NFSv4.1 fix incorrect return value in copy_file_range

According to the NFSv4.2 spec if the input and output file is the
same file, operation should fail with EINVAL. However, linux
copy_file_range() system call has no such restrictions. Therefore,
in such case let's return EOPNOTSUPP and allow VFS to fallback
to doing do_splice_direct(). Also when copy_file_range is called
on an NFSv4.0 or 4.1 mount (ie., a server that doesn't support
COPY functionality), we also need to return EOPNOTSUPP and
fallback to a regular copy.

Fixes xfstest generic/075, generic/091, generic/112, generic/263
for all NFSv4.x versions.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

2 files changed, 3 insertions, 4 deletions

diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index ff6f85fb676b..5196bfa7894d 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -329,9 +329,6 @@ ssize_t nfs42_proc_copy(struct file *src, loff_t pos_src,
         };
         ssize_t err, err2;
 
-        if (!nfs_server_capable(file_inode(dst), NFS_CAP_COPY))
-                return -EOPNOTSUPP;
-
         src_lock = nfs_get_lock_context(nfs_file_open_context(src));
         if (IS_ERR(src_lock))
                 return PTR_ERR(src_lock);
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 45b2322e092d..00d17198ee12 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -133,8 +133,10 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
                                     struct file *file_out, loff_t pos_out,
                                     size_t count, unsigned int flags)
 {
+        if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY))
+                return -EOPNOTSUPP;
         if (file_inode(file_in) == file_inode(file_out))
-                return -EINVAL;
+                return -EOPNOTSUPP;
         return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 }