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];
227 /* we found one, but it isn't big enough yet */
228 leaf
= path
->nodes
[0];
229 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
230 if ((item_size
/ csum_size
) >= MAX_CSUM_ITEMS(root
, csum_size
)) {
231 /* already at max size, make a new one */
235 int slot
= path
->slots
[0] + 1;
236 /* we didn't find a csum item, insert one */
237 nritems
= btrfs_header_nritems(path
->nodes
[0]);
238 if (path
->slots
[0] >= nritems
- 1) {
239 ret
= btrfs_next_leaf(root
, path
);
246 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, slot
);
247 if (found_key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
248 found_key
.type
!= BTRFS_EXTENT_CSUM_KEY
) {
252 next_offset
= found_key
.offset
;
258 * at this point, we know the tree has an item, but it isn't big
259 * enough yet to put our csum in. Grow it
261 btrfs_release_path(root
, path
);
262 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
,
269 if (path
->slots
[0] == 0) {
273 leaf
= path
->nodes
[0];
274 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
275 csum_offset
= (file_key
.offset
- found_key
.offset
) / root
->sectorsize
;
276 if (found_key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
277 found_key
.type
!= BTRFS_EXTENT_CSUM_KEY
||
278 csum_offset
>= MAX_CSUM_ITEMS(root
, csum_size
)) {
281 if (csum_offset
>= btrfs_item_size_nr(leaf
, path
->slots
[0]) /
283 u32 diff
= (csum_offset
+ 1) * csum_size
;
284 diff
= diff
- btrfs_item_size_nr(leaf
, path
->slots
[0]);
285 if (diff
!= csum_size
)
287 ret
= btrfs_extend_item(trans
, root
, path
, diff
);
293 btrfs_release_path(root
, path
);
296 u64 tmp
= min(alloc_end
, next_offset
);
297 tmp
-= file_key
.offset
;
298 tmp
/= root
->sectorsize
;
299 tmp
= max((u64
)1, tmp
);
300 tmp
= min(tmp
, (u64
)MAX_CSUM_ITEMS(root
, csum_size
));
301 ins_size
= csum_size
* tmp
;
303 ins_size
= csum_size
;
305 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
314 leaf
= path
->nodes
[0];
315 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
317 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
318 csum_offset
* csum_size
);
320 csum_result
= btrfs_csum_data(root
, data
, csum_result
, len
);
321 btrfs_csum_final(csum_result
, (char *)&csum_result
);
322 if (csum_result
== 0) {
323 printk("csum result is 0 for block %llu\n",
324 (unsigned long long)bytenr
);
327 write_extent_buffer(leaf
, &csum_result
, (unsigned long)item
,
329 btrfs_mark_buffer_dirty(path
->nodes
[0]);
331 btrfs_release_path(root
, path
);
332 btrfs_free_path(path
);
337 * helper function for csum removal, this expects the
338 * key to describe the csum pointed to by the path, and it expects
339 * the csum to overlap the range [bytenr, len]
341 * The csum should not be entirely contained in the range and the
342 * range should not be entirely contained in the csum.
344 * This calls btrfs_truncate_item with the correct args based on the
345 * overlap, and fixes up the key as required.
347 static noinline
int truncate_one_csum(struct btrfs_trans_handle
*trans
,
348 struct btrfs_root
*root
,
349 struct btrfs_path
*path
,
350 struct btrfs_key
*key
,
353 struct extent_buffer
*leaf
;
355 btrfs_super_csum_size(&root
->fs_info
->super_copy
);
357 u64 end_byte
= bytenr
+ len
;
358 u32 blocksize
= root
->sectorsize
;
361 leaf
= path
->nodes
[0];
362 csum_end
= btrfs_item_size_nr(leaf
, path
->slots
[0]) / csum_size
;
363 csum_end
*= root
->sectorsize
;
364 csum_end
+= key
->offset
;
366 if (key
->offset
< bytenr
&& csum_end
<= end_byte
) {
371 * A simple truncate off the end of the item
373 u32 new_size
= (bytenr
- key
->offset
) / blocksize
;
374 new_size
*= csum_size
;
375 ret
= btrfs_truncate_item(trans
, root
, path
, new_size
, 1);
377 } else if (key
->offset
>= bytenr
&& csum_end
> end_byte
&&
378 end_byte
> key
->offset
) {
383 * we need to truncate from the beginning of the csum
385 u32 new_size
= (csum_end
- end_byte
) / blocksize
;
386 new_size
*= csum_size
;
388 ret
= btrfs_truncate_item(trans
, root
, path
, new_size
, 0);
391 key
->offset
= end_byte
;
392 ret
= btrfs_set_item_key_safe(trans
, root
, path
, key
);
401 * deletes the csum items from the csum tree for a given
404 int btrfs_del_csums(struct btrfs_trans_handle
*trans
,
405 struct btrfs_root
*root
, u64 bytenr
, u64 len
)
407 struct btrfs_path
*path
;
408 struct btrfs_key key
;
409 u64 end_byte
= bytenr
+ len
;
411 struct extent_buffer
*leaf
;
414 btrfs_super_csum_size(&root
->fs_info
->super_copy
);
415 int blocksize
= root
->sectorsize
;
417 root
= root
->fs_info
->csum_root
;
419 path
= btrfs_alloc_path();
422 key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
423 key
.offset
= end_byte
- 1;
424 key
.type
= BTRFS_EXTENT_CSUM_KEY
;
426 ret
= btrfs_search_slot(trans
, root
, &key
, path
, -1, 1);
428 if (path
->slots
[0] == 0)
432 leaf
= path
->nodes
[0];
433 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
435 if (key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
436 key
.type
!= BTRFS_EXTENT_CSUM_KEY
) {
440 if (key
.offset
>= end_byte
)
443 csum_end
= btrfs_item_size_nr(leaf
, path
->slots
[0]) / csum_size
;
444 csum_end
*= blocksize
;
445 csum_end
+= key
.offset
;
447 /* this csum ends before we start, we're done */
448 if (csum_end
<= bytenr
)
451 /* delete the entire item, it is inside our range */
452 if (key
.offset
>= bytenr
&& csum_end
<= end_byte
) {
453 ret
= btrfs_del_item(trans
, root
, path
);
455 } else if (key
.offset
< bytenr
&& csum_end
> end_byte
) {
456 unsigned long offset
;
457 unsigned long shift_len
;
458 unsigned long item_offset
;
463 * Our bytes are in the middle of the csum,
464 * we need to split this item and insert a new one.
466 * But we can't drop the path because the
467 * csum could change, get removed, extended etc.
469 * The trick here is the max size of a csum item leaves
470 * enough room in the tree block for a single
471 * item header. So, we split the item in place,
472 * adding a new header pointing to the existing
473 * bytes. Then we loop around again and we have
474 * a nicely formed csum item that we can neatly
477 offset
= (bytenr
- key
.offset
) / blocksize
;
480 shift_len
= (len
/ blocksize
) * csum_size
;
482 item_offset
= btrfs_item_ptr_offset(leaf
,
485 memset_extent_buffer(leaf
, 0, item_offset
+ offset
,
490 * btrfs_split_item returns -EAGAIN when the
491 * item changed size or key
493 ret
= btrfs_split_item(trans
, root
, path
, &key
, offset
);
494 BUG_ON(ret
&& ret
!= -EAGAIN
);
496 key
.offset
= end_byte
- 1;
498 ret
= truncate_one_csum(trans
, root
, path
,
502 btrfs_release_path(root
, path
);
505 btrfs_free_path(path
);