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1 /*
2  * rs_bitmap.c --- routine for changing the size of a bitmap
3  *
4  * Copyright (C) 1996, 1997 Theodore Ts'o.
5  *
6  * %Begin-Header%
7  * This file may be redistributed under the terms of the GNU Public
8  * License.
9  * %End-Header%
10  */
11 
12 #include <stdio.h>
13 #include <string.h>
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #include <fcntl.h>
18 #include <time.h>
19 #ifdef HAVE_SYS_STAT_H
20 #include <sys/stat.h>
21 #endif
22 #ifdef HAVE_SYS_TYPES_H
23 #include <sys/types.h>
24 #endif
25 
26 #include "ext2_fs.h"
27 #include "ext2fs.h"
28 
ext2fs_resize_generic_bitmap(__u32 new_end,__u32 new_real_end,ext2fs_generic_bitmap bmap)29 errcode_t ext2fs_resize_generic_bitmap(__u32 new_end, __u32 new_real_end,
30 				       ext2fs_generic_bitmap bmap)
31 {
32 	errcode_t	retval;
33 	size_t		size, new_size;
34 	__u32		bitno;
35 
36 	if (!bmap)
37 		return EXT2_ET_INVALID_ARGUMENT;
38 
39 	EXT2_CHECK_MAGIC(bmap, EXT2_ET_MAGIC_GENERIC_BITMAP);
40 
41 	/*
42 	 * If we're expanding the bitmap, make sure all of the new
43 	 * parts of the bitmap are zero.
44 	 */
45 	if (new_end > bmap->end) {
46 		bitno = bmap->real_end;
47 		if (bitno > new_end)
48 			bitno = new_end;
49 		for (; bitno > bmap->end; bitno--)
50 			ext2fs_clear_bit(bitno - bmap->start, bmap->bitmap);
51 	}
52 	if (new_real_end == bmap->real_end) {
53 		bmap->end = new_end;
54 		return 0;
55 	}
56 
57 	size = ((bmap->real_end - bmap->start) / 8) + 1;
58 	new_size = ((new_real_end - bmap->start) / 8) + 1;
59 
60 	if (size != new_size) {
61 		retval = ext2fs_resize_mem(size, new_size, &bmap->bitmap);
62 		if (retval)
63 			return retval;
64 	}
65 	if (new_size > size)
66 		memset(bmap->bitmap + size, 0, new_size - size);
67 
68 	bmap->end = new_end;
69 	bmap->real_end = new_real_end;
70 	return 0;
71 }
72 
ext2fs_resize_inode_bitmap(__u32 new_end,__u32 new_real_end,ext2fs_inode_bitmap bmap)73 errcode_t ext2fs_resize_inode_bitmap(__u32 new_end, __u32 new_real_end,
74 				     ext2fs_inode_bitmap bmap)
75 {
76 	errcode_t	retval;
77 
78 	if (!bmap)
79 		return EXT2_ET_INVALID_ARGUMENT;
80 
81 	EXT2_CHECK_MAGIC(bmap, EXT2_ET_MAGIC_INODE_BITMAP);
82 
83 	bmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP;
84 	retval = ext2fs_resize_generic_bitmap(new_end, new_real_end,
85 					      bmap);
86 	bmap->magic = EXT2_ET_MAGIC_INODE_BITMAP;
87 	return retval;
88 }
89 
ext2fs_resize_block_bitmap(__u32 new_end,__u32 new_real_end,ext2fs_block_bitmap bmap)90 errcode_t ext2fs_resize_block_bitmap(__u32 new_end, __u32 new_real_end,
91 				     ext2fs_block_bitmap bmap)
92 {
93 	errcode_t	retval;
94 
95 	if (!bmap)
96 		return EXT2_ET_INVALID_ARGUMENT;
97 
98 	EXT2_CHECK_MAGIC(bmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
99 
100 	bmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP;
101 	retval = ext2fs_resize_generic_bitmap(new_end, new_real_end,
102 					      bmap);
103 	bmap->magic = EXT2_ET_MAGIC_BLOCK_BITMAP;
104 	return retval;
105 }
106 
107