tree b1b049dce9f3013334ddca6019e5835c4c994ae6
parent 52a5e15f665385ac99607d6b9e0c3dbdf17c5cfa
author Jens Axboe <axboe@suse.de> 1119876579 +0200
committer Linus Torvalds <torvalds@ppc970.osdl.org> 1119908010 -0700

[PATCH] CFQ io scheduler: scheduler switch oops

If cfq is managing a queue and a new scheduler is later selected, it is
possible for the cfqd unplug_work work to be queued after the kblockd
work struct has been flushed.  The problem is the ordering of
cfq_shutdown_timer_wq() and blk_put_queue() in cfq_put_cfqd().  The
latter may rearm the work, leaving cfq_kick_queue() with dead data.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>