From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46909) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZfMKz-000771-9j for qemu-devel@nongnu.org; Fri, 25 Sep 2015 02:18:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZfMKx-00048o-Ki for qemu-devel@nongnu.org; Fri, 25 Sep 2015 02:18:29 -0400 From: Wen Congyang Date: Fri, 25 Sep 2015 14:17:36 +0800 Message-ID: <1443161858-20533-9-git-send-email-wency@cn.fujitsu.com> In-Reply-To: <1443161858-20533-1-git-send-email-wency@cn.fujitsu.com> References: <1443161858-20533-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH v10 08/10] Implement new driver for block replication List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu devel , Fam Zheng , Max Reitz , Paolo Bonzini , Stefan Hajnoczi Cc: Kevin Wolf , qemu block , Jiang Yunhong , Dong Eddie , "Dr. David Alan Gilbert" , "Michael R. Hines" , Gonglei , Yang Hongyang , zhanghailiang Signed-off-by: Wen Congyang Signed-off-by: zhanghailiang Signed-off-by: Gonglei --- block/Makefile.objs | 1 + block/replication.c | 471 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 472 insertions(+) create mode 100644 block/replication.c diff --git a/block/Makefile.objs b/block/Makefile.objs index fa05f37..94c1d03 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -23,6 +23,7 @@ block-obj-$(CONFIG_LIBSSH2) += ssh.o block-obj-y += accounting.o block-obj-y += write-threshold.o block-obj-y += backup.o +block-obj-y += replication.o common-obj-y += stream.o common-obj-y += commit.o diff --git a/block/replication.c b/block/replication.c new file mode 100644 index 0000000..813f610 --- /dev/null +++ b/block/replication.c @@ -0,0 +1,471 @@ +/* + * Replication Block filter + * + * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO., LTD. + * Copyright (c) 2015 Intel Corporation + * Copyright (c) 2015 FUJITSU LIMITED + * + * Author: + * Wen Congyang + * + * 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-common.h" +#include "block/block_int.h" +#include "block/blockjob.h" +#include "block/nbd.h" + +typedef struct BDRVReplicationState { + ReplicationMode mode; + int replication_state; + BlockDriverState *active_disk; + BlockDriverState *hidden_disk; + BlockDriverState *secondary_disk; + int error; +} BDRVReplicationState; + +enum { + BLOCK_REPLICATION_NONE, /* block replication is not started */ + BLOCK_REPLICATION_RUNNING, /* block replication is running */ + BLOCK_REPLICATION_DONE, /* block replication is done(failover) */ +}; + +#define COMMIT_CLUSTER_BITS 16 +#define COMMIT_CLUSTER_SIZE (1 << COMMIT_CLUSTER_BITS) +#define COMMIT_SECTORS_PER_CLUSTER (COMMIT_CLUSTER_SIZE / BDRV_SECTOR_SIZE) + +static void replication_stop(BlockDriverState *bs, bool failover, Error **errp); + +#define REPLICATION_MODE "mode" +static QemuOptsList replication_runtime_opts = { + .name = "replication", + .head = QTAILQ_HEAD_INITIALIZER(replication_runtime_opts.head), + .desc = { + { + .name = REPLICATION_MODE, + .type = QEMU_OPT_STRING, + }, + { /* end of list */ } + }, +}; + +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; + + 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; + } else { + error_setg(&local_err, + "The option mode's value should be primary or secondary"); + goto fail; + } + + ret = 0; + +fail: + qemu_opts_del(opts); + /* propagate error */ + if (local_err) { + 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(bs, false, NULL); + } +} + +static int64_t replication_getlength(BlockDriverState *bs) +{ + return bdrv_getlength(bs->file); +} + +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_DONE: + return s->mode == REPLICATION_MODE_PRIMARY ? -EIO : 1; + 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; + 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; + } + + /* + * After failover, because we don't commit active disk/hidden disk + * to secondary disk, so we should read from active disk directly. + */ + ret = bdrv_co_readv(bs->file, sector_num, remaining_sectors, qiov); + 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; + BlockDriverState *top = bs->file; + BlockDriverState *base = s->secondary_disk; + BlockDriverState *target; + int ret, n; + + ret = replication_get_io_status(s); + if (ret < 0) { + return ret; + } + + if (ret == 0) { + ret = bdrv_co_writev(bs->file, sector_num, remaining_sectors, qiov); + return replication_return_value(s, ret); + } + + /* + * 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, base, sector_num, + remaining_sectors, &n); + if (ret < 0) { + return ret; + } + + qemu_iovec_reset(&hd_qiov); + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, n * 512); + + target = ret ? top: base; + ret = bdrv_co_writev(target, sector_num, n, &hd_qiov); + if (ret < 0) { + return ret; + } + + remaining_sectors -= n; + sector_num += n; + bytes_done += n * BDRV_SECTOR_SIZE; + } + + return 0; +} + +static coroutine_fn int replication_co_discard(BlockDriverState *bs, + int64_t sector_num, + int nb_sectors) +{ + BDRVReplicationState *s = bs->opaque; + int ret; + + ret = replication_get_io_status(s); + if (ret < 0) { + return ret; + } + + if (ret == 1) { + /* It is secondary qemu and we are after failover */ + ret = bdrv_co_discard(s->secondary_disk, sector_num, nb_sectors); + if (ret) { + return ret; + } + } + + ret = bdrv_co_discard(bs->file, sector_num, nb_sectors); + return replication_return_value(s, ret); +} + +static bool replication_recurse_is_first_non_filter(BlockDriverState *bs, + BlockDriverState *candidate) +{ + return bdrv_recurse_is_first_non_filter(bs->file, candidate); +} + +static void secondary_do_checkpoint(BDRVReplicationState *s, Error **errp) +{ + Error *local_err = NULL; + int ret; + + if (!s->secondary_disk->job) { + error_setg(errp, "Backup job is cancelled unexpectedly"); + return; + } + + block_job_do_checkpoint(s->secondary_disk->job, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + + ret = s->active_disk->drv->bdrv_make_empty(s->active_disk); + if (ret < 0) { + error_setg(errp, "Cannot make active disk empty"); + return; + } + + ret = s->hidden_disk->drv->bdrv_make_empty(s->hidden_disk); + if (ret < 0) { + error_setg(errp, "Cannot make hidden disk empty"); + return; + } +} + +static void backup_job_completed(void *opaque, int ret) +{ + BDRVReplicationState *s = opaque; + + if (s->replication_state != BLOCK_REPLICATION_DONE) { + /* The backup job is cancelled unexpectedly */ + s->error = -EIO; + } + + bdrv_op_block(s->hidden_disk, BLOCK_OP_TYPE_BACKUP_TARGET, + s->active_disk->backing_blocker); + bdrv_op_block(s->secondary_disk, BLOCK_OP_TYPE_BACKUP_SOURCE, + s->hidden_disk->backing_blocker); + + bdrv_put_ref_bh_schedule(s->secondary_disk); +} + +static void replication_start(BlockDriverState *bs, ReplicationMode mode, + Error **errp) +{ + BDRVReplicationState *s = bs->opaque; + int64_t active_length, hidden_length, disk_length; + AioContext *aio_context; + Error *local_err = NULL; + + if (s->replication_state != BLOCK_REPLICATION_NONE) { + error_setg(errp, "Block replication is running or done"); + return; + } + + if (s->mode != mode) { + error_setg(errp, "The parameter mode's value is invalid, needs %d," + " but receives %d", s->mode, mode); + return; + } + + switch (s->mode) { + case REPLICATION_MODE_PRIMARY: + break; + case REPLICATION_MODE_SECONDARY: + s->active_disk = bs->file; + if (!bs->file->backing_hd) { + error_setg(errp, "Active disk doesn't have backing file"); + return; + } + + s->hidden_disk = s->active_disk->backing_hd; + if (!s->hidden_disk->backing_hd) { + error_setg(errp, "Hidden disk doesn't have backing file"); + return; + } + + s->secondary_disk = s->hidden_disk->backing_hd; + if (!s->secondary_disk->blk) { + error_setg(errp, "The secondary disk doesn't have block backend"); + return; + } + + /* verify the length */ + active_length = bdrv_getlength(s->active_disk); + hidden_length = bdrv_getlength(s->hidden_disk); + disk_length = bdrv_getlength(s->secondary_disk); + 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"); + return; + } + + if (!s->active_disk->drv->bdrv_make_empty || + !s->hidden_disk->drv->bdrv_make_empty) { + error_setg(errp, + "active disk or hidden disk doesn't support make_empty"); + return; + } + + /* start backup job now */ + bdrv_op_unblock(s->hidden_disk, BLOCK_OP_TYPE_BACKUP_TARGET, + s->active_disk->backing_blocker); + bdrv_op_unblock(s->secondary_disk, BLOCK_OP_TYPE_BACKUP_SOURCE, + s->hidden_disk->backing_blocker); + bdrv_ref(s->hidden_disk); + + aio_context = bdrv_get_aio_context(bs); + aio_context_acquire(aio_context); + bdrv_set_aio_context(s->secondary_disk, aio_context); + backup_start(s->secondary_disk, s->hidden_disk, 0, + MIRROR_SYNC_MODE_NONE, NULL, BLOCKDEV_ON_ERROR_REPORT, + BLOCKDEV_ON_ERROR_REPORT, backup_job_completed, + s, &local_err); + aio_context_release(aio_context); + if (local_err) { + error_propagate(errp, local_err); + bdrv_op_block(s->hidden_disk, BLOCK_OP_TYPE_BACKUP_TARGET, + s->active_disk->backing_blocker); + bdrv_op_block(s->secondary_disk, BLOCK_OP_TYPE_BACKUP_SOURCE, + s->hidden_disk->backing_blocker); + bdrv_unref(s->hidden_disk); + return; + } + break; + default: + abort(); + } + + s->replication_state = BLOCK_REPLICATION_RUNNING; + + if (s->mode == REPLICATION_MODE_SECONDARY) { + secondary_do_checkpoint(s, errp); + } + + s->error = 0; +} + +static void replication_do_checkpoint(BlockDriverState *bs, Error **errp) +{ + BDRVReplicationState *s = bs->opaque; + + if (s->replication_state != BLOCK_REPLICATION_RUNNING) { + error_setg(errp, "Block replication is not running"); + return; + } + + if (s->error) { + error_setg(errp, "I/O error occurs"); + return; + } + + if (s->mode == REPLICATION_MODE_SECONDARY) { + secondary_do_checkpoint(s, errp); + } +} + +static void replication_stop(BlockDriverState *bs, bool failover, Error **errp) +{ + BDRVReplicationState *s = bs->opaque; + + if (s->replication_state != BLOCK_REPLICATION_RUNNING) { + error_setg(errp, "Block replication is not running"); + return; + } + + s->replication_state = BLOCK_REPLICATION_DONE; + + switch (s->mode) { + case REPLICATION_MODE_PRIMARY: + break; + case REPLICATION_MODE_SECONDARY: + if (!failover) { + /* + * The guest will be shutdown, and secondary disk is the + * same as the primary disk. Just make active disk and + * hidden disk empty. + */ + secondary_do_checkpoint(s, errp); + return; + } + + if (s->secondary_disk->job) { + block_job_cancel(s->secondary_disk->job); + } + break; + default: + abort(); + } +} + +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, + .bdrv_co_discard = replication_co_discard, + + .is_filter = true, + .bdrv_recurse_is_first_non_filter = replication_recurse_is_first_non_filter, + + .bdrv_start_replication = replication_start, + .bdrv_do_checkpoint = replication_do_checkpoint, + .bdrv_stop_replication = replication_stop, + + .has_variable_length = true, +}; + +static void bdrv_replication_init(void) +{ + bdrv_register(&bdrv_replication); +} + +block_init(bdrv_replication_init); -- 2.4.3