Messages in this thread Patch in this message | | | Date | Wed, 28 Sep 2011 15:03:28 -0700 | From | Greg KH <> | Subject | [244/244] block: Free queue resources at blk_release_queue() |
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3.0-stable review patch. If anyone has any objections, please let us know.
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From: Hannes Reinecke <hare@suse.de>
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>
--- block/blk-core.c | 13 ++++++------- block/blk-sysfs.c | 5 +++++ 2 files changed, 11 insertions(+), 7 deletions(-)
--- a/block/blk-core.c +++ b/block/blk-core.c @@ -348,9 +348,10 @@ void blk_put_queue(struct request_queue EXPORT_SYMBOL(blk_put_queue); /* - * 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_qu queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q); mutex_unlock(&q->sysfs_lock); - if (q->elevator) - elevator_exit(q->elevator); - - blk_throtl_exit(q); + if (q->queue_lock != &q->__queue_lock) + q->queue_lock = &q->__queue_lock; blk_put_queue(q); } --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -472,6 +472,11 @@ static void blk_release_queue(struct kob blk_sync_queue(q); + if (q->elevator) + elevator_exit(q->elevator); + + blk_throtl_exit(q); + if (rl->rq_pool) mempool_destroy(rl->rq_pool);
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