Add dax mount option to man xfs(5)

Details are already in kernel's documentation, but make dax mount option
information accessible through xfs(5) manpage.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/man/man5/xfs.5 b/man/man5/xfs.5
index b657f0e4597cd0a5200d4d915aafbb8bce541b91..0c1edc53e227ce59e6ea5c8b330c882e282ef304 100644 (file)
--- a/man/man5/xfs.5
+++ b/man/man5/xfs.5
@@ -139,6 +139,23 @@ by the filesystem.
 CRC enabled filesystems always use the attr2 format, and so
 will reject the noattr2 mount option if it is set.
 .TP
+.BR dax=value
+Set CPU direct access (DAX) behavior for the current filesystem. This mount
+option accepts the following values:
+
+"dax=inode" DAX will be enabled only on regular files with FS_XFLAG_DAX applied.
+
+"dax=never" DAX will not be enabled for any files. FS_XFLAG_DAX will be ignored.
+
+"dax=always" DAX will be enabled for all regular files, regardless of the
+FS_XFLAG_DAX state.
+
+If no option is used when mounting a filesystem stored on a DAX capable device,
+dax=inode will be used as default.
+
+For details regarding DAX behavior in kernel, please refer to kernel's
+documentation at filesystems/dax.txt
+.TP
 .BR discard | nodiscard
 Enable/disable the issuing of commands to let the block
 device reclaim space freed by the filesystem.  This is