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author | Bart Van Assche <bvanassche@acm.org> | 2012-06-29 15:36:07 +0000 |
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committer | James Bottomley <JBottomley@Parallels.com> | 2012-07-20 08:58:41 +0100 |
commit | b485462aca7df4e32bcf7efb6f84a69e8b640243 (patch) | |
tree | 744345ebe5c761a46a28a495fae82b6dd4d9e28b /drivers/scsi/scsi_lib.c | |
parent | 84feb1664e5e6823105414df77740fda70846b99 (diff) | |
download | op-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.c | 7 |
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); } /* |