Ritika,
> + /*
> + * At least SCSI device does not have a good way to return if
> + * Write Same/Zero is actually supported. To detect this, first
> + * try to issue one and if it fails clear the max sectors value.
> + * If this occurs on the lower device, the right error code
> + * needs to be propagated to upper layers.
> + */
> + if (max_sectors == 0)
> + return BLK_STS_NOTSUPP;
Maybe we should make it more explicit in the comment that there is a
window of error where this condition can occur? Something like:
If a device rejects a non-read/write command (discard, write same,
etc.) the low-level device driver will set the relevant queue limit
to 0 to prevent blk-lib from issuing more of the offending
operations. Commands queued prior to the queue limit being reset
need to be completed with BLK_STS_NOTSUPP to avoid I/O errors being
propagated to upper layers.
Otherwise looks good.
Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
--
Martin K. Petersen Oracle Linux Engineering
