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nbd: BLOCK_STATUS constants
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fc01f7e7
FB
1/*
2 * QEMU System Emulator block driver
5fafdf24 3 *
fc01f7e7 4 * Copyright (c) 2003 Fabrice Bellard
5fafdf24 5 *
fc01f7e7
FB
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 */
e688df6b 24
d38ea87a 25#include "qemu/osdep.h"
0ab8ed18 26#include "block/trace.h"
737e150e
PB
27#include "block/block_int.h"
28#include "block/blockjob.h"
cd7fca95 29#include "block/nbd.h"
d49b6836 30#include "qemu/error-report.h"
88d88798 31#include "module_block.h"
1de7afc9 32#include "qemu/module.h"
e688df6b 33#include "qapi/error.h"
452fcdbc 34#include "qapi/qmp/qdict.h"
cc7a8ea7 35#include "qapi/qmp/qerror.h"
7b1b5d19 36#include "qapi/qmp/qjson.h"
fc81fa1e 37#include "qapi/qmp/qstring.h"
bfb197e0 38#include "sysemu/block-backend.h"
9c17d615 39#include "sysemu/sysemu.h"
1de7afc9 40#include "qemu/notify.h"
922a01a0 41#include "qemu/option.h"
10817bf0 42#include "qemu/coroutine.h"
c13163fb 43#include "block/qapi.h"
1de7afc9 44#include "qemu/timer.h"
a5ee7bd4 45#include "qapi-event.h"
f348b6d1
VB
46#include "qemu/cutils.h"
47#include "qemu/id.h"
fc01f7e7 48
71e72a19 49#ifdef CONFIG_BSD
7674e7bf 50#include <sys/ioctl.h>
72cf2d4f 51#include <sys/queue.h>
c5e97233 52#ifndef __DragonFly__
7674e7bf
FB
53#include <sys/disk.h>
54#endif
c5e97233 55#endif
7674e7bf 56
49dc768d
AL
57#ifdef _WIN32
58#include <windows.h>
59#endif
60
1c9805a3
SH
61#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
62
dc364f4c
BC
63static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
64 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
65
2c1d04e0
HR
66static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states =
67 QTAILQ_HEAD_INITIALIZER(all_bdrv_states);
68
8a22f02a
SH
69static QLIST_HEAD(, BlockDriver) bdrv_drivers =
70 QLIST_HEAD_INITIALIZER(bdrv_drivers);
ea2384d3 71
5b363937
HR
72static BlockDriverState *bdrv_open_inherit(const char *filename,
73 const char *reference,
74 QDict *options, int flags,
75 BlockDriverState *parent,
76 const BdrvChildRole *child_role,
77 Error **errp);
f3930ed0 78
eb852011
MA
79/* If non-zero, use only whitelisted block drivers */
80static int use_bdrv_whitelist;
81
9e0b22f4
SH
82#ifdef _WIN32
83static int is_windows_drive_prefix(const char *filename)
84{
85 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
86 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
87 filename[1] == ':');
88}
89
90int is_windows_drive(const char *filename)
91{
92 if (is_windows_drive_prefix(filename) &&
93 filename[2] == '\0')
94 return 1;
95 if (strstart(filename, "\\\\.\\", NULL) ||
96 strstart(filename, "//./", NULL))
97 return 1;
98 return 0;
99}
100#endif
101
339064d5
KW
102size_t bdrv_opt_mem_align(BlockDriverState *bs)
103{
104 if (!bs || !bs->drv) {
459b4e66
DL
105 /* page size or 4k (hdd sector size) should be on the safe side */
106 return MAX(4096, getpagesize());
339064d5
KW
107 }
108
109 return bs->bl.opt_mem_alignment;
110}
111
4196d2f0
DL
112size_t bdrv_min_mem_align(BlockDriverState *bs)
113{
114 if (!bs || !bs->drv) {
459b4e66
DL
115 /* page size or 4k (hdd sector size) should be on the safe side */
116 return MAX(4096, getpagesize());
4196d2f0
DL
117 }
118
119 return bs->bl.min_mem_alignment;
120}
121
9e0b22f4 122/* check if the path starts with "<protocol>:" */
5c98415b 123int path_has_protocol(const char *path)
9e0b22f4 124{
947995c0
PB
125 const char *p;
126
9e0b22f4
SH
127#ifdef _WIN32
128 if (is_windows_drive(path) ||
129 is_windows_drive_prefix(path)) {
130 return 0;
131 }
947995c0
PB
132 p = path + strcspn(path, ":/\\");
133#else
134 p = path + strcspn(path, ":/");
9e0b22f4
SH
135#endif
136
947995c0 137 return *p == ':';
9e0b22f4
SH
138}
139
83f64091 140int path_is_absolute(const char *path)
3b0d4f61 141{
21664424
FB
142#ifdef _WIN32
143 /* specific case for names like: "\\.\d:" */
f53f4da9 144 if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
21664424 145 return 1;
f53f4da9
PB
146 }
147 return (*path == '/' || *path == '\\');
3b9f94e1 148#else
f53f4da9 149 return (*path == '/');
3b9f94e1 150#endif
3b0d4f61
FB
151}
152
83f64091
FB
153/* if filename is absolute, just copy it to dest. Otherwise, build a
154 path to it by considering it is relative to base_path. URL are
155 supported. */
156void path_combine(char *dest, int dest_size,
157 const char *base_path,
158 const char *filename)
3b0d4f61 159{
83f64091
FB
160 const char *p, *p1;
161 int len;
162
163 if (dest_size <= 0)
164 return;
165 if (path_is_absolute(filename)) {
166 pstrcpy(dest, dest_size, filename);
167 } else {
0d54a6fe
HR
168 const char *protocol_stripped = NULL;
169
170 if (path_has_protocol(base_path)) {
171 protocol_stripped = strchr(base_path, ':');
172 if (protocol_stripped) {
173 protocol_stripped++;
174 }
175 }
176 p = protocol_stripped ?: base_path;
177
3b9f94e1
FB
178 p1 = strrchr(base_path, '/');
179#ifdef _WIN32
180 {
181 const char *p2;
182 p2 = strrchr(base_path, '\\');
183 if (!p1 || p2 > p1)
184 p1 = p2;
185 }
186#endif
83f64091
FB
187 if (p1)
188 p1++;
189 else
190 p1 = base_path;
191 if (p1 > p)
192 p = p1;
193 len = p - base_path;
194 if (len > dest_size - 1)
195 len = dest_size - 1;
196 memcpy(dest, base_path, len);
197 dest[len] = '\0';
198 pstrcat(dest, dest_size, filename);
3b0d4f61 199 }
3b0d4f61
FB
200}
201
03c320d8
HR
202/*
203 * Helper function for bdrv_parse_filename() implementations to remove optional
204 * protocol prefixes (especially "file:") from a filename and for putting the
205 * stripped filename into the options QDict if there is such a prefix.
206 */
207void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
208 QDict *options)
209{
210 if (strstart(filename, prefix, &filename)) {
211 /* Stripping the explicit protocol prefix may result in a protocol
212 * prefix being (wrongly) detected (if the filename contains a colon) */
213 if (path_has_protocol(filename)) {
214 QString *fat_filename;
215
216 /* This means there is some colon before the first slash; therefore,
217 * this cannot be an absolute path */
218 assert(!path_is_absolute(filename));
219
220 /* And we can thus fix the protocol detection issue by prefixing it
221 * by "./" */
222 fat_filename = qstring_from_str("./");
223 qstring_append(fat_filename, filename);
224
225 assert(!path_has_protocol(qstring_get_str(fat_filename)));
226
227 qdict_put(options, "filename", fat_filename);
228 } else {
229 /* If no protocol prefix was detected, we can use the shortened
230 * filename as-is */
231 qdict_put_str(options, "filename", filename);
232 }
233 }
234}
235
236
9c5e6594
KW
237/* Returns whether the image file is opened as read-only. Note that this can
238 * return false and writing to the image file is still not possible because the
239 * image is inactivated. */
93ed524e
JC
240bool bdrv_is_read_only(BlockDriverState *bs)
241{
242 return bs->read_only;
243}
244
54a32bfe
KW
245int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
246 bool ignore_allow_rdw, Error **errp)
fe5241bf 247{
e2b8247a
JC
248 /* Do not set read_only if copy_on_read is enabled */
249 if (bs->copy_on_read && read_only) {
250 error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled",
251 bdrv_get_device_or_node_name(bs));
252 return -EINVAL;
253 }
254
d6fcdf06 255 /* Do not clear read_only if it is prohibited */
54a32bfe
KW
256 if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) &&
257 !ignore_allow_rdw)
258 {
d6fcdf06
JC
259 error_setg(errp, "Node '%s' is read only",
260 bdrv_get_device_or_node_name(bs));
261 return -EPERM;
262 }
263
45803a03
JC
264 return 0;
265}
266
398e6ad0
KW
267/* TODO Remove (deprecated since 2.11)
268 * Block drivers are not supposed to automatically change bs->read_only.
269 * Instead, they should just check whether they can provide what the user
270 * explicitly requested and error out if read-write is requested, but they can
271 * only provide read-only access. */
45803a03
JC
272int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp)
273{
274 int ret = 0;
275
54a32bfe 276 ret = bdrv_can_set_read_only(bs, read_only, false, errp);
45803a03
JC
277 if (ret < 0) {
278 return ret;
279 }
280
fe5241bf 281 bs->read_only = read_only;
e2b8247a 282 return 0;
fe5241bf
JC
283}
284
0a82855a
HR
285void bdrv_get_full_backing_filename_from_filename(const char *backed,
286 const char *backing,
9f07429e
HR
287 char *dest, size_t sz,
288 Error **errp)
dc5a1371 289{
9f07429e
HR
290 if (backing[0] == '\0' || path_has_protocol(backing) ||
291 path_is_absolute(backing))
292 {
0a82855a 293 pstrcpy(dest, sz, backing);
9f07429e
HR
294 } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
295 error_setg(errp, "Cannot use relative backing file names for '%s'",
296 backed);
dc5a1371 297 } else {
0a82855a 298 path_combine(dest, sz, backed, backing);
dc5a1371
PB
299 }
300}
301
9f07429e
HR
302void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz,
303 Error **errp)
0a82855a 304{
9f07429e
HR
305 char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename;
306
307 bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file,
308 dest, sz, errp);
0a82855a
HR
309}
310
0eb7217e
SH
311void bdrv_register(BlockDriver *bdrv)
312{
8a22f02a 313 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
ea2384d3 314}
b338082b 315
e4e9986b
MA
316BlockDriverState *bdrv_new(void)
317{
318 BlockDriverState *bs;
319 int i;
320
5839e53b 321 bs = g_new0(BlockDriverState, 1);
e4654d2d 322 QLIST_INIT(&bs->dirty_bitmaps);
fbe40ff7
FZ
323 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
324 QLIST_INIT(&bs->op_blockers[i]);
325 }
d616b224 326 notifier_with_return_list_init(&bs->before_write_notifiers);
3783fa3d 327 qemu_co_mutex_init(&bs->reqs_lock);
2119882c 328 qemu_mutex_init(&bs->dirty_bitmap_mutex);
9fcb0251 329 bs->refcnt = 1;
dcd04228 330 bs->aio_context = qemu_get_aio_context();
d7d512f6 331
3ff2f67a
EY
332 qemu_co_queue_init(&bs->flush_queue);
333
2c1d04e0
HR
334 QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list);
335
b338082b
FB
336 return bs;
337}
338
88d88798 339static BlockDriver *bdrv_do_find_format(const char *format_name)
ea2384d3
FB
340{
341 BlockDriver *drv1;
88d88798 342
8a22f02a
SH
343 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
344 if (!strcmp(drv1->format_name, format_name)) {
ea2384d3 345 return drv1;
8a22f02a 346 }
ea2384d3 347 }
88d88798 348
ea2384d3
FB
349 return NULL;
350}
351
88d88798
MM
352BlockDriver *bdrv_find_format(const char *format_name)
353{
354 BlockDriver *drv1;
355 int i;
356
357 drv1 = bdrv_do_find_format(format_name);
358 if (drv1) {
359 return drv1;
360 }
361
362 /* The driver isn't registered, maybe we need to load a module */
363 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
364 if (!strcmp(block_driver_modules[i].format_name, format_name)) {
365 block_module_load_one(block_driver_modules[i].library_name);
366 break;
367 }
368 }
369
370 return bdrv_do_find_format(format_name);
371}
372
b64ec4e4 373static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
eb852011 374{
b64ec4e4
FZ
375 static const char *whitelist_rw[] = {
376 CONFIG_BDRV_RW_WHITELIST
377 };
378 static const char *whitelist_ro[] = {
379 CONFIG_BDRV_RO_WHITELIST
eb852011
MA
380 };
381 const char **p;
382
b64ec4e4 383 if (!whitelist_rw[0] && !whitelist_ro[0]) {
eb852011 384 return 1; /* no whitelist, anything goes */
b64ec4e4 385 }
eb852011 386
b64ec4e4 387 for (p = whitelist_rw; *p; p++) {
eb852011
MA
388 if (!strcmp(drv->format_name, *p)) {
389 return 1;
390 }
391 }
b64ec4e4
FZ
392 if (read_only) {
393 for (p = whitelist_ro; *p; p++) {
394 if (!strcmp(drv->format_name, *p)) {
395 return 1;
396 }
397 }
398 }
eb852011
MA
399 return 0;
400}
401
e6ff69bf
DB
402bool bdrv_uses_whitelist(void)
403{
404 return use_bdrv_whitelist;
405}
406
5b7e1542
ZYW
407typedef struct CreateCo {
408 BlockDriver *drv;
409 char *filename;
83d0521a 410 QemuOpts *opts;
5b7e1542 411 int ret;
cc84d90f 412 Error *err;
5b7e1542
ZYW
413} CreateCo;
414
415static void coroutine_fn bdrv_create_co_entry(void *opaque)
416{
cc84d90f
HR
417 Error *local_err = NULL;
418 int ret;
419
5b7e1542
ZYW
420 CreateCo *cco = opaque;
421 assert(cco->drv);
422
c282e1fd 423 ret = cco->drv->bdrv_create(cco->filename, cco->opts, &local_err);
621ff94d 424 error_propagate(&cco->err, local_err);
cc84d90f 425 cco->ret = ret;
5b7e1542
ZYW
426}
427
0e7e1989 428int bdrv_create(BlockDriver *drv, const char* filename,
83d0521a 429 QemuOpts *opts, Error **errp)
ea2384d3 430{
5b7e1542
ZYW
431 int ret;
432
433 Coroutine *co;
434 CreateCo cco = {
435 .drv = drv,
436 .filename = g_strdup(filename),
83d0521a 437 .opts = opts,
5b7e1542 438 .ret = NOT_DONE,
cc84d90f 439 .err = NULL,
5b7e1542
ZYW
440 };
441
c282e1fd 442 if (!drv->bdrv_create) {
cc84d90f 443 error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
80168bff
LC
444 ret = -ENOTSUP;
445 goto out;
5b7e1542
ZYW
446 }
447
448 if (qemu_in_coroutine()) {
449 /* Fast-path if already in coroutine context */
450 bdrv_create_co_entry(&cco);
451 } else {
0b8b8753
PB
452 co = qemu_coroutine_create(bdrv_create_co_entry, &cco);
453 qemu_coroutine_enter(co);
5b7e1542 454 while (cco.ret == NOT_DONE) {
b47ec2c4 455 aio_poll(qemu_get_aio_context(), true);
5b7e1542
ZYW
456 }
457 }
458
459 ret = cco.ret;
cc84d90f 460 if (ret < 0) {
84d18f06 461 if (cco.err) {
cc84d90f
HR
462 error_propagate(errp, cco.err);
463 } else {
464 error_setg_errno(errp, -ret, "Could not create image");
465 }
466 }
0e7e1989 467
80168bff
LC
468out:
469 g_free(cco.filename);
5b7e1542 470 return ret;
ea2384d3
FB
471}
472
c282e1fd 473int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
84a12e66
CH
474{
475 BlockDriver *drv;
cc84d90f
HR
476 Error *local_err = NULL;
477 int ret;
84a12e66 478
b65a5e12 479 drv = bdrv_find_protocol(filename, true, errp);
84a12e66 480 if (drv == NULL) {
16905d71 481 return -ENOENT;
84a12e66
CH
482 }
483
c282e1fd 484 ret = bdrv_create(drv, filename, opts, &local_err);
621ff94d 485 error_propagate(errp, local_err);
cc84d90f 486 return ret;
84a12e66
CH
487}
488
892b7de8
ET
489/**
490 * Try to get @bs's logical and physical block size.
491 * On success, store them in @bsz struct and return 0.
492 * On failure return -errno.
493 * @bs must not be empty.
494 */
495int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
496{
497 BlockDriver *drv = bs->drv;
498
499 if (drv && drv->bdrv_probe_blocksizes) {
500 return drv->bdrv_probe_blocksizes(bs, bsz);
5a612c00
MP
501 } else if (drv && drv->is_filter && bs->file) {
502 return bdrv_probe_blocksizes(bs->file->bs, bsz);
892b7de8
ET
503 }
504
505 return -ENOTSUP;
506}
507
508/**
509 * Try to get @bs's geometry (cyls, heads, sectors).
510 * On success, store them in @geo struct and return 0.
511 * On failure return -errno.
512 * @bs must not be empty.
513 */
514int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
515{
516 BlockDriver *drv = bs->drv;
517
518 if (drv && drv->bdrv_probe_geometry) {
519 return drv->bdrv_probe_geometry(bs, geo);
5a612c00
MP
520 } else if (drv && drv->is_filter && bs->file) {
521 return bdrv_probe_geometry(bs->file->bs, geo);
892b7de8
ET
522 }
523
524 return -ENOTSUP;
525}
526
eba25057
JM
527/*
528 * Create a uniquely-named empty temporary file.
529 * Return 0 upon success, otherwise a negative errno value.
530 */
531int get_tmp_filename(char *filename, int size)
d5249393 532{
eba25057 533#ifdef _WIN32
3b9f94e1 534 char temp_dir[MAX_PATH];
eba25057
JM
535 /* GetTempFileName requires that its output buffer (4th param)
536 have length MAX_PATH or greater. */
537 assert(size >= MAX_PATH);
538 return (GetTempPath(MAX_PATH, temp_dir)
539 && GetTempFileName(temp_dir, "qem", 0, filename)
540 ? 0 : -GetLastError());
d5249393 541#else
67b915a5 542 int fd;
7ccfb2eb 543 const char *tmpdir;
0badc1ee 544 tmpdir = getenv("TMPDIR");
69bef793
AS
545 if (!tmpdir) {
546 tmpdir = "/var/tmp";
547 }
eba25057
JM
548 if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
549 return -EOVERFLOW;
550 }
ea2384d3 551 fd = mkstemp(filename);
fe235a06
DH
552 if (fd < 0) {
553 return -errno;
554 }
555 if (close(fd) != 0) {
556 unlink(filename);
eba25057
JM
557 return -errno;
558 }
559 return 0;
d5249393 560#endif
eba25057 561}
fc01f7e7 562
84a12e66
CH
563/*
564 * Detect host devices. By convention, /dev/cdrom[N] is always
565 * recognized as a host CDROM.
566 */
567static BlockDriver *find_hdev_driver(const char *filename)
568{
569 int score_max = 0, score;
570 BlockDriver *drv = NULL, *d;
571
572 QLIST_FOREACH(d, &bdrv_drivers, list) {
573 if (d->bdrv_probe_device) {
574 score = d->bdrv_probe_device(filename);
575 if (score > score_max) {
576 score_max = score;
577 drv = d;
578 }
579 }
580 }
581
582 return drv;
583}
584
88d88798
MM
585static BlockDriver *bdrv_do_find_protocol(const char *protocol)
586{
587 BlockDriver *drv1;
588
589 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
590 if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) {
591 return drv1;
592 }
593 }
594
595 return NULL;
596}
597
98289620 598BlockDriver *bdrv_find_protocol(const char *filename,
b65a5e12
HR
599 bool allow_protocol_prefix,
600 Error **errp)
83f64091
FB
601{
602 BlockDriver *drv1;
603 char protocol[128];
1cec71e3 604 int len;
83f64091 605 const char *p;
88d88798 606 int i;
19cb3738 607
66f82cee
KW
608 /* TODO Drivers without bdrv_file_open must be specified explicitly */
609
39508e7a
CH
610 /*
611 * XXX(hch): we really should not let host device detection
612 * override an explicit protocol specification, but moving this
613 * later breaks access to device names with colons in them.
614 * Thanks to the brain-dead persistent naming schemes on udev-
615 * based Linux systems those actually are quite common.
616 */
617 drv1 = find_hdev_driver(filename);
618 if (drv1) {
619 return drv1;
620 }
621
98289620 622 if (!path_has_protocol(filename) || !allow_protocol_prefix) {
ef810437 623 return &bdrv_file;
84a12e66 624 }
98289620 625
9e0b22f4
SH
626 p = strchr(filename, ':');
627 assert(p != NULL);
1cec71e3
AL
628 len = p - filename;
629 if (len > sizeof(protocol) - 1)
630 len = sizeof(protocol) - 1;
631 memcpy(protocol, filename, len);
632 protocol[len] = '\0';
88d88798
MM
633
634 drv1 = bdrv_do_find_protocol(protocol);
635 if (drv1) {
636 return drv1;
637 }
638
639 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
640 if (block_driver_modules[i].protocol_name &&
641 !strcmp(block_driver_modules[i].protocol_name, protocol)) {
642 block_module_load_one(block_driver_modules[i].library_name);
643 break;
8a22f02a 644 }
83f64091 645 }
b65a5e12 646
88d88798
MM
647 drv1 = bdrv_do_find_protocol(protocol);
648 if (!drv1) {
649 error_setg(errp, "Unknown protocol '%s'", protocol);
650 }
651 return drv1;
83f64091
FB
652}
653
c6684249
MA
654/*
655 * Guess image format by probing its contents.
656 * This is not a good idea when your image is raw (CVE-2008-2004), but
657 * we do it anyway for backward compatibility.
658 *
659 * @buf contains the image's first @buf_size bytes.
7cddd372
KW
660 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
661 * but can be smaller if the image file is smaller)
c6684249
MA
662 * @filename is its filename.
663 *
664 * For all block drivers, call the bdrv_probe() method to get its
665 * probing score.
666 * Return the first block driver with the highest probing score.
667 */
38f3ef57
KW
668BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
669 const char *filename)
c6684249
MA
670{
671 int score_max = 0, score;
672 BlockDriver *drv = NULL, *d;
673
674 QLIST_FOREACH(d, &bdrv_drivers, list) {
675 if (d->bdrv_probe) {
676 score = d->bdrv_probe(buf, buf_size, filename);
677 if (score > score_max) {
678 score_max = score;
679 drv = d;
680 }
681 }
682 }
683
684 return drv;
685}
686
5696c6e3 687static int find_image_format(BlockBackend *file, const char *filename,
34b5d2c6 688 BlockDriver **pdrv, Error **errp)
f3a5d3f8 689{
c6684249 690 BlockDriver *drv;
7cddd372 691 uint8_t buf[BLOCK_PROBE_BUF_SIZE];
f500a6d3 692 int ret = 0;
f8ea0b00 693
08a00559 694 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
5696c6e3 695 if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) {
ef810437 696 *pdrv = &bdrv_raw;
c98ac35d 697 return ret;
1a396859 698 }
f8ea0b00 699
5696c6e3 700 ret = blk_pread(file, 0, buf, sizeof(buf));
83f64091 701 if (ret < 0) {
34b5d2c6
HR
702 error_setg_errno(errp, -ret, "Could not read image for determining its "
703 "format");
c98ac35d
SW
704 *pdrv = NULL;
705 return ret;
83f64091
FB
706 }
707
c6684249 708 drv = bdrv_probe_all(buf, ret, filename);
c98ac35d 709 if (!drv) {
34b5d2c6
HR
710 error_setg(errp, "Could not determine image format: No compatible "
711 "driver found");
c98ac35d
SW
712 ret = -ENOENT;
713 }
714 *pdrv = drv;
715 return ret;
ea2384d3
FB
716}
717
51762288
SH
718/**
719 * Set the current 'total_sectors' value
65a9bb25 720 * Return 0 on success, -errno on error.
51762288
SH
721 */
722static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
723{
724 BlockDriver *drv = bs->drv;
725
d470ad42
HR
726 if (!drv) {
727 return -ENOMEDIUM;
728 }
729
396759ad 730 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
b192af8a 731 if (bdrv_is_sg(bs))
396759ad
NB
732 return 0;
733
51762288
SH
734 /* query actual device if possible, otherwise just trust the hint */
735 if (drv->bdrv_getlength) {
736 int64_t length = drv->bdrv_getlength(bs);
737 if (length < 0) {
738 return length;
739 }
7e382003 740 hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE);
51762288
SH
741 }
742
743 bs->total_sectors = hint;
744 return 0;
745}
746
cddff5ba
KW
747/**
748 * Combines a QDict of new block driver @options with any missing options taken
749 * from @old_options, so that leaving out an option defaults to its old value.
750 */
751static void bdrv_join_options(BlockDriverState *bs, QDict *options,
752 QDict *old_options)
753{
754 if (bs->drv && bs->drv->bdrv_join_options) {
755 bs->drv->bdrv_join_options(options, old_options);
756 } else {
757 qdict_join(options, old_options, false);
758 }
759}
760
9e8f1835
PB
761/**
762 * Set open flags for a given discard mode
763 *
764 * Return 0 on success, -1 if the discard mode was invalid.
765 */
766int bdrv_parse_discard_flags(const char *mode, int *flags)
767{
768 *flags &= ~BDRV_O_UNMAP;
769
770 if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) {
771 /* do nothing */
772 } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) {
773 *flags |= BDRV_O_UNMAP;
774 } else {
775 return -1;
776 }
777
778 return 0;
779}
780
c3993cdc
SH
781/**
782 * Set open flags for a given cache mode
783 *
784 * Return 0 on success, -1 if the cache mode was invalid.
785 */
53e8ae01 786int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough)
c3993cdc
SH
787{
788 *flags &= ~BDRV_O_CACHE_MASK;
789
790 if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
53e8ae01
KW
791 *writethrough = false;
792 *flags |= BDRV_O_NOCACHE;
92196b2f 793 } else if (!strcmp(mode, "directsync")) {
53e8ae01 794 *writethrough = true;
92196b2f 795 *flags |= BDRV_O_NOCACHE;
c3993cdc 796 } else if (!strcmp(mode, "writeback")) {
53e8ae01 797 *writethrough = false;
c3993cdc 798 } else if (!strcmp(mode, "unsafe")) {
53e8ae01 799 *writethrough = false;
c3993cdc
SH
800 *flags |= BDRV_O_NO_FLUSH;
801 } else if (!strcmp(mode, "writethrough")) {
53e8ae01 802 *writethrough = true;
c3993cdc
SH
803 } else {
804 return -1;
805 }
806
807 return 0;
808}
809
b5411555
KW
810static char *bdrv_child_get_parent_desc(BdrvChild *c)
811{
812 BlockDriverState *parent = c->opaque;
813 return g_strdup(bdrv_get_device_or_node_name(parent));
814}
815
20018e12
KW
816static void bdrv_child_cb_drained_begin(BdrvChild *child)
817{
818 BlockDriverState *bs = child->opaque;
819 bdrv_drained_begin(bs);
820}
821
822static void bdrv_child_cb_drained_end(BdrvChild *child)
823{
824 BlockDriverState *bs = child->opaque;
825 bdrv_drained_end(bs);
826}
827
d736f119
KW
828static void bdrv_child_cb_attach(BdrvChild *child)
829{
830 BlockDriverState *bs = child->opaque;
831 bdrv_apply_subtree_drain(child, bs);
832}
833
834static void bdrv_child_cb_detach(BdrvChild *child)
835{
836 BlockDriverState *bs = child->opaque;
837 bdrv_unapply_subtree_drain(child, bs);
838}
839
38701b6a
KW
840static int bdrv_child_cb_inactivate(BdrvChild *child)
841{
842 BlockDriverState *bs = child->opaque;
843 assert(bs->open_flags & BDRV_O_INACTIVE);
844 return 0;
845}
846
b1e6fc08 847/*
73176bee
KW
848 * Returns the options and flags that a temporary snapshot should get, based on
849 * the originally requested flags (the originally requested image will have
850 * flags like a backing file)
b1e6fc08 851 */
73176bee
KW
852static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
853 int parent_flags, QDict *parent_options)
b1e6fc08 854{
73176bee
KW
855 *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
856
857 /* For temporary files, unconditional cache=unsafe is fine */
73176bee
KW
858 qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
859 qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
41869044 860
f87a0e29
AG
861 /* Copy the read-only option from the parent */
862 qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
863
41869044
KW
864 /* aio=native doesn't work for cache.direct=off, so disable it for the
865 * temporary snapshot */
866 *child_flags &= ~BDRV_O_NATIVE_AIO;
b1e6fc08
KW
867}
868
0b50cc88 869/*
8e2160e2
KW
870 * Returns the options and flags that bs->file should get if a protocol driver
871 * is expected, based on the given options and flags for the parent BDS
0b50cc88 872 */
8e2160e2
KW
873static void bdrv_inherited_options(int *child_flags, QDict *child_options,
874 int parent_flags, QDict *parent_options)
0b50cc88 875{
8e2160e2
KW
876 int flags = parent_flags;
877
0b50cc88
KW
878 /* Enable protocol handling, disable format probing for bs->file */
879 flags |= BDRV_O_PROTOCOL;
880
91a097e7
KW
881 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
882 * the parent. */
883 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
884 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
5a9347c6 885 qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
91a097e7 886
f87a0e29
AG
887 /* Inherit the read-only option from the parent if it's not set */
888 qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
889
0b50cc88 890 /* Our block drivers take care to send flushes and respect unmap policy,
91a097e7
KW
891 * so we can default to enable both on lower layers regardless of the
892 * corresponding parent options. */
818584a4 893 qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap");
0b50cc88 894
0b50cc88 895 /* Clear flags that only apply to the top layer */
abb06c5a
DB
896 flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ |
897 BDRV_O_NO_IO);
0b50cc88 898
8e2160e2 899 *child_flags = flags;
0b50cc88
KW
900}
901
f3930ed0 902const BdrvChildRole child_file = {
b5411555 903 .get_parent_desc = bdrv_child_get_parent_desc,
8e2160e2 904 .inherit_options = bdrv_inherited_options,
20018e12
KW
905 .drained_begin = bdrv_child_cb_drained_begin,
906 .drained_end = bdrv_child_cb_drained_end,
d736f119
KW
907 .attach = bdrv_child_cb_attach,
908 .detach = bdrv_child_cb_detach,
38701b6a 909 .inactivate = bdrv_child_cb_inactivate,
f3930ed0
KW
910};
911
912/*
8e2160e2
KW
913 * Returns the options and flags that bs->file should get if the use of formats
914 * (and not only protocols) is permitted for it, based on the given options and
915 * flags for the parent BDS
f3930ed0 916 */
8e2160e2
KW
917static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options,
918 int parent_flags, QDict *parent_options)
f3930ed0 919{
8e2160e2
KW
920 child_file.inherit_options(child_flags, child_options,
921 parent_flags, parent_options);
922
abb06c5a 923 *child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO);
f3930ed0
KW
924}
925
926const BdrvChildRole child_format = {
b5411555 927 .get_parent_desc = bdrv_child_get_parent_desc,
8e2160e2 928 .inherit_options = bdrv_inherited_fmt_options,
20018e12
KW
929 .drained_begin = bdrv_child_cb_drained_begin,
930 .drained_end = bdrv_child_cb_drained_end,
d736f119
KW
931 .attach = bdrv_child_cb_attach,
932 .detach = bdrv_child_cb_detach,
38701b6a 933 .inactivate = bdrv_child_cb_inactivate,
f3930ed0
KW
934};
935
db95dbba
KW
936static void bdrv_backing_attach(BdrvChild *c)
937{
938 BlockDriverState *parent = c->opaque;
939 BlockDriverState *backing_hd = c->bs;
940
941 assert(!parent->backing_blocker);
942 error_setg(&parent->backing_blocker,
943 "node is used as backing hd of '%s'",
944 bdrv_get_device_or_node_name(parent));
945
946 parent->open_flags &= ~BDRV_O_NO_BACKING;
947 pstrcpy(parent->backing_file, sizeof(parent->backing_file),
948 backing_hd->filename);
949 pstrcpy(parent->backing_format, sizeof(parent->backing_format),
950 backing_hd->drv ? backing_hd->drv->format_name : "");
951
952 bdrv_op_block_all(backing_hd, parent->backing_blocker);
953 /* Otherwise we won't be able to commit or stream */
954 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
955 parent->backing_blocker);
956 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM,
957 parent->backing_blocker);
958 /*
959 * We do backup in 3 ways:
960 * 1. drive backup
961 * The target bs is new opened, and the source is top BDS
962 * 2. blockdev backup
963 * Both the source and the target are top BDSes.
964 * 3. internal backup(used for block replication)
965 * Both the source and the target are backing file
966 *
967 * In case 1 and 2, neither the source nor the target is the backing file.
968 * In case 3, we will block the top BDS, so there is only one block job
969 * for the top BDS and its backing chain.
970 */
971 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE,
972 parent->backing_blocker);
973 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET,
974 parent->backing_blocker);
d736f119
KW
975
976 bdrv_child_cb_attach(c);
db95dbba
KW
977}
978
979static void bdrv_backing_detach(BdrvChild *c)
980{
981 BlockDriverState *parent = c->opaque;
982
983 assert(parent->backing_blocker);
984 bdrv_op_unblock_all(c->bs, parent->backing_blocker);
985 error_free(parent->backing_blocker);
986 parent->backing_blocker = NULL;
d736f119
KW
987
988 bdrv_child_cb_detach(c);
db95dbba
KW
989}
990
317fc44e 991/*
8e2160e2
KW
992 * Returns the options and flags that bs->backing should get, based on the
993 * given options and flags for the parent BDS
317fc44e 994 */
8e2160e2
KW
995static void bdrv_backing_options(int *child_flags, QDict *child_options,
996 int parent_flags, QDict *parent_options)
317fc44e 997{
8e2160e2
KW
998 int flags = parent_flags;
999
b8816a43
KW
1000 /* The cache mode is inherited unmodified for backing files; except WCE,
1001 * which is only applied on the top level (BlockBackend) */
91a097e7
KW
1002 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
1003 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
5a9347c6 1004 qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
91a097e7 1005
317fc44e 1006 /* backing files always opened read-only */
f87a0e29
AG
1007 qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on");
1008 flags &= ~BDRV_O_COPY_ON_READ;
317fc44e
KW
1009
1010 /* snapshot=on is handled on the top layer */
8bfea15d 1011 flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY);
317fc44e 1012
8e2160e2 1013 *child_flags = flags;
317fc44e
KW
1014}
1015
6858eba0
KW
1016static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
1017 const char *filename, Error **errp)
1018{
1019 BlockDriverState *parent = c->opaque;
61f09cea 1020 int orig_flags = bdrv_get_flags(parent);
6858eba0
KW
1021 int ret;
1022
61f09cea
KW
1023 if (!(orig_flags & BDRV_O_RDWR)) {
1024 ret = bdrv_reopen(parent, orig_flags | BDRV_O_RDWR, errp);
1025 if (ret < 0) {
1026 return ret;
1027 }
1028 }
1029
6858eba0
KW
1030 ret = bdrv_change_backing_file(parent, filename,
1031 base->drv ? base->drv->format_name : "");
1032 if (ret < 0) {
64730694 1033 error_setg_errno(errp, -ret, "Could not update backing file link");
6858eba0
KW
1034 }
1035
61f09cea
KW
1036 if (!(orig_flags & BDRV_O_RDWR)) {
1037 bdrv_reopen(parent, orig_flags, NULL);
1038 }
1039
6858eba0
KW
1040 return ret;
1041}
1042
91ef3825 1043const BdrvChildRole child_backing = {
b5411555 1044 .get_parent_desc = bdrv_child_get_parent_desc,
db95dbba
KW
1045 .attach = bdrv_backing_attach,
1046 .detach = bdrv_backing_detach,
8e2160e2 1047 .inherit_options = bdrv_backing_options,
20018e12
KW
1048 .drained_begin = bdrv_child_cb_drained_begin,
1049 .drained_end = bdrv_child_cb_drained_end,
38701b6a 1050 .inactivate = bdrv_child_cb_inactivate,
6858eba0 1051 .update_filename = bdrv_backing_update_filename,
f3930ed0
KW
1052};
1053
7b272452
KW
1054static int bdrv_open_flags(BlockDriverState *bs, int flags)
1055{
61de4c68 1056 int open_flags = flags;
7b272452
KW
1057
1058 /*
1059 * Clear flags that are internal to the block layer before opening the
1060 * image.
1061 */
20cca275 1062 open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL);
7b272452
KW
1063
1064 /*
1065 * Snapshots should be writable.
1066 */
8bfea15d 1067 if (flags & BDRV_O_TEMPORARY) {
7b272452
KW
1068 open_flags |= BDRV_O_RDWR;
1069 }
1070
1071 return open_flags;
1072}
1073
91a097e7
KW
1074static void update_flags_from_options(int *flags, QemuOpts *opts)
1075{
1076 *flags &= ~BDRV_O_CACHE_MASK;
1077
91a097e7
KW
1078 assert(qemu_opt_find(opts, BDRV_OPT_CACHE_NO_FLUSH));
1079 if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
1080 *flags |= BDRV_O_NO_FLUSH;
1081 }
1082
1083 assert(qemu_opt_find(opts, BDRV_OPT_CACHE_DIRECT));
1084 if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) {
1085 *flags |= BDRV_O_NOCACHE;
1086 }
f87a0e29
AG
1087
1088 *flags &= ~BDRV_O_RDWR;
1089
1090 assert(qemu_opt_find(opts, BDRV_OPT_READ_ONLY));
1091 if (!qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false)) {
1092 *flags |= BDRV_O_RDWR;
1093 }
1094
91a097e7
KW
1095}
1096
1097static void update_options_from_flags(QDict *options, int flags)
1098{
91a097e7 1099 if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) {
46f5ac20 1100 qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE);
91a097e7
KW
1101 }
1102 if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) {
46f5ac20
EB
1103 qdict_put_bool(options, BDRV_OPT_CACHE_NO_FLUSH,
1104 flags & BDRV_O_NO_FLUSH);
91a097e7 1105 }
f87a0e29 1106 if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) {
46f5ac20 1107 qdict_put_bool(options, BDRV_OPT_READ_ONLY, !(flags & BDRV_O_RDWR));
f87a0e29 1108 }
91a097e7
KW
1109}
1110
636ea370
KW
1111static void bdrv_assign_node_name(BlockDriverState *bs,
1112 const char *node_name,
1113 Error **errp)
6913c0c2 1114{
15489c76 1115 char *gen_node_name = NULL;
6913c0c2 1116
15489c76
JC
1117 if (!node_name) {
1118 node_name = gen_node_name = id_generate(ID_BLOCK);
1119 } else if (!id_wellformed(node_name)) {
1120 /*
1121 * Check for empty string or invalid characters, but not if it is
1122 * generated (generated names use characters not available to the user)
1123 */
9aebf3b8 1124 error_setg(errp, "Invalid node name");
636ea370 1125 return;
6913c0c2
BC
1126 }
1127
0c5e94ee 1128 /* takes care of avoiding namespaces collisions */
7f06d47e 1129 if (blk_by_name(node_name)) {
0c5e94ee
BC
1130 error_setg(errp, "node-name=%s is conflicting with a device id",
1131 node_name);
15489c76 1132 goto out;
0c5e94ee
BC
1133 }
1134
6913c0c2
BC
1135 /* takes care of avoiding duplicates node names */
1136 if (bdrv_find_node(node_name)) {
1137 error_setg(errp, "Duplicate node name");
15489c76 1138 goto out;
6913c0c2
BC
1139 }
1140
1141 /* copy node name into the bs and insert it into the graph list */
1142 pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
1143 QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
15489c76
JC
1144out:
1145 g_free(gen_node_name);
6913c0c2
BC
1146}
1147
01a56501
KW
1148static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv,
1149 const char *node_name, QDict *options,
1150 int open_flags, Error **errp)
1151{
1152 Error *local_err = NULL;
1153 int ret;
1154
1155 bdrv_assign_node_name(bs, node_name, &local_err);
1156 if (local_err) {
1157 error_propagate(errp, local_err);
1158 return -EINVAL;
1159 }
1160
1161 bs->drv = drv;
680c7f96 1162 bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
01a56501
KW
1163 bs->opaque = g_malloc0(drv->instance_size);
1164
1165 if (drv->bdrv_file_open) {
1166 assert(!drv->bdrv_needs_filename || bs->filename[0]);
1167 ret = drv->bdrv_file_open(bs, options, open_flags, &local_err);
680c7f96 1168 } else if (drv->bdrv_open) {
01a56501 1169 ret = drv->bdrv_open(bs, options, open_flags, &local_err);
680c7f96
KW
1170 } else {
1171 ret = 0;
01a56501
KW
1172 }
1173
1174 if (ret < 0) {
1175 if (local_err) {
1176 error_propagate(errp, local_err);
1177 } else if (bs->filename[0]) {
1178 error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename);
1179 } else {
1180 error_setg_errno(errp, -ret, "Could not open image");
1181 }
180ca19a 1182 goto open_failed;
01a56501
KW
1183 }
1184
1185 ret = refresh_total_sectors(bs, bs->total_sectors);
1186 if (ret < 0) {
1187 error_setg_errno(errp, -ret, "Could not refresh total sector count");
180ca19a 1188 return ret;
01a56501
KW
1189 }
1190
1191 bdrv_refresh_limits(bs, &local_err);
1192 if (local_err) {
1193 error_propagate(errp, local_err);
180ca19a 1194 return -EINVAL;
01a56501
KW
1195 }
1196
1197 assert(bdrv_opt_mem_align(bs) != 0);
1198 assert(bdrv_min_mem_align(bs) != 0);
1199 assert(is_power_of_2(bs->bl.request_alignment));
1200
1201 return 0;
180ca19a
MP
1202open_failed:
1203 bs->drv = NULL;
1204 if (bs->file != NULL) {
1205 bdrv_unref_child(bs, bs->file);
1206 bs->file = NULL;
1207 }
01a56501
KW
1208 g_free(bs->opaque);
1209 bs->opaque = NULL;
01a56501
KW
1210 return ret;
1211}
1212
680c7f96
KW
1213BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
1214 int flags, Error **errp)
1215{
1216 BlockDriverState *bs;
1217 int ret;
1218
1219 bs = bdrv_new();
1220 bs->open_flags = flags;
1221 bs->explicit_options = qdict_new();
1222 bs->options = qdict_new();
1223 bs->opaque = NULL;
1224
1225 update_options_from_flags(bs->options, flags);
1226
1227 ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp);
1228 if (ret < 0) {
1229 QDECREF(bs->explicit_options);
180ca19a 1230 bs->explicit_options = NULL;
680c7f96 1231 QDECREF(bs->options);
180ca19a 1232 bs->options = NULL;
680c7f96
KW
1233 bdrv_unref(bs);
1234 return NULL;
1235 }
1236
1237 return bs;
1238}
1239
c5f3014b 1240QemuOptsList bdrv_runtime_opts = {
18edf289
KW
1241 .name = "bdrv_common",
1242 .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head),
1243 .desc = {
1244 {
1245 .name = "node-name",
1246 .type = QEMU_OPT_STRING,
1247 .help = "Node name of the block device node",
1248 },
62392ebb
KW
1249 {
1250 .name = "driver",
1251 .type = QEMU_OPT_STRING,
1252 .help = "Block driver to use for the node",
1253 },
91a097e7
KW
1254 {
1255 .name = BDRV_OPT_CACHE_DIRECT,
1256 .type = QEMU_OPT_BOOL,
1257 .help = "Bypass software writeback cache on the host",
1258 },
1259 {
1260 .name = BDRV_OPT_CACHE_NO_FLUSH,
1261 .type = QEMU_OPT_BOOL,
1262 .help = "Ignore flush requests",
1263 },
f87a0e29
AG
1264 {
1265 .name = BDRV_OPT_READ_ONLY,
1266 .type = QEMU_OPT_BOOL,
1267 .help = "Node is opened in read-only mode",
1268 },
692e01a2
KW
1269 {
1270 .name = "detect-zeroes",
1271 .type = QEMU_OPT_STRING,
1272 .help = "try to optimize zero writes (off, on, unmap)",
1273 },
818584a4
KW
1274 {
1275 .name = "discard",
1276 .type = QEMU_OPT_STRING,
1277 .help = "discard operation (ignore/off, unmap/on)",
1278 },
5a9347c6
FZ
1279 {
1280 .name = BDRV_OPT_FORCE_SHARE,
1281 .type = QEMU_OPT_BOOL,
1282 .help = "always accept other writers (default: off)",
1283 },
18edf289
KW
1284 { /* end of list */ }
1285 },
1286};
1287
57915332
KW
1288/*
1289 * Common part for opening disk images and files
b6ad491a
KW
1290 *
1291 * Removes all processed options from *options.
57915332 1292 */
5696c6e3 1293static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
82dc8b41 1294 QDict *options, Error **errp)
57915332
KW
1295{
1296 int ret, open_flags;
035fccdf 1297 const char *filename;
62392ebb 1298 const char *driver_name = NULL;
6913c0c2 1299 const char *node_name = NULL;
818584a4 1300 const char *discard;
692e01a2 1301 const char *detect_zeroes;
18edf289 1302 QemuOpts *opts;
62392ebb 1303 BlockDriver *drv;
34b5d2c6 1304 Error *local_err = NULL;
57915332 1305
6405875c 1306 assert(bs->file == NULL);
707ff828 1307 assert(options != NULL && bs->options != options);
57915332 1308
62392ebb
KW
1309 opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
1310 qemu_opts_absorb_qdict(opts, options, &local_err);
1311 if (local_err) {
1312 error_propagate(errp, local_err);
1313 ret = -EINVAL;
1314 goto fail_opts;
1315 }
1316
9b7e8691
AG
1317 update_flags_from_options(&bs->open_flags, opts);
1318
62392ebb
KW
1319 driver_name = qemu_opt_get(opts, "driver");
1320 drv = bdrv_find_format(driver_name);
1321 assert(drv != NULL);
1322
5a9347c6
FZ
1323 bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false);
1324
1325 if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) {
1326 error_setg(errp,
1327 BDRV_OPT_FORCE_SHARE
1328 "=on can only be used with read-only images");
1329 ret = -EINVAL;
1330 goto fail_opts;
1331 }
1332
45673671 1333 if (file != NULL) {
5696c6e3 1334 filename = blk_bs(file)->filename;
45673671 1335 } else {
129c7d1c
MA
1336 /*
1337 * Caution: while qdict_get_try_str() is fine, getting
1338 * non-string types would require more care. When @options
1339 * come from -blockdev or blockdev_add, its members are typed
1340 * according to the QAPI schema, but when they come from
1341 * -drive, they're all QString.
1342 */
45673671
KW
1343 filename = qdict_get_try_str(options, "filename");
1344 }
1345
4a008240 1346 if (drv->bdrv_needs_filename && (!filename || !filename[0])) {
765003db
KW
1347 error_setg(errp, "The '%s' block driver requires a file name",
1348 drv->format_name);
18edf289
KW
1349 ret = -EINVAL;
1350 goto fail_opts;
6913c0c2 1351 }
6913c0c2 1352
82dc8b41
KW
1353 trace_bdrv_open_common(bs, filename ?: "", bs->open_flags,
1354 drv->format_name);
62392ebb 1355
82dc8b41 1356 bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
b64ec4e4
FZ
1357
1358 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
8f94a6e4
KW
1359 error_setg(errp,
1360 !bs->read_only && bdrv_is_whitelisted(drv, true)
1361 ? "Driver '%s' can only be used for read-only devices"
1362 : "Driver '%s' is not whitelisted",
1363 drv->format_name);
18edf289
KW
1364 ret = -ENOTSUP;
1365 goto fail_opts;
b64ec4e4 1366 }
57915332 1367
d3faa13e
PB
1368 /* bdrv_new() and bdrv_close() make it so */
1369 assert(atomic_read(&bs->copy_on_read) == 0);
1370
82dc8b41 1371 if (bs->open_flags & BDRV_O_COPY_ON_READ) {
0ebd24e0
KW
1372 if (!bs->read_only) {
1373 bdrv_enable_copy_on_read(bs);
1374 } else {
1375 error_setg(errp, "Can't use copy-on-read on read-only device");
18edf289
KW
1376 ret = -EINVAL;
1377 goto fail_opts;
0ebd24e0 1378 }
53fec9d3
SH
1379 }
1380
818584a4
KW
1381 discard = qemu_opt_get(opts, "discard");
1382 if (discard != NULL) {
1383 if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) {
1384 error_setg(errp, "Invalid discard option");
1385 ret = -EINVAL;
1386 goto fail_opts;
1387 }
1388 }
1389
692e01a2
KW
1390 detect_zeroes = qemu_opt_get(opts, "detect-zeroes");
1391 if (detect_zeroes) {
1392 BlockdevDetectZeroesOptions value =
f7abe0ec 1393 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
692e01a2 1394 detect_zeroes,
692e01a2
KW
1395 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
1396 &local_err);
1397 if (local_err) {
1398 error_propagate(errp, local_err);
1399 ret = -EINVAL;
1400 goto fail_opts;
1401 }
1402
1403 if (value == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
1404 !(bs->open_flags & BDRV_O_UNMAP))
1405 {
1406 error_setg(errp, "setting detect-zeroes to unmap is not allowed "
1407 "without setting discard operation to unmap");
1408 ret = -EINVAL;
1409 goto fail_opts;
1410 }
1411
1412 bs->detect_zeroes = value;
1413 }
1414
c2ad1b0c
KW
1415 if (filename != NULL) {
1416 pstrcpy(bs->filename, sizeof(bs->filename), filename);
1417 } else {
1418 bs->filename[0] = '\0';
1419 }
91af7014 1420 pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename);
57915332 1421
66f82cee 1422 /* Open the image, either directly or using a protocol */
82dc8b41 1423 open_flags = bdrv_open_flags(bs, bs->open_flags);
01a56501 1424 node_name = qemu_opt_get(opts, "node-name");
57915332 1425
01a56501
KW
1426 assert(!drv->bdrv_file_open || file == NULL);
1427 ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp);
51762288 1428 if (ret < 0) {
01a56501 1429 goto fail_opts;
3baca891
KW
1430 }
1431
18edf289 1432 qemu_opts_del(opts);
57915332
KW
1433 return 0;
1434
18edf289
KW
1435fail_opts:
1436 qemu_opts_del(opts);
57915332
KW
1437 return ret;
1438}
1439
5e5c4f63
KW
1440static QDict *parse_json_filename(const char *filename, Error **errp)
1441{
1442 QObject *options_obj;
1443 QDict *options;
1444 int ret;
1445
1446 ret = strstart(filename, "json:", &filename);
1447 assert(ret);
1448
5577fff7 1449 options_obj = qobject_from_json(filename, errp);
5e5c4f63 1450 if (!options_obj) {
5577fff7
MA
1451 /* Work around qobject_from_json() lossage TODO fix that */
1452 if (errp && !*errp) {
1453 error_setg(errp, "Could not parse the JSON options");
1454 return NULL;
1455 }
1456 error_prepend(errp, "Could not parse the JSON options: ");
5e5c4f63
KW
1457 return NULL;
1458 }
1459
ca6b6e1e
MA
1460 options = qobject_to_qdict(options_obj);
1461 if (!options) {
5e5c4f63
KW
1462 qobject_decref(options_obj);
1463 error_setg(errp, "Invalid JSON object given");
1464 return NULL;
1465 }
1466
5e5c4f63
KW
1467 qdict_flatten(options);
1468
1469 return options;
1470}
1471
de3b53f0
KW
1472static void parse_json_protocol(QDict *options, const char **pfilename,
1473 Error **errp)
1474{
1475 QDict *json_options;
1476 Error *local_err = NULL;
1477
1478 /* Parse json: pseudo-protocol */
1479 if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) {
1480 return;
1481 }
1482
1483 json_options = parse_json_filename(*pfilename, &local_err);
1484 if (local_err) {
1485 error_propagate(errp, local_err);
1486 return;
1487 }
1488
1489 /* Options given in the filename have lower priority than options
1490 * specified directly */
1491 qdict_join(options, json_options, false);
1492 QDECREF(json_options);
1493 *pfilename = NULL;
1494}
1495
b6ce07aa 1496/*
f54120ff
KW
1497 * Fills in default options for opening images and converts the legacy
1498 * filename/flags pair to option QDict entries.
53a29513
HR
1499 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1500 * block driver has been specified explicitly.
b6ce07aa 1501 */
de3b53f0 1502static int bdrv_fill_options(QDict **options, const char *filename,
053e1578 1503 int *flags, Error **errp)
ea2384d3 1504{
c2ad1b0c 1505 const char *drvname;
53a29513 1506 bool protocol = *flags & BDRV_O_PROTOCOL;
e3fa4bfa 1507 bool parse_filename = false;
053e1578 1508 BlockDriver *drv = NULL;
34b5d2c6 1509 Error *local_err = NULL;
83f64091 1510
129c7d1c
MA
1511 /*
1512 * Caution: while qdict_get_try_str() is fine, getting non-string
1513 * types would require more care. When @options come from
1514 * -blockdev or blockdev_add, its members are typed according to
1515 * the QAPI schema, but when they come from -drive, they're all
1516 * QString.
1517 */
53a29513 1518 drvname = qdict_get_try_str(*options, "driver");
053e1578
HR
1519 if (drvname) {
1520 drv = bdrv_find_format(drvname);
1521 if (!drv) {
1522 error_setg(errp, "Unknown driver '%s'", drvname);
1523 return -ENOENT;
1524 }
1525 /* If the user has explicitly specified the driver, this choice should
1526 * override the BDRV_O_PROTOCOL flag */
1527 protocol = drv->bdrv_file_open;
53a29513
HR
1528 }
1529
1530 if (protocol) {
1531 *flags |= BDRV_O_PROTOCOL;
1532 } else {
1533 *flags &= ~BDRV_O_PROTOCOL;
1534 }
1535
91a097e7
KW
1536 /* Translate cache options from flags into options */
1537 update_options_from_flags(*options, *flags);
1538
035fccdf 1539 /* Fetch the file name from the options QDict if necessary */
17b005f1 1540 if (protocol && filename) {
f54120ff 1541 if (!qdict_haskey(*options, "filename")) {
46f5ac20 1542 qdict_put_str(*options, "filename", filename);
f54120ff
KW
1543 parse_filename = true;
1544 } else {
1545 error_setg(errp, "Can't specify 'file' and 'filename' options at "
1546 "the same time");
1547 return -EINVAL;
1548 }
035fccdf
KW
1549 }
1550
c2ad1b0c 1551 /* Find the right block driver */
129c7d1c 1552 /* See cautionary note on accessing @options above */
f54120ff 1553 filename = qdict_get_try_str(*options, "filename");
f54120ff 1554
053e1578
HR
1555 if (!drvname && protocol) {
1556 if (filename) {
1557 drv = bdrv_find_protocol(filename, parse_filename, errp);
17b005f1 1558 if (!drv) {
053e1578 1559 return -EINVAL;
17b005f1 1560 }
053e1578
HR
1561
1562 drvname = drv->format_name;
46f5ac20 1563 qdict_put_str(*options, "driver", drvname);
053e1578
HR
1564 } else {
1565 error_setg(errp, "Must specify either driver or file");
1566 return -EINVAL;
98289620 1567 }
c2ad1b0c
KW
1568 }
1569
17b005f1 1570 assert(drv || !protocol);
c2ad1b0c 1571
f54120ff 1572 /* Driver-specific filename parsing */
17b005f1 1573 if (drv && drv->bdrv_parse_filename && parse_filename) {
5acd9d81 1574 drv->bdrv_parse_filename(filename, *options, &local_err);
84d18f06 1575 if (local_err) {
34b5d2c6 1576 error_propagate(errp, local_err);
f54120ff 1577 return -EINVAL;
6963a30d 1578 }
cd5d031e
HR
1579
1580 if (!drv->bdrv_needs_filename) {
1581 qdict_del(*options, "filename");
cd5d031e 1582 }
6963a30d
KW
1583 }
1584
f54120ff
KW
1585 return 0;
1586}
1587
3121fb45
KW
1588static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q,
1589 uint64_t perm, uint64_t shared,
c1cef672
FZ
1590 GSList *ignore_children, Error **errp);
1591static void bdrv_child_abort_perm_update(BdrvChild *c);
1592static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
1593
148eb13c
KW
1594typedef struct BlockReopenQueueEntry {
1595 bool prepared;
1596 BDRVReopenState state;
1597 QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry;
1598} BlockReopenQueueEntry;
1599
1600/*
1601 * Return the flags that @bs will have after the reopens in @q have
1602 * successfully completed. If @q is NULL (or @bs is not contained in @q),
1603 * return the current flags.
1604 */
1605static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs)
1606{
1607 BlockReopenQueueEntry *entry;
1608
1609 if (q != NULL) {
1610 QSIMPLEQ_FOREACH(entry, q, entry) {
1611 if (entry->state.bs == bs) {
1612 return entry->state.flags;
1613 }
1614 }
1615 }
1616
1617 return bs->open_flags;
1618}
1619
1620/* Returns whether the image file can be written to after the reopen queue @q
1621 * has been successfully applied, or right now if @q is NULL. */
1622static bool bdrv_is_writable(BlockDriverState *bs, BlockReopenQueue *q)
1623{
1624 int flags = bdrv_reopen_get_flags(q, bs);
1625
1626 return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR;
1627}
1628
ffd1a5a2 1629static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs,
e0995dc3
KW
1630 BdrvChild *c, const BdrvChildRole *role,
1631 BlockReopenQueue *reopen_queue,
ffd1a5a2
FZ
1632 uint64_t parent_perm, uint64_t parent_shared,
1633 uint64_t *nperm, uint64_t *nshared)
1634{
1635 if (bs->drv && bs->drv->bdrv_child_perm) {
e0995dc3 1636 bs->drv->bdrv_child_perm(bs, c, role, reopen_queue,
ffd1a5a2
FZ
1637 parent_perm, parent_shared,
1638 nperm, nshared);
1639 }
e0995dc3 1640 /* TODO Take force_share from reopen_queue */
ffd1a5a2
FZ
1641 if (child_bs && child_bs->force_share) {
1642 *nshared = BLK_PERM_ALL;
1643 }
1644}
1645
33a610c3
KW
1646/*
1647 * Check whether permissions on this node can be changed in a way that
1648 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1649 * permissions of all its parents. This involves checking whether all necessary
1650 * permission changes to child nodes can be performed.
1651 *
1652 * A call to this function must always be followed by a call to bdrv_set_perm()
1653 * or bdrv_abort_perm_update().
1654 */
3121fb45
KW
1655static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q,
1656 uint64_t cumulative_perms,
46181129
KW
1657 uint64_t cumulative_shared_perms,
1658 GSList *ignore_children, Error **errp)
33a610c3
KW
1659{
1660 BlockDriver *drv = bs->drv;
1661 BdrvChild *c;
1662 int ret;
1663
1664 /* Write permissions never work with read-only images */
1665 if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) &&
148eb13c 1666 !bdrv_is_writable(bs, q))
33a610c3
KW
1667 {
1668 error_setg(errp, "Block node is read-only");
1669 return -EPERM;
1670 }
1671
1672 /* Check this node */
1673 if (!drv) {
1674 return 0;
1675 }
1676
1677 if (drv->bdrv_check_perm) {
1678 return drv->bdrv_check_perm(bs, cumulative_perms,
1679 cumulative_shared_perms, errp);
1680 }
1681
78e421c9 1682 /* Drivers that never have children can omit .bdrv_child_perm() */
33a610c3 1683 if (!drv->bdrv_child_perm) {
78e421c9 1684 assert(QLIST_EMPTY(&bs->children));
33a610c3
KW
1685 return 0;
1686 }
1687
1688 /* Check all children */
1689 QLIST_FOREACH(c, &bs->children, next) {
1690 uint64_t cur_perm, cur_shared;
3121fb45 1691 bdrv_child_perm(bs, c->bs, c, c->role, q,
ffd1a5a2
FZ
1692 cumulative_perms, cumulative_shared_perms,
1693 &cur_perm, &cur_shared);
3121fb45
KW
1694 ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared,
1695 ignore_children, errp);
33a610c3
KW
1696 if (ret < 0) {
1697 return ret;
1698 }
1699 }
1700
1701 return 0;
1702}
1703
1704/*
1705 * Notifies drivers that after a previous bdrv_check_perm() call, the
1706 * permission update is not performed and any preparations made for it (e.g.
1707 * taken file locks) need to be undone.
1708 *
1709 * This function recursively notifies all child nodes.
1710 */
1711static void bdrv_abort_perm_update(BlockDriverState *bs)
1712{
1713 BlockDriver *drv = bs->drv;
1714 BdrvChild *c;
1715
1716 if (!drv) {
1717 return;
1718 }
1719
1720 if (drv->bdrv_abort_perm_update) {
1721 drv->bdrv_abort_perm_update(bs);
1722 }
1723
1724 QLIST_FOREACH(c, &bs->children, next) {
1725 bdrv_child_abort_perm_update(c);
1726 }
1727}
1728
1729static void bdrv_set_perm(BlockDriverState *bs, uint64_t cumulative_perms,
1730 uint64_t cumulative_shared_perms)
1731{
1732 BlockDriver *drv = bs->drv;
1733 BdrvChild *c;
1734
1735 if (!drv) {
1736 return;
1737 }
1738
1739 /* Update this node */
1740 if (drv->bdrv_set_perm) {
1741 drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms);
1742 }
1743
78e421c9 1744 /* Drivers that never have children can omit .bdrv_child_perm() */
33a610c3 1745 if (!drv->bdrv_child_perm) {
78e421c9 1746 assert(QLIST_EMPTY(&bs->children));
33a610c3
KW
1747 return;
1748 }
1749
1750 /* Update all children */
1751 QLIST_FOREACH(c, &bs->children, next) {
1752 uint64_t cur_perm, cur_shared;
e0995dc3 1753 bdrv_child_perm(bs, c->bs, c, c->role, NULL,
ffd1a5a2
FZ
1754 cumulative_perms, cumulative_shared_perms,
1755 &cur_perm, &cur_shared);
33a610c3
KW
1756 bdrv_child_set_perm(c, cur_perm, cur_shared);
1757 }
1758}
1759
1760static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
1761 uint64_t *shared_perm)
1762{
1763 BdrvChild *c;
1764 uint64_t cumulative_perms = 0;
1765 uint64_t cumulative_shared_perms = BLK_PERM_ALL;
1766
1767 QLIST_FOREACH(c, &bs->parents, next_parent) {
1768 cumulative_perms |= c->perm;
1769 cumulative_shared_perms &= c->shared_perm;
1770 }
1771
1772 *perm = cumulative_perms;
1773 *shared_perm = cumulative_shared_perms;
1774}
1775
d083319f
KW
1776static char *bdrv_child_user_desc(BdrvChild *c)
1777{
1778 if (c->role->get_parent_desc) {
1779 return c->role->get_parent_desc(c);
1780 }
1781
1782 return g_strdup("another user");
1783}
1784
5176196c 1785char *bdrv_perm_names(uint64_t perm)
d083319f
KW
1786{
1787 struct perm_name {
1788 uint64_t perm;
1789 const char *name;
1790 } permissions[] = {
1791 { BLK_PERM_CONSISTENT_READ, "consistent read" },
1792 { BLK_PERM_WRITE, "write" },
1793 { BLK_PERM_WRITE_UNCHANGED, "write unchanged" },
1794 { BLK_PERM_RESIZE, "resize" },
1795 { BLK_PERM_GRAPH_MOD, "change children" },
1796 { 0, NULL }
1797 };
1798
1799 char *result = g_strdup("");
1800 struct perm_name *p;
1801
1802 for (p = permissions; p->name; p++) {
1803 if (perm & p->perm) {
1804 char *old = result;
1805 result = g_strdup_printf("%s%s%s", old, *old ? ", " : "", p->name);
1806 g_free(old);
1807 }
1808 }
1809
1810 return result;
1811}
1812
33a610c3
KW
1813/*
1814 * Checks whether a new reference to @bs can be added if the new user requires
46181129
KW
1815 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1816 * set, the BdrvChild objects in this list are ignored in the calculations;
1817 * this allows checking permission updates for an existing reference.
33a610c3
KW
1818 *
1819 * Needs to be followed by a call to either bdrv_set_perm() or
1820 * bdrv_abort_perm_update(). */
3121fb45
KW
1821static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q,
1822 uint64_t new_used_perm,
d5e6f437 1823 uint64_t new_shared_perm,
46181129 1824 GSList *ignore_children, Error **errp)
d5e6f437
KW
1825{
1826 BdrvChild *c;
33a610c3
KW
1827 uint64_t cumulative_perms = new_used_perm;
1828 uint64_t cumulative_shared_perms = new_shared_perm;
d5e6f437
KW
1829
1830 /* There is no reason why anyone couldn't tolerate write_unchanged */
1831 assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED);
1832
1833 QLIST_FOREACH(c, &bs->parents, next_parent) {
46181129 1834 if (g_slist_find(ignore_children, c)) {
d5e6f437
KW
1835 continue;
1836 }
1837
d083319f
KW
1838 if ((new_used_perm & c->shared_perm) != new_used_perm) {
1839 char *user = bdrv_child_user_desc(c);
1840 char *perm_names = bdrv_perm_names(new_used_perm & ~c->shared_perm);
1841 error_setg(errp, "Conflicts with use by %s as '%s', which does not "
1842 "allow '%s' on %s",
1843 user, c->name, perm_names, bdrv_get_node_name(c->bs));
1844 g_free(user);
1845 g_free(perm_names);
1846 return -EPERM;
1847 }
1848
1849 if ((c->perm & new_shared_perm) != c->perm) {
1850 char *user = bdrv_child_user_desc(c);
1851 char *perm_names = bdrv_perm_names(c->perm & ~new_shared_perm);
1852 error_setg(errp, "Conflicts with use by %s as '%s', which uses "
1853 "'%s' on %s",
1854 user, c->name, perm_names, bdrv_get_node_name(c->bs));
1855 g_free(user);
1856 g_free(perm_names);
d5e6f437
KW
1857 return -EPERM;
1858 }
33a610c3
KW
1859
1860 cumulative_perms |= c->perm;
1861 cumulative_shared_perms &= c->shared_perm;
d5e6f437
KW
1862 }
1863
3121fb45 1864 return bdrv_check_perm(bs, q, cumulative_perms, cumulative_shared_perms,
46181129 1865 ignore_children, errp);
33a610c3
KW
1866}
1867
1868/* Needs to be followed by a call to either bdrv_child_set_perm() or
1869 * bdrv_child_abort_perm_update(). */
3121fb45
KW
1870static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q,
1871 uint64_t perm, uint64_t shared,
c1cef672 1872 GSList *ignore_children, Error **errp)
33a610c3 1873{
46181129
KW
1874 int ret;
1875
1876 ignore_children = g_slist_prepend(g_slist_copy(ignore_children), c);
3121fb45 1877 ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, errp);
46181129
KW
1878 g_slist_free(ignore_children);
1879
1880 return ret;
33a610c3
KW
1881}
1882
c1cef672 1883static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
33a610c3
KW
1884{
1885 uint64_t cumulative_perms, cumulative_shared_perms;
1886
1887 c->perm = perm;
1888 c->shared_perm = shared;
1889
1890 bdrv_get_cumulative_perm(c->bs, &cumulative_perms,
1891 &cumulative_shared_perms);
1892 bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms);
1893}
1894
c1cef672 1895static void bdrv_child_abort_perm_update(BdrvChild *c)
33a610c3
KW
1896{
1897 bdrv_abort_perm_update(c->bs);
1898}
1899
1900int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
1901 Error **errp)
1902{
1903 int ret;
1904
3121fb45 1905 ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL, errp);
33a610c3
KW
1906 if (ret < 0) {
1907 bdrv_child_abort_perm_update(c);
1908 return ret;
1909 }
1910
1911 bdrv_child_set_perm(c, perm, shared);
1912
d5e6f437
KW
1913 return 0;
1914}
1915
6a1b9ee1
KW
1916#define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
1917 | BLK_PERM_WRITE \
1918 | BLK_PERM_WRITE_UNCHANGED \
1919 | BLK_PERM_RESIZE)
1920#define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
1921
1922void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
1923 const BdrvChildRole *role,
e0995dc3 1924 BlockReopenQueue *reopen_queue,
6a1b9ee1
KW
1925 uint64_t perm, uint64_t shared,
1926 uint64_t *nperm, uint64_t *nshared)
1927{
1928 if (c == NULL) {
1929 *nperm = perm & DEFAULT_PERM_PASSTHROUGH;
1930 *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
1931 return;
1932 }
1933
1934 *nperm = (perm & DEFAULT_PERM_PASSTHROUGH) |
1935 (c->perm & DEFAULT_PERM_UNCHANGED);
1936 *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) |
1937 (c->shared_perm & DEFAULT_PERM_UNCHANGED);
1938}
1939
6b1a044a
KW
1940void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
1941 const BdrvChildRole *role,
e0995dc3 1942 BlockReopenQueue *reopen_queue,
6b1a044a
KW
1943 uint64_t perm, uint64_t shared,
1944 uint64_t *nperm, uint64_t *nshared)
1945{
1946 bool backing = (role == &child_backing);
1947 assert(role == &child_backing || role == &child_file);
1948
1949 if (!backing) {
5fbfabd3
KW
1950 int flags = bdrv_reopen_get_flags(reopen_queue, bs);
1951
6b1a044a
KW
1952 /* Apart from the modifications below, the same permissions are
1953 * forwarded and left alone as for filters */
e0995dc3
KW
1954 bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared,
1955 &perm, &shared);
6b1a044a
KW
1956
1957 /* Format drivers may touch metadata even if the guest doesn't write */
148eb13c 1958 if (bdrv_is_writable(bs, reopen_queue)) {
6b1a044a
KW
1959 perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
1960 }
1961
1962 /* bs->file always needs to be consistent because of the metadata. We
1963 * can never allow other users to resize or write to it. */
5fbfabd3
KW
1964 if (!(flags & BDRV_O_NO_IO)) {
1965 perm |= BLK_PERM_CONSISTENT_READ;
1966 }
6b1a044a
KW
1967 shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
1968 } else {
1969 /* We want consistent read from backing files if the parent needs it.
1970 * No other operations are performed on backing files. */
1971 perm &= BLK_PERM_CONSISTENT_READ;
1972
1973 /* If the parent can deal with changing data, we're okay with a
1974 * writable and resizable backing file. */
1975 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
1976 if (shared & BLK_PERM_WRITE) {
1977 shared = BLK_PERM_WRITE | BLK_PERM_RESIZE;
1978 } else {
1979 shared = 0;
1980 }
1981
1982 shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
1983 BLK_PERM_WRITE_UNCHANGED;
1984 }
1985
9c5e6594
KW
1986 if (bs->open_flags & BDRV_O_INACTIVE) {
1987 shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
1988 }
1989
6b1a044a
KW
1990 *nperm = perm;
1991 *nshared = shared;
1992}
1993
8ee03995
KW
1994static void bdrv_replace_child_noperm(BdrvChild *child,
1995 BlockDriverState *new_bs)
e9740bc6
KW
1996{
1997 BlockDriverState *old_bs = child->bs;
0152bf40 1998 int i;
e9740bc6 1999
bb2614e9
FZ
2000 if (old_bs && new_bs) {
2001 assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
2002 }
e9740bc6 2003 if (old_bs) {
d736f119
KW
2004 /* Detach first so that the recursive drain sections coming from @child
2005 * are already gone and we only end the drain sections that came from
2006 * elsewhere. */
2007 if (child->role->detach) {
2008 child->role->detach(child);
2009 }
36fe1331 2010 if (old_bs->quiesce_counter && child->role->drained_end) {
0152bf40
KW
2011 for (i = 0; i < old_bs->quiesce_counter; i++) {
2012 child->role->drained_end(child);
2013 }
36fe1331 2014 }
e9740bc6
KW
2015 QLIST_REMOVE(child, next_parent);
2016 }
36fe1331
KW
2017
2018 child->bs = new_bs;
2019
e9740bc6
KW
2020 if (new_bs) {
2021 QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
36fe1331 2022 if (new_bs->quiesce_counter && child->role->drained_begin) {
0152bf40
KW
2023 for (i = 0; i < new_bs->quiesce_counter; i++) {
2024 child->role->drained_begin(child);
2025 }
36fe1331 2026 }
33a610c3 2027
d736f119
KW
2028 /* Attach only after starting new drained sections, so that recursive
2029 * drain sections coming from @child don't get an extra .drained_begin
2030 * callback. */
8ee03995
KW
2031 if (child->role->attach) {
2032 child->role->attach(child);
2033 }
2034 }
2035}
33a610c3 2036
466787fb
KW
2037/*
2038 * Updates @child to change its reference to point to @new_bs, including
2039 * checking and applying the necessary permisson updates both to the old node
2040 * and to @new_bs.
2041 *
2042 * NULL is passed as @new_bs for removing the reference before freeing @child.
2043 *
2044 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
2045 * function uses bdrv_set_perm() to update the permissions according to the new
2046 * reference that @new_bs gets.
2047 */
2048static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs)
8ee03995
KW
2049{
2050 BlockDriverState *old_bs = child->bs;
2051 uint64_t perm, shared_perm;
2052
8aecf1d1
KW
2053 bdrv_replace_child_noperm(child, new_bs);
2054
8ee03995 2055 if (old_bs) {
33a610c3
KW
2056 /* Update permissions for old node. This is guaranteed to succeed
2057 * because we're just taking a parent away, so we're loosening
2058 * restrictions. */
2059 bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm);
3121fb45 2060 bdrv_check_perm(old_bs, NULL, perm, shared_perm, NULL, &error_abort);
33a610c3 2061 bdrv_set_perm(old_bs, perm, shared_perm);
e9740bc6 2062 }
36fe1331 2063
e9740bc6 2064 if (new_bs) {
33a610c3 2065 bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm);
33a610c3 2066 bdrv_set_perm(new_bs, perm, shared_perm);
e9740bc6 2067 }
e9740bc6
KW
2068}
2069
f21d96d0
KW
2070BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
2071 const char *child_name,
36fe1331 2072 const BdrvChildRole *child_role,
d5e6f437
KW
2073 uint64_t perm, uint64_t shared_perm,
2074 void *opaque, Error **errp)
df581792 2075{
d5e6f437
KW
2076 BdrvChild *child;
2077 int ret;
2078
3121fb45 2079 ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, errp);
d5e6f437 2080 if (ret < 0) {
33a610c3 2081 bdrv_abort_perm_update(child_bs);
d5e6f437
KW
2082 return NULL;
2083 }
2084
2085 child = g_new(BdrvChild, 1);
df581792 2086 *child = (BdrvChild) {
d5e6f437
KW
2087 .bs = NULL,
2088 .name = g_strdup(child_name),
2089 .role = child_role,
2090 .perm = perm,
2091 .shared_perm = shared_perm,
2092 .opaque = opaque,
df581792
KW
2093 };
2094
33a610c3 2095 /* This performs the matching bdrv_set_perm() for the above check. */
466787fb 2096 bdrv_replace_child(child, child_bs);
b4b059f6
KW
2097
2098 return child;
df581792
KW
2099}
2100
98292c61
WC
2101BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
2102 BlockDriverState *child_bs,
2103 const char *child_name,
8b2ff529
KW
2104 const BdrvChildRole *child_role,
2105 Error **errp)
f21d96d0 2106{
d5e6f437 2107 BdrvChild *child;
f68c598b
KW
2108 uint64_t perm, shared_perm;
2109
2110 bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm);
2111
2112 assert(parent_bs->drv);
bb2614e9 2113 assert(bdrv_get_aio_context(parent_bs) == bdrv_get_aio_context(child_bs));
e0995dc3 2114 bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL,
ffd1a5a2 2115 perm, shared_perm, &perm, &shared_perm);
d5e6f437 2116
d5e6f437 2117 child = bdrv_root_attach_child(child_bs, child_name, child_role,
f68c598b 2118 perm, shared_perm, parent_bs, errp);
d5e6f437
KW
2119 if (child == NULL) {
2120 return NULL;
2121 }
2122
f21d96d0
KW
2123 QLIST_INSERT_HEAD(&parent_bs->children, child, next);
2124 return child;
2125}
2126
3f09bfbc 2127static void bdrv_detach_child(BdrvChild *child)
33a60407 2128{
f21d96d0
KW
2129 if (child->next.le_prev) {
2130 QLIST_REMOVE(child, next);
2131 child->next.le_prev = NULL;
2132 }
e9740bc6 2133
466787fb 2134 bdrv_replace_child(child, NULL);
e9740bc6 2135
260fecf1 2136 g_free(child->name);
33a60407
KW
2137 g_free(child);
2138}
2139
f21d96d0 2140void bdrv_root_unref_child(BdrvChild *child)
33a60407 2141{
779020cb
KW
2142 BlockDriverState *child_bs;
2143
f21d96d0
KW
2144 child_bs = child->bs;
2145 bdrv_detach_child(child);
2146 bdrv_unref(child_bs);
2147}
2148
2149void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
2150{
779020cb
KW
2151 if (child == NULL) {
2152 return;
2153 }
33a60407
KW
2154
2155 if (child->bs->inherits_from == parent) {
4e4bf5c4
KW
2156 BdrvChild *c;
2157
2158 /* Remove inherits_from only when the last reference between parent and
2159 * child->bs goes away. */
2160 QLIST_FOREACH(c, &parent->children, next) {
2161 if (c != child && c->bs == child->bs) {
2162 break;
2163 }
2164 }
2165 if (c == NULL) {
2166 child->bs->inherits_from = NULL;
2167 }
33a60407
KW
2168 }
2169
f21d96d0 2170 bdrv_root_unref_child(child);
33a60407
KW
2171}
2172
5c8cab48
KW
2173
2174static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)
2175{
2176 BdrvChild *c;
2177 QLIST_FOREACH(c, &bs->parents, next_parent) {
2178 if (c->role->change_media) {
2179 c->role->change_media(c, load);
2180 }
2181 }
2182}
2183
2184static void bdrv_parent_cb_resize(BlockDriverState *bs)
2185{
2186 BdrvChild *c;
2187 QLIST_FOREACH(c, &bs->parents, next_parent) {
2188 if (c->role->resize) {
2189 c->role->resize(c);
2190 }
2191 }
2192}
2193
5db15a57
KW
2194/*
2195 * Sets the backing file link of a BDS. A new reference is created; callers
2196 * which don't need their own reference any more must call bdrv_unref().
2197 */
12fa4af6
KW
2198void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
2199 Error **errp)
8d24cce1 2200{
5db15a57
KW
2201 if (backing_hd) {
2202 bdrv_ref(backing_hd);
2203 }
8d24cce1 2204
760e0063 2205 if (bs->backing) {
5db15a57 2206 bdrv_unref_child(bs, bs->backing);
826b6ca0
FZ
2207 }
2208
8d24cce1 2209 if (!backing_hd) {
760e0063 2210 bs->backing = NULL;
8d24cce1
FZ
2211 goto out;
2212 }
12fa4af6 2213
8b2ff529 2214 bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing,
12fa4af6
KW
2215 errp);
2216 if (!bs->backing) {
2217 bdrv_unref(backing_hd);
2218 }
826b6ca0 2219
9e7e940c
KW
2220 bdrv_refresh_filename(bs);
2221
8d24cce1 2222out:
3baca891 2223 bdrv_refresh_limits(bs, NULL);
8d24cce1
FZ
2224}
2225
31ca6d07
KW
2226/*
2227 * Opens the backing file for a BlockDriverState if not yet open
2228 *
d9b7b057
KW
2229 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2230 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2231 * itself, all options starting with "${bdref_key}." are considered part of the
2232 * BlockdevRef.
2233 *
2234 * TODO Can this be unified with bdrv_open_image()?
31ca6d07 2235 */
d9b7b057
KW
2236int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
2237 const char *bdref_key, Error **errp)
9156df12 2238{
1ba4b6a5 2239 char *backing_filename = g_malloc0(PATH_MAX);
d9b7b057
KW
2240 char *bdref_key_dot;
2241 const char *reference = NULL;
317fc44e 2242 int ret = 0;
8d24cce1 2243 BlockDriverState *backing_hd;
d9b7b057
KW
2244 QDict *options;
2245 QDict *tmp_parent_options = NULL;
34b5d2c6 2246 Error *local_err = NULL;
9156df12 2247
760e0063 2248 if (bs->backing != NULL) {
1ba4b6a5 2249 goto free_exit;
9156df12
PB
2250 }
2251
31ca6d07 2252 /* NULL means an empty set of options */
d9b7b057
KW
2253 if (parent_options == NULL) {
2254 tmp_parent_options = qdict_new();
2255 parent_options = tmp_parent_options;
31ca6d07
KW
2256 }
2257
9156df12 2258 bs->open_flags &= ~BDRV_O_NO_BACKING;
d9b7b057
KW
2259
2260 bdref_key_dot = g_strdup_printf("%s.", bdref_key);
2261 qdict_extract_subqdict(parent_options, &options, bdref_key_dot);
2262 g_free(bdref_key_dot);
2263
129c7d1c
MA
2264 /*
2265 * Caution: while qdict_get_try_str() is fine, getting non-string
2266 * types would require more care. When @parent_options come from
2267 * -blockdev or blockdev_add, its members are typed according to
2268 * the QAPI schema, but when they come from -drive, they're all
2269 * QString.
2270 */
d9b7b057
KW
2271 reference = qdict_get_try_str(parent_options, bdref_key);
2272 if (reference || qdict_haskey(options, "file.filename")) {
1cb6f506
KW
2273 backing_filename[0] = '\0';
2274 } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
31ca6d07 2275 QDECREF(options);
1ba4b6a5 2276 goto free_exit;
dbecebdd 2277 } else {
9f07429e
HR
2278 bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX,
2279 &local_err);
2280 if (local_err) {
2281 ret = -EINVAL;
2282 error_propagate(errp, local_err);
2283 QDECREF(options);
2284 goto free_exit;
2285 }
9156df12
PB
2286 }
2287
8ee79e70
KW
2288 if (!bs->drv || !bs->drv->supports_backing) {
2289 ret = -EINVAL;
2290 error_setg(errp, "Driver doesn't support backing files");
2291 QDECREF(options);
2292 goto free_exit;
2293 }
2294
6bff597b
PK
2295 if (!reference &&
2296 bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
46f5ac20 2297 qdict_put_str(options, "driver", bs->backing_format);
9156df12
PB
2298 }
2299
5b363937
HR
2300 backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL,
2301 reference, options, 0, bs, &child_backing,
2302 errp);
2303 if (!backing_hd) {
9156df12 2304 bs->open_flags |= BDRV_O_NO_BACKING;
e43bfd9c 2305 error_prepend(errp, "Could not open backing file: ");
5b363937 2306 ret = -EINVAL;
1ba4b6a5 2307 goto free_exit;
9156df12 2308 }
5ce6bfe2 2309 bdrv_set_aio_context(backing_hd, bdrv_get_aio_context(bs));
df581792 2310
5db15a57
KW
2311 /* Hook up the backing file link; drop our reference, bs owns the
2312 * backing_hd reference now */
12fa4af6 2313 bdrv_set_backing_hd(bs, backing_hd, &local_err);
5db15a57 2314 bdrv_unref(backing_hd);
12fa4af6 2315 if (local_err) {
8cd1a3e4 2316 error_propagate(errp, local_err);
12fa4af6
KW
2317 ret = -EINVAL;
2318 goto free_exit;
2319 }
d80ac658 2320
d9b7b057
KW
2321 qdict_del(parent_options, bdref_key);
2322
1ba4b6a5
BC
2323free_exit:
2324 g_free(backing_filename);
d9b7b057 2325 QDECREF(tmp_parent_options);
1ba4b6a5 2326 return ret;
9156df12
PB
2327}
2328
2d6b86af
KW
2329static BlockDriverState *
2330bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key,
2331 BlockDriverState *parent, const BdrvChildRole *child_role,
2332 bool allow_none, Error **errp)
da557aac 2333{
2d6b86af 2334 BlockDriverState *bs = NULL;
da557aac 2335 QDict *image_options;
da557aac
HR
2336 char *bdref_key_dot;
2337 const char *reference;
2338
df581792 2339 assert(child_role != NULL);
f67503e5 2340
da557aac
HR
2341 bdref_key_dot = g_strdup_printf("%s.", bdref_key);
2342 qdict_extract_subqdict(options, &image_options, bdref_key_dot);
2343 g_free(bdref_key_dot);
2344
129c7d1c
MA
2345 /*
2346 * Caution: while qdict_get_try_str() is fine, getting non-string
2347 * types would require more care. When @options come from
2348 * -blockdev or blockdev_add, its members are typed according to
2349 * the QAPI schema, but when they come from -drive, they're all
2350 * QString.
2351 */
da557aac
HR
2352 reference = qdict_get_try_str(options, bdref_key);
2353 if (!filename && !reference && !qdict_size(image_options)) {
b4b059f6 2354 if (!allow_none) {
da557aac
HR
2355 error_setg(errp, "A block device must be specified for \"%s\"",
2356 bdref_key);
da557aac 2357 }
b20e61e0 2358 QDECREF(image_options);
da557aac
HR
2359 goto done;
2360 }
2361
5b363937
HR
2362 bs = bdrv_open_inherit(filename, reference, image_options, 0,
2363 parent, child_role, errp);
2364 if (!bs) {
df581792
KW
2365 goto done;
2366 }
2367
da557aac
HR
2368done:
2369 qdict_del(options, bdref_key);
2d6b86af
KW
2370 return bs;
2371}
2372
2373/*
2374 * Opens a disk image whose options are given as BlockdevRef in another block
2375 * device's options.
2376 *
2377 * If allow_none is true, no image will be opened if filename is false and no
2378 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2379 *
2380 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2381 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2382 * itself, all options starting with "${bdref_key}." are considered part of the
2383 * BlockdevRef.
2384 *
2385 * The BlockdevRef will be removed from the options QDict.
2386 */
2387BdrvChild *bdrv_open_child(const char *filename,
2388 QDict *options, const char *bdref_key,
2389 BlockDriverState *parent,
2390 const BdrvChildRole *child_role,
2391 bool allow_none, Error **errp)
2392{
8b2ff529 2393 BdrvChild *c;
2d6b86af
KW
2394 BlockDriverState *bs;
2395
2396 bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_role,
2397 allow_none, errp);
2398 if (bs == NULL) {
2399 return NULL;
2400 }
2401
8b2ff529
KW
2402 c = bdrv_attach_child(parent, bs, bdref_key, child_role, errp);
2403 if (!c) {
2404 bdrv_unref(bs);
2405 return NULL;
2406 }
2407
2408 return c;
b4b059f6
KW
2409}
2410
66836189
HR
2411static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
2412 int flags,
2413 QDict *snapshot_options,
2414 Error **errp)
b998875d
KW
2415{
2416 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
1ba4b6a5 2417 char *tmp_filename = g_malloc0(PATH_MAX + 1);
b998875d 2418 int64_t total_size;
83d0521a 2419 QemuOpts *opts = NULL;
ff6ed714 2420 BlockDriverState *bs_snapshot = NULL;
b2c2832c 2421 Error *local_err = NULL;
b998875d
KW
2422 int ret;
2423
2424 /* if snapshot, we create a temporary backing file and open it
2425 instead of opening 'filename' directly */
2426
2427 /* Get the required size from the image */
f187743a
KW
2428 total_size = bdrv_getlength(bs);
2429 if (total_size < 0) {
2430 error_setg_errno(errp, -total_size, "Could not get image size");
1ba4b6a5 2431 goto out;
f187743a 2432 }
b998875d
KW
2433
2434 /* Create the temporary image */
1ba4b6a5 2435 ret = get_tmp_filename(tmp_filename, PATH_MAX + 1);
b998875d
KW
2436 if (ret < 0) {
2437 error_setg_errno(errp, -ret, "Could not get temporary filename");
1ba4b6a5 2438 goto out;
b998875d
KW
2439 }
2440
ef810437 2441 opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0,
c282e1fd 2442 &error_abort);
39101f25 2443 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort);
e43bfd9c 2444 ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp);
83d0521a 2445 qemu_opts_del(opts);
b998875d 2446 if (ret < 0) {
e43bfd9c
MA
2447 error_prepend(errp, "Could not create temporary overlay '%s': ",
2448 tmp_filename);
1ba4b6a5 2449 goto out;
b998875d
KW
2450 }
2451
73176bee 2452 /* Prepare options QDict for the temporary file */
46f5ac20
EB
2453 qdict_put_str(snapshot_options, "file.driver", "file");
2454 qdict_put_str(snapshot_options, "file.filename", tmp_filename);
2455 qdict_put_str(snapshot_options, "driver", "qcow2");
b998875d 2456
5b363937 2457 bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp);
73176bee 2458 snapshot_options = NULL;
5b363937 2459 if (!bs_snapshot) {
1ba4b6a5 2460 goto out;
b998875d
KW
2461 }
2462
ff6ed714
EB
2463 /* bdrv_append() consumes a strong reference to bs_snapshot
2464 * (i.e. it will call bdrv_unref() on it) even on error, so in
2465 * order to be able to return one, we have to increase
2466 * bs_snapshot's refcount here */
66836189 2467 bdrv_ref(bs_snapshot);
b2c2832c
KW
2468 bdrv_append(bs_snapshot, bs, &local_err);
2469 if (local_err) {
2470 error_propagate(errp, local_err);
ff6ed714 2471 bs_snapshot = NULL;
b2c2832c
KW
2472 goto out;
2473 }
1ba4b6a5
BC
2474
2475out:
73176bee 2476 QDECREF(snapshot_options);
1ba4b6a5 2477 g_free(tmp_filename);
ff6ed714 2478 return bs_snapshot;
b998875d
KW
2479}
2480
b6ce07aa
KW
2481/*
2482 * Opens a disk image (raw, qcow2, vmdk, ...)
de9c0cec
KW
2483 *
2484 * options is a QDict of options to pass to the block drivers, or NULL for an
2485 * empty set of options. The reference to the QDict belongs to the block layer
2486 * after the call (even on failure), so if the caller intends to reuse the
2487 * dictionary, it needs to use QINCREF() before calling bdrv_open.
f67503e5
HR
2488 *
2489 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2490 * If it is not NULL, the referenced BDS will be reused.
ddf5636d
HR
2491 *
2492 * The reference parameter may be used to specify an existing block device which
2493 * should be opened. If specified, neither options nor a filename may be given,
2494 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
b6ce07aa 2495 */
5b363937
HR
2496static BlockDriverState *bdrv_open_inherit(const char *filename,
2497 const char *reference,
2498 QDict *options, int flags,
2499 BlockDriverState *parent,
2500 const BdrvChildRole *child_role,
2501 Error **errp)
ea2384d3 2502{
b6ce07aa 2503 int ret;
5696c6e3 2504 BlockBackend *file = NULL;
9a4f4c31 2505 BlockDriverState *bs;
ce343771 2506 BlockDriver *drv = NULL;
74fe54f2 2507 const char *drvname;
3e8c2e57 2508 const char *backing;
34b5d2c6 2509 Error *local_err = NULL;
73176bee 2510 QDict *snapshot_options = NULL;
b1e6fc08 2511 int snapshot_flags = 0;
712e7874 2512
f3930ed0
KW
2513 assert(!child_role || !flags);
2514 assert(!child_role == !parent);
f67503e5 2515
ddf5636d
HR
2516 if (reference) {
2517 bool options_non_empty = options ? qdict_size(options) : false;
2518 QDECREF(options);
2519
ddf5636d
HR
2520 if (filename || options_non_empty) {
2521 error_setg(errp, "Cannot reference an existing block device with "
2522 "additional options or a new filename");
5b363937 2523 return NULL;
ddf5636d
HR
2524 }
2525
2526 bs = bdrv_lookup_bs(reference, reference, errp);
2527 if (!bs) {
5b363937 2528 return NULL;
ddf5636d 2529 }
76b22320 2530
ddf5636d 2531 bdrv_ref(bs);
5b363937 2532 return bs;
ddf5636d
HR
2533 }
2534
5b363937 2535 bs = bdrv_new();
f67503e5 2536
de9c0cec
KW
2537 /* NULL means an empty set of options */
2538 if (options == NULL) {
2539 options = qdict_new();
2540 }
2541
145f598e 2542 /* json: syntax counts as explicit options, as if in the QDict */
de3b53f0
KW
2543 parse_json_protocol(options, &filename, &local_err);
2544 if (local_err) {
de3b53f0
KW
2545 goto fail;
2546 }
2547
145f598e
KW
2548 bs->explicit_options = qdict_clone_shallow(options);
2549
f3930ed0 2550 if (child_role) {
bddcec37 2551 bs->inherits_from = parent;
8e2160e2
KW
2552 child_role->inherit_options(&flags, options,
2553 parent->open_flags, parent->options);
f3930ed0
KW
2554 }
2555
de3b53f0 2556 ret = bdrv_fill_options(&options, filename, &flags, &local_err);
462f5bcf
KW
2557 if (local_err) {
2558 goto fail;
2559 }
2560
129c7d1c
MA
2561 /*
2562 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2563 * Caution: getting a boolean member of @options requires care.
2564 * When @options come from -blockdev or blockdev_add, members are
2565 * typed according to the QAPI schema, but when they come from
2566 * -drive, they're all QString.
2567 */
f87a0e29
AG
2568 if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") &&
2569 !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) {
2570 flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR);
2571 } else {
2572 flags &= ~BDRV_O_RDWR;
14499ea5
AG
2573 }
2574
2575 if (flags & BDRV_O_SNAPSHOT) {
2576 snapshot_options = qdict_new();
2577 bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options,
2578 flags, options);
f87a0e29
AG
2579 /* Let bdrv_backing_options() override "read-only" */
2580 qdict_del(options, BDRV_OPT_READ_ONLY);
14499ea5
AG
2581 bdrv_backing_options(&flags, options, flags, options);
2582 }
2583
62392ebb
KW
2584 bs->open_flags = flags;
2585 bs->options = options;
2586 options = qdict_clone_shallow(options);
2587
76c591b0 2588 /* Find the right image format driver */
129c7d1c 2589 /* See cautionary note on accessing @options above */
76c591b0
KW
2590 drvname = qdict_get_try_str(options, "driver");
2591 if (drvname) {
2592 drv = bdrv_find_format(drvname);
76c591b0
KW
2593 if (!drv) {
2594 error_setg(errp, "Unknown driver: '%s'", drvname);
76c591b0
KW
2595 goto fail;
2596 }
2597 }
2598
2599 assert(drvname || !(flags & BDRV_O_PROTOCOL));
76c591b0 2600
129c7d1c 2601 /* See cautionary note on accessing @options above */
3e8c2e57
AG
2602 backing = qdict_get_try_str(options, "backing");
2603 if (backing && *backing == '\0') {
2604 flags |= BDRV_O_NO_BACKING;
2605 qdict_del(options, "backing");
2606 }
2607
5696c6e3 2608 /* Open image file without format layer. This BlockBackend is only used for
4e4bf5c4
KW
2609 * probing, the block drivers will do their own bdrv_open_child() for the
2610 * same BDS, which is why we put the node name back into options. */
f4788adc 2611 if ((flags & BDRV_O_PROTOCOL) == 0) {
5696c6e3
KW
2612 BlockDriverState *file_bs;
2613
2614 file_bs = bdrv_open_child_bs(filename, options, "file", bs,
2615 &child_file, true, &local_err);
1fdd6933 2616 if (local_err) {
f4788adc
KW
2617 goto fail;
2618 }
5696c6e3 2619 if (file_bs != NULL) {
dacaa162
KW
2620 /* Not requesting BLK_PERM_CONSISTENT_READ because we're only
2621 * looking at the header to guess the image format. This works even
2622 * in cases where a guest would not see a consistent state. */
2623 file = blk_new(0, BLK_PERM_ALL);
d7086422 2624 blk_insert_bs(file, file_bs, &local_err);
5696c6e3 2625 bdrv_unref(file_bs);
d7086422
KW
2626 if (local_err) {
2627 goto fail;
2628 }
5696c6e3 2629
46f5ac20 2630 qdict_put_str(options, "file", bdrv_get_node_name(file_bs));
4e4bf5c4 2631 }
f500a6d3
KW
2632 }
2633
76c591b0 2634 /* Image format probing */
38f3ef57 2635 bs->probed = !drv;
76c591b0 2636 if (!drv && file) {
cf2ab8fc 2637 ret = find_image_format(file, filename, &drv, &local_err);
17b005f1 2638 if (ret < 0) {
8bfea15d 2639 goto fail;
2a05cbe4 2640 }
62392ebb
KW
2641 /*
2642 * This option update would logically belong in bdrv_fill_options(),
2643 * but we first need to open bs->file for the probing to work, while
2644 * opening bs->file already requires the (mostly) final set of options
2645 * so that cache mode etc. can be inherited.
2646 *
2647 * Adding the driver later is somewhat ugly, but it's not an option
2648 * that would ever be inherited, so it's correct. We just need to make
2649 * sure to update both bs->options (which has the full effective
2650 * options for bs) and options (which has file.* already removed).
2651 */
46f5ac20
EB
2652 qdict_put_str(bs->options, "driver", drv->format_name);
2653 qdict_put_str(options, "driver", drv->format_name);
76c591b0 2654 } else if (!drv) {
17b005f1 2655 error_setg(errp, "Must specify either driver or file");
8bfea15d 2656 goto fail;
ea2384d3 2657 }
b6ce07aa 2658
53a29513
HR
2659 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2660 assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open);
2661 /* file must be NULL if a protocol BDS is about to be created
2662 * (the inverse results in an error message from bdrv_open_common()) */
2663 assert(!(flags & BDRV_O_PROTOCOL) || !file);
2664
b6ce07aa 2665 /* Open the image */
82dc8b41 2666 ret = bdrv_open_common(bs, file, options, &local_err);
b6ce07aa 2667 if (ret < 0) {
8bfea15d 2668 goto fail;
6987307c
CH
2669 }
2670
4e4bf5c4 2671 if (file) {
5696c6e3 2672 blk_unref(file);
f500a6d3
KW
2673 file = NULL;
2674 }
2675
b6ce07aa 2676 /* If there is a backing file, use it */
9156df12 2677 if ((flags & BDRV_O_NO_BACKING) == 0) {
d9b7b057 2678 ret = bdrv_open_backing_file(bs, options, "backing", &local_err);
b6ce07aa 2679 if (ret < 0) {
b6ad491a 2680 goto close_and_fail;
b6ce07aa 2681 }
b6ce07aa
KW
2682 }
2683
91af7014
HR
2684 bdrv_refresh_filename(bs);
2685
b6ad491a 2686 /* Check if any unknown options were used */
7ad2757f 2687 if (qdict_size(options) != 0) {
b6ad491a 2688 const QDictEntry *entry = qdict_first(options);
5acd9d81
HR
2689 if (flags & BDRV_O_PROTOCOL) {
2690 error_setg(errp, "Block protocol '%s' doesn't support the option "
2691 "'%s'", drv->format_name, entry->key);
2692 } else {
d0e46a55
HR
2693 error_setg(errp,
2694 "Block format '%s' does not support the option '%s'",
2695 drv->format_name, entry->key);
5acd9d81 2696 }
b6ad491a 2697
b6ad491a
KW
2698 goto close_and_fail;
2699 }
b6ad491a 2700
c01c214b 2701 bdrv_parent_cb_change_media(bs, true);
b6ce07aa 2702
c3adb58f 2703 QDECREF(options);
dd62f1ca
KW
2704
2705 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2706 * temporary snapshot afterwards. */
2707 if (snapshot_flags) {
66836189
HR
2708 BlockDriverState *snapshot_bs;
2709 snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags,
2710 snapshot_options, &local_err);
73176bee 2711 snapshot_options = NULL;
dd62f1ca
KW
2712 if (local_err) {
2713 goto close_and_fail;
2714 }
5b363937
HR
2715 /* We are not going to return bs but the overlay on top of it
2716 * (snapshot_bs); thus, we have to drop the strong reference to bs
2717 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2718 * though, because the overlay still has a reference to it. */
2719 bdrv_unref(bs);
2720 bs = snapshot_bs;
dd62f1ca
KW
2721 }
2722
5b363937 2723 return bs;
b6ce07aa 2724
8bfea15d 2725fail:
5696c6e3 2726 blk_unref(file);
73176bee 2727 QDECREF(snapshot_options);
145f598e 2728 QDECREF(bs->explicit_options);
de9c0cec 2729 QDECREF(bs->options);
b6ad491a 2730 QDECREF(options);
de9c0cec 2731 bs->options = NULL;
998cbd6a 2732 bs->explicit_options = NULL;
5b363937 2733 bdrv_unref(bs);
621ff94d 2734 error_propagate(errp, local_err);
5b363937 2735 return NULL;
de9c0cec 2736
b6ad491a 2737close_and_fail:
5b363937 2738 bdrv_unref(bs);
73176bee 2739 QDECREF(snapshot_options);
b6ad491a 2740 QDECREF(options);
621ff94d 2741 error_propagate(errp, local_err);
5b363937 2742 return NULL;
b6ce07aa
KW
2743}
2744
5b363937
HR
2745BlockDriverState *bdrv_open(const char *filename, const char *reference,
2746 QDict *options, int flags, Error **errp)
f3930ed0 2747{
5b363937 2748 return bdrv_open_inherit(filename, reference, options, flags, NULL,
ce343771 2749 NULL, errp);
f3930ed0
KW
2750}
2751
e971aa12
JC
2752/*
2753 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2754 * reopen of multiple devices.
2755 *
2756 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2757 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2758 * be created and initialized. This newly created BlockReopenQueue should be
2759 * passed back in for subsequent calls that are intended to be of the same
2760 * atomic 'set'.
2761 *
2762 * bs is the BlockDriverState to add to the reopen queue.
2763 *
4d2cb092
KW
2764 * options contains the changed options for the associated bs
2765 * (the BlockReopenQueue takes ownership)
2766 *
e971aa12
JC
2767 * flags contains the open flags for the associated bs
2768 *
2769 * returns a pointer to bs_queue, which is either the newly allocated
2770 * bs_queue, or the existing bs_queue being used.
2771 *
1a63a907 2772 * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
e971aa12 2773 */
28518102
KW
2774static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
2775 BlockDriverState *bs,
2776 QDict *options,
2777 int flags,
2778 const BdrvChildRole *role,
2779 QDict *parent_options,
2780 int parent_flags)
e971aa12
JC
2781{
2782 assert(bs != NULL);
2783
2784 BlockReopenQueueEntry *bs_entry;
67251a31 2785 BdrvChild *child;
145f598e 2786 QDict *old_options, *explicit_options;
67251a31 2787
1a63a907
KW
2788 /* Make sure that the caller remembered to use a drained section. This is
2789 * important to avoid graph changes between the recursive queuing here and
2790 * bdrv_reopen_multiple(). */
2791 assert(bs->quiesce_counter > 0);
2792
e971aa12
JC
2793 if (bs_queue == NULL) {
2794 bs_queue = g_new0(BlockReopenQueue, 1);
2795 QSIMPLEQ_INIT(bs_queue);
2796 }
2797
4d2cb092
KW
2798 if (!options) {
2799 options = qdict_new();
2800 }
2801
5b7ba05f
AG
2802 /* Check if this BlockDriverState is already in the queue */
2803 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
2804 if (bs == bs_entry->state.bs) {
2805 break;
2806 }
2807 }
2808
28518102
KW
2809 /*
2810 * Precedence of options:
2811 * 1. Explicitly passed in options (highest)
91a097e7 2812 * 2. Set in flags (only for top level)
145f598e 2813 * 3. Retained from explicitly set options of bs
8e2160e2 2814 * 4. Inherited from parent node
28518102
KW
2815 * 5. Retained from effective options of bs
2816 */
2817
91a097e7
KW
2818 if (!parent_options) {
2819 /*
2820 * Any setting represented by flags is always updated. If the
2821 * corresponding QDict option is set, it takes precedence. Otherwise
2822 * the flag is translated into a QDict option. The old setting of bs is
2823 * not considered.
2824 */
2825 update_options_from_flags(options, flags);
2826 }
2827
145f598e 2828 /* Old explicitly set values (don't overwrite by inherited value) */
5b7ba05f
AG
2829 if (bs_entry) {
2830 old_options = qdict_clone_shallow(bs_entry->state.explicit_options);
2831 } else {
2832 old_options = qdict_clone_shallow(bs->explicit_options);
2833 }
145f598e
KW
2834 bdrv_join_options(bs, options, old_options);
2835 QDECREF(old_options);
2836
2837 explicit_options = qdict_clone_shallow(options);
2838
28518102
KW
2839 /* Inherit from parent node */
2840 if (parent_options) {
2841 assert(!flags);
8e2160e2 2842 role->inherit_options(&flags, options, parent_flags, parent_options);
28518102
KW
2843 }
2844
2845 /* Old values are used for options that aren't set yet */
4d2cb092 2846 old_options = qdict_clone_shallow(bs->options);
cddff5ba 2847 bdrv_join_options(bs, options, old_options);
4d2cb092
KW
2848 QDECREF(old_options);
2849
fd452021 2850 /* bdrv_open_inherit() sets and clears some additional flags internally */
f1f25a2e 2851 flags &= ~BDRV_O_PROTOCOL;
fd452021
KW
2852 if (flags & BDRV_O_RDWR) {
2853 flags |= BDRV_O_ALLOW_RDWR;
2854 }
f1f25a2e 2855
1857c97b
KW
2856 if (!bs_entry) {
2857 bs_entry = g_new0(BlockReopenQueueEntry, 1);
2858 QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry);
2859 } else {
2860 QDECREF(bs_entry->state.options);
2861 QDECREF(bs_entry->state.explicit_options);
2862 }
2863
2864 bs_entry->state.bs = bs;
2865 bs_entry->state.options = options;
2866 bs_entry->state.explicit_options = explicit_options;
2867 bs_entry->state.flags = flags;
2868
30450259
KW
2869 /* This needs to be overwritten in bdrv_reopen_prepare() */
2870 bs_entry->state.perm = UINT64_MAX;
2871 bs_entry->state.shared_perm = 0;
2872
67251a31 2873 QLIST_FOREACH(child, &bs->children, next) {
4c9dfe5d
KW
2874 QDict *new_child_options;
2875 char *child_key_dot;
67251a31 2876
4c9dfe5d
KW
2877 /* reopen can only change the options of block devices that were
2878 * implicitly created and inherited options. For other (referenced)
2879 * block devices, a syntax like "backing.foo" results in an error. */
67251a31
KW
2880 if (child->bs->inherits_from != bs) {
2881 continue;
2882 }
2883
4c9dfe5d
KW
2884 child_key_dot = g_strdup_printf("%s.", child->name);
2885 qdict_extract_subqdict(options, &new_child_options, child_key_dot);
2886 g_free(child_key_dot);
2887
28518102
KW
2888 bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options, 0,
2889 child->role, options, flags);
e971aa12
JC
2890 }
2891
e971aa12
JC
2892 return bs_queue;
2893}
2894
28518102
KW
2895BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
2896 BlockDriverState *bs,
2897 QDict *options, int flags)
2898{
2899 return bdrv_reopen_queue_child(bs_queue, bs, options, flags,
2900 NULL, NULL, 0);
2901}
2902
e971aa12
JC
2903/*
2904 * Reopen multiple BlockDriverStates atomically & transactionally.
2905 *
2906 * The queue passed in (bs_queue) must have been built up previous
2907 * via bdrv_reopen_queue().
2908 *
2909 * Reopens all BDS specified in the queue, with the appropriate
2910 * flags. All devices are prepared for reopen, and failure of any
2911 * device will cause all device changes to be abandonded, and intermediate
2912 * data cleaned up.
2913 *
2914 * If all devices prepare successfully, then the changes are committed
2915 * to all devices.
2916 *
1a63a907
KW
2917 * All affected nodes must be drained between bdrv_reopen_queue() and
2918 * bdrv_reopen_multiple().
e971aa12 2919 */
720150f3 2920int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp)
e971aa12
JC
2921{
2922 int ret = -1;
2923 BlockReopenQueueEntry *bs_entry, *next;
2924 Error *local_err = NULL;
2925
2926 assert(bs_queue != NULL);
2927
e971aa12 2928 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
1a63a907 2929 assert(bs_entry->state.bs->quiesce_counter > 0);
e971aa12
JC
2930 if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) {
2931 error_propagate(errp, local_err);
2932 goto cleanup;
2933 }
2934 bs_entry->prepared = true;
2935 }
2936
2937 /* If we reach this point, we have success and just need to apply the
2938 * changes
2939 */
2940 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
2941 bdrv_reopen_commit(&bs_entry->state);
2942 }
2943
2944 ret = 0;
2945
2946cleanup:
2947 QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
2948 if (ret && bs_entry->prepared) {
2949 bdrv_reopen_abort(&bs_entry->state);
145f598e
KW
2950 } else if (ret) {
2951 QDECREF(bs_entry->state.explicit_options);
e971aa12 2952 }
4d2cb092 2953 QDECREF(bs_entry->state.options);
e971aa12
JC
2954 g_free(bs_entry);
2955 }
2956 g_free(bs_queue);
40840e41 2957
e971aa12
JC
2958 return ret;
2959}
2960
2961
2962/* Reopen a single BlockDriverState with the specified flags. */
2963int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp)
2964{
2965 int ret = -1;
2966 Error *local_err = NULL;
1a63a907 2967 BlockReopenQueue *queue;
e971aa12 2968
1a63a907
KW
2969 bdrv_subtree_drained_begin(bs);
2970
2971 queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
720150f3 2972 ret = bdrv_reopen_multiple(bdrv_get_aio_context(bs), queue, &local_err);
e971aa12
JC
2973 if (local_err != NULL) {
2974 error_propagate(errp, local_err);
2975 }
1a63a907
KW
2976
2977 bdrv_subtree_drained_end(bs);
2978
e971aa12
JC
2979 return ret;
2980}
2981
30450259
KW
2982static BlockReopenQueueEntry *find_parent_in_reopen_queue(BlockReopenQueue *q,
2983 BdrvChild *c)
2984{
2985 BlockReopenQueueEntry *entry;
2986
2987 QSIMPLEQ_FOREACH(entry, q, entry) {
2988 BlockDriverState *bs = entry->state.bs;
2989 BdrvChild *child;
2990
2991 QLIST_FOREACH(child, &bs->children, next) {
2992 if (child == c) {
2993 return entry;
2994 }
2995 }
2996 }
2997
2998 return NULL;
2999}
3000
3001static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs,
3002 uint64_t *perm, uint64_t *shared)
3003{
3004 BdrvChild *c;
3005 BlockReopenQueueEntry *parent;
3006 uint64_t cumulative_perms = 0;
3007 uint64_t cumulative_shared_perms = BLK_PERM_ALL;
3008
3009 QLIST_FOREACH(c, &bs->parents, next_parent) {
3010 parent = find_parent_in_reopen_queue(q, c);
3011 if (!parent) {
3012 cumulative_perms |= c->perm;
3013 cumulative_shared_perms &= c->shared_perm;
3014 } else {
3015 uint64_t nperm, nshared;
3016
3017 bdrv_child_perm(parent->state.bs, bs, c, c->role, q,
3018 parent->state.perm, parent->state.shared_perm,
3019 &nperm, &nshared);
3020
3021 cumulative_perms |= nperm;
3022 cumulative_shared_perms &= nshared;
3023 }
3024 }
3025 *perm = cumulative_perms;
3026 *shared = cumulative_shared_perms;
3027}
e971aa12
JC
3028
3029/*
3030 * Prepares a BlockDriverState for reopen. All changes are staged in the
3031 * 'opaque' field of the BDRVReopenState, which is used and allocated by
3032 * the block driver layer .bdrv_reopen_prepare()
3033 *
3034 * bs is the BlockDriverState to reopen
3035 * flags are the new open flags
3036 * queue is the reopen queue
3037 *
3038 * Returns 0 on success, non-zero on error. On error errp will be set
3039 * as well.
3040 *
3041 * On failure, bdrv_reopen_abort() will be called to clean up any data.
3042 * It is the responsibility of the caller to then call the abort() or
3043 * commit() for any other BDS that have been left in a prepare() state
3044 *
3045 */
3046int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
3047 Error **errp)
3048{
3049 int ret = -1;
3050 Error *local_err = NULL;
3051 BlockDriver *drv;
ccf9dc07
KW
3052 QemuOpts *opts;
3053 const char *value;
3d8ce171 3054 bool read_only;
e971aa12
JC
3055
3056 assert(reopen_state != NULL);
3057 assert(reopen_state->bs->drv != NULL);
3058 drv = reopen_state->bs->drv;
3059
ccf9dc07
KW
3060 /* Process generic block layer options */
3061 opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
3062 qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err);
3063 if (local_err) {
3064 error_propagate(errp, local_err);
3065 ret = -EINVAL;
3066 goto error;
3067 }
3068
91a097e7
KW
3069 update_flags_from_options(&reopen_state->flags, opts);
3070
ccf9dc07
KW
3071 /* node-name and driver must be unchanged. Put them back into the QDict, so
3072 * that they are checked at the end of this function. */
3073 value = qemu_opt_get(opts, "node-name");
3074 if (value) {
46f5ac20 3075 qdict_put_str(reopen_state->options, "node-name", value);
ccf9dc07
KW
3076 }
3077
3078 value = qemu_opt_get(opts, "driver");
3079 if (value) {
46f5ac20 3080 qdict_put_str(reopen_state->options, "driver", value);
ccf9dc07
KW
3081 }
3082
3d8ce171
JC
3083 /* If we are to stay read-only, do not allow permission change
3084 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
3085 * not set, or if the BDS still has copy_on_read enabled */
3086 read_only = !(reopen_state->flags & BDRV_O_RDWR);
54a32bfe 3087 ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err);
3d8ce171
JC
3088 if (local_err) {
3089 error_propagate(errp, local_err);
e971aa12
JC
3090 goto error;
3091 }
3092
30450259
KW
3093 /* Calculate required permissions after reopening */
3094 bdrv_reopen_perm(queue, reopen_state->bs,
3095 &reopen_state->perm, &reopen_state->shared_perm);
e971aa12
JC
3096
3097 ret = bdrv_flush(reopen_state->bs);
3098 if (ret) {
455b0fde 3099 error_setg_errno(errp, -ret, "Error flushing drive");
e971aa12
JC
3100 goto error;
3101 }
3102
3103 if (drv->bdrv_reopen_prepare) {
3104 ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
3105 if (ret) {
3106 if (local_err != NULL) {
3107 error_propagate(errp, local_err);
3108 } else {
d8b6895f
LC
3109 error_setg(errp, "failed while preparing to reopen image '%s'",
3110 reopen_state->bs->filename);
e971aa12
JC
3111 }
3112 goto error;
3113 }
3114 } else {
3115 /* It is currently mandatory to have a bdrv_reopen_prepare()
3116 * handler for each supported drv. */
81e5f78a
AG
3117 error_setg(errp, "Block format '%s' used by node '%s' "
3118 "does not support reopening files", drv->format_name,
3119 bdrv_get_device_or_node_name(reopen_state->bs));
e971aa12
JC
3120 ret = -1;
3121 goto error;
3122 }
3123
4d2cb092
KW
3124 /* Options that are not handled are only okay if they are unchanged
3125 * compared to the old state. It is expected that some options are only
3126 * used for the initial open, but not reopen (e.g. filename) */
3127 if (qdict_size(reopen_state->options)) {
3128 const QDictEntry *entry = qdict_first(reopen_state->options);
3129
3130 do {
54fd1b0d
HR
3131 QObject *new = entry->value;
3132 QObject *old = qdict_get(reopen_state->bs->options, entry->key);
3133
129c7d1c 3134 /*
54fd1b0d
HR
3135 * TODO: When using -drive to specify blockdev options, all values
3136 * will be strings; however, when using -blockdev, blockdev-add or
3137 * filenames using the json:{} pseudo-protocol, they will be
3138 * correctly typed.
3139 * In contrast, reopening options are (currently) always strings
3140 * (because you can only specify them through qemu-io; all other
3141 * callers do not specify any options).
3142 * Therefore, when using anything other than -drive to create a BDS,
3143 * this cannot detect non-string options as unchanged, because
3144 * qobject_is_equal() always returns false for objects of different
3145 * type. In the future, this should be remedied by correctly typing
3146 * all options. For now, this is not too big of an issue because
3147 * the user can simply omit options which cannot be changed anyway,
3148 * so they will stay unchanged.
129c7d1c 3149 */
54fd1b0d 3150 if (!qobject_is_equal(new, old)) {
4d2cb092
KW
3151 error_setg(errp, "Cannot change the option '%s'", entry->key);
3152 ret = -EINVAL;
3153 goto error;
3154 }
3155 } while ((entry = qdict_next(reopen_state->options, entry)));
3156 }
3157
30450259
KW
3158 ret = bdrv_check_perm(reopen_state->bs, queue, reopen_state->perm,
3159 reopen_state->shared_perm, NULL, errp);
3160 if (ret < 0) {
3161 goto error;
3162 }
3163
e971aa12
JC
3164 ret = 0;
3165
3166error:
ccf9dc07 3167 qemu_opts_del(opts);
e971aa12
JC
3168 return ret;
3169}
3170
3171/*
3172 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
3173 * makes them final by swapping the staging BlockDriverState contents into
3174 * the active BlockDriverState contents.
3175 */
3176void bdrv_reopen_commit(BDRVReopenState *reopen_state)
3177{
3178 BlockDriver *drv;
50bf65ba 3179 BlockDriverState *bs;
cb9ff6c2 3180 bool old_can_write, new_can_write;
e971aa12
JC
3181
3182 assert(reopen_state != NULL);
50bf65ba
VSO
3183 bs = reopen_state->bs;
3184 drv = bs->drv;
e971aa12
JC
3185 assert(drv != NULL);
3186
cb9ff6c2
VSO
3187 old_can_write =
3188 !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
3189
e971aa12
JC
3190 /* If there are any driver level actions to take */
3191 if (drv->bdrv_reopen_commit) {
3192 drv->bdrv_reopen_commit(reopen_state);
3193 }
3194
3195 /* set BDS specific flags now */
50bf65ba 3196 QDECREF(bs->explicit_options);
145f598e 3197
50bf65ba
VSO
3198 bs->explicit_options = reopen_state->explicit_options;
3199 bs->open_flags = reopen_state->flags;
3200 bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
355ef4ac 3201
50bf65ba 3202 bdrv_refresh_limits(bs, NULL);
cb9ff6c2 3203
30450259
KW
3204 bdrv_set_perm(reopen_state->bs, reopen_state->perm,
3205 reopen_state->shared_perm);
3206
cb9ff6c2
VSO
3207 new_can_write =
3208 !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
3209 if (!old_can_write && new_can_write && drv->bdrv_reopen_bitmaps_rw) {
3210 Error *local_err = NULL;
3211 if (drv->bdrv_reopen_bitmaps_rw(bs, &local_err) < 0) {
3212 /* This is not fatal, bitmaps just left read-only, so all following
3213 * writes will fail. User can remove read-only bitmaps to unblock
3214 * writes.
3215 */
3216 error_reportf_err(local_err,
3217 "%s: Failed to make dirty bitmaps writable: ",
3218 bdrv_get_node_name(bs));
3219 }
3220 }
e971aa12
JC
3221}
3222
3223/*
3224 * Abort the reopen, and delete and free the staged changes in
3225 * reopen_state
3226 */
3227void bdrv_reopen_abort(BDRVReopenState *reopen_state)
3228{
3229 BlockDriver *drv;
3230
3231 assert(reopen_state != NULL);
3232 drv = reopen_state->bs->drv;
3233 assert(drv != NULL);
3234
3235 if (drv->bdrv_reopen_abort) {
3236 drv->bdrv_reopen_abort(reopen_state);
3237 }
145f598e
KW
3238
3239 QDECREF(reopen_state->explicit_options);
30450259
KW
3240
3241 bdrv_abort_perm_update(reopen_state->bs);
e971aa12
JC
3242}
3243
3244
64dff520 3245static void bdrv_close(BlockDriverState *bs)
fc01f7e7 3246{
33384421 3247 BdrvAioNotifier *ban, *ban_next;
50a3efb0 3248 BdrvChild *child, *next;
33384421 3249
ca9bd24c 3250 assert(!bs->job);
30f55fb8 3251 assert(!bs->refcnt);
99b7e775 3252
fc27291d 3253 bdrv_drained_begin(bs); /* complete I/O */
58fda173 3254 bdrv_flush(bs);
53ec73e2 3255 bdrv_drain(bs); /* in case flush left pending I/O */
fc27291d 3256
3cbc002c 3257 if (bs->drv) {
9a7dedbc 3258 bs->drv->bdrv_close(bs);
9a4f4c31 3259 bs->drv = NULL;
50a3efb0 3260 }
9a7dedbc 3261
50a3efb0 3262 bdrv_set_backing_hd(bs, NULL, &error_abort);
9a7dedbc 3263
50a3efb0
AG
3264 if (bs->file != NULL) {
3265 bdrv_unref_child(bs, bs->file);
3266 bs->file = NULL;
3267 }
9a4f4c31 3268
50a3efb0
AG
3269 QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
3270 /* TODO Remove bdrv_unref() from drivers' close function and use
3271 * bdrv_unref_child() here */
3272 if (child->bs->inherits_from == bs) {
3273 child->bs->inherits_from = NULL;
6e93e7c4 3274 }
50a3efb0 3275 bdrv_detach_child(child);
b338082b 3276 }
98f90dba 3277
50a3efb0
AG
3278 g_free(bs->opaque);
3279 bs->opaque = NULL;
3280 atomic_set(&bs->copy_on_read, 0);
3281 bs->backing_file[0] = '\0';
3282 bs->backing_format[0] = '\0';
3283 bs->total_sectors = 0;
3284 bs->encrypted = false;
3285 bs->sg = false;
3286 QDECREF(bs->options);
3287 QDECREF(bs->explicit_options);
3288 bs->options = NULL;
3289 bs->explicit_options = NULL;
3290 QDECREF(bs->full_open_options);
3291 bs->full_open_options = NULL;
3292
cca43ae1
VSO
3293 bdrv_release_named_dirty_bitmaps(bs);
3294 assert(QLIST_EMPTY(&bs->dirty_bitmaps));
3295
33384421
HR
3296 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
3297 g_free(ban);
3298 }
3299 QLIST_INIT(&bs->aio_notifiers);
fc27291d 3300 bdrv_drained_end(bs);
b338082b
FB
3301}
3302
2bc93fed
MK
3303void bdrv_close_all(void)
3304{
a1a2af07 3305 block_job_cancel_sync_all();
cd7fca95 3306 nbd_export_close_all();
ca9bd24c
HR
3307
3308 /* Drop references from requests still in flight, such as canceled block
3309 * jobs whose AIO context has not been polled yet */
3310 bdrv_drain_all();
2bc93fed 3311
ca9bd24c
HR
3312 blk_remove_all_bs();
3313 blockdev_close_all_bdrv_states();
ed78cda3 3314
a1a2af07 3315 assert(QTAILQ_EMPTY(&all_bdrv_states));
2bc93fed
MK
3316}
3317
d0ac0380
KW
3318static bool should_update_child(BdrvChild *c, BlockDriverState *to)
3319{
3320 BdrvChild *to_c;
3321
3322 if (c->role->stay_at_node) {
3323 return false;
3324 }
3325
3326 if (c->role == &child_backing) {
3327 /* If @from is a backing file of @to, ignore the child to avoid
3328 * creating a loop. We only want to change the pointer of other
3329 * parents. */
3330 QLIST_FOREACH(to_c, &to->children, next) {
3331 if (to_c == c) {
3332 break;
3333 }
3334 }
3335 if (to_c) {
3336 return false;
3337 }
3338 }
3339
3340 return true;
3341}
3342
5fe31c25
KW
3343void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
3344 Error **errp)
dd62f1ca 3345{
d0ac0380 3346 BdrvChild *c, *next;
234ac1a9
KW
3347 GSList *list = NULL, *p;
3348 uint64_t old_perm, old_shared;
3349 uint64_t perm = 0, shared = BLK_PERM_ALL;
3350 int ret;
3351
5fe31c25
KW
3352 assert(!atomic_read(&from->in_flight));
3353 assert(!atomic_read(&to->in_flight));
dd62f1ca 3354
234ac1a9
KW
3355 /* Make sure that @from doesn't go away until we have successfully attached
3356 * all of its parents to @to. */
3357 bdrv_ref(from);
dd62f1ca 3358
234ac1a9 3359 /* Put all parents into @list and calculate their cumulative permissions */
dd62f1ca 3360 QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
d0ac0380 3361 if (!should_update_child(c, to)) {
26de9438
KW
3362 continue;
3363 }
234ac1a9
KW
3364 list = g_slist_prepend(list, c);
3365 perm |= c->perm;
3366 shared &= c->shared_perm;
3367 }
3368
3369 /* Check whether the required permissions can be granted on @to, ignoring
3370 * all BdrvChild in @list so that they can't block themselves. */
3121fb45 3371 ret = bdrv_check_update_perm(to, NULL, perm, shared, list, errp);
234ac1a9
KW
3372 if (ret < 0) {
3373 bdrv_abort_perm_update(to);
3374 goto out;
3375 }
3376
3377 /* Now actually perform the change. We performed the permission check for
3378 * all elements of @list at once, so set the permissions all at once at the
3379 * very end. */
3380 for (p = list; p != NULL; p = p->next) {
3381 c = p->data;
9bd910e2 3382
dd62f1ca 3383 bdrv_ref(to);
234ac1a9 3384 bdrv_replace_child_noperm(c, to);
dd62f1ca
KW
3385 bdrv_unref(from);
3386 }
234ac1a9
KW
3387
3388 bdrv_get_cumulative_perm(to, &old_perm, &old_shared);
3389 bdrv_set_perm(to, old_perm | perm, old_shared | shared);
3390
3391out:
3392 g_slist_free(list);
3393 bdrv_unref(from);
dd62f1ca
KW
3394}
3395
4ddc07ca
PB
3396/*
3397 * Add new bs contents at the top of an image chain while the chain is
3398 * live, while keeping required fields on the top layer.
3399 *
3400 * This will modify the BlockDriverState fields, and swap contents
3401 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3402 *
bfb197e0 3403 * bs_new must not be attached to a BlockBackend.
4ddc07ca
PB
3404 *
3405 * This function does not create any image files.
dd62f1ca
KW
3406 *
3407 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3408 * that's what the callers commonly need. bs_new will be referenced by the old
3409 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3410 * reference of its own, it must call bdrv_ref().
4ddc07ca 3411 */
b2c2832c
KW
3412void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
3413 Error **errp)
4ddc07ca 3414{
b2c2832c
KW
3415 Error *local_err = NULL;
3416
b2c2832c
KW
3417 bdrv_set_backing_hd(bs_new, bs_top, &local_err);
3418 if (local_err) {
3419 error_propagate(errp, local_err);
3420 goto out;
3421 }
dd62f1ca 3422
5fe31c25 3423 bdrv_replace_node(bs_top, bs_new, &local_err);
234ac1a9
KW
3424 if (local_err) {
3425 error_propagate(errp, local_err);
3426 bdrv_set_backing_hd(bs_new, NULL, &error_abort);
3427 goto out;
3428 }
4ddc07ca 3429
dd62f1ca
KW
3430 /* bs_new is now referenced by its new parents, we don't need the
3431 * additional reference any more. */
b2c2832c 3432out:
dd62f1ca 3433 bdrv_unref(bs_new);
8802d1fd
JC
3434}
3435
4f6fd349 3436static void bdrv_delete(BlockDriverState *bs)
b338082b 3437{
3e914655 3438 assert(!bs->job);
3718d8ab 3439 assert(bdrv_op_blocker_is_empty(bs));
4f6fd349 3440 assert(!bs->refcnt);
18846dee 3441
e1b5c52e
SH
3442 bdrv_close(bs);
3443
1b7bdbc1 3444 /* remove from list, if necessary */
63eaaae0
KW
3445 if (bs->node_name[0] != '\0') {
3446 QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
3447 }
2c1d04e0
HR
3448 QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list);
3449
7267c094 3450 g_free(bs);
fc01f7e7
FB
3451}
3452
e97fc193
AL
3453/*
3454 * Run consistency checks on an image
3455 *
e076f338 3456 * Returns 0 if the check could be completed (it doesn't mean that the image is
a1c7273b 3457 * free of errors) or -errno when an internal error occurred. The results of the
e076f338 3458 * check are stored in res.
e97fc193 3459 */
4534ff54 3460int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
e97fc193 3461{
908bcd54
HR
3462 if (bs->drv == NULL) {
3463 return -ENOMEDIUM;
3464 }
e97fc193
AL
3465 if (bs->drv->bdrv_check == NULL) {
3466 return -ENOTSUP;
3467 }
3468
e076f338 3469 memset(res, 0, sizeof(*res));
4534ff54 3470 return bs->drv->bdrv_check(bs, res, fix);
e97fc193
AL
3471}
3472
756e6736
KW
3473/*
3474 * Return values:
3475 * 0 - success
3476 * -EINVAL - backing format specified, but no file
3477 * -ENOSPC - can't update the backing file because no space is left in the
3478 * image file header
3479 * -ENOTSUP - format driver doesn't support changing the backing file
3480 */
3481int bdrv_change_backing_file(BlockDriverState *bs,
3482 const char *backing_file, const char *backing_fmt)
3483{
3484 BlockDriver *drv = bs->drv;
469ef350 3485 int ret;
756e6736 3486
d470ad42
HR
3487 if (!drv) {
3488 return -ENOMEDIUM;
3489 }
3490
5f377794
PB
3491 /* Backing file format doesn't make sense without a backing file */
3492 if (backing_fmt && !backing_file) {
3493 return -EINVAL;
3494 }
3495
756e6736 3496 if (drv->bdrv_change_backing_file != NULL) {
469ef350 3497 ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
756e6736 3498 } else {
469ef350 3499 ret = -ENOTSUP;
756e6736 3500 }
469ef350
PB
3501
3502 if (ret == 0) {
3503 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
3504 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
3505 }
3506 return ret;
756e6736
KW
3507}
3508
6ebdcee2
JC
3509/*
3510 * Finds the image layer in the chain that has 'bs' as its backing file.
3511 *
3512 * active is the current topmost image.
3513 *
3514 * Returns NULL if bs is not found in active's image chain,
3515 * or if active == bs.
4caf0fcd
JC
3516 *
3517 * Returns the bottommost base image if bs == NULL.
6ebdcee2
JC
3518 */
3519BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
3520 BlockDriverState *bs)
3521{
760e0063
KW
3522 while (active && bs != backing_bs(active)) {
3523 active = backing_bs(active);
6ebdcee2
JC
3524 }
3525
4caf0fcd
JC
3526 return active;
3527}
6ebdcee2 3528
4caf0fcd
JC
3529/* Given a BDS, searches for the base layer. */
3530BlockDriverState *bdrv_find_base(BlockDriverState *bs)
3531{
3532 return bdrv_find_overlay(bs, NULL);
6ebdcee2
JC
3533}
3534
6ebdcee2
JC
3535/*
3536 * Drops images above 'base' up to and including 'top', and sets the image
3537 * above 'top' to have base as its backing file.
3538 *
3539 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3540 * information in 'bs' can be properly updated.
3541 *
3542 * E.g., this will convert the following chain:
3543 * bottom <- base <- intermediate <- top <- active
3544 *
3545 * to
3546 *
3547 * bottom <- base <- active
3548 *
3549 * It is allowed for bottom==base, in which case it converts:
3550 *
3551 * base <- intermediate <- top <- active
3552 *
3553 * to
3554 *
3555 * base <- active
3556 *
54e26900
JC
3557 * If backing_file_str is non-NULL, it will be used when modifying top's
3558 * overlay image metadata.
3559 *
6ebdcee2
JC
3560 * Error conditions:
3561 * if active == top, that is considered an error
3562 *
3563 */
bde70715
KW
3564int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
3565 const char *backing_file_str)
6ebdcee2 3566{
61f09cea 3567 BdrvChild *c, *next;
12fa4af6 3568 Error *local_err = NULL;
6ebdcee2
JC
3569 int ret = -EIO;
3570
6858eba0
KW
3571 bdrv_ref(top);
3572
6ebdcee2
JC
3573 if (!top->drv || !base->drv) {
3574 goto exit;
3575 }
3576
5db15a57
KW
3577 /* Make sure that base is in the backing chain of top */
3578 if (!bdrv_chain_contains(top, base)) {
6ebdcee2
JC
3579 goto exit;
3580 }
3581
3582 /* success - we can delete the intermediate states, and link top->base */
bde70715
KW
3583 /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
3584 * we've figured out how they should work. */
61f09cea
KW
3585 backing_file_str = backing_file_str ? backing_file_str : base->filename;
3586
3587 QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
3588 /* Check whether we are allowed to switch c from top to base */
3589 GSList *ignore_children = g_slist_prepend(NULL, c);
3590 bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
3591 ignore_children, &local_err);
3592 if (local_err) {
3593 ret = -EPERM;
3594 error_report_err(local_err);
6858eba0
KW
3595 goto exit;
3596 }
61f09cea 3597 g_slist_free(ignore_children);
12fa4af6 3598
61f09cea
KW
3599 /* If so, update the backing file path in the image file */
3600 if (c->role->update_filename) {
3601 ret = c->role->update_filename(c, base, backing_file_str,
3602 &local_err);
3603 if (ret < 0) {
3604 bdrv_abort_perm_update(base);
3605 error_report_err(local_err);
3606 goto exit;
3607 }
3608 }
3609
3610 /* Do the actual switch in the in-memory graph.
3611 * Completes bdrv_check_update_perm() transaction internally. */
3612 bdrv_ref(base);
3613 bdrv_replace_child(c, base);
3614 bdrv_unref(top);
12fa4af6 3615 }
6ebdcee2 3616
6ebdcee2 3617 ret = 0;
6ebdcee2 3618exit:
6858eba0 3619 bdrv_unref(top);
6ebdcee2
JC
3620 return ret;
3621}
3622
61007b31
SH
3623/**
3624 * Truncate file to 'offset' bytes (needed only for file protocols)
3625 */
7ea37c30
HR
3626int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc,
3627 Error **errp)
71d0770c 3628{
52cdbc58 3629 BlockDriverState *bs = child->bs;
61007b31
SH
3630 BlockDriver *drv = bs->drv;
3631 int ret;
c8f6d58e 3632
362b3786 3633 assert(child->perm & BLK_PERM_RESIZE);
c8f6d58e 3634
5a612c00 3635 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
ed3d2ec9
HR
3636 if (!drv) {
3637 error_setg(errp, "No medium inserted");
71d0770c 3638 return -ENOMEDIUM;
ed3d2ec9
HR
3639 }
3640 if (!drv->bdrv_truncate) {
5a612c00
MP
3641 if (bs->file && drv->is_filter) {
3642 return bdrv_truncate(bs->file, offset, prealloc, errp);
3643 }
ed3d2ec9 3644 error_setg(errp, "Image format driver does not support resize");
61007b31 3645 return -ENOTSUP;
ed3d2ec9
HR
3646 }
3647 if (bs->read_only) {
3648 error_setg(errp, "Image is read-only");
61007b31 3649 return -EACCES;
ed3d2ec9 3650 }
71d0770c 3651
504c205a
DL
3652 assert(!(bs->open_flags & BDRV_O_INACTIVE));
3653
7ea37c30 3654 ret = drv->bdrv_truncate(bs, offset, prealloc, errp);
1b6cc579
EB
3655 if (ret < 0) {
3656 return ret;
3657 }
3658 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
3659 if (ret < 0) {
3660 error_setg_errno(errp, -ret, "Could not refresh total sector count");
3661 } else {
3662 offset = bs->total_sectors * BDRV_SECTOR_SIZE;
c0191e76 3663 }
1b6cc579
EB
3664 bdrv_dirty_bitmap_truncate(bs, offset);
3665 bdrv_parent_cb_resize(bs);
3666 atomic_inc(&bs->write_gen);
61007b31 3667 return ret;
71d0770c
AL
3668}
3669
61007b31
SH
3670/**
3671 * Length of a allocated file in bytes. Sparse files are counted by actual
3672 * allocated space. Return < 0 if error or unknown.
3673 */
3674int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
71d0770c 3675{
61007b31
SH
3676 BlockDriver *drv = bs->drv;
3677 if (!drv) {
3678 return -ENOMEDIUM;
8f4754ed 3679 }
61007b31
SH
3680 if (drv->bdrv_get_allocated_file_size) {
3681 return drv->bdrv_get_allocated_file_size(bs);
3682 }
3683 if (bs->file) {
9a4f4c31 3684 return bdrv_get_allocated_file_size(bs->file->bs);
1c9805a3 3685 }
61007b31 3686 return -ENOTSUP;
1c9805a3 3687}
e7a8a783 3688
90880ff1
SH
3689/*
3690 * bdrv_measure:
3691 * @drv: Format driver
3692 * @opts: Creation options for new image
3693 * @in_bs: Existing image containing data for new image (may be NULL)
3694 * @errp: Error object
3695 * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
3696 * or NULL on error
3697 *
3698 * Calculate file size required to create a new image.
3699 *
3700 * If @in_bs is given then space for allocated clusters and zero clusters
3701 * from that image are included in the calculation. If @opts contains a
3702 * backing file that is shared by @in_bs then backing clusters may be omitted
3703 * from the calculation.
3704 *
3705 * If @in_bs is NULL then the calculation includes no allocated clusters
3706 * unless a preallocation option is given in @opts.
3707 *
3708 * Note that @in_bs may use a different BlockDriver from @drv.
3709 *
3710 * If an error occurs the @errp pointer is set.
3711 */
3712BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
3713 BlockDriverState *in_bs, Error **errp)
3714{
3715 if (!drv->bdrv_measure) {
3716 error_setg(errp, "Block driver '%s' does not support size measurement",
3717 drv->format_name);
3718 return NULL;
3719 }
3720
3721 return drv->bdrv_measure(opts, in_bs, errp);
3722}
3723
61007b31
SH
3724/**
3725 * Return number of sectors on success, -errno on error.
1c9805a3 3726 */
61007b31 3727int64_t bdrv_nb_sectors(BlockDriverState *bs)
1c9805a3 3728{
61007b31 3729 BlockDriver *drv = bs->drv;
498e386c 3730
61007b31
SH
3731 if (!drv)
3732 return -ENOMEDIUM;
2572b37a 3733
61007b31
SH
3734 if (drv->has_variable_length) {
3735 int ret = refresh_total_sectors(bs, bs->total_sectors);
3736 if (ret < 0) {
3737 return ret;
1c9805a3
SH
3738 }
3739 }
61007b31 3740 return bs->total_sectors;
1c9805a3 3741}
b338082b 3742
61007b31
SH
3743/**
3744 * Return length in bytes on success, -errno on error.
3745 * The length is always a multiple of BDRV_SECTOR_SIZE.
8d3b1a2d 3746 */
61007b31 3747int64_t bdrv_getlength(BlockDriverState *bs)
8d3b1a2d 3748{
61007b31 3749 int64_t ret = bdrv_nb_sectors(bs);
8d3b1a2d 3750
4a9c9ea0 3751 ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret;
61007b31 3752 return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
fc01f7e7
FB
3753}
3754
61007b31
SH
3755/* return 0 as number of sectors if no device present or error */
3756void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
07d27a44 3757{
61007b31 3758 int64_t nb_sectors = bdrv_nb_sectors(bs);
07d27a44 3759
61007b31 3760 *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
07d27a44
MA
3761}
3762
54115412 3763bool bdrv_is_sg(BlockDriverState *bs)
f08145fe 3764{
61007b31 3765 return bs->sg;
f08145fe
KW
3766}
3767
54115412 3768bool bdrv_is_encrypted(BlockDriverState *bs)
fc3959e4 3769{
760e0063 3770 if (bs->backing && bs->backing->bs->encrypted) {
54115412 3771 return true;
760e0063 3772 }
61007b31 3773 return bs->encrypted;
fc3959e4
FZ
3774}
3775
61007b31 3776const char *bdrv_get_format_name(BlockDriverState *bs)
40b4f539 3777{
61007b31 3778 return bs->drv ? bs->drv->format_name : NULL;
40b4f539
KW
3779}
3780
61007b31 3781static int qsort_strcmp(const void *a, const void *b)
40b4f539 3782{
ceff5bd7 3783 return strcmp(*(char *const *)a, *(char *const *)b);
40b4f539
KW
3784}
3785
61007b31
SH
3786void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
3787 void *opaque)
40b4f539 3788{
61007b31
SH
3789 BlockDriver *drv;
3790 int count = 0;
3791 int i;
3792 const char **formats = NULL;
40b4f539 3793
61007b31
SH
3794 QLIST_FOREACH(drv, &bdrv_drivers, list) {
3795 if (drv->format_name) {
3796 bool found = false;
3797 int i = count;
3798 while (formats && i && !found) {
3799 found = !strcmp(formats[--i], drv->format_name);
3800 }
e2a305fb 3801
61007b31
SH
3802 if (!found) {
3803 formats = g_renew(const char *, formats, count + 1);
3804 formats[count++] = drv->format_name;
3805 }
6c5a42ac 3806 }
61007b31 3807 }
6c5a42ac 3808
eb0df69f
HR
3809 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) {
3810 const char *format_name = block_driver_modules[i].format_name;
3811
3812 if (format_name) {
3813 bool found = false;
3814 int j = count;
3815
3816 while (formats && j && !found) {
3817 found = !strcmp(formats[--j], format_name);
3818 }
3819
3820 if (!found) {
3821 formats = g_renew(const char *, formats, count + 1);
3822 formats[count++] = format_name;
3823 }
3824 }
3825 }
3826
61007b31 3827 qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
40b4f539 3828
61007b31
SH
3829 for (i = 0; i < count; i++) {
3830 it(opaque, formats[i]);
3831 }
40b4f539 3832
61007b31
SH
3833 g_free(formats);
3834}
40b4f539 3835
61007b31
SH
3836/* This function is to find a node in the bs graph */
3837BlockDriverState *bdrv_find_node(const char *node_name)
3838{
3839 BlockDriverState *bs;
391827eb 3840
61007b31 3841 assert(node_name);
40b4f539 3842
61007b31
SH
3843 QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
3844 if (!strcmp(node_name, bs->node_name)) {
3845 return bs;
40b4f539
KW
3846 }
3847 }
61007b31 3848 return NULL;
40b4f539
KW
3849}
3850
61007b31
SH
3851/* Put this QMP function here so it can access the static graph_bdrv_states. */
3852BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
40b4f539 3853{
61007b31
SH
3854 BlockDeviceInfoList *list, *entry;
3855 BlockDriverState *bs;
40b4f539 3856
61007b31
SH
3857 list = NULL;
3858 QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
c83f9fba 3859 BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp);
61007b31
SH
3860 if (!info) {
3861 qapi_free_BlockDeviceInfoList(list);
3862 return NULL;
301db7c2 3863 }
61007b31
SH
3864 entry = g_malloc0(sizeof(*entry));
3865 entry->value = info;
3866 entry->next = list;
3867 list = entry;
301db7c2
RH
3868 }
3869
61007b31
SH
3870 return list;
3871}
40b4f539 3872
61007b31
SH
3873BlockDriverState *bdrv_lookup_bs(const char *device,
3874 const char *node_name,
3875 Error **errp)
3876{
3877 BlockBackend *blk;
3878 BlockDriverState *bs;
40b4f539 3879
61007b31
SH
3880 if (device) {
3881 blk = blk_by_name(device);
40b4f539 3882
61007b31 3883 if (blk) {
9f4ed6fb
AG
3884 bs = blk_bs(blk);
3885 if (!bs) {
5433c24f 3886 error_setg(errp, "Device '%s' has no medium", device);
5433c24f
HR
3887 }
3888
9f4ed6fb 3889 return bs;
61007b31
SH
3890 }
3891 }
40b4f539 3892
61007b31
SH
3893 if (node_name) {
3894 bs = bdrv_find_node(node_name);
6d519a5f 3895
61007b31
SH
3896 if (bs) {
3897 return bs;
3898 }
40b4f539
KW
3899 }
3900
61007b31
SH
3901 error_setg(errp, "Cannot find device=%s nor node_name=%s",
3902 device ? device : "",
3903 node_name ? node_name : "");
3904 return NULL;
40b4f539
KW
3905}
3906
61007b31
SH
3907/* If 'base' is in the same chain as 'top', return true. Otherwise,
3908 * return false. If either argument is NULL, return false. */
3909bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
83f64091 3910{
61007b31 3911 while (top && top != base) {
760e0063 3912 top = backing_bs(top);
02c50efe 3913 }
61007b31
SH
3914
3915 return top != NULL;
02c50efe
FZ
3916}
3917
61007b31 3918BlockDriverState *bdrv_next_node(BlockDriverState *bs)
02c50efe 3919{
61007b31
SH
3920 if (!bs) {
3921 return QTAILQ_FIRST(&graph_bdrv_states);
02c50efe 3922 }
61007b31 3923 return QTAILQ_NEXT(bs, node_list);
83f64091
FB
3924}
3925
61007b31 3926const char *bdrv_get_node_name(const BlockDriverState *bs)
83f64091 3927{
61007b31 3928 return bs->node_name;
beac80cd
FB
3929}
3930
1f0c461b 3931const char *bdrv_get_parent_name(const BlockDriverState *bs)
4c265bf9
KW
3932{
3933 BdrvChild *c;
3934 const char *name;
3935
3936 /* If multiple parents have a name, just pick the first one. */
3937 QLIST_FOREACH(c, &bs->parents, next_parent) {
3938 if (c->role->get_name) {
3939 name = c->role->get_name(c);
3940 if (name && *name) {
3941 return name;
3942 }
3943 }
3944 }
3945
3946 return NULL;
3947}
3948
61007b31
SH
3949/* TODO check what callers really want: bs->node_name or blk_name() */
3950const char *bdrv_get_device_name(const BlockDriverState *bs)
beac80cd 3951{
4c265bf9 3952 return bdrv_get_parent_name(bs) ?: "";
f141eafe 3953}
83f64091 3954
61007b31
SH
3955/* This can be used to identify nodes that might not have a device
3956 * name associated. Since node and device names live in the same
3957 * namespace, the result is unambiguous. The exception is if both are
3958 * absent, then this returns an empty (non-null) string. */
3959const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
f141eafe 3960{
4c265bf9 3961 return bdrv_get_parent_name(bs) ?: bs->node_name;
beac80cd 3962}
beac80cd 3963
61007b31 3964int bdrv_get_flags(BlockDriverState *bs)
0b5a2445 3965{
61007b31 3966 return bs->open_flags;
0b5a2445
PB
3967}
3968
61007b31 3969int bdrv_has_zero_init_1(BlockDriverState *bs)
68485420 3970{
61007b31 3971 return 1;
0b5a2445
PB
3972}
3973
61007b31 3974int bdrv_has_zero_init(BlockDriverState *bs)
0b5a2445 3975{
d470ad42
HR
3976 if (!bs->drv) {
3977 return 0;
3978 }
0b5a2445 3979
61007b31
SH
3980 /* If BS is a copy on write image, it is initialized to
3981 the contents of the base image, which may not be zeroes. */
760e0063 3982 if (bs->backing) {
61007b31
SH
3983 return 0;
3984 }
3985 if (bs->drv->bdrv_has_zero_init) {
3986 return bs->drv->bdrv_has_zero_init(bs);
0b5a2445 3987 }
5a612c00
MP
3988 if (bs->file && bs->drv->is_filter) {
3989 return bdrv_has_zero_init(bs->file->bs);
3990 }
61007b31
SH
3991
3992 /* safe default */
3993 return 0;
68485420
KW
3994}
3995
61007b31 3996bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
b2a61371 3997{
61007b31 3998 BlockDriverInfo bdi;
b2a61371 3999
760e0063 4000 if (bs->backing) {
61007b31
SH
4001 return false;
4002 }
4003
4004 if (bdrv_get_info(bs, &bdi) == 0) {
4005 return bdi.unallocated_blocks_are_zero;
b2a61371
SH
4006 }
4007
61007b31 4008 return false;
b2a61371
SH
4009}
4010
61007b31 4011bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
68485420 4012{
2f0342ef 4013 if (!(bs->open_flags & BDRV_O_UNMAP)) {
61007b31
SH
4014 return false;
4015 }
68485420 4016
e24d813b 4017 return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP;
68485420
KW
4018}
4019
61007b31 4020const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
b2e12bc6 4021{
760e0063 4022 if (bs->backing && bs->backing->bs->encrypted)
61007b31
SH
4023 return bs->backing_file;
4024 else if (bs->encrypted)
4025 return bs->filename;
4026 else
4027 return NULL;
b2e12bc6
CH
4028}
4029
61007b31
SH
4030void bdrv_get_backing_filename(BlockDriverState *bs,
4031 char *filename, int filename_size)
016f5cf6 4032{
61007b31
SH
4033 pstrcpy(filename, filename_size, bs->backing_file);
4034}
d318aea9 4035
61007b31
SH
4036int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
4037{
4038 BlockDriver *drv = bs->drv;
5a612c00
MP
4039 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
4040 if (!drv) {
61007b31 4041 return -ENOMEDIUM;
5a612c00
MP
4042 }
4043 if (!drv->bdrv_get_info) {
4044 if (bs->file && drv->is_filter) {
4045 return bdrv_get_info(bs->file->bs, bdi);
4046 }
61007b31 4047 return -ENOTSUP;
5a612c00 4048 }
61007b31
SH
4049 memset(bdi, 0, sizeof(*bdi));
4050 return drv->bdrv_get_info(bs, bdi);
4051}
016f5cf6 4052
61007b31
SH
4053ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs)
4054{
4055 BlockDriver *drv = bs->drv;
4056 if (drv && drv->bdrv_get_specific_info) {
4057 return drv->bdrv_get_specific_info(bs);
4058 }
4059 return NULL;
016f5cf6
AG
4060}
4061
a31939e6 4062void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
4265d620 4063{
61007b31
SH
4064 if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
4065 return;
4066 }
4265d620 4067
61007b31 4068 bs->drv->bdrv_debug_event(bs, event);
4265d620
PB
4069}
4070
61007b31
SH
4071int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
4072 const char *tag)
4265d620 4073{
61007b31 4074 while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
9a4f4c31 4075 bs = bs->file ? bs->file->bs : NULL;
61007b31 4076 }
4265d620 4077
61007b31
SH
4078 if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
4079 return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
4080 }
4265d620 4081
61007b31 4082 return -ENOTSUP;
4265d620
PB
4083}
4084
61007b31 4085int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
ea2384d3 4086{
61007b31 4087 while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
9a4f4c31 4088 bs = bs->file ? bs->file->bs : NULL;
61007b31 4089 }
ce1a14dc 4090
61007b31
SH
4091 if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
4092 return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
4093 }
4094
4095 return -ENOTSUP;
eb852011
MA
4096}
4097
61007b31 4098int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
ce1a14dc 4099{
61007b31 4100 while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
9a4f4c31 4101 bs = bs->file ? bs->file->bs : NULL;
61007b31 4102 }
ce1a14dc 4103
61007b31
SH
4104 if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
4105 return bs->drv->bdrv_debug_resume(bs, tag);
4106 }
ce1a14dc 4107
61007b31 4108 return -ENOTSUP;
f197fe2b
FZ
4109}
4110
61007b31 4111bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
ce1a14dc 4112{
61007b31 4113 while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
9a4f4c31 4114 bs = bs->file ? bs->file->bs : NULL;
f197fe2b 4115 }
19cb3738 4116
61007b31
SH
4117 if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
4118 return bs->drv->bdrv_debug_is_suspended(bs, tag);
4119 }
f9f05dc5 4120
61007b31
SH
4121 return false;
4122}
f9f05dc5 4123
61007b31
SH
4124/* backing_file can either be relative, or absolute, or a protocol. If it is
4125 * relative, it must be relative to the chain. So, passing in bs->filename
4126 * from a BDS as backing_file should not be done, as that may be relative to
4127 * the CWD rather than the chain. */
4128BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
4129 const char *backing_file)
f9f05dc5 4130{
61007b31
SH
4131 char *filename_full = NULL;
4132 char *backing_file_full = NULL;
4133 char *filename_tmp = NULL;
4134 int is_protocol = 0;
4135 BlockDriverState *curr_bs = NULL;
4136 BlockDriverState *retval = NULL;
418661e0 4137 Error *local_error = NULL;
f9f05dc5 4138
61007b31
SH
4139 if (!bs || !bs->drv || !backing_file) {
4140 return NULL;
f9f05dc5
KW
4141 }
4142
61007b31
SH
4143 filename_full = g_malloc(PATH_MAX);
4144 backing_file_full = g_malloc(PATH_MAX);
4145 filename_tmp = g_malloc(PATH_MAX);
f9f05dc5 4146
61007b31 4147 is_protocol = path_has_protocol(backing_file);
f9f05dc5 4148
760e0063 4149 for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) {
f9f05dc5 4150
61007b31
SH
4151 /* If either of the filename paths is actually a protocol, then
4152 * compare unmodified paths; otherwise make paths relative */
4153 if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
4154 if (strcmp(backing_file, curr_bs->backing_file) == 0) {
760e0063 4155 retval = curr_bs->backing->bs;
61007b31
SH
4156 break;
4157 }
418661e0
JC
4158 /* Also check against the full backing filename for the image */
4159 bdrv_get_full_backing_filename(curr_bs, backing_file_full, PATH_MAX,
4160 &local_error);
4161 if (local_error == NULL) {
4162 if (strcmp(backing_file, backing_file_full) == 0) {
4163 retval = curr_bs->backing->bs;
4164 break;
4165 }
4166 } else {
4167 error_free(local_error);
4168 local_error = NULL;
4169 }
61007b31
SH
4170 } else {
4171 /* If not an absolute filename path, make it relative to the current
4172 * image's filename path */
4173 path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
4174 backing_file);
f9f05dc5 4175
61007b31
SH
4176 /* We are going to compare absolute pathnames */
4177 if (!realpath(filename_tmp, filename_full)) {
4178 continue;
4179 }
07f07615 4180
61007b31
SH
4181 /* We need to make sure the backing filename we are comparing against
4182 * is relative to the current image filename (or absolute) */
4183 path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
4184 curr_bs->backing_file);
07f07615 4185
61007b31
SH
4186 if (!realpath(filename_tmp, backing_file_full)) {
4187 continue;
4188 }
eb489bb1 4189
61007b31 4190 if (strcmp(backing_file_full, filename_full) == 0) {
760e0063 4191 retval = curr_bs->backing->bs;
61007b31
SH
4192 break;
4193 }
4194 }
eb489bb1
KW
4195 }
4196
61007b31
SH
4197 g_free(filename_full);
4198 g_free(backing_file_full);
4199 g_free(filename_tmp);
4200 return retval;
4201}
4202
61007b31
SH
4203void bdrv_init(void)
4204{
4205 module_call_init(MODULE_INIT_BLOCK);
4206}
29cdb251 4207
61007b31
SH
4208void bdrv_init_with_whitelist(void)
4209{
4210 use_bdrv_whitelist = 1;
4211 bdrv_init();
07f07615
PB
4212}
4213
5a8a30db 4214void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
0f15423c 4215{
4417ab7a 4216 BdrvChild *child, *parent;
9c5e6594 4217 uint64_t perm, shared_perm;
5a8a30db
KW
4218 Error *local_err = NULL;
4219 int ret;
4220
3456a8d1
KW
4221 if (!bs->drv) {
4222 return;
4223 }
4224
04c01a5c 4225 if (!(bs->open_flags & BDRV_O_INACTIVE)) {
7ea2d269
AK
4226 return;
4227 }
7ea2d269 4228
16e977d5
VSO
4229 QLIST_FOREACH(child, &bs->children, next) {
4230 bdrv_invalidate_cache(child->bs, &local_err);
0d1c5c91 4231 if (local_err) {
0d1c5c91
FZ
4232 error_propagate(errp, local_err);
4233 return;
4234 }
5a8a30db 4235 }
0d1c5c91 4236
dafe0960
KW
4237 /*
4238 * Update permissions, they may differ for inactive nodes.
4239 *
4240 * Note that the required permissions of inactive images are always a
4241 * subset of the permissions required after activating the image. This
4242 * allows us to just get the permissions upfront without restricting
4243 * drv->bdrv_invalidate_cache().
4244 *
4245 * It also means that in error cases, we don't have to try and revert to
4246 * the old permissions (which is an operation that could fail, too). We can
4247 * just keep the extended permissions for the next time that an activation
4248 * of the image is tried.
4249 */
16e977d5 4250 bs->open_flags &= ~BDRV_O_INACTIVE;
dafe0960
KW
4251 bdrv_get_cumulative_perm(bs, &perm, &shared_perm);
4252 ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &local_err);
4253 if (ret < 0) {
4254 bs->open_flags |= BDRV_O_INACTIVE;
4255 error_propagate(errp, local_err);
4256 return;
4257 }
4258 bdrv_set_perm(bs, perm, shared_perm);
4259
16e977d5
VSO
4260 if (bs->drv->bdrv_invalidate_cache) {
4261 bs->drv->bdrv_invalidate_cache(bs, &local_err);
0d1c5c91
FZ
4262 if (local_err) {
4263 bs->open_flags |= BDRV_O_INACTIVE;
4264 error_propagate(errp, local_err);
4265 return;
4266 }
0f15423c 4267 }
3456a8d1 4268
5a8a30db
KW
4269 ret = refresh_total_sectors(bs, bs->total_sectors);
4270 if (ret < 0) {
04c01a5c 4271 bs->open_flags |= BDRV_O_INACTIVE;
5a8a30db
KW
4272 error_setg_errno(errp, -ret, "Could not refresh total sector count");
4273 return;
4274 }
4417ab7a
KW
4275
4276 QLIST_FOREACH(parent, &bs->parents, next_parent) {
4277 if (parent->role->activate) {
4278 parent->role->activate(parent, &local_err);
4279 if (local_err) {
4280 error_propagate(errp, local_err);
4281 return;
4282 }
4283 }
4284 }
0f15423c
AL
4285}
4286
5a8a30db 4287void bdrv_invalidate_cache_all(Error **errp)
0f15423c 4288{
7c8eece4 4289 BlockDriverState *bs;
5a8a30db 4290 Error *local_err = NULL;
88be7b4b 4291 BdrvNextIterator it;
0f15423c 4292
88be7b4b 4293 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
ed78cda3
SH
4294 AioContext *aio_context = bdrv_get_aio_context(bs);
4295
4296 aio_context_acquire(aio_context);
5a8a30db 4297 bdrv_invalidate_cache(bs, &local_err);
ed78cda3 4298 aio_context_release(aio_context);
5a8a30db
KW
4299 if (local_err) {
4300 error_propagate(errp, local_err);
5e003f17 4301 bdrv_next_cleanup(&it);
5a8a30db
KW
4302 return;
4303 }
0f15423c
AL
4304 }
4305}
4306
aad0b7a0
FZ
4307static int bdrv_inactivate_recurse(BlockDriverState *bs,
4308 bool setting_flag)
76b1c7fe 4309{
cfa1a572 4310 BdrvChild *child, *parent;
76b1c7fe
KW
4311 int ret;
4312
d470ad42
HR
4313 if (!bs->drv) {
4314 return -ENOMEDIUM;
4315 }
4316
aad0b7a0 4317 if (!setting_flag && bs->drv->bdrv_inactivate) {
76b1c7fe
KW
4318 ret = bs->drv->bdrv_inactivate(bs);
4319 if (ret < 0) {
4320 return ret;
4321 }
4322 }
4323
7d5b5261 4324 if (setting_flag && !(bs->open_flags & BDRV_O_INACTIVE)) {
9c5e6594
KW
4325 uint64_t perm, shared_perm;
4326
cfa1a572
KW
4327 QLIST_FOREACH(parent, &bs->parents, next_parent) {
4328 if (parent->role->inactivate) {
4329 ret = parent->role->inactivate(parent);
4330 if (ret < 0) {
cfa1a572
KW
4331 return ret;
4332 }
4333 }
4334 }
9c5e6594 4335
7d5b5261
SH
4336 bs->open_flags |= BDRV_O_INACTIVE;
4337
9c5e6594
KW
4338 /* Update permissions, they may differ for inactive nodes */
4339 bdrv_get_cumulative_perm(bs, &perm, &shared_perm);
3121fb45 4340 bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &error_abort);
9c5e6594 4341 bdrv_set_perm(bs, perm, shared_perm);
aad0b7a0 4342 }
38701b6a
KW
4343
4344 QLIST_FOREACH(child, &bs->children, next) {
4345 ret = bdrv_inactivate_recurse(child->bs, setting_flag);
4346 if (ret < 0) {
4347 return ret;
4348 }
4349 }
4350
615b5dcf
VSO
4351 /* At this point persistent bitmaps should be already stored by the format
4352 * driver */
4353 bdrv_release_persistent_dirty_bitmaps(bs);
4354
76b1c7fe
KW
4355 return 0;
4356}
4357
4358int bdrv_inactivate_all(void)
4359{
79720af6 4360 BlockDriverState *bs = NULL;
88be7b4b 4361 BdrvNextIterator it;
aad0b7a0
FZ
4362 int ret = 0;
4363 int pass;
bd6458e4 4364 GSList *aio_ctxs = NULL, *ctx;
76b1c7fe 4365
88be7b4b 4366 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
bd6458e4
PB
4367 AioContext *aio_context = bdrv_get_aio_context(bs);
4368
4369 if (!g_slist_find(aio_ctxs, aio_context)) {
4370 aio_ctxs = g_slist_prepend(aio_ctxs, aio_context);
4371 aio_context_acquire(aio_context);
4372 }
aad0b7a0 4373 }
76b1c7fe 4374
aad0b7a0
FZ
4375 /* We do two passes of inactivation. The first pass calls to drivers'
4376 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
4377 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
4378 * is allowed. */
4379 for (pass = 0; pass < 2; pass++) {
88be7b4b 4380 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
aad0b7a0
FZ
4381 ret = bdrv_inactivate_recurse(bs, pass);
4382 if (ret < 0) {
5e003f17 4383 bdrv_next_cleanup(&it);
aad0b7a0
FZ
4384 goto out;
4385 }
76b1c7fe
KW
4386 }
4387 }
4388
aad0b7a0 4389out:
bd6458e4
PB
4390 for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) {
4391 AioContext *aio_context = ctx->data;
4392 aio_context_release(aio_context);
aad0b7a0 4393 }
bd6458e4 4394 g_slist_free(aio_ctxs);
aad0b7a0
FZ
4395
4396 return ret;
76b1c7fe
KW
4397}
4398
19cb3738
FB
4399/**************************************************************/
4400/* removable device support */
4401
4402/**
4403 * Return TRUE if the media is present
4404 */
e031f750 4405bool bdrv_is_inserted(BlockDriverState *bs)
19cb3738
FB
4406{
4407 BlockDriver *drv = bs->drv;
28d7a789 4408 BdrvChild *child;
a1aff5bf 4409
e031f750
HR
4410 if (!drv) {
4411 return false;
4412 }
28d7a789
HR
4413 if (drv->bdrv_is_inserted) {
4414 return drv->bdrv_is_inserted(bs);
4415 }
4416 QLIST_FOREACH(child, &bs->children, next) {
4417 if (!bdrv_is_inserted(child->bs)) {
4418 return false;
4419 }
e031f750 4420 }
28d7a789 4421 return true;
19cb3738
FB
4422}
4423
19cb3738
FB
4424/**
4425 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
4426 */
f36f3949 4427void bdrv_eject(BlockDriverState *bs, bool eject_flag)
19cb3738
FB
4428{
4429 BlockDriver *drv = bs->drv;
19cb3738 4430
822e1cd1
MA
4431 if (drv && drv->bdrv_eject) {
4432 drv->bdrv_eject(bs, eject_flag);
19cb3738
FB
4433 }
4434}
4435
19cb3738
FB
4436/**
4437 * Lock or unlock the media (if it is locked, the user won't be able
4438 * to eject it manually).
4439 */
025e849a 4440void bdrv_lock_medium(BlockDriverState *bs, bool locked)
19cb3738
FB
4441{
4442 BlockDriver *drv = bs->drv;
4443
025e849a 4444 trace_bdrv_lock_medium(bs, locked);
b8c6d095 4445
025e849a
MA
4446 if (drv && drv->bdrv_lock_medium) {
4447 drv->bdrv_lock_medium(bs, locked);
19cb3738
FB
4448 }
4449}
985a03b0 4450
9fcb0251
FZ
4451/* Get a reference to bs */
4452void bdrv_ref(BlockDriverState *bs)
4453{
4454 bs->refcnt++;
4455}
4456
4457/* Release a previously grabbed reference to bs.
4458 * If after releasing, reference count is zero, the BlockDriverState is
4459 * deleted. */
4460void bdrv_unref(BlockDriverState *bs)
4461{
9a4d5ca6
JC
4462 if (!bs) {
4463 return;
4464 }
9fcb0251
FZ
4465 assert(bs->refcnt > 0);
4466 if (--bs->refcnt == 0) {
4467 bdrv_delete(bs);
4468 }
4469}
4470
fbe40ff7
FZ
4471struct BdrvOpBlocker {
4472 Error *reason;
4473 QLIST_ENTRY(BdrvOpBlocker) list;
4474};
4475
4476bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
4477{
4478 BdrvOpBlocker *blocker;
4479 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
4480 if (!QLIST_EMPTY(&bs->op_blockers[op])) {
4481 blocker = QLIST_FIRST(&bs->op_blockers[op]);
57ef3f12
EH
4482 error_propagate(errp, error_copy(blocker->reason));
4483 error_prepend(errp, "Node '%s' is busy: ",
4484 bdrv_get_device_or_node_name(bs));
fbe40ff7
FZ
4485 return true;
4486 }
4487 return false;
4488}
4489
4490void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
4491{
4492 BdrvOpBlocker *blocker;
4493 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
4494
5839e53b 4495 blocker = g_new0(BdrvOpBlocker, 1);
fbe40ff7
FZ
4496 blocker->reason = reason;
4497 QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);
4498}
4499
4500void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
4501{
4502 BdrvOpBlocker *blocker, *next;
4503 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
4504 QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
4505 if (blocker->reason == reason) {
4506 QLIST_REMOVE(blocker, list);
4507 g_free(blocker);
4508 }
4509 }
4510}
4511
4512void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
4513{
4514 int i;
4515 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
4516 bdrv_op_block(bs, i, reason);
4517 }
4518}
4519
4520void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
4521{
4522 int i;
4523 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
4524 bdrv_op_unblock(bs, i, reason);
4525 }
4526}
4527
4528bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
4529{
4530 int i;
4531
4532 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
4533 if (!QLIST_EMPTY(&bs->op_blockers[i])) {
4534 return false;
4535 }
4536 }
4537 return true;
4538}
4539
d92ada22
LC
4540void bdrv_img_create(const char *filename, const char *fmt,
4541 const char *base_filename, const char *base_fmt,
9217283d
FZ
4542 char *options, uint64_t img_size, int flags, bool quiet,
4543 Error **errp)
f88e1a42 4544{
83d0521a
CL
4545 QemuOptsList *create_opts = NULL;
4546 QemuOpts *opts = NULL;
4547 const char *backing_fmt, *backing_file;
4548 int64_t size;
f88e1a42 4549 BlockDriver *drv, *proto_drv;
cc84d90f 4550 Error *local_err = NULL;
f88e1a42
JS
4551 int ret = 0;
4552
4553 /* Find driver and parse its options */
4554 drv = bdrv_find_format(fmt);
4555 if (!drv) {
71c79813 4556 error_setg(errp, "Unknown file format '%s'", fmt);
d92ada22 4557 return;
f88e1a42
JS
4558 }
4559
b65a5e12 4560 proto_drv = bdrv_find_protocol(filename, true, errp);
f88e1a42 4561 if (!proto_drv) {
d92ada22 4562 return;
f88e1a42
JS
4563 }
4564
c6149724
HR
4565 if (!drv->create_opts) {
4566 error_setg(errp, "Format driver '%s' does not support image creation",
4567 drv->format_name);
4568 return;
4569 }
4570
4571 if (!proto_drv->create_opts) {
4572 error_setg(errp, "Protocol driver '%s' does not support image creation",
4573 proto_drv->format_name);
4574 return;
4575 }
4576
c282e1fd
CL
4577 create_opts = qemu_opts_append(create_opts, drv->create_opts);
4578 create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
f88e1a42
JS
4579
4580 /* Create parameter list with default values */
83d0521a 4581 opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
39101f25 4582 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort);
f88e1a42
JS
4583
4584 /* Parse -o options */
4585 if (options) {
dc523cd3
MA
4586 qemu_opts_do_parse(opts, options, NULL, &local_err);
4587 if (local_err) {
4588 error_report_err(local_err);
4589 local_err = NULL;
83d0521a 4590 error_setg(errp, "Invalid options for file format '%s'", fmt);
f88e1a42
JS
4591 goto out;
4592 }
4593 }
4594
4595 if (base_filename) {
f43e47db 4596 qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err);
6be4194b 4597 if (local_err) {
71c79813
LC
4598 error_setg(errp, "Backing file not supported for file format '%s'",
4599 fmt);
f88e1a42
JS
4600 goto out;
4601 }
4602 }
4603
4604 if (base_fmt) {
f43e47db 4605 qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err);
6be4194b 4606 if (local_err) {
71c79813
LC
4607 error_setg(errp, "Backing file format not supported for file "
4608 "format '%s'", fmt);
f88e1a42
JS
4609 goto out;
4610 }
4611 }
4612
83d0521a
CL
4613 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
4614 if (backing_file) {
4615 if (!strcmp(filename, backing_file)) {
71c79813
LC
4616 error_setg(errp, "Error: Trying to create an image with the "
4617 "same filename as the backing file");
792da93a
JS
4618 goto out;
4619 }
4620 }
4621
83d0521a 4622 backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
f88e1a42 4623
6e6e55f5
JS
4624 /* The size for the image must always be specified, unless we have a backing
4625 * file and we have not been forbidden from opening it. */
a8b42a1c 4626 size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size);
6e6e55f5
JS
4627 if (backing_file && !(flags & BDRV_O_NO_BACKING)) {
4628 BlockDriverState *bs;
4629 char *full_backing = g_new0(char, PATH_MAX);
4630 int back_flags;
4631 QDict *backing_options = NULL;
4632
4633 bdrv_get_full_backing_filename_from_filename(filename, backing_file,
4634 full_backing, PATH_MAX,
4635 &local_err);
4636 if (local_err) {
4637 g_free(full_backing);
4638 goto out;
4639 }
29168018 4640
6e6e55f5
JS
4641 /* backing files always opened read-only */
4642 back_flags = flags;
4643 back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
f88e1a42 4644
cc954f01 4645 backing_options = qdict_new();
6e6e55f5 4646 if (backing_fmt) {
6e6e55f5
JS
4647 qdict_put_str(backing_options, "driver", backing_fmt);
4648 }
cc954f01 4649 qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true);
e6641719 4650
6e6e55f5
JS
4651 bs = bdrv_open(full_backing, NULL, backing_options, back_flags,
4652 &local_err);
4653 g_free(full_backing);
4654 if (!bs && size != -1) {
4655 /* Couldn't open BS, but we have a size, so it's nonfatal */
4656 warn_reportf_err(local_err,
4657 "Could not verify backing image. "
4658 "This may become an error in future versions.\n");
4659 local_err = NULL;
4660 } else if (!bs) {
4661 /* Couldn't open bs, do not have size */
4662 error_append_hint(&local_err,
4663 "Could not open backing image to determine size.\n");
4664 goto out;
4665 } else {
4666 if (size == -1) {
4667 /* Opened BS, have no size */
4668 size = bdrv_getlength(bs);
4669 if (size < 0) {
4670 error_setg_errno(errp, -size, "Could not get size of '%s'",
4671 backing_file);
4672 bdrv_unref(bs);
4673 goto out;
4674 }
4675 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort);
52bf1e72 4676 }
66f6b814 4677 bdrv_unref(bs);
f88e1a42 4678 }
6e6e55f5
JS
4679 } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
4680
4681 if (size == -1) {
4682 error_setg(errp, "Image creation needs a size parameter");
4683 goto out;
f88e1a42
JS
4684 }
4685
f382d43a 4686 if (!quiet) {
fe646693 4687 printf("Formatting '%s', fmt=%s ", filename, fmt);
43c5d8f8 4688 qemu_opts_print(opts, " ");
f382d43a
MR
4689 puts("");
4690 }
83d0521a 4691
c282e1fd 4692 ret = bdrv_create(drv, filename, opts, &local_err);
83d0521a 4693
cc84d90f
HR
4694 if (ret == -EFBIG) {
4695 /* This is generally a better message than whatever the driver would
4696 * deliver (especially because of the cluster_size_hint), since that
4697 * is most probably not much different from "image too large". */
4698 const char *cluster_size_hint = "";
83d0521a 4699 if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) {
cc84d90f 4700 cluster_size_hint = " (try using a larger cluster size)";
f88e1a42 4701 }
cc84d90f
HR
4702 error_setg(errp, "The image size is too large for file format '%s'"
4703 "%s", fmt, cluster_size_hint);
4704 error_free(local_err);
4705 local_err = NULL;
f88e1a42
JS
4706 }
4707
4708out:
83d0521a
CL
4709 qemu_opts_del(opts);
4710 qemu_opts_free(create_opts);
621ff94d 4711 error_propagate(errp, local_err);
f88e1a42 4712}
85d126f3
SH
4713
4714AioContext *bdrv_get_aio_context(BlockDriverState *bs)
4715{
dcd04228
SH
4716 return bs->aio_context;
4717}
4718
052a7572
FZ
4719void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co)
4720{
4721 aio_co_enter(bdrv_get_aio_context(bs), co);
4722}
4723
e8a095da
SH
4724static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban)
4725{
4726 QLIST_REMOVE(ban, list);
4727 g_free(ban);
4728}
4729
dcd04228
SH
4730void bdrv_detach_aio_context(BlockDriverState *bs)
4731{
e8a095da 4732 BdrvAioNotifier *baf, *baf_tmp;
b97511c7 4733 BdrvChild *child;
33384421 4734
dcd04228
SH
4735 if (!bs->drv) {
4736 return;
4737 }
4738
e8a095da
SH
4739 assert(!bs->walking_aio_notifiers);
4740 bs->walking_aio_notifiers = true;
4741 QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) {
4742 if (baf->deleted) {
4743 bdrv_do_remove_aio_context_notifier(baf);
4744 } else {
4745 baf->detach_aio_context(baf->opaque);
4746 }
33384421 4747 }
e8a095da
SH
4748 /* Never mind iterating again to check for ->deleted. bdrv_close() will
4749 * remove remaining aio notifiers if we aren't called again.
4750 */
4751 bs->walking_aio_notifiers = false;
33384421 4752
dcd04228
SH
4753 if (bs->drv->bdrv_detach_aio_context) {
4754 bs->drv->bdrv_detach_aio_context(bs);
4755 }
b97511c7
HR
4756 QLIST_FOREACH(child, &bs->children, next) {
4757 bdrv_detach_aio_context(child->bs);
dcd04228
SH
4758 }
4759
4760 bs->aio_context = NULL;
4761}
4762
4763void bdrv_attach_aio_context(BlockDriverState *bs,
4764 AioContext *new_context)
4765{
e8a095da 4766 BdrvAioNotifier *ban, *ban_tmp;
b97511c7 4767 BdrvChild *child;
33384421 4768
dcd04228
SH
4769 if (!bs->drv) {
4770 return;
4771 }
4772
4773 bs->aio_context = new_context;
4774
b97511c7
HR
4775 QLIST_FOREACH(child, &bs->children, next) {
4776 bdrv_attach_aio_context(child->bs, new_context);
dcd04228
SH
4777 }
4778 if (bs->drv->bdrv_attach_aio_context) {
4779 bs->drv->bdrv_attach_aio_context(bs, new_context);
4780 }
33384421 4781
e8a095da
SH
4782 assert(!bs->walking_aio_notifiers);
4783 bs->walking_aio_notifiers = true;
4784 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) {
4785 if (ban->deleted) {
4786 bdrv_do_remove_aio_context_notifier(ban);
4787 } else {
4788 ban->attached_aio_context(new_context, ban->opaque);
4789 }
33384421 4790 }
e8a095da 4791 bs->walking_aio_notifiers = false;
dcd04228
SH
4792}
4793
4794void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
4795{
aabf5910 4796 AioContext *ctx = bdrv_get_aio_context(bs);
c2b6428d 4797
aabf5910 4798 aio_disable_external(ctx);
0152bf40 4799 bdrv_parent_drained_begin(bs, NULL);
53ec73e2 4800 bdrv_drain(bs); /* ensure there are no in-flight requests */
dcd04228 4801
c2b6428d
PB
4802 while (aio_poll(ctx, false)) {
4803 /* wait for all bottom halves to execute */
4804 }
4805
dcd04228
SH
4806 bdrv_detach_aio_context(bs);
4807
4808 /* This function executes in the old AioContext so acquire the new one in
4809 * case it runs in a different thread.
4810 */
4811 aio_context_acquire(new_context);
4812 bdrv_attach_aio_context(bs, new_context);
0152bf40 4813 bdrv_parent_drained_end(bs, NULL);
aabf5910 4814 aio_enable_external(ctx);
dcd04228 4815 aio_context_release(new_context);
85d126f3 4816}
d616b224 4817
33384421
HR
4818void bdrv_add_aio_context_notifier(BlockDriverState *bs,
4819 void (*attached_aio_context)(AioContext *new_context, void *opaque),
4820 void (*detach_aio_context)(void *opaque), void *opaque)
4821{
4822 BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1);
4823 *ban = (BdrvAioNotifier){
4824 .attached_aio_context = attached_aio_context,
4825 .detach_aio_context = detach_aio_context,
4826 .opaque = opaque
4827 };
4828
4829 QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list);
4830}
4831
4832void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
4833 void (*attached_aio_context)(AioContext *,
4834 void *),
4835 void (*detach_aio_context)(void *),
4836 void *opaque)
4837{
4838 BdrvAioNotifier *ban, *ban_next;
4839
4840 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
4841 if (ban->attached_aio_context == attached_aio_context &&
4842 ban->detach_aio_context == detach_aio_context &&
e8a095da
SH
4843 ban->opaque == opaque &&
4844 ban->deleted == false)
33384421 4845 {
e8a095da
SH
4846 if (bs->walking_aio_notifiers) {
4847 ban->deleted = true;
4848 } else {
4849 bdrv_do_remove_aio_context_notifier(ban);
4850 }
33384421
HR
4851 return;
4852 }
4853 }
4854
4855 abort();
4856}
4857
77485434 4858int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
8b13976d 4859 BlockDriverAmendStatusCB *status_cb, void *cb_opaque)
6f176b48 4860{
d470ad42
HR
4861 if (!bs->drv) {
4862 return -ENOMEDIUM;
4863 }
c282e1fd 4864 if (!bs->drv->bdrv_amend_options) {
6f176b48
HR
4865 return -ENOTSUP;
4866 }
8b13976d 4867 return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque);
6f176b48 4868}
f6186f49 4869
b5042a36
BC
4870/* This function will be called by the bdrv_recurse_is_first_non_filter method
4871 * of block filter and by bdrv_is_first_non_filter.
4872 * It is used to test if the given bs is the candidate or recurse more in the
4873 * node graph.
212a5a8f 4874 */
b5042a36 4875bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
212a5a8f 4876 BlockDriverState *candidate)
f6186f49 4877{
b5042a36
BC
4878 /* return false if basic checks fails */
4879 if (!bs || !bs->drv) {
212a5a8f 4880 return false;
f6186f49
BC
4881 }
4882
b5042a36
BC
4883 /* the code reached a non block filter driver -> check if the bs is
4884 * the same as the candidate. It's the recursion termination condition.
4885 */
4886 if (!bs->drv->is_filter) {
4887 return bs == candidate;
212a5a8f 4888 }
b5042a36 4889 /* Down this path the driver is a block filter driver */
212a5a8f 4890
b5042a36
BC
4891 /* If the block filter recursion method is defined use it to recurse down
4892 * the node graph.
4893 */
4894 if (bs->drv->bdrv_recurse_is_first_non_filter) {
212a5a8f 4895 return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
f6186f49
BC
4896 }
4897
b5042a36
BC
4898 /* the driver is a block filter but don't allow to recurse -> return false
4899 */
4900 return false;
f6186f49
BC
4901}
4902
212a5a8f
BC
4903/* This function checks if the candidate is the first non filter bs down it's
4904 * bs chain. Since we don't have pointers to parents it explore all bs chains
4905 * from the top. Some filters can choose not to pass down the recursion.
4906 */
4907bool bdrv_is_first_non_filter(BlockDriverState *candidate)
f6186f49 4908{
7c8eece4 4909 BlockDriverState *bs;
88be7b4b 4910 BdrvNextIterator it;
212a5a8f
BC
4911
4912 /* walk down the bs forest recursively */
88be7b4b 4913 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
212a5a8f
BC
4914 bool perm;
4915
b5042a36 4916 /* try to recurse in this top level bs */
e6dc8a1f 4917 perm = bdrv_recurse_is_first_non_filter(bs, candidate);
212a5a8f
BC
4918
4919 /* candidate is the first non filter */
4920 if (perm) {
5e003f17 4921 bdrv_next_cleanup(&it);
212a5a8f
BC
4922 return true;
4923 }
4924 }
4925
4926 return false;
f6186f49 4927}
09158f00 4928
e12f3784
WC
4929BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
4930 const char *node_name, Error **errp)
09158f00
BC
4931{
4932 BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
5a7e7a0b
SH
4933 AioContext *aio_context;
4934
09158f00
BC
4935 if (!to_replace_bs) {
4936 error_setg(errp, "Node name '%s' not found", node_name);
4937 return NULL;
4938 }
4939
5a7e7a0b
SH
4940 aio_context = bdrv_get_aio_context(to_replace_bs);
4941 aio_context_acquire(aio_context);
4942
09158f00 4943 if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) {
5a7e7a0b
SH
4944 to_replace_bs = NULL;
4945 goto out;
09158f00
BC
4946 }
4947
4948 /* We don't want arbitrary node of the BDS chain to be replaced only the top
4949 * most non filter in order to prevent data corruption.
4950 * Another benefit is that this tests exclude backing files which are
4951 * blocked by the backing blockers.
4952 */
e12f3784 4953 if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) {
09158f00 4954 error_setg(errp, "Only top most non filter can be replaced");
5a7e7a0b
SH
4955 to_replace_bs = NULL;
4956 goto out;
09158f00
BC
4957 }
4958
5a7e7a0b
SH
4959out:
4960 aio_context_release(aio_context);
09158f00
BC
4961 return to_replace_bs;
4962}
448ad91d 4963
91af7014
HR
4964static bool append_open_options(QDict *d, BlockDriverState *bs)
4965{
4966 const QDictEntry *entry;
9e700c1a 4967 QemuOptDesc *desc;
260fecf1 4968 BdrvChild *child;
91af7014 4969 bool found_any = false;
260fecf1 4970 const char *p;
91af7014
HR
4971
4972 for (entry = qdict_first(bs->options); entry;
4973 entry = qdict_next(bs->options, entry))
4974 {
260fecf1
KW
4975 /* Exclude options for children */
4976 QLIST_FOREACH(child, &bs->children, next) {
4977 if (strstart(qdict_entry_key(entry), child->name, &p)
4978 && (!*p || *p == '.'))
4979 {
4980 break;
4981 }
4982 }
4983 if (child) {
9e700c1a 4984 continue;
91af7014 4985 }
9e700c1a
KW
4986
4987 /* And exclude all non-driver-specific options */
4988 for (desc = bdrv_runtime_opts.desc; desc->name; desc++) {
4989 if (!strcmp(qdict_entry_key(entry), desc->name)) {
4990 break;
4991 }
4992 }
4993 if (desc->name) {
4994 continue;
4995 }
4996
4997 qobject_incref(qdict_entry_value(entry));
4998 qdict_put_obj(d, qdict_entry_key(entry), qdict_entry_value(entry));
4999 found_any = true;
91af7014
HR
5000 }
5001
5002 return found_any;
5003}
5004
5005/* Updates the following BDS fields:
5006 * - exact_filename: A filename which may be used for opening a block device
5007 * which (mostly) equals the given BDS (even without any
5008 * other options; so reading and writing must return the same
5009 * results, but caching etc. may be different)
5010 * - full_open_options: Options which, when given when opening a block device
5011 * (without a filename), result in a BDS (mostly)
5012 * equalling the given one
5013 * - filename: If exact_filename is set, it is copied here. Otherwise,
5014 * full_open_options is converted to a JSON object, prefixed with
5015 * "json:" (for use through the JSON pseudo protocol) and put here.
5016 */
5017void bdrv_refresh_filename(BlockDriverState *bs)
5018{
5019 BlockDriver *drv = bs->drv;
5020 QDict *opts;
5021
5022 if (!drv) {
5023 return;
5024 }
5025
5026 /* This BDS's file name will most probably depend on its file's name, so
5027 * refresh that first */
5028 if (bs->file) {
9a4f4c31 5029 bdrv_refresh_filename(bs->file->bs);
91af7014
HR
5030 }
5031
5032 if (drv->bdrv_refresh_filename) {
5033 /* Obsolete information is of no use here, so drop the old file name
5034 * information before refreshing it */
5035 bs->exact_filename[0] = '\0';
5036 if (bs->full_open_options) {
5037 QDECREF(bs->full_open_options);
5038 bs->full_open_options = NULL;
5039 }
5040
4cdd01d3
KW
5041 opts = qdict_new();
5042 append_open_options(opts, bs);
5043 drv->bdrv_refresh_filename(bs, opts);
5044 QDECREF(opts);
91af7014
HR
5045 } else if (bs->file) {
5046 /* Try to reconstruct valid information from the underlying file */
5047 bool has_open_options;
5048
5049 bs->exact_filename[0] = '\0';
5050 if (bs->full_open_options) {
5051 QDECREF(bs->full_open_options);
5052 bs->full_open_options = NULL;
5053 }
5054
5055 opts = qdict_new();
5056 has_open_options = append_open_options(opts, bs);
5057
5058 /* If no specific options have been given for this BDS, the filename of
5059 * the underlying file should suffice for this one as well */
9a4f4c31
KW
5060 if (bs->file->bs->exact_filename[0] && !has_open_options) {
5061 strcpy(bs->exact_filename, bs->file->bs->exact_filename);
91af7014
HR
5062 }
5063 /* Reconstructing the full options QDict is simple for most format block
5064 * drivers, as long as the full options are known for the underlying
5065 * file BDS. The full options QDict of that file BDS should somehow
5066 * contain a representation of the filename, therefore the following
5067 * suffices without querying the (exact_)filename of this BDS. */
9a4f4c31 5068 if (bs->file->bs->full_open_options) {
46f5ac20 5069 qdict_put_str(opts, "driver", drv->format_name);
9a4f4c31 5070 QINCREF(bs->file->bs->full_open_options);
de6e7951 5071 qdict_put(opts, "file", bs->file->bs->full_open_options);
91af7014
HR
5072
5073 bs->full_open_options = opts;
5074 } else {
5075 QDECREF(opts);
5076 }
5077 } else if (!bs->full_open_options && qdict_size(bs->options)) {
5078 /* There is no underlying file BDS (at least referenced by BDS.file),
5079 * so the full options QDict should be equal to the options given
5080 * specifically for this block device when it was opened (plus the
5081 * driver specification).
5082 * Because those options don't change, there is no need to update
5083 * full_open_options when it's already set. */
5084
5085 opts = qdict_new();
5086 append_open_options(opts, bs);
46f5ac20 5087 qdict_put_str(opts, "driver", drv->format_name);
91af7014
HR
5088
5089 if (bs->exact_filename[0]) {
5090 /* This may not work for all block protocol drivers (some may
5091 * require this filename to be parsed), but we have to find some
5092 * default solution here, so just include it. If some block driver
5093 * does not support pure options without any filename at all or
5094 * needs some special format of the options QDict, it needs to
5095 * implement the driver-specific bdrv_refresh_filename() function.
5096 */
46f5ac20 5097 qdict_put_str(opts, "filename", bs->exact_filename);
91af7014
HR
5098 }
5099
5100 bs->full_open_options = opts;
5101 }
5102
5103 if (bs->exact_filename[0]) {
5104 pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename);
5105 } else if (bs->full_open_options) {
5106 QString *json = qobject_to_json(QOBJECT(bs->full_open_options));
5107 snprintf(bs->filename, sizeof(bs->filename), "json:%s",
5108 qstring_get_str(json));
5109 QDECREF(json);
5110 }
5111}
e06018ad
WC
5112
5113/*
5114 * Hot add/remove a BDS's child. So the user can take a child offline when
5115 * it is broken and take a new child online
5116 */
5117void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs,
5118 Error **errp)
5119{
5120
5121 if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) {
5122 error_setg(errp, "The node %s does not support adding a child",
5123 bdrv_get_device_or_node_name(parent_bs));
5124 return;
5125 }
5126
5127 if (!QLIST_EMPTY(&child_bs->parents)) {
5128 error_setg(errp, "The node %s already has a parent",
5129 child_bs->node_name);
5130 return;
5131 }
5132
5133 parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp);
5134}
5135
5136void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp)
5137{
5138 BdrvChild *tmp;
5139
5140 if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) {
5141 error_setg(errp, "The node %s does not support removing a child",
5142 bdrv_get_device_or_node_name(parent_bs));
5143 return;
5144 }
5145
5146 QLIST_FOREACH(tmp, &parent_bs->children, next) {
5147 if (tmp == child) {
5148 break;
5149 }
5150 }
5151
5152 if (!tmp) {
5153 error_setg(errp, "The node %s does not have a child named %s",
5154 bdrv_get_device_or_node_name(parent_bs),
5155 bdrv_get_device_or_node_name(child->bs));
5156 return;
5157 }
5158
5159 parent_bs->drv->bdrv_del_child(parent_bs, child, errp);
5160}
67b792f5
VSO
5161
5162bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
5163 uint32_t granularity, Error **errp)
5164{
5165 BlockDriver *drv = bs->drv;
5166
5167 if (!drv) {
5168 error_setg_errno(errp, ENOMEDIUM,
5169 "Can't store persistent bitmaps to %s",
5170 bdrv_get_device_or_node_name(bs));
5171 return false;
5172 }
5173
5174 if (!drv->bdrv_can_store_new_dirty_bitmap) {
5175 error_setg_errno(errp, ENOTSUP,
5176 "Can't store persistent bitmaps to %s",
5177 bdrv_get_device_or_node_name(bs));
5178 return false;
5179 }
5180
5181 return drv->bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp);
5182}