1 /* $NetBSD: buf.c,v 1.22 2015/03/29 05:52:59 agc Exp $ */
2
3 /*
4 * Copyright (c) 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Luke Mewburn for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #if HAVE_NBTOOL_CONFIG_H
39 #include "nbtool_config.h"
40 #endif
41
42 #include <sys/cdefs.h>
43 #if defined(__RCSID) && !defined(__lint)
44 __RCSID("$NetBSD: buf.c,v 1.22 2015/03/29 05:52:59 agc Exp $");
45 #endif /* !__lint */
46
47 #include <sys/param.h>
48 #include <sys/time.h>
49
50 #include <assert.h>
51 #include <errno.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <unistd.h>
55 #include <util.h>
56
57 #include "makefs.h"
58 #include "buf.h"
59
60 TAILQ_HEAD(buftailhead,buf) buftail;
61
62 int
bread(struct vnode * vp,daddr_t blkno,int size,int u2 __unused,struct buf ** bpp)63 bread(struct vnode *vp, daddr_t blkno, int size, int u2 __unused,
64 struct buf **bpp)
65 {
66 off_t offset;
67 ssize_t rv;
68 fsinfo_t *fs = vp->fs;
69
70 assert (bpp != NULL);
71
72 if (debug & DEBUG_BUF_BREAD)
73 printf("bread: blkno %lld size %d\n", (long long)blkno, size);
74 *bpp = getblk(vp, blkno, size, 0, 0);
75 offset = (*bpp)->b_blkno * fs->sectorsize + fs->offset;
76 if (debug & DEBUG_BUF_BREAD)
77 printf("bread: blkno %lld offset %lld bcount %ld\n",
78 (long long)(*bpp)->b_blkno, (long long) offset,
79 (*bpp)->b_bcount);
80 if (lseek((*bpp)->b_fs->fd, offset, SEEK_SET) == -1)
81 err(1, "%s: lseek %lld (%lld)", __func__,
82 (long long)(*bpp)->b_blkno, (long long)offset);
83 rv = read((*bpp)->b_fs->fd, (*bpp)->b_data, (*bpp)->b_bcount);
84 if (debug & DEBUG_BUF_BREAD)
85 printf("bread: read %ld (%lld) returned %zd\n",
86 (*bpp)->b_bcount, (long long)offset, rv);
87 if (rv == -1) /* read error */
88 err(1, "%s: read %ld (%lld) returned %zd", __func__,
89 (*bpp)->b_bcount, (long long)offset, rv);
90 else if (rv != (*bpp)->b_bcount) /* short read */
91 err(1, "%s: read %ld (%lld) returned %zd", __func__,
92 (*bpp)->b_bcount, (long long)offset, rv);
93 else
94 return (0);
95 }
96
97 void
brelse(struct buf * bp,int u1 __unused)98 brelse(struct buf *bp, int u1 __unused)
99 {
100
101 assert (bp != NULL);
102 assert (bp->b_data != NULL);
103
104 if (bp->b_lblkno < 0) {
105 /*
106 * XXX don't remove any buffers with negative logical block
107 * numbers (lblkno), so that we retain the mapping
108 * of negative lblkno -> real blkno that ffs_balloc()
109 * sets up.
110 *
111 * if we instead released these buffers, and implemented
112 * ufs_strategy() (and ufs_bmaparray()) and called those
113 * from bread() and bwrite() to convert the lblkno to
114 * a real blkno, we'd add a lot more code & complexity
115 * and reading off disk, for little gain, because this
116 * simple hack works for our purpose.
117 */
118 bp->b_bcount = 0;
119 return;
120 }
121
122 TAILQ_REMOVE(&buftail, bp, b_tailq);
123 free(bp->b_data);
124 free(bp);
125 }
126
127 int
bwrite(struct buf * bp)128 bwrite(struct buf *bp)
129 {
130 off_t offset;
131 ssize_t rv;
132 int bytes;
133 fsinfo_t *fs = bp->b_fs;
134
135 assert (bp != NULL);
136 offset = bp->b_blkno * fs->sectorsize + fs->offset;
137 bytes = bp->b_bcount;
138 if (debug & DEBUG_BUF_BWRITE)
139 printf("bwrite: blkno %lld offset %lld bcount %d\n",
140 (long long)bp->b_blkno, (long long) offset, bytes);
141 if (lseek(bp->b_fs->fd, offset, SEEK_SET) == -1)
142 return (errno);
143 rv = write(bp->b_fs->fd, bp->b_data, bytes);
144 if (debug & DEBUG_BUF_BWRITE)
145 printf("bwrite: write %ld (offset %lld) returned %lld\n",
146 bp->b_bcount, (long long)offset, (long long)rv);
147 brelse(bp, 0);
148 if (rv == bytes)
149 return (0);
150 else if (rv == -1) /* write error */
151 return (errno);
152 else /* short write ? */
153 return (EAGAIN);
154 }
155
156 void
bcleanup(void)157 bcleanup(void)
158 {
159 struct buf *bp;
160
161 /*
162 * XXX this really shouldn't be necessary, but i'm curious to
163 * know why there's still some buffers lying around that
164 * aren't brelse()d
165 */
166
167 if (TAILQ_EMPTY(&buftail))
168 return;
169
170 printf("bcleanup: unflushed buffers:\n");
171 TAILQ_FOREACH(bp, &buftail, b_tailq) {
172 printf("\tlblkno %10lld blkno %10lld count %6ld bufsize %6ld\n",
173 (long long)bp->b_lblkno, (long long)bp->b_blkno,
174 bp->b_bcount, bp->b_bufsize);
175 }
176 printf("bcleanup: done\n");
177 }
178
179 struct buf *
getblk(struct vnode * vp,daddr_t blkno,int size,int u1 __unused,int u2 __unused)180 getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused,
181 int u2 __unused)
182 {
183 static int buftailinitted;
184 struct buf *bp;
185 void *n;
186
187 if (debug & DEBUG_BUF_GETBLK)
188 printf("getblk: blkno %lld size %d\n", (long long)blkno, size);
189
190 bp = NULL;
191 if (!buftailinitted) {
192 if (debug & DEBUG_BUF_GETBLK)
193 printf("getblk: initialising tailq\n");
194 TAILQ_INIT(&buftail);
195 buftailinitted = 1;
196 } else {
197 TAILQ_FOREACH(bp, &buftail, b_tailq) {
198 if (bp->b_lblkno != blkno)
199 continue;
200 break;
201 }
202 }
203 if (bp == NULL) {
204 bp = ecalloc(1, sizeof(*bp));
205 bp->b_bufsize = 0;
206 bp->b_blkno = bp->b_lblkno = blkno;
207 bp->b_fs = vp->fs;
208 bp->b_data = NULL;
209 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq);
210 }
211 bp->b_bcount = size;
212 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) {
213 n = erealloc(bp->b_data, size);
214 memset(n, 0, size);
215 bp->b_data = n;
216 bp->b_bufsize = size;
217 }
218
219 return (bp);
220 }
221