From 068132bad1de70f85f5f6d12c36d64f8f7848d92 Mon Sep 17 00:00:00 2001 From: Daniel J Blueman Date: Thu, 23 Jun 2011 23:01:01 +0800 Subject: [PATCH] btrfs: fix oops on failure path If lookup_extent_backref fails, path->nodes[0] reasonably could be null along with other callers of btrfs_print_leaf, so ensure we have a valid extent buffer before dereferencing. Signed-off-by: Daniel J Blueman --- fs/btrfs/print-tree.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c index fb2605d998e..f38e452486b 100644 --- a/fs/btrfs/print-tree.c +++ b/fs/btrfs/print-tree.c @@ -158,8 +158,7 @@ static void print_extent_ref_v0(struct extent_buffer *eb, int slot) void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l) { int i; - u32 type; - u32 nr = btrfs_header_nritems(l); + u32 type, nr; struct btrfs_item *item; struct btrfs_root_item *ri; struct btrfs_dir_item *di; @@ -172,6 +171,11 @@ void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l) struct btrfs_key key; struct btrfs_key found_key; + if (!l) + return; + + nr = btrfs_header_nritems(l); + printk(KERN_INFO "leaf %llu total ptrs %d free space %d\n", (unsigned long long)btrfs_header_bytenr(l), nr, btrfs_leaf_free_space(root, l)); -- 2.39.2