Commit ec601924 authored by Omar Sandoval's avatar Omar Sandoval Committed by Darrick J. Wong
Browse files

iomap: provide more useful errors for invalid swap files 



Currently, for an invalid swap file, we print the same error message
regardless of the reason. This isn't very useful for an admin, who will
likely want to know why exactly they can't use their swap file. So,
let's add specific error messages for each reason, and also move the
bdev check after the flags checks, since the latter are more
fundamental.

Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent f7664b31

fs/iomap.c

+24 −16
Original line number Diff line number Diff line
@@ -1214,26 +1214,37 @@ static loff_t iomap_swapfile_activate_actor(struct inode *inode, loff_t pos, 
	struct iomap_swapfile_info *isi = data;

	int error;



	/* No inline data. */

	if (iomap->flags & IOMAP_F_DATA_INLINE) {

		pr_err("swapon: file is inline\n");

		return -EINVAL;

	}



	/* Skip holes. */

	if (iomap->type == IOMAP_HOLE)

		goto out;



	/* Only one bdev per swap file. */

	if (iomap->bdev != isi->sis->bdev)

		goto err;



	/* Only real or unwritten extents. */

	if (iomap->type != IOMAP_MAPPED && iomap->type != IOMAP_UNWRITTEN)

		goto err;

	if (iomap->type != IOMAP_MAPPED && iomap->type != IOMAP_UNWRITTEN) {

		pr_err("swapon: file has unallocated extents\n");

		return -EINVAL;

	}



	/* No uncommitted metadata or shared blocks or inline data. */

	if (iomap->flags & (IOMAP_F_DIRTY | IOMAP_F_SHARED |

			    IOMAP_F_DATA_INLINE))

		goto err;

	/* No uncommitted metadata or shared blocks. */

	if (iomap->flags & IOMAP_F_DIRTY) {

		pr_err("swapon: file is not committed\n");

		return -EINVAL;

	}

	if (iomap->flags & IOMAP_F_SHARED) {

		pr_err("swapon: file has shared extents\n");

		return -EINVAL;

	}



	/* No null physical addresses. */

	if (iomap->addr == IOMAP_NULL_ADDR)

		goto err;

	/* Only one bdev per swap file. */

	if (iomap->bdev != isi->sis->bdev) {

		pr_err("swapon: file is on multiple devices\n");

		return -EINVAL;

	}



	if (isi->iomap.length == 0) {

		/* No accumulated extent, so just store it. */
@@ -1250,9 +1261,6 @@ static loff_t iomap_swapfile_activate_actor(struct inode *inode, loff_t pos, 
	}

out:

	return count;

err:

	pr_err("swapon: file cannot be used for swap\n");

	return -EINVAL;

}



/*

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