diff options
Diffstat (limited to 'fs/btrfs/uuid-tree.c')
| -rw-r--r-- | fs/btrfs/uuid-tree.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/fs/btrfs/uuid-tree.c b/fs/btrfs/uuid-tree.c index eae75bb572b9..c6399513c66f 100644 --- a/fs/btrfs/uuid-tree.c +++ b/fs/btrfs/uuid-tree.c @@ -3,6 +3,7 @@ * Copyright (C) STRATO AG 2013. All rights reserved. */ +#include <linux/kthread.h> #include <linux/uuid.h> #include <asm/unaligned.h> #include "messages.h" @@ -12,6 +13,7 @@ #include "fs.h" #include "accessors.h" #include "uuid-tree.h" +#include "ioctl.h" static void btrfs_uuid_to_key(const u8 *uuid, u8 type, struct btrfs_key *key) { @@ -390,3 +392,180 @@ out: btrfs_free_path(path); return ret; } + +int btrfs_uuid_scan_kthread(void *data) +{ + struct btrfs_fs_info *fs_info = data; + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_key key; + struct btrfs_path *path = NULL; + int ret = 0; + struct extent_buffer *eb; + int slot; + struct btrfs_root_item root_item; + u32 item_size; + struct btrfs_trans_handle *trans = NULL; + bool closing = false; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + key.objectid = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = 0; + + while (1) { + if (btrfs_fs_closing(fs_info)) { + closing = true; + break; + } + ret = btrfs_search_forward(root, &key, path, + BTRFS_OLDEST_GENERATION); + if (ret) { + if (ret > 0) + ret = 0; + break; + } + + if (key.type != BTRFS_ROOT_ITEM_KEY || + (key.objectid < BTRFS_FIRST_FREE_OBJECTID && + key.objectid != BTRFS_FS_TREE_OBJECTID) || + key.objectid > BTRFS_LAST_FREE_OBJECTID) + goto skip; + + eb = path->nodes[0]; + slot = path->slots[0]; + item_size = btrfs_item_size(eb, slot); + if (item_size < sizeof(root_item)) + goto skip; + + read_extent_buffer(eb, &root_item, + btrfs_item_ptr_offset(eb, slot), + (int)sizeof(root_item)); + if (btrfs_root_refs(&root_item) == 0) + goto skip; + + if (!btrfs_is_empty_uuid(root_item.uuid) || + !btrfs_is_empty_uuid(root_item.received_uuid)) { + if (trans) + goto update_tree; + + btrfs_release_path(path); + /* + * 1 - subvol uuid item + * 1 - received_subvol uuid item + */ + trans = btrfs_start_transaction(fs_info->uuid_root, 2); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + continue; + } else { + goto skip; + } +update_tree: + btrfs_release_path(path); + if (!btrfs_is_empty_uuid(root_item.uuid)) { + ret = btrfs_uuid_tree_add(trans, root_item.uuid, + BTRFS_UUID_KEY_SUBVOL, + key.objectid); + if (ret < 0) { + btrfs_warn(fs_info, "uuid_tree_add failed %d", + ret); + break; + } + } + + if (!btrfs_is_empty_uuid(root_item.received_uuid)) { + ret = btrfs_uuid_tree_add(trans, + root_item.received_uuid, + BTRFS_UUID_KEY_RECEIVED_SUBVOL, + key.objectid); + if (ret < 0) { + btrfs_warn(fs_info, "uuid_tree_add failed %d", + ret); + break; + } + } + +skip: + btrfs_release_path(path); + if (trans) { + ret = btrfs_end_transaction(trans); + trans = NULL; + if (ret) + break; + } + + if (key.offset < (u64)-1) { + key.offset++; + } else if (key.type < BTRFS_ROOT_ITEM_KEY) { + key.offset = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + } else if (key.objectid < (u64)-1) { + key.offset = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + key.objectid++; + } else { + break; + } + cond_resched(); + } + +out: + btrfs_free_path(path); + if (trans && !IS_ERR(trans)) + btrfs_end_transaction(trans); + if (ret) + btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret); + else if (!closing) + set_bit(BTRFS_FS_UPDATE_UUID_TREE_GEN, &fs_info->flags); + up(&fs_info->uuid_tree_rescan_sem); + return 0; +} + +int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_root *uuid_root; + struct task_struct *task; + int ret; + + /* + * 1 - root node + * 1 - root item + */ + trans = btrfs_start_transaction(tree_root, 2); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + uuid_root = btrfs_create_tree(trans, BTRFS_UUID_TREE_OBJECTID); + if (IS_ERR(uuid_root)) { + ret = PTR_ERR(uuid_root); + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + return ret; + } + + fs_info->uuid_root = uuid_root; + + ret = btrfs_commit_transaction(trans); + if (ret) + return ret; + + down(&fs_info->uuid_tree_rescan_sem); + task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid"); + if (IS_ERR(task)) { + /* fs_info->update_uuid_tree_gen remains 0 in all error case */ + btrfs_warn(fs_info, "failed to start uuid_scan task"); + up(&fs_info->uuid_tree_rescan_sem); + return PTR_ERR(task); + } + + return 0; +} |