xref: /openbmc/qemu/block/qcow2.h (revision 2cc0e2e8)
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 /* 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_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
104 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
105 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
106 
107 typedef struct QCowHeader {
108     uint32_t magic;
109     uint32_t version;
110     uint64_t backing_file_offset;
111     uint32_t backing_file_size;
112     uint32_t cluster_bits;
113     uint64_t size; /* in bytes */
114     uint32_t crypt_method;
115     uint32_t l1_size; /* XXX: save number of clusters instead ? */
116     uint64_t l1_table_offset;
117     uint64_t refcount_table_offset;
118     uint32_t refcount_table_clusters;
119     uint32_t nb_snapshots;
120     uint64_t snapshots_offset;
121 
122     /* The following fields are only valid for version >= 3 */
123     uint64_t incompatible_features;
124     uint64_t compatible_features;
125     uint64_t autoclear_features;
126 
127     uint32_t refcount_order;
128     uint32_t header_length;
129 } QEMU_PACKED QCowHeader;
130 
131 typedef struct QEMU_PACKED QCowSnapshotHeader {
132     /* header is 8 byte aligned */
133     uint64_t l1_table_offset;
134 
135     uint32_t l1_size;
136     uint16_t id_str_size;
137     uint16_t name_size;
138 
139     uint32_t date_sec;
140     uint32_t date_nsec;
141 
142     uint64_t vm_clock_nsec;
143 
144     uint32_t vm_state_size;
145     uint32_t extra_data_size; /* for extension */
146     /* extra data follows */
147     /* id_str follows */
148     /* name follows  */
149 } QCowSnapshotHeader;
150 
151 typedef struct QEMU_PACKED QCowSnapshotExtraData {
152     uint64_t vm_state_size_large;
153     uint64_t disk_size;
154 } QCowSnapshotExtraData;
155 
156 
157 typedef struct QCowSnapshot {
158     uint64_t l1_table_offset;
159     uint32_t l1_size;
160     char *id_str;
161     char *name;
162     uint64_t disk_size;
163     uint64_t vm_state_size;
164     uint32_t date_sec;
165     uint32_t date_nsec;
166     uint64_t vm_clock_nsec;
167 } QCowSnapshot;
168 
169 struct Qcow2Cache;
170 typedef struct Qcow2Cache Qcow2Cache;
171 
172 typedef struct Qcow2CryptoHeaderExtension {
173     uint64_t offset;
174     uint64_t length;
175 } QEMU_PACKED Qcow2CryptoHeaderExtension;
176 
177 typedef struct Qcow2UnknownHeaderExtension {
178     uint32_t magic;
179     uint32_t len;
180     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
181     uint8_t data[];
182 } Qcow2UnknownHeaderExtension;
183 
184 enum {
185     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
186     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
187     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
188 };
189 
190 /* Incompatible feature bits */
191 enum {
192     QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
193     QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
194     QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
195     QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
196 
197     QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
198                                  | QCOW2_INCOMPAT_CORRUPT,
199 };
200 
201 /* Compatible feature bits */
202 enum {
203     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
204     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
205 
206     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
207 };
208 
209 /* Autoclear feature bits */
210 enum {
211     QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
212     QCOW2_AUTOCLEAR_BITMAPS       = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
213 
214     QCOW2_AUTOCLEAR_MASK          = QCOW2_AUTOCLEAR_BITMAPS,
215 };
216 
217 enum qcow2_discard_type {
218     QCOW2_DISCARD_NEVER = 0,
219     QCOW2_DISCARD_ALWAYS,
220     QCOW2_DISCARD_REQUEST,
221     QCOW2_DISCARD_SNAPSHOT,
222     QCOW2_DISCARD_OTHER,
223     QCOW2_DISCARD_MAX
224 };
225 
226 typedef struct Qcow2Feature {
227     uint8_t type;
228     uint8_t bit;
229     char    name[46];
230 } QEMU_PACKED Qcow2Feature;
231 
232 typedef struct Qcow2DiscardRegion {
233     BlockDriverState *bs;
234     uint64_t offset;
235     uint64_t bytes;
236     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
237 } Qcow2DiscardRegion;
238 
239 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
240                                       uint64_t index);
241 typedef void Qcow2SetRefcountFunc(void *refcount_array,
242                                   uint64_t index, uint64_t value);
243 
244 typedef struct Qcow2BitmapHeaderExt {
245     uint32_t nb_bitmaps;
246     uint32_t reserved32;
247     uint64_t bitmap_directory_size;
248     uint64_t bitmap_directory_offset;
249 } QEMU_PACKED Qcow2BitmapHeaderExt;
250 
251 typedef struct BDRVQcow2State {
252     int cluster_bits;
253     int cluster_size;
254     int cluster_sectors;
255     int l2_slice_size;
256     int l2_bits;
257     int l2_size;
258     int l1_size;
259     int l1_vm_state_index;
260     int refcount_block_bits;
261     int refcount_block_size;
262     int csize_shift;
263     int csize_mask;
264     uint64_t cluster_offset_mask;
265     uint64_t l1_table_offset;
266     uint64_t *l1_table;
267 
268     Qcow2Cache* l2_table_cache;
269     Qcow2Cache* refcount_block_cache;
270     QEMUTimer *cache_clean_timer;
271     unsigned cache_clean_interval;
272 
273     uint8_t *cluster_cache;
274     uint8_t *cluster_data;
275     uint64_t cluster_cache_offset;
276     QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
277 
278     uint64_t *refcount_table;
279     uint64_t refcount_table_offset;
280     uint32_t refcount_table_size;
281     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
282     uint64_t free_cluster_index;
283     uint64_t free_byte_offset;
284 
285     CoMutex lock;
286 
287     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
288     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
289     QCryptoBlock *crypto; /* Disk encryption format driver */
290     bool crypt_physical_offset; /* Whether to use virtual or physical offset
291                                    for encryption initialization vector tweak */
292     uint32_t crypt_method_header;
293     uint64_t snapshots_offset;
294     int snapshots_size;
295     unsigned int nb_snapshots;
296     QCowSnapshot *snapshots;
297 
298     uint32_t nb_bitmaps;
299     uint64_t bitmap_directory_size;
300     uint64_t bitmap_directory_offset;
301     bool dirty_bitmaps_loaded;
302 
303     int flags;
304     int qcow_version;
305     bool use_lazy_refcounts;
306     int refcount_order;
307     int refcount_bits;
308     uint64_t refcount_max;
309 
310     Qcow2GetRefcountFunc *get_refcount;
311     Qcow2SetRefcountFunc *set_refcount;
312 
313     bool discard_passthrough[QCOW2_DISCARD_MAX];
314 
315     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
316     bool signaled_corruption;
317 
318     uint64_t incompatible_features;
319     uint64_t compatible_features;
320     uint64_t autoclear_features;
321 
322     size_t unknown_header_fields_size;
323     void* unknown_header_fields;
324     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
325     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
326     bool cache_discards;
327 
328     /* Backing file path and format as stored in the image (this is not the
329      * effective path/format, which may be the result of a runtime option
330      * override) */
331     char *image_backing_file;
332     char *image_backing_format;
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 
413     QCOW2_OL_MAX_BITNR            = 8,
414 
415     QCOW2_OL_NONE           = 0,
416     QCOW2_OL_MAIN_HEADER    = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
417     QCOW2_OL_ACTIVE_L1      = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
418     QCOW2_OL_ACTIVE_L2      = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
419     QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
420     QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
421     QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
422     QCOW2_OL_INACTIVE_L1    = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
423     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
424      * reads. */
425     QCOW2_OL_INACTIVE_L2    = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
426 } QCow2MetadataOverlap;
427 
428 /* Perform all overlap checks which can be done in constant time */
429 #define QCOW2_OL_CONSTANT \
430     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
431      QCOW2_OL_SNAPSHOT_TABLE)
432 
433 /* Perform all overlap checks which don't require disk access */
434 #define QCOW2_OL_CACHED \
435     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
436      QCOW2_OL_INACTIVE_L1)
437 
438 /* Perform all overlap checks */
439 #define QCOW2_OL_ALL \
440     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
441 
442 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
443 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
444 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
445 
446 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
447 
448 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
449 {
450     return offset & ~(s->cluster_size - 1);
451 }
452 
453 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
454 {
455     return offset & (s->cluster_size - 1);
456 }
457 
458 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
459 {
460     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
461 }
462 
463 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
464 {
465     int shift = s->cluster_bits + s->l2_bits;
466     return (size + (1ULL << shift) - 1) >> shift;
467 }
468 
469 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
470 {
471     return offset >> (s->l2_bits + s->cluster_bits);
472 }
473 
474 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
475 {
476     return (offset >> s->cluster_bits) & (s->l2_size - 1);
477 }
478 
479 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
480 {
481     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
482 }
483 
484 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
485 {
486     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
487 }
488 
489 static inline QCow2ClusterType qcow2_get_cluster_type(uint64_t l2_entry)
490 {
491     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
492         return QCOW2_CLUSTER_COMPRESSED;
493     } else if (l2_entry & QCOW_OFLAG_ZERO) {
494         if (l2_entry & L2E_OFFSET_MASK) {
495             return QCOW2_CLUSTER_ZERO_ALLOC;
496         }
497         return QCOW2_CLUSTER_ZERO_PLAIN;
498     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
499         return QCOW2_CLUSTER_UNALLOCATED;
500     } else {
501         return QCOW2_CLUSTER_NORMAL;
502     }
503 }
504 
505 /* Check whether refcounts are eager or lazy */
506 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
507 {
508     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
509 }
510 
511 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
512 {
513     return m->offset + m->cow_start.offset;
514 }
515 
516 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
517 {
518     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
519 }
520 
521 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
522 {
523     return r1 > r2 ? r1 - r2 : r2 - r1;
524 }
525 
526 static inline
527 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
528 {
529     return offset >> (s->refcount_block_bits + s->cluster_bits);
530 }
531 
532 /* qcow2.c functions */
533 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
534                                      int refcount_order, bool generous_increase,
535                                      uint64_t *refblock_count);
536 
537 int qcow2_mark_dirty(BlockDriverState *bs);
538 int qcow2_mark_corrupt(BlockDriverState *bs);
539 int qcow2_mark_consistent(BlockDriverState *bs);
540 int qcow2_update_header(BlockDriverState *bs);
541 
542 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
543                              int64_t size, const char *message_format, ...)
544                              GCC_FMT_ATTR(5, 6);
545 
546 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
547                          uint64_t entries, size_t entry_len,
548                          int64_t max_size_bytes, const char *table_name,
549                          Error **errp);
550 
551 /* qcow2-refcount.c functions */
552 int qcow2_refcount_init(BlockDriverState *bs);
553 void qcow2_refcount_close(BlockDriverState *bs);
554 
555 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
556                        uint64_t *refcount);
557 
558 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
559                                   uint64_t addend, bool decrease,
560                                   enum qcow2_discard_type type);
561 
562 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
563                             uint64_t additional_clusters, bool exact_size,
564                             int new_refblock_index,
565                             uint64_t new_refblock_offset);
566 
567 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
568 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
569                                 int64_t nb_clusters);
570 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
571 void qcow2_free_clusters(BlockDriverState *bs,
572                           int64_t offset, int64_t size,
573                           enum qcow2_discard_type type);
574 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
575                              int nb_clusters, enum qcow2_discard_type type);
576 
577 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
578     int64_t l1_table_offset, int l1_size, int addend);
579 
580 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
581 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
582 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
583                           BdrvCheckMode fix);
584 
585 void qcow2_process_discards(BlockDriverState *bs, int ret);
586 
587 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
588                                  int64_t size);
589 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
590                                   int64_t size);
591 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
592                              void **refcount_table,
593                              int64_t *refcount_table_size,
594                              int64_t offset, int64_t size);
595 
596 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
597                                 BlockDriverAmendStatusCB *status_cb,
598                                 void *cb_opaque, Error **errp);
599 int qcow2_shrink_reftable(BlockDriverState *bs);
600 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
601 
602 /* qcow2-cluster.c functions */
603 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
604                         bool exact_size);
605 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
606 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
607 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
608 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
609                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
610 
611 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
612                              unsigned int *bytes, uint64_t *cluster_offset);
613 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
614                                unsigned int *bytes, uint64_t *host_offset,
615                                QCowL2Meta **m);
616 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
617                                          uint64_t offset,
618                                          int compressed_size);
619 
620 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
621 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
622                           uint64_t bytes, enum qcow2_discard_type type,
623                           bool full_discard);
624 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
625                           uint64_t bytes, int flags);
626 
627 int qcow2_expand_zero_clusters(BlockDriverState *bs,
628                                BlockDriverAmendStatusCB *status_cb,
629                                void *cb_opaque);
630 
631 /* qcow2-snapshot.c functions */
632 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
633 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
634 int qcow2_snapshot_delete(BlockDriverState *bs,
635                           const char *snapshot_id,
636                           const char *name,
637                           Error **errp);
638 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
639 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
640                             const char *snapshot_id,
641                             const char *name,
642                             Error **errp);
643 
644 void qcow2_free_snapshots(BlockDriverState *bs);
645 int qcow2_read_snapshots(BlockDriverState *bs);
646 
647 /* qcow2-cache.c functions */
648 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
649                                unsigned table_size);
650 int qcow2_cache_destroy(Qcow2Cache *c);
651 
652 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
653 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
654 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
655 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
656     Qcow2Cache *dependency);
657 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
658 
659 void qcow2_cache_clean_unused(Qcow2Cache *c);
660 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
661 
662 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
663     void **table);
664 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
665     void **table);
666 void qcow2_cache_put(Qcow2Cache *c, void **table);
667 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
668 void qcow2_cache_discard(Qcow2Cache *c, void *table);
669 
670 /* qcow2-bitmap.c functions */
671 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
672                                   void **refcount_table,
673                                   int64_t *refcount_table_size);
674 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
675 int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
676                                  Error **errp);
677 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
678 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
679 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
680 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
681                                       const char *name,
682                                       uint32_t granularity,
683                                       Error **errp);
684 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
685                                           const char *name,
686                                           Error **errp);
687 
688 #endif
689