[PATCH 3.2 065/126] ubifs: Fix regression in ubifs_readdir()

From: Ben Hutchings
Date: Wed Feb 15 2017 - 19:33:22 EST


3.2.85-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Richard Weinberger <richard@xxxxxx>

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@xxxxxxxxxx>
Tested-by: Peter Rosin <peda@xxxxxxxxxx>
Reported-by: Ralph Sennhauser <ralph.sennhauser@xxxxxxxxx>
Tested-by: Ralph Sennhauser <ralph.sennhauser@xxxxxxxxx>
Fixes: c83ed4c9dbb35 ("ubifs: Abort readdir upon error")
Signed-off-by: Richard Weinberger <richard@xxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
fs/ubifs/dir.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -477,6 +477,14 @@ static int ubifs_readdir(struct file *fi
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;