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| author | David Sterba <dsterba@suse.cz> | 2011-04-19 16:45:00 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.cz> | 2011-05-02 13:57:20 +0200 |
| commit | 4891aca2dac612a2f21a3278d9906ade13b55788 (patch) | |
| tree | 6ec35a8d5cae40ab8755cd3e70d471e85827c87c | |
| parent | edc95aec57661c8e568e18f6c3f002aefa07ebc8 (diff) | |
| download | linux-4891aca2dac612a2f21a3278d9906ade13b55788.tar.bz2 | |
btrfs: fix dereference before check
The superblock's ->s_fs_info is properly set in btrfs_fill_super, after
a call to open_ctree, which derefereces it before check. Although
tree_root is set via btrfs_set_super, let's be defensive and leave the
check in place.
Signed-off-by: David Sterba <dsterba@suse.cz>
| -rw-r--r-- | fs/btrfs/disk-io.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 990afa8656a2..25e4b8f1d0ef 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1611,7 +1611,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_root *tree_root = btrfs_sb(sb); - struct btrfs_fs_info *fs_info = tree_root->fs_info; + struct btrfs_fs_info *fs_info = NULL; struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root), @@ -1623,11 +1623,12 @@ struct btrfs_root *open_ctree(struct super_block *sb, struct btrfs_super_block *disk_super; - if (!extent_root || !tree_root || !fs_info || + if (!extent_root || !tree_root || !tree_root->fs_info || !chunk_root || !dev_root || !csum_root) { err = -ENOMEM; goto fail; } + fs_info = tree_root->fs_info; ret = init_srcu_struct(&fs_info->subvol_srcu); if (ret) { |