[SCSI] refactor sdev/starget/shost busy checking

This patch refactors the busy checking codes of scsi_device,
Scsi_Host and scsi_target.  There should be no functional change.

This is a preparation for another patch which exports scsi's busy
state to the block layer for request stacking drivers.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 20 insertions, 10 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index f35a0951e469..1e7c9e9ef772 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -529,6 +529,14 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev)
         spin_unlock_irqrestore(shost->host_lock, flags);
 }
 
+static inline int scsi_device_is_busy(struct scsi_device *sdev)
+{
+        if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked)
+                return 1;
+
+        return 0;
+}
+
 static inline int scsi_target_is_busy(struct scsi_target *starget)
 {
         return ((starget->can_queue > 0 &&
@@ -536,6 +544,15 @@ static inline int scsi_target_is_busy(struct scsi_target *starget)
                  starget->target_blocked);
 }
 
+static inline int scsi_host_is_busy(struct Scsi_Host *shost)
+{
+        if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) ||
+            shost->host_blocked || shost->host_self_blocked)
+                return 1;
+
+        return 0;
+}
+
 /*
  * Function:    scsi_run_queue()
  *
@@ -558,11 +575,7 @@ static void scsi_run_queue(struct request_queue *q)
                 scsi_single_lun_run(sdev);
 
         spin_lock_irqsave(shost->host_lock, flags);
-        while (!list_empty(&shost->starved_list) &&
-               !shost->host_blocked && !shost->host_self_blocked &&
-                !((shost->can_queue > 0) &&
-                  (shost->host_busy >= shost->can_queue))) {
-
+        while (!list_empty(&shost->starved_list) && !scsi_host_is_busy(shost)) {
                 int flagset;
 
                 /*
@@ -1348,8 +1361,6 @@ int scsi_prep_fn(struct request_queue *q, struct request *req)
 static inline int scsi_dev_queue_ready(struct request_queue *q,
                                   struct scsi_device *sdev)
 {
-        if (sdev->device_busy >= sdev->queue_depth)
-                return 0;
         if (sdev->device_busy == 0 && sdev->device_blocked) {
                 /*
                  * unblock after device_blocked iterates to zero
@@ -1363,7 +1374,7 @@ static inline int scsi_dev_queue_ready(struct request_queue *q,
                         return 0;
                 }
         }
-        if (sdev->device_blocked)
+        if (scsi_device_is_busy(sdev))
                 return 0;
 
         return 1;
@@ -1440,8 +1451,7 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
                         return 0;
                 }
         }
-        if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) ||
-            shost->host_blocked || shost->host_self_blocked) {
+        if (scsi_host_is_busy(shost)) {
                 if (list_empty(&sdev->starved_entry))
                         list_add_tail(&sdev->starved_entry, &shost->starved_list);
                 return 0;