summaryrefslogtreecommitdiff
path: root/fs/hpfs/buffer.c
blob: 7cef5d5c360816ea9292129953b709fd0339cd66 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/*
 *  linux/fs/hpfs/buffer.c
 *
 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
 *
 *  general buffer i/o
 */
#include <linux/sched.h>
#include <linux/slab.h>
#include "hpfs_fn.h"

void hpfs_lock_creation(struct super_block *s)
{
#ifdef DEBUG_LOCKS
	printk("lock creation\n");
#endif
	mutex_lock(&hpfs_sb(s)->hpfs_creation_de);
}

void hpfs_unlock_creation(struct super_block *s)
{
#ifdef DEBUG_LOCKS
	printk("unlock creation\n");
#endif
	mutex_unlock(&hpfs_sb(s)->hpfs_creation_de);
}

/* Map a sector into a buffer and return pointers to it and to the buffer. */

void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
		 int ahead)
{
	struct buffer_head *bh;

	hpfs_lock_assert(s);

	cond_resched();

	*bhp = bh = sb_bread(s, secno);
	if (bh != NULL)
		return bh->b_data;
	else {
		printk("HPFS: hpfs_map_sector: read error\n");
		return NULL;
	}
}

/* Like hpfs_map_sector but don't read anything */

void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
{
	struct buffer_head *bh;
	/*return hpfs_map_sector(s, secno, bhp, 0);*/

	hpfs_lock_assert(s);

	cond_resched();

	if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
		if (!buffer_uptodate(bh)) wait_on_buffer(bh);
		set_buffer_uptodate(bh);
		return bh->b_data;
	} else {
		printk("HPFS: hpfs_get_sector: getblk failed\n");
		return NULL;
	}
}

/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */

void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
		   int ahead)
{
	struct buffer_head *bh;
	char *data;

	hpfs_lock_assert(s);

	cond_resched();

	if (secno & 3) {
		printk("HPFS: hpfs_map_4sectors: unaligned read\n");
		return NULL;
	}

	qbh->data = data = kmalloc(2048, GFP_NOFS);
	if (!data) {
		printk("HPFS: hpfs_map_4sectors: out of memory\n");
		goto bail;
	}

	qbh->bh[0] = bh = sb_bread(s, secno);
	if (!bh)
		goto bail0;
	memcpy(data, bh->b_data, 512);

	qbh->bh[1] = bh = sb_bread(s, secno + 1);
	if (!bh)
		goto bail1;
	memcpy(data + 512, bh->b_data, 512);

	qbh->bh[2] = bh = sb_bread(s, secno + 2);
	if (!bh)
		goto bail2;
	memcpy(data + 2 * 512, bh->b_data, 512);

	qbh->bh[3] = bh = sb_bread(s, secno + 3);
	if (!bh)
		goto bail3;
	memcpy(data + 3 * 512, bh->b_data, 512);

	return data;

 bail3:
	brelse(qbh->bh[2]);
 bail2:
	brelse(qbh->bh[1]);
 bail1:
	brelse(qbh->bh[0]);
 bail0:
	kfree(data);
	printk("HPFS: hpfs_map_4sectors: read error\n");
 bail:
	return NULL;
}

/* Don't read sectors */

void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
                          struct quad_buffer_head *qbh)
{
	cond_resched();

	hpfs_lock_assert(s);

	if (secno & 3) {
		printk("HPFS: hpfs_get_4sectors: unaligned read\n");
		return NULL;
	}

	/*return hpfs_map_4sectors(s, secno, qbh, 0);*/
	if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
		printk("HPFS: hpfs_get_4sectors: out of memory\n");
		return NULL;
	}
	if (!(hpfs_get_sector(s, secno, &qbh->bh[0]))) goto bail0;
	if (!(hpfs_get_sector(s, secno + 1, &qbh->bh[1]))) goto bail1;
	if (!(hpfs_get_sector(s, secno + 2, &qbh->bh[2]))) goto bail2;
	if (!(hpfs_get_sector(s, secno + 3, &qbh->bh[3]))) goto bail3;
	memcpy(qbh->data, qbh->bh[0]->b_data, 512);
	memcpy(qbh->data + 512, qbh->bh[1]->b_data, 512);
	memcpy(qbh->data + 2*512, qbh->bh[2]->b_data, 512);
	memcpy(qbh->data + 3*512, qbh->bh[3]->b_data, 512);
	return qbh->data;

	bail3:	brelse(qbh->bh[2]);
	bail2:	brelse(qbh->bh[1]);
	bail1:	brelse(qbh->bh[0]);
	bail0:
	return NULL;
}
	

void hpfs_brelse4(struct quad_buffer_head *qbh)
{
	brelse(qbh->bh[3]);
	brelse(qbh->bh[2]);
	brelse(qbh->bh[1]);
	brelse(qbh->bh[0]);
	kfree(qbh->data);
}	

void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
{
	PRINTK(("hpfs_mark_4buffers_dirty\n"));
	memcpy(qbh->bh[0]->b_data, qbh->data, 512);
	memcpy(qbh->bh[1]->b_data, qbh->data + 512, 512);
	memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
	memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
	mark_buffer_dirty(qbh->bh[0]);
	mark_buffer_dirty(qbh->bh[1]);
	mark_buffer_dirty(qbh->bh[2]);
	mark_buffer_dirty(qbh->bh[3]);
}