[patch 2/2] Ocfs2/move_extents: NULL dereference moving extents

Dan Carpenter
2013-04-04T06:39:41Z

We can't dereference "bg" before it has been assigned.

GCC should have warned about this but "bg" was initialized to NULL.
I've fixed that as well.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
Static analysis stuff. Compile tested only.

diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 995d1b4..f81d23c 100644
--- a/fs/ocfs2/move_extents.c
+++ b/fs/ocfs2/move_extents.c
@@ -471,7 +471,7 @@ static int ocfs2_validate_and_adjust_move_goal(struct inode *inode,
int ret, goal_bit = 0;

struct buffer_head *gd_bh = NULL;
- struct ocfs2_group_desc *bg = NULL;
+ struct ocfs2_group_desc *bg;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
int c_to_b = 1 << (osb->s_clustersize_bits -
inode->i_sb->s_blocksize_bits);
@@ -482,13 +482,6 @@ static int ocfs2_validate_and_adjust_move_goal(struct inode *inode,
range->me_goal = ocfs2_block_to_cluster_start(inode->i_sb,
range->me_goal);
/*
- * moving goal is not allowd to start with a group desc blok(#0 blk)
- * let's compromise to the latter cluster.
- */
- if (range->me_goal = le64_to_cpu(bg->bg_blkno))
- range->me_goal += c_to_b;
-
- /*
* validate goal sits within global_bitmap, and return the victim
* group desc
*/
@@ -502,6 +495,13 @@ static int ocfs2_validate_and_adjust_move_goal(struct inode *inode,
bg = (struct ocfs2_group_desc *)gd_bh->b_data;

/*
+ * moving goal is not allowd to start with a group desc blok(#0 blk)
+ * let's compromise to the latter cluster.
+ */
+ if (range->me_goal = le64_to_cpu(bg->bg_blkno))
+ range->me_goal += c_to_b;
+
+ /*
* movement is not gonna cross two groups.
*/
if ((le16_to_cpu(bg->bg_bits) - goal_bit) * osb->s_clustersize <