[PATCH 5.2 010/124] nfs: disable client side deduplication

[Greg Kroah-Hartman]

From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

commit 9026b3a973b0b0b73c15ba40aff87cd0959fd0f3 upstream.

The NFS protocol doesn't support deduplication, so turn it off again.

Fixes: ce96e888fe48e ("Fix nfs4.2 return -EINVAL when do dedupe operation")
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/nfs/nfs4file.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -187,7 +187,11 @@ static loff_t nfs42_remap_file_range(str
 	bool same_inode = false;
 	int ret;
 
-	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
+	/* NFS does not support deduplication. */
+	if (remap_flags & REMAP_FILE_DEDUP)
+		return -EOPNOTSUPP;
+
+	if (remap_flags & ~REMAP_FILE_ADVISORY)
 		return -EINVAL;
 
 	/* check alignment w.r.t. clone_blksize */