From: "Ewan D. Milne" emilne@redhat.com
mainline inclusion from mainline-v5.7-rc1 commit b0962c53bde9a485c8ebc401fa1dbe821a76bc3e category: bugfix bugzilla: 34604 CVE: NA
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Large queues of I/O to offline devices that are eventually submitted when devices are unblocked result in a many repeated "rejecting I/O to offline device" messages. These messages can fill up the dmesg buffer in crash dumps so no useful prior messages remain. In addition, if a serial console is used, the flood of messages can cause a hard lockup in the console code.
Introduce a flag indicating the message has already been logged for the device, and reset the flag when scsi_device_set_state() changes the device state.
Link: https://lore.kernel.org/r/20200311143930.20674-1-emilne@redhat.com Reviewed-by: Bart van Assche bvanassche@acm.org Signed-off-by: Ewan D. Milne emilne@redhat.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com
conflicts: drivers/scsi/scsi_lib.c include/scsi/scsi_device.h
Signed-off-by: Ye Bin yebin10@huawei.com Reviewed-by: Hou Tao houtao1@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/scsi/scsi_lib.c | 8 ++++++-- include/scsi/scsi_device.h | 2 ++ 2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index e9428458abbb..a8043039f53e 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1437,8 +1437,11 @@ scsi_prep_state_check(struct scsi_device *sdev, struct request *req) * commands. The device must be brought online * before trying any recovery commands. */ - sdev_printk(KERN_ERR, sdev, - "rejecting I/O to offline device\n"); + if (!sdev->offline_already) { + sdev->offline_already = true; + sdev_printk(KERN_ERR, sdev, + "rejecting I/O to offline device\n"); + } ret = BLKPREP_KILL; break; case SDEV_DEL: @@ -2856,6 +2859,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) break;
} + sdev->offline_already = false; sdev->sdev_state = state; return 0;
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index d0de8e8579eb..52b255e868a9 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -201,6 +201,8 @@ struct scsi_device { unsigned lun_in_cdb:1; /* Store LUN bits in CDB[1] */ unsigned unmap_limit_for_ws:1; /* Use the UNMAP limit for WRITE SAME */
+ bool offline_already; /* Device offline message logged */ + atomic_t disk_events_disable_depth; /* disable depth for disk events */
DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */