qcow2: skip writing zero buffers to empty COW areas
[qemu.git] / block / qcow2.h
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 #include "qemu/units.h"
31 #include "block/block_int.h"
32
33 //#define DEBUG_ALLOC
34 //#define DEBUG_ALLOC2
35 //#define DEBUG_EXT
36
37 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
38
39 #define QCOW_CRYPT_NONE 0
40 #define QCOW_CRYPT_AES 1
41 #define QCOW_CRYPT_LUKS 2
42
43 #define QCOW_MAX_CRYPT_CLUSTERS 32
44 #define QCOW_MAX_SNAPSHOTS 65536
45
46 /* Field widths in qcow2 mean normal cluster offsets cannot reach
47 * 64PB; depending on cluster size, compressed clusters can have a
48 * smaller limit (64PB for up to 16k clusters, then ramps down to
49 * 512TB for 2M clusters). */
50 #define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1)
51
52 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
53 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
54 #define QCOW_MAX_REFTABLE_SIZE (8 * MiB)
55
56 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
57 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
58 #define QCOW_MAX_L1_SIZE (32 * MiB)
59
60 /* Allow for an average of 1k per snapshot table entry, should be plenty of
61 * space for snapshot names and IDs */
62 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
63
64 /* Bitmap header extension constraints */
65 #define QCOW2_MAX_BITMAPS 65535
66 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
67
68 /* indicate that the refcount of the referenced cluster is exactly one. */
69 #define QCOW_OFLAG_COPIED (1ULL << 63)
70 /* indicate that the cluster is compressed (they never have the copied flag) */
71 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
72 /* The cluster reads as all zeros */
73 #define QCOW_OFLAG_ZERO (1ULL << 0)
74
75 #define MIN_CLUSTER_BITS 9
76 #define MAX_CLUSTER_BITS 21
77
78 /* Defined in the qcow2 spec (compressed cluster descriptor) */
79 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U
80 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1))
81
82 /* Must be at least 2 to cover COW */
83 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
84
85 /* Must be at least 4 to cover all cases of refcount table growth */
86 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
87
88 #ifdef CONFIG_LINUX
89 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
90 #define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */
91 #else
92 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
93 /* Cache clean interval is currently available only on Linux, so must be 0 */
94 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
95 #endif
96
97 #define DEFAULT_CLUSTER_SIZE 65536
98
99 #define QCOW2_OPT_DATA_FILE "data-file"
100 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
101 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
102 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
103 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
104 #define QCOW2_OPT_OVERLAP "overlap-check"
105 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
106 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
107 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
108 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
109 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
110 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
111 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
112 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
113 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
114 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
115 #define QCOW2_OPT_CACHE_SIZE "cache-size"
116 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
117 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
118 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
119 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
120
121 typedef struct QCowHeader {
122 uint32_t magic;
123 uint32_t version;
124 uint64_t backing_file_offset;
125 uint32_t backing_file_size;
126 uint32_t cluster_bits;
127 uint64_t size; /* in bytes */
128 uint32_t crypt_method;
129 uint32_t l1_size; /* XXX: save number of clusters instead ? */
130 uint64_t l1_table_offset;
131 uint64_t refcount_table_offset;
132 uint32_t refcount_table_clusters;
133 uint32_t nb_snapshots;
134 uint64_t snapshots_offset;
135
136 /* The following fields are only valid for version >= 3 */
137 uint64_t incompatible_features;
138 uint64_t compatible_features;
139 uint64_t autoclear_features;
140
141 uint32_t refcount_order;
142 uint32_t header_length;
143 } QEMU_PACKED QCowHeader;
144
145 typedef struct QEMU_PACKED QCowSnapshotHeader {
146 /* header is 8 byte aligned */
147 uint64_t l1_table_offset;
148
149 uint32_t l1_size;
150 uint16_t id_str_size;
151 uint16_t name_size;
152
153 uint32_t date_sec;
154 uint32_t date_nsec;
155
156 uint64_t vm_clock_nsec;
157
158 uint32_t vm_state_size;
159 uint32_t extra_data_size; /* for extension */
160 /* extra data follows */
161 /* id_str follows */
162 /* name follows */
163 } QCowSnapshotHeader;
164
165 typedef struct QEMU_PACKED QCowSnapshotExtraData {
166 uint64_t vm_state_size_large;
167 uint64_t disk_size;
168 } QCowSnapshotExtraData;
169
170
171 typedef struct QCowSnapshot {
172 uint64_t l1_table_offset;
173 uint32_t l1_size;
174 char *id_str;
175 char *name;
176 uint64_t disk_size;
177 uint64_t vm_state_size;
178 uint32_t date_sec;
179 uint32_t date_nsec;
180 uint64_t vm_clock_nsec;
181 } QCowSnapshot;
182
183 struct Qcow2Cache;
184 typedef struct Qcow2Cache Qcow2Cache;
185
186 typedef struct Qcow2CryptoHeaderExtension {
187 uint64_t offset;
188 uint64_t length;
189 } QEMU_PACKED Qcow2CryptoHeaderExtension;
190
191 typedef struct Qcow2UnknownHeaderExtension {
192 uint32_t magic;
193 uint32_t len;
194 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
195 uint8_t data[];
196 } Qcow2UnknownHeaderExtension;
197
198 enum {
199 QCOW2_FEAT_TYPE_INCOMPATIBLE = 0,
200 QCOW2_FEAT_TYPE_COMPATIBLE = 1,
201 QCOW2_FEAT_TYPE_AUTOCLEAR = 2,
202 };
203
204 /* Incompatible feature bits */
205 enum {
206 QCOW2_INCOMPAT_DIRTY_BITNR = 0,
207 QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
208 QCOW2_INCOMPAT_DATA_FILE_BITNR = 2,
209 QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
210 QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
211 QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
212
213 QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY
214 | QCOW2_INCOMPAT_CORRUPT
215 | QCOW2_INCOMPAT_DATA_FILE,
216 };
217
218 /* Compatible feature bits */
219 enum {
220 QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
221 QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
222
223 QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS,
224 };
225
226 /* Autoclear feature bits */
227 enum {
228 QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
229 QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
230 QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
231 QCOW2_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
232
233 QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS
234 | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
235 };
236
237 enum qcow2_discard_type {
238 QCOW2_DISCARD_NEVER = 0,
239 QCOW2_DISCARD_ALWAYS,
240 QCOW2_DISCARD_REQUEST,
241 QCOW2_DISCARD_SNAPSHOT,
242 QCOW2_DISCARD_OTHER,
243 QCOW2_DISCARD_MAX
244 };
245
246 typedef struct Qcow2Feature {
247 uint8_t type;
248 uint8_t bit;
249 char name[46];
250 } QEMU_PACKED Qcow2Feature;
251
252 typedef struct Qcow2DiscardRegion {
253 BlockDriverState *bs;
254 uint64_t offset;
255 uint64_t bytes;
256 QTAILQ_ENTRY(Qcow2DiscardRegion) next;
257 } Qcow2DiscardRegion;
258
259 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
260 uint64_t index);
261 typedef void Qcow2SetRefcountFunc(void *refcount_array,
262 uint64_t index, uint64_t value);
263
264 typedef struct Qcow2BitmapHeaderExt {
265 uint32_t nb_bitmaps;
266 uint32_t reserved32;
267 uint64_t bitmap_directory_size;
268 uint64_t bitmap_directory_offset;
269 } QEMU_PACKED Qcow2BitmapHeaderExt;
270
271 #define QCOW2_MAX_THREADS 4
272
273 typedef struct BDRVQcow2State {
274 int cluster_bits;
275 int cluster_size;
276 int l2_slice_size;
277 int l2_bits;
278 int l2_size;
279 int l1_size;
280 int l1_vm_state_index;
281 int refcount_block_bits;
282 int refcount_block_size;
283 int csize_shift;
284 int csize_mask;
285 uint64_t cluster_offset_mask;
286 uint64_t l1_table_offset;
287 uint64_t *l1_table;
288
289 Qcow2Cache* l2_table_cache;
290 Qcow2Cache* refcount_block_cache;
291 QEMUTimer *cache_clean_timer;
292 unsigned cache_clean_interval;
293
294 uint8_t *cluster_cache;
295 uint8_t *cluster_data;
296 uint64_t cluster_cache_offset;
297 QLIST_HEAD(, QCowL2Meta) cluster_allocs;
298
299 uint64_t *refcount_table;
300 uint64_t refcount_table_offset;
301 uint32_t refcount_table_size;
302 uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
303 uint64_t free_cluster_index;
304 uint64_t free_byte_offset;
305
306 CoMutex lock;
307
308 Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
309 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
310 QCryptoBlock *crypto; /* Disk encryption format driver */
311 bool crypt_physical_offset; /* Whether to use virtual or physical offset
312 for encryption initialization vector tweak */
313 uint32_t crypt_method_header;
314 uint64_t snapshots_offset;
315 int snapshots_size;
316 unsigned int nb_snapshots;
317 QCowSnapshot *snapshots;
318
319 uint32_t nb_bitmaps;
320 uint64_t bitmap_directory_size;
321 uint64_t bitmap_directory_offset;
322
323 int flags;
324 int qcow_version;
325 bool use_lazy_refcounts;
326 int refcount_order;
327 int refcount_bits;
328 uint64_t refcount_max;
329
330 Qcow2GetRefcountFunc *get_refcount;
331 Qcow2SetRefcountFunc *set_refcount;
332
333 bool discard_passthrough[QCOW2_DISCARD_MAX];
334
335 int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
336 bool signaled_corruption;
337
338 uint64_t incompatible_features;
339 uint64_t compatible_features;
340 uint64_t autoclear_features;
341
342 size_t unknown_header_fields_size;
343 void* unknown_header_fields;
344 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
345 QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
346 bool cache_discards;
347
348 /* Backing file path and format as stored in the image (this is not the
349 * effective path/format, which may be the result of a runtime option
350 * override) */
351 char *image_backing_file;
352 char *image_backing_format;
353 char *image_data_file;
354
355 CoQueue thread_task_queue;
356 int nb_threads;
357
358 BdrvChild *data_file;
359 } BDRVQcow2State;
360
361 typedef struct Qcow2COWRegion {
362 /**
363 * Offset of the COW region in bytes from the start of the first cluster
364 * touched by the request.
365 */
366 unsigned offset;
367
368 /** Number of bytes to copy */
369 unsigned nb_bytes;
370 } Qcow2COWRegion;
371
372 /**
373 * Describes an in-flight (part of a) write request that writes to clusters
374 * that are not referenced in their L2 table yet.
375 */
376 typedef struct QCowL2Meta
377 {
378 /** Guest offset of the first newly allocated cluster */
379 uint64_t offset;
380
381 /** Host offset of the first newly allocated cluster */
382 uint64_t alloc_offset;
383
384 /** Number of newly allocated clusters */
385 int nb_clusters;
386
387 /** Do not free the old clusters */
388 bool keep_old_clusters;
389
390 /**
391 * Requests that overlap with this allocation and wait to be restarted
392 * when the allocating request has completed.
393 */
394 CoQueue dependent_requests;
395
396 /**
397 * The COW Region between the start of the first allocated cluster and the
398 * area the guest actually writes to.
399 */
400 Qcow2COWRegion cow_start;
401
402 /**
403 * The COW Region between the area the guest actually writes to and the
404 * end of the last allocated cluster.
405 */
406 Qcow2COWRegion cow_end;
407
408 /*
409 * Indicates that COW regions are already handled and do not require
410 * any more processing.
411 */
412 bool skip_cow;
413
414 /**
415 * The I/O vector with the data from the actual guest write request.
416 * If non-NULL, this is meant to be merged together with the data
417 * from @cow_start and @cow_end into one single write operation.
418 */
419 QEMUIOVector *data_qiov;
420
421 /** Pointer to next L2Meta of the same write request */
422 struct QCowL2Meta *next;
423
424 QLIST_ENTRY(QCowL2Meta) next_in_flight;
425 } QCowL2Meta;
426
427 typedef enum QCow2ClusterType {
428 QCOW2_CLUSTER_UNALLOCATED,
429 QCOW2_CLUSTER_ZERO_PLAIN,
430 QCOW2_CLUSTER_ZERO_ALLOC,
431 QCOW2_CLUSTER_NORMAL,
432 QCOW2_CLUSTER_COMPRESSED,
433 } QCow2ClusterType;
434
435 typedef enum QCow2MetadataOverlap {
436 QCOW2_OL_MAIN_HEADER_BITNR = 0,
437 QCOW2_OL_ACTIVE_L1_BITNR = 1,
438 QCOW2_OL_ACTIVE_L2_BITNR = 2,
439 QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
440 QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
441 QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
442 QCOW2_OL_INACTIVE_L1_BITNR = 6,
443 QCOW2_OL_INACTIVE_L2_BITNR = 7,
444 QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
445
446 QCOW2_OL_MAX_BITNR = 9,
447
448 QCOW2_OL_NONE = 0,
449 QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
450 QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
451 QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
452 QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
453 QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
454 QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
455 QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
456 /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
457 * reads. */
458 QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
459 QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
460 } QCow2MetadataOverlap;
461
462 /* Perform all overlap checks which can be done in constant time */
463 #define QCOW2_OL_CONSTANT \
464 (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
465 QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
466
467 /* Perform all overlap checks which don't require disk access */
468 #define QCOW2_OL_CACHED \
469 (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
470 QCOW2_OL_INACTIVE_L1)
471
472 /* Perform all overlap checks */
473 #define QCOW2_OL_ALL \
474 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
475
476 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
477 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
478 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
479
480 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
481
482 #define INV_OFFSET (-1ULL)
483
484 static inline bool has_data_file(BlockDriverState *bs)
485 {
486 BDRVQcow2State *s = bs->opaque;
487 return (s->data_file != bs->file);
488 }
489
490 static inline bool data_file_is_raw(BlockDriverState *bs)
491 {
492 BDRVQcow2State *s = bs->opaque;
493 return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
494 }
495
496 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
497 {
498 return offset & ~(s->cluster_size - 1);
499 }
500
501 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
502 {
503 return offset & (s->cluster_size - 1);
504 }
505
506 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
507 {
508 return (size + (s->cluster_size - 1)) >> s->cluster_bits;
509 }
510
511 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
512 {
513 int shift = s->cluster_bits + s->l2_bits;
514 return (size + (1ULL << shift) - 1) >> shift;
515 }
516
517 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
518 {
519 return offset >> (s->l2_bits + s->cluster_bits);
520 }
521
522 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
523 {
524 return (offset >> s->cluster_bits) & (s->l2_size - 1);
525 }
526
527 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
528 {
529 return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
530 }
531
532 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
533 {
534 return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
535 }
536
537 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
538 uint64_t l2_entry)
539 {
540 if (l2_entry & QCOW_OFLAG_COMPRESSED) {
541 return QCOW2_CLUSTER_COMPRESSED;
542 } else if (l2_entry & QCOW_OFLAG_ZERO) {
543 if (l2_entry & L2E_OFFSET_MASK) {
544 return QCOW2_CLUSTER_ZERO_ALLOC;
545 }
546 return QCOW2_CLUSTER_ZERO_PLAIN;
547 } else if (!(l2_entry & L2E_OFFSET_MASK)) {
548 /* Offset 0 generally means unallocated, but it is ambiguous with
549 * external data files because 0 is a valid offset there. However, all
550 * clusters in external data files always have refcount 1, so we can
551 * rely on QCOW_OFLAG_COPIED to disambiguate. */
552 if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
553 return QCOW2_CLUSTER_NORMAL;
554 } else {
555 return QCOW2_CLUSTER_UNALLOCATED;
556 }
557 } else {
558 return QCOW2_CLUSTER_NORMAL;
559 }
560 }
561
562 /* Check whether refcounts are eager or lazy */
563 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
564 {
565 return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
566 }
567
568 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
569 {
570 return m->offset + m->cow_start.offset;
571 }
572
573 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
574 {
575 return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
576 }
577
578 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
579 {
580 return r1 > r2 ? r1 - r2 : r2 - r1;
581 }
582
583 static inline
584 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
585 {
586 return offset >> (s->refcount_block_bits + s->cluster_bits);
587 }
588
589 /* qcow2.c functions */
590 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
591 int refcount_order, bool generous_increase,
592 uint64_t *refblock_count);
593
594 int qcow2_mark_dirty(BlockDriverState *bs);
595 int qcow2_mark_corrupt(BlockDriverState *bs);
596 int qcow2_mark_consistent(BlockDriverState *bs);
597 int qcow2_update_header(BlockDriverState *bs);
598
599 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
600 int64_t size, const char *message_format, ...)
601 GCC_FMT_ATTR(5, 6);
602
603 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
604 uint64_t entries, size_t entry_len,
605 int64_t max_size_bytes, const char *table_name,
606 Error **errp);
607
608 /* qcow2-refcount.c functions */
609 int qcow2_refcount_init(BlockDriverState *bs);
610 void qcow2_refcount_close(BlockDriverState *bs);
611
612 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
613 uint64_t *refcount);
614
615 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
616 uint64_t addend, bool decrease,
617 enum qcow2_discard_type type);
618
619 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
620 uint64_t additional_clusters, bool exact_size,
621 int new_refblock_index,
622 uint64_t new_refblock_offset);
623
624 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
625 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
626 int64_t nb_clusters);
627 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
628 void qcow2_free_clusters(BlockDriverState *bs,
629 int64_t offset, int64_t size,
630 enum qcow2_discard_type type);
631 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
632 int nb_clusters, enum qcow2_discard_type type);
633
634 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
635 int64_t l1_table_offset, int l1_size, int addend);
636
637 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
638 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
639 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
640 BdrvCheckMode fix);
641
642 void qcow2_process_discards(BlockDriverState *bs, int ret);
643
644 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
645 int64_t size);
646 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
647 int64_t size, bool data_file);
648 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
649 void **refcount_table,
650 int64_t *refcount_table_size,
651 int64_t offset, int64_t size);
652
653 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
654 BlockDriverAmendStatusCB *status_cb,
655 void *cb_opaque, Error **errp);
656 int qcow2_shrink_reftable(BlockDriverState *bs);
657 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
658
659 /* qcow2-cluster.c functions */
660 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
661 bool exact_size);
662 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
663 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
664 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
665 uint8_t *buf, int nb_sectors, bool enc, Error **errp);
666
667 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
668 unsigned int *bytes, uint64_t *cluster_offset);
669 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
670 unsigned int *bytes, uint64_t *host_offset,
671 QCowL2Meta **m);
672 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
673 uint64_t offset,
674 int compressed_size,
675 uint64_t *host_offset);
676
677 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
678 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
679 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
680 uint64_t bytes, enum qcow2_discard_type type,
681 bool full_discard);
682 int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
683 uint64_t bytes, int flags);
684
685 int qcow2_expand_zero_clusters(BlockDriverState *bs,
686 BlockDriverAmendStatusCB *status_cb,
687 void *cb_opaque);
688
689 /* qcow2-snapshot.c functions */
690 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
691 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
692 int qcow2_snapshot_delete(BlockDriverState *bs,
693 const char *snapshot_id,
694 const char *name,
695 Error **errp);
696 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
697 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
698 const char *snapshot_id,
699 const char *name,
700 Error **errp);
701
702 void qcow2_free_snapshots(BlockDriverState *bs);
703 int qcow2_read_snapshots(BlockDriverState *bs);
704
705 /* qcow2-cache.c functions */
706 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
707 unsigned table_size);
708 int qcow2_cache_destroy(Qcow2Cache *c);
709
710 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
711 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
712 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
713 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
714 Qcow2Cache *dependency);
715 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
716
717 void qcow2_cache_clean_unused(Qcow2Cache *c);
718 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
719
720 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
721 void **table);
722 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
723 void **table);
724 void qcow2_cache_put(Qcow2Cache *c, void **table);
725 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
726 void qcow2_cache_discard(Qcow2Cache *c, void *table);
727
728 /* qcow2-bitmap.c functions */
729 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
730 void **refcount_table,
731 int64_t *refcount_table_size);
732 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
733 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
734 Error **errp);
735 int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
736 Error **errp);
737 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
738 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
739 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp);
740 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
741 bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs,
742 const char *name,
743 uint32_t granularity,
744 Error **errp);
745 void qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
746 const char *name,
747 Error **errp);
748
749 ssize_t coroutine_fn
750 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
751 const void *src, size_t src_size);
752 ssize_t coroutine_fn
753 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
754 const void *src, size_t src_size);
755 int coroutine_fn
756 qcow2_co_encrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
757 uint64_t offset, void *buf, size_t len);
758 int coroutine_fn
759 qcow2_co_decrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
760 uint64_t offset, void *buf, size_t len);
761
762 #endif