tree 1a7a09dcbf4b518cf5d695fa8dbe41e21a1ab413
parent eafa6cb18ec7e5424ce54017b5ce6d11dff58b79
author Jens Axboe <jens.axboe@oracle.com> 1162300915 +0100
committer Linus Torvalds <torvalds@g5.osdl.org> 1162311165 -0800

[PATCH] CFQ: request <-> request merging rr_list fixup

In very rare circumstances would we be pruning a merged request and at
the same time delete the implicated cfqq from the rr_list, and not readd
it when the merged request got added. This could cause io stalls until
that process issued io again.

Fix it up by putting the rr_list add handling into cfq_add_rq_rb(),
identical to how pruning is handled in cfq_del_rq_rb(). This fixes a
hang reproducible with fsx-linux.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>