| /* |
| * Replication Block filter |
| * |
| * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD. |
| * Copyright (c) 2016 Intel Corporation |
| * Copyright (c) 2016 FUJITSU LIMITED |
| * |
| * Author: |
| * Wen Congyang <wency@cn.fujitsu.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2 or later. |
| * See the COPYING file in the top-level directory. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "qemu-common.h" |
| #include "block/nbd.h" |
| #include "block/blockjob.h" |
| #include "block/block_int.h" |
| #include "block/block_backup.h" |
| #include "sysemu/block-backend.h" |
| #include "qapi/error.h" |
| #include "replication.h" |
| |
| typedef enum { |
| BLOCK_REPLICATION_NONE, /* block replication is not started */ |
| BLOCK_REPLICATION_RUNNING, /* block replication is running */ |
| BLOCK_REPLICATION_FAILOVER, /* failover is running in background */ |
| BLOCK_REPLICATION_FAILOVER_FAILED, /* failover failed */ |
| BLOCK_REPLICATION_DONE, /* block replication is done */ |
| } ReplicationStage; |
| |
| typedef struct BDRVReplicationState { |
| ReplicationMode mode; |
| ReplicationStage stage; |
| BdrvChild *active_disk; |
| BdrvChild *hidden_disk; |
| BdrvChild *secondary_disk; |
| char *top_id; |
| ReplicationState *rs; |
| Error *blocker; |
| int orig_hidden_flags; |
| int orig_secondary_flags; |
| int error; |
| } BDRVReplicationState; |
| |
| static void replication_start(ReplicationState *rs, ReplicationMode mode, |
| Error **errp); |
| static void replication_do_checkpoint(ReplicationState *rs, Error **errp); |
| static void replication_get_error(ReplicationState *rs, Error **errp); |
| static void replication_stop(ReplicationState *rs, bool failover, |
| Error **errp); |
| |
| #define REPLICATION_MODE "mode" |
| #define REPLICATION_TOP_ID "top-id" |
| static QemuOptsList replication_runtime_opts = { |
| .name = "replication", |
| .head = QTAILQ_HEAD_INITIALIZER(replication_runtime_opts.head), |
| .desc = { |
| { |
| .name = REPLICATION_MODE, |
| .type = QEMU_OPT_STRING, |
| }, |
| { |
| .name = REPLICATION_TOP_ID, |
| .type = QEMU_OPT_STRING, |
| }, |
| { /* end of list */ } |
| }, |
| }; |
| |
| static ReplicationOps replication_ops = { |
| .start = replication_start, |
| .checkpoint = replication_do_checkpoint, |
| .get_error = replication_get_error, |
| .stop = replication_stop, |
| }; |
| |
| static int replication_open(BlockDriverState *bs, QDict *options, |
| int flags, Error **errp) |
| { |
| int ret; |
| BDRVReplicationState *s = bs->opaque; |
| Error *local_err = NULL; |
| QemuOpts *opts = NULL; |
| const char *mode; |
| const char *top_id; |
| |
| bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, |
| false, errp); |
| if (!bs->file) { |
| return -EINVAL; |
| } |
| |
| ret = -EINVAL; |
| opts = qemu_opts_create(&replication_runtime_opts, NULL, 0, &error_abort); |
| qemu_opts_absorb_qdict(opts, options, &local_err); |
| if (local_err) { |
| goto fail; |
| } |
| |
| mode = qemu_opt_get(opts, REPLICATION_MODE); |
| if (!mode) { |
| error_setg(&local_err, "Missing the option mode"); |
| goto fail; |
| } |
| |
| if (!strcmp(mode, "primary")) { |
| s->mode = REPLICATION_MODE_PRIMARY; |
| top_id = qemu_opt_get(opts, REPLICATION_TOP_ID); |
| if (top_id) { |
| error_setg(&local_err, "The primary side does not support option top-id"); |
| goto fail; |
| } |
| } else if (!strcmp(mode, "secondary")) { |
| s->mode = REPLICATION_MODE_SECONDARY; |
| top_id = qemu_opt_get(opts, REPLICATION_TOP_ID); |
| s->top_id = g_strdup(top_id); |
| if (!s->top_id) { |
| error_setg(&local_err, "Missing the option top-id"); |
| goto fail; |
| } |
| } else { |
| error_setg(&local_err, |
| "The option mode's value should be primary or secondary"); |
| goto fail; |
| } |
| |
| s->rs = replication_new(bs, &replication_ops); |
| |
| ret = 0; |
| |
| fail: |
| qemu_opts_del(opts); |
| error_propagate(errp, local_err); |
| |
| return ret; |
| } |
| |
| static void replication_close(BlockDriverState *bs) |
| { |
| BDRVReplicationState *s = bs->opaque; |
| |
| if (s->stage == BLOCK_REPLICATION_RUNNING) { |
| replication_stop(s->rs, false, NULL); |
| } |
| if (s->stage == BLOCK_REPLICATION_FAILOVER) { |
| block_job_cancel_sync(s->active_disk->bs->job); |
| } |
| |
| if (s->mode == REPLICATION_MODE_SECONDARY) { |
| g_free(s->top_id); |
| } |
| |
| replication_remove(s->rs); |
| } |
| |
| static void replication_child_perm(BlockDriverState *bs, BdrvChild *c, |
| const BdrvChildRole *role, |
| BlockReopenQueue *reopen_queue, |
| uint64_t perm, uint64_t shared, |
| uint64_t *nperm, uint64_t *nshared) |
| { |
| *nperm = *nshared = BLK_PERM_CONSISTENT_READ \ |
| | BLK_PERM_WRITE \ |
| | BLK_PERM_WRITE_UNCHANGED; |
| |
| return; |
| } |
| |
| static int64_t replication_getlength(BlockDriverState *bs) |
| { |
| return bdrv_getlength(bs->file->bs); |
| } |
| |
| static int replication_get_io_status(BDRVReplicationState *s) |
| { |
| switch (s->stage) { |
| case BLOCK_REPLICATION_NONE: |
| return -EIO; |
| case BLOCK_REPLICATION_RUNNING: |
| return 0; |
| case BLOCK_REPLICATION_FAILOVER: |
| return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 0; |
| case BLOCK_REPLICATION_FAILOVER_FAILED: |
| return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 1; |
| case BLOCK_REPLICATION_DONE: |
| /* |
| * active commit job completes, and active disk and secondary_disk |
| * is swapped, so we can operate bs->file directly |
| */ |
| return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 0; |
| default: |
| abort(); |
| } |
| } |
| |
| static int replication_return_value(BDRVReplicationState *s, int ret) |
| { |
| if (s->mode == REPLICATION_MODE_SECONDARY) { |
| return ret; |
| } |
| |
| if (ret < 0) { |
| s->error = ret; |
| ret = 0; |
| } |
| |
| return ret; |
| } |
| |
| static coroutine_fn int replication_co_readv(BlockDriverState *bs, |
| int64_t sector_num, |
| int remaining_sectors, |
| QEMUIOVector *qiov) |
| { |
| BDRVReplicationState *s = bs->opaque; |
| BdrvChild *child = s->secondary_disk; |
| BlockJob *job = NULL; |
| CowRequest req; |
| int ret; |
| |
| if (s->mode == REPLICATION_MODE_PRIMARY) { |
| /* We only use it to forward primary write requests */ |
| return -EIO; |
| } |
| |
| ret = replication_get_io_status(s); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| if (child && child->bs) { |
| job = child->bs->job; |
| } |
| |
| if (job) { |
| uint64_t remaining_bytes = remaining_sectors * BDRV_SECTOR_SIZE; |
| |
| backup_wait_for_overlapping_requests(child->bs->job, |
| sector_num * BDRV_SECTOR_SIZE, |
| remaining_bytes); |
| backup_cow_request_begin(&req, child->bs->job, |
| sector_num * BDRV_SECTOR_SIZE, |
| remaining_bytes); |
| ret = bdrv_co_readv(bs->file, sector_num, remaining_sectors, |
| qiov); |
| backup_cow_request_end(&req); |
| goto out; |
| } |
| |
| ret = bdrv_co_readv(bs->file, sector_num, remaining_sectors, qiov); |
| out: |
| return replication_return_value(s, ret); |
| } |
| |
| static coroutine_fn int replication_co_writev(BlockDriverState *bs, |
| int64_t sector_num, |
| int remaining_sectors, |
| QEMUIOVector *qiov) |
| { |
| BDRVReplicationState *s = bs->opaque; |
| QEMUIOVector hd_qiov; |
| uint64_t bytes_done = 0; |
| BdrvChild *top = bs->file; |
| BdrvChild *base = s->secondary_disk; |
| BdrvChild *target; |
| int ret; |
| int64_t n; |
| |
| ret = replication_get_io_status(s); |
| if (ret < 0) { |
| goto out; |
| } |
| |
| if (ret == 0) { |
| ret = bdrv_co_writev(top, sector_num, |
| remaining_sectors, qiov); |
| return replication_return_value(s, ret); |
| } |
| |
| /* |
| * Failover failed, only write to active disk if the sectors |
| * have already been allocated in active disk/hidden disk. |
| */ |
| qemu_iovec_init(&hd_qiov, qiov->niov); |
| while (remaining_sectors > 0) { |
| int64_t count; |
| |
| ret = bdrv_is_allocated_above(top->bs, base->bs, |
| sector_num * BDRV_SECTOR_SIZE, |
| remaining_sectors * BDRV_SECTOR_SIZE, |
| &count); |
| if (ret < 0) { |
| goto out1; |
| } |
| |
| assert(QEMU_IS_ALIGNED(count, BDRV_SECTOR_SIZE)); |
| n = count >> BDRV_SECTOR_BITS; |
| qemu_iovec_reset(&hd_qiov); |
| qemu_iovec_concat(&hd_qiov, qiov, bytes_done, count); |
| |
| target = ret ? top : base; |
| ret = bdrv_co_writev(target, sector_num, n, &hd_qiov); |
| if (ret < 0) { |
| goto out1; |
| } |
| |
| remaining_sectors -= n; |
| sector_num += n; |
| bytes_done += count; |
| } |
| |
| out1: |
| qemu_iovec_destroy(&hd_qiov); |
| out: |
| return ret; |
| } |
| |
| static bool replication_recurse_is_first_non_filter(BlockDriverState *bs, |
| BlockDriverState *candidate) |
| { |
| return bdrv_recurse_is_first_non_filter(bs->file->bs, candidate); |
| } |
| |
| static void secondary_do_checkpoint(BDRVReplicationState *s, Error **errp) |
| { |
| Error *local_err = NULL; |
| int ret; |
| |
| if (!s->secondary_disk->bs->job) { |
| error_setg(errp, "Backup job was cancelled unexpectedly"); |
| return; |
| } |
| |
| backup_do_checkpoint(s->secondary_disk->bs->job, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return; |
| } |
| |
| ret = s->active_disk->bs->drv->bdrv_make_empty(s->active_disk->bs); |
| if (ret < 0) { |
| error_setg(errp, "Cannot make active disk empty"); |
| return; |
| } |
| |
| ret = s->hidden_disk->bs->drv->bdrv_make_empty(s->hidden_disk->bs); |
| if (ret < 0) { |
| error_setg(errp, "Cannot make hidden disk empty"); |
| return; |
| } |
| } |
| |
| static void reopen_backing_file(BlockDriverState *bs, bool writable, |
| Error **errp) |
| { |
| BDRVReplicationState *s = bs->opaque; |
| BlockReopenQueue *reopen_queue = NULL; |
| int orig_hidden_flags, orig_secondary_flags; |
| int new_hidden_flags, new_secondary_flags; |
| Error *local_err = NULL; |
| |
| if (writable) { |
| orig_hidden_flags = s->orig_hidden_flags = |
| bdrv_get_flags(s->hidden_disk->bs); |
| new_hidden_flags = (orig_hidden_flags | BDRV_O_RDWR) & |
| ~BDRV_O_INACTIVE; |
| orig_secondary_flags = s->orig_secondary_flags = |
| bdrv_get_flags(s->secondary_disk->bs); |
| new_secondary_flags = (orig_secondary_flags | BDRV_O_RDWR) & |
| ~BDRV_O_INACTIVE; |
| } else { |
| orig_hidden_flags = (s->orig_hidden_flags | BDRV_O_RDWR) & |
| ~BDRV_O_INACTIVE; |
| new_hidden_flags = s->orig_hidden_flags; |
| orig_secondary_flags = (s->orig_secondary_flags | BDRV_O_RDWR) & |
| ~BDRV_O_INACTIVE; |
| new_secondary_flags = s->orig_secondary_flags; |
| } |
| |
| if (orig_hidden_flags != new_hidden_flags) { |
| reopen_queue = bdrv_reopen_queue(reopen_queue, s->hidden_disk->bs, NULL, |
| new_hidden_flags); |
| } |
| |
| if (!(orig_secondary_flags & BDRV_O_RDWR)) { |
| reopen_queue = bdrv_reopen_queue(reopen_queue, s->secondary_disk->bs, |
| NULL, new_secondary_flags); |
| } |
| |
| if (reopen_queue) { |
| bdrv_reopen_multiple(bdrv_get_aio_context(bs), |
| reopen_queue, &local_err); |
| error_propagate(errp, local_err); |
| } |
| } |
| |
| static void backup_job_cleanup(BlockDriverState *bs) |
| { |
| BDRVReplicationState *s = bs->opaque; |
| BlockDriverState *top_bs; |
| |
| top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL); |
| if (!top_bs) { |
| return; |
| } |
| bdrv_op_unblock_all(top_bs, s->blocker); |
| error_free(s->blocker); |
| reopen_backing_file(bs, false, NULL); |
| } |
| |
| static void backup_job_completed(void *opaque, int ret) |
| { |
| BlockDriverState *bs = opaque; |
| BDRVReplicationState *s = bs->opaque; |
| |
| if (s->stage != BLOCK_REPLICATION_FAILOVER) { |
| /* The backup job is cancelled unexpectedly */ |
| s->error = -EIO; |
| } |
| |
| backup_job_cleanup(bs); |
| } |
| |
| static bool check_top_bs(BlockDriverState *top_bs, BlockDriverState *bs) |
| { |
| BdrvChild *child; |
| |
| /* The bs itself is the top_bs */ |
| if (top_bs == bs) { |
| return true; |
| } |
| |
| /* Iterate over top_bs's children */ |
| QLIST_FOREACH(child, &top_bs->children, next) { |
| if (child->bs == bs || check_top_bs(child->bs, bs)) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| static void replication_start(ReplicationState *rs, ReplicationMode mode, |
| Error **errp) |
| { |
| BlockDriverState *bs = rs->opaque; |
| BDRVReplicationState *s; |
| BlockDriverState *top_bs; |
| int64_t active_length, hidden_length, disk_length; |
| AioContext *aio_context; |
| Error *local_err = NULL; |
| BlockJob *job; |
| |
| aio_context = bdrv_get_aio_context(bs); |
| aio_context_acquire(aio_context); |
| s = bs->opaque; |
| |
| if (s->stage != BLOCK_REPLICATION_NONE) { |
| error_setg(errp, "Block replication is running or done"); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| if (s->mode != mode) { |
| error_setg(errp, "The parameter mode's value is invalid, needs %d," |
| " but got %d", s->mode, mode); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| switch (s->mode) { |
| case REPLICATION_MODE_PRIMARY: |
| break; |
| case REPLICATION_MODE_SECONDARY: |
| s->active_disk = bs->file; |
| if (!s->active_disk || !s->active_disk->bs || |
| !s->active_disk->bs->backing) { |
| error_setg(errp, "Active disk doesn't have backing file"); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| s->hidden_disk = s->active_disk->bs->backing; |
| if (!s->hidden_disk->bs || !s->hidden_disk->bs->backing) { |
| error_setg(errp, "Hidden disk doesn't have backing file"); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| s->secondary_disk = s->hidden_disk->bs->backing; |
| if (!s->secondary_disk->bs || !bdrv_has_blk(s->secondary_disk->bs)) { |
| error_setg(errp, "The secondary disk doesn't have block backend"); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| /* verify the length */ |
| active_length = bdrv_getlength(s->active_disk->bs); |
| hidden_length = bdrv_getlength(s->hidden_disk->bs); |
| disk_length = bdrv_getlength(s->secondary_disk->bs); |
| if (active_length < 0 || hidden_length < 0 || disk_length < 0 || |
| active_length != hidden_length || hidden_length != disk_length) { |
| error_setg(errp, "Active disk, hidden disk, secondary disk's length" |
| " are not the same"); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| if (!s->active_disk->bs->drv->bdrv_make_empty || |
| !s->hidden_disk->bs->drv->bdrv_make_empty) { |
| error_setg(errp, |
| "Active disk or hidden disk doesn't support make_empty"); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| /* reopen the backing file in r/w mode */ |
| reopen_backing_file(bs, true, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| /* start backup job now */ |
| error_setg(&s->blocker, |
| "Block device is in use by internal backup job"); |
| |
| top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL); |
| if (!top_bs || !bdrv_is_root_node(top_bs) || |
| !check_top_bs(top_bs, bs)) { |
| error_setg(errp, "No top_bs or it is invalid"); |
| reopen_backing_file(bs, false, NULL); |
| aio_context_release(aio_context); |
| return; |
| } |
| bdrv_op_block_all(top_bs, s->blocker); |
| bdrv_op_unblock(top_bs, BLOCK_OP_TYPE_DATAPLANE, s->blocker); |
| |
| job = backup_job_create(NULL, s->secondary_disk->bs, s->hidden_disk->bs, |
| 0, MIRROR_SYNC_MODE_NONE, NULL, false, |
| BLOCKDEV_ON_ERROR_REPORT, |
| BLOCKDEV_ON_ERROR_REPORT, BLOCK_JOB_INTERNAL, |
| backup_job_completed, bs, NULL, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| backup_job_cleanup(bs); |
| aio_context_release(aio_context); |
| return; |
| } |
| block_job_start(job); |
| break; |
| default: |
| aio_context_release(aio_context); |
| abort(); |
| } |
| |
| s->stage = BLOCK_REPLICATION_RUNNING; |
| |
| if (s->mode == REPLICATION_MODE_SECONDARY) { |
| secondary_do_checkpoint(s, errp); |
| } |
| |
| s->error = 0; |
| aio_context_release(aio_context); |
| } |
| |
| static void replication_do_checkpoint(ReplicationState *rs, Error **errp) |
| { |
| BlockDriverState *bs = rs->opaque; |
| BDRVReplicationState *s; |
| AioContext *aio_context; |
| |
| aio_context = bdrv_get_aio_context(bs); |
| aio_context_acquire(aio_context); |
| s = bs->opaque; |
| |
| if (s->mode == REPLICATION_MODE_SECONDARY) { |
| secondary_do_checkpoint(s, errp); |
| } |
| aio_context_release(aio_context); |
| } |
| |
| static void replication_get_error(ReplicationState *rs, Error **errp) |
| { |
| BlockDriverState *bs = rs->opaque; |
| BDRVReplicationState *s; |
| AioContext *aio_context; |
| |
| aio_context = bdrv_get_aio_context(bs); |
| aio_context_acquire(aio_context); |
| s = bs->opaque; |
| |
| if (s->stage != BLOCK_REPLICATION_RUNNING) { |
| error_setg(errp, "Block replication is not running"); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| if (s->error) { |
| error_setg(errp, "I/O error occurred"); |
| aio_context_release(aio_context); |
| return; |
| } |
| aio_context_release(aio_context); |
| } |
| |
| static void replication_done(void *opaque, int ret) |
| { |
| BlockDriverState *bs = opaque; |
| BDRVReplicationState *s = bs->opaque; |
| |
| if (ret == 0) { |
| s->stage = BLOCK_REPLICATION_DONE; |
| |
| /* refresh top bs's filename */ |
| bdrv_refresh_filename(bs); |
| s->active_disk = NULL; |
| s->secondary_disk = NULL; |
| s->hidden_disk = NULL; |
| s->error = 0; |
| } else { |
| s->stage = BLOCK_REPLICATION_FAILOVER_FAILED; |
| s->error = -EIO; |
| } |
| } |
| |
| static void replication_stop(ReplicationState *rs, bool failover, Error **errp) |
| { |
| BlockDriverState *bs = rs->opaque; |
| BDRVReplicationState *s; |
| AioContext *aio_context; |
| |
| aio_context = bdrv_get_aio_context(bs); |
| aio_context_acquire(aio_context); |
| s = bs->opaque; |
| |
| if (s->stage != BLOCK_REPLICATION_RUNNING) { |
| error_setg(errp, "Block replication is not running"); |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| switch (s->mode) { |
| case REPLICATION_MODE_PRIMARY: |
| s->stage = BLOCK_REPLICATION_DONE; |
| s->error = 0; |
| break; |
| case REPLICATION_MODE_SECONDARY: |
| /* |
| * This BDS will be closed, and the job should be completed |
| * before the BDS is closed, because we will access hidden |
| * disk, secondary disk in backup_job_completed(). |
| */ |
| if (s->secondary_disk->bs->job) { |
| block_job_cancel_sync(s->secondary_disk->bs->job); |
| } |
| |
| if (!failover) { |
| secondary_do_checkpoint(s, errp); |
| s->stage = BLOCK_REPLICATION_DONE; |
| aio_context_release(aio_context); |
| return; |
| } |
| |
| s->stage = BLOCK_REPLICATION_FAILOVER; |
| commit_active_start(NULL, s->active_disk->bs, s->secondary_disk->bs, |
| BLOCK_JOB_INTERNAL, 0, BLOCKDEV_ON_ERROR_REPORT, |
| NULL, replication_done, bs, true, errp); |
| break; |
| default: |
| aio_context_release(aio_context); |
| abort(); |
| } |
| aio_context_release(aio_context); |
| } |
| |
| BlockDriver bdrv_replication = { |
| .format_name = "replication", |
| .protocol_name = "replication", |
| .instance_size = sizeof(BDRVReplicationState), |
| |
| .bdrv_open = replication_open, |
| .bdrv_close = replication_close, |
| .bdrv_child_perm = replication_child_perm, |
| |
| .bdrv_getlength = replication_getlength, |
| .bdrv_co_readv = replication_co_readv, |
| .bdrv_co_writev = replication_co_writev, |
| |
| .is_filter = true, |
| .bdrv_recurse_is_first_non_filter = replication_recurse_is_first_non_filter, |
| |
| .has_variable_length = true, |
| }; |
| |
| static void bdrv_replication_init(void) |
| { |
| bdrv_register(&bdrv_replication); |
| } |
| |
| block_init(bdrv_replication_init); |