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author | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2009-01-14 16:29:51 +1100 |
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committer | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2009-01-14 16:29:51 +1100 |
commit | cb7a97d01521797cad9f63e8478403c3e51fea49 (patch) | |
tree | 84cddf20369f82f10c1c3712e6cce20dd1b9d863 /fs/btrfs/root-tree.c | |
parent | 0335cb76aa3fa913a2164bc9b669e5aef9d56fa3 (diff) | |
parent | a6525042bfdfcab128bd91fad264de10fd24a55e (diff) | |
download | linux-cb7a97d01521797cad9f63e8478403c3e51fea49.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus
Diffstat (limited to 'fs/btrfs/root-tree.c')
-rw-r--r-- | fs/btrfs/root-tree.c | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c new file mode 100644 index 000000000000..b48650de4472 --- /dev/null +++ b/fs/btrfs/root-tree.c @@ -0,0 +1,366 @@ +/* + * 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" + +/* + * search forward for a root, starting with objectid 'search_start' + * if a root key is found, the objectid we find is filled into 'found_objectid' + * and 0 is returned. < 0 is returned on error, 1 if there is nothing + * left in the tree. + */ +int btrfs_search_root(struct btrfs_root *root, u64 search_start, + u64 *found_objectid) +{ + struct btrfs_path *path; + struct btrfs_key search_key; + int ret; + + root = root->fs_info->tree_root; + search_key.objectid = search_start; + search_key.type = (u8)-1; + search_key.offset = (u64)-1; + + path = btrfs_alloc_path(); + BUG_ON(!path); +again: + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + if (ret < 0) + goto out; + if (ret == 0) { + ret = 1; + goto out; + } + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(root, path); + if (ret) + goto out; + } + btrfs_item_key_to_cpu(path->nodes[0], &search_key, path->slots[0]); + if (search_key.type != BTRFS_ROOT_ITEM_KEY) { + search_key.offset++; + btrfs_release_path(root, path); + goto again; + } + ret = 0; + *found_objectid = search_key.objectid; + +out: + btrfs_free_path(path); + return ret; +} + +/* + * 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(); + BUG_ON(!path); + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + if (ret < 0) + goto out; + + BUG_ON(ret == 0); + l = path->nodes[0]; + BUG_ON(path->slots[0] == 0); + slot = path->slots[0] - 1; + btrfs_item_key_to_cpu(l, &found_key, slot); + if (found_key.objectid != objectid) { + ret = 1; + goto out; + } + read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), + sizeof(*item)); + memcpy(key, &found_key, sizeof(found_key)); + ret = 0; +out: + btrfs_free_path(path); + return ret; +} + +/* + * 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(); + BUG_ON(!path); + ret = btrfs_search_slot(trans, root, key, path, 0, 1); + if (ret < 0) + 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_release_path(root, path); + 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) +{ + int ret; + ret = btrfs_insert_item(trans, root, key, item, sizeof(*item)); + return ret; +} + +/* + * 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 *latest) +{ + struct btrfs_root *dead_root; + struct btrfs_item *item; + 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]; + } + item = btrfs_item_nr(leaf, slot); + 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(root, 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; + } + + if (objectid == BTRFS_TREE_RELOC_OBJECTID) + ret = btrfs_add_dead_reloc_root(dead_root); + else + ret = btrfs_add_dead_root(dead_root, latest); + if (ret) + goto err; + goto again; +next: + slot++; + path->slots[0]++; + } + ret = 0; +err: + btrfs_free_path(path); + return ret; +} + +/* 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; + u32 refs; + struct btrfs_root_item *ri; + struct extent_buffer *leaf; + + path = btrfs_alloc_path(); + BUG_ON(!path); + 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); + + refs = btrfs_disk_root_refs(leaf, ri); + BUG_ON(refs != 0); + ret = btrfs_del_item(trans, root, path); +out: + btrfs_release_path(root, path); + btrfs_free_path(path); + return ret; +} + +#if 0 /* this will get used when snapshot deletion is implemented */ +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; +} +#endif + +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. + */ +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; +} |