2 * Block driver for the QCOW version 2 format
4 * Copyright (c) 2004-2006 Fabrice Bellard
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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
25 #include "qemu/osdep.h"
26 #include "block/block_int.h"
27 #include "sysemu/block-backend.h"
28 #include "qemu/module.h"
30 #include "block/qcow2.h"
31 #include "qemu/error-report.h"
32 #include "qapi/error.h"
33 #include "qapi/qmp/qerror.h"
34 #include "qapi/qmp/qdict.h"
35 #include "qapi/qmp/qstring.h"
36 #include "qapi-event.h"
38 #include "qemu/option_int.h"
39 #include "qemu/cutils.h"
40 #include "qemu/bswap.h"
41 #include "qapi/opts-visitor.h"
42 #include "qapi-visit.h"
43 #include "block/crypto.h"
46 Differences with QCOW:
48 - Support for multiple incremental snapshots.
49 - Memory management by reference counts.
50 - Clusters which have a reference count of one have the bit
51 QCOW_OFLAG_COPIED to optimize write performance.
52 - Size of compressed clusters is stored in sectors to reduce bit usage
53 in the cluster offsets.
54 - Support for storing additional data (such as the VM state) in the
56 - If a backing store is used, the cluster size is not constrained
57 (could be backported to QCOW).
58 - L2 tables have always a size of one cluster.
65 } QEMU_PACKED QCowExtension
;
67 #define QCOW2_EXT_MAGIC_END 0
68 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
69 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
70 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
71 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875
73 static int qcow2_probe(const uint8_t *buf
, int buf_size
, const char *filename
)
75 const QCowHeader
*cow_header
= (const void *)buf
;
77 if (buf_size
>= sizeof(QCowHeader
) &&
78 be32_to_cpu(cow_header
->magic
) == QCOW_MAGIC
&&
79 be32_to_cpu(cow_header
->version
) >= 2)
86 static ssize_t
qcow2_crypto_hdr_read_func(QCryptoBlock
*block
, size_t offset
,
87 uint8_t *buf
, size_t buflen
,
88 void *opaque
, Error
**errp
)
90 BlockDriverState
*bs
= opaque
;
91 BDRVQcow2State
*s
= bs
->opaque
;
94 if ((offset
+ buflen
) > s
->crypto_header
.length
) {
95 error_setg(errp
, "Request for data outside of extension header");
99 ret
= bdrv_pread(bs
->file
,
100 s
->crypto_header
.offset
+ offset
, buf
, buflen
);
102 error_setg_errno(errp
, -ret
, "Could not read encryption header");
109 static ssize_t
qcow2_crypto_hdr_init_func(QCryptoBlock
*block
, size_t headerlen
,
110 void *opaque
, Error
**errp
)
112 BlockDriverState
*bs
= opaque
;
113 BDRVQcow2State
*s
= bs
->opaque
;
117 ret
= qcow2_alloc_clusters(bs
, headerlen
);
119 error_setg_errno(errp
, -ret
,
120 "Cannot allocate cluster for LUKS header size %zu",
125 s
->crypto_header
.length
= headerlen
;
126 s
->crypto_header
.offset
= ret
;
128 /* Zero fill remaining space in cluster so it has predictable
129 * content in case of future spec changes */
130 clusterlen
= size_to_clusters(s
, headerlen
) * s
->cluster_size
;
131 assert(qcow2_pre_write_overlap_check(bs
, 0, ret
, clusterlen
) == 0);
132 ret
= bdrv_pwrite_zeroes(bs
->file
,
134 clusterlen
- headerlen
, 0);
136 error_setg_errno(errp
, -ret
, "Could not zero fill encryption header");
144 static ssize_t
qcow2_crypto_hdr_write_func(QCryptoBlock
*block
, size_t offset
,
145 const uint8_t *buf
, size_t buflen
,
146 void *opaque
, Error
**errp
)
148 BlockDriverState
*bs
= opaque
;
149 BDRVQcow2State
*s
= bs
->opaque
;
152 if ((offset
+ buflen
) > s
->crypto_header
.length
) {
153 error_setg(errp
, "Request for data outside of extension header");
157 ret
= bdrv_pwrite(bs
->file
,
158 s
->crypto_header
.offset
+ offset
, buf
, buflen
);
160 error_setg_errno(errp
, -ret
, "Could not read encryption header");
168 * read qcow2 extension and fill bs
169 * start reading from start_offset
170 * finish reading upon magic of value 0 or when end_offset reached
171 * unknown magic is skipped (future extension this version knows nothing about)
172 * return 0 upon success, non-0 otherwise
174 static int qcow2_read_extensions(BlockDriverState
*bs
, uint64_t start_offset
,
175 uint64_t end_offset
, void **p_feature_table
,
176 int flags
, bool *need_update_header
,
179 BDRVQcow2State
*s
= bs
->opaque
;
183 Qcow2BitmapHeaderExt bitmaps_ext
;
185 if (need_update_header
!= NULL
) {
186 *need_update_header
= false;
190 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset
, end_offset
);
192 offset
= start_offset
;
193 while (offset
< end_offset
) {
197 if (offset
> s
->cluster_size
)
198 printf("qcow2_read_extension: suspicious offset %lu\n", offset
);
200 printf("attempting to read extended header in offset %lu\n", offset
);
203 ret
= bdrv_pread(bs
->file
, offset
, &ext
, sizeof(ext
));
205 error_setg_errno(errp
, -ret
, "qcow2_read_extension: ERROR: "
206 "pread fail from offset %" PRIu64
, offset
);
209 be32_to_cpus(&ext
.magic
);
210 be32_to_cpus(&ext
.len
);
211 offset
+= sizeof(ext
);
213 printf("ext.magic = 0x%x\n", ext
.magic
);
215 if (offset
> end_offset
|| ext
.len
> end_offset
- offset
) {
216 error_setg(errp
, "Header extension too large");
221 case QCOW2_EXT_MAGIC_END
:
224 case QCOW2_EXT_MAGIC_BACKING_FORMAT
:
225 if (ext
.len
>= sizeof(bs
->backing_format
)) {
226 error_setg(errp
, "ERROR: ext_backing_format: len=%" PRIu32
227 " too large (>=%zu)", ext
.len
,
228 sizeof(bs
->backing_format
));
231 ret
= bdrv_pread(bs
->file
, offset
, bs
->backing_format
, ext
.len
);
233 error_setg_errno(errp
, -ret
, "ERROR: ext_backing_format: "
234 "Could not read format name");
237 bs
->backing_format
[ext
.len
] = '\0';
238 s
->image_backing_format
= g_strdup(bs
->backing_format
);
240 printf("Qcow2: Got format extension %s\n", bs
->backing_format
);
244 case QCOW2_EXT_MAGIC_FEATURE_TABLE
:
245 if (p_feature_table
!= NULL
) {
246 void* feature_table
= g_malloc0(ext
.len
+ 2 * sizeof(Qcow2Feature
));
247 ret
= bdrv_pread(bs
->file
, offset
, feature_table
, ext
.len
);
249 error_setg_errno(errp
, -ret
, "ERROR: ext_feature_table: "
250 "Could not read table");
254 *p_feature_table
= feature_table
;
258 case QCOW2_EXT_MAGIC_CRYPTO_HEADER
: {
259 unsigned int cflags
= 0;
260 if (s
->crypt_method_header
!= QCOW_CRYPT_LUKS
) {
261 error_setg(errp
, "CRYPTO header extension only "
262 "expected with LUKS encryption method");
265 if (ext
.len
!= sizeof(Qcow2CryptoHeaderExtension
)) {
266 error_setg(errp
, "CRYPTO header extension size %u, "
267 "but expected size %zu", ext
.len
,
268 sizeof(Qcow2CryptoHeaderExtension
));
272 ret
= bdrv_pread(bs
->file
, offset
, &s
->crypto_header
, ext
.len
);
274 error_setg_errno(errp
, -ret
,
275 "Unable to read CRYPTO header extension");
278 be64_to_cpus(&s
->crypto_header
.offset
);
279 be64_to_cpus(&s
->crypto_header
.length
);
281 if ((s
->crypto_header
.offset
% s
->cluster_size
) != 0) {
282 error_setg(errp
, "Encryption header offset '%" PRIu64
"' is "
283 "not a multiple of cluster size '%u'",
284 s
->crypto_header
.offset
, s
->cluster_size
);
288 if (flags
& BDRV_O_NO_IO
) {
289 cflags
|= QCRYPTO_BLOCK_OPEN_NO_IO
;
291 s
->crypto
= qcrypto_block_open(s
->crypto_opts
, "encrypt.",
292 qcow2_crypto_hdr_read_func
,
299 case QCOW2_EXT_MAGIC_BITMAPS
:
300 if (ext
.len
!= sizeof(bitmaps_ext
)) {
301 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
302 "Invalid extension length");
306 if (!(s
->autoclear_features
& QCOW2_AUTOCLEAR_BITMAPS
)) {
307 if (s
->qcow_version
< 3) {
308 /* Let's be a bit more specific */
309 warn_report("This qcow2 v2 image contains bitmaps, but "
310 "they may have been modified by a program "
311 "without persistent bitmap support; so now "
312 "they must all be considered inconsistent");
314 warn_report("a program lacking bitmap support "
315 "modified this file, so all bitmaps are now "
316 "considered inconsistent");
318 error_printf("Some clusters may be leaked, "
319 "run 'qemu-img check -r' on the image "
321 if (need_update_header
!= NULL
) {
322 /* Updating is needed to drop invalid bitmap extension. */
323 *need_update_header
= true;
328 ret
= bdrv_pread(bs
->file
, offset
, &bitmaps_ext
, ext
.len
);
330 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
331 "Could not read ext header");
335 if (bitmaps_ext
.reserved32
!= 0) {
336 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
337 "Reserved field is not zero");
341 be32_to_cpus(&bitmaps_ext
.nb_bitmaps
);
342 be64_to_cpus(&bitmaps_ext
.bitmap_directory_size
);
343 be64_to_cpus(&bitmaps_ext
.bitmap_directory_offset
);
345 if (bitmaps_ext
.nb_bitmaps
> QCOW2_MAX_BITMAPS
) {
347 "bitmaps_ext: Image has %" PRIu32
" bitmaps, "
348 "exceeding the QEMU supported maximum of %d",
349 bitmaps_ext
.nb_bitmaps
, QCOW2_MAX_BITMAPS
);
353 if (bitmaps_ext
.nb_bitmaps
== 0) {
354 error_setg(errp
, "found bitmaps extension with zero bitmaps");
358 if (bitmaps_ext
.bitmap_directory_offset
& (s
->cluster_size
- 1)) {
359 error_setg(errp
, "bitmaps_ext: "
360 "invalid bitmap directory offset");
364 if (bitmaps_ext
.bitmap_directory_size
>
365 QCOW2_MAX_BITMAP_DIRECTORY_SIZE
) {
366 error_setg(errp
, "bitmaps_ext: "
367 "bitmap directory size (%" PRIu64
") exceeds "
368 "the maximum supported size (%d)",
369 bitmaps_ext
.bitmap_directory_size
,
370 QCOW2_MAX_BITMAP_DIRECTORY_SIZE
);
374 s
->nb_bitmaps
= bitmaps_ext
.nb_bitmaps
;
375 s
->bitmap_directory_offset
=
376 bitmaps_ext
.bitmap_directory_offset
;
377 s
->bitmap_directory_size
=
378 bitmaps_ext
.bitmap_directory_size
;
381 printf("Qcow2: Got bitmaps extension: "
382 "offset=%" PRIu64
" nb_bitmaps=%" PRIu32
"\n",
383 s
->bitmap_directory_offset
, s
->nb_bitmaps
);
388 /* unknown magic - save it in case we need to rewrite the header */
389 /* If you add a new feature, make sure to also update the fast
390 * path of qcow2_make_empty() to deal with it. */
392 Qcow2UnknownHeaderExtension
*uext
;
394 uext
= g_malloc0(sizeof(*uext
) + ext
.len
);
395 uext
->magic
= ext
.magic
;
397 QLIST_INSERT_HEAD(&s
->unknown_header_ext
, uext
, next
);
399 ret
= bdrv_pread(bs
->file
, offset
, uext
->data
, uext
->len
);
401 error_setg_errno(errp
, -ret
, "ERROR: unknown extension: "
402 "Could not read data");
409 offset
+= ((ext
.len
+ 7) & ~7);
415 static void cleanup_unknown_header_ext(BlockDriverState
*bs
)
417 BDRVQcow2State
*s
= bs
->opaque
;
418 Qcow2UnknownHeaderExtension
*uext
, *next
;
420 QLIST_FOREACH_SAFE(uext
, &s
->unknown_header_ext
, next
, next
) {
421 QLIST_REMOVE(uext
, next
);
426 static void report_unsupported_feature(Error
**errp
, Qcow2Feature
*table
,
429 char *features
= g_strdup("");
432 while (table
&& table
->name
[0] != '\0') {
433 if (table
->type
== QCOW2_FEAT_TYPE_INCOMPATIBLE
) {
434 if (mask
& (1ULL << table
->bit
)) {
436 features
= g_strdup_printf("%s%s%.46s", old
, *old
? ", " : "",
439 mask
&= ~(1ULL << table
->bit
);
447 features
= g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64
,
448 old
, *old
? ", " : "", mask
);
452 error_setg(errp
, "Unsupported qcow2 feature(s): %s", features
);
457 * Sets the dirty bit and flushes afterwards if necessary.
459 * The incompatible_features bit is only set if the image file header was
460 * updated successfully. Therefore it is not required to check the return
461 * value of this function.
463 int qcow2_mark_dirty(BlockDriverState
*bs
)
465 BDRVQcow2State
*s
= bs
->opaque
;
469 assert(s
->qcow_version
>= 3);
471 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
472 return 0; /* already dirty */
475 val
= cpu_to_be64(s
->incompatible_features
| QCOW2_INCOMPAT_DIRTY
);
476 ret
= bdrv_pwrite(bs
->file
, offsetof(QCowHeader
, incompatible_features
),
481 ret
= bdrv_flush(bs
->file
->bs
);
486 /* Only treat image as dirty if the header was updated successfully */
487 s
->incompatible_features
|= QCOW2_INCOMPAT_DIRTY
;
492 * Clears the dirty bit and flushes before if necessary. Only call this
493 * function when there are no pending requests, it does not guard against
494 * concurrent requests dirtying the image.
496 static int qcow2_mark_clean(BlockDriverState
*bs
)
498 BDRVQcow2State
*s
= bs
->opaque
;
500 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
503 s
->incompatible_features
&= ~QCOW2_INCOMPAT_DIRTY
;
505 ret
= bdrv_flush(bs
);
510 return qcow2_update_header(bs
);
516 * Marks the image as corrupt.
518 int qcow2_mark_corrupt(BlockDriverState
*bs
)
520 BDRVQcow2State
*s
= bs
->opaque
;
522 s
->incompatible_features
|= QCOW2_INCOMPAT_CORRUPT
;
523 return qcow2_update_header(bs
);
527 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes
528 * before if necessary.
530 int qcow2_mark_consistent(BlockDriverState
*bs
)
532 BDRVQcow2State
*s
= bs
->opaque
;
534 if (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
) {
535 int ret
= bdrv_flush(bs
);
540 s
->incompatible_features
&= ~QCOW2_INCOMPAT_CORRUPT
;
541 return qcow2_update_header(bs
);
546 static int qcow2_check(BlockDriverState
*bs
, BdrvCheckResult
*result
,
549 int ret
= qcow2_check_refcounts(bs
, result
, fix
);
554 if (fix
&& result
->check_errors
== 0 && result
->corruptions
== 0) {
555 ret
= qcow2_mark_clean(bs
);
559 return qcow2_mark_consistent(bs
);
564 static int validate_table_offset(BlockDriverState
*bs
, uint64_t offset
,
565 uint64_t entries
, size_t entry_len
)
567 BDRVQcow2State
*s
= bs
->opaque
;
570 /* Use signed INT64_MAX as the maximum even for uint64_t header fields,
571 * because values will be passed to qemu functions taking int64_t. */
572 if (entries
> INT64_MAX
/ entry_len
) {
576 size
= entries
* entry_len
;
578 if (INT64_MAX
- size
< offset
) {
582 /* Tables must be cluster aligned */
583 if (offset_into_cluster(s
, offset
) != 0) {
590 static QemuOptsList qcow2_runtime_opts
= {
592 .head
= QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts
.head
),
595 .name
= QCOW2_OPT_LAZY_REFCOUNTS
,
596 .type
= QEMU_OPT_BOOL
,
597 .help
= "Postpone refcount updates",
600 .name
= QCOW2_OPT_DISCARD_REQUEST
,
601 .type
= QEMU_OPT_BOOL
,
602 .help
= "Pass guest discard requests to the layer below",
605 .name
= QCOW2_OPT_DISCARD_SNAPSHOT
,
606 .type
= QEMU_OPT_BOOL
,
607 .help
= "Generate discard requests when snapshot related space "
611 .name
= QCOW2_OPT_DISCARD_OTHER
,
612 .type
= QEMU_OPT_BOOL
,
613 .help
= "Generate discard requests when other clusters are freed",
616 .name
= QCOW2_OPT_OVERLAP
,
617 .type
= QEMU_OPT_STRING
,
618 .help
= "Selects which overlap checks to perform from a range of "
619 "templates (none, constant, cached, all)",
622 .name
= QCOW2_OPT_OVERLAP_TEMPLATE
,
623 .type
= QEMU_OPT_STRING
,
624 .help
= "Selects which overlap checks to perform from a range of "
625 "templates (none, constant, cached, all)",
628 .name
= QCOW2_OPT_OVERLAP_MAIN_HEADER
,
629 .type
= QEMU_OPT_BOOL
,
630 .help
= "Check for unintended writes into the main qcow2 header",
633 .name
= QCOW2_OPT_OVERLAP_ACTIVE_L1
,
634 .type
= QEMU_OPT_BOOL
,
635 .help
= "Check for unintended writes into the active L1 table",
638 .name
= QCOW2_OPT_OVERLAP_ACTIVE_L2
,
639 .type
= QEMU_OPT_BOOL
,
640 .help
= "Check for unintended writes into an active L2 table",
643 .name
= QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
644 .type
= QEMU_OPT_BOOL
,
645 .help
= "Check for unintended writes into the refcount table",
648 .name
= QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
649 .type
= QEMU_OPT_BOOL
,
650 .help
= "Check for unintended writes into a refcount block",
653 .name
= QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
654 .type
= QEMU_OPT_BOOL
,
655 .help
= "Check for unintended writes into the snapshot table",
658 .name
= QCOW2_OPT_OVERLAP_INACTIVE_L1
,
659 .type
= QEMU_OPT_BOOL
,
660 .help
= "Check for unintended writes into an inactive L1 table",
663 .name
= QCOW2_OPT_OVERLAP_INACTIVE_L2
,
664 .type
= QEMU_OPT_BOOL
,
665 .help
= "Check for unintended writes into an inactive L2 table",
668 .name
= QCOW2_OPT_CACHE_SIZE
,
669 .type
= QEMU_OPT_SIZE
,
670 .help
= "Maximum combined metadata (L2 tables and refcount blocks) "
674 .name
= QCOW2_OPT_L2_CACHE_SIZE
,
675 .type
= QEMU_OPT_SIZE
,
676 .help
= "Maximum L2 table cache size",
679 .name
= QCOW2_OPT_L2_CACHE_ENTRY_SIZE
,
680 .type
= QEMU_OPT_SIZE
,
681 .help
= "Size of each entry in the L2 cache",
684 .name
= QCOW2_OPT_REFCOUNT_CACHE_SIZE
,
685 .type
= QEMU_OPT_SIZE
,
686 .help
= "Maximum refcount block cache size",
689 .name
= QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
690 .type
= QEMU_OPT_NUMBER
,
691 .help
= "Clean unused cache entries after this time (in seconds)",
693 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
694 "ID of secret providing qcow2 AES key or LUKS passphrase"),
695 { /* end of list */ }
699 static const char *overlap_bool_option_names
[QCOW2_OL_MAX_BITNR
] = {
700 [QCOW2_OL_MAIN_HEADER_BITNR
] = QCOW2_OPT_OVERLAP_MAIN_HEADER
,
701 [QCOW2_OL_ACTIVE_L1_BITNR
] = QCOW2_OPT_OVERLAP_ACTIVE_L1
,
702 [QCOW2_OL_ACTIVE_L2_BITNR
] = QCOW2_OPT_OVERLAP_ACTIVE_L2
,
703 [QCOW2_OL_REFCOUNT_TABLE_BITNR
] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
704 [QCOW2_OL_REFCOUNT_BLOCK_BITNR
] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
705 [QCOW2_OL_SNAPSHOT_TABLE_BITNR
] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
706 [QCOW2_OL_INACTIVE_L1_BITNR
] = QCOW2_OPT_OVERLAP_INACTIVE_L1
,
707 [QCOW2_OL_INACTIVE_L2_BITNR
] = QCOW2_OPT_OVERLAP_INACTIVE_L2
,
710 static void cache_clean_timer_cb(void *opaque
)
712 BlockDriverState
*bs
= opaque
;
713 BDRVQcow2State
*s
= bs
->opaque
;
714 qcow2_cache_clean_unused(s
->l2_table_cache
);
715 qcow2_cache_clean_unused(s
->refcount_block_cache
);
716 timer_mod(s
->cache_clean_timer
, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
) +
717 (int64_t) s
->cache_clean_interval
* 1000);
720 static void cache_clean_timer_init(BlockDriverState
*bs
, AioContext
*context
)
722 BDRVQcow2State
*s
= bs
->opaque
;
723 if (s
->cache_clean_interval
> 0) {
724 s
->cache_clean_timer
= aio_timer_new(context
, QEMU_CLOCK_VIRTUAL
,
725 SCALE_MS
, cache_clean_timer_cb
,
727 timer_mod(s
->cache_clean_timer
, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
) +
728 (int64_t) s
->cache_clean_interval
* 1000);
732 static void cache_clean_timer_del(BlockDriverState
*bs
)
734 BDRVQcow2State
*s
= bs
->opaque
;
735 if (s
->cache_clean_timer
) {
736 timer_del(s
->cache_clean_timer
);
737 timer_free(s
->cache_clean_timer
);
738 s
->cache_clean_timer
= NULL
;
742 static void qcow2_detach_aio_context(BlockDriverState
*bs
)
744 cache_clean_timer_del(bs
);
747 static void qcow2_attach_aio_context(BlockDriverState
*bs
,
748 AioContext
*new_context
)
750 cache_clean_timer_init(bs
, new_context
);
753 static void read_cache_sizes(BlockDriverState
*bs
, QemuOpts
*opts
,
754 uint64_t *l2_cache_size
,
755 uint64_t *l2_cache_entry_size
,
756 uint64_t *refcount_cache_size
, Error
**errp
)
758 BDRVQcow2State
*s
= bs
->opaque
;
759 uint64_t combined_cache_size
;
760 bool l2_cache_size_set
, refcount_cache_size_set
, combined_cache_size_set
;
762 combined_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_CACHE_SIZE
);
763 l2_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_L2_CACHE_SIZE
);
764 refcount_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
766 combined_cache_size
= qemu_opt_get_size(opts
, QCOW2_OPT_CACHE_SIZE
, 0);
767 *l2_cache_size
= qemu_opt_get_size(opts
, QCOW2_OPT_L2_CACHE_SIZE
, 0);
768 *refcount_cache_size
= qemu_opt_get_size(opts
,
769 QCOW2_OPT_REFCOUNT_CACHE_SIZE
, 0);
771 *l2_cache_entry_size
= qemu_opt_get_size(
772 opts
, QCOW2_OPT_L2_CACHE_ENTRY_SIZE
, s
->cluster_size
);
774 if (combined_cache_size_set
) {
775 if (l2_cache_size_set
&& refcount_cache_size_set
) {
776 error_setg(errp
, QCOW2_OPT_CACHE_SIZE
", " QCOW2_OPT_L2_CACHE_SIZE
777 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE
" may not be set "
780 } else if (*l2_cache_size
> combined_cache_size
) {
781 error_setg(errp
, QCOW2_OPT_L2_CACHE_SIZE
" may not exceed "
782 QCOW2_OPT_CACHE_SIZE
);
784 } else if (*refcount_cache_size
> combined_cache_size
) {
785 error_setg(errp
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
" may not exceed "
786 QCOW2_OPT_CACHE_SIZE
);
790 if (l2_cache_size_set
) {
791 *refcount_cache_size
= combined_cache_size
- *l2_cache_size
;
792 } else if (refcount_cache_size_set
) {
793 *l2_cache_size
= combined_cache_size
- *refcount_cache_size
;
795 *refcount_cache_size
= combined_cache_size
796 / (DEFAULT_L2_REFCOUNT_SIZE_RATIO
+ 1);
797 *l2_cache_size
= combined_cache_size
- *refcount_cache_size
;
800 if (!l2_cache_size_set
&& !refcount_cache_size_set
) {
801 *l2_cache_size
= MAX(DEFAULT_L2_CACHE_BYTE_SIZE
,
802 (uint64_t)DEFAULT_L2_CACHE_CLUSTERS
804 *refcount_cache_size
= *l2_cache_size
805 / DEFAULT_L2_REFCOUNT_SIZE_RATIO
;
806 } else if (!l2_cache_size_set
) {
807 *l2_cache_size
= *refcount_cache_size
808 * DEFAULT_L2_REFCOUNT_SIZE_RATIO
;
809 } else if (!refcount_cache_size_set
) {
810 *refcount_cache_size
= *l2_cache_size
811 / DEFAULT_L2_REFCOUNT_SIZE_RATIO
;
815 if (*l2_cache_entry_size
< (1 << MIN_CLUSTER_BITS
) ||
816 *l2_cache_entry_size
> s
->cluster_size
||
817 !is_power_of_2(*l2_cache_entry_size
)) {
818 error_setg(errp
, "L2 cache entry size must be a power of two "
819 "between %d and the cluster size (%d)",
820 1 << MIN_CLUSTER_BITS
, s
->cluster_size
);
825 typedef struct Qcow2ReopenState
{
826 Qcow2Cache
*l2_table_cache
;
827 Qcow2Cache
*refcount_block_cache
;
828 int l2_slice_size
; /* Number of entries in a slice of the L2 table */
829 bool use_lazy_refcounts
;
831 bool discard_passthrough
[QCOW2_DISCARD_MAX
];
832 uint64_t cache_clean_interval
;
833 QCryptoBlockOpenOptions
*crypto_opts
; /* Disk encryption runtime options */
836 static int qcow2_update_options_prepare(BlockDriverState
*bs
,
838 QDict
*options
, int flags
,
841 BDRVQcow2State
*s
= bs
->opaque
;
842 QemuOpts
*opts
= NULL
;
843 const char *opt_overlap_check
, *opt_overlap_check_template
;
844 int overlap_check_template
= 0;
845 uint64_t l2_cache_size
, l2_cache_entry_size
, refcount_cache_size
;
847 const char *encryptfmt
;
848 QDict
*encryptopts
= NULL
;
849 Error
*local_err
= NULL
;
852 qdict_extract_subqdict(options
, &encryptopts
, "encrypt.");
853 encryptfmt
= qdict_get_try_str(encryptopts
, "format");
855 opts
= qemu_opts_create(&qcow2_runtime_opts
, NULL
, 0, &error_abort
);
856 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
858 error_propagate(errp
, local_err
);
863 /* get L2 table/refcount block cache size from command line options */
864 read_cache_sizes(bs
, opts
, &l2_cache_size
, &l2_cache_entry_size
,
865 &refcount_cache_size
, &local_err
);
867 error_propagate(errp
, local_err
);
872 l2_cache_size
/= l2_cache_entry_size
;
873 if (l2_cache_size
< MIN_L2_CACHE_SIZE
) {
874 l2_cache_size
= MIN_L2_CACHE_SIZE
;
876 if (l2_cache_size
> INT_MAX
) {
877 error_setg(errp
, "L2 cache size too big");
882 refcount_cache_size
/= s
->cluster_size
;
883 if (refcount_cache_size
< MIN_REFCOUNT_CACHE_SIZE
) {
884 refcount_cache_size
= MIN_REFCOUNT_CACHE_SIZE
;
886 if (refcount_cache_size
> INT_MAX
) {
887 error_setg(errp
, "Refcount cache size too big");
892 /* alloc new L2 table/refcount block cache, flush old one */
893 if (s
->l2_table_cache
) {
894 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
896 error_setg_errno(errp
, -ret
, "Failed to flush the L2 table cache");
901 if (s
->refcount_block_cache
) {
902 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
904 error_setg_errno(errp
, -ret
,
905 "Failed to flush the refcount block cache");
910 r
->l2_slice_size
= l2_cache_entry_size
/ sizeof(uint64_t);
911 r
->l2_table_cache
= qcow2_cache_create(bs
, l2_cache_size
,
912 l2_cache_entry_size
);
913 r
->refcount_block_cache
= qcow2_cache_create(bs
, refcount_cache_size
,
915 if (r
->l2_table_cache
== NULL
|| r
->refcount_block_cache
== NULL
) {
916 error_setg(errp
, "Could not allocate metadata caches");
921 /* New interval for cache cleanup timer */
922 r
->cache_clean_interval
=
923 qemu_opt_get_number(opts
, QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
924 s
->cache_clean_interval
);
926 if (r
->cache_clean_interval
!= 0) {
927 error_setg(errp
, QCOW2_OPT_CACHE_CLEAN_INTERVAL
928 " not supported on this host");
933 if (r
->cache_clean_interval
> UINT_MAX
) {
934 error_setg(errp
, "Cache clean interval too big");
939 /* lazy-refcounts; flush if going from enabled to disabled */
940 r
->use_lazy_refcounts
= qemu_opt_get_bool(opts
, QCOW2_OPT_LAZY_REFCOUNTS
,
941 (s
->compatible_features
& QCOW2_COMPAT_LAZY_REFCOUNTS
));
942 if (r
->use_lazy_refcounts
&& s
->qcow_version
< 3) {
943 error_setg(errp
, "Lazy refcounts require a qcow2 image with at least "
944 "qemu 1.1 compatibility level");
949 if (s
->use_lazy_refcounts
&& !r
->use_lazy_refcounts
) {
950 ret
= qcow2_mark_clean(bs
);
952 error_setg_errno(errp
, -ret
, "Failed to disable lazy refcounts");
957 /* Overlap check options */
958 opt_overlap_check
= qemu_opt_get(opts
, QCOW2_OPT_OVERLAP
);
959 opt_overlap_check_template
= qemu_opt_get(opts
, QCOW2_OPT_OVERLAP_TEMPLATE
);
960 if (opt_overlap_check_template
&& opt_overlap_check
&&
961 strcmp(opt_overlap_check_template
, opt_overlap_check
))
963 error_setg(errp
, "Conflicting values for qcow2 options '"
964 QCOW2_OPT_OVERLAP
"' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE
965 "' ('%s')", opt_overlap_check
, opt_overlap_check_template
);
969 if (!opt_overlap_check
) {
970 opt_overlap_check
= opt_overlap_check_template
?: "cached";
973 if (!strcmp(opt_overlap_check
, "none")) {
974 overlap_check_template
= 0;
975 } else if (!strcmp(opt_overlap_check
, "constant")) {
976 overlap_check_template
= QCOW2_OL_CONSTANT
;
977 } else if (!strcmp(opt_overlap_check
, "cached")) {
978 overlap_check_template
= QCOW2_OL_CACHED
;
979 } else if (!strcmp(opt_overlap_check
, "all")) {
980 overlap_check_template
= QCOW2_OL_ALL
;
982 error_setg(errp
, "Unsupported value '%s' for qcow2 option "
983 "'overlap-check'. Allowed are any of the following: "
984 "none, constant, cached, all", opt_overlap_check
);
989 r
->overlap_check
= 0;
990 for (i
= 0; i
< QCOW2_OL_MAX_BITNR
; i
++) {
991 /* overlap-check defines a template bitmask, but every flag may be
992 * overwritten through the associated boolean option */
994 qemu_opt_get_bool(opts
, overlap_bool_option_names
[i
],
995 overlap_check_template
& (1 << i
)) << i
;
998 r
->discard_passthrough
[QCOW2_DISCARD_NEVER
] = false;
999 r
->discard_passthrough
[QCOW2_DISCARD_ALWAYS
] = true;
1000 r
->discard_passthrough
[QCOW2_DISCARD_REQUEST
] =
1001 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_REQUEST
,
1002 flags
& BDRV_O_UNMAP
);
1003 r
->discard_passthrough
[QCOW2_DISCARD_SNAPSHOT
] =
1004 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_SNAPSHOT
, true);
1005 r
->discard_passthrough
[QCOW2_DISCARD_OTHER
] =
1006 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_OTHER
, false);
1008 switch (s
->crypt_method_header
) {
1009 case QCOW_CRYPT_NONE
:
1011 error_setg(errp
, "No encryption in image header, but options "
1012 "specified format '%s'", encryptfmt
);
1018 case QCOW_CRYPT_AES
:
1019 if (encryptfmt
&& !g_str_equal(encryptfmt
, "aes")) {
1021 "Header reported 'aes' encryption format but "
1022 "options specify '%s'", encryptfmt
);
1026 qdict_del(encryptopts
, "format");
1027 r
->crypto_opts
= block_crypto_open_opts_init(
1028 Q_CRYPTO_BLOCK_FORMAT_QCOW
, encryptopts
, errp
);
1031 case QCOW_CRYPT_LUKS
:
1032 if (encryptfmt
&& !g_str_equal(encryptfmt
, "luks")) {
1034 "Header reported 'luks' encryption format but "
1035 "options specify '%s'", encryptfmt
);
1039 qdict_del(encryptopts
, "format");
1040 r
->crypto_opts
= block_crypto_open_opts_init(
1041 Q_CRYPTO_BLOCK_FORMAT_LUKS
, encryptopts
, errp
);
1045 error_setg(errp
, "Unsupported encryption method %d",
1046 s
->crypt_method_header
);
1049 if (s
->crypt_method_header
!= QCOW_CRYPT_NONE
&& !r
->crypto_opts
) {
1056 QDECREF(encryptopts
);
1057 qemu_opts_del(opts
);
1062 static void qcow2_update_options_commit(BlockDriverState
*bs
,
1063 Qcow2ReopenState
*r
)
1065 BDRVQcow2State
*s
= bs
->opaque
;
1068 if (s
->l2_table_cache
) {
1069 qcow2_cache_destroy(s
->l2_table_cache
);
1071 if (s
->refcount_block_cache
) {
1072 qcow2_cache_destroy(s
->refcount_block_cache
);
1074 s
->l2_table_cache
= r
->l2_table_cache
;
1075 s
->refcount_block_cache
= r
->refcount_block_cache
;
1076 s
->l2_slice_size
= r
->l2_slice_size
;
1078 s
->overlap_check
= r
->overlap_check
;
1079 s
->use_lazy_refcounts
= r
->use_lazy_refcounts
;
1081 for (i
= 0; i
< QCOW2_DISCARD_MAX
; i
++) {
1082 s
->discard_passthrough
[i
] = r
->discard_passthrough
[i
];
1085 if (s
->cache_clean_interval
!= r
->cache_clean_interval
) {
1086 cache_clean_timer_del(bs
);
1087 s
->cache_clean_interval
= r
->cache_clean_interval
;
1088 cache_clean_timer_init(bs
, bdrv_get_aio_context(bs
));
1091 qapi_free_QCryptoBlockOpenOptions(s
->crypto_opts
);
1092 s
->crypto_opts
= r
->crypto_opts
;
1095 static void qcow2_update_options_abort(BlockDriverState
*bs
,
1096 Qcow2ReopenState
*r
)
1098 if (r
->l2_table_cache
) {
1099 qcow2_cache_destroy(r
->l2_table_cache
);
1101 if (r
->refcount_block_cache
) {
1102 qcow2_cache_destroy(r
->refcount_block_cache
);
1104 qapi_free_QCryptoBlockOpenOptions(r
->crypto_opts
);
1107 static int qcow2_update_options(BlockDriverState
*bs
, QDict
*options
,
1108 int flags
, Error
**errp
)
1110 Qcow2ReopenState r
= {};
1113 ret
= qcow2_update_options_prepare(bs
, &r
, options
, flags
, errp
);
1115 qcow2_update_options_commit(bs
, &r
);
1117 qcow2_update_options_abort(bs
, &r
);
1123 static int qcow2_do_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
1126 BDRVQcow2State
*s
= bs
->opaque
;
1127 unsigned int len
, i
;
1130 Error
*local_err
= NULL
;
1132 uint64_t l1_vm_state_index
;
1133 bool update_header
= false;
1135 ret
= bdrv_pread(bs
->file
, 0, &header
, sizeof(header
));
1137 error_setg_errno(errp
, -ret
, "Could not read qcow2 header");
1140 be32_to_cpus(&header
.magic
);
1141 be32_to_cpus(&header
.version
);
1142 be64_to_cpus(&header
.backing_file_offset
);
1143 be32_to_cpus(&header
.backing_file_size
);
1144 be64_to_cpus(&header
.size
);
1145 be32_to_cpus(&header
.cluster_bits
);
1146 be32_to_cpus(&header
.crypt_method
);
1147 be64_to_cpus(&header
.l1_table_offset
);
1148 be32_to_cpus(&header
.l1_size
);
1149 be64_to_cpus(&header
.refcount_table_offset
);
1150 be32_to_cpus(&header
.refcount_table_clusters
);
1151 be64_to_cpus(&header
.snapshots_offset
);
1152 be32_to_cpus(&header
.nb_snapshots
);
1154 if (header
.magic
!= QCOW_MAGIC
) {
1155 error_setg(errp
, "Image is not in qcow2 format");
1159 if (header
.version
< 2 || header
.version
> 3) {
1160 error_setg(errp
, "Unsupported qcow2 version %" PRIu32
, header
.version
);
1165 s
->qcow_version
= header
.version
;
1167 /* Initialise cluster size */
1168 if (header
.cluster_bits
< MIN_CLUSTER_BITS
||
1169 header
.cluster_bits
> MAX_CLUSTER_BITS
) {
1170 error_setg(errp
, "Unsupported cluster size: 2^%" PRIu32
,
1171 header
.cluster_bits
);
1176 s
->cluster_bits
= header
.cluster_bits
;
1177 s
->cluster_size
= 1 << s
->cluster_bits
;
1178 s
->cluster_sectors
= 1 << (s
->cluster_bits
- BDRV_SECTOR_BITS
);
1180 /* Initialise version 3 header fields */
1181 if (header
.version
== 2) {
1182 header
.incompatible_features
= 0;
1183 header
.compatible_features
= 0;
1184 header
.autoclear_features
= 0;
1185 header
.refcount_order
= 4;
1186 header
.header_length
= 72;
1188 be64_to_cpus(&header
.incompatible_features
);
1189 be64_to_cpus(&header
.compatible_features
);
1190 be64_to_cpus(&header
.autoclear_features
);
1191 be32_to_cpus(&header
.refcount_order
);
1192 be32_to_cpus(&header
.header_length
);
1194 if (header
.header_length
< 104) {
1195 error_setg(errp
, "qcow2 header too short");
1201 if (header
.header_length
> s
->cluster_size
) {
1202 error_setg(errp
, "qcow2 header exceeds cluster size");
1207 if (header
.header_length
> sizeof(header
)) {
1208 s
->unknown_header_fields_size
= header
.header_length
- sizeof(header
);
1209 s
->unknown_header_fields
= g_malloc(s
->unknown_header_fields_size
);
1210 ret
= bdrv_pread(bs
->file
, sizeof(header
), s
->unknown_header_fields
,
1211 s
->unknown_header_fields_size
);
1213 error_setg_errno(errp
, -ret
, "Could not read unknown qcow2 header "
1219 if (header
.backing_file_offset
> s
->cluster_size
) {
1220 error_setg(errp
, "Invalid backing file offset");
1225 if (header
.backing_file_offset
) {
1226 ext_end
= header
.backing_file_offset
;
1228 ext_end
= 1 << header
.cluster_bits
;
1231 /* Handle feature bits */
1232 s
->incompatible_features
= header
.incompatible_features
;
1233 s
->compatible_features
= header
.compatible_features
;
1234 s
->autoclear_features
= header
.autoclear_features
;
1236 if (s
->incompatible_features
& ~QCOW2_INCOMPAT_MASK
) {
1237 void *feature_table
= NULL
;
1238 qcow2_read_extensions(bs
, header
.header_length
, ext_end
,
1239 &feature_table
, flags
, NULL
, NULL
);
1240 report_unsupported_feature(errp
, feature_table
,
1241 s
->incompatible_features
&
1242 ~QCOW2_INCOMPAT_MASK
);
1244 g_free(feature_table
);
1248 if (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
) {
1249 /* Corrupt images may not be written to unless they are being repaired
1251 if ((flags
& BDRV_O_RDWR
) && !(flags
& BDRV_O_CHECK
)) {
1252 error_setg(errp
, "qcow2: Image is corrupt; cannot be opened "
1259 /* Check support for various header values */
1260 if (header
.refcount_order
> 6) {
1261 error_setg(errp
, "Reference count entry width too large; may not "
1266 s
->refcount_order
= header
.refcount_order
;
1267 s
->refcount_bits
= 1 << s
->refcount_order
;
1268 s
->refcount_max
= UINT64_C(1) << (s
->refcount_bits
- 1);
1269 s
->refcount_max
+= s
->refcount_max
- 1;
1271 s
->crypt_method_header
= header
.crypt_method
;
1272 if (s
->crypt_method_header
) {
1273 if (bdrv_uses_whitelist() &&
1274 s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1276 "Use of AES-CBC encrypted qcow2 images is no longer "
1277 "supported in system emulators");
1278 error_append_hint(errp
,
1279 "You can use 'qemu-img convert' to convert your "
1280 "image to an alternative supported format, such "
1281 "as unencrypted qcow2, or raw with the LUKS "
1282 "format instead.\n");
1287 if (s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1288 s
->crypt_physical_offset
= false;
1290 /* Assuming LUKS and any future crypt methods we
1291 * add will all use physical offsets, due to the
1292 * fact that the alternative is insecure... */
1293 s
->crypt_physical_offset
= true;
1296 bs
->encrypted
= true;
1299 s
->l2_bits
= s
->cluster_bits
- 3; /* L2 is always one cluster */
1300 s
->l2_size
= 1 << s
->l2_bits
;
1301 /* 2^(s->refcount_order - 3) is the refcount width in bytes */
1302 s
->refcount_block_bits
= s
->cluster_bits
- (s
->refcount_order
- 3);
1303 s
->refcount_block_size
= 1 << s
->refcount_block_bits
;
1304 bs
->total_sectors
= header
.size
/ 512;
1305 s
->csize_shift
= (62 - (s
->cluster_bits
- 8));
1306 s
->csize_mask
= (1 << (s
->cluster_bits
- 8)) - 1;
1307 s
->cluster_offset_mask
= (1LL << s
->csize_shift
) - 1;
1309 s
->refcount_table_offset
= header
.refcount_table_offset
;
1310 s
->refcount_table_size
=
1311 header
.refcount_table_clusters
<< (s
->cluster_bits
- 3);
1313 if (header
.refcount_table_clusters
> qcow2_max_refcount_clusters(s
)) {
1314 error_setg(errp
, "Reference count table too large");
1319 if (header
.refcount_table_clusters
== 0 && !(flags
& BDRV_O_CHECK
)) {
1320 error_setg(errp
, "Image does not contain a reference count table");
1325 ret
= validate_table_offset(bs
, s
->refcount_table_offset
,
1326 s
->refcount_table_size
, sizeof(uint64_t));
1328 error_setg(errp
, "Invalid reference count table offset");
1332 /* Snapshot table offset/length */
1333 if (header
.nb_snapshots
> QCOW_MAX_SNAPSHOTS
) {
1334 error_setg(errp
, "Too many snapshots");
1339 ret
= validate_table_offset(bs
, header
.snapshots_offset
,
1340 header
.nb_snapshots
,
1341 sizeof(QCowSnapshotHeader
));
1343 error_setg(errp
, "Invalid snapshot table offset");
1347 /* read the level 1 table */
1348 if (header
.l1_size
> QCOW_MAX_L1_SIZE
/ sizeof(uint64_t)) {
1349 error_setg(errp
, "Active L1 table too large");
1353 s
->l1_size
= header
.l1_size
;
1355 l1_vm_state_index
= size_to_l1(s
, header
.size
);
1356 if (l1_vm_state_index
> INT_MAX
) {
1357 error_setg(errp
, "Image is too big");
1361 s
->l1_vm_state_index
= l1_vm_state_index
;
1363 /* the L1 table must contain at least enough entries to put
1364 header.size bytes */
1365 if (s
->l1_size
< s
->l1_vm_state_index
) {
1366 error_setg(errp
, "L1 table is too small");
1371 ret
= validate_table_offset(bs
, header
.l1_table_offset
,
1372 header
.l1_size
, sizeof(uint64_t));
1374 error_setg(errp
, "Invalid L1 table offset");
1377 s
->l1_table_offset
= header
.l1_table_offset
;
1380 if (s
->l1_size
> 0) {
1381 s
->l1_table
= qemu_try_blockalign(bs
->file
->bs
,
1382 align_offset(s
->l1_size
* sizeof(uint64_t), 512));
1383 if (s
->l1_table
== NULL
) {
1384 error_setg(errp
, "Could not allocate L1 table");
1388 ret
= bdrv_pread(bs
->file
, s
->l1_table_offset
, s
->l1_table
,
1389 s
->l1_size
* sizeof(uint64_t));
1391 error_setg_errno(errp
, -ret
, "Could not read L1 table");
1394 for(i
= 0;i
< s
->l1_size
; i
++) {
1395 be64_to_cpus(&s
->l1_table
[i
]);
1399 /* Parse driver-specific options */
1400 ret
= qcow2_update_options(bs
, options
, flags
, errp
);
1405 s
->cluster_cache_offset
= -1;
1408 ret
= qcow2_refcount_init(bs
);
1410 error_setg_errno(errp
, -ret
, "Could not initialize refcount handling");
1414 QLIST_INIT(&s
->cluster_allocs
);
1415 QTAILQ_INIT(&s
->discards
);
1417 /* read qcow2 extensions */
1418 if (qcow2_read_extensions(bs
, header
.header_length
, ext_end
, NULL
,
1419 flags
, &update_header
, &local_err
)) {
1420 error_propagate(errp
, local_err
);
1425 /* qcow2_read_extension may have set up the crypto context
1426 * if the crypt method needs a header region, some methods
1427 * don't need header extensions, so must check here
1429 if (s
->crypt_method_header
&& !s
->crypto
) {
1430 if (s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1431 unsigned int cflags
= 0;
1432 if (flags
& BDRV_O_NO_IO
) {
1433 cflags
|= QCRYPTO_BLOCK_OPEN_NO_IO
;
1435 s
->crypto
= qcrypto_block_open(s
->crypto_opts
, "encrypt.",
1436 NULL
, NULL
, cflags
, errp
);
1441 } else if (!(flags
& BDRV_O_NO_IO
)) {
1442 error_setg(errp
, "Missing CRYPTO header for crypt method %d",
1443 s
->crypt_method_header
);
1449 /* read the backing file name */
1450 if (header
.backing_file_offset
!= 0) {
1451 len
= header
.backing_file_size
;
1452 if (len
> MIN(1023, s
->cluster_size
- header
.backing_file_offset
) ||
1453 len
>= sizeof(bs
->backing_file
)) {
1454 error_setg(errp
, "Backing file name too long");
1458 ret
= bdrv_pread(bs
->file
, header
.backing_file_offset
,
1459 bs
->backing_file
, len
);
1461 error_setg_errno(errp
, -ret
, "Could not read backing file name");
1464 bs
->backing_file
[len
] = '\0';
1465 s
->image_backing_file
= g_strdup(bs
->backing_file
);
1468 /* Internal snapshots */
1469 s
->snapshots_offset
= header
.snapshots_offset
;
1470 s
->nb_snapshots
= header
.nb_snapshots
;
1472 ret
= qcow2_read_snapshots(bs
);
1474 error_setg_errno(errp
, -ret
, "Could not read snapshots");
1478 /* Clear unknown autoclear feature bits */
1479 update_header
|= s
->autoclear_features
& ~QCOW2_AUTOCLEAR_MASK
;
1481 update_header
&& !bs
->read_only
&& !(flags
& BDRV_O_INACTIVE
);
1482 if (update_header
) {
1483 s
->autoclear_features
&= QCOW2_AUTOCLEAR_MASK
;
1486 if (qcow2_load_dirty_bitmaps(bs
, &local_err
)) {
1487 update_header
= false;
1489 if (local_err
!= NULL
) {
1490 error_propagate(errp
, local_err
);
1495 if (update_header
) {
1496 ret
= qcow2_update_header(bs
);
1498 error_setg_errno(errp
, -ret
, "Could not update qcow2 header");
1503 /* Initialise locks */
1504 qemu_co_mutex_init(&s
->lock
);
1505 bs
->supported_zero_flags
= header
.version
>= 3 ? BDRV_REQ_MAY_UNMAP
: 0;
1507 /* Repair image if dirty */
1508 if (!(flags
& (BDRV_O_CHECK
| BDRV_O_INACTIVE
)) && !bs
->read_only
&&
1509 (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
)) {
1510 BdrvCheckResult result
= {0};
1512 ret
= qcow2_check(bs
, &result
, BDRV_FIX_ERRORS
| BDRV_FIX_LEAKS
);
1513 if (ret
< 0 || result
.check_errors
) {
1517 error_setg_errno(errp
, -ret
, "Could not repair dirty image");
1524 BdrvCheckResult result
= {0};
1525 qcow2_check_refcounts(bs
, &result
, 0);
1531 g_free(s
->unknown_header_fields
);
1532 cleanup_unknown_header_ext(bs
);
1533 qcow2_free_snapshots(bs
);
1534 qcow2_refcount_close(bs
);
1535 qemu_vfree(s
->l1_table
);
1536 /* else pre-write overlap checks in cache_destroy may crash */
1538 cache_clean_timer_del(bs
);
1539 if (s
->l2_table_cache
) {
1540 qcow2_cache_destroy(s
->l2_table_cache
);
1542 if (s
->refcount_block_cache
) {
1543 qcow2_cache_destroy(s
->refcount_block_cache
);
1545 qcrypto_block_free(s
->crypto
);
1546 qapi_free_QCryptoBlockOpenOptions(s
->crypto_opts
);
1550 static int qcow2_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
1553 bs
->file
= bdrv_open_child(NULL
, options
, "file", bs
, &child_file
,
1559 return qcow2_do_open(bs
, options
, flags
, errp
);
1562 static void qcow2_refresh_limits(BlockDriverState
*bs
, Error
**errp
)
1564 BDRVQcow2State
*s
= bs
->opaque
;
1566 if (bs
->encrypted
) {
1567 /* Encryption works on a sector granularity */
1568 bs
->bl
.request_alignment
= BDRV_SECTOR_SIZE
;
1570 bs
->bl
.pwrite_zeroes_alignment
= s
->cluster_size
;
1571 bs
->bl
.pdiscard_alignment
= s
->cluster_size
;
1574 static int qcow2_reopen_prepare(BDRVReopenState
*state
,
1575 BlockReopenQueue
*queue
, Error
**errp
)
1577 Qcow2ReopenState
*r
;
1580 r
= g_new0(Qcow2ReopenState
, 1);
1583 ret
= qcow2_update_options_prepare(state
->bs
, r
, state
->options
,
1584 state
->flags
, errp
);
1589 /* We need to write out any unwritten data if we reopen read-only. */
1590 if ((state
->flags
& BDRV_O_RDWR
) == 0) {
1591 ret
= qcow2_reopen_bitmaps_ro(state
->bs
, errp
);
1596 ret
= bdrv_flush(state
->bs
);
1601 ret
= qcow2_mark_clean(state
->bs
);
1610 qcow2_update_options_abort(state
->bs
, r
);
1615 static void qcow2_reopen_commit(BDRVReopenState
*state
)
1617 qcow2_update_options_commit(state
->bs
, state
->opaque
);
1618 g_free(state
->opaque
);
1621 static void qcow2_reopen_abort(BDRVReopenState
*state
)
1623 qcow2_update_options_abort(state
->bs
, state
->opaque
);
1624 g_free(state
->opaque
);
1627 static void qcow2_join_options(QDict
*options
, QDict
*old_options
)
1629 bool has_new_overlap_template
=
1630 qdict_haskey(options
, QCOW2_OPT_OVERLAP
) ||
1631 qdict_haskey(options
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1632 bool has_new_total_cache_size
=
1633 qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
);
1634 bool has_all_cache_options
;
1636 /* New overlap template overrides all old overlap options */
1637 if (has_new_overlap_template
) {
1638 qdict_del(old_options
, QCOW2_OPT_OVERLAP
);
1639 qdict_del(old_options
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1640 qdict_del(old_options
, QCOW2_OPT_OVERLAP_MAIN_HEADER
);
1641 qdict_del(old_options
, QCOW2_OPT_OVERLAP_ACTIVE_L1
);
1642 qdict_del(old_options
, QCOW2_OPT_OVERLAP_ACTIVE_L2
);
1643 qdict_del(old_options
, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
);
1644 qdict_del(old_options
, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
);
1645 qdict_del(old_options
, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
);
1646 qdict_del(old_options
, QCOW2_OPT_OVERLAP_INACTIVE_L1
);
1647 qdict_del(old_options
, QCOW2_OPT_OVERLAP_INACTIVE_L2
);
1650 /* New total cache size overrides all old options */
1651 if (qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
)) {
1652 qdict_del(old_options
, QCOW2_OPT_L2_CACHE_SIZE
);
1653 qdict_del(old_options
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
1656 qdict_join(options
, old_options
, false);
1659 * If after merging all cache size options are set, an old total size is
1660 * overwritten. Do keep all options, however, if all three are new. The
1661 * resulting error message is what we want to happen.
1663 has_all_cache_options
=
1664 qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
) ||
1665 qdict_haskey(options
, QCOW2_OPT_L2_CACHE_SIZE
) ||
1666 qdict_haskey(options
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
1668 if (has_all_cache_options
&& !has_new_total_cache_size
) {
1669 qdict_del(options
, QCOW2_OPT_CACHE_SIZE
);
1673 static int64_t coroutine_fn
qcow2_co_get_block_status(BlockDriverState
*bs
,
1674 int64_t sector_num
, int nb_sectors
, int *pnum
, BlockDriverState
**file
)
1676 BDRVQcow2State
*s
= bs
->opaque
;
1677 uint64_t cluster_offset
;
1678 int index_in_cluster
, ret
;
1682 bytes
= MIN(INT_MAX
, nb_sectors
* BDRV_SECTOR_SIZE
);
1683 qemu_co_mutex_lock(&s
->lock
);
1684 ret
= qcow2_get_cluster_offset(bs
, sector_num
<< BDRV_SECTOR_BITS
, &bytes
,
1686 qemu_co_mutex_unlock(&s
->lock
);
1691 *pnum
= bytes
>> BDRV_SECTOR_BITS
;
1693 if (cluster_offset
!= 0 && ret
!= QCOW2_CLUSTER_COMPRESSED
&&
1695 index_in_cluster
= sector_num
& (s
->cluster_sectors
- 1);
1696 cluster_offset
|= (index_in_cluster
<< BDRV_SECTOR_BITS
);
1697 *file
= bs
->file
->bs
;
1698 status
|= BDRV_BLOCK_OFFSET_VALID
| cluster_offset
;
1700 if (ret
== QCOW2_CLUSTER_ZERO_PLAIN
|| ret
== QCOW2_CLUSTER_ZERO_ALLOC
) {
1701 status
|= BDRV_BLOCK_ZERO
;
1702 } else if (ret
!= QCOW2_CLUSTER_UNALLOCATED
) {
1703 status
|= BDRV_BLOCK_DATA
;
1708 static coroutine_fn
int qcow2_co_preadv(BlockDriverState
*bs
, uint64_t offset
,
1709 uint64_t bytes
, QEMUIOVector
*qiov
,
1712 BDRVQcow2State
*s
= bs
->opaque
;
1713 int offset_in_cluster
;
1715 unsigned int cur_bytes
; /* number of bytes in current iteration */
1716 uint64_t cluster_offset
= 0;
1717 uint64_t bytes_done
= 0;
1718 QEMUIOVector hd_qiov
;
1719 uint8_t *cluster_data
= NULL
;
1721 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
1723 qemu_co_mutex_lock(&s
->lock
);
1725 while (bytes
!= 0) {
1727 /* prepare next request */
1728 cur_bytes
= MIN(bytes
, INT_MAX
);
1730 cur_bytes
= MIN(cur_bytes
,
1731 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
1734 ret
= qcow2_get_cluster_offset(bs
, offset
, &cur_bytes
, &cluster_offset
);
1739 offset_in_cluster
= offset_into_cluster(s
, offset
);
1741 qemu_iovec_reset(&hd_qiov
);
1742 qemu_iovec_concat(&hd_qiov
, qiov
, bytes_done
, cur_bytes
);
1745 case QCOW2_CLUSTER_UNALLOCATED
:
1748 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_BACKING_AIO
);
1749 qemu_co_mutex_unlock(&s
->lock
);
1750 ret
= bdrv_co_preadv(bs
->backing
, offset
, cur_bytes
,
1752 qemu_co_mutex_lock(&s
->lock
);
1757 /* Note: in this case, no need to wait */
1758 qemu_iovec_memset(&hd_qiov
, 0, 0, cur_bytes
);
1762 case QCOW2_CLUSTER_ZERO_PLAIN
:
1763 case QCOW2_CLUSTER_ZERO_ALLOC
:
1764 qemu_iovec_memset(&hd_qiov
, 0, 0, cur_bytes
);
1767 case QCOW2_CLUSTER_COMPRESSED
:
1768 /* add AIO support for compressed blocks ? */
1769 ret
= qcow2_decompress_cluster(bs
, cluster_offset
);
1774 qemu_iovec_from_buf(&hd_qiov
, 0,
1775 s
->cluster_cache
+ offset_in_cluster
,
1779 case QCOW2_CLUSTER_NORMAL
:
1780 if ((cluster_offset
& 511) != 0) {
1785 if (bs
->encrypted
) {
1789 * For encrypted images, read everything into a temporary
1790 * contiguous buffer on which the AES functions can work.
1792 if (!cluster_data
) {
1794 qemu_try_blockalign(bs
->file
->bs
,
1795 QCOW_MAX_CRYPT_CLUSTERS
1797 if (cluster_data
== NULL
) {
1803 assert(cur_bytes
<= QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
1804 qemu_iovec_reset(&hd_qiov
);
1805 qemu_iovec_add(&hd_qiov
, cluster_data
, cur_bytes
);
1808 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
1809 qemu_co_mutex_unlock(&s
->lock
);
1810 ret
= bdrv_co_preadv(bs
->file
,
1811 cluster_offset
+ offset_in_cluster
,
1812 cur_bytes
, &hd_qiov
, 0);
1813 qemu_co_mutex_lock(&s
->lock
);
1817 if (bs
->encrypted
) {
1819 assert((offset
& (BDRV_SECTOR_SIZE
- 1)) == 0);
1820 assert((cur_bytes
& (BDRV_SECTOR_SIZE
- 1)) == 0);
1821 if (qcrypto_block_decrypt(s
->crypto
,
1822 (s
->crypt_physical_offset
?
1823 cluster_offset
+ offset_in_cluster
:
1831 qemu_iovec_from_buf(qiov
, bytes_done
, cluster_data
, cur_bytes
);
1836 g_assert_not_reached();
1842 offset
+= cur_bytes
;
1843 bytes_done
+= cur_bytes
;
1848 qemu_co_mutex_unlock(&s
->lock
);
1850 qemu_iovec_destroy(&hd_qiov
);
1851 qemu_vfree(cluster_data
);
1856 /* Check if it's possible to merge a write request with the writing of
1857 * the data from the COW regions */
1858 static bool merge_cow(uint64_t offset
, unsigned bytes
,
1859 QEMUIOVector
*hd_qiov
, QCowL2Meta
*l2meta
)
1863 for (m
= l2meta
; m
!= NULL
; m
= m
->next
) {
1864 /* If both COW regions are empty then there's nothing to merge */
1865 if (m
->cow_start
.nb_bytes
== 0 && m
->cow_end
.nb_bytes
== 0) {
1869 /* The data (middle) region must be immediately after the
1871 if (l2meta_cow_start(m
) + m
->cow_start
.nb_bytes
!= offset
) {
1875 /* The end region must be immediately after the data (middle)
1877 if (m
->offset
+ m
->cow_end
.offset
!= offset
+ bytes
) {
1881 /* Make sure that adding both COW regions to the QEMUIOVector
1882 * does not exceed IOV_MAX */
1883 if (hd_qiov
->niov
> IOV_MAX
- 2) {
1887 m
->data_qiov
= hd_qiov
;
1894 static coroutine_fn
int qcow2_co_pwritev(BlockDriverState
*bs
, uint64_t offset
,
1895 uint64_t bytes
, QEMUIOVector
*qiov
,
1898 BDRVQcow2State
*s
= bs
->opaque
;
1899 int offset_in_cluster
;
1901 unsigned int cur_bytes
; /* number of sectors in current iteration */
1902 uint64_t cluster_offset
;
1903 QEMUIOVector hd_qiov
;
1904 uint64_t bytes_done
= 0;
1905 uint8_t *cluster_data
= NULL
;
1906 QCowL2Meta
*l2meta
= NULL
;
1908 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset
, bytes
);
1910 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
1912 s
->cluster_cache_offset
= -1; /* disable compressed cache */
1914 qemu_co_mutex_lock(&s
->lock
);
1916 while (bytes
!= 0) {
1920 trace_qcow2_writev_start_part(qemu_coroutine_self());
1921 offset_in_cluster
= offset_into_cluster(s
, offset
);
1922 cur_bytes
= MIN(bytes
, INT_MAX
);
1923 if (bs
->encrypted
) {
1924 cur_bytes
= MIN(cur_bytes
,
1925 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
1926 - offset_in_cluster
);
1929 ret
= qcow2_alloc_cluster_offset(bs
, offset
, &cur_bytes
,
1930 &cluster_offset
, &l2meta
);
1935 assert((cluster_offset
& 511) == 0);
1937 qemu_iovec_reset(&hd_qiov
);
1938 qemu_iovec_concat(&hd_qiov
, qiov
, bytes_done
, cur_bytes
);
1940 if (bs
->encrypted
) {
1942 if (!cluster_data
) {
1943 cluster_data
= qemu_try_blockalign(bs
->file
->bs
,
1944 QCOW_MAX_CRYPT_CLUSTERS
1946 if (cluster_data
== NULL
) {
1952 assert(hd_qiov
.size
<=
1953 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
1954 qemu_iovec_to_buf(&hd_qiov
, 0, cluster_data
, hd_qiov
.size
);
1956 if (qcrypto_block_encrypt(s
->crypto
,
1957 (s
->crypt_physical_offset
?
1958 cluster_offset
+ offset_in_cluster
:
1961 cur_bytes
, NULL
) < 0) {
1966 qemu_iovec_reset(&hd_qiov
);
1967 qemu_iovec_add(&hd_qiov
, cluster_data
, cur_bytes
);
1970 ret
= qcow2_pre_write_overlap_check(bs
, 0,
1971 cluster_offset
+ offset_in_cluster
, cur_bytes
);
1976 /* If we need to do COW, check if it's possible to merge the
1977 * writing of the guest data together with that of the COW regions.
1978 * If it's not possible (or not necessary) then write the
1979 * guest data now. */
1980 if (!merge_cow(offset
, cur_bytes
, &hd_qiov
, l2meta
)) {
1981 qemu_co_mutex_unlock(&s
->lock
);
1982 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_AIO
);
1983 trace_qcow2_writev_data(qemu_coroutine_self(),
1984 cluster_offset
+ offset_in_cluster
);
1985 ret
= bdrv_co_pwritev(bs
->file
,
1986 cluster_offset
+ offset_in_cluster
,
1987 cur_bytes
, &hd_qiov
, 0);
1988 qemu_co_mutex_lock(&s
->lock
);
1994 while (l2meta
!= NULL
) {
1997 ret
= qcow2_alloc_cluster_link_l2(bs
, l2meta
);
2002 /* Take the request off the list of running requests */
2003 if (l2meta
->nb_clusters
!= 0) {
2004 QLIST_REMOVE(l2meta
, next_in_flight
);
2007 qemu_co_queue_restart_all(&l2meta
->dependent_requests
);
2009 next
= l2meta
->next
;
2015 offset
+= cur_bytes
;
2016 bytes_done
+= cur_bytes
;
2017 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes
);
2022 while (l2meta
!= NULL
) {
2025 if (l2meta
->nb_clusters
!= 0) {
2026 QLIST_REMOVE(l2meta
, next_in_flight
);
2028 qemu_co_queue_restart_all(&l2meta
->dependent_requests
);
2030 next
= l2meta
->next
;
2035 qemu_co_mutex_unlock(&s
->lock
);
2037 qemu_iovec_destroy(&hd_qiov
);
2038 qemu_vfree(cluster_data
);
2039 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret
);
2044 static int qcow2_inactivate(BlockDriverState
*bs
)
2046 BDRVQcow2State
*s
= bs
->opaque
;
2047 int ret
, result
= 0;
2048 Error
*local_err
= NULL
;
2050 qcow2_store_persistent_dirty_bitmaps(bs
, &local_err
);
2051 if (local_err
!= NULL
) {
2053 error_report_err(local_err
);
2054 error_report("Persistent bitmaps are lost for node '%s'",
2055 bdrv_get_device_or_node_name(bs
));
2058 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
2061 error_report("Failed to flush the L2 table cache: %s",
2065 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
2068 error_report("Failed to flush the refcount block cache: %s",
2073 qcow2_mark_clean(bs
);
2079 static void qcow2_close(BlockDriverState
*bs
)
2081 BDRVQcow2State
*s
= bs
->opaque
;
2082 qemu_vfree(s
->l1_table
);
2083 /* else pre-write overlap checks in cache_destroy may crash */
2086 if (!(s
->flags
& BDRV_O_INACTIVE
)) {
2087 qcow2_inactivate(bs
);
2090 cache_clean_timer_del(bs
);
2091 qcow2_cache_destroy(s
->l2_table_cache
);
2092 qcow2_cache_destroy(s
->refcount_block_cache
);
2094 qcrypto_block_free(s
->crypto
);
2097 g_free(s
->unknown_header_fields
);
2098 cleanup_unknown_header_ext(bs
);
2100 g_free(s
->image_backing_file
);
2101 g_free(s
->image_backing_format
);
2103 g_free(s
->cluster_cache
);
2104 qemu_vfree(s
->cluster_data
);
2105 qcow2_refcount_close(bs
);
2106 qcow2_free_snapshots(bs
);
2109 static void qcow2_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
2111 BDRVQcow2State
*s
= bs
->opaque
;
2112 int flags
= s
->flags
;
2113 QCryptoBlock
*crypto
= NULL
;
2115 Error
*local_err
= NULL
;
2119 * Backing files are read-only which makes all of their metadata immutable,
2120 * that means we don't have to worry about reopening them here.
2128 memset(s
, 0, sizeof(BDRVQcow2State
));
2129 options
= qdict_clone_shallow(bs
->options
);
2131 flags
&= ~BDRV_O_INACTIVE
;
2132 ret
= qcow2_do_open(bs
, options
, flags
, &local_err
);
2135 error_propagate(errp
, local_err
);
2136 error_prepend(errp
, "Could not reopen qcow2 layer: ");
2139 } else if (ret
< 0) {
2140 error_setg_errno(errp
, -ret
, "Could not reopen qcow2 layer");
2148 static size_t header_ext_add(char *buf
, uint32_t magic
, const void *s
,
2149 size_t len
, size_t buflen
)
2151 QCowExtension
*ext_backing_fmt
= (QCowExtension
*) buf
;
2152 size_t ext_len
= sizeof(QCowExtension
) + ((len
+ 7) & ~7);
2154 if (buflen
< ext_len
) {
2158 *ext_backing_fmt
= (QCowExtension
) {
2159 .magic
= cpu_to_be32(magic
),
2160 .len
= cpu_to_be32(len
),
2164 memcpy(buf
+ sizeof(QCowExtension
), s
, len
);
2171 * Updates the qcow2 header, including the variable length parts of it, i.e.
2172 * the backing file name and all extensions. qcow2 was not designed to allow
2173 * such changes, so if we run out of space (we can only use the first cluster)
2174 * this function may fail.
2176 * Returns 0 on success, -errno in error cases.
2178 int qcow2_update_header(BlockDriverState
*bs
)
2180 BDRVQcow2State
*s
= bs
->opaque
;
2183 size_t buflen
= s
->cluster_size
;
2185 uint64_t total_size
;
2186 uint32_t refcount_table_clusters
;
2187 size_t header_length
;
2188 Qcow2UnknownHeaderExtension
*uext
;
2190 buf
= qemu_blockalign(bs
, buflen
);
2192 /* Header structure */
2193 header
= (QCowHeader
*) buf
;
2195 if (buflen
< sizeof(*header
)) {
2200 header_length
= sizeof(*header
) + s
->unknown_header_fields_size
;
2201 total_size
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
2202 refcount_table_clusters
= s
->refcount_table_size
>> (s
->cluster_bits
- 3);
2204 *header
= (QCowHeader
) {
2205 /* Version 2 fields */
2206 .magic
= cpu_to_be32(QCOW_MAGIC
),
2207 .version
= cpu_to_be32(s
->qcow_version
),
2208 .backing_file_offset
= 0,
2209 .backing_file_size
= 0,
2210 .cluster_bits
= cpu_to_be32(s
->cluster_bits
),
2211 .size
= cpu_to_be64(total_size
),
2212 .crypt_method
= cpu_to_be32(s
->crypt_method_header
),
2213 .l1_size
= cpu_to_be32(s
->l1_size
),
2214 .l1_table_offset
= cpu_to_be64(s
->l1_table_offset
),
2215 .refcount_table_offset
= cpu_to_be64(s
->refcount_table_offset
),
2216 .refcount_table_clusters
= cpu_to_be32(refcount_table_clusters
),
2217 .nb_snapshots
= cpu_to_be32(s
->nb_snapshots
),
2218 .snapshots_offset
= cpu_to_be64(s
->snapshots_offset
),
2220 /* Version 3 fields */
2221 .incompatible_features
= cpu_to_be64(s
->incompatible_features
),
2222 .compatible_features
= cpu_to_be64(s
->compatible_features
),
2223 .autoclear_features
= cpu_to_be64(s
->autoclear_features
),
2224 .refcount_order
= cpu_to_be32(s
->refcount_order
),
2225 .header_length
= cpu_to_be32(header_length
),
2228 /* For older versions, write a shorter header */
2229 switch (s
->qcow_version
) {
2231 ret
= offsetof(QCowHeader
, incompatible_features
);
2234 ret
= sizeof(*header
);
2243 memset(buf
, 0, buflen
);
2245 /* Preserve any unknown field in the header */
2246 if (s
->unknown_header_fields_size
) {
2247 if (buflen
< s
->unknown_header_fields_size
) {
2252 memcpy(buf
, s
->unknown_header_fields
, s
->unknown_header_fields_size
);
2253 buf
+= s
->unknown_header_fields_size
;
2254 buflen
-= s
->unknown_header_fields_size
;
2257 /* Backing file format header extension */
2258 if (s
->image_backing_format
) {
2259 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_BACKING_FORMAT
,
2260 s
->image_backing_format
,
2261 strlen(s
->image_backing_format
),
2271 /* Full disk encryption header pointer extension */
2272 if (s
->crypto_header
.offset
!= 0) {
2273 cpu_to_be64s(&s
->crypto_header
.offset
);
2274 cpu_to_be64s(&s
->crypto_header
.length
);
2275 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_CRYPTO_HEADER
,
2276 &s
->crypto_header
, sizeof(s
->crypto_header
),
2278 be64_to_cpus(&s
->crypto_header
.offset
);
2279 be64_to_cpus(&s
->crypto_header
.length
);
2288 if (s
->qcow_version
>= 3) {
2289 Qcow2Feature features
[] = {
2291 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2292 .bit
= QCOW2_INCOMPAT_DIRTY_BITNR
,
2293 .name
= "dirty bit",
2296 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2297 .bit
= QCOW2_INCOMPAT_CORRUPT_BITNR
,
2298 .name
= "corrupt bit",
2301 .type
= QCOW2_FEAT_TYPE_COMPATIBLE
,
2302 .bit
= QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR
,
2303 .name
= "lazy refcounts",
2307 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_FEATURE_TABLE
,
2308 features
, sizeof(features
), buflen
);
2316 /* Bitmap extension */
2317 if (s
->nb_bitmaps
> 0) {
2318 Qcow2BitmapHeaderExt bitmaps_header
= {
2319 .nb_bitmaps
= cpu_to_be32(s
->nb_bitmaps
),
2320 .bitmap_directory_size
=
2321 cpu_to_be64(s
->bitmap_directory_size
),
2322 .bitmap_directory_offset
=
2323 cpu_to_be64(s
->bitmap_directory_offset
)
2325 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_BITMAPS
,
2326 &bitmaps_header
, sizeof(bitmaps_header
),
2335 /* Keep unknown header extensions */
2336 QLIST_FOREACH(uext
, &s
->unknown_header_ext
, next
) {
2337 ret
= header_ext_add(buf
, uext
->magic
, uext
->data
, uext
->len
, buflen
);
2346 /* End of header extensions */
2347 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_END
, NULL
, 0, buflen
);
2355 /* Backing file name */
2356 if (s
->image_backing_file
) {
2357 size_t backing_file_len
= strlen(s
->image_backing_file
);
2359 if (buflen
< backing_file_len
) {
2364 /* Using strncpy is ok here, since buf is not NUL-terminated. */
2365 strncpy(buf
, s
->image_backing_file
, buflen
);
2367 header
->backing_file_offset
= cpu_to_be64(buf
- ((char*) header
));
2368 header
->backing_file_size
= cpu_to_be32(backing_file_len
);
2371 /* Write the new header */
2372 ret
= bdrv_pwrite(bs
->file
, 0, header
, s
->cluster_size
);
2383 static int qcow2_change_backing_file(BlockDriverState
*bs
,
2384 const char *backing_file
, const char *backing_fmt
)
2386 BDRVQcow2State
*s
= bs
->opaque
;
2388 if (backing_file
&& strlen(backing_file
) > 1023) {
2392 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2393 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2395 g_free(s
->image_backing_file
);
2396 g_free(s
->image_backing_format
);
2398 s
->image_backing_file
= backing_file
? g_strdup(bs
->backing_file
) : NULL
;
2399 s
->image_backing_format
= backing_fmt
? g_strdup(bs
->backing_format
) : NULL
;
2401 return qcow2_update_header(bs
);
2404 static int qcow2_crypt_method_from_format(const char *encryptfmt
)
2406 if (g_str_equal(encryptfmt
, "luks")) {
2407 return QCOW_CRYPT_LUKS
;
2408 } else if (g_str_equal(encryptfmt
, "aes")) {
2409 return QCOW_CRYPT_AES
;
2415 static int qcow2_set_up_encryption(BlockDriverState
*bs
, const char *encryptfmt
,
2416 QemuOpts
*opts
, Error
**errp
)
2418 BDRVQcow2State
*s
= bs
->opaque
;
2419 QCryptoBlockCreateOptions
*cryptoopts
= NULL
;
2420 QCryptoBlock
*crypto
= NULL
;
2422 QDict
*options
, *encryptopts
;
2425 options
= qemu_opts_to_qdict(opts
, NULL
);
2426 qdict_extract_subqdict(options
, &encryptopts
, "encrypt.");
2429 fmt
= qcow2_crypt_method_from_format(encryptfmt
);
2432 case QCOW_CRYPT_LUKS
:
2433 cryptoopts
= block_crypto_create_opts_init(
2434 Q_CRYPTO_BLOCK_FORMAT_LUKS
, encryptopts
, errp
);
2436 case QCOW_CRYPT_AES
:
2437 cryptoopts
= block_crypto_create_opts_init(
2438 Q_CRYPTO_BLOCK_FORMAT_QCOW
, encryptopts
, errp
);
2441 error_setg(errp
, "Unknown encryption format '%s'", encryptfmt
);
2448 s
->crypt_method_header
= fmt
;
2450 crypto
= qcrypto_block_create(cryptoopts
, "encrypt.",
2451 qcow2_crypto_hdr_init_func
,
2452 qcow2_crypto_hdr_write_func
,
2459 ret
= qcow2_update_header(bs
);
2461 error_setg_errno(errp
, -ret
, "Could not write encryption header");
2466 QDECREF(encryptopts
);
2467 qcrypto_block_free(crypto
);
2468 qapi_free_QCryptoBlockCreateOptions(cryptoopts
);
2473 typedef struct PreallocCo
{
2474 BlockDriverState
*bs
;
2476 uint64_t new_length
;
2482 * Preallocates metadata structures for data clusters between @offset (in the
2483 * guest disk) and @new_length (which is thus generally the new guest disk
2486 * Returns: 0 on success, -errno on failure.
2488 static void coroutine_fn
preallocate_co(void *opaque
)
2490 PreallocCo
*params
= opaque
;
2491 BlockDriverState
*bs
= params
->bs
;
2492 uint64_t offset
= params
->offset
;
2493 uint64_t new_length
= params
->new_length
;
2494 BDRVQcow2State
*s
= bs
->opaque
;
2496 uint64_t host_offset
= 0;
2497 unsigned int cur_bytes
;
2501 qemu_co_mutex_lock(&s
->lock
);
2503 assert(offset
<= new_length
);
2504 bytes
= new_length
- offset
;
2507 cur_bytes
= MIN(bytes
, INT_MAX
);
2508 ret
= qcow2_alloc_cluster_offset(bs
, offset
, &cur_bytes
,
2509 &host_offset
, &meta
);
2515 QCowL2Meta
*next
= meta
->next
;
2517 ret
= qcow2_alloc_cluster_link_l2(bs
, meta
);
2519 qcow2_free_any_clusters(bs
, meta
->alloc_offset
,
2520 meta
->nb_clusters
, QCOW2_DISCARD_NEVER
);
2524 /* There are no dependent requests, but we need to remove our
2525 * request from the list of in-flight requests */
2526 QLIST_REMOVE(meta
, next_in_flight
);
2532 /* TODO Preallocate data if requested */
2535 offset
+= cur_bytes
;
2539 * It is expected that the image file is large enough to actually contain
2540 * all of the allocated clusters (otherwise we get failing reads after
2541 * EOF). Extend the image to the last allocated sector.
2543 if (host_offset
!= 0) {
2545 ret
= bdrv_pwrite(bs
->file
, (host_offset
+ cur_bytes
) - 1,
2555 qemu_co_mutex_unlock(&s
->lock
);
2559 static int preallocate(BlockDriverState
*bs
,
2560 uint64_t offset
, uint64_t new_length
)
2562 PreallocCo params
= {
2565 .new_length
= new_length
,
2566 .ret
= -EINPROGRESS
,
2569 if (qemu_in_coroutine()) {
2570 preallocate_co(¶ms
);
2572 Coroutine
*co
= qemu_coroutine_create(preallocate_co
, ¶ms
);
2573 bdrv_coroutine_enter(bs
, co
);
2574 BDRV_POLL_WHILE(bs
, params
.ret
== -EINPROGRESS
);
2579 /* qcow2_refcount_metadata_size:
2580 * @clusters: number of clusters to refcount (including data and L1/L2 tables)
2581 * @cluster_size: size of a cluster, in bytes
2582 * @refcount_order: refcount bits power-of-2 exponent
2583 * @generous_increase: allow for the refcount table to be 1.5x as large as it
2586 * Returns: Number of bytes required for refcount blocks and table metadata.
2588 int64_t qcow2_refcount_metadata_size(int64_t clusters
, size_t cluster_size
,
2589 int refcount_order
, bool generous_increase
,
2590 uint64_t *refblock_count
)
2593 * Every host cluster is reference-counted, including metadata (even
2594 * refcount metadata is recursively included).
2596 * An accurate formula for the size of refcount metadata size is difficult
2597 * to derive. An easier method of calculation is finding the fixed point
2598 * where no further refcount blocks or table clusters are required to
2599 * reference count every cluster.
2601 int64_t blocks_per_table_cluster
= cluster_size
/ sizeof(uint64_t);
2602 int64_t refcounts_per_block
= cluster_size
* 8 / (1 << refcount_order
);
2603 int64_t table
= 0; /* number of refcount table clusters */
2604 int64_t blocks
= 0; /* number of refcount block clusters */
2610 blocks
= DIV_ROUND_UP(clusters
+ table
+ blocks
, refcounts_per_block
);
2611 table
= DIV_ROUND_UP(blocks
, blocks_per_table_cluster
);
2612 n
= clusters
+ blocks
+ table
;
2614 if (n
== last
&& generous_increase
) {
2615 clusters
+= DIV_ROUND_UP(table
, 2);
2616 n
= 0; /* force another loop */
2617 generous_increase
= false;
2619 } while (n
!= last
);
2621 if (refblock_count
) {
2622 *refblock_count
= blocks
;
2625 return (blocks
+ table
) * cluster_size
;
2629 * qcow2_calc_prealloc_size:
2630 * @total_size: virtual disk size in bytes
2631 * @cluster_size: cluster size in bytes
2632 * @refcount_order: refcount bits power-of-2 exponent
2634 * Returns: Total number of bytes required for the fully allocated image
2635 * (including metadata).
2637 static int64_t qcow2_calc_prealloc_size(int64_t total_size
,
2638 size_t cluster_size
,
2641 int64_t meta_size
= 0;
2642 uint64_t nl1e
, nl2e
;
2643 int64_t aligned_total_size
= align_offset(total_size
, cluster_size
);
2645 /* header: 1 cluster */
2646 meta_size
+= cluster_size
;
2648 /* total size of L2 tables */
2649 nl2e
= aligned_total_size
/ cluster_size
;
2650 nl2e
= align_offset(nl2e
, cluster_size
/ sizeof(uint64_t));
2651 meta_size
+= nl2e
* sizeof(uint64_t);
2653 /* total size of L1 tables */
2654 nl1e
= nl2e
* sizeof(uint64_t) / cluster_size
;
2655 nl1e
= align_offset(nl1e
, cluster_size
/ sizeof(uint64_t));
2656 meta_size
+= nl1e
* sizeof(uint64_t);
2658 /* total size of refcount table and blocks */
2659 meta_size
+= qcow2_refcount_metadata_size(
2660 (meta_size
+ aligned_total_size
) / cluster_size
,
2661 cluster_size
, refcount_order
, false, NULL
);
2663 return meta_size
+ aligned_total_size
;
2666 static size_t qcow2_opt_get_cluster_size_del(QemuOpts
*opts
, Error
**errp
)
2668 size_t cluster_size
;
2671 cluster_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_CLUSTER_SIZE
,
2672 DEFAULT_CLUSTER_SIZE
);
2673 cluster_bits
= ctz32(cluster_size
);
2674 if (cluster_bits
< MIN_CLUSTER_BITS
|| cluster_bits
> MAX_CLUSTER_BITS
||
2675 (1 << cluster_bits
) != cluster_size
)
2677 error_setg(errp
, "Cluster size must be a power of two between %d and "
2678 "%dk", 1 << MIN_CLUSTER_BITS
, 1 << (MAX_CLUSTER_BITS
- 10));
2681 return cluster_size
;
2684 static int qcow2_opt_get_version_del(QemuOpts
*opts
, Error
**errp
)
2689 buf
= qemu_opt_get_del(opts
, BLOCK_OPT_COMPAT_LEVEL
);
2691 ret
= 3; /* default */
2692 } else if (!strcmp(buf
, "0.10")) {
2694 } else if (!strcmp(buf
, "1.1")) {
2697 error_setg(errp
, "Invalid compatibility level: '%s'", buf
);
2704 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts
*opts
, int version
,
2707 uint64_t refcount_bits
;
2709 refcount_bits
= qemu_opt_get_number_del(opts
, BLOCK_OPT_REFCOUNT_BITS
, 16);
2710 if (refcount_bits
> 64 || !is_power_of_2(refcount_bits
)) {
2711 error_setg(errp
, "Refcount width must be a power of two and may not "
2716 if (version
< 3 && refcount_bits
!= 16) {
2717 error_setg(errp
, "Different refcount widths than 16 bits require "
2718 "compatibility level 1.1 or above (use compat=1.1 or "
2723 return refcount_bits
;
2726 static int qcow2_create2(const char *filename
, int64_t total_size
,
2727 const char *backing_file
, const char *backing_format
,
2728 int flags
, size_t cluster_size
, PreallocMode prealloc
,
2729 QemuOpts
*opts
, int version
, int refcount_order
,
2730 const char *encryptfmt
, Error
**errp
)
2735 * Open the image file and write a minimal qcow2 header.
2737 * We keep things simple and start with a zero-sized image. We also
2738 * do without refcount blocks or a L1 table for now. We'll fix the
2739 * inconsistency later.
2741 * We do need a refcount table because growing the refcount table means
2742 * allocating two new refcount blocks - the seconds of which would be at
2743 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
2744 * size for any qcow2 image.
2748 uint64_t* refcount_table
;
2749 Error
*local_err
= NULL
;
2752 if (prealloc
== PREALLOC_MODE_FULL
|| prealloc
== PREALLOC_MODE_FALLOC
) {
2753 int64_t prealloc_size
=
2754 qcow2_calc_prealloc_size(total_size
, cluster_size
, refcount_order
);
2755 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
, prealloc_size
, &error_abort
);
2756 qemu_opt_set(opts
, BLOCK_OPT_PREALLOC
, PreallocMode_str(prealloc
),
2760 ret
= bdrv_create_file(filename
, opts
, &local_err
);
2762 error_propagate(errp
, local_err
);
2766 blk
= blk_new_open(filename
, NULL
, NULL
,
2767 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_PROTOCOL
,
2770 error_propagate(errp
, local_err
);
2774 blk_set_allow_write_beyond_eof(blk
, true);
2776 /* Write the header */
2777 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS
) < sizeof(*header
));
2778 header
= g_malloc0(cluster_size
);
2779 *header
= (QCowHeader
) {
2780 .magic
= cpu_to_be32(QCOW_MAGIC
),
2781 .version
= cpu_to_be32(version
),
2782 .cluster_bits
= cpu_to_be32(ctz32(cluster_size
)),
2783 .size
= cpu_to_be64(0),
2784 .l1_table_offset
= cpu_to_be64(0),
2785 .l1_size
= cpu_to_be32(0),
2786 .refcount_table_offset
= cpu_to_be64(cluster_size
),
2787 .refcount_table_clusters
= cpu_to_be32(1),
2788 .refcount_order
= cpu_to_be32(refcount_order
),
2789 .header_length
= cpu_to_be32(sizeof(*header
)),
2792 /* We'll update this to correct value later */
2793 header
->crypt_method
= cpu_to_be32(QCOW_CRYPT_NONE
);
2795 if (flags
& BLOCK_FLAG_LAZY_REFCOUNTS
) {
2796 header
->compatible_features
|=
2797 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS
);
2800 ret
= blk_pwrite(blk
, 0, header
, cluster_size
, 0);
2803 error_setg_errno(errp
, -ret
, "Could not write qcow2 header");
2807 /* Write a refcount table with one refcount block */
2808 refcount_table
= g_malloc0(2 * cluster_size
);
2809 refcount_table
[0] = cpu_to_be64(2 * cluster_size
);
2810 ret
= blk_pwrite(blk
, cluster_size
, refcount_table
, 2 * cluster_size
, 0);
2811 g_free(refcount_table
);
2814 error_setg_errno(errp
, -ret
, "Could not write refcount table");
2822 * And now open the image and make it consistent first (i.e. increase the
2823 * refcount of the cluster that is occupied by the header and the refcount
2826 options
= qdict_new();
2827 qdict_put_str(options
, "driver", "qcow2");
2828 blk
= blk_new_open(filename
, NULL
, options
,
2829 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_NO_FLUSH
,
2832 error_propagate(errp
, local_err
);
2837 ret
= qcow2_alloc_clusters(blk_bs(blk
), 3 * cluster_size
);
2839 error_setg_errno(errp
, -ret
, "Could not allocate clusters for qcow2 "
2840 "header and refcount table");
2843 } else if (ret
!= 0) {
2844 error_report("Huh, first cluster in empty image is already in use?");
2848 /* Create a full header (including things like feature table) */
2849 ret
= qcow2_update_header(blk_bs(blk
));
2851 error_setg_errno(errp
, -ret
, "Could not update qcow2 header");
2855 /* Okay, now that we have a valid image, let's give it the right size */
2856 ret
= blk_truncate(blk
, total_size
, PREALLOC_MODE_OFF
, errp
);
2858 error_prepend(errp
, "Could not resize image: ");
2862 /* Want a backing file? There you go.*/
2864 ret
= bdrv_change_backing_file(blk_bs(blk
), backing_file
, backing_format
);
2866 error_setg_errno(errp
, -ret
, "Could not assign backing file '%s' "
2867 "with format '%s'", backing_file
, backing_format
);
2872 /* Want encryption? There you go. */
2874 ret
= qcow2_set_up_encryption(blk_bs(blk
), encryptfmt
, opts
, errp
);
2880 /* And if we're supposed to preallocate metadata, do that now */
2881 if (prealloc
!= PREALLOC_MODE_OFF
) {
2882 ret
= preallocate(blk_bs(blk
), 0, total_size
);
2884 error_setg_errno(errp
, -ret
, "Could not preallocate metadata");
2892 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning.
2893 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to
2894 * have to setup decryption context. We're not doing any I/O on the top
2895 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does
2898 options
= qdict_new();
2899 qdict_put_str(options
, "driver", "qcow2");
2900 blk
= blk_new_open(filename
, NULL
, options
,
2901 BDRV_O_RDWR
| BDRV_O_NO_BACKING
| BDRV_O_NO_IO
,
2904 error_propagate(errp
, local_err
);
2917 static int qcow2_create(const char *filename
, QemuOpts
*opts
, Error
**errp
)
2919 char *backing_file
= NULL
;
2920 char *backing_fmt
= NULL
;
2924 size_t cluster_size
= DEFAULT_CLUSTER_SIZE
;
2925 PreallocMode prealloc
;
2927 uint64_t refcount_bits
;
2929 char *encryptfmt
= NULL
;
2930 Error
*local_err
= NULL
;
2933 /* Read out options */
2934 size
= ROUND_UP(qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0),
2936 backing_file
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
2937 backing_fmt
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FMT
);
2938 encryptfmt
= qemu_opt_get_del(opts
, BLOCK_OPT_ENCRYPT_FORMAT
);
2940 if (qemu_opt_get(opts
, BLOCK_OPT_ENCRYPT
)) {
2941 error_setg(errp
, "Options " BLOCK_OPT_ENCRYPT
" and "
2942 BLOCK_OPT_ENCRYPT_FORMAT
" are mutually exclusive");
2946 } else if (qemu_opt_get_bool_del(opts
, BLOCK_OPT_ENCRYPT
, false)) {
2947 encryptfmt
= g_strdup("aes");
2949 cluster_size
= qcow2_opt_get_cluster_size_del(opts
, &local_err
);
2951 error_propagate(errp
, local_err
);
2955 buf
= qemu_opt_get_del(opts
, BLOCK_OPT_PREALLOC
);
2956 prealloc
= qapi_enum_parse(&PreallocMode_lookup
, buf
,
2957 PREALLOC_MODE_OFF
, &local_err
);
2959 error_propagate(errp
, local_err
);
2964 version
= qcow2_opt_get_version_del(opts
, &local_err
);
2966 error_propagate(errp
, local_err
);
2971 if (qemu_opt_get_bool_del(opts
, BLOCK_OPT_LAZY_REFCOUNTS
, false)) {
2972 flags
|= BLOCK_FLAG_LAZY_REFCOUNTS
;
2975 if (backing_file
&& prealloc
!= PREALLOC_MODE_OFF
) {
2976 error_setg(errp
, "Backing file and preallocation cannot be used at "
2982 if (version
< 3 && (flags
& BLOCK_FLAG_LAZY_REFCOUNTS
)) {
2983 error_setg(errp
, "Lazy refcounts only supported with compatibility "
2984 "level 1.1 and above (use compat=1.1 or greater)");
2989 refcount_bits
= qcow2_opt_get_refcount_bits_del(opts
, version
, &local_err
);
2991 error_propagate(errp
, local_err
);
2996 refcount_order
= ctz32(refcount_bits
);
2998 ret
= qcow2_create2(filename
, size
, backing_file
, backing_fmt
, flags
,
2999 cluster_size
, prealloc
, opts
, version
, refcount_order
,
3000 encryptfmt
, &local_err
);
3001 error_propagate(errp
, local_err
);
3004 g_free(backing_file
);
3005 g_free(backing_fmt
);
3012 static bool is_zero(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
)
3017 /* Clamp to image length, before checking status of underlying sectors */
3018 if (offset
+ bytes
> bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3019 bytes
= bs
->total_sectors
* BDRV_SECTOR_SIZE
- offset
;
3025 res
= bdrv_block_status_above(bs
, NULL
, offset
, bytes
, &nr
, NULL
, NULL
);
3026 return res
>= 0 && (res
& BDRV_BLOCK_ZERO
) && nr
== bytes
;
3029 static coroutine_fn
int qcow2_co_pwrite_zeroes(BlockDriverState
*bs
,
3030 int64_t offset
, int bytes
, BdrvRequestFlags flags
)
3033 BDRVQcow2State
*s
= bs
->opaque
;
3035 uint32_t head
= offset
% s
->cluster_size
;
3036 uint32_t tail
= (offset
+ bytes
) % s
->cluster_size
;
3038 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset
, bytes
);
3039 if (offset
+ bytes
== bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3047 assert(head
+ bytes
<= s
->cluster_size
);
3049 /* check whether remainder of cluster already reads as zero */
3050 if (!(is_zero(bs
, offset
- head
, head
) &&
3051 is_zero(bs
, offset
+ bytes
,
3052 tail
? s
->cluster_size
- tail
: 0))) {
3056 qemu_co_mutex_lock(&s
->lock
);
3057 /* We can have new write after previous check */
3058 offset
= QEMU_ALIGN_DOWN(offset
, s
->cluster_size
);
3059 bytes
= s
->cluster_size
;
3060 nr
= s
->cluster_size
;
3061 ret
= qcow2_get_cluster_offset(bs
, offset
, &nr
, &off
);
3062 if (ret
!= QCOW2_CLUSTER_UNALLOCATED
&&
3063 ret
!= QCOW2_CLUSTER_ZERO_PLAIN
&&
3064 ret
!= QCOW2_CLUSTER_ZERO_ALLOC
) {
3065 qemu_co_mutex_unlock(&s
->lock
);
3069 qemu_co_mutex_lock(&s
->lock
);
3072 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset
, bytes
);
3074 /* Whatever is left can use real zero clusters */
3075 ret
= qcow2_cluster_zeroize(bs
, offset
, bytes
, flags
);
3076 qemu_co_mutex_unlock(&s
->lock
);
3081 static coroutine_fn
int qcow2_co_pdiscard(BlockDriverState
*bs
,
3082 int64_t offset
, int bytes
)
3085 BDRVQcow2State
*s
= bs
->opaque
;
3087 if (!QEMU_IS_ALIGNED(offset
| bytes
, s
->cluster_size
)) {
3088 assert(bytes
< s
->cluster_size
);
3089 /* Ignore partial clusters, except for the special case of the
3090 * complete partial cluster at the end of an unaligned file */
3091 if (!QEMU_IS_ALIGNED(offset
, s
->cluster_size
) ||
3092 offset
+ bytes
!= bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3097 qemu_co_mutex_lock(&s
->lock
);
3098 ret
= qcow2_cluster_discard(bs
, offset
, bytes
, QCOW2_DISCARD_REQUEST
,
3100 qemu_co_mutex_unlock(&s
->lock
);
3104 static int qcow2_truncate(BlockDriverState
*bs
, int64_t offset
,
3105 PreallocMode prealloc
, Error
**errp
)
3107 BDRVQcow2State
*s
= bs
->opaque
;
3108 uint64_t old_length
;
3109 int64_t new_l1_size
;
3112 if (prealloc
!= PREALLOC_MODE_OFF
&& prealloc
!= PREALLOC_MODE_METADATA
&&
3113 prealloc
!= PREALLOC_MODE_FALLOC
&& prealloc
!= PREALLOC_MODE_FULL
)
3115 error_setg(errp
, "Unsupported preallocation mode '%s'",
3116 PreallocMode_str(prealloc
));
3121 error_setg(errp
, "The new size must be a multiple of 512");
3125 /* cannot proceed if image has snapshots */
3126 if (s
->nb_snapshots
) {
3127 error_setg(errp
, "Can't resize an image which has snapshots");
3131 /* cannot proceed if image has bitmaps */
3132 if (s
->nb_bitmaps
) {
3133 /* TODO: resize bitmaps in the image */
3134 error_setg(errp
, "Can't resize an image which has bitmaps");
3138 old_length
= bs
->total_sectors
* 512;
3139 new_l1_size
= size_to_l1(s
, offset
);
3141 if (offset
< old_length
) {
3142 int64_t last_cluster
, old_file_size
;
3143 if (prealloc
!= PREALLOC_MODE_OFF
) {
3145 "Preallocation can't be used for shrinking an image");
3149 ret
= qcow2_cluster_discard(bs
, ROUND_UP(offset
, s
->cluster_size
),
3150 old_length
- ROUND_UP(offset
,
3152 QCOW2_DISCARD_ALWAYS
, true);
3154 error_setg_errno(errp
, -ret
, "Failed to discard cropped clusters");
3158 ret
= qcow2_shrink_l1_table(bs
, new_l1_size
);
3160 error_setg_errno(errp
, -ret
,
3161 "Failed to reduce the number of L2 tables");
3165 ret
= qcow2_shrink_reftable(bs
);
3167 error_setg_errno(errp
, -ret
,
3168 "Failed to discard unused refblocks");
3172 old_file_size
= bdrv_getlength(bs
->file
->bs
);
3173 if (old_file_size
< 0) {
3174 error_setg_errno(errp
, -old_file_size
,
3175 "Failed to inquire current file length");
3176 return old_file_size
;
3178 last_cluster
= qcow2_get_last_cluster(bs
, old_file_size
);
3179 if (last_cluster
< 0) {
3180 error_setg_errno(errp
, -last_cluster
,
3181 "Failed to find the last cluster");
3182 return last_cluster
;
3184 if ((last_cluster
+ 1) * s
->cluster_size
< old_file_size
) {
3185 Error
*local_err
= NULL
;
3187 bdrv_truncate(bs
->file
, (last_cluster
+ 1) * s
->cluster_size
,
3188 PREALLOC_MODE_OFF
, &local_err
);
3190 warn_reportf_err(local_err
,
3191 "Failed to truncate the tail of the image: ");
3195 ret
= qcow2_grow_l1_table(bs
, new_l1_size
, true);
3197 error_setg_errno(errp
, -ret
, "Failed to grow the L1 table");
3203 case PREALLOC_MODE_OFF
:
3206 case PREALLOC_MODE_METADATA
:
3207 ret
= preallocate(bs
, old_length
, offset
);
3209 error_setg_errno(errp
, -ret
, "Preallocation failed");
3214 case PREALLOC_MODE_FALLOC
:
3215 case PREALLOC_MODE_FULL
:
3217 int64_t allocation_start
, host_offset
, guest_offset
;
3218 int64_t clusters_allocated
;
3219 int64_t old_file_size
, new_file_size
;
3220 uint64_t nb_new_data_clusters
, nb_new_l2_tables
;
3222 old_file_size
= bdrv_getlength(bs
->file
->bs
);
3223 if (old_file_size
< 0) {
3224 error_setg_errno(errp
, -old_file_size
,
3225 "Failed to inquire current file length");
3226 return old_file_size
;
3228 old_file_size
= ROUND_UP(old_file_size
, s
->cluster_size
);
3230 nb_new_data_clusters
= DIV_ROUND_UP(offset
- old_length
,
3233 /* This is an overestimation; we will not actually allocate space for
3234 * these in the file but just make sure the new refcount structures are
3235 * able to cover them so we will not have to allocate new refblocks
3236 * while entering the data blocks in the potentially new L2 tables.
3237 * (We do not actually care where the L2 tables are placed. Maybe they
3238 * are already allocated or they can be placed somewhere before
3239 * @old_file_size. It does not matter because they will be fully
3240 * allocated automatically, so they do not need to be covered by the
3241 * preallocation. All that matters is that we will not have to allocate
3242 * new refcount structures for them.) */
3243 nb_new_l2_tables
= DIV_ROUND_UP(nb_new_data_clusters
,
3244 s
->cluster_size
/ sizeof(uint64_t));
3245 /* The cluster range may not be aligned to L2 boundaries, so add one L2
3246 * table for a potential head/tail */
3249 allocation_start
= qcow2_refcount_area(bs
, old_file_size
,
3250 nb_new_data_clusters
+
3253 if (allocation_start
< 0) {
3254 error_setg_errno(errp
, -allocation_start
,
3255 "Failed to resize refcount structures");
3256 return allocation_start
;
3259 clusters_allocated
= qcow2_alloc_clusters_at(bs
, allocation_start
,
3260 nb_new_data_clusters
);
3261 if (clusters_allocated
< 0) {
3262 error_setg_errno(errp
, -clusters_allocated
,
3263 "Failed to allocate data clusters");
3264 return -clusters_allocated
;
3267 assert(clusters_allocated
== nb_new_data_clusters
);
3269 /* Allocate the data area */
3270 new_file_size
= allocation_start
+
3271 nb_new_data_clusters
* s
->cluster_size
;
3272 ret
= bdrv_truncate(bs
->file
, new_file_size
, prealloc
, errp
);
3274 error_prepend(errp
, "Failed to resize underlying file: ");
3275 qcow2_free_clusters(bs
, allocation_start
,
3276 nb_new_data_clusters
* s
->cluster_size
,
3277 QCOW2_DISCARD_OTHER
);
3281 /* Create the necessary L2 entries */
3282 host_offset
= allocation_start
;
3283 guest_offset
= old_length
;
3284 while (nb_new_data_clusters
) {
3285 int64_t nb_clusters
= MIN(
3286 nb_new_data_clusters
,
3287 s
->l2_slice_size
- offset_to_l2_slice_index(s
, guest_offset
));
3288 QCowL2Meta allocation
= {
3289 .offset
= guest_offset
,
3290 .alloc_offset
= host_offset
,
3291 .nb_clusters
= nb_clusters
,
3293 qemu_co_queue_init(&allocation
.dependent_requests
);
3295 ret
= qcow2_alloc_cluster_link_l2(bs
, &allocation
);
3297 error_setg_errno(errp
, -ret
, "Failed to update L2 tables");
3298 qcow2_free_clusters(bs
, host_offset
,
3299 nb_new_data_clusters
* s
->cluster_size
,
3300 QCOW2_DISCARD_OTHER
);
3304 guest_offset
+= nb_clusters
* s
->cluster_size
;
3305 host_offset
+= nb_clusters
* s
->cluster_size
;
3306 nb_new_data_clusters
-= nb_clusters
;
3312 g_assert_not_reached();
3315 if (prealloc
!= PREALLOC_MODE_OFF
) {
3316 /* Flush metadata before actually changing the image size */
3317 ret
= bdrv_flush(bs
);
3319 error_setg_errno(errp
, -ret
,
3320 "Failed to flush the preallocated area to disk");
3325 /* write updated header.size */
3326 offset
= cpu_to_be64(offset
);
3327 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, size
),
3328 &offset
, sizeof(uint64_t));
3330 error_setg_errno(errp
, -ret
, "Failed to update the image size");
3334 s
->l1_vm_state_index
= new_l1_size
;
3338 /* XXX: put compressed sectors first, then all the cluster aligned
3339 tables to avoid losing bytes in alignment */
3340 static coroutine_fn
int
3341 qcow2_co_pwritev_compressed(BlockDriverState
*bs
, uint64_t offset
,
3342 uint64_t bytes
, QEMUIOVector
*qiov
)
3344 BDRVQcow2State
*s
= bs
->opaque
;
3345 QEMUIOVector hd_qiov
;
3349 uint8_t *buf
, *out_buf
;
3350 int64_t cluster_offset
;
3353 /* align end of file to a sector boundary to ease reading with
3354 sector based I/Os */
3355 cluster_offset
= bdrv_getlength(bs
->file
->bs
);
3356 if (cluster_offset
< 0) {
3357 return cluster_offset
;
3359 return bdrv_truncate(bs
->file
, cluster_offset
, PREALLOC_MODE_OFF
, NULL
);
3362 if (offset_into_cluster(s
, offset
)) {
3366 buf
= qemu_blockalign(bs
, s
->cluster_size
);
3367 if (bytes
!= s
->cluster_size
) {
3368 if (bytes
> s
->cluster_size
||
3369 offset
+ bytes
!= bs
->total_sectors
<< BDRV_SECTOR_BITS
)
3374 /* Zero-pad last write if image size is not cluster aligned */
3375 memset(buf
+ bytes
, 0, s
->cluster_size
- bytes
);
3377 qemu_iovec_to_buf(qiov
, 0, buf
, bytes
);
3379 out_buf
= g_malloc(s
->cluster_size
);
3381 /* best compression, small window, no zlib header */
3382 memset(&strm
, 0, sizeof(strm
));
3383 ret
= deflateInit2(&strm
, Z_DEFAULT_COMPRESSION
,
3385 9, Z_DEFAULT_STRATEGY
);
3391 strm
.avail_in
= s
->cluster_size
;
3392 strm
.next_in
= (uint8_t *)buf
;
3393 strm
.avail_out
= s
->cluster_size
;
3394 strm
.next_out
= out_buf
;
3396 ret
= deflate(&strm
, Z_FINISH
);
3397 if (ret
!= Z_STREAM_END
&& ret
!= Z_OK
) {
3402 out_len
= strm
.next_out
- out_buf
;
3406 if (ret
!= Z_STREAM_END
|| out_len
>= s
->cluster_size
) {
3407 /* could not compress: write normal cluster */
3408 ret
= qcow2_co_pwritev(bs
, offset
, bytes
, qiov
, 0);
3415 qemu_co_mutex_lock(&s
->lock
);
3417 qcow2_alloc_compressed_cluster_offset(bs
, offset
, out_len
);
3418 if (!cluster_offset
) {
3419 qemu_co_mutex_unlock(&s
->lock
);
3423 cluster_offset
&= s
->cluster_offset_mask
;
3425 ret
= qcow2_pre_write_overlap_check(bs
, 0, cluster_offset
, out_len
);
3426 qemu_co_mutex_unlock(&s
->lock
);
3431 iov
= (struct iovec
) {
3432 .iov_base
= out_buf
,
3435 qemu_iovec_init_external(&hd_qiov
, &iov
, 1);
3437 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_COMPRESSED
);
3438 ret
= bdrv_co_pwritev(bs
->file
, cluster_offset
, out_len
, &hd_qiov
, 0);
3450 static int make_completely_empty(BlockDriverState
*bs
)
3452 BDRVQcow2State
*s
= bs
->opaque
;
3453 Error
*local_err
= NULL
;
3454 int ret
, l1_clusters
;
3456 uint64_t *new_reftable
= NULL
;
3457 uint64_t rt_entry
, l1_size2
;
3460 uint64_t reftable_offset
;
3461 uint32_t reftable_clusters
;
3462 } QEMU_PACKED l1_ofs_rt_ofs_cls
;
3464 ret
= qcow2_cache_empty(bs
, s
->l2_table_cache
);
3469 ret
= qcow2_cache_empty(bs
, s
->refcount_block_cache
);
3474 /* Refcounts will be broken utterly */
3475 ret
= qcow2_mark_dirty(bs
);
3480 BLKDBG_EVENT(bs
->file
, BLKDBG_L1_UPDATE
);
3482 l1_clusters
= DIV_ROUND_UP(s
->l1_size
, s
->cluster_size
/ sizeof(uint64_t));
3483 l1_size2
= (uint64_t)s
->l1_size
* sizeof(uint64_t);
3485 /* After this call, neither the in-memory nor the on-disk refcount
3486 * information accurately describe the actual references */
3488 ret
= bdrv_pwrite_zeroes(bs
->file
, s
->l1_table_offset
,
3489 l1_clusters
* s
->cluster_size
, 0);
3491 goto fail_broken_refcounts
;
3493 memset(s
->l1_table
, 0, l1_size2
);
3495 BLKDBG_EVENT(bs
->file
, BLKDBG_EMPTY_IMAGE_PREPARE
);
3497 /* Overwrite enough clusters at the beginning of the sectors to place
3498 * the refcount table, a refcount block and the L1 table in; this may
3499 * overwrite parts of the existing refcount and L1 table, which is not
3500 * an issue because the dirty flag is set, complete data loss is in fact
3501 * desired and partial data loss is consequently fine as well */
3502 ret
= bdrv_pwrite_zeroes(bs
->file
, s
->cluster_size
,
3503 (2 + l1_clusters
) * s
->cluster_size
, 0);
3504 /* This call (even if it failed overall) may have overwritten on-disk
3505 * refcount structures; in that case, the in-memory refcount information
3506 * will probably differ from the on-disk information which makes the BDS
3509 goto fail_broken_refcounts
;
3512 BLKDBG_EVENT(bs
->file
, BLKDBG_L1_UPDATE
);
3513 BLKDBG_EVENT(bs
->file
, BLKDBG_REFTABLE_UPDATE
);
3515 /* "Create" an empty reftable (one cluster) directly after the image
3516 * header and an empty L1 table three clusters after the image header;
3517 * the cluster between those two will be used as the first refblock */
3518 l1_ofs_rt_ofs_cls
.l1_offset
= cpu_to_be64(3 * s
->cluster_size
);
3519 l1_ofs_rt_ofs_cls
.reftable_offset
= cpu_to_be64(s
->cluster_size
);
3520 l1_ofs_rt_ofs_cls
.reftable_clusters
= cpu_to_be32(1);
3521 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, l1_table_offset
),
3522 &l1_ofs_rt_ofs_cls
, sizeof(l1_ofs_rt_ofs_cls
));
3524 goto fail_broken_refcounts
;
3527 s
->l1_table_offset
= 3 * s
->cluster_size
;
3529 new_reftable
= g_try_new0(uint64_t, s
->cluster_size
/ sizeof(uint64_t));
3530 if (!new_reftable
) {
3532 goto fail_broken_refcounts
;
3535 s
->refcount_table_offset
= s
->cluster_size
;
3536 s
->refcount_table_size
= s
->cluster_size
/ sizeof(uint64_t);
3537 s
->max_refcount_table_index
= 0;
3539 g_free(s
->refcount_table
);
3540 s
->refcount_table
= new_reftable
;
3541 new_reftable
= NULL
;
3543 /* Now the in-memory refcount information again corresponds to the on-disk
3544 * information (reftable is empty and no refblocks (the refblock cache is
3545 * empty)); however, this means some clusters (e.g. the image header) are
3546 * referenced, but not refcounted, but the normal qcow2 code assumes that
3547 * the in-memory information is always correct */
3549 BLKDBG_EVENT(bs
->file
, BLKDBG_REFBLOCK_ALLOC
);
3551 /* Enter the first refblock into the reftable */
3552 rt_entry
= cpu_to_be64(2 * s
->cluster_size
);
3553 ret
= bdrv_pwrite_sync(bs
->file
, s
->cluster_size
,
3554 &rt_entry
, sizeof(rt_entry
));
3556 goto fail_broken_refcounts
;
3558 s
->refcount_table
[0] = 2 * s
->cluster_size
;
3560 s
->free_cluster_index
= 0;
3561 assert(3 + l1_clusters
<= s
->refcount_block_size
);
3562 offset
= qcow2_alloc_clusters(bs
, 3 * s
->cluster_size
+ l1_size2
);
3565 goto fail_broken_refcounts
;
3566 } else if (offset
> 0) {
3567 error_report("First cluster in emptied image is in use");
3571 /* Now finally the in-memory information corresponds to the on-disk
3572 * structures and is correct */
3573 ret
= qcow2_mark_clean(bs
);
3578 ret
= bdrv_truncate(bs
->file
, (3 + l1_clusters
) * s
->cluster_size
,
3579 PREALLOC_MODE_OFF
, &local_err
);
3581 error_report_err(local_err
);
3587 fail_broken_refcounts
:
3588 /* The BDS is unusable at this point. If we wanted to make it usable, we
3589 * would have to call qcow2_refcount_close(), qcow2_refcount_init(),
3590 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init()
3591 * again. However, because the functions which could have caused this error
3592 * path to be taken are used by those functions as well, it's very likely
3593 * that that sequence will fail as well. Therefore, just eject the BDS. */
3597 g_free(new_reftable
);
3601 static int qcow2_make_empty(BlockDriverState
*bs
)
3603 BDRVQcow2State
*s
= bs
->opaque
;
3604 uint64_t offset
, end_offset
;
3605 int step
= QEMU_ALIGN_DOWN(INT_MAX
, s
->cluster_size
);
3606 int l1_clusters
, ret
= 0;
3608 l1_clusters
= DIV_ROUND_UP(s
->l1_size
, s
->cluster_size
/ sizeof(uint64_t));
3610 if (s
->qcow_version
>= 3 && !s
->snapshots
&& !s
->nb_bitmaps
&&
3611 3 + l1_clusters
<= s
->refcount_block_size
&&
3612 s
->crypt_method_header
!= QCOW_CRYPT_LUKS
) {
3613 /* The following function only works for qcow2 v3 images (it
3614 * requires the dirty flag) and only as long as there are no
3615 * features that reserve extra clusters (such as snapshots,
3616 * LUKS header, or persistent bitmaps), because it completely
3617 * empties the image. Furthermore, the L1 table and three
3618 * additional clusters (image header, refcount table, one
3619 * refcount block) have to fit inside one refcount block. */
3620 return make_completely_empty(bs
);
3623 /* This fallback code simply discards every active cluster; this is slow,
3624 * but works in all cases */
3625 end_offset
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
3626 for (offset
= 0; offset
< end_offset
; offset
+= step
) {
3627 /* As this function is generally used after committing an external
3628 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the
3629 * default action for this kind of discard is to pass the discard,
3630 * which will ideally result in an actually smaller image file, as
3631 * is probably desired. */
3632 ret
= qcow2_cluster_discard(bs
, offset
, MIN(step
, end_offset
- offset
),
3633 QCOW2_DISCARD_SNAPSHOT
, true);
3642 static coroutine_fn
int qcow2_co_flush_to_os(BlockDriverState
*bs
)
3644 BDRVQcow2State
*s
= bs
->opaque
;
3647 qemu_co_mutex_lock(&s
->lock
);
3648 ret
= qcow2_cache_write(bs
, s
->l2_table_cache
);
3650 qemu_co_mutex_unlock(&s
->lock
);
3654 if (qcow2_need_accurate_refcounts(s
)) {
3655 ret
= qcow2_cache_write(bs
, s
->refcount_block_cache
);
3657 qemu_co_mutex_unlock(&s
->lock
);
3661 qemu_co_mutex_unlock(&s
->lock
);
3666 static BlockMeasureInfo
*qcow2_measure(QemuOpts
*opts
, BlockDriverState
*in_bs
,
3669 Error
*local_err
= NULL
;
3670 BlockMeasureInfo
*info
;
3671 uint64_t required
= 0; /* bytes that contribute to required size */
3672 uint64_t virtual_size
; /* disk size as seen by guest */
3673 uint64_t refcount_bits
;
3675 size_t cluster_size
;
3678 PreallocMode prealloc
;
3679 bool has_backing_file
;
3681 /* Parse image creation options */
3682 cluster_size
= qcow2_opt_get_cluster_size_del(opts
, &local_err
);
3687 version
= qcow2_opt_get_version_del(opts
, &local_err
);
3692 refcount_bits
= qcow2_opt_get_refcount_bits_del(opts
, version
, &local_err
);
3697 optstr
= qemu_opt_get_del(opts
, BLOCK_OPT_PREALLOC
);
3698 prealloc
= qapi_enum_parse(&PreallocMode_lookup
, optstr
,
3699 PREALLOC_MODE_OFF
, &local_err
);
3705 optstr
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
3706 has_backing_file
= !!optstr
;
3709 virtual_size
= align_offset(qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0),
3712 /* Check that virtual disk size is valid */
3713 l2_tables
= DIV_ROUND_UP(virtual_size
/ cluster_size
,
3714 cluster_size
/ sizeof(uint64_t));
3715 if (l2_tables
* sizeof(uint64_t) > QCOW_MAX_L1_SIZE
) {
3716 error_setg(&local_err
, "The image size is too large "
3717 "(try using a larger cluster size)");
3721 /* Account for input image */
3723 int64_t ssize
= bdrv_getlength(in_bs
);
3725 error_setg_errno(&local_err
, -ssize
,
3726 "Unable to get image virtual_size");
3730 virtual_size
= align_offset(ssize
, cluster_size
);
3732 if (has_backing_file
) {
3733 /* We don't how much of the backing chain is shared by the input
3734 * image and the new image file. In the worst case the new image's
3735 * backing file has nothing in common with the input image. Be
3736 * conservative and assume all clusters need to be written.
3738 required
= virtual_size
;
3743 for (offset
= 0; offset
< ssize
; offset
+= pnum
) {
3746 ret
= bdrv_block_status_above(in_bs
, NULL
, offset
,
3747 ssize
- offset
, &pnum
, NULL
,
3750 error_setg_errno(&local_err
, -ret
,
3751 "Unable to get block status");
3755 if (ret
& BDRV_BLOCK_ZERO
) {
3756 /* Skip zero regions (safe with no backing file) */
3757 } else if ((ret
& (BDRV_BLOCK_DATA
| BDRV_BLOCK_ALLOCATED
)) ==
3758 (BDRV_BLOCK_DATA
| BDRV_BLOCK_ALLOCATED
)) {
3759 /* Extend pnum to end of cluster for next iteration */
3760 pnum
= ROUND_UP(offset
+ pnum
, cluster_size
) - offset
;
3762 /* Count clusters we've seen */
3763 required
+= offset
% cluster_size
+ pnum
;
3769 /* Take into account preallocation. Nothing special is needed for
3770 * PREALLOC_MODE_METADATA since metadata is always counted.
3772 if (prealloc
== PREALLOC_MODE_FULL
|| prealloc
== PREALLOC_MODE_FALLOC
) {
3773 required
= virtual_size
;
3776 info
= g_new(BlockMeasureInfo
, 1);
3777 info
->fully_allocated
=
3778 qcow2_calc_prealloc_size(virtual_size
, cluster_size
,
3779 ctz32(refcount_bits
));
3781 /* Remove data clusters that are not required. This overestimates the
3782 * required size because metadata needed for the fully allocated file is
3785 info
->required
= info
->fully_allocated
- virtual_size
+ required
;
3789 error_propagate(errp
, local_err
);
3793 static int qcow2_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3795 BDRVQcow2State
*s
= bs
->opaque
;
3796 bdi
->unallocated_blocks_are_zero
= true;
3797 bdi
->cluster_size
= s
->cluster_size
;
3798 bdi
->vm_state_offset
= qcow2_vm_state_offset(s
);
3802 static ImageInfoSpecific
*qcow2_get_specific_info(BlockDriverState
*bs
)
3804 BDRVQcow2State
*s
= bs
->opaque
;
3805 ImageInfoSpecific
*spec_info
;
3806 QCryptoBlockInfo
*encrypt_info
= NULL
;
3808 if (s
->crypto
!= NULL
) {
3809 encrypt_info
= qcrypto_block_get_info(s
->crypto
, &error_abort
);
3812 spec_info
= g_new(ImageInfoSpecific
, 1);
3813 *spec_info
= (ImageInfoSpecific
){
3814 .type
= IMAGE_INFO_SPECIFIC_KIND_QCOW2
,
3815 .u
.qcow2
.data
= g_new(ImageInfoSpecificQCow2
, 1),
3817 if (s
->qcow_version
== 2) {
3818 *spec_info
->u
.qcow2
.data
= (ImageInfoSpecificQCow2
){
3819 .compat
= g_strdup("0.10"),
3820 .refcount_bits
= s
->refcount_bits
,
3822 } else if (s
->qcow_version
== 3) {
3823 *spec_info
->u
.qcow2
.data
= (ImageInfoSpecificQCow2
){
3824 .compat
= g_strdup("1.1"),
3825 .lazy_refcounts
= s
->compatible_features
&
3826 QCOW2_COMPAT_LAZY_REFCOUNTS
,
3827 .has_lazy_refcounts
= true,
3828 .corrupt
= s
->incompatible_features
&
3829 QCOW2_INCOMPAT_CORRUPT
,
3830 .has_corrupt
= true,
3831 .refcount_bits
= s
->refcount_bits
,
3834 /* if this assertion fails, this probably means a new version was
3835 * added without having it covered here */
3840 ImageInfoSpecificQCow2Encryption
*qencrypt
=
3841 g_new(ImageInfoSpecificQCow2Encryption
, 1);
3842 switch (encrypt_info
->format
) {
3843 case Q_CRYPTO_BLOCK_FORMAT_QCOW
:
3844 qencrypt
->format
= BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES
;
3845 qencrypt
->u
.aes
= encrypt_info
->u
.qcow
;
3847 case Q_CRYPTO_BLOCK_FORMAT_LUKS
:
3848 qencrypt
->format
= BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS
;
3849 qencrypt
->u
.luks
= encrypt_info
->u
.luks
;
3854 /* Since we did shallow copy above, erase any pointers
3855 * in the original info */
3856 memset(&encrypt_info
->u
, 0, sizeof(encrypt_info
->u
));
3857 qapi_free_QCryptoBlockInfo(encrypt_info
);
3859 spec_info
->u
.qcow2
.data
->has_encrypt
= true;
3860 spec_info
->u
.qcow2
.data
->encrypt
= qencrypt
;
3866 static int qcow2_save_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
3869 BDRVQcow2State
*s
= bs
->opaque
;
3871 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_SAVE
);
3872 return bs
->drv
->bdrv_co_pwritev(bs
, qcow2_vm_state_offset(s
) + pos
,
3873 qiov
->size
, qiov
, 0);
3876 static int qcow2_load_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
3879 BDRVQcow2State
*s
= bs
->opaque
;
3881 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_LOAD
);
3882 return bs
->drv
->bdrv_co_preadv(bs
, qcow2_vm_state_offset(s
) + pos
,
3883 qiov
->size
, qiov
, 0);
3887 * Downgrades an image's version. To achieve this, any incompatible features
3888 * have to be removed.
3890 static int qcow2_downgrade(BlockDriverState
*bs
, int target_version
,
3891 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
3893 BDRVQcow2State
*s
= bs
->opaque
;
3894 int current_version
= s
->qcow_version
;
3897 if (target_version
== current_version
) {
3899 } else if (target_version
> current_version
) {
3901 } else if (target_version
!= 2) {
3905 if (s
->refcount_order
!= 4) {
3906 error_report("compat=0.10 requires refcount_bits=16");
3910 /* clear incompatible features */
3911 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
3912 ret
= qcow2_mark_clean(bs
);
3918 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
3919 * the first place; if that happens nonetheless, returning -ENOTSUP is the
3920 * best thing to do anyway */
3922 if (s
->incompatible_features
) {
3926 /* since we can ignore compatible features, we can set them to 0 as well */
3927 s
->compatible_features
= 0;
3928 /* if lazy refcounts have been used, they have already been fixed through
3929 * clearing the dirty flag */
3931 /* clearing autoclear features is trivial */
3932 s
->autoclear_features
= 0;
3934 ret
= qcow2_expand_zero_clusters(bs
, status_cb
, cb_opaque
);
3939 s
->qcow_version
= target_version
;
3940 ret
= qcow2_update_header(bs
);
3942 s
->qcow_version
= current_version
;
3948 typedef enum Qcow2AmendOperation
{
3949 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be
3950 * statically initialized to so that the helper CB can discern the first
3951 * invocation from an operation change */
3952 QCOW2_NO_OPERATION
= 0,
3954 QCOW2_CHANGING_REFCOUNT_ORDER
,
3956 } Qcow2AmendOperation
;
3958 typedef struct Qcow2AmendHelperCBInfo
{
3959 /* The code coordinating the amend operations should only modify
3960 * these four fields; the rest will be managed by the CB */
3961 BlockDriverAmendStatusCB
*original_status_cb
;
3962 void *original_cb_opaque
;
3964 Qcow2AmendOperation current_operation
;
3966 /* Total number of operations to perform (only set once) */
3967 int total_operations
;
3969 /* The following fields are managed by the CB */
3971 /* Number of operations completed */
3972 int operations_completed
;
3974 /* Cumulative offset of all completed operations */
3975 int64_t offset_completed
;
3977 Qcow2AmendOperation last_operation
;
3978 int64_t last_work_size
;
3979 } Qcow2AmendHelperCBInfo
;
3981 static void qcow2_amend_helper_cb(BlockDriverState
*bs
,
3982 int64_t operation_offset
,
3983 int64_t operation_work_size
, void *opaque
)
3985 Qcow2AmendHelperCBInfo
*info
= opaque
;
3986 int64_t current_work_size
;
3987 int64_t projected_work_size
;
3989 if (info
->current_operation
!= info
->last_operation
) {
3990 if (info
->last_operation
!= QCOW2_NO_OPERATION
) {
3991 info
->offset_completed
+= info
->last_work_size
;
3992 info
->operations_completed
++;
3995 info
->last_operation
= info
->current_operation
;
3998 assert(info
->total_operations
> 0);
3999 assert(info
->operations_completed
< info
->total_operations
);
4001 info
->last_work_size
= operation_work_size
;
4003 current_work_size
= info
->offset_completed
+ operation_work_size
;
4005 /* current_work_size is the total work size for (operations_completed + 1)
4006 * operations (which includes this one), so multiply it by the number of
4007 * operations not covered and divide it by the number of operations
4008 * covered to get a projection for the operations not covered */
4009 projected_work_size
= current_work_size
* (info
->total_operations
-
4010 info
->operations_completed
- 1)
4011 / (info
->operations_completed
+ 1);
4013 info
->original_status_cb(bs
, info
->offset_completed
+ operation_offset
,
4014 current_work_size
+ projected_work_size
,
4015 info
->original_cb_opaque
);
4018 static int qcow2_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4019 BlockDriverAmendStatusCB
*status_cb
,
4022 BDRVQcow2State
*s
= bs
->opaque
;
4023 int old_version
= s
->qcow_version
, new_version
= old_version
;
4024 uint64_t new_size
= 0;
4025 const char *backing_file
= NULL
, *backing_format
= NULL
;
4026 bool lazy_refcounts
= s
->use_lazy_refcounts
;
4027 const char *compat
= NULL
;
4028 uint64_t cluster_size
= s
->cluster_size
;
4031 int refcount_bits
= s
->refcount_bits
;
4032 Error
*local_err
= NULL
;
4034 QemuOptDesc
*desc
= opts
->list
->desc
;
4035 Qcow2AmendHelperCBInfo helper_cb_info
;
4037 while (desc
&& desc
->name
) {
4038 if (!qemu_opt_find(opts
, desc
->name
)) {
4039 /* only change explicitly defined options */
4044 if (!strcmp(desc
->name
, BLOCK_OPT_COMPAT_LEVEL
)) {
4045 compat
= qemu_opt_get(opts
, BLOCK_OPT_COMPAT_LEVEL
);
4047 /* preserve default */
4048 } else if (!strcmp(compat
, "0.10")) {
4050 } else if (!strcmp(compat
, "1.1")) {
4053 error_report("Unknown compatibility level %s", compat
);
4056 } else if (!strcmp(desc
->name
, BLOCK_OPT_PREALLOC
)) {
4057 error_report("Cannot change preallocation mode");
4059 } else if (!strcmp(desc
->name
, BLOCK_OPT_SIZE
)) {
4060 new_size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
4061 } else if (!strcmp(desc
->name
, BLOCK_OPT_BACKING_FILE
)) {
4062 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4063 } else if (!strcmp(desc
->name
, BLOCK_OPT_BACKING_FMT
)) {
4064 backing_format
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4065 } else if (!strcmp(desc
->name
, BLOCK_OPT_ENCRYPT
)) {
4066 encrypt
= qemu_opt_get_bool(opts
, BLOCK_OPT_ENCRYPT
,
4069 if (encrypt
!= !!s
->crypto
) {
4070 error_report("Changing the encryption flag is not supported");
4073 } else if (!strcmp(desc
->name
, BLOCK_OPT_ENCRYPT_FORMAT
)) {
4074 encformat
= qcow2_crypt_method_from_format(
4075 qemu_opt_get(opts
, BLOCK_OPT_ENCRYPT_FORMAT
));
4077 if (encformat
!= s
->crypt_method_header
) {
4078 error_report("Changing the encryption format is not supported");
4081 } else if (g_str_has_prefix(desc
->name
, "encrypt.")) {
4082 error_report("Changing the encryption parameters is not supported");
4084 } else if (!strcmp(desc
->name
, BLOCK_OPT_CLUSTER_SIZE
)) {
4085 cluster_size
= qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
,
4087 if (cluster_size
!= s
->cluster_size
) {
4088 error_report("Changing the cluster size is not supported");
4091 } else if (!strcmp(desc
->name
, BLOCK_OPT_LAZY_REFCOUNTS
)) {
4092 lazy_refcounts
= qemu_opt_get_bool(opts
, BLOCK_OPT_LAZY_REFCOUNTS
,
4094 } else if (!strcmp(desc
->name
, BLOCK_OPT_REFCOUNT_BITS
)) {
4095 refcount_bits
= qemu_opt_get_number(opts
, BLOCK_OPT_REFCOUNT_BITS
,
4098 if (refcount_bits
<= 0 || refcount_bits
> 64 ||
4099 !is_power_of_2(refcount_bits
))
4101 error_report("Refcount width must be a power of two and may "
4102 "not exceed 64 bits");
4106 /* if this point is reached, this probably means a new option was
4107 * added without having it covered here */
4114 helper_cb_info
= (Qcow2AmendHelperCBInfo
){
4115 .original_status_cb
= status_cb
,
4116 .original_cb_opaque
= cb_opaque
,
4117 .total_operations
= (new_version
< old_version
)
4118 + (s
->refcount_bits
!= refcount_bits
)
4121 /* Upgrade first (some features may require compat=1.1) */
4122 if (new_version
> old_version
) {
4123 s
->qcow_version
= new_version
;
4124 ret
= qcow2_update_header(bs
);
4126 s
->qcow_version
= old_version
;
4131 if (s
->refcount_bits
!= refcount_bits
) {
4132 int refcount_order
= ctz32(refcount_bits
);
4134 if (new_version
< 3 && refcount_bits
!= 16) {
4135 error_report("Different refcount widths than 16 bits require "
4136 "compatibility level 1.1 or above (use compat=1.1 or "
4141 helper_cb_info
.current_operation
= QCOW2_CHANGING_REFCOUNT_ORDER
;
4142 ret
= qcow2_change_refcount_order(bs
, refcount_order
,
4143 &qcow2_amend_helper_cb
,
4144 &helper_cb_info
, &local_err
);
4146 error_report_err(local_err
);
4151 if (backing_file
|| backing_format
) {
4152 ret
= qcow2_change_backing_file(bs
,
4153 backing_file
?: s
->image_backing_file
,
4154 backing_format
?: s
->image_backing_format
);
4160 if (s
->use_lazy_refcounts
!= lazy_refcounts
) {
4161 if (lazy_refcounts
) {
4162 if (new_version
< 3) {
4163 error_report("Lazy refcounts only supported with compatibility "
4164 "level 1.1 and above (use compat=1.1 or greater)");
4167 s
->compatible_features
|= QCOW2_COMPAT_LAZY_REFCOUNTS
;
4168 ret
= qcow2_update_header(bs
);
4170 s
->compatible_features
&= ~QCOW2_COMPAT_LAZY_REFCOUNTS
;
4173 s
->use_lazy_refcounts
= true;
4175 /* make image clean first */
4176 ret
= qcow2_mark_clean(bs
);
4180 /* now disallow lazy refcounts */
4181 s
->compatible_features
&= ~QCOW2_COMPAT_LAZY_REFCOUNTS
;
4182 ret
= qcow2_update_header(bs
);
4184 s
->compatible_features
|= QCOW2_COMPAT_LAZY_REFCOUNTS
;
4187 s
->use_lazy_refcounts
= false;
4192 BlockBackend
*blk
= blk_new(BLK_PERM_RESIZE
, BLK_PERM_ALL
);
4193 ret
= blk_insert_bs(blk
, bs
, &local_err
);
4195 error_report_err(local_err
);
4200 ret
= blk_truncate(blk
, new_size
, PREALLOC_MODE_OFF
, &local_err
);
4203 error_report_err(local_err
);
4208 /* Downgrade last (so unsupported features can be removed before) */
4209 if (new_version
< old_version
) {
4210 helper_cb_info
.current_operation
= QCOW2_DOWNGRADING
;
4211 ret
= qcow2_downgrade(bs
, new_version
, &qcow2_amend_helper_cb
,
4222 * If offset or size are negative, respectively, they will not be included in
4223 * the BLOCK_IMAGE_CORRUPTED event emitted.
4224 * fatal will be ignored for read-only BDS; corruptions found there will always
4225 * be considered non-fatal.
4227 void qcow2_signal_corruption(BlockDriverState
*bs
, bool fatal
, int64_t offset
,
4228 int64_t size
, const char *message_format
, ...)
4230 BDRVQcow2State
*s
= bs
->opaque
;
4231 const char *node_name
;
4235 fatal
= fatal
&& !bs
->read_only
;
4237 if (s
->signaled_corruption
&&
4238 (!fatal
|| (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
)))
4243 va_start(ap
, message_format
);
4244 message
= g_strdup_vprintf(message_format
, ap
);
4248 fprintf(stderr
, "qcow2: Marking image as corrupt: %s; further "
4249 "corruption events will be suppressed\n", message
);
4251 fprintf(stderr
, "qcow2: Image is corrupt: %s; further non-fatal "
4252 "corruption events will be suppressed\n", message
);
4255 node_name
= bdrv_get_node_name(bs
);
4256 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs
),
4257 *node_name
!= '\0', node_name
,
4258 message
, offset
>= 0, offset
,
4260 fatal
, &error_abort
);
4264 qcow2_mark_corrupt(bs
);
4265 bs
->drv
= NULL
; /* make BDS unusable */
4268 s
->signaled_corruption
= true;
4271 static QemuOptsList qcow2_create_opts
= {
4272 .name
= "qcow2-create-opts",
4273 .head
= QTAILQ_HEAD_INITIALIZER(qcow2_create_opts
.head
),
4276 .name
= BLOCK_OPT_SIZE
,
4277 .type
= QEMU_OPT_SIZE
,
4278 .help
= "Virtual disk size"
4281 .name
= BLOCK_OPT_COMPAT_LEVEL
,
4282 .type
= QEMU_OPT_STRING
,
4283 .help
= "Compatibility level (0.10 or 1.1)"
4286 .name
= BLOCK_OPT_BACKING_FILE
,
4287 .type
= QEMU_OPT_STRING
,
4288 .help
= "File name of a base image"
4291 .name
= BLOCK_OPT_BACKING_FMT
,
4292 .type
= QEMU_OPT_STRING
,
4293 .help
= "Image format of the base image"
4296 .name
= BLOCK_OPT_ENCRYPT
,
4297 .type
= QEMU_OPT_BOOL
,
4298 .help
= "Encrypt the image with format 'aes'. (Deprecated "
4299 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT
"=aes)",
4302 .name
= BLOCK_OPT_ENCRYPT_FORMAT
,
4303 .type
= QEMU_OPT_STRING
,
4304 .help
= "Encrypt the image, format choices: 'aes', 'luks'",
4306 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
4307 "ID of secret providing qcow AES key or LUKS passphrase"),
4308 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."),
4309 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."),
4310 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."),
4311 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."),
4312 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."),
4313 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."),
4315 .name
= BLOCK_OPT_CLUSTER_SIZE
,
4316 .type
= QEMU_OPT_SIZE
,
4317 .help
= "qcow2 cluster size",
4318 .def_value_str
= stringify(DEFAULT_CLUSTER_SIZE
)
4321 .name
= BLOCK_OPT_PREALLOC
,
4322 .type
= QEMU_OPT_STRING
,
4323 .help
= "Preallocation mode (allowed values: off, metadata, "
4327 .name
= BLOCK_OPT_LAZY_REFCOUNTS
,
4328 .type
= QEMU_OPT_BOOL
,
4329 .help
= "Postpone refcount updates",
4330 .def_value_str
= "off"
4333 .name
= BLOCK_OPT_REFCOUNT_BITS
,
4334 .type
= QEMU_OPT_NUMBER
,
4335 .help
= "Width of a reference count entry in bits",
4336 .def_value_str
= "16"
4338 { /* end of list */ }
4342 BlockDriver bdrv_qcow2
= {
4343 .format_name
= "qcow2",
4344 .instance_size
= sizeof(BDRVQcow2State
),
4345 .bdrv_probe
= qcow2_probe
,
4346 .bdrv_open
= qcow2_open
,
4347 .bdrv_close
= qcow2_close
,
4348 .bdrv_reopen_prepare
= qcow2_reopen_prepare
,
4349 .bdrv_reopen_commit
= qcow2_reopen_commit
,
4350 .bdrv_reopen_abort
= qcow2_reopen_abort
,
4351 .bdrv_join_options
= qcow2_join_options
,
4352 .bdrv_child_perm
= bdrv_format_default_perms
,
4353 .bdrv_create
= qcow2_create
,
4354 .bdrv_has_zero_init
= bdrv_has_zero_init_1
,
4355 .bdrv_co_get_block_status
= qcow2_co_get_block_status
,
4357 .bdrv_co_preadv
= qcow2_co_preadv
,
4358 .bdrv_co_pwritev
= qcow2_co_pwritev
,
4359 .bdrv_co_flush_to_os
= qcow2_co_flush_to_os
,
4361 .bdrv_co_pwrite_zeroes
= qcow2_co_pwrite_zeroes
,
4362 .bdrv_co_pdiscard
= qcow2_co_pdiscard
,
4363 .bdrv_truncate
= qcow2_truncate
,
4364 .bdrv_co_pwritev_compressed
= qcow2_co_pwritev_compressed
,
4365 .bdrv_make_empty
= qcow2_make_empty
,
4367 .bdrv_snapshot_create
= qcow2_snapshot_create
,
4368 .bdrv_snapshot_goto
= qcow2_snapshot_goto
,
4369 .bdrv_snapshot_delete
= qcow2_snapshot_delete
,
4370 .bdrv_snapshot_list
= qcow2_snapshot_list
,
4371 .bdrv_snapshot_load_tmp
= qcow2_snapshot_load_tmp
,
4372 .bdrv_measure
= qcow2_measure
,
4373 .bdrv_get_info
= qcow2_get_info
,
4374 .bdrv_get_specific_info
= qcow2_get_specific_info
,
4376 .bdrv_save_vmstate
= qcow2_save_vmstate
,
4377 .bdrv_load_vmstate
= qcow2_load_vmstate
,
4379 .supports_backing
= true,
4380 .bdrv_change_backing_file
= qcow2_change_backing_file
,
4382 .bdrv_refresh_limits
= qcow2_refresh_limits
,
4383 .bdrv_invalidate_cache
= qcow2_invalidate_cache
,
4384 .bdrv_inactivate
= qcow2_inactivate
,
4386 .create_opts
= &qcow2_create_opts
,
4387 .bdrv_check
= qcow2_check
,
4388 .bdrv_amend_options
= qcow2_amend_options
,
4390 .bdrv_detach_aio_context
= qcow2_detach_aio_context
,
4391 .bdrv_attach_aio_context
= qcow2_attach_aio_context
,
4393 .bdrv_reopen_bitmaps_rw
= qcow2_reopen_bitmaps_rw
,
4394 .bdrv_can_store_new_dirty_bitmap
= qcow2_can_store_new_dirty_bitmap
,
4395 .bdrv_remove_persistent_dirty_bitmap
= qcow2_remove_persistent_dirty_bitmap
,
4398 static void bdrv_qcow2_init(void)
4400 bdrv_register(&bdrv_qcow2
);
4403 block_init(bdrv_qcow2_init
);