diff options
Diffstat (limited to 'fs/btrfs/qgroup.c')
| -rw-r--r-- | fs/btrfs/qgroup.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 7086353153f3..0b49575698da 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1874,6 +1874,141 @@ out: return ret; } +/* + * Helper function to do recursive generation-aware depth-first search, to + * locate all new tree blocks in a subtree of reloc tree. + * + * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot) + * reloc tree + * L2 NN (a) + * / \ + * L1 OO NN (b) + * / \ / \ + * L0 OO OO OO NN + * (c) (d) + * If we pass: + * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ], + * @cur_level = 1 + * @root_level = 1 + * + * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace + * above tree blocks along with their counter parts in file tree. + * While during search, old tree blocsk OO(c) will be skiped as tree block swap + * won't affect OO(c). + */ +static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans, + struct extent_buffer *src_eb, + struct btrfs_path *dst_path, + int cur_level, int root_level, + u64 last_snapshot) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct extent_buffer *eb; + bool need_cleanup = false; + int ret = 0; + int i; + + /* Level sanity check */ + if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL || + root_level < 0 || root_level >= BTRFS_MAX_LEVEL || + root_level < cur_level) { + btrfs_err_rl(fs_info, + "%s: bad levels, cur_level=%d root_level=%d", + __func__, cur_level, root_level); + return -EUCLEAN; + } + + /* Read the tree block if needed */ + if (dst_path->nodes[cur_level] == NULL) { + struct btrfs_key first_key; + int parent_slot; + u64 child_gen; + u64 child_bytenr; + + /* + * dst_path->nodes[root_level] must be initialized before + * calling this function. + */ + if (cur_level == root_level) { + btrfs_err_rl(fs_info, + "%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d", + __func__, root_level, root_level, cur_level); + return -EUCLEAN; + } + + /* + * We need to get child blockptr/gen from parent before we can + * read it. + */ + eb = dst_path->nodes[cur_level + 1]; + parent_slot = dst_path->slots[cur_level + 1]; + child_bytenr = btrfs_node_blockptr(eb, parent_slot); + child_gen = btrfs_node_ptr_generation(eb, parent_slot); + btrfs_node_key_to_cpu(eb, &first_key, parent_slot); + + /* This node is old, no need to trace */ + if (child_gen < last_snapshot) + goto out; + + eb = read_tree_block(fs_info, child_bytenr, child_gen, + cur_level, &first_key); + if (IS_ERR(eb)) { + ret = PTR_ERR(eb); + goto out; + } else if (!extent_buffer_uptodate(eb)) { + free_extent_buffer(eb); + ret = -EIO; + goto out; + } + + dst_path->nodes[cur_level] = eb; + dst_path->slots[cur_level] = 0; + + btrfs_tree_read_lock(eb); + btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); + dst_path->locks[cur_level] = BTRFS_READ_LOCK_BLOCKING; + need_cleanup = true; + } + + /* Now record this tree block and its counter part for qgroups */ + ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level, + root_level); + if (ret < 0) + goto cleanup; + + eb = dst_path->nodes[cur_level]; + + if (cur_level > 0) { + /* Iterate all child tree blocks */ + for (i = 0; i < btrfs_header_nritems(eb); i++) { + /* Skip old tree blocks as they won't be swapped */ + if (btrfs_node_ptr_generation(eb, i) < last_snapshot) + continue; + dst_path->slots[cur_level] = i; + + /* Recursive call (at most 7 times) */ + ret = qgroup_trace_new_subtree_blocks(trans, src_eb, + dst_path, cur_level - 1, root_level, + last_snapshot); + if (ret < 0) + goto cleanup; + } + } + +cleanup: + if (need_cleanup) { + /* Clean up */ + btrfs_tree_unlock_rw(dst_path->nodes[cur_level], + dst_path->locks[cur_level]); + free_extent_buffer(dst_path->nodes[cur_level]); + dst_path->nodes[cur_level] = NULL; + dst_path->slots[cur_level] = 0; + dst_path->locks[cur_level] = 0; + } +out: + return ret; +} + int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans, struct extent_buffer *root_eb, u64 root_gen, int root_level) |