Commit 99800ced authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: refacto blkdev_issue_zeroout 



Split out two well-defined helpers for hardware supported Write Zeroes
and manually writing zeroes using the Write command.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240701165219.1571322-9-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f6eacb26

block/blk-lib.c

+55 −39
Original line number Diff line number Diff line
@@ -135,6 +135,32 @@ static void __blkdev_issue_write_zeroes(struct block_device *bdev, 
	*biop = bio;

}



static int blkdev_issue_write_zeroes(struct block_device *bdev, sector_t sector,

		sector_t nr_sects, gfp_t gfp, unsigned flags)

{

	struct bio *bio = NULL;

	struct blk_plug plug;

	int ret = 0;



	blk_start_plug(&plug);

	__blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp, &bio, flags);

	if (bio) {

		ret = submit_bio_wait(bio);

		bio_put(bio);

	}

	blk_finish_plug(&plug);



	/*

	 * For some devices there is no non-destructive way to verify whether

	 * WRITE ZEROES is actually supported.  These will clear the capability

	 * on an I/O error, in which case we'll turn any error into

	 * "not supported" here.

	 */

	if (ret && !bdev_write_zeroes_sectors(bdev))

		return -EOPNOTSUPP;

	return ret;

}



/*

 * Convert a number of 512B sectors to a number of pages.

 * The result is limited to a number of pages that can fit into a BIO.
@@ -175,6 +201,27 @@ static void __blkdev_issue_zero_pages(struct block_device *bdev, 
	*biop = bio;

}



static int blkdev_issue_zero_pages(struct block_device *bdev, sector_t sector,

		sector_t nr_sects, gfp_t gfp, unsigned flags)

{

	struct bio *bio = NULL;

	struct blk_plug plug;

	int ret = 0;



	if (flags & BLKDEV_ZERO_NOFALLBACK)

		return -EOPNOTSUPP;



	blk_start_plug(&plug);

	__blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp, &bio);

	if (bio) {

		ret = submit_bio_wait(bio);

		bio_put(bio);

	}

	blk_finish_plug(&plug);



	return ret;

}



/**

 * __blkdev_issue_zeroout - generate number of zero filed write bios

 * @bdev:	blockdev to issue
@@ -230,52 +277,21 @@ EXPORT_SYMBOL(__blkdev_issue_zeroout); 
int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,

		sector_t nr_sects, gfp_t gfp_mask, unsigned flags)

{

	int ret = 0;

	sector_t bs_mask;

	struct bio *bio;

	struct blk_plug plug;

	bool try_write_zeroes = !!bdev_write_zeroes_sectors(bdev);

	int ret;



	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;

	if ((sector | nr_sects) & bs_mask)

	if ((sector | nr_sects) & ((bdev_logical_block_size(bdev) >> 9) - 1))

		return -EINVAL;

	if (bdev_read_only(bdev))

		return -EPERM;

	if ((flags & BLKDEV_ZERO_NOFALLBACK) && !try_write_zeroes)

		return -EOPNOTSUPP;



retry:

	bio = NULL;

	blk_start_plug(&plug);

	if (try_write_zeroes) {

		__blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp_mask,

				&bio, flags);

	} else {

		__blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask,

				&bio);

	}

	if (bio) {

		ret = submit_bio_wait(bio);

		bio_put(bio);

	}

	blk_finish_plug(&plug);

	if (ret && try_write_zeroes) {

		if (!(flags & BLKDEV_ZERO_NOFALLBACK)) {

			try_write_zeroes = false;

			goto retry;

		}

		if (!bdev_write_zeroes_sectors(bdev)) {

			/*

			 * Zeroing offload support was indicated, but the

			 * device reported ILLEGAL REQUEST (for some devices

			 * there is no non-destructive way to verify whether

			 * WRITE ZEROES is actually supported).

			 */

			ret = -EOPNOTSUPP;

		}

	if (bdev_write_zeroes_sectors(bdev)) {

		ret = blkdev_issue_write_zeroes(bdev, sector, nr_sects,

				gfp_mask, flags);

		if (!ret)

			return ret;

	}



	return ret;

	return blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp_mask, flags);

}

EXPORT_SYMBOL(blkdev_issue_zeroout);