vfs: vfs_dedupe_file_range() doesn't return EOPNOTSUPP

It returns EINVAL when the operation is not supported by the
filesystem. Fix it to return EOPNOTSUPP to be consistent with
the man page and clone_file_range().

Clean up the inconsistent error return handling while I'm there.
(I know, lipstick on a pig, but every little bit helps...)

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

1 files changed, 7 insertions, 8 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index bfcb4ced5664..4dae0399c75a 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -2094,17 +2094,18 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
         off = same->src_offset;
         len = same->src_length;
 
-        ret = -EISDIR;
         if (S_ISDIR(src->i_mode))
-                goto out;
+                return -EISDIR;
 
-        ret = -EINVAL;
         if (!S_ISREG(src->i_mode))
-                goto out;
+                return -EINVAL;
+
+        if (!file->f_op->remap_file_range)
+                return -EOPNOTSUPP;
 
         ret = remap_verify_area(file, off, len, false);
         if (ret < 0)
-                goto out;
+                return ret;
         ret = 0;
 
         if (off + len > i_size_read(src))
@@ -2147,10 +2148,8 @@ next_fdput:
                 fdput(dst_fd);
 next_loop:
                 if (fatal_signal_pending(current))
-                        goto out;
+                        break;
         }
-
-out:
         return ret;
 }
 EXPORT_SYMBOL(vfs_dedupe_file_range);