[SCSI] host state model update: replace old host bitmap state
Migrate the current SCSI host state model to a model like SCSI
device is using.
Signed-off-by: Mike Anderson <andmike@us.ibm.com>
Rejections fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 5feb886..6828ca3 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -52,6 +52,82 @@
};
/**
+ * 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.
+ **/
+int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
+{
+ 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;
+
+ }
+ 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_host_cancel - cancel outstanding IO to this host
* @shost: pointer to struct Scsi_Host
* recovery: recovery requested to run.
@@ -60,12 +136,11 @@
{
struct scsi_device *sdev;
- set_bit(SHOST_CANCEL, &shost->shost_state);
+ scsi_host_set_state(shost, SHOST_CANCEL);
shost_for_each_device(sdev, shost) {
scsi_device_cancel(sdev, recovery);
}
- wait_event(shost->host_wait, (!test_bit(SHOST_RECOVERY,
- &shost->shost_state)));
+ wait_event(shost->host_wait, (shost->shost_state != SHOST_RECOVERY));
}
/**
@@ -78,7 +153,7 @@
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 +190,7 @@
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);
@@ -226,6 +301,7 @@
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);
@@ -382,7 +458,7 @@
**/
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;
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index d14523d..fb85b3c 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -627,7 +627,7 @@
spin_lock_irqsave(host->host_lock, flags);
scsi_cmd_get_serial(host, cmd);
- if (unlikely(test_bit(SHOST_CANCEL, &host->shost_state))) {
+ if (unlikely(host->shost_state == SHOST_CANCEL)) {
cmd->result = (DID_NO_CONNECT << 16);
scsi_done(cmd);
} else {
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 0fc8b48..e9c451b 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -75,7 +75,7 @@
scmd->eh_eflags |= eh_flag;
list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
- set_bit(SHOST_RECOVERY, &shost->shost_state);
+ scsi_host_set_state(shost, SHOST_RECOVERY);
shost->host_failed++;
scsi_eh_wakeup(shost);
spin_unlock_irqrestore(shost->host_lock, flags);
@@ -197,7 +197,8 @@
{
int online;
- wait_event(sdev->host->host_wait, (!test_bit(SHOST_RECOVERY, &sdev->host->shost_state)));
+ wait_event(sdev->host->host_wait, (sdev->host->shost_state !=
+ SHOST_RECOVERY));
online = scsi_device_online(sdev);
@@ -1458,7 +1459,7 @@
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
__FUNCTION__));
- clear_bit(SHOST_RECOVERY, &shost->shost_state);
+ scsi_host_set_state(shost, SHOST_RUNNING);
wake_up(&shost->host_wait);
diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c
index 7a6b530..f5bf5c0 100644
--- a/drivers/scsi/scsi_ioctl.c
+++ b/drivers/scsi/scsi_ioctl.c
@@ -475,8 +475,7 @@
* error processing, as long as the device was opened
* non-blocking */
if (filp && filp->f_flags & O_NONBLOCK) {
- if (test_bit(SHOST_RECOVERY,
- &sdev->host->shost_state))
+ if (sdev->host->shost_state == SHOST_RECOVERY)
return -ENODEV;
} else if (!scsi_block_when_processing_errors(sdev))
return -ENODEV;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7a91ca3..060010b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -348,7 +348,7 @@
spin_lock_irqsave(shost->host_lock, flags);
shost->host_busy--;
- if (unlikely(test_bit(SHOST_RECOVERY, &shost->shost_state) &&
+ if (unlikely((shost->shost_state == SHOST_RECOVERY) &&
shost->host_failed))
scsi_eh_wakeup(shost);
spin_unlock(shost->host_lock);
@@ -1207,7 +1207,7 @@
struct Scsi_Host *shost,
struct scsi_device *sdev)
{
- if (test_bit(SHOST_RECOVERY, &shost->shost_state))
+ if (shost->shost_state == SHOST_RECOVERY)
return 0;
if (shost->host_busy == 0 && shost->host_blocked) {
/*
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index beed7fb..dae59d1 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -48,6 +48,30 @@
return name;
}
+static struct {
+ enum scsi_host_state value;
+ char *name;
+} shost_states[] = {
+ { SHOST_CREATED, "created" },
+ { SHOST_RUNNING, "running" },
+ { SHOST_CANCEL, "cancel" },
+ { SHOST_DEL, "deleted" },
+ { SHOST_RECOVERY, "recovery" },
+};
+const char *scsi_host_state_name(enum scsi_host_state state)
+{
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < sizeof(shost_states)/sizeof(shost_states[0]); i++) {
+ if (shost_states[i].value == state) {
+ name = shost_states[i].name;
+ break;
+ }
+ }
+ return name;
+}
+
static int check_set(unsigned int *val, char *src)
{
char *last;
@@ -124,6 +148,43 @@
};
static CLASS_DEVICE_ATTR(scan, S_IWUSR, NULL, store_scan);
+static ssize_t
+store_shost_state(struct class_device *class_dev, const char *buf, size_t count)
+{
+ int i;
+ struct Scsi_Host *shost = class_to_shost(class_dev);
+ enum scsi_host_state state = 0;
+
+ for (i = 0; i < sizeof(shost_states)/sizeof(shost_states[0]); i++) {
+ const int len = strlen(shost_states[i].name);
+ if (strncmp(shost_states[i].name, buf, len) == 0 &&
+ buf[len] == '\n') {
+ state = shost_states[i].value;
+ break;
+ }
+ }
+ if (!state)
+ return -EINVAL;
+
+ if (scsi_host_set_state(shost, state))
+ return -EINVAL;
+ return count;
+}
+
+static ssize_t
+show_shost_state(struct class_device *class_dev, char *buf)
+{
+ struct Scsi_Host *shost = class_to_shost(class_dev);
+ const char *name = scsi_host_state_name(shost->shost_state);
+
+ if (!name)
+ return -EINVAL;
+
+ return snprintf(buf, 20, "%s\n", name);
+}
+
+static CLASS_DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_shost_state, store_shost_state);
+
shost_rd_attr(unique_id, "%u\n");
shost_rd_attr(host_busy, "%hu\n");
shost_rd_attr(cmd_per_lun, "%hd\n");
@@ -139,6 +200,7 @@
&class_device_attr_unchecked_isa_dma,
&class_device_attr_proc_name,
&class_device_attr_scan,
+ &class_device_attr_state,
NULL
};
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 51292f2..14fb179 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1027,8 +1027,7 @@
if (sdp->detached)
return -ENODEV;
if (filp->f_flags & O_NONBLOCK) {
- if (test_bit(SHOST_RECOVERY,
- &sdp->device->host->shost_state))
+ if (sdp->device->host->shost_state == SHOST_RECOVERY)
return -EBUSY;
} else if (!scsi_block_when_processing_errors(sdp->device))
return -EBUSY;
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 81d5234..0b1e275 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -429,12 +429,15 @@
};
/*
- * shost states
+ * shost state: If you alter this, you also need to alter scsi_sysfs.c
+ * (for the ascii descriptions) and the state model enforcer:
+ * scsi_host_set_state()
*/
-enum {
- SHOST_ADD,
- SHOST_DEL,
+enum scsi_host_state {
+ SHOST_CREATED = 1,
+ SHOST_RUNNING,
SHOST_CANCEL,
+ SHOST_DEL,
SHOST_RECOVERY,
};
@@ -575,7 +578,7 @@
unsigned int irq;
- unsigned long shost_state;
+ enum scsi_host_state shost_state;
/* ldm bits */
struct device shost_gendev;
@@ -633,6 +636,7 @@
extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
extern void scsi_host_put(struct Scsi_Host *t);
extern struct Scsi_Host *scsi_host_lookup(unsigned short);
+extern const char *scsi_host_state_name(enum scsi_host_state);
extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *);