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15#include "qemu/osdep.h"
16
17#include "trace.h"
18#include "block/block.h"
19#include "block/block_int.h"
20#include "block/blockjob_int.h"
21#include "block/block_backup.h"
22#include "block/block-copy.h"
23#include "qapi/error.h"
24#include "qapi/qmp/qerror.h"
25#include "qemu/ratelimit.h"
26#include "qemu/cutils.h"
27#include "sysemu/block-backend.h"
28#include "qemu/bitmap.h"
29#include "qemu/error-report.h"
30
31#include "block/backup-top.h"
32
33#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
34
35typedef struct BackupBlockJob {
36 BlockJob common;
37 BlockDriverState *backup_top;
38 BlockDriverState *source_bs;
39
40 BdrvDirtyBitmap *sync_bitmap;
41
42 MirrorSyncMode sync_mode;
43 BitmapSyncMode bitmap_mode;
44 BlockdevOnError on_source_error;
45 BlockdevOnError on_target_error;
46 uint64_t len;
47 uint64_t bytes_read;
48 int64_t cluster_size;
49
50 BlockCopyState *bcs;
51} BackupBlockJob;
52
53static const BlockJobDriver backup_job_driver;
54
55static void backup_progress_bytes_callback(int64_t bytes, void *opaque)
56{
57 BackupBlockJob *s = opaque;
58
59 s->bytes_read += bytes;
60 job_progress_update(&s->common.job, bytes);
61}
62
63static void backup_progress_reset_callback(void *opaque)
64{
65 BackupBlockJob *s = opaque;
66 uint64_t estimate = bdrv_get_dirty_count(s->bcs->copy_bitmap);
67
68 job_progress_set_remaining(&s->common.job, estimate);
69}
70
71static int coroutine_fn backup_do_cow(BackupBlockJob *job,
72 int64_t offset, uint64_t bytes,
73 bool *error_is_read)
74{
75 int ret = 0;
76 int64_t start, end;
77
78 start = QEMU_ALIGN_DOWN(offset, job->cluster_size);
79 end = QEMU_ALIGN_UP(bytes + offset, job->cluster_size);
80
81 trace_backup_do_cow_enter(job, start, offset, bytes);
82
83 ret = block_copy(job->bcs, start, end - start, error_is_read);
84
85 trace_backup_do_cow_return(job, offset, bytes, ret);
86
87 return ret;
88}
89
90static void backup_cleanup_sync_bitmap(BackupBlockJob *job, int ret)
91{
92 BdrvDirtyBitmap *bm;
93 bool sync = (((ret == 0) || (job->bitmap_mode == BITMAP_SYNC_MODE_ALWAYS)) \
94 && (job->bitmap_mode != BITMAP_SYNC_MODE_NEVER));
95
96 if (sync) {
97
98
99
100
101 bm = bdrv_dirty_bitmap_abdicate(job->sync_bitmap, NULL);
102 } else {
103
104
105
106
107 bm = bdrv_reclaim_dirty_bitmap(job->sync_bitmap, NULL);
108 }
109
110 assert(bm);
111
112 if (ret < 0 && job->bitmap_mode == BITMAP_SYNC_MODE_ALWAYS) {
113
114 bdrv_dirty_bitmap_merge_internal(bm, job->bcs->copy_bitmap,
115 NULL, true);
116 }
117}
118
119static void backup_commit(Job *job)
120{
121 BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
122 if (s->sync_bitmap) {
123 backup_cleanup_sync_bitmap(s, 0);
124 }
125}
126
127static void backup_abort(Job *job)
128{
129 BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
130 if (s->sync_bitmap) {
131 backup_cleanup_sync_bitmap(s, -1);
132 }
133}
134
135static void backup_clean(Job *job)
136{
137 BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
138
139 bdrv_backup_top_drop(s->backup_top);
140}
141
142void backup_do_checkpoint(BlockJob *job, Error **errp)
143{
144 BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
145
146 assert(block_job_driver(job) == &backup_job_driver);
147
148 if (backup_job->sync_mode != MIRROR_SYNC_MODE_NONE) {
149 error_setg(errp, "The backup job only supports block checkpoint in"
150 " sync=none mode");
151 return;
152 }
153
154 bdrv_set_dirty_bitmap(backup_job->bcs->copy_bitmap, 0, backup_job->len);
155}
156
157static BlockErrorAction backup_error_action(BackupBlockJob *job,
158 bool read, int error)
159{
160 if (read) {
161 return block_job_error_action(&job->common, job->on_source_error,
162 true, error);
163 } else {
164 return block_job_error_action(&job->common, job->on_target_error,
165 false, error);
166 }
167}
168
169static bool coroutine_fn yield_and_check(BackupBlockJob *job)
170{
171 uint64_t delay_ns;
172
173 if (job_is_cancelled(&job->common.job)) {
174 return true;
175 }
176
177
178
179
180
181 delay_ns = block_job_ratelimit_get_delay(&job->common, job->bytes_read);
182 job->bytes_read = 0;
183 job_sleep_ns(&job->common.job, delay_ns);
184
185 if (job_is_cancelled(&job->common.job)) {
186 return true;
187 }
188
189 return false;
190}
191
192static int coroutine_fn backup_loop(BackupBlockJob *job)
193{
194 bool error_is_read;
195 int64_t offset;
196 BdrvDirtyBitmapIter *bdbi;
197 int ret = 0;
198
199 bdbi = bdrv_dirty_iter_new(job->bcs->copy_bitmap);
200 while ((offset = bdrv_dirty_iter_next(bdbi)) != -1) {
201 do {
202 if (yield_and_check(job)) {
203 goto out;
204 }
205 ret = backup_do_cow(job, offset, job->cluster_size, &error_is_read);
206 if (ret < 0 && backup_error_action(job, error_is_read, -ret) ==
207 BLOCK_ERROR_ACTION_REPORT)
208 {
209 goto out;
210 }
211 } while (ret < 0);
212 }
213
214 out:
215 bdrv_dirty_iter_free(bdbi);
216 return ret;
217}
218
219static void backup_init_copy_bitmap(BackupBlockJob *job)
220{
221 bool ret;
222 uint64_t estimate;
223
224 if (job->sync_mode == MIRROR_SYNC_MODE_BITMAP) {
225 ret = bdrv_dirty_bitmap_merge_internal(job->bcs->copy_bitmap,
226 job->sync_bitmap,
227 NULL, true);
228 assert(ret);
229 } else {
230 if (job->sync_mode == MIRROR_SYNC_MODE_TOP) {
231
232
233
234
235 job->bcs->skip_unallocated = true;
236 }
237 bdrv_set_dirty_bitmap(job->bcs->copy_bitmap, 0, job->len);
238 }
239
240 estimate = bdrv_get_dirty_count(job->bcs->copy_bitmap);
241 job_progress_set_remaining(&job->common.job, estimate);
242}
243
244static int coroutine_fn backup_run(Job *job, Error **errp)
245{
246 BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
247 int ret = 0;
248
249 backup_init_copy_bitmap(s);
250
251 if (s->sync_mode == MIRROR_SYNC_MODE_TOP) {
252 int64_t offset = 0;
253 int64_t count;
254
255 for (offset = 0; offset < s->len; ) {
256 if (yield_and_check(s)) {
257 ret = -ECANCELED;
258 goto out;
259 }
260
261 ret = block_copy_reset_unallocated(s->bcs, offset, &count);
262 if (ret < 0) {
263 goto out;
264 }
265
266 offset += count;
267 }
268 s->bcs->skip_unallocated = false;
269 }
270
271 if (s->sync_mode == MIRROR_SYNC_MODE_NONE) {
272
273
274
275
276 while (!job_is_cancelled(job)) {
277
278
279
280
281 job_yield(job);
282 }
283 } else {
284 ret = backup_loop(s);
285 }
286
287 out:
288 return ret;
289}
290
291static const BlockJobDriver backup_job_driver = {
292 .job_driver = {
293 .instance_size = sizeof(BackupBlockJob),
294 .job_type = JOB_TYPE_BACKUP,
295 .free = block_job_free,
296 .user_resume = block_job_user_resume,
297 .run = backup_run,
298 .commit = backup_commit,
299 .abort = backup_abort,
300 .clean = backup_clean,
301 }
302};
303
304static int64_t backup_calculate_cluster_size(BlockDriverState *target,
305 Error **errp)
306{
307 int ret;
308 BlockDriverInfo bdi;
309
310
311
312
313
314
315 ret = bdrv_get_info(target, &bdi);
316 if (ret == -ENOTSUP && !target->backing) {
317
318 warn_report("The target block device doesn't provide "
319 "information about the block size and it doesn't have a "
320 "backing file. The default block size of %u bytes is "
321 "used. If the actual block size of the target exceeds "
322 "this default, the backup may be unusable",
323 BACKUP_CLUSTER_SIZE_DEFAULT);
324 return BACKUP_CLUSTER_SIZE_DEFAULT;
325 } else if (ret < 0 && !target->backing) {
326 error_setg_errno(errp, -ret,
327 "Couldn't determine the cluster size of the target image, "
328 "which has no backing file");
329 error_append_hint(errp,
330 "Aborting, since this may create an unusable destination image\n");
331 return ret;
332 } else if (ret < 0 && target->backing) {
333
334 return BACKUP_CLUSTER_SIZE_DEFAULT;
335 }
336
337 return MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
338}
339
340BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
341 BlockDriverState *target, int64_t speed,
342 MirrorSyncMode sync_mode, BdrvDirtyBitmap *sync_bitmap,
343 BitmapSyncMode bitmap_mode,
344 bool compress,
345 const char *filter_node_name,
346 BlockdevOnError on_source_error,
347 BlockdevOnError on_target_error,
348 int creation_flags,
349 BlockCompletionFunc *cb, void *opaque,
350 JobTxn *txn, Error **errp)
351{
352 int64_t len;
353 BackupBlockJob *job = NULL;
354 int64_t cluster_size;
355 BdrvRequestFlags write_flags;
356 BlockDriverState *backup_top = NULL;
357 BlockCopyState *bcs = NULL;
358
359 assert(bs);
360 assert(target);
361
362
363 assert(sync_mode != MIRROR_SYNC_MODE_INCREMENTAL);
364 assert(sync_bitmap || sync_mode != MIRROR_SYNC_MODE_BITMAP);
365
366 if (bs == target) {
367 error_setg(errp, "Source and target cannot be the same");
368 return NULL;
369 }
370
371 if (!bdrv_is_inserted(bs)) {
372 error_setg(errp, "Device is not inserted: %s",
373 bdrv_get_device_name(bs));
374 return NULL;
375 }
376
377 if (!bdrv_is_inserted(target)) {
378 error_setg(errp, "Device is not inserted: %s",
379 bdrv_get_device_name(target));
380 return NULL;
381 }
382
383 if (compress && !block_driver_can_compress(target->drv)) {
384 error_setg(errp, "Compression is not supported for this drive %s",
385 bdrv_get_device_name(target));
386 return NULL;
387 }
388
389 if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
390 return NULL;
391 }
392
393 if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_BACKUP_TARGET, errp)) {
394 return NULL;
395 }
396
397 if (sync_bitmap) {
398
399 if (bitmap_mode != BITMAP_SYNC_MODE_NEVER &&
400 bdrv_dirty_bitmap_check(sync_bitmap, BDRV_BITMAP_DEFAULT, errp)) {
401 return NULL;
402 }
403
404
405 if (bdrv_dirty_bitmap_create_successor(sync_bitmap, errp) < 0) {
406 return NULL;
407 }
408 }
409
410 len = bdrv_getlength(bs);
411 if (len < 0) {
412 error_setg_errno(errp, -len, "unable to get length for '%s'",
413 bdrv_get_device_name(bs));
414 goto error;
415 }
416
417 cluster_size = backup_calculate_cluster_size(target, errp);
418 if (cluster_size < 0) {
419 goto error;
420 }
421
422
423
424
425
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427
428
429
430
431
432
433
434
435
436 write_flags = (bdrv_chain_contains(target, bs) ? BDRV_REQ_SERIALISING : 0) |
437 (compress ? BDRV_REQ_WRITE_COMPRESSED : 0),
438
439 backup_top = bdrv_backup_top_append(bs, target, filter_node_name,
440 cluster_size, write_flags, &bcs, errp);
441 if (!backup_top) {
442 goto error;
443 }
444
445
446 job = block_job_create(job_id, &backup_job_driver, txn, backup_top,
447 0, BLK_PERM_ALL,
448 speed, creation_flags, cb, opaque, errp);
449 if (!job) {
450 goto error;
451 }
452
453 job->backup_top = backup_top;
454 job->source_bs = bs;
455 job->on_source_error = on_source_error;
456 job->on_target_error = on_target_error;
457 job->sync_mode = sync_mode;
458 job->sync_bitmap = sync_bitmap;
459 job->bitmap_mode = bitmap_mode;
460 job->bcs = bcs;
461 job->cluster_size = cluster_size;
462 job->len = len;
463
464 block_copy_set_callbacks(bcs, backup_progress_bytes_callback,
465 backup_progress_reset_callback, job);
466
467
468 block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL,
469 &error_abort);
470
471 return &job->common;
472
473 error:
474 if (sync_bitmap) {
475 bdrv_reclaim_dirty_bitmap(sync_bitmap, NULL);
476 }
477 if (backup_top) {
478 bdrv_backup_top_drop(backup_top);
479 }
480
481 return NULL;
482}
483