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.
21 #include "transaction.h"
22 #include "print-tree.h"
24 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
25 sizeof(struct btrfs_item) * 2) / \
26 BTRFS_CRC32_SIZE) - 1))
27 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
28 struct btrfs_root *root,
29 u64 objectid, u64 pos,
30 u64 offset, u64 disk_num_blocks,
34 struct btrfs_file_extent_item *item;
35 struct btrfs_key file_key;
36 struct btrfs_path *path;
38 path = btrfs_alloc_path();
40 file_key.objectid = objectid;
41 file_key.offset = pos;
43 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
45 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
50 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
51 struct btrfs_file_extent_item);
52 btrfs_set_file_extent_disk_blocknr(item, offset);
53 btrfs_set_file_extent_disk_num_blocks(item, disk_num_blocks);
54 btrfs_set_file_extent_offset(item, 0);
55 btrfs_set_file_extent_num_blocks(item, num_blocks);
56 btrfs_set_file_extent_generation(item, trans->transid);
57 btrfs_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
58 btrfs_mark_buffer_dirty(path->nodes[0]);
60 btrfs_free_path(path);
64 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
65 struct btrfs_root *root,
66 struct btrfs_path *path,
67 u64 objectid, u64 offset,
71 struct btrfs_key file_key;
72 struct btrfs_key found_key;
73 struct btrfs_csum_item *item;
74 struct btrfs_leaf *leaf;
78 file_key.objectid = objectid;
79 file_key.offset = offset;
81 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
82 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
85 leaf = btrfs_buffer_leaf(path->nodes[0]);
88 if (path->slots[0] == 0)
91 btrfs_disk_key_to_cpu(&found_key,
92 &leaf->items[path->slots[0]].key);
93 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
94 found_key.objectid != objectid) {
97 csum_offset = (offset - found_key.offset) >>
98 root->fs_info->sb->s_blocksize_bits;
99 csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
100 csums_in_item /= BTRFS_CRC32_SIZE;
102 if (csum_offset >= csums_in_item) {
107 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
108 item = (struct btrfs_csum_item *)((unsigned char *)item +
109 csum_offset * BTRFS_CRC32_SIZE);
118 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
119 struct btrfs_root *root,
120 struct btrfs_path *path, u64 objectid,
124 struct btrfs_key file_key;
125 int ins_len = mod < 0 ? -1 : 0;
128 file_key.objectid = objectid;
129 file_key.offset = offset;
131 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
132 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
136 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
137 struct btrfs_root *root,
138 u64 objectid, u64 offset,
139 char *data, size_t len)
142 struct btrfs_key file_key;
143 struct btrfs_key found_key;
144 struct btrfs_path *path;
145 struct btrfs_csum_item *item;
146 struct btrfs_leaf *leaf;
149 path = btrfs_alloc_path();
152 file_key.objectid = objectid;
153 file_key.offset = offset;
155 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
157 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
163 /* we found one, but it isn't big enough yet */
164 leaf = btrfs_buffer_leaf(path->nodes[0]);
165 item_size = btrfs_item_size(leaf->items + path->slots[0]);
166 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
167 /* already at max size, make a new one */
171 /* we didn't find a csum item, insert one */
176 * at this point, we know the tree has an item, but it isn't big
177 * enough yet to put our csum in. Grow it
179 btrfs_release_path(root, path);
180 ret = btrfs_search_slot(trans, root, &file_key, path,
181 BTRFS_CRC32_SIZE, 1);
187 if (path->slots[0] == 0) {
191 leaf = btrfs_buffer_leaf(path->nodes[0]);
192 btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
193 csum_offset = (offset - found_key.offset) >>
194 root->fs_info->sb->s_blocksize_bits;
195 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
196 found_key.objectid != objectid ||
197 csum_offset >= MAX_CSUM_ITEMS(root)) {
200 if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
202 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
203 diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
204 if (diff != BTRFS_CRC32_SIZE)
206 ret = btrfs_extend_item(trans, root, path, diff);
212 btrfs_release_path(root, path);
214 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
223 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
224 struct btrfs_csum_item);
226 item = (struct btrfs_csum_item *)((unsigned char *)item +
227 csum_offset * BTRFS_CRC32_SIZE);
229 btrfs_check_bounds(&item->csum, BTRFS_CRC32_SIZE,
230 path->nodes[0]->b_data,
231 root->fs_info->sb->s_blocksize);
232 ret = btrfs_csum_data(root, data, len, &item->csum);
233 btrfs_mark_buffer_dirty(path->nodes[0]);
235 btrfs_release_path(root, path);
236 btrfs_free_path(path);
240 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
241 struct btrfs_root *root, struct btrfs_path *path,
244 struct btrfs_key key;
245 struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[0]);
246 int slot = path->slots[0];
252 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
253 if (isize <= key.offset)
255 new_item_span = isize - key.offset;
256 blocks = (new_item_span + root->blocksize - 1) >>
257 root->fs_info->sb->s_blocksize_bits;
258 new_item_size = blocks * BTRFS_CRC32_SIZE;
259 if (new_item_size >= btrfs_item_size(leaf->items + slot))
261 ret = btrfs_truncate_item(trans, root, path, new_item_size);