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authorJames Bottomley <James.Bottomley@HansenPartnership.com>2008-08-22 23:53:31 +0200
committerJames Bottomley <James.Bottomley@HansenPartnership.com>2008-10-03 18:46:13 +0200
commit6f4267e3bd1211b3d09130e626b0b3d885077610 (patch)
treee9350f919238866c3bcd9c340ffea639a0c5de1d /drivers/scsi/scsi_lib.c
parent[SCSI] add inline functions for recognising created and blocked states (diff)
downloadlinux-6f4267e3bd1211b3d09130e626b0b3d885077610.tar.xz
linux-6f4267e3bd1211b3d09130e626b0b3d885077610.zip
[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>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c39
1 files changed, 30 insertions, 9 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 62307bd794a9..d2884bffa1b9 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1251,6 +1251,7 @@ int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
break;
case SDEV_QUIESCE:
case SDEV_BLOCK:
+ case SDEV_CREATED_BLOCK:
/*
* If the devices is blocked we defer normal commands.
*/
@@ -2064,10 +2065,13 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
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 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
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 @@ scsi_internal_device_block(struct scsi_device *sdev)
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 @@ scsi_internal_device_unblock(struct scsi_device *sdev)
* 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);