xref: /qemu/block/qcow2.h (revision 9277d81f)
1 /*
2  * Block driver for the QCOW version 2 format
3  *
4  * Copyright (c) 2004-2006 Fabrice Bellard
5  *
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:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
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
22  * THE SOFTWARE.
23  */
24 
25 #ifndef BLOCK_QCOW2_H
26 #define BLOCK_QCOW2_H
27 
28 #include "crypto/block.h"
29 #include "qemu/coroutine.h"
30 
31 //#define DEBUG_ALLOC
32 //#define DEBUG_ALLOC2
33 //#define DEBUG_EXT
34 
35 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
36 
37 #define QCOW_CRYPT_NONE 0
38 #define QCOW_CRYPT_AES  1
39 #define QCOW_CRYPT_LUKS 2
40 
41 #define QCOW_MAX_CRYPT_CLUSTERS 32
42 #define QCOW_MAX_SNAPSHOTS 65536
43 
44 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
45  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
46 #define QCOW_MAX_REFTABLE_SIZE 0x800000
47 
48 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
49  * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
50 #define QCOW_MAX_L1_SIZE 0x2000000
51 
52 /* Allow for an average of 1k per snapshot table entry, should be plenty of
53  * space for snapshot names and IDs */
54 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
55 
56 /* Bitmap header extension constraints */
57 #define QCOW2_MAX_BITMAPS 65535
58 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
59 
60 /* indicate that the refcount of the referenced cluster is exactly one. */
61 #define QCOW_OFLAG_COPIED     (1ULL << 63)
62 /* indicate that the cluster is compressed (they never have the copied flag) */
63 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
64 /* The cluster reads as all zeros */
65 #define QCOW_OFLAG_ZERO (1ULL << 0)
66 
67 #define MIN_CLUSTER_BITS 9
68 #define MAX_CLUSTER_BITS 21
69 
70 /* Must be at least 2 to cover COW */
71 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
72 
73 /* Must be at least 4 to cover all cases of refcount table growth */
74 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
75 
76 /* Whichever is more */
77 #define DEFAULT_L2_CACHE_CLUSTERS 8 /* clusters */
78 #define DEFAULT_L2_CACHE_BYTE_SIZE 1048576 /* bytes */
79 
80 #define DEFAULT_CLUSTER_SIZE 65536
81 
82 
83 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
84 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
85 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
86 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
87 #define QCOW2_OPT_OVERLAP "overlap-check"
88 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
89 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
90 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
91 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
92 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
93 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
94 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
95 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
96 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
97 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
98 #define QCOW2_OPT_CACHE_SIZE "cache-size"
99 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
100 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
101 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
102 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
103 
104 typedef struct QCowHeader {
105     uint32_t magic;
106     uint32_t version;
107     uint64_t backing_file_offset;
108     uint32_t backing_file_size;
109     uint32_t cluster_bits;
110     uint64_t size; /* in bytes */
111     uint32_t crypt_method;
112     uint32_t l1_size; /* XXX: save number of clusters instead ? */
113     uint64_t l1_table_offset;
114     uint64_t refcount_table_offset;
115     uint32_t refcount_table_clusters;
116     uint32_t nb_snapshots;
117     uint64_t snapshots_offset;
118 
119     /* The following fields are only valid for version >= 3 */
120     uint64_t incompatible_features;
121     uint64_t compatible_features;
122     uint64_t autoclear_features;
123 
124     uint32_t refcount_order;
125     uint32_t header_length;
126 } QEMU_PACKED QCowHeader;
127 
128 typedef struct QEMU_PACKED QCowSnapshotHeader {
129     /* header is 8 byte aligned */
130     uint64_t l1_table_offset;
131 
132     uint32_t l1_size;
133     uint16_t id_str_size;
134     uint16_t name_size;
135 
136     uint32_t date_sec;
137     uint32_t date_nsec;
138 
139     uint64_t vm_clock_nsec;
140 
141     uint32_t vm_state_size;
142     uint32_t extra_data_size; /* for extension */
143     /* extra data follows */
144     /* id_str follows */
145     /* name follows  */
146 } QCowSnapshotHeader;
147 
148 typedef struct QEMU_PACKED QCowSnapshotExtraData {
149     uint64_t vm_state_size_large;
150     uint64_t disk_size;
151 } QCowSnapshotExtraData;
152 
153 
154 typedef struct QCowSnapshot {
155     uint64_t l1_table_offset;
156     uint32_t l1_size;
157     char *id_str;
158     char *name;
159     uint64_t disk_size;
160     uint64_t vm_state_size;
161     uint32_t date_sec;
162     uint32_t date_nsec;
163     uint64_t vm_clock_nsec;
164 } QCowSnapshot;
165 
166 struct Qcow2Cache;
167 typedef struct Qcow2Cache Qcow2Cache;
168 
169 typedef struct Qcow2CryptoHeaderExtension {
170     uint64_t offset;
171     uint64_t length;
172 } QEMU_PACKED Qcow2CryptoHeaderExtension;
173 
174 typedef struct Qcow2UnknownHeaderExtension {
175     uint32_t magic;
176     uint32_t len;
177     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
178     uint8_t data[];
179 } Qcow2UnknownHeaderExtension;
180 
181 enum {
182     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
183     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
184     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
185 };
186 
187 /* Incompatible feature bits */
188 enum {
189     QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
190     QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
191     QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
192     QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
193 
194     QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
195                                  | QCOW2_INCOMPAT_CORRUPT,
196 };
197 
198 /* Compatible feature bits */
199 enum {
200     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
201     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
202 
203     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
204 };
205 
206 /* Autoclear feature bits */
207 enum {
208     QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
209     QCOW2_AUTOCLEAR_BITMAPS       = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
210 
211     QCOW2_AUTOCLEAR_MASK          = QCOW2_AUTOCLEAR_BITMAPS,
212 };
213 
214 enum qcow2_discard_type {
215     QCOW2_DISCARD_NEVER = 0,
216     QCOW2_DISCARD_ALWAYS,
217     QCOW2_DISCARD_REQUEST,
218     QCOW2_DISCARD_SNAPSHOT,
219     QCOW2_DISCARD_OTHER,
220     QCOW2_DISCARD_MAX
221 };
222 
223 typedef struct Qcow2Feature {
224     uint8_t type;
225     uint8_t bit;
226     char    name[46];
227 } QEMU_PACKED Qcow2Feature;
228 
229 typedef struct Qcow2DiscardRegion {
230     BlockDriverState *bs;
231     uint64_t offset;
232     uint64_t bytes;
233     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
234 } Qcow2DiscardRegion;
235 
236 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
237                                       uint64_t index);
238 typedef void Qcow2SetRefcountFunc(void *refcount_array,
239                                   uint64_t index, uint64_t value);
240 
241 typedef struct Qcow2BitmapHeaderExt {
242     uint32_t nb_bitmaps;
243     uint32_t reserved32;
244     uint64_t bitmap_directory_size;
245     uint64_t bitmap_directory_offset;
246 } QEMU_PACKED Qcow2BitmapHeaderExt;
247 
248 typedef struct BDRVQcow2State {
249     int cluster_bits;
250     int cluster_size;
251     int cluster_sectors;
252     int l2_slice_size;
253     int l2_bits;
254     int l2_size;
255     int l1_size;
256     int l1_vm_state_index;
257     int refcount_block_bits;
258     int refcount_block_size;
259     int csize_shift;
260     int csize_mask;
261     uint64_t cluster_offset_mask;
262     uint64_t l1_table_offset;
263     uint64_t *l1_table;
264 
265     Qcow2Cache* l2_table_cache;
266     Qcow2Cache* refcount_block_cache;
267     QEMUTimer *cache_clean_timer;
268     unsigned cache_clean_interval;
269 
270     uint8_t *cluster_cache;
271     uint8_t *cluster_data;
272     uint64_t cluster_cache_offset;
273     QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
274 
275     uint64_t *refcount_table;
276     uint64_t refcount_table_offset;
277     uint32_t refcount_table_size;
278     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
279     uint64_t free_cluster_index;
280     uint64_t free_byte_offset;
281 
282     CoMutex lock;
283 
284     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
285     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
286     QCryptoBlock *crypto; /* Disk encryption format driver */
287     bool crypt_physical_offset; /* Whether to use virtual or physical offset
288                                    for encryption initialization vector tweak */
289     uint32_t crypt_method_header;
290     uint64_t snapshots_offset;
291     int snapshots_size;
292     unsigned int nb_snapshots;
293     QCowSnapshot *snapshots;
294 
295     uint32_t nb_bitmaps;
296     uint64_t bitmap_directory_size;
297     uint64_t bitmap_directory_offset;
298     bool dirty_bitmaps_loaded;
299 
300     int flags;
301     int qcow_version;
302     bool use_lazy_refcounts;
303     int refcount_order;
304     int refcount_bits;
305     uint64_t refcount_max;
306 
307     Qcow2GetRefcountFunc *get_refcount;
308     Qcow2SetRefcountFunc *set_refcount;
309 
310     bool discard_passthrough[QCOW2_DISCARD_MAX];
311 
312     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
313     bool signaled_corruption;
314 
315     uint64_t incompatible_features;
316     uint64_t compatible_features;
317     uint64_t autoclear_features;
318 
319     size_t unknown_header_fields_size;
320     void* unknown_header_fields;
321     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
322     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
323     bool cache_discards;
324 
325     /* Backing file path and format as stored in the image (this is not the
326      * effective path/format, which may be the result of a runtime option
327      * override) */
328     char *image_backing_file;
329     char *image_backing_format;
330 
331     CoQueue compress_wait_queue;
332     int nb_compress_threads;
333 } BDRVQcow2State;
334 
335 typedef struct Qcow2COWRegion {
336     /**
337      * Offset of the COW region in bytes from the start of the first cluster
338      * touched by the request.
339      */
340     unsigned    offset;
341 
342     /** Number of bytes to copy */
343     unsigned    nb_bytes;
344 } Qcow2COWRegion;
345 
346 /**
347  * Describes an in-flight (part of a) write request that writes to clusters
348  * that are not referenced in their L2 table yet.
349  */
350 typedef struct QCowL2Meta
351 {
352     /** Guest offset of the first newly allocated cluster */
353     uint64_t offset;
354 
355     /** Host offset of the first newly allocated cluster */
356     uint64_t alloc_offset;
357 
358     /** Number of newly allocated clusters */
359     int nb_clusters;
360 
361     /** Do not free the old clusters */
362     bool keep_old_clusters;
363 
364     /**
365      * Requests that overlap with this allocation and wait to be restarted
366      * when the allocating request has completed.
367      */
368     CoQueue dependent_requests;
369 
370     /**
371      * The COW Region between the start of the first allocated cluster and the
372      * area the guest actually writes to.
373      */
374     Qcow2COWRegion cow_start;
375 
376     /**
377      * The COW Region between the area the guest actually writes to and the
378      * end of the last allocated cluster.
379      */
380     Qcow2COWRegion cow_end;
381 
382     /**
383      * The I/O vector with the data from the actual guest write request.
384      * If non-NULL, this is meant to be merged together with the data
385      * from @cow_start and @cow_end into one single write operation.
386      */
387     QEMUIOVector *data_qiov;
388 
389     /** Pointer to next L2Meta of the same write request */
390     struct QCowL2Meta *next;
391 
392     QLIST_ENTRY(QCowL2Meta) next_in_flight;
393 } QCowL2Meta;
394 
395 typedef enum QCow2ClusterType {
396     QCOW2_CLUSTER_UNALLOCATED,
397     QCOW2_CLUSTER_ZERO_PLAIN,
398     QCOW2_CLUSTER_ZERO_ALLOC,
399     QCOW2_CLUSTER_NORMAL,
400     QCOW2_CLUSTER_COMPRESSED,
401 } QCow2ClusterType;
402 
403 typedef enum QCow2MetadataOverlap {
404     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
405     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
406     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
407     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
408     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
409     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
410     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
411     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
412     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
413 
414     QCOW2_OL_MAX_BITNR              = 9,
415 
416     QCOW2_OL_NONE             = 0,
417     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
418     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
419     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
420     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
421     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
422     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
423     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
424     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
425      * reads. */
426     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
427     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
428 } QCow2MetadataOverlap;
429 
430 /* Perform all overlap checks which can be done in constant time */
431 #define QCOW2_OL_CONSTANT \
432     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
433      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
434 
435 /* Perform all overlap checks which don't require disk access */
436 #define QCOW2_OL_CACHED \
437     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
438      QCOW2_OL_INACTIVE_L1)
439 
440 /* Perform all overlap checks */
441 #define QCOW2_OL_ALL \
442     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
443 
444 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
445 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
446 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
447 
448 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
449 
450 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
451 {
452     return offset & ~(s->cluster_size - 1);
453 }
454 
455 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
456 {
457     return offset & (s->cluster_size - 1);
458 }
459 
460 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
461 {
462     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
463 }
464 
465 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
466 {
467     int shift = s->cluster_bits + s->l2_bits;
468     return (size + (1ULL << shift) - 1) >> shift;
469 }
470 
471 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
472 {
473     return offset >> (s->l2_bits + s->cluster_bits);
474 }
475 
476 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
477 {
478     return (offset >> s->cluster_bits) & (s->l2_size - 1);
479 }
480 
481 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
482 {
483     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
484 }
485 
486 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
487 {
488     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
489 }
490 
491 static inline QCow2ClusterType qcow2_get_cluster_type(uint64_t l2_entry)
492 {
493     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
494         return QCOW2_CLUSTER_COMPRESSED;
495     } else if (l2_entry & QCOW_OFLAG_ZERO) {
496         if (l2_entry & L2E_OFFSET_MASK) {
497             return QCOW2_CLUSTER_ZERO_ALLOC;
498         }
499         return QCOW2_CLUSTER_ZERO_PLAIN;
500     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
501         return QCOW2_CLUSTER_UNALLOCATED;
502     } else {
503         return QCOW2_CLUSTER_NORMAL;
504     }
505 }
506 
507 /* Check whether refcounts are eager or lazy */
508 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
509 {
510     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
511 }
512 
513 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
514 {
515     return m->offset + m->cow_start.offset;
516 }
517 
518 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
519 {
520     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
521 }
522 
523 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
524 {
525     return r1 > r2 ? r1 - r2 : r2 - r1;
526 }
527 
528 static inline
529 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
530 {
531     return offset >> (s->refcount_block_bits + s->cluster_bits);
532 }
533 
534 /* qcow2.c functions */
535 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
536                                      int refcount_order, bool generous_increase,
537                                      uint64_t *refblock_count);
538 
539 int qcow2_mark_dirty(BlockDriverState *bs);
540 int qcow2_mark_corrupt(BlockDriverState *bs);
541 int qcow2_mark_consistent(BlockDriverState *bs);
542 int qcow2_update_header(BlockDriverState *bs);
543 
544 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
545                              int64_t size, const char *message_format, ...)
546                              GCC_FMT_ATTR(5, 6);
547 
548 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
549                          uint64_t entries, size_t entry_len,
550                          int64_t max_size_bytes, const char *table_name,
551                          Error **errp);
552 
553 /* qcow2-refcount.c functions */
554 int qcow2_refcount_init(BlockDriverState *bs);
555 void qcow2_refcount_close(BlockDriverState *bs);
556 
557 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
558                        uint64_t *refcount);
559 
560 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
561                                   uint64_t addend, bool decrease,
562                                   enum qcow2_discard_type type);
563 
564 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
565                             uint64_t additional_clusters, bool exact_size,
566                             int new_refblock_index,
567                             uint64_t new_refblock_offset);
568 
569 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
570 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
571                                 int64_t nb_clusters);
572 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
573 void qcow2_free_clusters(BlockDriverState *bs,
574                           int64_t offset, int64_t size,
575                           enum qcow2_discard_type type);
576 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
577                              int nb_clusters, enum qcow2_discard_type type);
578 
579 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
580     int64_t l1_table_offset, int l1_size, int addend);
581 
582 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
583 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
584 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
585                           BdrvCheckMode fix);
586 
587 void qcow2_process_discards(BlockDriverState *bs, int ret);
588 
589 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
590                                  int64_t size);
591 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
592                                   int64_t size);
593 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
594                              void **refcount_table,
595                              int64_t *refcount_table_size,
596                              int64_t offset, int64_t size);
597 
598 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
599                                 BlockDriverAmendStatusCB *status_cb,
600                                 void *cb_opaque, Error **errp);
601 int qcow2_shrink_reftable(BlockDriverState *bs);
602 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
603 
604 /* qcow2-cluster.c functions */
605 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
606                         bool exact_size);
607 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
608 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
609 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
610 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
611                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
612 
613 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
614                              unsigned int *bytes, uint64_t *cluster_offset);
615 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
616                                unsigned int *bytes, uint64_t *host_offset,
617                                QCowL2Meta **m);
618 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
619                                          uint64_t offset,
620                                          int compressed_size);
621 
622 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
623 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
624 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
625                           uint64_t bytes, enum qcow2_discard_type type,
626                           bool full_discard);
627 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
628                           uint64_t bytes, int flags);
629 
630 int qcow2_expand_zero_clusters(BlockDriverState *bs,
631                                BlockDriverAmendStatusCB *status_cb,
632                                void *cb_opaque);
633 
634 /* qcow2-snapshot.c functions */
635 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
636 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
637 int qcow2_snapshot_delete(BlockDriverState *bs,
638                           const char *snapshot_id,
639                           const char *name,
640                           Error **errp);
641 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
642 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
643                             const char *snapshot_id,
644                             const char *name,
645                             Error **errp);
646 
647 void qcow2_free_snapshots(BlockDriverState *bs);
648 int qcow2_read_snapshots(BlockDriverState *bs);
649 
650 /* qcow2-cache.c functions */
651 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
652                                unsigned table_size);
653 int qcow2_cache_destroy(Qcow2Cache *c);
654 
655 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
656 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
657 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
658 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
659     Qcow2Cache *dependency);
660 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
661 
662 void qcow2_cache_clean_unused(Qcow2Cache *c);
663 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
664 
665 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
666     void **table);
667 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
668     void **table);
669 void qcow2_cache_put(Qcow2Cache *c, void **table);
670 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
671 void qcow2_cache_discard(Qcow2Cache *c, void *table);
672 
673 /* qcow2-bitmap.c functions */
674 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
675                                   void **refcount_table,
676                                   int64_t *refcount_table_size);
677 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
678 int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
679                                  Error **errp);
680 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
681 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
682 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
683 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
684                                       const char *name,
685                                       uint32_t granularity,
686                                       Error **errp);
687 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
688                                           const char *name,
689                                           Error **errp);
690 
691 #endif
692