diff options
| -rw-r--r-- | block/Makefile.objs | 1 | ||||
| -rw-r--r-- | block/replication.c | 659 |
2 files changed, 660 insertions, 0 deletions
diff --git a/block/Makefile.objs b/block/Makefile.objs index 8a3270bfcc..55da6266fe 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -23,6 +23,7 @@ block-obj-$(CONFIG_LIBSSH2) += ssh.o block-obj-y += accounting.o dirty-bitmap.o block-obj-y += write-threshold.o block-obj-y += backup.o +block-obj-$(CONFIG_REPLICATION) += replication.o block-obj-y += crypto.o diff --git a/block/replication.c b/block/replication.c new file mode 100644 index 0000000000..3bd1cf1809 --- /dev/null +++ b/block/replication.c @@ -0,0 +1,659 @@ +/* + * 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 struct BDRVReplicationState { + ReplicationMode mode; + int replication_state; + 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; + +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 */ +}; + +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; + + 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; + } 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->replication_state == BLOCK_REPLICATION_RUNNING) { + replication_stop(s->rs, false, NULL); + } + + if (s->mode == REPLICATION_MODE_SECONDARY) { + g_free(s->top_id); + } + + replication_remove(s->rs); +} + +static int64_t replication_getlength(BlockDriverState *bs) +{ + return bdrv_getlength(bs->file->bs); +} + +static int replication_get_io_status(BDRVReplicationState *s) +{ + switch (s->replication_state) { + 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) { + backup_wait_for_overlapping_requests(child->bs->job, sector_num, + remaining_sectors); + backup_cow_request_begin(&req, child->bs->job, sector_num, + remaining_sectors); + 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, 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) { + ret = bdrv_is_allocated_above(top->bs, base->bs, sector_num, + remaining_sectors, &n); + if (ret < 0) { + goto out1; + } + + qemu_iovec_reset(&hd_qiov); + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, n * BDRV_SECTOR_SIZE); + + 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 += n * BDRV_SECTOR_SIZE; + } + +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(BDRVReplicationState *s, bool writable, + Error **errp) +{ + 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(reopen_queue, &local_err); + error_propagate(errp, local_err); + } +} + +static void backup_job_cleanup(BDRVReplicationState *s) +{ + 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(s, false, NULL); +} + +static void backup_job_completed(void *opaque, int ret) +{ + BDRVReplicationState *s = opaque; + + if (s->replication_state != BLOCK_REPLICATION_FAILOVER) { + /* The backup job is cancelled unexpectedly */ + s->error = -EIO; + } + + backup_job_cleanup(s); +} + +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; + + aio_context = bdrv_get_aio_context(bs); + aio_context_acquire(aio_context); + s = bs->opaque; + + if (s->replication_state != 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(s, 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(s, 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); + + backup_start("replication-backup", s->secondary_disk->bs, + s->hidden_disk->bs, 0, MIRROR_SYNC_MODE_NONE, NULL, false, + BLOCKDEV_ON_ERROR_REPORT, BLOCKDEV_ON_ERROR_REPORT, + backup_job_completed, s, NULL, &local_err); + if (local_err) { + error_propagate(errp, local_err); + backup_job_cleanup(s); + aio_context_release(aio_context); + return; + } + break; + default: + aio_context_release(aio_context); + abort(); + } + + s->replication_state = 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->replication_state != 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->replication_state = 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->replication_state = 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->replication_state != 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->replication_state = 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->replication_state = BLOCK_REPLICATION_DONE; + aio_context_release(aio_context); + return; + } + + s->replication_state = BLOCK_REPLICATION_FAILOVER; + commit_active_start("replication-commit", s->active_disk->bs, + s->secondary_disk->bs, 0, BLOCKDEV_ON_ERROR_REPORT, + replication_done, + bs, errp, true); + 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_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); |