[ 3.5.y.z extended stable ] Patch "ext3, ext4: don't mess with dir_file->f_pos in" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ext3,ext4: don't mess with dir_file->f_pos in

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 91eea0ef646e22390472ffaf2ba6404b6cb90de8 Mon Sep 17 00:00:00 2001
From: Al Viro <viro at ZenIV.linux.org.uk>
Date: Mon, 1 Jul 2013 08:12:38 -0400
Subject: [PATCH] ext3,ext4: don't mess with dir_file->f_pos in
 htree_dirblock_to_tree()

commit 64cb927371cd2ec43758d8a094a003d27bc3d0dc upstream.

Both ext3 and ext4 htree_dirblock_to_tree() is just filling the
in-core rbtree for use by call_filldir().  All updates of ->f_pos are
done by the latter; bumping it here (on error) is obviously wrong - we
might very well have it nowhere near the block we'd found an error in.

Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
Signed-off-by: "Theodore Ts'o" <tytso at mit.edu>
[ luis: backported to 3.5: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/ext3/namei.c | 7 ++-----
 fs/ext4/namei.c | 7 ++-----
 2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
index eeb63df..336256a 100644
--- a/fs/ext3/namei.c
+++ b/fs/ext3/namei.c
@@ -573,11 +573,8 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 		if (!ext3_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
 					(block<<EXT3_BLOCK_SIZE_BITS(dir->i_sb))
 						+((char *)de - bh->b_data))) {
-			/* On error, skip the f_pos to the next block. */
-			dir_file->f_pos = (dir_file->f_pos |
-					(dir->i_sb->s_blocksize - 1)) + 1;
-			brelse (bh);
-			return count;
+			/* silently ignore the rest of the block */
+			break;
 		}
 		ext3fs_dirhash(de->name, de->name_len, hinfo);
 		if ((hinfo->hash < start_hash) ||
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 20c13eb..43a35db 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -859,11 +859,8 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 		if (ext4_check_dir_entry(dir, NULL, de, bh,
 				(block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 					 + ((char *)de - bh->b_data))) {
-			/* On error, skip the f_pos to the next block. */
-			dir_file->f_pos = (dir_file->f_pos |
-					(dir->i_sb->s_blocksize - 1)) + 1;
-			brelse(bh);
-			return count;
+			/* silently ignore the rest of the block */
+			break;
 		}
 		ext4fs_dirhash(de->name, de->name_len, hinfo);
 		if ((hinfo->hash < start_hash) ||
--
1.8.1.2