[PATCH] blk: fix merge bug in as-iosched
authorTejun Heo <htejun@gmail.com>
Sat, 29 Oct 2005 09:18:42 +0000 (18:18 +0900)
committerLinus Torvalds <torvalds@g5.osdl.org>
Sat, 29 Oct 2005 17:28:13 +0000 (10:28 -0700)
commit47e627ce83b6df9f4bb8e4b0a4dde1c5d7a4c929
treee41ee81ad1c584fd93184cf43acbcbd986ad858d
parentfc228a04a4c01bbb2f898e180a14f9a976001f79
[PATCH] blk: fix merge bug in as-iosched

as-iosched deals with aliased requests differently from other ioscheds.

It links together aliased requests using rq->queuelist instead of
spilling alises to dispatch queue like other ioscheds do.  Requests
linked in this way cannot be merged.

Unfortunately, generic q->last_merge handling patch didn't take this
into account and q->last_merge could be set to an aliased request
resulting in Badness, corrupt list and eventually panic.

This explicitly marks aliased requests to be unmergeable.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/block/as-iosched.c