diff options
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index f5d3b96890dc..148d3af92aef 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); |