| /* |
| * 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 "disk-io.h" |
| #include "hash.h" |
| #include "transaction.h" |
| #include "print-tree.h" |
| |
| static int find_name_in_backref(struct btrfs_path *path, const char *name, |
| int name_len, struct btrfs_inode_ref **ref_ret) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_inode_ref *ref; |
| unsigned long ptr; |
| unsigned long name_ptr; |
| u32 item_size; |
| u32 cur_offset = 0; |
| int len; |
| |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| while (cur_offset < item_size) { |
| ref = (struct btrfs_inode_ref *)(ptr + cur_offset); |
| len = btrfs_inode_ref_name_len(leaf, ref); |
| name_ptr = (unsigned long)(ref + 1); |
| cur_offset += len + sizeof(*ref); |
| if (len != name_len) |
| continue; |
| if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) { |
| *ref_ret = ref; |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid, |
| const char *name, int name_len, |
| struct btrfs_inode_extref **extref_ret) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_inode_extref *extref; |
| unsigned long ptr; |
| unsigned long name_ptr; |
| u32 item_size; |
| u32 cur_offset = 0; |
| int ref_name_len; |
| |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| |
| /* |
| * Search all extended backrefs in this item. We're only |
| * looking through any collisions so most of the time this is |
| * just going to compare against one buffer. If all is well, |
| * we'll return success and the inode ref object. |
| */ |
| while (cur_offset < item_size) { |
| extref = (struct btrfs_inode_extref *) (ptr + cur_offset); |
| name_ptr = (unsigned long)(&extref->name); |
| ref_name_len = btrfs_inode_extref_name_len(leaf, extref); |
| |
| if (ref_name_len == name_len && |
| btrfs_inode_extref_parent(leaf, extref) == ref_objectid && |
| (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) { |
| if (extref_ret) |
| *extref_ret = extref; |
| return 1; |
| } |
| |
| cur_offset += ref_name_len + sizeof(*extref); |
| } |
| return 0; |
| } |
| |
| /* Returns NULL if no extref found */ |
| struct btrfs_inode_extref * |
| btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| const char *name, int name_len, |
| u64 inode_objectid, u64 ref_objectid, int ins_len, |
| int cow) |
| { |
| int ret; |
| struct btrfs_key key; |
| struct btrfs_inode_extref *extref; |
| |
| key.objectid = inode_objectid; |
| key.type = BTRFS_INODE_EXTREF_KEY; |
| key.offset = btrfs_extref_hash(ref_objectid, name, name_len); |
| |
| ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); |
| if (ret < 0) |
| return ERR_PTR(ret); |
| if (ret > 0) |
| return NULL; |
| if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref)) |
| return NULL; |
| return extref; |
| } |
| |
| static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| const char *name, int name_len, |
| u64 inode_objectid, u64 ref_objectid, |
| u64 *index) |
| { |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| struct btrfs_inode_extref *extref; |
| struct extent_buffer *leaf; |
| int ret; |
| int del_len = name_len + sizeof(*extref); |
| unsigned long ptr; |
| unsigned long item_start; |
| u32 item_size; |
| |
| key.objectid = inode_objectid; |
| key.type = BTRFS_INODE_EXTREF_KEY; |
| key.offset = btrfs_extref_hash(ref_objectid, name, name_len); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->leave_spinning = 1; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret > 0) |
| ret = -ENOENT; |
| if (ret < 0) |
| goto out; |
| |
| /* |
| * Sanity check - did we find the right item for this name? |
| * This should always succeed so error here will make the FS |
| * readonly. |
| */ |
| if (!btrfs_find_name_in_ext_backref(path, ref_objectid, |
| name, name_len, &extref)) { |
| btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL); |
| ret = -EROFS; |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| if (index) |
| *index = btrfs_inode_extref_index(leaf, extref); |
| |
| if (del_len == item_size) { |
| /* |
| * Common case only one ref in the item, remove the |
| * whole item. |
| */ |
| ret = btrfs_del_item(trans, root, path); |
| goto out; |
| } |
| |
| ptr = (unsigned long)extref; |
| item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| |
| memmove_extent_buffer(leaf, ptr, ptr + del_len, |
| item_size - (ptr + del_len - item_start)); |
| |
| btrfs_truncate_item(root, path, item_size - del_len, 1); |
| |
| out: |
| btrfs_free_path(path); |
| |
| return ret; |
| } |
| |
| int btrfs_del_inode_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| const char *name, int name_len, |
| u64 inode_objectid, u64 ref_objectid, u64 *index) |
| { |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| struct btrfs_inode_ref *ref; |
| struct extent_buffer *leaf; |
| unsigned long ptr; |
| unsigned long item_start; |
| u32 item_size; |
| u32 sub_item_len; |
| int ret; |
| int search_ext_refs = 0; |
| int del_len = name_len + sizeof(*ref); |
| |
| key.objectid = inode_objectid; |
| key.offset = ref_objectid; |
| key.type = BTRFS_INODE_REF_KEY; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->leave_spinning = 1; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret > 0) { |
| ret = -ENOENT; |
| search_ext_refs = 1; |
| goto out; |
| } else if (ret < 0) { |
| goto out; |
| } |
| if (!find_name_in_backref(path, name, name_len, &ref)) { |
| ret = -ENOENT; |
| search_ext_refs = 1; |
| goto out; |
| } |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| |
| if (index) |
| *index = btrfs_inode_ref_index(leaf, ref); |
| |
| if (del_len == item_size) { |
| ret = btrfs_del_item(trans, root, path); |
| goto out; |
| } |
| ptr = (unsigned long)ref; |
| sub_item_len = name_len + sizeof(*ref); |
| item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| memmove_extent_buffer(leaf, ptr, ptr + sub_item_len, |
| item_size - (ptr + sub_item_len - item_start)); |
| btrfs_truncate_item(root, path, item_size - sub_item_len, 1); |
| out: |
| btrfs_free_path(path); |
| |
| if (search_ext_refs) { |
| /* |
| * No refs were found, or we could not find the |
| * name in our ref array. Find and remove the extended |
| * inode ref then. |
| */ |
| return btrfs_del_inode_extref(trans, root, name, name_len, |
| inode_objectid, ref_objectid, index); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree. |
| * |
| * The caller must have checked against BTRFS_LINK_MAX already. |
| */ |
| static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| const char *name, int name_len, |
| u64 inode_objectid, u64 ref_objectid, u64 index) |
| { |
| struct btrfs_inode_extref *extref; |
| int ret; |
| int ins_len = name_len + sizeof(*extref); |
| unsigned long ptr; |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| |
| key.objectid = inode_objectid; |
| key.type = BTRFS_INODE_EXTREF_KEY; |
| key.offset = btrfs_extref_hash(ref_objectid, name, name_len); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->leave_spinning = 1; |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| ins_len); |
| if (ret == -EEXIST) { |
| if (btrfs_find_name_in_ext_backref(path, ref_objectid, |
| name, name_len, NULL)) |
| goto out; |
| |
| btrfs_extend_item(root, path, ins_len); |
| ret = 0; |
| } |
| if (ret < 0) |
| goto out; |
| |
| leaf = path->nodes[0]; |
| item = btrfs_item_nr(path->slots[0]); |
| ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char); |
| ptr += btrfs_item_size(leaf, item) - ins_len; |
| extref = (struct btrfs_inode_extref *)ptr; |
| |
| btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len); |
| btrfs_set_inode_extref_index(path->nodes[0], extref, index); |
| btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid); |
| |
| ptr = (unsigned long)&extref->name; |
| write_extent_buffer(path->nodes[0], name, ptr, name_len); |
| btrfs_mark_buffer_dirty(path->nodes[0]); |
| |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */ |
| int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| const char *name, int name_len, |
| u64 inode_objectid, u64 ref_objectid, u64 index) |
| { |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| struct btrfs_inode_ref *ref; |
| unsigned long ptr; |
| int ret; |
| int ins_len = name_len + sizeof(*ref); |
| |
| key.objectid = inode_objectid; |
| key.offset = ref_objectid; |
| key.type = BTRFS_INODE_REF_KEY; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->leave_spinning = 1; |
| path->skip_release_on_error = 1; |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| ins_len); |
| if (ret == -EEXIST) { |
| u32 old_size; |
| |
| if (find_name_in_backref(path, name, name_len, &ref)) |
| goto out; |
| |
| old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); |
| btrfs_extend_item(root, path, ins_len); |
| ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_inode_ref); |
| ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size); |
| btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); |
| btrfs_set_inode_ref_index(path->nodes[0], ref, index); |
| ptr = (unsigned long)(ref + 1); |
| ret = 0; |
| } else if (ret < 0) { |
| if (ret == -EOVERFLOW) { |
| if (find_name_in_backref(path, name, name_len, &ref)) |
| ret = -EEXIST; |
| else |
| ret = -EMLINK; |
| } |
| goto out; |
| } else { |
| ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_inode_ref); |
| btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); |
| btrfs_set_inode_ref_index(path->nodes[0], ref, index); |
| ptr = (unsigned long)(ref + 1); |
| } |
| write_extent_buffer(path->nodes[0], name, ptr, name_len); |
| btrfs_mark_buffer_dirty(path->nodes[0]); |
| |
| out: |
| btrfs_free_path(path); |
| |
| if (ret == -EMLINK) { |
| struct btrfs_super_block *disk_super = root->fs_info->super_copy; |
| /* We ran out of space in the ref array. Need to |
| * add an extended ref. */ |
| if (btrfs_super_incompat_flags(disk_super) |
| & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF) |
| ret = btrfs_insert_inode_extref(trans, root, name, |
| name_len, |
| inode_objectid, |
| ref_objectid, index); |
| } |
| |
| return ret; |
| } |
| |
| int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, u64 objectid) |
| { |
| struct btrfs_key key; |
| int ret; |
| key.objectid = objectid; |
| key.type = BTRFS_INODE_ITEM_KEY; |
| key.offset = 0; |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| sizeof(struct btrfs_inode_item)); |
| return ret; |
| } |
| |
| int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, |
| struct btrfs_key *location, int mod) |
| { |
| int ins_len = mod < 0 ? -1 : 0; |
| int cow = mod != 0; |
| int ret; |
| int slot; |
| struct extent_buffer *leaf; |
| struct btrfs_key found_key; |
| |
| ret = btrfs_search_slot(trans, root, location, path, ins_len, cow); |
| if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY && |
| location->offset == (u64)-1 && path->slots[0] != 0) { |
| slot = path->slots[0] - 1; |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &found_key, slot); |
| if (found_key.objectid == location->objectid && |
| found_key.type == location->type) { |
| path->slots[0]--; |
| return 0; |
| } |
| } |
| return ret; |
| } |