On Wed, May 15, 2024 at 01:50:53AM +0100, Matthew Wilcox wrote: > On Tue, May 07, 2024 at 04:58:12PM +0200, Pankaj Raghav (Samsung) wrote: > > Instead of looping with ZERO_PAGE, use a huge zero folio to zero pad the > > block. Fallback to ZERO_PAGE if mm_get_huge_zero_folio() fails. > > So the block people say we're doing this all wrong. We should be > issuing a REQ_OP_WRITE_ZEROES bio, and the block layer will take care of > using the ZERO_PAGE if the hardware doesn't natively support > WRITE_ZEROES or a DISCARD that zeroes or ... Wait a second, I think you've gone too far if you're setting the bio op to REQ_OP_WRITE_ZEROES. The block layer handles the difference only through the blkdev_issue_zeroout() helper. If you actually submit a bio with that op to a block device that doesn't support it, you'll just get a BLK_STS_NOTSUPP error from submit_bio_noacct().
