A race between scanning and fc_remote_port_delete() may result in a
permanent stop if the device gets blocked before scsi_sysfs_add_sdev()
and unblocked after. The reason is that blocking a device sets both
the SDEV_BLOCKED state and the QUEUE_FLAG_STOPPED. However,
scsi_sysfs_add_sdev() unconditionally sets SDEV_RUNNING which causes
the device to be ignored by scsi_target_unblock() and thus never have
its QUEUE_FLAG_STOPPED cleared leading to a device which is apparently
running but has a stopped queue.
We actually have two places where SDEV_RUNNING is set: once in
scsi_add_lun() which respects the blocked flag and once in
scsi_sysfs_add_sdev() which doesn't. Since the second set is entirely
spurious, simply remove it to fix the problem.
Reported-by: Zengxi Chen <chenzen...@huawei.com>
Signed-off-by: Wei Fang <fangw...@huawei.com>
---
Changes v1->v2:
- don't modify scsi_internal_device_unblock(), just remove changing
state to SDEV_RUNNING in scsi_sysfs_add_sdev(), suggested by
James Bottomley and Ewan D. Milne.
Changes v2->v3
- Use a clearer description of this problem
drivers/scsi/scsi_sysfs.c | 4 ----
include/scsi/scsi_device.h | 2 +-
2 files changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 0734927..82dfe07 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1204,10 +1204,6 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
struct request_queue *rq = sdev->request_queue;
struct scsi_target *starget = sdev->sdev_target;
- error = scsi_device_set_state(sdev, SDEV_RUNNING);
- if (error)
- return error;
-
error = scsi_target_add(starget);
if (error)
return error;
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 8990e58..8bfb37f 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -31,7 +31,7 @@ struct scsi_mode_data {
enum scsi_device_state {
SDEV_CREATED = 1, /* device created but not added to sysfs
* Only internal commands allowed (for inq) */
- SDEV_RUNNING, /* device properly configured
+ SDEV_RUNNING, /* device properly configured and not blocked
* All commands allowed */
SDEV_CANCEL, /* beginning to delete device
* Only error handler commands allowed */
--
2.4.11
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