diff options
| -rw-r--r-- | fs/btrfs/ctree.h | 2 | ||||
| -rw-r--r-- | fs/btrfs/dir-item.c | 59 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 24 | ||||
| -rw-r--r-- | fs/btrfs/ioctl.c | 10 | ||||
| -rw-r--r-- | fs/btrfs/transaction.c | 2 |
5 files changed, 95 insertions, 2 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 44d9bc87e863..547b7b05727f 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3283,6 +3283,8 @@ void btrfs_update_root_times(struct btrfs_trans_handle *trans, struct btrfs_root *root); /* dir-item.c */ +int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir, + const char *name, int name_len); int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, int name_len, struct inode *dir, diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c index c1a074d0696f..502c2158167c 100644 --- a/fs/btrfs/dir-item.c +++ b/fs/btrfs/dir-item.c @@ -213,6 +213,65 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, return btrfs_match_dir_item_name(root, path, name, name_len); } +int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir, + const char *name, int name_len) +{ + int ret; + struct btrfs_key key; + struct btrfs_dir_item *di; + int data_size; + struct extent_buffer *leaf; + int slot; + struct btrfs_path *path; + + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = dir; + btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY); + key.offset = btrfs_name_hash(name, name_len); + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + + /* return back any errors */ + if (ret < 0) + goto out; + + /* nothing found, we're safe */ + if (ret > 0) { + ret = 0; + goto out; + } + + /* we found an item, look for our name in the item */ + di = btrfs_match_dir_item_name(root, path, name, name_len); + if (di) { + /* our exact name was found */ + ret = -EEXIST; + goto out; + } + + /* + * see if there is room in the item to insert this + * name + */ + data_size = sizeof(*di) + name_len + sizeof(struct btrfs_item); + leaf = path->nodes[0]; + slot = path->slots[0]; + if (data_size + btrfs_item_size_nr(leaf, slot) + + sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) { + ret = -EOVERFLOW; + } else { + /* plenty of insertion room */ + ret = 0; + } +out: + btrfs_free_path(path); + return ret; +} + /* * lookup a directory item based on index. 'dir' is the objectid * we're searching in, and 'mod' tells us if you plan on deleting the diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 2e6918c85b72..e95b1f90a1f6 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4885,7 +4885,7 @@ int btrfs_add_link(struct btrfs_trans_handle *trans, ret = btrfs_insert_dir_item(trans, root, name, name_len, parent_inode, &key, btrfs_inode_type(inode), index); - if (ret == -EEXIST) + if (ret == -EEXIST || ret == -EOVERFLOW) goto fail_dir_item; else if (ret) { btrfs_abort_transaction(trans, root, ret); @@ -7336,6 +7336,28 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, if (S_ISDIR(old_inode->i_mode) && new_inode && new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) return -ENOTEMPTY; + + + /* check for collisions, even if the name isn't there */ + ret = btrfs_check_dir_item_collision(root, new_dir->i_ino, + new_dentry->d_name.name, + new_dentry->d_name.len); + + if (ret) { + if (ret == -EEXIST) { + /* we shouldn't get + * eexist without a new_inode */ + if (!new_inode) { + WARN_ON(1); + return ret; + } + } else { + /* maybe -EOVERFLOW */ + return ret; + } + } + ret = 0; + /* * we're using rename to replace one file with another. * and the replacement file is large. Start IO on it now so diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 657d83ca9dea..d4608ab72b79 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -710,6 +710,16 @@ static noinline int btrfs_mksubvol(struct path *parent, if (error) goto out_dput; + /* + * even if this name doesn't exist, we may get hash collisions. + * check for them now when we can safely fail + */ + error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root, + dir->i_ino, name, + namelen); + if (error) + goto out_dput; + down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index e6509b92433b..87fac9a21ea5 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1190,7 +1190,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, parent_inode, &key, BTRFS_FT_DIR, index); /* We have check then name at the beginning, so it is impossible. */ - BUG_ON(ret == -EEXIST); + BUG_ON(ret == -EEXIST || ret == -EOVERFLOW); if (ret) { btrfs_abort_transaction(trans, root, ret); goto fail; |