On Mon, 2020-03-09 at 14:14 -0400, Ewan D. Milne wrote:
> 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.
>
> Signed-off-by: Ewan D. Milne <emilne@xxxxxxxxxx>
> ---
> 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 610ee41..d3a6d97 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1240,8 +1240,11 @@ 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 = 1;
> + sdev_printk(KERN_ERR, sdev,
> + "rejecting I/O to offline
> device\n");
> + }
Offline->online is a legal transition, so you'll need to clear this
flag when that happens so we get another offline message if it goes
offline again.
James
