xref: /openbmc/qemu/block/qcow2.h (revision 80adf54e)
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 /* clusters */
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 /* The refblock cache needs only a fourth of the L2 cache size to cover as many
81  * clusters */
82 #define DEFAULT_L2_REFCOUNT_SIZE_RATIO 4
83 
84 #define DEFAULT_CLUSTER_SIZE 65536
85 
86 
87 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
88 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
89 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
90 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
91 #define QCOW2_OPT_OVERLAP "overlap-check"
92 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
93 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
94 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
95 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
96 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
97 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
98 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
99 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
100 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
101 #define QCOW2_OPT_CACHE_SIZE "cache-size"
102 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
103 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
104 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
105 
106 typedef struct QCowHeader {
107     uint32_t magic;
108     uint32_t version;
109     uint64_t backing_file_offset;
110     uint32_t backing_file_size;
111     uint32_t cluster_bits;
112     uint64_t size; /* in bytes */
113     uint32_t crypt_method;
114     uint32_t l1_size; /* XXX: save number of clusters instead ? */
115     uint64_t l1_table_offset;
116     uint64_t refcount_table_offset;
117     uint32_t refcount_table_clusters;
118     uint32_t nb_snapshots;
119     uint64_t snapshots_offset;
120 
121     /* The following fields are only valid for version >= 3 */
122     uint64_t incompatible_features;
123     uint64_t compatible_features;
124     uint64_t autoclear_features;
125 
126     uint32_t refcount_order;
127     uint32_t header_length;
128 } QEMU_PACKED QCowHeader;
129 
130 typedef struct QEMU_PACKED QCowSnapshotHeader {
131     /* header is 8 byte aligned */
132     uint64_t l1_table_offset;
133 
134     uint32_t l1_size;
135     uint16_t id_str_size;
136     uint16_t name_size;
137 
138     uint32_t date_sec;
139     uint32_t date_nsec;
140 
141     uint64_t vm_clock_nsec;
142 
143     uint32_t vm_state_size;
144     uint32_t extra_data_size; /* for extension */
145     /* extra data follows */
146     /* id_str follows */
147     /* name follows  */
148 } QCowSnapshotHeader;
149 
150 typedef struct QEMU_PACKED QCowSnapshotExtraData {
151     uint64_t vm_state_size_large;
152     uint64_t disk_size;
153 } QCowSnapshotExtraData;
154 
155 
156 typedef struct QCowSnapshot {
157     uint64_t l1_table_offset;
158     uint32_t l1_size;
159     char *id_str;
160     char *name;
161     uint64_t disk_size;
162     uint64_t vm_state_size;
163     uint32_t date_sec;
164     uint32_t date_nsec;
165     uint64_t vm_clock_nsec;
166 } QCowSnapshot;
167 
168 struct Qcow2Cache;
169 typedef struct Qcow2Cache Qcow2Cache;
170 
171 typedef struct Qcow2CryptoHeaderExtension {
172     uint64_t offset;
173     uint64_t length;
174 } QEMU_PACKED Qcow2CryptoHeaderExtension;
175 
176 typedef struct Qcow2UnknownHeaderExtension {
177     uint32_t magic;
178     uint32_t len;
179     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
180     uint8_t data[];
181 } Qcow2UnknownHeaderExtension;
182 
183 enum {
184     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
185     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
186     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
187 };
188 
189 /* Incompatible feature bits */
190 enum {
191     QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
192     QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
193     QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
194     QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
195 
196     QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
197                                  | QCOW2_INCOMPAT_CORRUPT,
198 };
199 
200 /* Compatible feature bits */
201 enum {
202     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
203     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
204 
205     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
206 };
207 
208 /* Autoclear feature bits */
209 enum {
210     QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
211     QCOW2_AUTOCLEAR_BITMAPS       = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
212 
213     QCOW2_AUTOCLEAR_MASK          = QCOW2_AUTOCLEAR_BITMAPS,
214 };
215 
216 enum qcow2_discard_type {
217     QCOW2_DISCARD_NEVER = 0,
218     QCOW2_DISCARD_ALWAYS,
219     QCOW2_DISCARD_REQUEST,
220     QCOW2_DISCARD_SNAPSHOT,
221     QCOW2_DISCARD_OTHER,
222     QCOW2_DISCARD_MAX
223 };
224 
225 typedef struct Qcow2Feature {
226     uint8_t type;
227     uint8_t bit;
228     char    name[46];
229 } QEMU_PACKED Qcow2Feature;
230 
231 typedef struct Qcow2DiscardRegion {
232     BlockDriverState *bs;
233     uint64_t offset;
234     uint64_t bytes;
235     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
236 } Qcow2DiscardRegion;
237 
238 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
239                                       uint64_t index);
240 typedef void Qcow2SetRefcountFunc(void *refcount_array,
241                                   uint64_t index, uint64_t value);
242 
243 typedef struct Qcow2BitmapHeaderExt {
244     uint32_t nb_bitmaps;
245     uint32_t reserved32;
246     uint64_t bitmap_directory_size;
247     uint64_t bitmap_directory_offset;
248 } QEMU_PACKED Qcow2BitmapHeaderExt;
249 
250 typedef struct BDRVQcow2State {
251     int cluster_bits;
252     int cluster_size;
253     int cluster_sectors;
254     int l2_bits;
255     int l2_size;
256     int l1_size;
257     int l1_vm_state_index;
258     int refcount_block_bits;
259     int refcount_block_size;
260     int csize_shift;
261     int csize_mask;
262     uint64_t cluster_offset_mask;
263     uint64_t l1_table_offset;
264     uint64_t *l1_table;
265 
266     Qcow2Cache* l2_table_cache;
267     Qcow2Cache* refcount_block_cache;
268     QEMUTimer *cache_clean_timer;
269     unsigned cache_clean_interval;
270 
271     uint8_t *cluster_cache;
272     uint8_t *cluster_data;
273     uint64_t cluster_cache_offset;
274     QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
275 
276     uint64_t *refcount_table;
277     uint64_t refcount_table_offset;
278     uint32_t refcount_table_size;
279     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
280     uint64_t free_cluster_index;
281     uint64_t free_byte_offset;
282 
283     CoMutex lock;
284 
285     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
286     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
287     QCryptoBlock *crypto; /* Disk encryption format driver */
288     bool crypt_physical_offset; /* Whether to use virtual or physical offset
289                                    for encryption initialization vector tweak */
290     uint32_t crypt_method_header;
291     uint64_t snapshots_offset;
292     int snapshots_size;
293     unsigned int nb_snapshots;
294     QCowSnapshot *snapshots;
295 
296     uint32_t nb_bitmaps;
297     uint64_t bitmap_directory_size;
298     uint64_t bitmap_directory_offset;
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 } BDRVQcow2State;
331 
332 typedef struct Qcow2COWRegion {
333     /**
334      * Offset of the COW region in bytes from the start of the first cluster
335      * touched by the request.
336      */
337     unsigned    offset;
338 
339     /** Number of bytes to copy */
340     unsigned    nb_bytes;
341 } Qcow2COWRegion;
342 
343 /**
344  * Describes an in-flight (part of a) write request that writes to clusters
345  * that are not referenced in their L2 table yet.
346  */
347 typedef struct QCowL2Meta
348 {
349     /** Guest offset of the first newly allocated cluster */
350     uint64_t offset;
351 
352     /** Host offset of the first newly allocated cluster */
353     uint64_t alloc_offset;
354 
355     /** Number of newly allocated clusters */
356     int nb_clusters;
357 
358     /** Do not free the old clusters */
359     bool keep_old_clusters;
360 
361     /**
362      * Requests that overlap with this allocation and wait to be restarted
363      * when the allocating request has completed.
364      */
365     CoQueue dependent_requests;
366 
367     /**
368      * The COW Region between the start of the first allocated cluster and the
369      * area the guest actually writes to.
370      */
371     Qcow2COWRegion cow_start;
372 
373     /**
374      * The COW Region between the area the guest actually writes to and the
375      * end of the last allocated cluster.
376      */
377     Qcow2COWRegion cow_end;
378 
379     /**
380      * The I/O vector with the data from the actual guest write request.
381      * If non-NULL, this is meant to be merged together with the data
382      * from @cow_start and @cow_end into one single write operation.
383      */
384     QEMUIOVector *data_qiov;
385 
386     /** Pointer to next L2Meta of the same write request */
387     struct QCowL2Meta *next;
388 
389     QLIST_ENTRY(QCowL2Meta) next_in_flight;
390 } QCowL2Meta;
391 
392 typedef enum QCow2ClusterType {
393     QCOW2_CLUSTER_UNALLOCATED,
394     QCOW2_CLUSTER_ZERO_PLAIN,
395     QCOW2_CLUSTER_ZERO_ALLOC,
396     QCOW2_CLUSTER_NORMAL,
397     QCOW2_CLUSTER_COMPRESSED,
398 } QCow2ClusterType;
399 
400 typedef enum QCow2MetadataOverlap {
401     QCOW2_OL_MAIN_HEADER_BITNR    = 0,
402     QCOW2_OL_ACTIVE_L1_BITNR      = 1,
403     QCOW2_OL_ACTIVE_L2_BITNR      = 2,
404     QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
405     QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
406     QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
407     QCOW2_OL_INACTIVE_L1_BITNR    = 6,
408     QCOW2_OL_INACTIVE_L2_BITNR    = 7,
409 
410     QCOW2_OL_MAX_BITNR            = 8,
411 
412     QCOW2_OL_NONE           = 0,
413     QCOW2_OL_MAIN_HEADER    = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
414     QCOW2_OL_ACTIVE_L1      = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
415     QCOW2_OL_ACTIVE_L2      = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
416     QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
417     QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
418     QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
419     QCOW2_OL_INACTIVE_L1    = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
420     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
421      * reads. */
422     QCOW2_OL_INACTIVE_L2    = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
423 } QCow2MetadataOverlap;
424 
425 /* Perform all overlap checks which can be done in constant time */
426 #define QCOW2_OL_CONSTANT \
427     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
428      QCOW2_OL_SNAPSHOT_TABLE)
429 
430 /* Perform all overlap checks which don't require disk access */
431 #define QCOW2_OL_CACHED \
432     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
433      QCOW2_OL_INACTIVE_L1)
434 
435 /* Perform all overlap checks */
436 #define QCOW2_OL_ALL \
437     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
438 
439 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
440 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
441 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
442 
443 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
444 
445 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
446 {
447     return offset & ~(s->cluster_size - 1);
448 }
449 
450 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
451 {
452     return offset & (s->cluster_size - 1);
453 }
454 
455 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
456 {
457     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
458 }
459 
460 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
461 {
462     int shift = s->cluster_bits + s->l2_bits;
463     return (size + (1ULL << shift) - 1) >> shift;
464 }
465 
466 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
467 {
468     return (offset >> s->cluster_bits) & (s->l2_size - 1);
469 }
470 
471 static inline int64_t align_offset(int64_t offset, int n)
472 {
473     offset = (offset + n - 1) & ~(n - 1);
474     return offset;
475 }
476 
477 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
478 {
479     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
480 }
481 
482 static inline uint64_t qcow2_max_refcount_clusters(BDRVQcow2State *s)
483 {
484     return QCOW_MAX_REFTABLE_SIZE >> s->cluster_bits;
485 }
486 
487 static inline QCow2ClusterType qcow2_get_cluster_type(uint64_t l2_entry)
488 {
489     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
490         return QCOW2_CLUSTER_COMPRESSED;
491     } else if (l2_entry & QCOW_OFLAG_ZERO) {
492         if (l2_entry & L2E_OFFSET_MASK) {
493             return QCOW2_CLUSTER_ZERO_ALLOC;
494         }
495         return QCOW2_CLUSTER_ZERO_PLAIN;
496     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
497         return QCOW2_CLUSTER_UNALLOCATED;
498     } else {
499         return QCOW2_CLUSTER_NORMAL;
500     }
501 }
502 
503 /* Check whether refcounts are eager or lazy */
504 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
505 {
506     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
507 }
508 
509 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
510 {
511     return m->offset + m->cow_start.offset;
512 }
513 
514 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
515 {
516     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
517 }
518 
519 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
520 {
521     return r1 > r2 ? r1 - r2 : r2 - r1;
522 }
523 
524 /* qcow2.c functions */
525 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
526                   int64_t sector_num, int nb_sectors);
527 
528 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
529                                      int refcount_order, bool generous_increase,
530                                      uint64_t *refblock_count);
531 
532 int qcow2_mark_dirty(BlockDriverState *bs);
533 int qcow2_mark_corrupt(BlockDriverState *bs);
534 int qcow2_mark_consistent(BlockDriverState *bs);
535 int qcow2_update_header(BlockDriverState *bs);
536 
537 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
538                              int64_t size, const char *message_format, ...)
539                              GCC_FMT_ATTR(5, 6);
540 
541 /* qcow2-refcount.c functions */
542 int qcow2_refcount_init(BlockDriverState *bs);
543 void qcow2_refcount_close(BlockDriverState *bs);
544 
545 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
546                        uint64_t *refcount);
547 
548 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
549                                   uint64_t addend, bool decrease,
550                                   enum qcow2_discard_type type);
551 
552 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
553                             uint64_t additional_clusters, bool exact_size,
554                             int new_refblock_index,
555                             uint64_t new_refblock_offset);
556 
557 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
558 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
559                                 int64_t nb_clusters);
560 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
561 void qcow2_free_clusters(BlockDriverState *bs,
562                           int64_t offset, int64_t size,
563                           enum qcow2_discard_type type);
564 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
565                              int nb_clusters, enum qcow2_discard_type type);
566 
567 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
568     int64_t l1_table_offset, int l1_size, int addend);
569 
570 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
571                           BdrvCheckMode fix);
572 
573 void qcow2_process_discards(BlockDriverState *bs, int ret);
574 
575 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
576                                  int64_t size);
577 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
578                                   int64_t size);
579 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
580                              void **refcount_table,
581                              int64_t *refcount_table_size,
582                              int64_t offset, int64_t size);
583 
584 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
585                                 BlockDriverAmendStatusCB *status_cb,
586                                 void *cb_opaque, Error **errp);
587 
588 /* qcow2-cluster.c functions */
589 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
590                         bool exact_size);
591 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
592 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
593 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
594                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
595 
596 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
597                              unsigned int *bytes, uint64_t *cluster_offset);
598 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
599                                unsigned int *bytes, uint64_t *host_offset,
600                                QCowL2Meta **m);
601 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
602                                          uint64_t offset,
603                                          int compressed_size);
604 
605 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
606 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
607                           uint64_t bytes, enum qcow2_discard_type type,
608                           bool full_discard);
609 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
610                           uint64_t bytes, int flags);
611 
612 int qcow2_expand_zero_clusters(BlockDriverState *bs,
613                                BlockDriverAmendStatusCB *status_cb,
614                                void *cb_opaque);
615 
616 /* qcow2-snapshot.c functions */
617 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
618 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
619 int qcow2_snapshot_delete(BlockDriverState *bs,
620                           const char *snapshot_id,
621                           const char *name,
622                           Error **errp);
623 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
624 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
625                             const char *snapshot_id,
626                             const char *name,
627                             Error **errp);
628 
629 void qcow2_free_snapshots(BlockDriverState *bs);
630 int qcow2_read_snapshots(BlockDriverState *bs);
631 
632 /* qcow2-cache.c functions */
633 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables);
634 int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
635 
636 void qcow2_cache_entry_mark_dirty(BlockDriverState *bs, Qcow2Cache *c,
637      void *table);
638 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
639 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
640 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
641     Qcow2Cache *dependency);
642 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
643 
644 void qcow2_cache_clean_unused(BlockDriverState *bs, Qcow2Cache *c);
645 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
646 
647 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
648     void **table);
649 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
650     void **table);
651 void qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table);
652 
653 /* qcow2-bitmap.c functions */
654 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
655                                   void **refcount_table,
656                                   int64_t *refcount_table_size);
657 bool qcow2_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **errp);
658 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
659 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
660 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
661 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
662                                       const char *name,
663                                       uint32_t granularity,
664                                       Error **errp);
665 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
666                                           const char *name,
667                                           Error **errp);
668 
669 #endif
670