From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liuwenyi Subject: [PATCH] Avoid a NULL pointer in btrfs Date: Wed, 19 Jan 2011 22:08:13 +0800 Message-ID: <4D36F04D.70505@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=GB2312 To: strongzgy@gmail.com, onlyflyer@gmail.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, ak@linux.intel.com, akpm@linux-foundation.org, miaox@cn.fujitsu.com, josef@redhat. Return-path: List-ID: In Yang Ruirui's mail, the btrfs will create a oops. This is caused by a null pointer in test_range_bit() while lock the spinlock. So, It is necessary to add a pointer check into test_range_bit() --- Signed-off-by: Liu Wenyi --- fs/btrfs/extent_io.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 5e7a94d..0da42b5 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1553,6 +1553,9 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, struct rb_node *node; int bitset = 0; + if (tree == NULL) + return bitset; + spin_lock(&tree->lock); if (cached && cached->tree && cached->start == start) node = &cached->rb_node; -- 1.7.3.3 --- Best Regards, Liu Wenyi