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authorHannes Reinecke <hare@suse.de>2009-02-18 10:30:15 +0100
committerJens Axboe <jens.axboe@oracle.com>2009-02-18 10:34:16 +0100
commitbe987fdb55a4726e2fcbab7501f89276bdb57288 (patch)
treebc92a402a4d710718883e67eeab6e0ced221e7ff
parent41b8c853a495438208faa5be03bbb0050859163b (diff)
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block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list
blk_abort_queue() iterates the timeout list and aborts each request on the list, but if the driver error handling readds a request to the timeout list during this processing, we could be looping forever. Fix this by splicing current entries to a local list and run over that list instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
-rw-r--r--block/blk-timeout.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index a09535377a94..bbbdc4b8ccf2 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -209,12 +209,19 @@ void blk_abort_queue(struct request_queue *q)
{
unsigned long flags;
struct request *rq, *tmp;
+ LIST_HEAD(list);
spin_lock_irqsave(q->queue_lock, flags);
elv_abort_queue(q);
- list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list)
+ /*
+ * Splice entries to local list, to avoid deadlocking if entries
+ * get readded to the timeout list by error handling
+ */
+ list_splice_init(&q->timeout_list, &list);
+
+ list_for_each_entry_safe(rq, tmp, &list, timeout_list)
blk_abort_request(rq);
spin_unlock_irqrestore(q->queue_lock, flags);