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 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 = (*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 96 brelse(struct buf *bp, int u1 __unused) 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 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 = 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 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 * 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