[v2.6.34-stable 173/213] ext4: don't dereference null pointer when make_indexed_dir() fails

[Paul Gortmaker]

From: Allison Henderson <achender@xxxxxxxxxxxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 6976a6f2acde2b0443cd64f1d08af90630e4ce81 upstream.

Fix for a null pointer bug found while running punch hole tests

Signed-off-by: Allison Henderson <achender@xxxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 fs/ext4/namei.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index caa3c77f1743..41198b355a26 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1451,6 +1451,10 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	frame->at = entries;
 	frame->bh = bh;
 	bh = bh2;
+
+	ext4_handle_dirty_metadata(handle, dir, frame->bh);
+	ext4_handle_dirty_metadata(handle, dir, bh);
+
 	de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
 	if (!de) {
 		/*
@@ -1459,8 +1463,6 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 		 * with corrupted filesystem.
 		 */
 		ext4_mark_inode_dirty(handle, dir);
-		ext4_handle_dirty_metadata(handle, dir, frame->bh);
-		ext4_handle_dirty_metadata(handle, dir, bh);
 		dx_release(frames);
 		return retval;
 	}
-- 
1.8.5.2

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