1 /* $NetBSD: buf.c,v 1.13 2004/06/20 22:20:18 jmc Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-4-Clause
5 *
6 * Copyright (c) 2001 Wasabi Systems, Inc.
7 * All rights reserved.
8 *
9 * Written by Luke Mewburn for Wasabi Systems, Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed for the NetBSD Project by
22 * Wasabi Systems, Inc.
23 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
24 * or promote products derived from this software without specific prior
25 * written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42
43 #include <sys/param.h>
44 #include <sys/time.h>
45
46 #include <assert.h>
47 #include <errno.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <util.h>
53
54 #include "makefs.h"
55 #include "buf.h"
56
57 static TAILQ_HEAD(buftailhead,buf) buftail;
58
59 int
bread(struct vnode * vp,daddr_t blkno,int size,struct ucred * u1 __unused,struct buf ** bpp)60 bread(struct vnode *vp, daddr_t blkno, int size, struct ucred *u1 __unused,
61 struct buf **bpp)
62 {
63 off_t offset;
64 ssize_t rv;
65 fsinfo_t *fs = vp->fs;
66
67 assert (bpp != NULL);
68
69 if (debug & DEBUG_BUF_BREAD)
70 printf("%s: blkno %lld size %d\n", __func__, (long long)blkno,
71 size);
72 *bpp = getblk(vp, blkno, size, 0, 0, 0);
73 offset = (off_t)(*bpp)->b_blkno * fs->sectorsize + fs->offset;
74 if (debug & DEBUG_BUF_BREAD)
75 printf("%s: blkno %lld offset %lld bcount %ld\n", __func__,
76 (long long)(*bpp)->b_blkno, (long long) offset,
77 (*bpp)->b_bcount);
78 if (lseek((*bpp)->b_fs->fd, offset, SEEK_SET) == -1)
79 err(1, "%s: lseek %lld (%lld)", __func__,
80 (long long)(*bpp)->b_blkno, (long long)offset);
81 rv = read((*bpp)->b_fs->fd, (*bpp)->b_data, (*bpp)->b_bcount);
82 if (debug & DEBUG_BUF_BREAD)
83 printf("%s: read %ld (%lld) returned %d\n", __func__,
84 (*bpp)->b_bcount, (long long)offset, (int)rv);
85 if (rv == -1) /* read error */
86 err(1, "%s: read %ld (%lld) returned %d", __func__,
87 (*bpp)->b_bcount, (long long)offset, (int)rv);
88 else if (rv != (*bpp)->b_bcount) /* short read */
89 err(1, "%s: read %ld (%lld) returned %d", __func__,
90 (*bpp)->b_bcount, (long long)offset, (int)rv);
91 else
92 return (0);
93 }
94
95 void
brelse(struct buf * bp)96 brelse(struct buf *bp)
97 {
98
99 assert (bp != NULL);
100 assert (bp->b_data != NULL);
101
102 if (bp->b_lblkno < 0) {
103 /*
104 * XXX don't remove any buffers with negative logical block
105 * numbers (lblkno), so that we retain the mapping
106 * of negative lblkno -> real blkno that ffs_balloc()
107 * sets up.
108 *
109 * if we instead released these buffers, and implemented
110 * ufs_strategy() (and ufs_bmaparray()) and called those
111 * from bread() and bwrite() to convert the lblkno to
112 * a real blkno, we'd add a lot more code & complexity
113 * and reading off disk, for little gain, because this
114 * simple hack works for our purpose.
115 */
116 bp->b_bcount = 0;
117 return;
118 }
119
120 TAILQ_REMOVE(&buftail, bp, b_tailq);
121 free(bp->b_data);
122 free(bp);
123 }
124
125 int
bwrite(struct buf * bp)126 bwrite(struct buf *bp)
127 {
128 off_t offset;
129 ssize_t rv;
130 fsinfo_t *fs = bp->b_fs;
131
132 assert (bp != NULL);
133 offset = (off_t)bp->b_blkno * fs->sectorsize + fs->offset;
134 if (debug & DEBUG_BUF_BWRITE)
135 printf("bwrite: blkno %lld offset %lld bcount %ld\n",
136 (long long)bp->b_blkno, (long long) offset,
137 bp->b_bcount);
138 if (lseek(bp->b_fs->fd, offset, SEEK_SET) == -1)
139 return (errno);
140 rv = write(bp->b_fs->fd, bp->b_data, bp->b_bcount);
141 if (debug & DEBUG_BUF_BWRITE)
142 printf("bwrite: write %ld (offset %lld) returned %lld\n",
143 bp->b_bcount, (long long)offset, (long long)rv);
144 if (rv == bp->b_bcount)
145 return (0);
146 else if (rv == -1) /* write error */
147 return (errno);
148 else /* short write ? */
149 return (EAGAIN);
150 }
151
152 void
bcleanup(void)153 bcleanup(void)
154 {
155 struct buf *bp;
156
157 /*
158 * XXX this really shouldn't be necessary, but i'm curious to
159 * know why there's still some buffers lying around that
160 * aren't brelse()d
161 */
162
163 if (TAILQ_EMPTY(&buftail))
164 return;
165
166 printf("bcleanup: unflushed buffers:\n");
167 TAILQ_FOREACH(bp, &buftail, b_tailq) {
168 printf("\tlblkno %10lld blkno %10lld count %6ld bufsize %6ld\n",
169 (long long)bp->b_lblkno, (long long)bp->b_blkno,
170 bp->b_bcount, bp->b_bufsize);
171 }
172 printf("bcleanup: done\n");
173 }
174
175 struct buf *
getblk(struct vnode * vp,daddr_t blkno,int size,int u1 __unused,int u2 __unused,int u3 __unused)176 getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused,
177 int u2 __unused, int u3 __unused)
178 {
179 static int buftailinitted;
180 struct buf *bp;
181 void *n;
182
183 if (debug & DEBUG_BUF_GETBLK)
184 printf("getblk: blkno %lld size %d\n", (long long)blkno, size);
185
186 bp = NULL;
187 if (!buftailinitted) {
188 if (debug & DEBUG_BUF_GETBLK)
189 printf("getblk: initialising tailq\n");
190 TAILQ_INIT(&buftail);
191 buftailinitted = 1;
192 } else {
193 TAILQ_FOREACH(bp, &buftail, b_tailq) {
194 if (bp->b_lblkno != blkno)
195 continue;
196 break;
197 }
198 }
199 if (bp == NULL) {
200 bp = ecalloc(1, sizeof(*bp));
201 bp->b_bufsize = 0;
202 bp->b_blkno = bp->b_lblkno = blkno;
203 bp->b_fs = vp->fs;
204 bp->b_data = NULL;
205 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq);
206 }
207 bp->b_bcount = size;
208 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) {
209 n = erealloc(bp->b_data, size);
210 memset(n, 0, size);
211 bp->b_data = n;
212 bp->b_bufsize = size;
213 }
214
215 return (bp);
216 }
217