Functions like sd_shutdown() use scsi_execute_req() and hence set
the REQ_PREEMPT flag. Requests for which this flag is set are
passed to the LLD queuecommand callback for devices that are in the
state SDEV_CANCEL. This means that the scsi_device_set_state(sdev,
SDEV_CANCEL) call in __scsi_remove_device() will reenable I/O
for offline devices.
Avoid this by introducing a new SCSI device state SDEV_CANCEL_OFFLINE.
This state is reached once deleting an offline device starts. Allow
the SDEV_{TRANSPORT_,}OFFLINE to SDEV_CANCEL_OFFLINE and
SDEV_CANCEL_OFFLINE to SDEV_DEL transitions. Disallow the
SDEV_{TRANSPORT_,}OFFLINE to SDEV_CANCEL transitions.
Note: 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 function already prevents commands to
be submitted to the HBA for SCSI devices in state SDEV_CANCEL if
the transport is offline.
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Mike Christie <michaelc@xxxxxxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
---
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 7e50061..9a5cde9 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" },
@@ -985,7 +986,8 @@ 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 69540bf..f0aad47 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
@@ -443,6 +445,7 @@ 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)
@@ -458,6 +461,7 @@ 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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