[RFC PATCH v2 6/8] xfs: Use dax_is_supported()

[Mathieu Desnoyers]

Use dax_is_supported() to validate whether the architecture has
virtually aliased data caches at mount time. Silently disable
DAX if dax=always is requested as a mount option on an architecture
which does not support DAX.

This is relevant for architectures which require a dynamic check
to validate whether they have virtually aliased data caches.

Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Chandan Babu R <chandan.babu@xxxxxxxxxx>
Cc: Darrick J. Wong <djwong@xxxxxxxxxx>
Cc: linux-xfs@xxxxxxxxxxxxxxx
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: nvdimm@xxxxxxxxxxxxxxx
Cc: linux-cxl@xxxxxxxxxxxxxxx
---
 fs/xfs/xfs_iops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index a0d77f5f512e..360f640159b0 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1208,7 +1208,7 @@ static bool
 xfs_inode_should_enable_dax(
 	struct xfs_inode *ip)
 {
-	if (!IS_ENABLED(CONFIG_FS_DAX))
+	if (!dax_is_supported())
 		return false;
 	if (xfs_has_dax_never(ip->i_mount))
 		return false;
-- 
2.39.2