1 /* $OpenBSD: buf.c,v 1.7 2021/10/06 00:40:41 deraadt Exp $ */
2 /* $NetBSD: buf.c,v 1.24 2016/06/24 19:24:11 christos Exp $ */
3
4 /*
5 * Copyright (c) 2001 Wasabi Systems, Inc.
6 * All rights reserved.
7 *
8 * Written by Luke Mewburn for Wasabi Systems, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed for the NetBSD Project by
21 * Wasabi Systems, Inc.
22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
23 * or promote products derived from this software without specific prior
24 * written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 #include <sys/time.h>
40
41 #include <assert.h>
42 #include <errno.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 #include <util.h>
47
48 #include "makefs.h"
49 #include "buf.h"
50
51 TAILQ_HEAD(buftailhead,mkfsbuf) buftail;
52
53 int
bread(struct mkfsvnode * vp,daddr_t blkno,int size,int u2 __unused,struct mkfsbuf ** bpp)54 bread(struct mkfsvnode *vp, daddr_t blkno, int size, int u2 __unused,
55 struct mkfsbuf **bpp)
56 {
57 off_t offset;
58 ssize_t rv;
59 fsinfo_t *fs = vp->fs;
60
61 assert (bpp != NULL);
62
63 *bpp = getblk(vp, blkno, size, 0, 0);
64 offset = (*bpp)->b_blkno * fs->sectorsize + fs->offset;
65 if (lseek((*bpp)->b_fs->fd, offset, SEEK_SET) == -1)
66 err(1, "%s: lseek %lld (%lld)", __func__,
67 (long long)(*bpp)->b_blkno, (long long)offset);
68 rv = read((*bpp)->b_fs->fd, (*bpp)->b_data, (size_t)(*bpp)->b_bcount);
69 if (rv == -1) /* read error */
70 err(1, "%s: read %ld (%lld) returned %zd", __func__,
71 (*bpp)->b_bcount, (long long)offset, rv);
72 else if (rv != (*bpp)->b_bcount) /* short read */
73 errx(1, "%s: read %ld (%lld) returned %zd", __func__,
74 (*bpp)->b_bcount, (long long)offset, rv);
75 else
76 return (0);
77 }
78
79 void
brelse(struct mkfsbuf * bp,int u1 __unused)80 brelse(struct mkfsbuf *bp, int u1 __unused)
81 {
82
83 assert (bp != NULL);
84 assert (bp->b_data != NULL);
85
86 if (bp->b_lblkno < 0) {
87 /*
88 * XXX don't remove any buffers with negative logical block
89 * numbers (lblkno), so that we retain the mapping
90 * of negative lblkno -> real blkno that ffs_balloc()
91 * sets up.
92 *
93 * if we instead released these buffers, and implemented
94 * ufs_strategy() (and ufs_bmaparray()) and called those
95 * from bread() and bwrite() to convert the lblkno to
96 * a real blkno, we'd add a lot more code & complexity
97 * and reading off disk, for little gain, because this
98 * simple hack works for our purpose.
99 */
100 bp->b_bcount = 0;
101 return;
102 }
103
104 TAILQ_REMOVE(&buftail, bp, b_tailq);
105 free(bp->b_data);
106 free(bp);
107 }
108
109 int
bwrite(struct mkfsbuf * bp)110 bwrite(struct mkfsbuf *bp)
111 {
112 off_t offset;
113 ssize_t rv;
114 size_t bytes;
115 fsinfo_t *fs = bp->b_fs;
116
117 assert (bp != NULL);
118 offset = bp->b_blkno * fs->sectorsize + fs->offset;
119 bytes = (size_t)bp->b_bcount;
120 if (lseek(bp->b_fs->fd, offset, SEEK_SET) == -1)
121 return (errno);
122 rv = write(bp->b_fs->fd, bp->b_data, bytes);
123 brelse(bp, 0);
124 if (rv == (ssize_t)bytes)
125 return (0);
126 else if (rv == -1) /* write error */
127 return (errno);
128 else /* short write ? */
129 return (EAGAIN);
130 }
131
132 void
bcleanup(void)133 bcleanup(void)
134 {
135 #if DEBUG_BUFFERS
136 struct mkfsbuf *bp;
137
138 /*
139 * XXX this really shouldn't be necessary, but i'm curious to
140 * know why there's still some buffers lying around that
141 * aren't brelse()d
142 */
143
144 if (TAILQ_EMPTY(&buftail))
145 return;
146
147 printf("bcleanup: unflushed buffers:\n");
148 TAILQ_FOREACH(bp, &buftail, b_tailq) {
149 printf("\tlblkno %10lld blkno %10lld count %6ld bufsize %6ld\n",
150 (long long)bp->b_lblkno, (long long)bp->b_blkno,
151 bp->b_bcount, bp->b_bufsize);
152 }
153 printf("bcleanup: done\n");
154 #endif
155 }
156
157 struct mkfsbuf *
getblk(struct mkfsvnode * vp,daddr_t blkno,int size,int u1 __unused,int u2 __unused)158 getblk(struct mkfsvnode *vp, daddr_t blkno, int size, int u1 __unused,
159 int u2 __unused)
160 {
161 static int buftailinitted;
162 struct mkfsbuf *bp;
163 void *n;
164
165 bp = NULL;
166 if (!buftailinitted) {
167 TAILQ_INIT(&buftail);
168 buftailinitted = 1;
169 } else {
170 TAILQ_FOREACH(bp, &buftail, b_tailq) {
171 if (bp->b_lblkno != blkno)
172 continue;
173 break;
174 }
175 }
176 if (bp == NULL) {
177 bp = ecalloc(1, sizeof(*bp));
178 bp->b_bufsize = 0;
179 bp->b_blkno = bp->b_lblkno = blkno;
180 bp->b_fs = vp->fs;
181 bp->b_data = NULL;
182 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq);
183 }
184 bp->b_bcount = size;
185 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) {
186 n = erealloc(bp->b_data, (size_t)size);
187 memset(n, 0, (size_t)size);
188 bp->b_data = n;
189 bp->b_bufsize = size;
190 }
191
192 return (bp);
193 }
194