2 * Block driver for the QCOW version 2 format
4 * Copyright (c) 2004-2006 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 #include "qemu-common.h"
25 #include "block_int.h"
31 Differences with QCOW:
33 - Support for multiple incremental snapshots.
34 - Memory management by reference counts.
35 - Clusters which have a reference count of one have the bit
36 QCOW_OFLAG_COPIED to optimize write performance.
37 - Size of compressed clusters is stored in sectors to reduce bit usage
38 in the cluster offsets.
39 - Support for storing additional data (such as the VM state) in the
41 - If a backing store is used, the cluster size is not constrained
42 (could be backported to QCOW).
43 - L2 tables have always a size of one cluster.
47 //#define DEBUG_ALLOC2
49 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
50 #define QCOW_VERSION 2
52 #define QCOW_CRYPT_NONE 0
53 #define QCOW_CRYPT_AES 1
55 /* indicate that the refcount of the referenced cluster is exactly one. */
56 #define QCOW_OFLAG_COPIED (1LL << 63)
57 /* indicate that the cluster is compressed (they never have the copied flag) */
58 #define QCOW_OFLAG_COMPRESSED (1LL << 62)
60 #define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */
63 #define offsetof(type, field) ((size_t) &((type *)0)->field)
66 typedef struct QCowHeader
{
69 uint64_t backing_file_offset
;
70 uint32_t backing_file_size
;
71 uint32_t cluster_bits
;
72 uint64_t size
; /* in bytes */
73 uint32_t crypt_method
;
74 uint32_t l1_size
; /* XXX: save number of clusters instead ? */
75 uint64_t l1_table_offset
;
76 uint64_t refcount_table_offset
;
77 uint32_t refcount_table_clusters
;
78 uint32_t nb_snapshots
;
79 uint64_t snapshots_offset
;
82 typedef struct __attribute__((packed
)) QCowSnapshotHeader
{
83 /* header is 8 byte aligned */
84 uint64_t l1_table_offset
;
93 uint64_t vm_clock_nsec
;
95 uint32_t vm_state_size
;
96 uint32_t extra_data_size
; /* for extension */
97 /* extra data follows */
100 } QCowSnapshotHeader
;
102 #define L2_CACHE_SIZE 16
104 typedef struct QCowSnapshot
{
105 uint64_t l1_table_offset
;
109 uint32_t vm_state_size
;
112 uint64_t vm_clock_nsec
;
115 typedef struct BDRVQcowState
{
116 BlockDriverState
*hd
;
123 int l1_vm_state_index
;
126 uint64_t cluster_offset_mask
;
127 uint64_t l1_table_offset
;
130 uint64_t l2_cache_offsets
[L2_CACHE_SIZE
];
131 uint32_t l2_cache_counts
[L2_CACHE_SIZE
];
132 uint8_t *cluster_cache
;
133 uint8_t *cluster_data
;
134 uint64_t cluster_cache_offset
;
136 uint64_t *refcount_table
;
137 uint64_t refcount_table_offset
;
138 uint32_t refcount_table_size
;
139 uint64_t refcount_block_cache_offset
;
140 uint16_t *refcount_block_cache
;
141 int64_t free_cluster_index
;
142 int64_t free_byte_offset
;
144 uint32_t crypt_method
; /* current crypt method, 0 if no key yet */
145 uint32_t crypt_method_header
;
146 AES_KEY aes_encrypt_key
;
147 AES_KEY aes_decrypt_key
;
148 uint64_t snapshots_offset
;
151 QCowSnapshot
*snapshots
;
154 static int decompress_cluster(BDRVQcowState
*s
, uint64_t cluster_offset
);
155 static int qcow_read(BlockDriverState
*bs
, int64_t sector_num
,
156 uint8_t *buf
, int nb_sectors
);
157 static int qcow_read_snapshots(BlockDriverState
*bs
);
158 static void qcow_free_snapshots(BlockDriverState
*bs
);
159 static int refcount_init(BlockDriverState
*bs
);
160 static void refcount_close(BlockDriverState
*bs
);
161 static int get_refcount(BlockDriverState
*bs
, int64_t cluster_index
);
162 static int update_cluster_refcount(BlockDriverState
*bs
,
163 int64_t cluster_index
,
165 static void update_refcount(BlockDriverState
*bs
,
166 int64_t offset
, int64_t length
,
168 static int64_t alloc_clusters(BlockDriverState
*bs
, int64_t size
);
169 static int64_t alloc_bytes(BlockDriverState
*bs
, int size
);
170 static void free_clusters(BlockDriverState
*bs
,
171 int64_t offset
, int64_t size
);
173 static void check_refcounts(BlockDriverState
*bs
);
176 static int qcow_probe(const uint8_t *buf
, int buf_size
, const char *filename
)
178 const QCowHeader
*cow_header
= (const void *)buf
;
180 if (buf_size
>= sizeof(QCowHeader
) &&
181 be32_to_cpu(cow_header
->magic
) == QCOW_MAGIC
&&
182 be32_to_cpu(cow_header
->version
) == QCOW_VERSION
)
188 static int qcow_open(BlockDriverState
*bs
, const char *filename
, int flags
)
190 BDRVQcowState
*s
= bs
->opaque
;
191 int len
, i
, shift
, ret
;
194 ret
= bdrv_file_open(&s
->hd
, filename
, flags
);
197 if (bdrv_pread(s
->hd
, 0, &header
, sizeof(header
)) != sizeof(header
))
199 be32_to_cpus(&header
.magic
);
200 be32_to_cpus(&header
.version
);
201 be64_to_cpus(&header
.backing_file_offset
);
202 be32_to_cpus(&header
.backing_file_size
);
203 be64_to_cpus(&header
.size
);
204 be32_to_cpus(&header
.cluster_bits
);
205 be32_to_cpus(&header
.crypt_method
);
206 be64_to_cpus(&header
.l1_table_offset
);
207 be32_to_cpus(&header
.l1_size
);
208 be64_to_cpus(&header
.refcount_table_offset
);
209 be32_to_cpus(&header
.refcount_table_clusters
);
210 be64_to_cpus(&header
.snapshots_offset
);
211 be32_to_cpus(&header
.nb_snapshots
);
213 if (header
.magic
!= QCOW_MAGIC
|| header
.version
!= QCOW_VERSION
)
215 if (header
.size
<= 1 ||
216 header
.cluster_bits
< 9 ||
217 header
.cluster_bits
> 16)
219 if (header
.crypt_method
> QCOW_CRYPT_AES
)
221 s
->crypt_method_header
= header
.crypt_method
;
222 if (s
->crypt_method_header
)
224 s
->cluster_bits
= header
.cluster_bits
;
225 s
->cluster_size
= 1 << s
->cluster_bits
;
226 s
->cluster_sectors
= 1 << (s
->cluster_bits
- 9);
227 s
->l2_bits
= s
->cluster_bits
- 3; /* L2 is always one cluster */
228 s
->l2_size
= 1 << s
->l2_bits
;
229 bs
->total_sectors
= header
.size
/ 512;
230 s
->csize_shift
= (62 - (s
->cluster_bits
- 8));
231 s
->csize_mask
= (1 << (s
->cluster_bits
- 8)) - 1;
232 s
->cluster_offset_mask
= (1LL << s
->csize_shift
) - 1;
233 s
->refcount_table_offset
= header
.refcount_table_offset
;
234 s
->refcount_table_size
=
235 header
.refcount_table_clusters
<< (s
->cluster_bits
- 3);
237 s
->snapshots_offset
= header
.snapshots_offset
;
238 s
->nb_snapshots
= header
.nb_snapshots
;
240 /* read the level 1 table */
241 s
->l1_size
= header
.l1_size
;
242 shift
= s
->cluster_bits
+ s
->l2_bits
;
243 s
->l1_vm_state_index
= (header
.size
+ (1LL << shift
) - 1) >> shift
;
244 /* the L1 table must contain at least enough entries to put
246 if (s
->l1_size
< s
->l1_vm_state_index
)
248 s
->l1_table_offset
= header
.l1_table_offset
;
249 s
->l1_table
= qemu_malloc(s
->l1_size
* sizeof(uint64_t));
252 if (bdrv_pread(s
->hd
, s
->l1_table_offset
, s
->l1_table
, s
->l1_size
* sizeof(uint64_t)) !=
253 s
->l1_size
* sizeof(uint64_t))
255 for(i
= 0;i
< s
->l1_size
; i
++) {
256 be64_to_cpus(&s
->l1_table
[i
]);
259 s
->l2_cache
= qemu_malloc(s
->l2_size
* L2_CACHE_SIZE
* sizeof(uint64_t));
262 s
->cluster_cache
= qemu_malloc(s
->cluster_size
);
263 if (!s
->cluster_cache
)
265 /* one more sector for decompressed data alignment */
266 s
->cluster_data
= qemu_malloc(s
->cluster_size
+ 512);
267 if (!s
->cluster_data
)
269 s
->cluster_cache_offset
= -1;
271 if (refcount_init(bs
) < 0)
274 /* read the backing file name */
275 if (header
.backing_file_offset
!= 0) {
276 len
= header
.backing_file_size
;
279 if (bdrv_pread(s
->hd
, header
.backing_file_offset
, bs
->backing_file
, len
) != len
)
281 bs
->backing_file
[len
] = '\0';
283 if (qcow_read_snapshots(bs
) < 0)
292 qcow_free_snapshots(bs
);
294 qemu_free(s
->l1_table
);
295 qemu_free(s
->l2_cache
);
296 qemu_free(s
->cluster_cache
);
297 qemu_free(s
->cluster_data
);
302 static int qcow_set_key(BlockDriverState
*bs
, const char *key
)
304 BDRVQcowState
*s
= bs
->opaque
;
308 memset(keybuf
, 0, 16);
312 /* XXX: we could compress the chars to 7 bits to increase
314 for(i
= 0;i
< len
;i
++) {
317 s
->crypt_method
= s
->crypt_method_header
;
319 if (AES_set_encrypt_key(keybuf
, 128, &s
->aes_encrypt_key
) != 0)
321 if (AES_set_decrypt_key(keybuf
, 128, &s
->aes_decrypt_key
) != 0)
331 AES_encrypt(in
, tmp
, &s
->aes_encrypt_key
);
332 AES_decrypt(tmp
, out
, &s
->aes_decrypt_key
);
333 for(i
= 0; i
< 16; i
++)
334 printf(" %02x", tmp
[i
]);
336 for(i
= 0; i
< 16; i
++)
337 printf(" %02x", out
[i
]);
344 /* The crypt function is compatible with the linux cryptoloop
345 algorithm for < 4 GB images. NOTE: out_buf == in_buf is
347 static void encrypt_sectors(BDRVQcowState
*s
, int64_t sector_num
,
348 uint8_t *out_buf
, const uint8_t *in_buf
,
349 int nb_sectors
, int enc
,
358 for(i
= 0; i
< nb_sectors
; i
++) {
359 ivec
.ll
[0] = cpu_to_le64(sector_num
);
361 AES_cbc_encrypt(in_buf
, out_buf
, 512, key
,
369 static int copy_sectors(BlockDriverState
*bs
, uint64_t start_sect
,
370 uint64_t cluster_offset
, int n_start
, int n_end
)
372 BDRVQcowState
*s
= bs
->opaque
;
378 ret
= qcow_read(bs
, start_sect
+ n_start
, s
->cluster_data
, n
);
381 if (s
->crypt_method
) {
382 encrypt_sectors(s
, start_sect
+ n_start
,
384 s
->cluster_data
, n
, 1,
385 &s
->aes_encrypt_key
);
387 ret
= bdrv_write(s
->hd
, (cluster_offset
>> 9) + n_start
,
394 static void l2_cache_reset(BlockDriverState
*bs
)
396 BDRVQcowState
*s
= bs
->opaque
;
398 memset(s
->l2_cache
, 0, s
->l2_size
* L2_CACHE_SIZE
* sizeof(uint64_t));
399 memset(s
->l2_cache_offsets
, 0, L2_CACHE_SIZE
* sizeof(uint64_t));
400 memset(s
->l2_cache_counts
, 0, L2_CACHE_SIZE
* sizeof(uint32_t));
403 static inline int l2_cache_new_entry(BlockDriverState
*bs
)
405 BDRVQcowState
*s
= bs
->opaque
;
409 /* find a new entry in the least used one */
411 min_count
= 0xffffffff;
412 for(i
= 0; i
< L2_CACHE_SIZE
; i
++) {
413 if (s
->l2_cache_counts
[i
] < min_count
) {
414 min_count
= s
->l2_cache_counts
[i
];
421 static int64_t align_offset(int64_t offset
, int n
)
423 offset
= (offset
+ n
- 1) & ~(n
- 1);
427 static int grow_l1_table(BlockDriverState
*bs
, int min_size
)
429 BDRVQcowState
*s
= bs
->opaque
;
430 int new_l1_size
, new_l1_size2
, ret
, i
;
431 uint64_t *new_l1_table
;
432 uint64_t new_l1_table_offset
;
436 new_l1_size
= s
->l1_size
;
437 if (min_size
<= new_l1_size
)
439 while (min_size
> new_l1_size
) {
440 new_l1_size
= (new_l1_size
* 3 + 1) / 2;
443 printf("grow l1_table from %d to %d\n", s
->l1_size
, new_l1_size
);
446 new_l1_size2
= sizeof(uint64_t) * new_l1_size
;
447 new_l1_table
= qemu_mallocz(new_l1_size2
);
450 memcpy(new_l1_table
, s
->l1_table
, s
->l1_size
* sizeof(uint64_t));
452 /* write new table (align to cluster) */
453 new_l1_table_offset
= alloc_clusters(bs
, new_l1_size2
);
455 for(i
= 0; i
< s
->l1_size
; i
++)
456 new_l1_table
[i
] = cpu_to_be64(new_l1_table
[i
]);
457 ret
= bdrv_pwrite(s
->hd
, new_l1_table_offset
, new_l1_table
, new_l1_size2
);
458 if (ret
!= new_l1_size2
)
460 for(i
= 0; i
< s
->l1_size
; i
++)
461 new_l1_table
[i
] = be64_to_cpu(new_l1_table
[i
]);
464 data64
= cpu_to_be64(new_l1_table_offset
);
465 if (bdrv_pwrite(s
->hd
, offsetof(QCowHeader
, l1_table_offset
),
466 &data64
, sizeof(data64
)) != sizeof(data64
))
468 data32
= cpu_to_be32(new_l1_size
);
469 if (bdrv_pwrite(s
->hd
, offsetof(QCowHeader
, l1_size
),
470 &data32
, sizeof(data32
)) != sizeof(data32
))
472 qemu_free(s
->l1_table
);
473 free_clusters(bs
, s
->l1_table_offset
, s
->l1_size
* sizeof(uint64_t));
474 s
->l1_table_offset
= new_l1_table_offset
;
475 s
->l1_table
= new_l1_table
;
476 s
->l1_size
= new_l1_size
;
479 qemu_free(s
->l1_table
);
486 * seek l2_offset in the l2_cache table
487 * if not found, return NULL,
489 * increments the l2 cache hit count of the entry,
490 * if counter overflow, divide by two all counters
491 * return the pointer to the l2 cache entry
495 static uint64_t *seek_l2_table(BDRVQcowState
*s
, uint64_t l2_offset
)
499 for(i
= 0; i
< L2_CACHE_SIZE
; i
++) {
500 if (l2_offset
== s
->l2_cache_offsets
[i
]) {
501 /* increment the hit count */
502 if (++s
->l2_cache_counts
[i
] == 0xffffffff) {
503 for(j
= 0; j
< L2_CACHE_SIZE
; j
++) {
504 s
->l2_cache_counts
[j
] >>= 1;
507 return s
->l2_cache
+ (i
<< s
->l2_bits
);
516 * Loads a L2 table into memory. If the table is in the cache, the cache
517 * is used; otherwise the L2 table is loaded from the image file.
519 * Returns a pointer to the L2 table on success, or NULL if the read from
520 * the image file failed.
523 static uint64_t *l2_load(BlockDriverState
*bs
, uint64_t l2_offset
)
525 BDRVQcowState
*s
= bs
->opaque
;
529 /* seek if the table for the given offset is in the cache */
531 l2_table
= seek_l2_table(s
, l2_offset
);
532 if (l2_table
!= NULL
)
535 /* not found: load a new entry in the least used one */
537 min_index
= l2_cache_new_entry(bs
);
538 l2_table
= s
->l2_cache
+ (min_index
<< s
->l2_bits
);
539 if (bdrv_pread(s
->hd
, l2_offset
, l2_table
, s
->l2_size
* sizeof(uint64_t)) !=
540 s
->l2_size
* sizeof(uint64_t))
542 s
->l2_cache_offsets
[min_index
] = l2_offset
;
543 s
->l2_cache_counts
[min_index
] = 1;
551 * Allocate a new l2 entry in the file. If l1_index points to an already
552 * used entry in the L2 table (i.e. we are doing a copy on write for the L2
553 * table) copy the contents of the old L2 table into the newly allocated one.
554 * Otherwise the new table is initialized with zeros.
558 static uint64_t *l2_allocate(BlockDriverState
*bs
, int l1_index
)
560 BDRVQcowState
*s
= bs
->opaque
;
562 uint64_t old_l2_offset
, tmp
;
563 uint64_t *l2_table
, l2_offset
;
565 old_l2_offset
= s
->l1_table
[l1_index
];
567 /* allocate a new l2 entry */
569 l2_offset
= alloc_clusters(bs
, s
->l2_size
* sizeof(uint64_t));
571 /* update the L1 entry */
573 s
->l1_table
[l1_index
] = l2_offset
| QCOW_OFLAG_COPIED
;
575 tmp
= cpu_to_be64(l2_offset
| QCOW_OFLAG_COPIED
);
576 if (bdrv_pwrite(s
->hd
, s
->l1_table_offset
+ l1_index
* sizeof(tmp
),
577 &tmp
, sizeof(tmp
)) != sizeof(tmp
))
580 /* allocate a new entry in the l2 cache */
582 min_index
= l2_cache_new_entry(bs
);
583 l2_table
= s
->l2_cache
+ (min_index
<< s
->l2_bits
);
585 if (old_l2_offset
== 0) {
586 /* if there was no old l2 table, clear the new table */
587 memset(l2_table
, 0, s
->l2_size
* sizeof(uint64_t));
589 /* if there was an old l2 table, read it from the disk */
590 if (bdrv_pread(s
->hd
, old_l2_offset
,
591 l2_table
, s
->l2_size
* sizeof(uint64_t)) !=
592 s
->l2_size
* sizeof(uint64_t))
595 /* write the l2 table to the file */
596 if (bdrv_pwrite(s
->hd
, l2_offset
,
597 l2_table
, s
->l2_size
* sizeof(uint64_t)) !=
598 s
->l2_size
* sizeof(uint64_t))
601 /* update the l2 cache entry */
603 s
->l2_cache_offsets
[min_index
] = l2_offset
;
604 s
->l2_cache_counts
[min_index
] = 1;
612 * For a given offset of the disk image, return cluster offset in
615 * Return 1, if the offset is found
616 * Return 0, otherwise.
620 static uint64_t get_cluster_offset(BlockDriverState
*bs
, uint64_t offset
)
622 BDRVQcowState
*s
= bs
->opaque
;
623 int l1_index
, l2_index
;
624 uint64_t l2_offset
, *l2_table
, cluster_offset
;
626 /* seek the the l2 offset in the l1 table */
628 l1_index
= offset
>> (s
->l2_bits
+ s
->cluster_bits
);
629 if (l1_index
>= s
->l1_size
)
632 l2_offset
= s
->l1_table
[l1_index
];
634 /* seek the l2 table of the given l2 offset */
639 /* load the l2 table in memory */
641 l2_offset
&= ~QCOW_OFLAG_COPIED
;
642 l2_table
= l2_load(bs
, l2_offset
);
643 if (l2_table
== NULL
)
646 /* find the cluster offset for the given disk offset */
648 l2_index
= (offset
>> s
->cluster_bits
) & (s
->l2_size
- 1);
649 cluster_offset
= be64_to_cpu(l2_table
[l2_index
]);
651 return cluster_offset
& ~QCOW_OFLAG_COPIED
;
655 * alloc_cluster_offset
657 * For a given offset of the disk image, return cluster offset in
660 * If the offset is not found, allocate a new cluster.
662 * Return the cluster offset if successful,
663 * Return 0, otherwise.
667 static uint64_t alloc_cluster_offset(BlockDriverState
*bs
,
670 int n_start
, int n_end
)
672 BDRVQcowState
*s
= bs
->opaque
;
673 int l1_index
, l2_index
, ret
;
674 uint64_t l2_offset
, *l2_table
, cluster_offset
;
676 /* seek the the l2 offset in the l1 table */
678 l1_index
= offset
>> (s
->l2_bits
+ s
->cluster_bits
);
679 if (l1_index
>= s
->l1_size
) {
680 ret
= grow_l1_table(bs
, l1_index
+ 1);
684 l2_offset
= s
->l1_table
[l1_index
];
686 /* seek the l2 table of the given l2 offset */
688 if (l2_offset
& QCOW_OFLAG_COPIED
) {
689 /* load the l2 table in memory */
690 l2_offset
&= ~QCOW_OFLAG_COPIED
;
691 l2_table
= l2_load(bs
, l2_offset
);
692 if (l2_table
== NULL
)
696 free_clusters(bs
, l2_offset
, s
->l2_size
* sizeof(uint64_t));
697 l2_table
= l2_allocate(bs
, l1_index
);
698 if (l2_table
== NULL
)
700 l2_offset
= s
->l1_table
[l1_index
] & ~QCOW_OFLAG_COPIED
;
703 /* find the cluster offset for the given disk offset */
705 l2_index
= (offset
>> s
->cluster_bits
) & (s
->l2_size
- 1);
706 cluster_offset
= be64_to_cpu(l2_table
[l2_index
]);
708 if (cluster_offset
& QCOW_OFLAG_COPIED
)
709 return cluster_offset
& ~QCOW_OFLAG_COPIED
;
711 if (cluster_offset
) {
712 /* free the cluster */
713 if (cluster_offset
& QCOW_OFLAG_COMPRESSED
) {
715 nb_csectors
= ((cluster_offset
>> s
->csize_shift
) &
717 free_clusters(bs
, (cluster_offset
& s
->cluster_offset_mask
) & ~511,
720 free_clusters(bs
, cluster_offset
, s
->cluster_size
);
724 if (compressed_size
) {
727 cluster_offset
= alloc_bytes(bs
, compressed_size
);
728 nb_csectors
= ((cluster_offset
+ compressed_size
- 1) >> 9) -
729 (cluster_offset
>> 9);
731 cluster_offset
|= QCOW_OFLAG_COMPRESSED
|
732 ((uint64_t)nb_csectors
<< s
->csize_shift
);
734 /* update L2 table */
736 /* compressed clusters never have the copied flag */
738 l2_table
[l2_index
] = cpu_to_be64(cluster_offset
);
739 if (bdrv_pwrite(s
->hd
,
740 l2_offset
+ l2_index
* sizeof(uint64_t),
742 sizeof(uint64_t)) != sizeof(uint64_t))
745 return cluster_offset
;
748 /* allocate a new cluster */
750 cluster_offset
= alloc_clusters(bs
, s
->cluster_size
);
752 /* we must initialize the cluster content which won't be
755 if ((n_end
- n_start
) < s
->cluster_sectors
) {
758 start_sect
= (offset
& ~(s
->cluster_size
- 1)) >> 9;
759 ret
= copy_sectors(bs
, start_sect
,
760 cluster_offset
, 0, n_start
);
763 ret
= copy_sectors(bs
, start_sect
,
764 cluster_offset
, n_end
, s
->cluster_sectors
);
769 /* update L2 table */
771 l2_table
[l2_index
] = cpu_to_be64(cluster_offset
| QCOW_OFLAG_COPIED
);
772 if (bdrv_pwrite(s
->hd
,
773 l2_offset
+ l2_index
* sizeof(uint64_t),
775 sizeof(uint64_t)) != sizeof(uint64_t))
778 return cluster_offset
;
781 static int qcow_is_allocated(BlockDriverState
*bs
, int64_t sector_num
,
782 int nb_sectors
, int *pnum
)
784 BDRVQcowState
*s
= bs
->opaque
;
785 int index_in_cluster
, n
;
786 uint64_t cluster_offset
;
788 cluster_offset
= get_cluster_offset(bs
, sector_num
<< 9);
789 index_in_cluster
= sector_num
& (s
->cluster_sectors
- 1);
790 n
= s
->cluster_sectors
- index_in_cluster
;
794 return (cluster_offset
!= 0);
797 static int decompress_buffer(uint8_t *out_buf
, int out_buf_size
,
798 const uint8_t *buf
, int buf_size
)
800 z_stream strm1
, *strm
= &strm1
;
803 memset(strm
, 0, sizeof(*strm
));
805 strm
->next_in
= (uint8_t *)buf
;
806 strm
->avail_in
= buf_size
;
807 strm
->next_out
= out_buf
;
808 strm
->avail_out
= out_buf_size
;
810 ret
= inflateInit2(strm
, -12);
813 ret
= inflate(strm
, Z_FINISH
);
814 out_len
= strm
->next_out
- out_buf
;
815 if ((ret
!= Z_STREAM_END
&& ret
!= Z_BUF_ERROR
) ||
816 out_len
!= out_buf_size
) {
824 static int decompress_cluster(BDRVQcowState
*s
, uint64_t cluster_offset
)
826 int ret
, csize
, nb_csectors
, sector_offset
;
829 coffset
= cluster_offset
& s
->cluster_offset_mask
;
830 if (s
->cluster_cache_offset
!= coffset
) {
831 nb_csectors
= ((cluster_offset
>> s
->csize_shift
) & s
->csize_mask
) + 1;
832 sector_offset
= coffset
& 511;
833 csize
= nb_csectors
* 512 - sector_offset
;
834 ret
= bdrv_read(s
->hd
, coffset
>> 9, s
->cluster_data
, nb_csectors
);
838 if (decompress_buffer(s
->cluster_cache
, s
->cluster_size
,
839 s
->cluster_data
+ sector_offset
, csize
) < 0) {
842 s
->cluster_cache_offset
= coffset
;
847 /* handle reading after the end of the backing file */
848 static int backing_read1(BlockDriverState
*bs
,
849 int64_t sector_num
, uint8_t *buf
, int nb_sectors
)
852 if ((sector_num
+ nb_sectors
) <= bs
->total_sectors
)
854 if (sector_num
>= bs
->total_sectors
)
857 n1
= bs
->total_sectors
- sector_num
;
858 memset(buf
+ n1
* 512, 0, 512 * (nb_sectors
- n1
));
862 static int qcow_read(BlockDriverState
*bs
, int64_t sector_num
,
863 uint8_t *buf
, int nb_sectors
)
865 BDRVQcowState
*s
= bs
->opaque
;
866 int ret
, index_in_cluster
, n
, n1
;
867 uint64_t cluster_offset
;
869 while (nb_sectors
> 0) {
870 cluster_offset
= get_cluster_offset(bs
, sector_num
<< 9);
871 index_in_cluster
= sector_num
& (s
->cluster_sectors
- 1);
872 n
= s
->cluster_sectors
- index_in_cluster
;
875 if (!cluster_offset
) {
876 if (bs
->backing_hd
) {
877 /* read from the base image */
878 n1
= backing_read1(bs
->backing_hd
, sector_num
, buf
, n
);
880 ret
= bdrv_read(bs
->backing_hd
, sector_num
, buf
, n1
);
885 memset(buf
, 0, 512 * n
);
887 } else if (cluster_offset
& QCOW_OFLAG_COMPRESSED
) {
888 if (decompress_cluster(s
, cluster_offset
) < 0)
890 memcpy(buf
, s
->cluster_cache
+ index_in_cluster
* 512, 512 * n
);
892 ret
= bdrv_pread(s
->hd
, cluster_offset
+ index_in_cluster
* 512, buf
, n
* 512);
895 if (s
->crypt_method
) {
896 encrypt_sectors(s
, sector_num
, buf
, buf
, n
, 0,
897 &s
->aes_decrypt_key
);
907 static int qcow_write(BlockDriverState
*bs
, int64_t sector_num
,
908 const uint8_t *buf
, int nb_sectors
)
910 BDRVQcowState
*s
= bs
->opaque
;
911 int ret
, index_in_cluster
, n
;
912 uint64_t cluster_offset
;
914 while (nb_sectors
> 0) {
915 index_in_cluster
= sector_num
& (s
->cluster_sectors
- 1);
916 n
= s
->cluster_sectors
- index_in_cluster
;
919 cluster_offset
= alloc_cluster_offset(bs
, sector_num
<< 9, 0,
921 index_in_cluster
+ n
);
924 if (s
->crypt_method
) {
925 encrypt_sectors(s
, sector_num
, s
->cluster_data
, buf
, n
, 1,
926 &s
->aes_encrypt_key
);
927 ret
= bdrv_pwrite(s
->hd
, cluster_offset
+ index_in_cluster
* 512,
928 s
->cluster_data
, n
* 512);
930 ret
= bdrv_pwrite(s
->hd
, cluster_offset
+ index_in_cluster
* 512, buf
, n
* 512);
938 s
->cluster_cache_offset
= -1; /* disable compressed cache */
942 typedef struct QCowAIOCB
{
943 BlockDriverAIOCB common
;
948 uint64_t cluster_offset
;
949 uint8_t *cluster_data
;
950 BlockDriverAIOCB
*hd_aiocb
;
953 static void qcow_aio_read_cb(void *opaque
, int ret
)
955 QCowAIOCB
*acb
= opaque
;
956 BlockDriverState
*bs
= acb
->common
.bs
;
957 BDRVQcowState
*s
= bs
->opaque
;
958 int index_in_cluster
, n1
;
960 acb
->hd_aiocb
= NULL
;
963 acb
->common
.cb(acb
->common
.opaque
, ret
);
964 qemu_aio_release(acb
);
969 /* post process the read buffer */
970 if (!acb
->cluster_offset
) {
972 } else if (acb
->cluster_offset
& QCOW_OFLAG_COMPRESSED
) {
975 if (s
->crypt_method
) {
976 encrypt_sectors(s
, acb
->sector_num
, acb
->buf
, acb
->buf
,
978 &s
->aes_decrypt_key
);
982 acb
->nb_sectors
-= acb
->n
;
983 acb
->sector_num
+= acb
->n
;
984 acb
->buf
+= acb
->n
* 512;
986 if (acb
->nb_sectors
== 0) {
987 /* request completed */
988 acb
->common
.cb(acb
->common
.opaque
, 0);
989 qemu_aio_release(acb
);
993 /* prepare next AIO request */
994 acb
->cluster_offset
= get_cluster_offset(bs
, acb
->sector_num
<< 9);
995 index_in_cluster
= acb
->sector_num
& (s
->cluster_sectors
- 1);
996 acb
->n
= s
->cluster_sectors
- index_in_cluster
;
997 if (acb
->n
> acb
->nb_sectors
)
998 acb
->n
= acb
->nb_sectors
;
1000 if (!acb
->cluster_offset
) {
1001 if (bs
->backing_hd
) {
1002 /* read from the base image */
1003 n1
= backing_read1(bs
->backing_hd
, acb
->sector_num
,
1006 acb
->hd_aiocb
= bdrv_aio_read(bs
->backing_hd
, acb
->sector_num
,
1007 acb
->buf
, acb
->n
, qcow_aio_read_cb
, acb
);
1008 if (acb
->hd_aiocb
== NULL
)
1014 /* Note: in this case, no need to wait */
1015 memset(acb
->buf
, 0, 512 * acb
->n
);
1018 } else if (acb
->cluster_offset
& QCOW_OFLAG_COMPRESSED
) {
1019 /* add AIO support for compressed blocks ? */
1020 if (decompress_cluster(s
, acb
->cluster_offset
) < 0)
1023 s
->cluster_cache
+ index_in_cluster
* 512, 512 * acb
->n
);
1026 if ((acb
->cluster_offset
& 511) != 0) {
1030 acb
->hd_aiocb
= bdrv_aio_read(s
->hd
,
1031 (acb
->cluster_offset
>> 9) + index_in_cluster
,
1032 acb
->buf
, acb
->n
, qcow_aio_read_cb
, acb
);
1033 if (acb
->hd_aiocb
== NULL
)
1038 static QCowAIOCB
*qcow_aio_setup(BlockDriverState
*bs
,
1039 int64_t sector_num
, uint8_t *buf
, int nb_sectors
,
1040 BlockDriverCompletionFunc
*cb
, void *opaque
)
1044 acb
= qemu_aio_get(bs
, cb
, opaque
);
1047 acb
->hd_aiocb
= NULL
;
1048 acb
->sector_num
= sector_num
;
1050 acb
->nb_sectors
= nb_sectors
;
1052 acb
->cluster_offset
= 0;
1056 static BlockDriverAIOCB
*qcow_aio_read(BlockDriverState
*bs
,
1057 int64_t sector_num
, uint8_t *buf
, int nb_sectors
,
1058 BlockDriverCompletionFunc
*cb
, void *opaque
)
1062 acb
= qcow_aio_setup(bs
, sector_num
, buf
, nb_sectors
, cb
, opaque
);
1066 qcow_aio_read_cb(acb
, 0);
1067 return &acb
->common
;
1070 static void qcow_aio_write_cb(void *opaque
, int ret
)
1072 QCowAIOCB
*acb
= opaque
;
1073 BlockDriverState
*bs
= acb
->common
.bs
;
1074 BDRVQcowState
*s
= bs
->opaque
;
1075 int index_in_cluster
;
1076 uint64_t cluster_offset
;
1077 const uint8_t *src_buf
;
1079 acb
->hd_aiocb
= NULL
;
1083 acb
->common
.cb(acb
->common
.opaque
, ret
);
1084 qemu_aio_release(acb
);
1088 acb
->nb_sectors
-= acb
->n
;
1089 acb
->sector_num
+= acb
->n
;
1090 acb
->buf
+= acb
->n
* 512;
1092 if (acb
->nb_sectors
== 0) {
1093 /* request completed */
1094 acb
->common
.cb(acb
->common
.opaque
, 0);
1095 qemu_aio_release(acb
);
1099 index_in_cluster
= acb
->sector_num
& (s
->cluster_sectors
- 1);
1100 acb
->n
= s
->cluster_sectors
- index_in_cluster
;
1101 if (acb
->n
> acb
->nb_sectors
)
1102 acb
->n
= acb
->nb_sectors
;
1103 cluster_offset
= alloc_cluster_offset(bs
, acb
->sector_num
<< 9, 0,
1105 index_in_cluster
+ acb
->n
);
1106 if (!cluster_offset
|| (cluster_offset
& 511) != 0) {
1110 if (s
->crypt_method
) {
1111 if (!acb
->cluster_data
) {
1112 acb
->cluster_data
= qemu_mallocz(s
->cluster_size
);
1113 if (!acb
->cluster_data
) {
1118 encrypt_sectors(s
, acb
->sector_num
, acb
->cluster_data
, acb
->buf
,
1119 acb
->n
, 1, &s
->aes_encrypt_key
);
1120 src_buf
= acb
->cluster_data
;
1124 acb
->hd_aiocb
= bdrv_aio_write(s
->hd
,
1125 (cluster_offset
>> 9) + index_in_cluster
,
1127 qcow_aio_write_cb
, acb
);
1128 if (acb
->hd_aiocb
== NULL
)
1132 static BlockDriverAIOCB
*qcow_aio_write(BlockDriverState
*bs
,
1133 int64_t sector_num
, const uint8_t *buf
, int nb_sectors
,
1134 BlockDriverCompletionFunc
*cb
, void *opaque
)
1136 BDRVQcowState
*s
= bs
->opaque
;
1139 s
->cluster_cache_offset
= -1; /* disable compressed cache */
1141 acb
= qcow_aio_setup(bs
, sector_num
, (uint8_t*)buf
, nb_sectors
, cb
, opaque
);
1145 qcow_aio_write_cb(acb
, 0);
1146 return &acb
->common
;
1149 static void qcow_aio_cancel(BlockDriverAIOCB
*blockacb
)
1151 QCowAIOCB
*acb
= (QCowAIOCB
*)blockacb
;
1153 bdrv_aio_cancel(acb
->hd_aiocb
);
1154 qemu_aio_release(acb
);
1157 static void qcow_close(BlockDriverState
*bs
)
1159 BDRVQcowState
*s
= bs
->opaque
;
1160 qemu_free(s
->l1_table
);
1161 qemu_free(s
->l2_cache
);
1162 qemu_free(s
->cluster_cache
);
1163 qemu_free(s
->cluster_data
);
1168 /* XXX: use std qcow open function ? */
1169 typedef struct QCowCreateState
{
1172 uint16_t *refcount_block
;
1173 uint64_t *refcount_table
;
1174 int64_t l1_table_offset
;
1175 int64_t refcount_table_offset
;
1176 int64_t refcount_block_offset
;
1179 static void create_refcount_update(QCowCreateState
*s
,
1180 int64_t offset
, int64_t size
)
1183 int64_t start
, last
, cluster_offset
;
1186 start
= offset
& ~(s
->cluster_size
- 1);
1187 last
= (offset
+ size
- 1) & ~(s
->cluster_size
- 1);
1188 for(cluster_offset
= start
; cluster_offset
<= last
;
1189 cluster_offset
+= s
->cluster_size
) {
1190 p
= &s
->refcount_block
[cluster_offset
>> s
->cluster_bits
];
1191 refcount
= be16_to_cpu(*p
);
1193 *p
= cpu_to_be16(refcount
);
1197 static int qcow_create(const char *filename
, int64_t total_size
,
1198 const char *backing_file
, int flags
)
1200 int fd
, header_size
, backing_filename_len
, l1_size
, i
, shift
, l2_bits
;
1202 uint64_t tmp
, offset
;
1203 QCowCreateState s1
, *s
= &s1
;
1205 memset(s
, 0, sizeof(*s
));
1207 fd
= open(filename
, O_WRONLY
| O_CREAT
| O_TRUNC
| O_BINARY
, 0644);
1210 memset(&header
, 0, sizeof(header
));
1211 header
.magic
= cpu_to_be32(QCOW_MAGIC
);
1212 header
.version
= cpu_to_be32(QCOW_VERSION
);
1213 header
.size
= cpu_to_be64(total_size
* 512);
1214 header_size
= sizeof(header
);
1215 backing_filename_len
= 0;
1217 header
.backing_file_offset
= cpu_to_be64(header_size
);
1218 backing_filename_len
= strlen(backing_file
);
1219 header
.backing_file_size
= cpu_to_be32(backing_filename_len
);
1220 header_size
+= backing_filename_len
;
1222 s
->cluster_bits
= 12; /* 4 KB clusters */
1223 s
->cluster_size
= 1 << s
->cluster_bits
;
1224 header
.cluster_bits
= cpu_to_be32(s
->cluster_bits
);
1225 header_size
= (header_size
+ 7) & ~7;
1226 if (flags
& BLOCK_FLAG_ENCRYPT
) {
1227 header
.crypt_method
= cpu_to_be32(QCOW_CRYPT_AES
);
1229 header
.crypt_method
= cpu_to_be32(QCOW_CRYPT_NONE
);
1231 l2_bits
= s
->cluster_bits
- 3;
1232 shift
= s
->cluster_bits
+ l2_bits
;
1233 l1_size
= (((total_size
* 512) + (1LL << shift
) - 1) >> shift
);
1234 offset
= align_offset(header_size
, s
->cluster_size
);
1235 s
->l1_table_offset
= offset
;
1236 header
.l1_table_offset
= cpu_to_be64(s
->l1_table_offset
);
1237 header
.l1_size
= cpu_to_be32(l1_size
);
1238 offset
+= align_offset(l1_size
* sizeof(uint64_t), s
->cluster_size
);
1240 s
->refcount_table
= qemu_mallocz(s
->cluster_size
);
1241 if (!s
->refcount_table
)
1243 s
->refcount_block
= qemu_mallocz(s
->cluster_size
);
1244 if (!s
->refcount_block
)
1247 s
->refcount_table_offset
= offset
;
1248 header
.refcount_table_offset
= cpu_to_be64(offset
);
1249 header
.refcount_table_clusters
= cpu_to_be32(1);
1250 offset
+= s
->cluster_size
;
1252 s
->refcount_table
[0] = cpu_to_be64(offset
);
1253 s
->refcount_block_offset
= offset
;
1254 offset
+= s
->cluster_size
;
1256 /* update refcounts */
1257 create_refcount_update(s
, 0, header_size
);
1258 create_refcount_update(s
, s
->l1_table_offset
, l1_size
* sizeof(uint64_t));
1259 create_refcount_update(s
, s
->refcount_table_offset
, s
->cluster_size
);
1260 create_refcount_update(s
, s
->refcount_block_offset
, s
->cluster_size
);
1262 /* write all the data */
1263 write(fd
, &header
, sizeof(header
));
1265 write(fd
, backing_file
, backing_filename_len
);
1267 lseek(fd
, s
->l1_table_offset
, SEEK_SET
);
1269 for(i
= 0;i
< l1_size
; i
++) {
1270 write(fd
, &tmp
, sizeof(tmp
));
1272 lseek(fd
, s
->refcount_table_offset
, SEEK_SET
);
1273 write(fd
, s
->refcount_table
, s
->cluster_size
);
1275 lseek(fd
, s
->refcount_block_offset
, SEEK_SET
);
1276 write(fd
, s
->refcount_block
, s
->cluster_size
);
1278 qemu_free(s
->refcount_table
);
1279 qemu_free(s
->refcount_block
);
1283 qemu_free(s
->refcount_table
);
1284 qemu_free(s
->refcount_block
);
1289 static int qcow_make_empty(BlockDriverState
*bs
)
1292 /* XXX: not correct */
1293 BDRVQcowState
*s
= bs
->opaque
;
1294 uint32_t l1_length
= s
->l1_size
* sizeof(uint64_t);
1297 memset(s
->l1_table
, 0, l1_length
);
1298 if (bdrv_pwrite(s
->hd
, s
->l1_table_offset
, s
->l1_table
, l1_length
) < 0)
1300 ret
= bdrv_truncate(s
->hd
, s
->l1_table_offset
+ l1_length
);
1309 /* XXX: put compressed sectors first, then all the cluster aligned
1310 tables to avoid losing bytes in alignment */
1311 static int qcow_write_compressed(BlockDriverState
*bs
, int64_t sector_num
,
1312 const uint8_t *buf
, int nb_sectors
)
1314 BDRVQcowState
*s
= bs
->opaque
;
1318 uint64_t cluster_offset
;
1320 if (nb_sectors
== 0) {
1321 /* align end of file to a sector boundary to ease reading with
1322 sector based I/Os */
1323 cluster_offset
= bdrv_getlength(s
->hd
);
1324 cluster_offset
= (cluster_offset
+ 511) & ~511;
1325 bdrv_truncate(s
->hd
, cluster_offset
);
1329 if (nb_sectors
!= s
->cluster_sectors
)
1332 out_buf
= qemu_malloc(s
->cluster_size
+ (s
->cluster_size
/ 1000) + 128);
1336 /* best compression, small window, no zlib header */
1337 memset(&strm
, 0, sizeof(strm
));
1338 ret
= deflateInit2(&strm
, Z_DEFAULT_COMPRESSION
,
1340 9, Z_DEFAULT_STRATEGY
);
1346 strm
.avail_in
= s
->cluster_size
;
1347 strm
.next_in
= (uint8_t *)buf
;
1348 strm
.avail_out
= s
->cluster_size
;
1349 strm
.next_out
= out_buf
;
1351 ret
= deflate(&strm
, Z_FINISH
);
1352 if (ret
!= Z_STREAM_END
&& ret
!= Z_OK
) {
1357 out_len
= strm
.next_out
- out_buf
;
1361 if (ret
!= Z_STREAM_END
|| out_len
>= s
->cluster_size
) {
1362 /* could not compress: write normal cluster */
1363 qcow_write(bs
, sector_num
, buf
, s
->cluster_sectors
);
1365 cluster_offset
= alloc_cluster_offset(bs
, sector_num
<< 9,
1367 cluster_offset
&= s
->cluster_offset_mask
;
1368 if (bdrv_pwrite(s
->hd
, cluster_offset
, out_buf
, out_len
) != out_len
) {
1378 static void qcow_flush(BlockDriverState
*bs
)
1380 BDRVQcowState
*s
= bs
->opaque
;
1384 static int qcow_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
1386 BDRVQcowState
*s
= bs
->opaque
;
1387 bdi
->cluster_size
= s
->cluster_size
;
1388 bdi
->vm_state_offset
= (int64_t)s
->l1_vm_state_index
<<
1389 (s
->cluster_bits
+ s
->l2_bits
);
1393 /*********************************************************/
1394 /* snapshot support */
1396 /* update the refcounts of snapshots and the copied flag */
1397 static int update_snapshot_refcount(BlockDriverState
*bs
,
1398 int64_t l1_table_offset
,
1402 BDRVQcowState
*s
= bs
->opaque
;
1403 uint64_t *l1_table
, *l2_table
, l2_offset
, offset
, l1_size2
, l1_allocated
;
1404 int64_t old_offset
, old_l2_offset
;
1405 int l2_size
, i
, j
, l1_modified
, l2_modified
, nb_csectors
, refcount
;
1411 l1_size2
= l1_size
* sizeof(uint64_t);
1413 if (l1_table_offset
!= s
->l1_table_offset
) {
1414 l1_table
= qemu_malloc(l1_size2
);
1418 if (bdrv_pread(s
->hd
, l1_table_offset
,
1419 l1_table
, l1_size2
) != l1_size2
)
1421 for(i
= 0;i
< l1_size
; i
++)
1422 be64_to_cpus(&l1_table
[i
]);
1424 assert(l1_size
== s
->l1_size
);
1425 l1_table
= s
->l1_table
;
1429 l2_size
= s
->l2_size
* sizeof(uint64_t);
1430 l2_table
= qemu_malloc(l2_size
);
1434 for(i
= 0; i
< l1_size
; i
++) {
1435 l2_offset
= l1_table
[i
];
1437 old_l2_offset
= l2_offset
;
1438 l2_offset
&= ~QCOW_OFLAG_COPIED
;
1440 if (bdrv_pread(s
->hd
, l2_offset
, l2_table
, l2_size
) != l2_size
)
1442 for(j
= 0; j
< s
->l2_size
; j
++) {
1443 offset
= be64_to_cpu(l2_table
[j
]);
1445 old_offset
= offset
;
1446 offset
&= ~QCOW_OFLAG_COPIED
;
1447 if (offset
& QCOW_OFLAG_COMPRESSED
) {
1448 nb_csectors
= ((offset
>> s
->csize_shift
) &
1451 update_refcount(bs
, (offset
& s
->cluster_offset_mask
) & ~511,
1452 nb_csectors
* 512, addend
);
1453 /* compressed clusters are never modified */
1457 refcount
= update_cluster_refcount(bs
, offset
>> s
->cluster_bits
, addend
);
1459 refcount
= get_refcount(bs
, offset
>> s
->cluster_bits
);
1463 if (refcount
== 1) {
1464 offset
|= QCOW_OFLAG_COPIED
;
1466 if (offset
!= old_offset
) {
1467 l2_table
[j
] = cpu_to_be64(offset
);
1473 if (bdrv_pwrite(s
->hd
,
1474 l2_offset
, l2_table
, l2_size
) != l2_size
)
1479 refcount
= update_cluster_refcount(bs
, l2_offset
>> s
->cluster_bits
, addend
);
1481 refcount
= get_refcount(bs
, l2_offset
>> s
->cluster_bits
);
1483 if (refcount
== 1) {
1484 l2_offset
|= QCOW_OFLAG_COPIED
;
1486 if (l2_offset
!= old_l2_offset
) {
1487 l1_table
[i
] = l2_offset
;
1493 for(i
= 0; i
< l1_size
; i
++)
1494 cpu_to_be64s(&l1_table
[i
]);
1495 if (bdrv_pwrite(s
->hd
, l1_table_offset
, l1_table
,
1496 l1_size2
) != l1_size2
)
1498 for(i
= 0; i
< l1_size
; i
++)
1499 be64_to_cpus(&l1_table
[i
]);
1502 qemu_free(l1_table
);
1503 qemu_free(l2_table
);
1507 qemu_free(l1_table
);
1508 qemu_free(l2_table
);
1512 static void qcow_free_snapshots(BlockDriverState
*bs
)
1514 BDRVQcowState
*s
= bs
->opaque
;
1517 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
1518 qemu_free(s
->snapshots
[i
].name
);
1519 qemu_free(s
->snapshots
[i
].id_str
);
1521 qemu_free(s
->snapshots
);
1522 s
->snapshots
= NULL
;
1523 s
->nb_snapshots
= 0;
1526 static int qcow_read_snapshots(BlockDriverState
*bs
)
1528 BDRVQcowState
*s
= bs
->opaque
;
1529 QCowSnapshotHeader h
;
1531 int i
, id_str_size
, name_size
;
1533 uint32_t extra_data_size
;
1535 offset
= s
->snapshots_offset
;
1536 s
->snapshots
= qemu_mallocz(s
->nb_snapshots
* sizeof(QCowSnapshot
));
1539 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
1540 offset
= align_offset(offset
, 8);
1541 if (bdrv_pread(s
->hd
, offset
, &h
, sizeof(h
)) != sizeof(h
))
1543 offset
+= sizeof(h
);
1544 sn
= s
->snapshots
+ i
;
1545 sn
->l1_table_offset
= be64_to_cpu(h
.l1_table_offset
);
1546 sn
->l1_size
= be32_to_cpu(h
.l1_size
);
1547 sn
->vm_state_size
= be32_to_cpu(h
.vm_state_size
);
1548 sn
->date_sec
= be32_to_cpu(h
.date_sec
);
1549 sn
->date_nsec
= be32_to_cpu(h
.date_nsec
);
1550 sn
->vm_clock_nsec
= be64_to_cpu(h
.vm_clock_nsec
);
1551 extra_data_size
= be32_to_cpu(h
.extra_data_size
);
1553 id_str_size
= be16_to_cpu(h
.id_str_size
);
1554 name_size
= be16_to_cpu(h
.name_size
);
1556 offset
+= extra_data_size
;
1558 sn
->id_str
= qemu_malloc(id_str_size
+ 1);
1561 if (bdrv_pread(s
->hd
, offset
, sn
->id_str
, id_str_size
) != id_str_size
)
1563 offset
+= id_str_size
;
1564 sn
->id_str
[id_str_size
] = '\0';
1566 sn
->name
= qemu_malloc(name_size
+ 1);
1569 if (bdrv_pread(s
->hd
, offset
, sn
->name
, name_size
) != name_size
)
1571 offset
+= name_size
;
1572 sn
->name
[name_size
] = '\0';
1574 s
->snapshots_size
= offset
- s
->snapshots_offset
;
1577 qcow_free_snapshots(bs
);
1581 /* add at the end of the file a new list of snapshots */
1582 static int qcow_write_snapshots(BlockDriverState
*bs
)
1584 BDRVQcowState
*s
= bs
->opaque
;
1586 QCowSnapshotHeader h
;
1587 int i
, name_size
, id_str_size
, snapshots_size
;
1590 int64_t offset
, snapshots_offset
;
1592 /* compute the size of the snapshots */
1594 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
1595 sn
= s
->snapshots
+ i
;
1596 offset
= align_offset(offset
, 8);
1597 offset
+= sizeof(h
);
1598 offset
+= strlen(sn
->id_str
);
1599 offset
+= strlen(sn
->name
);
1601 snapshots_size
= offset
;
1603 snapshots_offset
= alloc_clusters(bs
, snapshots_size
);
1604 offset
= snapshots_offset
;
1606 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
1607 sn
= s
->snapshots
+ i
;
1608 memset(&h
, 0, sizeof(h
));
1609 h
.l1_table_offset
= cpu_to_be64(sn
->l1_table_offset
);
1610 h
.l1_size
= cpu_to_be32(sn
->l1_size
);
1611 h
.vm_state_size
= cpu_to_be32(sn
->vm_state_size
);
1612 h
.date_sec
= cpu_to_be32(sn
->date_sec
);
1613 h
.date_nsec
= cpu_to_be32(sn
->date_nsec
);
1614 h
.vm_clock_nsec
= cpu_to_be64(sn
->vm_clock_nsec
);
1616 id_str_size
= strlen(sn
->id_str
);
1617 name_size
= strlen(sn
->name
);
1618 h
.id_str_size
= cpu_to_be16(id_str_size
);
1619 h
.name_size
= cpu_to_be16(name_size
);
1620 offset
= align_offset(offset
, 8);
1621 if (bdrv_pwrite(s
->hd
, offset
, &h
, sizeof(h
)) != sizeof(h
))
1623 offset
+= sizeof(h
);
1624 if (bdrv_pwrite(s
->hd
, offset
, sn
->id_str
, id_str_size
) != id_str_size
)
1626 offset
+= id_str_size
;
1627 if (bdrv_pwrite(s
->hd
, offset
, sn
->name
, name_size
) != name_size
)
1629 offset
+= name_size
;
1632 /* update the various header fields */
1633 data64
= cpu_to_be64(snapshots_offset
);
1634 if (bdrv_pwrite(s
->hd
, offsetof(QCowHeader
, snapshots_offset
),
1635 &data64
, sizeof(data64
)) != sizeof(data64
))
1637 data32
= cpu_to_be32(s
->nb_snapshots
);
1638 if (bdrv_pwrite(s
->hd
, offsetof(QCowHeader
, nb_snapshots
),
1639 &data32
, sizeof(data32
)) != sizeof(data32
))
1642 /* free the old snapshot table */
1643 free_clusters(bs
, s
->snapshots_offset
, s
->snapshots_size
);
1644 s
->snapshots_offset
= snapshots_offset
;
1645 s
->snapshots_size
= snapshots_size
;
1651 static void find_new_snapshot_id(BlockDriverState
*bs
,
1652 char *id_str
, int id_str_size
)
1654 BDRVQcowState
*s
= bs
->opaque
;
1656 int i
, id
, id_max
= 0;
1658 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
1659 sn
= s
->snapshots
+ i
;
1660 id
= strtoul(sn
->id_str
, NULL
, 10);
1664 snprintf(id_str
, id_str_size
, "%d", id_max
+ 1);
1667 static int find_snapshot_by_id(BlockDriverState
*bs
, const char *id_str
)
1669 BDRVQcowState
*s
= bs
->opaque
;
1672 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
1673 if (!strcmp(s
->snapshots
[i
].id_str
, id_str
))
1679 static int find_snapshot_by_id_or_name(BlockDriverState
*bs
, const char *name
)
1681 BDRVQcowState
*s
= bs
->opaque
;
1684 ret
= find_snapshot_by_id(bs
, name
);
1687 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
1688 if (!strcmp(s
->snapshots
[i
].name
, name
))
1694 /* if no id is provided, a new one is constructed */
1695 static int qcow_snapshot_create(BlockDriverState
*bs
,
1696 QEMUSnapshotInfo
*sn_info
)
1698 BDRVQcowState
*s
= bs
->opaque
;
1699 QCowSnapshot
*snapshots1
, sn1
, *sn
= &sn1
;
1701 uint64_t *l1_table
= NULL
;
1703 memset(sn
, 0, sizeof(*sn
));
1705 if (sn_info
->id_str
[0] == '\0') {
1706 /* compute a new id */
1707 find_new_snapshot_id(bs
, sn_info
->id_str
, sizeof(sn_info
->id_str
));
1710 /* check that the ID is unique */
1711 if (find_snapshot_by_id(bs
, sn_info
->id_str
) >= 0)
1714 sn
->id_str
= qemu_strdup(sn_info
->id_str
);
1717 sn
->name
= qemu_strdup(sn_info
->name
);
1720 sn
->vm_state_size
= sn_info
->vm_state_size
;
1721 sn
->date_sec
= sn_info
->date_sec
;
1722 sn
->date_nsec
= sn_info
->date_nsec
;
1723 sn
->vm_clock_nsec
= sn_info
->vm_clock_nsec
;
1725 ret
= update_snapshot_refcount(bs
, s
->l1_table_offset
, s
->l1_size
, 1);
1729 /* create the L1 table of the snapshot */
1730 sn
->l1_table_offset
= alloc_clusters(bs
, s
->l1_size
* sizeof(uint64_t));
1731 sn
->l1_size
= s
->l1_size
;
1733 l1_table
= qemu_malloc(s
->l1_size
* sizeof(uint64_t));
1736 for(i
= 0; i
< s
->l1_size
; i
++) {
1737 l1_table
[i
] = cpu_to_be64(s
->l1_table
[i
]);
1739 if (bdrv_pwrite(s
->hd
, sn
->l1_table_offset
,
1740 l1_table
, s
->l1_size
* sizeof(uint64_t)) !=
1741 (s
->l1_size
* sizeof(uint64_t)))
1743 qemu_free(l1_table
);
1746 snapshots1
= qemu_malloc((s
->nb_snapshots
+ 1) * sizeof(QCowSnapshot
));
1749 memcpy(snapshots1
, s
->snapshots
, s
->nb_snapshots
* sizeof(QCowSnapshot
));
1750 s
->snapshots
= snapshots1
;
1751 s
->snapshots
[s
->nb_snapshots
++] = *sn
;
1753 if (qcow_write_snapshots(bs
) < 0)
1756 check_refcounts(bs
);
1760 qemu_free(sn
->name
);
1761 qemu_free(l1_table
);
1765 /* copy the snapshot 'snapshot_name' into the current disk image */
1766 static int qcow_snapshot_goto(BlockDriverState
*bs
,
1767 const char *snapshot_id
)
1769 BDRVQcowState
*s
= bs
->opaque
;
1771 int i
, snapshot_index
, l1_size2
;
1773 snapshot_index
= find_snapshot_by_id_or_name(bs
, snapshot_id
);
1774 if (snapshot_index
< 0)
1776 sn
= &s
->snapshots
[snapshot_index
];
1778 if (update_snapshot_refcount(bs
, s
->l1_table_offset
, s
->l1_size
, -1) < 0)
1781 if (grow_l1_table(bs
, sn
->l1_size
) < 0)
1784 s
->l1_size
= sn
->l1_size
;
1785 l1_size2
= s
->l1_size
* sizeof(uint64_t);
1786 /* copy the snapshot l1 table to the current l1 table */
1787 if (bdrv_pread(s
->hd
, sn
->l1_table_offset
,
1788 s
->l1_table
, l1_size2
) != l1_size2
)
1790 if (bdrv_pwrite(s
->hd
, s
->l1_table_offset
,
1791 s
->l1_table
, l1_size2
) != l1_size2
)
1793 for(i
= 0;i
< s
->l1_size
; i
++) {
1794 be64_to_cpus(&s
->l1_table
[i
]);
1797 if (update_snapshot_refcount(bs
, s
->l1_table_offset
, s
->l1_size
, 1) < 0)
1801 check_refcounts(bs
);
1808 static int qcow_snapshot_delete(BlockDriverState
*bs
, const char *snapshot_id
)
1810 BDRVQcowState
*s
= bs
->opaque
;
1812 int snapshot_index
, ret
;
1814 snapshot_index
= find_snapshot_by_id_or_name(bs
, snapshot_id
);
1815 if (snapshot_index
< 0)
1817 sn
= &s
->snapshots
[snapshot_index
];
1819 ret
= update_snapshot_refcount(bs
, sn
->l1_table_offset
, sn
->l1_size
, -1);
1822 /* must update the copied flag on the current cluster offsets */
1823 ret
= update_snapshot_refcount(bs
, s
->l1_table_offset
, s
->l1_size
, 0);
1826 free_clusters(bs
, sn
->l1_table_offset
, sn
->l1_size
* sizeof(uint64_t));
1828 qemu_free(sn
->id_str
);
1829 qemu_free(sn
->name
);
1830 memmove(sn
, sn
+ 1, (s
->nb_snapshots
- snapshot_index
- 1) * sizeof(*sn
));
1832 ret
= qcow_write_snapshots(bs
);
1834 /* XXX: restore snapshot if error ? */
1838 check_refcounts(bs
);
1843 static int qcow_snapshot_list(BlockDriverState
*bs
,
1844 QEMUSnapshotInfo
**psn_tab
)
1846 BDRVQcowState
*s
= bs
->opaque
;
1847 QEMUSnapshotInfo
*sn_tab
, *sn_info
;
1851 sn_tab
= qemu_mallocz(s
->nb_snapshots
* sizeof(QEMUSnapshotInfo
));
1854 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
1855 sn_info
= sn_tab
+ i
;
1856 sn
= s
->snapshots
+ i
;
1857 pstrcpy(sn_info
->id_str
, sizeof(sn_info
->id_str
),
1859 pstrcpy(sn_info
->name
, sizeof(sn_info
->name
),
1861 sn_info
->vm_state_size
= sn
->vm_state_size
;
1862 sn_info
->date_sec
= sn
->date_sec
;
1863 sn_info
->date_nsec
= sn
->date_nsec
;
1864 sn_info
->vm_clock_nsec
= sn
->vm_clock_nsec
;
1867 return s
->nb_snapshots
;
1874 /*********************************************************/
1875 /* refcount handling */
1877 static int refcount_init(BlockDriverState
*bs
)
1879 BDRVQcowState
*s
= bs
->opaque
;
1880 int ret
, refcount_table_size2
, i
;
1882 s
->refcount_block_cache
= qemu_malloc(s
->cluster_size
);
1883 if (!s
->refcount_block_cache
)
1885 refcount_table_size2
= s
->refcount_table_size
* sizeof(uint64_t);
1886 s
->refcount_table
= qemu_malloc(refcount_table_size2
);
1887 if (!s
->refcount_table
)
1889 if (s
->refcount_table_size
> 0) {
1890 ret
= bdrv_pread(s
->hd
, s
->refcount_table_offset
,
1891 s
->refcount_table
, refcount_table_size2
);
1892 if (ret
!= refcount_table_size2
)
1894 for(i
= 0; i
< s
->refcount_table_size
; i
++)
1895 be64_to_cpus(&s
->refcount_table
[i
]);
1902 static void refcount_close(BlockDriverState
*bs
)
1904 BDRVQcowState
*s
= bs
->opaque
;
1905 qemu_free(s
->refcount_block_cache
);
1906 qemu_free(s
->refcount_table
);
1910 static int load_refcount_block(BlockDriverState
*bs
,
1911 int64_t refcount_block_offset
)
1913 BDRVQcowState
*s
= bs
->opaque
;
1915 ret
= bdrv_pread(s
->hd
, refcount_block_offset
, s
->refcount_block_cache
,
1917 if (ret
!= s
->cluster_size
)
1919 s
->refcount_block_cache_offset
= refcount_block_offset
;
1923 static int get_refcount(BlockDriverState
*bs
, int64_t cluster_index
)
1925 BDRVQcowState
*s
= bs
->opaque
;
1926 int refcount_table_index
, block_index
;
1927 int64_t refcount_block_offset
;
1929 refcount_table_index
= cluster_index
>> (s
->cluster_bits
- REFCOUNT_SHIFT
);
1930 if (refcount_table_index
>= s
->refcount_table_size
)
1932 refcount_block_offset
= s
->refcount_table
[refcount_table_index
];
1933 if (!refcount_block_offset
)
1935 if (refcount_block_offset
!= s
->refcount_block_cache_offset
) {
1936 /* better than nothing: return allocated if read error */
1937 if (load_refcount_block(bs
, refcount_block_offset
) < 0)
1940 block_index
= cluster_index
&
1941 ((1 << (s
->cluster_bits
- REFCOUNT_SHIFT
)) - 1);
1942 return be16_to_cpu(s
->refcount_block_cache
[block_index
]);
1945 /* return < 0 if error */
1946 static int64_t alloc_clusters_noref(BlockDriverState
*bs
, int64_t size
)
1948 BDRVQcowState
*s
= bs
->opaque
;
1951 nb_clusters
= (size
+ s
->cluster_size
- 1) >> s
->cluster_bits
;
1953 if (get_refcount(bs
, s
->free_cluster_index
) == 0) {
1954 s
->free_cluster_index
++;
1955 for(i
= 1; i
< nb_clusters
; i
++) {
1956 if (get_refcount(bs
, s
->free_cluster_index
) != 0)
1958 s
->free_cluster_index
++;
1961 printf("alloc_clusters: size=%lld -> %lld\n",
1963 (s
->free_cluster_index
- nb_clusters
) << s
->cluster_bits
);
1965 return (s
->free_cluster_index
- nb_clusters
) << s
->cluster_bits
;
1968 s
->free_cluster_index
++;
1973 static int64_t alloc_clusters(BlockDriverState
*bs
, int64_t size
)
1977 offset
= alloc_clusters_noref(bs
, size
);
1978 update_refcount(bs
, offset
, size
, 1);
1982 /* only used to allocate compressed sectors. We try to allocate
1983 contiguous sectors. size must be <= cluster_size */
1984 static int64_t alloc_bytes(BlockDriverState
*bs
, int size
)
1986 BDRVQcowState
*s
= bs
->opaque
;
1987 int64_t offset
, cluster_offset
;
1988 int free_in_cluster
;
1990 assert(size
> 0 && size
<= s
->cluster_size
);
1991 if (s
->free_byte_offset
== 0) {
1992 s
->free_byte_offset
= alloc_clusters(bs
, s
->cluster_size
);
1995 free_in_cluster
= s
->cluster_size
-
1996 (s
->free_byte_offset
& (s
->cluster_size
- 1));
1997 if (size
<= free_in_cluster
) {
1998 /* enough space in current cluster */
1999 offset
= s
->free_byte_offset
;
2000 s
->free_byte_offset
+= size
;
2001 free_in_cluster
-= size
;
2002 if (free_in_cluster
== 0)
2003 s
->free_byte_offset
= 0;
2004 if ((offset
& (s
->cluster_size
- 1)) != 0)
2005 update_cluster_refcount(bs
, offset
>> s
->cluster_bits
, 1);
2007 offset
= alloc_clusters(bs
, s
->cluster_size
);
2008 cluster_offset
= s
->free_byte_offset
& ~(s
->cluster_size
- 1);
2009 if ((cluster_offset
+ s
->cluster_size
) == offset
) {
2010 /* we are lucky: contiguous data */
2011 offset
= s
->free_byte_offset
;
2012 update_cluster_refcount(bs
, offset
>> s
->cluster_bits
, 1);
2013 s
->free_byte_offset
+= size
;
2015 s
->free_byte_offset
= offset
;
2022 static void free_clusters(BlockDriverState
*bs
,
2023 int64_t offset
, int64_t size
)
2025 update_refcount(bs
, offset
, size
, -1);
2028 static int grow_refcount_table(BlockDriverState
*bs
, int min_size
)
2030 BDRVQcowState
*s
= bs
->opaque
;
2031 int new_table_size
, new_table_size2
, refcount_table_clusters
, i
, ret
;
2032 uint64_t *new_table
;
2033 int64_t table_offset
;
2037 int64_t old_table_offset
;
2039 if (min_size
<= s
->refcount_table_size
)
2041 /* compute new table size */
2042 refcount_table_clusters
= s
->refcount_table_size
>> (s
->cluster_bits
- 3);
2044 if (refcount_table_clusters
== 0) {
2045 refcount_table_clusters
= 1;
2047 refcount_table_clusters
= (refcount_table_clusters
* 3 + 1) / 2;
2049 new_table_size
= refcount_table_clusters
<< (s
->cluster_bits
- 3);
2050 if (min_size
<= new_table_size
)
2054 printf("grow_refcount_table from %d to %d\n",
2055 s
->refcount_table_size
,
2058 new_table_size2
= new_table_size
* sizeof(uint64_t);
2059 new_table
= qemu_mallocz(new_table_size2
);
2062 memcpy(new_table
, s
->refcount_table
,
2063 s
->refcount_table_size
* sizeof(uint64_t));
2064 for(i
= 0; i
< s
->refcount_table_size
; i
++)
2065 cpu_to_be64s(&new_table
[i
]);
2066 /* Note: we cannot update the refcount now to avoid recursion */
2067 table_offset
= alloc_clusters_noref(bs
, new_table_size2
);
2068 ret
= bdrv_pwrite(s
->hd
, table_offset
, new_table
, new_table_size2
);
2069 if (ret
!= new_table_size2
)
2071 for(i
= 0; i
< s
->refcount_table_size
; i
++)
2072 be64_to_cpus(&new_table
[i
]);
2074 data64
= cpu_to_be64(table_offset
);
2075 if (bdrv_pwrite(s
->hd
, offsetof(QCowHeader
, refcount_table_offset
),
2076 &data64
, sizeof(data64
)) != sizeof(data64
))
2078 data32
= cpu_to_be32(refcount_table_clusters
);
2079 if (bdrv_pwrite(s
->hd
, offsetof(QCowHeader
, refcount_table_clusters
),
2080 &data32
, sizeof(data32
)) != sizeof(data32
))
2082 qemu_free(s
->refcount_table
);
2083 old_table_offset
= s
->refcount_table_offset
;
2084 old_table_size
= s
->refcount_table_size
;
2085 s
->refcount_table
= new_table
;
2086 s
->refcount_table_size
= new_table_size
;
2087 s
->refcount_table_offset
= table_offset
;
2089 update_refcount(bs
, table_offset
, new_table_size2
, 1);
2090 free_clusters(bs
, old_table_offset
, old_table_size
* sizeof(uint64_t));
2093 free_clusters(bs
, table_offset
, new_table_size2
);
2094 qemu_free(new_table
);
2098 /* addend must be 1 or -1 */
2099 /* XXX: cache several refcount block clusters ? */
2100 static int update_cluster_refcount(BlockDriverState
*bs
,
2101 int64_t cluster_index
,
2104 BDRVQcowState
*s
= bs
->opaque
;
2105 int64_t offset
, refcount_block_offset
;
2106 int ret
, refcount_table_index
, block_index
, refcount
;
2109 refcount_table_index
= cluster_index
>> (s
->cluster_bits
- REFCOUNT_SHIFT
);
2110 if (refcount_table_index
>= s
->refcount_table_size
) {
2113 ret
= grow_refcount_table(bs
, refcount_table_index
+ 1);
2117 refcount_block_offset
= s
->refcount_table
[refcount_table_index
];
2118 if (!refcount_block_offset
) {
2121 /* create a new refcount block */
2122 /* Note: we cannot update the refcount now to avoid recursion */
2123 offset
= alloc_clusters_noref(bs
, s
->cluster_size
);
2124 memset(s
->refcount_block_cache
, 0, s
->cluster_size
);
2125 ret
= bdrv_pwrite(s
->hd
, offset
, s
->refcount_block_cache
, s
->cluster_size
);
2126 if (ret
!= s
->cluster_size
)
2128 s
->refcount_table
[refcount_table_index
] = offset
;
2129 data64
= cpu_to_be64(offset
);
2130 ret
= bdrv_pwrite(s
->hd
, s
->refcount_table_offset
+
2131 refcount_table_index
* sizeof(uint64_t),
2132 &data64
, sizeof(data64
));
2133 if (ret
!= sizeof(data64
))
2136 refcount_block_offset
= offset
;
2137 s
->refcount_block_cache_offset
= offset
;
2138 update_refcount(bs
, offset
, s
->cluster_size
, 1);
2140 if (refcount_block_offset
!= s
->refcount_block_cache_offset
) {
2141 if (load_refcount_block(bs
, refcount_block_offset
) < 0)
2145 /* we can update the count and save it */
2146 block_index
= cluster_index
&
2147 ((1 << (s
->cluster_bits
- REFCOUNT_SHIFT
)) - 1);
2148 refcount
= be16_to_cpu(s
->refcount_block_cache
[block_index
]);
2150 if (refcount
< 0 || refcount
> 0xffff)
2152 if (refcount
== 0 && cluster_index
< s
->free_cluster_index
) {
2153 s
->free_cluster_index
= cluster_index
;
2155 s
->refcount_block_cache
[block_index
] = cpu_to_be16(refcount
);
2156 if (bdrv_pwrite(s
->hd
,
2157 refcount_block_offset
+ (block_index
<< REFCOUNT_SHIFT
),
2158 &s
->refcount_block_cache
[block_index
], 2) != 2)
2163 static void update_refcount(BlockDriverState
*bs
,
2164 int64_t offset
, int64_t length
,
2167 BDRVQcowState
*s
= bs
->opaque
;
2168 int64_t start
, last
, cluster_offset
;
2171 printf("update_refcount: offset=%lld size=%lld addend=%d\n",
2172 offset
, length
, addend
);
2176 start
= offset
& ~(s
->cluster_size
- 1);
2177 last
= (offset
+ length
- 1) & ~(s
->cluster_size
- 1);
2178 for(cluster_offset
= start
; cluster_offset
<= last
;
2179 cluster_offset
+= s
->cluster_size
) {
2180 update_cluster_refcount(bs
, cluster_offset
>> s
->cluster_bits
, addend
);
2185 static void inc_refcounts(BlockDriverState
*bs
,
2186 uint16_t *refcount_table
,
2187 int refcount_table_size
,
2188 int64_t offset
, int64_t size
)
2190 BDRVQcowState
*s
= bs
->opaque
;
2191 int64_t start
, last
, cluster_offset
;
2197 start
= offset
& ~(s
->cluster_size
- 1);
2198 last
= (offset
+ size
- 1) & ~(s
->cluster_size
- 1);
2199 for(cluster_offset
= start
; cluster_offset
<= last
;
2200 cluster_offset
+= s
->cluster_size
) {
2201 k
= cluster_offset
>> s
->cluster_bits
;
2202 if (k
< 0 || k
>= refcount_table_size
) {
2203 printf("ERROR: invalid cluster offset=0x%llx\n", cluster_offset
);
2205 if (++refcount_table
[k
] == 0) {
2206 printf("ERROR: overflow cluster offset=0x%llx\n", cluster_offset
);
2212 static int check_refcounts_l1(BlockDriverState
*bs
,
2213 uint16_t *refcount_table
,
2214 int refcount_table_size
,
2215 int64_t l1_table_offset
, int l1_size
,
2218 BDRVQcowState
*s
= bs
->opaque
;
2219 uint64_t *l1_table
, *l2_table
, l2_offset
, offset
, l1_size2
;
2220 int l2_size
, i
, j
, nb_csectors
, refcount
;
2223 l1_size2
= l1_size
* sizeof(uint64_t);
2225 inc_refcounts(bs
, refcount_table
, refcount_table_size
,
2226 l1_table_offset
, l1_size2
);
2228 l1_table
= qemu_malloc(l1_size2
);
2231 if (bdrv_pread(s
->hd
, l1_table_offset
,
2232 l1_table
, l1_size2
) != l1_size2
)
2234 for(i
= 0;i
< l1_size
; i
++)
2235 be64_to_cpus(&l1_table
[i
]);
2237 l2_size
= s
->l2_size
* sizeof(uint64_t);
2238 l2_table
= qemu_malloc(l2_size
);
2241 for(i
= 0; i
< l1_size
; i
++) {
2242 l2_offset
= l1_table
[i
];
2245 refcount
= get_refcount(bs
, (l2_offset
& ~QCOW_OFLAG_COPIED
) >> s
->cluster_bits
);
2246 if ((refcount
== 1) != ((l2_offset
& QCOW_OFLAG_COPIED
) != 0)) {
2247 printf("ERROR OFLAG_COPIED: l2_offset=%llx refcount=%d\n",
2248 l2_offset
, refcount
);
2251 l2_offset
&= ~QCOW_OFLAG_COPIED
;
2252 if (bdrv_pread(s
->hd
, l2_offset
, l2_table
, l2_size
) != l2_size
)
2254 for(j
= 0; j
< s
->l2_size
; j
++) {
2255 offset
= be64_to_cpu(l2_table
[j
]);
2257 if (offset
& QCOW_OFLAG_COMPRESSED
) {
2258 if (offset
& QCOW_OFLAG_COPIED
) {
2259 printf("ERROR: cluster %lld: copied flag must never be set for compressed clusters\n",
2260 offset
>> s
->cluster_bits
);
2261 offset
&= ~QCOW_OFLAG_COPIED
;
2263 nb_csectors
= ((offset
>> s
->csize_shift
) &
2265 offset
&= s
->cluster_offset_mask
;
2266 inc_refcounts(bs
, refcount_table
,
2267 refcount_table_size
,
2268 offset
& ~511, nb_csectors
* 512);
2271 refcount
= get_refcount(bs
, (offset
& ~QCOW_OFLAG_COPIED
) >> s
->cluster_bits
);
2272 if ((refcount
== 1) != ((offset
& QCOW_OFLAG_COPIED
) != 0)) {
2273 printf("ERROR OFLAG_COPIED: offset=%llx refcount=%d\n",
2277 offset
&= ~QCOW_OFLAG_COPIED
;
2278 inc_refcounts(bs
, refcount_table
,
2279 refcount_table_size
,
2280 offset
, s
->cluster_size
);
2284 inc_refcounts(bs
, refcount_table
,
2285 refcount_table_size
,
2290 qemu_free(l1_table
);
2291 qemu_free(l2_table
);
2294 printf("ERROR: I/O error in check_refcounts_l1\n");
2295 qemu_free(l1_table
);
2296 qemu_free(l2_table
);
2300 static void check_refcounts(BlockDriverState
*bs
)
2302 BDRVQcowState
*s
= bs
->opaque
;
2304 int nb_clusters
, refcount1
, refcount2
, i
;
2306 uint16_t *refcount_table
;
2308 size
= bdrv_getlength(s
->hd
);
2309 nb_clusters
= (size
+ s
->cluster_size
- 1) >> s
->cluster_bits
;
2310 refcount_table
= qemu_mallocz(nb_clusters
* sizeof(uint16_t));
2313 inc_refcounts(bs
, refcount_table
, nb_clusters
,
2314 0, s
->cluster_size
);
2316 check_refcounts_l1(bs
, refcount_table
, nb_clusters
,
2317 s
->l1_table_offset
, s
->l1_size
, 1);
2320 for(i
= 0; i
< s
->nb_snapshots
; i
++) {
2321 sn
= s
->snapshots
+ i
;
2322 check_refcounts_l1(bs
, refcount_table
, nb_clusters
,
2323 sn
->l1_table_offset
, sn
->l1_size
, 0);
2325 inc_refcounts(bs
, refcount_table
, nb_clusters
,
2326 s
->snapshots_offset
, s
->snapshots_size
);
2329 inc_refcounts(bs
, refcount_table
, nb_clusters
,
2330 s
->refcount_table_offset
,
2331 s
->refcount_table_size
* sizeof(uint64_t));
2332 for(i
= 0; i
< s
->refcount_table_size
; i
++) {
2334 offset
= s
->refcount_table
[i
];
2336 inc_refcounts(bs
, refcount_table
, nb_clusters
,
2337 offset
, s
->cluster_size
);
2341 /* compare ref counts */
2342 for(i
= 0; i
< nb_clusters
; i
++) {
2343 refcount1
= get_refcount(bs
, i
);
2344 refcount2
= refcount_table
[i
];
2345 if (refcount1
!= refcount2
)
2346 printf("ERROR cluster %d refcount=%d reference=%d\n",
2347 i
, refcount1
, refcount2
);
2350 qemu_free(refcount_table
);
2354 static void dump_refcounts(BlockDriverState
*bs
)
2356 BDRVQcowState
*s
= bs
->opaque
;
2357 int64_t nb_clusters
, k
, k1
, size
;
2360 size
= bdrv_getlength(s
->hd
);
2361 nb_clusters
= (size
+ s
->cluster_size
- 1) >> s
->cluster_bits
;
2362 for(k
= 0; k
< nb_clusters
;) {
2364 refcount
= get_refcount(bs
, k
);
2366 while (k
< nb_clusters
&& get_refcount(bs
, k
) == refcount
)
2368 printf("%lld: refcount=%d nb=%lld\n", k
, refcount
, k
- k1
);
2374 BlockDriver bdrv_qcow2
= {
2376 sizeof(BDRVQcowState
),
2388 .bdrv_aio_read
= qcow_aio_read
,
2389 .bdrv_aio_write
= qcow_aio_write
,
2390 .bdrv_aio_cancel
= qcow_aio_cancel
,
2391 .aiocb_size
= sizeof(QCowAIOCB
),
2392 .bdrv_write_compressed
= qcow_write_compressed
,
2394 .bdrv_snapshot_create
= qcow_snapshot_create
,
2395 .bdrv_snapshot_goto
= qcow_snapshot_goto
,
2396 .bdrv_snapshot_delete
= qcow_snapshot_delete
,
2397 .bdrv_snapshot_list
= qcow_snapshot_list
,
2398 .bdrv_get_info
= qcow_get_info
,