diff options
| -rw-r--r-- | fs/btrfs/ctree.h | 67 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 6 | ||||
| -rw-r--r-- | fs/btrfs/ioctl.c | 24 | ||||
| -rw-r--r-- | fs/btrfs/root-tree.c | 76 | ||||
| -rw-r--r-- | fs/btrfs/transaction.c | 31 |
5 files changed, 172 insertions, 32 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index b3bc65b08c6a..ad2cbe63503c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -469,6 +469,15 @@ struct btrfs_root_item { u8 level; } __attribute__ ((__packed__)); +/* + * this is used for both forward and backward root refs + */ +struct btrfs_root_ref { + __le64 dirid; + __le64 sequence; + __le16 name_len; +} __attribute__ ((__packed__)); + #define BTRFS_FILE_EXTENT_INLINE 0 #define BTRFS_FILE_EXTENT_REG 1 #define BTRFS_FILE_EXTENT_PREALLOC 2 @@ -814,27 +823,27 @@ struct btrfs_root { * the FS */ #define BTRFS_INODE_ITEM_KEY 1 -#define BTRFS_INODE_REF_KEY 2 -#define BTRFS_XATTR_ITEM_KEY 8 -#define BTRFS_ORPHAN_ITEM_KEY 9 +#define BTRFS_INODE_REF_KEY 12 +#define BTRFS_XATTR_ITEM_KEY 24 +#define BTRFS_ORPHAN_ITEM_KEY 48 /* reserve 2-15 close to the inode for later flexibility */ /* * dir items are the name -> inode pointers in a directory. There is one * for every name in a directory. */ -#define BTRFS_DIR_LOG_ITEM_KEY 14 -#define BTRFS_DIR_LOG_INDEX_KEY 15 -#define BTRFS_DIR_ITEM_KEY 16 -#define BTRFS_DIR_INDEX_KEY 17 +#define BTRFS_DIR_LOG_ITEM_KEY 60 +#define BTRFS_DIR_LOG_INDEX_KEY 72 +#define BTRFS_DIR_ITEM_KEY 84 +#define BTRFS_DIR_INDEX_KEY 96 /* * extent data is for file data */ -#define BTRFS_EXTENT_DATA_KEY 18 +#define BTRFS_EXTENT_DATA_KEY 108 /* * csum items have the checksums for data in the extents */ -#define BTRFS_CSUM_ITEM_KEY 19 +#define BTRFS_CSUM_ITEM_KEY 120 /* reserve 21-31 for other file/dir stuff */ @@ -843,23 +852,37 @@ struct btrfs_root { * root items point to tree roots. There are typically in the root * tree used by the super block to find all the other trees */ -#define BTRFS_ROOT_ITEM_KEY 32 +#define BTRFS_ROOT_ITEM_KEY 132 + +/* + * root backrefs tie subvols and snapshots to the directory entries that + * reference them + */ +#define BTRFS_ROOT_BACKREF_KEY 144 + +/* + * root refs make a fast index for listing all of the snapshots and + * subvolumes referenced by a given root. They point directly to the + * directory item in the root that references the subvol + */ +#define BTRFS_ROOT_REF_KEY 156 + /* * extent items are in the extent map tree. These record which blocks * are used, and how many references there are to each block */ -#define BTRFS_EXTENT_ITEM_KEY 33 -#define BTRFS_EXTENT_REF_KEY 34 +#define BTRFS_EXTENT_ITEM_KEY 168 +#define BTRFS_EXTENT_REF_KEY 180 /* * block groups give us hints into the extent allocation trees. Which * blocks are free etc etc */ -#define BTRFS_BLOCK_GROUP_ITEM_KEY 50 +#define BTRFS_BLOCK_GROUP_ITEM_KEY 192 -#define BTRFS_DEV_EXTENT_KEY 75 -#define BTRFS_DEV_ITEM_KEY 76 -#define BTRFS_CHUNK_ITEM_KEY 77 +#define BTRFS_DEV_EXTENT_KEY 204 +#define BTRFS_DEV_ITEM_KEY 216 +#define BTRFS_CHUNK_ITEM_KEY 228 /* * string items are for debugging. They just store a short string of @@ -1274,6 +1297,13 @@ static inline void btrfs_set_item_key(struct extent_buffer *eb, BTRFS_SETGET_FUNCS(dir_log_end, struct btrfs_dir_log_item, end, 64); +/* + * struct btrfs_root_ref + */ +BTRFS_SETGET_FUNCS(root_ref_dirid, struct btrfs_root_ref, dirid, 64); +BTRFS_SETGET_FUNCS(root_ref_sequence, struct btrfs_root_ref, sequence, 64); +BTRFS_SETGET_FUNCS(root_ref_name_len, struct btrfs_root_ref, name_len, 16); + /* struct btrfs_dir_item */ BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16); BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8); @@ -1771,6 +1801,11 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans, struct extent_buffer *node, struct extent_buffer *parent); /* root-item.c */ +int btrfs_add_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *tree_root, + u64 root_id, u8 type, u64 ref_id, + u64 dirid, u64 sequence, + const char *name, int name_len); int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_key *key); int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 7ef79ce86e25..6854bf41856a 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4580,6 +4580,12 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry, return -ENOTEMPTY; } + /* to rename a snapshot or subvolume, we need to juggle the + * backrefs. This isn't coded yet + */ + if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) + return -EXDEV; + ret = btrfs_check_free_space(root, 1, 0); if (ret) goto out_unlock; diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 773db07b5f72..536ae8837801 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -145,13 +145,23 @@ static noinline int create_subvol(struct btrfs_root *root, BTRFS_FT_DIR, index); if (ret) goto fail; -#if 0 - ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root, - name, namelen, objectid, - root->fs_info->sb->s_root->d_inode->i_ino, 0); - if (ret) - goto fail; -#endif + + /* add the backref first */ + ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, + objectid, BTRFS_ROOT_BACKREF_KEY, + root->root_key.objectid, + dir->i_ino, index, name, namelen); + + BUG_ON(ret); + + /* now add the forward ref */ + ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, + root->root_key.objectid, BTRFS_ROOT_REF_KEY, + objectid, + dir->i_ino, index, name, namelen); + + BUG_ON(ret); + ret = btrfs_commit_transaction(trans, root); if (ret) goto fail_commit; diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index eb7f7655e9d5..e9be3abcb368 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -84,7 +84,7 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, int slot; search_key.objectid = objectid; - search_key.type = (u8)-1; + search_key.type = BTRFS_ROOT_ITEM_KEY; search_key.offset = (u64)-1; path = btrfs_alloc_path(); @@ -275,3 +275,77 @@ out: btrfs_free_path(path); return ret; } + +int btrfs_del_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *tree_root, + u64 root_id, u8 type, u64 ref_id) +{ + struct btrfs_key key; + int ret; + struct btrfs_path *path; + + path = btrfs_alloc_path(); + + key.objectid = root_id; + key.type = type; + key.offset = ref_id; + + ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); + BUG_ON(ret); + + ret = btrfs_del_item(trans, tree_root, path); + BUG_ON(ret); + + btrfs_free_path(path); + return ret; +} + +/* + * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY + * or BTRFS_ROOT_BACKREF_KEY. + * + * The dirid, sequence, name and name_len refer to the directory entry + * that is referencing the root. + * + * For a forward ref, the root_id is the id of the tree referencing + * the root and ref_id is the id of the subvol or snapshot. + * + * For a back ref the root_id is the id of the subvol or snapshot and + * ref_id is the id of the tree referencing it. + */ +int btrfs_add_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *tree_root, + u64 root_id, u8 type, u64 ref_id, + u64 dirid, u64 sequence, + const char *name, int name_len) +{ + struct btrfs_key key; + int ret; + struct btrfs_path *path; + struct btrfs_root_ref *ref; + struct extent_buffer *leaf; + unsigned long ptr; + + + path = btrfs_alloc_path(); + + key.objectid = root_id; + key.type = type; + key.offset = ref_id; + + ret = btrfs_insert_empty_item(trans, tree_root, path, &key, + sizeof(*ref) + name_len); + BUG_ON(ret); + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); + btrfs_set_root_ref_dirid(leaf, ref, dirid); + btrfs_set_root_ref_sequence(leaf, ref, sequence); + btrfs_set_root_ref_name_len(leaf, ref, name_len); + ptr = (unsigned long)(ref + 1); + write_extent_buffer(leaf, name, ptr, name_len); + btrfs_mark_buffer_dirty(leaf); + + btrfs_free_path(path); + return ret; +} diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 93f23a456a36..e9c8ebeedd7e 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -831,28 +831,43 @@ static noinline int finish_pending_snapshot(struct btrfs_fs_info *fs_info, struct btrfs_trans_handle *trans; struct inode *parent_inode; struct inode *inode; + struct btrfs_root *parent_root; parent_inode = pending->dentry->d_parent->d_inode; - trans = btrfs_start_transaction(BTRFS_I(parent_inode)->root, 1); + parent_root = BTRFS_I(parent_inode)->root; + trans = btrfs_start_transaction(parent_root, 1); /* * insert the directory item */ namelen = strlen(pending->name); ret = btrfs_set_inode_index(parent_inode, &index); - ret = btrfs_insert_dir_item(trans, - BTRFS_I(parent_inode)->root, + ret = btrfs_insert_dir_item(trans, parent_root, pending->name, namelen, parent_inode->i_ino, &pending->root_key, BTRFS_FT_DIR, index); if (ret) goto fail; -#if 0 - ret = btrfs_insert_inode_ref(trans, root->fs_info->tree_root, - pending->name, strlen(pending->name), objectid, - root->fs_info->sb->s_root->d_inode->i_ino, 0); -#endif + + /* add the backref first */ + ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root, + pending->root_key.objectid, + BTRFS_ROOT_BACKREF_KEY, + parent_root->root_key.objectid, + parent_inode->i_ino, index, pending->name, + namelen); + + BUG_ON(ret); + + /* now add the forward ref */ + ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root, + parent_root->root_key.objectid, + BTRFS_ROOT_REF_KEY, + pending->root_key.objectid, + parent_inode->i_ino, index, pending->name, + namelen); + inode = btrfs_lookup_dentry(parent_inode, pending->dentry); d_instantiate(pending->dentry, inode); fail: |