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gerrit-public.fairphone.software / kernel / msm-4.9 / refs/tags/FP3-REL-Q-3.A.0107 / . / fs / ext4 / bitmap.c
blob: 4a606afb171f04dc42064e7e7c8b09f4172281ed [file] [log] [blame]
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]1/*
Mingming Cao617ba132006-10-11 01:20:53 -0700[diff] [blame]2 * linux/fs/ext4/bitmap.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 */
9
10#include <linux/buffer_head.h>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -0400[diff] [blame]11#include "ext4.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]12
Theodore Ts'of6fb99c2012-06-30 19:14:57 -0400[diff] [blame]13unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]14{
Akinobu Mita6017b482012-07-30 14:41:08 -0700[diff] [blame]15 return numchars * BITS_PER_BYTE - memweight(bitmap, numchars);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700[diff] [blame]16}
17
Darrick J. Wong41a246d2012-04-29 18:33:10 -0400[diff] [blame]18int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
19 struct ext4_group_desc *gdp,
20 struct buffer_head *bh, int sz)
21{
22 __u32 hi;
23 __u32 provided, calculated;
24 struct ext4_sb_info *sbi = EXT4_SB(sb);
25
Dmitry Monakhov9aa5d322014-10-13 03:36:16 -0400[diff] [blame]26 if (!ext4_has_metadata_csum(sb))
Darrick J. Wong41a246d2012-04-29 18:33:10 -0400[diff] [blame]27 return 1;
28
29 provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
30 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
31 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
32 hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
33 provided |= (hi << 16);
34 } else
35 calculated &= 0xFFFF;
36
37 return provided == calculated;
38}
39
40void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
41 struct ext4_group_desc *gdp,
42 struct buffer_head *bh, int sz)
43{
44 __u32 csum;
45 struct ext4_sb_info *sbi = EXT4_SB(sb);
46
Dmitry Monakhov9aa5d322014-10-13 03:36:16 -0400[diff] [blame]47 if (!ext4_has_metadata_csum(sb))
Darrick J. Wong41a246d2012-04-29 18:33:10 -0400[diff] [blame]48 return;
49
50 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
51 gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
52 if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
53 gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
54}
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]55
56int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
57 struct ext4_group_desc *gdp,
Tao Ma79f1ba42012-10-22 00:34:32 -0400[diff] [blame]58 struct buffer_head *bh)
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]59{
60 __u32 hi;
61 __u32 provided, calculated;
62 struct ext4_sb_info *sbi = EXT4_SB(sb);
Tao Ma79f1ba42012-10-22 00:34:32 -0400[diff] [blame]63 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]64
Dmitry Monakhov9aa5d322014-10-13 03:36:16 -0400[diff] [blame]65 if (!ext4_has_metadata_csum(sb))
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]66 return 1;
67
68 provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
69 calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
70 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
71 hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
72 provided |= (hi << 16);
73 } else
74 calculated &= 0xFFFF;
75
76 if (provided == calculated)
77 return 1;
78
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]79 return 0;
80}
81
82void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
83 struct ext4_group_desc *gdp,
Tao Ma79f1ba42012-10-22 00:34:32 -0400[diff] [blame]84 struct buffer_head *bh)
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]85{
Tao Ma79f1ba42012-10-22 00:34:32 -0400[diff] [blame]86 int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]87 __u32 csum;
88 struct ext4_sb_info *sbi = EXT4_SB(sb);
89
Dmitry Monakhov9aa5d322014-10-13 03:36:16 -0400[diff] [blame]90 if (!ext4_has_metadata_csum(sb))
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -0400[diff] [blame]91 return;
92
93 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
94 gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
95 if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
96 gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
97}