1 /* $NetBSD: buf.c,v 1.13 2004/06/20 22:20:18 jmc Exp $ */
4 * SPDX-License-Identifier: BSD-4-Clause
6 * Copyright (c) 2001 Wasabi Systems, Inc.
9 * Written by Luke Mewburn for Wasabi Systems, Inc.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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
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.
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
43 #include <sys/param.h>
57 static TAILQ_HEAD(buftailhead,buf) buftail;
60 bread(struct vnode *vp, daddr_t blkno, int size, struct ucred *u1 __unused,
65 fsinfo_t *fs = vp->fs;
69 if (debug & DEBUG_BUF_BREAD)
70 printf("%s: blkno %lld size %d\n", __func__, (long long)blkno,
72 *bpp = getblk(vp, blkno, size, 0, 0, 0);
73 offset = (*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,
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);
96 brelse(struct buf *bp)
100 assert (bp->b_data != NULL);
102 if (bp->b_lblkno < 0) {
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()
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.
120 TAILQ_REMOVE(&buftail, bp, b_tailq);
126 bwrite(struct buf *bp)
130 fsinfo_t *fs = bp->b_fs;
133 offset = 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,
138 if (lseek(bp->b_fs->fd, offset, SEEK_SET) == -1)
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)
146 else if (rv == -1) /* write error */
148 else /* short write ? */
158 * XXX this really shouldn't be necessary, but i'm curious to
159 * know why there's still some buffers lying around that
163 if (TAILQ_EMPTY(&buftail))
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);
172 printf("bcleanup: done\n");
176 getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused,
177 int u2 __unused, int u3 __unused)
179 static int buftailinitted;
183 if (debug & DEBUG_BUF_GETBLK)
184 printf("getblk: blkno %lld size %d\n", (long long)blkno, size);
187 if (!buftailinitted) {
188 if (debug & DEBUG_BUF_GETBLK)
189 printf("getblk: initialising tailq\n");
190 TAILQ_INIT(&buftail);
193 TAILQ_FOREACH(bp, &buftail, b_tailq) {
194 if (bp->b_lblkno != blkno)
200 bp = ecalloc(1, sizeof(*bp));
202 bp->b_blkno = bp->b_lblkno = blkno;
205 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq);
208 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) {
209 n = erealloc(bp->b_data, size);
212 bp->b_bufsize = size;