{
struct Scsi_Host *host = cmd->device->host;
struct scsi_device *device = cmd->device;
+ struct scsi_target *starget = scsi_target(device);
struct request_queue *q = device->request_queue;
unsigned long flags;
* if a command is requeued with no other commands outstanding
* either for the device or for the host.
*/
- if (reason == SCSI_MLQUEUE_HOST_BUSY)
+ switch (reason) {
+ case SCSI_MLQUEUE_HOST_BUSY:
host->host_blocked = host->max_host_blocked;
- else if (reason == SCSI_MLQUEUE_DEVICE_BUSY)
+ break;
+ case SCSI_MLQUEUE_DEVICE_BUSY:
device->device_blocked = device->max_device_blocked;
+ break;
+ case SCSI_MLQUEUE_TARGET_BUSY:
+ starget->target_blocked = starget->max_target_blocked;
+ break;
+ }
/*
* Decrement the counters, since these commands are no longer
void scsi_device_unbusy(struct scsi_device *sdev)
{
struct Scsi_Host *shost = sdev->host;
+ struct scsi_target *starget = scsi_target(sdev);
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
shost->host_busy--;
+ starget->target_busy--;
if (unlikely(scsi_host_in_recovery(shost) &&
(shost->host_failed || shost->host_eh_scheduled)))
scsi_eh_wakeup(shost);
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 &&
+ starget->target_busy >= starget->can_queue) ||
+ 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()
*
*/
static void scsi_run_queue(struct request_queue *q)
{
- struct scsi_device *sdev = q->queuedata;
+ struct scsi_device *starved_head = NULL, *sdev = q->queuedata;
struct Scsi_Host *shost = sdev->host;
unsigned long flags;
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;
/*
*/
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)
+ break;
+ if (!starved_head)
+ starved_head = sdev;
+
+ 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_unlock(sdev->request_queue->queue_lock);
spin_lock(shost->host_lock);
- if (unlikely(!list_empty(&sdev->starved_entry)))
- /*
- * sdev lost a race, and was put back on the
- * starved list. This is unlikely but without this
- * in theory we could loop forever.
- */
- break;
}
spin_unlock_irqrestore(shost->host_lock, flags);
leftover = req->data_len;
/* kill remainder if no retrys */
- if (error && blk_noretry_request(req))
+ if (error && scsi_noretry_cmd(cmd))
blk_end_request(req, error, leftover);
else {
if (requeue) {
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
return 0;
}
}
- if (sdev->device_blocked)
+ if (scsi_device_is_busy(sdev))
return 0;
return 1;
}
+
+/*
+ * 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);
+
+ if (starget->single_lun) {
+ if (starget->starget_sdev_user &&
+ starget->starget_sdev_user != sdev)
+ return 0;
+ starget->starget_sdev_user = sdev;
+ }
+
+ if (starget->target_busy == 0 && starget->target_blocked) {
+ /*
+ * 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 {
+ blk_plug_device(sdev->request_queue);
+ return 0;
+ }
+ }
+
+ if (scsi_target_is_busy(starget)) {
+ if (list_empty(&sdev->starved_entry)) {
+ list_add_tail(&sdev->starved_entry,
+ &shost->starved_list);
+ return 0;
+ }
+ }
+
+ /* 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;
+}
+
/*
* 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
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;
{
struct scsi_cmnd *cmd = req->special;
struct scsi_device *sdev = cmd->device;
+ struct scsi_target *starget = scsi_target(sdev);
struct Scsi_Host *shost = sdev->host;
blkdev_dequeue_request(req);
spin_unlock(sdev->request_queue->queue_lock);
spin_lock(shost->host_lock);
shost->host_busy++;
+ starget->target_busy++;
spin_unlock(shost->host_lock);
spin_lock(sdev->request_queue->queue_lock);
goto not_ready;
}
+ if (!scsi_target_queue_ready(shost, sdev))
+ goto not_ready;
+
if (!scsi_host_queue_ready(q, shost, sdev))
goto not_ready;
- if (scsi_target(sdev)->single_lun) {
- if (scsi_target(sdev)->starget_sdev_user &&
- scsi_target(sdev)->starget_sdev_user != sdev)
- goto not_ready;
- scsi_target(sdev)->starget_sdev_user = sdev;
- }
+
+ scsi_target(sdev)->target_busy++;
shost->host_busy++;
/*
do {
result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
timeout, retries);
- } while ((driver_byte(result) & DRIVER_SENSE) &&
- sshdr && sshdr->sense_key == UNIT_ATTENTION &&
- --retries);
+ if (sdev->removable && scsi_sense_valid(sshdr) &&
+ sshdr->sense_key == UNIT_ATTENTION)
+ sdev->changed = 1;
+ } while (scsi_sense_valid(sshdr) &&
+ sshdr->sense_key == UNIT_ATTENTION && --retries);
if (!sshdr)
/* could not allocate sense buffer, so can't process it */
return result;
- if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) {
-
- if ((scsi_sense_valid(sshdr)) &&
- ((sshdr->sense_key == UNIT_ATTENTION) ||
- (sshdr->sense_key == NOT_READY))) {
- sdev->changed = 1;
- result = 0;
- }
+ if (sdev->removable && scsi_sense_valid(sshdr) &&
+ (sshdr->sense_key == UNIT_ATTENTION ||
+ sshdr->sense_key == NOT_READY)) {
+ sdev->changed = 1;
+ result = 0;
}
if (!sshdr_external)
kfree(sshdr);
projects / linux-2.6-omap-h63xx.git / blobdiff