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authorBart Van Assche <bvanassche@acm.org>2012-06-29 15:36:07 +0000
committerJames Bottomley <JBottomley@Parallels.com>2012-07-20 08:58:41 +0100
commitb485462aca7df4e32bcf7efb6f84a69e8b640243 (patch)
tree744345ebe5c761a46a28a495fae82b6dd4d9e28b /drivers/scsi/scsi_lib.c
parent84feb1664e5e6823105414df77740fda70846b99 (diff)
downloadop-kernel-dev-b485462aca7df4e32bcf7efb6f84a69e8b640243.zip
op-kernel-dev-b485462aca7df4e32bcf7efb6f84a69e8b640243.tar.gz
[SCSI] Stop accepting SCSI requests before removing a device
Avoid that the code for requeueing SCSI requests triggers a crash by making sure that that code isn't scheduled anymore after a device has been removed. Also, source code inspection of __scsi_remove_device() revealed a race condition in this function: no new SCSI requests must be accepted for a SCSI device after device removal started. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8af6a64..b583277 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -155,13 +155,14 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
/*
* Requeue this command. It will go before all other commands
- * that are already in the queue.
+ * that are already in the queue. Schedule requeue work under
+ * lock such that the kblockd_schedule_work() call happens
+ * before blk_cleanup_queue() finishes.
*/
spin_lock_irqsave(q->queue_lock, flags);
blk_requeue_request(q, cmd->request);
- spin_unlock_irqrestore(q->queue_lock, flags);
-
kblockd_schedule_work(q, &device->requeue_work);
+ spin_unlock_irqrestore(q->queue_lock, flags);
}
/*
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