diff options
Diffstat (limited to 'fs/btrfs/volumes.c')
| -rw-r--r-- | fs/btrfs/volumes.c | 151 |
1 files changed, 150 insertions, 1 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index e084218..4066803 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -26,6 +26,7 @@ #include <linux/ratelimit.h> #include <linux/kthread.h> #include <linux/raid/pq.h> +#include <linux/semaphore.h> #include <asm/div64.h> #include "compat.h" #include "ctree.h" @@ -3429,11 +3430,146 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info) return 0; } +static 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_key max_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; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + key.objectid = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = 0; + + max_key.objectid = (u64)-1; + max_key.type = BTRFS_ROOT_ITEM_KEY; + max_key.offset = (u64)-1; + + path->keep_locks = 1; + + while (1) { + ret = btrfs_search_forward(root, &key, &max_key, path, 0); + 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_nr(eb, slot); + if (item_size < sizeof(root_item)) + goto skip; + + trans = NULL; + 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)) { + /* + * 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; + } + ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, + root_item.uuid, + BTRFS_UUID_KEY_SUBVOL, + key.objectid); + if (ret < 0) { + pr_warn("btrfs: uuid_tree_add failed %d\n", + ret); + btrfs_end_transaction(trans, + fs_info->uuid_root); + break; + } + } + + if (!btrfs_is_empty_uuid(root_item.received_uuid)) { + if (!trans) { + /* 1 - received_subvol uuid item */ + trans = btrfs_start_transaction( + fs_info->uuid_root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + } + ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, + root_item.received_uuid, + BTRFS_UUID_KEY_RECEIVED_SUBVOL, + key.objectid); + if (ret < 0) { + pr_warn("btrfs: uuid_tree_add failed %d\n", + ret); + btrfs_end_transaction(trans, + fs_info->uuid_root); + break; + } + } + + if (trans) { + ret = btrfs_end_transaction(trans, fs_info->uuid_root); + if (ret) + break; + } + +skip: + btrfs_release_path(path); + 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 (ret) + pr_warn("btrfs: btrfs_uuid_scan_kthread failed %d\n", ret); + 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 @@ -3453,8 +3589,21 @@ int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info) fs_info->uuid_root = uuid_root; - return btrfs_commit_transaction(trans, tree_root); + ret = btrfs_commit_transaction(trans, tree_root); + 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)) { + pr_warn("btrfs: failed to start uuid_scan task\n"); + up(&fs_info->uuid_tree_rescan_sem); + return PTR_ERR(task); + } + + return 0; } + /* * shrinking a device means finding all of the device extents past * the new size, and then following the back refs to the chunks. |