When emulating small logical block sizes, the only overlaps that matter are at host block size granularity, not cluster. Make wait_for_overlapping_requests more flexible in this respect, too.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- block.c | 43 ++++++++++++++++++++++++++++--------------- 1 files changed, 28 insertions(+), 15 deletions(-) diff --git a/block.c b/block.c index 9a2ef83..07b9cf4 100644 --- a/block.c +++ b/block.c @@ -1159,24 +1159,33 @@ static void tracked_request_begin(BdrvTrackedRequest *req, /** * Round a region to cluster boundaries */ -static void round_to_clusters(BlockDriverState *bs, - int64_t sector_num, int nb_sectors, - int64_t *cluster_sector_num, - int *cluster_nb_sectors) +static void round_sectors(int64_t alignment, + int64_t sector_num, int nb_sectors, + int64_t *cluster_sector_num, + int *cluster_nb_sectors) { - BlockDriverInfo bdi; - - if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { + if (alignment == BDRV_SECTOR_SIZE) { *cluster_sector_num = sector_num; *cluster_nb_sectors = nb_sectors; } else { - int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; + int64_t c = alignment / BDRV_SECTOR_SIZE; *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + nb_sectors, c); } } +static int64_t get_cluster_size(BlockDriverState *bs) +{ + BlockDriverInfo bdi; + + if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { + return BDRV_SECTOR_SIZE; + } else { + return bdi.cluster_size / BDRV_SECTOR_SIZE; + } +} + static bool tracked_request_overlaps(BdrvTrackedRequest *req, int64_t sector_num, int nb_sectors) { /* aaaa bbbb */ @@ -1191,7 +1200,8 @@ static bool tracked_request_overlaps(BdrvTrackedRequest *req, } static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, - int64_t sector_num, int nb_sectors, bool writes_only) + int64_t sector_num, int nb_sectors, + int64_t granularity, bool writes_only) { BdrvTrackedRequest *req; int64_t cluster_sector_num; @@ -1204,8 +1214,8 @@ static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, * CoR read and write operations are atomic and guest writes cannot * interleave between them. */ - round_to_clusters(bs, sector_num, nb_sectors, - &cluster_sector_num, &cluster_nb_sectors); + round_sectors(granularity, sector_num, nb_sectors, + &cluster_sector_num, &cluster_nb_sectors); if (writes_only && !(bs->open_flags & BDRV_O_RDWR)) { return; @@ -1525,8 +1535,9 @@ static int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, /* Cover entire cluster so no additional backing file I/O is required when * allocating cluster in the image file. */ - round_to_clusters(bs, sector_num, nb_sectors, - &cluster_sector_num, &cluster_nb_sectors); + round_sectors(get_cluster_size(bs), + sector_num, nb_sectors, + &cluster_sector_num, &cluster_nb_sectors); trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, cluster_sector_num, cluster_nb_sectors); @@ -1583,7 +1594,8 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, } if (bs->copy_on_read) { - wait_for_overlapping_requests(bs, sector_num, nb_sectors, false); + wait_for_overlapping_requests(bs, sector_num, nb_sectors, + get_cluster_size(bs), false); } tracked_request_begin(&req, bs, sector_num, nb_sectors, false); @@ -1643,7 +1655,8 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, } if (bs->copy_on_read) { - wait_for_overlapping_requests(bs, sector_num, nb_sectors, false); + wait_for_overlapping_requests(bs, sector_num, nb_sectors, + get_cluster_size(bs), false); } tracked_request_begin(&req, bs, sector_num, nb_sectors, true); -- 1.7.7.1