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
24 #include "qemu/osdep.h"
25 #include "block/block_int.h"
26 #include "sysemu/block-backend.h"
27 #include "qemu/module.h"
29 #include "block/qcow2.h"
30 #include "qemu/error-report.h"
31 #include "qapi/qmp/qerror.h"
32 #include "qapi/qmp/qbool.h"
33 #include "qapi/util.h"
34 #include "qapi/qmp/types.h"
35 #include "qapi-event.h"
37 #include "qemu/option_int.h"
38 #include "qemu/cutils.h"
39 #include "qemu/bswap.h"
40 #include "qapi/opts-visitor.h"
41 #include "qapi-visit.h"
42 #include "block/crypto.h"
45 Differences with QCOW:
47 - Support for multiple incremental snapshots.
48 - Memory management by reference counts.
49 - Clusters which have a reference count of one have the bit
50 QCOW_OFLAG_COPIED to optimize write performance.
51 - Size of compressed clusters is stored in sectors to reduce bit usage
52 in the cluster offsets.
53 - Support for storing additional data (such as the VM state) in the
55 - If a backing store is used, the cluster size is not constrained
56 (could be backported to QCOW).
57 - L2 tables have always a size of one cluster.
64 } QEMU_PACKED QCowExtension
;
66 #define QCOW2_EXT_MAGIC_END 0
67 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
68 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
69 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
71 static int qcow2_probe(const uint8_t *buf
, int buf_size
, const char *filename
)
73 const QCowHeader
*cow_header
= (const void *)buf
;
75 if (buf_size
>= sizeof(QCowHeader
) &&
76 be32_to_cpu(cow_header
->magic
) == QCOW_MAGIC
&&
77 be32_to_cpu(cow_header
->version
) >= 2)
84 static ssize_t
qcow2_crypto_hdr_read_func(QCryptoBlock
*block
, size_t offset
,
85 uint8_t *buf
, size_t buflen
,
86 void *opaque
, Error
**errp
)
88 BlockDriverState
*bs
= opaque
;
89 BDRVQcow2State
*s
= bs
->opaque
;
92 if ((offset
+ buflen
) > s
->crypto_header
.length
) {
93 error_setg(errp
, "Request for data outside of extension header");
97 ret
= bdrv_pread(bs
->file
,
98 s
->crypto_header
.offset
+ offset
, buf
, buflen
);
100 error_setg_errno(errp
, -ret
, "Could not read encryption header");
107 static ssize_t
qcow2_crypto_hdr_init_func(QCryptoBlock
*block
, size_t headerlen
,
108 void *opaque
, Error
**errp
)
110 BlockDriverState
*bs
= opaque
;
111 BDRVQcow2State
*s
= bs
->opaque
;
115 ret
= qcow2_alloc_clusters(bs
, headerlen
);
117 error_setg_errno(errp
, -ret
,
118 "Cannot allocate cluster for LUKS header size %zu",
123 s
->crypto_header
.length
= headerlen
;
124 s
->crypto_header
.offset
= ret
;
126 /* Zero fill remaining space in cluster so it has predictable
127 * content in case of future spec changes */
128 clusterlen
= size_to_clusters(s
, headerlen
) * s
->cluster_size
;
129 ret
= bdrv_pwrite_zeroes(bs
->file
,
131 clusterlen
- headerlen
, 0);
133 error_setg_errno(errp
, -ret
, "Could not zero fill encryption header");
141 static ssize_t
qcow2_crypto_hdr_write_func(QCryptoBlock
*block
, size_t offset
,
142 const uint8_t *buf
, size_t buflen
,
143 void *opaque
, Error
**errp
)
145 BlockDriverState
*bs
= opaque
;
146 BDRVQcow2State
*s
= bs
->opaque
;
149 if ((offset
+ buflen
) > s
->crypto_header
.length
) {
150 error_setg(errp
, "Request for data outside of extension header");
154 ret
= bdrv_pwrite(bs
->file
,
155 s
->crypto_header
.offset
+ offset
, buf
, buflen
);
157 error_setg_errno(errp
, -ret
, "Could not read encryption header");
165 * read qcow2 extension and fill bs
166 * start reading from start_offset
167 * finish reading upon magic of value 0 or when end_offset reached
168 * unknown magic is skipped (future extension this version knows nothing about)
169 * return 0 upon success, non-0 otherwise
171 static int qcow2_read_extensions(BlockDriverState
*bs
, uint64_t start_offset
,
172 uint64_t end_offset
, void **p_feature_table
,
173 int flags
, Error
**errp
)
175 BDRVQcow2State
*s
= bs
->opaque
;
181 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset
, end_offset
);
183 offset
= start_offset
;
184 while (offset
< end_offset
) {
188 if (offset
> s
->cluster_size
)
189 printf("qcow2_read_extension: suspicious offset %lu\n", offset
);
191 printf("attempting to read extended header in offset %lu\n", offset
);
194 ret
= bdrv_pread(bs
->file
, offset
, &ext
, sizeof(ext
));
196 error_setg_errno(errp
, -ret
, "qcow2_read_extension: ERROR: "
197 "pread fail from offset %" PRIu64
, offset
);
200 be32_to_cpus(&ext
.magic
);
201 be32_to_cpus(&ext
.len
);
202 offset
+= sizeof(ext
);
204 printf("ext.magic = 0x%x\n", ext
.magic
);
206 if (offset
> end_offset
|| ext
.len
> end_offset
- offset
) {
207 error_setg(errp
, "Header extension too large");
212 case QCOW2_EXT_MAGIC_END
:
215 case QCOW2_EXT_MAGIC_BACKING_FORMAT
:
216 if (ext
.len
>= sizeof(bs
->backing_format
)) {
217 error_setg(errp
, "ERROR: ext_backing_format: len=%" PRIu32
218 " too large (>=%zu)", ext
.len
,
219 sizeof(bs
->backing_format
));
222 ret
= bdrv_pread(bs
->file
, offset
, bs
->backing_format
, ext
.len
);
224 error_setg_errno(errp
, -ret
, "ERROR: ext_backing_format: "
225 "Could not read format name");
228 bs
->backing_format
[ext
.len
] = '\0';
229 s
->image_backing_format
= g_strdup(bs
->backing_format
);
231 printf("Qcow2: Got format extension %s\n", bs
->backing_format
);
235 case QCOW2_EXT_MAGIC_FEATURE_TABLE
:
236 if (p_feature_table
!= NULL
) {
237 void* feature_table
= g_malloc0(ext
.len
+ 2 * sizeof(Qcow2Feature
));
238 ret
= bdrv_pread(bs
->file
, offset
, feature_table
, ext
.len
);
240 error_setg_errno(errp
, -ret
, "ERROR: ext_feature_table: "
241 "Could not read table");
245 *p_feature_table
= feature_table
;
249 case QCOW2_EXT_MAGIC_CRYPTO_HEADER
: {
250 unsigned int cflags
= 0;
251 if (s
->crypt_method_header
!= QCOW_CRYPT_LUKS
) {
252 error_setg(errp
, "CRYPTO header extension only "
253 "expected with LUKS encryption method");
256 if (ext
.len
!= sizeof(Qcow2CryptoHeaderExtension
)) {
257 error_setg(errp
, "CRYPTO header extension size %u, "
258 "but expected size %zu", ext
.len
,
259 sizeof(Qcow2CryptoHeaderExtension
));
263 ret
= bdrv_pread(bs
->file
, offset
, &s
->crypto_header
, ext
.len
);
265 error_setg_errno(errp
, -ret
,
266 "Unable to read CRYPTO header extension");
269 be64_to_cpus(&s
->crypto_header
.offset
);
270 be64_to_cpus(&s
->crypto_header
.length
);
272 if ((s
->crypto_header
.offset
% s
->cluster_size
) != 0) {
273 error_setg(errp
, "Encryption header offset '%" PRIu64
"' is "
274 "not a multiple of cluster size '%u'",
275 s
->crypto_header
.offset
, s
->cluster_size
);
279 if (flags
& BDRV_O_NO_IO
) {
280 cflags
|= QCRYPTO_BLOCK_OPEN_NO_IO
;
282 s
->crypto
= qcrypto_block_open(s
->crypto_opts
,
283 qcow2_crypto_hdr_read_func
,
291 /* unknown magic - save it in case we need to rewrite the header */
293 Qcow2UnknownHeaderExtension
*uext
;
295 uext
= g_malloc0(sizeof(*uext
) + ext
.len
);
296 uext
->magic
= ext
.magic
;
298 QLIST_INSERT_HEAD(&s
->unknown_header_ext
, uext
, next
);
300 ret
= bdrv_pread(bs
->file
, offset
, uext
->data
, uext
->len
);
302 error_setg_errno(errp
, -ret
, "ERROR: unknown extension: "
303 "Could not read data");
310 offset
+= ((ext
.len
+ 7) & ~7);
316 static void cleanup_unknown_header_ext(BlockDriverState
*bs
)
318 BDRVQcow2State
*s
= bs
->opaque
;
319 Qcow2UnknownHeaderExtension
*uext
, *next
;
321 QLIST_FOREACH_SAFE(uext
, &s
->unknown_header_ext
, next
, next
) {
322 QLIST_REMOVE(uext
, next
);
327 static void report_unsupported_feature(Error
**errp
, Qcow2Feature
*table
,
330 char *features
= g_strdup("");
333 while (table
&& table
->name
[0] != '\0') {
334 if (table
->type
== QCOW2_FEAT_TYPE_INCOMPATIBLE
) {
335 if (mask
& (1ULL << table
->bit
)) {
337 features
= g_strdup_printf("%s%s%.46s", old
, *old
? ", " : "",
340 mask
&= ~(1ULL << table
->bit
);
348 features
= g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64
,
349 old
, *old
? ", " : "", mask
);
353 error_setg(errp
, "Unsupported qcow2 feature(s): %s", features
);
358 * Sets the dirty bit and flushes afterwards if necessary.
360 * The incompatible_features bit is only set if the image file header was
361 * updated successfully. Therefore it is not required to check the return
362 * value of this function.
364 int qcow2_mark_dirty(BlockDriverState
*bs
)
366 BDRVQcow2State
*s
= bs
->opaque
;
370 assert(s
->qcow_version
>= 3);
372 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
373 return 0; /* already dirty */
376 val
= cpu_to_be64(s
->incompatible_features
| QCOW2_INCOMPAT_DIRTY
);
377 ret
= bdrv_pwrite(bs
->file
, offsetof(QCowHeader
, incompatible_features
),
382 ret
= bdrv_flush(bs
->file
->bs
);
387 /* Only treat image as dirty if the header was updated successfully */
388 s
->incompatible_features
|= QCOW2_INCOMPAT_DIRTY
;
393 * Clears the dirty bit and flushes before if necessary. Only call this
394 * function when there are no pending requests, it does not guard against
395 * concurrent requests dirtying the image.
397 static int qcow2_mark_clean(BlockDriverState
*bs
)
399 BDRVQcow2State
*s
= bs
->opaque
;
401 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
404 s
->incompatible_features
&= ~QCOW2_INCOMPAT_DIRTY
;
406 ret
= bdrv_flush(bs
);
411 return qcow2_update_header(bs
);
417 * Marks the image as corrupt.
419 int qcow2_mark_corrupt(BlockDriverState
*bs
)
421 BDRVQcow2State
*s
= bs
->opaque
;
423 s
->incompatible_features
|= QCOW2_INCOMPAT_CORRUPT
;
424 return qcow2_update_header(bs
);
428 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes
429 * before if necessary.
431 int qcow2_mark_consistent(BlockDriverState
*bs
)
433 BDRVQcow2State
*s
= bs
->opaque
;
435 if (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
) {
436 int ret
= bdrv_flush(bs
);
441 s
->incompatible_features
&= ~QCOW2_INCOMPAT_CORRUPT
;
442 return qcow2_update_header(bs
);
447 static int qcow2_check(BlockDriverState
*bs
, BdrvCheckResult
*result
,
450 int ret
= qcow2_check_refcounts(bs
, result
, fix
);
455 if (fix
&& result
->check_errors
== 0 && result
->corruptions
== 0) {
456 ret
= qcow2_mark_clean(bs
);
460 return qcow2_mark_consistent(bs
);
465 static int validate_table_offset(BlockDriverState
*bs
, uint64_t offset
,
466 uint64_t entries
, size_t entry_len
)
468 BDRVQcow2State
*s
= bs
->opaque
;
471 /* Use signed INT64_MAX as the maximum even for uint64_t header fields,
472 * because values will be passed to qemu functions taking int64_t. */
473 if (entries
> INT64_MAX
/ entry_len
) {
477 size
= entries
* entry_len
;
479 if (INT64_MAX
- size
< offset
) {
483 /* Tables must be cluster aligned */
484 if (offset_into_cluster(s
, offset
) != 0) {
491 static QemuOptsList qcow2_runtime_opts
= {
493 .head
= QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts
.head
),
496 .name
= QCOW2_OPT_LAZY_REFCOUNTS
,
497 .type
= QEMU_OPT_BOOL
,
498 .help
= "Postpone refcount updates",
501 .name
= QCOW2_OPT_DISCARD_REQUEST
,
502 .type
= QEMU_OPT_BOOL
,
503 .help
= "Pass guest discard requests to the layer below",
506 .name
= QCOW2_OPT_DISCARD_SNAPSHOT
,
507 .type
= QEMU_OPT_BOOL
,
508 .help
= "Generate discard requests when snapshot related space "
512 .name
= QCOW2_OPT_DISCARD_OTHER
,
513 .type
= QEMU_OPT_BOOL
,
514 .help
= "Generate discard requests when other clusters are freed",
517 .name
= QCOW2_OPT_OVERLAP
,
518 .type
= QEMU_OPT_STRING
,
519 .help
= "Selects which overlap checks to perform from a range of "
520 "templates (none, constant, cached, all)",
523 .name
= QCOW2_OPT_OVERLAP_TEMPLATE
,
524 .type
= QEMU_OPT_STRING
,
525 .help
= "Selects which overlap checks to perform from a range of "
526 "templates (none, constant, cached, all)",
529 .name
= QCOW2_OPT_OVERLAP_MAIN_HEADER
,
530 .type
= QEMU_OPT_BOOL
,
531 .help
= "Check for unintended writes into the main qcow2 header",
534 .name
= QCOW2_OPT_OVERLAP_ACTIVE_L1
,
535 .type
= QEMU_OPT_BOOL
,
536 .help
= "Check for unintended writes into the active L1 table",
539 .name
= QCOW2_OPT_OVERLAP_ACTIVE_L2
,
540 .type
= QEMU_OPT_BOOL
,
541 .help
= "Check for unintended writes into an active L2 table",
544 .name
= QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
545 .type
= QEMU_OPT_BOOL
,
546 .help
= "Check for unintended writes into the refcount table",
549 .name
= QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
550 .type
= QEMU_OPT_BOOL
,
551 .help
= "Check for unintended writes into a refcount block",
554 .name
= QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
555 .type
= QEMU_OPT_BOOL
,
556 .help
= "Check for unintended writes into the snapshot table",
559 .name
= QCOW2_OPT_OVERLAP_INACTIVE_L1
,
560 .type
= QEMU_OPT_BOOL
,
561 .help
= "Check for unintended writes into an inactive L1 table",
564 .name
= QCOW2_OPT_OVERLAP_INACTIVE_L2
,
565 .type
= QEMU_OPT_BOOL
,
566 .help
= "Check for unintended writes into an inactive L2 table",
569 .name
= QCOW2_OPT_CACHE_SIZE
,
570 .type
= QEMU_OPT_SIZE
,
571 .help
= "Maximum combined metadata (L2 tables and refcount blocks) "
575 .name
= QCOW2_OPT_L2_CACHE_SIZE
,
576 .type
= QEMU_OPT_SIZE
,
577 .help
= "Maximum L2 table cache size",
580 .name
= QCOW2_OPT_REFCOUNT_CACHE_SIZE
,
581 .type
= QEMU_OPT_SIZE
,
582 .help
= "Maximum refcount block cache size",
585 .name
= QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
586 .type
= QEMU_OPT_NUMBER
,
587 .help
= "Clean unused cache entries after this time (in seconds)",
589 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
590 "ID of secret providing qcow2 AES key or LUKS passphrase"),
591 { /* end of list */ }
595 static const char *overlap_bool_option_names
[QCOW2_OL_MAX_BITNR
] = {
596 [QCOW2_OL_MAIN_HEADER_BITNR
] = QCOW2_OPT_OVERLAP_MAIN_HEADER
,
597 [QCOW2_OL_ACTIVE_L1_BITNR
] = QCOW2_OPT_OVERLAP_ACTIVE_L1
,
598 [QCOW2_OL_ACTIVE_L2_BITNR
] = QCOW2_OPT_OVERLAP_ACTIVE_L2
,
599 [QCOW2_OL_REFCOUNT_TABLE_BITNR
] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
600 [QCOW2_OL_REFCOUNT_BLOCK_BITNR
] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
601 [QCOW2_OL_SNAPSHOT_TABLE_BITNR
] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
602 [QCOW2_OL_INACTIVE_L1_BITNR
] = QCOW2_OPT_OVERLAP_INACTIVE_L1
,
603 [QCOW2_OL_INACTIVE_L2_BITNR
] = QCOW2_OPT_OVERLAP_INACTIVE_L2
,
606 static void cache_clean_timer_cb(void *opaque
)
608 BlockDriverState
*bs
= opaque
;
609 BDRVQcow2State
*s
= bs
->opaque
;
610 qcow2_cache_clean_unused(bs
, s
->l2_table_cache
);
611 qcow2_cache_clean_unused(bs
, s
->refcount_block_cache
);
612 timer_mod(s
->cache_clean_timer
, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
) +
613 (int64_t) s
->cache_clean_interval
* 1000);
616 static void cache_clean_timer_init(BlockDriverState
*bs
, AioContext
*context
)
618 BDRVQcow2State
*s
= bs
->opaque
;
619 if (s
->cache_clean_interval
> 0) {
620 s
->cache_clean_timer
= aio_timer_new(context
, QEMU_CLOCK_VIRTUAL
,
621 SCALE_MS
, cache_clean_timer_cb
,
623 timer_mod(s
->cache_clean_timer
, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
) +
624 (int64_t) s
->cache_clean_interval
* 1000);
628 static void cache_clean_timer_del(BlockDriverState
*bs
)
630 BDRVQcow2State
*s
= bs
->opaque
;
631 if (s
->cache_clean_timer
) {
632 timer_del(s
->cache_clean_timer
);
633 timer_free(s
->cache_clean_timer
);
634 s
->cache_clean_timer
= NULL
;
638 static void qcow2_detach_aio_context(BlockDriverState
*bs
)
640 cache_clean_timer_del(bs
);
643 static void qcow2_attach_aio_context(BlockDriverState
*bs
,
644 AioContext
*new_context
)
646 cache_clean_timer_init(bs
, new_context
);
649 static void read_cache_sizes(BlockDriverState
*bs
, QemuOpts
*opts
,
650 uint64_t *l2_cache_size
,
651 uint64_t *refcount_cache_size
, Error
**errp
)
653 BDRVQcow2State
*s
= bs
->opaque
;
654 uint64_t combined_cache_size
;
655 bool l2_cache_size_set
, refcount_cache_size_set
, combined_cache_size_set
;
657 combined_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_CACHE_SIZE
);
658 l2_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_L2_CACHE_SIZE
);
659 refcount_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
661 combined_cache_size
= qemu_opt_get_size(opts
, QCOW2_OPT_CACHE_SIZE
, 0);
662 *l2_cache_size
= qemu_opt_get_size(opts
, QCOW2_OPT_L2_CACHE_SIZE
, 0);
663 *refcount_cache_size
= qemu_opt_get_size(opts
,
664 QCOW2_OPT_REFCOUNT_CACHE_SIZE
, 0);
666 if (combined_cache_size_set
) {
667 if (l2_cache_size_set
&& refcount_cache_size_set
) {
668 error_setg(errp
, QCOW2_OPT_CACHE_SIZE
", " QCOW2_OPT_L2_CACHE_SIZE
669 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE
" may not be set "
672 } else if (*l2_cache_size
> combined_cache_size
) {
673 error_setg(errp
, QCOW2_OPT_L2_CACHE_SIZE
" may not exceed "
674 QCOW2_OPT_CACHE_SIZE
);
676 } else if (*refcount_cache_size
> combined_cache_size
) {
677 error_setg(errp
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
" may not exceed "
678 QCOW2_OPT_CACHE_SIZE
);
682 if (l2_cache_size_set
) {
683 *refcount_cache_size
= combined_cache_size
- *l2_cache_size
;
684 } else if (refcount_cache_size_set
) {
685 *l2_cache_size
= combined_cache_size
- *refcount_cache_size
;
687 *refcount_cache_size
= combined_cache_size
688 / (DEFAULT_L2_REFCOUNT_SIZE_RATIO
+ 1);
689 *l2_cache_size
= combined_cache_size
- *refcount_cache_size
;
692 if (!l2_cache_size_set
&& !refcount_cache_size_set
) {
693 *l2_cache_size
= MAX(DEFAULT_L2_CACHE_BYTE_SIZE
,
694 (uint64_t)DEFAULT_L2_CACHE_CLUSTERS
696 *refcount_cache_size
= *l2_cache_size
697 / DEFAULT_L2_REFCOUNT_SIZE_RATIO
;
698 } else if (!l2_cache_size_set
) {
699 *l2_cache_size
= *refcount_cache_size
700 * DEFAULT_L2_REFCOUNT_SIZE_RATIO
;
701 } else if (!refcount_cache_size_set
) {
702 *refcount_cache_size
= *l2_cache_size
703 / DEFAULT_L2_REFCOUNT_SIZE_RATIO
;
708 typedef struct Qcow2ReopenState
{
709 Qcow2Cache
*l2_table_cache
;
710 Qcow2Cache
*refcount_block_cache
;
711 bool use_lazy_refcounts
;
713 bool discard_passthrough
[QCOW2_DISCARD_MAX
];
714 uint64_t cache_clean_interval
;
715 QCryptoBlockOpenOptions
*crypto_opts
; /* Disk encryption runtime options */
718 static int qcow2_update_options_prepare(BlockDriverState
*bs
,
720 QDict
*options
, int flags
,
723 BDRVQcow2State
*s
= bs
->opaque
;
724 QemuOpts
*opts
= NULL
;
725 const char *opt_overlap_check
, *opt_overlap_check_template
;
726 int overlap_check_template
= 0;
727 uint64_t l2_cache_size
, refcount_cache_size
;
729 const char *encryptfmt
;
730 QDict
*encryptopts
= NULL
;
731 Error
*local_err
= NULL
;
734 qdict_extract_subqdict(options
, &encryptopts
, "encrypt.");
735 encryptfmt
= qdict_get_try_str(encryptopts
, "format");
737 opts
= qemu_opts_create(&qcow2_runtime_opts
, NULL
, 0, &error_abort
);
738 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
740 error_propagate(errp
, local_err
);
745 /* get L2 table/refcount block cache size from command line options */
746 read_cache_sizes(bs
, opts
, &l2_cache_size
, &refcount_cache_size
,
749 error_propagate(errp
, local_err
);
754 l2_cache_size
/= s
->cluster_size
;
755 if (l2_cache_size
< MIN_L2_CACHE_SIZE
) {
756 l2_cache_size
= MIN_L2_CACHE_SIZE
;
758 if (l2_cache_size
> INT_MAX
) {
759 error_setg(errp
, "L2 cache size too big");
764 refcount_cache_size
/= s
->cluster_size
;
765 if (refcount_cache_size
< MIN_REFCOUNT_CACHE_SIZE
) {
766 refcount_cache_size
= MIN_REFCOUNT_CACHE_SIZE
;
768 if (refcount_cache_size
> INT_MAX
) {
769 error_setg(errp
, "Refcount cache size too big");
774 /* alloc new L2 table/refcount block cache, flush old one */
775 if (s
->l2_table_cache
) {
776 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
778 error_setg_errno(errp
, -ret
, "Failed to flush the L2 table cache");
783 if (s
->refcount_block_cache
) {
784 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
786 error_setg_errno(errp
, -ret
,
787 "Failed to flush the refcount block cache");
792 r
->l2_table_cache
= qcow2_cache_create(bs
, l2_cache_size
);
793 r
->refcount_block_cache
= qcow2_cache_create(bs
, refcount_cache_size
);
794 if (r
->l2_table_cache
== NULL
|| r
->refcount_block_cache
== NULL
) {
795 error_setg(errp
, "Could not allocate metadata caches");
800 /* New interval for cache cleanup timer */
801 r
->cache_clean_interval
=
802 qemu_opt_get_number(opts
, QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
803 s
->cache_clean_interval
);
805 if (r
->cache_clean_interval
!= 0) {
806 error_setg(errp
, QCOW2_OPT_CACHE_CLEAN_INTERVAL
807 " not supported on this host");
812 if (r
->cache_clean_interval
> UINT_MAX
) {
813 error_setg(errp
, "Cache clean interval too big");
818 /* lazy-refcounts; flush if going from enabled to disabled */
819 r
->use_lazy_refcounts
= qemu_opt_get_bool(opts
, QCOW2_OPT_LAZY_REFCOUNTS
,
820 (s
->compatible_features
& QCOW2_COMPAT_LAZY_REFCOUNTS
));
821 if (r
->use_lazy_refcounts
&& s
->qcow_version
< 3) {
822 error_setg(errp
, "Lazy refcounts require a qcow2 image with at least "
823 "qemu 1.1 compatibility level");
828 if (s
->use_lazy_refcounts
&& !r
->use_lazy_refcounts
) {
829 ret
= qcow2_mark_clean(bs
);
831 error_setg_errno(errp
, -ret
, "Failed to disable lazy refcounts");
836 /* Overlap check options */
837 opt_overlap_check
= qemu_opt_get(opts
, QCOW2_OPT_OVERLAP
);
838 opt_overlap_check_template
= qemu_opt_get(opts
, QCOW2_OPT_OVERLAP_TEMPLATE
);
839 if (opt_overlap_check_template
&& opt_overlap_check
&&
840 strcmp(opt_overlap_check_template
, opt_overlap_check
))
842 error_setg(errp
, "Conflicting values for qcow2 options '"
843 QCOW2_OPT_OVERLAP
"' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE
844 "' ('%s')", opt_overlap_check
, opt_overlap_check_template
);
848 if (!opt_overlap_check
) {
849 opt_overlap_check
= opt_overlap_check_template
?: "cached";
852 if (!strcmp(opt_overlap_check
, "none")) {
853 overlap_check_template
= 0;
854 } else if (!strcmp(opt_overlap_check
, "constant")) {
855 overlap_check_template
= QCOW2_OL_CONSTANT
;
856 } else if (!strcmp(opt_overlap_check
, "cached")) {
857 overlap_check_template
= QCOW2_OL_CACHED
;
858 } else if (!strcmp(opt_overlap_check
, "all")) {
859 overlap_check_template
= QCOW2_OL_ALL
;
861 error_setg(errp
, "Unsupported value '%s' for qcow2 option "
862 "'overlap-check'. Allowed are any of the following: "
863 "none, constant, cached, all", opt_overlap_check
);
868 r
->overlap_check
= 0;
869 for (i
= 0; i
< QCOW2_OL_MAX_BITNR
; i
++) {
870 /* overlap-check defines a template bitmask, but every flag may be
871 * overwritten through the associated boolean option */
873 qemu_opt_get_bool(opts
, overlap_bool_option_names
[i
],
874 overlap_check_template
& (1 << i
)) << i
;
877 r
->discard_passthrough
[QCOW2_DISCARD_NEVER
] = false;
878 r
->discard_passthrough
[QCOW2_DISCARD_ALWAYS
] = true;
879 r
->discard_passthrough
[QCOW2_DISCARD_REQUEST
] =
880 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_REQUEST
,
881 flags
& BDRV_O_UNMAP
);
882 r
->discard_passthrough
[QCOW2_DISCARD_SNAPSHOT
] =
883 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_SNAPSHOT
, true);
884 r
->discard_passthrough
[QCOW2_DISCARD_OTHER
] =
885 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_OTHER
, false);
887 switch (s
->crypt_method_header
) {
888 case QCOW_CRYPT_NONE
:
890 error_setg(errp
, "No encryption in image header, but options "
891 "specified format '%s'", encryptfmt
);
898 if (encryptfmt
&& !g_str_equal(encryptfmt
, "aes")) {
900 "Header reported 'aes' encryption format but "
901 "options specify '%s'", encryptfmt
);
905 qdict_del(encryptopts
, "format");
906 r
->crypto_opts
= block_crypto_open_opts_init(
907 Q_CRYPTO_BLOCK_FORMAT_QCOW
, encryptopts
, errp
);
910 case QCOW_CRYPT_LUKS
:
911 if (encryptfmt
&& !g_str_equal(encryptfmt
, "luks")) {
913 "Header reported 'luks' encryption format but "
914 "options specify '%s'", encryptfmt
);
918 qdict_del(encryptopts
, "format");
919 r
->crypto_opts
= block_crypto_open_opts_init(
920 Q_CRYPTO_BLOCK_FORMAT_LUKS
, encryptopts
, errp
);
924 error_setg(errp
, "Unsupported encryption method %d",
925 s
->crypt_method_header
);
928 if (s
->crypt_method_header
!= QCOW_CRYPT_NONE
&& !r
->crypto_opts
) {
935 QDECREF(encryptopts
);
941 static void qcow2_update_options_commit(BlockDriverState
*bs
,
944 BDRVQcow2State
*s
= bs
->opaque
;
947 if (s
->l2_table_cache
) {
948 qcow2_cache_destroy(bs
, s
->l2_table_cache
);
950 if (s
->refcount_block_cache
) {
951 qcow2_cache_destroy(bs
, s
->refcount_block_cache
);
953 s
->l2_table_cache
= r
->l2_table_cache
;
954 s
->refcount_block_cache
= r
->refcount_block_cache
;
956 s
->overlap_check
= r
->overlap_check
;
957 s
->use_lazy_refcounts
= r
->use_lazy_refcounts
;
959 for (i
= 0; i
< QCOW2_DISCARD_MAX
; i
++) {
960 s
->discard_passthrough
[i
] = r
->discard_passthrough
[i
];
963 if (s
->cache_clean_interval
!= r
->cache_clean_interval
) {
964 cache_clean_timer_del(bs
);
965 s
->cache_clean_interval
= r
->cache_clean_interval
;
966 cache_clean_timer_init(bs
, bdrv_get_aio_context(bs
));
969 qapi_free_QCryptoBlockOpenOptions(s
->crypto_opts
);
970 s
->crypto_opts
= r
->crypto_opts
;
973 static void qcow2_update_options_abort(BlockDriverState
*bs
,
976 if (r
->l2_table_cache
) {
977 qcow2_cache_destroy(bs
, r
->l2_table_cache
);
979 if (r
->refcount_block_cache
) {
980 qcow2_cache_destroy(bs
, r
->refcount_block_cache
);
982 qapi_free_QCryptoBlockOpenOptions(r
->crypto_opts
);
985 static int qcow2_update_options(BlockDriverState
*bs
, QDict
*options
,
986 int flags
, Error
**errp
)
988 Qcow2ReopenState r
= {};
991 ret
= qcow2_update_options_prepare(bs
, &r
, options
, flags
, errp
);
993 qcow2_update_options_commit(bs
, &r
);
995 qcow2_update_options_abort(bs
, &r
);
1001 static int qcow2_do_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
1004 BDRVQcow2State
*s
= bs
->opaque
;
1005 unsigned int len
, i
;
1008 Error
*local_err
= NULL
;
1010 uint64_t l1_vm_state_index
;
1012 ret
= bdrv_pread(bs
->file
, 0, &header
, sizeof(header
));
1014 error_setg_errno(errp
, -ret
, "Could not read qcow2 header");
1017 be32_to_cpus(&header
.magic
);
1018 be32_to_cpus(&header
.version
);
1019 be64_to_cpus(&header
.backing_file_offset
);
1020 be32_to_cpus(&header
.backing_file_size
);
1021 be64_to_cpus(&header
.size
);
1022 be32_to_cpus(&header
.cluster_bits
);
1023 be32_to_cpus(&header
.crypt_method
);
1024 be64_to_cpus(&header
.l1_table_offset
);
1025 be32_to_cpus(&header
.l1_size
);
1026 be64_to_cpus(&header
.refcount_table_offset
);
1027 be32_to_cpus(&header
.refcount_table_clusters
);
1028 be64_to_cpus(&header
.snapshots_offset
);
1029 be32_to_cpus(&header
.nb_snapshots
);
1031 if (header
.magic
!= QCOW_MAGIC
) {
1032 error_setg(errp
, "Image is not in qcow2 format");
1036 if (header
.version
< 2 || header
.version
> 3) {
1037 error_setg(errp
, "Unsupported qcow2 version %" PRIu32
, header
.version
);
1042 s
->qcow_version
= header
.version
;
1044 /* Initialise cluster size */
1045 if (header
.cluster_bits
< MIN_CLUSTER_BITS
||
1046 header
.cluster_bits
> MAX_CLUSTER_BITS
) {
1047 error_setg(errp
, "Unsupported cluster size: 2^%" PRIu32
,
1048 header
.cluster_bits
);
1053 s
->cluster_bits
= header
.cluster_bits
;
1054 s
->cluster_size
= 1 << s
->cluster_bits
;
1055 s
->cluster_sectors
= 1 << (s
->cluster_bits
- 9);
1057 /* Initialise version 3 header fields */
1058 if (header
.version
== 2) {
1059 header
.incompatible_features
= 0;
1060 header
.compatible_features
= 0;
1061 header
.autoclear_features
= 0;
1062 header
.refcount_order
= 4;
1063 header
.header_length
= 72;
1065 be64_to_cpus(&header
.incompatible_features
);
1066 be64_to_cpus(&header
.compatible_features
);
1067 be64_to_cpus(&header
.autoclear_features
);
1068 be32_to_cpus(&header
.refcount_order
);
1069 be32_to_cpus(&header
.header_length
);
1071 if (header
.header_length
< 104) {
1072 error_setg(errp
, "qcow2 header too short");
1078 if (header
.header_length
> s
->cluster_size
) {
1079 error_setg(errp
, "qcow2 header exceeds cluster size");
1084 if (header
.header_length
> sizeof(header
)) {
1085 s
->unknown_header_fields_size
= header
.header_length
- sizeof(header
);
1086 s
->unknown_header_fields
= g_malloc(s
->unknown_header_fields_size
);
1087 ret
= bdrv_pread(bs
->file
, sizeof(header
), s
->unknown_header_fields
,
1088 s
->unknown_header_fields_size
);
1090 error_setg_errno(errp
, -ret
, "Could not read unknown qcow2 header "
1096 if (header
.backing_file_offset
> s
->cluster_size
) {
1097 error_setg(errp
, "Invalid backing file offset");
1102 if (header
.backing_file_offset
) {
1103 ext_end
= header
.backing_file_offset
;
1105 ext_end
= 1 << header
.cluster_bits
;
1108 /* Handle feature bits */
1109 s
->incompatible_features
= header
.incompatible_features
;
1110 s
->compatible_features
= header
.compatible_features
;
1111 s
->autoclear_features
= header
.autoclear_features
;
1113 if (s
->incompatible_features
& ~QCOW2_INCOMPAT_MASK
) {
1114 void *feature_table
= NULL
;
1115 qcow2_read_extensions(bs
, header
.header_length
, ext_end
,
1116 &feature_table
, flags
, NULL
);
1117 report_unsupported_feature(errp
, feature_table
,
1118 s
->incompatible_features
&
1119 ~QCOW2_INCOMPAT_MASK
);
1121 g_free(feature_table
);
1125 if (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
) {
1126 /* Corrupt images may not be written to unless they are being repaired
1128 if ((flags
& BDRV_O_RDWR
) && !(flags
& BDRV_O_CHECK
)) {
1129 error_setg(errp
, "qcow2: Image is corrupt; cannot be opened "
1136 /* Check support for various header values */
1137 if (header
.refcount_order
> 6) {
1138 error_setg(errp
, "Reference count entry width too large; may not "
1143 s
->refcount_order
= header
.refcount_order
;
1144 s
->refcount_bits
= 1 << s
->refcount_order
;
1145 s
->refcount_max
= UINT64_C(1) << (s
->refcount_bits
- 1);
1146 s
->refcount_max
+= s
->refcount_max
- 1;
1148 s
->crypt_method_header
= header
.crypt_method
;
1149 if (s
->crypt_method_header
) {
1150 if (bdrv_uses_whitelist() &&
1151 s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1153 "Use of AES-CBC encrypted qcow2 images is no longer "
1154 "supported in system emulators");
1155 error_append_hint(errp
,
1156 "You can use 'qemu-img convert' to convert your "
1157 "image to an alternative supported format, such "
1158 "as unencrypted qcow2, or raw with the LUKS "
1159 "format instead.\n");
1164 if (s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1165 s
->crypt_physical_offset
= false;
1167 /* Assuming LUKS and any future crypt methods we
1168 * add will all use physical offsets, due to the
1169 * fact that the alternative is insecure... */
1170 s
->crypt_physical_offset
= true;
1173 bs
->encrypted
= true;
1176 s
->l2_bits
= s
->cluster_bits
- 3; /* L2 is always one cluster */
1177 s
->l2_size
= 1 << s
->l2_bits
;
1178 /* 2^(s->refcount_order - 3) is the refcount width in bytes */
1179 s
->refcount_block_bits
= s
->cluster_bits
- (s
->refcount_order
- 3);
1180 s
->refcount_block_size
= 1 << s
->refcount_block_bits
;
1181 bs
->total_sectors
= header
.size
/ 512;
1182 s
->csize_shift
= (62 - (s
->cluster_bits
- 8));
1183 s
->csize_mask
= (1 << (s
->cluster_bits
- 8)) - 1;
1184 s
->cluster_offset_mask
= (1LL << s
->csize_shift
) - 1;
1186 s
->refcount_table_offset
= header
.refcount_table_offset
;
1187 s
->refcount_table_size
=
1188 header
.refcount_table_clusters
<< (s
->cluster_bits
- 3);
1190 if (header
.refcount_table_clusters
> qcow2_max_refcount_clusters(s
)) {
1191 error_setg(errp
, "Reference count table too large");
1196 ret
= validate_table_offset(bs
, s
->refcount_table_offset
,
1197 s
->refcount_table_size
, sizeof(uint64_t));
1199 error_setg(errp
, "Invalid reference count table offset");
1203 /* Snapshot table offset/length */
1204 if (header
.nb_snapshots
> QCOW_MAX_SNAPSHOTS
) {
1205 error_setg(errp
, "Too many snapshots");
1210 ret
= validate_table_offset(bs
, header
.snapshots_offset
,
1211 header
.nb_snapshots
,
1212 sizeof(QCowSnapshotHeader
));
1214 error_setg(errp
, "Invalid snapshot table offset");
1218 /* read the level 1 table */
1219 if (header
.l1_size
> QCOW_MAX_L1_SIZE
/ sizeof(uint64_t)) {
1220 error_setg(errp
, "Active L1 table too large");
1224 s
->l1_size
= header
.l1_size
;
1226 l1_vm_state_index
= size_to_l1(s
, header
.size
);
1227 if (l1_vm_state_index
> INT_MAX
) {
1228 error_setg(errp
, "Image is too big");
1232 s
->l1_vm_state_index
= l1_vm_state_index
;
1234 /* the L1 table must contain at least enough entries to put
1235 header.size bytes */
1236 if (s
->l1_size
< s
->l1_vm_state_index
) {
1237 error_setg(errp
, "L1 table is too small");
1242 ret
= validate_table_offset(bs
, header
.l1_table_offset
,
1243 header
.l1_size
, sizeof(uint64_t));
1245 error_setg(errp
, "Invalid L1 table offset");
1248 s
->l1_table_offset
= header
.l1_table_offset
;
1251 if (s
->l1_size
> 0) {
1252 s
->l1_table
= qemu_try_blockalign(bs
->file
->bs
,
1253 align_offset(s
->l1_size
* sizeof(uint64_t), 512));
1254 if (s
->l1_table
== NULL
) {
1255 error_setg(errp
, "Could not allocate L1 table");
1259 ret
= bdrv_pread(bs
->file
, s
->l1_table_offset
, s
->l1_table
,
1260 s
->l1_size
* sizeof(uint64_t));
1262 error_setg_errno(errp
, -ret
, "Could not read L1 table");
1265 for(i
= 0;i
< s
->l1_size
; i
++) {
1266 be64_to_cpus(&s
->l1_table
[i
]);
1270 /* Parse driver-specific options */
1271 ret
= qcow2_update_options(bs
, options
, flags
, errp
);
1276 s
->cluster_cache
= g_malloc(s
->cluster_size
);
1277 /* one more sector for decompressed data alignment */
1278 s
->cluster_data
= qemu_try_blockalign(bs
->file
->bs
, QCOW_MAX_CRYPT_CLUSTERS
1279 * s
->cluster_size
+ 512);
1280 if (s
->cluster_data
== NULL
) {
1281 error_setg(errp
, "Could not allocate temporary cluster buffer");
1286 s
->cluster_cache_offset
= -1;
1289 ret
= qcow2_refcount_init(bs
);
1291 error_setg_errno(errp
, -ret
, "Could not initialize refcount handling");
1295 QLIST_INIT(&s
->cluster_allocs
);
1296 QTAILQ_INIT(&s
->discards
);
1298 /* read qcow2 extensions */
1299 if (qcow2_read_extensions(bs
, header
.header_length
, ext_end
, NULL
,
1300 flags
, &local_err
)) {
1301 error_propagate(errp
, local_err
);
1306 /* qcow2_read_extension may have set up the crypto context
1307 * if the crypt method needs a header region, some methods
1308 * don't need header extensions, so must check here
1310 if (s
->crypt_method_header
&& !s
->crypto
) {
1311 if (s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1312 unsigned int cflags
= 0;
1313 if (flags
& BDRV_O_NO_IO
) {
1314 cflags
|= QCRYPTO_BLOCK_OPEN_NO_IO
;
1316 s
->crypto
= qcrypto_block_open(s
->crypto_opts
, NULL
, NULL
,
1322 } else if (!(flags
& BDRV_O_NO_IO
)) {
1323 error_setg(errp
, "Missing CRYPTO header for crypt method %d",
1324 s
->crypt_method_header
);
1330 /* read the backing file name */
1331 if (header
.backing_file_offset
!= 0) {
1332 len
= header
.backing_file_size
;
1333 if (len
> MIN(1023, s
->cluster_size
- header
.backing_file_offset
) ||
1334 len
>= sizeof(bs
->backing_file
)) {
1335 error_setg(errp
, "Backing file name too long");
1339 ret
= bdrv_pread(bs
->file
, header
.backing_file_offset
,
1340 bs
->backing_file
, len
);
1342 error_setg_errno(errp
, -ret
, "Could not read backing file name");
1345 bs
->backing_file
[len
] = '\0';
1346 s
->image_backing_file
= g_strdup(bs
->backing_file
);
1349 /* Internal snapshots */
1350 s
->snapshots_offset
= header
.snapshots_offset
;
1351 s
->nb_snapshots
= header
.nb_snapshots
;
1353 ret
= qcow2_read_snapshots(bs
);
1355 error_setg_errno(errp
, -ret
, "Could not read snapshots");
1359 /* Clear unknown autoclear feature bits */
1360 if (!bs
->read_only
&& !(flags
& BDRV_O_INACTIVE
) && s
->autoclear_features
) {
1361 s
->autoclear_features
= 0;
1362 ret
= qcow2_update_header(bs
);
1364 error_setg_errno(errp
, -ret
, "Could not update qcow2 header");
1369 /* Initialise locks */
1370 qemu_co_mutex_init(&s
->lock
);
1371 bs
->supported_zero_flags
= BDRV_REQ_MAY_UNMAP
;
1373 /* Repair image if dirty */
1374 if (!(flags
& (BDRV_O_CHECK
| BDRV_O_INACTIVE
)) && !bs
->read_only
&&
1375 (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
)) {
1376 BdrvCheckResult result
= {0};
1378 ret
= qcow2_check(bs
, &result
, BDRV_FIX_ERRORS
| BDRV_FIX_LEAKS
);
1380 error_setg_errno(errp
, -ret
, "Could not repair dirty image");
1387 BdrvCheckResult result
= {0};
1388 qcow2_check_refcounts(bs
, &result
, 0);
1394 g_free(s
->unknown_header_fields
);
1395 cleanup_unknown_header_ext(bs
);
1396 qcow2_free_snapshots(bs
);
1397 qcow2_refcount_close(bs
);
1398 qemu_vfree(s
->l1_table
);
1399 /* else pre-write overlap checks in cache_destroy may crash */
1401 cache_clean_timer_del(bs
);
1402 if (s
->l2_table_cache
) {
1403 qcow2_cache_destroy(bs
, s
->l2_table_cache
);
1405 if (s
->refcount_block_cache
) {
1406 qcow2_cache_destroy(bs
, s
->refcount_block_cache
);
1408 g_free(s
->cluster_cache
);
1409 qemu_vfree(s
->cluster_data
);
1410 qcrypto_block_free(s
->crypto
);
1411 qapi_free_QCryptoBlockOpenOptions(s
->crypto_opts
);
1415 static int qcow2_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
1418 bs
->file
= bdrv_open_child(NULL
, options
, "file", bs
, &child_file
,
1424 return qcow2_do_open(bs
, options
, flags
, errp
);
1427 static void qcow2_refresh_limits(BlockDriverState
*bs
, Error
**errp
)
1429 BDRVQcow2State
*s
= bs
->opaque
;
1431 if (bs
->encrypted
) {
1432 /* Encryption works on a sector granularity */
1433 bs
->bl
.request_alignment
= BDRV_SECTOR_SIZE
;
1435 bs
->bl
.pwrite_zeroes_alignment
= s
->cluster_size
;
1436 bs
->bl
.pdiscard_alignment
= s
->cluster_size
;
1439 static int qcow2_reopen_prepare(BDRVReopenState
*state
,
1440 BlockReopenQueue
*queue
, Error
**errp
)
1442 Qcow2ReopenState
*r
;
1445 r
= g_new0(Qcow2ReopenState
, 1);
1448 ret
= qcow2_update_options_prepare(state
->bs
, r
, state
->options
,
1449 state
->flags
, errp
);
1454 /* We need to write out any unwritten data if we reopen read-only. */
1455 if ((state
->flags
& BDRV_O_RDWR
) == 0) {
1456 ret
= bdrv_flush(state
->bs
);
1461 ret
= qcow2_mark_clean(state
->bs
);
1470 qcow2_update_options_abort(state
->bs
, r
);
1475 static void qcow2_reopen_commit(BDRVReopenState
*state
)
1477 qcow2_update_options_commit(state
->bs
, state
->opaque
);
1478 g_free(state
->opaque
);
1481 static void qcow2_reopen_abort(BDRVReopenState
*state
)
1483 qcow2_update_options_abort(state
->bs
, state
->opaque
);
1484 g_free(state
->opaque
);
1487 static void qcow2_join_options(QDict
*options
, QDict
*old_options
)
1489 bool has_new_overlap_template
=
1490 qdict_haskey(options
, QCOW2_OPT_OVERLAP
) ||
1491 qdict_haskey(options
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1492 bool has_new_total_cache_size
=
1493 qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
);
1494 bool has_all_cache_options
;
1496 /* New overlap template overrides all old overlap options */
1497 if (has_new_overlap_template
) {
1498 qdict_del(old_options
, QCOW2_OPT_OVERLAP
);
1499 qdict_del(old_options
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1500 qdict_del(old_options
, QCOW2_OPT_OVERLAP_MAIN_HEADER
);
1501 qdict_del(old_options
, QCOW2_OPT_OVERLAP_ACTIVE_L1
);
1502 qdict_del(old_options
, QCOW2_OPT_OVERLAP_ACTIVE_L2
);
1503 qdict_del(old_options
, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
);
1504 qdict_del(old_options
, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
);
1505 qdict_del(old_options
, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
);
1506 qdict_del(old_options
, QCOW2_OPT_OVERLAP_INACTIVE_L1
);
1507 qdict_del(old_options
, QCOW2_OPT_OVERLAP_INACTIVE_L2
);
1510 /* New total cache size overrides all old options */
1511 if (qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
)) {
1512 qdict_del(old_options
, QCOW2_OPT_L2_CACHE_SIZE
);
1513 qdict_del(old_options
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
1516 qdict_join(options
, old_options
, false);
1519 * If after merging all cache size options are set, an old total size is
1520 * overwritten. Do keep all options, however, if all three are new. The
1521 * resulting error message is what we want to happen.
1523 has_all_cache_options
=
1524 qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
) ||
1525 qdict_haskey(options
, QCOW2_OPT_L2_CACHE_SIZE
) ||
1526 qdict_haskey(options
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
1528 if (has_all_cache_options
&& !has_new_total_cache_size
) {
1529 qdict_del(options
, QCOW2_OPT_CACHE_SIZE
);
1533 static int64_t coroutine_fn
qcow2_co_get_block_status(BlockDriverState
*bs
,
1534 int64_t sector_num
, int nb_sectors
, int *pnum
, BlockDriverState
**file
)
1536 BDRVQcow2State
*s
= bs
->opaque
;
1537 uint64_t cluster_offset
;
1538 int index_in_cluster
, ret
;
1542 bytes
= MIN(INT_MAX
, nb_sectors
* BDRV_SECTOR_SIZE
);
1543 qemu_co_mutex_lock(&s
->lock
);
1544 ret
= qcow2_get_cluster_offset(bs
, sector_num
<< 9, &bytes
,
1546 qemu_co_mutex_unlock(&s
->lock
);
1551 *pnum
= bytes
>> BDRV_SECTOR_BITS
;
1553 if (cluster_offset
!= 0 && ret
!= QCOW2_CLUSTER_COMPRESSED
&&
1555 index_in_cluster
= sector_num
& (s
->cluster_sectors
- 1);
1556 cluster_offset
|= (index_in_cluster
<< BDRV_SECTOR_BITS
);
1557 *file
= bs
->file
->bs
;
1558 status
|= BDRV_BLOCK_OFFSET_VALID
| cluster_offset
;
1560 if (ret
== QCOW2_CLUSTER_ZERO_PLAIN
|| ret
== QCOW2_CLUSTER_ZERO_ALLOC
) {
1561 status
|= BDRV_BLOCK_ZERO
;
1562 } else if (ret
!= QCOW2_CLUSTER_UNALLOCATED
) {
1563 status
|= BDRV_BLOCK_DATA
;
1568 /* handle reading after the end of the backing file */
1569 int qcow2_backing_read1(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
1570 int64_t offset
, int bytes
)
1572 uint64_t bs_size
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
1575 if ((offset
+ bytes
) <= bs_size
) {
1579 if (offset
>= bs_size
) {
1582 n1
= bs_size
- offset
;
1585 qemu_iovec_memset(qiov
, n1
, 0, bytes
- n1
);
1590 static coroutine_fn
int qcow2_co_preadv(BlockDriverState
*bs
, uint64_t offset
,
1591 uint64_t bytes
, QEMUIOVector
*qiov
,
1594 BDRVQcow2State
*s
= bs
->opaque
;
1595 int offset_in_cluster
, n1
;
1597 unsigned int cur_bytes
; /* number of bytes in current iteration */
1598 uint64_t cluster_offset
= 0;
1599 uint64_t bytes_done
= 0;
1600 QEMUIOVector hd_qiov
;
1601 uint8_t *cluster_data
= NULL
;
1603 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
1605 qemu_co_mutex_lock(&s
->lock
);
1607 while (bytes
!= 0) {
1609 /* prepare next request */
1610 cur_bytes
= MIN(bytes
, INT_MAX
);
1612 cur_bytes
= MIN(cur_bytes
,
1613 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
1616 ret
= qcow2_get_cluster_offset(bs
, offset
, &cur_bytes
, &cluster_offset
);
1621 offset_in_cluster
= offset_into_cluster(s
, offset
);
1623 qemu_iovec_reset(&hd_qiov
);
1624 qemu_iovec_concat(&hd_qiov
, qiov
, bytes_done
, cur_bytes
);
1627 case QCOW2_CLUSTER_UNALLOCATED
:
1630 /* read from the base image */
1631 n1
= qcow2_backing_read1(bs
->backing
->bs
, &hd_qiov
,
1634 QEMUIOVector local_qiov
;
1636 qemu_iovec_init(&local_qiov
, hd_qiov
.niov
);
1637 qemu_iovec_concat(&local_qiov
, &hd_qiov
, 0, n1
);
1639 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_BACKING_AIO
);
1640 qemu_co_mutex_unlock(&s
->lock
);
1641 ret
= bdrv_co_preadv(bs
->backing
, offset
, n1
,
1643 qemu_co_mutex_lock(&s
->lock
);
1645 qemu_iovec_destroy(&local_qiov
);
1652 /* Note: in this case, no need to wait */
1653 qemu_iovec_memset(&hd_qiov
, 0, 0, cur_bytes
);
1657 case QCOW2_CLUSTER_ZERO_PLAIN
:
1658 case QCOW2_CLUSTER_ZERO_ALLOC
:
1659 qemu_iovec_memset(&hd_qiov
, 0, 0, cur_bytes
);
1662 case QCOW2_CLUSTER_COMPRESSED
:
1663 /* add AIO support for compressed blocks ? */
1664 ret
= qcow2_decompress_cluster(bs
, cluster_offset
);
1669 qemu_iovec_from_buf(&hd_qiov
, 0,
1670 s
->cluster_cache
+ offset_in_cluster
,
1674 case QCOW2_CLUSTER_NORMAL
:
1675 if ((cluster_offset
& 511) != 0) {
1680 if (bs
->encrypted
) {
1684 * For encrypted images, read everything into a temporary
1685 * contiguous buffer on which the AES functions can work.
1687 if (!cluster_data
) {
1689 qemu_try_blockalign(bs
->file
->bs
,
1690 QCOW_MAX_CRYPT_CLUSTERS
1692 if (cluster_data
== NULL
) {
1698 assert(cur_bytes
<= QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
1699 qemu_iovec_reset(&hd_qiov
);
1700 qemu_iovec_add(&hd_qiov
, cluster_data
, cur_bytes
);
1703 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
1704 qemu_co_mutex_unlock(&s
->lock
);
1705 ret
= bdrv_co_preadv(bs
->file
,
1706 cluster_offset
+ offset_in_cluster
,
1707 cur_bytes
, &hd_qiov
, 0);
1708 qemu_co_mutex_lock(&s
->lock
);
1712 if (bs
->encrypted
) {
1714 assert((offset
& (BDRV_SECTOR_SIZE
- 1)) == 0);
1715 assert((cur_bytes
& (BDRV_SECTOR_SIZE
- 1)) == 0);
1717 if (qcrypto_block_decrypt(s
->crypto
,
1718 (s
->crypt_physical_offset
?
1719 cluster_offset
+ offset_in_cluster
:
1720 offset
) >> BDRV_SECTOR_BITS
,
1728 qemu_iovec_from_buf(qiov
, bytes_done
, cluster_data
, cur_bytes
);
1733 g_assert_not_reached();
1739 offset
+= cur_bytes
;
1740 bytes_done
+= cur_bytes
;
1745 qemu_co_mutex_unlock(&s
->lock
);
1747 qemu_iovec_destroy(&hd_qiov
);
1748 qemu_vfree(cluster_data
);
1753 /* Check if it's possible to merge a write request with the writing of
1754 * the data from the COW regions */
1755 static bool merge_cow(uint64_t offset
, unsigned bytes
,
1756 QEMUIOVector
*hd_qiov
, QCowL2Meta
*l2meta
)
1760 for (m
= l2meta
; m
!= NULL
; m
= m
->next
) {
1761 /* If both COW regions are empty then there's nothing to merge */
1762 if (m
->cow_start
.nb_bytes
== 0 && m
->cow_end
.nb_bytes
== 0) {
1766 /* The data (middle) region must be immediately after the
1768 if (l2meta_cow_start(m
) + m
->cow_start
.nb_bytes
!= offset
) {
1772 /* The end region must be immediately after the data (middle)
1774 if (m
->offset
+ m
->cow_end
.offset
!= offset
+ bytes
) {
1778 /* Make sure that adding both COW regions to the QEMUIOVector
1779 * does not exceed IOV_MAX */
1780 if (hd_qiov
->niov
> IOV_MAX
- 2) {
1784 m
->data_qiov
= hd_qiov
;
1791 static coroutine_fn
int qcow2_co_pwritev(BlockDriverState
*bs
, uint64_t offset
,
1792 uint64_t bytes
, QEMUIOVector
*qiov
,
1795 BDRVQcow2State
*s
= bs
->opaque
;
1796 int offset_in_cluster
;
1798 unsigned int cur_bytes
; /* number of sectors in current iteration */
1799 uint64_t cluster_offset
;
1800 QEMUIOVector hd_qiov
;
1801 uint64_t bytes_done
= 0;
1802 uint8_t *cluster_data
= NULL
;
1803 QCowL2Meta
*l2meta
= NULL
;
1805 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset
, bytes
);
1807 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
1809 s
->cluster_cache_offset
= -1; /* disable compressed cache */
1811 qemu_co_mutex_lock(&s
->lock
);
1813 while (bytes
!= 0) {
1817 trace_qcow2_writev_start_part(qemu_coroutine_self());
1818 offset_in_cluster
= offset_into_cluster(s
, offset
);
1819 cur_bytes
= MIN(bytes
, INT_MAX
);
1820 if (bs
->encrypted
) {
1821 cur_bytes
= MIN(cur_bytes
,
1822 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
1823 - offset_in_cluster
);
1826 ret
= qcow2_alloc_cluster_offset(bs
, offset
, &cur_bytes
,
1827 &cluster_offset
, &l2meta
);
1832 assert((cluster_offset
& 511) == 0);
1834 qemu_iovec_reset(&hd_qiov
);
1835 qemu_iovec_concat(&hd_qiov
, qiov
, bytes_done
, cur_bytes
);
1837 if (bs
->encrypted
) {
1840 if (!cluster_data
) {
1841 cluster_data
= qemu_try_blockalign(bs
->file
->bs
,
1842 QCOW_MAX_CRYPT_CLUSTERS
1844 if (cluster_data
== NULL
) {
1850 assert(hd_qiov
.size
<=
1851 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
1852 qemu_iovec_to_buf(&hd_qiov
, 0, cluster_data
, hd_qiov
.size
);
1854 if (qcrypto_block_encrypt(s
->crypto
,
1855 (s
->crypt_physical_offset
?
1856 cluster_offset
+ offset_in_cluster
:
1857 offset
) >> BDRV_SECTOR_BITS
,
1859 cur_bytes
, &err
) < 0) {
1865 qemu_iovec_reset(&hd_qiov
);
1866 qemu_iovec_add(&hd_qiov
, cluster_data
, cur_bytes
);
1869 ret
= qcow2_pre_write_overlap_check(bs
, 0,
1870 cluster_offset
+ offset_in_cluster
, cur_bytes
);
1875 /* If we need to do COW, check if it's possible to merge the
1876 * writing of the guest data together with that of the COW regions.
1877 * If it's not possible (or not necessary) then write the
1878 * guest data now. */
1879 if (!merge_cow(offset
, cur_bytes
, &hd_qiov
, l2meta
)) {
1880 qemu_co_mutex_unlock(&s
->lock
);
1881 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_AIO
);
1882 trace_qcow2_writev_data(qemu_coroutine_self(),
1883 cluster_offset
+ offset_in_cluster
);
1884 ret
= bdrv_co_pwritev(bs
->file
,
1885 cluster_offset
+ offset_in_cluster
,
1886 cur_bytes
, &hd_qiov
, 0);
1887 qemu_co_mutex_lock(&s
->lock
);
1893 while (l2meta
!= NULL
) {
1896 ret
= qcow2_alloc_cluster_link_l2(bs
, l2meta
);
1901 /* Take the request off the list of running requests */
1902 if (l2meta
->nb_clusters
!= 0) {
1903 QLIST_REMOVE(l2meta
, next_in_flight
);
1906 qemu_co_queue_restart_all(&l2meta
->dependent_requests
);
1908 next
= l2meta
->next
;
1914 offset
+= cur_bytes
;
1915 bytes_done
+= cur_bytes
;
1916 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes
);
1921 qemu_co_mutex_unlock(&s
->lock
);
1923 while (l2meta
!= NULL
) {
1926 if (l2meta
->nb_clusters
!= 0) {
1927 QLIST_REMOVE(l2meta
, next_in_flight
);
1929 qemu_co_queue_restart_all(&l2meta
->dependent_requests
);
1931 next
= l2meta
->next
;
1936 qemu_iovec_destroy(&hd_qiov
);
1937 qemu_vfree(cluster_data
);
1938 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret
);
1943 static int qcow2_inactivate(BlockDriverState
*bs
)
1945 BDRVQcow2State
*s
= bs
->opaque
;
1946 int ret
, result
= 0;
1948 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
1951 error_report("Failed to flush the L2 table cache: %s",
1955 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
1958 error_report("Failed to flush the refcount block cache: %s",
1963 qcow2_mark_clean(bs
);
1969 static void qcow2_close(BlockDriverState
*bs
)
1971 BDRVQcow2State
*s
= bs
->opaque
;
1972 qemu_vfree(s
->l1_table
);
1973 /* else pre-write overlap checks in cache_destroy may crash */
1976 if (!(s
->flags
& BDRV_O_INACTIVE
)) {
1977 qcow2_inactivate(bs
);
1980 cache_clean_timer_del(bs
);
1981 qcow2_cache_destroy(bs
, s
->l2_table_cache
);
1982 qcow2_cache_destroy(bs
, s
->refcount_block_cache
);
1984 qcrypto_block_free(s
->crypto
);
1987 g_free(s
->unknown_header_fields
);
1988 cleanup_unknown_header_ext(bs
);
1990 g_free(s
->image_backing_file
);
1991 g_free(s
->image_backing_format
);
1993 g_free(s
->cluster_cache
);
1994 qemu_vfree(s
->cluster_data
);
1995 qcow2_refcount_close(bs
);
1996 qcow2_free_snapshots(bs
);
1999 static void qcow2_invalidate_cache(BlockDriverState
*bs
, Error
**errp
)
2001 BDRVQcow2State
*s
= bs
->opaque
;
2002 int flags
= s
->flags
;
2003 QCryptoBlock
*crypto
= NULL
;
2005 Error
*local_err
= NULL
;
2009 * Backing files are read-only which makes all of their metadata immutable,
2010 * that means we don't have to worry about reopening them here.
2018 memset(s
, 0, sizeof(BDRVQcow2State
));
2019 options
= qdict_clone_shallow(bs
->options
);
2021 flags
&= ~BDRV_O_INACTIVE
;
2022 ret
= qcow2_do_open(bs
, options
, flags
, &local_err
);
2025 error_propagate(errp
, local_err
);
2026 error_prepend(errp
, "Could not reopen qcow2 layer: ");
2029 } else if (ret
< 0) {
2030 error_setg_errno(errp
, -ret
, "Could not reopen qcow2 layer");
2038 static size_t header_ext_add(char *buf
, uint32_t magic
, const void *s
,
2039 size_t len
, size_t buflen
)
2041 QCowExtension
*ext_backing_fmt
= (QCowExtension
*) buf
;
2042 size_t ext_len
= sizeof(QCowExtension
) + ((len
+ 7) & ~7);
2044 if (buflen
< ext_len
) {
2048 *ext_backing_fmt
= (QCowExtension
) {
2049 .magic
= cpu_to_be32(magic
),
2050 .len
= cpu_to_be32(len
),
2054 memcpy(buf
+ sizeof(QCowExtension
), s
, len
);
2061 * Updates the qcow2 header, including the variable length parts of it, i.e.
2062 * the backing file name and all extensions. qcow2 was not designed to allow
2063 * such changes, so if we run out of space (we can only use the first cluster)
2064 * this function may fail.
2066 * Returns 0 on success, -errno in error cases.
2068 int qcow2_update_header(BlockDriverState
*bs
)
2070 BDRVQcow2State
*s
= bs
->opaque
;
2073 size_t buflen
= s
->cluster_size
;
2075 uint64_t total_size
;
2076 uint32_t refcount_table_clusters
;
2077 size_t header_length
;
2078 Qcow2UnknownHeaderExtension
*uext
;
2080 buf
= qemu_blockalign(bs
, buflen
);
2082 /* Header structure */
2083 header
= (QCowHeader
*) buf
;
2085 if (buflen
< sizeof(*header
)) {
2090 header_length
= sizeof(*header
) + s
->unknown_header_fields_size
;
2091 total_size
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
2092 refcount_table_clusters
= s
->refcount_table_size
>> (s
->cluster_bits
- 3);
2094 *header
= (QCowHeader
) {
2095 /* Version 2 fields */
2096 .magic
= cpu_to_be32(QCOW_MAGIC
),
2097 .version
= cpu_to_be32(s
->qcow_version
),
2098 .backing_file_offset
= 0,
2099 .backing_file_size
= 0,
2100 .cluster_bits
= cpu_to_be32(s
->cluster_bits
),
2101 .size
= cpu_to_be64(total_size
),
2102 .crypt_method
= cpu_to_be32(s
->crypt_method_header
),
2103 .l1_size
= cpu_to_be32(s
->l1_size
),
2104 .l1_table_offset
= cpu_to_be64(s
->l1_table_offset
),
2105 .refcount_table_offset
= cpu_to_be64(s
->refcount_table_offset
),
2106 .refcount_table_clusters
= cpu_to_be32(refcount_table_clusters
),
2107 .nb_snapshots
= cpu_to_be32(s
->nb_snapshots
),
2108 .snapshots_offset
= cpu_to_be64(s
->snapshots_offset
),
2110 /* Version 3 fields */
2111 .incompatible_features
= cpu_to_be64(s
->incompatible_features
),
2112 .compatible_features
= cpu_to_be64(s
->compatible_features
),
2113 .autoclear_features
= cpu_to_be64(s
->autoclear_features
),
2114 .refcount_order
= cpu_to_be32(s
->refcount_order
),
2115 .header_length
= cpu_to_be32(header_length
),
2118 /* For older versions, write a shorter header */
2119 switch (s
->qcow_version
) {
2121 ret
= offsetof(QCowHeader
, incompatible_features
);
2124 ret
= sizeof(*header
);
2133 memset(buf
, 0, buflen
);
2135 /* Preserve any unknown field in the header */
2136 if (s
->unknown_header_fields_size
) {
2137 if (buflen
< s
->unknown_header_fields_size
) {
2142 memcpy(buf
, s
->unknown_header_fields
, s
->unknown_header_fields_size
);
2143 buf
+= s
->unknown_header_fields_size
;
2144 buflen
-= s
->unknown_header_fields_size
;
2147 /* Backing file format header extension */
2148 if (s
->image_backing_format
) {
2149 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_BACKING_FORMAT
,
2150 s
->image_backing_format
,
2151 strlen(s
->image_backing_format
),
2161 /* Full disk encryption header pointer extension */
2162 if (s
->crypto_header
.offset
!= 0) {
2163 cpu_to_be64s(&s
->crypto_header
.offset
);
2164 cpu_to_be64s(&s
->crypto_header
.length
);
2165 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_CRYPTO_HEADER
,
2166 &s
->crypto_header
, sizeof(s
->crypto_header
),
2168 be64_to_cpus(&s
->crypto_header
.offset
);
2169 be64_to_cpus(&s
->crypto_header
.length
);
2178 if (s
->qcow_version
>= 3) {
2179 Qcow2Feature features
[] = {
2181 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2182 .bit
= QCOW2_INCOMPAT_DIRTY_BITNR
,
2183 .name
= "dirty bit",
2186 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2187 .bit
= QCOW2_INCOMPAT_CORRUPT_BITNR
,
2188 .name
= "corrupt bit",
2191 .type
= QCOW2_FEAT_TYPE_COMPATIBLE
,
2192 .bit
= QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR
,
2193 .name
= "lazy refcounts",
2197 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_FEATURE_TABLE
,
2198 features
, sizeof(features
), buflen
);
2206 /* Keep unknown header extensions */
2207 QLIST_FOREACH(uext
, &s
->unknown_header_ext
, next
) {
2208 ret
= header_ext_add(buf
, uext
->magic
, uext
->data
, uext
->len
, buflen
);
2217 /* End of header extensions */
2218 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_END
, NULL
, 0, buflen
);
2226 /* Backing file name */
2227 if (s
->image_backing_file
) {
2228 size_t backing_file_len
= strlen(s
->image_backing_file
);
2230 if (buflen
< backing_file_len
) {
2235 /* Using strncpy is ok here, since buf is not NUL-terminated. */
2236 strncpy(buf
, s
->image_backing_file
, buflen
);
2238 header
->backing_file_offset
= cpu_to_be64(buf
- ((char*) header
));
2239 header
->backing_file_size
= cpu_to_be32(backing_file_len
);
2242 /* Write the new header */
2243 ret
= bdrv_pwrite(bs
->file
, 0, header
, s
->cluster_size
);
2254 static int qcow2_change_backing_file(BlockDriverState
*bs
,
2255 const char *backing_file
, const char *backing_fmt
)
2257 BDRVQcow2State
*s
= bs
->opaque
;
2259 if (backing_file
&& strlen(backing_file
) > 1023) {
2263 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2264 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2266 g_free(s
->image_backing_file
);
2267 g_free(s
->image_backing_format
);
2269 s
->image_backing_file
= backing_file
? g_strdup(bs
->backing_file
) : NULL
;
2270 s
->image_backing_format
= backing_fmt
? g_strdup(bs
->backing_format
) : NULL
;
2272 return qcow2_update_header(bs
);
2275 static int qcow2_crypt_method_from_format(const char *encryptfmt
)
2277 if (g_str_equal(encryptfmt
, "luks")) {
2278 return QCOW_CRYPT_LUKS
;
2279 } else if (g_str_equal(encryptfmt
, "aes")) {
2280 return QCOW_CRYPT_AES
;
2286 static int qcow2_set_up_encryption(BlockDriverState
*bs
, const char *encryptfmt
,
2287 QemuOpts
*opts
, Error
**errp
)
2289 BDRVQcow2State
*s
= bs
->opaque
;
2290 QCryptoBlockCreateOptions
*cryptoopts
= NULL
;
2291 QCryptoBlock
*crypto
= NULL
;
2293 QDict
*options
, *encryptopts
;
2296 options
= qemu_opts_to_qdict(opts
, NULL
);
2297 qdict_extract_subqdict(options
, &encryptopts
, "encrypt.");
2300 fmt
= qcow2_crypt_method_from_format(encryptfmt
);
2303 case QCOW_CRYPT_LUKS
:
2304 cryptoopts
= block_crypto_create_opts_init(
2305 Q_CRYPTO_BLOCK_FORMAT_LUKS
, encryptopts
, errp
);
2307 case QCOW_CRYPT_AES
:
2308 cryptoopts
= block_crypto_create_opts_init(
2309 Q_CRYPTO_BLOCK_FORMAT_QCOW
, encryptopts
, errp
);
2312 error_setg(errp
, "Unknown encryption format '%s'", encryptfmt
);
2319 s
->crypt_method_header
= fmt
;
2321 crypto
= qcrypto_block_create(cryptoopts
,
2322 qcow2_crypto_hdr_init_func
,
2323 qcow2_crypto_hdr_write_func
,
2330 ret
= qcow2_update_header(bs
);
2332 error_setg_errno(errp
, -ret
, "Could not write encryption header");
2337 QDECREF(encryptopts
);
2338 qcrypto_block_free(crypto
);
2339 qapi_free_QCryptoBlockCreateOptions(cryptoopts
);
2344 static int preallocate(BlockDriverState
*bs
)
2348 uint64_t host_offset
= 0;
2349 unsigned int cur_bytes
;
2353 bytes
= bdrv_getlength(bs
);
2357 cur_bytes
= MIN(bytes
, INT_MAX
);
2358 ret
= qcow2_alloc_cluster_offset(bs
, offset
, &cur_bytes
,
2359 &host_offset
, &meta
);
2365 QCowL2Meta
*next
= meta
->next
;
2367 ret
= qcow2_alloc_cluster_link_l2(bs
, meta
);
2369 qcow2_free_any_clusters(bs
, meta
->alloc_offset
,
2370 meta
->nb_clusters
, QCOW2_DISCARD_NEVER
);
2374 /* There are no dependent requests, but we need to remove our
2375 * request from the list of in-flight requests */
2376 QLIST_REMOVE(meta
, next_in_flight
);
2382 /* TODO Preallocate data if requested */
2385 offset
+= cur_bytes
;
2389 * It is expected that the image file is large enough to actually contain
2390 * all of the allocated clusters (otherwise we get failing reads after
2391 * EOF). Extend the image to the last allocated sector.
2393 if (host_offset
!= 0) {
2395 ret
= bdrv_pwrite(bs
->file
, (host_offset
+ cur_bytes
) - 1,
2405 static int qcow2_create2(const char *filename
, int64_t total_size
,
2406 const char *backing_file
, const char *backing_format
,
2407 int flags
, size_t cluster_size
, PreallocMode prealloc
,
2408 QemuOpts
*opts
, int version
, int refcount_order
,
2409 const char *encryptfmt
, Error
**errp
)
2414 /* Calculate cluster_bits */
2415 cluster_bits
= ctz32(cluster_size
);
2416 if (cluster_bits
< MIN_CLUSTER_BITS
|| cluster_bits
> MAX_CLUSTER_BITS
||
2417 (1 << cluster_bits
) != cluster_size
)
2419 error_setg(errp
, "Cluster size must be a power of two between %d and "
2420 "%dk", 1 << MIN_CLUSTER_BITS
, 1 << (MAX_CLUSTER_BITS
- 10));
2425 * Open the image file and write a minimal qcow2 header.
2427 * We keep things simple and start with a zero-sized image. We also
2428 * do without refcount blocks or a L1 table for now. We'll fix the
2429 * inconsistency later.
2431 * We do need a refcount table because growing the refcount table means
2432 * allocating two new refcount blocks - the seconds of which would be at
2433 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
2434 * size for any qcow2 image.
2438 uint64_t* refcount_table
;
2439 Error
*local_err
= NULL
;
2442 if (prealloc
== PREALLOC_MODE_FULL
|| prealloc
== PREALLOC_MODE_FALLOC
) {
2443 /* Note: The following calculation does not need to be exact; if it is a
2444 * bit off, either some bytes will be "leaked" (which is fine) or we
2445 * will need to increase the file size by some bytes (which is fine,
2446 * too, as long as the bulk is allocated here). Therefore, using
2447 * floating point arithmetic is fine. */
2448 int64_t meta_size
= 0;
2449 uint64_t nreftablee
, nrefblocke
, nl1e
, nl2e
, refblock_count
;
2450 int64_t aligned_total_size
= align_offset(total_size
, cluster_size
);
2451 int refblock_bits
, refblock_size
;
2452 /* refcount entry size in bytes */
2453 double rces
= (1 << refcount_order
) / 8.;
2455 /* see qcow2_open() */
2456 refblock_bits
= cluster_bits
- (refcount_order
- 3);
2457 refblock_size
= 1 << refblock_bits
;
2459 /* header: 1 cluster */
2460 meta_size
+= cluster_size
;
2462 /* total size of L2 tables */
2463 nl2e
= aligned_total_size
/ cluster_size
;
2464 nl2e
= align_offset(nl2e
, cluster_size
/ sizeof(uint64_t));
2465 meta_size
+= nl2e
* sizeof(uint64_t);
2467 /* total size of L1 tables */
2468 nl1e
= nl2e
* sizeof(uint64_t) / cluster_size
;
2469 nl1e
= align_offset(nl1e
, cluster_size
/ sizeof(uint64_t));
2470 meta_size
+= nl1e
* sizeof(uint64_t);
2472 /* total size of refcount blocks
2474 * note: every host cluster is reference-counted, including metadata
2475 * (even refcount blocks are recursively included).
2477 * a = total_size (this is the guest disk size)
2478 * m = meta size not including refcount blocks and refcount tables
2480 * y1 = number of refcount blocks entries
2481 * y2 = meta size including everything
2482 * rces = refcount entry size in bytes
2485 * y2 = y1 * rces + y1 * rces * sizeof(u64) / c + m
2487 * y1 = (a + m) / (c - rces - rces * sizeof(u64) / c)
2489 nrefblocke
= (aligned_total_size
+ meta_size
+ cluster_size
)
2490 / (cluster_size
- rces
- rces
* sizeof(uint64_t)
2492 refblock_count
= DIV_ROUND_UP(nrefblocke
, refblock_size
);
2493 meta_size
+= refblock_count
* cluster_size
;
2495 /* total size of refcount tables */
2496 nreftablee
= align_offset(refblock_count
,
2497 cluster_size
/ sizeof(uint64_t));
2498 meta_size
+= nreftablee
* sizeof(uint64_t);
2500 qemu_opt_set_number(opts
, BLOCK_OPT_SIZE
,
2501 aligned_total_size
+ meta_size
, &error_abort
);
2502 qemu_opt_set(opts
, BLOCK_OPT_PREALLOC
, PreallocMode_lookup
[prealloc
],
2506 ret
= bdrv_create_file(filename
, opts
, &local_err
);
2508 error_propagate(errp
, local_err
);
2512 blk
= blk_new_open(filename
, NULL
, NULL
,
2513 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_PROTOCOL
,
2516 error_propagate(errp
, local_err
);
2520 blk_set_allow_write_beyond_eof(blk
, true);
2522 /* Write the header */
2523 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS
) < sizeof(*header
));
2524 header
= g_malloc0(cluster_size
);
2525 *header
= (QCowHeader
) {
2526 .magic
= cpu_to_be32(QCOW_MAGIC
),
2527 .version
= cpu_to_be32(version
),
2528 .cluster_bits
= cpu_to_be32(cluster_bits
),
2529 .size
= cpu_to_be64(0),
2530 .l1_table_offset
= cpu_to_be64(0),
2531 .l1_size
= cpu_to_be32(0),
2532 .refcount_table_offset
= cpu_to_be64(cluster_size
),
2533 .refcount_table_clusters
= cpu_to_be32(1),
2534 .refcount_order
= cpu_to_be32(refcount_order
),
2535 .header_length
= cpu_to_be32(sizeof(*header
)),
2538 /* We'll update this to correct value later */
2539 header
->crypt_method
= cpu_to_be32(QCOW_CRYPT_NONE
);
2541 if (flags
& BLOCK_FLAG_LAZY_REFCOUNTS
) {
2542 header
->compatible_features
|=
2543 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS
);
2546 ret
= blk_pwrite(blk
, 0, header
, cluster_size
, 0);
2549 error_setg_errno(errp
, -ret
, "Could not write qcow2 header");
2553 /* Write a refcount table with one refcount block */
2554 refcount_table
= g_malloc0(2 * cluster_size
);
2555 refcount_table
[0] = cpu_to_be64(2 * cluster_size
);
2556 ret
= blk_pwrite(blk
, cluster_size
, refcount_table
, 2 * cluster_size
, 0);
2557 g_free(refcount_table
);
2560 error_setg_errno(errp
, -ret
, "Could not write refcount table");
2568 * And now open the image and make it consistent first (i.e. increase the
2569 * refcount of the cluster that is occupied by the header and the refcount
2572 options
= qdict_new();
2573 qdict_put_str(options
, "driver", "qcow2");
2574 blk
= blk_new_open(filename
, NULL
, options
,
2575 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_NO_FLUSH
,
2578 error_propagate(errp
, local_err
);
2583 ret
= qcow2_alloc_clusters(blk_bs(blk
), 3 * cluster_size
);
2585 error_setg_errno(errp
, -ret
, "Could not allocate clusters for qcow2 "
2586 "header and refcount table");
2589 } else if (ret
!= 0) {
2590 error_report("Huh, first cluster in empty image is already in use?");
2594 /* Create a full header (including things like feature table) */
2595 ret
= qcow2_update_header(blk_bs(blk
));
2597 error_setg_errno(errp
, -ret
, "Could not update qcow2 header");
2601 /* Okay, now that we have a valid image, let's give it the right size */
2602 ret
= blk_truncate(blk
, total_size
, errp
);
2604 error_prepend(errp
, "Could not resize image: ");
2608 /* Want a backing file? There you go.*/
2610 ret
= bdrv_change_backing_file(blk_bs(blk
), backing_file
, backing_format
);
2612 error_setg_errno(errp
, -ret
, "Could not assign backing file '%s' "
2613 "with format '%s'", backing_file
, backing_format
);
2618 /* Want encryption? There you go. */
2620 ret
= qcow2_set_up_encryption(blk_bs(blk
), encryptfmt
, opts
, errp
);
2626 /* And if we're supposed to preallocate metadata, do that now */
2627 if (prealloc
!= PREALLOC_MODE_OFF
) {
2628 BDRVQcow2State
*s
= blk_bs(blk
)->opaque
;
2629 qemu_co_mutex_lock(&s
->lock
);
2630 ret
= preallocate(blk_bs(blk
));
2631 qemu_co_mutex_unlock(&s
->lock
);
2633 error_setg_errno(errp
, -ret
, "Could not preallocate metadata");
2641 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning.
2642 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to
2643 * have to setup decryption context. We're not doing any I/O on the top
2644 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does
2647 options
= qdict_new();
2648 qdict_put_str(options
, "driver", "qcow2");
2649 blk
= blk_new_open(filename
, NULL
, options
,
2650 BDRV_O_RDWR
| BDRV_O_NO_BACKING
| BDRV_O_NO_IO
,
2653 error_propagate(errp
, local_err
);
2666 static int qcow2_create(const char *filename
, QemuOpts
*opts
, Error
**errp
)
2668 char *backing_file
= NULL
;
2669 char *backing_fmt
= NULL
;
2673 size_t cluster_size
= DEFAULT_CLUSTER_SIZE
;
2674 PreallocMode prealloc
;
2676 uint64_t refcount_bits
= 16;
2678 const char *encryptfmt
= NULL
;
2679 Error
*local_err
= NULL
;
2682 /* Read out options */
2683 size
= ROUND_UP(qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0),
2685 backing_file
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
2686 backing_fmt
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FMT
);
2687 encryptfmt
= qemu_opt_get_del(opts
, BLOCK_OPT_ENCRYPT_FORMAT
);
2689 if (qemu_opt_get_del(opts
, BLOCK_OPT_ENCRYPT
)) {
2690 error_setg(errp
, "Options " BLOCK_OPT_ENCRYPT
" and "
2691 BLOCK_OPT_ENCRYPT_FORMAT
" are mutually exclusive");
2695 } else if (qemu_opt_get_bool_del(opts
, BLOCK_OPT_ENCRYPT
, false)) {
2698 cluster_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_CLUSTER_SIZE
,
2699 DEFAULT_CLUSTER_SIZE
);
2700 buf
= qemu_opt_get_del(opts
, BLOCK_OPT_PREALLOC
);
2701 prealloc
= qapi_enum_parse(PreallocMode_lookup
, buf
,
2702 PREALLOC_MODE__MAX
, PREALLOC_MODE_OFF
,
2705 error_propagate(errp
, local_err
);
2710 buf
= qemu_opt_get_del(opts
, BLOCK_OPT_COMPAT_LEVEL
);
2712 /* keep the default */
2713 } else if (!strcmp(buf
, "0.10")) {
2715 } else if (!strcmp(buf
, "1.1")) {
2718 error_setg(errp
, "Invalid compatibility level: '%s'", buf
);
2723 if (qemu_opt_get_bool_del(opts
, BLOCK_OPT_LAZY_REFCOUNTS
, false)) {
2724 flags
|= BLOCK_FLAG_LAZY_REFCOUNTS
;
2727 if (backing_file
&& prealloc
!= PREALLOC_MODE_OFF
) {
2728 error_setg(errp
, "Backing file and preallocation cannot be used at "
2734 if (version
< 3 && (flags
& BLOCK_FLAG_LAZY_REFCOUNTS
)) {
2735 error_setg(errp
, "Lazy refcounts only supported with compatibility "
2736 "level 1.1 and above (use compat=1.1 or greater)");
2741 refcount_bits
= qemu_opt_get_number_del(opts
, BLOCK_OPT_REFCOUNT_BITS
,
2743 if (refcount_bits
> 64 || !is_power_of_2(refcount_bits
)) {
2744 error_setg(errp
, "Refcount width must be a power of two and may not "
2750 if (version
< 3 && refcount_bits
!= 16) {
2751 error_setg(errp
, "Different refcount widths than 16 bits require "
2752 "compatibility level 1.1 or above (use compat=1.1 or "
2758 refcount_order
= ctz32(refcount_bits
);
2760 ret
= qcow2_create2(filename
, size
, backing_file
, backing_fmt
, flags
,
2761 cluster_size
, prealloc
, opts
, version
, refcount_order
,
2762 encryptfmt
, &local_err
);
2763 error_propagate(errp
, local_err
);
2766 g_free(backing_file
);
2767 g_free(backing_fmt
);
2773 static bool is_zero_sectors(BlockDriverState
*bs
, int64_t start
,
2777 BlockDriverState
*file
;
2780 if (start
+ count
> bs
->total_sectors
) {
2781 count
= bs
->total_sectors
- start
;
2787 res
= bdrv_get_block_status_above(bs
, NULL
, start
, count
,
2789 return res
>= 0 && (res
& BDRV_BLOCK_ZERO
) && nr
== count
;
2792 static coroutine_fn
int qcow2_co_pwrite_zeroes(BlockDriverState
*bs
,
2793 int64_t offset
, int bytes
, BdrvRequestFlags flags
)
2796 BDRVQcow2State
*s
= bs
->opaque
;
2798 uint32_t head
= offset
% s
->cluster_size
;
2799 uint32_t tail
= (offset
+ bytes
) % s
->cluster_size
;
2801 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset
, bytes
);
2802 if (offset
+ bytes
== bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
2807 int64_t cl_start
= (offset
- head
) >> BDRV_SECTOR_BITS
;
2811 assert(head
+ bytes
<= s
->cluster_size
);
2813 /* check whether remainder of cluster already reads as zero */
2814 if (!(is_zero_sectors(bs
, cl_start
,
2815 DIV_ROUND_UP(head
, BDRV_SECTOR_SIZE
)) &&
2816 is_zero_sectors(bs
, (offset
+ bytes
) >> BDRV_SECTOR_BITS
,
2817 DIV_ROUND_UP(-tail
& (s
->cluster_size
- 1),
2818 BDRV_SECTOR_SIZE
)))) {
2822 qemu_co_mutex_lock(&s
->lock
);
2823 /* We can have new write after previous check */
2824 offset
= cl_start
<< BDRV_SECTOR_BITS
;
2825 bytes
= s
->cluster_size
;
2826 nr
= s
->cluster_size
;
2827 ret
= qcow2_get_cluster_offset(bs
, offset
, &nr
, &off
);
2828 if (ret
!= QCOW2_CLUSTER_UNALLOCATED
&&
2829 ret
!= QCOW2_CLUSTER_ZERO_PLAIN
&&
2830 ret
!= QCOW2_CLUSTER_ZERO_ALLOC
) {
2831 qemu_co_mutex_unlock(&s
->lock
);
2835 qemu_co_mutex_lock(&s
->lock
);
2838 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset
, bytes
);
2840 /* Whatever is left can use real zero clusters */
2841 ret
= qcow2_cluster_zeroize(bs
, offset
, bytes
, flags
);
2842 qemu_co_mutex_unlock(&s
->lock
);
2847 static coroutine_fn
int qcow2_co_pdiscard(BlockDriverState
*bs
,
2848 int64_t offset
, int bytes
)
2851 BDRVQcow2State
*s
= bs
->opaque
;
2853 if (!QEMU_IS_ALIGNED(offset
| bytes
, s
->cluster_size
)) {
2854 assert(bytes
< s
->cluster_size
);
2855 /* Ignore partial clusters, except for the special case of the
2856 * complete partial cluster at the end of an unaligned file */
2857 if (!QEMU_IS_ALIGNED(offset
, s
->cluster_size
) ||
2858 offset
+ bytes
!= bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
2863 qemu_co_mutex_lock(&s
->lock
);
2864 ret
= qcow2_cluster_discard(bs
, offset
, bytes
, QCOW2_DISCARD_REQUEST
,
2866 qemu_co_mutex_unlock(&s
->lock
);
2870 static int qcow2_truncate(BlockDriverState
*bs
, int64_t offset
, Error
**errp
)
2872 BDRVQcow2State
*s
= bs
->opaque
;
2873 int64_t new_l1_size
;
2877 error_setg(errp
, "The new size must be a multiple of 512");
2881 /* cannot proceed if image has snapshots */
2882 if (s
->nb_snapshots
) {
2883 error_setg(errp
, "Can't resize an image which has snapshots");
2887 /* shrinking is currently not supported */
2888 if (offset
< bs
->total_sectors
* 512) {
2889 error_setg(errp
, "qcow2 doesn't support shrinking images yet");
2893 new_l1_size
= size_to_l1(s
, offset
);
2894 ret
= qcow2_grow_l1_table(bs
, new_l1_size
, true);
2896 error_setg_errno(errp
, -ret
, "Failed to grow the L1 table");
2900 /* write updated header.size */
2901 offset
= cpu_to_be64(offset
);
2902 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, size
),
2903 &offset
, sizeof(uint64_t));
2905 error_setg_errno(errp
, -ret
, "Failed to update the image size");
2909 s
->l1_vm_state_index
= new_l1_size
;
2913 /* XXX: put compressed sectors first, then all the cluster aligned
2914 tables to avoid losing bytes in alignment */
2915 static coroutine_fn
int
2916 qcow2_co_pwritev_compressed(BlockDriverState
*bs
, uint64_t offset
,
2917 uint64_t bytes
, QEMUIOVector
*qiov
)
2919 BDRVQcow2State
*s
= bs
->opaque
;
2920 QEMUIOVector hd_qiov
;
2924 uint8_t *buf
, *out_buf
;
2925 uint64_t cluster_offset
;
2928 /* align end of file to a sector boundary to ease reading with
2929 sector based I/Os */
2930 cluster_offset
= bdrv_getlength(bs
->file
->bs
);
2931 return bdrv_truncate(bs
->file
, cluster_offset
, NULL
);
2934 buf
= qemu_blockalign(bs
, s
->cluster_size
);
2935 if (bytes
!= s
->cluster_size
) {
2936 if (bytes
> s
->cluster_size
||
2937 offset
+ bytes
!= bs
->total_sectors
<< BDRV_SECTOR_BITS
)
2942 /* Zero-pad last write if image size is not cluster aligned */
2943 memset(buf
+ bytes
, 0, s
->cluster_size
- bytes
);
2945 qemu_iovec_to_buf(qiov
, 0, buf
, bytes
);
2947 out_buf
= g_malloc(s
->cluster_size
);
2949 /* best compression, small window, no zlib header */
2950 memset(&strm
, 0, sizeof(strm
));
2951 ret
= deflateInit2(&strm
, Z_DEFAULT_COMPRESSION
,
2953 9, Z_DEFAULT_STRATEGY
);
2959 strm
.avail_in
= s
->cluster_size
;
2960 strm
.next_in
= (uint8_t *)buf
;
2961 strm
.avail_out
= s
->cluster_size
;
2962 strm
.next_out
= out_buf
;
2964 ret
= deflate(&strm
, Z_FINISH
);
2965 if (ret
!= Z_STREAM_END
&& ret
!= Z_OK
) {
2970 out_len
= strm
.next_out
- out_buf
;
2974 if (ret
!= Z_STREAM_END
|| out_len
>= s
->cluster_size
) {
2975 /* could not compress: write normal cluster */
2976 ret
= qcow2_co_pwritev(bs
, offset
, bytes
, qiov
, 0);
2983 qemu_co_mutex_lock(&s
->lock
);
2985 qcow2_alloc_compressed_cluster_offset(bs
, offset
, out_len
);
2986 if (!cluster_offset
) {
2987 qemu_co_mutex_unlock(&s
->lock
);
2991 cluster_offset
&= s
->cluster_offset_mask
;
2993 ret
= qcow2_pre_write_overlap_check(bs
, 0, cluster_offset
, out_len
);
2994 qemu_co_mutex_unlock(&s
->lock
);
2999 iov
= (struct iovec
) {
3000 .iov_base
= out_buf
,
3003 qemu_iovec_init_external(&hd_qiov
, &iov
, 1);
3005 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_COMPRESSED
);
3006 ret
= bdrv_co_pwritev(bs
->file
, cluster_offset
, out_len
, &hd_qiov
, 0);
3018 static int make_completely_empty(BlockDriverState
*bs
)
3020 BDRVQcow2State
*s
= bs
->opaque
;
3021 Error
*local_err
= NULL
;
3022 int ret
, l1_clusters
;
3024 uint64_t *new_reftable
= NULL
;
3025 uint64_t rt_entry
, l1_size2
;
3028 uint64_t reftable_offset
;
3029 uint32_t reftable_clusters
;
3030 } QEMU_PACKED l1_ofs_rt_ofs_cls
;
3032 ret
= qcow2_cache_empty(bs
, s
->l2_table_cache
);
3037 ret
= qcow2_cache_empty(bs
, s
->refcount_block_cache
);
3042 /* Refcounts will be broken utterly */
3043 ret
= qcow2_mark_dirty(bs
);
3048 BLKDBG_EVENT(bs
->file
, BLKDBG_L1_UPDATE
);
3050 l1_clusters
= DIV_ROUND_UP(s
->l1_size
, s
->cluster_size
/ sizeof(uint64_t));
3051 l1_size2
= (uint64_t)s
->l1_size
* sizeof(uint64_t);
3053 /* After this call, neither the in-memory nor the on-disk refcount
3054 * information accurately describe the actual references */
3056 ret
= bdrv_pwrite_zeroes(bs
->file
, s
->l1_table_offset
,
3057 l1_clusters
* s
->cluster_size
, 0);
3059 goto fail_broken_refcounts
;
3061 memset(s
->l1_table
, 0, l1_size2
);
3063 BLKDBG_EVENT(bs
->file
, BLKDBG_EMPTY_IMAGE_PREPARE
);
3065 /* Overwrite enough clusters at the beginning of the sectors to place
3066 * the refcount table, a refcount block and the L1 table in; this may
3067 * overwrite parts of the existing refcount and L1 table, which is not
3068 * an issue because the dirty flag is set, complete data loss is in fact
3069 * desired and partial data loss is consequently fine as well */
3070 ret
= bdrv_pwrite_zeroes(bs
->file
, s
->cluster_size
,
3071 (2 + l1_clusters
) * s
->cluster_size
, 0);
3072 /* This call (even if it failed overall) may have overwritten on-disk
3073 * refcount structures; in that case, the in-memory refcount information
3074 * will probably differ from the on-disk information which makes the BDS
3077 goto fail_broken_refcounts
;
3080 BLKDBG_EVENT(bs
->file
, BLKDBG_L1_UPDATE
);
3081 BLKDBG_EVENT(bs
->file
, BLKDBG_REFTABLE_UPDATE
);
3083 /* "Create" an empty reftable (one cluster) directly after the image
3084 * header and an empty L1 table three clusters after the image header;
3085 * the cluster between those two will be used as the first refblock */
3086 l1_ofs_rt_ofs_cls
.l1_offset
= cpu_to_be64(3 * s
->cluster_size
);
3087 l1_ofs_rt_ofs_cls
.reftable_offset
= cpu_to_be64(s
->cluster_size
);
3088 l1_ofs_rt_ofs_cls
.reftable_clusters
= cpu_to_be32(1);
3089 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, l1_table_offset
),
3090 &l1_ofs_rt_ofs_cls
, sizeof(l1_ofs_rt_ofs_cls
));
3092 goto fail_broken_refcounts
;
3095 s
->l1_table_offset
= 3 * s
->cluster_size
;
3097 new_reftable
= g_try_new0(uint64_t, s
->cluster_size
/ sizeof(uint64_t));
3098 if (!new_reftable
) {
3100 goto fail_broken_refcounts
;
3103 s
->refcount_table_offset
= s
->cluster_size
;
3104 s
->refcount_table_size
= s
->cluster_size
/ sizeof(uint64_t);
3105 s
->max_refcount_table_index
= 0;
3107 g_free(s
->refcount_table
);
3108 s
->refcount_table
= new_reftable
;
3109 new_reftable
= NULL
;
3111 /* Now the in-memory refcount information again corresponds to the on-disk
3112 * information (reftable is empty and no refblocks (the refblock cache is
3113 * empty)); however, this means some clusters (e.g. the image header) are
3114 * referenced, but not refcounted, but the normal qcow2 code assumes that
3115 * the in-memory information is always correct */
3117 BLKDBG_EVENT(bs
->file
, BLKDBG_REFBLOCK_ALLOC
);
3119 /* Enter the first refblock into the reftable */
3120 rt_entry
= cpu_to_be64(2 * s
->cluster_size
);
3121 ret
= bdrv_pwrite_sync(bs
->file
, s
->cluster_size
,
3122 &rt_entry
, sizeof(rt_entry
));
3124 goto fail_broken_refcounts
;
3126 s
->refcount_table
[0] = 2 * s
->cluster_size
;
3128 s
->free_cluster_index
= 0;
3129 assert(3 + l1_clusters
<= s
->refcount_block_size
);
3130 offset
= qcow2_alloc_clusters(bs
, 3 * s
->cluster_size
+ l1_size2
);
3133 goto fail_broken_refcounts
;
3134 } else if (offset
> 0) {
3135 error_report("First cluster in emptied image is in use");
3139 /* Now finally the in-memory information corresponds to the on-disk
3140 * structures and is correct */
3141 ret
= qcow2_mark_clean(bs
);
3146 ret
= bdrv_truncate(bs
->file
, (3 + l1_clusters
) * s
->cluster_size
,
3149 error_report_err(local_err
);
3155 fail_broken_refcounts
:
3156 /* The BDS is unusable at this point. If we wanted to make it usable, we
3157 * would have to call qcow2_refcount_close(), qcow2_refcount_init(),
3158 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init()
3159 * again. However, because the functions which could have caused this error
3160 * path to be taken are used by those functions as well, it's very likely
3161 * that that sequence will fail as well. Therefore, just eject the BDS. */
3165 g_free(new_reftable
);
3169 static int qcow2_make_empty(BlockDriverState
*bs
)
3171 BDRVQcow2State
*s
= bs
->opaque
;
3172 uint64_t offset
, end_offset
;
3173 int step
= QEMU_ALIGN_DOWN(INT_MAX
, s
->cluster_size
);
3174 int l1_clusters
, ret
= 0;
3176 l1_clusters
= DIV_ROUND_UP(s
->l1_size
, s
->cluster_size
/ sizeof(uint64_t));
3178 if (s
->qcow_version
>= 3 && !s
->snapshots
&&
3179 3 + l1_clusters
<= s
->refcount_block_size
) {
3180 /* The following function only works for qcow2 v3 images (it requires
3181 * the dirty flag) and only as long as there are no snapshots (because
3182 * it completely empties the image). Furthermore, the L1 table and three
3183 * additional clusters (image header, refcount table, one refcount
3184 * block) have to fit inside one refcount block. */
3185 return make_completely_empty(bs
);
3188 /* This fallback code simply discards every active cluster; this is slow,
3189 * but works in all cases */
3190 end_offset
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
3191 for (offset
= 0; offset
< end_offset
; offset
+= step
) {
3192 /* As this function is generally used after committing an external
3193 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the
3194 * default action for this kind of discard is to pass the discard,
3195 * which will ideally result in an actually smaller image file, as
3196 * is probably desired. */
3197 ret
= qcow2_cluster_discard(bs
, offset
, MIN(step
, end_offset
- offset
),
3198 QCOW2_DISCARD_SNAPSHOT
, true);
3207 static coroutine_fn
int qcow2_co_flush_to_os(BlockDriverState
*bs
)
3209 BDRVQcow2State
*s
= bs
->opaque
;
3212 qemu_co_mutex_lock(&s
->lock
);
3213 ret
= qcow2_cache_write(bs
, s
->l2_table_cache
);
3215 qemu_co_mutex_unlock(&s
->lock
);
3219 if (qcow2_need_accurate_refcounts(s
)) {
3220 ret
= qcow2_cache_write(bs
, s
->refcount_block_cache
);
3222 qemu_co_mutex_unlock(&s
->lock
);
3226 qemu_co_mutex_unlock(&s
->lock
);
3231 static int qcow2_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
3233 BDRVQcow2State
*s
= bs
->opaque
;
3234 bdi
->unallocated_blocks_are_zero
= true;
3235 bdi
->can_write_zeroes_with_unmap
= (s
->qcow_version
>= 3);
3236 bdi
->cluster_size
= s
->cluster_size
;
3237 bdi
->vm_state_offset
= qcow2_vm_state_offset(s
);
3241 static ImageInfoSpecific
*qcow2_get_specific_info(BlockDriverState
*bs
)
3243 BDRVQcow2State
*s
= bs
->opaque
;
3244 ImageInfoSpecific
*spec_info
= g_new(ImageInfoSpecific
, 1);
3246 *spec_info
= (ImageInfoSpecific
){
3247 .type
= IMAGE_INFO_SPECIFIC_KIND_QCOW2
,
3248 .u
.qcow2
.data
= g_new(ImageInfoSpecificQCow2
, 1),
3250 if (s
->qcow_version
== 2) {
3251 *spec_info
->u
.qcow2
.data
= (ImageInfoSpecificQCow2
){
3252 .compat
= g_strdup("0.10"),
3253 .refcount_bits
= s
->refcount_bits
,
3255 } else if (s
->qcow_version
== 3) {
3256 *spec_info
->u
.qcow2
.data
= (ImageInfoSpecificQCow2
){
3257 .compat
= g_strdup("1.1"),
3258 .lazy_refcounts
= s
->compatible_features
&
3259 QCOW2_COMPAT_LAZY_REFCOUNTS
,
3260 .has_lazy_refcounts
= true,
3261 .corrupt
= s
->incompatible_features
&
3262 QCOW2_INCOMPAT_CORRUPT
,
3263 .has_corrupt
= true,
3264 .refcount_bits
= s
->refcount_bits
,
3267 /* if this assertion fails, this probably means a new version was
3268 * added without having it covered here */
3276 static void dump_refcounts(BlockDriverState
*bs
)
3278 BDRVQcow2State
*s
= bs
->opaque
;
3279 int64_t nb_clusters
, k
, k1
, size
;
3282 size
= bdrv_getlength(bs
->file
->bs
);
3283 nb_clusters
= size_to_clusters(s
, size
);
3284 for(k
= 0; k
< nb_clusters
;) {
3286 refcount
= get_refcount(bs
, k
);
3288 while (k
< nb_clusters
&& get_refcount(bs
, k
) == refcount
)
3290 printf("%" PRId64
": refcount=%d nb=%" PRId64
"\n", k
, refcount
,
3296 static int qcow2_save_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
3299 BDRVQcow2State
*s
= bs
->opaque
;
3301 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_SAVE
);
3302 return bs
->drv
->bdrv_co_pwritev(bs
, qcow2_vm_state_offset(s
) + pos
,
3303 qiov
->size
, qiov
, 0);
3306 static int qcow2_load_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
3309 BDRVQcow2State
*s
= bs
->opaque
;
3311 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_LOAD
);
3312 return bs
->drv
->bdrv_co_preadv(bs
, qcow2_vm_state_offset(s
) + pos
,
3313 qiov
->size
, qiov
, 0);
3317 * Downgrades an image's version. To achieve this, any incompatible features
3318 * have to be removed.
3320 static int qcow2_downgrade(BlockDriverState
*bs
, int target_version
,
3321 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
)
3323 BDRVQcow2State
*s
= bs
->opaque
;
3324 int current_version
= s
->qcow_version
;
3327 if (target_version
== current_version
) {
3329 } else if (target_version
> current_version
) {
3331 } else if (target_version
!= 2) {
3335 if (s
->refcount_order
!= 4) {
3336 error_report("compat=0.10 requires refcount_bits=16");
3340 /* clear incompatible features */
3341 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
3342 ret
= qcow2_mark_clean(bs
);
3348 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
3349 * the first place; if that happens nonetheless, returning -ENOTSUP is the
3350 * best thing to do anyway */
3352 if (s
->incompatible_features
) {
3356 /* since we can ignore compatible features, we can set them to 0 as well */
3357 s
->compatible_features
= 0;
3358 /* if lazy refcounts have been used, they have already been fixed through
3359 * clearing the dirty flag */
3361 /* clearing autoclear features is trivial */
3362 s
->autoclear_features
= 0;
3364 ret
= qcow2_expand_zero_clusters(bs
, status_cb
, cb_opaque
);
3369 s
->qcow_version
= target_version
;
3370 ret
= qcow2_update_header(bs
);
3372 s
->qcow_version
= current_version
;
3378 typedef enum Qcow2AmendOperation
{
3379 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be
3380 * statically initialized to so that the helper CB can discern the first
3381 * invocation from an operation change */
3382 QCOW2_NO_OPERATION
= 0,
3384 QCOW2_CHANGING_REFCOUNT_ORDER
,
3386 } Qcow2AmendOperation
;
3388 typedef struct Qcow2AmendHelperCBInfo
{
3389 /* The code coordinating the amend operations should only modify
3390 * these four fields; the rest will be managed by the CB */
3391 BlockDriverAmendStatusCB
*original_status_cb
;
3392 void *original_cb_opaque
;
3394 Qcow2AmendOperation current_operation
;
3396 /* Total number of operations to perform (only set once) */
3397 int total_operations
;
3399 /* The following fields are managed by the CB */
3401 /* Number of operations completed */
3402 int operations_completed
;
3404 /* Cumulative offset of all completed operations */
3405 int64_t offset_completed
;
3407 Qcow2AmendOperation last_operation
;
3408 int64_t last_work_size
;
3409 } Qcow2AmendHelperCBInfo
;
3411 static void qcow2_amend_helper_cb(BlockDriverState
*bs
,
3412 int64_t operation_offset
,
3413 int64_t operation_work_size
, void *opaque
)
3415 Qcow2AmendHelperCBInfo
*info
= opaque
;
3416 int64_t current_work_size
;
3417 int64_t projected_work_size
;
3419 if (info
->current_operation
!= info
->last_operation
) {
3420 if (info
->last_operation
!= QCOW2_NO_OPERATION
) {
3421 info
->offset_completed
+= info
->last_work_size
;
3422 info
->operations_completed
++;
3425 info
->last_operation
= info
->current_operation
;
3428 assert(info
->total_operations
> 0);
3429 assert(info
->operations_completed
< info
->total_operations
);
3431 info
->last_work_size
= operation_work_size
;
3433 current_work_size
= info
->offset_completed
+ operation_work_size
;
3435 /* current_work_size is the total work size for (operations_completed + 1)
3436 * operations (which includes this one), so multiply it by the number of
3437 * operations not covered and divide it by the number of operations
3438 * covered to get a projection for the operations not covered */
3439 projected_work_size
= current_work_size
* (info
->total_operations
-
3440 info
->operations_completed
- 1)
3441 / (info
->operations_completed
+ 1);
3443 info
->original_status_cb(bs
, info
->offset_completed
+ operation_offset
,
3444 current_work_size
+ projected_work_size
,
3445 info
->original_cb_opaque
);
3448 static int qcow2_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
3449 BlockDriverAmendStatusCB
*status_cb
,
3452 BDRVQcow2State
*s
= bs
->opaque
;
3453 int old_version
= s
->qcow_version
, new_version
= old_version
;
3454 uint64_t new_size
= 0;
3455 const char *backing_file
= NULL
, *backing_format
= NULL
;
3456 bool lazy_refcounts
= s
->use_lazy_refcounts
;
3457 const char *compat
= NULL
;
3458 uint64_t cluster_size
= s
->cluster_size
;
3461 int refcount_bits
= s
->refcount_bits
;
3462 Error
*local_err
= NULL
;
3464 QemuOptDesc
*desc
= opts
->list
->desc
;
3465 Qcow2AmendHelperCBInfo helper_cb_info
;
3467 while (desc
&& desc
->name
) {
3468 if (!qemu_opt_find(opts
, desc
->name
)) {
3469 /* only change explicitly defined options */
3474 if (!strcmp(desc
->name
, BLOCK_OPT_COMPAT_LEVEL
)) {
3475 compat
= qemu_opt_get(opts
, BLOCK_OPT_COMPAT_LEVEL
);
3477 /* preserve default */
3478 } else if (!strcmp(compat
, "0.10")) {
3480 } else if (!strcmp(compat
, "1.1")) {
3483 error_report("Unknown compatibility level %s", compat
);
3486 } else if (!strcmp(desc
->name
, BLOCK_OPT_PREALLOC
)) {
3487 error_report("Cannot change preallocation mode");
3489 } else if (!strcmp(desc
->name
, BLOCK_OPT_SIZE
)) {
3490 new_size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
3491 } else if (!strcmp(desc
->name
, BLOCK_OPT_BACKING_FILE
)) {
3492 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
3493 } else if (!strcmp(desc
->name
, BLOCK_OPT_BACKING_FMT
)) {
3494 backing_format
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
3495 } else if (!strcmp(desc
->name
, BLOCK_OPT_ENCRYPT
)) {
3496 encrypt
= qemu_opt_get_bool(opts
, BLOCK_OPT_ENCRYPT
,
3499 if (encrypt
!= !!s
->crypto
) {
3500 error_report("Changing the encryption flag is not supported");
3503 } else if (!strcmp(desc
->name
, BLOCK_OPT_ENCRYPT_FORMAT
)) {
3504 encformat
= qcow2_crypt_method_from_format(
3505 qemu_opt_get(opts
, BLOCK_OPT_ENCRYPT_FORMAT
));
3507 if (encformat
!= s
->crypt_method_header
) {
3508 error_report("Changing the encryption format is not supported");
3511 } else if (!strcmp(desc
->name
, BLOCK_OPT_CLUSTER_SIZE
)) {
3512 cluster_size
= qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
,
3514 if (cluster_size
!= s
->cluster_size
) {
3515 error_report("Changing the cluster size is not supported");
3518 } else if (!strcmp(desc
->name
, BLOCK_OPT_LAZY_REFCOUNTS
)) {
3519 lazy_refcounts
= qemu_opt_get_bool(opts
, BLOCK_OPT_LAZY_REFCOUNTS
,
3521 } else if (!strcmp(desc
->name
, BLOCK_OPT_REFCOUNT_BITS
)) {
3522 refcount_bits
= qemu_opt_get_number(opts
, BLOCK_OPT_REFCOUNT_BITS
,
3525 if (refcount_bits
<= 0 || refcount_bits
> 64 ||
3526 !is_power_of_2(refcount_bits
))
3528 error_report("Refcount width must be a power of two and may "
3529 "not exceed 64 bits");
3533 /* if this point is reached, this probably means a new option was
3534 * added without having it covered here */
3541 helper_cb_info
= (Qcow2AmendHelperCBInfo
){
3542 .original_status_cb
= status_cb
,
3543 .original_cb_opaque
= cb_opaque
,
3544 .total_operations
= (new_version
< old_version
)
3545 + (s
->refcount_bits
!= refcount_bits
)
3548 /* Upgrade first (some features may require compat=1.1) */
3549 if (new_version
> old_version
) {
3550 s
->qcow_version
= new_version
;
3551 ret
= qcow2_update_header(bs
);
3553 s
->qcow_version
= old_version
;
3558 if (s
->refcount_bits
!= refcount_bits
) {
3559 int refcount_order
= ctz32(refcount_bits
);
3561 if (new_version
< 3 && refcount_bits
!= 16) {
3562 error_report("Different refcount widths than 16 bits require "
3563 "compatibility level 1.1 or above (use compat=1.1 or "
3568 helper_cb_info
.current_operation
= QCOW2_CHANGING_REFCOUNT_ORDER
;
3569 ret
= qcow2_change_refcount_order(bs
, refcount_order
,
3570 &qcow2_amend_helper_cb
,
3571 &helper_cb_info
, &local_err
);
3573 error_report_err(local_err
);
3578 if (backing_file
|| backing_format
) {
3579 ret
= qcow2_change_backing_file(bs
,
3580 backing_file
?: s
->image_backing_file
,
3581 backing_format
?: s
->image_backing_format
);
3587 if (s
->use_lazy_refcounts
!= lazy_refcounts
) {
3588 if (lazy_refcounts
) {
3589 if (new_version
< 3) {
3590 error_report("Lazy refcounts only supported with compatibility "
3591 "level 1.1 and above (use compat=1.1 or greater)");
3594 s
->compatible_features
|= QCOW2_COMPAT_LAZY_REFCOUNTS
;
3595 ret
= qcow2_update_header(bs
);
3597 s
->compatible_features
&= ~QCOW2_COMPAT_LAZY_REFCOUNTS
;
3600 s
->use_lazy_refcounts
= true;
3602 /* make image clean first */
3603 ret
= qcow2_mark_clean(bs
);
3607 /* now disallow lazy refcounts */
3608 s
->compatible_features
&= ~QCOW2_COMPAT_LAZY_REFCOUNTS
;
3609 ret
= qcow2_update_header(bs
);
3611 s
->compatible_features
|= QCOW2_COMPAT_LAZY_REFCOUNTS
;
3614 s
->use_lazy_refcounts
= false;
3619 BlockBackend
*blk
= blk_new(BLK_PERM_RESIZE
, BLK_PERM_ALL
);
3620 ret
= blk_insert_bs(blk
, bs
, &local_err
);
3622 error_report_err(local_err
);
3627 ret
= blk_truncate(blk
, new_size
, &local_err
);
3630 error_report_err(local_err
);
3635 /* Downgrade last (so unsupported features can be removed before) */
3636 if (new_version
< old_version
) {
3637 helper_cb_info
.current_operation
= QCOW2_DOWNGRADING
;
3638 ret
= qcow2_downgrade(bs
, new_version
, &qcow2_amend_helper_cb
,
3649 * If offset or size are negative, respectively, they will not be included in
3650 * the BLOCK_IMAGE_CORRUPTED event emitted.
3651 * fatal will be ignored for read-only BDS; corruptions found there will always
3652 * be considered non-fatal.
3654 void qcow2_signal_corruption(BlockDriverState
*bs
, bool fatal
, int64_t offset
,
3655 int64_t size
, const char *message_format
, ...)
3657 BDRVQcow2State
*s
= bs
->opaque
;
3658 const char *node_name
;
3662 fatal
= fatal
&& !bs
->read_only
;
3664 if (s
->signaled_corruption
&&
3665 (!fatal
|| (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
)))
3670 va_start(ap
, message_format
);
3671 message
= g_strdup_vprintf(message_format
, ap
);
3675 fprintf(stderr
, "qcow2: Marking image as corrupt: %s; further "
3676 "corruption events will be suppressed\n", message
);
3678 fprintf(stderr
, "qcow2: Image is corrupt: %s; further non-fatal "
3679 "corruption events will be suppressed\n", message
);
3682 node_name
= bdrv_get_node_name(bs
);
3683 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs
),
3684 *node_name
!= '\0', node_name
,
3685 message
, offset
>= 0, offset
,
3687 fatal
, &error_abort
);
3691 qcow2_mark_corrupt(bs
);
3692 bs
->drv
= NULL
; /* make BDS unusable */
3695 s
->signaled_corruption
= true;
3698 static QemuOptsList qcow2_create_opts
= {
3699 .name
= "qcow2-create-opts",
3700 .head
= QTAILQ_HEAD_INITIALIZER(qcow2_create_opts
.head
),
3703 .name
= BLOCK_OPT_SIZE
,
3704 .type
= QEMU_OPT_SIZE
,
3705 .help
= "Virtual disk size"
3708 .name
= BLOCK_OPT_COMPAT_LEVEL
,
3709 .type
= QEMU_OPT_STRING
,
3710 .help
= "Compatibility level (0.10 or 1.1)"
3713 .name
= BLOCK_OPT_BACKING_FILE
,
3714 .type
= QEMU_OPT_STRING
,
3715 .help
= "File name of a base image"
3718 .name
= BLOCK_OPT_BACKING_FMT
,
3719 .type
= QEMU_OPT_STRING
,
3720 .help
= "Image format of the base image"
3723 .name
= BLOCK_OPT_ENCRYPT
,
3724 .type
= QEMU_OPT_BOOL
,
3725 .help
= "Encrypt the image with format 'aes'. (Deprecated "
3726 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT
"=aes)",
3729 .name
= BLOCK_OPT_ENCRYPT_FORMAT
,
3730 .type
= QEMU_OPT_STRING
,
3731 .help
= "Encrypt the image, format choices: 'aes', 'luks'",
3733 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
3734 "ID of secret providing qcow AES key or LUKS passphrase"),
3735 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."),
3736 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."),
3737 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."),
3738 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."),
3739 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."),
3740 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."),
3742 .name
= BLOCK_OPT_CLUSTER_SIZE
,
3743 .type
= QEMU_OPT_SIZE
,
3744 .help
= "qcow2 cluster size",
3745 .def_value_str
= stringify(DEFAULT_CLUSTER_SIZE
)
3748 .name
= BLOCK_OPT_PREALLOC
,
3749 .type
= QEMU_OPT_STRING
,
3750 .help
= "Preallocation mode (allowed values: off, metadata, "
3754 .name
= BLOCK_OPT_LAZY_REFCOUNTS
,
3755 .type
= QEMU_OPT_BOOL
,
3756 .help
= "Postpone refcount updates",
3757 .def_value_str
= "off"
3760 .name
= BLOCK_OPT_REFCOUNT_BITS
,
3761 .type
= QEMU_OPT_NUMBER
,
3762 .help
= "Width of a reference count entry in bits",
3763 .def_value_str
= "16"
3765 { /* end of list */ }
3769 BlockDriver bdrv_qcow2
= {
3770 .format_name
= "qcow2",
3771 .instance_size
= sizeof(BDRVQcow2State
),
3772 .bdrv_probe
= qcow2_probe
,
3773 .bdrv_open
= qcow2_open
,
3774 .bdrv_close
= qcow2_close
,
3775 .bdrv_reopen_prepare
= qcow2_reopen_prepare
,
3776 .bdrv_reopen_commit
= qcow2_reopen_commit
,
3777 .bdrv_reopen_abort
= qcow2_reopen_abort
,
3778 .bdrv_join_options
= qcow2_join_options
,
3779 .bdrv_child_perm
= bdrv_format_default_perms
,
3780 .bdrv_create
= qcow2_create
,
3781 .bdrv_has_zero_init
= bdrv_has_zero_init_1
,
3782 .bdrv_co_get_block_status
= qcow2_co_get_block_status
,
3784 .bdrv_co_preadv
= qcow2_co_preadv
,
3785 .bdrv_co_pwritev
= qcow2_co_pwritev
,
3786 .bdrv_co_flush_to_os
= qcow2_co_flush_to_os
,
3788 .bdrv_co_pwrite_zeroes
= qcow2_co_pwrite_zeroes
,
3789 .bdrv_co_pdiscard
= qcow2_co_pdiscard
,
3790 .bdrv_truncate
= qcow2_truncate
,
3791 .bdrv_co_pwritev_compressed
= qcow2_co_pwritev_compressed
,
3792 .bdrv_make_empty
= qcow2_make_empty
,
3794 .bdrv_snapshot_create
= qcow2_snapshot_create
,
3795 .bdrv_snapshot_goto
= qcow2_snapshot_goto
,
3796 .bdrv_snapshot_delete
= qcow2_snapshot_delete
,
3797 .bdrv_snapshot_list
= qcow2_snapshot_list
,
3798 .bdrv_snapshot_load_tmp
= qcow2_snapshot_load_tmp
,
3799 .bdrv_get_info
= qcow2_get_info
,
3800 .bdrv_get_specific_info
= qcow2_get_specific_info
,
3802 .bdrv_save_vmstate
= qcow2_save_vmstate
,
3803 .bdrv_load_vmstate
= qcow2_load_vmstate
,
3805 .supports_backing
= true,
3806 .bdrv_change_backing_file
= qcow2_change_backing_file
,
3808 .bdrv_refresh_limits
= qcow2_refresh_limits
,
3809 .bdrv_invalidate_cache
= qcow2_invalidate_cache
,
3810 .bdrv_inactivate
= qcow2_inactivate
,
3812 .create_opts
= &qcow2_create_opts
,
3813 .bdrv_check
= qcow2_check
,
3814 .bdrv_amend_options
= qcow2_amend_options
,
3816 .bdrv_detach_aio_context
= qcow2_detach_aio_context
,
3817 .bdrv_attach_aio_context
= qcow2_attach_aio_context
,
3820 static void bdrv_qcow2_init(void)
3822 bdrv_register(&bdrv_qcow2
);
3825 block_init(bdrv_qcow2_init
);