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_insert_file_extent(struct btrfs_trans_handle
*trans
,
33 struct btrfs_root
*root
,
34 u64 objectid
, u64 pos
, u64 offset
,
35 u64 disk_num_bytes
, u64 num_bytes
)
38 struct btrfs_file_extent_item
*item
;
39 struct btrfs_key file_key
;
40 struct btrfs_path
*path
;
41 struct extent_buffer
*leaf
;
43 path
= btrfs_alloc_path();
45 file_key
.objectid
= objectid
;
46 file_key
.offset
= pos
;
47 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
49 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
54 leaf
= path
->nodes
[0];
55 item
= btrfs_item_ptr(leaf
, path
->slots
[0],
56 struct btrfs_file_extent_item
);
57 btrfs_set_file_extent_disk_bytenr(leaf
, item
, offset
);
58 btrfs_set_file_extent_disk_num_bytes(leaf
, item
, disk_num_bytes
);
59 btrfs_set_file_extent_offset(leaf
, item
, 0);
60 btrfs_set_file_extent_num_bytes(leaf
, item
, num_bytes
);
61 btrfs_set_file_extent_ram_bytes(leaf
, item
, num_bytes
);
62 btrfs_set_file_extent_generation(leaf
, item
, trans
->transid
);
63 btrfs_set_file_extent_type(leaf
, item
, BTRFS_FILE_EXTENT_REG
);
64 btrfs_set_file_extent_compression(leaf
, item
, 0);
65 btrfs_set_file_extent_encryption(leaf
, item
, 0);
66 btrfs_set_file_extent_other_encoding(leaf
, item
, 0);
67 btrfs_mark_buffer_dirty(leaf
);
69 btrfs_free_path(path
);
73 int btrfs_insert_inline_extent(struct btrfs_trans_handle
*trans
,
74 struct btrfs_root
*root
, u64 objectid
,
75 u64 offset
, char *buffer
, size_t size
)
78 struct btrfs_path
*path
;
79 struct extent_buffer
*leaf
;
81 struct btrfs_file_extent_item
*ei
;
86 path
= btrfs_alloc_path();
90 key
.objectid
= objectid
;
92 btrfs_set_key_type(&key
, BTRFS_EXTENT_DATA_KEY
);
94 datasize
= btrfs_file_extent_calc_inline_size(size
);
95 ret
= btrfs_insert_empty_item(trans
, root
, path
, &key
, datasize
);
101 leaf
= path
->nodes
[0];
102 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
103 struct btrfs_file_extent_item
);
104 btrfs_set_file_extent_generation(leaf
, ei
, trans
->transid
);
105 btrfs_set_file_extent_type(leaf
, ei
, BTRFS_FILE_EXTENT_INLINE
);
106 btrfs_set_file_extent_ram_bytes(leaf
, ei
, size
);
107 btrfs_set_file_extent_compression(leaf
, ei
, 0);
108 btrfs_set_file_extent_encryption(leaf
, ei
, 0);
109 btrfs_set_file_extent_other_encoding(leaf
, ei
, 0);
111 ptr
= btrfs_file_extent_inline_start(ei
) + offset
- key
.offset
;
112 write_extent_buffer(leaf
, buffer
, ptr
, size
);
113 btrfs_mark_buffer_dirty(leaf
);
115 btrfs_free_path(path
);
119 static struct btrfs_csum_item
*
120 btrfs_lookup_csum(struct btrfs_trans_handle
*trans
,
121 struct btrfs_root
*root
,
122 struct btrfs_path
*path
,
126 struct btrfs_key file_key
;
127 struct btrfs_key found_key
;
128 struct btrfs_csum_item
*item
;
129 struct extent_buffer
*leaf
;
132 btrfs_super_csum_size(root
->fs_info
->super_copy
);
135 file_key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
136 file_key
.offset
= bytenr
;
137 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_CSUM_KEY
);
138 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, 0, cow
);
141 leaf
= path
->nodes
[0];
144 if (path
->slots
[0] == 0)
147 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
148 if (btrfs_key_type(&found_key
) != BTRFS_EXTENT_CSUM_KEY
)
151 csum_offset
= (bytenr
- found_key
.offset
) / root
->sectorsize
;
152 csums_in_item
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
153 csums_in_item
/= csum_size
;
155 if (csum_offset
>= csums_in_item
) {
160 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
161 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
162 csum_offset
* csum_size
);
170 int btrfs_csum_file_block(struct btrfs_trans_handle
*trans
,
171 struct btrfs_root
*root
, u64 alloc_end
,
172 u64 bytenr
, char *data
, size_t len
)
175 struct btrfs_key file_key
;
176 struct btrfs_key found_key
;
177 u64 next_offset
= (u64
)-1;
179 struct btrfs_path
*path
;
180 struct btrfs_csum_item
*item
;
181 struct extent_buffer
*leaf
= NULL
;
183 u32 csum_result
= ~(u32
)0;
187 btrfs_super_csum_size(root
->fs_info
->super_copy
);
189 path
= btrfs_alloc_path();
192 file_key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
193 file_key
.offset
= bytenr
;
194 file_key
.type
= BTRFS_EXTENT_CSUM_KEY
;
196 item
= btrfs_lookup_csum(trans
, root
, path
, bytenr
, 1);
198 leaf
= path
->nodes
[0];
205 /* we found one, but it isn't big enough yet */
206 leaf
= path
->nodes
[0];
207 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
208 if ((item_size
/ csum_size
) >= MAX_CSUM_ITEMS(root
, csum_size
)) {
209 /* already at max size, make a new one */
213 int slot
= path
->slots
[0] + 1;
214 /* we didn't find a csum item, insert one */
215 nritems
= btrfs_header_nritems(path
->nodes
[0]);
216 if (path
->slots
[0] >= nritems
- 1) {
217 ret
= btrfs_next_leaf(root
, path
);
224 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, slot
);
225 if (found_key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
226 found_key
.type
!= BTRFS_EXTENT_CSUM_KEY
) {
230 next_offset
= found_key
.offset
;
236 * at this point, we know the tree has an item, but it isn't big
237 * enough yet to put our csum in. Grow it
239 btrfs_release_path(path
);
240 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
,
247 if (path
->slots
[0] == 0) {
251 leaf
= path
->nodes
[0];
252 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
253 csum_offset
= (file_key
.offset
- found_key
.offset
) / root
->sectorsize
;
254 if (found_key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
255 found_key
.type
!= BTRFS_EXTENT_CSUM_KEY
||
256 csum_offset
>= MAX_CSUM_ITEMS(root
, csum_size
)) {
259 if (csum_offset
>= btrfs_item_size_nr(leaf
, path
->slots
[0]) /
261 u32 diff
= (csum_offset
+ 1) * csum_size
;
262 diff
= diff
- btrfs_item_size_nr(leaf
, path
->slots
[0]);
263 if (diff
!= csum_size
)
265 ret
= btrfs_extend_item(trans
, root
, path
, diff
);
271 btrfs_release_path(path
);
274 u64 tmp
= min(alloc_end
, next_offset
);
275 tmp
-= file_key
.offset
;
276 tmp
/= root
->sectorsize
;
277 tmp
= max((u64
)1, tmp
);
278 tmp
= min(tmp
, (u64
)MAX_CSUM_ITEMS(root
, csum_size
));
279 ins_size
= csum_size
* tmp
;
281 ins_size
= csum_size
;
283 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
292 leaf
= path
->nodes
[0];
293 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
295 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
296 csum_offset
* csum_size
);
298 csum_result
= btrfs_csum_data(root
, data
, csum_result
, len
);
299 btrfs_csum_final(csum_result
, (char *)&csum_result
);
300 if (csum_result
== 0) {
301 printk("csum result is 0 for block %llu\n",
302 (unsigned long long)bytenr
);
305 write_extent_buffer(leaf
, &csum_result
, (unsigned long)item
,
307 btrfs_mark_buffer_dirty(path
->nodes
[0]);
309 btrfs_free_path(path
);
314 * helper function for csum removal, this expects the
315 * key to describe the csum pointed to by the path, and it expects
316 * the csum to overlap the range [bytenr, len]
318 * The csum should not be entirely contained in the range and the
319 * range should not be entirely contained in the csum.
321 * This calls btrfs_truncate_item with the correct args based on the
322 * overlap, and fixes up the key as required.
324 static noinline
int truncate_one_csum(struct btrfs_trans_handle
*trans
,
325 struct btrfs_root
*root
,
326 struct btrfs_path
*path
,
327 struct btrfs_key
*key
,
330 struct extent_buffer
*leaf
;
332 btrfs_super_csum_size(root
->fs_info
->super_copy
);
334 u64 end_byte
= bytenr
+ len
;
335 u32 blocksize
= root
->sectorsize
;
338 leaf
= path
->nodes
[0];
339 csum_end
= btrfs_item_size_nr(leaf
, path
->slots
[0]) / csum_size
;
340 csum_end
*= root
->sectorsize
;
341 csum_end
+= key
->offset
;
343 if (key
->offset
< bytenr
&& csum_end
<= end_byte
) {
348 * A simple truncate off the end of the item
350 u32 new_size
= (bytenr
- key
->offset
) / blocksize
;
351 new_size
*= csum_size
;
352 ret
= btrfs_truncate_item(trans
, root
, path
, new_size
, 1);
354 } else if (key
->offset
>= bytenr
&& csum_end
> end_byte
&&
355 end_byte
> key
->offset
) {
360 * we need to truncate from the beginning of the csum
362 u32 new_size
= (csum_end
- end_byte
) / blocksize
;
363 new_size
*= csum_size
;
365 ret
= btrfs_truncate_item(trans
, root
, path
, new_size
, 0);
368 key
->offset
= end_byte
;
369 ret
= btrfs_set_item_key_safe(root
, path
, key
);
378 * deletes the csum items from the csum tree for a given
381 int btrfs_del_csums(struct btrfs_trans_handle
*trans
,
382 struct btrfs_root
*root
, u64 bytenr
, u64 len
)
384 struct btrfs_path
*path
;
385 struct btrfs_key key
;
386 u64 end_byte
= bytenr
+ len
;
388 struct extent_buffer
*leaf
;
391 btrfs_super_csum_size(root
->fs_info
->super_copy
);
392 int blocksize
= root
->sectorsize
;
394 root
= root
->fs_info
->csum_root
;
396 path
= btrfs_alloc_path();
401 key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
402 key
.offset
= end_byte
- 1;
403 key
.type
= BTRFS_EXTENT_CSUM_KEY
;
405 ret
= btrfs_search_slot(trans
, root
, &key
, path
, -1, 1);
407 if (path
->slots
[0] == 0)
411 leaf
= path
->nodes
[0];
412 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
414 if (key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
415 key
.type
!= BTRFS_EXTENT_CSUM_KEY
) {
419 if (key
.offset
>= end_byte
)
422 csum_end
= btrfs_item_size_nr(leaf
, path
->slots
[0]) / csum_size
;
423 csum_end
*= blocksize
;
424 csum_end
+= key
.offset
;
426 /* this csum ends before we start, we're done */
427 if (csum_end
<= bytenr
)
430 /* delete the entire item, it is inside our range */
431 if (key
.offset
>= bytenr
&& csum_end
<= end_byte
) {
432 ret
= btrfs_del_item(trans
, root
, path
);
434 } else if (key
.offset
< bytenr
&& csum_end
> end_byte
) {
435 unsigned long offset
;
436 unsigned long shift_len
;
437 unsigned long item_offset
;
442 * Our bytes are in the middle of the csum,
443 * we need to split this item and insert a new one.
445 * But we can't drop the path because the
446 * csum could change, get removed, extended etc.
448 * The trick here is the max size of a csum item leaves
449 * enough room in the tree block for a single
450 * item header. So, we split the item in place,
451 * adding a new header pointing to the existing
452 * bytes. Then we loop around again and we have
453 * a nicely formed csum item that we can neatly
456 offset
= (bytenr
- key
.offset
) / blocksize
;
459 shift_len
= (len
/ blocksize
) * csum_size
;
461 item_offset
= btrfs_item_ptr_offset(leaf
,
464 memset_extent_buffer(leaf
, 0, item_offset
+ offset
,
469 * btrfs_split_item returns -EAGAIN when the
470 * item changed size or key
472 ret
= btrfs_split_item(trans
, root
, path
, &key
, offset
);
473 BUG_ON(ret
&& ret
!= -EAGAIN
);
475 key
.offset
= end_byte
- 1;
477 ret
= truncate_one_csum(trans
, root
, path
,
481 btrfs_release_path(path
);
484 btrfs_free_path(path
);