xfs: factor out a xfs_buftarg_is_dax helper

Refactor the DAX setup code in preparation of removing
bdev_dax_supported.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20210826135510.6293-9-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 2c9e26a..5a89bf6 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -314,6 +314,14 @@ xfs_set_inode_alloc(
        return (mp->m_flags & XFS_MOUNT_32BITINODES) ? maxagi : agcount;
 }
 
+static bool
+xfs_buftarg_is_dax(
+       struct super_block      *sb,
+       struct xfs_buftarg      *bt)
+{
+       return bdev_dax_supported(bt->bt_bdev, sb->s_blocksize);
+}
+
 STATIC int
 xfs_blkdev_get(
        xfs_mount_t             *mp,
@@ -1549,11 +1557,10 @@ xfs_fs_fill_super(
                xfs_warn(mp,
                "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
 
-               datadev_is_dax = bdev_dax_supported(mp->m_ddev_targp->bt_bdev,
-                       sb->s_blocksize);
+               datadev_is_dax = xfs_buftarg_is_dax(sb, mp->m_ddev_targp);
                if (mp->m_rtdev_targp)
-                       rtdev_is_dax = bdev_dax_supported(
-                               mp->m_rtdev_targp->bt_bdev, sb->s_blocksize);
+                       rtdev_is_dax = xfs_buftarg_is_dax(sb,
+                                               mp->m_rtdev_targp);
                if (!rtdev_is_dax && !datadev_is_dax) {
                        xfs_alert(mp,
                        "DAX unsupported by block device. Turning off DAX.");