From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 31 Oct 2006 13:21:55 +0000 (+0100)
Subject: [PATCH] CFQ: request <-> request merging rr_list fixup
X-Git-Tag: v2.6.19-rc5~99
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5fccbf61be2a7f32d2002b04afca4c5009612a58;p=pandora-kernel.git

[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>
---

Reading git-diff-tree failed