From: Paolo Bonzini <pbonz...@redhat.com> Marking without waiting would not result in actual serialising behavior. Thus, make a call bdrv_mark_request_serialising sufficient for serialisation to happen.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> Message-id: 1578495356-46219-3-git-send-email-pbonz...@redhat.com Message-Id: <1578495356-46219-3-git-send-email-pbonz...@redhat.com> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> --- block/file-posix.c | 1 - block/io.c | 40 +++++++++++++++++---------------------- include/block/block_int.h | 3 +-- 3 files changed, 18 insertions(+), 26 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 1b805bd938..2b08b02d27 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -2753,7 +2753,6 @@ raw_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes, req->overlap_bytes = req->bytes; bdrv_mark_request_serialising(req, bs->bl.request_alignment); - bdrv_wait_serialising_requests(req); } #endif diff --git a/block/io.c b/block/io.c index b3a67fe1db..c466df8ed5 100644 --- a/block/io.c +++ b/block/io.c @@ -41,6 +41,7 @@ #define MAX_BOUNCE_BUFFER (32768 << BDRV_SECTOR_BITS) static void bdrv_parent_cb_resize(BlockDriverState *bs); +static bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self); static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes, BdrvRequestFlags flags); @@ -715,7 +716,7 @@ static void tracked_request_begin(BdrvTrackedRequest *req, qemu_co_mutex_unlock(&bs->reqs_lock); } -void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) +bool bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) { int64_t overlap_offset = req->offset & ~(align - 1); uint64_t overlap_bytes = ROUND_UP(req->offset + req->bytes, align) @@ -728,18 +729,7 @@ void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) req->overlap_offset = MIN(req->overlap_offset, overlap_offset); req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes); -} - -static bool is_request_serialising_and_aligned(BdrvTrackedRequest *req) -{ - /* - * If the request is serialising, overlap_offset and overlap_bytes are set, - * so we can check if the request is aligned. Otherwise, don't care and - * return false. - */ - - return req->serialising && (req->offset == req->overlap_offset) && - (req->bytes == req->overlap_bytes); + return bdrv_wait_serialising_requests(req); } /** @@ -823,7 +813,7 @@ void bdrv_dec_in_flight(BlockDriverState *bs) bdrv_wakeup(bs); } -bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self) +static bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self) { BlockDriverState *bs = self->bs; BdrvTrackedRequest *req; @@ -1455,10 +1445,10 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, * it ensures that the CoR read and write operations are atomic and * guest writes cannot interleave between them. */ bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs)); + } else { + bdrv_wait_serialising_requests(req); } - bdrv_wait_serialising_requests(req); - if (flags & BDRV_REQ_COPY_ON_READ) { int64_t pnum; @@ -1851,13 +1841,19 @@ bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes, assert(!(flags & ~BDRV_REQ_MASK)); if (flags & BDRV_REQ_SERIALISING) { - bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs)); + waited = bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs)); + /* + * For a misaligned request we should have already waited earlier, + * because we come after bdrv_padding_rmw_read which must be called + * with the request already marked as serialising. + */ + assert(!waited || + (req->offset == req->overlap_offset && + req->bytes == req->overlap_bytes)); + } else { + bdrv_wait_serialising_requests(req); } - waited = bdrv_wait_serialising_requests(req); - - assert(!waited || !req->serialising || - is_request_serialising_and_aligned(req)); assert(req->overlap_offset <= offset); assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); assert(end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE); @@ -2019,7 +2015,6 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child, padding = bdrv_init_padding(bs, offset, bytes, &pad); if (padding) { bdrv_mark_request_serialising(req, align); - bdrv_wait_serialising_requests(req); bdrv_padding_rmw_read(child, req, &pad, true); @@ -2122,7 +2117,6 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child, if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) { bdrv_mark_request_serialising(&req, align); - bdrv_wait_serialising_requests(&req); bdrv_padding_rmw_read(child, &req, &pad, false); } diff --git a/include/block/block_int.h b/include/block/block_int.h index dd033d0b37..640fb82c78 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -999,8 +999,7 @@ extern unsigned int bdrv_drain_all_count; void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent); void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent); -bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self); -void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align); +bool coroutine_fn bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align); BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs); int get_tmp_filename(char *filename, int size); -- 2.24.1