[3.13.y-ckt stable] Patch "hfs: fix B-tree corruption after insertion at position 0" has been added to staging queue

[Kamal Mostafa]

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

    hfs: fix B-tree corruption after insertion at position 0

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt28.

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

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From cd176cdc902fdb9e91eafa2f4996f798fdb60392 Mon Sep 17 00:00:00 2001
From: Hin-Tak Leung <htl10 at users.sourceforge.net>
Date: Wed, 9 Sep 2015 15:38:07 -0700
Subject: hfs: fix B-tree corruption after insertion at position 0

commit b4cc0efea4f0bfa2477c56af406cfcf3d3e58680 upstream.

Fix B-tree corruption when a new record is inserted at position 0 in the
node in hfs_brec_insert().

This is an identical change to the corresponding hfs b-tree code to Sergei
Antonov's "hfsplus: fix B-tree corruption after insertion at position 0",
to keep similar code paths in the hfs and hfsplus drivers in sync, where
appropriate.

Signed-off-by: Hin-Tak Leung <htl10 at users.sourceforge.net>
Cc: Sergei Antonov <saproj at gmail.com>
Cc: Joe Perches <joe at perches.com>
Reviewed-by: Vyacheslav Dubeyko <slava at dubeyko.com>
Cc: Anton Altaparmakov <anton at tuxera.com>
Cc: Al Viro <viro at zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch at infradead.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/hfs/brec.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/fs/hfs/brec.c b/fs/hfs/brec.c
index 9f4ee7f..6fc766d 100644
--- a/fs/hfs/brec.c
+++ b/fs/hfs/brec.c
@@ -131,13 +131,16 @@ skip:
 	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
 	hfs_bnode_dump(node);

-	if (new_node) {
-		/* update parent key if we inserted a key
-		 * at the start of the first node
-		 */
-		if (!rec && new_node != node)
-			hfs_brec_update_parent(fd);
+	/*
+	 * update parent key if we inserted a key
+	 * at the start of the node and it is not the new node
+	 */
+	if (!rec && new_node != node) {
+		hfs_bnode_read_key(node, fd->search_key, data_off + size);
+		hfs_brec_update_parent(fd);
+	}

+	if (new_node) {
 		hfs_bnode_put(fd->bnode);
 		if (!new_node->parent) {
 			hfs_btree_inc_height(tree);
@@ -166,9 +169,6 @@ skip:
 		goto again;
 	}

-	if (!rec)
-		hfs_brec_update_parent(fd);
-
 	return 0;
 }

@@ -366,6 +366,8 @@ again:
 	if (IS_ERR(parent))
 		return PTR_ERR(parent);
 	__hfs_brec_find(parent, fd);
+	if (fd->record < 0)
+		return -ENOENT;
 	hfs_bnode_dump(parent);
 	rec = fd->record;

--
1.9.1