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_bytes,
34 struct btrfs_file_extent_item *item;
35 struct btrfs_key file_key;
36 struct btrfs_path *path;
37 struct extent_buffer *leaf;
39 path = btrfs_alloc_path();
41 file_key.objectid = objectid;
42 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 leaf = path->nodes[0];
51 item = btrfs_item_ptr(leaf, path->slots[0],
52 struct btrfs_file_extent_item);
53 btrfs_set_file_extent_disk_bytenr(leaf, item, offset);
54 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
55 btrfs_set_file_extent_offset(leaf, item, 0);
56 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
57 btrfs_set_file_extent_generation(leaf, item, trans->transid);
58 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
59 btrfs_mark_buffer_dirty(leaf);
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 extent_buffer *leaf;
79 file_key.objectid = objectid;
80 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 = path->nodes[0];
88 if (path->slots[0] == 0)
91 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
92 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
93 found_key.objectid != objectid) {
96 csum_offset = (offset - found_key.offset) >>
97 root->fs_info->sb->s_blocksize_bits;
98 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
99 csums_in_item /= BTRFS_CRC32_SIZE;
101 if (csum_offset >= csums_in_item) {
106 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
107 item = (struct btrfs_csum_item *)((unsigned char *)item +
108 csum_offset * BTRFS_CRC32_SIZE);
117 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
118 struct btrfs_root *root,
119 struct btrfs_path *path, u64 objectid,
123 struct btrfs_key file_key;
124 int ins_len = mod < 0 ? -1 : 0;
127 file_key.objectid = objectid;
128 file_key.offset = offset;
129 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
130 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
134 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
135 struct btrfs_root *root,
137 u64 objectid, u64 offset,
138 char *data, size_t len)
141 struct btrfs_key file_key;
142 struct btrfs_key found_key;
143 u64 next_offset = (u64)-1;
145 struct btrfs_path *path;
146 struct btrfs_csum_item *item;
147 struct extent_buffer *leaf = NULL;
149 u32 csum_result = ~(u32)0;
153 path = btrfs_alloc_path();
156 file_key.objectid = objectid;
157 file_key.offset = offset;
158 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
160 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
162 leaf = path->nodes[0];
168 /* we found one, but it isn't big enough yet */
169 leaf = path->nodes[0];
170 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
171 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
172 /* already at max size, make a new one */
176 int slot = path->slots[0] + 1;
177 /* we didn't find a csum item, insert one */
178 nritems = btrfs_header_nritems(path->nodes[0]);
179 if (path->slots[0] >= nritems - 1) {
180 ret = btrfs_next_leaf(root, path);
187 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
188 if (found_key.objectid != objectid ||
189 found_key.type != BTRFS_CSUM_ITEM_KEY) {
193 next_offset = found_key.offset;
199 * at this point, we know the tree has an item, but it isn't big
200 * enough yet to put our csum in. Grow it
202 btrfs_release_path(root, path);
203 ret = btrfs_search_slot(trans, root, &file_key, path,
204 BTRFS_CRC32_SIZE, 1);
210 if (path->slots[0] == 0) {
214 leaf = path->nodes[0];
215 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
216 csum_offset = (offset - found_key.offset) >>
217 root->fs_info->sb->s_blocksize_bits;
218 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
219 found_key.objectid != objectid ||
220 csum_offset >= MAX_CSUM_ITEMS(root)) {
223 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
225 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
226 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
227 if (diff != BTRFS_CRC32_SIZE)
229 ret = btrfs_extend_item(trans, root, path, diff);
235 btrfs_release_path(root, path);
238 u64 tmp = min((u64)i_size_read(inode), next_offset);
239 tmp -= offset & ~((u64)root->sectorsize -1);
240 tmp >>= root->fs_info->sb->s_blocksize_bits;
241 tmp = max((u64)1, tmp);
242 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
243 ins_size = BTRFS_CRC32_SIZE * tmp;
245 ins_size = BTRFS_CRC32_SIZE;
247 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
256 leaf = path->nodes[0];
257 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
259 item = (struct btrfs_csum_item *)((unsigned char *)item +
260 csum_offset * BTRFS_CRC32_SIZE);
262 csum_result = btrfs_csum_data(root, data, csum_result, len);
263 btrfs_csum_final(csum_result, (char *)&csum_result);
264 if (csum_result == 0) {
265 printk("csum result is 0 for inode %lu offset %Lu\n", inode->i_ino, offset);
268 write_extent_buffer(leaf, &csum_result, (unsigned long)item,
270 btrfs_mark_buffer_dirty(path->nodes[0]);
272 btrfs_release_path(root, path);
273 btrfs_free_path(path);
277 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
278 struct btrfs_root *root, struct btrfs_path *path,
281 struct btrfs_key key;
282 struct extent_buffer *leaf = path->nodes[0];
283 int slot = path->slots[0];
289 btrfs_item_key_to_cpu(leaf, &key, slot);
290 if (isize <= key.offset)
292 new_item_span = isize - key.offset;
293 blocks = (new_item_span + root->sectorsize - 1) >>
294 root->fs_info->sb->s_blocksize_bits;
295 new_item_size = blocks * BTRFS_CRC32_SIZE;
296 if (new_item_size >= btrfs_item_size_nr(leaf, slot))
298 ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);