2 * bitmaps.c --- routines to read, write, and manipulate the inode and
5 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
8 * This file may be redistributed under the terms of the GNU Public
24 #include <sys/types.h>
30 static errcode_t make_bitmap(__u32 start, __u32 end, __u32 real_end,
31 const char *descr, char *init_map,
32 ext2fs_generic_bitmap *ret)
34 ext2fs_generic_bitmap bitmap;
38 retval = ext2fs_get_mem(sizeof(struct ext2fs_struct_generic_bitmap),
43 bitmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP;
45 bitmap->start = start;
47 bitmap->real_end = real_end;
48 bitmap->base_error_code = EXT2_ET_BAD_GENERIC_MARK;
50 retval = ext2fs_get_mem(strlen(descr)+1, &bitmap->description);
52 ext2fs_free_mem(&bitmap);
55 strcpy(bitmap->description, descr);
57 bitmap->description = 0;
59 size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1);
60 retval = ext2fs_get_mem(size, &bitmap->bitmap);
62 ext2fs_free_mem(&bitmap->description);
63 ext2fs_free_mem(&bitmap);
68 memcpy(bitmap->bitmap, init_map, size);
70 memset(bitmap->bitmap, 0, size);
75 errcode_t ext2fs_allocate_generic_bitmap(__u32 start,
79 ext2fs_generic_bitmap *ret)
81 return make_bitmap(start, end, real_end, descr, 0, ret);
84 errcode_t ext2fs_copy_bitmap(ext2fs_generic_bitmap src,
85 ext2fs_generic_bitmap *dest)
88 ext2fs_generic_bitmap new_map;
90 retval = make_bitmap(src->start, src->end, src->real_end,
91 src->description, src->bitmap, &new_map);
94 new_map->magic = src->magic;
95 new_map->fs = src->fs;
96 new_map->base_error_code = src->base_error_code;
101 void ext2fs_set_bitmap_padding(ext2fs_generic_bitmap map)
105 /* Protect loop from wrap-around if map->real_end is maxed */
106 for (i=map->end+1, j = i - map->start;
107 i <= map->real_end && i > map->end;
109 ext2fs_set_bit(j, map->bitmap);
114 errcode_t ext2fs_allocate_inode_bitmap(ext2_filsys fs,
116 ext2fs_inode_bitmap *ret)
118 ext2fs_inode_bitmap bitmap;
120 __u32 start, end, real_end;
122 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
124 fs->write_bitmaps = ext2fs_write_bitmaps;
127 end = fs->super->s_inodes_count;
128 real_end = (EXT2_INODES_PER_GROUP(fs->super) * fs->group_desc_count);
130 retval = ext2fs_allocate_generic_bitmap(start, end, real_end,
135 bitmap->magic = EXT2_ET_MAGIC_INODE_BITMAP;
137 bitmap->base_error_code = EXT2_ET_BAD_INODE_MARK;
143 errcode_t ext2fs_allocate_block_bitmap(ext2_filsys fs,
145 ext2fs_block_bitmap *ret)
147 ext2fs_block_bitmap bitmap;
149 __u32 start, end, real_end;
151 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
153 fs->write_bitmaps = ext2fs_write_bitmaps;
155 start = fs->super->s_first_data_block;
156 end = fs->super->s_blocks_count-1;
157 real_end = (EXT2_BLOCKS_PER_GROUP(fs->super)
158 * fs->group_desc_count)-1 + start;
160 retval = ext2fs_allocate_generic_bitmap(start, end, real_end,
165 bitmap->magic = EXT2_ET_MAGIC_BLOCK_BITMAP;
167 bitmap->base_error_code = EXT2_ET_BAD_BLOCK_MARK;
173 errcode_t ext2fs_fudge_inode_bitmap_end(ext2fs_inode_bitmap bitmap,
174 ext2_ino_t end, ext2_ino_t *oend)
176 EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_INODE_BITMAP);
178 if (end > bitmap->real_end)
179 return EXT2_ET_FUDGE_INODE_BITMAP_END;
186 errcode_t ext2fs_fudge_block_bitmap_end(ext2fs_block_bitmap bitmap,
187 blk_t end, blk_t *oend)
189 EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
191 if (end > bitmap->real_end)
192 return EXT2_ET_FUDGE_BLOCK_BITMAP_END;
199 void ext2fs_clear_inode_bitmap(ext2fs_inode_bitmap bitmap)
201 if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_INODE_BITMAP))
204 memset(bitmap->bitmap, 0,
205 (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));
208 void ext2fs_clear_block_bitmap(ext2fs_block_bitmap bitmap)
210 if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_BLOCK_BITMAP))
213 memset(bitmap->bitmap, 0,
214 (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));