buf.c revision 1.1
1 /* $NetBSD: buf.c,v 1.1 2001/10/26 06:20:18 lukem Exp $ */ 2 3 /* 4 * Copyright 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/param.h> 39 #include <sys/time.h> 40 41 #include <assert.h> 42 #include <err.h> 43 #include <errno.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <unistd.h> 47 48 #include <ufs/ufs/inode.h> 49 #include <ufs/ffs/fs.h> 50 51 #include "makefs.h" 52 53 #include "ffs/buf.h" 54 55 extern int sectorsize; /* XXX: from ffs.c & mkfs.c */ 56 57 TAILQ_HEAD(buftailhead,buf) buftail; 58 59 int 60 bread(int fd, struct fs *fs, daddr_t blkno, int size, struct buf **bpp) 61 { 62 off_t offset; 63 ssize_t rv; 64 65 assert (fs != NULL); 66 assert (bpp != NULL); 67 68 if (debug & DEBUG_BUF_BREAD) 69 printf("bread: fs %p blkno %d size %d\n", 70 fs, blkno, size); 71 *bpp = getblk(fd, fs, blkno, size); 72 offset = (*bpp)->b_blkno * sectorsize; /* XXX */ 73 if (debug & DEBUG_BUF_BREAD) 74 printf("bread: bp %p blkno %d offset %lld bcount %ld\n", 75 (*bpp), (*bpp)->b_blkno, (long long) offset, 76 (*bpp)->b_bcount); 77 if (lseek((*bpp)->b_fd, offset, SEEK_SET) == -1) 78 err(1, "bread: lseek %lld (%lld)", 79 (long long)(*bpp)->b_blkno, (long long)offset); 80 rv = read((*bpp)->b_fd, (*bpp)->b_data, (*bpp)->b_bcount); 81 if (debug & DEBUG_BUF_BREAD) 82 printf("bread: read %ld (%lld) returned %d\n", 83 (*bpp)->b_bcount, (long long)offset, (int)rv); 84 if (rv == -1) /* read error */ 85 err(1, "bread: read %ld (%lld) returned %d", 86 (*bpp)->b_bcount, (long long)offset, (int)rv); 87 else if (rv != (*bpp)->b_bcount) /* short read */ 88 err(1, "bread: read %ld (%lld) returned %d", 89 (*bpp)->b_bcount, (long long)offset, (int)rv); 90 else 91 return (0); 92 } 93 94 void 95 brelse(struct buf *bp) 96 { 97 98 assert (bp != NULL); 99 assert (bp->b_data != NULL); 100 101 if (bp->b_lblkno < 0) { 102 /* 103 * XXX don't remove any buffers with negative logical block 104 * numbers (lblkno), so that we retain the mapping 105 * of negative lblkno -> real blkno that ffs_balloc() 106 * sets up. 107 * 108 * if we instead released these buffers, and implemented 109 * ufs_strategy() (and ufs_bmaparray()) and called those 110 * from bread() and bwrite() to convert the lblkno to 111 * a real blkno, we'd add a lot more code & complexity 112 * and reading off disk, for little gain, because this 113 * simple hack works for our purpose. 114 */ 115 bp->b_bcount = 0; 116 return; 117 } 118 119 TAILQ_REMOVE(&buftail, bp, b_tailq); 120 free(bp->b_data); 121 free(bp); 122 } 123 124 int 125 bwrite(struct buf *bp) 126 { 127 off_t offset; 128 ssize_t rv; 129 130 assert (bp != NULL); 131 offset = bp->b_blkno * sectorsize; /* XXX */ 132 if (debug & DEBUG_BUF_BWRITE) 133 printf("bwrite: bp %p blkno %d offset %lld bcount %ld\n", 134 bp, bp->b_blkno, (long long) offset, bp->b_bcount); 135 if (lseek(bp->b_fd, offset, SEEK_SET) == -1) 136 return (errno); 137 rv = write(bp->b_fd, bp->b_data, bp->b_bcount); 138 if (debug & DEBUG_BUF_BWRITE) 139 printf("bwrite: write %ld (offset %lld) returned %lld\n", 140 bp->b_bcount, (long long)offset, (long long)rv); 141 if (rv == bp->b_bcount) 142 return (0); 143 else if (rv == -1) /* write error */ 144 return (errno); 145 else /* short write ? */ 146 return (EAGAIN); 147 } 148 149 void 150 bcleanup(void) 151 { 152 struct buf *bp; 153 154 /* 155 * XXX this really shouldn't be necessary, but i'm curious to 156 * know why there's still some buffers lying around that 157 * aren't brelse()d 158 */ 159 160 if (TAILQ_EMPTY(&buftail)) 161 return; 162 163 printf("bcleanup: unflushed buffers:\n"); 164 TAILQ_FOREACH(bp, &buftail, b_tailq) { 165 printf("\tlblkno %10d blkno %10d count %6ld bufsize %6ld\n", 166 bp->b_lblkno, bp->b_blkno, bp->b_bcount, bp->b_bufsize); 167 } 168 printf("bcleanup: done\n"); 169 } 170 171 struct buf * 172 getblk(int fd, struct fs *fs, daddr_t blkno, int size) 173 { 174 static int buftailinitted; 175 struct buf *bp; 176 177 assert (fs != NULL); 178 if (debug & DEBUG_BUF_GETBLK) 179 printf("getblk: fs %p blkno %d size %d\n", fs, blkno, size); 180 181 bp = NULL; 182 if (!buftailinitted) { 183 if (debug & DEBUG_BUF_GETBLK) 184 printf("getblk: initialising tailq\n"); 185 TAILQ_INIT(&buftail); 186 buftailinitted = 1; 187 } else { 188 TAILQ_FOREACH(bp, &buftail, b_tailq) { 189 if (bp->b_lblkno != blkno) 190 continue; 191 break; 192 } 193 } 194 if (bp == NULL) { 195 if ((bp = calloc(1, sizeof(struct buf))) == NULL) 196 err(1, "getblk: calloc"); 197 198 bp->b_bufsize = 0; 199 bp->b_blkno = bp->b_lblkno = blkno; 200 bp->b_fd = fd; 201 bp->b_fs = fs; 202 bp->b_data = NULL; 203 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq); 204 } 205 bp->b_bcount = size; 206 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) { 207 bp->b_bufsize = size; 208 if ((bp->b_data = realloc(bp->b_data, bp->b_bufsize)) == NULL) 209 err(1, "getblk: realloc b_data %ld", bp->b_bcount); 210 } 211 212 return (bp); 213 } 214
Indexes created Fri Sep 26 20:09:58 GMT 2025