Read side was already fully supported, for the write side all that's
needed now is calling generic_uncached_write() when uncached writes
have been submitted. With that, enable the use of RWF_UNCACHED with XFS
by flagging support with FOP_UNCACHED.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/xfs/xfs_file.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index b19916b11fd5..1a7f46e13464 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -825,6 +825,7 @@ xfs_file_buffered_write(
 
 	if (ret > 0) {
 		XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
+		generic_uncached_write(iocb, ret);
 		/* Handle various SYNC-type writes */
 		ret = generic_write_sync(iocb, ret);
 	}
@@ -1595,7 +1596,8 @@ const struct file_operations xfs_file_operations = {
 	.fadvise	= xfs_file_fadvise,
 	.remap_file_range = xfs_file_remap_range,
 	.fop_flags	= FOP_MMAP_SYNC | FOP_BUFFER_RASYNC |
-			  FOP_BUFFER_WASYNC | FOP_DIO_PARALLEL_WRITE,
+			  FOP_BUFFER_WASYNC | FOP_DIO_PARALLEL_WRITE |
+			  FOP_UNCACHED,
 };
 
 const struct file_operations xfs_dir_file_operations = {
-- 
2.45.2