buf.c revision 1.3
1 /* $NetBSD: buf.c,v 1.3 2001/11/02 03:12:49 lukem 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 #include <sys/cdefs.h> 39 #ifndef __lint 40 __RCSID("$NetBSD: buf.c,v 1.3 2001/11/02 03:12:49 lukem Exp $"); 41 #endif /* !__lint */ 42 43 #include <sys/param.h> 44 #include <sys/time.h> 45 46 #include <assert.h> 47 #include <err.h> 48 #include <errno.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <unistd.h> 52 53 #include <ufs/ufs/inode.h> 54 #include <ufs/ffs/fs.h> 55 56 #include "makefs.h" 57 58 #include "ffs/buf.h" 59 60 extern int sectorsize; /* XXX: from ffs.c & mkfs.c */ 61 62 TAILQ_HEAD(buftailhead,buf) buftail; 63 64 int 65 bread(int fd, struct fs *fs, daddr_t blkno, int size, struct buf **bpp) 66 { 67 off_t offset; 68 ssize_t rv; 69 70 assert (fs != NULL); 71 assert (bpp != NULL); 72 73 if (debug & DEBUG_BUF_BREAD) 74 printf("bread: fs %p blkno %d size %d\n", 75 fs, blkno, size); 76 *bpp = getblk(fd, fs, blkno, size); 77 offset = (*bpp)->b_blkno * sectorsize; /* XXX */ 78 if (debug & DEBUG_BUF_BREAD) 79 printf("bread: bp %p blkno %d offset %lld bcount %ld\n", 80 (*bpp), (*bpp)->b_blkno, (long long) offset, 81 (*bpp)->b_bcount); 82 if (lseek((*bpp)->b_fd, offset, SEEK_SET) == -1) 83 err(1, "bread: lseek %lld (%lld)", 84 (long long)(*bpp)->b_blkno, (long long)offset); 85 rv = read((*bpp)->b_fd, (*bpp)->b_data, (*bpp)->b_bcount); 86 if (debug & DEBUG_BUF_BREAD) 87 printf("bread: read %ld (%lld) returned %d\n", 88 (*bpp)->b_bcount, (long long)offset, (int)rv); 89 if (rv == -1) /* read error */ 90 err(1, "bread: read %ld (%lld) returned %d", 91 (*bpp)->b_bcount, (long long)offset, (int)rv); 92 else if (rv != (*bpp)->b_bcount) /* short read */ 93 err(1, "bread: read %ld (%lld) returned %d", 94 (*bpp)->b_bcount, (long long)offset, (int)rv); 95 else 96 return (0); 97 } 98 99 void 100 brelse(struct buf *bp) 101 { 102 103 assert (bp != NULL); 104 assert (bp->b_data != NULL); 105 106 if (bp->b_lblkno < 0) { 107 /* 108 * XXX don't remove any buffers with negative logical block 109 * numbers (lblkno), so that we retain the mapping 110 * of negative lblkno -> real blkno that ffs_balloc() 111 * sets up. 112 * 113 * if we instead released these buffers, and implemented 114 * ufs_strategy() (and ufs_bmaparray()) and called those 115 * from bread() and bwrite() to convert the lblkno to 116 * a real blkno, we'd add a lot more code & complexity 117 * and reading off disk, for little gain, because this 118 * simple hack works for our purpose. 119 */ 120 bp->b_bcount = 0; 121 return; 122 } 123 124 TAILQ_REMOVE(&buftail, bp, b_tailq); 125 free(bp->b_data); 126 free(bp); 127 } 128 129 int 130 bwrite(struct buf *bp) 131 { 132 off_t offset; 133 ssize_t rv; 134 135 assert (bp != NULL); 136 offset = bp->b_blkno * sectorsize; /* XXX */ 137 if (debug & DEBUG_BUF_BWRITE) 138 printf("bwrite: bp %p blkno %d offset %lld bcount %ld\n", 139 bp, bp->b_blkno, (long long) offset, bp->b_bcount); 140 if (lseek(bp->b_fd, offset, SEEK_SET) == -1) 141 return (errno); 142 rv = write(bp->b_fd, bp->b_data, bp->b_bcount); 143 if (debug & DEBUG_BUF_BWRITE) 144 printf("bwrite: write %ld (offset %lld) returned %lld\n", 145 bp->b_bcount, (long long)offset, (long long)rv); 146 if (rv == bp->b_bcount) 147 return (0); 148 else if (rv == -1) /* write error */ 149 return (errno); 150 else /* short write ? */ 151 return (EAGAIN); 152 } 153 154 void 155 bcleanup(void) 156 { 157 struct buf *bp; 158 159 /* 160 * XXX this really shouldn't be necessary, but i'm curious to 161 * know why there's still some buffers lying around that 162 * aren't brelse()d 163 */ 164 165 if (TAILQ_EMPTY(&buftail)) 166 return; 167 168 printf("bcleanup: unflushed buffers:\n"); 169 TAILQ_FOREACH(bp, &buftail, b_tailq) { 170 printf("\tlblkno %10d blkno %10d count %6ld bufsize %6ld\n", 171 bp->b_lblkno, bp->b_blkno, bp->b_bcount, bp->b_bufsize); 172 } 173 printf("bcleanup: done\n"); 174 } 175 176 struct buf * 177 getblk(int fd, struct fs *fs, daddr_t blkno, int size) 178 { 179 static int buftailinitted; 180 struct buf *bp; 181 182 assert (fs != NULL); 183 if (debug & DEBUG_BUF_GETBLK) 184 printf("getblk: fs %p blkno %d size %d\n", fs, 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 if ((bp = calloc(1, sizeof(struct buf))) == NULL) 201 err(1, "getblk: calloc"); 202 203 bp->b_bufsize = 0; 204 bp->b_blkno = bp->b_lblkno = blkno; 205 bp->b_fd = fd; 206 bp->b_fs = fs; 207 bp->b_data = NULL; 208 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq); 209 } 210 bp->b_bcount = size; 211 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) { 212 bp->b_bufsize = size; 213 if ((bp->b_data = realloc(bp->b_data, bp->b_bufsize)) == NULL) 214 err(1, "getblk: realloc b_data %ld", bp->b_bcount); 215 } 216 217 return (bp); 218 } 219
Indexes created Fri Sep 26 08:10:20 GMT 2025