[libata] remove SCSI host lock and serial number usage from ata_scsi_queuecmd

cmd->serial_number is never tested in any path we reach; therefore we may
remove the call to scsi_cmd_get_serial() inside DEF_SCSI_QCMD, the SCSI
host_lock acquisition surrounding it, and our own SCSI host_lock
unlock+relock cycle.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 19835d39289dd7497f689f7c6a57681e84f6e637..66aa4bee80a659712b75e8b3949678d56e8bd5a3 100644 (file)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3166,8 +3166,8 @@ static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
 
 /**
  *     ata_scsi_queuecmd - Issue SCSI cdb to libata-managed device
+ *     @shost: SCSI host of command to be sent
  *     @cmd: SCSI command to be sent
- *     @done: Completion function, called when command is complete
  *
  *     In some cases, this function translates SCSI commands into
  *     ATA taskfiles, and queues the taskfiles to be sent to
@@ -3177,42 +3177,39 @@ 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.
+ *     ATA host lock
  *
  *     RETURNS:
  *     Return value from __ata_scsi_queuecmd() if @cmd can be queued,
  *     0 otherwise.
  */
-static int ata_scsi_queuecmd_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
+int ata_scsi_queuecmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
 {
        struct ata_port *ap;
        struct ata_device *dev;
        struct scsi_device *scsidev = cmd->device;
-       struct Scsi_Host *shost = scsidev->host;
        int rc = 0;
+       unsigned long irq_flags;
 
        ap = ata_shost_to_port(shost);
 
-       spin_unlock(shost->host_lock);
-       spin_lock(ap->lock);
+       spin_lock_irqsave(ap->lock, irq_flags);
 
        ata_scsi_dump_cdb(ap, cmd);
 
        dev = ata_scsi_find_dev(ap, scsidev);
        if (likely(dev))
-               rc = __ata_scsi_queuecmd(cmd, done, dev);
+               rc = __ata_scsi_queuecmd(cmd, cmd->scsi_done, dev);
        else {
                cmd->result = (DID_BAD_TARGET << 16);
-               done(cmd);
+               cmd->scsi_done(cmd);
        }
 
-       spin_unlock(ap->lock);
-       spin_lock(shost->host_lock);
+       spin_unlock_irqrestore(ap->lock, irq_flags);
+
        return rc;
 }
 
-DEF_SCSI_QCMD(ata_scsi_queuecmd)
-
 /**
  *     ata_scsi_simulate - simulate SCSI command on ATA device
  *     @dev: the target device