diff options
| -rw-r--r-- | block/mirror.c | 252 | ||||
| -rw-r--r-- | qapi/block-core.json | 18 |
2 files changed, 265 insertions, 5 deletions
diff --git a/block/mirror.c b/block/mirror.c index 7da5e43c0d..99b9b92c30 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -51,8 +51,12 @@ typedef struct MirrorBlockJob { Error *replace_blocker; bool is_none_mode; BlockMirrorBackingMode backing_mode; + MirrorCopyMode copy_mode; BlockdevOnError on_source_error, on_target_error; bool synced; + /* Set when the target is synced (dirty bitmap is clean, nothing + * in flight) and the job is running in active mode */ + bool actively_synced; bool should_complete; int64_t granularity; size_t buf_size; @@ -74,6 +78,7 @@ typedef struct MirrorBlockJob { int target_cluster_size; int max_iov; bool initial_zeroing_ongoing; + int in_active_write_counter; } MirrorBlockJob; typedef struct MirrorBDSOpaque { @@ -91,6 +96,7 @@ struct MirrorOp { int64_t *bytes_handled; bool is_pseudo_op; + bool is_active_write; CoQueue waiting_requests; QTAILQ_ENTRY(MirrorOp) next; @@ -106,6 +112,7 @@ static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read, int error) { s->synced = false; + s->actively_synced = false; if (read) { return block_job_error_action(&s->common, s->on_source_error, true, error); @@ -272,7 +279,7 @@ static int mirror_cow_align(MirrorBlockJob *s, int64_t *offset, return ret; } -static inline void mirror_wait_for_free_in_flight_slot(MirrorBlockJob *s) +static inline void mirror_wait_for_any_operation(MirrorBlockJob *s, bool active) { MirrorOp *op; @@ -282,7 +289,7 @@ static inline void mirror_wait_for_free_in_flight_slot(MirrorBlockJob *s) * caller of this function. Since there is only one pseudo op * at any given time, we will always find some real operation * to wait on. */ - if (!op->is_pseudo_op) { + if (!op->is_pseudo_op && op->is_active_write == active) { qemu_co_queue_wait(&op->waiting_requests, NULL); return; } @@ -290,6 +297,12 @@ static inline void mirror_wait_for_free_in_flight_slot(MirrorBlockJob *s) abort(); } +static inline void mirror_wait_for_free_in_flight_slot(MirrorBlockJob *s) +{ + /* Only non-active operations use up in-flight slots */ + mirror_wait_for_any_operation(s, false); +} + /* Perform a mirror copy operation. * * *op->bytes_handled is set to the number of bytes copied after and @@ -846,6 +859,7 @@ static void coroutine_fn mirror_run(void *opaque) /* Transition to the READY state and wait for complete. */ job_transition_to_ready(&s->common.job); s->synced = true; + s->actively_synced = true; while (!job_is_cancelled(&s->common.job) && !s->should_complete) { job_yield(&s->common.job); } @@ -897,6 +911,12 @@ static void coroutine_fn mirror_run(void *opaque) int64_t cnt, delta; bool should_complete; + /* Do not start passive operations while there are active + * writes in progress */ + while (s->in_active_write_counter) { + mirror_wait_for_any_operation(s, true); + } + if (s->ret < 0) { ret = s->ret; goto immediate_exit; @@ -942,6 +962,9 @@ static void coroutine_fn mirror_run(void *opaque) */ job_transition_to_ready(&s->common.job); s->synced = true; + if (s->copy_mode != MIRROR_COPY_MODE_BACKGROUND) { + s->actively_synced = true; + } } should_complete = s->should_complete || @@ -1140,16 +1163,232 @@ static const BlockJobDriver commit_active_job_driver = { .drain = mirror_drain, }; +static void do_sync_target_write(MirrorBlockJob *job, MirrorMethod method, + uint64_t offset, uint64_t bytes, + QEMUIOVector *qiov, int flags) +{ + BdrvDirtyBitmapIter *iter; + QEMUIOVector target_qiov; + uint64_t dirty_offset; + int dirty_bytes; + + if (qiov) { + qemu_iovec_init(&target_qiov, qiov->niov); + } + + iter = bdrv_dirty_iter_new(job->dirty_bitmap); + bdrv_set_dirty_iter(iter, offset); + + while (true) { + bool valid_area; + int ret; + + bdrv_dirty_bitmap_lock(job->dirty_bitmap); + valid_area = bdrv_dirty_iter_next_area(iter, offset + bytes, + &dirty_offset, &dirty_bytes); + if (!valid_area) { + bdrv_dirty_bitmap_unlock(job->dirty_bitmap); + break; + } + + bdrv_reset_dirty_bitmap_locked(job->dirty_bitmap, + dirty_offset, dirty_bytes); + bdrv_dirty_bitmap_unlock(job->dirty_bitmap); + + job_progress_increase_remaining(&job->common.job, dirty_bytes); + + assert(dirty_offset - offset <= SIZE_MAX); + if (qiov) { + qemu_iovec_reset(&target_qiov); + qemu_iovec_concat(&target_qiov, qiov, + dirty_offset - offset, dirty_bytes); + } + + switch (method) { + case MIRROR_METHOD_COPY: + ret = blk_co_pwritev(job->target, dirty_offset, dirty_bytes, + qiov ? &target_qiov : NULL, flags); + break; + + case MIRROR_METHOD_ZERO: + assert(!qiov); + ret = blk_co_pwrite_zeroes(job->target, dirty_offset, dirty_bytes, + flags); + break; + + case MIRROR_METHOD_DISCARD: + assert(!qiov); + ret = blk_co_pdiscard(job->target, dirty_offset, dirty_bytes); + break; + + default: + abort(); + } + + if (ret >= 0) { + job_progress_update(&job->common.job, dirty_bytes); + } else { + BlockErrorAction action; + + bdrv_set_dirty_bitmap(job->dirty_bitmap, dirty_offset, dirty_bytes); + job->actively_synced = false; + + action = mirror_error_action(job, false, -ret); + if (action == BLOCK_ERROR_ACTION_REPORT) { + if (!job->ret) { + job->ret = ret; + } + break; + } + } + } + + bdrv_dirty_iter_free(iter); + if (qiov) { + qemu_iovec_destroy(&target_qiov); + } +} + +static MirrorOp *coroutine_fn active_write_prepare(MirrorBlockJob *s, + uint64_t offset, + uint64_t bytes) +{ + MirrorOp *op; + uint64_t start_chunk = offset / s->granularity; + uint64_t end_chunk = DIV_ROUND_UP(offset + bytes, s->granularity); + + op = g_new(MirrorOp, 1); + *op = (MirrorOp){ + .s = s, + .offset = offset, + .bytes = bytes, + .is_active_write = true, + }; + qemu_co_queue_init(&op->waiting_requests); + QTAILQ_INSERT_TAIL(&s->ops_in_flight, op, next); + + s->in_active_write_counter++; + + mirror_wait_on_conflicts(op, s, offset, bytes); + + bitmap_set(s->in_flight_bitmap, start_chunk, end_chunk - start_chunk); + + return op; +} + +static void coroutine_fn active_write_settle(MirrorOp *op) +{ + uint64_t start_chunk = op->offset / op->s->granularity; + uint64_t end_chunk = DIV_ROUND_UP(op->offset + op->bytes, + op->s->granularity); + + if (!--op->s->in_active_write_counter && op->s->actively_synced) { + BdrvChild *source = op->s->mirror_top_bs->backing; + + if (QLIST_FIRST(&source->bs->parents) == source && + QLIST_NEXT(source, next_parent) == NULL) + { + /* Assert that we are back in sync once all active write + * operations are settled. + * Note that we can only assert this if the mirror node + * is the source node's only parent. */ + assert(!bdrv_get_dirty_count(op->s->dirty_bitmap)); + } + } + bitmap_clear(op->s->in_flight_bitmap, start_chunk, end_chunk - start_chunk); + QTAILQ_REMOVE(&op->s->ops_in_flight, op, next); + qemu_co_queue_restart_all(&op->waiting_requests); + g_free(op); +} + static int coroutine_fn bdrv_mirror_top_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags); } +static int coroutine_fn bdrv_mirror_top_do_write(BlockDriverState *bs, + MirrorMethod method, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, + int flags) +{ + MirrorOp *op = NULL; + MirrorBDSOpaque *s = bs->opaque; + int ret = 0; + bool copy_to_target; + + copy_to_target = s->job->ret >= 0 && + s->job->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING; + + if (copy_to_target) { + op = active_write_prepare(s->job, offset, bytes); + } + + switch (method) { + case MIRROR_METHOD_COPY: + ret = bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags); + break; + + case MIRROR_METHOD_ZERO: + ret = bdrv_co_pwrite_zeroes(bs->backing, offset, bytes, flags); + break; + + case MIRROR_METHOD_DISCARD: + ret = bdrv_co_pdiscard(bs->backing->bs, offset, bytes); + break; + + default: + abort(); + } + + if (ret < 0) { + goto out; + } + + if (copy_to_target) { + do_sync_target_write(s->job, method, offset, bytes, qiov, flags); + } + +out: + if (copy_to_target) { + active_write_settle(op); + } + return ret; +} + static int coroutine_fn bdrv_mirror_top_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { - return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags); + MirrorBDSOpaque *s = bs->opaque; + QEMUIOVector bounce_qiov; + void *bounce_buf; + int ret = 0; + bool copy_to_target; + + copy_to_target = s->job->ret >= 0 && + s->job->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING; + + if (copy_to_target) { + /* The guest might concurrently modify the data to write; but + * the data on source and destination must match, so we have + * to use a bounce buffer if we are going to write to the + * target now. */ + bounce_buf = qemu_blockalign(bs, bytes); + iov_to_buf_full(qiov->iov, qiov->niov, 0, bounce_buf, bytes); + + qemu_iovec_init(&bounce_qiov, 1); + qemu_iovec_add(&bounce_qiov, bounce_buf, bytes); + qiov = &bounce_qiov; + } + + ret = bdrv_mirror_top_do_write(bs, MIRROR_METHOD_COPY, offset, bytes, qiov, + flags); + + if (copy_to_target) { + qemu_iovec_destroy(&bounce_qiov); + qemu_vfree(bounce_buf); + } + + return ret; } static int coroutine_fn bdrv_mirror_top_flush(BlockDriverState *bs) @@ -1164,13 +1403,15 @@ static int coroutine_fn bdrv_mirror_top_flush(BlockDriverState *bs) static int coroutine_fn bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes, BdrvRequestFlags flags) { - return bdrv_co_pwrite_zeroes(bs->backing, offset, bytes, flags); + return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_ZERO, offset, bytes, NULL, + flags); } static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs, int64_t offset, int bytes) { - return bdrv_co_pdiscard(bs->backing->bs, offset, bytes); + return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_DISCARD, offset, bytes, + NULL, 0); } static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs, QDict *opts) @@ -1340,6 +1581,7 @@ static void mirror_start_job(const char *job_id, BlockDriverState *bs, s->on_target_error = on_target_error; s->is_none_mode = is_none_mode; s->backing_mode = backing_mode; + s->copy_mode = MIRROR_COPY_MODE_BACKGROUND; s->base = base; s->granularity = granularity; s->buf_size = ROUND_UP(buf_size, granularity); diff --git a/qapi/block-core.json b/qapi/block-core.json index ab629d1647..96f8da1322 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1051,6 +1051,24 @@ 'data': ['top', 'full', 'none', 'incremental'] } ## +# @MirrorCopyMode: +# +# An enumeration whose values tell the mirror block job when to +# trigger writes to the target. +# +# @background: copy data in background only. +# +# @write-blocking: when data is written to the source, write it +# (synchronously) to the target as well. In +# addition, data is copied in background just like in +# @background mode. +# +# Since: 3.0 +## +{ 'enum': 'MirrorCopyMode', + 'data': ['background', 'write-blocking'] } + +## # @BlockJobInfo: # # Information about a long-running block device operation. |