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"
30 #define MAX_CSUM_ITEMS(r,size) ((((BTRFS_LEAF_DATA_SIZE(r) - \
31 sizeof(struct btrfs_item) * 2) / \
33 int btrfs_insert_file_extent(struct btrfs_trans_handle
*trans
,
34 struct btrfs_root
*root
,
35 u64 objectid
, u64 pos
, u64 offset
,
36 u64 disk_num_bytes
, u64 num_bytes
)
39 struct btrfs_file_extent_item
*item
;
40 struct btrfs_key file_key
;
41 struct btrfs_path
*path
;
42 struct extent_buffer
*leaf
;
44 path
= btrfs_alloc_path();
48 file_key
.objectid
= objectid
;
49 file_key
.offset
= pos
;
50 file_key
.type
= BTRFS_EXTENT_DATA_KEY
;
52 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
57 leaf
= path
->nodes
[0];
58 item
= btrfs_item_ptr(leaf
, path
->slots
[0],
59 struct btrfs_file_extent_item
);
60 btrfs_set_file_extent_disk_bytenr(leaf
, item
, offset
);
61 btrfs_set_file_extent_disk_num_bytes(leaf
, item
, disk_num_bytes
);
62 btrfs_set_file_extent_offset(leaf
, item
, 0);
63 btrfs_set_file_extent_num_bytes(leaf
, item
, num_bytes
);
64 btrfs_set_file_extent_ram_bytes(leaf
, item
, num_bytes
);
65 btrfs_set_file_extent_generation(leaf
, item
, trans
->transid
);
66 btrfs_set_file_extent_type(leaf
, item
, BTRFS_FILE_EXTENT_REG
);
67 btrfs_set_file_extent_compression(leaf
, item
, 0);
68 btrfs_set_file_extent_encryption(leaf
, item
, 0);
69 btrfs_set_file_extent_other_encoding(leaf
, item
, 0);
70 btrfs_mark_buffer_dirty(leaf
);
72 btrfs_free_path(path
);
76 int btrfs_insert_inline_extent(struct btrfs_trans_handle
*trans
,
77 struct btrfs_root
*root
, u64 objectid
,
78 u64 offset
, char *buffer
, size_t size
)
81 struct btrfs_path
*path
;
82 struct extent_buffer
*leaf
;
84 struct btrfs_file_extent_item
*ei
;
89 path
= btrfs_alloc_path();
93 key
.objectid
= objectid
;
95 key
.type
= BTRFS_EXTENT_DATA_KEY
;
97 datasize
= btrfs_file_extent_calc_inline_size(size
);
98 ret
= btrfs_insert_empty_item(trans
, root
, path
, &key
, datasize
);
104 leaf
= path
->nodes
[0];
105 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
106 struct btrfs_file_extent_item
);
107 btrfs_set_file_extent_generation(leaf
, ei
, trans
->transid
);
108 btrfs_set_file_extent_type(leaf
, ei
, BTRFS_FILE_EXTENT_INLINE
);
109 btrfs_set_file_extent_ram_bytes(leaf
, ei
, size
);
110 btrfs_set_file_extent_compression(leaf
, ei
, 0);
111 btrfs_set_file_extent_encryption(leaf
, ei
, 0);
112 btrfs_set_file_extent_other_encoding(leaf
, ei
, 0);
114 ptr
= btrfs_file_extent_inline_start(ei
) + offset
- key
.offset
;
115 write_extent_buffer(leaf
, buffer
, ptr
, size
);
116 btrfs_mark_buffer_dirty(leaf
);
118 btrfs_free_path(path
);
122 static struct btrfs_csum_item
*
123 btrfs_lookup_csum(struct btrfs_trans_handle
*trans
,
124 struct btrfs_root
*root
,
125 struct btrfs_path
*path
,
129 struct btrfs_key file_key
;
130 struct btrfs_key found_key
;
131 struct btrfs_csum_item
*item
;
132 struct extent_buffer
*leaf
;
135 btrfs_super_csum_size(root
->fs_info
->super_copy
);
138 file_key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
139 file_key
.offset
= bytenr
;
140 file_key
.type
= BTRFS_EXTENT_CSUM_KEY
;
141 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, 0, cow
);
144 leaf
= path
->nodes
[0];
147 if (path
->slots
[0] == 0)
150 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
151 if (found_key
.type
!= BTRFS_EXTENT_CSUM_KEY
)
154 csum_offset
= (bytenr
- found_key
.offset
) / root
->sectorsize
;
155 csums_in_item
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
156 csums_in_item
/= csum_size
;
158 if (csum_offset
>= csums_in_item
) {
163 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
164 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
165 csum_offset
* csum_size
);
173 int btrfs_csum_file_block(struct btrfs_trans_handle
*trans
,
174 struct btrfs_root
*root
, u64 alloc_end
,
175 u64 bytenr
, char *data
, size_t len
)
178 struct btrfs_key file_key
;
179 struct btrfs_key found_key
;
180 u64 next_offset
= (u64
)-1;
182 struct btrfs_path
*path
;
183 struct btrfs_csum_item
*item
;
184 struct extent_buffer
*leaf
= NULL
;
186 u32 csum_result
= ~(u32
)0;
190 btrfs_super_csum_size(root
->fs_info
->super_copy
);
192 path
= btrfs_alloc_path();
196 file_key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
197 file_key
.offset
= bytenr
;
198 file_key
.type
= BTRFS_EXTENT_CSUM_KEY
;
200 item
= btrfs_lookup_csum(trans
, root
, path
, bytenr
, 1);
202 leaf
= path
->nodes
[0];
209 /* we found one, but it isn't big enough yet */
210 leaf
= path
->nodes
[0];
211 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
212 if ((item_size
/ csum_size
) >= MAX_CSUM_ITEMS(root
, csum_size
)) {
213 /* already at max size, make a new one */
217 int slot
= path
->slots
[0] + 1;
218 /* we didn't find a csum item, insert one */
219 nritems
= btrfs_header_nritems(path
->nodes
[0]);
220 if (path
->slots
[0] >= nritems
- 1) {
221 ret
= btrfs_next_leaf(root
, path
);
228 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, slot
);
229 if (found_key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
230 found_key
.type
!= BTRFS_EXTENT_CSUM_KEY
) {
234 next_offset
= found_key
.offset
;
240 * at this point, we know the tree has an item, but it isn't big
241 * enough yet to put our csum in. Grow it
243 btrfs_release_path(path
);
244 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
,
251 if (path
->slots
[0] == 0) {
255 leaf
= path
->nodes
[0];
256 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
257 csum_offset
= (file_key
.offset
- found_key
.offset
) / root
->sectorsize
;
258 if (found_key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
259 found_key
.type
!= BTRFS_EXTENT_CSUM_KEY
||
260 csum_offset
>= MAX_CSUM_ITEMS(root
, csum_size
)) {
263 if (csum_offset
>= btrfs_item_size_nr(leaf
, path
->slots
[0]) /
265 u32 diff
= (csum_offset
+ 1) * csum_size
;
266 diff
= diff
- btrfs_item_size_nr(leaf
, path
->slots
[0]);
267 if (diff
!= csum_size
)
269 ret
= btrfs_extend_item(trans
, root
, path
, diff
);
275 btrfs_release_path(path
);
278 u64 tmp
= min(alloc_end
, next_offset
);
279 tmp
-= file_key
.offset
;
280 tmp
/= root
->sectorsize
;
281 tmp
= max((u64
)1, tmp
);
282 tmp
= min(tmp
, (u64
)MAX_CSUM_ITEMS(root
, csum_size
));
283 ins_size
= csum_size
* tmp
;
285 ins_size
= csum_size
;
287 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
296 leaf
= path
->nodes
[0];
297 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
299 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
300 csum_offset
* csum_size
);
302 csum_result
= btrfs_csum_data(root
, data
, csum_result
, len
);
303 btrfs_csum_final(csum_result
, (u8
*)&csum_result
);
304 if (csum_result
== 0) {
305 printk("csum result is 0 for block %llu\n",
306 (unsigned long long)bytenr
);
309 write_extent_buffer(leaf
, &csum_result
, (unsigned long)item
,
311 btrfs_mark_buffer_dirty(path
->nodes
[0]);
313 btrfs_free_path(path
);
318 * helper function for csum removal, this expects the
319 * key to describe the csum pointed to by the path, and it expects
320 * the csum to overlap the range [bytenr, len]
322 * The csum should not be entirely contained in the range and the
323 * range should not be entirely contained in the csum.
325 * This calls btrfs_truncate_item with the correct args based on the
326 * overlap, and fixes up the key as required.
328 static noinline
int truncate_one_csum(struct btrfs_trans_handle
*trans
,
329 struct btrfs_root
*root
,
330 struct btrfs_path
*path
,
331 struct btrfs_key
*key
,
334 struct extent_buffer
*leaf
;
336 btrfs_super_csum_size(root
->fs_info
->super_copy
);
338 u64 end_byte
= bytenr
+ len
;
339 u32 blocksize
= root
->sectorsize
;
342 leaf
= path
->nodes
[0];
343 csum_end
= btrfs_item_size_nr(leaf
, path
->slots
[0]) / csum_size
;
344 csum_end
*= root
->sectorsize
;
345 csum_end
+= key
->offset
;
347 if (key
->offset
< bytenr
&& csum_end
<= end_byte
) {
352 * A simple truncate off the end of the item
354 u32 new_size
= (bytenr
- key
->offset
) / blocksize
;
355 new_size
*= csum_size
;
356 ret
= btrfs_truncate_item(trans
, root
, path
, new_size
, 1);
358 } else if (key
->offset
>= bytenr
&& csum_end
> end_byte
&&
359 end_byte
> key
->offset
) {
364 * we need to truncate from the beginning of the csum
366 u32 new_size
= (csum_end
- end_byte
) / blocksize
;
367 new_size
*= csum_size
;
369 ret
= btrfs_truncate_item(trans
, root
, path
, new_size
, 0);
372 key
->offset
= end_byte
;
373 ret
= btrfs_set_item_key_safe(root
, path
, key
);
382 * deletes the csum items from the csum tree for a given
385 int btrfs_del_csums(struct btrfs_trans_handle
*trans
,
386 struct btrfs_root
*root
, u64 bytenr
, u64 len
)
388 struct btrfs_path
*path
;
389 struct btrfs_key key
;
390 u64 end_byte
= bytenr
+ len
;
392 struct extent_buffer
*leaf
;
395 btrfs_super_csum_size(root
->fs_info
->super_copy
);
396 int blocksize
= root
->sectorsize
;
398 root
= root
->fs_info
->csum_root
;
400 path
= btrfs_alloc_path();
405 key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
406 key
.offset
= end_byte
- 1;
407 key
.type
= BTRFS_EXTENT_CSUM_KEY
;
409 ret
= btrfs_search_slot(trans
, root
, &key
, path
, -1, 1);
411 if (path
->slots
[0] == 0)
415 leaf
= path
->nodes
[0];
416 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
418 if (key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
419 key
.type
!= BTRFS_EXTENT_CSUM_KEY
) {
423 if (key
.offset
>= end_byte
)
426 csum_end
= btrfs_item_size_nr(leaf
, path
->slots
[0]) / csum_size
;
427 csum_end
*= blocksize
;
428 csum_end
+= key
.offset
;
430 /* this csum ends before we start, we're done */
431 if (csum_end
<= bytenr
)
434 /* delete the entire item, it is inside our range */
435 if (key
.offset
>= bytenr
&& csum_end
<= end_byte
) {
436 ret
= btrfs_del_item(trans
, root
, path
);
438 } else if (key
.offset
< bytenr
&& csum_end
> end_byte
) {
439 unsigned long offset
;
440 unsigned long shift_len
;
441 unsigned long item_offset
;
446 * Our bytes are in the middle of the csum,
447 * we need to split this item and insert a new one.
449 * But we can't drop the path because the
450 * csum could change, get removed, extended etc.
452 * The trick here is the max size of a csum item leaves
453 * enough room in the tree block for a single
454 * item header. So, we split the item in place,
455 * adding a new header pointing to the existing
456 * bytes. Then we loop around again and we have
457 * a nicely formed csum item that we can neatly
460 offset
= (bytenr
- key
.offset
) / blocksize
;
463 shift_len
= (len
/ blocksize
) * csum_size
;
465 item_offset
= btrfs_item_ptr_offset(leaf
,
468 memset_extent_buffer(leaf
, 0, item_offset
+ offset
,
473 * btrfs_split_item returns -EAGAIN when the
474 * item changed size or key
476 ret
= btrfs_split_item(trans
, root
, path
, &key
, offset
);
477 BUG_ON(ret
&& ret
!= -EAGAIN
);
479 key
.offset
= end_byte
- 1;
481 ret
= truncate_one_csum(trans
, root
, path
,
485 btrfs_release_path(path
);
488 btrfs_free_path(path
);