From a817e73fe693f0718b6210f4b959478877fb2e2f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 7 Nov 2017 09:04:32 -0800 Subject: [PATCH] Revert "scsi: make 'state' device attribute pollable" 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 Acked-by: Tejun Heo Acked-by: Martin K. Petersen Acked-by: Hannes Reinecke Signed-off-by: Linus Torvalds --- 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) { -- 2.20.1