Patch "MD: make bio mergeable" has been added to the 4.5-stable tree
Subsystems (2)
This is a note to let you know that I've just added the patch titled
MD: make bio mergeable
to the 4.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
md-make-bio-mergeable.patch
and it can be found in the queue-4.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From
9c573de3283af007ea11c17bde1e4568d9417328Mon Sep 17 00:00:00 2001
From: Shaohua Li <[email protected]>
Date: Mon, 25 Apr 2016 16:52:38 -0700
Subject: MD: make bio mergeable
From: Shaohua Li <[email protected]>
commit 9c573de3283af007ea11c17bde1e4568d9417328 upstream.
blk_queue_split marks bio unmergeable, which makes sense for normal bio. But if dispatching the bio to underlayer disk, the blk_queue_split checks are invalid, hence it's possible the bio becomes mergeable.
In the reported bug, this bug causes trim against raid0 performance slash
https://bugzilla.kernel.org/show_bug.cgi?id=117051
--- drivers/md/md.c | 2 ++ 1 file changed, 2 insertions(+)
drivers/md/md.c +2 -0
@@ -284,6 +284,8 @@ static blk_qc_t md_make_request(struct r* go away inside make_request */ sectors =bio_sectors (bio); +/* bio could be mergeable after passing to underlayer */ + bio->bi_rw &= ~REQ_NOMERGE ; mddev->pers->make_request (mddev, bio); cpu =part_stat_lock ();
Patches currently in stable-queue which might be from [email protected] are
queue-4.5/md-make-bio-mergeable.patch