From: Richard Weinberger <richard@nod.at>
Date: Fri, 28 Oct 2016 09:49:03 +0000 (+0200)
Subject: ubifs: Fix regression in ubifs_readdir()
X-Git-Tag: firefly_0821_release~176^2~4^2~19^2~51
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=dc70a200aac2dafd2502ac1cfc1a5ca6dde6486f;p=firefly-linux-kernel-4.4.55.git

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 102ae0c582c1..f5d5ee43ae6e 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -454,6 +454,14 @@ out:
 
 	if (err != -ENOENT)
 		ubifs_err(c, "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;
+
 
 	/* 2 is a special value indicating that there are no more direntries */
 	ctx->pos = 2;