1 #include <sys/types.h>
2 #include <sys/stat.h>
3 #include "basefs_allocator.h"
4 #include "block_range.h"
5 #include "hashmap.h"
6 #include "base_fs.h"
7
8 struct base_fs_allocator {
9 struct ext2fs_hashmap *entries;
10 struct basefs_entry *cur_entry;
11 };
12
13 static errcode_t basefs_block_allocator(ext2_filsys, blk64_t, blk64_t *,
14 struct blk_alloc_ctx *ctx);
15
fs_free_blocks_range(ext2_filsys fs,struct block_range * blocks)16 static void fs_free_blocks_range(ext2_filsys fs, struct block_range *blocks)
17 {
18 while (blocks) {
19 ext2fs_unmark_block_bitmap_range2(fs->block_map, blocks->start,
20 blocks->end - blocks->start + 1);
21 blocks = blocks->next;
22 }
23 }
24
fs_reserve_blocks_range(ext2_filsys fs,struct block_range * blocks)25 static void fs_reserve_blocks_range(ext2_filsys fs, struct block_range *blocks)
26 {
27 while (blocks) {
28 ext2fs_mark_block_bitmap_range2(fs->block_map,
29 blocks->start, blocks->end - blocks->start + 1);
30 blocks = blocks->next;
31 }
32 }
33
base_fs_alloc_load(ext2_filsys fs,const char * file,const char * mountpoint)34 errcode_t base_fs_alloc_load(ext2_filsys fs, const char *file,
35 const char *mountpoint)
36 {
37 errcode_t retval;
38 struct basefs_entry *e;
39 struct ext2fs_hashmap_entry *it = NULL;
40 struct base_fs_allocator *allocator;
41 struct ext2fs_hashmap *entries = basefs_parse(file, mountpoint);
42 if (!entries)
43 return -1;
44
45 allocator = malloc(sizeof(*allocator));
46 if (!allocator)
47 goto err_alloc;
48
49 retval = ext2fs_read_bitmaps(fs);
50 if (retval)
51 goto err_bitmap;
52 while ((e = ext2fs_hashmap_iter_in_order(entries, &it)))
53 fs_reserve_blocks_range(fs, e->head);
54
55 allocator->cur_entry = NULL;
56 allocator->entries = entries;
57
58 /* Overhide the default allocator */
59 fs->get_alloc_block2 = basefs_block_allocator;
60 fs->priv_data = allocator;
61
62 return 0;
63
64 err_bitmap:
65 free(allocator);
66 err_alloc:
67 ext2fs_hashmap_free(entries);
68 return EXIT_FAILURE;
69 }
70
basefs_block_allocator(ext2_filsys fs,blk64_t goal,blk64_t * ret,struct blk_alloc_ctx * ctx)71 static errcode_t basefs_block_allocator(ext2_filsys fs, blk64_t goal,
72 blk64_t *ret, struct blk_alloc_ctx *ctx)
73 {
74 errcode_t retval;
75 struct block_range *next_range;
76 struct base_fs_allocator *allocator = fs->priv_data;
77 struct basefs_entry *e = allocator->cur_entry;
78
79 /* Try to get a block from the base_fs */
80 if (e && e->head && ctx && (ctx->flags & BLOCK_ALLOC_DATA)) {
81 *ret = e->head->start;
82 e->head->start += 1;
83 if (e->head->start > e->head->end) {
84 next_range = e->head->next;
85 free(e->head);
86 e->head = next_range;
87 }
88 } else { /* Allocate a new block */
89 retval = ext2fs_new_block2(fs, goal, fs->block_map, ret);
90 if (retval)
91 return retval;
92 ext2fs_mark_block_bitmap2(fs->block_map, *ret);
93 }
94 return 0;
95 }
96
base_fs_alloc_cleanup(ext2_filsys fs)97 void base_fs_alloc_cleanup(ext2_filsys fs)
98 {
99 struct basefs_entry *e;
100 struct ext2fs_hashmap_entry *it = NULL;
101 struct base_fs_allocator *allocator = fs->priv_data;
102
103 while ((e = ext2fs_hashmap_iter_in_order(allocator->entries, &it))) {
104 fs_free_blocks_range(fs, e->head);
105 delete_block_ranges(e->head);
106 e->head = e->tail = NULL;
107 }
108
109 fs->priv_data = NULL;
110 fs->get_alloc_block2 = NULL;
111 ext2fs_hashmap_free(allocator->entries);
112 free(allocator);
113 }
114
base_fs_alloc_set_target(ext2_filsys fs,const char * target_path,const char * name EXT2FS_ATTR ((unused)),ext2_ino_t parent_ino EXT2FS_ATTR ((unused)),ext2_ino_t root EXT2FS_ATTR ((unused)),mode_t mode)115 errcode_t base_fs_alloc_set_target(ext2_filsys fs, const char *target_path,
116 const char *name EXT2FS_ATTR((unused)),
117 ext2_ino_t parent_ino EXT2FS_ATTR((unused)),
118 ext2_ino_t root EXT2FS_ATTR((unused)), mode_t mode)
119 {
120 struct base_fs_allocator *allocator = fs->priv_data;
121
122 if (mode != S_IFREG)
123 return 0;
124
125 if (allocator)
126 allocator->cur_entry = ext2fs_hashmap_lookup(allocator->entries,
127 target_path,
128 strlen(target_path));
129 return 0;
130 }
131
base_fs_alloc_unset_target(ext2_filsys fs,const char * target_path EXT2FS_ATTR ((unused)),const char * name EXT2FS_ATTR ((unused)),ext2_ino_t parent_ino EXT2FS_ATTR ((unused)),ext2_ino_t root EXT2FS_ATTR ((unused)),mode_t mode)132 errcode_t base_fs_alloc_unset_target(ext2_filsys fs,
133 const char *target_path EXT2FS_ATTR((unused)),
134 const char *name EXT2FS_ATTR((unused)),
135 ext2_ino_t parent_ino EXT2FS_ATTR((unused)),
136 ext2_ino_t root EXT2FS_ATTR((unused)), mode_t mode)
137 {
138 struct base_fs_allocator *allocator = fs->priv_data;
139
140 if (!allocator || !allocator->cur_entry || mode != S_IFREG)
141 return 0;
142
143 fs_free_blocks_range(fs, allocator->cur_entry->head);
144 delete_block_ranges(allocator->cur_entry->head);
145 allocator->cur_entry->head = allocator->cur_entry->tail = NULL;
146 allocator->cur_entry = NULL;
147 return 0;
148 }
149