From 897dd0ec4fdea4e6fa7674729750d05acc1bf41e Mon Sep 17 00:00:00 2001 From: Andrey Shinkevich Date: Wed, 16 Dec 2020 09:16:57 +0300 Subject: block: include supported_read_flags into BDS structure Add the new member supported_read_flags to the BlockDriverState structure. It will control the flags set for copy-on-read operations. Make the block generic layer evaluate supported read flags before they go to a block driver. Suggested-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Andrey Shinkevich Signed-off-by: Vladimir Sementsov-Ogievskiy [vsementsov: use assert instead of abort] Reviewed-by: Max Reitz Message-Id: <20201216061703.70908-8-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz --- block/io.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'block') diff --git a/block/io.c b/block/io.c index 95b1c56c06..d203435a73 100644 --- a/block/io.c +++ b/block/io.c @@ -1453,6 +1453,9 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, if (flags & BDRV_REQ_COPY_ON_READ) { int64_t pnum; + /* The flag BDRV_REQ_COPY_ON_READ has reached its addressee */ + flags &= ~BDRV_REQ_COPY_ON_READ; + ret = bdrv_is_allocated(bs, offset, bytes, &pnum); if (ret < 0) { goto out; @@ -1474,9 +1477,11 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, goto out; } + assert(!(flags & ~bs->supported_read_flags)); + max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align); if (bytes <= max_bytes && bytes <= max_transfer) { - ret = bdrv_driver_preadv(bs, offset, bytes, qiov, qiov_offset, 0); + ret = bdrv_driver_preadv(bs, offset, bytes, qiov, qiov_offset, flags); goto out; } @@ -1489,7 +1494,8 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, ret = bdrv_driver_preadv(bs, offset + bytes - bytes_remaining, num, qiov, - qiov_offset + bytes - bytes_remaining, 0); + qiov_offset + bytes - bytes_remaining, + flags); max_bytes -= num; } else { num = bytes_remaining; -- cgit v1.2.3