1 /*
2  * brel_ma.c
3  *
4  * Copyright (C) 1996, 1997 Theodore Ts'o.
5  *
6  * TODO: rewrite to not use a direct array!!!  (Fortunately this
7  * module isn't really used yet.)
8  *
9  * %Begin-Header%
10  * This file may be redistributed under the terms of the GNU Library
11  * General Public License, version 2.
12  * %End-Header%
13  */
14 
15 #include "config.h"
16 #include <fcntl.h>
17 #include <stdio.h>
18 #include <string.h>
19 #if HAVE_UNISTD_H
20 #include <unistd.h>
21 #endif
22 #if HAVE_ERRNO_H
23 #include <errno.h>
24 #endif
25 
26 #include "ext2_fs.h"
27 #include "ext2fs.h"
28 #include "brel.h"
29 
30 static errcode_t bma_put(ext2_brel brel, blk64_t old,
31 			struct ext2_block_relocate_entry *ent);
32 static errcode_t bma_get(ext2_brel brel, blk64_t old,
33 			struct ext2_block_relocate_entry *ent);
34 static errcode_t bma_start_iter(ext2_brel brel);
35 static errcode_t bma_next(ext2_brel brel, blk64_t *old,
36 			 struct ext2_block_relocate_entry *ent);
37 static errcode_t bma_move(ext2_brel brel, blk64_t old, blk64_t new);
38 static errcode_t bma_delete(ext2_brel brel, blk64_t old);
39 static errcode_t bma_free(ext2_brel brel);
40 
41 struct brel_ma {
42 	__u32 magic;
43 	blk64_t max_block;
44 	struct ext2_block_relocate_entry *entries;
45 };
46 
ext2fs_brel_memarray_create(char * name,blk64_t max_block,ext2_brel * new_brel)47 errcode_t ext2fs_brel_memarray_create(char *name, blk64_t max_block,
48 				      ext2_brel *new_brel)
49 {
50 	ext2_brel		brel = 0;
51 	errcode_t	retval;
52 	struct brel_ma 	*ma = 0;
53 	size_t		size;
54 
55 	*new_brel = 0;
56 
57 	/*
58 	 * Allocate memory structures
59 	 */
60 	retval = ext2fs_get_mem(sizeof(struct ext2_block_relocation_table),
61 				&brel);
62 	if (retval)
63 		goto errout;
64 	memset(brel, 0, sizeof(struct ext2_block_relocation_table));
65 
66 	retval = ext2fs_get_mem(strlen(name)+1, &brel->name);
67 	if (retval)
68 		goto errout;
69 	strcpy(brel->name, name);
70 
71 	retval = ext2fs_get_mem(sizeof(struct brel_ma), &ma);
72 	if (retval)
73 		goto errout;
74 	memset(ma, 0, sizeof(struct brel_ma));
75 	brel->priv_data = ma;
76 
77 	size = (size_t) (sizeof(struct ext2_block_relocate_entry) *
78 			 (max_block+1));
79 	retval = ext2fs_get_array(max_block+1,
80 		sizeof(struct ext2_block_relocate_entry), &ma->entries);
81 	if (retval)
82 		goto errout;
83 	memset(ma->entries, 0, size);
84 	ma->max_block = max_block;
85 
86 	/*
87 	 * Fill in the brel data structure
88 	 */
89 	brel->put = bma_put;
90 	brel->get = bma_get;
91 	brel->start_iter = bma_start_iter;
92 	brel->next = bma_next;
93 	brel->move = bma_move;
94 	brel->delete = bma_delete;
95 	brel->free = bma_free;
96 
97 	*new_brel = brel;
98 	return 0;
99 
100 errout:
101 	bma_free(brel);
102 	return retval;
103 }
104 
bma_put(ext2_brel brel,blk64_t old,struct ext2_block_relocate_entry * ent)105 static errcode_t bma_put(ext2_brel brel, blk64_t old,
106 			struct ext2_block_relocate_entry *ent)
107 {
108 	struct brel_ma 	*ma;
109 
110 	ma = brel->priv_data;
111 	if (old > ma->max_block)
112 		return EXT2_ET_INVALID_ARGUMENT;
113 	ma->entries[(unsigned)old] = *ent;
114 	return 0;
115 }
116 
bma_get(ext2_brel brel,blk64_t old,struct ext2_block_relocate_entry * ent)117 static errcode_t bma_get(ext2_brel brel, blk64_t old,
118 			struct ext2_block_relocate_entry *ent)
119 {
120 	struct brel_ma 	*ma;
121 
122 	ma = brel->priv_data;
123 	if (old > ma->max_block)
124 		return EXT2_ET_INVALID_ARGUMENT;
125 	if (ma->entries[(unsigned)old].new == 0)
126 		return ENOENT;
127 	*ent = ma->entries[old];
128 	return 0;
129 }
130 
bma_start_iter(ext2_brel brel)131 static errcode_t bma_start_iter(ext2_brel brel)
132 {
133 	brel->current = 0;
134 	return 0;
135 }
136 
bma_next(ext2_brel brel,blk64_t * old,struct ext2_block_relocate_entry * ent)137 static errcode_t bma_next(ext2_brel brel, blk64_t *old,
138 			  struct ext2_block_relocate_entry *ent)
139 {
140 	struct brel_ma 	*ma;
141 
142 	ma = brel->priv_data;
143 	while (++brel->current < ma->max_block) {
144 		if (ma->entries[(unsigned)brel->current].new == 0)
145 			continue;
146 		*old = brel->current;
147 		*ent = ma->entries[(unsigned)brel->current];
148 		return 0;
149 	}
150 	*old = 0;
151 	return 0;
152 }
153 
bma_move(ext2_brel brel,blk64_t old,blk64_t new)154 static errcode_t bma_move(ext2_brel brel, blk64_t old, blk64_t new)
155 {
156 	struct brel_ma 	*ma;
157 
158 	ma = brel->priv_data;
159 	if ((old > ma->max_block) || (new > ma->max_block))
160 		return EXT2_ET_INVALID_ARGUMENT;
161 	if (ma->entries[(unsigned)old].new == 0)
162 		return ENOENT;
163 	ma->entries[(unsigned)new] = ma->entries[old];
164 	ma->entries[(unsigned)old].new = 0;
165 	return 0;
166 }
167 
bma_delete(ext2_brel brel,blk64_t old)168 static errcode_t bma_delete(ext2_brel brel, blk64_t old)
169 {
170 	struct brel_ma 	*ma;
171 
172 	ma = brel->priv_data;
173 	if (old > ma->max_block)
174 		return EXT2_ET_INVALID_ARGUMENT;
175 	if (ma->entries[(unsigned)old].new == 0)
176 		return ENOENT;
177 	ma->entries[(unsigned)old].new = 0;
178 	return 0;
179 }
180 
bma_free(ext2_brel brel)181 static errcode_t bma_free(ext2_brel brel)
182 {
183 	struct brel_ma 	*ma;
184 
185 	if (!brel)
186 		return 0;
187 
188 	ma = brel->priv_data;
189 
190 	if (ma) {
191 		if (ma->entries)
192 			ext2fs_free_mem(&ma->entries);
193 		ext2fs_free_mem(&ma);
194 	}
195 	if (brel->name)
196 		ext2fs_free_mem(&brel->name);
197 	ext2fs_free_mem(&brel);
198 	return 0;
199 }
200