[RFC v4 09/19] libata: Remove host_lock unlock() + lock() from ata_scsi_queuecmd()

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch removes the now legacy host_lock unlock() + lock() optimization
from libata-scsi.c:ata_scsi_queuecmd().  This also includes setting the
of SHT->unlocked_qcmd=1 for libata ata_scsi_queuecmd().

Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
---
 drivers/ata/libata-scsi.c |    4 +---
 include/linux/libata.h    |    1 +
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index a89172c..acb6669 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3161,7 +3161,7 @@ static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
  *	ATA and ATAPI devices appearing as SCSI devices.
  *
  *	LOCKING:
- *	Releases scsi-layer-held lock, and obtains host lock.
+ *	None
  *
  *	RETURNS:
  *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
@@ -3177,7 +3177,6 @@ int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 
 	ap = ata_shost_to_port(shost);
 
-	spin_unlock(shost->host_lock);
 	spin_lock(ap->lock);
 
 	ata_scsi_dump_cdb(ap, cmd);
@@ -3191,7 +3190,6 @@ int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 	}
 
 	spin_unlock(ap->lock);
-	spin_lock(shost->host_lock);
 	return rc;
 }
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 45fb296..c08a0b9 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1171,6 +1171,7 @@ extern struct device_attribute *ata_common_sdev_attrs[];
 	.queuecommand		= ata_scsi_queuecmd,		\
 	.can_queue		= ATA_DEF_QUEUE,		\
 	.this_id		= ATA_SHT_THIS_ID,		\
+	.unlocked_qcmd		= 1,				\
 	.cmd_per_lun		= ATA_SHT_CMD_PER_LUN,		\
 	.emulated		= ATA_SHT_EMULATED,		\
 	.use_clustering		= ATA_SHT_USE_CLUSTERING,	\
-- 
1.7.3