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>
27 #include <linux/ext2_fs.h>
31 static errcode_t make_bitmap(__u32 start, __u32 end, __u32 real_end,
32 const char *descr, char *init_map,
33 ext2fs_generic_bitmap *ret)
35 ext2fs_generic_bitmap bitmap;
39 retval = ext2fs_get_mem(sizeof(struct ext2fs_struct_generic_bitmap),
44 bitmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP;
46 bitmap->start = start;
48 bitmap->real_end = real_end;
49 bitmap->base_error_code = EXT2_ET_BAD_GENERIC_MARK;
51 retval = ext2fs_get_mem(strlen(descr)+1,
52 (void **) &bitmap->description);
54 ext2fs_free_mem((void **) &bitmap);
57 strcpy(bitmap->description, descr);
59 bitmap->description = 0;
61 size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1);
62 retval = ext2fs_get_mem(size, (void **) &bitmap->bitmap);
64 ext2fs_free_mem((void **) &bitmap->description);
65 ext2fs_free_mem((void **) &bitmap);
70 memcpy(bitmap->bitmap, init_map, size);
72 memset(bitmap->bitmap, 0, size);
77 errcode_t ext2fs_allocate_generic_bitmap(__u32 start,
81 ext2fs_generic_bitmap *ret)
83 return make_bitmap(start, end, real_end, descr, 0, ret);
86 errcode_t ext2fs_copy_bitmap(ext2fs_generic_bitmap src,
87 ext2fs_generic_bitmap *dest)
90 ext2fs_generic_bitmap new;
92 retval = make_bitmap(src->start, src->end, src->real_end,
93 src->description, src->bitmap, &new);
96 new->magic = src->magic;
98 new->base_error_code = src->base_error_code;
103 void ext2fs_set_bitmap_padding(ext2fs_generic_bitmap map)
107 for (i=map->end+1, j = i - map->start; i <= map->real_end; i++, j++)
108 ext2fs_set_bit(j, map->bitmap);
113 errcode_t ext2fs_allocate_inode_bitmap(ext2_filsys fs,
115 ext2fs_inode_bitmap *ret)
117 ext2fs_inode_bitmap bitmap;
119 __u32 start, end, real_end;
121 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
123 fs->write_bitmaps = ext2fs_write_bitmaps;
126 end = fs->super->s_inodes_count;
127 real_end = (EXT2_INODES_PER_GROUP(fs->super) * fs->group_desc_count);
129 retval = ext2fs_allocate_generic_bitmap(start, end, real_end,
134 bitmap->magic = EXT2_ET_MAGIC_INODE_BITMAP;
136 bitmap->base_error_code = EXT2_ET_BAD_INODE_MARK;
142 errcode_t ext2fs_allocate_block_bitmap(ext2_filsys fs,
144 ext2fs_block_bitmap *ret)
146 ext2fs_block_bitmap bitmap;
148 __u32 start, end, real_end;
150 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
152 fs->write_bitmaps = ext2fs_write_bitmaps;
154 start = fs->super->s_first_data_block;
155 end = fs->super->s_blocks_count-1;
156 real_end = (EXT2_BLOCKS_PER_GROUP(fs->super)
157 * fs->group_desc_count)-1 + start;
159 retval = ext2fs_allocate_generic_bitmap(start, end, real_end,
164 bitmap->magic = EXT2_ET_MAGIC_BLOCK_BITMAP;
166 bitmap->base_error_code = EXT2_ET_BAD_BLOCK_MARK;
172 errcode_t ext2fs_fudge_inode_bitmap_end(ext2fs_inode_bitmap bitmap,
173 ino_t end, ino_t *oend)
175 EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_INODE_BITMAP);
177 if (end > bitmap->real_end)
178 return EXT2_ET_FUDGE_INODE_BITMAP_END;
185 errcode_t ext2fs_fudge_block_bitmap_end(ext2fs_block_bitmap bitmap,
186 blk_t end, blk_t *oend)
188 EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
190 if (end > bitmap->real_end)
191 return EXT2_ET_FUDGE_BLOCK_BITMAP_END;
198 void ext2fs_clear_inode_bitmap(ext2fs_inode_bitmap bitmap)
200 if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_INODE_BITMAP))
203 memset(bitmap->bitmap, 0,
204 (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));
207 void ext2fs_clear_block_bitmap(ext2fs_block_bitmap bitmap)
209 if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_BLOCK_BITMAP))
212 memset(bitmap->bitmap, 0,
213 (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));