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eb60ceac CM |
1 | #define _XOPEN_SOURCE 500 |
2 | #include <stdio.h> | |
3 | #include <stdlib.h> | |
4 | #include <sys/types.h> | |
5 | #include <sys/stat.h> | |
6 | #include <fcntl.h> | |
7 | #include <unistd.h> | |
8 | #include "kerncompat.h" | |
9 | #include "radix-tree.h" | |
10 | #include "ctree.h" | |
11 | #include "disk-io.h" | |
12 | ||
13 | static int allocated_blocks = 0; | |
14 | ||
eb60ceac CM |
15 | static int get_free_block(struct ctree_root *root, u64 *block) |
16 | { | |
17 | struct stat st; | |
18 | int ret; | |
19 | ||
d97e63b6 CM |
20 | if (root->alloc_extent->num_used >= root->alloc_extent->num_blocks) |
21 | return -1; | |
22 | ||
23 | *block = root->alloc_extent->blocknr + root->alloc_extent->num_used; | |
24 | root->alloc_extent->num_used += 1; | |
25 | if (root->alloc_extent->num_used >= root->alloc_extent->num_blocks) { | |
26 | struct alloc_extent *ae = root->alloc_extent; | |
27 | root->alloc_extent = root->reserve_extent; | |
28 | root->reserve_extent = ae; | |
29 | ae->num_blocks = 0; | |
30 | } | |
eb60ceac CM |
31 | st.st_size = 0; |
32 | ret = fstat(root->fp, &st); | |
d97e63b6 CM |
33 | if (st.st_size < (*block + 1) * CTREE_BLOCKSIZE) |
34 | ret = ftruncate(root->fp, | |
35 | (*block + 1) * CTREE_BLOCKSIZE); | |
eb60ceac CM |
36 | return ret; |
37 | } | |
38 | ||
39 | struct tree_buffer *alloc_tree_block(struct ctree_root *root, u64 blocknr) | |
40 | { | |
41 | struct tree_buffer *buf; | |
42 | int ret; | |
43 | buf = malloc(sizeof(struct tree_buffer)); | |
44 | if (!buf) | |
45 | return buf; | |
46 | allocated_blocks++; | |
47 | buf->blocknr = blocknr; | |
48 | buf->count = 1; | |
49 | radix_tree_preload(GFP_KERNEL); | |
50 | ret = radix_tree_insert(&root->cache_radix, blocknr, buf); | |
51 | radix_tree_preload_end(); | |
52 | if (ret) { | |
53 | free(buf); | |
54 | return NULL; | |
55 | } | |
56 | return buf; | |
57 | } | |
58 | ||
59 | struct tree_buffer *alloc_free_block(struct ctree_root *root) | |
60 | { | |
61 | u64 free_block; | |
62 | int ret; | |
63 | struct tree_buffer * buf; | |
64 | ret = get_free_block(root, &free_block); | |
65 | if (ret) { | |
66 | BUG(); | |
67 | return NULL; | |
68 | } | |
69 | buf = alloc_tree_block(root, free_block); | |
70 | if (!buf) | |
71 | BUG(); | |
72 | return buf; | |
73 | } | |
74 | ||
75 | struct tree_buffer *read_tree_block(struct ctree_root *root, u64 blocknr) | |
76 | { | |
d97e63b6 | 77 | loff_t offset = blocknr * CTREE_BLOCKSIZE; |
eb60ceac CM |
78 | struct tree_buffer *buf; |
79 | int ret; | |
80 | ||
81 | buf = radix_tree_lookup(&root->cache_radix, blocknr); | |
82 | if (buf) { | |
83 | buf->count++; | |
84 | if (buf->blocknr != blocknr) | |
85 | BUG(); | |
86 | if (buf->blocknr != buf->node.header.blocknr) | |
87 | BUG(); | |
88 | return buf; | |
89 | } | |
90 | buf = alloc_tree_block(root, blocknr); | |
91 | if (!buf) | |
92 | return NULL; | |
93 | ret = pread(root->fp, &buf->node, CTREE_BLOCKSIZE, offset); | |
94 | if (ret != CTREE_BLOCKSIZE) { | |
95 | free(buf); | |
96 | return NULL; | |
97 | } | |
98 | if (buf->blocknr != buf->node.header.blocknr) | |
99 | BUG(); | |
100 | return buf; | |
101 | } | |
102 | ||
103 | int write_tree_block(struct ctree_root *root, struct tree_buffer *buf) | |
104 | { | |
105 | u64 blocknr = buf->blocknr; | |
d97e63b6 | 106 | loff_t offset = blocknr * CTREE_BLOCKSIZE; |
eb60ceac CM |
107 | int ret; |
108 | ||
109 | if (buf->blocknr != buf->node.header.blocknr) | |
110 | BUG(); | |
111 | ret = pwrite(root->fp, &buf->node, CTREE_BLOCKSIZE, offset); | |
112 | if (ret != CTREE_BLOCKSIZE) | |
113 | return ret; | |
114 | if (buf == root->node) | |
115 | return update_root_block(root); | |
116 | return 0; | |
117 | } | |
118 | ||
d97e63b6 CM |
119 | struct ctree_super_block { |
120 | struct ctree_root_info root_info; | |
121 | struct ctree_root_info extent_info; | |
122 | } __attribute__ ((__packed__)); | |
123 | ||
124 | static int __setup_root(struct ctree_root *root, struct ctree_root *extent_root, | |
125 | struct ctree_root_info *info, int fp) | |
126 | { | |
127 | root->fp = fp; | |
128 | root->node = read_tree_block(root, info->tree_root); | |
129 | root->extent_root = extent_root; | |
130 | memcpy(&root->ai1, &info->alloc_extent, sizeof(info->alloc_extent)); | |
131 | memcpy(&root->ai2, &info->reserve_extent, sizeof(info->reserve_extent)); | |
132 | root->alloc_extent = &root->ai1; | |
133 | root->reserve_extent = &root->ai2; | |
134 | INIT_RADIX_TREE(&root->cache_radix, GFP_KERNEL); | |
135 | printf("setup done reading root %p, used %lu\n", root, root->alloc_extent->num_used); | |
136 | return 0; | |
137 | } | |
138 | ||
eb60ceac CM |
139 | struct ctree_root *open_ctree(char *filename) |
140 | { | |
141 | struct ctree_root *root = malloc(sizeof(struct ctree_root)); | |
d97e63b6 CM |
142 | struct ctree_root *extent_root = malloc(sizeof(struct ctree_root)); |
143 | struct ctree_super_block super; | |
eb60ceac | 144 | int fp; |
eb60ceac CM |
145 | int ret; |
146 | ||
147 | fp = open(filename, O_CREAT | O_RDWR); | |
148 | if (fp < 0) { | |
149 | free(root); | |
150 | return NULL; | |
151 | } | |
d97e63b6 CM |
152 | ret = pread(fp, &super, sizeof(struct ctree_super_block), |
153 | CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE)); | |
154 | if (ret == 0) { | |
155 | ret = mkfs(fp); | |
156 | if (ret) | |
157 | return NULL; | |
158 | ret = pread(fp, &super, sizeof(struct ctree_super_block), | |
159 | CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE)); | |
160 | if (ret != sizeof(struct ctree_super_block)) | |
161 | return NULL; | |
162 | } | |
163 | BUG_ON(ret < 0); | |
164 | __setup_root(root, extent_root, &super.root_info, fp); | |
165 | __setup_root(extent_root, extent_root, &super.extent_info, fp); | |
eb60ceac CM |
166 | return root; |
167 | } | |
168 | ||
169 | int close_ctree(struct ctree_root *root) | |
170 | { | |
171 | close(root->fp); | |
172 | if (root->node) | |
173 | tree_block_release(root, root->node); | |
174 | free(root); | |
175 | printf("on close %d blocks are allocated\n", allocated_blocks); | |
176 | return 0; | |
177 | } | |
178 | ||
179 | int update_root_block(struct ctree_root *root) | |
180 | { | |
181 | int ret; | |
182 | u64 root_block = root->node->blocknr; | |
183 | ||
184 | ret = pwrite(root->fp, &root_block, sizeof(u64), 0); | |
185 | if (ret != sizeof(u64)) | |
186 | return ret; | |
187 | return 0; | |
188 | } | |
189 | ||
190 | void tree_block_release(struct ctree_root *root, struct tree_buffer *buf) | |
191 | { | |
d97e63b6 | 192 | return; |
eb60ceac CM |
193 | buf->count--; |
194 | if (buf->count == 0) { | |
195 | if (!radix_tree_lookup(&root->cache_radix, buf->blocknr)) | |
196 | BUG(); | |
197 | radix_tree_delete(&root->cache_radix, buf->blocknr); | |
198 | memset(buf, 0, sizeof(*buf)); | |
199 | free(buf); | |
200 | BUG_ON(allocated_blocks == 0); | |
201 | allocated_blocks--; | |
202 | } | |
203 | } | |
204 |