diff options
Diffstat (limited to 'qemu/block/mirror.c')
| -rw-r--r-- | qemu/block/mirror.c | 465 |
1 files changed, 309 insertions, 156 deletions
diff --git a/qemu/block/mirror.c b/qemu/block/mirror.c index fc4d8f561..039f48125 100644 --- a/qemu/block/mirror.c +++ b/qemu/block/mirror.c @@ -11,12 +11,16 @@ * */ +#include "qemu/osdep.h" #include "trace.h" #include "block/blockjob.h" #include "block/block_int.h" +#include "sysemu/block-backend.h" +#include "qapi/error.h" #include "qapi/qmp/qerror.h" #include "qemu/ratelimit.h" #include "qemu/bitmap.h" +#include "qemu/error-report.h" #define SLICE_TIME 100000000ULL /* ns */ #define MAX_IN_FLIGHT 16 @@ -44,7 +48,6 @@ typedef struct MirrorBlockJob { 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; @@ -60,6 +63,9 @@ typedef struct MirrorBlockJob { int sectors_in_flight; int ret; bool unmap; + bool waiting_for_io; + int target_cluster_sectors; + int max_iov; } MirrorBlockJob; typedef struct MirrorOp { @@ -102,7 +108,7 @@ static void mirror_iteration_done(MirrorOp *op, int ret) sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; chunk_num = op->sector_num / sectors_per_chunk; - nb_chunks = op->nb_sectors / sectors_per_chunk; + nb_chunks = DIV_ROUND_UP(op->nb_sectors, sectors_per_chunk); bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); if (ret >= 0) { if (s->cow_bitmap) { @@ -112,13 +118,9 @@ static void mirror_iteration_done(MirrorOp *op, int ret) } qemu_iovec_destroy(&op->qiov); - g_slice_free(MirrorOp, op); + g_free(op); - /* Enter coroutine when it is not sleeping. The coroutine sleeps to - * rate-limit itself. The coroutine will eventually resume since there is - * a sleep timeout so don't wake it early. - */ - if (s->common.busy) { + if (s->waiting_for_io) { qemu_coroutine_enter(s->common.co, NULL); } } @@ -159,107 +161,97 @@ static void mirror_read_complete(void *opaque, int ret) mirror_write_complete, op); } -static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) +static inline void mirror_clip_sectors(MirrorBlockJob *s, + int64_t sector_num, + int *nb_sectors) { - 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; + *nb_sectors = MIN(*nb_sectors, + s->bdev_length / BDRV_SECTOR_SIZE - sector_num); +} - /* 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); - qemu_coroutine_yield(); +/* Round sector_num and/or nb_sectors to target cluster if COW is needed, and + * return the offset of the adjusted tail sector against original. */ +static int mirror_cow_align(MirrorBlockJob *s, + int64_t *sector_num, + int *nb_sectors) +{ + bool need_cow; + int ret = 0; + int chunk_sectors = s->granularity >> BDRV_SECTOR_BITS; + int64_t align_sector_num = *sector_num; + int align_nb_sectors = *nb_sectors; + int max_sectors = chunk_sectors * s->max_iov; + + need_cow = !test_bit(*sector_num / chunk_sectors, s->cow_bitmap); + need_cow |= !test_bit((*sector_num + *nb_sectors - 1) / chunk_sectors, + s->cow_bitmap); + if (need_cow) { + bdrv_round_to_clusters(s->target, *sector_num, *nb_sectors, + &align_sector_num, &align_nb_sectors); + } + + if (align_nb_sectors > max_sectors) { + align_nb_sectors = max_sectors; + if (need_cow) { + align_nb_sectors = QEMU_ALIGN_DOWN(align_nb_sectors, + s->target_cluster_sectors); + } } + /* Clipping may result in align_nb_sectors unaligned to chunk boundary, but + * that doesn't matter because it's already the end of source image. */ + mirror_clip_sectors(s, align_sector_num, &align_nb_sectors); - 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; - } + ret = align_sector_num + align_nb_sectors - (*sector_num + *nb_sectors); + *sector_num = align_sector_num; + *nb_sectors = align_nb_sectors; + assert(ret >= 0); + return ret; +} - 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); +static inline void mirror_wait_for_io(MirrorBlockJob *s) +{ + assert(!s->waiting_for_io); + s->waiting_for_io = true; + qemu_coroutine_yield(); + s->waiting_for_io = false; +} - /* 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; - } - } +/* Submit async read while handling COW. + * Returns: nb_sectors if no alignment is necessary, or + * (new_end - sector_num) if tail is rounded up or down due to + * alignment or buffer limit. + */ +static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num, + int nb_sectors) +{ + BlockDriverState *source = s->common.bs; + int sectors_per_chunk, nb_chunks; + int ret = nb_sectors; + MirrorOp *op; - added_sectors = MIN(added_sectors, end - (sector_num + nb_sectors)); - added_chunks = (added_sectors + sectors_per_chunk - 1) / sectors_per_chunk; + sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; - /* 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); - qemu_coroutine_yield(); - } - if (s->buf_free_count < nb_chunks + added_chunks) { - trace_mirror_break_buf_busy(s, nb_chunks, s->in_flight); - break; - } + /* We can only handle as much as buf_size at a time. */ + nb_sectors = MIN(s->buf_size >> BDRV_SECTOR_BITS, nb_sectors); + assert(nb_sectors); - /* We have enough free space to copy these sectors. */ - bitmap_set(s->in_flight_bitmap, next_chunk, added_chunks); + if (s->cow_bitmap) { + ret += mirror_cow_align(s, §or_num, &nb_sectors); + } + assert(nb_sectors << BDRV_SECTOR_BITS <= s->buf_size); + /* The sector range must meet granularity because: + * 1) Caller passes in aligned values; + * 2) mirror_cow_align is used only when target cluster is larger. */ + assert(!(sector_num % sectors_per_chunk)); + nb_chunks = DIV_ROUND_UP(nb_sectors, sectors_per_chunk); - 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); + while (s->buf_free_count < nb_chunks) { + trace_mirror_yield_in_flight(s, sector_num, s->in_flight); + mirror_wait_for_io(s); + } /* Allocate a MirrorOp that is used as an AIO callback. */ - op = g_slice_new(MirrorOp); + op = g_new(MirrorOp, 1); op->s = s; op->sector_num = sector_num; op->nb_sectors = nb_sectors; @@ -268,47 +260,158 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) * 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; + 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_readv(source, sector_num, &op->qiov, nb_sectors, + mirror_read_complete, op); + return ret; +} + +static void mirror_do_zero_or_discard(MirrorBlockJob *s, + int64_t sector_num, + int nb_sectors, + bool is_discard) +{ + MirrorOp *op; + + /* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed + * so the freeing in mirror_iteration_done is nop. */ + op = g_new0(MirrorOp, 1); + op->s = s; + op->sector_num = sector_num; + op->nb_sectors = nb_sectors; + + s->in_flight++; + s->sectors_in_flight += nb_sectors; + if (is_discard) { + bdrv_aio_discard(s->target, sector_num, op->nb_sectors, + mirror_write_complete, op); + } else { 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); + } +} + +static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) +{ + BlockDriverState *source = s->common.bs; + int64_t sector_num, first_chunk; + uint64_t delay_ns = 0; + /* At least the first dirty chunk is mirrored in one iteration. */ + int nb_chunks = 1; + int64_t end = s->bdev_length / BDRV_SECTOR_SIZE; + int sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; + + sector_num = hbitmap_iter_next(&s->hbi); + if (sector_num < 0) { + bdrv_dirty_iter_init(s->dirty_bitmap, &s->hbi); + sector_num = hbitmap_iter_next(&s->hbi); + trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap)); + assert(sector_num >= 0); + } + + first_chunk = sector_num / sectors_per_chunk; + while (test_bit(first_chunk, s->in_flight_bitmap)) { + trace_mirror_yield_in_flight(s, first_chunk, s->in_flight); + mirror_wait_for_io(s); + } + + /* Find the number of consective dirty chunks following the first dirty + * one, and wait for in flight requests in them. */ + while (nb_chunks * sectors_per_chunk < (s->buf_size >> BDRV_SECTOR_BITS)) { + int64_t hbitmap_next; + int64_t next_sector = sector_num + nb_chunks * sectors_per_chunk; + int64_t next_chunk = next_sector / sectors_per_chunk; + if (next_sector >= end || + !bdrv_get_dirty(source, s->dirty_bitmap, next_sector)) { + break; + } + if (test_bit(next_chunk, s->in_flight_bitmap)) { + break; + } + + hbitmap_next = hbitmap_iter_next(&s->hbi); + if (hbitmap_next > next_sector || hbitmap_next < 0) { + /* The bitmap iterator's cache is stale, refresh it */ + bdrv_set_dirty_iter(&s->hbi, next_sector); + hbitmap_next = hbitmap_iter_next(&s->hbi); + } + assert(hbitmap_next == next_sector); + nb_chunks++; + } + + /* Clear dirty bits before querying the block status, because + * calling bdrv_get_block_status_above could yield - if some blocks are + * marked dirty in this window, we need to know. + */ + bdrv_reset_dirty_bitmap(s->dirty_bitmap, sector_num, + nb_chunks * sectors_per_chunk); + bitmap_set(s->in_flight_bitmap, sector_num / sectors_per_chunk, nb_chunks); + while (nb_chunks > 0 && sector_num < end) { + int ret; + int io_sectors; + BlockDriverState *file; + enum MirrorMethod { + MIRROR_METHOD_COPY, + MIRROR_METHOD_ZERO, + MIRROR_METHOD_DISCARD + } mirror_method = MIRROR_METHOD_COPY; + + assert(!(sector_num % sectors_per_chunk)); + ret = bdrv_get_block_status_above(source, NULL, sector_num, + nb_chunks * sectors_per_chunk, + &io_sectors, &file); + if (ret < 0) { + io_sectors = nb_chunks * sectors_per_chunk; + } + + io_sectors -= io_sectors % sectors_per_chunk; + if (io_sectors < sectors_per_chunk) { + io_sectors = sectors_per_chunk; + } else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) { + int64_t target_sector_num; + int target_nb_sectors; + bdrv_round_to_clusters(s->target, sector_num, io_sectors, + &target_sector_num, &target_nb_sectors); + if (target_sector_num == sector_num && + target_nb_sectors == io_sectors) { + mirror_method = ret & BDRV_BLOCK_ZERO ? + MIRROR_METHOD_ZERO : + MIRROR_METHOD_DISCARD; + } + } + + mirror_clip_sectors(s, sector_num, &io_sectors); + switch (mirror_method) { + case MIRROR_METHOD_COPY: + io_sectors = mirror_do_read(s, sector_num, io_sectors); + break; + case MIRROR_METHOD_ZERO: + mirror_do_zero_or_discard(s, sector_num, io_sectors, false); + break; + case MIRROR_METHOD_DISCARD: + mirror_do_zero_or_discard(s, sector_num, io_sectors, true); + break; + default: + abort(); + } + assert(io_sectors); + sector_num += io_sectors; + nb_chunks -= DIV_ROUND_UP(io_sectors, sectors_per_chunk); + delay_ns += ratelimit_calculate_delay(&s->limit, io_sectors); } return delay_ns; } @@ -333,7 +436,7 @@ static void mirror_free_init(MirrorBlockJob *s) static void mirror_drain(MirrorBlockJob *s) { while (s->in_flight > 0) { - qemu_coroutine_yield(); + mirror_wait_for_io(s); } } @@ -346,6 +449,11 @@ 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); @@ -357,18 +465,22 @@ static void mirror_exit(BlockJob *job, void *opaque) if (s->to_replace) { to_replace = s->to_replace; } + + /* This was checked in mirror_start_job(), but meanwhile one of the + * nodes could have been newly attached to a BlockBackend. */ + if (to_replace->blk && s->target->blk) { + error_report("block job: Can't create node with two BlockBackends"); + data->ret = -EINVAL; + goto out; + } + if (bdrv_get_flags(s->target) != bdrv_get_flags(to_replace)) { bdrv_reopen(s->target, bdrv_get_flags(to_replace), NULL); } - bdrv_swap(s->target, to_replace); - if (s->common.driver->job_type == BLOCK_JOB_TYPE_COMMIT) { - /* drop the bs loop chain formed by the swap: break the loop then - * trigger the unref from the top one */ - BlockDriverState *p = s->base->backing_hd; - bdrv_set_backing_hd(s->base, NULL); - bdrv_unref(p); - } + bdrv_replace_in_backing_chain(to_replace, s->target); } + +out: if (s->to_replace) { bdrv_op_unblock_all(s->to_replace, s->replace_blocker); error_free(s->replace_blocker); @@ -378,9 +490,15 @@ static void mirror_exit(BlockJob *job, void *opaque) 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); + if (qemu_get_aio_context() == bdrv_get_aio_context(src)) { + aio_enable_external(iohandler_get_aio_context()); + } + bdrv_unref(src); } static void coroutine_fn mirror_run(void *opaque) @@ -395,6 +513,7 @@ static void coroutine_fn mirror_run(void *opaque) checking for a NULL string */ int ret = 0; int n; + int target_cluster_size = BDRV_SECTOR_SIZE; if (block_job_is_cancelled(&s->common)) { goto immediate_exit; @@ -424,16 +543,16 @@ static void coroutine_fn mirror_run(void *opaque) */ bdrv_get_backing_filename(s->target, backing_filename, sizeof(backing_filename)); - if (backing_filename[0] && !s->target->backing_hd) { - 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); - } + if (!bdrv_get_info(s->target, &bdi) && bdi.cluster_size) { + target_cluster_size = bdi.cluster_size; } + if (backing_filename[0] && !s->target->backing + && s->granularity < target_cluster_size) { + s->buf_size = MAX(s->buf_size, target_cluster_size); + s->cow_bitmap = bitmap_new(length); + } + s->target_cluster_sectors = target_cluster_size >> BDRV_SECTOR_BITS; + s->max_iov = MIN(s->common.bs->bl.max_iov, s->target->bl.max_iov); end = s->bdev_length / BDRV_SECTOR_SIZE; s->buf = qemu_try_blockalign(bs, s->buf_size); @@ -448,6 +567,8 @@ static void coroutine_fn mirror_run(void *opaque) 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, @@ -470,7 +591,7 @@ static void coroutine_fn mirror_run(void *opaque) } assert(n > 0); - if (ret == 1) { + if (ret == 1 || mark_all_dirty) { bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n); } sector_num += n; @@ -506,7 +627,7 @@ static void coroutine_fn mirror_run(void *opaque) 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); - qemu_coroutine_yield(); + mirror_wait_for_io(s); continue; } else if (cnt != 0) { delay_ns = mirror_iteration(s); @@ -549,7 +670,7 @@ static void coroutine_fn mirror_run(void *opaque) * mirror_populate runs. */ trace_mirror_before_drain(s, cnt); - bdrv_drain(bs); + bdrv_co_drain(bs); cnt = bdrv_get_dirty_count(s->dirty_bitmap); } @@ -589,10 +710,21 @@ immediate_exit: g_free(s->cow_bitmap); g_free(s->in_flight_bitmap); bdrv_release_dirty_bitmap(bs, s->dirty_bitmap); - bdrv_iostatus_disable(s->target); + 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); + if (qemu_get_aio_context() == bdrv_get_aio_context(bs)) { + /* FIXME: virtio host notifiers run on iohandler_ctx, therefore the + * above bdrv_drained_end isn't enough to quiesce it. This is ugly, we + * need a block layer API change to achieve this. */ + aio_disable_external(iohandler_get_aio_context()); + } block_job_defer_to_main_loop(&s->common, mirror_exit, data); } @@ -611,7 +743,9 @@ static void mirror_iostatus_reset(BlockJob *job) { MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); - bdrv_iostatus_reset(s->target); + if (s->target->blk) { + blk_iostatus_reset(s->target->blk); + } } static void mirror_complete(BlockJob *job, Error **errp) @@ -620,14 +754,13 @@ static void mirror_complete(BlockJob *job, Error **errp) Error *local_err = NULL; int ret; - ret = bdrv_open_backing_file(s->target, NULL, &local_err); + ret = bdrv_open_backing_file(s->target, NULL, "backing", &local_err); if (ret < 0) { error_propagate(errp, local_err); return; } if (!s->synced) { - error_setg(errp, QERR_BLOCK_JOB_NOT_READY, - bdrv_get_device_name(job->bs)); + error_setg(errp, QERR_BLOCK_JOB_NOT_READY, job->id); return; } @@ -635,9 +768,9 @@ static void mirror_complete(BlockJob *job, Error **errp) if (s->replaces) { AioContext *replace_aio_context; - s->to_replace = check_to_replace_node(s->replaces, &local_err); + s->to_replace = bdrv_find_node(s->replaces); if (!s->to_replace) { - error_propagate(errp, local_err); + error_setg(errp, "Node name '%s' not found", s->replaces); return; } @@ -686,6 +819,7 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, bool is_none_mode, BlockDriverState *base) { MirrorBlockJob *s; + BlockDriverState *replaced_bs; if (granularity == 0) { granularity = bdrv_get_default_bitmap_granularity(target); @@ -695,7 +829,7 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, if ((on_source_error == BLOCKDEV_ON_ERROR_STOP || on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) && - !bdrv_iostatus_is_enabled(bs)) { + (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) { error_setg(errp, QERR_INVALID_PARAMETER, "on-source-error"); return; } @@ -709,6 +843,21 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, buf_size = DEFAULT_MIRROR_BUF_SIZE; } + /* We can't support this case as long as the block layer can't handle + * multiple BlockBackends per BlockDriverState. */ + if (replaces) { + replaced_bs = bdrv_lookup_bs(replaces, replaces, errp); + if (replaced_bs == NULL) { + return; + } + } else { + replaced_bs = bs; + } + if (replaced_bs->blk && target->blk) { + error_setg(errp, "Can't create node with two BlockBackends"); + return; + } + s = block_job_create(driver, bs, speed, cb, opaque, errp); if (!s) { return; @@ -727,12 +876,16 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); if (!s->dirty_bitmap) { g_free(s->replaces); - block_job_release(bs); + block_job_unref(&s->common); return; } - bdrv_set_enable_write_cache(s->target, true); - bdrv_set_on_error(s->target, on_target_error, on_target_error); - bdrv_iostatus_enable(s->target); + + bdrv_op_block_all(s->target, s->common.blocker); + + 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); @@ -755,7 +908,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target, return; } is_none_mode = mode == MIRROR_SYNC_MODE_NONE; - base = mode == MIRROR_SYNC_MODE_TOP ? bs->backing_hd : NULL; + 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, |