1 #define _XOPEN_SOURCE 500
8 #include "kerncompat.h"
9 #include "radix-tree.h"
13 static int allocated_blocks = 0;
15 static int get_free_block(struct ctree_root *root, u64 *block)
20 if (root->alloc_extent->num_used >= root->alloc_extent->num_blocks)
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;
32 ret = fstat(root->fp, &st);
33 if (st.st_size < (*block + 1) * CTREE_BLOCKSIZE)
34 ret = ftruncate(root->fp,
35 (*block + 1) * CTREE_BLOCKSIZE);
39 struct tree_buffer *alloc_tree_block(struct ctree_root *root, u64 blocknr)
41 struct tree_buffer *buf;
43 buf = malloc(sizeof(struct tree_buffer));
47 buf->blocknr = blocknr;
49 radix_tree_preload(GFP_KERNEL);
50 ret = radix_tree_insert(&root->cache_radix, blocknr, buf);
51 radix_tree_preload_end();
59 struct tree_buffer *alloc_free_block(struct ctree_root *root)
63 struct tree_buffer * buf;
64 ret = get_free_block(root, &free_block);
69 buf = alloc_tree_block(root, free_block);
75 struct tree_buffer *read_tree_block(struct ctree_root *root, u64 blocknr)
77 loff_t offset = blocknr * CTREE_BLOCKSIZE;
78 struct tree_buffer *buf;
81 buf = radix_tree_lookup(&root->cache_radix, blocknr);
84 if (buf->blocknr != blocknr)
86 if (buf->blocknr != buf->node.header.blocknr)
90 buf = alloc_tree_block(root, blocknr);
93 ret = pread(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
94 if (ret != CTREE_BLOCKSIZE) {
98 if (buf->blocknr != buf->node.header.blocknr)
103 int write_tree_block(struct ctree_root *root, struct tree_buffer *buf)
105 u64 blocknr = buf->blocknr;
106 loff_t offset = blocknr * CTREE_BLOCKSIZE;
109 if (buf->blocknr != buf->node.header.blocknr)
111 ret = pwrite(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
112 if (ret != CTREE_BLOCKSIZE)
114 if (buf == root->node)
115 return update_root_block(root);
119 struct ctree_super_block {
120 struct ctree_root_info root_info;
121 struct ctree_root_info extent_info;
122 } __attribute__ ((__packed__));
124 static int __setup_root(struct ctree_root *root, struct ctree_root *extent_root,
125 struct ctree_root_info *info, int 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);
139 struct ctree_root *open_ctree(char *filename)
141 struct ctree_root *root = malloc(sizeof(struct ctree_root));
142 struct ctree_root *extent_root = malloc(sizeof(struct ctree_root));
143 struct ctree_super_block super;
147 fp = open(filename, O_CREAT | O_RDWR);
152 ret = pread(fp, &super, sizeof(struct ctree_super_block),
153 CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
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))
164 __setup_root(root, extent_root, &super.root_info, fp);
165 __setup_root(extent_root, extent_root, &super.extent_info, fp);
169 int close_ctree(struct ctree_root *root)
173 tree_block_release(root, root->node);
175 printf("on close %d blocks are allocated\n", allocated_blocks);
179 int update_root_block(struct ctree_root *root)
182 u64 root_block = root->node->blocknr;
184 ret = pwrite(root->fp, &root_block, sizeof(u64), 0);
185 if (ret != sizeof(u64))
190 void tree_block_release(struct ctree_root *root, struct tree_buffer *buf)
194 if (buf->count == 0) {
195 if (!radix_tree_lookup(&root->cache_radix, buf->blocknr))
197 radix_tree_delete(&root->cache_radix, buf->blocknr);
198 memset(buf, 0, sizeof(*buf));
200 BUG_ON(allocated_blocks == 0);