2 * Replication Block filter
4 * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
5 * Copyright (c) 2016 Intel Corporation
6 * Copyright (c) 2016 FUJITSU LIMITED
9 * Wen Congyang <wency@cn.fujitsu.com>
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.
15 #include "qemu/osdep.h"
16 #include "qemu-common.h"
17 #include "block/nbd.h"
18 #include "block/blockjob.h"
19 #include "block/block_int.h"
20 #include "block/block_backup.h"
21 #include "sysemu/block-backend.h"
22 #include "qapi/error.h"
23 #include "replication.h"
26 BLOCK_REPLICATION_NONE
, /* block replication is not started */
27 BLOCK_REPLICATION_RUNNING
, /* block replication is running */
28 BLOCK_REPLICATION_FAILOVER
, /* failover is running in background */
29 BLOCK_REPLICATION_FAILOVER_FAILED
, /* failover failed */
30 BLOCK_REPLICATION_DONE
, /* block replication is done */
33 typedef struct BDRVReplicationState
{
35 ReplicationStage stage
;
36 BdrvChild
*active_disk
;
37 BdrvChild
*hidden_disk
;
38 BdrvChild
*secondary_disk
;
42 int orig_hidden_flags
;
43 int orig_secondary_flags
;
45 } BDRVReplicationState
;
47 static void replication_start(ReplicationState
*rs
, ReplicationMode mode
,
49 static void replication_do_checkpoint(ReplicationState
*rs
, Error
**errp
);
50 static void replication_get_error(ReplicationState
*rs
, Error
**errp
);
51 static void replication_stop(ReplicationState
*rs
, bool failover
,
54 #define REPLICATION_MODE "mode"
55 #define REPLICATION_TOP_ID "top-id"
56 static QemuOptsList replication_runtime_opts
= {
57 .name
= "replication",
58 .head
= QTAILQ_HEAD_INITIALIZER(replication_runtime_opts
.head
),
61 .name
= REPLICATION_MODE
,
62 .type
= QEMU_OPT_STRING
,
65 .name
= REPLICATION_TOP_ID
,
66 .type
= QEMU_OPT_STRING
,
72 static ReplicationOps replication_ops
= {
73 .start
= replication_start
,
74 .checkpoint
= replication_do_checkpoint
,
75 .get_error
= replication_get_error
,
76 .stop
= replication_stop
,
79 static int replication_open(BlockDriverState
*bs
, QDict
*options
,
80 int flags
, Error
**errp
)
83 BDRVReplicationState
*s
= bs
->opaque
;
84 Error
*local_err
= NULL
;
85 QemuOpts
*opts
= NULL
;
89 bs
->file
= bdrv_open_child(NULL
, options
, "file", bs
, &child_file
,
96 opts
= qemu_opts_create(&replication_runtime_opts
, NULL
, 0, &error_abort
);
97 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
102 mode
= qemu_opt_get(opts
, REPLICATION_MODE
);
104 error_setg(&local_err
, "Missing the option mode");
108 if (!strcmp(mode
, "primary")) {
109 s
->mode
= REPLICATION_MODE_PRIMARY
;
110 top_id
= qemu_opt_get(opts
, REPLICATION_TOP_ID
);
112 error_setg(&local_err
, "The primary side does not support option top-id");
115 } else if (!strcmp(mode
, "secondary")) {
116 s
->mode
= REPLICATION_MODE_SECONDARY
;
117 top_id
= qemu_opt_get(opts
, REPLICATION_TOP_ID
);
118 s
->top_id
= g_strdup(top_id
);
120 error_setg(&local_err
, "Missing the option top-id");
124 error_setg(&local_err
,
125 "The option mode's value should be primary or secondary");
129 s
->rs
= replication_new(bs
, &replication_ops
);
135 error_propagate(errp
, local_err
);
140 static void replication_close(BlockDriverState
*bs
)
142 BDRVReplicationState
*s
= bs
->opaque
;
144 if (s
->stage
== BLOCK_REPLICATION_RUNNING
) {
145 replication_stop(s
->rs
, false, NULL
);
147 if (s
->stage
== BLOCK_REPLICATION_FAILOVER
) {
148 block_job_cancel_sync(s
->active_disk
->bs
->job
);
151 if (s
->mode
== REPLICATION_MODE_SECONDARY
) {
155 replication_remove(s
->rs
);
158 static void replication_child_perm(BlockDriverState
*bs
, BdrvChild
*c
,
159 const BdrvChildRole
*role
,
160 BlockReopenQueue
*reopen_queue
,
161 uint64_t perm
, uint64_t shared
,
162 uint64_t *nperm
, uint64_t *nshared
)
164 *nperm
= BLK_PERM_CONSISTENT_READ
;
165 if ((bs
->open_flags
& (BDRV_O_INACTIVE
| BDRV_O_RDWR
)) == BDRV_O_RDWR
) {
166 *nperm
|= BLK_PERM_WRITE
;
168 *nshared
= BLK_PERM_CONSISTENT_READ \
170 | BLK_PERM_WRITE_UNCHANGED
;
174 static int64_t replication_getlength(BlockDriverState
*bs
)
176 return bdrv_getlength(bs
->file
->bs
);
179 static int replication_get_io_status(BDRVReplicationState
*s
)
182 case BLOCK_REPLICATION_NONE
:
184 case BLOCK_REPLICATION_RUNNING
:
186 case BLOCK_REPLICATION_FAILOVER
:
187 return s
->mode
== REPLICATION_MODE_PRIMARY
? -EIO
: 0;
188 case BLOCK_REPLICATION_FAILOVER_FAILED
:
189 return s
->mode
== REPLICATION_MODE_PRIMARY
? -EIO
: 1;
190 case BLOCK_REPLICATION_DONE
:
192 * active commit job completes, and active disk and secondary_disk
193 * is swapped, so we can operate bs->file directly
195 return s
->mode
== REPLICATION_MODE_PRIMARY
? -EIO
: 0;
201 static int replication_return_value(BDRVReplicationState
*s
, int ret
)
203 if (s
->mode
== REPLICATION_MODE_SECONDARY
) {
215 static coroutine_fn
int replication_co_readv(BlockDriverState
*bs
,
217 int remaining_sectors
,
220 BDRVReplicationState
*s
= bs
->opaque
;
221 BdrvChild
*child
= s
->secondary_disk
;
222 BlockJob
*job
= NULL
;
226 if (s
->mode
== REPLICATION_MODE_PRIMARY
) {
227 /* We only use it to forward primary write requests */
231 ret
= replication_get_io_status(s
);
236 if (child
&& child
->bs
) {
237 job
= child
->bs
->job
;
241 uint64_t remaining_bytes
= remaining_sectors
* BDRV_SECTOR_SIZE
;
243 backup_wait_for_overlapping_requests(child
->bs
->job
,
244 sector_num
* BDRV_SECTOR_SIZE
,
246 backup_cow_request_begin(&req
, child
->bs
->job
,
247 sector_num
* BDRV_SECTOR_SIZE
,
249 ret
= bdrv_co_readv(bs
->file
, sector_num
, remaining_sectors
,
251 backup_cow_request_end(&req
);
255 ret
= bdrv_co_readv(bs
->file
, sector_num
, remaining_sectors
, qiov
);
257 return replication_return_value(s
, ret
);
260 static coroutine_fn
int replication_co_writev(BlockDriverState
*bs
,
262 int remaining_sectors
,
265 BDRVReplicationState
*s
= bs
->opaque
;
266 QEMUIOVector hd_qiov
;
267 uint64_t bytes_done
= 0;
268 BdrvChild
*top
= bs
->file
;
269 BdrvChild
*base
= s
->secondary_disk
;
274 ret
= replication_get_io_status(s
);
280 ret
= bdrv_co_writev(top
, sector_num
,
281 remaining_sectors
, qiov
);
282 return replication_return_value(s
, ret
);
286 * Failover failed, only write to active disk if the sectors
287 * have already been allocated in active disk/hidden disk.
289 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
290 while (remaining_sectors
> 0) {
293 ret
= bdrv_is_allocated_above(top
->bs
, base
->bs
,
294 sector_num
* BDRV_SECTOR_SIZE
,
295 remaining_sectors
* BDRV_SECTOR_SIZE
,
301 assert(QEMU_IS_ALIGNED(count
, BDRV_SECTOR_SIZE
));
302 n
= count
>> BDRV_SECTOR_BITS
;
303 qemu_iovec_reset(&hd_qiov
);
304 qemu_iovec_concat(&hd_qiov
, qiov
, bytes_done
, count
);
306 target
= ret
? top
: base
;
307 ret
= bdrv_co_writev(target
, sector_num
, n
, &hd_qiov
);
312 remaining_sectors
-= n
;
318 qemu_iovec_destroy(&hd_qiov
);
323 static bool replication_recurse_is_first_non_filter(BlockDriverState
*bs
,
324 BlockDriverState
*candidate
)
326 return bdrv_recurse_is_first_non_filter(bs
->file
->bs
, candidate
);
329 static void secondary_do_checkpoint(BDRVReplicationState
*s
, Error
**errp
)
331 Error
*local_err
= NULL
;
334 if (!s
->secondary_disk
->bs
->job
) {
335 error_setg(errp
, "Backup job was cancelled unexpectedly");
339 backup_do_checkpoint(s
->secondary_disk
->bs
->job
, &local_err
);
341 error_propagate(errp
, local_err
);
345 if (!s
->active_disk
->bs
->drv
) {
346 error_setg(errp
, "Active disk %s is ejected",
347 s
->active_disk
->bs
->node_name
);
351 ret
= s
->active_disk
->bs
->drv
->bdrv_make_empty(s
->active_disk
->bs
);
353 error_setg(errp
, "Cannot make active disk empty");
357 if (!s
->hidden_disk
->bs
->drv
) {
358 error_setg(errp
, "Hidden disk %s is ejected",
359 s
->hidden_disk
->bs
->node_name
);
363 ret
= s
->hidden_disk
->bs
->drv
->bdrv_make_empty(s
->hidden_disk
->bs
);
365 error_setg(errp
, "Cannot make hidden disk empty");
370 static void reopen_backing_file(BlockDriverState
*bs
, bool writable
,
373 BDRVReplicationState
*s
= bs
->opaque
;
374 BlockReopenQueue
*reopen_queue
= NULL
;
375 int orig_hidden_flags
, orig_secondary_flags
;
376 int new_hidden_flags
, new_secondary_flags
;
377 Error
*local_err
= NULL
;
380 orig_hidden_flags
= s
->orig_hidden_flags
=
381 bdrv_get_flags(s
->hidden_disk
->bs
);
382 new_hidden_flags
= (orig_hidden_flags
| BDRV_O_RDWR
) &
384 orig_secondary_flags
= s
->orig_secondary_flags
=
385 bdrv_get_flags(s
->secondary_disk
->bs
);
386 new_secondary_flags
= (orig_secondary_flags
| BDRV_O_RDWR
) &
389 orig_hidden_flags
= (s
->orig_hidden_flags
| BDRV_O_RDWR
) &
391 new_hidden_flags
= s
->orig_hidden_flags
;
392 orig_secondary_flags
= (s
->orig_secondary_flags
| BDRV_O_RDWR
) &
394 new_secondary_flags
= s
->orig_secondary_flags
;
397 if (orig_hidden_flags
!= new_hidden_flags
) {
398 reopen_queue
= bdrv_reopen_queue(reopen_queue
, s
->hidden_disk
->bs
, NULL
,
402 if (!(orig_secondary_flags
& BDRV_O_RDWR
)) {
403 reopen_queue
= bdrv_reopen_queue(reopen_queue
, s
->secondary_disk
->bs
,
404 NULL
, new_secondary_flags
);
408 bdrv_reopen_multiple(bdrv_get_aio_context(bs
),
409 reopen_queue
, &local_err
);
410 error_propagate(errp
, local_err
);
414 static void backup_job_cleanup(BlockDriverState
*bs
)
416 BDRVReplicationState
*s
= bs
->opaque
;
417 BlockDriverState
*top_bs
;
419 top_bs
= bdrv_lookup_bs(s
->top_id
, s
->top_id
, NULL
);
423 bdrv_op_unblock_all(top_bs
, s
->blocker
);
424 error_free(s
->blocker
);
425 reopen_backing_file(bs
, false, NULL
);
428 static void backup_job_completed(void *opaque
, int ret
)
430 BlockDriverState
*bs
= opaque
;
431 BDRVReplicationState
*s
= bs
->opaque
;
433 if (s
->stage
!= BLOCK_REPLICATION_FAILOVER
) {
434 /* The backup job is cancelled unexpectedly */
438 backup_job_cleanup(bs
);
441 static bool check_top_bs(BlockDriverState
*top_bs
, BlockDriverState
*bs
)
445 /* The bs itself is the top_bs */
450 /* Iterate over top_bs's children */
451 QLIST_FOREACH(child
, &top_bs
->children
, next
) {
452 if (child
->bs
== bs
|| check_top_bs(child
->bs
, bs
)) {
460 static void replication_start(ReplicationState
*rs
, ReplicationMode mode
,
463 BlockDriverState
*bs
= rs
->opaque
;
464 BDRVReplicationState
*s
;
465 BlockDriverState
*top_bs
;
466 int64_t active_length
, hidden_length
, disk_length
;
467 AioContext
*aio_context
;
468 Error
*local_err
= NULL
;
471 aio_context
= bdrv_get_aio_context(bs
);
472 aio_context_acquire(aio_context
);
475 if (s
->stage
!= BLOCK_REPLICATION_NONE
) {
476 error_setg(errp
, "Block replication is running or done");
477 aio_context_release(aio_context
);
481 if (s
->mode
!= mode
) {
482 error_setg(errp
, "The parameter mode's value is invalid, needs %d,"
483 " but got %d", s
->mode
, mode
);
484 aio_context_release(aio_context
);
489 case REPLICATION_MODE_PRIMARY
:
491 case REPLICATION_MODE_SECONDARY
:
492 s
->active_disk
= bs
->file
;
493 if (!s
->active_disk
|| !s
->active_disk
->bs
||
494 !s
->active_disk
->bs
->backing
) {
495 error_setg(errp
, "Active disk doesn't have backing file");
496 aio_context_release(aio_context
);
500 s
->hidden_disk
= s
->active_disk
->bs
->backing
;
501 if (!s
->hidden_disk
->bs
|| !s
->hidden_disk
->bs
->backing
) {
502 error_setg(errp
, "Hidden disk doesn't have backing file");
503 aio_context_release(aio_context
);
507 s
->secondary_disk
= s
->hidden_disk
->bs
->backing
;
508 if (!s
->secondary_disk
->bs
|| !bdrv_has_blk(s
->secondary_disk
->bs
)) {
509 error_setg(errp
, "The secondary disk doesn't have block backend");
510 aio_context_release(aio_context
);
514 /* verify the length */
515 active_length
= bdrv_getlength(s
->active_disk
->bs
);
516 hidden_length
= bdrv_getlength(s
->hidden_disk
->bs
);
517 disk_length
= bdrv_getlength(s
->secondary_disk
->bs
);
518 if (active_length
< 0 || hidden_length
< 0 || disk_length
< 0 ||
519 active_length
!= hidden_length
|| hidden_length
!= disk_length
) {
520 error_setg(errp
, "Active disk, hidden disk, secondary disk's length"
521 " are not the same");
522 aio_context_release(aio_context
);
526 /* Must be true, or the bdrv_getlength() calls would have failed */
527 assert(s
->active_disk
->bs
->drv
&& s
->hidden_disk
->bs
->drv
);
529 if (!s
->active_disk
->bs
->drv
->bdrv_make_empty
||
530 !s
->hidden_disk
->bs
->drv
->bdrv_make_empty
) {
532 "Active disk or hidden disk doesn't support make_empty");
533 aio_context_release(aio_context
);
537 /* reopen the backing file in r/w mode */
538 reopen_backing_file(bs
, true, &local_err
);
540 error_propagate(errp
, local_err
);
541 aio_context_release(aio_context
);
545 /* start backup job now */
546 error_setg(&s
->blocker
,
547 "Block device is in use by internal backup job");
549 top_bs
= bdrv_lookup_bs(s
->top_id
, s
->top_id
, NULL
);
550 if (!top_bs
|| !bdrv_is_root_node(top_bs
) ||
551 !check_top_bs(top_bs
, bs
)) {
552 error_setg(errp
, "No top_bs or it is invalid");
553 reopen_backing_file(bs
, false, NULL
);
554 aio_context_release(aio_context
);
557 bdrv_op_block_all(top_bs
, s
->blocker
);
558 bdrv_op_unblock(top_bs
, BLOCK_OP_TYPE_DATAPLANE
, s
->blocker
);
560 job
= backup_job_create(NULL
, s
->secondary_disk
->bs
, s
->hidden_disk
->bs
,
561 0, MIRROR_SYNC_MODE_NONE
, NULL
, false,
562 BLOCKDEV_ON_ERROR_REPORT
,
563 BLOCKDEV_ON_ERROR_REPORT
, BLOCK_JOB_INTERNAL
,
564 backup_job_completed
, bs
, NULL
, &local_err
);
566 error_propagate(errp
, local_err
);
567 backup_job_cleanup(bs
);
568 aio_context_release(aio_context
);
571 block_job_start(job
);
574 aio_context_release(aio_context
);
578 s
->stage
= BLOCK_REPLICATION_RUNNING
;
580 if (s
->mode
== REPLICATION_MODE_SECONDARY
) {
581 secondary_do_checkpoint(s
, errp
);
585 aio_context_release(aio_context
);
588 static void replication_do_checkpoint(ReplicationState
*rs
, Error
**errp
)
590 BlockDriverState
*bs
= rs
->opaque
;
591 BDRVReplicationState
*s
;
592 AioContext
*aio_context
;
594 aio_context
= bdrv_get_aio_context(bs
);
595 aio_context_acquire(aio_context
);
598 if (s
->mode
== REPLICATION_MODE_SECONDARY
) {
599 secondary_do_checkpoint(s
, errp
);
601 aio_context_release(aio_context
);
604 static void replication_get_error(ReplicationState
*rs
, Error
**errp
)
606 BlockDriverState
*bs
= rs
->opaque
;
607 BDRVReplicationState
*s
;
608 AioContext
*aio_context
;
610 aio_context
= bdrv_get_aio_context(bs
);
611 aio_context_acquire(aio_context
);
614 if (s
->stage
!= BLOCK_REPLICATION_RUNNING
) {
615 error_setg(errp
, "Block replication is not running");
616 aio_context_release(aio_context
);
621 error_setg(errp
, "I/O error occurred");
622 aio_context_release(aio_context
);
625 aio_context_release(aio_context
);
628 static void replication_done(void *opaque
, int ret
)
630 BlockDriverState
*bs
= opaque
;
631 BDRVReplicationState
*s
= bs
->opaque
;
634 s
->stage
= BLOCK_REPLICATION_DONE
;
636 /* refresh top bs's filename */
637 bdrv_refresh_filename(bs
);
638 s
->active_disk
= NULL
;
639 s
->secondary_disk
= NULL
;
640 s
->hidden_disk
= NULL
;
643 s
->stage
= BLOCK_REPLICATION_FAILOVER_FAILED
;
648 static void replication_stop(ReplicationState
*rs
, bool failover
, Error
**errp
)
650 BlockDriverState
*bs
= rs
->opaque
;
651 BDRVReplicationState
*s
;
652 AioContext
*aio_context
;
654 aio_context
= bdrv_get_aio_context(bs
);
655 aio_context_acquire(aio_context
);
658 if (s
->stage
!= BLOCK_REPLICATION_RUNNING
) {
659 error_setg(errp
, "Block replication is not running");
660 aio_context_release(aio_context
);
665 case REPLICATION_MODE_PRIMARY
:
666 s
->stage
= BLOCK_REPLICATION_DONE
;
669 case REPLICATION_MODE_SECONDARY
:
671 * This BDS will be closed, and the job should be completed
672 * before the BDS is closed, because we will access hidden
673 * disk, secondary disk in backup_job_completed().
675 if (s
->secondary_disk
->bs
->job
) {
676 block_job_cancel_sync(s
->secondary_disk
->bs
->job
);
680 secondary_do_checkpoint(s
, errp
);
681 s
->stage
= BLOCK_REPLICATION_DONE
;
682 aio_context_release(aio_context
);
686 s
->stage
= BLOCK_REPLICATION_FAILOVER
;
687 commit_active_start(NULL
, s
->active_disk
->bs
, s
->secondary_disk
->bs
,
688 BLOCK_JOB_INTERNAL
, 0, BLOCKDEV_ON_ERROR_REPORT
,
689 NULL
, replication_done
, bs
, true, errp
);
692 aio_context_release(aio_context
);
695 aio_context_release(aio_context
);
698 BlockDriver bdrv_replication
= {
699 .format_name
= "replication",
700 .protocol_name
= "replication",
701 .instance_size
= sizeof(BDRVReplicationState
),
703 .bdrv_open
= replication_open
,
704 .bdrv_close
= replication_close
,
705 .bdrv_child_perm
= replication_child_perm
,
707 .bdrv_getlength
= replication_getlength
,
708 .bdrv_co_readv
= replication_co_readv
,
709 .bdrv_co_writev
= replication_co_writev
,
712 .bdrv_recurse_is_first_non_filter
= replication_recurse_is_first_non_filter
,
714 .has_variable_length
= true,
717 static void bdrv_replication_init(void)
719 bdrv_register(&bdrv_replication
);
722 block_init(bdrv_replication_init
);