Commit 912b6038 authored by Zhang Yi's avatar Zhang Yi Committed by Christian Brauner
Browse files

block: add FALLOC_FL_WRITE_ZEROES support 



Add support for FALLOC_FL_WRITE_ZEROES, if the block device enables the
unmap write zeroes operation, it will issue a write zeroes command.

Signed-off-by: default avatarZhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/20250619111806.3546162-9-yi.zhang@huaweicloud.com


Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatar"Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 562108d5

block/fops.c

+11 −1
Original line number Diff line number Diff line
@@ -841,7 +841,7 @@ static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) 


#define	BLKDEV_FALLOC_FL_SUPPORTED					\

		(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |		\

		 FALLOC_FL_ZERO_RANGE)

		 FALLOC_FL_ZERO_RANGE | FALLOC_FL_WRITE_ZEROES)



static long blkdev_fallocate(struct file *file, int mode, loff_t start,

			     loff_t len)
@@ -856,6 +856,13 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, 
	/* Fail if we don't recognize the flags. */

	if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED)

		return -EOPNOTSUPP;

	/*

	 * Don't allow writing zeroes if the device does not enable the

	 * unmap write zeroes operation.

	 */

	if ((mode & FALLOC_FL_WRITE_ZEROES) &&

	    !bdev_write_zeroes_unmap_sectors(bdev))

		return -EOPNOTSUPP;



	/* Don't go off the end of the device. */

	isize = bdev_nr_bytes(bdev);
@@ -886,6 +893,9 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, 
	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:

		flags = BLKDEV_ZERO_NOFALLBACK;

		break;

	case FALLOC_FL_WRITE_ZEROES:

		flags = 0;

		break;

	default:

		error = -EOPNOTSUPP;

		goto fail;