From e0f594c3eac9fb0a89c76de3b77bce03c235b36e Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Tue, 3 Dec 2013 15:31:25 +0100 Subject: [PATCH 16/37] block: Switch BdrvTrackedRequest to byte granularity Message-id: <1392117622-28812-17-git-send-email-kwolf@redhat.com> Patchwork-id: 57181 O-Subject: [RHEL-7.0 qemu-kvm PATCH v2 16/37] block: Switch BdrvTrackedRequest to byte granularity Bugzilla: 748906 RH-Acked-by: Laszlo Ersek RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Max Reitz Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Reviewed-by: Benoit Canet (cherry picked from commit 793ed47a7a2b09b67cb2a8863dff531436532b5c) Conflicts: block/backup.c include/block/block_int.h Conflicts because in RHEL 7... - ...block-backup doesn't exist - ...BdrvTrackedRequest is in block.c rather than block_int.h Signed-off-by: Kevin Wolf --- block.c | 56 ++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 36 insertions(+), 20 deletions(-) --- block.c | 56 ++++++++++++++++++++++++++++++++++++-------------------- 1 files changed, 36 insertions(+), 20 deletions(-) diff --git a/block.c b/block.c index 7b8131c..09bb127 100644 --- a/block.c +++ b/block.c @@ -2036,8 +2036,8 @@ int bdrv_commit_all(void) struct BdrvTrackedRequest { BlockDriverState *bs; - int64_t sector_num; - int nb_sectors; + int64_t offset; + unsigned int bytes; bool is_write; QLIST_ENTRY(BdrvTrackedRequest) list; Coroutine *co; /* owner, used for deadlock detection */ @@ -2060,13 +2060,13 @@ static void tracked_request_end(BdrvTrackedRequest *req) */ static void tracked_request_begin(BdrvTrackedRequest *req, BlockDriverState *bs, - int64_t sector_num, - int nb_sectors, bool is_write) + int64_t offset, + unsigned int bytes, bool is_write) { *req = (BdrvTrackedRequest){ .bs = bs, - .sector_num = sector_num, - .nb_sectors = nb_sectors, + .offset = offset, + .bytes = bytes, .is_write = is_write, .co = qemu_coroutine_self(), }; @@ -2097,25 +2097,43 @@ void bdrv_round_to_clusters(BlockDriverState *bs, } } +static void round_bytes_to_clusters(BlockDriverState *bs, + int64_t offset, unsigned int bytes, + int64_t *cluster_offset, + unsigned int *cluster_bytes) +{ + BlockDriverInfo bdi; + + if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { + *cluster_offset = offset; + *cluster_bytes = bytes; + } else { + *cluster_offset = QEMU_ALIGN_DOWN(offset, bdi.cluster_size); + *cluster_bytes = QEMU_ALIGN_UP(offset - *cluster_offset + bytes, + bdi.cluster_size); + } +} + static bool tracked_request_overlaps(BdrvTrackedRequest *req, - int64_t sector_num, int nb_sectors) { + int64_t offset, unsigned int bytes) +{ /* aaaa bbbb */ - if (sector_num >= req->sector_num + req->nb_sectors) { + if (offset >= req->offset + req->bytes) { return false; } /* bbbb aaaa */ - if (req->sector_num >= sector_num + nb_sectors) { + if (req->offset >= offset + bytes) { return false; } return true; } static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, - int64_t sector_num, int nb_sectors) + int64_t offset, unsigned int bytes) { BdrvTrackedRequest *req; - int64_t cluster_sector_num; - int cluster_nb_sectors; + int64_t cluster_offset; + unsigned int cluster_bytes; bool retry; /* If we touch the same cluster it counts as an overlap. This guarantees @@ -2124,14 +2142,12 @@ static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, * CoR read and write operations are atomic and guest writes cannot * interleave between them. */ - bdrv_round_to_clusters(bs, sector_num, nb_sectors, - &cluster_sector_num, &cluster_nb_sectors); + round_bytes_to_clusters(bs, offset, bytes, &cluster_offset, &cluster_bytes); do { retry = false; QLIST_FOREACH(req, &bs->tracked_requests, list) { - if (tracked_request_overlaps(req, cluster_sector_num, - cluster_nb_sectors)) { + if (tracked_request_overlaps(req, cluster_offset, cluster_bytes)) { /* Hitting this means there was a reentrant request, for * example, a block driver issuing nested requests. This must * never happen since it means deadlock. @@ -2746,10 +2762,10 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, } if (bs->copy_on_read_in_flight) { - wait_for_overlapping_requests(bs, sector_num, nb_sectors); + wait_for_overlapping_requests(bs, offset, bytes); } - tracked_request_begin(&req, bs, sector_num, nb_sectors, false); + tracked_request_begin(&req, bs, offset, bytes, false); if (flags & BDRV_REQ_COPY_ON_READ) { int pnum; @@ -2998,10 +3014,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); if (bs->copy_on_read_in_flight) { - wait_for_overlapping_requests(bs, sector_num, nb_sectors); + wait_for_overlapping_requests(bs, offset, bytes); } - tracked_request_begin(&req, bs, sector_num, nb_sectors, true); + tracked_request_begin(&req, bs, offset, bytes, true); if (flags & BDRV_REQ_ZERO_WRITE) { ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags); -- 1.7.1