[SCSI] Update the SCSI state model to allow blocking in the created state
Brian King <brking@linux.vnet.ibm.com> reported that fibre channel
devices can oops during scanning if their ports block (because the
device goes from CREATED -> BLOCK -> RUNNING rather than CREATED ->
BLOCK -> CREATED).
Fix this by adding a new state: CREATED_BLOCK which can only transition
back to CREATED and disallow the CREATED -> BLOCK transition. Now both
the created and blocked states that the mid-layer recognises can include
CREATED_BLOCK.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 62307bd..d2884bf 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1251,6 +1251,7 @@
break;
case SDEV_QUIESCE:
case SDEV_BLOCK:
+ case SDEV_CREATED_BLOCK:
/*
* If the devices is blocked we defer normal commands.
*/
@@ -2064,10 +2065,13 @@
switch (state) {
case SDEV_CREATED:
- /* There are no legal states that come back to
- * created. This is the manually initialised start
- * state */
- goto illegal;
+ switch (oldstate) {
+ case SDEV_CREATED_BLOCK:
+ break;
+ default:
+ goto illegal;
+ }
+ break;
case SDEV_RUNNING:
switch (oldstate) {
@@ -2105,8 +2109,17 @@
case SDEV_BLOCK:
switch (oldstate) {
- case SDEV_CREATED:
case SDEV_RUNNING:
+ case SDEV_CREATED_BLOCK:
+ break;
+ default:
+ goto illegal;
+ }
+ break;
+
+ case SDEV_CREATED_BLOCK:
+ switch (oldstate) {
+ case SDEV_CREATED:
break;
default:
goto illegal;
@@ -2394,8 +2407,12 @@
int err = 0;
err = scsi_device_set_state(sdev, SDEV_BLOCK);
- if (err)
- return err;
+ if (err) {
+ err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
+
+ if (err)
+ return err;
+ }
/*
* The device has transitioned to SDEV_BLOCK. Stop the
@@ -2438,8 +2455,12 @@
* and goose the device queue if successful.
*/
err = scsi_device_set_state(sdev, SDEV_RUNNING);
- if (err)
- return err;
+ if (err) {
+ err = scsi_device_set_state(sdev, SDEV_CREATED);
+
+ if (err)
+ return err;
+ }
spin_lock_irqsave(q->queue_lock, flags);
blk_start_queue(q);
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 2926baa..334862e 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -730,6 +730,8 @@
static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
int *bflags, int async)
{
+ int ret;
+
/*
* XXX do not save the inquiry, since it can change underneath us,
* save just vendor/model/rev.
@@ -885,7 +887,17 @@
/* set the device running here so that slave configure
* may do I/O */
- scsi_device_set_state(sdev, SDEV_RUNNING);
+ ret = scsi_device_set_state(sdev, SDEV_RUNNING);
+ if (ret) {
+ ret = scsi_device_set_state(sdev, SDEV_BLOCK);
+
+ if (ret) {
+ sdev_printk(KERN_ERR, sdev,
+ "in wrong state %s to complete scan\n",
+ scsi_device_state_name(sdev->sdev_state));
+ return SCSI_SCAN_NO_RESPONSE;
+ }
+ }
if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
sdev->use_192_bytes_for_3f = 1;
@@ -899,7 +911,7 @@
transport_configure_device(&sdev->sdev_gendev);
if (sdev->host->hostt->slave_configure) {
- int ret = sdev->host->hostt->slave_configure(sdev);
+ ret = sdev->host->hostt->slave_configure(sdev);
if (ret) {
/*
* if LLDD reports slave not present, don't clutter
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index ab3c718..09d311d 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -34,6 +34,7 @@
{ SDEV_QUIESCE, "quiesce" },
{ SDEV_OFFLINE, "offline" },
{ SDEV_BLOCK, "blocked" },
+ { SDEV_CREATED_BLOCK, "created-blocked" },
};
const char *scsi_device_state_name(enum scsi_device_state state)