SCSI host lock push-down

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation.  No locking or other behavior should change
with this patch.  All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
	struct Scsi_Host *
and remove one parameter from queuecommand,
	void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change.  Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/scsi/pas16.h b/drivers/scsi/pas16.h
index 8dc5b1a5f5da..a04281cace2e 100644
--- a/drivers/scsi/pas16.h
+++ b/drivers/scsi/pas16.h
@@ -118,7 +118,7 @@ static int pas16_abort(Scsi_Cmnd *);
 static int pas16_biosparam(struct scsi_device *, struct block_device *,
                            sector_t, int*);
 static int pas16_detect(struct scsi_host_template *);
-static int pas16_queue_command(Scsi_Cmnd *, void (*done)(Scsi_Cmnd *));
+static int pas16_queue_command(struct Scsi_Host *, struct scsi_cmnd *);
 static int pas16_bus_reset(Scsi_Cmnd *);
 
 #ifndef CMD_PER_LUN