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path: root/drivers/scsi/hosts.c
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Diffstat (limited to 'drivers/scsi/hosts.c')
-rw-r--r--drivers/scsi/hosts.c113
1 files changed, 84 insertions, 29 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 5feb886c339..85503fad789 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -24,6 +24,7 @@
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/kernel.h>
+#include <linux/kthread.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/init.h>
@@ -52,21 +53,80 @@ static struct class shost_class = {
};
/**
- * scsi_host_cancel - cancel outstanding IO to this host
- * @shost: pointer to struct Scsi_Host
- * recovery: recovery requested to run.
+ * scsi_host_set_state - Take the given host through the host
+ * state model.
+ * @shost: scsi host to change the state of.
+ * @state: state to change to.
+ *
+ * Returns zero if unsuccessful or an error if the requested
+ * transition is illegal.
**/
-static void scsi_host_cancel(struct Scsi_Host *shost, int recovery)
+int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
{
- struct scsi_device *sdev;
+ enum scsi_host_state oldstate = shost->shost_state;
+
+ if (state == oldstate)
+ return 0;
+
+ switch (state) {
+ case SHOST_CREATED:
+ /* There are no legal states that come back to
+ * created. This is the manually initialised start
+ * state */
+ goto illegal;
+
+ case SHOST_RUNNING:
+ switch (oldstate) {
+ case SHOST_CREATED:
+ case SHOST_RECOVERY:
+ break;
+ default:
+ goto illegal;
+ }
+ break;
+
+ case SHOST_RECOVERY:
+ switch (oldstate) {
+ case SHOST_RUNNING:
+ break;
+ default:
+ goto illegal;
+ }
+ break;
+
+ case SHOST_CANCEL:
+ switch (oldstate) {
+ case SHOST_CREATED:
+ case SHOST_RUNNING:
+ break;
+ default:
+ goto illegal;
+ }
+ break;
+
+ case SHOST_DEL:
+ switch (oldstate) {
+ case SHOST_CANCEL:
+ break;
+ default:
+ goto illegal;
+ }
+ break;
- set_bit(SHOST_CANCEL, &shost->shost_state);
- shost_for_each_device(sdev, shost) {
- scsi_device_cancel(sdev, recovery);
}
- wait_event(shost->host_wait, (!test_bit(SHOST_RECOVERY,
- &shost->shost_state)));
+ shost->shost_state = state;
+ return 0;
+
+ illegal:
+ SCSI_LOG_ERROR_RECOVERY(1,
+ dev_printk(KERN_ERR, &shost->shost_gendev,
+ "Illegal host state transition"
+ "%s->%s\n",
+ scsi_host_state_name(oldstate),
+ scsi_host_state_name(state)));
+ return -EINVAL;
}
+EXPORT_SYMBOL(scsi_host_set_state);
/**
* scsi_remove_host - remove a scsi host
@@ -74,11 +134,13 @@ static void scsi_host_cancel(struct Scsi_Host *shost, int recovery)
**/
void scsi_remove_host(struct Scsi_Host *shost)
{
+ down(&shost->scan_mutex);
+ scsi_host_set_state(shost, SHOST_CANCEL);
+ up(&shost->scan_mutex);
scsi_forget_host(shost);
- scsi_host_cancel(shost, 0);
scsi_proc_host_rm(shost);
- set_bit(SHOST_DEL, &shost->shost_state);
+ scsi_host_set_state(shost, SHOST_DEL);
transport_unregister_device(&shost->shost_gendev);
class_device_unregister(&shost->shost_classdev);
@@ -115,7 +177,7 @@ int scsi_add_host(struct Scsi_Host *shost, struct device *dev)
if (error)
goto out;
- set_bit(SHOST_ADD, &shost->shost_state);
+ scsi_host_set_state(shost, SHOST_RUNNING);
get_device(shost->shost_gendev.parent);
error = class_device_add(&shost->shost_classdev);
@@ -164,15 +226,8 @@ static void scsi_host_dev_release(struct device *dev)
struct Scsi_Host *shost = dev_to_shost(dev);
struct device *parent = dev->parent;
- if (shost->ehandler) {
- DECLARE_COMPLETION(sem);
- shost->eh_notify = &sem;
- shost->eh_kill = 1;
- up(shost->eh_wait);
- wait_for_completion(&sem);
- shost->eh_notify = NULL;
- }
-
+ if (shost->ehandler)
+ kthread_stop(shost->ehandler);
if (shost->work_q)
destroy_workqueue(shost->work_q);
@@ -202,7 +257,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
{
struct Scsi_Host *shost;
int gfp_mask = GFP_KERNEL, rval;
- DECLARE_COMPLETION(complete);
if (sht->unchecked_isa_dma && privsize)
gfp_mask |= __GFP_DMA;
@@ -226,6 +280,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
spin_lock_init(&shost->default_lock);
scsi_assign_lock(shost, &shost->default_lock);
+ shost->shost_state = SHOST_CREATED;
INIT_LIST_HEAD(&shost->__devices);
INIT_LIST_HEAD(&shost->__targets);
INIT_LIST_HEAD(&shost->eh_cmd_q);
@@ -307,12 +362,12 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d",
shost->host_no);
- shost->eh_notify = &complete;
- rval = kernel_thread(scsi_error_handler, shost, 0);
- if (rval < 0)
+ shost->ehandler = kthread_run(scsi_error_handler, shost,
+ "scsi_eh_%d", shost->host_no);
+ if (IS_ERR(shost->ehandler)) {
+ rval = PTR_ERR(shost->ehandler);
goto fail_destroy_freelist;
- wait_for_completion(&complete);
- shost->eh_notify = NULL;
+ }
scsi_proc_hostdir_add(shost->hostt);
return shost;
@@ -382,7 +437,7 @@ EXPORT_SYMBOL(scsi_host_lookup);
**/
struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
{
- if (test_bit(SHOST_DEL, &shost->shost_state) ||
+ if ((shost->shost_state == SHOST_DEL) ||
!get_device(&shost->shost_gendev))
return NULL;
return shost;