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"
30 #include "block/block_int.h"
31 #include "block/qdict.h"
32 #include "sysemu/block-backend.h"
33 #include "qemu/module.h"
35 #include "qemu/error-report.h"
36 #include "qapi/error.h"
37 #include "qapi/qapi-events-block-core.h"
38 #include "qapi/qmp/qdict.h"
39 #include "qapi/qmp/qstring.h"
41 #include "qemu/option_int.h"
42 #include "qemu/cutils.h"
43 #include "qemu/bswap.h"
44 #include "qapi/qobject-input-visitor.h"
45 #include "qapi/qapi-visit-block-core.h"
47 #include "block/thread-pool.h"
50 Differences with QCOW:
52 - Support for multiple incremental snapshots.
53 - Memory management by reference counts.
54 - Clusters which have a reference count of one have the bit
55 QCOW_OFLAG_COPIED to optimize write performance.
56 - Size of compressed clusters is stored in sectors to reduce bit usage
57 in the cluster offsets.
58 - Support for storing additional data (such as the VM state) in the
60 - If a backing store is used, the cluster size is not constrained
61 (could be backported to QCOW).
62 - L2 tables have always a size of one cluster.
69 } QEMU_PACKED QCowExtension
;
71 #define QCOW2_EXT_MAGIC_END 0
72 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
73 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
74 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
75 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875
76 #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441
78 static int coroutine_fn
79 qcow2_co_preadv_compressed(BlockDriverState
*bs
,
80 uint64_t file_cluster_offset
,
85 static int qcow2_probe(const uint8_t *buf
, int buf_size
, const char *filename
)
87 const QCowHeader
*cow_header
= (const void *)buf
;
89 if (buf_size
>= sizeof(QCowHeader
) &&
90 be32_to_cpu(cow_header
->magic
) == QCOW_MAGIC
&&
91 be32_to_cpu(cow_header
->version
) >= 2)
98 static ssize_t
qcow2_crypto_hdr_read_func(QCryptoBlock
*block
, size_t offset
,
99 uint8_t *buf
, size_t buflen
,
100 void *opaque
, Error
**errp
)
102 BlockDriverState
*bs
= opaque
;
103 BDRVQcow2State
*s
= bs
->opaque
;
106 if ((offset
+ buflen
) > s
->crypto_header
.length
) {
107 error_setg(errp
, "Request for data outside of extension header");
111 ret
= bdrv_pread(bs
->file
,
112 s
->crypto_header
.offset
+ offset
, buf
, buflen
);
114 error_setg_errno(errp
, -ret
, "Could not read encryption header");
121 static ssize_t
qcow2_crypto_hdr_init_func(QCryptoBlock
*block
, size_t headerlen
,
122 void *opaque
, Error
**errp
)
124 BlockDriverState
*bs
= opaque
;
125 BDRVQcow2State
*s
= bs
->opaque
;
129 ret
= qcow2_alloc_clusters(bs
, headerlen
);
131 error_setg_errno(errp
, -ret
,
132 "Cannot allocate cluster for LUKS header size %zu",
137 s
->crypto_header
.length
= headerlen
;
138 s
->crypto_header
.offset
= ret
;
140 /* Zero fill remaining space in cluster so it has predictable
141 * content in case of future spec changes */
142 clusterlen
= size_to_clusters(s
, headerlen
) * s
->cluster_size
;
143 assert(qcow2_pre_write_overlap_check(bs
, 0, ret
, clusterlen
, false) == 0);
144 ret
= bdrv_pwrite_zeroes(bs
->file
,
146 clusterlen
- headerlen
, 0);
148 error_setg_errno(errp
, -ret
, "Could not zero fill encryption header");
156 static ssize_t
qcow2_crypto_hdr_write_func(QCryptoBlock
*block
, size_t offset
,
157 const uint8_t *buf
, size_t buflen
,
158 void *opaque
, Error
**errp
)
160 BlockDriverState
*bs
= opaque
;
161 BDRVQcow2State
*s
= bs
->opaque
;
164 if ((offset
+ buflen
) > s
->crypto_header
.length
) {
165 error_setg(errp
, "Request for data outside of extension header");
169 ret
= bdrv_pwrite(bs
->file
,
170 s
->crypto_header
.offset
+ offset
, buf
, buflen
);
172 error_setg_errno(errp
, -ret
, "Could not read encryption header");
180 * read qcow2 extension and fill bs
181 * start reading from start_offset
182 * finish reading upon magic of value 0 or when end_offset reached
183 * unknown magic is skipped (future extension this version knows nothing about)
184 * return 0 upon success, non-0 otherwise
186 static int qcow2_read_extensions(BlockDriverState
*bs
, uint64_t start_offset
,
187 uint64_t end_offset
, void **p_feature_table
,
188 int flags
, bool *need_update_header
,
191 BDRVQcow2State
*s
= bs
->opaque
;
195 Qcow2BitmapHeaderExt bitmaps_ext
;
197 if (need_update_header
!= NULL
) {
198 *need_update_header
= false;
202 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset
, end_offset
);
204 offset
= start_offset
;
205 while (offset
< end_offset
) {
209 if (offset
> s
->cluster_size
)
210 printf("qcow2_read_extension: suspicious offset %lu\n", offset
);
212 printf("attempting to read extended header in offset %lu\n", offset
);
215 ret
= bdrv_pread(bs
->file
, offset
, &ext
, sizeof(ext
));
217 error_setg_errno(errp
, -ret
, "qcow2_read_extension: ERROR: "
218 "pread fail from offset %" PRIu64
, offset
);
221 ext
.magic
= be32_to_cpu(ext
.magic
);
222 ext
.len
= be32_to_cpu(ext
.len
);
223 offset
+= sizeof(ext
);
225 printf("ext.magic = 0x%x\n", ext
.magic
);
227 if (offset
> end_offset
|| ext
.len
> end_offset
- offset
) {
228 error_setg(errp
, "Header extension too large");
233 case QCOW2_EXT_MAGIC_END
:
236 case QCOW2_EXT_MAGIC_BACKING_FORMAT
:
237 if (ext
.len
>= sizeof(bs
->backing_format
)) {
238 error_setg(errp
, "ERROR: ext_backing_format: len=%" PRIu32
239 " too large (>=%zu)", ext
.len
,
240 sizeof(bs
->backing_format
));
243 ret
= bdrv_pread(bs
->file
, offset
, bs
->backing_format
, ext
.len
);
245 error_setg_errno(errp
, -ret
, "ERROR: ext_backing_format: "
246 "Could not read format name");
249 bs
->backing_format
[ext
.len
] = '\0';
250 s
->image_backing_format
= g_strdup(bs
->backing_format
);
252 printf("Qcow2: Got format extension %s\n", bs
->backing_format
);
256 case QCOW2_EXT_MAGIC_FEATURE_TABLE
:
257 if (p_feature_table
!= NULL
) {
258 void* feature_table
= g_malloc0(ext
.len
+ 2 * sizeof(Qcow2Feature
));
259 ret
= bdrv_pread(bs
->file
, offset
, feature_table
, ext
.len
);
261 error_setg_errno(errp
, -ret
, "ERROR: ext_feature_table: "
262 "Could not read table");
266 *p_feature_table
= feature_table
;
270 case QCOW2_EXT_MAGIC_CRYPTO_HEADER
: {
271 unsigned int cflags
= 0;
272 if (s
->crypt_method_header
!= QCOW_CRYPT_LUKS
) {
273 error_setg(errp
, "CRYPTO header extension only "
274 "expected with LUKS encryption method");
277 if (ext
.len
!= sizeof(Qcow2CryptoHeaderExtension
)) {
278 error_setg(errp
, "CRYPTO header extension size %u, "
279 "but expected size %zu", ext
.len
,
280 sizeof(Qcow2CryptoHeaderExtension
));
284 ret
= bdrv_pread(bs
->file
, offset
, &s
->crypto_header
, ext
.len
);
286 error_setg_errno(errp
, -ret
,
287 "Unable to read CRYPTO header extension");
290 s
->crypto_header
.offset
= be64_to_cpu(s
->crypto_header
.offset
);
291 s
->crypto_header
.length
= be64_to_cpu(s
->crypto_header
.length
);
293 if ((s
->crypto_header
.offset
% s
->cluster_size
) != 0) {
294 error_setg(errp
, "Encryption header offset '%" PRIu64
"' is "
295 "not a multiple of cluster size '%u'",
296 s
->crypto_header
.offset
, s
->cluster_size
);
300 if (flags
& BDRV_O_NO_IO
) {
301 cflags
|= QCRYPTO_BLOCK_OPEN_NO_IO
;
303 s
->crypto
= qcrypto_block_open(s
->crypto_opts
, "encrypt.",
304 qcow2_crypto_hdr_read_func
,
305 bs
, cflags
, 1, errp
);
311 case QCOW2_EXT_MAGIC_BITMAPS
:
312 if (ext
.len
!= sizeof(bitmaps_ext
)) {
313 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
314 "Invalid extension length");
318 if (!(s
->autoclear_features
& QCOW2_AUTOCLEAR_BITMAPS
)) {
319 if (s
->qcow_version
< 3) {
320 /* Let's be a bit more specific */
321 warn_report("This qcow2 v2 image contains bitmaps, but "
322 "they may have been modified by a program "
323 "without persistent bitmap support; so now "
324 "they must all be considered inconsistent");
326 warn_report("a program lacking bitmap support "
327 "modified this file, so all bitmaps are now "
328 "considered inconsistent");
330 error_printf("Some clusters may be leaked, "
331 "run 'qemu-img check -r' on the image "
333 if (need_update_header
!= NULL
) {
334 /* Updating is needed to drop invalid bitmap extension. */
335 *need_update_header
= true;
340 ret
= bdrv_pread(bs
->file
, offset
, &bitmaps_ext
, ext
.len
);
342 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
343 "Could not read ext header");
347 if (bitmaps_ext
.reserved32
!= 0) {
348 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
349 "Reserved field is not zero");
353 bitmaps_ext
.nb_bitmaps
= be32_to_cpu(bitmaps_ext
.nb_bitmaps
);
354 bitmaps_ext
.bitmap_directory_size
=
355 be64_to_cpu(bitmaps_ext
.bitmap_directory_size
);
356 bitmaps_ext
.bitmap_directory_offset
=
357 be64_to_cpu(bitmaps_ext
.bitmap_directory_offset
);
359 if (bitmaps_ext
.nb_bitmaps
> QCOW2_MAX_BITMAPS
) {
361 "bitmaps_ext: Image has %" PRIu32
" bitmaps, "
362 "exceeding the QEMU supported maximum of %d",
363 bitmaps_ext
.nb_bitmaps
, QCOW2_MAX_BITMAPS
);
367 if (bitmaps_ext
.nb_bitmaps
== 0) {
368 error_setg(errp
, "found bitmaps extension with zero bitmaps");
372 if (bitmaps_ext
.bitmap_directory_offset
& (s
->cluster_size
- 1)) {
373 error_setg(errp
, "bitmaps_ext: "
374 "invalid bitmap directory offset");
378 if (bitmaps_ext
.bitmap_directory_size
>
379 QCOW2_MAX_BITMAP_DIRECTORY_SIZE
) {
380 error_setg(errp
, "bitmaps_ext: "
381 "bitmap directory size (%" PRIu64
") exceeds "
382 "the maximum supported size (%d)",
383 bitmaps_ext
.bitmap_directory_size
,
384 QCOW2_MAX_BITMAP_DIRECTORY_SIZE
);
388 s
->nb_bitmaps
= bitmaps_ext
.nb_bitmaps
;
389 s
->bitmap_directory_offset
=
390 bitmaps_ext
.bitmap_directory_offset
;
391 s
->bitmap_directory_size
=
392 bitmaps_ext
.bitmap_directory_size
;
395 printf("Qcow2: Got bitmaps extension: "
396 "offset=%" PRIu64
" nb_bitmaps=%" PRIu32
"\n",
397 s
->bitmap_directory_offset
, s
->nb_bitmaps
);
401 case QCOW2_EXT_MAGIC_DATA_FILE
:
403 s
->image_data_file
= g_malloc0(ext
.len
+ 1);
404 ret
= bdrv_pread(bs
->file
, offset
, s
->image_data_file
, ext
.len
);
406 error_setg_errno(errp
, -ret
,
407 "ERROR: Could not read data file name");
411 printf("Qcow2: Got external data file %s\n", s
->image_data_file
);
417 /* unknown magic - save it in case we need to rewrite the header */
418 /* If you add a new feature, make sure to also update the fast
419 * path of qcow2_make_empty() to deal with it. */
421 Qcow2UnknownHeaderExtension
*uext
;
423 uext
= g_malloc0(sizeof(*uext
) + ext
.len
);
424 uext
->magic
= ext
.magic
;
426 QLIST_INSERT_HEAD(&s
->unknown_header_ext
, uext
, next
);
428 ret
= bdrv_pread(bs
->file
, offset
, uext
->data
, uext
->len
);
430 error_setg_errno(errp
, -ret
, "ERROR: unknown extension: "
431 "Could not read data");
438 offset
+= ((ext
.len
+ 7) & ~7);
444 static void cleanup_unknown_header_ext(BlockDriverState
*bs
)
446 BDRVQcow2State
*s
= bs
->opaque
;
447 Qcow2UnknownHeaderExtension
*uext
, *next
;
449 QLIST_FOREACH_SAFE(uext
, &s
->unknown_header_ext
, next
, next
) {
450 QLIST_REMOVE(uext
, next
);
455 static void report_unsupported_feature(Error
**errp
, Qcow2Feature
*table
,
458 char *features
= g_strdup("");
461 while (table
&& table
->name
[0] != '\0') {
462 if (table
->type
== QCOW2_FEAT_TYPE_INCOMPATIBLE
) {
463 if (mask
& (1ULL << table
->bit
)) {
465 features
= g_strdup_printf("%s%s%.46s", old
, *old
? ", " : "",
468 mask
&= ~(1ULL << table
->bit
);
476 features
= g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64
,
477 old
, *old
? ", " : "", mask
);
481 error_setg(errp
, "Unsupported qcow2 feature(s): %s", features
);
486 * Sets the dirty bit and flushes afterwards if necessary.
488 * The incompatible_features bit is only set if the image file header was
489 * updated successfully. Therefore it is not required to check the return
490 * value of this function.
492 int qcow2_mark_dirty(BlockDriverState
*bs
)
494 BDRVQcow2State
*s
= bs
->opaque
;
498 assert(s
->qcow_version
>= 3);
500 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
501 return 0; /* already dirty */
504 val
= cpu_to_be64(s
->incompatible_features
| QCOW2_INCOMPAT_DIRTY
);
505 ret
= bdrv_pwrite(bs
->file
, offsetof(QCowHeader
, incompatible_features
),
510 ret
= bdrv_flush(bs
->file
->bs
);
515 /* Only treat image as dirty if the header was updated successfully */
516 s
->incompatible_features
|= QCOW2_INCOMPAT_DIRTY
;
521 * Clears the dirty bit and flushes before if necessary. Only call this
522 * function when there are no pending requests, it does not guard against
523 * concurrent requests dirtying the image.
525 static int qcow2_mark_clean(BlockDriverState
*bs
)
527 BDRVQcow2State
*s
= bs
->opaque
;
529 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
532 s
->incompatible_features
&= ~QCOW2_INCOMPAT_DIRTY
;
534 ret
= qcow2_flush_caches(bs
);
539 return qcow2_update_header(bs
);
545 * Marks the image as corrupt.
547 int qcow2_mark_corrupt(BlockDriverState
*bs
)
549 BDRVQcow2State
*s
= bs
->opaque
;
551 s
->incompatible_features
|= QCOW2_INCOMPAT_CORRUPT
;
552 return qcow2_update_header(bs
);
556 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes
557 * before if necessary.
559 int qcow2_mark_consistent(BlockDriverState
*bs
)
561 BDRVQcow2State
*s
= bs
->opaque
;
563 if (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
) {
564 int ret
= qcow2_flush_caches(bs
);
569 s
->incompatible_features
&= ~QCOW2_INCOMPAT_CORRUPT
;
570 return qcow2_update_header(bs
);
575 static int coroutine_fn
qcow2_co_check_locked(BlockDriverState
*bs
,
576 BdrvCheckResult
*result
,
579 int ret
= qcow2_check_refcounts(bs
, result
, fix
);
584 if (fix
&& result
->check_errors
== 0 && result
->corruptions
== 0) {
585 ret
= qcow2_mark_clean(bs
);
589 return qcow2_mark_consistent(bs
);
594 static int coroutine_fn
qcow2_co_check(BlockDriverState
*bs
,
595 BdrvCheckResult
*result
,
598 BDRVQcow2State
*s
= bs
->opaque
;
601 qemu_co_mutex_lock(&s
->lock
);
602 ret
= qcow2_co_check_locked(bs
, result
, fix
);
603 qemu_co_mutex_unlock(&s
->lock
);
607 int qcow2_validate_table(BlockDriverState
*bs
, uint64_t offset
,
608 uint64_t entries
, size_t entry_len
,
609 int64_t max_size_bytes
, const char *table_name
,
612 BDRVQcow2State
*s
= bs
->opaque
;
614 if (entries
> max_size_bytes
/ entry_len
) {
615 error_setg(errp
, "%s too large", table_name
);
619 /* Use signed INT64_MAX as the maximum even for uint64_t header fields,
620 * because values will be passed to qemu functions taking int64_t. */
621 if ((INT64_MAX
- entries
* entry_len
< offset
) ||
622 (offset_into_cluster(s
, offset
) != 0)) {
623 error_setg(errp
, "%s offset invalid", table_name
);
630 static const char *const mutable_opts
[] = {
631 QCOW2_OPT_LAZY_REFCOUNTS
,
632 QCOW2_OPT_DISCARD_REQUEST
,
633 QCOW2_OPT_DISCARD_SNAPSHOT
,
634 QCOW2_OPT_DISCARD_OTHER
,
636 QCOW2_OPT_OVERLAP_TEMPLATE
,
637 QCOW2_OPT_OVERLAP_MAIN_HEADER
,
638 QCOW2_OPT_OVERLAP_ACTIVE_L1
,
639 QCOW2_OPT_OVERLAP_ACTIVE_L2
,
640 QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
641 QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
642 QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
643 QCOW2_OPT_OVERLAP_INACTIVE_L1
,
644 QCOW2_OPT_OVERLAP_INACTIVE_L2
,
645 QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY
,
646 QCOW2_OPT_CACHE_SIZE
,
647 QCOW2_OPT_L2_CACHE_SIZE
,
648 QCOW2_OPT_L2_CACHE_ENTRY_SIZE
,
649 QCOW2_OPT_REFCOUNT_CACHE_SIZE
,
650 QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
654 static QemuOptsList qcow2_runtime_opts
= {
656 .head
= QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts
.head
),
659 .name
= QCOW2_OPT_LAZY_REFCOUNTS
,
660 .type
= QEMU_OPT_BOOL
,
661 .help
= "Postpone refcount updates",
664 .name
= QCOW2_OPT_DISCARD_REQUEST
,
665 .type
= QEMU_OPT_BOOL
,
666 .help
= "Pass guest discard requests to the layer below",
669 .name
= QCOW2_OPT_DISCARD_SNAPSHOT
,
670 .type
= QEMU_OPT_BOOL
,
671 .help
= "Generate discard requests when snapshot related space "
675 .name
= QCOW2_OPT_DISCARD_OTHER
,
676 .type
= QEMU_OPT_BOOL
,
677 .help
= "Generate discard requests when other clusters are freed",
680 .name
= QCOW2_OPT_OVERLAP
,
681 .type
= QEMU_OPT_STRING
,
682 .help
= "Selects which overlap checks to perform from a range of "
683 "templates (none, constant, cached, all)",
686 .name
= QCOW2_OPT_OVERLAP_TEMPLATE
,
687 .type
= QEMU_OPT_STRING
,
688 .help
= "Selects which overlap checks to perform from a range of "
689 "templates (none, constant, cached, all)",
692 .name
= QCOW2_OPT_OVERLAP_MAIN_HEADER
,
693 .type
= QEMU_OPT_BOOL
,
694 .help
= "Check for unintended writes into the main qcow2 header",
697 .name
= QCOW2_OPT_OVERLAP_ACTIVE_L1
,
698 .type
= QEMU_OPT_BOOL
,
699 .help
= "Check for unintended writes into the active L1 table",
702 .name
= QCOW2_OPT_OVERLAP_ACTIVE_L2
,
703 .type
= QEMU_OPT_BOOL
,
704 .help
= "Check for unintended writes into an active L2 table",
707 .name
= QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
708 .type
= QEMU_OPT_BOOL
,
709 .help
= "Check for unintended writes into the refcount table",
712 .name
= QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
713 .type
= QEMU_OPT_BOOL
,
714 .help
= "Check for unintended writes into a refcount block",
717 .name
= QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
718 .type
= QEMU_OPT_BOOL
,
719 .help
= "Check for unintended writes into the snapshot table",
722 .name
= QCOW2_OPT_OVERLAP_INACTIVE_L1
,
723 .type
= QEMU_OPT_BOOL
,
724 .help
= "Check for unintended writes into an inactive L1 table",
727 .name
= QCOW2_OPT_OVERLAP_INACTIVE_L2
,
728 .type
= QEMU_OPT_BOOL
,
729 .help
= "Check for unintended writes into an inactive L2 table",
732 .name
= QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY
,
733 .type
= QEMU_OPT_BOOL
,
734 .help
= "Check for unintended writes into the bitmap directory",
737 .name
= QCOW2_OPT_CACHE_SIZE
,
738 .type
= QEMU_OPT_SIZE
,
739 .help
= "Maximum combined metadata (L2 tables and refcount blocks) "
743 .name
= QCOW2_OPT_L2_CACHE_SIZE
,
744 .type
= QEMU_OPT_SIZE
,
745 .help
= "Maximum L2 table cache size",
748 .name
= QCOW2_OPT_L2_CACHE_ENTRY_SIZE
,
749 .type
= QEMU_OPT_SIZE
,
750 .help
= "Size of each entry in the L2 cache",
753 .name
= QCOW2_OPT_REFCOUNT_CACHE_SIZE
,
754 .type
= QEMU_OPT_SIZE
,
755 .help
= "Maximum refcount block cache size",
758 .name
= QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
759 .type
= QEMU_OPT_NUMBER
,
760 .help
= "Clean unused cache entries after this time (in seconds)",
762 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
763 "ID of secret providing qcow2 AES key or LUKS passphrase"),
764 { /* end of list */ }
768 static const char *overlap_bool_option_names
[QCOW2_OL_MAX_BITNR
] = {
769 [QCOW2_OL_MAIN_HEADER_BITNR
] = QCOW2_OPT_OVERLAP_MAIN_HEADER
,
770 [QCOW2_OL_ACTIVE_L1_BITNR
] = QCOW2_OPT_OVERLAP_ACTIVE_L1
,
771 [QCOW2_OL_ACTIVE_L2_BITNR
] = QCOW2_OPT_OVERLAP_ACTIVE_L2
,
772 [QCOW2_OL_REFCOUNT_TABLE_BITNR
] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
773 [QCOW2_OL_REFCOUNT_BLOCK_BITNR
] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
774 [QCOW2_OL_SNAPSHOT_TABLE_BITNR
] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
775 [QCOW2_OL_INACTIVE_L1_BITNR
] = QCOW2_OPT_OVERLAP_INACTIVE_L1
,
776 [QCOW2_OL_INACTIVE_L2_BITNR
] = QCOW2_OPT_OVERLAP_INACTIVE_L2
,
777 [QCOW2_OL_BITMAP_DIRECTORY_BITNR
] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY
,
780 static void cache_clean_timer_cb(void *opaque
)
782 BlockDriverState
*bs
= opaque
;
783 BDRVQcow2State
*s
= bs
->opaque
;
784 qcow2_cache_clean_unused(s
->l2_table_cache
);
785 qcow2_cache_clean_unused(s
->refcount_block_cache
);
786 timer_mod(s
->cache_clean_timer
, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
) +
787 (int64_t) s
->cache_clean_interval
* 1000);
790 static void cache_clean_timer_init(BlockDriverState
*bs
, AioContext
*context
)
792 BDRVQcow2State
*s
= bs
->opaque
;
793 if (s
->cache_clean_interval
> 0) {
794 s
->cache_clean_timer
= aio_timer_new(context
, QEMU_CLOCK_VIRTUAL
,
795 SCALE_MS
, cache_clean_timer_cb
,
797 timer_mod(s
->cache_clean_timer
, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
) +
798 (int64_t) s
->cache_clean_interval
* 1000);
802 static void cache_clean_timer_del(BlockDriverState
*bs
)
804 BDRVQcow2State
*s
= bs
->opaque
;
805 if (s
->cache_clean_timer
) {
806 timer_del(s
->cache_clean_timer
);
807 timer_free(s
->cache_clean_timer
);
808 s
->cache_clean_timer
= NULL
;
812 static void qcow2_detach_aio_context(BlockDriverState
*bs
)
814 cache_clean_timer_del(bs
);
817 static void qcow2_attach_aio_context(BlockDriverState
*bs
,
818 AioContext
*new_context
)
820 cache_clean_timer_init(bs
, new_context
);
823 static void read_cache_sizes(BlockDriverState
*bs
, QemuOpts
*opts
,
824 uint64_t *l2_cache_size
,
825 uint64_t *l2_cache_entry_size
,
826 uint64_t *refcount_cache_size
, Error
**errp
)
828 BDRVQcow2State
*s
= bs
->opaque
;
829 uint64_t combined_cache_size
, l2_cache_max_setting
;
830 bool l2_cache_size_set
, refcount_cache_size_set
, combined_cache_size_set
;
831 bool l2_cache_entry_size_set
;
832 int min_refcount_cache
= MIN_REFCOUNT_CACHE_SIZE
* s
->cluster_size
;
833 uint64_t virtual_disk_size
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
834 uint64_t max_l2_cache
= virtual_disk_size
/ (s
->cluster_size
/ 8);
836 combined_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_CACHE_SIZE
);
837 l2_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_L2_CACHE_SIZE
);
838 refcount_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
839 l2_cache_entry_size_set
= qemu_opt_get(opts
, QCOW2_OPT_L2_CACHE_ENTRY_SIZE
);
841 combined_cache_size
= qemu_opt_get_size(opts
, QCOW2_OPT_CACHE_SIZE
, 0);
842 l2_cache_max_setting
= qemu_opt_get_size(opts
, QCOW2_OPT_L2_CACHE_SIZE
,
843 DEFAULT_L2_CACHE_MAX_SIZE
);
844 *refcount_cache_size
= qemu_opt_get_size(opts
,
845 QCOW2_OPT_REFCOUNT_CACHE_SIZE
, 0);
847 *l2_cache_entry_size
= qemu_opt_get_size(
848 opts
, QCOW2_OPT_L2_CACHE_ENTRY_SIZE
, s
->cluster_size
);
850 *l2_cache_size
= MIN(max_l2_cache
, l2_cache_max_setting
);
852 if (combined_cache_size_set
) {
853 if (l2_cache_size_set
&& refcount_cache_size_set
) {
854 error_setg(errp
, QCOW2_OPT_CACHE_SIZE
", " QCOW2_OPT_L2_CACHE_SIZE
855 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE
" may not be set "
858 } else if (l2_cache_size_set
&&
859 (l2_cache_max_setting
> combined_cache_size
)) {
860 error_setg(errp
, QCOW2_OPT_L2_CACHE_SIZE
" may not exceed "
861 QCOW2_OPT_CACHE_SIZE
);
863 } else if (*refcount_cache_size
> combined_cache_size
) {
864 error_setg(errp
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
" may not exceed "
865 QCOW2_OPT_CACHE_SIZE
);
869 if (l2_cache_size_set
) {
870 *refcount_cache_size
= combined_cache_size
- *l2_cache_size
;
871 } else if (refcount_cache_size_set
) {
872 *l2_cache_size
= combined_cache_size
- *refcount_cache_size
;
874 /* Assign as much memory as possible to the L2 cache, and
875 * use the remainder for the refcount cache */
876 if (combined_cache_size
>= max_l2_cache
+ min_refcount_cache
) {
877 *l2_cache_size
= max_l2_cache
;
878 *refcount_cache_size
= combined_cache_size
- *l2_cache_size
;
880 *refcount_cache_size
=
881 MIN(combined_cache_size
, min_refcount_cache
);
882 *l2_cache_size
= combined_cache_size
- *refcount_cache_size
;
888 * If the L2 cache is not enough to cover the whole disk then
889 * default to 4KB entries. Smaller entries reduce the cost of
890 * loads and evictions and increase I/O performance.
892 if (*l2_cache_size
< max_l2_cache
&& !l2_cache_entry_size_set
) {
893 *l2_cache_entry_size
= MIN(s
->cluster_size
, 4096);
896 /* l2_cache_size and refcount_cache_size are ensured to have at least
897 * their minimum values in qcow2_update_options_prepare() */
899 if (*l2_cache_entry_size
< (1 << MIN_CLUSTER_BITS
) ||
900 *l2_cache_entry_size
> s
->cluster_size
||
901 !is_power_of_2(*l2_cache_entry_size
)) {
902 error_setg(errp
, "L2 cache entry size must be a power of two "
903 "between %d and the cluster size (%d)",
904 1 << MIN_CLUSTER_BITS
, s
->cluster_size
);
909 typedef struct Qcow2ReopenState
{
910 Qcow2Cache
*l2_table_cache
;
911 Qcow2Cache
*refcount_block_cache
;
912 int l2_slice_size
; /* Number of entries in a slice of the L2 table */
913 bool use_lazy_refcounts
;
915 bool discard_passthrough
[QCOW2_DISCARD_MAX
];
916 uint64_t cache_clean_interval
;
917 QCryptoBlockOpenOptions
*crypto_opts
; /* Disk encryption runtime options */
920 static int qcow2_update_options_prepare(BlockDriverState
*bs
,
922 QDict
*options
, int flags
,
925 BDRVQcow2State
*s
= bs
->opaque
;
926 QemuOpts
*opts
= NULL
;
927 const char *opt_overlap_check
, *opt_overlap_check_template
;
928 int overlap_check_template
= 0;
929 uint64_t l2_cache_size
, l2_cache_entry_size
, refcount_cache_size
;
931 const char *encryptfmt
;
932 QDict
*encryptopts
= NULL
;
933 Error
*local_err
= NULL
;
936 qdict_extract_subqdict(options
, &encryptopts
, "encrypt.");
937 encryptfmt
= qdict_get_try_str(encryptopts
, "format");
939 opts
= qemu_opts_create(&qcow2_runtime_opts
, NULL
, 0, &error_abort
);
940 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
942 error_propagate(errp
, local_err
);
947 /* get L2 table/refcount block cache size from command line options */
948 read_cache_sizes(bs
, opts
, &l2_cache_size
, &l2_cache_entry_size
,
949 &refcount_cache_size
, &local_err
);
951 error_propagate(errp
, local_err
);
956 l2_cache_size
/= l2_cache_entry_size
;
957 if (l2_cache_size
< MIN_L2_CACHE_SIZE
) {
958 l2_cache_size
= MIN_L2_CACHE_SIZE
;
960 if (l2_cache_size
> INT_MAX
) {
961 error_setg(errp
, "L2 cache size too big");
966 refcount_cache_size
/= s
->cluster_size
;
967 if (refcount_cache_size
< MIN_REFCOUNT_CACHE_SIZE
) {
968 refcount_cache_size
= MIN_REFCOUNT_CACHE_SIZE
;
970 if (refcount_cache_size
> INT_MAX
) {
971 error_setg(errp
, "Refcount cache size too big");
976 /* alloc new L2 table/refcount block cache, flush old one */
977 if (s
->l2_table_cache
) {
978 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
980 error_setg_errno(errp
, -ret
, "Failed to flush the L2 table cache");
985 if (s
->refcount_block_cache
) {
986 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
988 error_setg_errno(errp
, -ret
,
989 "Failed to flush the refcount block cache");
994 r
->l2_slice_size
= l2_cache_entry_size
/ sizeof(uint64_t);
995 r
->l2_table_cache
= qcow2_cache_create(bs
, l2_cache_size
,
996 l2_cache_entry_size
);
997 r
->refcount_block_cache
= qcow2_cache_create(bs
, refcount_cache_size
,
999 if (r
->l2_table_cache
== NULL
|| r
->refcount_block_cache
== NULL
) {
1000 error_setg(errp
, "Could not allocate metadata caches");
1005 /* New interval for cache cleanup timer */
1006 r
->cache_clean_interval
=
1007 qemu_opt_get_number(opts
, QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
1008 DEFAULT_CACHE_CLEAN_INTERVAL
);
1009 #ifndef CONFIG_LINUX
1010 if (r
->cache_clean_interval
!= 0) {
1011 error_setg(errp
, QCOW2_OPT_CACHE_CLEAN_INTERVAL
1012 " not supported on this host");
1017 if (r
->cache_clean_interval
> UINT_MAX
) {
1018 error_setg(errp
, "Cache clean interval too big");
1023 /* lazy-refcounts; flush if going from enabled to disabled */
1024 r
->use_lazy_refcounts
= qemu_opt_get_bool(opts
, QCOW2_OPT_LAZY_REFCOUNTS
,
1025 (s
->compatible_features
& QCOW2_COMPAT_LAZY_REFCOUNTS
));
1026 if (r
->use_lazy_refcounts
&& s
->qcow_version
< 3) {
1027 error_setg(errp
, "Lazy refcounts require a qcow2 image with at least "
1028 "qemu 1.1 compatibility level");
1033 if (s
->use_lazy_refcounts
&& !r
->use_lazy_refcounts
) {
1034 ret
= qcow2_mark_clean(bs
);
1036 error_setg_errno(errp
, -ret
, "Failed to disable lazy refcounts");
1041 /* Overlap check options */
1042 opt_overlap_check
= qemu_opt_get(opts
, QCOW2_OPT_OVERLAP
);
1043 opt_overlap_check_template
= qemu_opt_get(opts
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1044 if (opt_overlap_check_template
&& opt_overlap_check
&&
1045 strcmp(opt_overlap_check_template
, opt_overlap_check
))
1047 error_setg(errp
, "Conflicting values for qcow2 options '"
1048 QCOW2_OPT_OVERLAP
"' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE
1049 "' ('%s')", opt_overlap_check
, opt_overlap_check_template
);
1053 if (!opt_overlap_check
) {
1054 opt_overlap_check
= opt_overlap_check_template
?: "cached";
1057 if (!strcmp(opt_overlap_check
, "none")) {
1058 overlap_check_template
= 0;
1059 } else if (!strcmp(opt_overlap_check
, "constant")) {
1060 overlap_check_template
= QCOW2_OL_CONSTANT
;
1061 } else if (!strcmp(opt_overlap_check
, "cached")) {
1062 overlap_check_template
= QCOW2_OL_CACHED
;
1063 } else if (!strcmp(opt_overlap_check
, "all")) {
1064 overlap_check_template
= QCOW2_OL_ALL
;
1066 error_setg(errp
, "Unsupported value '%s' for qcow2 option "
1067 "'overlap-check'. Allowed are any of the following: "
1068 "none, constant, cached, all", opt_overlap_check
);
1073 r
->overlap_check
= 0;
1074 for (i
= 0; i
< QCOW2_OL_MAX_BITNR
; i
++) {
1075 /* overlap-check defines a template bitmask, but every flag may be
1076 * overwritten through the associated boolean option */
1078 qemu_opt_get_bool(opts
, overlap_bool_option_names
[i
],
1079 overlap_check_template
& (1 << i
)) << i
;
1082 r
->discard_passthrough
[QCOW2_DISCARD_NEVER
] = false;
1083 r
->discard_passthrough
[QCOW2_DISCARD_ALWAYS
] = true;
1084 r
->discard_passthrough
[QCOW2_DISCARD_REQUEST
] =
1085 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_REQUEST
,
1086 flags
& BDRV_O_UNMAP
);
1087 r
->discard_passthrough
[QCOW2_DISCARD_SNAPSHOT
] =
1088 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_SNAPSHOT
, true);
1089 r
->discard_passthrough
[QCOW2_DISCARD_OTHER
] =
1090 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_OTHER
, false);
1092 switch (s
->crypt_method_header
) {
1093 case QCOW_CRYPT_NONE
:
1095 error_setg(errp
, "No encryption in image header, but options "
1096 "specified format '%s'", encryptfmt
);
1102 case QCOW_CRYPT_AES
:
1103 if (encryptfmt
&& !g_str_equal(encryptfmt
, "aes")) {
1105 "Header reported 'aes' encryption format but "
1106 "options specify '%s'", encryptfmt
);
1110 qdict_put_str(encryptopts
, "format", "qcow");
1111 r
->crypto_opts
= block_crypto_open_opts_init(encryptopts
, errp
);
1114 case QCOW_CRYPT_LUKS
:
1115 if (encryptfmt
&& !g_str_equal(encryptfmt
, "luks")) {
1117 "Header reported 'luks' encryption format but "
1118 "options specify '%s'", encryptfmt
);
1122 qdict_put_str(encryptopts
, "format", "luks");
1123 r
->crypto_opts
= block_crypto_open_opts_init(encryptopts
, errp
);
1127 error_setg(errp
, "Unsupported encryption method %d",
1128 s
->crypt_method_header
);
1131 if (s
->crypt_method_header
!= QCOW_CRYPT_NONE
&& !r
->crypto_opts
) {
1138 qobject_unref(encryptopts
);
1139 qemu_opts_del(opts
);
1144 static void qcow2_update_options_commit(BlockDriverState
*bs
,
1145 Qcow2ReopenState
*r
)
1147 BDRVQcow2State
*s
= bs
->opaque
;
1150 if (s
->l2_table_cache
) {
1151 qcow2_cache_destroy(s
->l2_table_cache
);
1153 if (s
->refcount_block_cache
) {
1154 qcow2_cache_destroy(s
->refcount_block_cache
);
1156 s
->l2_table_cache
= r
->l2_table_cache
;
1157 s
->refcount_block_cache
= r
->refcount_block_cache
;
1158 s
->l2_slice_size
= r
->l2_slice_size
;
1160 s
->overlap_check
= r
->overlap_check
;
1161 s
->use_lazy_refcounts
= r
->use_lazy_refcounts
;
1163 for (i
= 0; i
< QCOW2_DISCARD_MAX
; i
++) {
1164 s
->discard_passthrough
[i
] = r
->discard_passthrough
[i
];
1167 if (s
->cache_clean_interval
!= r
->cache_clean_interval
) {
1168 cache_clean_timer_del(bs
);
1169 s
->cache_clean_interval
= r
->cache_clean_interval
;
1170 cache_clean_timer_init(bs
, bdrv_get_aio_context(bs
));
1173 qapi_free_QCryptoBlockOpenOptions(s
->crypto_opts
);
1174 s
->crypto_opts
= r
->crypto_opts
;
1177 static void qcow2_update_options_abort(BlockDriverState
*bs
,
1178 Qcow2ReopenState
*r
)
1180 if (r
->l2_table_cache
) {
1181 qcow2_cache_destroy(r
->l2_table_cache
);
1183 if (r
->refcount_block_cache
) {
1184 qcow2_cache_destroy(r
->refcount_block_cache
);
1186 qapi_free_QCryptoBlockOpenOptions(r
->crypto_opts
);
1189 static int qcow2_update_options(BlockDriverState
*bs
, QDict
*options
,
1190 int flags
, Error
**errp
)
1192 Qcow2ReopenState r
= {};
1195 ret
= qcow2_update_options_prepare(bs
, &r
, options
, flags
, errp
);
1197 qcow2_update_options_commit(bs
, &r
);
1199 qcow2_update_options_abort(bs
, &r
);
1205 /* Called with s->lock held. */
1206 static int coroutine_fn
qcow2_do_open(BlockDriverState
*bs
, QDict
*options
,
1207 int flags
, Error
**errp
)
1209 BDRVQcow2State
*s
= bs
->opaque
;
1210 unsigned int len
, i
;
1213 Error
*local_err
= NULL
;
1215 uint64_t l1_vm_state_index
;
1216 bool update_header
= false;
1218 ret
= bdrv_pread(bs
->file
, 0, &header
, sizeof(header
));
1220 error_setg_errno(errp
, -ret
, "Could not read qcow2 header");
1223 header
.magic
= be32_to_cpu(header
.magic
);
1224 header
.version
= be32_to_cpu(header
.version
);
1225 header
.backing_file_offset
= be64_to_cpu(header
.backing_file_offset
);
1226 header
.backing_file_size
= be32_to_cpu(header
.backing_file_size
);
1227 header
.size
= be64_to_cpu(header
.size
);
1228 header
.cluster_bits
= be32_to_cpu(header
.cluster_bits
);
1229 header
.crypt_method
= be32_to_cpu(header
.crypt_method
);
1230 header
.l1_table_offset
= be64_to_cpu(header
.l1_table_offset
);
1231 header
.l1_size
= be32_to_cpu(header
.l1_size
);
1232 header
.refcount_table_offset
= be64_to_cpu(header
.refcount_table_offset
);
1233 header
.refcount_table_clusters
=
1234 be32_to_cpu(header
.refcount_table_clusters
);
1235 header
.snapshots_offset
= be64_to_cpu(header
.snapshots_offset
);
1236 header
.nb_snapshots
= be32_to_cpu(header
.nb_snapshots
);
1238 if (header
.magic
!= QCOW_MAGIC
) {
1239 error_setg(errp
, "Image is not in qcow2 format");
1243 if (header
.version
< 2 || header
.version
> 3) {
1244 error_setg(errp
, "Unsupported qcow2 version %" PRIu32
, header
.version
);
1249 s
->qcow_version
= header
.version
;
1251 /* Initialise cluster size */
1252 if (header
.cluster_bits
< MIN_CLUSTER_BITS
||
1253 header
.cluster_bits
> MAX_CLUSTER_BITS
) {
1254 error_setg(errp
, "Unsupported cluster size: 2^%" PRIu32
,
1255 header
.cluster_bits
);
1260 s
->cluster_bits
= header
.cluster_bits
;
1261 s
->cluster_size
= 1 << s
->cluster_bits
;
1263 /* Initialise version 3 header fields */
1264 if (header
.version
== 2) {
1265 header
.incompatible_features
= 0;
1266 header
.compatible_features
= 0;
1267 header
.autoclear_features
= 0;
1268 header
.refcount_order
= 4;
1269 header
.header_length
= 72;
1271 header
.incompatible_features
=
1272 be64_to_cpu(header
.incompatible_features
);
1273 header
.compatible_features
= be64_to_cpu(header
.compatible_features
);
1274 header
.autoclear_features
= be64_to_cpu(header
.autoclear_features
);
1275 header
.refcount_order
= be32_to_cpu(header
.refcount_order
);
1276 header
.header_length
= be32_to_cpu(header
.header_length
);
1278 if (header
.header_length
< 104) {
1279 error_setg(errp
, "qcow2 header too short");
1285 if (header
.header_length
> s
->cluster_size
) {
1286 error_setg(errp
, "qcow2 header exceeds cluster size");
1291 if (header
.header_length
> sizeof(header
)) {
1292 s
->unknown_header_fields_size
= header
.header_length
- sizeof(header
);
1293 s
->unknown_header_fields
= g_malloc(s
->unknown_header_fields_size
);
1294 ret
= bdrv_pread(bs
->file
, sizeof(header
), s
->unknown_header_fields
,
1295 s
->unknown_header_fields_size
);
1297 error_setg_errno(errp
, -ret
, "Could not read unknown qcow2 header "
1303 if (header
.backing_file_offset
> s
->cluster_size
) {
1304 error_setg(errp
, "Invalid backing file offset");
1309 if (header
.backing_file_offset
) {
1310 ext_end
= header
.backing_file_offset
;
1312 ext_end
= 1 << header
.cluster_bits
;
1315 /* Handle feature bits */
1316 s
->incompatible_features
= header
.incompatible_features
;
1317 s
->compatible_features
= header
.compatible_features
;
1318 s
->autoclear_features
= header
.autoclear_features
;
1320 if (s
->incompatible_features
& ~QCOW2_INCOMPAT_MASK
) {
1321 void *feature_table
= NULL
;
1322 qcow2_read_extensions(bs
, header
.header_length
, ext_end
,
1323 &feature_table
, flags
, NULL
, NULL
);
1324 report_unsupported_feature(errp
, feature_table
,
1325 s
->incompatible_features
&
1326 ~QCOW2_INCOMPAT_MASK
);
1328 g_free(feature_table
);
1332 if (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
) {
1333 /* Corrupt images may not be written to unless they are being repaired
1335 if ((flags
& BDRV_O_RDWR
) && !(flags
& BDRV_O_CHECK
)) {
1336 error_setg(errp
, "qcow2: Image is corrupt; cannot be opened "
1343 /* Check support for various header values */
1344 if (header
.refcount_order
> 6) {
1345 error_setg(errp
, "Reference count entry width too large; may not "
1350 s
->refcount_order
= header
.refcount_order
;
1351 s
->refcount_bits
= 1 << s
->refcount_order
;
1352 s
->refcount_max
= UINT64_C(1) << (s
->refcount_bits
- 1);
1353 s
->refcount_max
+= s
->refcount_max
- 1;
1355 s
->crypt_method_header
= header
.crypt_method
;
1356 if (s
->crypt_method_header
) {
1357 if (bdrv_uses_whitelist() &&
1358 s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1360 "Use of AES-CBC encrypted qcow2 images is no longer "
1361 "supported in system emulators");
1362 error_append_hint(errp
,
1363 "You can use 'qemu-img convert' to convert your "
1364 "image to an alternative supported format, such "
1365 "as unencrypted qcow2, or raw with the LUKS "
1366 "format instead.\n");
1371 if (s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1372 s
->crypt_physical_offset
= false;
1374 /* Assuming LUKS and any future crypt methods we
1375 * add will all use physical offsets, due to the
1376 * fact that the alternative is insecure... */
1377 s
->crypt_physical_offset
= true;
1380 bs
->encrypted
= true;
1383 s
->l2_bits
= s
->cluster_bits
- 3; /* L2 is always one cluster */
1384 s
->l2_size
= 1 << s
->l2_bits
;
1385 /* 2^(s->refcount_order - 3) is the refcount width in bytes */
1386 s
->refcount_block_bits
= s
->cluster_bits
- (s
->refcount_order
- 3);
1387 s
->refcount_block_size
= 1 << s
->refcount_block_bits
;
1388 bs
->total_sectors
= header
.size
/ BDRV_SECTOR_SIZE
;
1389 s
->csize_shift
= (62 - (s
->cluster_bits
- 8));
1390 s
->csize_mask
= (1 << (s
->cluster_bits
- 8)) - 1;
1391 s
->cluster_offset_mask
= (1LL << s
->csize_shift
) - 1;
1393 s
->refcount_table_offset
= header
.refcount_table_offset
;
1394 s
->refcount_table_size
=
1395 header
.refcount_table_clusters
<< (s
->cluster_bits
- 3);
1397 if (header
.refcount_table_clusters
== 0 && !(flags
& BDRV_O_CHECK
)) {
1398 error_setg(errp
, "Image does not contain a reference count table");
1403 ret
= qcow2_validate_table(bs
, s
->refcount_table_offset
,
1404 header
.refcount_table_clusters
,
1405 s
->cluster_size
, QCOW_MAX_REFTABLE_SIZE
,
1406 "Reference count table", errp
);
1411 /* The total size in bytes of the snapshot table is checked in
1412 * qcow2_read_snapshots() because the size of each snapshot is
1413 * variable and we don't know it yet.
1414 * Here we only check the offset and number of snapshots. */
1415 ret
= qcow2_validate_table(bs
, header
.snapshots_offset
,
1416 header
.nb_snapshots
,
1417 sizeof(QCowSnapshotHeader
),
1418 sizeof(QCowSnapshotHeader
) * QCOW_MAX_SNAPSHOTS
,
1419 "Snapshot table", errp
);
1424 /* read the level 1 table */
1425 ret
= qcow2_validate_table(bs
, header
.l1_table_offset
,
1426 header
.l1_size
, sizeof(uint64_t),
1427 QCOW_MAX_L1_SIZE
, "Active L1 table", errp
);
1431 s
->l1_size
= header
.l1_size
;
1432 s
->l1_table_offset
= header
.l1_table_offset
;
1434 l1_vm_state_index
= size_to_l1(s
, header
.size
);
1435 if (l1_vm_state_index
> INT_MAX
) {
1436 error_setg(errp
, "Image is too big");
1440 s
->l1_vm_state_index
= l1_vm_state_index
;
1442 /* the L1 table must contain at least enough entries to put
1443 header.size bytes */
1444 if (s
->l1_size
< s
->l1_vm_state_index
) {
1445 error_setg(errp
, "L1 table is too small");
1450 if (s
->l1_size
> 0) {
1451 s
->l1_table
= qemu_try_blockalign(bs
->file
->bs
,
1452 ROUND_UP(s
->l1_size
* sizeof(uint64_t), 512));
1453 if (s
->l1_table
== NULL
) {
1454 error_setg(errp
, "Could not allocate L1 table");
1458 ret
= bdrv_pread(bs
->file
, s
->l1_table_offset
, s
->l1_table
,
1459 s
->l1_size
* sizeof(uint64_t));
1461 error_setg_errno(errp
, -ret
, "Could not read L1 table");
1464 for(i
= 0;i
< s
->l1_size
; i
++) {
1465 s
->l1_table
[i
] = be64_to_cpu(s
->l1_table
[i
]);
1469 /* Parse driver-specific options */
1470 ret
= qcow2_update_options(bs
, options
, flags
, errp
);
1477 ret
= qcow2_refcount_init(bs
);
1479 error_setg_errno(errp
, -ret
, "Could not initialize refcount handling");
1483 QLIST_INIT(&s
->cluster_allocs
);
1484 QTAILQ_INIT(&s
->discards
);
1486 /* read qcow2 extensions */
1487 if (qcow2_read_extensions(bs
, header
.header_length
, ext_end
, NULL
,
1488 flags
, &update_header
, &local_err
)) {
1489 error_propagate(errp
, local_err
);
1494 /* Open external data file */
1495 s
->data_file
= bdrv_open_child(NULL
, options
, "data-file", bs
, &child_file
,
1498 error_propagate(errp
, local_err
);
1503 if (s
->incompatible_features
& QCOW2_INCOMPAT_DATA_FILE
) {
1504 if (!s
->data_file
&& s
->image_data_file
) {
1505 s
->data_file
= bdrv_open_child(s
->image_data_file
, options
,
1506 "data-file", bs
, &child_file
,
1508 if (!s
->data_file
) {
1513 if (!s
->data_file
) {
1514 error_setg(errp
, "'data-file' is required for this image");
1520 error_setg(errp
, "'data-file' can only be set for images with an "
1521 "external data file");
1526 s
->data_file
= bs
->file
;
1528 if (data_file_is_raw(bs
)) {
1529 error_setg(errp
, "data-file-raw requires a data file");
1535 /* qcow2_read_extension may have set up the crypto context
1536 * if the crypt method needs a header region, some methods
1537 * don't need header extensions, so must check here
1539 if (s
->crypt_method_header
&& !s
->crypto
) {
1540 if (s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1541 unsigned int cflags
= 0;
1542 if (flags
& BDRV_O_NO_IO
) {
1543 cflags
|= QCRYPTO_BLOCK_OPEN_NO_IO
;
1545 s
->crypto
= qcrypto_block_open(s
->crypto_opts
, "encrypt.",
1546 NULL
, NULL
, cflags
, 1, errp
);
1551 } else if (!(flags
& BDRV_O_NO_IO
)) {
1552 error_setg(errp
, "Missing CRYPTO header for crypt method %d",
1553 s
->crypt_method_header
);
1559 /* read the backing file name */
1560 if (header
.backing_file_offset
!= 0) {
1561 len
= header
.backing_file_size
;
1562 if (len
> MIN(1023, s
->cluster_size
- header
.backing_file_offset
) ||
1563 len
>= sizeof(bs
->backing_file
)) {
1564 error_setg(errp
, "Backing file name too long");
1568 ret
= bdrv_pread(bs
->file
, header
.backing_file_offset
,
1569 bs
->auto_backing_file
, len
);
1571 error_setg_errno(errp
, -ret
, "Could not read backing file name");
1574 bs
->auto_backing_file
[len
] = '\0';
1575 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
),
1576 bs
->auto_backing_file
);
1577 s
->image_backing_file
= g_strdup(bs
->auto_backing_file
);
1580 /* Internal snapshots */
1581 s
->snapshots_offset
= header
.snapshots_offset
;
1582 s
->nb_snapshots
= header
.nb_snapshots
;
1584 ret
= qcow2_read_snapshots(bs
);
1586 error_setg_errno(errp
, -ret
, "Could not read snapshots");
1590 /* Clear unknown autoclear feature bits */
1591 update_header
|= s
->autoclear_features
& ~QCOW2_AUTOCLEAR_MASK
;
1593 update_header
&& !bs
->read_only
&& !(flags
& BDRV_O_INACTIVE
);
1594 if (update_header
) {
1595 s
->autoclear_features
&= QCOW2_AUTOCLEAR_MASK
;
1598 /* == Handle persistent dirty bitmaps ==
1600 * We want load dirty bitmaps in three cases:
1602 * 1. Normal open of the disk in active mode, not related to invalidation
1605 * 2. Invalidation of the target vm after pre-copy phase of migration, if
1606 * bitmaps are _not_ migrating through migration channel, i.e.
1607 * 'dirty-bitmaps' capability is disabled.
1609 * 3. Invalidation of source vm after failed or canceled migration.
1610 * This is a very interesting case. There are two possible types of
1613 * A. Stored on inactivation and removed. They should be loaded from the
1616 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through
1617 * the migration channel (with dirty-bitmaps capability).
1619 * On the other hand, there are two possible sub-cases:
1621 * 3.1 disk was changed by somebody else while were inactive. In this
1622 * case all in-RAM dirty bitmaps (both persistent and not) are
1623 * definitely invalid. And we don't have any method to determine
1626 * Simple and safe thing is to just drop all the bitmaps of type B on
1627 * inactivation. But in this case we lose bitmaps in valid 4.2 case.
1629 * On the other hand, resuming source vm, if disk was already changed
1630 * is a bad thing anyway: not only bitmaps, the whole vm state is
1631 * out of sync with disk.
1633 * This means, that user or management tool, who for some reason
1634 * decided to resume source vm, after disk was already changed by
1635 * target vm, should at least drop all dirty bitmaps by hand.
1637 * So, we can ignore this case for now, but TODO: "generation"
1638 * extension for qcow2, to determine, that image was changed after
1639 * last inactivation. And if it is changed, we will drop (or at least
1640 * mark as 'invalid' all the bitmaps of type B, both persistent
1643 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved
1644 * to disk ('dirty-bitmaps' capability disabled), or not saved
1645 * ('dirty-bitmaps' capability enabled), but we don't need to care
1646 * of: let's load bitmaps as always: stored bitmaps will be loaded,
1647 * and not stored has flag IN_USE=1 in the image and will be skipped
1650 * One remaining possible case when we don't want load bitmaps:
1652 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or
1653 * will be loaded on invalidation, no needs try loading them before)
1656 if (!(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
)) {
1657 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */
1658 bool header_updated
= qcow2_load_dirty_bitmaps(bs
, &local_err
);
1660 update_header
= update_header
&& !header_updated
;
1662 if (local_err
!= NULL
) {
1663 error_propagate(errp
, local_err
);
1668 if (update_header
) {
1669 ret
= qcow2_update_header(bs
);
1671 error_setg_errno(errp
, -ret
, "Could not update qcow2 header");
1676 bs
->supported_zero_flags
= header
.version
>= 3 ? BDRV_REQ_MAY_UNMAP
: 0;
1678 /* Repair image if dirty */
1679 if (!(flags
& (BDRV_O_CHECK
| BDRV_O_INACTIVE
)) && !bs
->read_only
&&
1680 (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
)) {
1681 BdrvCheckResult result
= {0};
1683 ret
= qcow2_co_check_locked(bs
, &result
,
1684 BDRV_FIX_ERRORS
| BDRV_FIX_LEAKS
);
1685 if (ret
< 0 || result
.check_errors
) {
1689 error_setg_errno(errp
, -ret
, "Could not repair dirty image");
1696 BdrvCheckResult result
= {0};
1697 qcow2_check_refcounts(bs
, &result
, 0);
1701 qemu_co_queue_init(&s
->compress_wait_queue
);
1706 g_free(s
->image_data_file
);
1707 if (has_data_file(bs
)) {
1708 bdrv_unref_child(bs
, s
->data_file
);
1710 g_free(s
->unknown_header_fields
);
1711 cleanup_unknown_header_ext(bs
);
1712 qcow2_free_snapshots(bs
);
1713 qcow2_refcount_close(bs
);
1714 qemu_vfree(s
->l1_table
);
1715 /* else pre-write overlap checks in cache_destroy may crash */
1717 cache_clean_timer_del(bs
);
1718 if (s
->l2_table_cache
) {
1719 qcow2_cache_destroy(s
->l2_table_cache
);
1721 if (s
->refcount_block_cache
) {
1722 qcow2_cache_destroy(s
->refcount_block_cache
);
1724 qcrypto_block_free(s
->crypto
);
1725 qapi_free_QCryptoBlockOpenOptions(s
->crypto_opts
);
1729 typedef struct QCow2OpenCo
{
1730 BlockDriverState
*bs
;
1737 static void coroutine_fn
qcow2_open_entry(void *opaque
)
1739 QCow2OpenCo
*qoc
= opaque
;
1740 BDRVQcow2State
*s
= qoc
->bs
->opaque
;
1742 qemu_co_mutex_lock(&s
->lock
);
1743 qoc
->ret
= qcow2_do_open(qoc
->bs
, qoc
->options
, qoc
->flags
, qoc
->errp
);
1744 qemu_co_mutex_unlock(&s
->lock
);
1747 static int qcow2_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
1750 BDRVQcow2State
*s
= bs
->opaque
;
1759 bs
->file
= bdrv_open_child(NULL
, options
, "file", bs
, &child_file
,
1765 /* Initialise locks */
1766 qemu_co_mutex_init(&s
->lock
);
1768 if (qemu_in_coroutine()) {
1769 /* From bdrv_co_create. */
1770 qcow2_open_entry(&qoc
);
1772 assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1773 qemu_coroutine_enter(qemu_coroutine_create(qcow2_open_entry
, &qoc
));
1774 BDRV_POLL_WHILE(bs
, qoc
.ret
== -EINPROGRESS
);
1779 static void qcow2_refresh_limits(BlockDriverState
*bs
, Error
**errp
)
1781 BDRVQcow2State
*s
= bs
->opaque
;
1783 if (bs
->encrypted
) {
1784 /* Encryption works on a sector granularity */
1785 bs
->bl
.request_alignment
= qcrypto_block_get_sector_size(s
->crypto
);
1787 bs
->bl
.pwrite_zeroes_alignment
= s
->cluster_size
;
1788 bs
->bl
.pdiscard_alignment
= s
->cluster_size
;
1791 static int qcow2_reopen_prepare(BDRVReopenState
*state
,
1792 BlockReopenQueue
*queue
, Error
**errp
)
1794 Qcow2ReopenState
*r
;
1797 r
= g_new0(Qcow2ReopenState
, 1);
1800 ret
= qcow2_update_options_prepare(state
->bs
, r
, state
->options
,
1801 state
->flags
, errp
);
1806 /* We need to write out any unwritten data if we reopen read-only. */
1807 if ((state
->flags
& BDRV_O_RDWR
) == 0) {
1808 ret
= qcow2_reopen_bitmaps_ro(state
->bs
, errp
);
1813 ret
= bdrv_flush(state
->bs
);
1818 ret
= qcow2_mark_clean(state
->bs
);
1827 qcow2_update_options_abort(state
->bs
, r
);
1832 static void qcow2_reopen_commit(BDRVReopenState
*state
)
1834 qcow2_update_options_commit(state
->bs
, state
->opaque
);
1835 g_free(state
->opaque
);
1838 static void qcow2_reopen_abort(BDRVReopenState
*state
)
1840 qcow2_update_options_abort(state
->bs
, state
->opaque
);
1841 g_free(state
->opaque
);
1844 static void qcow2_join_options(QDict
*options
, QDict
*old_options
)
1846 bool has_new_overlap_template
=
1847 qdict_haskey(options
, QCOW2_OPT_OVERLAP
) ||
1848 qdict_haskey(options
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1849 bool has_new_total_cache_size
=
1850 qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
);
1851 bool has_all_cache_options
;
1853 /* New overlap template overrides all old overlap options */
1854 if (has_new_overlap_template
) {
1855 qdict_del(old_options
, QCOW2_OPT_OVERLAP
);
1856 qdict_del(old_options
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1857 qdict_del(old_options
, QCOW2_OPT_OVERLAP_MAIN_HEADER
);
1858 qdict_del(old_options
, QCOW2_OPT_OVERLAP_ACTIVE_L1
);
1859 qdict_del(old_options
, QCOW2_OPT_OVERLAP_ACTIVE_L2
);
1860 qdict_del(old_options
, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
);
1861 qdict_del(old_options
, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
);
1862 qdict_del(old_options
, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
);
1863 qdict_del(old_options
, QCOW2_OPT_OVERLAP_INACTIVE_L1
);
1864 qdict_del(old_options
, QCOW2_OPT_OVERLAP_INACTIVE_L2
);
1867 /* New total cache size overrides all old options */
1868 if (qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
)) {
1869 qdict_del(old_options
, QCOW2_OPT_L2_CACHE_SIZE
);
1870 qdict_del(old_options
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
1873 qdict_join(options
, old_options
, false);
1876 * If after merging all cache size options are set, an old total size is
1877 * overwritten. Do keep all options, however, if all three are new. The
1878 * resulting error message is what we want to happen.
1880 has_all_cache_options
=
1881 qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
) ||
1882 qdict_haskey(options
, QCOW2_OPT_L2_CACHE_SIZE
) ||
1883 qdict_haskey(options
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
1885 if (has_all_cache_options
&& !has_new_total_cache_size
) {
1886 qdict_del(options
, QCOW2_OPT_CACHE_SIZE
);
1890 static int coroutine_fn
qcow2_co_block_status(BlockDriverState
*bs
,
1892 int64_t offset
, int64_t count
,
1893 int64_t *pnum
, int64_t *map
,
1894 BlockDriverState
**file
)
1896 BDRVQcow2State
*s
= bs
->opaque
;
1897 uint64_t cluster_offset
;
1898 int index_in_cluster
, ret
;
1902 bytes
= MIN(INT_MAX
, count
);
1903 qemu_co_mutex_lock(&s
->lock
);
1904 ret
= qcow2_get_cluster_offset(bs
, offset
, &bytes
, &cluster_offset
);
1905 qemu_co_mutex_unlock(&s
->lock
);
1912 if ((ret
== QCOW2_CLUSTER_NORMAL
|| ret
== QCOW2_CLUSTER_ZERO_ALLOC
) &&
1914 index_in_cluster
= offset
& (s
->cluster_size
- 1);
1915 *map
= cluster_offset
| index_in_cluster
;
1916 *file
= s
->data_file
->bs
;
1917 status
|= BDRV_BLOCK_OFFSET_VALID
;
1919 if (ret
== QCOW2_CLUSTER_ZERO_PLAIN
|| ret
== QCOW2_CLUSTER_ZERO_ALLOC
) {
1920 status
|= BDRV_BLOCK_ZERO
;
1921 } else if (ret
!= QCOW2_CLUSTER_UNALLOCATED
) {
1922 status
|= BDRV_BLOCK_DATA
;
1927 static coroutine_fn
int qcow2_handle_l2meta(BlockDriverState
*bs
,
1928 QCowL2Meta
**pl2meta
,
1932 QCowL2Meta
*l2meta
= *pl2meta
;
1934 while (l2meta
!= NULL
) {
1938 ret
= qcow2_alloc_cluster_link_l2(bs
, l2meta
);
1943 qcow2_alloc_cluster_abort(bs
, l2meta
);
1946 /* Take the request off the list of running requests */
1947 if (l2meta
->nb_clusters
!= 0) {
1948 QLIST_REMOVE(l2meta
, next_in_flight
);
1951 qemu_co_queue_restart_all(&l2meta
->dependent_requests
);
1953 next
= l2meta
->next
;
1962 static coroutine_fn
int qcow2_co_preadv(BlockDriverState
*bs
, uint64_t offset
,
1963 uint64_t bytes
, QEMUIOVector
*qiov
,
1966 BDRVQcow2State
*s
= bs
->opaque
;
1967 int offset_in_cluster
;
1969 unsigned int cur_bytes
; /* number of bytes in current iteration */
1970 uint64_t cluster_offset
= 0;
1971 uint64_t bytes_done
= 0;
1972 QEMUIOVector hd_qiov
;
1973 uint8_t *cluster_data
= NULL
;
1975 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
1977 qemu_co_mutex_lock(&s
->lock
);
1979 while (bytes
!= 0) {
1981 /* prepare next request */
1982 cur_bytes
= MIN(bytes
, INT_MAX
);
1984 cur_bytes
= MIN(cur_bytes
,
1985 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
1988 ret
= qcow2_get_cluster_offset(bs
, offset
, &cur_bytes
, &cluster_offset
);
1993 offset_in_cluster
= offset_into_cluster(s
, offset
);
1995 qemu_iovec_reset(&hd_qiov
);
1996 qemu_iovec_concat(&hd_qiov
, qiov
, bytes_done
, cur_bytes
);
1999 case QCOW2_CLUSTER_UNALLOCATED
:
2002 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_BACKING_AIO
);
2003 qemu_co_mutex_unlock(&s
->lock
);
2004 ret
= bdrv_co_preadv(bs
->backing
, offset
, cur_bytes
,
2006 qemu_co_mutex_lock(&s
->lock
);
2011 /* Note: in this case, no need to wait */
2012 qemu_iovec_memset(&hd_qiov
, 0, 0, cur_bytes
);
2016 case QCOW2_CLUSTER_ZERO_PLAIN
:
2017 case QCOW2_CLUSTER_ZERO_ALLOC
:
2018 qemu_iovec_memset(&hd_qiov
, 0, 0, cur_bytes
);
2021 case QCOW2_CLUSTER_COMPRESSED
:
2022 qemu_co_mutex_unlock(&s
->lock
);
2023 ret
= qcow2_co_preadv_compressed(bs
, cluster_offset
,
2026 qemu_co_mutex_lock(&s
->lock
);
2033 case QCOW2_CLUSTER_NORMAL
:
2034 if ((cluster_offset
& 511) != 0) {
2039 if (bs
->encrypted
) {
2043 * For encrypted images, read everything into a temporary
2044 * contiguous buffer on which the AES functions can work.
2046 if (!cluster_data
) {
2048 qemu_try_blockalign(s
->data_file
->bs
,
2049 QCOW_MAX_CRYPT_CLUSTERS
2051 if (cluster_data
== NULL
) {
2057 assert(cur_bytes
<= QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
2058 qemu_iovec_reset(&hd_qiov
);
2059 qemu_iovec_add(&hd_qiov
, cluster_data
, cur_bytes
);
2062 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
2063 qemu_co_mutex_unlock(&s
->lock
);
2064 ret
= bdrv_co_preadv(s
->data_file
,
2065 cluster_offset
+ offset_in_cluster
,
2066 cur_bytes
, &hd_qiov
, 0);
2067 qemu_co_mutex_lock(&s
->lock
);
2071 if (bs
->encrypted
) {
2073 assert((offset
& (BDRV_SECTOR_SIZE
- 1)) == 0);
2074 assert((cur_bytes
& (BDRV_SECTOR_SIZE
- 1)) == 0);
2075 if (qcrypto_block_decrypt(s
->crypto
,
2076 (s
->crypt_physical_offset
?
2077 cluster_offset
+ offset_in_cluster
:
2085 qemu_iovec_from_buf(qiov
, bytes_done
, cluster_data
, cur_bytes
);
2090 g_assert_not_reached();
2096 offset
+= cur_bytes
;
2097 bytes_done
+= cur_bytes
;
2102 qemu_co_mutex_unlock(&s
->lock
);
2104 qemu_iovec_destroy(&hd_qiov
);
2105 qemu_vfree(cluster_data
);
2110 /* Check if it's possible to merge a write request with the writing of
2111 * the data from the COW regions */
2112 static bool merge_cow(uint64_t offset
, unsigned bytes
,
2113 QEMUIOVector
*hd_qiov
, QCowL2Meta
*l2meta
)
2117 for (m
= l2meta
; m
!= NULL
; m
= m
->next
) {
2118 /* If both COW regions are empty then there's nothing to merge */
2119 if (m
->cow_start
.nb_bytes
== 0 && m
->cow_end
.nb_bytes
== 0) {
2123 /* The data (middle) region must be immediately after the
2125 if (l2meta_cow_start(m
) + m
->cow_start
.nb_bytes
!= offset
) {
2129 /* The end region must be immediately after the data (middle)
2131 if (m
->offset
+ m
->cow_end
.offset
!= offset
+ bytes
) {
2135 /* Make sure that adding both COW regions to the QEMUIOVector
2136 * does not exceed IOV_MAX */
2137 if (hd_qiov
->niov
> IOV_MAX
- 2) {
2141 m
->data_qiov
= hd_qiov
;
2148 static coroutine_fn
int qcow2_co_pwritev(BlockDriverState
*bs
, uint64_t offset
,
2149 uint64_t bytes
, QEMUIOVector
*qiov
,
2152 BDRVQcow2State
*s
= bs
->opaque
;
2153 int offset_in_cluster
;
2155 unsigned int cur_bytes
; /* number of sectors in current iteration */
2156 uint64_t cluster_offset
;
2157 QEMUIOVector hd_qiov
;
2158 uint64_t bytes_done
= 0;
2159 uint8_t *cluster_data
= NULL
;
2160 QCowL2Meta
*l2meta
= NULL
;
2162 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset
, bytes
);
2164 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
2166 qemu_co_mutex_lock(&s
->lock
);
2168 while (bytes
!= 0) {
2172 trace_qcow2_writev_start_part(qemu_coroutine_self());
2173 offset_in_cluster
= offset_into_cluster(s
, offset
);
2174 cur_bytes
= MIN(bytes
, INT_MAX
);
2175 if (bs
->encrypted
) {
2176 cur_bytes
= MIN(cur_bytes
,
2177 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
2178 - offset_in_cluster
);
2181 ret
= qcow2_alloc_cluster_offset(bs
, offset
, &cur_bytes
,
2182 &cluster_offset
, &l2meta
);
2187 assert((cluster_offset
& 511) == 0);
2189 qemu_iovec_reset(&hd_qiov
);
2190 qemu_iovec_concat(&hd_qiov
, qiov
, bytes_done
, cur_bytes
);
2192 if (bs
->encrypted
) {
2194 if (!cluster_data
) {
2195 cluster_data
= qemu_try_blockalign(bs
->file
->bs
,
2196 QCOW_MAX_CRYPT_CLUSTERS
2198 if (cluster_data
== NULL
) {
2204 assert(hd_qiov
.size
<=
2205 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
2206 qemu_iovec_to_buf(&hd_qiov
, 0, cluster_data
, hd_qiov
.size
);
2208 if (qcrypto_block_encrypt(s
->crypto
,
2209 (s
->crypt_physical_offset
?
2210 cluster_offset
+ offset_in_cluster
:
2213 cur_bytes
, NULL
) < 0) {
2218 qemu_iovec_reset(&hd_qiov
);
2219 qemu_iovec_add(&hd_qiov
, cluster_data
, cur_bytes
);
2222 ret
= qcow2_pre_write_overlap_check(bs
, 0,
2223 cluster_offset
+ offset_in_cluster
, cur_bytes
, true);
2228 /* If we need to do COW, check if it's possible to merge the
2229 * writing of the guest data together with that of the COW regions.
2230 * If it's not possible (or not necessary) then write the
2231 * guest data now. */
2232 if (!merge_cow(offset
, cur_bytes
, &hd_qiov
, l2meta
)) {
2233 qemu_co_mutex_unlock(&s
->lock
);
2234 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_AIO
);
2235 trace_qcow2_writev_data(qemu_coroutine_self(),
2236 cluster_offset
+ offset_in_cluster
);
2237 ret
= bdrv_co_pwritev(s
->data_file
,
2238 cluster_offset
+ offset_in_cluster
,
2239 cur_bytes
, &hd_qiov
, 0);
2240 qemu_co_mutex_lock(&s
->lock
);
2246 ret
= qcow2_handle_l2meta(bs
, &l2meta
, true);
2252 offset
+= cur_bytes
;
2253 bytes_done
+= cur_bytes
;
2254 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes
);
2259 qcow2_handle_l2meta(bs
, &l2meta
, false);
2261 qemu_co_mutex_unlock(&s
->lock
);
2263 qemu_iovec_destroy(&hd_qiov
);
2264 qemu_vfree(cluster_data
);
2265 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret
);
2270 static int qcow2_inactivate(BlockDriverState
*bs
)
2272 BDRVQcow2State
*s
= bs
->opaque
;
2273 int ret
, result
= 0;
2274 Error
*local_err
= NULL
;
2276 qcow2_store_persistent_dirty_bitmaps(bs
, &local_err
);
2277 if (local_err
!= NULL
) {
2279 error_reportf_err(local_err
, "Lost persistent bitmaps during "
2280 "inactivation of node '%s': ",
2281 bdrv_get_device_or_node_name(bs
));
2284 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
2287 error_report("Failed to flush the L2 table cache: %s",
2291 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
2294 error_report("Failed to flush the refcount block cache: %s",
2299 qcow2_mark_clean(bs
);
2305 static void qcow2_close(BlockDriverState
*bs
)
2307 BDRVQcow2State
*s
= bs
->opaque
;
2308 qemu_vfree(s
->l1_table
);
2309 /* else pre-write overlap checks in cache_destroy may crash */
2312 if (!(s
->flags
& BDRV_O_INACTIVE
)) {
2313 qcow2_inactivate(bs
);
2316 cache_clean_timer_del(bs
);
2317 qcow2_cache_destroy(s
->l2_table_cache
);
2318 qcow2_cache_destroy(s
->refcount_block_cache
);
2320 qcrypto_block_free(s
->crypto
);
2323 g_free(s
->unknown_header_fields
);
2324 cleanup_unknown_header_ext(bs
);
2326 g_free(s
->image_data_file
);
2327 g_free(s
->image_backing_file
);
2328 g_free(s
->image_backing_format
);
2330 if (has_data_file(bs
)) {
2331 bdrv_unref_child(bs
, s
->data_file
);
2334 qcow2_refcount_close(bs
);
2335 qcow2_free_snapshots(bs
);
2338 static void coroutine_fn
qcow2_co_invalidate_cache(BlockDriverState
*bs
,
2341 BDRVQcow2State
*s
= bs
->opaque
;
2342 int flags
= s
->flags
;
2343 QCryptoBlock
*crypto
= NULL
;
2345 Error
*local_err
= NULL
;
2349 * Backing files are read-only which makes all of their metadata immutable,
2350 * that means we don't have to worry about reopening them here.
2358 memset(s
, 0, sizeof(BDRVQcow2State
));
2359 options
= qdict_clone_shallow(bs
->options
);
2361 flags
&= ~BDRV_O_INACTIVE
;
2362 qemu_co_mutex_lock(&s
->lock
);
2363 ret
= qcow2_do_open(bs
, options
, flags
, &local_err
);
2364 qemu_co_mutex_unlock(&s
->lock
);
2365 qobject_unref(options
);
2367 error_propagate_prepend(errp
, local_err
,
2368 "Could not reopen qcow2 layer: ");
2371 } else if (ret
< 0) {
2372 error_setg_errno(errp
, -ret
, "Could not reopen qcow2 layer");
2380 static size_t header_ext_add(char *buf
, uint32_t magic
, const void *s
,
2381 size_t len
, size_t buflen
)
2383 QCowExtension
*ext_backing_fmt
= (QCowExtension
*) buf
;
2384 size_t ext_len
= sizeof(QCowExtension
) + ((len
+ 7) & ~7);
2386 if (buflen
< ext_len
) {
2390 *ext_backing_fmt
= (QCowExtension
) {
2391 .magic
= cpu_to_be32(magic
),
2392 .len
= cpu_to_be32(len
),
2396 memcpy(buf
+ sizeof(QCowExtension
), s
, len
);
2403 * Updates the qcow2 header, including the variable length parts of it, i.e.
2404 * the backing file name and all extensions. qcow2 was not designed to allow
2405 * such changes, so if we run out of space (we can only use the first cluster)
2406 * this function may fail.
2408 * Returns 0 on success, -errno in error cases.
2410 int qcow2_update_header(BlockDriverState
*bs
)
2412 BDRVQcow2State
*s
= bs
->opaque
;
2415 size_t buflen
= s
->cluster_size
;
2417 uint64_t total_size
;
2418 uint32_t refcount_table_clusters
;
2419 size_t header_length
;
2420 Qcow2UnknownHeaderExtension
*uext
;
2422 buf
= qemu_blockalign(bs
, buflen
);
2424 /* Header structure */
2425 header
= (QCowHeader
*) buf
;
2427 if (buflen
< sizeof(*header
)) {
2432 header_length
= sizeof(*header
) + s
->unknown_header_fields_size
;
2433 total_size
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
2434 refcount_table_clusters
= s
->refcount_table_size
>> (s
->cluster_bits
- 3);
2436 *header
= (QCowHeader
) {
2437 /* Version 2 fields */
2438 .magic
= cpu_to_be32(QCOW_MAGIC
),
2439 .version
= cpu_to_be32(s
->qcow_version
),
2440 .backing_file_offset
= 0,
2441 .backing_file_size
= 0,
2442 .cluster_bits
= cpu_to_be32(s
->cluster_bits
),
2443 .size
= cpu_to_be64(total_size
),
2444 .crypt_method
= cpu_to_be32(s
->crypt_method_header
),
2445 .l1_size
= cpu_to_be32(s
->l1_size
),
2446 .l1_table_offset
= cpu_to_be64(s
->l1_table_offset
),
2447 .refcount_table_offset
= cpu_to_be64(s
->refcount_table_offset
),
2448 .refcount_table_clusters
= cpu_to_be32(refcount_table_clusters
),
2449 .nb_snapshots
= cpu_to_be32(s
->nb_snapshots
),
2450 .snapshots_offset
= cpu_to_be64(s
->snapshots_offset
),
2452 /* Version 3 fields */
2453 .incompatible_features
= cpu_to_be64(s
->incompatible_features
),
2454 .compatible_features
= cpu_to_be64(s
->compatible_features
),
2455 .autoclear_features
= cpu_to_be64(s
->autoclear_features
),
2456 .refcount_order
= cpu_to_be32(s
->refcount_order
),
2457 .header_length
= cpu_to_be32(header_length
),
2460 /* For older versions, write a shorter header */
2461 switch (s
->qcow_version
) {
2463 ret
= offsetof(QCowHeader
, incompatible_features
);
2466 ret
= sizeof(*header
);
2475 memset(buf
, 0, buflen
);
2477 /* Preserve any unknown field in the header */
2478 if (s
->unknown_header_fields_size
) {
2479 if (buflen
< s
->unknown_header_fields_size
) {
2484 memcpy(buf
, s
->unknown_header_fields
, s
->unknown_header_fields_size
);
2485 buf
+= s
->unknown_header_fields_size
;
2486 buflen
-= s
->unknown_header_fields_size
;
2489 /* Backing file format header extension */
2490 if (s
->image_backing_format
) {
2491 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_BACKING_FORMAT
,
2492 s
->image_backing_format
,
2493 strlen(s
->image_backing_format
),
2503 /* External data file header extension */
2504 if (has_data_file(bs
) && s
->image_data_file
) {
2505 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_DATA_FILE
,
2506 s
->image_data_file
, strlen(s
->image_data_file
),
2516 /* Full disk encryption header pointer extension */
2517 if (s
->crypto_header
.offset
!= 0) {
2518 s
->crypto_header
.offset
= cpu_to_be64(s
->crypto_header
.offset
);
2519 s
->crypto_header
.length
= cpu_to_be64(s
->crypto_header
.length
);
2520 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_CRYPTO_HEADER
,
2521 &s
->crypto_header
, sizeof(s
->crypto_header
),
2523 s
->crypto_header
.offset
= be64_to_cpu(s
->crypto_header
.offset
);
2524 s
->crypto_header
.length
= be64_to_cpu(s
->crypto_header
.length
);
2533 if (s
->qcow_version
>= 3) {
2534 Qcow2Feature features
[] = {
2536 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2537 .bit
= QCOW2_INCOMPAT_DIRTY_BITNR
,
2538 .name
= "dirty bit",
2541 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2542 .bit
= QCOW2_INCOMPAT_CORRUPT_BITNR
,
2543 .name
= "corrupt bit",
2546 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2547 .bit
= QCOW2_INCOMPAT_DATA_FILE_BITNR
,
2548 .name
= "external data file",
2551 .type
= QCOW2_FEAT_TYPE_COMPATIBLE
,
2552 .bit
= QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR
,
2553 .name
= "lazy refcounts",
2557 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_FEATURE_TABLE
,
2558 features
, sizeof(features
), buflen
);
2566 /* Bitmap extension */
2567 if (s
->nb_bitmaps
> 0) {
2568 Qcow2BitmapHeaderExt bitmaps_header
= {
2569 .nb_bitmaps
= cpu_to_be32(s
->nb_bitmaps
),
2570 .bitmap_directory_size
=
2571 cpu_to_be64(s
->bitmap_directory_size
),
2572 .bitmap_directory_offset
=
2573 cpu_to_be64(s
->bitmap_directory_offset
)
2575 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_BITMAPS
,
2576 &bitmaps_header
, sizeof(bitmaps_header
),
2585 /* Keep unknown header extensions */
2586 QLIST_FOREACH(uext
, &s
->unknown_header_ext
, next
) {
2587 ret
= header_ext_add(buf
, uext
->magic
, uext
->data
, uext
->len
, buflen
);
2596 /* End of header extensions */
2597 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_END
, NULL
, 0, buflen
);
2605 /* Backing file name */
2606 if (s
->image_backing_file
) {
2607 size_t backing_file_len
= strlen(s
->image_backing_file
);
2609 if (buflen
< backing_file_len
) {
2614 /* Using strncpy is ok here, since buf is not NUL-terminated. */
2615 strncpy(buf
, s
->image_backing_file
, buflen
);
2617 header
->backing_file_offset
= cpu_to_be64(buf
- ((char*) header
));
2618 header
->backing_file_size
= cpu_to_be32(backing_file_len
);
2621 /* Write the new header */
2622 ret
= bdrv_pwrite(bs
->file
, 0, header
, s
->cluster_size
);
2633 static int qcow2_change_backing_file(BlockDriverState
*bs
,
2634 const char *backing_file
, const char *backing_fmt
)
2636 BDRVQcow2State
*s
= bs
->opaque
;
2638 /* Adding a backing file means that the external data file alone won't be
2639 * enough to make sense of the content */
2640 if (backing_file
&& data_file_is_raw(bs
)) {
2644 if (backing_file
&& strlen(backing_file
) > 1023) {
2648 pstrcpy(bs
->auto_backing_file
, sizeof(bs
->auto_backing_file
),
2649 backing_file
?: "");
2650 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2651 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2653 g_free(s
->image_backing_file
);
2654 g_free(s
->image_backing_format
);
2656 s
->image_backing_file
= backing_file
? g_strdup(bs
->backing_file
) : NULL
;
2657 s
->image_backing_format
= backing_fmt
? g_strdup(bs
->backing_format
) : NULL
;
2659 return qcow2_update_header(bs
);
2662 static int qcow2_crypt_method_from_format(const char *encryptfmt
)
2664 if (g_str_equal(encryptfmt
, "luks")) {
2665 return QCOW_CRYPT_LUKS
;
2666 } else if (g_str_equal(encryptfmt
, "aes")) {
2667 return QCOW_CRYPT_AES
;
2673 static int qcow2_set_up_encryption(BlockDriverState
*bs
,
2674 QCryptoBlockCreateOptions
*cryptoopts
,
2677 BDRVQcow2State
*s
= bs
->opaque
;
2678 QCryptoBlock
*crypto
= NULL
;
2681 switch (cryptoopts
->format
) {
2682 case Q_CRYPTO_BLOCK_FORMAT_LUKS
:
2683 fmt
= QCOW_CRYPT_LUKS
;
2685 case Q_CRYPTO_BLOCK_FORMAT_QCOW
:
2686 fmt
= QCOW_CRYPT_AES
;
2689 error_setg(errp
, "Crypto format not supported in qcow2");
2693 s
->crypt_method_header
= fmt
;
2695 crypto
= qcrypto_block_create(cryptoopts
, "encrypt.",
2696 qcow2_crypto_hdr_init_func
,
2697 qcow2_crypto_hdr_write_func
,
2703 ret
= qcow2_update_header(bs
);
2705 error_setg_errno(errp
, -ret
, "Could not write encryption header");
2711 qcrypto_block_free(crypto
);
2716 * Preallocates metadata structures for data clusters between @offset (in the
2717 * guest disk) and @new_length (which is thus generally the new guest disk
2720 * Returns: 0 on success, -errno on failure.
2722 static int coroutine_fn
preallocate_co(BlockDriverState
*bs
, uint64_t offset
,
2723 uint64_t new_length
, PreallocMode mode
,
2726 BDRVQcow2State
*s
= bs
->opaque
;
2728 uint64_t host_offset
= 0;
2729 int64_t file_length
;
2730 unsigned int cur_bytes
;
2734 assert(offset
<= new_length
);
2735 bytes
= new_length
- offset
;
2738 cur_bytes
= MIN(bytes
, QEMU_ALIGN_DOWN(INT_MAX
, s
->cluster_size
));
2739 ret
= qcow2_alloc_cluster_offset(bs
, offset
, &cur_bytes
,
2740 &host_offset
, &meta
);
2742 error_setg_errno(errp
, -ret
, "Allocating clusters failed");
2747 QCowL2Meta
*next
= meta
->next
;
2749 ret
= qcow2_alloc_cluster_link_l2(bs
, meta
);
2751 error_setg_errno(errp
, -ret
, "Mapping clusters failed");
2752 qcow2_free_any_clusters(bs
, meta
->alloc_offset
,
2753 meta
->nb_clusters
, QCOW2_DISCARD_NEVER
);
2757 /* There are no dependent requests, but we need to remove our
2758 * request from the list of in-flight requests */
2759 QLIST_REMOVE(meta
, next_in_flight
);
2765 /* TODO Preallocate data if requested */
2768 offset
+= cur_bytes
;
2772 * It is expected that the image file is large enough to actually contain
2773 * all of the allocated clusters (otherwise we get failing reads after
2774 * EOF). Extend the image to the last allocated sector.
2776 file_length
= bdrv_getlength(s
->data_file
->bs
);
2777 if (file_length
< 0) {
2778 error_setg_errno(errp
, -file_length
, "Could not get file size");
2782 if (host_offset
+ cur_bytes
> file_length
) {
2783 if (mode
== PREALLOC_MODE_METADATA
) {
2784 mode
= PREALLOC_MODE_OFF
;
2786 ret
= bdrv_co_truncate(s
->data_file
, host_offset
+ cur_bytes
, mode
,
2796 /* qcow2_refcount_metadata_size:
2797 * @clusters: number of clusters to refcount (including data and L1/L2 tables)
2798 * @cluster_size: size of a cluster, in bytes
2799 * @refcount_order: refcount bits power-of-2 exponent
2800 * @generous_increase: allow for the refcount table to be 1.5x as large as it
2803 * Returns: Number of bytes required for refcount blocks and table metadata.
2805 int64_t qcow2_refcount_metadata_size(int64_t clusters
, size_t cluster_size
,
2806 int refcount_order
, bool generous_increase
,
2807 uint64_t *refblock_count
)
2810 * Every host cluster is reference-counted, including metadata (even
2811 * refcount metadata is recursively included).
2813 * An accurate formula for the size of refcount metadata size is difficult
2814 * to derive. An easier method of calculation is finding the fixed point
2815 * where no further refcount blocks or table clusters are required to
2816 * reference count every cluster.
2818 int64_t blocks_per_table_cluster
= cluster_size
/ sizeof(uint64_t);
2819 int64_t refcounts_per_block
= cluster_size
* 8 / (1 << refcount_order
);
2820 int64_t table
= 0; /* number of refcount table clusters */
2821 int64_t blocks
= 0; /* number of refcount block clusters */
2827 blocks
= DIV_ROUND_UP(clusters
+ table
+ blocks
, refcounts_per_block
);
2828 table
= DIV_ROUND_UP(blocks
, blocks_per_table_cluster
);
2829 n
= clusters
+ blocks
+ table
;
2831 if (n
== last
&& generous_increase
) {
2832 clusters
+= DIV_ROUND_UP(table
, 2);
2833 n
= 0; /* force another loop */
2834 generous_increase
= false;
2836 } while (n
!= last
);
2838 if (refblock_count
) {
2839 *refblock_count
= blocks
;
2842 return (blocks
+ table
) * cluster_size
;
2846 * qcow2_calc_prealloc_size:
2847 * @total_size: virtual disk size in bytes
2848 * @cluster_size: cluster size in bytes
2849 * @refcount_order: refcount bits power-of-2 exponent
2851 * Returns: Total number of bytes required for the fully allocated image
2852 * (including metadata).
2854 static int64_t qcow2_calc_prealloc_size(int64_t total_size
,
2855 size_t cluster_size
,
2858 int64_t meta_size
= 0;
2859 uint64_t nl1e
, nl2e
;
2860 int64_t aligned_total_size
= ROUND_UP(total_size
, cluster_size
);
2862 /* header: 1 cluster */
2863 meta_size
+= cluster_size
;
2865 /* total size of L2 tables */
2866 nl2e
= aligned_total_size
/ cluster_size
;
2867 nl2e
= ROUND_UP(nl2e
, cluster_size
/ sizeof(uint64_t));
2868 meta_size
+= nl2e
* sizeof(uint64_t);
2870 /* total size of L1 tables */
2871 nl1e
= nl2e
* sizeof(uint64_t) / cluster_size
;
2872 nl1e
= ROUND_UP(nl1e
, cluster_size
/ sizeof(uint64_t));
2873 meta_size
+= nl1e
* sizeof(uint64_t);
2875 /* total size of refcount table and blocks */
2876 meta_size
+= qcow2_refcount_metadata_size(
2877 (meta_size
+ aligned_total_size
) / cluster_size
,
2878 cluster_size
, refcount_order
, false, NULL
);
2880 return meta_size
+ aligned_total_size
;
2883 static bool validate_cluster_size(size_t cluster_size
, Error
**errp
)
2885 int cluster_bits
= ctz32(cluster_size
);
2886 if (cluster_bits
< MIN_CLUSTER_BITS
|| cluster_bits
> MAX_CLUSTER_BITS
||
2887 (1 << cluster_bits
) != cluster_size
)
2889 error_setg(errp
, "Cluster size must be a power of two between %d and "
2890 "%dk", 1 << MIN_CLUSTER_BITS
, 1 << (MAX_CLUSTER_BITS
- 10));
2896 static size_t qcow2_opt_get_cluster_size_del(QemuOpts
*opts
, Error
**errp
)
2898 size_t cluster_size
;
2900 cluster_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_CLUSTER_SIZE
,
2901 DEFAULT_CLUSTER_SIZE
);
2902 if (!validate_cluster_size(cluster_size
, errp
)) {
2905 return cluster_size
;
2908 static int qcow2_opt_get_version_del(QemuOpts
*opts
, Error
**errp
)
2913 buf
= qemu_opt_get_del(opts
, BLOCK_OPT_COMPAT_LEVEL
);
2915 ret
= 3; /* default */
2916 } else if (!strcmp(buf
, "0.10")) {
2918 } else if (!strcmp(buf
, "1.1")) {
2921 error_setg(errp
, "Invalid compatibility level: '%s'", buf
);
2928 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts
*opts
, int version
,
2931 uint64_t refcount_bits
;
2933 refcount_bits
= qemu_opt_get_number_del(opts
, BLOCK_OPT_REFCOUNT_BITS
, 16);
2934 if (refcount_bits
> 64 || !is_power_of_2(refcount_bits
)) {
2935 error_setg(errp
, "Refcount width must be a power of two and may not "
2940 if (version
< 3 && refcount_bits
!= 16) {
2941 error_setg(errp
, "Different refcount widths than 16 bits require "
2942 "compatibility level 1.1 or above (use compat=1.1 or "
2947 return refcount_bits
;
2950 static int coroutine_fn
2951 qcow2_co_create(BlockdevCreateOptions
*create_options
, Error
**errp
)
2953 BlockdevCreateOptionsQcow2
*qcow2_opts
;
2957 * Open the image file and write a minimal qcow2 header.
2959 * We keep things simple and start with a zero-sized image. We also
2960 * do without refcount blocks or a L1 table for now. We'll fix the
2961 * inconsistency later.
2963 * We do need a refcount table because growing the refcount table means
2964 * allocating two new refcount blocks - the seconds of which would be at
2965 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
2966 * size for any qcow2 image.
2968 BlockBackend
*blk
= NULL
;
2969 BlockDriverState
*bs
= NULL
;
2970 BlockDriverState
*data_bs
= NULL
;
2972 size_t cluster_size
;
2975 uint64_t* refcount_table
;
2976 Error
*local_err
= NULL
;
2979 assert(create_options
->driver
== BLOCKDEV_DRIVER_QCOW2
);
2980 qcow2_opts
= &create_options
->u
.qcow2
;
2982 bs
= bdrv_open_blockdev_ref(qcow2_opts
->file
, errp
);
2987 /* Validate options and set default values */
2988 if (!QEMU_IS_ALIGNED(qcow2_opts
->size
, BDRV_SECTOR_SIZE
)) {
2989 error_setg(errp
, "Image size must be a multiple of 512 bytes");
2994 if (qcow2_opts
->has_version
) {
2995 switch (qcow2_opts
->version
) {
2996 case BLOCKDEV_QCOW2_VERSION_V2
:
2999 case BLOCKDEV_QCOW2_VERSION_V3
:
3003 g_assert_not_reached();
3009 if (qcow2_opts
->has_cluster_size
) {
3010 cluster_size
= qcow2_opts
->cluster_size
;
3012 cluster_size
= DEFAULT_CLUSTER_SIZE
;
3015 if (!validate_cluster_size(cluster_size
, errp
)) {
3020 if (!qcow2_opts
->has_preallocation
) {
3021 qcow2_opts
->preallocation
= PREALLOC_MODE_OFF
;
3023 if (qcow2_opts
->has_backing_file
&&
3024 qcow2_opts
->preallocation
!= PREALLOC_MODE_OFF
)
3026 error_setg(errp
, "Backing file and preallocation cannot be used at "
3031 if (qcow2_opts
->has_backing_fmt
&& !qcow2_opts
->has_backing_file
) {
3032 error_setg(errp
, "Backing format cannot be used without backing file");
3037 if (!qcow2_opts
->has_lazy_refcounts
) {
3038 qcow2_opts
->lazy_refcounts
= false;
3040 if (version
< 3 && qcow2_opts
->lazy_refcounts
) {
3041 error_setg(errp
, "Lazy refcounts only supported with compatibility "
3042 "level 1.1 and above (use version=v3 or greater)");
3047 if (!qcow2_opts
->has_refcount_bits
) {
3048 qcow2_opts
->refcount_bits
= 16;
3050 if (qcow2_opts
->refcount_bits
> 64 ||
3051 !is_power_of_2(qcow2_opts
->refcount_bits
))
3053 error_setg(errp
, "Refcount width must be a power of two and may not "
3058 if (version
< 3 && qcow2_opts
->refcount_bits
!= 16) {
3059 error_setg(errp
, "Different refcount widths than 16 bits require "
3060 "compatibility level 1.1 or above (use version=v3 or "
3065 refcount_order
= ctz32(qcow2_opts
->refcount_bits
);
3067 if (qcow2_opts
->data_file_raw
&& !qcow2_opts
->data_file
) {
3068 error_setg(errp
, "data-file-raw requires data-file");
3072 if (qcow2_opts
->data_file_raw
&& qcow2_opts
->has_backing_file
) {
3073 error_setg(errp
, "Backing file and data-file-raw cannot be used at "
3079 if (qcow2_opts
->data_file
) {
3081 error_setg(errp
, "External data files are only supported with "
3082 "compatibility level 1.1 and above (use version=v3 or "
3087 data_bs
= bdrv_open_blockdev_ref(qcow2_opts
->data_file
, errp
);
3088 if (data_bs
== NULL
) {
3094 /* Create BlockBackend to write to the image */
3095 blk
= blk_new(BLK_PERM_WRITE
| BLK_PERM_RESIZE
, BLK_PERM_ALL
);
3096 ret
= blk_insert_bs(blk
, bs
, errp
);
3100 blk_set_allow_write_beyond_eof(blk
, true);
3102 /* Clear the protocol layer and preallocate it if necessary */
3103 ret
= blk_truncate(blk
, 0, PREALLOC_MODE_OFF
, errp
);
3108 /* Write the header */
3109 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS
) < sizeof(*header
));
3110 header
= g_malloc0(cluster_size
);
3111 *header
= (QCowHeader
) {
3112 .magic
= cpu_to_be32(QCOW_MAGIC
),
3113 .version
= cpu_to_be32(version
),
3114 .cluster_bits
= cpu_to_be32(ctz32(cluster_size
)),
3115 .size
= cpu_to_be64(0),
3116 .l1_table_offset
= cpu_to_be64(0),
3117 .l1_size
= cpu_to_be32(0),
3118 .refcount_table_offset
= cpu_to_be64(cluster_size
),
3119 .refcount_table_clusters
= cpu_to_be32(1),
3120 .refcount_order
= cpu_to_be32(refcount_order
),
3121 .header_length
= cpu_to_be32(sizeof(*header
)),
3124 /* We'll update this to correct value later */
3125 header
->crypt_method
= cpu_to_be32(QCOW_CRYPT_NONE
);
3127 if (qcow2_opts
->lazy_refcounts
) {
3128 header
->compatible_features
|=
3129 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS
);
3132 header
->incompatible_features
|=
3133 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE
);
3135 if (qcow2_opts
->data_file_raw
) {
3136 header
->autoclear_features
|=
3137 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW
);
3140 ret
= blk_pwrite(blk
, 0, header
, cluster_size
, 0);
3143 error_setg_errno(errp
, -ret
, "Could not write qcow2 header");
3147 /* Write a refcount table with one refcount block */
3148 refcount_table
= g_malloc0(2 * cluster_size
);
3149 refcount_table
[0] = cpu_to_be64(2 * cluster_size
);
3150 ret
= blk_pwrite(blk
, cluster_size
, refcount_table
, 2 * cluster_size
, 0);
3151 g_free(refcount_table
);
3154 error_setg_errno(errp
, -ret
, "Could not write refcount table");
3162 * And now open the image and make it consistent first (i.e. increase the
3163 * refcount of the cluster that is occupied by the header and the refcount
3166 options
= qdict_new();
3167 qdict_put_str(options
, "driver", "qcow2");
3168 qdict_put_str(options
, "file", bs
->node_name
);
3170 qdict_put_str(options
, "data-file", data_bs
->node_name
);
3172 blk
= blk_new_open(NULL
, NULL
, options
,
3173 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_NO_FLUSH
,
3176 error_propagate(errp
, local_err
);
3181 ret
= qcow2_alloc_clusters(blk_bs(blk
), 3 * cluster_size
);
3183 error_setg_errno(errp
, -ret
, "Could not allocate clusters for qcow2 "
3184 "header and refcount table");
3187 } else if (ret
!= 0) {
3188 error_report("Huh, first cluster in empty image is already in use?");
3192 /* Set the external data file if necessary */
3194 BDRVQcow2State
*s
= blk_bs(blk
)->opaque
;
3195 s
->image_data_file
= g_strdup(data_bs
->filename
);
3198 /* Create a full header (including things like feature table) */
3199 ret
= qcow2_update_header(blk_bs(blk
));
3201 error_setg_errno(errp
, -ret
, "Could not update qcow2 header");
3205 /* Okay, now that we have a valid image, let's give it the right size */
3206 ret
= blk_truncate(blk
, qcow2_opts
->size
, qcow2_opts
->preallocation
, errp
);
3208 error_prepend(errp
, "Could not resize image: ");
3212 /* Want a backing file? There you go.*/
3213 if (qcow2_opts
->has_backing_file
) {
3214 const char *backing_format
= NULL
;
3216 if (qcow2_opts
->has_backing_fmt
) {
3217 backing_format
= BlockdevDriver_str(qcow2_opts
->backing_fmt
);
3220 ret
= bdrv_change_backing_file(blk_bs(blk
), qcow2_opts
->backing_file
,
3223 error_setg_errno(errp
, -ret
, "Could not assign backing file '%s' "
3224 "with format '%s'", qcow2_opts
->backing_file
,
3230 /* Want encryption? There you go. */
3231 if (qcow2_opts
->has_encrypt
) {
3232 ret
= qcow2_set_up_encryption(blk_bs(blk
), qcow2_opts
->encrypt
, errp
);
3241 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning.
3242 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to
3243 * have to setup decryption context. We're not doing any I/O on the top
3244 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does
3247 options
= qdict_new();
3248 qdict_put_str(options
, "driver", "qcow2");
3249 qdict_put_str(options
, "file", bs
->node_name
);
3251 qdict_put_str(options
, "data-file", data_bs
->node_name
);
3253 blk
= blk_new_open(NULL
, NULL
, options
,
3254 BDRV_O_RDWR
| BDRV_O_NO_BACKING
| BDRV_O_NO_IO
,
3257 error_propagate(errp
, local_err
);
3266 bdrv_unref(data_bs
);
3270 static int coroutine_fn
qcow2_co_create_opts(const char *filename
, QemuOpts
*opts
,
3273 BlockdevCreateOptions
*create_options
= NULL
;
3276 BlockDriverState
*bs
= NULL
;
3277 BlockDriverState
*data_bs
= NULL
;
3278 Error
*local_err
= NULL
;
3282 /* Only the keyval visitor supports the dotted syntax needed for
3283 * encryption, so go through a QDict before getting a QAPI type. Ignore
3284 * options meant for the protocol layer so that the visitor doesn't
3286 qdict
= qemu_opts_to_qdict_filtered(opts
, NULL
, bdrv_qcow2
.create_opts
,
3289 /* Handle encryption options */
3290 val
= qdict_get_try_str(qdict
, BLOCK_OPT_ENCRYPT
);
3291 if (val
&& !strcmp(val
, "on")) {
3292 qdict_put_str(qdict
, BLOCK_OPT_ENCRYPT
, "qcow");
3293 } else if (val
&& !strcmp(val
, "off")) {
3294 qdict_del(qdict
, BLOCK_OPT_ENCRYPT
);
3297 val
= qdict_get_try_str(qdict
, BLOCK_OPT_ENCRYPT_FORMAT
);
3298 if (val
&& !strcmp(val
, "aes")) {
3299 qdict_put_str(qdict
, BLOCK_OPT_ENCRYPT_FORMAT
, "qcow");
3302 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into
3303 * version=v2/v3 below. */
3304 val
= qdict_get_try_str(qdict
, BLOCK_OPT_COMPAT_LEVEL
);
3305 if (val
&& !strcmp(val
, "0.10")) {
3306 qdict_put_str(qdict
, BLOCK_OPT_COMPAT_LEVEL
, "v2");
3307 } else if (val
&& !strcmp(val
, "1.1")) {
3308 qdict_put_str(qdict
, BLOCK_OPT_COMPAT_LEVEL
, "v3");
3311 /* Change legacy command line options into QMP ones */
3312 static const QDictRenames opt_renames
[] = {
3313 { BLOCK_OPT_BACKING_FILE
, "backing-file" },
3314 { BLOCK_OPT_BACKING_FMT
, "backing-fmt" },
3315 { BLOCK_OPT_CLUSTER_SIZE
, "cluster-size" },
3316 { BLOCK_OPT_LAZY_REFCOUNTS
, "lazy-refcounts" },
3317 { BLOCK_OPT_REFCOUNT_BITS
, "refcount-bits" },
3318 { BLOCK_OPT_ENCRYPT
, BLOCK_OPT_ENCRYPT_FORMAT
},
3319 { BLOCK_OPT_COMPAT_LEVEL
, "version" },
3320 { BLOCK_OPT_DATA_FILE_RAW
, "data-file-raw" },
3324 if (!qdict_rename_keys(qdict
, opt_renames
, errp
)) {
3329 /* Create and open the file (protocol layer) */
3330 ret
= bdrv_create_file(filename
, opts
, errp
);
3335 bs
= bdrv_open(filename
, NULL
, NULL
,
3336 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_PROTOCOL
, errp
);
3342 /* Create and open an external data file (protocol layer) */
3343 val
= qdict_get_try_str(qdict
, BLOCK_OPT_DATA_FILE
);
3345 ret
= bdrv_create_file(val
, opts
, errp
);
3350 data_bs
= bdrv_open(val
, NULL
, NULL
,
3351 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_PROTOCOL
,
3353 if (data_bs
== NULL
) {
3358 qdict_del(qdict
, BLOCK_OPT_DATA_FILE
);
3359 qdict_put_str(qdict
, "data-file", data_bs
->node_name
);
3362 /* Set 'driver' and 'node' options */
3363 qdict_put_str(qdict
, "driver", "qcow2");
3364 qdict_put_str(qdict
, "file", bs
->node_name
);
3366 /* Now get the QAPI type BlockdevCreateOptions */
3367 v
= qobject_input_visitor_new_flat_confused(qdict
, errp
);
3373 visit_type_BlockdevCreateOptions(v
, NULL
, &create_options
, &local_err
);
3377 error_propagate(errp
, local_err
);
3382 /* Silently round up size */
3383 create_options
->u
.qcow2
.size
= ROUND_UP(create_options
->u
.qcow2
.size
,
3386 /* Create the qcow2 image (format layer) */
3387 ret
= qcow2_co_create(create_options
, errp
);
3394 qobject_unref(qdict
);
3396 bdrv_unref(data_bs
);
3397 qapi_free_BlockdevCreateOptions(create_options
);
3402 static bool is_zero(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
)
3407 /* Clamp to image length, before checking status of underlying sectors */
3408 if (offset
+ bytes
> bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3409 bytes
= bs
->total_sectors
* BDRV_SECTOR_SIZE
- offset
;
3415 res
= bdrv_block_status_above(bs
, NULL
, offset
, bytes
, &nr
, NULL
, NULL
);
3416 return res
>= 0 && (res
& BDRV_BLOCK_ZERO
) && nr
== bytes
;
3419 static coroutine_fn
int qcow2_co_pwrite_zeroes(BlockDriverState
*bs
,
3420 int64_t offset
, int bytes
, BdrvRequestFlags flags
)
3423 BDRVQcow2State
*s
= bs
->opaque
;
3425 uint32_t head
= offset
% s
->cluster_size
;
3426 uint32_t tail
= (offset
+ bytes
) % s
->cluster_size
;
3428 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset
, bytes
);
3429 if (offset
+ bytes
== bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3437 assert(head
+ bytes
<= s
->cluster_size
);
3439 /* check whether remainder of cluster already reads as zero */
3440 if (!(is_zero(bs
, offset
- head
, head
) &&
3441 is_zero(bs
, offset
+ bytes
,
3442 tail
? s
->cluster_size
- tail
: 0))) {
3446 qemu_co_mutex_lock(&s
->lock
);
3447 /* We can have new write after previous check */
3448 offset
= QEMU_ALIGN_DOWN(offset
, s
->cluster_size
);
3449 bytes
= s
->cluster_size
;
3450 nr
= s
->cluster_size
;
3451 ret
= qcow2_get_cluster_offset(bs
, offset
, &nr
, &off
);
3452 if (ret
!= QCOW2_CLUSTER_UNALLOCATED
&&
3453 ret
!= QCOW2_CLUSTER_ZERO_PLAIN
&&
3454 ret
!= QCOW2_CLUSTER_ZERO_ALLOC
) {
3455 qemu_co_mutex_unlock(&s
->lock
);
3459 qemu_co_mutex_lock(&s
->lock
);
3462 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset
, bytes
);
3464 /* Whatever is left can use real zero clusters */
3465 ret
= qcow2_cluster_zeroize(bs
, offset
, bytes
, flags
);
3466 qemu_co_mutex_unlock(&s
->lock
);
3471 static coroutine_fn
int qcow2_co_pdiscard(BlockDriverState
*bs
,
3472 int64_t offset
, int bytes
)
3475 BDRVQcow2State
*s
= bs
->opaque
;
3477 if (!QEMU_IS_ALIGNED(offset
| bytes
, s
->cluster_size
)) {
3478 assert(bytes
< s
->cluster_size
);
3479 /* Ignore partial clusters, except for the special case of the
3480 * complete partial cluster at the end of an unaligned file */
3481 if (!QEMU_IS_ALIGNED(offset
, s
->cluster_size
) ||
3482 offset
+ bytes
!= bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3487 qemu_co_mutex_lock(&s
->lock
);
3488 ret
= qcow2_cluster_discard(bs
, offset
, bytes
, QCOW2_DISCARD_REQUEST
,
3490 qemu_co_mutex_unlock(&s
->lock
);
3494 static int coroutine_fn
3495 qcow2_co_copy_range_from(BlockDriverState
*bs
,
3496 BdrvChild
*src
, uint64_t src_offset
,
3497 BdrvChild
*dst
, uint64_t dst_offset
,
3498 uint64_t bytes
, BdrvRequestFlags read_flags
,
3499 BdrvRequestFlags write_flags
)
3501 BDRVQcow2State
*s
= bs
->opaque
;
3503 unsigned int cur_bytes
; /* number of bytes in current iteration */
3504 BdrvChild
*child
= NULL
;
3505 BdrvRequestFlags cur_write_flags
;
3507 assert(!bs
->encrypted
);
3508 qemu_co_mutex_lock(&s
->lock
);
3510 while (bytes
!= 0) {
3511 uint64_t copy_offset
= 0;
3512 /* prepare next request */
3513 cur_bytes
= MIN(bytes
, INT_MAX
);
3514 cur_write_flags
= write_flags
;
3516 ret
= qcow2_get_cluster_offset(bs
, src_offset
, &cur_bytes
, ©_offset
);
3522 case QCOW2_CLUSTER_UNALLOCATED
:
3523 if (bs
->backing
&& bs
->backing
->bs
) {
3524 int64_t backing_length
= bdrv_getlength(bs
->backing
->bs
);
3525 if (src_offset
>= backing_length
) {
3526 cur_write_flags
|= BDRV_REQ_ZERO_WRITE
;
3528 child
= bs
->backing
;
3529 cur_bytes
= MIN(cur_bytes
, backing_length
- src_offset
);
3530 copy_offset
= src_offset
;
3533 cur_write_flags
|= BDRV_REQ_ZERO_WRITE
;
3537 case QCOW2_CLUSTER_ZERO_PLAIN
:
3538 case QCOW2_CLUSTER_ZERO_ALLOC
:
3539 cur_write_flags
|= BDRV_REQ_ZERO_WRITE
;
3542 case QCOW2_CLUSTER_COMPRESSED
:
3546 case QCOW2_CLUSTER_NORMAL
:
3547 child
= s
->data_file
;
3548 copy_offset
+= offset_into_cluster(s
, src_offset
);
3549 if ((copy_offset
& 511) != 0) {
3558 qemu_co_mutex_unlock(&s
->lock
);
3559 ret
= bdrv_co_copy_range_from(child
,
3562 cur_bytes
, read_flags
, cur_write_flags
);
3563 qemu_co_mutex_lock(&s
->lock
);
3569 src_offset
+= cur_bytes
;
3570 dst_offset
+= cur_bytes
;
3575 qemu_co_mutex_unlock(&s
->lock
);
3579 static int coroutine_fn
3580 qcow2_co_copy_range_to(BlockDriverState
*bs
,
3581 BdrvChild
*src
, uint64_t src_offset
,
3582 BdrvChild
*dst
, uint64_t dst_offset
,
3583 uint64_t bytes
, BdrvRequestFlags read_flags
,
3584 BdrvRequestFlags write_flags
)
3586 BDRVQcow2State
*s
= bs
->opaque
;
3587 int offset_in_cluster
;
3589 unsigned int cur_bytes
; /* number of sectors in current iteration */
3590 uint64_t cluster_offset
;
3591 QCowL2Meta
*l2meta
= NULL
;
3593 assert(!bs
->encrypted
);
3595 qemu_co_mutex_lock(&s
->lock
);
3597 while (bytes
!= 0) {
3601 offset_in_cluster
= offset_into_cluster(s
, dst_offset
);
3602 cur_bytes
= MIN(bytes
, INT_MAX
);
3605 * If src->bs == dst->bs, we could simply copy by incrementing
3606 * the refcnt, without copying user data.
3607 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */
3608 ret
= qcow2_alloc_cluster_offset(bs
, dst_offset
, &cur_bytes
,
3609 &cluster_offset
, &l2meta
);
3614 assert((cluster_offset
& 511) == 0);
3616 ret
= qcow2_pre_write_overlap_check(bs
, 0,
3617 cluster_offset
+ offset_in_cluster
, cur_bytes
, true);
3622 qemu_co_mutex_unlock(&s
->lock
);
3623 ret
= bdrv_co_copy_range_to(src
, src_offset
,
3625 cluster_offset
+ offset_in_cluster
,
3626 cur_bytes
, read_flags
, write_flags
);
3627 qemu_co_mutex_lock(&s
->lock
);
3632 ret
= qcow2_handle_l2meta(bs
, &l2meta
, true);
3638 src_offset
+= cur_bytes
;
3639 dst_offset
+= cur_bytes
;
3644 qcow2_handle_l2meta(bs
, &l2meta
, false);
3646 qemu_co_mutex_unlock(&s
->lock
);
3648 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret
);
3653 static int coroutine_fn
qcow2_co_truncate(BlockDriverState
*bs
, int64_t offset
,
3654 PreallocMode prealloc
, Error
**errp
)
3656 BDRVQcow2State
*s
= bs
->opaque
;
3657 uint64_t old_length
;
3658 int64_t new_l1_size
;
3662 if (prealloc
!= PREALLOC_MODE_OFF
&& prealloc
!= PREALLOC_MODE_METADATA
&&
3663 prealloc
!= PREALLOC_MODE_FALLOC
&& prealloc
!= PREALLOC_MODE_FULL
)
3665 error_setg(errp
, "Unsupported preallocation mode '%s'",
3666 PreallocMode_str(prealloc
));
3671 error_setg(errp
, "The new size must be a multiple of 512");
3675 qemu_co_mutex_lock(&s
->lock
);
3677 /* cannot proceed if image has snapshots */
3678 if (s
->nb_snapshots
) {
3679 error_setg(errp
, "Can't resize an image which has snapshots");
3684 /* cannot proceed if image has bitmaps */
3685 if (qcow2_truncate_bitmaps_check(bs
, errp
)) {
3690 old_length
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
3691 new_l1_size
= size_to_l1(s
, offset
);
3693 if (offset
< old_length
) {
3694 int64_t last_cluster
, old_file_size
;
3695 if (prealloc
!= PREALLOC_MODE_OFF
) {
3697 "Preallocation can't be used for shrinking an image");
3702 ret
= qcow2_cluster_discard(bs
, ROUND_UP(offset
, s
->cluster_size
),
3703 old_length
- ROUND_UP(offset
,
3705 QCOW2_DISCARD_ALWAYS
, true);
3707 error_setg_errno(errp
, -ret
, "Failed to discard cropped clusters");
3711 ret
= qcow2_shrink_l1_table(bs
, new_l1_size
);
3713 error_setg_errno(errp
, -ret
,
3714 "Failed to reduce the number of L2 tables");
3718 ret
= qcow2_shrink_reftable(bs
);
3720 error_setg_errno(errp
, -ret
,
3721 "Failed to discard unused refblocks");
3725 old_file_size
= bdrv_getlength(bs
->file
->bs
);
3726 if (old_file_size
< 0) {
3727 error_setg_errno(errp
, -old_file_size
,
3728 "Failed to inquire current file length");
3729 ret
= old_file_size
;
3732 last_cluster
= qcow2_get_last_cluster(bs
, old_file_size
);
3733 if (last_cluster
< 0) {
3734 error_setg_errno(errp
, -last_cluster
,
3735 "Failed to find the last cluster");
3739 if ((last_cluster
+ 1) * s
->cluster_size
< old_file_size
) {
3740 Error
*local_err
= NULL
;
3742 bdrv_co_truncate(bs
->file
, (last_cluster
+ 1) * s
->cluster_size
,
3743 PREALLOC_MODE_OFF
, &local_err
);
3745 warn_reportf_err(local_err
,
3746 "Failed to truncate the tail of the image: ");
3750 ret
= qcow2_grow_l1_table(bs
, new_l1_size
, true);
3752 error_setg_errno(errp
, -ret
, "Failed to grow the L1 table");
3758 case PREALLOC_MODE_OFF
:
3759 if (has_data_file(bs
)) {
3760 ret
= bdrv_co_truncate(s
->data_file
, offset
, prealloc
, errp
);
3767 case PREALLOC_MODE_METADATA
:
3768 ret
= preallocate_co(bs
, old_length
, offset
, prealloc
, errp
);
3774 case PREALLOC_MODE_FALLOC
:
3775 case PREALLOC_MODE_FULL
:
3777 int64_t allocation_start
, host_offset
, guest_offset
;
3778 int64_t clusters_allocated
;
3779 int64_t old_file_size
, new_file_size
;
3780 uint64_t nb_new_data_clusters
, nb_new_l2_tables
;
3782 /* With a data file, preallocation means just allocating the metadata
3783 * and forwarding the truncate request to the data file */
3784 if (has_data_file(bs
)) {
3785 ret
= preallocate_co(bs
, old_length
, offset
, prealloc
, errp
);
3792 old_file_size
= bdrv_getlength(bs
->file
->bs
);
3793 if (old_file_size
< 0) {
3794 error_setg_errno(errp
, -old_file_size
,
3795 "Failed to inquire current file length");
3796 ret
= old_file_size
;
3799 old_file_size
= ROUND_UP(old_file_size
, s
->cluster_size
);
3801 nb_new_data_clusters
= DIV_ROUND_UP(offset
- old_length
,
3804 /* This is an overestimation; we will not actually allocate space for
3805 * these in the file but just make sure the new refcount structures are
3806 * able to cover them so we will not have to allocate new refblocks
3807 * while entering the data blocks in the potentially new L2 tables.
3808 * (We do not actually care where the L2 tables are placed. Maybe they
3809 * are already allocated or they can be placed somewhere before
3810 * @old_file_size. It does not matter because they will be fully
3811 * allocated automatically, so they do not need to be covered by the
3812 * preallocation. All that matters is that we will not have to allocate
3813 * new refcount structures for them.) */
3814 nb_new_l2_tables
= DIV_ROUND_UP(nb_new_data_clusters
,
3815 s
->cluster_size
/ sizeof(uint64_t));
3816 /* The cluster range may not be aligned to L2 boundaries, so add one L2
3817 * table for a potential head/tail */
3820 allocation_start
= qcow2_refcount_area(bs
, old_file_size
,
3821 nb_new_data_clusters
+
3824 if (allocation_start
< 0) {
3825 error_setg_errno(errp
, -allocation_start
,
3826 "Failed to resize refcount structures");
3827 ret
= allocation_start
;
3831 clusters_allocated
= qcow2_alloc_clusters_at(bs
, allocation_start
,
3832 nb_new_data_clusters
);
3833 if (clusters_allocated
< 0) {
3834 error_setg_errno(errp
, -clusters_allocated
,
3835 "Failed to allocate data clusters");
3836 ret
= clusters_allocated
;
3840 assert(clusters_allocated
== nb_new_data_clusters
);
3842 /* Allocate the data area */
3843 new_file_size
= allocation_start
+
3844 nb_new_data_clusters
* s
->cluster_size
;
3845 ret
= bdrv_co_truncate(bs
->file
, new_file_size
, prealloc
, errp
);
3847 error_prepend(errp
, "Failed to resize underlying file: ");
3848 qcow2_free_clusters(bs
, allocation_start
,
3849 nb_new_data_clusters
* s
->cluster_size
,
3850 QCOW2_DISCARD_OTHER
);
3854 /* Create the necessary L2 entries */
3855 host_offset
= allocation_start
;
3856 guest_offset
= old_length
;
3857 while (nb_new_data_clusters
) {
3858 int64_t nb_clusters
= MIN(
3859 nb_new_data_clusters
,
3860 s
->l2_slice_size
- offset_to_l2_slice_index(s
, guest_offset
));
3861 QCowL2Meta allocation
= {
3862 .offset
= guest_offset
,
3863 .alloc_offset
= host_offset
,
3864 .nb_clusters
= nb_clusters
,
3866 qemu_co_queue_init(&allocation
.dependent_requests
);
3868 ret
= qcow2_alloc_cluster_link_l2(bs
, &allocation
);
3870 error_setg_errno(errp
, -ret
, "Failed to update L2 tables");
3871 qcow2_free_clusters(bs
, host_offset
,
3872 nb_new_data_clusters
* s
->cluster_size
,
3873 QCOW2_DISCARD_OTHER
);
3877 guest_offset
+= nb_clusters
* s
->cluster_size
;
3878 host_offset
+= nb_clusters
* s
->cluster_size
;
3879 nb_new_data_clusters
-= nb_clusters
;
3885 g_assert_not_reached();
3888 if (prealloc
!= PREALLOC_MODE_OFF
) {
3889 /* Flush metadata before actually changing the image size */
3890 ret
= qcow2_write_caches(bs
);
3892 error_setg_errno(errp
, -ret
,
3893 "Failed to flush the preallocated area to disk");
3898 bs
->total_sectors
= offset
/ BDRV_SECTOR_SIZE
;
3900 /* write updated header.size */
3901 offset
= cpu_to_be64(offset
);
3902 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, size
),
3903 &offset
, sizeof(uint64_t));
3905 error_setg_errno(errp
, -ret
, "Failed to update the image size");
3909 s
->l1_vm_state_index
= new_l1_size
;
3911 /* Update cache sizes */
3912 options
= qdict_clone_shallow(bs
->options
);
3913 ret
= qcow2_update_options(bs
, options
, s
->flags
, errp
);
3914 qobject_unref(options
);
3920 qemu_co_mutex_unlock(&s
->lock
);
3927 * @dest - destination buffer, @dest_size bytes
3928 * @src - source buffer, @src_size bytes
3930 * Returns: compressed size on success
3931 * -ENOMEM destination buffer is not enough to store compressed data
3932 * -EIO on any other error
3934 static ssize_t
qcow2_compress(void *dest
, size_t dest_size
,
3935 const void *src
, size_t src_size
)
3940 /* best compression, small window, no zlib header */
3941 memset(&strm
, 0, sizeof(strm
));
3942 ret
= deflateInit2(&strm
, Z_DEFAULT_COMPRESSION
, Z_DEFLATED
,
3943 -12, 9, Z_DEFAULT_STRATEGY
);
3948 /* strm.next_in is not const in old zlib versions, such as those used on
3949 * OpenBSD/NetBSD, so cast the const away */
3950 strm
.avail_in
= src_size
;
3951 strm
.next_in
= (void *) src
;
3952 strm
.avail_out
= dest_size
;
3953 strm
.next_out
= dest
;
3955 ret
= deflate(&strm
, Z_FINISH
);
3956 if (ret
== Z_STREAM_END
) {
3957 ret
= dest_size
- strm
.avail_out
;
3959 ret
= (ret
== Z_OK
? -ENOMEM
: -EIO
);
3968 * qcow2_decompress()
3970 * Decompress some data (not more than @src_size bytes) to produce exactly
3973 * @dest - destination buffer, @dest_size bytes
3974 * @src - source buffer, @src_size bytes
3976 * Returns: 0 on success
3979 static ssize_t
qcow2_decompress(void *dest
, size_t dest_size
,
3980 const void *src
, size_t src_size
)
3985 memset(&strm
, 0, sizeof(strm
));
3986 strm
.avail_in
= src_size
;
3987 strm
.next_in
= (void *) src
;
3988 strm
.avail_out
= dest_size
;
3989 strm
.next_out
= dest
;
3991 ret
= inflateInit2(&strm
, -12);
3996 ret
= inflate(&strm
, Z_FINISH
);
3997 if ((ret
!= Z_STREAM_END
&& ret
!= Z_BUF_ERROR
) || strm
.avail_out
!= 0) {
3998 /* We approve Z_BUF_ERROR because we need @dest buffer to be filled, but
3999 * @src buffer may be processed partly (because in qcow2 we know size of
4000 * compressed data with precision of one sector) */
4009 #define MAX_COMPRESS_THREADS 4
4011 typedef ssize_t (*Qcow2CompressFunc
)(void *dest
, size_t dest_size
,
4012 const void *src
, size_t src_size
);
4013 typedef struct Qcow2CompressData
{
4020 Qcow2CompressFunc func
;
4021 } Qcow2CompressData
;
4023 static int qcow2_compress_pool_func(void *opaque
)
4025 Qcow2CompressData
*data
= opaque
;
4027 data
->ret
= data
->func(data
->dest
, data
->dest_size
,
4028 data
->src
, data
->src_size
);
4033 static void qcow2_compress_complete(void *opaque
, int ret
)
4035 qemu_coroutine_enter(opaque
);
4038 static ssize_t coroutine_fn
4039 qcow2_co_do_compress(BlockDriverState
*bs
, void *dest
, size_t dest_size
,
4040 const void *src
, size_t src_size
, Qcow2CompressFunc func
)
4042 BDRVQcow2State
*s
= bs
->opaque
;
4044 ThreadPool
*pool
= aio_get_thread_pool(bdrv_get_aio_context(bs
));
4045 Qcow2CompressData arg
= {
4047 .dest_size
= dest_size
,
4049 .src_size
= src_size
,
4053 while (s
->nb_compress_threads
>= MAX_COMPRESS_THREADS
) {
4054 qemu_co_queue_wait(&s
->compress_wait_queue
, NULL
);
4057 s
->nb_compress_threads
++;
4058 acb
= thread_pool_submit_aio(pool
, qcow2_compress_pool_func
, &arg
,
4059 qcow2_compress_complete
,
4060 qemu_coroutine_self());
4063 s
->nb_compress_threads
--;
4066 qemu_coroutine_yield();
4067 s
->nb_compress_threads
--;
4068 qemu_co_queue_next(&s
->compress_wait_queue
);
4073 static ssize_t coroutine_fn
4074 qcow2_co_compress(BlockDriverState
*bs
, void *dest
, size_t dest_size
,
4075 const void *src
, size_t src_size
)
4077 return qcow2_co_do_compress(bs
, dest
, dest_size
, src
, src_size
,
4081 static ssize_t coroutine_fn
4082 qcow2_co_decompress(BlockDriverState
*bs
, void *dest
, size_t dest_size
,
4083 const void *src
, size_t src_size
)
4085 return qcow2_co_do_compress(bs
, dest
, dest_size
, src
, src_size
,
4089 /* XXX: put compressed sectors first, then all the cluster aligned
4090 tables to avoid losing bytes in alignment */
4091 static coroutine_fn
int
4092 qcow2_co_pwritev_compressed(BlockDriverState
*bs
, uint64_t offset
,
4093 uint64_t bytes
, QEMUIOVector
*qiov
)
4095 BDRVQcow2State
*s
= bs
->opaque
;
4098 uint8_t *buf
, *out_buf
;
4099 uint64_t cluster_offset
;
4101 if (has_data_file(bs
)) {
4106 /* align end of file to a sector boundary to ease reading with
4107 sector based I/Os */
4108 int64_t len
= bdrv_getlength(bs
->file
->bs
);
4112 return bdrv_co_truncate(bs
->file
, len
, PREALLOC_MODE_OFF
, NULL
);
4115 if (offset_into_cluster(s
, offset
)) {
4119 buf
= qemu_blockalign(bs
, s
->cluster_size
);
4120 if (bytes
!= s
->cluster_size
) {
4121 if (bytes
> s
->cluster_size
||
4122 offset
+ bytes
!= bs
->total_sectors
<< BDRV_SECTOR_BITS
)
4127 /* Zero-pad last write if image size is not cluster aligned */
4128 memset(buf
+ bytes
, 0, s
->cluster_size
- bytes
);
4130 qemu_iovec_to_buf(qiov
, 0, buf
, bytes
);
4132 out_buf
= g_malloc(s
->cluster_size
);
4134 out_len
= qcow2_co_compress(bs
, out_buf
, s
->cluster_size
- 1,
4135 buf
, s
->cluster_size
);
4136 if (out_len
== -ENOMEM
) {
4137 /* could not compress: write normal cluster */
4138 ret
= qcow2_co_pwritev(bs
, offset
, bytes
, qiov
, 0);
4143 } else if (out_len
< 0) {
4148 qemu_co_mutex_lock(&s
->lock
);
4149 ret
= qcow2_alloc_compressed_cluster_offset(bs
, offset
, out_len
,
4152 qemu_co_mutex_unlock(&s
->lock
);
4156 ret
= qcow2_pre_write_overlap_check(bs
, 0, cluster_offset
, out_len
, true);
4157 qemu_co_mutex_unlock(&s
->lock
);
4162 BLKDBG_EVENT(s
->data_file
, BLKDBG_WRITE_COMPRESSED
);
4163 ret
= bdrv_co_pwrite(s
->data_file
, cluster_offset
, out_len
, out_buf
, 0);
4175 static int coroutine_fn
4176 qcow2_co_preadv_compressed(BlockDriverState
*bs
,
4177 uint64_t file_cluster_offset
,
4182 BDRVQcow2State
*s
= bs
->opaque
;
4183 int ret
= 0, csize
, nb_csectors
;
4185 uint8_t *buf
, *out_buf
;
4186 int offset_in_cluster
= offset_into_cluster(s
, offset
);
4188 coffset
= file_cluster_offset
& s
->cluster_offset_mask
;
4189 nb_csectors
= ((file_cluster_offset
>> s
->csize_shift
) & s
->csize_mask
) + 1;
4190 csize
= nb_csectors
* 512 - (coffset
& 511);
4192 buf
= g_try_malloc(csize
);
4197 out_buf
= qemu_blockalign(bs
, s
->cluster_size
);
4199 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_COMPRESSED
);
4200 ret
= bdrv_co_pread(bs
->file
, coffset
, csize
, buf
, 0);
4205 if (qcow2_co_decompress(bs
, out_buf
, s
->cluster_size
, buf
, csize
) < 0) {
4210 qemu_iovec_from_buf(qiov
, 0, out_buf
+ offset_in_cluster
, bytes
);
4213 qemu_vfree(out_buf
);
4219 static int make_completely_empty(BlockDriverState
*bs
)
4221 BDRVQcow2State
*s
= bs
->opaque
;
4222 Error
*local_err
= NULL
;
4223 int ret
, l1_clusters
;
4225 uint64_t *new_reftable
= NULL
;
4226 uint64_t rt_entry
, l1_size2
;
4229 uint64_t reftable_offset
;
4230 uint32_t reftable_clusters
;
4231 } QEMU_PACKED l1_ofs_rt_ofs_cls
;
4233 ret
= qcow2_cache_empty(bs
, s
->l2_table_cache
);
4238 ret
= qcow2_cache_empty(bs
, s
->refcount_block_cache
);
4243 /* Refcounts will be broken utterly */
4244 ret
= qcow2_mark_dirty(bs
);
4249 BLKDBG_EVENT(bs
->file
, BLKDBG_L1_UPDATE
);
4251 l1_clusters
= DIV_ROUND_UP(s
->l1_size
, s
->cluster_size
/ sizeof(uint64_t));
4252 l1_size2
= (uint64_t)s
->l1_size
* sizeof(uint64_t);
4254 /* After this call, neither the in-memory nor the on-disk refcount
4255 * information accurately describe the actual references */
4257 ret
= bdrv_pwrite_zeroes(bs
->file
, s
->l1_table_offset
,
4258 l1_clusters
* s
->cluster_size
, 0);
4260 goto fail_broken_refcounts
;
4262 memset(s
->l1_table
, 0, l1_size2
);
4264 BLKDBG_EVENT(bs
->file
, BLKDBG_EMPTY_IMAGE_PREPARE
);
4266 /* Overwrite enough clusters at the beginning of the sectors to place
4267 * the refcount table, a refcount block and the L1 table in; this may
4268 * overwrite parts of the existing refcount and L1 table, which is not
4269 * an issue because the dirty flag is set, complete data loss is in fact
4270 * desired and partial data loss is consequently fine as well */
4271 ret
= bdrv_pwrite_zeroes(bs
->file
, s
->cluster_size
,
4272 (2 + l1_clusters
) * s
->cluster_size
, 0);
4273 /* This call (even if it failed overall) may have overwritten on-disk
4274 * refcount structures; in that case, the in-memory refcount information
4275 * will probably differ from the on-disk information which makes the BDS
4278 goto fail_broken_refcounts
;
4281 BLKDBG_EVENT(bs
->file
, BLKDBG_L1_UPDATE
);
4282 BLKDBG_EVENT(bs
->file
, BLKDBG_REFTABLE_UPDATE
);
4284 /* "Create" an empty reftable (one cluster) directly after the image
4285 * header and an empty L1 table three clusters after the image header;
4286 * the cluster between those two will be used as the first refblock */
4287 l1_ofs_rt_ofs_cls
.l1_offset
= cpu_to_be64(3 * s
->cluster_size
);
4288 l1_ofs_rt_ofs_cls
.reftable_offset
= cpu_to_be64(s
->cluster_size
);
4289 l1_ofs_rt_ofs_cls
.reftable_clusters
= cpu_to_be32(1);
4290 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, l1_table_offset
),
4291 &l1_ofs_rt_ofs_cls
, sizeof(l1_ofs_rt_ofs_cls
));
4293 goto fail_broken_refcounts
;
4296 s
->l1_table_offset
= 3 * s
->cluster_size
;
4298 new_reftable
= g_try_new0(uint64_t, s
->cluster_size
/ sizeof(uint64_t));
4299 if (!new_reftable
) {
4301 goto fail_broken_refcounts
;
4304 s
->refcount_table_offset
= s
->cluster_size
;
4305 s
->refcount_table_size
= s
->cluster_size
/ sizeof(uint64_t);
4306 s
->max_refcount_table_index
= 0;
4308 g_free(s
->refcount_table
);
4309 s
->refcount_table
= new_reftable
;
4310 new_reftable
= NULL
;
4312 /* Now the in-memory refcount information again corresponds to the on-disk
4313 * information (reftable is empty and no refblocks (the refblock cache is
4314 * empty)); however, this means some clusters (e.g. the image header) are
4315 * referenced, but not refcounted, but the normal qcow2 code assumes that
4316 * the in-memory information is always correct */
4318 BLKDBG_EVENT(bs
->file
, BLKDBG_REFBLOCK_ALLOC
);
4320 /* Enter the first refblock into the reftable */
4321 rt_entry
= cpu_to_be64(2 * s
->cluster_size
);
4322 ret
= bdrv_pwrite_sync(bs
->file
, s
->cluster_size
,
4323 &rt_entry
, sizeof(rt_entry
));
4325 goto fail_broken_refcounts
;
4327 s
->refcount_table
[0] = 2 * s
->cluster_size
;
4329 s
->free_cluster_index
= 0;
4330 assert(3 + l1_clusters
<= s
->refcount_block_size
);
4331 offset
= qcow2_alloc_clusters(bs
, 3 * s
->cluster_size
+ l1_size2
);
4334 goto fail_broken_refcounts
;
4335 } else if (offset
> 0) {
4336 error_report("First cluster in emptied image is in use");
4340 /* Now finally the in-memory information corresponds to the on-disk
4341 * structures and is correct */
4342 ret
= qcow2_mark_clean(bs
);
4347 ret
= bdrv_truncate(bs
->file
, (3 + l1_clusters
) * s
->cluster_size
,
4348 PREALLOC_MODE_OFF
, &local_err
);
4350 error_report_err(local_err
);
4356 fail_broken_refcounts
:
4357 /* The BDS is unusable at this point. If we wanted to make it usable, we
4358 * would have to call qcow2_refcount_close(), qcow2_refcount_init(),
4359 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init()
4360 * again. However, because the functions which could have caused this error
4361 * path to be taken are used by those functions as well, it's very likely
4362 * that that sequence will fail as well. Therefore, just eject the BDS. */
4366 g_free(new_reftable
);
4370 static int qcow2_make_empty(BlockDriverState
*bs
)
4372 BDRVQcow2State
*s
= bs
->opaque
;
4373 uint64_t offset
, end_offset
;
4374 int step
= QEMU_ALIGN_DOWN(INT_MAX
, s
->cluster_size
);
4375 int l1_clusters
, ret
= 0;
4377 l1_clusters
= DIV_ROUND_UP(s
->l1_size
, s
->cluster_size
/ sizeof(uint64_t));
4379 if (s
->qcow_version
>= 3 && !s
->snapshots
&& !s
->nb_bitmaps
&&
4380 3 + l1_clusters
<= s
->refcount_block_size
&&
4381 s
->crypt_method_header
!= QCOW_CRYPT_LUKS
&&
4382 !has_data_file(bs
)) {
4383 /* The following function only works for qcow2 v3 images (it
4384 * requires the dirty flag) and only as long as there are no
4385 * features that reserve extra clusters (such as snapshots,
4386 * LUKS header, or persistent bitmaps), because it completely
4387 * empties the image. Furthermore, the L1 table and three
4388 * additional clusters (image header, refcount table, one
4389 * refcount block) have to fit inside one refcount block. It
4390 * only resets the image file, i.e. does not work with an
4391 * external data file. */
4392 return make_completely_empty(bs
);
4395 /* This fallback code simply discards every active cluster; this is slow,
4396 * but works in all cases */
4397 end_offset
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
4398 for (offset
= 0; offset
< end_offset
; offset
+= step
) {
4399 /* As this function is generally used after committing an external
4400 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the
4401 * default action for this kind of discard is to pass the discard,
4402 * which will ideally result in an actually smaller image file, as
4403 * is probably desired. */
4404 ret
= qcow2_cluster_discard(bs
, offset
, MIN(step
, end_offset
- offset
),
4405 QCOW2_DISCARD_SNAPSHOT
, true);
4414 static coroutine_fn
int qcow2_co_flush_to_os(BlockDriverState
*bs
)
4416 BDRVQcow2State
*s
= bs
->opaque
;
4419 qemu_co_mutex_lock(&s
->lock
);
4420 ret
= qcow2_write_caches(bs
);
4421 qemu_co_mutex_unlock(&s
->lock
);
4426 static ssize_t
qcow2_measure_crypto_hdr_init_func(QCryptoBlock
*block
,
4427 size_t headerlen
, void *opaque
, Error
**errp
)
4429 size_t *headerlenp
= opaque
;
4431 /* Stash away the payload size */
4432 *headerlenp
= headerlen
;
4436 static ssize_t
qcow2_measure_crypto_hdr_write_func(QCryptoBlock
*block
,
4437 size_t offset
, const uint8_t *buf
, size_t buflen
,
4438 void *opaque
, Error
**errp
)
4440 /* Discard the bytes, we're not actually writing to an image */
4444 /* Determine the number of bytes for the LUKS payload */
4445 static bool qcow2_measure_luks_headerlen(QemuOpts
*opts
, size_t *len
,
4449 QDict
*cryptoopts_qdict
;
4450 QCryptoBlockCreateOptions
*cryptoopts
;
4451 QCryptoBlock
*crypto
;
4453 /* Extract "encrypt." options into a qdict */
4454 opts_qdict
= qemu_opts_to_qdict(opts
, NULL
);
4455 qdict_extract_subqdict(opts_qdict
, &cryptoopts_qdict
, "encrypt.");
4456 qobject_unref(opts_qdict
);
4458 /* Build QCryptoBlockCreateOptions object from qdict */
4459 qdict_put_str(cryptoopts_qdict
, "format", "luks");
4460 cryptoopts
= block_crypto_create_opts_init(cryptoopts_qdict
, errp
);
4461 qobject_unref(cryptoopts_qdict
);
4466 /* Fake LUKS creation in order to determine the payload size */
4467 crypto
= qcrypto_block_create(cryptoopts
, "encrypt.",
4468 qcow2_measure_crypto_hdr_init_func
,
4469 qcow2_measure_crypto_hdr_write_func
,
4471 qapi_free_QCryptoBlockCreateOptions(cryptoopts
);
4476 qcrypto_block_free(crypto
);
4480 static BlockMeasureInfo
*qcow2_measure(QemuOpts
*opts
, BlockDriverState
*in_bs
,
4483 Error
*local_err
= NULL
;
4484 BlockMeasureInfo
*info
;
4485 uint64_t required
= 0; /* bytes that contribute to required size */
4486 uint64_t virtual_size
; /* disk size as seen by guest */
4487 uint64_t refcount_bits
;
4489 uint64_t luks_payload_size
= 0;
4490 size_t cluster_size
;
4493 PreallocMode prealloc
;
4494 bool has_backing_file
;
4497 /* Parse image creation options */
4498 cluster_size
= qcow2_opt_get_cluster_size_del(opts
, &local_err
);
4503 version
= qcow2_opt_get_version_del(opts
, &local_err
);
4508 refcount_bits
= qcow2_opt_get_refcount_bits_del(opts
, version
, &local_err
);
4513 optstr
= qemu_opt_get_del(opts
, BLOCK_OPT_PREALLOC
);
4514 prealloc
= qapi_enum_parse(&PreallocMode_lookup
, optstr
,
4515 PREALLOC_MODE_OFF
, &local_err
);
4521 optstr
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
4522 has_backing_file
= !!optstr
;
4525 optstr
= qemu_opt_get_del(opts
, BLOCK_OPT_ENCRYPT_FORMAT
);
4526 has_luks
= optstr
&& strcmp(optstr
, "luks") == 0;
4532 if (!qcow2_measure_luks_headerlen(opts
, &headerlen
, &local_err
)) {
4536 luks_payload_size
= ROUND_UP(headerlen
, cluster_size
);
4539 virtual_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0);
4540 virtual_size
= ROUND_UP(virtual_size
, cluster_size
);
4542 /* Check that virtual disk size is valid */
4543 l2_tables
= DIV_ROUND_UP(virtual_size
/ cluster_size
,
4544 cluster_size
/ sizeof(uint64_t));
4545 if (l2_tables
* sizeof(uint64_t) > QCOW_MAX_L1_SIZE
) {
4546 error_setg(&local_err
, "The image size is too large "
4547 "(try using a larger cluster size)");
4551 /* Account for input image */
4553 int64_t ssize
= bdrv_getlength(in_bs
);
4555 error_setg_errno(&local_err
, -ssize
,
4556 "Unable to get image virtual_size");
4560 virtual_size
= ROUND_UP(ssize
, cluster_size
);
4562 if (has_backing_file
) {
4563 /* We don't how much of the backing chain is shared by the input
4564 * image and the new image file. In the worst case the new image's
4565 * backing file has nothing in common with the input image. Be
4566 * conservative and assume all clusters need to be written.
4568 required
= virtual_size
;
4573 for (offset
= 0; offset
< ssize
; offset
+= pnum
) {
4576 ret
= bdrv_block_status_above(in_bs
, NULL
, offset
,
4577 ssize
- offset
, &pnum
, NULL
,
4580 error_setg_errno(&local_err
, -ret
,
4581 "Unable to get block status");
4585 if (ret
& BDRV_BLOCK_ZERO
) {
4586 /* Skip zero regions (safe with no backing file) */
4587 } else if ((ret
& (BDRV_BLOCK_DATA
| BDRV_BLOCK_ALLOCATED
)) ==
4588 (BDRV_BLOCK_DATA
| BDRV_BLOCK_ALLOCATED
)) {
4589 /* Extend pnum to end of cluster for next iteration */
4590 pnum
= ROUND_UP(offset
+ pnum
, cluster_size
) - offset
;
4592 /* Count clusters we've seen */
4593 required
+= offset
% cluster_size
+ pnum
;
4599 /* Take into account preallocation. Nothing special is needed for
4600 * PREALLOC_MODE_METADATA since metadata is always counted.
4602 if (prealloc
== PREALLOC_MODE_FULL
|| prealloc
== PREALLOC_MODE_FALLOC
) {
4603 required
= virtual_size
;
4606 info
= g_new(BlockMeasureInfo
, 1);
4607 info
->fully_allocated
=
4608 qcow2_calc_prealloc_size(virtual_size
, cluster_size
,
4609 ctz32(refcount_bits
)) + luks_payload_size
;
4611 /* Remove data clusters that are not required. This overestimates the
4612 * required size because metadata needed for the fully allocated file is
4615 info
->required
= info
->fully_allocated
- virtual_size
+ required
;
4619 error_propagate(errp
, local_err
);
4623 static int qcow2_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
4625 BDRVQcow2State
*s
= bs
->opaque
;
4626 bdi
->unallocated_blocks_are_zero
= true;
4627 bdi
->cluster_size
= s
->cluster_size
;
4628 bdi
->vm_state_offset
= qcow2_vm_state_offset(s
);
4632 static ImageInfoSpecific
*qcow2_get_specific_info(BlockDriverState
*bs
,
4635 BDRVQcow2State
*s
= bs
->opaque
;
4636 ImageInfoSpecific
*spec_info
;
4637 QCryptoBlockInfo
*encrypt_info
= NULL
;
4638 Error
*local_err
= NULL
;
4640 if (s
->crypto
!= NULL
) {
4641 encrypt_info
= qcrypto_block_get_info(s
->crypto
, &local_err
);
4643 error_propagate(errp
, local_err
);
4648 spec_info
= g_new(ImageInfoSpecific
, 1);
4649 *spec_info
= (ImageInfoSpecific
){
4650 .type
= IMAGE_INFO_SPECIFIC_KIND_QCOW2
,
4651 .u
.qcow2
.data
= g_new0(ImageInfoSpecificQCow2
, 1),
4653 if (s
->qcow_version
== 2) {
4654 *spec_info
->u
.qcow2
.data
= (ImageInfoSpecificQCow2
){
4655 .compat
= g_strdup("0.10"),
4656 .refcount_bits
= s
->refcount_bits
,
4658 } else if (s
->qcow_version
== 3) {
4659 Qcow2BitmapInfoList
*bitmaps
;
4660 bitmaps
= qcow2_get_bitmap_info_list(bs
, &local_err
);
4662 error_propagate(errp
, local_err
);
4663 qapi_free_ImageInfoSpecific(spec_info
);
4666 *spec_info
->u
.qcow2
.data
= (ImageInfoSpecificQCow2
){
4667 .compat
= g_strdup("1.1"),
4668 .lazy_refcounts
= s
->compatible_features
&
4669 QCOW2_COMPAT_LAZY_REFCOUNTS
,
4670 .has_lazy_refcounts
= true,
4671 .corrupt
= s
->incompatible_features
&
4672 QCOW2_INCOMPAT_CORRUPT
,
4673 .has_corrupt
= true,
4674 .refcount_bits
= s
->refcount_bits
,
4675 .has_bitmaps
= !!bitmaps
,
4677 .has_data_file
= !!s
->image_data_file
,
4678 .data_file
= g_strdup(s
->image_data_file
),
4679 .has_data_file_raw
= has_data_file(bs
),
4680 .data_file_raw
= data_file_is_raw(bs
),
4683 /* if this assertion fails, this probably means a new version was
4684 * added without having it covered here */
4689 ImageInfoSpecificQCow2Encryption
*qencrypt
=
4690 g_new(ImageInfoSpecificQCow2Encryption
, 1);
4691 switch (encrypt_info
->format
) {
4692 case Q_CRYPTO_BLOCK_FORMAT_QCOW
:
4693 qencrypt
->format
= BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES
;
4695 case Q_CRYPTO_BLOCK_FORMAT_LUKS
:
4696 qencrypt
->format
= BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS
;
4697 qencrypt
->u
.luks
= encrypt_info
->u
.luks
;
4702 /* Since we did shallow copy above, erase any pointers
4703 * in the original info */
4704 memset(&encrypt_info
->u
, 0, sizeof(encrypt_info
->u
));
4705 qapi_free_QCryptoBlockInfo(encrypt_info
);
4707 spec_info
->u
.qcow2
.data
->has_encrypt
= true;
4708 spec_info
->u
.qcow2
.data
->encrypt
= qencrypt
;
4714 static int qcow2_save_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
4717 BDRVQcow2State
*s
= bs
->opaque
;
4719 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_SAVE
);
4720 return bs
->drv
->bdrv_co_pwritev(bs
, qcow2_vm_state_offset(s
) + pos
,
4721 qiov
->size
, qiov
, 0);
4724 static int qcow2_load_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
4727 BDRVQcow2State
*s
= bs
->opaque
;
4729 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_LOAD
);
4730 return bs
->drv
->bdrv_co_preadv(bs
, qcow2_vm_state_offset(s
) + pos
,
4731 qiov
->size
, qiov
, 0);
4735 * Downgrades an image's version. To achieve this, any incompatible features
4736 * have to be removed.
4738 static int qcow2_downgrade(BlockDriverState
*bs
, int target_version
,
4739 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
4742 BDRVQcow2State
*s
= bs
->opaque
;
4743 int current_version
= s
->qcow_version
;
4746 /* This is qcow2_downgrade(), not qcow2_upgrade() */
4747 assert(target_version
< current_version
);
4749 /* There are no other versions (now) that you can downgrade to */
4750 assert(target_version
== 2);
4752 if (s
->refcount_order
!= 4) {
4753 error_setg(errp
, "compat=0.10 requires refcount_bits=16");
4757 if (has_data_file(bs
)) {
4758 error_setg(errp
, "Cannot downgrade an image with a data file");
4762 /* clear incompatible features */
4763 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
4764 ret
= qcow2_mark_clean(bs
);
4766 error_setg_errno(errp
, -ret
, "Failed to make the image clean");
4771 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
4772 * the first place; if that happens nonetheless, returning -ENOTSUP is the
4773 * best thing to do anyway */
4775 if (s
->incompatible_features
) {
4776 error_setg(errp
, "Cannot downgrade an image with incompatible features "
4777 "%#" PRIx64
" set", s
->incompatible_features
);
4781 /* since we can ignore compatible features, we can set them to 0 as well */
4782 s
->compatible_features
= 0;
4783 /* if lazy refcounts have been used, they have already been fixed through
4784 * clearing the dirty flag */
4786 /* clearing autoclear features is trivial */
4787 s
->autoclear_features
= 0;
4789 ret
= qcow2_expand_zero_clusters(bs
, status_cb
, cb_opaque
);
4791 error_setg_errno(errp
, -ret
, "Failed to turn zero into data clusters");
4795 s
->qcow_version
= target_version
;
4796 ret
= qcow2_update_header(bs
);
4798 s
->qcow_version
= current_version
;
4799 error_setg_errno(errp
, -ret
, "Failed to update the image header");
4805 typedef enum Qcow2AmendOperation
{
4806 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be
4807 * statically initialized to so that the helper CB can discern the first
4808 * invocation from an operation change */
4809 QCOW2_NO_OPERATION
= 0,
4811 QCOW2_CHANGING_REFCOUNT_ORDER
,
4813 } Qcow2AmendOperation
;
4815 typedef struct Qcow2AmendHelperCBInfo
{
4816 /* The code coordinating the amend operations should only modify
4817 * these four fields; the rest will be managed by the CB */
4818 BlockDriverAmendStatusCB
*original_status_cb
;
4819 void *original_cb_opaque
;
4821 Qcow2AmendOperation current_operation
;
4823 /* Total number of operations to perform (only set once) */
4824 int total_operations
;
4826 /* The following fields are managed by the CB */
4828 /* Number of operations completed */
4829 int operations_completed
;
4831 /* Cumulative offset of all completed operations */
4832 int64_t offset_completed
;
4834 Qcow2AmendOperation last_operation
;
4835 int64_t last_work_size
;
4836 } Qcow2AmendHelperCBInfo
;
4838 static void qcow2_amend_helper_cb(BlockDriverState
*bs
,
4839 int64_t operation_offset
,
4840 int64_t operation_work_size
, void *opaque
)
4842 Qcow2AmendHelperCBInfo
*info
= opaque
;
4843 int64_t current_work_size
;
4844 int64_t projected_work_size
;
4846 if (info
->current_operation
!= info
->last_operation
) {
4847 if (info
->last_operation
!= QCOW2_NO_OPERATION
) {
4848 info
->offset_completed
+= info
->last_work_size
;
4849 info
->operations_completed
++;
4852 info
->last_operation
= info
->current_operation
;
4855 assert(info
->total_operations
> 0);
4856 assert(info
->operations_completed
< info
->total_operations
);
4858 info
->last_work_size
= operation_work_size
;
4860 current_work_size
= info
->offset_completed
+ operation_work_size
;
4862 /* current_work_size is the total work size for (operations_completed + 1)
4863 * operations (which includes this one), so multiply it by the number of
4864 * operations not covered and divide it by the number of operations
4865 * covered to get a projection for the operations not covered */
4866 projected_work_size
= current_work_size
* (info
->total_operations
-
4867 info
->operations_completed
- 1)
4868 / (info
->operations_completed
+ 1);
4870 info
->original_status_cb(bs
, info
->offset_completed
+ operation_offset
,
4871 current_work_size
+ projected_work_size
,
4872 info
->original_cb_opaque
);
4875 static int qcow2_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4876 BlockDriverAmendStatusCB
*status_cb
,
4880 BDRVQcow2State
*s
= bs
->opaque
;
4881 int old_version
= s
->qcow_version
, new_version
= old_version
;
4882 uint64_t new_size
= 0;
4883 const char *backing_file
= NULL
, *backing_format
= NULL
, *data_file
= NULL
;
4884 bool lazy_refcounts
= s
->use_lazy_refcounts
;
4885 bool data_file_raw
= data_file_is_raw(bs
);
4886 const char *compat
= NULL
;
4887 uint64_t cluster_size
= s
->cluster_size
;
4890 int refcount_bits
= s
->refcount_bits
;
4892 QemuOptDesc
*desc
= opts
->list
->desc
;
4893 Qcow2AmendHelperCBInfo helper_cb_info
;
4895 while (desc
&& desc
->name
) {
4896 if (!qemu_opt_find(opts
, desc
->name
)) {
4897 /* only change explicitly defined options */
4902 if (!strcmp(desc
->name
, BLOCK_OPT_COMPAT_LEVEL
)) {
4903 compat
= qemu_opt_get(opts
, BLOCK_OPT_COMPAT_LEVEL
);
4905 /* preserve default */
4906 } else if (!strcmp(compat
, "0.10")) {
4908 } else if (!strcmp(compat
, "1.1")) {
4911 error_setg(errp
, "Unknown compatibility level %s", compat
);
4914 } else if (!strcmp(desc
->name
, BLOCK_OPT_PREALLOC
)) {
4915 error_setg(errp
, "Cannot change preallocation mode");
4917 } else if (!strcmp(desc
->name
, BLOCK_OPT_SIZE
)) {
4918 new_size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
4919 } else if (!strcmp(desc
->name
, BLOCK_OPT_BACKING_FILE
)) {
4920 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4921 } else if (!strcmp(desc
->name
, BLOCK_OPT_BACKING_FMT
)) {
4922 backing_format
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4923 } else if (!strcmp(desc
->name
, BLOCK_OPT_ENCRYPT
)) {
4924 encrypt
= qemu_opt_get_bool(opts
, BLOCK_OPT_ENCRYPT
,
4927 if (encrypt
!= !!s
->crypto
) {
4929 "Changing the encryption flag is not supported");
4932 } else if (!strcmp(desc
->name
, BLOCK_OPT_ENCRYPT_FORMAT
)) {
4933 encformat
= qcow2_crypt_method_from_format(
4934 qemu_opt_get(opts
, BLOCK_OPT_ENCRYPT_FORMAT
));
4936 if (encformat
!= s
->crypt_method_header
) {
4938 "Changing the encryption format is not supported");
4941 } else if (g_str_has_prefix(desc
->name
, "encrypt.")) {
4943 "Changing the encryption parameters is not supported");
4945 } else if (!strcmp(desc
->name
, BLOCK_OPT_CLUSTER_SIZE
)) {
4946 cluster_size
= qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
,
4948 if (cluster_size
!= s
->cluster_size
) {
4949 error_setg(errp
, "Changing the cluster size is not supported");
4952 } else if (!strcmp(desc
->name
, BLOCK_OPT_LAZY_REFCOUNTS
)) {
4953 lazy_refcounts
= qemu_opt_get_bool(opts
, BLOCK_OPT_LAZY_REFCOUNTS
,
4955 } else if (!strcmp(desc
->name
, BLOCK_OPT_REFCOUNT_BITS
)) {
4956 refcount_bits
= qemu_opt_get_number(opts
, BLOCK_OPT_REFCOUNT_BITS
,
4959 if (refcount_bits
<= 0 || refcount_bits
> 64 ||
4960 !is_power_of_2(refcount_bits
))
4962 error_setg(errp
, "Refcount width must be a power of two and "
4963 "may not exceed 64 bits");
4966 } else if (!strcmp(desc
->name
, BLOCK_OPT_DATA_FILE
)) {
4967 data_file
= qemu_opt_get(opts
, BLOCK_OPT_DATA_FILE
);
4968 if (data_file
&& !has_data_file(bs
)) {
4969 error_setg(errp
, "data-file can only be set for images that "
4970 "use an external data file");
4973 } else if (!strcmp(desc
->name
, BLOCK_OPT_DATA_FILE_RAW
)) {
4974 data_file_raw
= qemu_opt_get_bool(opts
, BLOCK_OPT_DATA_FILE_RAW
,
4976 if (data_file_raw
&& !data_file_is_raw(bs
)) {
4977 error_setg(errp
, "data-file-raw cannot be set on existing "
4982 /* if this point is reached, this probably means a new option was
4983 * added without having it covered here */
4990 helper_cb_info
= (Qcow2AmendHelperCBInfo
){
4991 .original_status_cb
= status_cb
,
4992 .original_cb_opaque
= cb_opaque
,
4993 .total_operations
= (new_version
< old_version
)
4994 + (s
->refcount_bits
!= refcount_bits
)
4997 /* Upgrade first (some features may require compat=1.1) */
4998 if (new_version
> old_version
) {
4999 s
->qcow_version
= new_version
;
5000 ret
= qcow2_update_header(bs
);
5002 s
->qcow_version
= old_version
;
5003 error_setg_errno(errp
, -ret
, "Failed to update the image header");
5008 if (s
->refcount_bits
!= refcount_bits
) {
5009 int refcount_order
= ctz32(refcount_bits
);
5011 if (new_version
< 3 && refcount_bits
!= 16) {
5012 error_setg(errp
, "Refcount widths other than 16 bits require "
5013 "compatibility level 1.1 or above (use compat=1.1 or "
5018 helper_cb_info
.current_operation
= QCOW2_CHANGING_REFCOUNT_ORDER
;
5019 ret
= qcow2_change_refcount_order(bs
, refcount_order
,
5020 &qcow2_amend_helper_cb
,
5021 &helper_cb_info
, errp
);
5027 /* data-file-raw blocks backing files, so clear it first if requested */
5028 if (data_file_raw
) {
5029 s
->autoclear_features
|= QCOW2_AUTOCLEAR_DATA_FILE_RAW
;
5031 s
->autoclear_features
&= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW
;
5035 g_free(s
->image_data_file
);
5036 s
->image_data_file
= *data_file
? g_strdup(data_file
) : NULL
;
5039 ret
= qcow2_update_header(bs
);
5041 error_setg_errno(errp
, -ret
, "Failed to update the image header");
5045 if (backing_file
|| backing_format
) {
5046 ret
= qcow2_change_backing_file(bs
,
5047 backing_file
?: s
->image_backing_file
,
5048 backing_format
?: s
->image_backing_format
);
5050 error_setg_errno(errp
, -ret
, "Failed to change the backing file");
5055 if (s
->use_lazy_refcounts
!= lazy_refcounts
) {
5056 if (lazy_refcounts
) {
5057 if (new_version
< 3) {
5058 error_setg(errp
, "Lazy refcounts only supported with "
5059 "compatibility level 1.1 and above (use compat=1.1 "
5063 s
->compatible_features
|= QCOW2_COMPAT_LAZY_REFCOUNTS
;
5064 ret
= qcow2_update_header(bs
);
5066 s
->compatible_features
&= ~QCOW2_COMPAT_LAZY_REFCOUNTS
;
5067 error_setg_errno(errp
, -ret
, "Failed to update the image header");
5070 s
->use_lazy_refcounts
= true;
5072 /* make image clean first */
5073 ret
= qcow2_mark_clean(bs
);
5075 error_setg_errno(errp
, -ret
, "Failed to make the image clean");
5078 /* now disallow lazy refcounts */
5079 s
->compatible_features
&= ~QCOW2_COMPAT_LAZY_REFCOUNTS
;
5080 ret
= qcow2_update_header(bs
);
5082 s
->compatible_features
|= QCOW2_COMPAT_LAZY_REFCOUNTS
;
5083 error_setg_errno(errp
, -ret
, "Failed to update the image header");
5086 s
->use_lazy_refcounts
= false;
5091 BlockBackend
*blk
= blk_new(BLK_PERM_RESIZE
, BLK_PERM_ALL
);
5092 ret
= blk_insert_bs(blk
, bs
, errp
);
5098 ret
= blk_truncate(blk
, new_size
, PREALLOC_MODE_OFF
, errp
);
5105 /* Downgrade last (so unsupported features can be removed before) */
5106 if (new_version
< old_version
) {
5107 helper_cb_info
.current_operation
= QCOW2_DOWNGRADING
;
5108 ret
= qcow2_downgrade(bs
, new_version
, &qcow2_amend_helper_cb
,
5109 &helper_cb_info
, errp
);
5119 * If offset or size are negative, respectively, they will not be included in
5120 * the BLOCK_IMAGE_CORRUPTED event emitted.
5121 * fatal will be ignored for read-only BDS; corruptions found there will always
5122 * be considered non-fatal.
5124 void qcow2_signal_corruption(BlockDriverState
*bs
, bool fatal
, int64_t offset
,
5125 int64_t size
, const char *message_format
, ...)
5127 BDRVQcow2State
*s
= bs
->opaque
;
5128 const char *node_name
;
5132 fatal
= fatal
&& bdrv_is_writable(bs
);
5134 if (s
->signaled_corruption
&&
5135 (!fatal
|| (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
)))
5140 va_start(ap
, message_format
);
5141 message
= g_strdup_vprintf(message_format
, ap
);
5145 fprintf(stderr
, "qcow2: Marking image as corrupt: %s; further "
5146 "corruption events will be suppressed\n", message
);
5148 fprintf(stderr
, "qcow2: Image is corrupt: %s; further non-fatal "
5149 "corruption events will be suppressed\n", message
);
5152 node_name
= bdrv_get_node_name(bs
);
5153 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs
),
5154 *node_name
!= '\0', node_name
,
5155 message
, offset
>= 0, offset
,
5161 qcow2_mark_corrupt(bs
);
5162 bs
->drv
= NULL
; /* make BDS unusable */
5165 s
->signaled_corruption
= true;
5168 static QemuOptsList qcow2_create_opts
= {
5169 .name
= "qcow2-create-opts",
5170 .head
= QTAILQ_HEAD_INITIALIZER(qcow2_create_opts
.head
),
5173 .name
= BLOCK_OPT_SIZE
,
5174 .type
= QEMU_OPT_SIZE
,
5175 .help
= "Virtual disk size"
5178 .name
= BLOCK_OPT_COMPAT_LEVEL
,
5179 .type
= QEMU_OPT_STRING
,
5180 .help
= "Compatibility level (0.10 or 1.1)"
5183 .name
= BLOCK_OPT_BACKING_FILE
,
5184 .type
= QEMU_OPT_STRING
,
5185 .help
= "File name of a base image"
5188 .name
= BLOCK_OPT_BACKING_FMT
,
5189 .type
= QEMU_OPT_STRING
,
5190 .help
= "Image format of the base image"
5193 .name
= BLOCK_OPT_DATA_FILE
,
5194 .type
= QEMU_OPT_STRING
,
5195 .help
= "File name of an external data file"
5198 .name
= BLOCK_OPT_DATA_FILE_RAW
,
5199 .type
= QEMU_OPT_BOOL
,
5200 .help
= "The external data file must stay valid as a raw image"
5203 .name
= BLOCK_OPT_ENCRYPT
,
5204 .type
= QEMU_OPT_BOOL
,
5205 .help
= "Encrypt the image with format 'aes'. (Deprecated "
5206 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT
"=aes)",
5209 .name
= BLOCK_OPT_ENCRYPT_FORMAT
,
5210 .type
= QEMU_OPT_STRING
,
5211 .help
= "Encrypt the image, format choices: 'aes', 'luks'",
5213 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
5214 "ID of secret providing qcow AES key or LUKS passphrase"),
5215 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."),
5216 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."),
5217 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."),
5218 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."),
5219 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."),
5220 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."),
5222 .name
= BLOCK_OPT_CLUSTER_SIZE
,
5223 .type
= QEMU_OPT_SIZE
,
5224 .help
= "qcow2 cluster size",
5225 .def_value_str
= stringify(DEFAULT_CLUSTER_SIZE
)
5228 .name
= BLOCK_OPT_PREALLOC
,
5229 .type
= QEMU_OPT_STRING
,
5230 .help
= "Preallocation mode (allowed values: off, metadata, "
5234 .name
= BLOCK_OPT_LAZY_REFCOUNTS
,
5235 .type
= QEMU_OPT_BOOL
,
5236 .help
= "Postpone refcount updates",
5237 .def_value_str
= "off"
5240 .name
= BLOCK_OPT_REFCOUNT_BITS
,
5241 .type
= QEMU_OPT_NUMBER
,
5242 .help
= "Width of a reference count entry in bits",
5243 .def_value_str
= "16"
5245 { /* end of list */ }
5249 static const char *const qcow2_strong_runtime_opts
[] = {
5250 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET
,
5255 BlockDriver bdrv_qcow2
= {
5256 .format_name
= "qcow2",
5257 .instance_size
= sizeof(BDRVQcow2State
),
5258 .bdrv_probe
= qcow2_probe
,
5259 .bdrv_open
= qcow2_open
,
5260 .bdrv_close
= qcow2_close
,
5261 .bdrv_reopen_prepare
= qcow2_reopen_prepare
,
5262 .bdrv_reopen_commit
= qcow2_reopen_commit
,
5263 .bdrv_reopen_abort
= qcow2_reopen_abort
,
5264 .bdrv_join_options
= qcow2_join_options
,
5265 .bdrv_child_perm
= bdrv_format_default_perms
,
5266 .bdrv_co_create_opts
= qcow2_co_create_opts
,
5267 .bdrv_co_create
= qcow2_co_create
,
5268 .bdrv_has_zero_init
= bdrv_has_zero_init_1
,
5269 .bdrv_co_block_status
= qcow2_co_block_status
,
5271 .bdrv_co_preadv
= qcow2_co_preadv
,
5272 .bdrv_co_pwritev
= qcow2_co_pwritev
,
5273 .bdrv_co_flush_to_os
= qcow2_co_flush_to_os
,
5275 .bdrv_co_pwrite_zeroes
= qcow2_co_pwrite_zeroes
,
5276 .bdrv_co_pdiscard
= qcow2_co_pdiscard
,
5277 .bdrv_co_copy_range_from
= qcow2_co_copy_range_from
,
5278 .bdrv_co_copy_range_to
= qcow2_co_copy_range_to
,
5279 .bdrv_co_truncate
= qcow2_co_truncate
,
5280 .bdrv_co_pwritev_compressed
= qcow2_co_pwritev_compressed
,
5281 .bdrv_make_empty
= qcow2_make_empty
,
5283 .bdrv_snapshot_create
= qcow2_snapshot_create
,
5284 .bdrv_snapshot_goto
= qcow2_snapshot_goto
,
5285 .bdrv_snapshot_delete
= qcow2_snapshot_delete
,
5286 .bdrv_snapshot_list
= qcow2_snapshot_list
,
5287 .bdrv_snapshot_load_tmp
= qcow2_snapshot_load_tmp
,
5288 .bdrv_measure
= qcow2_measure
,
5289 .bdrv_get_info
= qcow2_get_info
,
5290 .bdrv_get_specific_info
= qcow2_get_specific_info
,
5292 .bdrv_save_vmstate
= qcow2_save_vmstate
,
5293 .bdrv_load_vmstate
= qcow2_load_vmstate
,
5295 .supports_backing
= true,
5296 .bdrv_change_backing_file
= qcow2_change_backing_file
,
5298 .bdrv_refresh_limits
= qcow2_refresh_limits
,
5299 .bdrv_co_invalidate_cache
= qcow2_co_invalidate_cache
,
5300 .bdrv_inactivate
= qcow2_inactivate
,
5302 .create_opts
= &qcow2_create_opts
,
5303 .strong_runtime_opts
= qcow2_strong_runtime_opts
,
5304 .mutable_opts
= mutable_opts
,
5305 .bdrv_co_check
= qcow2_co_check
,
5306 .bdrv_amend_options
= qcow2_amend_options
,
5308 .bdrv_detach_aio_context
= qcow2_detach_aio_context
,
5309 .bdrv_attach_aio_context
= qcow2_attach_aio_context
,
5311 .bdrv_reopen_bitmaps_rw
= qcow2_reopen_bitmaps_rw
,
5312 .bdrv_can_store_new_dirty_bitmap
= qcow2_can_store_new_dirty_bitmap
,
5313 .bdrv_remove_persistent_dirty_bitmap
= qcow2_remove_persistent_dirty_bitmap
,
5316 static void bdrv_qcow2_init(void)
5318 bdrv_register(&bdrv_qcow2
);
5321 block_init(bdrv_qcow2_init
);