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path: root/drivers/scsi/scsi_lib.c
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Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c25
1 files changed, 12 insertions, 13 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index f5d3b96890d..148d3af92ae 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -567,15 +567,18 @@ static inline int scsi_host_is_busy(struct Scsi_Host *shost)
*/
static void scsi_run_queue(struct request_queue *q)
{
- struct scsi_device *starved_head = NULL, *sdev = q->queuedata;
+ struct scsi_device *sdev = q->queuedata;
struct Scsi_Host *shost = sdev->host;
+ LIST_HEAD(starved_list);
unsigned long flags;
if (scsi_target(sdev)->single_lun)
scsi_single_lun_run(sdev);
spin_lock_irqsave(shost->host_lock, flags);
- while (!list_empty(&shost->starved_list) && !scsi_host_is_busy(shost)) {
+ list_splice_init(&shost->starved_list, &starved_list);
+
+ while (!list_empty(&starved_list)) {
int flagset;
/*
@@ -588,24 +591,18 @@ static void scsi_run_queue(struct request_queue *q)
* scsi_request_fn must get the host_lock before checking
* or modifying starved_list or starved_entry.
*/
- sdev = list_entry(shost->starved_list.next,
- struct scsi_device, starved_entry);
- /*
- * The *queue_ready functions can add a device back onto the
- * starved list's tail, so we must check for a infinite loop.
- */
- if (sdev == starved_head)
+ if (scsi_host_is_busy(shost))
break;
- if (!starved_head)
- starved_head = sdev;
+ sdev = list_entry(starved_list.next,
+ struct scsi_device, starved_entry);
+ list_del_init(&sdev->starved_entry);
if (scsi_target_is_busy(scsi_target(sdev))) {
list_move_tail(&sdev->starved_entry,
&shost->starved_list);
continue;
}
- list_del_init(&sdev->starved_entry);
spin_unlock(shost->host_lock);
spin_lock(sdev->request_queue->queue_lock);
@@ -621,6 +618,8 @@ static void scsi_run_queue(struct request_queue *q)
spin_lock(shost->host_lock);
}
+ /* put any unprocessed entries back */
+ list_splice(&starved_list, &shost->starved_list);
spin_unlock_irqrestore(shost->host_lock, flags);
blk_run_queue(q);
@@ -649,8 +648,8 @@ static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
struct request *req = cmd->request;
unsigned long flags;
- scsi_unprep_request(req);
spin_lock_irqsave(q->queue_lock, flags);
+ scsi_unprep_request(req);
blk_requeue_request(q, req);
spin_unlock_irqrestore(q->queue_lock, flags);