From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Tue, 7 Nov 2017 09:04:32 -0800
Subject: [PATCH] Revert "scsi: make 'state' device attribute pollable"
Git-commit: a817e73fe693f0718b6210f4b959478877fb2e2f
References: bsc#1085341
Patch-Mainline: v4.14
This reverts commit 8a97712e5314aefe16b3ffb4583a34deaa49de04.
This commit added a call to sysfs_notify() from within
scsi_device_set_state(), which in turn turns out to make libata very
unhappy, because ata_eh_detach_dev() does
spin_lock_irqsave(ap->lock, flags);
..
if (ata_scsi_offline_dev(dev)) {
dev->flags |= ATA_DFLAG_DETACHED;
ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
}
and ata_scsi_offline_dev() then does that scsi_device_set_state() to set
it offline.
So now we called sysfs_notify() from within a spinlocked region, which
really doesn't work. The 0day robot reported this as:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:238
because sysfs_notify() ends up calling kernfs_find_and_get_ns() which
then does mutex_lock(&kernfs_mutex)..
The pollability of the device state isn't critical, so revert this all
for now, and maybe we'll do it differently in the future.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/scsi/scsi_lib.c | 3 ---
drivers/scsi/scsi_transport_srp.c | 5 +----
2 files changed, 1 insertion(+), 7 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ad3ea24f0885..bcc1694cebcd 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2685,7 +2685,6 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
}
sdev->sdev_state = state;
- sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
return 0;
illegal:
@@ -3109,7 +3108,6 @@ int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
case SDEV_BLOCK:
case SDEV_TRANSPORT_OFFLINE:
sdev->sdev_state = new_state;
- sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
break;
case SDEV_CREATED_BLOCK:
if (new_state == SDEV_TRANSPORT_OFFLINE ||
@@ -3117,7 +3115,6 @@ int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
sdev->sdev_state = new_state;
else
sdev->sdev_state = SDEV_CREATED;
- sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
break;
case SDEV_CANCEL:
case SDEV_OFFLINE:
diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index 4f6f01cf9968..36f6190931bc 100644
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -556,11 +556,8 @@ int srp_reconnect_rport(struct srp_rport *rport)
*/
shost_for_each_device(sdev, shost) {
mutex_lock(&sdev->state_mutex);
- if (sdev->sdev_state == SDEV_OFFLINE) {
+ if (sdev->sdev_state == SDEV_OFFLINE)
sdev->sdev_state = SDEV_RUNNING;
- sysfs_notify(&sdev->sdev_gendev.kobj,
- NULL, "state");
- }
mutex_unlock(&sdev->state_mutex);
}
} else if (rport->state == SRP_RPORT_RUNNING) {
--
2.12.3