From a57195214358b75807a74bad96a8601a36262af7 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 24 Sep 2009 09:17:31 -0400 Subject: Btrfs: check size of inode backref before adding hardlink For every hardlink in btrfs, there is a corresponding inode back reference. All inode back references for hardlinks in a given directory are stored in single b-tree item. The size of b-tree item is limited by the size of b-tree leaf, so we can only create limited number of hardlinks to a given file in a directory. The original code lacks of the check, it oops if the number of hardlinks goes over the limit. This patch fixes the issue by adding check to btrfs_link and btrfs_rename. Signed-off-by: Yan Zheng Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/btrfs/ctree.c') diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 3fdcc05..ec96f3a 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2853,6 +2853,12 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans, int split; int num_doubles = 0; + l = path->nodes[0]; + slot = path->slots[0]; + if (extend && data_size + btrfs_item_size_nr(l, slot) + + sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) + return -EOVERFLOW; + /* first try to make some room by pushing left and right */ if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) { wret = push_leaf_right(trans, root, path, data_size, 0); -- cgit v1.1