i_block.c revision d1154eb460efe588eaed3d439c1caaca149fa362 
1/*
2 * i_block.c --- Manage the i_block field for i_blocks
3 *
4 * Copyright (C) 2008 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12#include "config.h"
13#include <stdio.h>
14#if HAVE_UNISTD_H
15#include <unistd.h>
16#endif
17#include <time.h>
18#include <string.h>
19#if HAVE_SYS_STAT_H
20#include <sys/stat.h>
21#endif
22#if HAVE_SYS_TYPES_H
23#include <sys/types.h>
24#endif
25#include <errno.h>
26
27#include "ext2_fs.h"
28#include "ext2fs.h"
29
30errcode_t ext2fs_iblk_add_blocks(ext2_filsys fs, struct ext2_inode *inode,
31				 blk64_t num_blocks)
32{
33	unsigned long long b = inode->i_blocks;
34
35	if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
36		b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
37
38	if (!(fs->super->s_feature_ro_compat &
39	      EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
40	    !(inode->i_flags & EXT4_HUGE_FILE_FL))
41	    num_blocks *= fs->blocksize / 512;
42	num_blocks *= EXT2FS_CLUSTER_RATIO(fs);
43
44	b += num_blocks;
45
46	if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
47		inode->osd2.linux2.l_i_blocks_hi = b >> 32;
48	else if (b > 0xFFFFFFFF)
49		return EOVERFLOW;
50	inode->i_blocks = b & 0xFFFFFFFF;
51	return 0;
52}
53
54errcode_t ext2fs_iblk_sub_blocks(ext2_filsys fs, struct ext2_inode *inode,
55				 blk64_t num_blocks)
56{
57	unsigned long long b = inode->i_blocks;
58
59	if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
60		b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
61
62	if (!(fs->super->s_feature_ro_compat &
63	      EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
64	    !(inode->i_flags & EXT4_HUGE_FILE_FL))
65	    num_blocks *= fs->blocksize / 512;
66	num_blocks *= EXT2FS_CLUSTER_RATIO(fs);
67
68	if (num_blocks > b)
69		return EOVERFLOW;
70
71	b -= num_blocks;
72
73	if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
74		inode->osd2.linux2.l_i_blocks_hi = b >> 32;
75	inode->i_blocks = b & 0xFFFFFFFF;
76	return 0;
77}
78
79errcode_t ext2fs_iblk_set(ext2_filsys fs, struct ext2_inode *inode, blk64_t b)
80{
81	if (!(fs->super->s_feature_ro_compat &
82	      EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
83	    !(inode->i_flags & EXT4_HUGE_FILE_FL))
84		b *= fs->blocksize / 512;
85	b *= EXT2FS_CLUSTER_RATIO(fs);
86
87	inode->i_blocks = b & 0xFFFFFFFF;
88	if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
89		inode->osd2.linux2.l_i_blocks_hi = b >> 32;
90	else if (b >> 32)
91		return EOVERFLOW;
92	return 0;
93}
94