diff options
Diffstat (limited to 'src/block/mirror.c')
| -rw-r--r-- | src/block/mirror.c | 847 |
1 files changed, 847 insertions, 0 deletions
diff --git a/src/block/mirror.c b/src/block/mirror.c new file mode 100644 index 0000000..0e8f556 --- /dev/null +++ b/src/block/mirror.c @@ -0,0 +1,847 @@ +/* + * Image mirroring + * + * Copyright Red Hat, Inc. 2012 + * + * Authors: + * Paolo Bonzini <pbonzini@redhat.com> + * + * This work is licensed under the terms of the GNU LGPL, version 2 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#include "trace.h" +#include "block/blockjob.h" +#include "block/block_int.h" +#include "sysemu/block-backend.h" +#include "qapi/qmp/qerror.h" +#include "qemu/ratelimit.h" +#include "qemu/bitmap.h" + +#define SLICE_TIME 100000000ULL /* ns */ +#define MAX_IN_FLIGHT 16 +#define DEFAULT_MIRROR_BUF_SIZE (10 << 20) + +/* The mirroring buffer is a list of granularity-sized chunks. + * Free chunks are organized in a list. + */ +typedef struct MirrorBuffer { + QSIMPLEQ_ENTRY(MirrorBuffer) next; +} MirrorBuffer; + +typedef struct MirrorBlockJob { + BlockJob common; + RateLimit limit; + BlockDriverState *target; + BlockDriverState *base; + /* The name of the graph node to replace */ + char *replaces; + /* The BDS to replace */ + BlockDriverState *to_replace; + /* Used to block operations on the drive-mirror-replace target */ + Error *replace_blocker; + bool is_none_mode; + BlockdevOnError on_source_error, on_target_error; + bool synced; + bool should_complete; + int64_t sector_num; + int64_t granularity; + size_t buf_size; + int64_t bdev_length; + unsigned long *cow_bitmap; + BdrvDirtyBitmap *dirty_bitmap; + HBitmapIter hbi; + uint8_t *buf; + QSIMPLEQ_HEAD(, MirrorBuffer) buf_free; + int buf_free_count; + + unsigned long *in_flight_bitmap; + int in_flight; + int sectors_in_flight; + int ret; + bool unmap; + bool waiting_for_io; +} MirrorBlockJob; + +typedef struct MirrorOp { + MirrorBlockJob *s; + QEMUIOVector qiov; + int64_t sector_num; + int nb_sectors; +} MirrorOp; + +static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read, + int error) +{ + s->synced = false; + if (read) { + return block_job_error_action(&s->common, s->common.bs, + s->on_source_error, true, error); + } else { + return block_job_error_action(&s->common, s->target, + s->on_target_error, false, error); + } +} + +static void mirror_iteration_done(MirrorOp *op, int ret) +{ + MirrorBlockJob *s = op->s; + struct iovec *iov; + int64_t chunk_num; + int i, nb_chunks, sectors_per_chunk; + + trace_mirror_iteration_done(s, op->sector_num, op->nb_sectors, ret); + + s->in_flight--; + s->sectors_in_flight -= op->nb_sectors; + iov = op->qiov.iov; + for (i = 0; i < op->qiov.niov; i++) { + MirrorBuffer *buf = (MirrorBuffer *) iov[i].iov_base; + QSIMPLEQ_INSERT_TAIL(&s->buf_free, buf, next); + s->buf_free_count++; + } + + sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; + chunk_num = op->sector_num / sectors_per_chunk; + nb_chunks = op->nb_sectors / sectors_per_chunk; + bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); + if (ret >= 0) { + if (s->cow_bitmap) { + bitmap_set(s->cow_bitmap, chunk_num, nb_chunks); + } + s->common.offset += (uint64_t)op->nb_sectors * BDRV_SECTOR_SIZE; + } + + qemu_iovec_destroy(&op->qiov); + g_free(op); + + if (s->waiting_for_io) { + qemu_coroutine_enter(s->common.co, NULL); + } +} + +static void mirror_write_complete(void *opaque, int ret) +{ + MirrorOp *op = opaque; + MirrorBlockJob *s = op->s; + if (ret < 0) { + BlockErrorAction action; + + bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); + action = mirror_error_action(s, false, -ret); + if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { + s->ret = ret; + } + } + mirror_iteration_done(op, ret); +} + +static void mirror_read_complete(void *opaque, int ret) +{ + MirrorOp *op = opaque; + MirrorBlockJob *s = op->s; + if (ret < 0) { + BlockErrorAction action; + + bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); + action = mirror_error_action(s, true, -ret); + if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { + s->ret = ret; + } + + mirror_iteration_done(op, ret); + return; + } + bdrv_aio_writev(s->target, op->sector_num, &op->qiov, op->nb_sectors, + mirror_write_complete, op); +} + +static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) +{ + BlockDriverState *source = s->common.bs; + int nb_sectors, sectors_per_chunk, nb_chunks; + int64_t end, sector_num, next_chunk, next_sector, hbitmap_next_sector; + uint64_t delay_ns = 0; + MirrorOp *op; + int pnum; + int64_t ret; + + s->sector_num = hbitmap_iter_next(&s->hbi); + if (s->sector_num < 0) { + bdrv_dirty_iter_init(s->dirty_bitmap, &s->hbi); + s->sector_num = hbitmap_iter_next(&s->hbi); + trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap)); + assert(s->sector_num >= 0); + } + + hbitmap_next_sector = s->sector_num; + sector_num = s->sector_num; + sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; + end = s->bdev_length / BDRV_SECTOR_SIZE; + + /* Extend the QEMUIOVector to include all adjacent blocks that will + * be copied in this operation. + * + * We have to do this if we have no backing file yet in the destination, + * and the cluster size is very large. Then we need to do COW ourselves. + * The first time a cluster is copied, copy it entirely. Note that, + * because both the granularity and the cluster size are powers of two, + * the number of sectors to copy cannot exceed one cluster. + * + * We also want to extend the QEMUIOVector to include more adjacent + * dirty blocks if possible, to limit the number of I/O operations and + * run efficiently even with a small granularity. + */ + nb_chunks = 0; + nb_sectors = 0; + next_sector = sector_num; + next_chunk = sector_num / sectors_per_chunk; + + /* Wait for I/O to this cluster (from a previous iteration) to be done. */ + while (test_bit(next_chunk, s->in_flight_bitmap)) { + trace_mirror_yield_in_flight(s, sector_num, s->in_flight); + s->waiting_for_io = true; + qemu_coroutine_yield(); + s->waiting_for_io = false; + } + + do { + int added_sectors, added_chunks; + + if (!bdrv_get_dirty(source, s->dirty_bitmap, next_sector) || + test_bit(next_chunk, s->in_flight_bitmap)) { + assert(nb_sectors > 0); + break; + } + + added_sectors = sectors_per_chunk; + if (s->cow_bitmap && !test_bit(next_chunk, s->cow_bitmap)) { + bdrv_round_to_clusters(s->target, + next_sector, added_sectors, + &next_sector, &added_sectors); + + /* On the first iteration, the rounding may make us copy + * sectors before the first dirty one. + */ + if (next_sector < sector_num) { + assert(nb_sectors == 0); + sector_num = next_sector; + next_chunk = next_sector / sectors_per_chunk; + } + } + + added_sectors = MIN(added_sectors, end - (sector_num + nb_sectors)); + added_chunks = (added_sectors + sectors_per_chunk - 1) / sectors_per_chunk; + + /* When doing COW, it may happen that there is not enough space for + * a full cluster. Wait if that is the case. + */ + while (nb_chunks == 0 && s->buf_free_count < added_chunks) { + trace_mirror_yield_buf_busy(s, nb_chunks, s->in_flight); + s->waiting_for_io = true; + qemu_coroutine_yield(); + s->waiting_for_io = false; + } + if (s->buf_free_count < nb_chunks + added_chunks) { + trace_mirror_break_buf_busy(s, nb_chunks, s->in_flight); + break; + } + if (IOV_MAX < nb_chunks + added_chunks) { + trace_mirror_break_iov_max(s, nb_chunks, added_chunks); + break; + } + + /* We have enough free space to copy these sectors. */ + bitmap_set(s->in_flight_bitmap, next_chunk, added_chunks); + + nb_sectors += added_sectors; + nb_chunks += added_chunks; + next_sector += added_sectors; + next_chunk += added_chunks; + if (!s->synced && s->common.speed) { + delay_ns = ratelimit_calculate_delay(&s->limit, added_sectors); + } + } while (delay_ns == 0 && next_sector < end); + + /* Allocate a MirrorOp that is used as an AIO callback. */ + op = g_new(MirrorOp, 1); + op->s = s; + op->sector_num = sector_num; + op->nb_sectors = nb_sectors; + + /* Now make a QEMUIOVector taking enough granularity-sized chunks + * from s->buf_free. + */ + qemu_iovec_init(&op->qiov, nb_chunks); + next_sector = sector_num; + while (nb_chunks-- > 0) { + MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free); + size_t remaining = (nb_sectors * BDRV_SECTOR_SIZE) - op->qiov.size; + + QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next); + s->buf_free_count--; + qemu_iovec_add(&op->qiov, buf, MIN(s->granularity, remaining)); + + /* Advance the HBitmapIter in parallel, so that we do not examine + * the same sector twice. + */ + if (next_sector > hbitmap_next_sector + && bdrv_get_dirty(source, s->dirty_bitmap, next_sector)) { + hbitmap_next_sector = hbitmap_iter_next(&s->hbi); + } + + next_sector += sectors_per_chunk; + } + + bdrv_reset_dirty_bitmap(s->dirty_bitmap, sector_num, nb_sectors); + + /* Copy the dirty cluster. */ + s->in_flight++; + s->sectors_in_flight += nb_sectors; + trace_mirror_one_iteration(s, sector_num, nb_sectors); + + ret = bdrv_get_block_status_above(source, NULL, sector_num, + nb_sectors, &pnum); + if (ret < 0 || pnum < nb_sectors || + (ret & BDRV_BLOCK_DATA && !(ret & BDRV_BLOCK_ZERO))) { + bdrv_aio_readv(source, sector_num, &op->qiov, nb_sectors, + mirror_read_complete, op); + } else if (ret & BDRV_BLOCK_ZERO) { + bdrv_aio_write_zeroes(s->target, sector_num, op->nb_sectors, + s->unmap ? BDRV_REQ_MAY_UNMAP : 0, + mirror_write_complete, op); + } else { + assert(!(ret & BDRV_BLOCK_DATA)); + bdrv_aio_discard(s->target, sector_num, op->nb_sectors, + mirror_write_complete, op); + } + return delay_ns; +} + +static void mirror_free_init(MirrorBlockJob *s) +{ + int granularity = s->granularity; + size_t buf_size = s->buf_size; + uint8_t *buf = s->buf; + + assert(s->buf_free_count == 0); + QSIMPLEQ_INIT(&s->buf_free); + while (buf_size != 0) { + MirrorBuffer *cur = (MirrorBuffer *)buf; + QSIMPLEQ_INSERT_TAIL(&s->buf_free, cur, next); + s->buf_free_count++; + buf_size -= granularity; + buf += granularity; + } +} + +static void mirror_drain(MirrorBlockJob *s) +{ + while (s->in_flight > 0) { + s->waiting_for_io = true; + qemu_coroutine_yield(); + s->waiting_for_io = false; + } +} + +typedef struct { + int ret; +} MirrorExitData; + +static void mirror_exit(BlockJob *job, void *opaque) +{ + MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); + MirrorExitData *data = opaque; + AioContext *replace_aio_context = NULL; + BlockDriverState *src = s->common.bs; + + /* Make sure that the source BDS doesn't go away before we called + * block_job_completed(). */ + bdrv_ref(src); + + if (s->to_replace) { + replace_aio_context = bdrv_get_aio_context(s->to_replace); + aio_context_acquire(replace_aio_context); + } + + if (s->should_complete && data->ret == 0) { + BlockDriverState *to_replace = s->common.bs; + if (s->to_replace) { + to_replace = s->to_replace; + } + if (bdrv_get_flags(s->target) != bdrv_get_flags(to_replace)) { + bdrv_reopen(s->target, bdrv_get_flags(to_replace), NULL); + } + bdrv_replace_in_backing_chain(to_replace, s->target); + } + if (s->to_replace) { + bdrv_op_unblock_all(s->to_replace, s->replace_blocker); + error_free(s->replace_blocker); + bdrv_unref(s->to_replace); + } + if (replace_aio_context) { + aio_context_release(replace_aio_context); + } + g_free(s->replaces); + bdrv_op_unblock_all(s->target, s->common.blocker); + bdrv_unref(s->target); + block_job_completed(&s->common, data->ret); + g_free(data); + bdrv_drained_end(src); + bdrv_unref(src); +} + +static void coroutine_fn mirror_run(void *opaque) +{ + MirrorBlockJob *s = opaque; + MirrorExitData *data; + BlockDriverState *bs = s->common.bs; + int64_t sector_num, end, length; + uint64_t last_pause_ns; + BlockDriverInfo bdi; + char backing_filename[2]; /* we only need 2 characters because we are only + checking for a NULL string */ + int ret = 0; + int n; + + if (block_job_is_cancelled(&s->common)) { + goto immediate_exit; + } + + s->bdev_length = bdrv_getlength(bs); + if (s->bdev_length < 0) { + ret = s->bdev_length; + goto immediate_exit; + } else if (s->bdev_length == 0) { + /* Report BLOCK_JOB_READY and wait for complete. */ + block_job_event_ready(&s->common); + s->synced = true; + while (!block_job_is_cancelled(&s->common) && !s->should_complete) { + block_job_yield(&s->common); + } + s->common.cancelled = false; + goto immediate_exit; + } + + length = DIV_ROUND_UP(s->bdev_length, s->granularity); + s->in_flight_bitmap = bitmap_new(length); + + /* If we have no backing file yet in the destination, we cannot let + * the destination do COW. Instead, we copy sectors around the + * dirty data if needed. We need a bitmap to do that. + */ + bdrv_get_backing_filename(s->target, backing_filename, + sizeof(backing_filename)); + if (backing_filename[0] && !s->target->backing) { + ret = bdrv_get_info(s->target, &bdi); + if (ret < 0) { + goto immediate_exit; + } + if (s->granularity < bdi.cluster_size) { + s->buf_size = MAX(s->buf_size, bdi.cluster_size); + s->cow_bitmap = bitmap_new(length); + } + } + + end = s->bdev_length / BDRV_SECTOR_SIZE; + s->buf = qemu_try_blockalign(bs, s->buf_size); + if (s->buf == NULL) { + ret = -ENOMEM; + goto immediate_exit; + } + + mirror_free_init(s); + + last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); + if (!s->is_none_mode) { + /* First part, loop on the sectors and initialize the dirty bitmap. */ + BlockDriverState *base = s->base; + bool mark_all_dirty = s->base == NULL && !bdrv_has_zero_init(s->target); + + for (sector_num = 0; sector_num < end; ) { + /* Just to make sure we are not exceeding int limit. */ + int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS, + end - sector_num); + int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); + + if (now - last_pause_ns > SLICE_TIME) { + last_pause_ns = now; + block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0); + } + + if (block_job_is_cancelled(&s->common)) { + goto immediate_exit; + } + + ret = bdrv_is_allocated_above(bs, base, sector_num, nb_sectors, &n); + + if (ret < 0) { + goto immediate_exit; + } + + assert(n > 0); + if (ret == 1 || mark_all_dirty) { + bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n); + } + sector_num += n; + } + } + + bdrv_dirty_iter_init(s->dirty_bitmap, &s->hbi); + for (;;) { + uint64_t delay_ns = 0; + int64_t cnt; + bool should_complete; + + if (s->ret < 0) { + ret = s->ret; + goto immediate_exit; + } + + cnt = bdrv_get_dirty_count(s->dirty_bitmap); + /* s->common.offset contains the number of bytes already processed so + * far, cnt is the number of dirty sectors remaining and + * s->sectors_in_flight is the number of sectors currently being + * processed; together those are the current total operation length */ + s->common.len = s->common.offset + + (cnt + s->sectors_in_flight) * BDRV_SECTOR_SIZE; + + /* Note that even when no rate limit is applied we need to yield + * periodically with no pending I/O so that bdrv_drain_all() returns. + * We do so every SLICE_TIME nanoseconds, or when there is an error, + * or when the source is clean, whichever comes first. + */ + if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - last_pause_ns < SLICE_TIME && + s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) { + if (s->in_flight == MAX_IN_FLIGHT || s->buf_free_count == 0 || + (cnt == 0 && s->in_flight > 0)) { + trace_mirror_yield(s, s->in_flight, s->buf_free_count, cnt); + s->waiting_for_io = true; + qemu_coroutine_yield(); + s->waiting_for_io = false; + continue; + } else if (cnt != 0) { + delay_ns = mirror_iteration(s); + } + } + + should_complete = false; + if (s->in_flight == 0 && cnt == 0) { + trace_mirror_before_flush(s); + ret = bdrv_flush(s->target); + if (ret < 0) { + if (mirror_error_action(s, false, -ret) == + BLOCK_ERROR_ACTION_REPORT) { + goto immediate_exit; + } + } else { + /* We're out of the streaming phase. From now on, if the job + * is cancelled we will actually complete all pending I/O and + * report completion. This way, block-job-cancel will leave + * the target in a consistent state. + */ + if (!s->synced) { + block_job_event_ready(&s->common); + s->synced = true; + } + + should_complete = s->should_complete || + block_job_is_cancelled(&s->common); + cnt = bdrv_get_dirty_count(s->dirty_bitmap); + } + } + + if (cnt == 0 && should_complete) { + /* The dirty bitmap is not updated while operations are pending. + * If we're about to exit, wait for pending operations before + * calling bdrv_get_dirty_count(bs), or we may exit while the + * source has dirty data to copy! + * + * Note that I/O can be submitted by the guest while + * mirror_populate runs. + */ + trace_mirror_before_drain(s, cnt); + bdrv_drain(bs); + cnt = bdrv_get_dirty_count(s->dirty_bitmap); + } + + ret = 0; + trace_mirror_before_sleep(s, cnt, s->synced, delay_ns); + if (!s->synced) { + block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); + if (block_job_is_cancelled(&s->common)) { + break; + } + } else if (!should_complete) { + delay_ns = (s->in_flight == 0 && cnt == 0 ? SLICE_TIME : 0); + block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); + } else if (cnt == 0) { + /* The two disks are in sync. Exit and report successful + * completion. + */ + assert(QLIST_EMPTY(&bs->tracked_requests)); + s->common.cancelled = false; + break; + } + last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); + } + +immediate_exit: + if (s->in_flight > 0) { + /* We get here only if something went wrong. Either the job failed, + * or it was cancelled prematurely so that we do not guarantee that + * the target is a copy of the source. + */ + assert(ret < 0 || (!s->synced && block_job_is_cancelled(&s->common))); + mirror_drain(s); + } + + assert(s->in_flight == 0); + qemu_vfree(s->buf); + g_free(s->cow_bitmap); + g_free(s->in_flight_bitmap); + bdrv_release_dirty_bitmap(bs, s->dirty_bitmap); + if (s->target->blk) { + blk_iostatus_disable(s->target->blk); + } + + data = g_malloc(sizeof(*data)); + data->ret = ret; + /* Before we switch to target in mirror_exit, make sure data doesn't + * change. */ + bdrv_drained_begin(s->common.bs); + block_job_defer_to_main_loop(&s->common, mirror_exit, data); +} + +static void mirror_set_speed(BlockJob *job, int64_t speed, Error **errp) +{ + MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); + + if (speed < 0) { + error_setg(errp, QERR_INVALID_PARAMETER, "speed"); + return; + } + ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME); +} + +static void mirror_iostatus_reset(BlockJob *job) +{ + MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); + + if (s->target->blk) { + blk_iostatus_reset(s->target->blk); + } +} + +static void mirror_complete(BlockJob *job, Error **errp) +{ + MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); + Error *local_err = NULL; + int ret; + + ret = bdrv_open_backing_file(s->target, NULL, &local_err); + if (ret < 0) { + error_propagate(errp, local_err); + return; + } + if (!s->synced) { + error_setg(errp, QERR_BLOCK_JOB_NOT_READY, job->id); + return; + } + + /* check the target bs is not blocked and block all operations on it */ + if (s->replaces) { + AioContext *replace_aio_context; + + s->to_replace = bdrv_find_node(s->replaces); + if (!s->to_replace) { + error_setg(errp, "Node name '%s' not found", s->replaces); + return; + } + + replace_aio_context = bdrv_get_aio_context(s->to_replace); + aio_context_acquire(replace_aio_context); + + error_setg(&s->replace_blocker, + "block device is in use by block-job-complete"); + bdrv_op_block_all(s->to_replace, s->replace_blocker); + bdrv_ref(s->to_replace); + + aio_context_release(replace_aio_context); + } + + s->should_complete = true; + block_job_enter(&s->common); +} + +static const BlockJobDriver mirror_job_driver = { + .instance_size = sizeof(MirrorBlockJob), + .job_type = BLOCK_JOB_TYPE_MIRROR, + .set_speed = mirror_set_speed, + .iostatus_reset= mirror_iostatus_reset, + .complete = mirror_complete, +}; + +static const BlockJobDriver commit_active_job_driver = { + .instance_size = sizeof(MirrorBlockJob), + .job_type = BLOCK_JOB_TYPE_COMMIT, + .set_speed = mirror_set_speed, + .iostatus_reset + = mirror_iostatus_reset, + .complete = mirror_complete, +}; + +static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, + const char *replaces, + int64_t speed, uint32_t granularity, + int64_t buf_size, + BlockdevOnError on_source_error, + BlockdevOnError on_target_error, + bool unmap, + BlockCompletionFunc *cb, + void *opaque, Error **errp, + const BlockJobDriver *driver, + bool is_none_mode, BlockDriverState *base) +{ + MirrorBlockJob *s; + + if (granularity == 0) { + granularity = bdrv_get_default_bitmap_granularity(target); + } + + assert ((granularity & (granularity - 1)) == 0); + + if ((on_source_error == BLOCKDEV_ON_ERROR_STOP || + on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) && + (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) { + error_setg(errp, QERR_INVALID_PARAMETER, "on-source-error"); + return; + } + + if (buf_size < 0) { + error_setg(errp, "Invalid parameter 'buf-size'"); + return; + } + + if (buf_size == 0) { + buf_size = DEFAULT_MIRROR_BUF_SIZE; + } + + s = block_job_create(driver, bs, speed, cb, opaque, errp); + if (!s) { + return; + } + + s->replaces = g_strdup(replaces); + s->on_source_error = on_source_error; + s->on_target_error = on_target_error; + s->target = target; + s->is_none_mode = is_none_mode; + s->base = base; + s->granularity = granularity; + s->buf_size = ROUND_UP(buf_size, granularity); + s->unmap = unmap; + + s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); + if (!s->dirty_bitmap) { + g_free(s->replaces); + block_job_unref(&s->common); + return; + } + + bdrv_op_block_all(s->target, s->common.blocker); + + bdrv_set_enable_write_cache(s->target, true); + if (s->target->blk) { + blk_set_on_error(s->target->blk, on_target_error, on_target_error); + blk_iostatus_enable(s->target->blk); + } + s->common.co = qemu_coroutine_create(mirror_run); + trace_mirror_start(bs, s, s->common.co, opaque); + qemu_coroutine_enter(s->common.co, s); +} + +void mirror_start(BlockDriverState *bs, BlockDriverState *target, + const char *replaces, + int64_t speed, uint32_t granularity, int64_t buf_size, + MirrorSyncMode mode, BlockdevOnError on_source_error, + BlockdevOnError on_target_error, + bool unmap, + BlockCompletionFunc *cb, + void *opaque, Error **errp) +{ + bool is_none_mode; + BlockDriverState *base; + + if (mode == MIRROR_SYNC_MODE_INCREMENTAL) { + error_setg(errp, "Sync mode 'incremental' not supported"); + return; + } + is_none_mode = mode == MIRROR_SYNC_MODE_NONE; + base = mode == MIRROR_SYNC_MODE_TOP ? backing_bs(bs) : NULL; + mirror_start_job(bs, target, replaces, + speed, granularity, buf_size, + on_source_error, on_target_error, unmap, cb, opaque, errp, + &mirror_job_driver, is_none_mode, base); +} + +void commit_active_start(BlockDriverState *bs, BlockDriverState *base, + int64_t speed, + BlockdevOnError on_error, + BlockCompletionFunc *cb, + void *opaque, Error **errp) +{ + int64_t length, base_length; + int orig_base_flags; + int ret; + Error *local_err = NULL; + + orig_base_flags = bdrv_get_flags(base); + + if (bdrv_reopen(base, bs->open_flags, errp)) { + return; + } + + length = bdrv_getlength(bs); + if (length < 0) { + error_setg_errno(errp, -length, + "Unable to determine length of %s", bs->filename); + goto error_restore_flags; + } + + base_length = bdrv_getlength(base); + if (base_length < 0) { + error_setg_errno(errp, -base_length, + "Unable to determine length of %s", base->filename); + goto error_restore_flags; + } + + if (length > base_length) { + ret = bdrv_truncate(base, length); + if (ret < 0) { + error_setg_errno(errp, -ret, + "Top image %s is larger than base image %s, and " + "resize of base image failed", + bs->filename, base->filename); + goto error_restore_flags; + } + } + + bdrv_ref(base); + mirror_start_job(bs, base, NULL, speed, 0, 0, + on_error, on_error, false, cb, opaque, &local_err, + &commit_active_job_driver, false, base); + if (local_err) { + error_propagate(errp, local_err); + goto error_restore_flags; + } + + return; + +error_restore_flags: + /* ignore error and errp for bdrv_reopen, because we want to propagate + * the original error */ + bdrv_reopen(base, orig_base_flags, NULL); + return; +} |
