[PATCH] libata: replace ap_lock w/ ap->lock in ata_scsi_error()

ap_lock was used because &ap->host_set->lock was too long and used a
lot.  Now that &ap->host_set->lock is replaced with ap->lock, there's
no reason to keep ap_lock.

[ed. note: that's not entirely true.  ap_lock is a local variable,
caching the results of a de-ref.  In theory, if the compiler is smart
enough, this patch is cosmetic.  However, since this is not a fast
path (it is the error path), this patch is nonetheless acceptable,
even though it _may_ introduce a performance regression.]

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 11 insertions, 12 deletions

diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 4a670db9aa05..d19666c376ad 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -190,7 +190,6 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
 void ata_scsi_error(struct Scsi_Host *host)
 {
         struct ata_port *ap = ata_shost_to_port(host);
-        spinlock_t *ap_lock = ap->lock;
         int i, repeat_cnt = ATA_EH_MAX_REPEAT;
         unsigned long flags;
 
@@ -217,7 +216,7 @@ void ata_scsi_error(struct Scsi_Host *host)
                 struct scsi_cmnd *scmd, *tmp;
                 int nr_timedout = 0;
 
-                spin_lock_irqsave(ap_lock, flags);
+                spin_lock_irqsave(ap->lock, flags);
 
                 list_for_each_entry_safe(scmd, tmp, &host->eh_cmd_q, eh_entry) {
                         struct ata_queued_cmd *qc;
@@ -256,15 +255,15 @@ void ata_scsi_error(struct Scsi_Host *host)
                 if (nr_timedout)
                         __ata_port_freeze(ap);
 
-                spin_unlock_irqrestore(ap_lock, flags);
+                spin_unlock_irqrestore(ap->lock, flags);
         } else
-                spin_unlock_wait(ap_lock);
+                spin_unlock_wait(ap->lock);
 
  repeat:
         /* invoke error handler */
         if (ap->ops->error_handler) {
                 /* fetch & clear EH info */
-                spin_lock_irqsave(ap_lock, flags);
+                spin_lock_irqsave(ap->lock, flags);
 
                 memset(&ap->eh_context, 0, sizeof(ap->eh_context));
                 ap->eh_context.i = ap->eh_info;
@@ -273,7 +272,7 @@ void ata_scsi_error(struct Scsi_Host *host)
                 ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
                 ap->pflags &= ~ATA_PFLAG_EH_PENDING;
 
-                spin_unlock_irqrestore(ap_lock, flags);
+                spin_unlock_irqrestore(ap->lock, flags);
 
                 /* invoke EH.  if unloading, just finish failed qcs */
                 if (!(ap->pflags & ATA_PFLAG_UNLOADING))
@@ -285,14 +284,14 @@ void ata_scsi_error(struct Scsi_Host *host)
                  * recovered the port but before this point.  Repeat
                  * EH in such case.
                  */
-                spin_lock_irqsave(ap_lock, flags);
+                spin_lock_irqsave(ap->lock, flags);
 
                 if (ap->pflags & ATA_PFLAG_EH_PENDING) {
                         if (--repeat_cnt) {
                                 ata_port_printk(ap, KERN_INFO,
                                         "EH pending after completion, "
                                         "repeating EH (cnt=%d)\n", repeat_cnt);
-                                spin_unlock_irqrestore(ap_lock, flags);
+                                spin_unlock_irqrestore(ap->lock, flags);
                                 goto repeat;
                         }
                         ata_port_printk(ap, KERN_ERR, "EH pending after %d "
@@ -302,14 +301,14 @@ void ata_scsi_error(struct Scsi_Host *host)
                 /* this run is complete, make sure EH info is clear */
                 memset(&ap->eh_info, 0, sizeof(ap->eh_info));
 
-                /* Clear host_eh_scheduled while holding ap_lock such
+                /* Clear host_eh_scheduled while holding ap->lock such
                  * that if exception occurs after this point but
                  * before EH completion, SCSI midlayer will
                  * re-initiate EH.
                  */
                 host->host_eh_scheduled = 0;
 
-                spin_unlock_irqrestore(ap_lock, flags);
+                spin_unlock_irqrestore(ap->lock, flags);
         } else {
                 WARN_ON(ata_qc_from_tag(ap, ap->active_tag) == NULL);
                 ap->ops->eng_timeout(ap);
@@ -321,7 +320,7 @@ void ata_scsi_error(struct Scsi_Host *host)
         scsi_eh_flush_done_q(&ap->eh_done_q);
 
         /* clean up */
-        spin_lock_irqsave(ap_lock, flags);
+        spin_lock_irqsave(ap->lock, flags);
 
         if (ap->pflags & ATA_PFLAG_LOADING) {
                 ap->pflags &= ~ATA_PFLAG_LOADING;
@@ -338,7 +337,7 @@ void ata_scsi_error(struct Scsi_Host *host)
         ap->pflags &= ~ATA_PFLAG_EH_IN_PROGRESS;
         wake_up_all(&ap->eh_wait_q);
 
-        spin_unlock_irqrestore(ap_lock, flags);
+        spin_unlock_irqrestore(ap->lock, flags);
 
         DPRINTK("EXIT\n");
 }