From 6f07e42ee6fcc252a210781d7262f4051e9fd8f6 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 17 Nov 2011 00:46:16 -0500 Subject: [PATCH] btrfs: sanitizing ->fs_info, part 4 A new helper: btrfs_alloc_root(fs_info); allocates btrfs_root and sets ->fs_info. All places allocating the suckers converted to it. At that point we *never* reassign ->fs_info of btrfs_root; it's set before anyone sees the address of newly allocated struct btrfs_root and never assigned anywhere else. Signed-off-by: Al Viro --- fs/btrfs/disk-io.c | 33 +++++++++++++++------------------ fs/btrfs/disk-io.h | 2 ++ fs/btrfs/super.c | 3 +-- 3 files changed, 18 insertions(+), 20 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 06480fcf0fb3..ee846ce58846 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1215,6 +1215,14 @@ static int find_and_setup_root(struct btrfs_root *tree_root, return 0; } +struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root = kzalloc(sizeof(*root), GFP_NOFS); + if (root) + root->fs_info = fs_info; + return root; +} + static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info) { @@ -1222,11 +1230,10 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *tree_root = fs_info->tree_root; struct extent_buffer *leaf; - root = kzalloc(sizeof(*root), GFP_NOFS); + root = btrfs_alloc_root(fs_info); if (!root) return ERR_PTR(-ENOMEM); - root->fs_info = fs_info; __setup_root(tree_root->nodesize, tree_root->leafsize, tree_root->sectorsize, tree_root->stripesize, root, fs_info, BTRFS_TREE_LOG_OBJECTID); @@ -1317,10 +1324,9 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root, u32 blocksize; int ret = 0; - root = kzalloc(sizeof(*root), GFP_NOFS); + root = btrfs_alloc_root(fs_info); if (!root) return ERR_PTR(-ENOMEM); - root->fs_info = fs_info; if (location->offset == (u64)-1) { ret = find_and_setup_root(tree_root, fs_info, location->objectid, root); @@ -1900,23 +1906,15 @@ struct btrfs_root *open_ctree(struct super_block *sb, int num_backups_tried = 0; int backup_index = 0; - extent_root = fs_info->extent_root = - kzalloc(sizeof(struct btrfs_root), GFP_NOFS); - csum_root = fs_info->csum_root = - kzalloc(sizeof(struct btrfs_root), GFP_NOFS); - chunk_root = fs_info->chunk_root = - kzalloc(sizeof(struct btrfs_root), GFP_NOFS); - dev_root = fs_info->dev_root = - kzalloc(sizeof(struct btrfs_root), GFP_NOFS); + extent_root = fs_info->extent_root = btrfs_alloc_root(fs_info); + csum_root = fs_info->csum_root = btrfs_alloc_root(fs_info); + chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info); + dev_root = fs_info->dev_root = btrfs_alloc_root(fs_info); if (!extent_root || !csum_root || !chunk_root || !dev_root) { err = -ENOMEM; goto fail; } - chunk_root->fs_info = fs_info; - extent_root->fs_info = fs_info; - dev_root->fs_info = fs_info; - csum_root->fs_info = fs_info; ret = init_srcu_struct(&fs_info->subvol_srcu); if (ret) { @@ -2372,13 +2370,12 @@ struct btrfs_root *open_ctree(struct super_block *sb, btrfs_level_size(tree_root, btrfs_super_log_root_level(disk_super)); - log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); + log_tree_root = btrfs_alloc_root(fs_info); if (!log_tree_root) { err = -ENOMEM; goto fail_trans_kthread; } - log_tree_root->fs_info = fs_info; __setup_root(nodesize, leafsize, sectorsize, stripesize, log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID); diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index c99d0a8f13fa..2bb5f59ddf95 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -86,6 +86,8 @@ int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans, int btrfs_add_log_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root); +struct btrfs_root *btrfs_alloc_root(struct btrfs_fs_info *fs_info); + #ifdef CONFIG_DEBUG_LOCK_ALLOC void btrfs_init_lockdep(void); void btrfs_set_buffer_lockdep_class(u64 objectid, diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index b9fd62a0fca2..e9f876a1655b 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -901,12 +901,11 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, if (!fs_info) return ERR_PTR(-ENOMEM); - fs_info->tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); + fs_info->tree_root = btrfs_alloc_root(fs_info); if (!fs_info->tree_root) { error = -ENOMEM; goto error_fs_info; } - fs_info->tree_root->fs_info = fs_info; fs_info->fs_devices = fs_devices; fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); -- GitLab