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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/hpfs/buffer.c
4 *
5 * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6 *
7 * general buffer i/o
8 */
9#include <linux/sched.h>
10#include <linux/slab.h>
11#include <linux/blkdev.h>
12#include "hpfs_fn.h"
13
14secno hpfs_search_hotfix_map(struct super_block *s, secno sec)
15{
16 unsigned i;
17 struct hpfs_sb_info *sbi = hpfs_sb(s);
18 for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
19 if (sbi->hotfix_from[i] == sec) {
20 return sbi->hotfix_to[i];
21 }
22 }
23 return sec;
24}
25
26unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n)
27{
28 unsigned i;
29 struct hpfs_sb_info *sbi = hpfs_sb(s);
30 for (i = 0; unlikely(i < sbi->n_hotfixes); i++) {
31 if (sbi->hotfix_from[i] >= sec && sbi->hotfix_from[i] < sec + n) {
32 n = sbi->hotfix_from[i] - sec;
33 }
34 }
35 return n;
36}
37
38void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n)
39{
40 struct buffer_head *bh;
41 struct blk_plug plug;
42
43 if (n <= 0 || unlikely(secno >= hpfs_sb(s)->sb_fs_size))
44 return;
45
46 if (unlikely(hpfs_search_hotfix_map_for_range(s, secno, n) != n))
47 return;
48
49 bh = sb_find_get_block(s, secno);
50 if (bh) {
51 if (buffer_uptodate(bh)) {
52 brelse(bh);
53 return;
54 }
55 brelse(bh);
56 }
57
58 blk_start_plug(&plug);
59 while (n > 0) {
60 if (unlikely(secno >= hpfs_sb(s)->sb_fs_size))
61 break;
62 sb_breadahead(s, secno);
63 secno++;
64 n--;
65 }
66 blk_finish_plug(&plug);
67}
68
69/* Map a sector into a buffer and return pointers to it and to the buffer. */
70
71void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp,
72 int ahead)
73{
74 struct buffer_head *bh;
75
76 hpfs_lock_assert(s);
77
78 hpfs_prefetch_sectors(s, secno, ahead);
79
80 cond_resched();
81
82 *bhp = bh = sb_bread(s, hpfs_search_hotfix_map(s, secno));
83 if (bh != NULL)
84 return bh->b_data;
85 else {
86 pr_err("%s(): read error\n", __func__);
87 return NULL;
88 }
89}
90
91/* Like hpfs_map_sector but don't read anything */
92
93void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp)
94{
95 struct buffer_head *bh;
96 /*return hpfs_map_sector(s, secno, bhp, 0);*/
97
98 hpfs_lock_assert(s);
99
100 cond_resched();
101
102 if ((*bhp = bh = sb_getblk(s, hpfs_search_hotfix_map(s, secno))) != NULL) {
103 if (!buffer_uptodate(bh)) wait_on_buffer(bh);
104 set_buffer_uptodate(bh);
105 return bh->b_data;
106 } else {
107 pr_err("%s(): getblk failed\n", __func__);
108 return NULL;
109 }
110}
111
112/* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */
113
114void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh,
115 int ahead)
116{
117 char *data;
118
119 hpfs_lock_assert(s);
120
121 cond_resched();
122
123 if (secno & 3) {
124 pr_err("%s(): unaligned read\n", __func__);
125 return NULL;
126 }
127
128 hpfs_prefetch_sectors(s, secno, 4 + ahead);
129
130 if (!hpfs_map_sector(s, secno + 0, &qbh->bh[0], 0)) goto bail0;
131 if (!hpfs_map_sector(s, secno + 1, &qbh->bh[1], 0)) goto bail1;
132 if (!hpfs_map_sector(s, secno + 2, &qbh->bh[2], 0)) goto bail2;
133 if (!hpfs_map_sector(s, secno + 3, &qbh->bh[3], 0)) goto bail3;
134
135 if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
136 likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
137 likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
138 return qbh->data = qbh->bh[0]->b_data;
139 }
140
141 qbh->data = data = kmalloc(2048, GFP_NOFS);
142 if (!data) {
143 pr_err("%s(): out of memory\n", __func__);
144 goto bail4;
145 }
146
147 memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512);
148 memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512);
149 memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512);
150 memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512);
151
152 return data;
153
154 bail4:
155 brelse(qbh->bh[3]);
156 bail3:
157 brelse(qbh->bh[2]);
158 bail2:
159 brelse(qbh->bh[1]);
160 bail1:
161 brelse(qbh->bh[0]);
162 bail0:
163 return NULL;
164}
165
166/* Don't read sectors */
167
168void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
169 struct quad_buffer_head *qbh)
170{
171 cond_resched();
172
173 hpfs_lock_assert(s);
174
175 if (secno & 3) {
176 pr_err("%s(): unaligned read\n", __func__);
177 return NULL;
178 }
179
180 if (!hpfs_get_sector(s, secno + 0, &qbh->bh[0])) goto bail0;
181 if (!hpfs_get_sector(s, secno + 1, &qbh->bh[1])) goto bail1;
182 if (!hpfs_get_sector(s, secno + 2, &qbh->bh[2])) goto bail2;
183 if (!hpfs_get_sector(s, secno + 3, &qbh->bh[3])) goto bail3;
184
185 if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) &&
186 likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) &&
187 likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) {
188 return qbh->data = qbh->bh[0]->b_data;
189 }
190
191 if (!(qbh->data = kmalloc(2048, GFP_NOFS))) {
192 pr_err("%s(): out of memory\n", __func__);
193 goto bail4;
194 }
195 return qbh->data;
196
197bail4:
198 brelse(qbh->bh[3]);
199bail3:
200 brelse(qbh->bh[2]);
201bail2:
202 brelse(qbh->bh[1]);
203bail1:
204 brelse(qbh->bh[0]);
205bail0:
206 return NULL;
207}
208
209
210void hpfs_brelse4(struct quad_buffer_head *qbh)
211{
212 if (unlikely(qbh->data != qbh->bh[0]->b_data))
213 kfree(qbh->data);
214 brelse(qbh->bh[0]);
215 brelse(qbh->bh[1]);
216 brelse(qbh->bh[2]);
217 brelse(qbh->bh[3]);
218}
219
220void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh)
221{
222 if (unlikely(qbh->data != qbh->bh[0]->b_data)) {
223 memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512);
224 memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 512, 512);
225 memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
226 memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
227 }
228 mark_buffer_dirty(qbh->bh[0]);
229 mark_buffer_dirty(qbh->bh[1]);
230 mark_buffer_dirty(qbh->bh[2]);
231 mark_buffer_dirty(qbh->bh[3]);
232}
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 memcpy(qbh->bh[0]->b_data, qbh->data, 512);
160 memcpy(qbh->bh[1]->b_data, qbh->data + 512, 512);
161 memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512);
162 memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512);
163 mark_buffer_dirty(qbh->bh[0]);
164 mark_buffer_dirty(qbh->bh[1]);
165 mark_buffer_dirty(qbh->bh[2]);
166 mark_buffer_dirty(qbh->bh[3]);
167}