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| author | James Bottomley <James.Bottomley@HansenPartnership.com> | 2008-08-22 16:53:31 -0500 |
|---|---|---|
| committer | James Bottomley <James.Bottomley@HansenPartnership.com> | 2008-10-03 11:46:13 -0500 |
| commit | 6f4267e3bd1211b3d09130e626b0b3d885077610 (patch) | |
| tree | e9350f919238866c3bcd9c340ffea639a0c5de1d /drivers/scsi/scsi_lib.c | |
| parent | 0f1d87a2acb8fd1f2ef8af109a785123ddc1a6cb (diff) | |
| download | lwn-6f4267e3bd1211b3d09130e626b0b3d885077610.tar.gz lwn-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.c | 39 |
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); |