diff options
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 75 |
1 files changed, 39 insertions, 36 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index b83269689542..112c737884c3 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1274,18 +1274,18 @@ static inline int scsi_dev_queue_ready(struct request_queue *q, /* * scsi_target_queue_ready: checks if there we can send commands to target * @sdev: scsi device on starget to check. - * - * Called with the host lock held. */ static inline int scsi_target_queue_ready(struct Scsi_Host *shost, struct scsi_device *sdev) { struct scsi_target *starget = scsi_target(sdev); + int ret = 0; + spin_lock_irq(shost->host_lock); if (starget->single_lun) { if (starget->starget_sdev_user && starget->starget_sdev_user != sdev) - return 0; + goto out; starget->starget_sdev_user = sdev; } @@ -1293,57 +1293,66 @@ static inline int scsi_target_queue_ready(struct Scsi_Host *shost, /* * unblock after target_blocked iterates to zero */ - if (--starget->target_blocked == 0) { - SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, - "unblocking target at zero depth\n")); - } else - return 0; + if (--starget->target_blocked != 0) + goto out; + + SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, + "unblocking target at zero depth\n")); } if (scsi_target_is_busy(starget)) { list_move_tail(&sdev->starved_entry, &shost->starved_list); - return 0; + goto out; } - return 1; + scsi_target(sdev)->target_busy++; + ret = 1; +out: + spin_unlock_irq(shost->host_lock); + return ret; } /* * scsi_host_queue_ready: if we can send requests to shost, return 1 else * return 0. We must end up running the queue again whenever 0 is * returned, else IO can hang. - * - * Called with host_lock held. */ static inline int scsi_host_queue_ready(struct request_queue *q, struct Scsi_Host *shost, struct scsi_device *sdev) { + int ret = 0; + + spin_lock_irq(shost->host_lock); + if (scsi_host_in_recovery(shost)) - return 0; + goto out; if (shost->host_busy == 0 && shost->host_blocked) { /* * unblock after host_blocked iterates to zero */ - if (--shost->host_blocked == 0) { - SCSI_LOG_MLQUEUE(3, - shost_printk(KERN_INFO, shost, - "unblocking host at zero depth\n")); - } else { - return 0; - } + if (--shost->host_blocked != 0) + goto out; + + SCSI_LOG_MLQUEUE(3, + shost_printk(KERN_INFO, shost, + "unblocking host at zero depth\n")); } if (scsi_host_is_busy(shost)) { if (list_empty(&sdev->starved_entry)) list_add_tail(&sdev->starved_entry, &shost->starved_list); - return 0; + goto out; } /* We're OK to process the command, so we can't be starved */ if (!list_empty(&sdev->starved_entry)) list_del_init(&sdev->starved_entry); - return 1; + shost->host_busy++; + ret = 1; +out: + spin_unlock_irq(shost->host_lock); + return ret; } /* @@ -1524,7 +1533,7 @@ static void scsi_request_fn(struct request_queue *q) blk_start_request(req); sdev->device_busy++; - spin_unlock(q->queue_lock); + spin_unlock_irq(q->queue_lock); cmd = req->special; if (unlikely(cmd == NULL)) { printk(KERN_CRIT "impossible request in %s.\n" @@ -1534,7 +1543,6 @@ static void scsi_request_fn(struct request_queue *q) blk_dump_rq_flags(req, "foo"); BUG(); } - spin_lock(shost->host_lock); /* * We hit this when the driver is using a host wide @@ -1545,9 +1553,11 @@ static void scsi_request_fn(struct request_queue *q) * a run when a tag is freed. */ if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { + spin_lock_irq(shost->host_lock); if (list_empty(&sdev->starved_entry)) list_add_tail(&sdev->starved_entry, &shost->starved_list); + spin_unlock_irq(shost->host_lock); goto not_ready; } @@ -1555,16 +1565,7 @@ static void scsi_request_fn(struct request_queue *q) goto not_ready; if (!scsi_host_queue_ready(q, shost, sdev)) - goto not_ready; - - scsi_target(sdev)->target_busy++; - shost->host_busy++; - - /* - * XXX(hch): This is rather suboptimal, scsi_dispatch_cmd will - * take the lock again. - */ - spin_unlock_irq(shost->host_lock); + goto host_not_ready; /* * Finally, initialize any error handling parameters, and set up @@ -1587,9 +1588,11 @@ static void scsi_request_fn(struct request_queue *q) return; - not_ready: + host_not_ready: + spin_lock_irq(shost->host_lock); + scsi_target(sdev)->target_busy--; spin_unlock_irq(shost->host_lock); - + not_ready: /* * lock q, handle tag, requeue req, and decrement device_busy. We * must return with queue_lock held. |