2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/module.h>
22 #include "transaction.h"
23 #include "print-tree.h"
25 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
26 sizeof(struct btrfs_item) * 2) / \
27 BTRFS_CRC32_SIZE) - 1))
28 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
29 struct btrfs_root *root,
30 u64 objectid, u64 pos,
31 u64 offset, u64 disk_num_blocks,
35 struct btrfs_file_extent_item *item;
36 struct btrfs_key file_key;
37 struct btrfs_path *path;
39 path = btrfs_alloc_path();
41 file_key.objectid = objectid;
42 file_key.offset = pos;
44 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
46 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
51 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
52 struct btrfs_file_extent_item);
53 btrfs_set_file_extent_disk_blocknr(item, offset);
54 btrfs_set_file_extent_disk_num_blocks(item, disk_num_blocks);
55 btrfs_set_file_extent_offset(item, 0);
56 btrfs_set_file_extent_num_blocks(item, num_blocks);
57 btrfs_set_file_extent_generation(item, trans->transid);
58 btrfs_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
59 btrfs_mark_buffer_dirty(path->nodes[0]);
61 btrfs_free_path(path);
65 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
66 struct btrfs_root *root,
67 struct btrfs_path *path,
68 u64 objectid, u64 offset,
72 struct btrfs_key file_key;
73 struct btrfs_key found_key;
74 struct btrfs_csum_item *item;
75 struct btrfs_leaf *leaf;
79 file_key.objectid = objectid;
80 file_key.offset = offset;
82 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
83 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
86 leaf = btrfs_buffer_leaf(path->nodes[0]);
89 if (path->slots[0] == 0)
92 btrfs_disk_key_to_cpu(&found_key,
93 &leaf->items[path->slots[0]].key);
94 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
95 found_key.objectid != objectid) {
98 csum_offset = (offset - found_key.offset) >>
99 root->fs_info->sb->s_blocksize_bits;
100 csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
101 csums_in_item /= BTRFS_CRC32_SIZE;
103 if (csum_offset >= csums_in_item) {
108 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
109 item = (struct btrfs_csum_item *)((unsigned char *)item +
110 csum_offset * BTRFS_CRC32_SIZE);
119 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
120 struct btrfs_root *root,
121 struct btrfs_path *path, u64 objectid,
125 struct btrfs_key file_key;
126 int ins_len = mod < 0 ? -1 : 0;
129 file_key.objectid = objectid;
130 file_key.offset = offset;
132 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
133 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
137 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
138 struct btrfs_root *root,
139 u64 objectid, u64 offset,
140 char *data, size_t len)
143 struct btrfs_key file_key;
144 struct btrfs_key found_key;
145 struct btrfs_path *path;
146 struct btrfs_csum_item *item;
147 struct btrfs_leaf *leaf;
150 path = btrfs_alloc_path();
153 file_key.objectid = objectid;
154 file_key.offset = offset;
156 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
158 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
164 /* we found one, but it isn't big enough yet */
165 leaf = btrfs_buffer_leaf(path->nodes[0]);
166 item_size = btrfs_item_size(leaf->items + path->slots[0]);
167 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
168 /* already at max size, make a new one */
172 /* we didn't find a csum item, insert one */
177 * at this point, we know the tree has an item, but it isn't big
178 * enough yet to put our csum in. Grow it
180 btrfs_release_path(root, path);
181 ret = btrfs_search_slot(trans, root, &file_key, path,
182 BTRFS_CRC32_SIZE, 1);
188 if (path->slots[0] == 0) {
192 leaf = btrfs_buffer_leaf(path->nodes[0]);
193 btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
194 csum_offset = (offset - found_key.offset) >>
195 root->fs_info->sb->s_blocksize_bits;
196 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
197 found_key.objectid != objectid ||
198 csum_offset >= MAX_CSUM_ITEMS(root)) {
201 if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
203 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
204 diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
205 if (diff != BTRFS_CRC32_SIZE)
207 ret = btrfs_extend_item(trans, root, path, diff);
213 btrfs_release_path(root, path);
215 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
224 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
225 struct btrfs_csum_item);
227 item = (struct btrfs_csum_item *)((unsigned char *)item +
228 csum_offset * BTRFS_CRC32_SIZE);
230 btrfs_check_bounds(&item->csum, BTRFS_CRC32_SIZE,
231 path->nodes[0]->b_data,
232 root->fs_info->sb->s_blocksize);
233 ret = btrfs_csum_data(root, data, len, &item->csum);
234 btrfs_mark_buffer_dirty(path->nodes[0]);
236 btrfs_release_path(root, path);
237 btrfs_free_path(path);
241 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
242 struct btrfs_root *root, struct btrfs_path *path,
245 struct btrfs_key key;
246 struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[0]);
247 int slot = path->slots[0];
253 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
254 if (isize <= key.offset)
256 new_item_span = isize - key.offset;
257 blocks = (new_item_span + root->blocksize - 1) >>
258 root->fs_info->sb->s_blocksize_bits;
259 new_item_size = blocks * BTRFS_CRC32_SIZE;
260 if (new_item_size >= btrfs_item_size(leaf->items + slot))
262 ret = btrfs_truncate_item(trans, root, path, new_item_size);