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 "kerncompat.h"
22 #include "radix-tree.h"
25 #include "transaction.h"
26 #include "print-tree.h"
29 #define MAX_CSUM_ITEMS(r,size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
30 sizeof(struct btrfs_item) * 2) / \
32 int btrfs_create_file(struct btrfs_trans_handle *trans,
33 struct btrfs_root *root, u64 dirid, u64 *objectid)
38 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
39 struct btrfs_root *root,
40 u64 objectid, u64 pos, u64 offset,
41 u64 disk_num_bytes, u64 num_bytes)
44 struct btrfs_file_extent_item *item;
45 struct btrfs_key file_key;
46 struct btrfs_path *path;
47 struct extent_buffer *leaf;
49 path = btrfs_alloc_path();
51 file_key.objectid = objectid;
52 file_key.offset = pos;
53 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
55 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
60 leaf = path->nodes[0];
61 item = btrfs_item_ptr(leaf, path->slots[0],
62 struct btrfs_file_extent_item);
63 btrfs_set_file_extent_disk_bytenr(leaf, item, offset);
64 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes);
65 btrfs_set_file_extent_offset(leaf, item, 0);
66 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
67 btrfs_set_file_extent_ram_bytes(leaf, item, num_bytes);
68 btrfs_set_file_extent_generation(leaf, item, trans->transid);
69 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
70 btrfs_set_file_extent_compression(leaf, item, 0);
71 btrfs_set_file_extent_encryption(leaf, item, 0);
72 btrfs_set_file_extent_other_encoding(leaf, item, 0);
73 btrfs_mark_buffer_dirty(leaf);
75 btrfs_free_path(path);
79 int btrfs_insert_inline_extent(struct btrfs_trans_handle *trans,
80 struct btrfs_root *root, u64 objectid,
81 u64 offset, char *buffer, size_t size)
84 struct btrfs_path *path;
85 struct extent_buffer *leaf;
87 struct btrfs_file_extent_item *ei;
92 path = btrfs_alloc_path();
96 key.objectid = objectid;
98 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
100 datasize = btrfs_file_extent_calc_inline_size(size);
101 ret = btrfs_insert_empty_item(trans, root, path, &key, datasize);
107 leaf = path->nodes[0];
108 ei = btrfs_item_ptr(leaf, path->slots[0],
109 struct btrfs_file_extent_item);
110 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
111 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
112 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
113 btrfs_set_file_extent_compression(leaf, ei, 0);
114 btrfs_set_file_extent_encryption(leaf, ei, 0);
115 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
117 ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset;
118 write_extent_buffer(leaf, buffer, ptr, size);
119 btrfs_mark_buffer_dirty(leaf);
121 btrfs_free_path(path);
125 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
126 struct btrfs_root *root,
127 struct btrfs_path *path,
131 struct btrfs_key file_key;
132 struct btrfs_key found_key;
133 struct btrfs_csum_item *item;
134 struct extent_buffer *leaf;
137 btrfs_super_csum_size(&root->fs_info->super_copy);
140 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
141 file_key.offset = bytenr;
142 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
143 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
146 leaf = path->nodes[0];
149 if (path->slots[0] == 0)
152 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
153 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
156 csum_offset = (bytenr - found_key.offset) / root->sectorsize;
157 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
158 csums_in_item /= csum_size;
160 if (csum_offset >= csums_in_item) {
165 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
166 item = (struct btrfs_csum_item *)((unsigned char *)item +
167 csum_offset * csum_size);
175 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
176 struct btrfs_root *root,
177 struct btrfs_path *path, u64 objectid,
181 struct btrfs_key file_key;
182 int ins_len = mod < 0 ? -1 : 0;
185 file_key.objectid = objectid;
186 file_key.offset = offset;
187 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
188 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
192 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
193 struct btrfs_root *root, u64 alloc_end,
194 u64 bytenr, char *data, size_t len)
197 struct btrfs_key file_key;
198 struct btrfs_key found_key;
199 u64 next_offset = (u64)-1;
201 struct btrfs_path *path;
202 struct btrfs_csum_item *item;
203 struct extent_buffer *leaf = NULL;
205 u32 csum_result = ~(u32)0;
209 btrfs_super_csum_size(&root->fs_info->super_copy);
211 path = btrfs_alloc_path();
214 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
215 file_key.offset = bytenr;
216 file_key.type = BTRFS_EXTENT_CSUM_KEY;
218 item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
220 leaf = path->nodes[0];
226 /* we found one, but it isn't big enough yet */
227 leaf = path->nodes[0];
228 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
229 if ((item_size / csum_size) >= MAX_CSUM_ITEMS(root, csum_size)) {
230 /* already at max size, make a new one */
234 int slot = path->slots[0] + 1;
235 /* we didn't find a csum item, insert one */
236 nritems = btrfs_header_nritems(path->nodes[0]);
237 if (path->slots[0] >= nritems - 1) {
238 ret = btrfs_next_leaf(root, path);
245 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
246 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
247 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
251 next_offset = found_key.offset;
257 * at this point, we know the tree has an item, but it isn't big
258 * enough yet to put our csum in. Grow it
260 btrfs_release_path(root, path);
261 ret = btrfs_search_slot(trans, root, &file_key, path,
268 if (path->slots[0] == 0) {
272 leaf = path->nodes[0];
273 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
274 csum_offset = (file_key.offset - found_key.offset) / root->sectorsize;
275 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
276 found_key.type != BTRFS_EXTENT_CSUM_KEY ||
277 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
280 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
282 u32 diff = (csum_offset + 1) * csum_size;
283 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
284 if (diff != csum_size)
286 ret = btrfs_extend_item(trans, root, path, diff);
292 btrfs_release_path(root, path);
295 u64 tmp = min(alloc_end, next_offset);
296 tmp -= file_key.offset;
297 tmp /= root->sectorsize;
298 tmp = max((u64)1, tmp);
299 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
300 ins_size = csum_size * tmp;
302 ins_size = csum_size;
304 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
313 leaf = path->nodes[0];
314 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
316 item = (struct btrfs_csum_item *)((unsigned char *)item +
317 csum_offset * csum_size);
319 csum_result = btrfs_csum_data(root, data, csum_result, len);
320 btrfs_csum_final(csum_result, (char *)&csum_result);
321 if (csum_result == 0) {
322 printk("csum result is 0 for block %llu\n",
323 (unsigned long long)bytenr);
326 write_extent_buffer(leaf, &csum_result, (unsigned long)item,
328 btrfs_mark_buffer_dirty(path->nodes[0]);
330 btrfs_release_path(root, path);
331 btrfs_free_path(path);
336 * helper function for csum removal, this expects the
337 * key to describe the csum pointed to by the path, and it expects
338 * the csum to overlap the range [bytenr, len]
340 * The csum should not be entirely contained in the range and the
341 * range should not be entirely contained in the csum.
343 * This calls btrfs_truncate_item with the correct args based on the
344 * overlap, and fixes up the key as required.
346 static noinline int truncate_one_csum(struct btrfs_trans_handle *trans,
347 struct btrfs_root *root,
348 struct btrfs_path *path,
349 struct btrfs_key *key,
352 struct extent_buffer *leaf;
354 btrfs_super_csum_size(&root->fs_info->super_copy);
356 u64 end_byte = bytenr + len;
357 u32 blocksize = root->sectorsize;
360 leaf = path->nodes[0];
361 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
362 csum_end *= root->sectorsize;
363 csum_end += key->offset;
365 if (key->offset < bytenr && csum_end <= end_byte) {
370 * A simple truncate off the end of the item
372 u32 new_size = (bytenr - key->offset) / blocksize;
373 new_size *= csum_size;
374 ret = btrfs_truncate_item(trans, root, path, new_size, 1);
376 } else if (key->offset >= bytenr && csum_end > end_byte &&
377 end_byte > key->offset) {
382 * we need to truncate from the beginning of the csum
384 u32 new_size = (csum_end - end_byte) / blocksize;
385 new_size *= csum_size;
387 ret = btrfs_truncate_item(trans, root, path, new_size, 0);
390 key->offset = end_byte;
391 ret = btrfs_set_item_key_safe(trans, root, path, key);
400 * deletes the csum items from the csum tree for a given
403 int btrfs_del_csums(struct btrfs_trans_handle *trans,
404 struct btrfs_root *root, u64 bytenr, u64 len)
406 struct btrfs_path *path;
407 struct btrfs_key key;
408 u64 end_byte = bytenr + len;
410 struct extent_buffer *leaf;
413 btrfs_super_csum_size(&root->fs_info->super_copy);
414 int blocksize = root->sectorsize;
416 root = root->fs_info->csum_root;
418 path = btrfs_alloc_path();
421 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
422 key.offset = end_byte - 1;
423 key.type = BTRFS_EXTENT_CSUM_KEY;
425 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
427 if (path->slots[0] == 0)
431 leaf = path->nodes[0];
432 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
434 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
435 key.type != BTRFS_EXTENT_CSUM_KEY) {
439 if (key.offset >= end_byte)
442 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
443 csum_end *= blocksize;
444 csum_end += key.offset;
446 /* this csum ends before we start, we're done */
447 if (csum_end <= bytenr)
450 /* delete the entire item, it is inside our range */
451 if (key.offset >= bytenr && csum_end <= end_byte) {
452 ret = btrfs_del_item(trans, root, path);
454 } else if (key.offset < bytenr && csum_end > end_byte) {
455 unsigned long offset;
456 unsigned long shift_len;
457 unsigned long item_offset;
462 * Our bytes are in the middle of the csum,
463 * we need to split this item and insert a new one.
465 * But we can't drop the path because the
466 * csum could change, get removed, extended etc.
468 * The trick here is the max size of a csum item leaves
469 * enough room in the tree block for a single
470 * item header. So, we split the item in place,
471 * adding a new header pointing to the existing
472 * bytes. Then we loop around again and we have
473 * a nicely formed csum item that we can neatly
476 offset = (bytenr - key.offset) / blocksize;
479 shift_len = (len / blocksize) * csum_size;
481 item_offset = btrfs_item_ptr_offset(leaf,
484 memset_extent_buffer(leaf, 0, item_offset + offset,
489 * btrfs_split_item returns -EAGAIN when the
490 * item changed size or key
492 ret = btrfs_split_item(trans, root, path, &key, offset);
493 BUG_ON(ret && ret != -EAGAIN);
495 key.offset = end_byte - 1;
497 ret = truncate_one_csum(trans, root, path,
501 btrfs_release_path(root, path);
504 btrfs_free_path(path);