aboutsummaryrefslogtreecommitdiffstats
path: root/drivers
diff options
context:
space:
mode:
Diffstat (limited to 'drivers')
-rw-r--r--drivers/scsi/scsi.c109
-rw-r--r--drivers/scsi/scsi_lib.c36
-rw-r--r--drivers/scsi/scsi_priv.h1
3 files changed, 45 insertions, 101 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 180676d7115a..ee5f4dfdab14 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -69,7 +69,6 @@
69#include "scsi_logging.h" 69#include "scsi_logging.h"
70 70
71static void scsi_done(struct scsi_cmnd *cmd); 71static void scsi_done(struct scsi_cmnd *cmd);
72static int scsi_retry_command(struct scsi_cmnd *cmd);
73 72
74/* 73/*
75 * Definitions and constants. 74 * Definitions and constants.
@@ -752,7 +751,7 @@ static void scsi_done(struct scsi_cmnd *cmd)
752 * isn't running --- used by scsi_times_out */ 751 * isn't running --- used by scsi_times_out */
753void __scsi_done(struct scsi_cmnd *cmd) 752void __scsi_done(struct scsi_cmnd *cmd)
754{ 753{
755 unsigned long flags; 754 struct request *rq = cmd->request;
756 755
757 /* 756 /*
758 * Set the serial numbers back to zero 757 * Set the serial numbers back to zero
@@ -763,71 +762,14 @@ void __scsi_done(struct scsi_cmnd *cmd)
763 if (cmd->result) 762 if (cmd->result)
764 atomic_inc(&cmd->device->ioerr_cnt); 763 atomic_inc(&cmd->device->ioerr_cnt);
765 764
765 BUG_ON(!rq);
766
766 /* 767 /*
767 * Next, enqueue the command into the done queue. 768 * The uptodate/nbytes values don't matter, as we allow partial
768 * It is a per-CPU queue, so we just disable local interrupts 769 * completes and thus will check this in the softirq callback
769 * and need no spinlock.
770 */ 770 */
771 local_irq_save(flags); 771 rq->completion_data = cmd;
772 list_add_tail(&cmd->eh_entry, &__get_cpu_var(scsi_done_q)); 772 blk_complete_request(rq);
773 raise_softirq_irqoff(SCSI_SOFTIRQ);
774 local_irq_restore(flags);
775}
776
777/**
778 * scsi_softirq - Perform post-interrupt processing of finished SCSI commands.
779 *
780 * This is the consumer of the done queue.
781 *
782 * This is called with all interrupts enabled. This should reduce
783 * interrupt latency, stack depth, and reentrancy of the low-level
784 * drivers.
785 */
786static void scsi_softirq(struct softirq_action *h)
787{
788 int disposition;
789 LIST_HEAD(local_q);
790
791 local_irq_disable();
792 list_splice_init(&__get_cpu_var(scsi_done_q), &local_q);
793 local_irq_enable();
794
795 while (!list_empty(&local_q)) {
796 struct scsi_cmnd *cmd = list_entry(local_q.next,
797 struct scsi_cmnd, eh_entry);
798 /* The longest time any command should be outstanding is the
799 * per command timeout multiplied by the number of retries.
800 *
801 * For a typical command, this is 2.5 minutes */
802 unsigned long wait_for
803 = cmd->allowed * cmd->timeout_per_command;
804 list_del_init(&cmd->eh_entry);
805
806 disposition = scsi_decide_disposition(cmd);
807 if (disposition != SUCCESS &&
808 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
809 sdev_printk(KERN_ERR, cmd->device,
810 "timing out command, waited %lus\n",
811 wait_for/HZ);
812 disposition = SUCCESS;
813 }
814
815 scsi_log_completion(cmd, disposition);
816 switch (disposition) {
817 case SUCCESS:
818 scsi_finish_command(cmd);
819 break;
820 case NEEDS_RETRY:
821 scsi_retry_command(cmd);
822 break;
823 case ADD_TO_MLQUEUE:
824 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
825 break;
826 default:
827 if (!scsi_eh_scmd_add(cmd, 0))
828 scsi_finish_command(cmd);
829 }
830 }
831} 773}
832 774
833/* 775/*
@@ -840,7 +782,7 @@ static void scsi_softirq(struct softirq_action *h)
840 * level drivers should not become re-entrant as a result of 782 * level drivers should not become re-entrant as a result of
841 * this. 783 * this.
842 */ 784 */
843static int scsi_retry_command(struct scsi_cmnd *cmd) 785int scsi_retry_command(struct scsi_cmnd *cmd)
844{ 786{
845 /* 787 /*
846 * Restore the SCSI command state. 788 * Restore the SCSI command state.
@@ -1273,38 +1215,6 @@ int scsi_device_cancel(struct scsi_device *sdev, int recovery)
1273} 1215}
1274EXPORT_SYMBOL(scsi_device_cancel); 1216EXPORT_SYMBOL(scsi_device_cancel);
1275 1217
1276#ifdef CONFIG_HOTPLUG_CPU
1277static int scsi_cpu_notify(struct notifier_block *self,
1278 unsigned long action, void *hcpu)
1279{
1280 int cpu = (unsigned long)hcpu;
1281
1282 switch(action) {
1283 case CPU_DEAD:
1284 /* Drain scsi_done_q. */
1285 local_irq_disable();
1286 list_splice_init(&per_cpu(scsi_done_q, cpu),
1287 &__get_cpu_var(scsi_done_q));
1288 raise_softirq_irqoff(SCSI_SOFTIRQ);
1289 local_irq_enable();
1290 break;
1291 default:
1292 break;
1293 }
1294 return NOTIFY_OK;
1295}
1296
1297static struct notifier_block __devinitdata scsi_cpu_nb = {
1298 .notifier_call = scsi_cpu_notify,
1299};
1300
1301#define register_scsi_cpu() register_cpu_notifier(&scsi_cpu_nb)
1302#define unregister_scsi_cpu() unregister_cpu_notifier(&scsi_cpu_nb)
1303#else
1304#define register_scsi_cpu()
1305#define unregister_scsi_cpu()
1306#endif /* CONFIG_HOTPLUG_CPU */
1307
1308MODULE_DESCRIPTION("SCSI core"); 1218MODULE_DESCRIPTION("SCSI core");
1309MODULE_LICENSE("GPL"); 1219MODULE_LICENSE("GPL");
1310 1220
@@ -1338,8 +1248,6 @@ static int __init init_scsi(void)
1338 INIT_LIST_HEAD(&per_cpu(scsi_done_q, i)); 1248 INIT_LIST_HEAD(&per_cpu(scsi_done_q, i));
1339 1249
1340 devfs_mk_dir("scsi"); 1250 devfs_mk_dir("scsi");
1341 open_softirq(SCSI_SOFTIRQ, scsi_softirq, NULL);
1342 register_scsi_cpu();
1343 printk(KERN_NOTICE "SCSI subsystem initialized\n"); 1251 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1344 return 0; 1252 return 0;
1345 1253
@@ -1367,7 +1275,6 @@ static void __exit exit_scsi(void)
1367 devfs_remove("scsi"); 1275 devfs_remove("scsi");
1368 scsi_exit_procfs(); 1276 scsi_exit_procfs();
1369 scsi_exit_queue(); 1277 scsi_exit_queue();
1370 unregister_scsi_cpu();
1371} 1278}
1372 1279
1373subsys_initcall(init_scsi); 1280subsys_initcall(init_scsi);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ba93d6e66d48..00c9bf383e23 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1493,6 +1493,41 @@ static void scsi_kill_request(struct request *req, request_queue_t *q)
1493 __scsi_done(cmd); 1493 __scsi_done(cmd);
1494} 1494}
1495 1495
1496static void scsi_softirq_done(struct request *rq)
1497{
1498 struct scsi_cmnd *cmd = rq->completion_data;
1499 unsigned long wait_for = cmd->allowed * cmd->timeout_per_command;
1500 int disposition;
1501
1502 INIT_LIST_HEAD(&cmd->eh_entry);
1503
1504 disposition = scsi_decide_disposition(cmd);
1505 if (disposition != SUCCESS &&
1506 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
1507 sdev_printk(KERN_ERR, cmd->device,
1508 "timing out command, waited %lus\n",
1509 wait_for/HZ);
1510 disposition = SUCCESS;
1511 }
1512
1513 scsi_log_completion(cmd, disposition);
1514
1515 switch (disposition) {
1516 case SUCCESS:
1517 scsi_finish_command(cmd);
1518 break;
1519 case NEEDS_RETRY:
1520 scsi_retry_command(cmd);
1521 break;
1522 case ADD_TO_MLQUEUE:
1523 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
1524 break;
1525 default:
1526 if (!scsi_eh_scmd_add(cmd, 0))
1527 scsi_finish_command(cmd);
1528 }
1529}
1530
1496/* 1531/*
1497 * Function: scsi_request_fn() 1532 * Function: scsi_request_fn()
1498 * 1533 *
@@ -1667,6 +1702,7 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
1667 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); 1702 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
1668 blk_queue_segment_boundary(q, shost->dma_boundary); 1703 blk_queue_segment_boundary(q, shost->dma_boundary);
1669 blk_queue_issue_flush_fn(q, scsi_issue_flush_fn); 1704 blk_queue_issue_flush_fn(q, scsi_issue_flush_fn);
1705 blk_queue_softirq_done(q, scsi_softirq_done);
1670 1706
1671 if (!shost->use_clustering) 1707 if (!shost->use_clustering)
1672 clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); 1708 clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index f04e7e11f57a..14a6198cb8d2 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -44,6 +44,7 @@ extern void scsi_init_cmd_from_req(struct scsi_cmnd *cmd,
44 struct scsi_request *sreq); 44 struct scsi_request *sreq);
45extern void __scsi_release_request(struct scsi_request *sreq); 45extern void __scsi_release_request(struct scsi_request *sreq);
46extern void __scsi_done(struct scsi_cmnd *cmd); 46extern void __scsi_done(struct scsi_cmnd *cmd);
47extern int scsi_retry_command(struct scsi_cmnd *cmd);
47#ifdef CONFIG_SCSI_LOGGING 48#ifdef CONFIG_SCSI_LOGGING
48void scsi_log_send(struct scsi_cmnd *cmd); 49void scsi_log_send(struct scsi_cmnd *cmd);
49void scsi_log_completion(struct scsi_cmnd *cmd, int disposition); 50void scsi_log_completion(struct scsi_cmnd *cmd, int disposition);