2 * Block driver for the QCOW version 2 format
4 * Copyright (c) 2004-2006 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 #include "qemu/osdep.h"
27 #include "block/qdict.h"
28 #include "sysemu/block-backend.h"
29 #include "qemu/main-loop.h"
30 #include "qemu/module.h"
32 #include "qemu/error-report.h"
33 #include "qapi/error.h"
34 #include "qapi/qapi-events-block-core.h"
35 #include "qapi/qmp/qdict.h"
36 #include "qapi/qmp/qstring.h"
38 #include "qemu/option_int.h"
39 #include "qemu/cutils.h"
40 #include "qemu/bswap.h"
41 #include "qapi/qobject-input-visitor.h"
42 #include "qapi/qapi-visit-block-core.h"
46 Differences with QCOW:
48 - Support for multiple incremental snapshots.
49 - Memory management by reference counts.
50 - Clusters which have a reference count of one have the bit
51 QCOW_OFLAG_COPIED to optimize write performance.
52 - Size of compressed clusters is stored in sectors to reduce bit usage
53 in the cluster offsets.
54 - Support for storing additional data (such as the VM state) in the
56 - If a backing store is used, the cluster size is not constrained
57 (could be backported to QCOW).
58 - L2 tables have always a size of one cluster.
65 } QEMU_PACKED QCowExtension
;
67 #define QCOW2_EXT_MAGIC_END 0
68 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
69 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
70 #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
71 #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875
72 #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441
74 static int coroutine_fn
75 qcow2_co_preadv_compressed(BlockDriverState
*bs
,
76 uint64_t file_cluster_offset
,
82 static int qcow2_probe(const uint8_t *buf
, int buf_size
, const char *filename
)
84 const QCowHeader
*cow_header
= (const void *)buf
;
86 if (buf_size
>= sizeof(QCowHeader
) &&
87 be32_to_cpu(cow_header
->magic
) == QCOW_MAGIC
&&
88 be32_to_cpu(cow_header
->version
) >= 2)
95 static ssize_t
qcow2_crypto_hdr_read_func(QCryptoBlock
*block
, size_t offset
,
96 uint8_t *buf
, size_t buflen
,
97 void *opaque
, Error
**errp
)
99 BlockDriverState
*bs
= opaque
;
100 BDRVQcow2State
*s
= bs
->opaque
;
103 if ((offset
+ buflen
) > s
->crypto_header
.length
) {
104 error_setg(errp
, "Request for data outside of extension header");
108 ret
= bdrv_pread(bs
->file
,
109 s
->crypto_header
.offset
+ offset
, buf
, buflen
);
111 error_setg_errno(errp
, -ret
, "Could not read encryption header");
118 static ssize_t
qcow2_crypto_hdr_init_func(QCryptoBlock
*block
, size_t headerlen
,
119 void *opaque
, Error
**errp
)
121 BlockDriverState
*bs
= opaque
;
122 BDRVQcow2State
*s
= bs
->opaque
;
126 ret
= qcow2_alloc_clusters(bs
, headerlen
);
128 error_setg_errno(errp
, -ret
,
129 "Cannot allocate cluster for LUKS header size %zu",
134 s
->crypto_header
.length
= headerlen
;
135 s
->crypto_header
.offset
= ret
;
137 /* Zero fill remaining space in cluster so it has predictable
138 * content in case of future spec changes */
139 clusterlen
= size_to_clusters(s
, headerlen
) * s
->cluster_size
;
140 assert(qcow2_pre_write_overlap_check(bs
, 0, ret
, clusterlen
, false) == 0);
141 ret
= bdrv_pwrite_zeroes(bs
->file
,
143 clusterlen
- headerlen
, 0);
145 error_setg_errno(errp
, -ret
, "Could not zero fill encryption header");
153 static ssize_t
qcow2_crypto_hdr_write_func(QCryptoBlock
*block
, size_t offset
,
154 const uint8_t *buf
, size_t buflen
,
155 void *opaque
, Error
**errp
)
157 BlockDriverState
*bs
= opaque
;
158 BDRVQcow2State
*s
= bs
->opaque
;
161 if ((offset
+ buflen
) > s
->crypto_header
.length
) {
162 error_setg(errp
, "Request for data outside of extension header");
166 ret
= bdrv_pwrite(bs
->file
,
167 s
->crypto_header
.offset
+ offset
, buf
, buflen
);
169 error_setg_errno(errp
, -ret
, "Could not read encryption header");
177 * read qcow2 extension and fill bs
178 * start reading from start_offset
179 * finish reading upon magic of value 0 or when end_offset reached
180 * unknown magic is skipped (future extension this version knows nothing about)
181 * return 0 upon success, non-0 otherwise
183 static int qcow2_read_extensions(BlockDriverState
*bs
, uint64_t start_offset
,
184 uint64_t end_offset
, void **p_feature_table
,
185 int flags
, bool *need_update_header
,
188 BDRVQcow2State
*s
= bs
->opaque
;
192 Qcow2BitmapHeaderExt bitmaps_ext
;
194 if (need_update_header
!= NULL
) {
195 *need_update_header
= false;
199 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset
, end_offset
);
201 offset
= start_offset
;
202 while (offset
< end_offset
) {
206 if (offset
> s
->cluster_size
)
207 printf("qcow2_read_extension: suspicious offset %lu\n", offset
);
209 printf("attempting to read extended header in offset %lu\n", offset
);
212 ret
= bdrv_pread(bs
->file
, offset
, &ext
, sizeof(ext
));
214 error_setg_errno(errp
, -ret
, "qcow2_read_extension: ERROR: "
215 "pread fail from offset %" PRIu64
, offset
);
218 ext
.magic
= be32_to_cpu(ext
.magic
);
219 ext
.len
= be32_to_cpu(ext
.len
);
220 offset
+= sizeof(ext
);
222 printf("ext.magic = 0x%x\n", ext
.magic
);
224 if (offset
> end_offset
|| ext
.len
> end_offset
- offset
) {
225 error_setg(errp
, "Header extension too large");
230 case QCOW2_EXT_MAGIC_END
:
233 case QCOW2_EXT_MAGIC_BACKING_FORMAT
:
234 if (ext
.len
>= sizeof(bs
->backing_format
)) {
235 error_setg(errp
, "ERROR: ext_backing_format: len=%" PRIu32
236 " too large (>=%zu)", ext
.len
,
237 sizeof(bs
->backing_format
));
240 ret
= bdrv_pread(bs
->file
, offset
, bs
->backing_format
, ext
.len
);
242 error_setg_errno(errp
, -ret
, "ERROR: ext_backing_format: "
243 "Could not read format name");
246 bs
->backing_format
[ext
.len
] = '\0';
247 s
->image_backing_format
= g_strdup(bs
->backing_format
);
249 printf("Qcow2: Got format extension %s\n", bs
->backing_format
);
253 case QCOW2_EXT_MAGIC_FEATURE_TABLE
:
254 if (p_feature_table
!= NULL
) {
255 void* feature_table
= g_malloc0(ext
.len
+ 2 * sizeof(Qcow2Feature
));
256 ret
= bdrv_pread(bs
->file
, offset
, feature_table
, ext
.len
);
258 error_setg_errno(errp
, -ret
, "ERROR: ext_feature_table: "
259 "Could not read table");
263 *p_feature_table
= feature_table
;
267 case QCOW2_EXT_MAGIC_CRYPTO_HEADER
: {
268 unsigned int cflags
= 0;
269 if (s
->crypt_method_header
!= QCOW_CRYPT_LUKS
) {
270 error_setg(errp
, "CRYPTO header extension only "
271 "expected with LUKS encryption method");
274 if (ext
.len
!= sizeof(Qcow2CryptoHeaderExtension
)) {
275 error_setg(errp
, "CRYPTO header extension size %u, "
276 "but expected size %zu", ext
.len
,
277 sizeof(Qcow2CryptoHeaderExtension
));
281 ret
= bdrv_pread(bs
->file
, offset
, &s
->crypto_header
, ext
.len
);
283 error_setg_errno(errp
, -ret
,
284 "Unable to read CRYPTO header extension");
287 s
->crypto_header
.offset
= be64_to_cpu(s
->crypto_header
.offset
);
288 s
->crypto_header
.length
= be64_to_cpu(s
->crypto_header
.length
);
290 if ((s
->crypto_header
.offset
% s
->cluster_size
) != 0) {
291 error_setg(errp
, "Encryption header offset '%" PRIu64
"' is "
292 "not a multiple of cluster size '%u'",
293 s
->crypto_header
.offset
, s
->cluster_size
);
297 if (flags
& BDRV_O_NO_IO
) {
298 cflags
|= QCRYPTO_BLOCK_OPEN_NO_IO
;
300 s
->crypto
= qcrypto_block_open(s
->crypto_opts
, "encrypt.",
301 qcow2_crypto_hdr_read_func
,
302 bs
, cflags
, QCOW2_MAX_THREADS
, errp
);
308 case QCOW2_EXT_MAGIC_BITMAPS
:
309 if (ext
.len
!= sizeof(bitmaps_ext
)) {
310 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
311 "Invalid extension length");
315 if (!(s
->autoclear_features
& QCOW2_AUTOCLEAR_BITMAPS
)) {
316 if (s
->qcow_version
< 3) {
317 /* Let's be a bit more specific */
318 warn_report("This qcow2 v2 image contains bitmaps, but "
319 "they may have been modified by a program "
320 "without persistent bitmap support; so now "
321 "they must all be considered inconsistent");
323 warn_report("a program lacking bitmap support "
324 "modified this file, so all bitmaps are now "
325 "considered inconsistent");
327 error_printf("Some clusters may be leaked, "
328 "run 'qemu-img check -r' on the image "
330 if (need_update_header
!= NULL
) {
331 /* Updating is needed to drop invalid bitmap extension. */
332 *need_update_header
= true;
337 ret
= bdrv_pread(bs
->file
, offset
, &bitmaps_ext
, ext
.len
);
339 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
340 "Could not read ext header");
344 if (bitmaps_ext
.reserved32
!= 0) {
345 error_setg_errno(errp
, -ret
, "bitmaps_ext: "
346 "Reserved field is not zero");
350 bitmaps_ext
.nb_bitmaps
= be32_to_cpu(bitmaps_ext
.nb_bitmaps
);
351 bitmaps_ext
.bitmap_directory_size
=
352 be64_to_cpu(bitmaps_ext
.bitmap_directory_size
);
353 bitmaps_ext
.bitmap_directory_offset
=
354 be64_to_cpu(bitmaps_ext
.bitmap_directory_offset
);
356 if (bitmaps_ext
.nb_bitmaps
> QCOW2_MAX_BITMAPS
) {
358 "bitmaps_ext: Image has %" PRIu32
" bitmaps, "
359 "exceeding the QEMU supported maximum of %d",
360 bitmaps_ext
.nb_bitmaps
, QCOW2_MAX_BITMAPS
);
364 if (bitmaps_ext
.nb_bitmaps
== 0) {
365 error_setg(errp
, "found bitmaps extension with zero bitmaps");
369 if (bitmaps_ext
.bitmap_directory_offset
& (s
->cluster_size
- 1)) {
370 error_setg(errp
, "bitmaps_ext: "
371 "invalid bitmap directory offset");
375 if (bitmaps_ext
.bitmap_directory_size
>
376 QCOW2_MAX_BITMAP_DIRECTORY_SIZE
) {
377 error_setg(errp
, "bitmaps_ext: "
378 "bitmap directory size (%" PRIu64
") exceeds "
379 "the maximum supported size (%d)",
380 bitmaps_ext
.bitmap_directory_size
,
381 QCOW2_MAX_BITMAP_DIRECTORY_SIZE
);
385 s
->nb_bitmaps
= bitmaps_ext
.nb_bitmaps
;
386 s
->bitmap_directory_offset
=
387 bitmaps_ext
.bitmap_directory_offset
;
388 s
->bitmap_directory_size
=
389 bitmaps_ext
.bitmap_directory_size
;
392 printf("Qcow2: Got bitmaps extension: "
393 "offset=%" PRIu64
" nb_bitmaps=%" PRIu32
"\n",
394 s
->bitmap_directory_offset
, s
->nb_bitmaps
);
398 case QCOW2_EXT_MAGIC_DATA_FILE
:
400 s
->image_data_file
= g_malloc0(ext
.len
+ 1);
401 ret
= bdrv_pread(bs
->file
, offset
, s
->image_data_file
, ext
.len
);
403 error_setg_errno(errp
, -ret
,
404 "ERROR: Could not read data file name");
408 printf("Qcow2: Got external data file %s\n", s
->image_data_file
);
414 /* unknown magic - save it in case we need to rewrite the header */
415 /* If you add a new feature, make sure to also update the fast
416 * path of qcow2_make_empty() to deal with it. */
418 Qcow2UnknownHeaderExtension
*uext
;
420 uext
= g_malloc0(sizeof(*uext
) + ext
.len
);
421 uext
->magic
= ext
.magic
;
423 QLIST_INSERT_HEAD(&s
->unknown_header_ext
, uext
, next
);
425 ret
= bdrv_pread(bs
->file
, offset
, uext
->data
, uext
->len
);
427 error_setg_errno(errp
, -ret
, "ERROR: unknown extension: "
428 "Could not read data");
435 offset
+= ((ext
.len
+ 7) & ~7);
441 static void cleanup_unknown_header_ext(BlockDriverState
*bs
)
443 BDRVQcow2State
*s
= bs
->opaque
;
444 Qcow2UnknownHeaderExtension
*uext
, *next
;
446 QLIST_FOREACH_SAFE(uext
, &s
->unknown_header_ext
, next
, next
) {
447 QLIST_REMOVE(uext
, next
);
452 static void report_unsupported_feature(Error
**errp
, Qcow2Feature
*table
,
455 char *features
= g_strdup("");
458 while (table
&& table
->name
[0] != '\0') {
459 if (table
->type
== QCOW2_FEAT_TYPE_INCOMPATIBLE
) {
460 if (mask
& (1ULL << table
->bit
)) {
462 features
= g_strdup_printf("%s%s%.46s", old
, *old
? ", " : "",
465 mask
&= ~(1ULL << table
->bit
);
473 features
= g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64
,
474 old
, *old
? ", " : "", mask
);
478 error_setg(errp
, "Unsupported qcow2 feature(s): %s", features
);
483 * Sets the dirty bit and flushes afterwards if necessary.
485 * The incompatible_features bit is only set if the image file header was
486 * updated successfully. Therefore it is not required to check the return
487 * value of this function.
489 int qcow2_mark_dirty(BlockDriverState
*bs
)
491 BDRVQcow2State
*s
= bs
->opaque
;
495 assert(s
->qcow_version
>= 3);
497 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
498 return 0; /* already dirty */
501 val
= cpu_to_be64(s
->incompatible_features
| QCOW2_INCOMPAT_DIRTY
);
502 ret
= bdrv_pwrite(bs
->file
, offsetof(QCowHeader
, incompatible_features
),
507 ret
= bdrv_flush(bs
->file
->bs
);
512 /* Only treat image as dirty if the header was updated successfully */
513 s
->incompatible_features
|= QCOW2_INCOMPAT_DIRTY
;
518 * Clears the dirty bit and flushes before if necessary. Only call this
519 * function when there are no pending requests, it does not guard against
520 * concurrent requests dirtying the image.
522 static int qcow2_mark_clean(BlockDriverState
*bs
)
524 BDRVQcow2State
*s
= bs
->opaque
;
526 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
529 s
->incompatible_features
&= ~QCOW2_INCOMPAT_DIRTY
;
531 ret
= qcow2_flush_caches(bs
);
536 return qcow2_update_header(bs
);
542 * Marks the image as corrupt.
544 int qcow2_mark_corrupt(BlockDriverState
*bs
)
546 BDRVQcow2State
*s
= bs
->opaque
;
548 s
->incompatible_features
|= QCOW2_INCOMPAT_CORRUPT
;
549 return qcow2_update_header(bs
);
553 * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes
554 * before if necessary.
556 int qcow2_mark_consistent(BlockDriverState
*bs
)
558 BDRVQcow2State
*s
= bs
->opaque
;
560 if (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
) {
561 int ret
= qcow2_flush_caches(bs
);
566 s
->incompatible_features
&= ~QCOW2_INCOMPAT_CORRUPT
;
567 return qcow2_update_header(bs
);
572 static int coroutine_fn
qcow2_co_check_locked(BlockDriverState
*bs
,
573 BdrvCheckResult
*result
,
576 int ret
= qcow2_check_refcounts(bs
, result
, fix
);
581 if (fix
&& result
->check_errors
== 0 && result
->corruptions
== 0) {
582 ret
= qcow2_mark_clean(bs
);
586 return qcow2_mark_consistent(bs
);
591 static int coroutine_fn
qcow2_co_check(BlockDriverState
*bs
,
592 BdrvCheckResult
*result
,
595 BDRVQcow2State
*s
= bs
->opaque
;
598 qemu_co_mutex_lock(&s
->lock
);
599 ret
= qcow2_co_check_locked(bs
, result
, fix
);
600 qemu_co_mutex_unlock(&s
->lock
);
604 int qcow2_validate_table(BlockDriverState
*bs
, uint64_t offset
,
605 uint64_t entries
, size_t entry_len
,
606 int64_t max_size_bytes
, const char *table_name
,
609 BDRVQcow2State
*s
= bs
->opaque
;
611 if (entries
> max_size_bytes
/ entry_len
) {
612 error_setg(errp
, "%s too large", table_name
);
616 /* Use signed INT64_MAX as the maximum even for uint64_t header fields,
617 * because values will be passed to qemu functions taking int64_t. */
618 if ((INT64_MAX
- entries
* entry_len
< offset
) ||
619 (offset_into_cluster(s
, offset
) != 0)) {
620 error_setg(errp
, "%s offset invalid", table_name
);
627 static const char *const mutable_opts
[] = {
628 QCOW2_OPT_LAZY_REFCOUNTS
,
629 QCOW2_OPT_DISCARD_REQUEST
,
630 QCOW2_OPT_DISCARD_SNAPSHOT
,
631 QCOW2_OPT_DISCARD_OTHER
,
633 QCOW2_OPT_OVERLAP_TEMPLATE
,
634 QCOW2_OPT_OVERLAP_MAIN_HEADER
,
635 QCOW2_OPT_OVERLAP_ACTIVE_L1
,
636 QCOW2_OPT_OVERLAP_ACTIVE_L2
,
637 QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
638 QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
639 QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
640 QCOW2_OPT_OVERLAP_INACTIVE_L1
,
641 QCOW2_OPT_OVERLAP_INACTIVE_L2
,
642 QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY
,
643 QCOW2_OPT_CACHE_SIZE
,
644 QCOW2_OPT_L2_CACHE_SIZE
,
645 QCOW2_OPT_L2_CACHE_ENTRY_SIZE
,
646 QCOW2_OPT_REFCOUNT_CACHE_SIZE
,
647 QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
651 static QemuOptsList qcow2_runtime_opts
= {
653 .head
= QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts
.head
),
656 .name
= QCOW2_OPT_LAZY_REFCOUNTS
,
657 .type
= QEMU_OPT_BOOL
,
658 .help
= "Postpone refcount updates",
661 .name
= QCOW2_OPT_DISCARD_REQUEST
,
662 .type
= QEMU_OPT_BOOL
,
663 .help
= "Pass guest discard requests to the layer below",
666 .name
= QCOW2_OPT_DISCARD_SNAPSHOT
,
667 .type
= QEMU_OPT_BOOL
,
668 .help
= "Generate discard requests when snapshot related space "
672 .name
= QCOW2_OPT_DISCARD_OTHER
,
673 .type
= QEMU_OPT_BOOL
,
674 .help
= "Generate discard requests when other clusters are freed",
677 .name
= QCOW2_OPT_OVERLAP
,
678 .type
= QEMU_OPT_STRING
,
679 .help
= "Selects which overlap checks to perform from a range of "
680 "templates (none, constant, cached, all)",
683 .name
= QCOW2_OPT_OVERLAP_TEMPLATE
,
684 .type
= QEMU_OPT_STRING
,
685 .help
= "Selects which overlap checks to perform from a range of "
686 "templates (none, constant, cached, all)",
689 .name
= QCOW2_OPT_OVERLAP_MAIN_HEADER
,
690 .type
= QEMU_OPT_BOOL
,
691 .help
= "Check for unintended writes into the main qcow2 header",
694 .name
= QCOW2_OPT_OVERLAP_ACTIVE_L1
,
695 .type
= QEMU_OPT_BOOL
,
696 .help
= "Check for unintended writes into the active L1 table",
699 .name
= QCOW2_OPT_OVERLAP_ACTIVE_L2
,
700 .type
= QEMU_OPT_BOOL
,
701 .help
= "Check for unintended writes into an active L2 table",
704 .name
= QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
705 .type
= QEMU_OPT_BOOL
,
706 .help
= "Check for unintended writes into the refcount table",
709 .name
= QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
710 .type
= QEMU_OPT_BOOL
,
711 .help
= "Check for unintended writes into a refcount block",
714 .name
= QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
715 .type
= QEMU_OPT_BOOL
,
716 .help
= "Check for unintended writes into the snapshot table",
719 .name
= QCOW2_OPT_OVERLAP_INACTIVE_L1
,
720 .type
= QEMU_OPT_BOOL
,
721 .help
= "Check for unintended writes into an inactive L1 table",
724 .name
= QCOW2_OPT_OVERLAP_INACTIVE_L2
,
725 .type
= QEMU_OPT_BOOL
,
726 .help
= "Check for unintended writes into an inactive L2 table",
729 .name
= QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY
,
730 .type
= QEMU_OPT_BOOL
,
731 .help
= "Check for unintended writes into the bitmap directory",
734 .name
= QCOW2_OPT_CACHE_SIZE
,
735 .type
= QEMU_OPT_SIZE
,
736 .help
= "Maximum combined metadata (L2 tables and refcount blocks) "
740 .name
= QCOW2_OPT_L2_CACHE_SIZE
,
741 .type
= QEMU_OPT_SIZE
,
742 .help
= "Maximum L2 table cache size",
745 .name
= QCOW2_OPT_L2_CACHE_ENTRY_SIZE
,
746 .type
= QEMU_OPT_SIZE
,
747 .help
= "Size of each entry in the L2 cache",
750 .name
= QCOW2_OPT_REFCOUNT_CACHE_SIZE
,
751 .type
= QEMU_OPT_SIZE
,
752 .help
= "Maximum refcount block cache size",
755 .name
= QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
756 .type
= QEMU_OPT_NUMBER
,
757 .help
= "Clean unused cache entries after this time (in seconds)",
759 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
760 "ID of secret providing qcow2 AES key or LUKS passphrase"),
761 { /* end of list */ }
765 static const char *overlap_bool_option_names
[QCOW2_OL_MAX_BITNR
] = {
766 [QCOW2_OL_MAIN_HEADER_BITNR
] = QCOW2_OPT_OVERLAP_MAIN_HEADER
,
767 [QCOW2_OL_ACTIVE_L1_BITNR
] = QCOW2_OPT_OVERLAP_ACTIVE_L1
,
768 [QCOW2_OL_ACTIVE_L2_BITNR
] = QCOW2_OPT_OVERLAP_ACTIVE_L2
,
769 [QCOW2_OL_REFCOUNT_TABLE_BITNR
] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
,
770 [QCOW2_OL_REFCOUNT_BLOCK_BITNR
] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
,
771 [QCOW2_OL_SNAPSHOT_TABLE_BITNR
] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
,
772 [QCOW2_OL_INACTIVE_L1_BITNR
] = QCOW2_OPT_OVERLAP_INACTIVE_L1
,
773 [QCOW2_OL_INACTIVE_L2_BITNR
] = QCOW2_OPT_OVERLAP_INACTIVE_L2
,
774 [QCOW2_OL_BITMAP_DIRECTORY_BITNR
] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY
,
777 static void cache_clean_timer_cb(void *opaque
)
779 BlockDriverState
*bs
= opaque
;
780 BDRVQcow2State
*s
= bs
->opaque
;
781 qcow2_cache_clean_unused(s
->l2_table_cache
);
782 qcow2_cache_clean_unused(s
->refcount_block_cache
);
783 timer_mod(s
->cache_clean_timer
, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
) +
784 (int64_t) s
->cache_clean_interval
* 1000);
787 static void cache_clean_timer_init(BlockDriverState
*bs
, AioContext
*context
)
789 BDRVQcow2State
*s
= bs
->opaque
;
790 if (s
->cache_clean_interval
> 0) {
791 s
->cache_clean_timer
= aio_timer_new(context
, QEMU_CLOCK_VIRTUAL
,
792 SCALE_MS
, cache_clean_timer_cb
,
794 timer_mod(s
->cache_clean_timer
, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL
) +
795 (int64_t) s
->cache_clean_interval
* 1000);
799 static void cache_clean_timer_del(BlockDriverState
*bs
)
801 BDRVQcow2State
*s
= bs
->opaque
;
802 if (s
->cache_clean_timer
) {
803 timer_del(s
->cache_clean_timer
);
804 timer_free(s
->cache_clean_timer
);
805 s
->cache_clean_timer
= NULL
;
809 static void qcow2_detach_aio_context(BlockDriverState
*bs
)
811 cache_clean_timer_del(bs
);
814 static void qcow2_attach_aio_context(BlockDriverState
*bs
,
815 AioContext
*new_context
)
817 cache_clean_timer_init(bs
, new_context
);
820 static void read_cache_sizes(BlockDriverState
*bs
, QemuOpts
*opts
,
821 uint64_t *l2_cache_size
,
822 uint64_t *l2_cache_entry_size
,
823 uint64_t *refcount_cache_size
, Error
**errp
)
825 BDRVQcow2State
*s
= bs
->opaque
;
826 uint64_t combined_cache_size
, l2_cache_max_setting
;
827 bool l2_cache_size_set
, refcount_cache_size_set
, combined_cache_size_set
;
828 bool l2_cache_entry_size_set
;
829 int min_refcount_cache
= MIN_REFCOUNT_CACHE_SIZE
* s
->cluster_size
;
830 uint64_t virtual_disk_size
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
831 uint64_t max_l2_entries
= DIV_ROUND_UP(virtual_disk_size
, s
->cluster_size
);
832 /* An L2 table is always one cluster in size so the max cache size
833 * should be a multiple of the cluster size. */
834 uint64_t max_l2_cache
= ROUND_UP(max_l2_entries
* sizeof(uint64_t),
837 combined_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_CACHE_SIZE
);
838 l2_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_L2_CACHE_SIZE
);
839 refcount_cache_size_set
= qemu_opt_get(opts
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
840 l2_cache_entry_size_set
= qemu_opt_get(opts
, QCOW2_OPT_L2_CACHE_ENTRY_SIZE
);
842 combined_cache_size
= qemu_opt_get_size(opts
, QCOW2_OPT_CACHE_SIZE
, 0);
843 l2_cache_max_setting
= qemu_opt_get_size(opts
, QCOW2_OPT_L2_CACHE_SIZE
,
844 DEFAULT_L2_CACHE_MAX_SIZE
);
845 *refcount_cache_size
= qemu_opt_get_size(opts
,
846 QCOW2_OPT_REFCOUNT_CACHE_SIZE
, 0);
848 *l2_cache_entry_size
= qemu_opt_get_size(
849 opts
, QCOW2_OPT_L2_CACHE_ENTRY_SIZE
, s
->cluster_size
);
851 *l2_cache_size
= MIN(max_l2_cache
, l2_cache_max_setting
);
853 if (combined_cache_size_set
) {
854 if (l2_cache_size_set
&& refcount_cache_size_set
) {
855 error_setg(errp
, QCOW2_OPT_CACHE_SIZE
", " QCOW2_OPT_L2_CACHE_SIZE
856 " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE
" may not be set "
859 } else if (l2_cache_size_set
&&
860 (l2_cache_max_setting
> combined_cache_size
)) {
861 error_setg(errp
, QCOW2_OPT_L2_CACHE_SIZE
" may not exceed "
862 QCOW2_OPT_CACHE_SIZE
);
864 } else if (*refcount_cache_size
> combined_cache_size
) {
865 error_setg(errp
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
" may not exceed "
866 QCOW2_OPT_CACHE_SIZE
);
870 if (l2_cache_size_set
) {
871 *refcount_cache_size
= combined_cache_size
- *l2_cache_size
;
872 } else if (refcount_cache_size_set
) {
873 *l2_cache_size
= combined_cache_size
- *refcount_cache_size
;
875 /* Assign as much memory as possible to the L2 cache, and
876 * use the remainder for the refcount cache */
877 if (combined_cache_size
>= max_l2_cache
+ min_refcount_cache
) {
878 *l2_cache_size
= max_l2_cache
;
879 *refcount_cache_size
= combined_cache_size
- *l2_cache_size
;
881 *refcount_cache_size
=
882 MIN(combined_cache_size
, min_refcount_cache
);
883 *l2_cache_size
= combined_cache_size
- *refcount_cache_size
;
889 * If the L2 cache is not enough to cover the whole disk then
890 * default to 4KB entries. Smaller entries reduce the cost of
891 * loads and evictions and increase I/O performance.
893 if (*l2_cache_size
< max_l2_cache
&& !l2_cache_entry_size_set
) {
894 *l2_cache_entry_size
= MIN(s
->cluster_size
, 4096);
897 /* l2_cache_size and refcount_cache_size are ensured to have at least
898 * their minimum values in qcow2_update_options_prepare() */
900 if (*l2_cache_entry_size
< (1 << MIN_CLUSTER_BITS
) ||
901 *l2_cache_entry_size
> s
->cluster_size
||
902 !is_power_of_2(*l2_cache_entry_size
)) {
903 error_setg(errp
, "L2 cache entry size must be a power of two "
904 "between %d and the cluster size (%d)",
905 1 << MIN_CLUSTER_BITS
, s
->cluster_size
);
910 typedef struct Qcow2ReopenState
{
911 Qcow2Cache
*l2_table_cache
;
912 Qcow2Cache
*refcount_block_cache
;
913 int l2_slice_size
; /* Number of entries in a slice of the L2 table */
914 bool use_lazy_refcounts
;
916 bool discard_passthrough
[QCOW2_DISCARD_MAX
];
917 uint64_t cache_clean_interval
;
918 QCryptoBlockOpenOptions
*crypto_opts
; /* Disk encryption runtime options */
921 static int qcow2_update_options_prepare(BlockDriverState
*bs
,
923 QDict
*options
, int flags
,
926 BDRVQcow2State
*s
= bs
->opaque
;
927 QemuOpts
*opts
= NULL
;
928 const char *opt_overlap_check
, *opt_overlap_check_template
;
929 int overlap_check_template
= 0;
930 uint64_t l2_cache_size
, l2_cache_entry_size
, refcount_cache_size
;
932 const char *encryptfmt
;
933 QDict
*encryptopts
= NULL
;
934 Error
*local_err
= NULL
;
937 qdict_extract_subqdict(options
, &encryptopts
, "encrypt.");
938 encryptfmt
= qdict_get_try_str(encryptopts
, "format");
940 opts
= qemu_opts_create(&qcow2_runtime_opts
, NULL
, 0, &error_abort
);
941 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
943 error_propagate(errp
, local_err
);
948 /* get L2 table/refcount block cache size from command line options */
949 read_cache_sizes(bs
, opts
, &l2_cache_size
, &l2_cache_entry_size
,
950 &refcount_cache_size
, &local_err
);
952 error_propagate(errp
, local_err
);
957 l2_cache_size
/= l2_cache_entry_size
;
958 if (l2_cache_size
< MIN_L2_CACHE_SIZE
) {
959 l2_cache_size
= MIN_L2_CACHE_SIZE
;
961 if (l2_cache_size
> INT_MAX
) {
962 error_setg(errp
, "L2 cache size too big");
967 refcount_cache_size
/= s
->cluster_size
;
968 if (refcount_cache_size
< MIN_REFCOUNT_CACHE_SIZE
) {
969 refcount_cache_size
= MIN_REFCOUNT_CACHE_SIZE
;
971 if (refcount_cache_size
> INT_MAX
) {
972 error_setg(errp
, "Refcount cache size too big");
977 /* alloc new L2 table/refcount block cache, flush old one */
978 if (s
->l2_table_cache
) {
979 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
981 error_setg_errno(errp
, -ret
, "Failed to flush the L2 table cache");
986 if (s
->refcount_block_cache
) {
987 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
989 error_setg_errno(errp
, -ret
,
990 "Failed to flush the refcount block cache");
995 r
->l2_slice_size
= l2_cache_entry_size
/ sizeof(uint64_t);
996 r
->l2_table_cache
= qcow2_cache_create(bs
, l2_cache_size
,
997 l2_cache_entry_size
);
998 r
->refcount_block_cache
= qcow2_cache_create(bs
, refcount_cache_size
,
1000 if (r
->l2_table_cache
== NULL
|| r
->refcount_block_cache
== NULL
) {
1001 error_setg(errp
, "Could not allocate metadata caches");
1006 /* New interval for cache cleanup timer */
1007 r
->cache_clean_interval
=
1008 qemu_opt_get_number(opts
, QCOW2_OPT_CACHE_CLEAN_INTERVAL
,
1009 DEFAULT_CACHE_CLEAN_INTERVAL
);
1010 #ifndef CONFIG_LINUX
1011 if (r
->cache_clean_interval
!= 0) {
1012 error_setg(errp
, QCOW2_OPT_CACHE_CLEAN_INTERVAL
1013 " not supported on this host");
1018 if (r
->cache_clean_interval
> UINT_MAX
) {
1019 error_setg(errp
, "Cache clean interval too big");
1024 /* lazy-refcounts; flush if going from enabled to disabled */
1025 r
->use_lazy_refcounts
= qemu_opt_get_bool(opts
, QCOW2_OPT_LAZY_REFCOUNTS
,
1026 (s
->compatible_features
& QCOW2_COMPAT_LAZY_REFCOUNTS
));
1027 if (r
->use_lazy_refcounts
&& s
->qcow_version
< 3) {
1028 error_setg(errp
, "Lazy refcounts require a qcow2 image with at least "
1029 "qemu 1.1 compatibility level");
1034 if (s
->use_lazy_refcounts
&& !r
->use_lazy_refcounts
) {
1035 ret
= qcow2_mark_clean(bs
);
1037 error_setg_errno(errp
, -ret
, "Failed to disable lazy refcounts");
1042 /* Overlap check options */
1043 opt_overlap_check
= qemu_opt_get(opts
, QCOW2_OPT_OVERLAP
);
1044 opt_overlap_check_template
= qemu_opt_get(opts
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1045 if (opt_overlap_check_template
&& opt_overlap_check
&&
1046 strcmp(opt_overlap_check_template
, opt_overlap_check
))
1048 error_setg(errp
, "Conflicting values for qcow2 options '"
1049 QCOW2_OPT_OVERLAP
"' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE
1050 "' ('%s')", opt_overlap_check
, opt_overlap_check_template
);
1054 if (!opt_overlap_check
) {
1055 opt_overlap_check
= opt_overlap_check_template
?: "cached";
1058 if (!strcmp(opt_overlap_check
, "none")) {
1059 overlap_check_template
= 0;
1060 } else if (!strcmp(opt_overlap_check
, "constant")) {
1061 overlap_check_template
= QCOW2_OL_CONSTANT
;
1062 } else if (!strcmp(opt_overlap_check
, "cached")) {
1063 overlap_check_template
= QCOW2_OL_CACHED
;
1064 } else if (!strcmp(opt_overlap_check
, "all")) {
1065 overlap_check_template
= QCOW2_OL_ALL
;
1067 error_setg(errp
, "Unsupported value '%s' for qcow2 option "
1068 "'overlap-check'. Allowed are any of the following: "
1069 "none, constant, cached, all", opt_overlap_check
);
1074 r
->overlap_check
= 0;
1075 for (i
= 0; i
< QCOW2_OL_MAX_BITNR
; i
++) {
1076 /* overlap-check defines a template bitmask, but every flag may be
1077 * overwritten through the associated boolean option */
1079 qemu_opt_get_bool(opts
, overlap_bool_option_names
[i
],
1080 overlap_check_template
& (1 << i
)) << i
;
1083 r
->discard_passthrough
[QCOW2_DISCARD_NEVER
] = false;
1084 r
->discard_passthrough
[QCOW2_DISCARD_ALWAYS
] = true;
1085 r
->discard_passthrough
[QCOW2_DISCARD_REQUEST
] =
1086 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_REQUEST
,
1087 flags
& BDRV_O_UNMAP
);
1088 r
->discard_passthrough
[QCOW2_DISCARD_SNAPSHOT
] =
1089 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_SNAPSHOT
, true);
1090 r
->discard_passthrough
[QCOW2_DISCARD_OTHER
] =
1091 qemu_opt_get_bool(opts
, QCOW2_OPT_DISCARD_OTHER
, false);
1093 switch (s
->crypt_method_header
) {
1094 case QCOW_CRYPT_NONE
:
1096 error_setg(errp
, "No encryption in image header, but options "
1097 "specified format '%s'", encryptfmt
);
1103 case QCOW_CRYPT_AES
:
1104 if (encryptfmt
&& !g_str_equal(encryptfmt
, "aes")) {
1106 "Header reported 'aes' encryption format but "
1107 "options specify '%s'", encryptfmt
);
1111 qdict_put_str(encryptopts
, "format", "qcow");
1112 r
->crypto_opts
= block_crypto_open_opts_init(encryptopts
, errp
);
1115 case QCOW_CRYPT_LUKS
:
1116 if (encryptfmt
&& !g_str_equal(encryptfmt
, "luks")) {
1118 "Header reported 'luks' encryption format but "
1119 "options specify '%s'", encryptfmt
);
1123 qdict_put_str(encryptopts
, "format", "luks");
1124 r
->crypto_opts
= block_crypto_open_opts_init(encryptopts
, errp
);
1128 error_setg(errp
, "Unsupported encryption method %d",
1129 s
->crypt_method_header
);
1132 if (s
->crypt_method_header
!= QCOW_CRYPT_NONE
&& !r
->crypto_opts
) {
1139 qobject_unref(encryptopts
);
1140 qemu_opts_del(opts
);
1145 static void qcow2_update_options_commit(BlockDriverState
*bs
,
1146 Qcow2ReopenState
*r
)
1148 BDRVQcow2State
*s
= bs
->opaque
;
1151 if (s
->l2_table_cache
) {
1152 qcow2_cache_destroy(s
->l2_table_cache
);
1154 if (s
->refcount_block_cache
) {
1155 qcow2_cache_destroy(s
->refcount_block_cache
);
1157 s
->l2_table_cache
= r
->l2_table_cache
;
1158 s
->refcount_block_cache
= r
->refcount_block_cache
;
1159 s
->l2_slice_size
= r
->l2_slice_size
;
1161 s
->overlap_check
= r
->overlap_check
;
1162 s
->use_lazy_refcounts
= r
->use_lazy_refcounts
;
1164 for (i
= 0; i
< QCOW2_DISCARD_MAX
; i
++) {
1165 s
->discard_passthrough
[i
] = r
->discard_passthrough
[i
];
1168 if (s
->cache_clean_interval
!= r
->cache_clean_interval
) {
1169 cache_clean_timer_del(bs
);
1170 s
->cache_clean_interval
= r
->cache_clean_interval
;
1171 cache_clean_timer_init(bs
, bdrv_get_aio_context(bs
));
1174 qapi_free_QCryptoBlockOpenOptions(s
->crypto_opts
);
1175 s
->crypto_opts
= r
->crypto_opts
;
1178 static void qcow2_update_options_abort(BlockDriverState
*bs
,
1179 Qcow2ReopenState
*r
)
1181 if (r
->l2_table_cache
) {
1182 qcow2_cache_destroy(r
->l2_table_cache
);
1184 if (r
->refcount_block_cache
) {
1185 qcow2_cache_destroy(r
->refcount_block_cache
);
1187 qapi_free_QCryptoBlockOpenOptions(r
->crypto_opts
);
1190 static int qcow2_update_options(BlockDriverState
*bs
, QDict
*options
,
1191 int flags
, Error
**errp
)
1193 Qcow2ReopenState r
= {};
1196 ret
= qcow2_update_options_prepare(bs
, &r
, options
, flags
, errp
);
1198 qcow2_update_options_commit(bs
, &r
);
1200 qcow2_update_options_abort(bs
, &r
);
1206 /* Called with s->lock held. */
1207 static int coroutine_fn
qcow2_do_open(BlockDriverState
*bs
, QDict
*options
,
1208 int flags
, Error
**errp
)
1210 BDRVQcow2State
*s
= bs
->opaque
;
1211 unsigned int len
, i
;
1214 Error
*local_err
= NULL
;
1216 uint64_t l1_vm_state_index
;
1217 bool update_header
= false;
1219 ret
= bdrv_pread(bs
->file
, 0, &header
, sizeof(header
));
1221 error_setg_errno(errp
, -ret
, "Could not read qcow2 header");
1224 header
.magic
= be32_to_cpu(header
.magic
);
1225 header
.version
= be32_to_cpu(header
.version
);
1226 header
.backing_file_offset
= be64_to_cpu(header
.backing_file_offset
);
1227 header
.backing_file_size
= be32_to_cpu(header
.backing_file_size
);
1228 header
.size
= be64_to_cpu(header
.size
);
1229 header
.cluster_bits
= be32_to_cpu(header
.cluster_bits
);
1230 header
.crypt_method
= be32_to_cpu(header
.crypt_method
);
1231 header
.l1_table_offset
= be64_to_cpu(header
.l1_table_offset
);
1232 header
.l1_size
= be32_to_cpu(header
.l1_size
);
1233 header
.refcount_table_offset
= be64_to_cpu(header
.refcount_table_offset
);
1234 header
.refcount_table_clusters
=
1235 be32_to_cpu(header
.refcount_table_clusters
);
1236 header
.snapshots_offset
= be64_to_cpu(header
.snapshots_offset
);
1237 header
.nb_snapshots
= be32_to_cpu(header
.nb_snapshots
);
1239 if (header
.magic
!= QCOW_MAGIC
) {
1240 error_setg(errp
, "Image is not in qcow2 format");
1244 if (header
.version
< 2 || header
.version
> 3) {
1245 error_setg(errp
, "Unsupported qcow2 version %" PRIu32
, header
.version
);
1250 s
->qcow_version
= header
.version
;
1252 /* Initialise cluster size */
1253 if (header
.cluster_bits
< MIN_CLUSTER_BITS
||
1254 header
.cluster_bits
> MAX_CLUSTER_BITS
) {
1255 error_setg(errp
, "Unsupported cluster size: 2^%" PRIu32
,
1256 header
.cluster_bits
);
1261 s
->cluster_bits
= header
.cluster_bits
;
1262 s
->cluster_size
= 1 << s
->cluster_bits
;
1264 /* Initialise version 3 header fields */
1265 if (header
.version
== 2) {
1266 header
.incompatible_features
= 0;
1267 header
.compatible_features
= 0;
1268 header
.autoclear_features
= 0;
1269 header
.refcount_order
= 4;
1270 header
.header_length
= 72;
1272 header
.incompatible_features
=
1273 be64_to_cpu(header
.incompatible_features
);
1274 header
.compatible_features
= be64_to_cpu(header
.compatible_features
);
1275 header
.autoclear_features
= be64_to_cpu(header
.autoclear_features
);
1276 header
.refcount_order
= be32_to_cpu(header
.refcount_order
);
1277 header
.header_length
= be32_to_cpu(header
.header_length
);
1279 if (header
.header_length
< 104) {
1280 error_setg(errp
, "qcow2 header too short");
1286 if (header
.header_length
> s
->cluster_size
) {
1287 error_setg(errp
, "qcow2 header exceeds cluster size");
1292 if (header
.header_length
> sizeof(header
)) {
1293 s
->unknown_header_fields_size
= header
.header_length
- sizeof(header
);
1294 s
->unknown_header_fields
= g_malloc(s
->unknown_header_fields_size
);
1295 ret
= bdrv_pread(bs
->file
, sizeof(header
), s
->unknown_header_fields
,
1296 s
->unknown_header_fields_size
);
1298 error_setg_errno(errp
, -ret
, "Could not read unknown qcow2 header "
1304 if (header
.backing_file_offset
> s
->cluster_size
) {
1305 error_setg(errp
, "Invalid backing file offset");
1310 if (header
.backing_file_offset
) {
1311 ext_end
= header
.backing_file_offset
;
1313 ext_end
= 1 << header
.cluster_bits
;
1316 /* Handle feature bits */
1317 s
->incompatible_features
= header
.incompatible_features
;
1318 s
->compatible_features
= header
.compatible_features
;
1319 s
->autoclear_features
= header
.autoclear_features
;
1321 if (s
->incompatible_features
& ~QCOW2_INCOMPAT_MASK
) {
1322 void *feature_table
= NULL
;
1323 qcow2_read_extensions(bs
, header
.header_length
, ext_end
,
1324 &feature_table
, flags
, NULL
, NULL
);
1325 report_unsupported_feature(errp
, feature_table
,
1326 s
->incompatible_features
&
1327 ~QCOW2_INCOMPAT_MASK
);
1329 g_free(feature_table
);
1333 if (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
) {
1334 /* Corrupt images may not be written to unless they are being repaired
1336 if ((flags
& BDRV_O_RDWR
) && !(flags
& BDRV_O_CHECK
)) {
1337 error_setg(errp
, "qcow2: Image is corrupt; cannot be opened "
1344 /* Check support for various header values */
1345 if (header
.refcount_order
> 6) {
1346 error_setg(errp
, "Reference count entry width too large; may not "
1351 s
->refcount_order
= header
.refcount_order
;
1352 s
->refcount_bits
= 1 << s
->refcount_order
;
1353 s
->refcount_max
= UINT64_C(1) << (s
->refcount_bits
- 1);
1354 s
->refcount_max
+= s
->refcount_max
- 1;
1356 s
->crypt_method_header
= header
.crypt_method
;
1357 if (s
->crypt_method_header
) {
1358 if (bdrv_uses_whitelist() &&
1359 s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1361 "Use of AES-CBC encrypted qcow2 images is no longer "
1362 "supported in system emulators");
1363 error_append_hint(errp
,
1364 "You can use 'qemu-img convert' to convert your "
1365 "image to an alternative supported format, such "
1366 "as unencrypted qcow2, or raw with the LUKS "
1367 "format instead.\n");
1372 if (s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1373 s
->crypt_physical_offset
= false;
1375 /* Assuming LUKS and any future crypt methods we
1376 * add will all use physical offsets, due to the
1377 * fact that the alternative is insecure... */
1378 s
->crypt_physical_offset
= true;
1381 bs
->encrypted
= true;
1384 s
->l2_bits
= s
->cluster_bits
- 3; /* L2 is always one cluster */
1385 s
->l2_size
= 1 << s
->l2_bits
;
1386 /* 2^(s->refcount_order - 3) is the refcount width in bytes */
1387 s
->refcount_block_bits
= s
->cluster_bits
- (s
->refcount_order
- 3);
1388 s
->refcount_block_size
= 1 << s
->refcount_block_bits
;
1389 bs
->total_sectors
= header
.size
/ BDRV_SECTOR_SIZE
;
1390 s
->csize_shift
= (62 - (s
->cluster_bits
- 8));
1391 s
->csize_mask
= (1 << (s
->cluster_bits
- 8)) - 1;
1392 s
->cluster_offset_mask
= (1LL << s
->csize_shift
) - 1;
1394 s
->refcount_table_offset
= header
.refcount_table_offset
;
1395 s
->refcount_table_size
=
1396 header
.refcount_table_clusters
<< (s
->cluster_bits
- 3);
1398 if (header
.refcount_table_clusters
== 0 && !(flags
& BDRV_O_CHECK
)) {
1399 error_setg(errp
, "Image does not contain a reference count table");
1404 ret
= qcow2_validate_table(bs
, s
->refcount_table_offset
,
1405 header
.refcount_table_clusters
,
1406 s
->cluster_size
, QCOW_MAX_REFTABLE_SIZE
,
1407 "Reference count table", errp
);
1412 /* The total size in bytes of the snapshot table is checked in
1413 * qcow2_read_snapshots() because the size of each snapshot is
1414 * variable and we don't know it yet.
1415 * Here we only check the offset and number of snapshots. */
1416 ret
= qcow2_validate_table(bs
, header
.snapshots_offset
,
1417 header
.nb_snapshots
,
1418 sizeof(QCowSnapshotHeader
),
1419 sizeof(QCowSnapshotHeader
) * QCOW_MAX_SNAPSHOTS
,
1420 "Snapshot table", errp
);
1425 /* read the level 1 table */
1426 ret
= qcow2_validate_table(bs
, header
.l1_table_offset
,
1427 header
.l1_size
, sizeof(uint64_t),
1428 QCOW_MAX_L1_SIZE
, "Active L1 table", errp
);
1432 s
->l1_size
= header
.l1_size
;
1433 s
->l1_table_offset
= header
.l1_table_offset
;
1435 l1_vm_state_index
= size_to_l1(s
, header
.size
);
1436 if (l1_vm_state_index
> INT_MAX
) {
1437 error_setg(errp
, "Image is too big");
1441 s
->l1_vm_state_index
= l1_vm_state_index
;
1443 /* the L1 table must contain at least enough entries to put
1444 header.size bytes */
1445 if (s
->l1_size
< s
->l1_vm_state_index
) {
1446 error_setg(errp
, "L1 table is too small");
1451 if (s
->l1_size
> 0) {
1452 s
->l1_table
= qemu_try_blockalign(bs
->file
->bs
,
1453 ROUND_UP(s
->l1_size
* sizeof(uint64_t), 512));
1454 if (s
->l1_table
== NULL
) {
1455 error_setg(errp
, "Could not allocate L1 table");
1459 ret
= bdrv_pread(bs
->file
, s
->l1_table_offset
, s
->l1_table
,
1460 s
->l1_size
* sizeof(uint64_t));
1462 error_setg_errno(errp
, -ret
, "Could not read L1 table");
1465 for(i
= 0;i
< s
->l1_size
; i
++) {
1466 s
->l1_table
[i
] = be64_to_cpu(s
->l1_table
[i
]);
1470 /* Parse driver-specific options */
1471 ret
= qcow2_update_options(bs
, options
, flags
, errp
);
1478 ret
= qcow2_refcount_init(bs
);
1480 error_setg_errno(errp
, -ret
, "Could not initialize refcount handling");
1484 QLIST_INIT(&s
->cluster_allocs
);
1485 QTAILQ_INIT(&s
->discards
);
1487 /* read qcow2 extensions */
1488 if (qcow2_read_extensions(bs
, header
.header_length
, ext_end
, NULL
,
1489 flags
, &update_header
, &local_err
)) {
1490 error_propagate(errp
, local_err
);
1495 /* Open external data file */
1496 s
->data_file
= bdrv_open_child(NULL
, options
, "data-file", bs
, &child_file
,
1499 error_propagate(errp
, local_err
);
1504 if (s
->incompatible_features
& QCOW2_INCOMPAT_DATA_FILE
) {
1505 if (!s
->data_file
&& s
->image_data_file
) {
1506 s
->data_file
= bdrv_open_child(s
->image_data_file
, options
,
1507 "data-file", bs
, &child_file
,
1509 if (!s
->data_file
) {
1514 if (!s
->data_file
) {
1515 error_setg(errp
, "'data-file' is required for this image");
1521 error_setg(errp
, "'data-file' can only be set for images with an "
1522 "external data file");
1527 s
->data_file
= bs
->file
;
1529 if (data_file_is_raw(bs
)) {
1530 error_setg(errp
, "data-file-raw requires a data file");
1536 /* qcow2_read_extension may have set up the crypto context
1537 * if the crypt method needs a header region, some methods
1538 * don't need header extensions, so must check here
1540 if (s
->crypt_method_header
&& !s
->crypto
) {
1541 if (s
->crypt_method_header
== QCOW_CRYPT_AES
) {
1542 unsigned int cflags
= 0;
1543 if (flags
& BDRV_O_NO_IO
) {
1544 cflags
|= QCRYPTO_BLOCK_OPEN_NO_IO
;
1546 s
->crypto
= qcrypto_block_open(s
->crypto_opts
, "encrypt.",
1548 QCOW2_MAX_THREADS
, errp
);
1553 } else if (!(flags
& BDRV_O_NO_IO
)) {
1554 error_setg(errp
, "Missing CRYPTO header for crypt method %d",
1555 s
->crypt_method_header
);
1561 /* read the backing file name */
1562 if (header
.backing_file_offset
!= 0) {
1563 len
= header
.backing_file_size
;
1564 if (len
> MIN(1023, s
->cluster_size
- header
.backing_file_offset
) ||
1565 len
>= sizeof(bs
->backing_file
)) {
1566 error_setg(errp
, "Backing file name too long");
1570 ret
= bdrv_pread(bs
->file
, header
.backing_file_offset
,
1571 bs
->auto_backing_file
, len
);
1573 error_setg_errno(errp
, -ret
, "Could not read backing file name");
1576 bs
->auto_backing_file
[len
] = '\0';
1577 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
),
1578 bs
->auto_backing_file
);
1579 s
->image_backing_file
= g_strdup(bs
->auto_backing_file
);
1582 /* Internal snapshots */
1583 s
->snapshots_offset
= header
.snapshots_offset
;
1584 s
->nb_snapshots
= header
.nb_snapshots
;
1586 ret
= qcow2_read_snapshots(bs
);
1588 error_setg_errno(errp
, -ret
, "Could not read snapshots");
1592 /* Clear unknown autoclear feature bits */
1593 update_header
|= s
->autoclear_features
& ~QCOW2_AUTOCLEAR_MASK
;
1595 update_header
&& !bs
->read_only
&& !(flags
& BDRV_O_INACTIVE
);
1596 if (update_header
) {
1597 s
->autoclear_features
&= QCOW2_AUTOCLEAR_MASK
;
1600 /* == Handle persistent dirty bitmaps ==
1602 * We want load dirty bitmaps in three cases:
1604 * 1. Normal open of the disk in active mode, not related to invalidation
1607 * 2. Invalidation of the target vm after pre-copy phase of migration, if
1608 * bitmaps are _not_ migrating through migration channel, i.e.
1609 * 'dirty-bitmaps' capability is disabled.
1611 * 3. Invalidation of source vm after failed or canceled migration.
1612 * This is a very interesting case. There are two possible types of
1615 * A. Stored on inactivation and removed. They should be loaded from the
1618 * B. Not stored: not-persistent bitmaps and bitmaps, migrated through
1619 * the migration channel (with dirty-bitmaps capability).
1621 * On the other hand, there are two possible sub-cases:
1623 * 3.1 disk was changed by somebody else while were inactive. In this
1624 * case all in-RAM dirty bitmaps (both persistent and not) are
1625 * definitely invalid. And we don't have any method to determine
1628 * Simple and safe thing is to just drop all the bitmaps of type B on
1629 * inactivation. But in this case we lose bitmaps in valid 4.2 case.
1631 * On the other hand, resuming source vm, if disk was already changed
1632 * is a bad thing anyway: not only bitmaps, the whole vm state is
1633 * out of sync with disk.
1635 * This means, that user or management tool, who for some reason
1636 * decided to resume source vm, after disk was already changed by
1637 * target vm, should at least drop all dirty bitmaps by hand.
1639 * So, we can ignore this case for now, but TODO: "generation"
1640 * extension for qcow2, to determine, that image was changed after
1641 * last inactivation. And if it is changed, we will drop (or at least
1642 * mark as 'invalid' all the bitmaps of type B, both persistent
1645 * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved
1646 * to disk ('dirty-bitmaps' capability disabled), or not saved
1647 * ('dirty-bitmaps' capability enabled), but we don't need to care
1648 * of: let's load bitmaps as always: stored bitmaps will be loaded,
1649 * and not stored has flag IN_USE=1 in the image and will be skipped
1652 * One remaining possible case when we don't want load bitmaps:
1654 * 4. Open disk in inactive mode in target vm (bitmaps are migrating or
1655 * will be loaded on invalidation, no needs try loading them before)
1658 if (!(bdrv_get_flags(bs
) & BDRV_O_INACTIVE
)) {
1659 /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */
1660 bool header_updated
= qcow2_load_dirty_bitmaps(bs
, &local_err
);
1662 update_header
= update_header
&& !header_updated
;
1664 if (local_err
!= NULL
) {
1665 error_propagate(errp
, local_err
);
1670 if (update_header
) {
1671 ret
= qcow2_update_header(bs
);
1673 error_setg_errno(errp
, -ret
, "Could not update qcow2 header");
1678 bs
->supported_zero_flags
= header
.version
>= 3 ? BDRV_REQ_MAY_UNMAP
: 0;
1680 /* Repair image if dirty */
1681 if (!(flags
& (BDRV_O_CHECK
| BDRV_O_INACTIVE
)) && !bs
->read_only
&&
1682 (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
)) {
1683 BdrvCheckResult result
= {0};
1685 ret
= qcow2_co_check_locked(bs
, &result
,
1686 BDRV_FIX_ERRORS
| BDRV_FIX_LEAKS
);
1687 if (ret
< 0 || result
.check_errors
) {
1691 error_setg_errno(errp
, -ret
, "Could not repair dirty image");
1698 BdrvCheckResult result
= {0};
1699 qcow2_check_refcounts(bs
, &result
, 0);
1703 qemu_co_queue_init(&s
->thread_task_queue
);
1708 g_free(s
->image_data_file
);
1709 if (has_data_file(bs
)) {
1710 bdrv_unref_child(bs
, s
->data_file
);
1712 g_free(s
->unknown_header_fields
);
1713 cleanup_unknown_header_ext(bs
);
1714 qcow2_free_snapshots(bs
);
1715 qcow2_refcount_close(bs
);
1716 qemu_vfree(s
->l1_table
);
1717 /* else pre-write overlap checks in cache_destroy may crash */
1719 cache_clean_timer_del(bs
);
1720 if (s
->l2_table_cache
) {
1721 qcow2_cache_destroy(s
->l2_table_cache
);
1723 if (s
->refcount_block_cache
) {
1724 qcow2_cache_destroy(s
->refcount_block_cache
);
1726 qcrypto_block_free(s
->crypto
);
1727 qapi_free_QCryptoBlockOpenOptions(s
->crypto_opts
);
1731 typedef struct QCow2OpenCo
{
1732 BlockDriverState
*bs
;
1739 static void coroutine_fn
qcow2_open_entry(void *opaque
)
1741 QCow2OpenCo
*qoc
= opaque
;
1742 BDRVQcow2State
*s
= qoc
->bs
->opaque
;
1744 qemu_co_mutex_lock(&s
->lock
);
1745 qoc
->ret
= qcow2_do_open(qoc
->bs
, qoc
->options
, qoc
->flags
, qoc
->errp
);
1746 qemu_co_mutex_unlock(&s
->lock
);
1749 static int qcow2_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
1752 BDRVQcow2State
*s
= bs
->opaque
;
1761 bs
->file
= bdrv_open_child(NULL
, options
, "file", bs
, &child_file
,
1767 /* Initialise locks */
1768 qemu_co_mutex_init(&s
->lock
);
1770 if (qemu_in_coroutine()) {
1771 /* From bdrv_co_create. */
1772 qcow2_open_entry(&qoc
);
1774 assert(qemu_get_current_aio_context() == qemu_get_aio_context());
1775 qemu_coroutine_enter(qemu_coroutine_create(qcow2_open_entry
, &qoc
));
1776 BDRV_POLL_WHILE(bs
, qoc
.ret
== -EINPROGRESS
);
1781 static void qcow2_refresh_limits(BlockDriverState
*bs
, Error
**errp
)
1783 BDRVQcow2State
*s
= bs
->opaque
;
1785 if (bs
->encrypted
) {
1786 /* Encryption works on a sector granularity */
1787 bs
->bl
.request_alignment
= qcrypto_block_get_sector_size(s
->crypto
);
1789 bs
->bl
.pwrite_zeroes_alignment
= s
->cluster_size
;
1790 bs
->bl
.pdiscard_alignment
= s
->cluster_size
;
1793 static int qcow2_reopen_prepare(BDRVReopenState
*state
,
1794 BlockReopenQueue
*queue
, Error
**errp
)
1796 Qcow2ReopenState
*r
;
1799 r
= g_new0(Qcow2ReopenState
, 1);
1802 ret
= qcow2_update_options_prepare(state
->bs
, r
, state
->options
,
1803 state
->flags
, errp
);
1808 /* We need to write out any unwritten data if we reopen read-only. */
1809 if ((state
->flags
& BDRV_O_RDWR
) == 0) {
1810 ret
= qcow2_reopen_bitmaps_ro(state
->bs
, errp
);
1815 ret
= bdrv_flush(state
->bs
);
1820 ret
= qcow2_mark_clean(state
->bs
);
1829 qcow2_update_options_abort(state
->bs
, r
);
1834 static void qcow2_reopen_commit(BDRVReopenState
*state
)
1836 qcow2_update_options_commit(state
->bs
, state
->opaque
);
1837 g_free(state
->opaque
);
1840 static void qcow2_reopen_abort(BDRVReopenState
*state
)
1842 qcow2_update_options_abort(state
->bs
, state
->opaque
);
1843 g_free(state
->opaque
);
1846 static void qcow2_join_options(QDict
*options
, QDict
*old_options
)
1848 bool has_new_overlap_template
=
1849 qdict_haskey(options
, QCOW2_OPT_OVERLAP
) ||
1850 qdict_haskey(options
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1851 bool has_new_total_cache_size
=
1852 qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
);
1853 bool has_all_cache_options
;
1855 /* New overlap template overrides all old overlap options */
1856 if (has_new_overlap_template
) {
1857 qdict_del(old_options
, QCOW2_OPT_OVERLAP
);
1858 qdict_del(old_options
, QCOW2_OPT_OVERLAP_TEMPLATE
);
1859 qdict_del(old_options
, QCOW2_OPT_OVERLAP_MAIN_HEADER
);
1860 qdict_del(old_options
, QCOW2_OPT_OVERLAP_ACTIVE_L1
);
1861 qdict_del(old_options
, QCOW2_OPT_OVERLAP_ACTIVE_L2
);
1862 qdict_del(old_options
, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE
);
1863 qdict_del(old_options
, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK
);
1864 qdict_del(old_options
, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE
);
1865 qdict_del(old_options
, QCOW2_OPT_OVERLAP_INACTIVE_L1
);
1866 qdict_del(old_options
, QCOW2_OPT_OVERLAP_INACTIVE_L2
);
1869 /* New total cache size overrides all old options */
1870 if (qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
)) {
1871 qdict_del(old_options
, QCOW2_OPT_L2_CACHE_SIZE
);
1872 qdict_del(old_options
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
1875 qdict_join(options
, old_options
, false);
1878 * If after merging all cache size options are set, an old total size is
1879 * overwritten. Do keep all options, however, if all three are new. The
1880 * resulting error message is what we want to happen.
1882 has_all_cache_options
=
1883 qdict_haskey(options
, QCOW2_OPT_CACHE_SIZE
) ||
1884 qdict_haskey(options
, QCOW2_OPT_L2_CACHE_SIZE
) ||
1885 qdict_haskey(options
, QCOW2_OPT_REFCOUNT_CACHE_SIZE
);
1887 if (has_all_cache_options
&& !has_new_total_cache_size
) {
1888 qdict_del(options
, QCOW2_OPT_CACHE_SIZE
);
1892 static int coroutine_fn
qcow2_co_block_status(BlockDriverState
*bs
,
1894 int64_t offset
, int64_t count
,
1895 int64_t *pnum
, int64_t *map
,
1896 BlockDriverState
**file
)
1898 BDRVQcow2State
*s
= bs
->opaque
;
1899 uint64_t cluster_offset
;
1900 int index_in_cluster
, ret
;
1904 if (!s
->metadata_preallocation_checked
) {
1905 ret
= qcow2_detect_metadata_preallocation(bs
);
1906 s
->metadata_preallocation
= (ret
== 1);
1907 s
->metadata_preallocation_checked
= true;
1910 bytes
= MIN(INT_MAX
, count
);
1911 qemu_co_mutex_lock(&s
->lock
);
1912 ret
= qcow2_get_cluster_offset(bs
, offset
, &bytes
, &cluster_offset
);
1913 qemu_co_mutex_unlock(&s
->lock
);
1920 if ((ret
== QCOW2_CLUSTER_NORMAL
|| ret
== QCOW2_CLUSTER_ZERO_ALLOC
) &&
1922 index_in_cluster
= offset
& (s
->cluster_size
- 1);
1923 *map
= cluster_offset
| index_in_cluster
;
1924 *file
= s
->data_file
->bs
;
1925 status
|= BDRV_BLOCK_OFFSET_VALID
;
1927 if (ret
== QCOW2_CLUSTER_ZERO_PLAIN
|| ret
== QCOW2_CLUSTER_ZERO_ALLOC
) {
1928 status
|= BDRV_BLOCK_ZERO
;
1929 } else if (ret
!= QCOW2_CLUSTER_UNALLOCATED
) {
1930 status
|= BDRV_BLOCK_DATA
;
1932 if (s
->metadata_preallocation
&& (status
& BDRV_BLOCK_DATA
) &&
1933 (status
& BDRV_BLOCK_OFFSET_VALID
))
1935 status
|= BDRV_BLOCK_RECURSE
;
1940 static coroutine_fn
int qcow2_handle_l2meta(BlockDriverState
*bs
,
1941 QCowL2Meta
**pl2meta
,
1945 QCowL2Meta
*l2meta
= *pl2meta
;
1947 while (l2meta
!= NULL
) {
1951 ret
= qcow2_alloc_cluster_link_l2(bs
, l2meta
);
1956 qcow2_alloc_cluster_abort(bs
, l2meta
);
1959 /* Take the request off the list of running requests */
1960 if (l2meta
->nb_clusters
!= 0) {
1961 QLIST_REMOVE(l2meta
, next_in_flight
);
1964 qemu_co_queue_restart_all(&l2meta
->dependent_requests
);
1966 next
= l2meta
->next
;
1975 static coroutine_fn
int qcow2_co_preadv_part(BlockDriverState
*bs
,
1976 uint64_t offset
, uint64_t bytes
,
1978 size_t qiov_offset
, int flags
)
1980 BDRVQcow2State
*s
= bs
->opaque
;
1981 int offset_in_cluster
;
1983 unsigned int cur_bytes
; /* number of bytes in current iteration */
1984 uint64_t cluster_offset
= 0;
1985 uint8_t *cluster_data
= NULL
;
1987 while (bytes
!= 0) {
1989 /* prepare next request */
1990 cur_bytes
= MIN(bytes
, INT_MAX
);
1992 cur_bytes
= MIN(cur_bytes
,
1993 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
1996 qemu_co_mutex_lock(&s
->lock
);
1997 ret
= qcow2_get_cluster_offset(bs
, offset
, &cur_bytes
, &cluster_offset
);
1998 qemu_co_mutex_unlock(&s
->lock
);
2003 offset_in_cluster
= offset_into_cluster(s
, offset
);
2006 case QCOW2_CLUSTER_UNALLOCATED
:
2009 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_BACKING_AIO
);
2010 ret
= bdrv_co_preadv_part(bs
->backing
, offset
, cur_bytes
,
2011 qiov
, qiov_offset
, 0);
2016 /* Note: in this case, no need to wait */
2017 qemu_iovec_memset(qiov
, qiov_offset
, 0, cur_bytes
);
2021 case QCOW2_CLUSTER_ZERO_PLAIN
:
2022 case QCOW2_CLUSTER_ZERO_ALLOC
:
2023 qemu_iovec_memset(qiov
, qiov_offset
, 0, cur_bytes
);
2026 case QCOW2_CLUSTER_COMPRESSED
:
2027 ret
= qcow2_co_preadv_compressed(bs
, cluster_offset
,
2036 case QCOW2_CLUSTER_NORMAL
:
2037 if ((cluster_offset
& 511) != 0) {
2042 if (bs
->encrypted
) {
2046 * For encrypted images, read everything into a temporary
2047 * contiguous buffer on which the AES functions can work.
2049 if (!cluster_data
) {
2051 qemu_try_blockalign(s
->data_file
->bs
,
2052 QCOW_MAX_CRYPT_CLUSTERS
2054 if (cluster_data
== NULL
) {
2060 assert(cur_bytes
<= QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
2062 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
2063 ret
= bdrv_co_pread(s
->data_file
,
2064 cluster_offset
+ offset_in_cluster
,
2065 cur_bytes
, cluster_data
, 0);
2070 assert((offset
& (BDRV_SECTOR_SIZE
- 1)) == 0);
2071 assert((cur_bytes
& (BDRV_SECTOR_SIZE
- 1)) == 0);
2072 if (qcow2_co_decrypt(bs
, cluster_offset
, offset
,
2073 cluster_data
, cur_bytes
) < 0) {
2077 qemu_iovec_from_buf(qiov
, qiov_offset
, cluster_data
, cur_bytes
);
2079 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
2080 ret
= bdrv_co_preadv_part(s
->data_file
,
2081 cluster_offset
+ offset_in_cluster
,
2082 cur_bytes
, qiov
, qiov_offset
, 0);
2090 g_assert_not_reached();
2096 offset
+= cur_bytes
;
2097 qiov_offset
+= cur_bytes
;
2102 qemu_vfree(cluster_data
);
2107 /* Check if it's possible to merge a write request with the writing of
2108 * the data from the COW regions */
2109 static bool merge_cow(uint64_t offset
, unsigned bytes
,
2110 QEMUIOVector
*qiov
, size_t qiov_offset
,
2115 for (m
= l2meta
; m
!= NULL
; m
= m
->next
) {
2116 /* If both COW regions are empty then there's nothing to merge */
2117 if (m
->cow_start
.nb_bytes
== 0 && m
->cow_end
.nb_bytes
== 0) {
2121 /* If COW regions are handled already, skip this too */
2126 /* The data (middle) region must be immediately after the
2128 if (l2meta_cow_start(m
) + m
->cow_start
.nb_bytes
!= offset
) {
2132 /* The end region must be immediately after the data (middle)
2134 if (m
->offset
+ m
->cow_end
.offset
!= offset
+ bytes
) {
2138 /* Make sure that adding both COW regions to the QEMUIOVector
2139 * does not exceed IOV_MAX */
2140 if (qemu_iovec_subvec_niov(qiov
, qiov_offset
, bytes
) > IOV_MAX
- 2) {
2144 m
->data_qiov
= qiov
;
2145 m
->data_qiov_offset
= qiov_offset
;
2152 static bool is_unallocated(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
)
2156 (!bdrv_is_allocated_above(bs
, NULL
, false, offset
, bytes
, &nr
) &&
2160 static bool is_zero_cow(BlockDriverState
*bs
, QCowL2Meta
*m
)
2163 * This check is designed for optimization shortcut so it must be
2165 * Instead of is_zero(), use is_unallocated() as it is faster (but not
2166 * as accurate and can result in false negatives).
2168 return is_unallocated(bs
, m
->offset
+ m
->cow_start
.offset
,
2169 m
->cow_start
.nb_bytes
) &&
2170 is_unallocated(bs
, m
->offset
+ m
->cow_end
.offset
,
2171 m
->cow_end
.nb_bytes
);
2174 static int handle_alloc_space(BlockDriverState
*bs
, QCowL2Meta
*l2meta
)
2176 BDRVQcow2State
*s
= bs
->opaque
;
2179 if (!(s
->data_file
->bs
->supported_zero_flags
& BDRV_REQ_NO_FALLBACK
)) {
2183 if (bs
->encrypted
) {
2187 for (m
= l2meta
; m
!= NULL
; m
= m
->next
) {
2190 if (!m
->cow_start
.nb_bytes
&& !m
->cow_end
.nb_bytes
) {
2194 if (!is_zero_cow(bs
, m
)) {
2199 * instead of writing zero COW buffers,
2200 * efficiently zero out the whole clusters
2203 ret
= qcow2_pre_write_overlap_check(bs
, 0, m
->alloc_offset
,
2204 m
->nb_clusters
* s
->cluster_size
,
2210 BLKDBG_EVENT(bs
->file
, BLKDBG_CLUSTER_ALLOC_SPACE
);
2211 ret
= bdrv_co_pwrite_zeroes(s
->data_file
, m
->alloc_offset
,
2212 m
->nb_clusters
* s
->cluster_size
,
2213 BDRV_REQ_NO_FALLBACK
);
2215 if (ret
!= -ENOTSUP
&& ret
!= -EAGAIN
) {
2221 trace_qcow2_skip_cow(qemu_coroutine_self(), m
->offset
, m
->nb_clusters
);
2227 static coroutine_fn
int qcow2_co_pwritev_part(
2228 BlockDriverState
*bs
, uint64_t offset
, uint64_t bytes
,
2229 QEMUIOVector
*qiov
, size_t qiov_offset
, int flags
)
2231 BDRVQcow2State
*s
= bs
->opaque
;
2232 int offset_in_cluster
;
2234 unsigned int cur_bytes
; /* number of sectors in current iteration */
2235 uint64_t cluster_offset
;
2236 QEMUIOVector encrypted_qiov
;
2237 uint64_t bytes_done
= 0;
2238 uint8_t *cluster_data
= NULL
;
2239 QCowL2Meta
*l2meta
= NULL
;
2241 trace_qcow2_writev_start_req(qemu_coroutine_self(), offset
, bytes
);
2243 qemu_co_mutex_lock(&s
->lock
);
2245 while (bytes
!= 0) {
2249 trace_qcow2_writev_start_part(qemu_coroutine_self());
2250 offset_in_cluster
= offset_into_cluster(s
, offset
);
2251 cur_bytes
= MIN(bytes
, INT_MAX
);
2252 if (bs
->encrypted
) {
2253 cur_bytes
= MIN(cur_bytes
,
2254 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
2255 - offset_in_cluster
);
2258 ret
= qcow2_alloc_cluster_offset(bs
, offset
, &cur_bytes
,
2259 &cluster_offset
, &l2meta
);
2264 assert((cluster_offset
& 511) == 0);
2266 ret
= qcow2_pre_write_overlap_check(bs
, 0,
2267 cluster_offset
+ offset_in_cluster
,
2273 qemu_co_mutex_unlock(&s
->lock
);
2275 if (bs
->encrypted
) {
2277 if (!cluster_data
) {
2278 cluster_data
= qemu_try_blockalign(bs
->file
->bs
,
2279 QCOW_MAX_CRYPT_CLUSTERS
2281 if (cluster_data
== NULL
) {
2287 assert(cur_bytes
<= QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
2288 qemu_iovec_to_buf(qiov
, qiov_offset
+ bytes_done
,
2289 cluster_data
, cur_bytes
);
2291 if (qcow2_co_encrypt(bs
, cluster_offset
, offset
,
2292 cluster_data
, cur_bytes
) < 0) {
2297 qemu_iovec_init_buf(&encrypted_qiov
, cluster_data
, cur_bytes
);
2300 /* Try to efficiently initialize the physical space with zeroes */
2301 ret
= handle_alloc_space(bs
, l2meta
);
2306 /* If we need to do COW, check if it's possible to merge the
2307 * writing of the guest data together with that of the COW regions.
2308 * If it's not possible (or not necessary) then write the
2309 * guest data now. */
2310 if (!merge_cow(offset
, cur_bytes
,
2311 bs
->encrypted
? &encrypted_qiov
: qiov
,
2312 bs
->encrypted
? 0 : qiov_offset
+ bytes_done
, l2meta
))
2314 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_AIO
);
2315 trace_qcow2_writev_data(qemu_coroutine_self(),
2316 cluster_offset
+ offset_in_cluster
);
2317 ret
= bdrv_co_pwritev_part(
2318 s
->data_file
, cluster_offset
+ offset_in_cluster
, cur_bytes
,
2319 bs
->encrypted
? &encrypted_qiov
: qiov
,
2320 bs
->encrypted
? 0 : qiov_offset
+ bytes_done
, 0);
2326 qemu_co_mutex_lock(&s
->lock
);
2328 ret
= qcow2_handle_l2meta(bs
, &l2meta
, true);
2334 offset
+= cur_bytes
;
2335 bytes_done
+= cur_bytes
;
2336 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes
);
2342 qemu_co_mutex_lock(&s
->lock
);
2345 qcow2_handle_l2meta(bs
, &l2meta
, false);
2347 qemu_co_mutex_unlock(&s
->lock
);
2349 qemu_vfree(cluster_data
);
2350 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret
);
2355 static int qcow2_inactivate(BlockDriverState
*bs
)
2357 BDRVQcow2State
*s
= bs
->opaque
;
2358 int ret
, result
= 0;
2359 Error
*local_err
= NULL
;
2361 qcow2_store_persistent_dirty_bitmaps(bs
, &local_err
);
2362 if (local_err
!= NULL
) {
2364 error_reportf_err(local_err
, "Lost persistent bitmaps during "
2365 "inactivation of node '%s': ",
2366 bdrv_get_device_or_node_name(bs
));
2369 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
2372 error_report("Failed to flush the L2 table cache: %s",
2376 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
2379 error_report("Failed to flush the refcount block cache: %s",
2384 qcow2_mark_clean(bs
);
2390 static void qcow2_close(BlockDriverState
*bs
)
2392 BDRVQcow2State
*s
= bs
->opaque
;
2393 qemu_vfree(s
->l1_table
);
2394 /* else pre-write overlap checks in cache_destroy may crash */
2397 if (!(s
->flags
& BDRV_O_INACTIVE
)) {
2398 qcow2_inactivate(bs
);
2401 cache_clean_timer_del(bs
);
2402 qcow2_cache_destroy(s
->l2_table_cache
);
2403 qcow2_cache_destroy(s
->refcount_block_cache
);
2405 qcrypto_block_free(s
->crypto
);
2408 g_free(s
->unknown_header_fields
);
2409 cleanup_unknown_header_ext(bs
);
2411 g_free(s
->image_data_file
);
2412 g_free(s
->image_backing_file
);
2413 g_free(s
->image_backing_format
);
2415 if (has_data_file(bs
)) {
2416 bdrv_unref_child(bs
, s
->data_file
);
2419 qcow2_refcount_close(bs
);
2420 qcow2_free_snapshots(bs
);
2423 static void coroutine_fn
qcow2_co_invalidate_cache(BlockDriverState
*bs
,
2426 BDRVQcow2State
*s
= bs
->opaque
;
2427 int flags
= s
->flags
;
2428 QCryptoBlock
*crypto
= NULL
;
2430 Error
*local_err
= NULL
;
2434 * Backing files are read-only which makes all of their metadata immutable,
2435 * that means we don't have to worry about reopening them here.
2443 memset(s
, 0, sizeof(BDRVQcow2State
));
2444 options
= qdict_clone_shallow(bs
->options
);
2446 flags
&= ~BDRV_O_INACTIVE
;
2447 qemu_co_mutex_lock(&s
->lock
);
2448 ret
= qcow2_do_open(bs
, options
, flags
, &local_err
);
2449 qemu_co_mutex_unlock(&s
->lock
);
2450 qobject_unref(options
);
2452 error_propagate_prepend(errp
, local_err
,
2453 "Could not reopen qcow2 layer: ");
2456 } else if (ret
< 0) {
2457 error_setg_errno(errp
, -ret
, "Could not reopen qcow2 layer");
2465 static size_t header_ext_add(char *buf
, uint32_t magic
, const void *s
,
2466 size_t len
, size_t buflen
)
2468 QCowExtension
*ext_backing_fmt
= (QCowExtension
*) buf
;
2469 size_t ext_len
= sizeof(QCowExtension
) + ((len
+ 7) & ~7);
2471 if (buflen
< ext_len
) {
2475 *ext_backing_fmt
= (QCowExtension
) {
2476 .magic
= cpu_to_be32(magic
),
2477 .len
= cpu_to_be32(len
),
2481 memcpy(buf
+ sizeof(QCowExtension
), s
, len
);
2488 * Updates the qcow2 header, including the variable length parts of it, i.e.
2489 * the backing file name and all extensions. qcow2 was not designed to allow
2490 * such changes, so if we run out of space (we can only use the first cluster)
2491 * this function may fail.
2493 * Returns 0 on success, -errno in error cases.
2495 int qcow2_update_header(BlockDriverState
*bs
)
2497 BDRVQcow2State
*s
= bs
->opaque
;
2500 size_t buflen
= s
->cluster_size
;
2502 uint64_t total_size
;
2503 uint32_t refcount_table_clusters
;
2504 size_t header_length
;
2505 Qcow2UnknownHeaderExtension
*uext
;
2507 buf
= qemu_blockalign(bs
, buflen
);
2509 /* Header structure */
2510 header
= (QCowHeader
*) buf
;
2512 if (buflen
< sizeof(*header
)) {
2517 header_length
= sizeof(*header
) + s
->unknown_header_fields_size
;
2518 total_size
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
2519 refcount_table_clusters
= s
->refcount_table_size
>> (s
->cluster_bits
- 3);
2521 *header
= (QCowHeader
) {
2522 /* Version 2 fields */
2523 .magic
= cpu_to_be32(QCOW_MAGIC
),
2524 .version
= cpu_to_be32(s
->qcow_version
),
2525 .backing_file_offset
= 0,
2526 .backing_file_size
= 0,
2527 .cluster_bits
= cpu_to_be32(s
->cluster_bits
),
2528 .size
= cpu_to_be64(total_size
),
2529 .crypt_method
= cpu_to_be32(s
->crypt_method_header
),
2530 .l1_size
= cpu_to_be32(s
->l1_size
),
2531 .l1_table_offset
= cpu_to_be64(s
->l1_table_offset
),
2532 .refcount_table_offset
= cpu_to_be64(s
->refcount_table_offset
),
2533 .refcount_table_clusters
= cpu_to_be32(refcount_table_clusters
),
2534 .nb_snapshots
= cpu_to_be32(s
->nb_snapshots
),
2535 .snapshots_offset
= cpu_to_be64(s
->snapshots_offset
),
2537 /* Version 3 fields */
2538 .incompatible_features
= cpu_to_be64(s
->incompatible_features
),
2539 .compatible_features
= cpu_to_be64(s
->compatible_features
),
2540 .autoclear_features
= cpu_to_be64(s
->autoclear_features
),
2541 .refcount_order
= cpu_to_be32(s
->refcount_order
),
2542 .header_length
= cpu_to_be32(header_length
),
2545 /* For older versions, write a shorter header */
2546 switch (s
->qcow_version
) {
2548 ret
= offsetof(QCowHeader
, incompatible_features
);
2551 ret
= sizeof(*header
);
2560 memset(buf
, 0, buflen
);
2562 /* Preserve any unknown field in the header */
2563 if (s
->unknown_header_fields_size
) {
2564 if (buflen
< s
->unknown_header_fields_size
) {
2569 memcpy(buf
, s
->unknown_header_fields
, s
->unknown_header_fields_size
);
2570 buf
+= s
->unknown_header_fields_size
;
2571 buflen
-= s
->unknown_header_fields_size
;
2574 /* Backing file format header extension */
2575 if (s
->image_backing_format
) {
2576 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_BACKING_FORMAT
,
2577 s
->image_backing_format
,
2578 strlen(s
->image_backing_format
),
2588 /* External data file header extension */
2589 if (has_data_file(bs
) && s
->image_data_file
) {
2590 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_DATA_FILE
,
2591 s
->image_data_file
, strlen(s
->image_data_file
),
2601 /* Full disk encryption header pointer extension */
2602 if (s
->crypto_header
.offset
!= 0) {
2603 s
->crypto_header
.offset
= cpu_to_be64(s
->crypto_header
.offset
);
2604 s
->crypto_header
.length
= cpu_to_be64(s
->crypto_header
.length
);
2605 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_CRYPTO_HEADER
,
2606 &s
->crypto_header
, sizeof(s
->crypto_header
),
2608 s
->crypto_header
.offset
= be64_to_cpu(s
->crypto_header
.offset
);
2609 s
->crypto_header
.length
= be64_to_cpu(s
->crypto_header
.length
);
2618 if (s
->qcow_version
>= 3) {
2619 Qcow2Feature features
[] = {
2621 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2622 .bit
= QCOW2_INCOMPAT_DIRTY_BITNR
,
2623 .name
= "dirty bit",
2626 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2627 .bit
= QCOW2_INCOMPAT_CORRUPT_BITNR
,
2628 .name
= "corrupt bit",
2631 .type
= QCOW2_FEAT_TYPE_INCOMPATIBLE
,
2632 .bit
= QCOW2_INCOMPAT_DATA_FILE_BITNR
,
2633 .name
= "external data file",
2636 .type
= QCOW2_FEAT_TYPE_COMPATIBLE
,
2637 .bit
= QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR
,
2638 .name
= "lazy refcounts",
2642 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_FEATURE_TABLE
,
2643 features
, sizeof(features
), buflen
);
2651 /* Bitmap extension */
2652 if (s
->nb_bitmaps
> 0) {
2653 Qcow2BitmapHeaderExt bitmaps_header
= {
2654 .nb_bitmaps
= cpu_to_be32(s
->nb_bitmaps
),
2655 .bitmap_directory_size
=
2656 cpu_to_be64(s
->bitmap_directory_size
),
2657 .bitmap_directory_offset
=
2658 cpu_to_be64(s
->bitmap_directory_offset
)
2660 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_BITMAPS
,
2661 &bitmaps_header
, sizeof(bitmaps_header
),
2670 /* Keep unknown header extensions */
2671 QLIST_FOREACH(uext
, &s
->unknown_header_ext
, next
) {
2672 ret
= header_ext_add(buf
, uext
->magic
, uext
->data
, uext
->len
, buflen
);
2681 /* End of header extensions */
2682 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_END
, NULL
, 0, buflen
);
2690 /* Backing file name */
2691 if (s
->image_backing_file
) {
2692 size_t backing_file_len
= strlen(s
->image_backing_file
);
2694 if (buflen
< backing_file_len
) {
2699 /* Using strncpy is ok here, since buf is not NUL-terminated. */
2700 strncpy(buf
, s
->image_backing_file
, buflen
);
2702 header
->backing_file_offset
= cpu_to_be64(buf
- ((char*) header
));
2703 header
->backing_file_size
= cpu_to_be32(backing_file_len
);
2706 /* Write the new header */
2707 ret
= bdrv_pwrite(bs
->file
, 0, header
, s
->cluster_size
);
2718 static int qcow2_change_backing_file(BlockDriverState
*bs
,
2719 const char *backing_file
, const char *backing_fmt
)
2721 BDRVQcow2State
*s
= bs
->opaque
;
2723 /* Adding a backing file means that the external data file alone won't be
2724 * enough to make sense of the content */
2725 if (backing_file
&& data_file_is_raw(bs
)) {
2729 if (backing_file
&& strlen(backing_file
) > 1023) {
2733 pstrcpy(bs
->auto_backing_file
, sizeof(bs
->auto_backing_file
),
2734 backing_file
?: "");
2735 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
2736 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
2738 g_free(s
->image_backing_file
);
2739 g_free(s
->image_backing_format
);
2741 s
->image_backing_file
= backing_file
? g_strdup(bs
->backing_file
) : NULL
;
2742 s
->image_backing_format
= backing_fmt
? g_strdup(bs
->backing_format
) : NULL
;
2744 return qcow2_update_header(bs
);
2747 static int qcow2_crypt_method_from_format(const char *encryptfmt
)
2749 if (g_str_equal(encryptfmt
, "luks")) {
2750 return QCOW_CRYPT_LUKS
;
2751 } else if (g_str_equal(encryptfmt
, "aes")) {
2752 return QCOW_CRYPT_AES
;
2758 static int qcow2_set_up_encryption(BlockDriverState
*bs
,
2759 QCryptoBlockCreateOptions
*cryptoopts
,
2762 BDRVQcow2State
*s
= bs
->opaque
;
2763 QCryptoBlock
*crypto
= NULL
;
2766 switch (cryptoopts
->format
) {
2767 case Q_CRYPTO_BLOCK_FORMAT_LUKS
:
2768 fmt
= QCOW_CRYPT_LUKS
;
2770 case Q_CRYPTO_BLOCK_FORMAT_QCOW
:
2771 fmt
= QCOW_CRYPT_AES
;
2774 error_setg(errp
, "Crypto format not supported in qcow2");
2778 s
->crypt_method_header
= fmt
;
2780 crypto
= qcrypto_block_create(cryptoopts
, "encrypt.",
2781 qcow2_crypto_hdr_init_func
,
2782 qcow2_crypto_hdr_write_func
,
2788 ret
= qcow2_update_header(bs
);
2790 error_setg_errno(errp
, -ret
, "Could not write encryption header");
2796 qcrypto_block_free(crypto
);
2801 * Preallocates metadata structures for data clusters between @offset (in the
2802 * guest disk) and @new_length (which is thus generally the new guest disk
2805 * Returns: 0 on success, -errno on failure.
2807 static int coroutine_fn
preallocate_co(BlockDriverState
*bs
, uint64_t offset
,
2808 uint64_t new_length
, PreallocMode mode
,
2811 BDRVQcow2State
*s
= bs
->opaque
;
2813 uint64_t host_offset
= 0;
2814 int64_t file_length
;
2815 unsigned int cur_bytes
;
2819 assert(offset
<= new_length
);
2820 bytes
= new_length
- offset
;
2823 cur_bytes
= MIN(bytes
, QEMU_ALIGN_DOWN(INT_MAX
, s
->cluster_size
));
2824 ret
= qcow2_alloc_cluster_offset(bs
, offset
, &cur_bytes
,
2825 &host_offset
, &meta
);
2827 error_setg_errno(errp
, -ret
, "Allocating clusters failed");
2832 QCowL2Meta
*next
= meta
->next
;
2834 ret
= qcow2_alloc_cluster_link_l2(bs
, meta
);
2836 error_setg_errno(errp
, -ret
, "Mapping clusters failed");
2837 qcow2_free_any_clusters(bs
, meta
->alloc_offset
,
2838 meta
->nb_clusters
, QCOW2_DISCARD_NEVER
);
2842 /* There are no dependent requests, but we need to remove our
2843 * request from the list of in-flight requests */
2844 QLIST_REMOVE(meta
, next_in_flight
);
2850 /* TODO Preallocate data if requested */
2853 offset
+= cur_bytes
;
2857 * It is expected that the image file is large enough to actually contain
2858 * all of the allocated clusters (otherwise we get failing reads after
2859 * EOF). Extend the image to the last allocated sector.
2861 file_length
= bdrv_getlength(s
->data_file
->bs
);
2862 if (file_length
< 0) {
2863 error_setg_errno(errp
, -file_length
, "Could not get file size");
2867 if (host_offset
+ cur_bytes
> file_length
) {
2868 if (mode
== PREALLOC_MODE_METADATA
) {
2869 mode
= PREALLOC_MODE_OFF
;
2871 ret
= bdrv_co_truncate(s
->data_file
, host_offset
+ cur_bytes
, mode
,
2881 /* qcow2_refcount_metadata_size:
2882 * @clusters: number of clusters to refcount (including data and L1/L2 tables)
2883 * @cluster_size: size of a cluster, in bytes
2884 * @refcount_order: refcount bits power-of-2 exponent
2885 * @generous_increase: allow for the refcount table to be 1.5x as large as it
2888 * Returns: Number of bytes required for refcount blocks and table metadata.
2890 int64_t qcow2_refcount_metadata_size(int64_t clusters
, size_t cluster_size
,
2891 int refcount_order
, bool generous_increase
,
2892 uint64_t *refblock_count
)
2895 * Every host cluster is reference-counted, including metadata (even
2896 * refcount metadata is recursively included).
2898 * An accurate formula for the size of refcount metadata size is difficult
2899 * to derive. An easier method of calculation is finding the fixed point
2900 * where no further refcount blocks or table clusters are required to
2901 * reference count every cluster.
2903 int64_t blocks_per_table_cluster
= cluster_size
/ sizeof(uint64_t);
2904 int64_t refcounts_per_block
= cluster_size
* 8 / (1 << refcount_order
);
2905 int64_t table
= 0; /* number of refcount table clusters */
2906 int64_t blocks
= 0; /* number of refcount block clusters */
2912 blocks
= DIV_ROUND_UP(clusters
+ table
+ blocks
, refcounts_per_block
);
2913 table
= DIV_ROUND_UP(blocks
, blocks_per_table_cluster
);
2914 n
= clusters
+ blocks
+ table
;
2916 if (n
== last
&& generous_increase
) {
2917 clusters
+= DIV_ROUND_UP(table
, 2);
2918 n
= 0; /* force another loop */
2919 generous_increase
= false;
2921 } while (n
!= last
);
2923 if (refblock_count
) {
2924 *refblock_count
= blocks
;
2927 return (blocks
+ table
) * cluster_size
;
2931 * qcow2_calc_prealloc_size:
2932 * @total_size: virtual disk size in bytes
2933 * @cluster_size: cluster size in bytes
2934 * @refcount_order: refcount bits power-of-2 exponent
2936 * Returns: Total number of bytes required for the fully allocated image
2937 * (including metadata).
2939 static int64_t qcow2_calc_prealloc_size(int64_t total_size
,
2940 size_t cluster_size
,
2943 int64_t meta_size
= 0;
2944 uint64_t nl1e
, nl2e
;
2945 int64_t aligned_total_size
= ROUND_UP(total_size
, cluster_size
);
2947 /* header: 1 cluster */
2948 meta_size
+= cluster_size
;
2950 /* total size of L2 tables */
2951 nl2e
= aligned_total_size
/ cluster_size
;
2952 nl2e
= ROUND_UP(nl2e
, cluster_size
/ sizeof(uint64_t));
2953 meta_size
+= nl2e
* sizeof(uint64_t);
2955 /* total size of L1 tables */
2956 nl1e
= nl2e
* sizeof(uint64_t) / cluster_size
;
2957 nl1e
= ROUND_UP(nl1e
, cluster_size
/ sizeof(uint64_t));
2958 meta_size
+= nl1e
* sizeof(uint64_t);
2960 /* total size of refcount table and blocks */
2961 meta_size
+= qcow2_refcount_metadata_size(
2962 (meta_size
+ aligned_total_size
) / cluster_size
,
2963 cluster_size
, refcount_order
, false, NULL
);
2965 return meta_size
+ aligned_total_size
;
2968 static bool validate_cluster_size(size_t cluster_size
, Error
**errp
)
2970 int cluster_bits
= ctz32(cluster_size
);
2971 if (cluster_bits
< MIN_CLUSTER_BITS
|| cluster_bits
> MAX_CLUSTER_BITS
||
2972 (1 << cluster_bits
) != cluster_size
)
2974 error_setg(errp
, "Cluster size must be a power of two between %d and "
2975 "%dk", 1 << MIN_CLUSTER_BITS
, 1 << (MAX_CLUSTER_BITS
- 10));
2981 static size_t qcow2_opt_get_cluster_size_del(QemuOpts
*opts
, Error
**errp
)
2983 size_t cluster_size
;
2985 cluster_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_CLUSTER_SIZE
,
2986 DEFAULT_CLUSTER_SIZE
);
2987 if (!validate_cluster_size(cluster_size
, errp
)) {
2990 return cluster_size
;
2993 static int qcow2_opt_get_version_del(QemuOpts
*opts
, Error
**errp
)
2998 buf
= qemu_opt_get_del(opts
, BLOCK_OPT_COMPAT_LEVEL
);
3000 ret
= 3; /* default */
3001 } else if (!strcmp(buf
, "0.10")) {
3003 } else if (!strcmp(buf
, "1.1")) {
3006 error_setg(errp
, "Invalid compatibility level: '%s'", buf
);
3013 static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts
*opts
, int version
,
3016 uint64_t refcount_bits
;
3018 refcount_bits
= qemu_opt_get_number_del(opts
, BLOCK_OPT_REFCOUNT_BITS
, 16);
3019 if (refcount_bits
> 64 || !is_power_of_2(refcount_bits
)) {
3020 error_setg(errp
, "Refcount width must be a power of two and may not "
3025 if (version
< 3 && refcount_bits
!= 16) {
3026 error_setg(errp
, "Different refcount widths than 16 bits require "
3027 "compatibility level 1.1 or above (use compat=1.1 or "
3032 return refcount_bits
;
3035 static int coroutine_fn
3036 qcow2_co_create(BlockdevCreateOptions
*create_options
, Error
**errp
)
3038 BlockdevCreateOptionsQcow2
*qcow2_opts
;
3042 * Open the image file and write a minimal qcow2 header.
3044 * We keep things simple and start with a zero-sized image. We also
3045 * do without refcount blocks or a L1 table for now. We'll fix the
3046 * inconsistency later.
3048 * We do need a refcount table because growing the refcount table means
3049 * allocating two new refcount blocks - the seconds of which would be at
3050 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
3051 * size for any qcow2 image.
3053 BlockBackend
*blk
= NULL
;
3054 BlockDriverState
*bs
= NULL
;
3055 BlockDriverState
*data_bs
= NULL
;
3057 size_t cluster_size
;
3060 uint64_t* refcount_table
;
3061 Error
*local_err
= NULL
;
3064 assert(create_options
->driver
== BLOCKDEV_DRIVER_QCOW2
);
3065 qcow2_opts
= &create_options
->u
.qcow2
;
3067 bs
= bdrv_open_blockdev_ref(qcow2_opts
->file
, errp
);
3072 /* Validate options and set default values */
3073 if (!QEMU_IS_ALIGNED(qcow2_opts
->size
, BDRV_SECTOR_SIZE
)) {
3074 error_setg(errp
, "Image size must be a multiple of 512 bytes");
3079 if (qcow2_opts
->has_version
) {
3080 switch (qcow2_opts
->version
) {
3081 case BLOCKDEV_QCOW2_VERSION_V2
:
3084 case BLOCKDEV_QCOW2_VERSION_V3
:
3088 g_assert_not_reached();
3094 if (qcow2_opts
->has_cluster_size
) {
3095 cluster_size
= qcow2_opts
->cluster_size
;
3097 cluster_size
= DEFAULT_CLUSTER_SIZE
;
3100 if (!validate_cluster_size(cluster_size
, errp
)) {
3105 if (!qcow2_opts
->has_preallocation
) {
3106 qcow2_opts
->preallocation
= PREALLOC_MODE_OFF
;
3108 if (qcow2_opts
->has_backing_file
&&
3109 qcow2_opts
->preallocation
!= PREALLOC_MODE_OFF
)
3111 error_setg(errp
, "Backing file and preallocation cannot be used at "
3116 if (qcow2_opts
->has_backing_fmt
&& !qcow2_opts
->has_backing_file
) {
3117 error_setg(errp
, "Backing format cannot be used without backing file");
3122 if (!qcow2_opts
->has_lazy_refcounts
) {
3123 qcow2_opts
->lazy_refcounts
= false;
3125 if (version
< 3 && qcow2_opts
->lazy_refcounts
) {
3126 error_setg(errp
, "Lazy refcounts only supported with compatibility "
3127 "level 1.1 and above (use version=v3 or greater)");
3132 if (!qcow2_opts
->has_refcount_bits
) {
3133 qcow2_opts
->refcount_bits
= 16;
3135 if (qcow2_opts
->refcount_bits
> 64 ||
3136 !is_power_of_2(qcow2_opts
->refcount_bits
))
3138 error_setg(errp
, "Refcount width must be a power of two and may not "
3143 if (version
< 3 && qcow2_opts
->refcount_bits
!= 16) {
3144 error_setg(errp
, "Different refcount widths than 16 bits require "
3145 "compatibility level 1.1 or above (use version=v3 or "
3150 refcount_order
= ctz32(qcow2_opts
->refcount_bits
);
3152 if (qcow2_opts
->data_file_raw
&& !qcow2_opts
->data_file
) {
3153 error_setg(errp
, "data-file-raw requires data-file");
3157 if (qcow2_opts
->data_file_raw
&& qcow2_opts
->has_backing_file
) {
3158 error_setg(errp
, "Backing file and data-file-raw cannot be used at "
3164 if (qcow2_opts
->data_file
) {
3166 error_setg(errp
, "External data files are only supported with "
3167 "compatibility level 1.1 and above (use version=v3 or "
3172 data_bs
= bdrv_open_blockdev_ref(qcow2_opts
->data_file
, errp
);
3173 if (data_bs
== NULL
) {
3179 /* Create BlockBackend to write to the image */
3180 blk
= blk_new(bdrv_get_aio_context(bs
),
3181 BLK_PERM_WRITE
| BLK_PERM_RESIZE
, BLK_PERM_ALL
);
3182 ret
= blk_insert_bs(blk
, bs
, errp
);
3186 blk_set_allow_write_beyond_eof(blk
, true);
3188 /* Clear the protocol layer and preallocate it if necessary */
3189 ret
= blk_truncate(blk
, 0, PREALLOC_MODE_OFF
, errp
);
3194 /* Write the header */
3195 QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS
) < sizeof(*header
));
3196 header
= g_malloc0(cluster_size
);
3197 *header
= (QCowHeader
) {
3198 .magic
= cpu_to_be32(QCOW_MAGIC
),
3199 .version
= cpu_to_be32(version
),
3200 .cluster_bits
= cpu_to_be32(ctz32(cluster_size
)),
3201 .size
= cpu_to_be64(0),
3202 .l1_table_offset
= cpu_to_be64(0),
3203 .l1_size
= cpu_to_be32(0),
3204 .refcount_table_offset
= cpu_to_be64(cluster_size
),
3205 .refcount_table_clusters
= cpu_to_be32(1),
3206 .refcount_order
= cpu_to_be32(refcount_order
),
3207 .header_length
= cpu_to_be32(sizeof(*header
)),
3210 /* We'll update this to correct value later */
3211 header
->crypt_method
= cpu_to_be32(QCOW_CRYPT_NONE
);
3213 if (qcow2_opts
->lazy_refcounts
) {
3214 header
->compatible_features
|=
3215 cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS
);
3218 header
->incompatible_features
|=
3219 cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE
);
3221 if (qcow2_opts
->data_file_raw
) {
3222 header
->autoclear_features
|=
3223 cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW
);
3226 ret
= blk_pwrite(blk
, 0, header
, cluster_size
, 0);
3229 error_setg_errno(errp
, -ret
, "Could not write qcow2 header");
3233 /* Write a refcount table with one refcount block */
3234 refcount_table
= g_malloc0(2 * cluster_size
);
3235 refcount_table
[0] = cpu_to_be64(2 * cluster_size
);
3236 ret
= blk_pwrite(blk
, cluster_size
, refcount_table
, 2 * cluster_size
, 0);
3237 g_free(refcount_table
);
3240 error_setg_errno(errp
, -ret
, "Could not write refcount table");
3248 * And now open the image and make it consistent first (i.e. increase the
3249 * refcount of the cluster that is occupied by the header and the refcount
3252 options
= qdict_new();
3253 qdict_put_str(options
, "driver", "qcow2");
3254 qdict_put_str(options
, "file", bs
->node_name
);
3256 qdict_put_str(options
, "data-file", data_bs
->node_name
);
3258 blk
= blk_new_open(NULL
, NULL
, options
,
3259 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_NO_FLUSH
,
3262 error_propagate(errp
, local_err
);
3267 ret
= qcow2_alloc_clusters(blk_bs(blk
), 3 * cluster_size
);
3269 error_setg_errno(errp
, -ret
, "Could not allocate clusters for qcow2 "
3270 "header and refcount table");
3273 } else if (ret
!= 0) {
3274 error_report("Huh, first cluster in empty image is already in use?");
3278 /* Set the external data file if necessary */
3280 BDRVQcow2State
*s
= blk_bs(blk
)->opaque
;
3281 s
->image_data_file
= g_strdup(data_bs
->filename
);
3284 /* Create a full header (including things like feature table) */
3285 ret
= qcow2_update_header(blk_bs(blk
));
3287 error_setg_errno(errp
, -ret
, "Could not update qcow2 header");
3291 /* Okay, now that we have a valid image, let's give it the right size */
3292 ret
= blk_truncate(blk
, qcow2_opts
->size
, qcow2_opts
->preallocation
, errp
);
3294 error_prepend(errp
, "Could not resize image: ");
3298 /* Want a backing file? There you go.*/
3299 if (qcow2_opts
->has_backing_file
) {
3300 const char *backing_format
= NULL
;
3302 if (qcow2_opts
->has_backing_fmt
) {
3303 backing_format
= BlockdevDriver_str(qcow2_opts
->backing_fmt
);
3306 ret
= bdrv_change_backing_file(blk_bs(blk
), qcow2_opts
->backing_file
,
3309 error_setg_errno(errp
, -ret
, "Could not assign backing file '%s' "
3310 "with format '%s'", qcow2_opts
->backing_file
,
3316 /* Want encryption? There you go. */
3317 if (qcow2_opts
->has_encrypt
) {
3318 ret
= qcow2_set_up_encryption(blk_bs(blk
), qcow2_opts
->encrypt
, errp
);
3327 /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning.
3328 * Using BDRV_O_NO_IO, since encryption is now setup we don't want to
3329 * have to setup decryption context. We're not doing any I/O on the top
3330 * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does
3333 options
= qdict_new();
3334 qdict_put_str(options
, "driver", "qcow2");
3335 qdict_put_str(options
, "file", bs
->node_name
);
3337 qdict_put_str(options
, "data-file", data_bs
->node_name
);
3339 blk
= blk_new_open(NULL
, NULL
, options
,
3340 BDRV_O_RDWR
| BDRV_O_NO_BACKING
| BDRV_O_NO_IO
,
3343 error_propagate(errp
, local_err
);
3352 bdrv_unref(data_bs
);
3356 static int coroutine_fn
qcow2_co_create_opts(const char *filename
, QemuOpts
*opts
,
3359 BlockdevCreateOptions
*create_options
= NULL
;
3362 BlockDriverState
*bs
= NULL
;
3363 BlockDriverState
*data_bs
= NULL
;
3364 Error
*local_err
= NULL
;
3368 /* Only the keyval visitor supports the dotted syntax needed for
3369 * encryption, so go through a QDict before getting a QAPI type. Ignore
3370 * options meant for the protocol layer so that the visitor doesn't
3372 qdict
= qemu_opts_to_qdict_filtered(opts
, NULL
, bdrv_qcow2
.create_opts
,
3375 /* Handle encryption options */
3376 val
= qdict_get_try_str(qdict
, BLOCK_OPT_ENCRYPT
);
3377 if (val
&& !strcmp(val
, "on")) {
3378 qdict_put_str(qdict
, BLOCK_OPT_ENCRYPT
, "qcow");
3379 } else if (val
&& !strcmp(val
, "off")) {
3380 qdict_del(qdict
, BLOCK_OPT_ENCRYPT
);
3383 val
= qdict_get_try_str(qdict
, BLOCK_OPT_ENCRYPT_FORMAT
);
3384 if (val
&& !strcmp(val
, "aes")) {
3385 qdict_put_str(qdict
, BLOCK_OPT_ENCRYPT_FORMAT
, "qcow");
3388 /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into
3389 * version=v2/v3 below. */
3390 val
= qdict_get_try_str(qdict
, BLOCK_OPT_COMPAT_LEVEL
);
3391 if (val
&& !strcmp(val
, "0.10")) {
3392 qdict_put_str(qdict
, BLOCK_OPT_COMPAT_LEVEL
, "v2");
3393 } else if (val
&& !strcmp(val
, "1.1")) {
3394 qdict_put_str(qdict
, BLOCK_OPT_COMPAT_LEVEL
, "v3");
3397 /* Change legacy command line options into QMP ones */
3398 static const QDictRenames opt_renames
[] = {
3399 { BLOCK_OPT_BACKING_FILE
, "backing-file" },
3400 { BLOCK_OPT_BACKING_FMT
, "backing-fmt" },
3401 { BLOCK_OPT_CLUSTER_SIZE
, "cluster-size" },
3402 { BLOCK_OPT_LAZY_REFCOUNTS
, "lazy-refcounts" },
3403 { BLOCK_OPT_REFCOUNT_BITS
, "refcount-bits" },
3404 { BLOCK_OPT_ENCRYPT
, BLOCK_OPT_ENCRYPT_FORMAT
},
3405 { BLOCK_OPT_COMPAT_LEVEL
, "version" },
3406 { BLOCK_OPT_DATA_FILE_RAW
, "data-file-raw" },
3410 if (!qdict_rename_keys(qdict
, opt_renames
, errp
)) {
3415 /* Create and open the file (protocol layer) */
3416 ret
= bdrv_create_file(filename
, opts
, errp
);
3421 bs
= bdrv_open(filename
, NULL
, NULL
,
3422 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_PROTOCOL
, errp
);
3428 /* Create and open an external data file (protocol layer) */
3429 val
= qdict_get_try_str(qdict
, BLOCK_OPT_DATA_FILE
);
3431 ret
= bdrv_create_file(val
, opts
, errp
);
3436 data_bs
= bdrv_open(val
, NULL
, NULL
,
3437 BDRV_O_RDWR
| BDRV_O_RESIZE
| BDRV_O_PROTOCOL
,
3439 if (data_bs
== NULL
) {
3444 qdict_del(qdict
, BLOCK_OPT_DATA_FILE
);
3445 qdict_put_str(qdict
, "data-file", data_bs
->node_name
);
3448 /* Set 'driver' and 'node' options */
3449 qdict_put_str(qdict
, "driver", "qcow2");
3450 qdict_put_str(qdict
, "file", bs
->node_name
);
3452 /* Now get the QAPI type BlockdevCreateOptions */
3453 v
= qobject_input_visitor_new_flat_confused(qdict
, errp
);
3459 visit_type_BlockdevCreateOptions(v
, NULL
, &create_options
, &local_err
);
3463 error_propagate(errp
, local_err
);
3468 /* Silently round up size */
3469 create_options
->u
.qcow2
.size
= ROUND_UP(create_options
->u
.qcow2
.size
,
3472 /* Create the qcow2 image (format layer) */
3473 ret
= qcow2_co_create(create_options
, errp
);
3480 qobject_unref(qdict
);
3482 bdrv_unref(data_bs
);
3483 qapi_free_BlockdevCreateOptions(create_options
);
3488 static bool is_zero(BlockDriverState
*bs
, int64_t offset
, int64_t bytes
)
3493 /* Clamp to image length, before checking status of underlying sectors */
3494 if (offset
+ bytes
> bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3495 bytes
= bs
->total_sectors
* BDRV_SECTOR_SIZE
- offset
;
3501 res
= bdrv_block_status_above(bs
, NULL
, offset
, bytes
, &nr
, NULL
, NULL
);
3502 return res
>= 0 && (res
& BDRV_BLOCK_ZERO
) && nr
== bytes
;
3505 static coroutine_fn
int qcow2_co_pwrite_zeroes(BlockDriverState
*bs
,
3506 int64_t offset
, int bytes
, BdrvRequestFlags flags
)
3509 BDRVQcow2State
*s
= bs
->opaque
;
3511 uint32_t head
= offset
% s
->cluster_size
;
3512 uint32_t tail
= (offset
+ bytes
) % s
->cluster_size
;
3514 trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset
, bytes
);
3515 if (offset
+ bytes
== bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3523 assert(head
+ bytes
<= s
->cluster_size
);
3525 /* check whether remainder of cluster already reads as zero */
3526 if (!(is_zero(bs
, offset
- head
, head
) &&
3527 is_zero(bs
, offset
+ bytes
,
3528 tail
? s
->cluster_size
- tail
: 0))) {
3532 qemu_co_mutex_lock(&s
->lock
);
3533 /* We can have new write after previous check */
3534 offset
= QEMU_ALIGN_DOWN(offset
, s
->cluster_size
);
3535 bytes
= s
->cluster_size
;
3536 nr
= s
->cluster_size
;
3537 ret
= qcow2_get_cluster_offset(bs
, offset
, &nr
, &off
);
3538 if (ret
!= QCOW2_CLUSTER_UNALLOCATED
&&
3539 ret
!= QCOW2_CLUSTER_ZERO_PLAIN
&&
3540 ret
!= QCOW2_CLUSTER_ZERO_ALLOC
) {
3541 qemu_co_mutex_unlock(&s
->lock
);
3545 qemu_co_mutex_lock(&s
->lock
);
3548 trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset
, bytes
);
3550 /* Whatever is left can use real zero clusters */
3551 ret
= qcow2_cluster_zeroize(bs
, offset
, bytes
, flags
);
3552 qemu_co_mutex_unlock(&s
->lock
);
3557 static coroutine_fn
int qcow2_co_pdiscard(BlockDriverState
*bs
,
3558 int64_t offset
, int bytes
)
3561 BDRVQcow2State
*s
= bs
->opaque
;
3563 if (!QEMU_IS_ALIGNED(offset
| bytes
, s
->cluster_size
)) {
3564 assert(bytes
< s
->cluster_size
);
3565 /* Ignore partial clusters, except for the special case of the
3566 * complete partial cluster at the end of an unaligned file */
3567 if (!QEMU_IS_ALIGNED(offset
, s
->cluster_size
) ||
3568 offset
+ bytes
!= bs
->total_sectors
* BDRV_SECTOR_SIZE
) {
3573 qemu_co_mutex_lock(&s
->lock
);
3574 ret
= qcow2_cluster_discard(bs
, offset
, bytes
, QCOW2_DISCARD_REQUEST
,
3576 qemu_co_mutex_unlock(&s
->lock
);
3580 static int coroutine_fn
3581 qcow2_co_copy_range_from(BlockDriverState
*bs
,
3582 BdrvChild
*src
, uint64_t src_offset
,
3583 BdrvChild
*dst
, uint64_t dst_offset
,
3584 uint64_t bytes
, BdrvRequestFlags read_flags
,
3585 BdrvRequestFlags write_flags
)
3587 BDRVQcow2State
*s
= bs
->opaque
;
3589 unsigned int cur_bytes
; /* number of bytes in current iteration */
3590 BdrvChild
*child
= NULL
;
3591 BdrvRequestFlags cur_write_flags
;
3593 assert(!bs
->encrypted
);
3594 qemu_co_mutex_lock(&s
->lock
);
3596 while (bytes
!= 0) {
3597 uint64_t copy_offset
= 0;
3598 /* prepare next request */
3599 cur_bytes
= MIN(bytes
, INT_MAX
);
3600 cur_write_flags
= write_flags
;
3602 ret
= qcow2_get_cluster_offset(bs
, src_offset
, &cur_bytes
, ©_offset
);
3608 case QCOW2_CLUSTER_UNALLOCATED
:
3609 if (bs
->backing
&& bs
->backing
->bs
) {
3610 int64_t backing_length
= bdrv_getlength(bs
->backing
->bs
);
3611 if (src_offset
>= backing_length
) {
3612 cur_write_flags
|= BDRV_REQ_ZERO_WRITE
;
3614 child
= bs
->backing
;
3615 cur_bytes
= MIN(cur_bytes
, backing_length
- src_offset
);
3616 copy_offset
= src_offset
;
3619 cur_write_flags
|= BDRV_REQ_ZERO_WRITE
;
3623 case QCOW2_CLUSTER_ZERO_PLAIN
:
3624 case QCOW2_CLUSTER_ZERO_ALLOC
:
3625 cur_write_flags
|= BDRV_REQ_ZERO_WRITE
;
3628 case QCOW2_CLUSTER_COMPRESSED
:
3632 case QCOW2_CLUSTER_NORMAL
:
3633 child
= s
->data_file
;
3634 copy_offset
+= offset_into_cluster(s
, src_offset
);
3635 if ((copy_offset
& 511) != 0) {
3644 qemu_co_mutex_unlock(&s
->lock
);
3645 ret
= bdrv_co_copy_range_from(child
,
3648 cur_bytes
, read_flags
, cur_write_flags
);
3649 qemu_co_mutex_lock(&s
->lock
);
3655 src_offset
+= cur_bytes
;
3656 dst_offset
+= cur_bytes
;
3661 qemu_co_mutex_unlock(&s
->lock
);
3665 static int coroutine_fn
3666 qcow2_co_copy_range_to(BlockDriverState
*bs
,
3667 BdrvChild
*src
, uint64_t src_offset
,
3668 BdrvChild
*dst
, uint64_t dst_offset
,
3669 uint64_t bytes
, BdrvRequestFlags read_flags
,
3670 BdrvRequestFlags write_flags
)
3672 BDRVQcow2State
*s
= bs
->opaque
;
3673 int offset_in_cluster
;
3675 unsigned int cur_bytes
; /* number of sectors in current iteration */
3676 uint64_t cluster_offset
;
3677 QCowL2Meta
*l2meta
= NULL
;
3679 assert(!bs
->encrypted
);
3681 qemu_co_mutex_lock(&s
->lock
);
3683 while (bytes
!= 0) {
3687 offset_in_cluster
= offset_into_cluster(s
, dst_offset
);
3688 cur_bytes
= MIN(bytes
, INT_MAX
);
3691 * If src->bs == dst->bs, we could simply copy by incrementing
3692 * the refcnt, without copying user data.
3693 * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */
3694 ret
= qcow2_alloc_cluster_offset(bs
, dst_offset
, &cur_bytes
,
3695 &cluster_offset
, &l2meta
);
3700 assert((cluster_offset
& 511) == 0);
3702 ret
= qcow2_pre_write_overlap_check(bs
, 0,
3703 cluster_offset
+ offset_in_cluster
, cur_bytes
, true);
3708 qemu_co_mutex_unlock(&s
->lock
);
3709 ret
= bdrv_co_copy_range_to(src
, src_offset
,
3711 cluster_offset
+ offset_in_cluster
,
3712 cur_bytes
, read_flags
, write_flags
);
3713 qemu_co_mutex_lock(&s
->lock
);
3718 ret
= qcow2_handle_l2meta(bs
, &l2meta
, true);
3724 src_offset
+= cur_bytes
;
3725 dst_offset
+= cur_bytes
;
3730 qcow2_handle_l2meta(bs
, &l2meta
, false);
3732 qemu_co_mutex_unlock(&s
->lock
);
3734 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret
);
3739 static int coroutine_fn
qcow2_co_truncate(BlockDriverState
*bs
, int64_t offset
,
3740 PreallocMode prealloc
, Error
**errp
)
3742 BDRVQcow2State
*s
= bs
->opaque
;
3743 uint64_t old_length
;
3744 int64_t new_l1_size
;
3748 if (prealloc
!= PREALLOC_MODE_OFF
&& prealloc
!= PREALLOC_MODE_METADATA
&&
3749 prealloc
!= PREALLOC_MODE_FALLOC
&& prealloc
!= PREALLOC_MODE_FULL
)
3751 error_setg(errp
, "Unsupported preallocation mode '%s'",
3752 PreallocMode_str(prealloc
));
3757 error_setg(errp
, "The new size must be a multiple of 512");
3761 qemu_co_mutex_lock(&s
->lock
);
3763 /* cannot proceed if image has snapshots */
3764 if (s
->nb_snapshots
) {
3765 error_setg(errp
, "Can't resize an image which has snapshots");
3770 /* cannot proceed if image has bitmaps */
3771 if (qcow2_truncate_bitmaps_check(bs
, errp
)) {
3776 old_length
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
3777 new_l1_size
= size_to_l1(s
, offset
);
3779 if (offset
< old_length
) {
3780 int64_t last_cluster
, old_file_size
;
3781 if (prealloc
!= PREALLOC_MODE_OFF
) {
3783 "Preallocation can't be used for shrinking an image");
3788 ret
= qcow2_cluster_discard(bs
, ROUND_UP(offset
, s
->cluster_size
),
3789 old_length
- ROUND_UP(offset
,
3791 QCOW2_DISCARD_ALWAYS
, true);
3793 error_setg_errno(errp
, -ret
, "Failed to discard cropped clusters");
3797 ret
= qcow2_shrink_l1_table(bs
, new_l1_size
);
3799 error_setg_errno(errp
, -ret
,
3800 "Failed to reduce the number of L2 tables");
3804 ret
= qcow2_shrink_reftable(bs
);
3806 error_setg_errno(errp
, -ret
,
3807 "Failed to discard unused refblocks");
3811 old_file_size
= bdrv_getlength(bs
->file
->bs
);
3812 if (old_file_size
< 0) {
3813 error_setg_errno(errp
, -old_file_size
,
3814 "Failed to inquire current file length");
3815 ret
= old_file_size
;
3818 last_cluster
= qcow2_get_last_cluster(bs
, old_file_size
);
3819 if (last_cluster
< 0) {
3820 error_setg_errno(errp
, -last_cluster
,
3821 "Failed to find the last cluster");
3825 if ((last_cluster
+ 1) * s
->cluster_size
< old_file_size
) {
3826 Error
*local_err
= NULL
;
3828 bdrv_co_truncate(bs
->file
, (last_cluster
+ 1) * s
->cluster_size
,
3829 PREALLOC_MODE_OFF
, &local_err
);
3831 warn_reportf_err(local_err
,
3832 "Failed to truncate the tail of the image: ");
3836 ret
= qcow2_grow_l1_table(bs
, new_l1_size
, true);
3838 error_setg_errno(errp
, -ret
, "Failed to grow the L1 table");
3844 case PREALLOC_MODE_OFF
:
3845 if (has_data_file(bs
)) {
3846 ret
= bdrv_co_truncate(s
->data_file
, offset
, prealloc
, errp
);
3853 case PREALLOC_MODE_METADATA
:
3854 ret
= preallocate_co(bs
, old_length
, offset
, prealloc
, errp
);
3860 case PREALLOC_MODE_FALLOC
:
3861 case PREALLOC_MODE_FULL
:
3863 int64_t allocation_start
, host_offset
, guest_offset
;
3864 int64_t clusters_allocated
;
3865 int64_t old_file_size
, new_file_size
;
3866 uint64_t nb_new_data_clusters
, nb_new_l2_tables
;
3868 /* With a data file, preallocation means just allocating the metadata
3869 * and forwarding the truncate request to the data file */
3870 if (has_data_file(bs
)) {
3871 ret
= preallocate_co(bs
, old_length
, offset
, prealloc
, errp
);
3878 old_file_size
= bdrv_getlength(bs
->file
->bs
);
3879 if (old_file_size
< 0) {
3880 error_setg_errno(errp
, -old_file_size
,
3881 "Failed to inquire current file length");
3882 ret
= old_file_size
;
3885 old_file_size
= ROUND_UP(old_file_size
, s
->cluster_size
);
3887 nb_new_data_clusters
= DIV_ROUND_UP(offset
- old_length
,
3890 /* This is an overestimation; we will not actually allocate space for
3891 * these in the file but just make sure the new refcount structures are
3892 * able to cover them so we will not have to allocate new refblocks
3893 * while entering the data blocks in the potentially new L2 tables.
3894 * (We do not actually care where the L2 tables are placed. Maybe they
3895 * are already allocated or they can be placed somewhere before
3896 * @old_file_size. It does not matter because they will be fully
3897 * allocated automatically, so they do not need to be covered by the
3898 * preallocation. All that matters is that we will not have to allocate
3899 * new refcount structures for them.) */
3900 nb_new_l2_tables
= DIV_ROUND_UP(nb_new_data_clusters
,
3901 s
->cluster_size
/ sizeof(uint64_t));
3902 /* The cluster range may not be aligned to L2 boundaries, so add one L2
3903 * table for a potential head/tail */
3906 allocation_start
= qcow2_refcount_area(bs
, old_file_size
,
3907 nb_new_data_clusters
+
3910 if (allocation_start
< 0) {
3911 error_setg_errno(errp
, -allocation_start
,
3912 "Failed to resize refcount structures");
3913 ret
= allocation_start
;
3917 clusters_allocated
= qcow2_alloc_clusters_at(bs
, allocation_start
,
3918 nb_new_data_clusters
);
3919 if (clusters_allocated
< 0) {
3920 error_setg_errno(errp
, -clusters_allocated
,
3921 "Failed to allocate data clusters");
3922 ret
= clusters_allocated
;
3926 assert(clusters_allocated
== nb_new_data_clusters
);
3928 /* Allocate the data area */
3929 new_file_size
= allocation_start
+
3930 nb_new_data_clusters
* s
->cluster_size
;
3931 ret
= bdrv_co_truncate(bs
->file
, new_file_size
, prealloc
, errp
);
3933 error_prepend(errp
, "Failed to resize underlying file: ");
3934 qcow2_free_clusters(bs
, allocation_start
,
3935 nb_new_data_clusters
* s
->cluster_size
,
3936 QCOW2_DISCARD_OTHER
);
3940 /* Create the necessary L2 entries */
3941 host_offset
= allocation_start
;
3942 guest_offset
= old_length
;
3943 while (nb_new_data_clusters
) {
3944 int64_t nb_clusters
= MIN(
3945 nb_new_data_clusters
,
3946 s
->l2_slice_size
- offset_to_l2_slice_index(s
, guest_offset
));
3947 QCowL2Meta allocation
= {
3948 .offset
= guest_offset
,
3949 .alloc_offset
= host_offset
,
3950 .nb_clusters
= nb_clusters
,
3952 qemu_co_queue_init(&allocation
.dependent_requests
);
3954 ret
= qcow2_alloc_cluster_link_l2(bs
, &allocation
);
3956 error_setg_errno(errp
, -ret
, "Failed to update L2 tables");
3957 qcow2_free_clusters(bs
, host_offset
,
3958 nb_new_data_clusters
* s
->cluster_size
,
3959 QCOW2_DISCARD_OTHER
);
3963 guest_offset
+= nb_clusters
* s
->cluster_size
;
3964 host_offset
+= nb_clusters
* s
->cluster_size
;
3965 nb_new_data_clusters
-= nb_clusters
;
3971 g_assert_not_reached();
3974 if (prealloc
!= PREALLOC_MODE_OFF
) {
3975 /* Flush metadata before actually changing the image size */
3976 ret
= qcow2_write_caches(bs
);
3978 error_setg_errno(errp
, -ret
,
3979 "Failed to flush the preallocated area to disk");
3984 bs
->total_sectors
= offset
/ BDRV_SECTOR_SIZE
;
3986 /* write updated header.size */
3987 offset
= cpu_to_be64(offset
);
3988 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, size
),
3989 &offset
, sizeof(uint64_t));
3991 error_setg_errno(errp
, -ret
, "Failed to update the image size");
3995 s
->l1_vm_state_index
= new_l1_size
;
3997 /* Update cache sizes */
3998 options
= qdict_clone_shallow(bs
->options
);
3999 ret
= qcow2_update_options(bs
, options
, s
->flags
, errp
);
4000 qobject_unref(options
);
4006 qemu_co_mutex_unlock(&s
->lock
);
4010 /* XXX: put compressed sectors first, then all the cluster aligned
4011 tables to avoid losing bytes in alignment */
4012 static coroutine_fn
int
4013 qcow2_co_pwritev_compressed_part(BlockDriverState
*bs
,
4014 uint64_t offset
, uint64_t bytes
,
4015 QEMUIOVector
*qiov
, size_t qiov_offset
)
4017 BDRVQcow2State
*s
= bs
->opaque
;
4020 uint8_t *buf
, *out_buf
;
4021 uint64_t cluster_offset
;
4023 if (has_data_file(bs
)) {
4028 /* align end of file to a sector boundary to ease reading with
4029 sector based I/Os */
4030 int64_t len
= bdrv_getlength(bs
->file
->bs
);
4034 return bdrv_co_truncate(bs
->file
, len
, PREALLOC_MODE_OFF
, NULL
);
4037 if (offset_into_cluster(s
, offset
)) {
4041 buf
= qemu_blockalign(bs
, s
->cluster_size
);
4042 if (bytes
!= s
->cluster_size
) {
4043 if (bytes
> s
->cluster_size
||
4044 offset
+ bytes
!= bs
->total_sectors
<< BDRV_SECTOR_BITS
)
4049 /* Zero-pad last write if image size is not cluster aligned */
4050 memset(buf
+ bytes
, 0, s
->cluster_size
- bytes
);
4052 qemu_iovec_to_buf(qiov
, qiov_offset
, buf
, bytes
);
4054 out_buf
= g_malloc(s
->cluster_size
);
4056 out_len
= qcow2_co_compress(bs
, out_buf
, s
->cluster_size
- 1,
4057 buf
, s
->cluster_size
);
4058 if (out_len
== -ENOMEM
) {
4059 /* could not compress: write normal cluster */
4060 ret
= qcow2_co_pwritev_part(bs
, offset
, bytes
, qiov
, qiov_offset
, 0);
4065 } else if (out_len
< 0) {
4070 qemu_co_mutex_lock(&s
->lock
);
4071 ret
= qcow2_alloc_compressed_cluster_offset(bs
, offset
, out_len
,
4074 qemu_co_mutex_unlock(&s
->lock
);
4078 ret
= qcow2_pre_write_overlap_check(bs
, 0, cluster_offset
, out_len
, true);
4079 qemu_co_mutex_unlock(&s
->lock
);
4084 BLKDBG_EVENT(s
->data_file
, BLKDBG_WRITE_COMPRESSED
);
4085 ret
= bdrv_co_pwrite(s
->data_file
, cluster_offset
, out_len
, out_buf
, 0);
4097 static int coroutine_fn
4098 qcow2_co_preadv_compressed(BlockDriverState
*bs
,
4099 uint64_t file_cluster_offset
,
4105 BDRVQcow2State
*s
= bs
->opaque
;
4106 int ret
= 0, csize
, nb_csectors
;
4108 uint8_t *buf
, *out_buf
;
4109 int offset_in_cluster
= offset_into_cluster(s
, offset
);
4111 coffset
= file_cluster_offset
& s
->cluster_offset_mask
;
4112 nb_csectors
= ((file_cluster_offset
>> s
->csize_shift
) & s
->csize_mask
) + 1;
4113 csize
= nb_csectors
* QCOW2_COMPRESSED_SECTOR_SIZE
-
4114 (coffset
& ~QCOW2_COMPRESSED_SECTOR_MASK
);
4116 buf
= g_try_malloc(csize
);
4121 out_buf
= qemu_blockalign(bs
, s
->cluster_size
);
4123 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_COMPRESSED
);
4124 ret
= bdrv_co_pread(bs
->file
, coffset
, csize
, buf
, 0);
4129 if (qcow2_co_decompress(bs
, out_buf
, s
->cluster_size
, buf
, csize
) < 0) {
4134 qemu_iovec_from_buf(qiov
, qiov_offset
, out_buf
+ offset_in_cluster
, bytes
);
4137 qemu_vfree(out_buf
);
4143 static int make_completely_empty(BlockDriverState
*bs
)
4145 BDRVQcow2State
*s
= bs
->opaque
;
4146 Error
*local_err
= NULL
;
4147 int ret
, l1_clusters
;
4149 uint64_t *new_reftable
= NULL
;
4150 uint64_t rt_entry
, l1_size2
;
4153 uint64_t reftable_offset
;
4154 uint32_t reftable_clusters
;
4155 } QEMU_PACKED l1_ofs_rt_ofs_cls
;
4157 ret
= qcow2_cache_empty(bs
, s
->l2_table_cache
);
4162 ret
= qcow2_cache_empty(bs
, s
->refcount_block_cache
);
4167 /* Refcounts will be broken utterly */
4168 ret
= qcow2_mark_dirty(bs
);
4173 BLKDBG_EVENT(bs
->file
, BLKDBG_L1_UPDATE
);
4175 l1_clusters
= DIV_ROUND_UP(s
->l1_size
, s
->cluster_size
/ sizeof(uint64_t));
4176 l1_size2
= (uint64_t)s
->l1_size
* sizeof(uint64_t);
4178 /* After this call, neither the in-memory nor the on-disk refcount
4179 * information accurately describe the actual references */
4181 ret
= bdrv_pwrite_zeroes(bs
->file
, s
->l1_table_offset
,
4182 l1_clusters
* s
->cluster_size
, 0);
4184 goto fail_broken_refcounts
;
4186 memset(s
->l1_table
, 0, l1_size2
);
4188 BLKDBG_EVENT(bs
->file
, BLKDBG_EMPTY_IMAGE_PREPARE
);
4190 /* Overwrite enough clusters at the beginning of the sectors to place
4191 * the refcount table, a refcount block and the L1 table in; this may
4192 * overwrite parts of the existing refcount and L1 table, which is not
4193 * an issue because the dirty flag is set, complete data loss is in fact
4194 * desired and partial data loss is consequently fine as well */
4195 ret
= bdrv_pwrite_zeroes(bs
->file
, s
->cluster_size
,
4196 (2 + l1_clusters
) * s
->cluster_size
, 0);
4197 /* This call (even if it failed overall) may have overwritten on-disk
4198 * refcount structures; in that case, the in-memory refcount information
4199 * will probably differ from the on-disk information which makes the BDS
4202 goto fail_broken_refcounts
;
4205 BLKDBG_EVENT(bs
->file
, BLKDBG_L1_UPDATE
);
4206 BLKDBG_EVENT(bs
->file
, BLKDBG_REFTABLE_UPDATE
);
4208 /* "Create" an empty reftable (one cluster) directly after the image
4209 * header and an empty L1 table three clusters after the image header;
4210 * the cluster between those two will be used as the first refblock */
4211 l1_ofs_rt_ofs_cls
.l1_offset
= cpu_to_be64(3 * s
->cluster_size
);
4212 l1_ofs_rt_ofs_cls
.reftable_offset
= cpu_to_be64(s
->cluster_size
);
4213 l1_ofs_rt_ofs_cls
.reftable_clusters
= cpu_to_be32(1);
4214 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, l1_table_offset
),
4215 &l1_ofs_rt_ofs_cls
, sizeof(l1_ofs_rt_ofs_cls
));
4217 goto fail_broken_refcounts
;
4220 s
->l1_table_offset
= 3 * s
->cluster_size
;
4222 new_reftable
= g_try_new0(uint64_t, s
->cluster_size
/ sizeof(uint64_t));
4223 if (!new_reftable
) {
4225 goto fail_broken_refcounts
;
4228 s
->refcount_table_offset
= s
->cluster_size
;
4229 s
->refcount_table_size
= s
->cluster_size
/ sizeof(uint64_t);
4230 s
->max_refcount_table_index
= 0;
4232 g_free(s
->refcount_table
);
4233 s
->refcount_table
= new_reftable
;
4234 new_reftable
= NULL
;
4236 /* Now the in-memory refcount information again corresponds to the on-disk
4237 * information (reftable is empty and no refblocks (the refblock cache is
4238 * empty)); however, this means some clusters (e.g. the image header) are
4239 * referenced, but not refcounted, but the normal qcow2 code assumes that
4240 * the in-memory information is always correct */
4242 BLKDBG_EVENT(bs
->file
, BLKDBG_REFBLOCK_ALLOC
);
4244 /* Enter the first refblock into the reftable */
4245 rt_entry
= cpu_to_be64(2 * s
->cluster_size
);
4246 ret
= bdrv_pwrite_sync(bs
->file
, s
->cluster_size
,
4247 &rt_entry
, sizeof(rt_entry
));
4249 goto fail_broken_refcounts
;
4251 s
->refcount_table
[0] = 2 * s
->cluster_size
;
4253 s
->free_cluster_index
= 0;
4254 assert(3 + l1_clusters
<= s
->refcount_block_size
);
4255 offset
= qcow2_alloc_clusters(bs
, 3 * s
->cluster_size
+ l1_size2
);
4258 goto fail_broken_refcounts
;
4259 } else if (offset
> 0) {
4260 error_report("First cluster in emptied image is in use");
4264 /* Now finally the in-memory information corresponds to the on-disk
4265 * structures and is correct */
4266 ret
= qcow2_mark_clean(bs
);
4271 ret
= bdrv_truncate(bs
->file
, (3 + l1_clusters
) * s
->cluster_size
,
4272 PREALLOC_MODE_OFF
, &local_err
);
4274 error_report_err(local_err
);
4280 fail_broken_refcounts
:
4281 /* The BDS is unusable at this point. If we wanted to make it usable, we
4282 * would have to call qcow2_refcount_close(), qcow2_refcount_init(),
4283 * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init()
4284 * again. However, because the functions which could have caused this error
4285 * path to be taken are used by those functions as well, it's very likely
4286 * that that sequence will fail as well. Therefore, just eject the BDS. */
4290 g_free(new_reftable
);
4294 static int qcow2_make_empty(BlockDriverState
*bs
)
4296 BDRVQcow2State
*s
= bs
->opaque
;
4297 uint64_t offset
, end_offset
;
4298 int step
= QEMU_ALIGN_DOWN(INT_MAX
, s
->cluster_size
);
4299 int l1_clusters
, ret
= 0;
4301 l1_clusters
= DIV_ROUND_UP(s
->l1_size
, s
->cluster_size
/ sizeof(uint64_t));
4303 if (s
->qcow_version
>= 3 && !s
->snapshots
&& !s
->nb_bitmaps
&&
4304 3 + l1_clusters
<= s
->refcount_block_size
&&
4305 s
->crypt_method_header
!= QCOW_CRYPT_LUKS
&&
4306 !has_data_file(bs
)) {
4307 /* The following function only works for qcow2 v3 images (it
4308 * requires the dirty flag) and only as long as there are no
4309 * features that reserve extra clusters (such as snapshots,
4310 * LUKS header, or persistent bitmaps), because it completely
4311 * empties the image. Furthermore, the L1 table and three
4312 * additional clusters (image header, refcount table, one
4313 * refcount block) have to fit inside one refcount block. It
4314 * only resets the image file, i.e. does not work with an
4315 * external data file. */
4316 return make_completely_empty(bs
);
4319 /* This fallback code simply discards every active cluster; this is slow,
4320 * but works in all cases */
4321 end_offset
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
4322 for (offset
= 0; offset
< end_offset
; offset
+= step
) {
4323 /* As this function is generally used after committing an external
4324 * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the
4325 * default action for this kind of discard is to pass the discard,
4326 * which will ideally result in an actually smaller image file, as
4327 * is probably desired. */
4328 ret
= qcow2_cluster_discard(bs
, offset
, MIN(step
, end_offset
- offset
),
4329 QCOW2_DISCARD_SNAPSHOT
, true);
4338 static coroutine_fn
int qcow2_co_flush_to_os(BlockDriverState
*bs
)
4340 BDRVQcow2State
*s
= bs
->opaque
;
4343 qemu_co_mutex_lock(&s
->lock
);
4344 ret
= qcow2_write_caches(bs
);
4345 qemu_co_mutex_unlock(&s
->lock
);
4350 static ssize_t
qcow2_measure_crypto_hdr_init_func(QCryptoBlock
*block
,
4351 size_t headerlen
, void *opaque
, Error
**errp
)
4353 size_t *headerlenp
= opaque
;
4355 /* Stash away the payload size */
4356 *headerlenp
= headerlen
;
4360 static ssize_t
qcow2_measure_crypto_hdr_write_func(QCryptoBlock
*block
,
4361 size_t offset
, const uint8_t *buf
, size_t buflen
,
4362 void *opaque
, Error
**errp
)
4364 /* Discard the bytes, we're not actually writing to an image */
4368 /* Determine the number of bytes for the LUKS payload */
4369 static bool qcow2_measure_luks_headerlen(QemuOpts
*opts
, size_t *len
,
4373 QDict
*cryptoopts_qdict
;
4374 QCryptoBlockCreateOptions
*cryptoopts
;
4375 QCryptoBlock
*crypto
;
4377 /* Extract "encrypt." options into a qdict */
4378 opts_qdict
= qemu_opts_to_qdict(opts
, NULL
);
4379 qdict_extract_subqdict(opts_qdict
, &cryptoopts_qdict
, "encrypt.");
4380 qobject_unref(opts_qdict
);
4382 /* Build QCryptoBlockCreateOptions object from qdict */
4383 qdict_put_str(cryptoopts_qdict
, "format", "luks");
4384 cryptoopts
= block_crypto_create_opts_init(cryptoopts_qdict
, errp
);
4385 qobject_unref(cryptoopts_qdict
);
4390 /* Fake LUKS creation in order to determine the payload size */
4391 crypto
= qcrypto_block_create(cryptoopts
, "encrypt.",
4392 qcow2_measure_crypto_hdr_init_func
,
4393 qcow2_measure_crypto_hdr_write_func
,
4395 qapi_free_QCryptoBlockCreateOptions(cryptoopts
);
4400 qcrypto_block_free(crypto
);
4404 static BlockMeasureInfo
*qcow2_measure(QemuOpts
*opts
, BlockDriverState
*in_bs
,
4407 Error
*local_err
= NULL
;
4408 BlockMeasureInfo
*info
;
4409 uint64_t required
= 0; /* bytes that contribute to required size */
4410 uint64_t virtual_size
; /* disk size as seen by guest */
4411 uint64_t refcount_bits
;
4413 uint64_t luks_payload_size
= 0;
4414 size_t cluster_size
;
4417 PreallocMode prealloc
;
4418 bool has_backing_file
;
4421 /* Parse image creation options */
4422 cluster_size
= qcow2_opt_get_cluster_size_del(opts
, &local_err
);
4427 version
= qcow2_opt_get_version_del(opts
, &local_err
);
4432 refcount_bits
= qcow2_opt_get_refcount_bits_del(opts
, version
, &local_err
);
4437 optstr
= qemu_opt_get_del(opts
, BLOCK_OPT_PREALLOC
);
4438 prealloc
= qapi_enum_parse(&PreallocMode_lookup
, optstr
,
4439 PREALLOC_MODE_OFF
, &local_err
);
4445 optstr
= qemu_opt_get_del(opts
, BLOCK_OPT_BACKING_FILE
);
4446 has_backing_file
= !!optstr
;
4449 optstr
= qemu_opt_get_del(opts
, BLOCK_OPT_ENCRYPT_FORMAT
);
4450 has_luks
= optstr
&& strcmp(optstr
, "luks") == 0;
4456 if (!qcow2_measure_luks_headerlen(opts
, &headerlen
, &local_err
)) {
4460 luks_payload_size
= ROUND_UP(headerlen
, cluster_size
);
4463 virtual_size
= qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0);
4464 virtual_size
= ROUND_UP(virtual_size
, cluster_size
);
4466 /* Check that virtual disk size is valid */
4467 l2_tables
= DIV_ROUND_UP(virtual_size
/ cluster_size
,
4468 cluster_size
/ sizeof(uint64_t));
4469 if (l2_tables
* sizeof(uint64_t) > QCOW_MAX_L1_SIZE
) {
4470 error_setg(&local_err
, "The image size is too large "
4471 "(try using a larger cluster size)");
4475 /* Account for input image */
4477 int64_t ssize
= bdrv_getlength(in_bs
);
4479 error_setg_errno(&local_err
, -ssize
,
4480 "Unable to get image virtual_size");
4484 virtual_size
= ROUND_UP(ssize
, cluster_size
);
4486 if (has_backing_file
) {
4487 /* We don't how much of the backing chain is shared by the input
4488 * image and the new image file. In the worst case the new image's
4489 * backing file has nothing in common with the input image. Be
4490 * conservative and assume all clusters need to be written.
4492 required
= virtual_size
;
4497 for (offset
= 0; offset
< ssize
; offset
+= pnum
) {
4500 ret
= bdrv_block_status_above(in_bs
, NULL
, offset
,
4501 ssize
- offset
, &pnum
, NULL
,
4504 error_setg_errno(&local_err
, -ret
,
4505 "Unable to get block status");
4509 if (ret
& BDRV_BLOCK_ZERO
) {
4510 /* Skip zero regions (safe with no backing file) */
4511 } else if ((ret
& (BDRV_BLOCK_DATA
| BDRV_BLOCK_ALLOCATED
)) ==
4512 (BDRV_BLOCK_DATA
| BDRV_BLOCK_ALLOCATED
)) {
4513 /* Extend pnum to end of cluster for next iteration */
4514 pnum
= ROUND_UP(offset
+ pnum
, cluster_size
) - offset
;
4516 /* Count clusters we've seen */
4517 required
+= offset
% cluster_size
+ pnum
;
4523 /* Take into account preallocation. Nothing special is needed for
4524 * PREALLOC_MODE_METADATA since metadata is always counted.
4526 if (prealloc
== PREALLOC_MODE_FULL
|| prealloc
== PREALLOC_MODE_FALLOC
) {
4527 required
= virtual_size
;
4530 info
= g_new(BlockMeasureInfo
, 1);
4531 info
->fully_allocated
=
4532 qcow2_calc_prealloc_size(virtual_size
, cluster_size
,
4533 ctz32(refcount_bits
)) + luks_payload_size
;
4535 /* Remove data clusters that are not required. This overestimates the
4536 * required size because metadata needed for the fully allocated file is
4539 info
->required
= info
->fully_allocated
- virtual_size
+ required
;
4543 error_propagate(errp
, local_err
);
4547 static int qcow2_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
4549 BDRVQcow2State
*s
= bs
->opaque
;
4550 bdi
->unallocated_blocks_are_zero
= true;
4551 bdi
->cluster_size
= s
->cluster_size
;
4552 bdi
->vm_state_offset
= qcow2_vm_state_offset(s
);
4556 static ImageInfoSpecific
*qcow2_get_specific_info(BlockDriverState
*bs
,
4559 BDRVQcow2State
*s
= bs
->opaque
;
4560 ImageInfoSpecific
*spec_info
;
4561 QCryptoBlockInfo
*encrypt_info
= NULL
;
4562 Error
*local_err
= NULL
;
4564 if (s
->crypto
!= NULL
) {
4565 encrypt_info
= qcrypto_block_get_info(s
->crypto
, &local_err
);
4567 error_propagate(errp
, local_err
);
4572 spec_info
= g_new(ImageInfoSpecific
, 1);
4573 *spec_info
= (ImageInfoSpecific
){
4574 .type
= IMAGE_INFO_SPECIFIC_KIND_QCOW2
,
4575 .u
.qcow2
.data
= g_new0(ImageInfoSpecificQCow2
, 1),
4577 if (s
->qcow_version
== 2) {
4578 *spec_info
->u
.qcow2
.data
= (ImageInfoSpecificQCow2
){
4579 .compat
= g_strdup("0.10"),
4580 .refcount_bits
= s
->refcount_bits
,
4582 } else if (s
->qcow_version
== 3) {
4583 Qcow2BitmapInfoList
*bitmaps
;
4584 bitmaps
= qcow2_get_bitmap_info_list(bs
, &local_err
);
4586 error_propagate(errp
, local_err
);
4587 qapi_free_ImageInfoSpecific(spec_info
);
4590 *spec_info
->u
.qcow2
.data
= (ImageInfoSpecificQCow2
){
4591 .compat
= g_strdup("1.1"),
4592 .lazy_refcounts
= s
->compatible_features
&
4593 QCOW2_COMPAT_LAZY_REFCOUNTS
,
4594 .has_lazy_refcounts
= true,
4595 .corrupt
= s
->incompatible_features
&
4596 QCOW2_INCOMPAT_CORRUPT
,
4597 .has_corrupt
= true,
4598 .refcount_bits
= s
->refcount_bits
,
4599 .has_bitmaps
= !!bitmaps
,
4601 .has_data_file
= !!s
->image_data_file
,
4602 .data_file
= g_strdup(s
->image_data_file
),
4603 .has_data_file_raw
= has_data_file(bs
),
4604 .data_file_raw
= data_file_is_raw(bs
),
4607 /* if this assertion fails, this probably means a new version was
4608 * added without having it covered here */
4613 ImageInfoSpecificQCow2Encryption
*qencrypt
=
4614 g_new(ImageInfoSpecificQCow2Encryption
, 1);
4615 switch (encrypt_info
->format
) {
4616 case Q_CRYPTO_BLOCK_FORMAT_QCOW
:
4617 qencrypt
->format
= BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES
;
4619 case Q_CRYPTO_BLOCK_FORMAT_LUKS
:
4620 qencrypt
->format
= BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS
;
4621 qencrypt
->u
.luks
= encrypt_info
->u
.luks
;
4626 /* Since we did shallow copy above, erase any pointers
4627 * in the original info */
4628 memset(&encrypt_info
->u
, 0, sizeof(encrypt_info
->u
));
4629 qapi_free_QCryptoBlockInfo(encrypt_info
);
4631 spec_info
->u
.qcow2
.data
->has_encrypt
= true;
4632 spec_info
->u
.qcow2
.data
->encrypt
= qencrypt
;
4638 static int qcow2_has_zero_init(BlockDriverState
*bs
)
4640 BDRVQcow2State
*s
= bs
->opaque
;
4643 if (qemu_in_coroutine()) {
4644 qemu_co_mutex_lock(&s
->lock
);
4647 * Check preallocation status: Preallocated images have all L2
4648 * tables allocated, nonpreallocated images have none. It is
4649 * therefore enough to check the first one.
4651 preallocated
= s
->l1_size
> 0 && s
->l1_table
[0] != 0;
4652 if (qemu_in_coroutine()) {
4653 qemu_co_mutex_unlock(&s
->lock
);
4656 if (!preallocated
) {
4658 } else if (bs
->encrypted
) {
4661 return bdrv_has_zero_init(s
->data_file
->bs
);
4665 static int qcow2_save_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
4668 BDRVQcow2State
*s
= bs
->opaque
;
4670 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_SAVE
);
4671 return bs
->drv
->bdrv_co_pwritev_part(bs
, qcow2_vm_state_offset(s
) + pos
,
4672 qiov
->size
, qiov
, 0, 0);
4675 static int qcow2_load_vmstate(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
4678 BDRVQcow2State
*s
= bs
->opaque
;
4680 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_LOAD
);
4681 return bs
->drv
->bdrv_co_preadv_part(bs
, qcow2_vm_state_offset(s
) + pos
,
4682 qiov
->size
, qiov
, 0, 0);
4686 * Downgrades an image's version. To achieve this, any incompatible features
4687 * have to be removed.
4689 static int qcow2_downgrade(BlockDriverState
*bs
, int target_version
,
4690 BlockDriverAmendStatusCB
*status_cb
, void *cb_opaque
,
4693 BDRVQcow2State
*s
= bs
->opaque
;
4694 int current_version
= s
->qcow_version
;
4697 /* This is qcow2_downgrade(), not qcow2_upgrade() */
4698 assert(target_version
< current_version
);
4700 /* There are no other versions (now) that you can downgrade to */
4701 assert(target_version
== 2);
4703 if (s
->refcount_order
!= 4) {
4704 error_setg(errp
, "compat=0.10 requires refcount_bits=16");
4708 if (has_data_file(bs
)) {
4709 error_setg(errp
, "Cannot downgrade an image with a data file");
4713 /* clear incompatible features */
4714 if (s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
) {
4715 ret
= qcow2_mark_clean(bs
);
4717 error_setg_errno(errp
, -ret
, "Failed to make the image clean");
4722 /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
4723 * the first place; if that happens nonetheless, returning -ENOTSUP is the
4724 * best thing to do anyway */
4726 if (s
->incompatible_features
) {
4727 error_setg(errp
, "Cannot downgrade an image with incompatible features "
4728 "%#" PRIx64
" set", s
->incompatible_features
);
4732 /* since we can ignore compatible features, we can set them to 0 as well */
4733 s
->compatible_features
= 0;
4734 /* if lazy refcounts have been used, they have already been fixed through
4735 * clearing the dirty flag */
4737 /* clearing autoclear features is trivial */
4738 s
->autoclear_features
= 0;
4740 ret
= qcow2_expand_zero_clusters(bs
, status_cb
, cb_opaque
);
4742 error_setg_errno(errp
, -ret
, "Failed to turn zero into data clusters");
4746 s
->qcow_version
= target_version
;
4747 ret
= qcow2_update_header(bs
);
4749 s
->qcow_version
= current_version
;
4750 error_setg_errno(errp
, -ret
, "Failed to update the image header");
4756 typedef enum Qcow2AmendOperation
{
4757 /* This is the value Qcow2AmendHelperCBInfo::last_operation will be
4758 * statically initialized to so that the helper CB can discern the first
4759 * invocation from an operation change */
4760 QCOW2_NO_OPERATION
= 0,
4762 QCOW2_CHANGING_REFCOUNT_ORDER
,
4764 } Qcow2AmendOperation
;
4766 typedef struct Qcow2AmendHelperCBInfo
{
4767 /* The code coordinating the amend operations should only modify
4768 * these four fields; the rest will be managed by the CB */
4769 BlockDriverAmendStatusCB
*original_status_cb
;
4770 void *original_cb_opaque
;
4772 Qcow2AmendOperation current_operation
;
4774 /* Total number of operations to perform (only set once) */
4775 int total_operations
;
4777 /* The following fields are managed by the CB */
4779 /* Number of operations completed */
4780 int operations_completed
;
4782 /* Cumulative offset of all completed operations */
4783 int64_t offset_completed
;
4785 Qcow2AmendOperation last_operation
;
4786 int64_t last_work_size
;
4787 } Qcow2AmendHelperCBInfo
;
4789 static void qcow2_amend_helper_cb(BlockDriverState
*bs
,
4790 int64_t operation_offset
,
4791 int64_t operation_work_size
, void *opaque
)
4793 Qcow2AmendHelperCBInfo
*info
= opaque
;
4794 int64_t current_work_size
;
4795 int64_t projected_work_size
;
4797 if (info
->current_operation
!= info
->last_operation
) {
4798 if (info
->last_operation
!= QCOW2_NO_OPERATION
) {
4799 info
->offset_completed
+= info
->last_work_size
;
4800 info
->operations_completed
++;
4803 info
->last_operation
= info
->current_operation
;
4806 assert(info
->total_operations
> 0);
4807 assert(info
->operations_completed
< info
->total_operations
);
4809 info
->last_work_size
= operation_work_size
;
4811 current_work_size
= info
->offset_completed
+ operation_work_size
;
4813 /* current_work_size is the total work size for (operations_completed + 1)
4814 * operations (which includes this one), so multiply it by the number of
4815 * operations not covered and divide it by the number of operations
4816 * covered to get a projection for the operations not covered */
4817 projected_work_size
= current_work_size
* (info
->total_operations
-
4818 info
->operations_completed
- 1)
4819 / (info
->operations_completed
+ 1);
4821 info
->original_status_cb(bs
, info
->offset_completed
+ operation_offset
,
4822 current_work_size
+ projected_work_size
,
4823 info
->original_cb_opaque
);
4826 static int qcow2_amend_options(BlockDriverState
*bs
, QemuOpts
*opts
,
4827 BlockDriverAmendStatusCB
*status_cb
,
4831 BDRVQcow2State
*s
= bs
->opaque
;
4832 int old_version
= s
->qcow_version
, new_version
= old_version
;
4833 uint64_t new_size
= 0;
4834 const char *backing_file
= NULL
, *backing_format
= NULL
, *data_file
= NULL
;
4835 bool lazy_refcounts
= s
->use_lazy_refcounts
;
4836 bool data_file_raw
= data_file_is_raw(bs
);
4837 const char *compat
= NULL
;
4838 uint64_t cluster_size
= s
->cluster_size
;
4841 int refcount_bits
= s
->refcount_bits
;
4843 QemuOptDesc
*desc
= opts
->list
->desc
;
4844 Qcow2AmendHelperCBInfo helper_cb_info
;
4846 while (desc
&& desc
->name
) {
4847 if (!qemu_opt_find(opts
, desc
->name
)) {
4848 /* only change explicitly defined options */
4853 if (!strcmp(desc
->name
, BLOCK_OPT_COMPAT_LEVEL
)) {
4854 compat
= qemu_opt_get(opts
, BLOCK_OPT_COMPAT_LEVEL
);
4856 /* preserve default */
4857 } else if (!strcmp(compat
, "0.10") || !strcmp(compat
, "v2")) {
4859 } else if (!strcmp(compat
, "1.1") || !strcmp(compat
, "v3")) {
4862 error_setg(errp
, "Unknown compatibility level %s", compat
);
4865 } else if (!strcmp(desc
->name
, BLOCK_OPT_PREALLOC
)) {
4866 error_setg(errp
, "Cannot change preallocation mode");
4868 } else if (!strcmp(desc
->name
, BLOCK_OPT_SIZE
)) {
4869 new_size
= qemu_opt_get_size(opts
, BLOCK_OPT_SIZE
, 0);
4870 } else if (!strcmp(desc
->name
, BLOCK_OPT_BACKING_FILE
)) {
4871 backing_file
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FILE
);
4872 } else if (!strcmp(desc
->name
, BLOCK_OPT_BACKING_FMT
)) {
4873 backing_format
= qemu_opt_get(opts
, BLOCK_OPT_BACKING_FMT
);
4874 } else if (!strcmp(desc
->name
, BLOCK_OPT_ENCRYPT
)) {
4875 encrypt
= qemu_opt_get_bool(opts
, BLOCK_OPT_ENCRYPT
,
4878 if (encrypt
!= !!s
->crypto
) {
4880 "Changing the encryption flag is not supported");
4883 } else if (!strcmp(desc
->name
, BLOCK_OPT_ENCRYPT_FORMAT
)) {
4884 encformat
= qcow2_crypt_method_from_format(
4885 qemu_opt_get(opts
, BLOCK_OPT_ENCRYPT_FORMAT
));
4887 if (encformat
!= s
->crypt_method_header
) {
4889 "Changing the encryption format is not supported");
4892 } else if (g_str_has_prefix(desc
->name
, "encrypt.")) {
4894 "Changing the encryption parameters is not supported");
4896 } else if (!strcmp(desc
->name
, BLOCK_OPT_CLUSTER_SIZE
)) {
4897 cluster_size
= qemu_opt_get_size(opts
, BLOCK_OPT_CLUSTER_SIZE
,
4899 if (cluster_size
!= s
->cluster_size
) {
4900 error_setg(errp
, "Changing the cluster size is not supported");
4903 } else if (!strcmp(desc
->name
, BLOCK_OPT_LAZY_REFCOUNTS
)) {
4904 lazy_refcounts
= qemu_opt_get_bool(opts
, BLOCK_OPT_LAZY_REFCOUNTS
,
4906 } else if (!strcmp(desc
->name
, BLOCK_OPT_REFCOUNT_BITS
)) {
4907 refcount_bits
= qemu_opt_get_number(opts
, BLOCK_OPT_REFCOUNT_BITS
,
4910 if (refcount_bits
<= 0 || refcount_bits
> 64 ||
4911 !is_power_of_2(refcount_bits
))
4913 error_setg(errp
, "Refcount width must be a power of two and "
4914 "may not exceed 64 bits");
4917 } else if (!strcmp(desc
->name
, BLOCK_OPT_DATA_FILE
)) {
4918 data_file
= qemu_opt_get(opts
, BLOCK_OPT_DATA_FILE
);
4919 if (data_file
&& !has_data_file(bs
)) {
4920 error_setg(errp
, "data-file can only be set for images that "
4921 "use an external data file");
4924 } else if (!strcmp(desc
->name
, BLOCK_OPT_DATA_FILE_RAW
)) {
4925 data_file_raw
= qemu_opt_get_bool(opts
, BLOCK_OPT_DATA_FILE_RAW
,
4927 if (data_file_raw
&& !data_file_is_raw(bs
)) {
4928 error_setg(errp
, "data-file-raw cannot be set on existing "
4933 /* if this point is reached, this probably means a new option was
4934 * added without having it covered here */
4941 helper_cb_info
= (Qcow2AmendHelperCBInfo
){
4942 .original_status_cb
= status_cb
,
4943 .original_cb_opaque
= cb_opaque
,
4944 .total_operations
= (new_version
< old_version
)
4945 + (s
->refcount_bits
!= refcount_bits
)
4948 /* Upgrade first (some features may require compat=1.1) */
4949 if (new_version
> old_version
) {
4950 s
->qcow_version
= new_version
;
4951 ret
= qcow2_update_header(bs
);
4953 s
->qcow_version
= old_version
;
4954 error_setg_errno(errp
, -ret
, "Failed to update the image header");
4959 if (s
->refcount_bits
!= refcount_bits
) {
4960 int refcount_order
= ctz32(refcount_bits
);
4962 if (new_version
< 3 && refcount_bits
!= 16) {
4963 error_setg(errp
, "Refcount widths other than 16 bits require "
4964 "compatibility level 1.1 or above (use compat=1.1 or "
4969 helper_cb_info
.current_operation
= QCOW2_CHANGING_REFCOUNT_ORDER
;
4970 ret
= qcow2_change_refcount_order(bs
, refcount_order
,
4971 &qcow2_amend_helper_cb
,
4972 &helper_cb_info
, errp
);
4978 /* data-file-raw blocks backing files, so clear it first if requested */
4979 if (data_file_raw
) {
4980 s
->autoclear_features
|= QCOW2_AUTOCLEAR_DATA_FILE_RAW
;
4982 s
->autoclear_features
&= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW
;
4986 g_free(s
->image_data_file
);
4987 s
->image_data_file
= *data_file
? g_strdup(data_file
) : NULL
;
4990 ret
= qcow2_update_header(bs
);
4992 error_setg_errno(errp
, -ret
, "Failed to update the image header");
4996 if (backing_file
|| backing_format
) {
4997 ret
= qcow2_change_backing_file(bs
,
4998 backing_file
?: s
->image_backing_file
,
4999 backing_format
?: s
->image_backing_format
);
5001 error_setg_errno(errp
, -ret
, "Failed to change the backing file");
5006 if (s
->use_lazy_refcounts
!= lazy_refcounts
) {
5007 if (lazy_refcounts
) {
5008 if (new_version
< 3) {
5009 error_setg(errp
, "Lazy refcounts only supported with "
5010 "compatibility level 1.1 and above (use compat=1.1 "
5014 s
->compatible_features
|= QCOW2_COMPAT_LAZY_REFCOUNTS
;
5015 ret
= qcow2_update_header(bs
);
5017 s
->compatible_features
&= ~QCOW2_COMPAT_LAZY_REFCOUNTS
;
5018 error_setg_errno(errp
, -ret
, "Failed to update the image header");
5021 s
->use_lazy_refcounts
= true;
5023 /* make image clean first */
5024 ret
= qcow2_mark_clean(bs
);
5026 error_setg_errno(errp
, -ret
, "Failed to make the image clean");
5029 /* now disallow lazy refcounts */
5030 s
->compatible_features
&= ~QCOW2_COMPAT_LAZY_REFCOUNTS
;
5031 ret
= qcow2_update_header(bs
);
5033 s
->compatible_features
|= QCOW2_COMPAT_LAZY_REFCOUNTS
;
5034 error_setg_errno(errp
, -ret
, "Failed to update the image header");
5037 s
->use_lazy_refcounts
= false;
5042 BlockBackend
*blk
= blk_new(bdrv_get_aio_context(bs
),
5043 BLK_PERM_RESIZE
, BLK_PERM_ALL
);
5044 ret
= blk_insert_bs(blk
, bs
, errp
);
5050 ret
= blk_truncate(blk
, new_size
, PREALLOC_MODE_OFF
, errp
);
5057 /* Downgrade last (so unsupported features can be removed before) */
5058 if (new_version
< old_version
) {
5059 helper_cb_info
.current_operation
= QCOW2_DOWNGRADING
;
5060 ret
= qcow2_downgrade(bs
, new_version
, &qcow2_amend_helper_cb
,
5061 &helper_cb_info
, errp
);
5071 * If offset or size are negative, respectively, they will not be included in
5072 * the BLOCK_IMAGE_CORRUPTED event emitted.
5073 * fatal will be ignored for read-only BDS; corruptions found there will always
5074 * be considered non-fatal.
5076 void qcow2_signal_corruption(BlockDriverState
*bs
, bool fatal
, int64_t offset
,
5077 int64_t size
, const char *message_format
, ...)
5079 BDRVQcow2State
*s
= bs
->opaque
;
5080 const char *node_name
;
5084 fatal
= fatal
&& bdrv_is_writable(bs
);
5086 if (s
->signaled_corruption
&&
5087 (!fatal
|| (s
->incompatible_features
& QCOW2_INCOMPAT_CORRUPT
)))
5092 va_start(ap
, message_format
);
5093 message
= g_strdup_vprintf(message_format
, ap
);
5097 fprintf(stderr
, "qcow2: Marking image as corrupt: %s; further "
5098 "corruption events will be suppressed\n", message
);
5100 fprintf(stderr
, "qcow2: Image is corrupt: %s; further non-fatal "
5101 "corruption events will be suppressed\n", message
);
5104 node_name
= bdrv_get_node_name(bs
);
5105 qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs
),
5106 *node_name
!= '\0', node_name
,
5107 message
, offset
>= 0, offset
,
5113 qcow2_mark_corrupt(bs
);
5114 bs
->drv
= NULL
; /* make BDS unusable */
5117 s
->signaled_corruption
= true;
5120 static QemuOptsList qcow2_create_opts
= {
5121 .name
= "qcow2-create-opts",
5122 .head
= QTAILQ_HEAD_INITIALIZER(qcow2_create_opts
.head
),
5125 .name
= BLOCK_OPT_SIZE
,
5126 .type
= QEMU_OPT_SIZE
,
5127 .help
= "Virtual disk size"
5130 .name
= BLOCK_OPT_COMPAT_LEVEL
,
5131 .type
= QEMU_OPT_STRING
,
5132 .help
= "Compatibility level (v2 [0.10] or v3 [1.1])"
5135 .name
= BLOCK_OPT_BACKING_FILE
,
5136 .type
= QEMU_OPT_STRING
,
5137 .help
= "File name of a base image"
5140 .name
= BLOCK_OPT_BACKING_FMT
,
5141 .type
= QEMU_OPT_STRING
,
5142 .help
= "Image format of the base image"
5145 .name
= BLOCK_OPT_DATA_FILE
,
5146 .type
= QEMU_OPT_STRING
,
5147 .help
= "File name of an external data file"
5150 .name
= BLOCK_OPT_DATA_FILE_RAW
,
5151 .type
= QEMU_OPT_BOOL
,
5152 .help
= "The external data file must stay valid as a raw image"
5155 .name
= BLOCK_OPT_ENCRYPT
,
5156 .type
= QEMU_OPT_BOOL
,
5157 .help
= "Encrypt the image with format 'aes'. (Deprecated "
5158 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT
"=aes)",
5161 .name
= BLOCK_OPT_ENCRYPT_FORMAT
,
5162 .type
= QEMU_OPT_STRING
,
5163 .help
= "Encrypt the image, format choices: 'aes', 'luks'",
5165 BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
5166 "ID of secret providing qcow AES key or LUKS passphrase"),
5167 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."),
5168 BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."),
5169 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."),
5170 BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."),
5171 BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."),
5172 BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."),
5174 .name
= BLOCK_OPT_CLUSTER_SIZE
,
5175 .type
= QEMU_OPT_SIZE
,
5176 .help
= "qcow2 cluster size",
5177 .def_value_str
= stringify(DEFAULT_CLUSTER_SIZE
)
5180 .name
= BLOCK_OPT_PREALLOC
,
5181 .type
= QEMU_OPT_STRING
,
5182 .help
= "Preallocation mode (allowed values: off, metadata, "
5186 .name
= BLOCK_OPT_LAZY_REFCOUNTS
,
5187 .type
= QEMU_OPT_BOOL
,
5188 .help
= "Postpone refcount updates",
5189 .def_value_str
= "off"
5192 .name
= BLOCK_OPT_REFCOUNT_BITS
,
5193 .type
= QEMU_OPT_NUMBER
,
5194 .help
= "Width of a reference count entry in bits",
5195 .def_value_str
= "16"
5197 { /* end of list */ }
5201 static const char *const qcow2_strong_runtime_opts
[] = {
5202 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET
,
5207 BlockDriver bdrv_qcow2
= {
5208 .format_name
= "qcow2",
5209 .instance_size
= sizeof(BDRVQcow2State
),
5210 .bdrv_probe
= qcow2_probe
,
5211 .bdrv_open
= qcow2_open
,
5212 .bdrv_close
= qcow2_close
,
5213 .bdrv_reopen_prepare
= qcow2_reopen_prepare
,
5214 .bdrv_reopen_commit
= qcow2_reopen_commit
,
5215 .bdrv_reopen_abort
= qcow2_reopen_abort
,
5216 .bdrv_join_options
= qcow2_join_options
,
5217 .bdrv_child_perm
= bdrv_format_default_perms
,
5218 .bdrv_co_create_opts
= qcow2_co_create_opts
,
5219 .bdrv_co_create
= qcow2_co_create
,
5220 .bdrv_has_zero_init
= qcow2_has_zero_init
,
5221 .bdrv_has_zero_init_truncate
= bdrv_has_zero_init_1
,
5222 .bdrv_co_block_status
= qcow2_co_block_status
,
5224 .bdrv_co_preadv_part
= qcow2_co_preadv_part
,
5225 .bdrv_co_pwritev_part
= qcow2_co_pwritev_part
,
5226 .bdrv_co_flush_to_os
= qcow2_co_flush_to_os
,
5228 .bdrv_co_pwrite_zeroes
= qcow2_co_pwrite_zeroes
,
5229 .bdrv_co_pdiscard
= qcow2_co_pdiscard
,
5230 .bdrv_co_copy_range_from
= qcow2_co_copy_range_from
,
5231 .bdrv_co_copy_range_to
= qcow2_co_copy_range_to
,
5232 .bdrv_co_truncate
= qcow2_co_truncate
,
5233 .bdrv_co_pwritev_compressed_part
= qcow2_co_pwritev_compressed_part
,
5234 .bdrv_make_empty
= qcow2_make_empty
,
5236 .bdrv_snapshot_create
= qcow2_snapshot_create
,
5237 .bdrv_snapshot_goto
= qcow2_snapshot_goto
,
5238 .bdrv_snapshot_delete
= qcow2_snapshot_delete
,
5239 .bdrv_snapshot_list
= qcow2_snapshot_list
,
5240 .bdrv_snapshot_load_tmp
= qcow2_snapshot_load_tmp
,
5241 .bdrv_measure
= qcow2_measure
,
5242 .bdrv_get_info
= qcow2_get_info
,
5243 .bdrv_get_specific_info
= qcow2_get_specific_info
,
5245 .bdrv_save_vmstate
= qcow2_save_vmstate
,
5246 .bdrv_load_vmstate
= qcow2_load_vmstate
,
5248 .supports_backing
= true,
5249 .bdrv_change_backing_file
= qcow2_change_backing_file
,
5251 .bdrv_refresh_limits
= qcow2_refresh_limits
,
5252 .bdrv_co_invalidate_cache
= qcow2_co_invalidate_cache
,
5253 .bdrv_inactivate
= qcow2_inactivate
,
5255 .create_opts
= &qcow2_create_opts
,
5256 .strong_runtime_opts
= qcow2_strong_runtime_opts
,
5257 .mutable_opts
= mutable_opts
,
5258 .bdrv_co_check
= qcow2_co_check
,
5259 .bdrv_amend_options
= qcow2_amend_options
,
5261 .bdrv_detach_aio_context
= qcow2_detach_aio_context
,
5262 .bdrv_attach_aio_context
= qcow2_attach_aio_context
,
5264 .bdrv_reopen_bitmaps_rw
= qcow2_reopen_bitmaps_rw
,
5265 .bdrv_can_store_new_dirty_bitmap
= qcow2_can_store_new_dirty_bitmap
,
5266 .bdrv_remove_persistent_dirty_bitmap
= qcow2_remove_persistent_dirty_bitmap
,
5269 static void bdrv_qcow2_init(void)
5271 bdrv_register(&bdrv_qcow2
);
5274 block_init(bdrv_qcow2_init
);