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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +04008#include <linux/sched.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09009#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include "hpfs_fn.h"
11
12void hpfs_lock_creation(struct super_block *s)
13{
14#ifdef DEBUG_LOCKS
15 printk("lock creation\n");
16#endif
17 down(&hpfs_sb(s)->hpfs_creation_de);
18}
19
20void hpfs_unlock_creation(struct super_block *s)
21{
22#ifdef DEBUG_LOCKS
23 printk("unlock creation\n");
24#endif
25 up(&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
30void *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
48void *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
67void *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
Panagiotis Issarisf52720c2006-09-27 01:49:39 -070080 qbh->data = data = kmalloc(2048, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 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
123void *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
156void 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
165void 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}