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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/* Map a sector into a buffer and return pointers to it and to the buffer. */
13
14void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
15 int ahead)
16{
17 struct buffer_head *bh;
18
19 hpfs_lock_assert(s);
20
21 cond_resched();
22
23 *bhp = bh = sb_bread(s, secno);
24 if (bh != NULL)
25 return bh->b_data;
26 else {
27 printk("HPFS: hpfs_map_sector: read error\n");
28 return NULL;
29 }
30}
31
32/* Like hpfs_map_sector but don't read anything */
33
34void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
35{
36 struct buffer_head *bh;
37 /*return hpfs_map_sector(s, secno, bhp, 0);*/
38
39 hpfs_lock_assert(s);
40
41 cond_resched();
42
43 if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
44 if (!buffer_uptodate(bh)) wait_on_buffer(bh);
45 set_buffer_uptodate(bh);
46 return bh->b_data;
47 } else {
48 printk("HPFS: hpfs_get_sector: getblk failed\n");
49 return NULL;
50 }
51}
52
53/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
54
55void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
56 int ahead)
57{
58 struct buffer_head *bh;
59 char *data;
60
61 hpfs_lock_assert(s);
62
63 cond_resched();
64
65 if (secno & 3) {
66 printk("HPFS: hpfs_map_4sectors: unaligned read\n");
67 return NULL;
68 }
69
70 qbh->data = data = kmalloc(2048, GFP_NOFS);
71 if (!data) {
72 printk("HPFS: hpfs_map_4sectors: out of memory\n");
73 goto bail;
74 }
75
76 qbh->bh[0] = bh = sb_bread(s, secno);
77 if (!bh)
78 goto bail0;
79 memcpy(data, bh->b_data, 512);
80
81 qbh->bh[1] = bh = sb_bread(s, secno + 1);
82 if (!bh)
83 goto bail1;
84 memcpy(data + 512, bh->b_data, 512);
85
86 qbh->bh[2] = bh = sb_bread(s, secno + 2);
87 if (!bh)
88 goto bail2;
89 memcpy(data + 2 * 512, bh->b_data, 512);
90
91 qbh->bh[3] = bh = sb_bread(s, secno + 3);
92 if (!bh)
93 goto bail3;
94 memcpy(data + 3 * 512, bh->b_data, 512);
95
96 return data;
97
98 bail3:
99 brelse(qbh->bh[2]);
100 bail2:
101 brelse(qbh->bh[1]);
102 bail1:
103 brelse(qbh->bh[0]);
104 bail0:
105 kfree(data);
106 printk("HPFS: hpfs_map_4sectors: read error\n");
107 bail:
108 return NULL;
109}
110
111/* Don't read sectors */
112
113void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
114 struct quad_buffer_head *qbh)
115{
116 cond_resched();
117
118 hpfs_lock_assert(s);
119
120 if (secno & 3) {
121 printk("HPFS: hpfs_get_4sectors: unaligned read\n");
122 return NULL;
123 }
124
125 /*return hpfs_map_4sectors(s, secno, qbh, 0);*/
126 if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
127 printk("HPFS: hpfs_get_4sectors: out of memory\n");
128 return NULL;
129 }
130 if (!(hpfs_get_sector(s, secno, &qbh->bh[0]))) goto bail0;
131 if (!(hpfs_get_sector(s, secno + 1, &qbh->bh[1]))) goto bail1;
132 if (!(hpfs_get_sector(s, secno + 2, &qbh->bh[2]))) goto bail2;
133 if (!(hpfs_get_sector(s, secno + 3, &qbh->bh[3]))) goto bail3;
134 memcpy(qbh->data, qbh->bh[0]->b_data, 512);
135 memcpy(qbh->data + 512, qbh->bh[1]->b_data, 512);
136 memcpy(qbh->data + 2*512, qbh->bh[2]->b_data, 512);
137 memcpy(qbh->data + 3*512, qbh->bh[3]->b_data, 512);
138 return qbh->data;
139
140 bail3: brelse(qbh->bh[2]);
141 bail2: brelse(qbh->bh[1]);
142 bail1: brelse(qbh->bh[0]);
143 bail0:
144 return NULL;
145}
146
147
148void hpfs_brelse4(struct quad_buffer_head *qbh)
149{
150 brelse(qbh->bh[3]);
151 brelse(qbh->bh[2]);
152 brelse(qbh->bh[1]);
153 brelse(qbh->bh[0]);
154 kfree(qbh->data);
155}
156
157void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
158{
159 PRINTK(("hpfs_mark_4buffers_dirty\n"));
160 memcpy(qbh->bh[0]->b_data, qbh->data, 512);
161 memcpy(qbh->bh[1]->b_data, qbh->data + 512, 512);
162 memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
163 memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
164 mark_buffer_dirty(qbh->bh[0]);
165 mark_buffer_dirty(qbh->bh[1]);
166 mark_buffer_dirty(qbh->bh[2]);
167 mark_buffer_dirty(qbh->bh[3]);
168}
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 <linux/blkdev.h>
11#include "hpfs_fn.h"
12
13void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n)
14{
15 struct buffer_head *bh;
16 struct blk_plug plug;
17
18 if (n <= 0 || unlikely(secno >= hpfs_sb(s)->sb_fs_size))
19 return;
20
21 bh = sb_find_get_block(s, secno);
22 if (bh) {
23 if (buffer_uptodate(bh)) {
24 brelse(bh);
25 return;
26 }
27 brelse(bh);
28 };
29
30 blk_start_plug(&plug);
31 while (n > 0) {
32 if (unlikely(secno >= hpfs_sb(s)->sb_fs_size))
33 break;
34 sb_breadahead(s, secno);
35 secno++;
36 n--;
37 }
38 blk_finish_plug(&plug);
39}
40
41/* Map a sector into a buffer and return pointers to it and to the buffer. */
42
43void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
44 int ahead)
45{
46 struct buffer_head *bh;
47
48 hpfs_lock_assert(s);
49
50 hpfs_prefetch_sectors(s, secno, ahead);
51
52 cond_resched();
53
54 *bhp = bh = sb_bread(s, secno);
55 if (bh != NULL)
56 return bh->b_data;
57 else {
58 printk("HPFS: hpfs_map_sector: read error\n");
59 return NULL;
60 }
61}
62
63/* Like hpfs_map_sector but don't read anything */
64
65void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
66{
67 struct buffer_head *bh;
68 /*return hpfs_map_sector(s, secno, bhp, 0);*/
69
70 hpfs_lock_assert(s);
71
72 cond_resched();
73
74 if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
75 if (!buffer_uptodate(bh)) wait_on_buffer(bh);
76 set_buffer_uptodate(bh);
77 return bh->b_data;
78 } else {
79 printk("HPFS: hpfs_get_sector: getblk failed\n");
80 return NULL;
81 }
82}
83
84/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
85
86void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
87 int ahead)
88{
89 char *data;
90
91 hpfs_lock_assert(s);
92
93 cond_resched();
94
95 if (secno & 3) {
96 printk("HPFS: hpfs_map_4sectors: unaligned read\n");
97 return NULL;
98 }
99
100 hpfs_prefetch_sectors(s, secno, 4 + ahead);
101
102 if (!(qbh->bh[0] = sb_bread(s, secno + 0))) goto bail0;
103 if (!(qbh->bh[1] = sb_bread(s, secno + 1))) goto bail1;
104 if (!(qbh->bh[2] = sb_bread(s, secno + 2))) goto bail2;
105 if (!(qbh->bh[3] = sb_bread(s, secno + 3))) goto bail3;
106
107 if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
108 likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
109 likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
110 return qbh->data = qbh->bh[0]->b_data;
111 }
112
113 qbh->data = data = kmalloc(2048, GFP_NOFS);
114 if (!data) {
115 printk("HPFS: hpfs_map_4sectors: out of memory\n");
116 goto bail4;
117 }
118
119 memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512);
120 memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512);
121 memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512);
122 memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512);
123
124 return data;
125
126 bail4:
127 brelse(qbh->bh[3]);
128 bail3:
129 brelse(qbh->bh[2]);
130 bail2:
131 brelse(qbh->bh[1]);
132 bail1:
133 brelse(qbh->bh[0]);
134 bail0:
135 return NULL;
136}
137
138/* Don't read sectors */
139
140void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
141 struct quad_buffer_head *qbh)
142{
143 cond_resched();
144
145 hpfs_lock_assert(s);
146
147 if (secno & 3) {
148 printk("HPFS: hpfs_get_4sectors: unaligned read\n");
149 return NULL;
150 }
151
152 if (!hpfs_get_sector(s, secno + 0, &qbh->bh[0])) goto bail0;
153 if (!hpfs_get_sector(s, secno + 1, &qbh->bh[1])) goto bail1;
154 if (!hpfs_get_sector(s, secno + 2, &qbh->bh[2])) goto bail2;
155 if (!hpfs_get_sector(s, secno + 3, &qbh->bh[3])) goto bail3;
156
157 if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
158 likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
159 likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
160 return qbh->data = qbh->bh[0]->b_data;
161 }
162
163 if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
164 printk("HPFS: hpfs_get_4sectors: out of memory\n");
165 goto bail4;
166 }
167 return qbh->data;
168
169bail4:
170 brelse(qbh->bh[3]);
171bail3:
172 brelse(qbh->bh[2]);
173bail2:
174 brelse(qbh->bh[1]);
175bail1:
176 brelse(qbh->bh[0]);
177bail0:
178 return NULL;
179}
180
181
182void hpfs_brelse4(struct quad_buffer_head *qbh)
183{
184 if (unlikely(qbh->data != qbh->bh[0]->b_data))
185 kfree(qbh->data);
186 brelse(qbh->bh[0]);
187 brelse(qbh->bh[1]);
188 brelse(qbh->bh[2]);
189 brelse(qbh->bh[3]);
190}
191
192void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
193{
194 if (unlikely(qbh->data != qbh->bh[0]->b_data)) {
195 memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512);
196 memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 512, 512);
197 memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
198 memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
199 }
200 mark_buffer_dirty(qbh->bh[0]);
201 mark_buffer_dirty(qbh->bh[1]);
202 mark_buffer_dirty(qbh->bh[2]);
203 mark_buffer_dirty(qbh->bh[3]);
204}