From a57195214358b75807a74bad96a8601a36262af7 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 24 Sep 2009 09:17:31 -0400 Subject: [PATCH] Btrfs: check size of inode backref before adding hardlink For every hardlink in btrfs, there is a corresponding inode back reference. All inode back references for hardlinks in a given directory are stored in single b-tree item. The size of b-tree item is limited by the size of b-tree leaf, so we can only create limited number of hardlinks to a given file in a directory. The original code lacks of the check, it oops if the number of hardlinks goes over the limit. This patch fixes the issue by adding check to btrfs_link and btrfs_rename. Signed-off-by: Yan Zheng Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 6 +++++ fs/btrfs/inode-item.c | 2 ++ fs/btrfs/inode.c | 53 +++++++++++++++++++++++-------------------- 3 files changed, 37 insertions(+), 24 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 3fdcc0512d3..ec96f3a6d53 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2853,6 +2853,12 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans, int split; int num_doubles = 0; + l = path->nodes[0]; + slot = path->slots[0]; + if (extend && data_size + btrfs_item_size_nr(l, slot) + + sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) + return -EOVERFLOW; + /* first try to make some room by pushing left and right */ if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) { wret = push_leaf_right(trans, root, path, data_size, 0); diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c index fc6f4a7f640..72ce3c173d6 100644 --- a/fs/btrfs/inode-item.c +++ b/fs/btrfs/inode-item.c @@ -149,6 +149,8 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans, ptr = (unsigned long)(ref + 1); ret = 0; } else if (ret < 0) { + if (ret == -EOVERFLOW) + ret = -EMLINK; goto out; } else { ref = btrfs_item_ptr(path->nodes[0], path->slots[0], diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index db9cbd91eb4..19fcde289dd 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4133,18 +4133,16 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir, err = btrfs_add_nondir(trans, dentry, inode, 1, index); - if (err) - drop_inode = 1; - - btrfs_update_inode_block_group(trans, dir); - err = btrfs_update_inode(trans, root, inode); - - if (err) + if (err) { drop_inode = 1; + } else { + btrfs_update_inode_block_group(trans, dir); + err = btrfs_update_inode(trans, root, inode); + BUG_ON(err); + btrfs_log_new_name(trans, inode, NULL, dentry->d_parent); + } nr = trans->blocks_used; - - btrfs_log_new_name(trans, inode, NULL, dentry->d_parent); btrfs_end_transaction_throttle(trans, root); fail: if (drop_inode) { @@ -5087,23 +5085,26 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, down_read(&root->fs_info->subvol_sem); trans = btrfs_start_transaction(root, 1); + btrfs_set_trans_block_group(trans, new_dir); if (dest != root) btrfs_record_root_in_trans(trans, dest); - /* - * make sure the inode gets flushed if it is replacing - * something. - */ - if (new_inode && new_inode->i_size && - old_inode && S_ISREG(old_inode->i_mode)) { - btrfs_add_ordered_operation(trans, root, old_inode); - } + ret = btrfs_set_inode_index(new_dir, &index); + if (ret) + goto out_fail; - if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) { + if (unlikely(old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) { /* force full log commit if subvolume involved. */ root->fs_info->last_trans_log_full_commit = trans->transid; } else { + ret = btrfs_insert_inode_ref(trans, dest, + new_dentry->d_name.name, + new_dentry->d_name.len, + old_inode->i_ino, + new_dir->i_ino, index); + if (ret) + goto out_fail; /* * this is an ugly little race, but the rename is required * to make sure that if we crash, the inode is either at the @@ -5113,8 +5114,14 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, */ btrfs_pin_log_trans(root); } - - btrfs_set_trans_block_group(trans, new_dir); + /* + * make sure the inode gets flushed if it is replacing + * something. + */ + if (new_inode && new_inode->i_size && + old_inode && S_ISREG(old_inode->i_mode)) { + btrfs_add_ordered_operation(trans, root, old_inode); + } old_dir->i_ctime = old_dir->i_mtime = ctime; new_dir->i_ctime = new_dir->i_mtime = ctime; @@ -5159,12 +5166,10 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, BUG_ON(ret); } } - ret = btrfs_set_inode_index(new_dir, &index); - BUG_ON(ret); ret = btrfs_add_link(trans, new_dir, old_inode, new_dentry->d_name.name, - new_dentry->d_name.len, 1, index); + new_dentry->d_name.len, 0, index); BUG_ON(ret); if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) { @@ -5172,7 +5177,7 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, new_dentry->d_parent); btrfs_end_log_trans(root); } - +out_fail: btrfs_end_transaction_throttle(trans, root); if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) -- 2.41.0