diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/btrfs/root-tree.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/btrfs/root-tree.c | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/btrfs/root-tree.c b/ANDROID_3.4.5/fs/btrfs/root-tree.c new file mode 100644 index 00000000..24fb8ce4 --- /dev/null +++ b/ANDROID_3.4.5/fs/btrfs/root-tree.c @@ -0,0 +1,456 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include "ctree.h" +#include "transaction.h" +#include "disk-io.h" +#include "print-tree.h" + +/* + * lookup the root with the highest offset for a given objectid. The key we do + * find is copied into 'key'. If we find something return 0, otherwise 1, < 0 + * on error. + */ +int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, + struct btrfs_root_item *item, struct btrfs_key *key) +{ + struct btrfs_path *path; + struct btrfs_key search_key; + struct btrfs_key found_key; + struct extent_buffer *l; + int ret; + int slot; + + search_key.objectid = objectid; + search_key.type = BTRFS_ROOT_ITEM_KEY; + search_key.offset = (u64)-1; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + if (ret < 0) + goto out; + + BUG_ON(ret == 0); + if (path->slots[0] == 0) { + ret = 1; + goto out; + } + l = path->nodes[0]; + slot = path->slots[0] - 1; + btrfs_item_key_to_cpu(l, &found_key, slot); + if (found_key.objectid != objectid || + found_key.type != BTRFS_ROOT_ITEM_KEY) { + ret = 1; + goto out; + } + if (item) + read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), + sizeof(*item)); + if (key) + memcpy(key, &found_key, sizeof(found_key)); + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + +void btrfs_set_root_node(struct btrfs_root_item *item, + struct extent_buffer *node) +{ + btrfs_set_root_bytenr(item, node->start); + btrfs_set_root_level(item, btrfs_header_level(node)); + btrfs_set_root_generation(item, btrfs_header_generation(node)); +} + +/* + * copy the data in 'item' into the btree + */ +int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root + *root, struct btrfs_key *key, struct btrfs_root_item + *item) +{ + struct btrfs_path *path; + struct extent_buffer *l; + int ret; + int slot; + unsigned long ptr; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(trans, root, key, path, 0, 1); + if (ret < 0) { + btrfs_abort_transaction(trans, root, ret); + goto out; + } + + if (ret != 0) { + btrfs_print_leaf(root, path->nodes[0]); + printk(KERN_CRIT "unable to update root key %llu %u %llu\n", + (unsigned long long)key->objectid, key->type, + (unsigned long long)key->offset); + BUG_ON(1); + } + + l = path->nodes[0]; + slot = path->slots[0]; + ptr = btrfs_item_ptr_offset(l, slot); + write_extent_buffer(l, item, ptr, sizeof(*item)); + btrfs_mark_buffer_dirty(path->nodes[0]); +out: + btrfs_free_path(path); + return ret; +} + +int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct btrfs_key *key, struct btrfs_root_item *item) +{ + return btrfs_insert_item(trans, root, key, item, sizeof(*item)); +} + +/* + * at mount time we want to find all the old transaction snapshots that were in + * the process of being deleted if we crashed. This is any root item with an + * offset lower than the latest root. They need to be queued for deletion to + * finish what was happening when we crashed. + */ +int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid) +{ + struct btrfs_root *dead_root; + struct btrfs_root_item *ri; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_path *path; + int ret; + u32 nritems; + struct extent_buffer *leaf; + int slot; + + key.objectid = objectid; + btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); + key.offset = 0; + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + +again: + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto err; + while (1) { + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + slot = path->slots[0]; + if (slot >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret) + break; + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + slot = path->slots[0]; + } + btrfs_item_key_to_cpu(leaf, &key, slot); + if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY) + goto next; + + if (key.objectid < objectid) + goto next; + + if (key.objectid > objectid) + break; + + ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item); + if (btrfs_disk_root_refs(leaf, ri) != 0) + goto next; + + memcpy(&found_key, &key, sizeof(key)); + key.offset++; + btrfs_release_path(path); + dead_root = + btrfs_read_fs_root_no_radix(root->fs_info->tree_root, + &found_key); + if (IS_ERR(dead_root)) { + ret = PTR_ERR(dead_root); + goto err; + } + + ret = btrfs_add_dead_root(dead_root); + if (ret) + goto err; + goto again; +next: + slot++; + path->slots[0]++; + } + ret = 0; +err: + btrfs_free_path(path); + return ret; +} + +int btrfs_find_orphan_roots(struct btrfs_root *tree_root) +{ + struct extent_buffer *leaf; + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key root_key; + struct btrfs_root *root; + int err = 0; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_ORPHAN_OBJECTID; + key.type = BTRFS_ORPHAN_ITEM_KEY; + key.offset = 0; + + root_key.type = BTRFS_ROOT_ITEM_KEY; + root_key.offset = (u64)-1; + + while (1) { + ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); + if (ret < 0) { + err = ret; + break; + } + + leaf = path->nodes[0]; + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(tree_root, path); + if (ret < 0) + err = ret; + if (ret != 0) + break; + leaf = path->nodes[0]; + } + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + btrfs_release_path(path); + + if (key.objectid != BTRFS_ORPHAN_OBJECTID || + key.type != BTRFS_ORPHAN_ITEM_KEY) + break; + + root_key.objectid = key.offset; + key.offset++; + + root = btrfs_read_fs_root_no_name(tree_root->fs_info, + &root_key); + if (!IS_ERR(root)) + continue; + + ret = PTR_ERR(root); + if (ret != -ENOENT) { + err = ret; + break; + } + + ret = btrfs_find_dead_roots(tree_root, root_key.objectid); + if (ret) { + err = ret; + break; + } + } + + btrfs_free_path(path); + return err; +} + +/* drop the root item for 'key' from 'root' */ +int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct btrfs_key *key) +{ + struct btrfs_path *path; + int ret; + struct btrfs_root_item *ri; + struct extent_buffer *leaf; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + ret = btrfs_search_slot(trans, root, key, path, -1, 1); + if (ret < 0) + goto out; + + BUG_ON(ret != 0); + leaf = path->nodes[0]; + ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item); + + ret = btrfs_del_item(trans, root, path); +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, u64 ref_id, u64 dirid, u64 *sequence, + const char *name, int name_len) + +{ + struct btrfs_path *path; + struct btrfs_root_ref *ref; + struct extent_buffer *leaf; + struct btrfs_key key; + unsigned long ptr; + int err = 0; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = root_id; + key.type = BTRFS_ROOT_BACKREF_KEY; + key.offset = ref_id; +again: + ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); + BUG_ON(ret < 0); + if (ret == 0) { + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_root_ref); + + WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid); + WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len); + ptr = (unsigned long)(ref + 1); + WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len)); + *sequence = btrfs_root_ref_sequence(leaf, ref); + + ret = btrfs_del_item(trans, tree_root, path); + if (ret) { + err = ret; + goto out; + } + } else + err = -ENOENT; + + if (key.type == BTRFS_ROOT_BACKREF_KEY) { + btrfs_release_path(path); + key.objectid = ref_id; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = root_id; + goto again; + } + +out: + btrfs_free_path(path); + return err; +} + +int btrfs_find_root_ref(struct btrfs_root *tree_root, + struct btrfs_path *path, + u64 root_id, u64 ref_id) +{ + struct btrfs_key key; + int ret; + + key.objectid = root_id; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = ref_id; + + ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); + 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. + * + * Will return 0, -ENOMEM, or anything from the CoW path + */ +int btrfs_add_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *tree_root, + u64 root_id, 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(); + if (!path) + return -ENOMEM; + + key.objectid = root_id; + key.type = BTRFS_ROOT_BACKREF_KEY; + key.offset = ref_id; +again: + ret = btrfs_insert_empty_item(trans, tree_root, path, &key, + sizeof(*ref) + name_len); + if (ret) { + btrfs_abort_transaction(trans, tree_root, ret); + btrfs_free_path(path); + return 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); + + if (key.type == BTRFS_ROOT_BACKREF_KEY) { + btrfs_release_path(path); + key.objectid = ref_id; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = root_id; + goto again; + } + + btrfs_free_path(path); + return 0; +} + +/* + * Old btrfs forgets to init root_item->flags and root_item->byte_limit + * for subvolumes. To work around this problem, we steal a bit from + * root_item->inode_item->flags, and use it to indicate if those fields + * have been properly initialized. + */ +void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item) +{ + u64 inode_flags = le64_to_cpu(root_item->inode.flags); + + if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) { + inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT; + root_item->inode.flags = cpu_to_le64(inode_flags); + root_item->flags = 0; + root_item->byte_limit = 0; + } +} |