | |
3863 | * "json:" (for use through the JSON pseudo protocol) and put here. | |
3864 | */ | |
3865 | void bdrv_refresh_filename(BlockDriverState *bs) | |
3866 | { | |
3867 | BlockDriver *drv = bs->drv; | |
3868 | QDict *opts; | |
3869 | ||
3870 | if (!drv) { | |
3871 | return; | |
3872 | } | |
3873 | ||
3874 | /* This BDS's file name will most probably depend on its file's name, so | |
3875 | * refresh that first */ | |
3876 | if (bs->file) { | |
3877 | bdrv_refresh_filename(bs->file->bs); | |
3878 | } | |
3879 | ||
3880 | if (drv->bdrv_refresh_filename) { | |
3881 | /* Obsolete information is of no use here, so drop the old file name | |
3882 | * information before refreshing it */ | |
3883 | bs->exact_filename[0] = '\0'; | |
3884 | if (bs->full_open_options) { | |
3885 | QDECREF(bs->full_open_options); | |
3886 | bs->full_open_options = NULL; | |
3887 | } | |
3888 | ||
3889 | opts = qdict_new(); | |
3890 | append_open_options(opts, bs); | |
3891 | drv->bdrv_refresh_filename(bs, opts); | |
3892 | QDECREF(opts); | |
3893 | } else if (bs->file) { | |
3894 | /* Try to reconstruct valid information from the underlying file */ | |
3895 | bool has_open_options; | |
3896 | ||
3897 | bs->exact_filename[0] = '\0'; | |
3898 | if (bs->full_open_options) { | |
3899 | QDECREF(bs->full_open_options); | |
3900 | bs->full_open_options = NULL; | |
3901 | } | |
3902 | ||
3903 | opts = qdict_new(); | |
3904 | has_open_options = append_open_options(opts, bs); | |
3905 | ||
3906 | /* If no specific options have been given for this BDS, the filename of | |
3907 | * the underlying file should suffice for this one as well */ | |
3908 | if (bs->file->bs->exact_filename[0] && !has_open_options) { | |
3909 | strcpy(bs->exact_filename, bs->file->bs->exact_filename); | |
3910 | } | |
3911 | /* Reconstructing the full options QDict is simple for most format block | |
3912 | * drivers, as long as the full options are known for the underlying | |
3913 | * file BDS. The full options QDict of that file BDS should somehow | |
3914 | * contain a representation of the filename, therefore the following | |
3915 | * suffices without querying the (exact_)filename of this BDS. */ | |
3916 | if (bs->file->bs->full_open_options) { | |
3917 | qdict_put_obj(opts, "driver", | |
3918 | QOBJECT(qstring_from_str(drv->format_name))); | |
3919 | QINCREF(bs->file->bs->full_open_options); | |
3920 | qdict_put_obj(opts, "file", | |
3921 | QOBJECT(bs->file->bs->full_open_options)); | |
3922 | ||
3923 | bs->full_open_options = opts; | |
3924 | } else { | |
3925 | QDECREF(opts); | |
3926 | } | |
3927 | } else if (!bs->full_open_options && qdict_size(bs->options)) { | |
3928 | /* There is no underlying file BDS (at least referenced by BDS.file), | |
3929 | * so the full options QDict should be equal to the options given | |
3930 | * specifically for this block device when it was opened (plus the | |
3931 | * driver specification). | |
3932 | * Because those options don't change, there is no need to update | |
3933 | * full_open_options when it's already set. */ | |
3934 | ||
3935 | opts = qdict_new(); | |
3936 | append_open_options(opts, bs); | |
3937 | qdict_put_obj(opts, "driver", | |
3938 | QOBJECT(qstring_from_str(drv->format_name))); | |
3939 | ||
3940 | if (bs->exact_filename[0]) { | |
3941 | /* This may not work for all block protocol drivers (some may | |
3942 | * require this filename to be parsed), but we have to find some | |
3943 | * default solution here, so just include it. If some block driver | |
3944 | * does not support pure options without any filename at all or | |
3945 | * needs some special format of the options QDict, it needs to | |
3946 | * implement the driver-specific bdrv_refresh_filename() function. | |
3947 | */ | |
3948 | qdict_put_obj(opts, "filename", | |
3949 | QOBJECT(qstring_from_str(bs->exact_filename))); | |
3950 | } | |
3951 | ||
3952 | bs->full_open_options = opts; | |
3953 | } | |
3954 | ||
3955 | if (bs->exact_filename[0]) { | |
3956 | pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); | |
3957 | } else if (bs->full_open_options) { | |
3958 | QString *json = qobject_to_json(QOBJECT(bs->full_open_options)); | |
3959 | snprintf(bs->filename, sizeof(bs->filename), "json:%s", | |
3960 | qstring_get_str(json)); | |
3961 | QDECREF(json); | |
3962 | } | |
3963 | } | |
3964 | ||
3965 | /* | |
3966 | * Hot add/remove a BDS's child. So the user can take a child offline when | |
3967 | * it is broken and take a new child online | |
3968 | */ | |
3969 | void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, | |
3970 | Error **errp) | |
3971 | { | |
3972 | ||
3973 | if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) { | |
3974 | error_setg(errp, "The node %s does not support adding a child", | |
3975 | bdrv_get_device_or_node_name(parent_bs)); | |
3976 | return; | |
3977 | } | |
3978 | ||
3979 | if (!QLIST_EMPTY(&child_bs->parents)) { | |
3980 | error_setg(errp, "The node %s already has a parent", | |
3981 | child_bs->node_name); | |
3982 | return; | |
3983 | } | |
3984 | ||
3985 | parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp); | |
3986 | } | |
3987 | ||
3988 | void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp) | |
3989 | { | |
3990 | BdrvChild *tmp; | |
3991 | ||
3992 | if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) { | |
3993 | error_setg(errp, "The node %s does not support removing a child", | |
3994 | bdrv_get_device_or_node_name(parent_bs)); | |
3995 | return; | |
3996 | } | |
3997 | ||
3998 | QLIST_FOREACH(tmp, &parent_bs->children, next) { | |
3999 | if (tmp == child) { | |
4000 | break; | |
4001 | } | |
4002 | } | |
4003 | ||
4004 | if (!tmp) { | |
4005 | error_setg(errp, "The node %s does not have a child named %s", | |
4006 | bdrv_get_device_or_node_name(parent_bs), | |
4007 | bdrv_get_device_or_node_name(child->bs)); | |
4008 | return; | |
4009 | } | |
4010 | ||
4011 | parent_bs->drv->bdrv_del_child(parent_bs, child, errp); | |
4012 | } |