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