From 7f4804d4c8b78ca223cee50e22ddaea9903f0930 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 29 Apr 2013 15:05:59 -0700 Subject: [PATCH] ocfs2: fix NULL dereference for moving extents 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 Signed-off-by: Jie Liu Reviewed-by: Jie Liu Cc: Mark Fasheh Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/move_extents.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c index 8f3d3cb7fa97..f1fc172175b6 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); @@ -481,13 +481,6 @@ 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 @@ -501,6 +494,13 @@ 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. */ -- 2.20.1