file-item.c (5caf2a002901f0fde475371c4bf1c553b51884af) file-item.c (1e1d27017c5986c1ea81181506042cf9cba3f6ea)
1#include <linux/module.h>
1#include <stdio.h>
2#include <stdlib.h>
3#include "kerncompat.h"
4#include "radix-tree.h"
2#include "ctree.h"
3#include "disk-io.h"
5#include "ctree.h"
6#include "disk-io.h"
4#include "transaction.h"
5
7
6int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
7 struct btrfs_root *root,
8 u64 objectid, u64 offset,
9 u64 num_blocks, u64 hint_block,
10 u64 *result)
11{
12 struct btrfs_key ins;
13 int ret = 0;
14 struct btrfs_file_extent_item *item;
15 struct btrfs_key file_key;
16 struct btrfs_path *path;
17
18 path = btrfs_alloc_path();
19 BUG_ON(!path);
20 btrfs_init_path(path);
21 ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
22 (u64)-1, objectid, &ins);
23 BUG_ON(ret);
24 file_key.objectid = objectid;
25 file_key.offset = offset;
26 file_key.flags = 0;
27 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
28
29 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
30 sizeof(*item));
31 BUG_ON(ret);
32 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
33 struct btrfs_file_extent_item);
34 btrfs_set_file_extent_disk_blocknr(item, ins.objectid);
35 btrfs_set_file_extent_disk_num_blocks(item, ins.offset);
36 btrfs_set_file_extent_offset(item, 0);
37 btrfs_set_file_extent_num_blocks(item, ins.offset);
38 btrfs_set_file_extent_generation(item, trans->transid);
39 btrfs_mark_buffer_dirty(path->nodes[0]);
40 *result = ins.objectid;
41 btrfs_release_path(root, path);
42 btrfs_free_path(path);
43 return 0;
44}
45
46int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
47 struct btrfs_root *root,
48 struct btrfs_path *path, u64 objectid,
49 u64 offset, int mod)
50{
51 int ret;
52 struct btrfs_key file_key;
53 int ins_len = mod < 0 ? -1 : 0;
54 int cow = mod != 0;
55
56 file_key.objectid = objectid;
57 file_key.offset = offset;
58 file_key.flags = 0;
59 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
60 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
61 return ret;
62}
63
64int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
65 struct btrfs_root *root,
66 u64 objectid, u64 offset,
67 char *data, size_t len)
68{
69 int ret;
70 struct btrfs_key file_key;
71 struct btrfs_path *path;
72 struct btrfs_csum_item *item;
73
74 path = btrfs_alloc_path();
75 BUG_ON(!path);
76 btrfs_init_path(path);
77 file_key.objectid = objectid;
78 file_key.offset = offset;
79 file_key.flags = 0;
80 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
81 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
82 BTRFS_CSUM_SIZE);
83 if (ret != 0 && ret != -EEXIST)
84 goto fail;
85 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
86 struct btrfs_csum_item);
87 ret = 0;
88 ret = btrfs_csum_data(root, data, len, item->csum);
89 btrfs_mark_buffer_dirty(path->nodes[0]);
90fail:
91 btrfs_release_path(root, path);
92 btrfs_free_path(path);
93 return ret;
94}
95
96int btrfs_csum_verify_file_block(struct btrfs_root *root,
97 u64 objectid, u64 offset,
98 char *data, size_t len)
99{
100 int ret;
101 struct btrfs_key file_key;
102 struct btrfs_path *path;
103 struct btrfs_csum_item *item;
104 char result[BTRFS_CSUM_SIZE];
105
106 path = btrfs_alloc_path();
107 BUG_ON(!path);
108 btrfs_init_path(path);
109 file_key.objectid = objectid;
110 file_key.offset = offset;
111 file_key.flags = 0;
112 btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
113 ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
114 if (ret)
115 goto fail;
116 item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
117 struct btrfs_csum_item);
118 ret = 0;
119 ret = btrfs_csum_data(root, data, len, result);
120 WARN_ON(ret);
121 if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
122 ret = 1;
123fail:
124 btrfs_release_path(root, path);
125 btrfs_free_path(path);
126 return ret;
127}
128