xref: /openbmc/linux/fs/hpfs/buffer.c (revision 4800cd83)
1 /*
2  *  linux/fs/hpfs/buffer.c
3  *
4  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
5  *
6  *  general buffer i/o
7  */
8 #include <linux/sched.h>
9 #include <linux/slab.h>
10 #include "hpfs_fn.h"
11 
12 void hpfs_lock_creation(struct super_block *s)
13 {
14 #ifdef DEBUG_LOCKS
15 	printk("lock creation\n");
16 #endif
17 	mutex_lock(&hpfs_sb(s)->hpfs_creation_de);
18 }
19 
20 void hpfs_unlock_creation(struct super_block *s)
21 {
22 #ifdef DEBUG_LOCKS
23 	printk("unlock creation\n");
24 #endif
25 	mutex_unlock(&hpfs_sb(s)->hpfs_creation_de);
26 }
27 
28 /* Map a sector into a buffer and return pointers to it and to the buffer. */
29 
30 void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
31 		 int ahead)
32 {
33 	struct buffer_head *bh;
34 
35 	cond_resched();
36 
37 	*bhp = bh = sb_bread(s, secno);
38 	if (bh != NULL)
39 		return bh->b_data;
40 	else {
41 		printk("HPFS: hpfs_map_sector: read error\n");
42 		return NULL;
43 	}
44 }
45 
46 /* Like hpfs_map_sector but don't read anything */
47 
48 void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
49 {
50 	struct buffer_head *bh;
51 	/*return hpfs_map_sector(s, secno, bhp, 0);*/
52 
53 	cond_resched();
54 
55 	if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
56 		if (!buffer_uptodate(bh)) wait_on_buffer(bh);
57 		set_buffer_uptodate(bh);
58 		return bh->b_data;
59 	} else {
60 		printk("HPFS: hpfs_get_sector: getblk failed\n");
61 		return NULL;
62 	}
63 }
64 
65 /* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
66 
67 void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
68 		   int ahead)
69 {
70 	struct buffer_head *bh;
71 	char *data;
72 
73 	cond_resched();
74 
75 	if (secno & 3) {
76 		printk("HPFS: hpfs_map_4sectors: unaligned read\n");
77 		return NULL;
78 	}
79 
80 	qbh->data = data = kmalloc(2048, GFP_NOFS);
81 	if (!data) {
82 		printk("HPFS: hpfs_map_4sectors: out of memory\n");
83 		goto bail;
84 	}
85 
86 	qbh->bh[0] = bh = sb_bread(s, secno);
87 	if (!bh)
88 		goto bail0;
89 	memcpy(data, bh->b_data, 512);
90 
91 	qbh->bh[1] = bh = sb_bread(s, secno + 1);
92 	if (!bh)
93 		goto bail1;
94 	memcpy(data + 512, bh->b_data, 512);
95 
96 	qbh->bh[2] = bh = sb_bread(s, secno + 2);
97 	if (!bh)
98 		goto bail2;
99 	memcpy(data + 2 * 512, bh->b_data, 512);
100 
101 	qbh->bh[3] = bh = sb_bread(s, secno + 3);
102 	if (!bh)
103 		goto bail3;
104 	memcpy(data + 3 * 512, bh->b_data, 512);
105 
106 	return data;
107 
108  bail3:
109 	brelse(qbh->bh[2]);
110  bail2:
111 	brelse(qbh->bh[1]);
112  bail1:
113 	brelse(qbh->bh[0]);
114  bail0:
115 	kfree(data);
116 	printk("HPFS: hpfs_map_4sectors: read error\n");
117  bail:
118 	return NULL;
119 }
120 
121 /* Don't read sectors */
122 
123 void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
124                           struct quad_buffer_head *qbh)
125 {
126 	cond_resched();
127 
128 	if (secno & 3) {
129 		printk("HPFS: hpfs_get_4sectors: unaligned read\n");
130 		return NULL;
131 	}
132 
133 	/*return hpfs_map_4sectors(s, secno, qbh, 0);*/
134 	if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
135 		printk("HPFS: hpfs_get_4sectors: out of memory\n");
136 		return NULL;
137 	}
138 	if (!(hpfs_get_sector(s, secno, &qbh->bh[0]))) goto bail0;
139 	if (!(hpfs_get_sector(s, secno + 1, &qbh->bh[1]))) goto bail1;
140 	if (!(hpfs_get_sector(s, secno + 2, &qbh->bh[2]))) goto bail2;
141 	if (!(hpfs_get_sector(s, secno + 3, &qbh->bh[3]))) goto bail3;
142 	memcpy(qbh->data, qbh->bh[0]->b_data, 512);
143 	memcpy(qbh->data + 512, qbh->bh[1]->b_data, 512);
144 	memcpy(qbh->data + 2*512, qbh->bh[2]->b_data, 512);
145 	memcpy(qbh->data + 3*512, qbh->bh[3]->b_data, 512);
146 	return qbh->data;
147 
148 	bail3:	brelse(qbh->bh[2]);
149 	bail2:	brelse(qbh->bh[1]);
150 	bail1:	brelse(qbh->bh[0]);
151 	bail0:
152 	return NULL;
153 }
154 
155 
156 void hpfs_brelse4(struct quad_buffer_head *qbh)
157 {
158 	brelse(qbh->bh[3]);
159 	brelse(qbh->bh[2]);
160 	brelse(qbh->bh[1]);
161 	brelse(qbh->bh[0]);
162 	kfree(qbh->data);
163 }
164 
165 void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
166 {
167 	PRINTK(("hpfs_mark_4buffers_dirty\n"));
168 	memcpy(qbh->bh[0]->b_data, qbh->data, 512);
169 	memcpy(qbh->bh[1]->b_data, qbh->data + 512, 512);
170 	memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
171 	memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
172 	mark_buffer_dirty(qbh->bh[0]);
173 	mark_buffer_dirty(qbh->bh[1]);
174 	mark_buffer_dirty(qbh->bh[2]);
175 	mark_buffer_dirty(qbh->bh[3]);
176 }
177