On Wed, 2016-04-13 at 09:29 -0700, Bart Van Assche wrote: > On 04/13/2016 09:21 AM, Martin K. Petersen wrote: > > From a filesystem/ioctl perspective, BLKDISCARD is a hint. We > > should not be > > rounding off or aligning anything. > > Hello Martin, > > Today if a BLKDISCARD ioctl passes a non-aligned start and/or end > sector to the kernel then the block layer will submit invalid (non > -aligned) REQ_DISCARD requests to the block driver the ioctl applies > to. This is not acceptable. Does the above mean that you are > proposing to fail such BLKDISCARD ioctls with an error code? The answer would be of course not. discard is a hint so malformed discard gets ignored by the device and success is returned because you can't oblige devices to obey hints (that's why they're called hints). However, the problem of needing a mandatory discard for scrubbing blocks is part of the fallocate discussion, I think. James -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
