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/bio.h>
20 #include <linux/pagemap.h>
21 #include <linux/highmem.h>
24 #include "transaction.h"
25 #include "print-tree.h"
27 #define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
28 sizeof(struct btrfs_item) * 2) / \
29 BTRFS_CRC32_SIZE) - 1))
30 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
31 struct btrfs_root *root,
32 u64 objectid, u64 pos,
33 u64 offset, u64 disk_num_bytes,
37 struct btrfs_file_extent_item *item;
38 struct btrfs_key file_key;
39 struct btrfs_path *path;
40 struct extent_buffer *leaf;
42 path = btrfs_alloc_path();
44 file_key.objectid = objectid;
45 file_key.offset = pos;
46 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
48 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
53 leaf = path->nodes[0];
54 item = btrfs_item_ptr(leaf, path->slots[0],
55 struct btrfs_file_extent_item);
56 btrfs_set_file_extent_disk_bytenr(leaf, item, offset);
57 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
58 btrfs_set_file_extent_offset(leaf, item, 0);
59 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
60 btrfs_set_file_extent_generation(leaf, item, trans->transid);
61 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
62 btrfs_mark_buffer_dirty(leaf);
64 btrfs_free_path(path);
68 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
69 struct btrfs_root *root,
70 struct btrfs_path *path,
71 u64 objectid, u64 offset,
75 struct btrfs_key file_key;
76 struct btrfs_key found_key;
77 struct btrfs_csum_item *item;
78 struct extent_buffer *leaf;
82 file_key.objectid = objectid;
83 file_key.offset = offset;
84 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
85 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
88 leaf = path->nodes[0];
91 if (path->slots[0] == 0)
94 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
95 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
96 found_key.objectid != objectid) {
99 csum_offset = (offset - found_key.offset) >>
100 root->fs_info->sb->s_blocksize_bits;
101 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
102 csums_in_item /= BTRFS_CRC32_SIZE;
104 if (csum_offset >= csums_in_item) {
109 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
110 item = (struct btrfs_csum_item *)((unsigned char *)item +
111 csum_offset * BTRFS_CRC32_SIZE);
120 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
121 struct btrfs_root *root,
122 struct btrfs_path *path, u64 objectid,
126 struct btrfs_key file_key;
127 int ins_len = mod < 0 ? -1 : 0;
130 file_key.objectid = objectid;
131 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_blocks(struct btrfs_trans_handle *trans,
138 struct btrfs_root *root, struct inode *inode,
141 u64 objectid = inode->i_ino;
144 struct btrfs_key file_key;
145 struct btrfs_key found_key;
148 struct btrfs_path *path;
149 struct btrfs_csum_item *item;
150 struct btrfs_csum_item *item_end;
151 struct extent_buffer *leaf = NULL;
157 struct bio_vec *bvec = bio->bi_io_vec;
161 unsigned long map_len;
162 unsigned long map_start;
164 path = btrfs_alloc_path();
167 next_offset = (u64)-1;
169 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
170 file_key.objectid = objectid;
171 file_key.offset = offset;
172 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
174 item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
176 leaf = path->nodes[0];
182 /* we found one, but it isn't big enough yet */
183 leaf = path->nodes[0];
184 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
185 if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
186 /* already at max size, make a new one */
190 int slot = path->slots[0] + 1;
191 /* we didn't find a csum item, insert one */
192 nritems = btrfs_header_nritems(path->nodes[0]);
193 if (path->slots[0] >= nritems - 1) {
194 ret = btrfs_next_leaf(root, path);
201 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
202 if (found_key.objectid != objectid ||
203 found_key.type != BTRFS_CSUM_ITEM_KEY) {
207 next_offset = found_key.offset;
213 * at this point, we know the tree has an item, but it isn't big
214 * enough yet to put our csum in. Grow it
216 btrfs_release_path(root, path);
217 ret = btrfs_search_slot(trans, root, &file_key, path,
218 BTRFS_CRC32_SIZE, 1);
224 if (path->slots[0] == 0) {
228 leaf = path->nodes[0];
229 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
230 csum_offset = (offset - found_key.offset) >>
231 root->fs_info->sb->s_blocksize_bits;
232 if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
233 found_key.objectid != objectid ||
234 csum_offset >= MAX_CSUM_ITEMS(root)) {
237 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
239 u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
240 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
241 if (diff != BTRFS_CRC32_SIZE)
243 ret = btrfs_extend_item(trans, root, path, diff);
249 btrfs_release_path(root, path);
252 u64 tmp = min((u64)i_size_read(inode), next_offset);
253 tmp -= offset & ~((u64)root->sectorsize -1);
254 tmp >>= root->fs_info->sb->s_blocksize_bits;
255 tmp = max((u64)1, tmp);
256 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root));
257 ins_size = BTRFS_CRC32_SIZE * tmp;
259 ins_size = BTRFS_CRC32_SIZE;
261 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
270 leaf = path->nodes[0];
271 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
273 item = (struct btrfs_csum_item *)((unsigned char *)item +
274 csum_offset * BTRFS_CRC32_SIZE);
276 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
277 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
278 btrfs_item_size_nr(leaf, path->slots[0]));
281 data = kmap_atomic(bvec->bv_page, KM_USER0);
282 csum_result = ~(u32)0;
283 csum_result = btrfs_csum_data(root, data + bvec->bv_offset,
284 csum_result, bvec->bv_len);
285 kunmap_atomic(data, KM_USER0);
286 btrfs_csum_final(csum_result, (char *)&csum_result);
287 if (csum_result == 0) {
288 printk("csum result is 0 for inode %lu offset %Lu\n", inode->i_ino, offset);
292 (unsigned long)item + BTRFS_CRC32_SIZE >= map_start + map_len) {
296 unmap_extent_buffer(leaf, eb_token, KM_USER1);
298 err = map_private_extent_buffer(leaf, (unsigned long)item,
301 &map_start, &map_len, KM_USER1);
306 memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)),
307 &csum_result, BTRFS_CRC32_SIZE);
309 write_extent_buffer(leaf, &csum_result, (unsigned long)item,
314 if (bio_index < bio->bi_vcnt) {
315 item = (struct btrfs_csum_item *)((char *)item +
317 if (item < item_end && offset + PAGE_CACHE_SIZE ==
318 page_offset(bvec->bv_page)) {
319 offset = page_offset(bvec->bv_page);
324 unmap_extent_buffer(leaf, eb_token, KM_USER1);
327 btrfs_mark_buffer_dirty(path->nodes[0]);
328 if (bio_index < bio->bi_vcnt) {
329 btrfs_release_path(root, path);
333 btrfs_free_path(path);
337 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
338 struct btrfs_root *root, struct btrfs_path *path,
341 struct btrfs_key key;
342 struct extent_buffer *leaf = path->nodes[0];
343 int slot = path->slots[0];
349 btrfs_item_key_to_cpu(leaf, &key, slot);
350 if (isize <= key.offset)
352 new_item_span = isize - key.offset;
353 blocks = (new_item_span + root->sectorsize - 1) >>
354 root->fs_info->sb->s_blocksize_bits;
355 new_item_size = blocks * BTRFS_CRC32_SIZE;
356 if (new_item_size >= btrfs_item_size_nr(leaf, slot))
358 ret = btrfs_truncate_item(trans, root, path, new_item_size, 1);