Re: [PATCH 3/7] block: simplify direct io validity check
From: Hannes Reinecke <hare@suse.de>
Date: 2025-08-05 06:57:10
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On 8/4/25 19:11, Keith Busch wrote:
On Mon, Aug 04, 2025 at 08:55:36AM +0200, Hannes Reinecke wrote:quoted
On 8/2/25 01:47, Keith Busch wrote:quoted
static bool blkdev_dio_invalid(struct block_device *bdev, struct kiocb *iocb, struct iov_iter *iter) { - return iocb->ki_pos & (bdev_logical_block_size(bdev) - 1) || - !bdev_iter_is_aligned(bdev, iter); + return (iocb->ki_pos | iov_iter_count(iter)) & + (bdev_logical_block_size(bdev) - 1);Bitwise or? Sure?Yep, this is correct. We need to return an error if either the size or offset are not aligned to the block size. "Or"ing the two together gets us a single check against the logical block size mask instead of doing each individually.
Oh, my. Wasn't aware that we're running an obfuscated C-contest ... Anyway. Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich