On 4/12/19 5:30 AM, Ming Lei wrote:
scsi_device's refcount is always grabbed in IO path.
Turns out it isn't necessary, because blk_queue_cleanup() will
drain any in-flight IOs, then cancel timeout/requeue work, and
SCSI's requeue_work is canceled too in __scsi_remove_device().
Also scsi_device won't go away until blk_cleanup_queue() is done.
So don't hold the refcount in IO path, especially the refcount isn't
required in IO path since blk_queue_enter() / blk_queue_exit()
is introduced in the legacy block layer.
Cc: Dongli Zhang <[email protected]>
Cc: James Smart <[email protected]>
Cc: Bart Van Assche <[email protected]>
Cc: [email protected],
Cc: Martin K . Petersen <[email protected]>,
Cc: Christoph Hellwig <[email protected]>,
Cc: James E . J . Bottomley <[email protected]>,
Cc: jianchao wang <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
---
drivers/scsi/scsi_lib.c | 28 ++--------------------------
1 file changed, 2 insertions(+), 26 deletions(-)
Reviewed-by: Hannes Reinecke <[email protected]>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
[email protected] +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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