Commit 1e937cdd authored May 10, 2016 by Toshi Kani Committed by Vishal Verma May 17, 2016

xfs: Add alignment check for DAX mount



When a partition is not aligned by 4KB, mount -o dax succeeds,
but any read/write access to the filesystem fails, except for
metadata update.

Call bdev_dax_supported() to perform proper precondition checks
which includes this partition alignment check.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

parent 284854be

fs/xfs/xfs_super.c

+5 −7

Original line number	Diff line number	Diff line
		@@ -1559,13 +1559,11 @@ xfs_fs_fill_super(
		if (mp->m_flags & XFS_MOUNT_DAX) {
		xfs_warn(mp,
		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
		if (sb->s_blocksize != PAGE_SIZE) {
		xfs_alert(mp,
		"Filesystem block size invalid for DAX Turning DAX off.");
		mp->m_flags &= ~XFS_MOUNT_DAX;
		} else if (!sb->s_bdev->bd_disk->fops->direct_access) {

		error = bdev_dax_supported(sb, sb->s_blocksize);
		if (error) {
		xfs_alert(mp,
		"Block device does not support DAX Turning DAX off.");
		"DAX unsupported by block device. Turning off DAX.");
		mp->m_flags &= ~XFS_MOUNT_DAX;
		}
		}

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