Patch "hfs: fix B-tree corruption after insertion at position 0" has been added to the 4.2-stable tree

This is a note to let you know that I've just added the patch titled

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

to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
hfs-fix-b-tree-corruption-after-insertion-at-position-0.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Hin-Tak Leung <[email protected]>
Date: Wed, 9 Sep 2015 15:38:07 -0700
Subject: hfs: fix B-tree corruption after insertion at position 0

From: Hin-Tak Leung <[email protected]>

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.

---
 fs/hfs/brec.c |   20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

@@ -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;
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.2/hfs-fix-b-tree-corruption-after-insertion-at-position-0.patch queue-4.2/hfs-hfsplus-cache-pages-correctly-between-bnode_create-and-bnode_free.patch