From b0962c53bde9a485c8ebc401fa1dbe821a76bc3e Mon Sep 17 00:00:00 2001 From: "Ewan D. Milne" Date: Wed, 11 Mar 2020 10:39:30 -0400 Subject: [PATCH] scsi: core: avoid repetitive logging of device offline messages 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 Signed-off-by: Ewan D. Milne Signed-off-by: Martin K. Petersen --- drivers/scsi/scsi_lib.c | 8 ++++++-- include/scsi/scsi_device.h | 3 +++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9f201194c46a..47835c4b4ee0 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1215,8 +1215,11 @@ 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"); + } return BLK_STS_IOERR; case SDEV_DEL: /* @@ -2326,6 +2329,7 @@ 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 579e24c92f2f..c3cba2aaf934 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -203,6 +203,9 @@ struct scsi_device { unsigned unmap_limit_for_ws:1; /* Use the UNMAP limit for WRITE SAME */ unsigned rpm_autosuspend:1; /* Enable runtime autosuspend at device * creation time */ + + 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 */