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authorJens Axboe <axboe@suse.de>2005-06-27 16:49:39 +0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-28 01:33:30 +0400
commit96c51ce94e8415d2dfb08358bbd50e1589111f33 (patch)
treeb1b049dce9f3013334ddca6019e5835c4c994ae6 /drivers/block
parent52a5e15f665385ac99607d6b9e0c3dbdf17c5cfa (diff)
downloadlinux-96c51ce94e8415d2dfb08358bbd50e1589111f33.tar.xz
[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>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/cfq-iosched.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/block/cfq-iosched.c b/drivers/block/cfq-iosched.c
index 1ecb179b8604..ff1cc968f96d 100644
--- a/drivers/block/cfq-iosched.c
+++ b/drivers/block/cfq-iosched.c
@@ -2249,10 +2249,11 @@ static void cfq_put_cfqd(struct cfq_data *cfqd)
if (!atomic_dec_and_test(&cfqd->ref))
return;
- cfq_shutdown_timer_wq(cfqd);
-
blk_put_queue(q);
+ cfq_shutdown_timer_wq(cfqd);
+ q->elevator->elevator_data = NULL;
+
mempool_destroy(cfqd->crq_pool);
kfree(cfqd->crq_hash);
kfree(cfqd->cfq_hash);