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1 | /* | |
2 | * Replication Block filter | |
3 | * | |
4 | * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD. | |
5 | * Copyright (c) 2016 Intel Corporation | |
6 | * Copyright (c) 2016 FUJITSU LIMITED | |
7 | * | |
8 | * Author: | |
9 | * Wen Congyang <wency@cn.fujitsu.com> | |
10 | * | |
11 | * This work is licensed under the terms of the GNU GPL, version 2 or later. | |
12 | * See the COPYING file in the top-level directory. | |
13 | */ | |
14 | ||
15 | #include "qemu/osdep.h" | |
16 | #include "qemu/module.h" | |
17 | #include "qemu/option.h" | |
18 | #include "block/nbd.h" | |
19 | #include "block/blockjob.h" | |
20 | #include "block/block_int.h" | |
21 | #include "block/block_backup.h" | |
22 | #include "sysemu/block-backend.h" | |
23 | #include "qapi/error.h" | |
24 | #include "qapi/qmp/qdict.h" | |
25 | #include "block/replication.h" | |
26 | ||
27 | typedef enum { | |
28 | BLOCK_REPLICATION_NONE, /* block replication is not started */ | |
29 | BLOCK_REPLICATION_RUNNING, /* block replication is running */ | |
30 | BLOCK_REPLICATION_FAILOVER, /* failover is running in background */ | |
31 | BLOCK_REPLICATION_FAILOVER_FAILED, /* failover failed */ | |
32 | BLOCK_REPLICATION_DONE, /* block replication is done */ | |
33 | } ReplicationStage; | |
34 | ||
35 | typedef struct BDRVReplicationState { | |
36 | ReplicationMode mode; | |
37 | ReplicationStage stage; | |
38 | BlockJob *commit_job; | |
39 | BdrvChild *hidden_disk; | |
40 | BdrvChild *secondary_disk; | |
41 | BlockJob *backup_job; | |
42 | char *top_id; | |
43 | ReplicationState *rs; | |
44 | Error *blocker; | |
45 | bool orig_hidden_read_only; | |
46 | bool orig_secondary_read_only; | |
47 | int error; | |
48 | } BDRVReplicationState; | |
49 | ||
50 | static void replication_start(ReplicationState *rs, ReplicationMode mode, | |
51 | Error **errp); | |
52 | static void replication_do_checkpoint(ReplicationState *rs, Error **errp); | |
53 | static void replication_get_error(ReplicationState *rs, Error **errp); | |
54 | static void replication_stop(ReplicationState *rs, bool failover, | |
55 | Error **errp); | |
56 | ||
57 | #define REPLICATION_MODE "mode" | |
58 | #define REPLICATION_TOP_ID "top-id" | |
59 | static QemuOptsList replication_runtime_opts = { | |
60 | .name = "replication", | |
61 | .head = QTAILQ_HEAD_INITIALIZER(replication_runtime_opts.head), | |
62 | .desc = { | |
63 | { | |
64 | .name = REPLICATION_MODE, | |
65 | .type = QEMU_OPT_STRING, | |
66 | }, | |
67 | { | |
68 | .name = REPLICATION_TOP_ID, | |
69 | .type = QEMU_OPT_STRING, | |
70 | }, | |
71 | { /* end of list */ } | |
72 | }, | |
73 | }; | |
74 | ||
75 | static ReplicationOps replication_ops = { | |
76 | .start = replication_start, | |
77 | .checkpoint = replication_do_checkpoint, | |
78 | .get_error = replication_get_error, | |
79 | .stop = replication_stop, | |
80 | }; | |
81 | ||
82 | static int replication_open(BlockDriverState *bs, QDict *options, | |
83 | int flags, Error **errp) | |
84 | { | |
85 | int ret; | |
86 | BDRVReplicationState *s = bs->opaque; | |
87 | QemuOpts *opts = NULL; | |
88 | const char *mode; | |
89 | const char *top_id; | |
90 | ||
91 | ret = bdrv_open_file_child(NULL, options, "file", bs, errp); | |
92 | if (ret < 0) { | |
93 | return ret; | |
94 | } | |
95 | ||
96 | ret = -EINVAL; | |
97 | opts = qemu_opts_create(&replication_runtime_opts, NULL, 0, &error_abort); | |
98 | if (!qemu_opts_absorb_qdict(opts, options, errp)) { | |
99 | goto fail; | |
100 | } | |
101 | ||
102 | mode = qemu_opt_get(opts, REPLICATION_MODE); | |
103 | if (!mode) { | |
104 | error_setg(errp, "Missing the option mode"); | |
105 | goto fail; | |
106 | } | |
107 | ||
108 | if (!strcmp(mode, "primary")) { | |
109 | s->mode = REPLICATION_MODE_PRIMARY; | |
110 | top_id = qemu_opt_get(opts, REPLICATION_TOP_ID); | |
111 | if (top_id) { | |
112 | error_setg(errp, | |
113 | "The primary side does not support option top-id"); | |
114 | goto fail; | |
115 | } | |
116 | } else if (!strcmp(mode, "secondary")) { | |
117 | s->mode = REPLICATION_MODE_SECONDARY; | |
118 | top_id = qemu_opt_get(opts, REPLICATION_TOP_ID); | |
119 | s->top_id = g_strdup(top_id); | |
120 | if (!s->top_id) { | |
121 | error_setg(errp, "Missing the option top-id"); | |
122 | goto fail; | |
123 | } | |
124 | } else { | |
125 | error_setg(errp, | |
126 | "The option mode's value should be primary or secondary"); | |
127 | goto fail; | |
128 | } | |
129 | ||
130 | s->rs = replication_new(bs, &replication_ops); | |
131 | ||
132 | ret = 0; | |
133 | ||
134 | fail: | |
135 | qemu_opts_del(opts); | |
136 | return ret; | |
137 | } | |
138 | ||
139 | static void replication_close(BlockDriverState *bs) | |
140 | { | |
141 | BDRVReplicationState *s = bs->opaque; | |
142 | Job *commit_job; | |
143 | GLOBAL_STATE_CODE(); | |
144 | ||
145 | if (s->stage == BLOCK_REPLICATION_RUNNING) { | |
146 | replication_stop(s->rs, false, NULL); | |
147 | } | |
148 | if (s->stage == BLOCK_REPLICATION_FAILOVER) { | |
149 | commit_job = &s->commit_job->job; | |
150 | assert(commit_job->aio_context == qemu_get_current_aio_context()); | |
151 | job_cancel_sync(commit_job, false); | |
152 | } | |
153 | ||
154 | if (s->mode == REPLICATION_MODE_SECONDARY) { | |
155 | g_free(s->top_id); | |
156 | } | |
157 | ||
158 | replication_remove(s->rs); | |
159 | } | |
160 | ||
161 | static void replication_child_perm(BlockDriverState *bs, BdrvChild *c, | |
162 | BdrvChildRole role, | |
163 | BlockReopenQueue *reopen_queue, | |
164 | uint64_t perm, uint64_t shared, | |
165 | uint64_t *nperm, uint64_t *nshared) | |
166 | { | |
167 | if (role & BDRV_CHILD_PRIMARY) { | |
168 | *nperm = BLK_PERM_CONSISTENT_READ; | |
169 | } else { | |
170 | *nperm = 0; | |
171 | } | |
172 | ||
173 | if ((bs->open_flags & (BDRV_O_INACTIVE | BDRV_O_RDWR)) == BDRV_O_RDWR) { | |
174 | *nperm |= BLK_PERM_WRITE; | |
175 | } | |
176 | *nshared = BLK_PERM_CONSISTENT_READ | |
177 | | BLK_PERM_WRITE | |
178 | | BLK_PERM_WRITE_UNCHANGED; | |
179 | return; | |
180 | } | |
181 | ||
182 | static int64_t coroutine_fn GRAPH_RDLOCK | |
183 | replication_co_getlength(BlockDriverState *bs) | |
184 | { | |
185 | return bdrv_co_getlength(bs->file->bs); | |
186 | } | |
187 | ||
188 | static int replication_get_io_status(BDRVReplicationState *s) | |
189 | { | |
190 | switch (s->stage) { | |
191 | case BLOCK_REPLICATION_NONE: | |
192 | return -EIO; | |
193 | case BLOCK_REPLICATION_RUNNING: | |
194 | return 0; | |
195 | case BLOCK_REPLICATION_FAILOVER: | |
196 | return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 0; | |
197 | case BLOCK_REPLICATION_FAILOVER_FAILED: | |
198 | return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 1; | |
199 | case BLOCK_REPLICATION_DONE: | |
200 | /* | |
201 | * active commit job completes, and active disk and secondary_disk | |
202 | * is swapped, so we can operate bs->file directly | |
203 | */ | |
204 | return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 0; | |
205 | default: | |
206 | abort(); | |
207 | } | |
208 | } | |
209 | ||
210 | static int replication_return_value(BDRVReplicationState *s, int ret) | |
211 | { | |
212 | if (s->mode == REPLICATION_MODE_SECONDARY) { | |
213 | return ret; | |
214 | } | |
215 | ||
216 | if (ret < 0) { | |
217 | s->error = ret; | |
218 | ret = 0; | |
219 | } | |
220 | ||
221 | return ret; | |
222 | } | |
223 | ||
224 | static int coroutine_fn GRAPH_RDLOCK | |
225 | replication_co_readv(BlockDriverState *bs, int64_t sector_num, | |
226 | int remaining_sectors, QEMUIOVector *qiov) | |
227 | { | |
228 | BDRVReplicationState *s = bs->opaque; | |
229 | int ret; | |
230 | ||
231 | if (s->mode == REPLICATION_MODE_PRIMARY) { | |
232 | /* We only use it to forward primary write requests */ | |
233 | return -EIO; | |
234 | } | |
235 | ||
236 | ret = replication_get_io_status(s); | |
237 | if (ret < 0) { | |
238 | return ret; | |
239 | } | |
240 | ||
241 | ret = bdrv_co_preadv(bs->file, sector_num * BDRV_SECTOR_SIZE, | |
242 | remaining_sectors * BDRV_SECTOR_SIZE, qiov, 0); | |
243 | ||
244 | return replication_return_value(s, ret); | |
245 | } | |
246 | ||
247 | static int coroutine_fn GRAPH_RDLOCK | |
248 | replication_co_writev(BlockDriverState *bs, int64_t sector_num, | |
249 | int remaining_sectors, QEMUIOVector *qiov, int flags) | |
250 | { | |
251 | BDRVReplicationState *s = bs->opaque; | |
252 | QEMUIOVector hd_qiov; | |
253 | uint64_t bytes_done = 0; | |
254 | BdrvChild *top = bs->file; | |
255 | BdrvChild *base = s->secondary_disk; | |
256 | BdrvChild *target; | |
257 | int ret; | |
258 | int64_t n; | |
259 | ||
260 | ret = replication_get_io_status(s); | |
261 | if (ret < 0) { | |
262 | goto out; | |
263 | } | |
264 | ||
265 | if (ret == 0) { | |
266 | ret = bdrv_co_pwritev(top, sector_num * BDRV_SECTOR_SIZE, | |
267 | remaining_sectors * BDRV_SECTOR_SIZE, qiov, 0); | |
268 | return replication_return_value(s, ret); | |
269 | } | |
270 | ||
271 | /* | |
272 | * Failover failed, only write to active disk if the sectors | |
273 | * have already been allocated in active disk/hidden disk. | |
274 | */ | |
275 | qemu_iovec_init(&hd_qiov, qiov->niov); | |
276 | while (remaining_sectors > 0) { | |
277 | int64_t count; | |
278 | ||
279 | ret = bdrv_co_is_allocated_above(top->bs, base->bs, false, | |
280 | sector_num * BDRV_SECTOR_SIZE, | |
281 | remaining_sectors * BDRV_SECTOR_SIZE, | |
282 | &count); | |
283 | if (ret < 0) { | |
284 | goto out1; | |
285 | } | |
286 | ||
287 | assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE)); | |
288 | n = count >> BDRV_SECTOR_BITS; | |
289 | qemu_iovec_reset(&hd_qiov); | |
290 | qemu_iovec_concat(&hd_qiov, qiov, bytes_done, count); | |
291 | ||
292 | target = ret ? top : base; | |
293 | ret = bdrv_co_pwritev(target, sector_num * BDRV_SECTOR_SIZE, | |
294 | n * BDRV_SECTOR_SIZE, &hd_qiov, 0); | |
295 | if (ret < 0) { | |
296 | goto out1; | |
297 | } | |
298 | ||
299 | remaining_sectors -= n; | |
300 | sector_num += n; | |
301 | bytes_done += count; | |
302 | } | |
303 | ||
304 | out1: | |
305 | qemu_iovec_destroy(&hd_qiov); | |
306 | out: | |
307 | return ret; | |
308 | } | |
309 | ||
310 | static void GRAPH_UNLOCKED | |
311 | secondary_do_checkpoint(BlockDriverState *bs, Error **errp) | |
312 | { | |
313 | BDRVReplicationState *s = bs->opaque; | |
314 | BdrvChild *active_disk; | |
315 | Error *local_err = NULL; | |
316 | int ret; | |
317 | ||
318 | GRAPH_RDLOCK_GUARD_MAINLOOP(); | |
319 | ||
320 | if (!s->backup_job) { | |
321 | error_setg(errp, "Backup job was cancelled unexpectedly"); | |
322 | return; | |
323 | } | |
324 | ||
325 | backup_do_checkpoint(s->backup_job, &local_err); | |
326 | if (local_err) { | |
327 | error_propagate(errp, local_err); | |
328 | return; | |
329 | } | |
330 | ||
331 | active_disk = bs->file; | |
332 | if (!active_disk->bs->drv) { | |
333 | error_setg(errp, "Active disk %s is ejected", | |
334 | active_disk->bs->node_name); | |
335 | return; | |
336 | } | |
337 | ||
338 | ret = bdrv_make_empty(active_disk, errp); | |
339 | if (ret < 0) { | |
340 | return; | |
341 | } | |
342 | ||
343 | if (!s->hidden_disk->bs->drv) { | |
344 | error_setg(errp, "Hidden disk %s is ejected", | |
345 | s->hidden_disk->bs->node_name); | |
346 | return; | |
347 | } | |
348 | ||
349 | ret = bdrv_make_empty(s->hidden_disk, errp); | |
350 | if (ret < 0) { | |
351 | return; | |
352 | } | |
353 | } | |
354 | ||
355 | /* This function is supposed to be called twice: | |
356 | * first with writable = true, then with writable = false. | |
357 | * The first call puts s->hidden_disk and s->secondary_disk in | |
358 | * r/w mode, and the second puts them back in their original state. | |
359 | */ | |
360 | static void reopen_backing_file(BlockDriverState *bs, bool writable, | |
361 | Error **errp) | |
362 | { | |
363 | BDRVReplicationState *s = bs->opaque; | |
364 | BdrvChild *hidden_disk, *secondary_disk; | |
365 | BlockReopenQueue *reopen_queue = NULL; | |
366 | ||
367 | GLOBAL_STATE_CODE(); | |
368 | GRAPH_RDLOCK_GUARD_MAINLOOP(); | |
369 | ||
370 | /* | |
371 | * s->hidden_disk and s->secondary_disk may not be set yet, as they will | |
372 | * only be set after the children are writable. | |
373 | */ | |
374 | hidden_disk = bs->file->bs->backing; | |
375 | secondary_disk = hidden_disk->bs->backing; | |
376 | ||
377 | if (writable) { | |
378 | s->orig_hidden_read_only = bdrv_is_read_only(hidden_disk->bs); | |
379 | s->orig_secondary_read_only = bdrv_is_read_only(secondary_disk->bs); | |
380 | } | |
381 | ||
382 | if (s->orig_hidden_read_only) { | |
383 | QDict *opts = qdict_new(); | |
384 | qdict_put_bool(opts, BDRV_OPT_READ_ONLY, !writable); | |
385 | reopen_queue = bdrv_reopen_queue(reopen_queue, hidden_disk->bs, | |
386 | opts, true); | |
387 | } | |
388 | ||
389 | if (s->orig_secondary_read_only) { | |
390 | QDict *opts = qdict_new(); | |
391 | qdict_put_bool(opts, BDRV_OPT_READ_ONLY, !writable); | |
392 | reopen_queue = bdrv_reopen_queue(reopen_queue, secondary_disk->bs, | |
393 | opts, true); | |
394 | } | |
395 | ||
396 | if (reopen_queue) { | |
397 | AioContext *ctx = bdrv_get_aio_context(bs); | |
398 | if (ctx != qemu_get_aio_context()) { | |
399 | aio_context_release(ctx); | |
400 | } | |
401 | bdrv_reopen_multiple(reopen_queue, errp); | |
402 | if (ctx != qemu_get_aio_context()) { | |
403 | aio_context_acquire(ctx); | |
404 | } | |
405 | } | |
406 | } | |
407 | ||
408 | static void backup_job_cleanup(BlockDriverState *bs) | |
409 | { | |
410 | BDRVReplicationState *s = bs->opaque; | |
411 | BlockDriverState *top_bs; | |
412 | ||
413 | s->backup_job = NULL; | |
414 | ||
415 | top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL); | |
416 | if (!top_bs) { | |
417 | return; | |
418 | } | |
419 | bdrv_op_unblock_all(top_bs, s->blocker); | |
420 | error_free(s->blocker); | |
421 | reopen_backing_file(bs, false, NULL); | |
422 | } | |
423 | ||
424 | static void backup_job_completed(void *opaque, int ret) | |
425 | { | |
426 | BlockDriverState *bs = opaque; | |
427 | BDRVReplicationState *s = bs->opaque; | |
428 | ||
429 | if (s->stage != BLOCK_REPLICATION_FAILOVER) { | |
430 | /* The backup job is cancelled unexpectedly */ | |
431 | s->error = -EIO; | |
432 | } | |
433 | ||
434 | backup_job_cleanup(bs); | |
435 | } | |
436 | ||
437 | static bool GRAPH_RDLOCK | |
438 | check_top_bs(BlockDriverState *top_bs, BlockDriverState *bs) | |
439 | { | |
440 | BdrvChild *child; | |
441 | ||
442 | /* The bs itself is the top_bs */ | |
443 | if (top_bs == bs) { | |
444 | return true; | |
445 | } | |
446 | ||
447 | /* Iterate over top_bs's children */ | |
448 | QLIST_FOREACH(child, &top_bs->children, next) { | |
449 | if (child->bs == bs || check_top_bs(child->bs, bs)) { | |
450 | return true; | |
451 | } | |
452 | } | |
453 | ||
454 | return false; | |
455 | } | |
456 | ||
457 | static void replication_start(ReplicationState *rs, ReplicationMode mode, | |
458 | Error **errp) | |
459 | { | |
460 | BlockDriverState *bs = rs->opaque; | |
461 | BDRVReplicationState *s; | |
462 | BlockDriverState *top_bs; | |
463 | BdrvChild *active_disk, *hidden_disk, *secondary_disk; | |
464 | int64_t active_length, hidden_length, disk_length; | |
465 | AioContext *aio_context; | |
466 | Error *local_err = NULL; | |
467 | BackupPerf perf = { .use_copy_range = true, .max_workers = 1 }; | |
468 | ||
469 | GLOBAL_STATE_CODE(); | |
470 | ||
471 | aio_context = bdrv_get_aio_context(bs); | |
472 | aio_context_acquire(aio_context); | |
473 | s = bs->opaque; | |
474 | ||
475 | if (s->stage == BLOCK_REPLICATION_DONE || | |
476 | s->stage == BLOCK_REPLICATION_FAILOVER) { | |
477 | /* | |
478 | * This case happens when a secondary is promoted to primary. | |
479 | * Ignore the request because the secondary side of replication | |
480 | * doesn't have to do anything anymore. | |
481 | */ | |
482 | aio_context_release(aio_context); | |
483 | return; | |
484 | } | |
485 | ||
486 | if (s->stage != BLOCK_REPLICATION_NONE) { | |
487 | error_setg(errp, "Block replication is running or done"); | |
488 | aio_context_release(aio_context); | |
489 | return; | |
490 | } | |
491 | ||
492 | if (s->mode != mode) { | |
493 | error_setg(errp, "The parameter mode's value is invalid, needs %d," | |
494 | " but got %d", s->mode, mode); | |
495 | aio_context_release(aio_context); | |
496 | return; | |
497 | } | |
498 | ||
499 | switch (s->mode) { | |
500 | case REPLICATION_MODE_PRIMARY: | |
501 | break; | |
502 | case REPLICATION_MODE_SECONDARY: | |
503 | bdrv_graph_rdlock_main_loop(); | |
504 | active_disk = bs->file; | |
505 | if (!active_disk || !active_disk->bs || !active_disk->bs->backing) { | |
506 | error_setg(errp, "Active disk doesn't have backing file"); | |
507 | bdrv_graph_rdunlock_main_loop(); | |
508 | aio_context_release(aio_context); | |
509 | return; | |
510 | } | |
511 | ||
512 | hidden_disk = active_disk->bs->backing; | |
513 | if (!hidden_disk->bs || !hidden_disk->bs->backing) { | |
514 | error_setg(errp, "Hidden disk doesn't have backing file"); | |
515 | bdrv_graph_rdunlock_main_loop(); | |
516 | aio_context_release(aio_context); | |
517 | return; | |
518 | } | |
519 | ||
520 | secondary_disk = hidden_disk->bs->backing; | |
521 | if (!secondary_disk->bs || !bdrv_has_blk(secondary_disk->bs)) { | |
522 | error_setg(errp, "The secondary disk doesn't have block backend"); | |
523 | bdrv_graph_rdunlock_main_loop(); | |
524 | aio_context_release(aio_context); | |
525 | return; | |
526 | } | |
527 | bdrv_graph_rdunlock_main_loop(); | |
528 | ||
529 | /* verify the length */ | |
530 | active_length = bdrv_getlength(active_disk->bs); | |
531 | hidden_length = bdrv_getlength(hidden_disk->bs); | |
532 | disk_length = bdrv_getlength(secondary_disk->bs); | |
533 | if (active_length < 0 || hidden_length < 0 || disk_length < 0 || | |
534 | active_length != hidden_length || hidden_length != disk_length) { | |
535 | error_setg(errp, "Active disk, hidden disk, secondary disk's length" | |
536 | " are not the same"); | |
537 | aio_context_release(aio_context); | |
538 | return; | |
539 | } | |
540 | ||
541 | /* Must be true, or the bdrv_getlength() calls would have failed */ | |
542 | assert(active_disk->bs->drv && hidden_disk->bs->drv); | |
543 | ||
544 | bdrv_graph_rdlock_main_loop(); | |
545 | if (!active_disk->bs->drv->bdrv_make_empty || | |
546 | !hidden_disk->bs->drv->bdrv_make_empty) { | |
547 | error_setg(errp, | |
548 | "Active disk or hidden disk doesn't support make_empty"); | |
549 | aio_context_release(aio_context); | |
550 | bdrv_graph_rdunlock_main_loop(); | |
551 | return; | |
552 | } | |
553 | bdrv_graph_rdunlock_main_loop(); | |
554 | ||
555 | /* reopen the backing file in r/w mode */ | |
556 | reopen_backing_file(bs, true, &local_err); | |
557 | if (local_err) { | |
558 | error_propagate(errp, local_err); | |
559 | aio_context_release(aio_context); | |
560 | return; | |
561 | } | |
562 | ||
563 | bdrv_graph_wrlock(bs); | |
564 | ||
565 | bdrv_ref(hidden_disk->bs); | |
566 | s->hidden_disk = bdrv_attach_child(bs, hidden_disk->bs, "hidden disk", | |
567 | &child_of_bds, BDRV_CHILD_DATA, | |
568 | &local_err); | |
569 | if (local_err) { | |
570 | error_propagate(errp, local_err); | |
571 | bdrv_graph_wrunlock(bs); | |
572 | aio_context_release(aio_context); | |
573 | return; | |
574 | } | |
575 | ||
576 | bdrv_ref(secondary_disk->bs); | |
577 | s->secondary_disk = bdrv_attach_child(bs, secondary_disk->bs, | |
578 | "secondary disk", &child_of_bds, | |
579 | BDRV_CHILD_DATA, &local_err); | |
580 | if (local_err) { | |
581 | error_propagate(errp, local_err); | |
582 | bdrv_graph_wrunlock(bs); | |
583 | aio_context_release(aio_context); | |
584 | return; | |
585 | } | |
586 | ||
587 | /* start backup job now */ | |
588 | error_setg(&s->blocker, | |
589 | "Block device is in use by internal backup job"); | |
590 | ||
591 | top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL); | |
592 | if (!top_bs || !bdrv_is_root_node(top_bs) || | |
593 | !check_top_bs(top_bs, bs)) { | |
594 | error_setg(errp, "No top_bs or it is invalid"); | |
595 | bdrv_graph_wrunlock(bs); | |
596 | reopen_backing_file(bs, false, NULL); | |
597 | aio_context_release(aio_context); | |
598 | return; | |
599 | } | |
600 | bdrv_op_block_all(top_bs, s->blocker); | |
601 | bdrv_op_unblock(top_bs, BLOCK_OP_TYPE_DATAPLANE, s->blocker); | |
602 | ||
603 | bdrv_graph_wrunlock(bs); | |
604 | ||
605 | s->backup_job = backup_job_create( | |
606 | NULL, s->secondary_disk->bs, s->hidden_disk->bs, | |
607 | 0, MIRROR_SYNC_MODE_NONE, NULL, 0, false, NULL, | |
608 | &perf, | |
609 | BLOCKDEV_ON_ERROR_REPORT, | |
610 | BLOCKDEV_ON_ERROR_REPORT, JOB_INTERNAL, | |
611 | backup_job_completed, bs, NULL, &local_err); | |
612 | if (local_err) { | |
613 | error_propagate(errp, local_err); | |
614 | backup_job_cleanup(bs); | |
615 | aio_context_release(aio_context); | |
616 | return; | |
617 | } | |
618 | job_start(&s->backup_job->job); | |
619 | break; | |
620 | default: | |
621 | aio_context_release(aio_context); | |
622 | abort(); | |
623 | } | |
624 | ||
625 | s->stage = BLOCK_REPLICATION_RUNNING; | |
626 | ||
627 | if (s->mode == REPLICATION_MODE_SECONDARY) { | |
628 | secondary_do_checkpoint(bs, errp); | |
629 | } | |
630 | ||
631 | s->error = 0; | |
632 | aio_context_release(aio_context); | |
633 | } | |
634 | ||
635 | static void replication_do_checkpoint(ReplicationState *rs, Error **errp) | |
636 | { | |
637 | BlockDriverState *bs = rs->opaque; | |
638 | BDRVReplicationState *s; | |
639 | AioContext *aio_context; | |
640 | ||
641 | aio_context = bdrv_get_aio_context(bs); | |
642 | aio_context_acquire(aio_context); | |
643 | s = bs->opaque; | |
644 | ||
645 | if (s->stage == BLOCK_REPLICATION_DONE || | |
646 | s->stage == BLOCK_REPLICATION_FAILOVER) { | |
647 | /* | |
648 | * This case happens when a secondary was promoted to primary. | |
649 | * Ignore the request because the secondary side of replication | |
650 | * doesn't have to do anything anymore. | |
651 | */ | |
652 | aio_context_release(aio_context); | |
653 | return; | |
654 | } | |
655 | ||
656 | if (s->mode == REPLICATION_MODE_SECONDARY) { | |
657 | secondary_do_checkpoint(bs, errp); | |
658 | } | |
659 | aio_context_release(aio_context); | |
660 | } | |
661 | ||
662 | static void replication_get_error(ReplicationState *rs, Error **errp) | |
663 | { | |
664 | BlockDriverState *bs = rs->opaque; | |
665 | BDRVReplicationState *s; | |
666 | AioContext *aio_context; | |
667 | ||
668 | aio_context = bdrv_get_aio_context(bs); | |
669 | aio_context_acquire(aio_context); | |
670 | s = bs->opaque; | |
671 | ||
672 | if (s->stage == BLOCK_REPLICATION_NONE) { | |
673 | error_setg(errp, "Block replication is not running"); | |
674 | aio_context_release(aio_context); | |
675 | return; | |
676 | } | |
677 | ||
678 | if (s->error) { | |
679 | error_setg(errp, "I/O error occurred"); | |
680 | aio_context_release(aio_context); | |
681 | return; | |
682 | } | |
683 | aio_context_release(aio_context); | |
684 | } | |
685 | ||
686 | static void replication_done(void *opaque, int ret) | |
687 | { | |
688 | BlockDriverState *bs = opaque; | |
689 | BDRVReplicationState *s = bs->opaque; | |
690 | ||
691 | if (ret == 0) { | |
692 | s->stage = BLOCK_REPLICATION_DONE; | |
693 | ||
694 | bdrv_graph_wrlock(NULL); | |
695 | bdrv_unref_child(bs, s->secondary_disk); | |
696 | s->secondary_disk = NULL; | |
697 | bdrv_unref_child(bs, s->hidden_disk); | |
698 | s->hidden_disk = NULL; | |
699 | bdrv_graph_wrunlock(NULL); | |
700 | ||
701 | s->error = 0; | |
702 | } else { | |
703 | s->stage = BLOCK_REPLICATION_FAILOVER_FAILED; | |
704 | s->error = -EIO; | |
705 | } | |
706 | } | |
707 | ||
708 | static void replication_stop(ReplicationState *rs, bool failover, Error **errp) | |
709 | { | |
710 | BlockDriverState *bs = rs->opaque; | |
711 | BDRVReplicationState *s; | |
712 | AioContext *aio_context; | |
713 | ||
714 | aio_context = bdrv_get_aio_context(bs); | |
715 | aio_context_acquire(aio_context); | |
716 | s = bs->opaque; | |
717 | ||
718 | if (s->stage == BLOCK_REPLICATION_DONE || | |
719 | s->stage == BLOCK_REPLICATION_FAILOVER) { | |
720 | /* | |
721 | * This case happens when a secondary was promoted to primary. | |
722 | * Ignore the request because the secondary side of replication | |
723 | * doesn't have to do anything anymore. | |
724 | */ | |
725 | aio_context_release(aio_context); | |
726 | return; | |
727 | } | |
728 | ||
729 | if (s->stage != BLOCK_REPLICATION_RUNNING) { | |
730 | error_setg(errp, "Block replication is not running"); | |
731 | aio_context_release(aio_context); | |
732 | return; | |
733 | } | |
734 | ||
735 | switch (s->mode) { | |
736 | case REPLICATION_MODE_PRIMARY: | |
737 | s->stage = BLOCK_REPLICATION_DONE; | |
738 | s->error = 0; | |
739 | break; | |
740 | case REPLICATION_MODE_SECONDARY: | |
741 | /* | |
742 | * This BDS will be closed, and the job should be completed | |
743 | * before the BDS is closed, because we will access hidden | |
744 | * disk, secondary disk in backup_job_completed(). | |
745 | */ | |
746 | if (s->backup_job) { | |
747 | aio_context_release(aio_context); | |
748 | job_cancel_sync(&s->backup_job->job, true); | |
749 | aio_context_acquire(aio_context); | |
750 | } | |
751 | ||
752 | if (!failover) { | |
753 | secondary_do_checkpoint(bs, errp); | |
754 | s->stage = BLOCK_REPLICATION_DONE; | |
755 | aio_context_release(aio_context); | |
756 | return; | |
757 | } | |
758 | ||
759 | bdrv_graph_rdlock_main_loop(); | |
760 | s->stage = BLOCK_REPLICATION_FAILOVER; | |
761 | s->commit_job = commit_active_start( | |
762 | NULL, bs->file->bs, s->secondary_disk->bs, | |
763 | JOB_INTERNAL, 0, BLOCKDEV_ON_ERROR_REPORT, | |
764 | NULL, replication_done, bs, true, errp); | |
765 | bdrv_graph_rdunlock_main_loop(); | |
766 | break; | |
767 | default: | |
768 | aio_context_release(aio_context); | |
769 | abort(); | |
770 | } | |
771 | aio_context_release(aio_context); | |
772 | } | |
773 | ||
774 | static const char *const replication_strong_runtime_opts[] = { | |
775 | REPLICATION_MODE, | |
776 | REPLICATION_TOP_ID, | |
777 | ||
778 | NULL | |
779 | }; | |
780 | ||
781 | static BlockDriver bdrv_replication = { | |
782 | .format_name = "replication", | |
783 | .instance_size = sizeof(BDRVReplicationState), | |
784 | ||
785 | .bdrv_open = replication_open, | |
786 | .bdrv_close = replication_close, | |
787 | .bdrv_child_perm = replication_child_perm, | |
788 | ||
789 | .bdrv_co_getlength = replication_co_getlength, | |
790 | .bdrv_co_readv = replication_co_readv, | |
791 | .bdrv_co_writev = replication_co_writev, | |
792 | ||
793 | .is_filter = true, | |
794 | ||
795 | .strong_runtime_opts = replication_strong_runtime_opts, | |
796 | }; | |
797 | ||
798 | static void bdrv_replication_init(void) | |
799 | { | |
800 | bdrv_register(&bdrv_replication); | |
801 | } | |
802 | ||
803 | block_init(bdrv_replication_init); |