ubifs: Fix regression in ubifs_readdir()

commit a00052a296e54205cf238c75bd98d17d5d02a6db upstream.

Commit c83ed4c9dbb35 ("ubifs: Abort readdir upon error") broke
overlayfs support because the fix exposed an internal error
code to VFS.

Reported-by: Peter Rosin <peda@axentia.se>
Tested-by: Peter Rosin <peda@axentia.se>
Reported-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Tested-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Fixes: c83ed4c9dbb35 ("ubifs: Abort readdir upon error")
Signed-off-by: Richard Weinberger <richard@nod.at>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index ca4eb94..348dcb2 100644 (file)
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -477,6 +477,14 @@ static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
 out:
        if (err != -ENOENT)
                ubifs_err("cannot find next direntry, error %d", err);
+       else
+               /*
+                * -ENOENT is a non-fatal error in this context, the TNC uses
+                * it to indicate that the cursor moved past the current directory
+                * and readdir() has to stop.
+                */
+               err = 0;
+
 
        kfree(file->private_data);
        file->private_data = NULL;