buf.c revision 1.8
1 /* $NetBSD: buf.c,v 1.8 2002/01/08 06:00:14 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 1.8 2002/01/08 06:00:14 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 "makefs.h" 54 55 #include <ufs/ufs/dinode.h> 56 #include <ufs/ffs/fs.h> 57 58 #include "ffs/buf.h" 59 #include "ffs/ufs_inode.h" 60 61 extern int sectorsize; /* XXX: from ffs.c & mkfs.c */ 62 63 TAILQ_HEAD(buftailhead,buf) buftail; 64 65 int 66 bread(int fd, struct fs *fs, daddr_t blkno, int size, struct buf **bpp) 67 { 68 off_t offset; 69 ssize_t rv; 70 71 assert (fs != NULL); 72 assert (bpp != NULL); 73 74 if (debug & DEBUG_BUF_BREAD) 75 printf("bread: fs %p blkno %d size %d\n", 76 fs, blkno, size); 77 *bpp = getblk(fd, fs, blkno, size); 78 offset = (*bpp)->b_blkno * sectorsize; /* XXX */ 79 if (debug & DEBUG_BUF_BREAD) 80 printf("bread: bp %p blkno %d offset %lld bcount %ld\n", 81 (*bpp), (*bpp)->b_blkno, (long long) offset, 82 (*bpp)->b_bcount); 83 if (lseek((*bpp)->b_fd, offset, SEEK_SET) == -1) 84 err(1, "bread: lseek %lld (%lld)", 85 (long long)(*bpp)->b_blkno, (long long)offset); 86 rv = read((*bpp)->b_fd, (*bpp)->b_data, (*bpp)->b_bcount); 87 if (debug & DEBUG_BUF_BREAD) 88 printf("bread: read %ld (%lld) returned %d\n", 89 (*bpp)->b_bcount, (long long)offset, (int)rv); 90 if (rv == -1) /* read error */ 91 err(1, "bread: read %ld (%lld) returned %d", 92 (*bpp)->b_bcount, (long long)offset, (int)rv); 93 else if (rv != (*bpp)->b_bcount) /* short read */ 94 err(1, "bread: read %ld (%lld) returned %d", 95 (*bpp)->b_bcount, (long long)offset, (int)rv); 96 else 97 return (0); 98 } 99 100 void 101 brelse(struct buf *bp) 102 { 103 104 assert (bp != NULL); 105 assert (bp->b_data != NULL); 106 107 if (bp->b_lblkno < 0) { 108 /* 109 * XXX don't remove any buffers with negative logical block 110 * numbers (lblkno), so that we retain the mapping 111 * of negative lblkno -> real blkno that ffs_balloc() 112 * sets up. 113 * 114 * if we instead released these buffers, and implemented 115 * ufs_strategy() (and ufs_bmaparray()) and called those 116 * from bread() and bwrite() to convert the lblkno to 117 * a real blkno, we'd add a lot more code & complexity 118 * and reading off disk, for little gain, because this 119 * simple hack works for our purpose. 120 */ 121 bp->b_bcount = 0; 122 return; 123 } 124 125 TAILQ_REMOVE(&buftail, bp, b_tailq); 126 free(bp->b_data); 127 free(bp); 128 } 129 130 int 131 bwrite(struct buf *bp) 132 { 133 off_t offset; 134 ssize_t rv; 135 136 assert (bp != NULL); 137 offset = bp->b_blkno * sectorsize; /* XXX */ 138 if (debug & DEBUG_BUF_BWRITE) 139 printf("bwrite: bp %p blkno %d offset %lld bcount %ld\n", 140 bp, bp->b_blkno, (long long) offset, bp->b_bcount); 141 if (lseek(bp->b_fd, offset, SEEK_SET) == -1) 142 return (errno); 143 rv = write(bp->b_fd, bp->b_data, bp->b_bcount); 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 if (rv == bp->b_bcount) 148 return (0); 149 else if (rv == -1) /* write error */ 150 return (errno); 151 else /* short write ? */ 152 return (EAGAIN); 153 } 154 155 void 156 bcleanup(void) 157 { 158 struct buf *bp; 159 160 /* 161 * XXX this really shouldn't be necessary, but i'm curious to 162 * know why there's still some buffers lying around that 163 * aren't brelse()d 164 */ 165 166 if (TAILQ_EMPTY(&buftail)) 167 return; 168 169 printf("bcleanup: unflushed buffers:\n"); 170 TAILQ_FOREACH(bp, &buftail, b_tailq) { 171 printf("\tlblkno %10d blkno %10d count %6ld bufsize %6ld\n", 172 bp->b_lblkno, bp->b_blkno, bp->b_bcount, bp->b_bufsize); 173 } 174 printf("bcleanup: done\n"); 175 } 176 177 struct buf * 178 getblk(int fd, struct fs *fs, daddr_t blkno, int size) 179 { 180 static int buftailinitted; 181 struct buf *bp; 182 183 assert (fs != NULL); 184 if (debug & DEBUG_BUF_GETBLK) 185 printf("getblk: fs %p blkno %d size %d\n", fs, blkno, size); 186 187 bp = NULL; 188 if (!buftailinitted) { 189 if (debug & DEBUG_BUF_GETBLK) 190 printf("getblk: initialising tailq\n"); 191 TAILQ_INIT(&buftail); 192 buftailinitted = 1; 193 } else { 194 TAILQ_FOREACH(bp, &buftail, b_tailq) { 195 if (bp->b_lblkno != blkno) 196 continue; 197 break; 198 } 199 } 200 if (bp == NULL) { 201 if ((bp = calloc(1, sizeof(struct buf))) == NULL) 202 err(1, "getblk: calloc"); 203 204 bp->b_bufsize = 0; 205 bp->b_blkno = bp->b_lblkno = blkno; 206 bp->b_fd = fd; 207 bp->b_fs = 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 bp->b_bufsize = size; 214 if ((bp->b_data = realloc(bp->b_data, bp->b_bufsize)) == NULL) 215 err(1, "getblk: realloc b_data %ld", bp->b_bcount); 216 } 217 218 return (bp); 219 } 220
Indexes created Fri Sep 26 20:09:58 GMT 2025