korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-15 08:14:15 +08:00
Code Issues Packages Projects Releases Wiki Activity

block: don't allow splitting of a REQ_NOWAIT bio

Browse Source 
commit 9cea62b2cb upstream.

If we split a bio marked with REQ_NOWAIT, then we can trigger spurious
EAGAIN if constituent parts of that split bio end up failing request
allocations. Parts will complete just fine, but just a single failure
in one of the chained bios will yield an EAGAIN final result for the
parent bio.

Return EAGAIN early if we end up needing to split such a bio, which
allows for saner recovery handling.

Cc: stable@vger.kernel.org # 5.15+
Link: https://github.com/axboe/liburing/issues/766
Reported-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jens Axboe 2023-01-04 08:52:06 -07:00 committed by Greg Kroah-Hartman
parent 39a20c4354
commit 6d47e0f6a5
1 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
block/blk-merge.c
View File

@ -300,6 +300,16 @@ static struct bio *bio_split_rw(struct bio *bio, struct queue_limits *lim,
*segs = nsegs;
return NULL;
split:
/*
* We can't sanely support splitting for a REQ_NOWAIT bio. End it
* with EAGAIN if splitting is required and return an error pointer.
*/
if (bio->bi_opf & REQ_NOWAIT) {
bio->bi_status = BLK_STS_AGAIN;
bio_endio(bio);
return ERR_PTR(-EAGAIN);
}
*segs = nsegs;
/*