Disallow the SDEV_TRANSPORT_OFFLINE to SDEV_CANCEL transition such
that no I/O is sent to devices for which the transport is offline.
Notes:
- Functions like sd_shutdown() use scsi_execute_req() and hence
set the REQ_PREEMPT flag. Such requests are passed to the LLD
queuecommand callback in the SDEV_CANCEL state.
- This patch does not affect Fibre Channel LLD drivers since these
drivers invoke fc_remote_port_chkready() before submitting a SCSI
request to the HBA. That prevents a timeout to occur in state
SDEV_CANCEL if the transport is offline.
Signed-off-by: Bart Van Assche <bvanass...@acm.org>
Cc: Mike Christie <micha...@cs.wisc.edu>
Cc: James Bottomley <jbottom...@parallels.com>
Cc: Hannes Reinecke <h...@suse.de>
---
drivers/scsi/scsi_lib.c | 12 +++++++++++-
drivers/scsi/scsi_sysfs.c | 4 +++-
include/scsi/scsi_device.h | 4 ++++
3 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 9eb05a7..362855d 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1232,6 +1232,7 @@ int scsi_prep_state_check(struct scsi_device *sdev,
struct request *req)
switch (sdev->sdev_state) {
case SDEV_OFFLINE:
case SDEV_TRANSPORT_OFFLINE:
+ case SDEV_CANCEL_OFFLINE:
/*
* If the device is offline we refuse to process any
* commands. The device must be brought online
@@ -2178,9 +2179,17 @@ scsi_device_set_state(struct scsi_device *sdev, enum
scsi_device_state state)
case SDEV_CREATED:
case SDEV_RUNNING:
case SDEV_QUIESCE:
+ case SDEV_BLOCK:
+ break;
+ default:
+ goto illegal;
+ }
+ break;
+
+ case SDEV_CANCEL_OFFLINE:
+ switch (oldstate) {
case SDEV_OFFLINE:
case SDEV_TRANSPORT_OFFLINE:
- case SDEV_BLOCK:
break;
default:
goto illegal;
@@ -2194,6 +2203,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum
scsi_device_state state)
case SDEV_OFFLINE:
case SDEV_TRANSPORT_OFFLINE:
case SDEV_CANCEL:
+ case SDEV_CANCEL_OFFLINE:
case SDEV_CREATED_BLOCK:
break;
default:
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 931a7d9..f6ce38e 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -32,6 +32,7 @@ static const struct {
{ SDEV_CREATED, "created" },
{ SDEV_RUNNING, "running" },
{ SDEV_CANCEL, "cancel" },
+ { SDEV_CANCEL_OFFLINE, "cancel-offline" },
{ SDEV_DEL, "deleted" },
{ SDEV_QUIESCE, "quiesce" },
{ SDEV_OFFLINE, "offline" },
@@ -955,7 +956,8 @@ void __scsi_remove_device(struct scsi_device *sdev)
struct device *dev = &sdev->sdev_gendev;
if (sdev->is_visible) {
- if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0)
+ if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0 &&
+ scsi_device_set_state(sdev, SDEV_CANCEL_OFFLINE) != 0)
return;
bsg_unregister_queue(sdev->request_queue);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index fead252..4ecf7ed1 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -35,6 +35,8 @@ enum scsi_device_state {
* All commands allowed */
SDEV_CANCEL, /* beginning to delete device
* Only error handler commands allowed */
+ SDEV_CANCEL_OFFLINE, /* beginning to delete offline device
+ * No commands allowed */
SDEV_DEL, /* device deleted
* no commands allowed */
SDEV_QUIESCE, /* Device quiescent. No block commands
@@ -442,6 +444,7 @@ static inline int scsi_device_online(struct scsi_device
*sdev)
{
return (sdev->sdev_state != SDEV_OFFLINE &&
sdev->sdev_state != SDEV_TRANSPORT_OFFLINE &&
+ sdev->sdev_state != SDEV_CANCEL_OFFLINE &&
sdev->sdev_state != SDEV_DEL);
}
static inline int scsi_device_blocked(struct scsi_device *sdev)
@@ -457,6 +460,7 @@ static inline int scsi_device_created(struct scsi_device
*sdev)
static inline int scsi_device_being_removed(struct scsi_device *sdev)
{
return sdev->sdev_state == SDEV_CANCEL ||
+ sdev->sdev_state == SDEV_CANCEL_OFFLINE ||
sdev->sdev_state == SDEV_DEL;
}
--
1.7.10.4
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