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-rw-r--r--drivers/message/fusion/mptsas.c2
-rw-r--r--drivers/scsi/scsi_lib.c50
-rw-r--r--drivers/scsi/scsi_sysfs.c10
-rw-r--r--drivers/scsi/sg.c2
-rw-r--r--include/scsi/scsi_device.h4
5 files changed, 40 insertions, 28 deletions
diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index 711fcb5cec87..d636dbe172a3 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -3763,7 +3763,7 @@ mptsas_send_link_status_event(struct fw_event_work *fw_event)
printk(MYIOC_s_DEBUG_FMT
"SDEV OUTSTANDING CMDS"
"%d\n", ioc->name,
- sdev->device_busy));
+ atomic_read(&sdev->device_busy)));
}
}
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d0bd7e0ab7a8..1ddf0fb43b59 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -302,9 +302,7 @@ void scsi_device_unbusy(struct scsi_device *sdev)
spin_unlock_irqrestore(shost->host_lock, flags);
}
- spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
- sdev->device_busy--;
- spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
+ atomic_dec(&sdev->device_busy);
}
/*
@@ -355,9 +353,9 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev)
static inline int scsi_device_is_busy(struct scsi_device *sdev)
{
- if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked)
+ if (atomic_read(&sdev->device_busy) >= sdev->queue_depth ||
+ sdev->device_blocked)
return 1;
-
return 0;
}
@@ -1204,7 +1202,7 @@ scsi_prep_return(struct request_queue *q, struct request *req, int ret)
* queue must be restarted, so we schedule a callback to happen
* shortly.
*/
- if (sdev->device_busy == 0)
+ if (atomic_read(&sdev->device_busy) == 0)
blk_delay_queue(q, SCSI_QUEUE_DELAY);
break;
default:
@@ -1255,26 +1253,33 @@ static void scsi_unprep_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 == 0 && sdev->device_blocked) {
+ unsigned int busy;
+
+ busy = atomic_inc_return(&sdev->device_busy) - 1;
+ if (sdev->device_blocked) {
+ if (busy)
+ goto out_dec;
+
/*
* unblock after device_blocked iterates to zero
*/
- if (--sdev->device_blocked == 0) {
- SCSI_LOG_MLQUEUE(3,
- sdev_printk(KERN_INFO, sdev,
- "unblocking device at zero depth\n"));
- } else {
+ if (--sdev->device_blocked != 0) {
blk_delay_queue(q, SCSI_QUEUE_DELAY);
- return 0;
+ goto out_dec;
}
+ SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
+ "unblocking device at zero depth\n"));
}
- if (scsi_device_is_busy(sdev))
- return 0;
+
+ if (busy >= sdev->queue_depth)
+ goto out_dec;
return 1;
+out_dec:
+ atomic_dec(&sdev->device_busy);
+ return 0;
}
-
/*
* scsi_target_queue_ready: checks if there we can send commands to target
* @sdev: scsi device on starget to check.
@@ -1448,7 +1453,7 @@ static void scsi_kill_request(struct request *req, struct request_queue *q)
* bump busy counts. To bump the counters, we need to dance
* with the locks as normal issue path does.
*/
- sdev->device_busy++;
+ atomic_inc(&sdev->device_busy);
atomic_inc(&shost->host_busy);
atomic_inc(&starget->target_busy);
@@ -1544,7 +1549,7 @@ static void scsi_request_fn(struct request_queue *q)
* accept it.
*/
req = blk_peek_request(q);
- if (!req || !scsi_dev_queue_ready(q, sdev))
+ if (!req)
break;
if (unlikely(!scsi_device_online(sdev))) {
@@ -1554,13 +1559,14 @@ static void scsi_request_fn(struct request_queue *q)
continue;
}
+ if (!scsi_dev_queue_ready(q, sdev))
+ break;
/*
* Remove the request from the request list.
*/
if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
blk_start_request(req);
- sdev->device_busy++;
spin_unlock_irq(q->queue_lock);
cmd = req->special;
@@ -1630,9 +1636,9 @@ static void scsi_request_fn(struct request_queue *q)
*/
spin_lock_irq(q->queue_lock);
blk_requeue_request(q, req);
- sdev->device_busy--;
+ atomic_dec(&sdev->device_busy);
out_delay:
- if (sdev->device_busy == 0 && !scsi_device_blocked(sdev))
+ if (atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev))
blk_delay_queue(q, SCSI_QUEUE_DELAY);
}
@@ -2371,7 +2377,7 @@ scsi_device_quiesce(struct scsi_device *sdev)
return err;
scsi_run_queue(sdev->request_queue);
- while (sdev->device_busy) {
+ while (atomic_read(&sdev->device_busy)) {
msleep_interruptible(200);
scsi_run_queue(sdev->request_queue);
}
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index de57b8bca7be..79df9847edef 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -585,13 +585,21 @@ static int scsi_sdev_check_buf_bit(const char *buf)
* Create the actual show/store functions and data structures.
*/
sdev_rd_attr (device_blocked, "%d\n");
-sdev_rd_attr (device_busy, "%d\n");
sdev_rd_attr (type, "%d\n");
sdev_rd_attr (scsi_level, "%d\n");
sdev_rd_attr (vendor, "%.8s\n");
sdev_rd_attr (model, "%.16s\n");
sdev_rd_attr (rev, "%.4s\n");
+static ssize_t
+sdev_show_device_busy(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ return snprintf(buf, 20, "%d\n", atomic_read(&sdev->device_busy));
+}
+static DEVICE_ATTR(device_busy, S_IRUGO, sdev_show_device_busy, NULL);
+
/*
* TODO: can we make these symlinks to the block layer ones?
*/
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 7a291f5c7227..01cf88888797 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -2574,7 +2574,7 @@ static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
scsidp->id, scsidp->lun, (int) scsidp->type,
1,
(int) scsidp->queue_depth,
- (int) scsidp->device_busy,
+ (int) atomic_read(&scsidp->device_busy),
(int) scsi_device_online(scsidp));
}
read_unlock_irqrestore(&sg_index_lock, iflags);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 4e078b63a9e5..3329901c7243 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -81,9 +81,7 @@ struct scsi_device {
struct list_head siblings; /* list of all devices on this host */
struct list_head same_target_siblings; /* just the devices sharing same target id */
- /* this is now protected by the request_queue->queue_lock */
- unsigned int device_busy; /* commands actually active on
- * low-level. protected by queue_lock. */
+ atomic_t device_busy; /* commands actually active on LLDD */
spinlock_t list_lock;
struct list_head cmd_list; /* queue of in use SCSI Command structures */
struct list_head starved_entry;
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