Re: [PATCH v4] scsi: sd: retry command SYNC CACHE if format in progress

[Damien Le Moal]

On 8/17/24 10:50, Yihang Li wrote:
> If formatting a suspended disk (such as formatting with different DIF
> type), the disk will be resuming first, and then the format command will
> submit to the disk through SG_IO ioctl.
> 
> When the disk is processing the format command, the system does not submit
> other commands to the disk. Therefore, the system attempts to suspend the
> disk again and sends the SYNC CACHE command. However, the SYNC CACHE

Why would the system try to suspend the disk with a request in flight ? Sounds
like there is a bug with PM reference counting, no ?

> command will fail because the disk is in the formatting process, which
> will cause the runtime_status of the disk to error and it is difficult
> for user to recover it. Error info like:
> 
> [  669.925325] sd 6:0:6:0: [sdg] Synchronizing SCSI cache
> [  670.202371] sd 6:0:6:0: [sdg] Synchronize Cache(10) failed: Result: hostbyte=0x00 driverbyte=DRIVER_OK
> [  670.216300] sd 6:0:6:0: [sdg] Sense Key : 0x2 [current]
> [  670.221860] sd 6:0:6:0: [sdg] ASC=0x4 ASCQ=0x4
> 
> To solve the issue, retry the command until format command is finished.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Yihang Li <liyihang9@xxxxxxxxxx>
> Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> Changes since v3:
> - Add Cc tag for kernel stable.
> 
> Changes since v2:
> - Add Reviewed-by for Bart.
> 
> Changes since v1:
> - Updated and added error information to the patch description.
> 
> ---
>  drivers/scsi/sd.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index adeaa8ab9951..5cd88a8eea73 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -1823,6 +1823,11 @@ static int sd_sync_cache(struct scsi_disk *sdkp)
>  			    (sshdr.asc == 0x74 && sshdr.ascq == 0x71))	/* drive is password locked */
>  				/* this is no error here */
>  				return 0;
> +
> +			/* retry if format in progress */
> +			if (sshdr.asc == 0x4 && sshdr.ascq == 0x4)
> +				return -EBUSY;
> +
>  			/*
>  			 * This drive doesn't support sync and there's not much
>  			 * we can do because this is called during shutdown

-- 
Damien Le Moal
Western Digital Research