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authorHannes Reinecke <hare@suse.de>2011-09-28 08:07:01 -0600
committerGreg Kroah-Hartman <gregkh@suse.de>2011-10-03 11:41:13 -0700
commitc2b387f0295ffaeb5e96f0d6f745fde507abd651 (patch)
parentf0e47138b26bd26d312aa63522a579acac5552c6 (diff)
block: Free queue resources at blk_release_queue()
commit 777eb1bf15b8532c396821774bf6451e563438f5 upstream. A kernel crash is observed when a mounted ext3/ext4 filesystem is physically removed. The problem is that blk_cleanup_queue() frees up some resources eg by calling elevator_exit(), which are not checked for in normal operation. So we should rather move these calls to the destructor function blk_release_queue() as at that point all remaining references are gone. However, in doing so we have to ensure that any externally supplied queue_lock is disconnected as the driver might free up the lock after the call of blk_cleanup_queue(), Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2 files changed, 11 insertions, 7 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 1d49e1c7c905..847d04ef9f19 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -348,9 +348,10 @@ void blk_put_queue(struct request_queue *q)
- * Note: If a driver supplied the queue lock, it should not zap that lock
- * unexpectedly as some queue cleanup components like elevator_exit() and
- * blk_throtl_exit() need queue lock.
+ * Note: If a driver supplied the queue lock, it is disconnected
+ * by this function. The actual state of the lock doesn't matter
+ * here as the request_queue isn't accessible after this point
+ * (QUEUE_FLAG_DEAD is set) and no other requests will be queued.
void blk_cleanup_queue(struct request_queue *q)
@@ -367,10 +368,8 @@ void blk_cleanup_queue(struct request_queue *q)
queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
- if (q->elevator)
- elevator_exit(q->elevator);
- blk_throtl_exit(q);
+ if (q->queue_lock != &q->__queue_lock)
+ q->queue_lock = &q->__queue_lock;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index d935bd859c87..45c56d86b826 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -472,6 +472,11 @@ static void blk_release_queue(struct kobject *kobj)
+ if (q->elevator)
+ elevator_exit(q->elevator);
+ blk_throtl_exit(q);
if (rl->rq_pool)