1 /* $NetBSD: buf.c,v 1.12 2004/06/20 22:20:18 jmc 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 __FBSDID("$FreeBSD$"); 40 41 #include <sys/param.h> 42 #include <sys/time.h> 43 44 #include <assert.h> 45 #include <errno.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <unistd.h> 49 50 #include "makefs.h" 51 52 #include <ufs/ufs/dinode.h> 53 #include <ufs/ffs/fs.h> 54 55 #include "ffs/buf.h" 56 #include "ffs/ufs_inode.h" 57 58 extern int sectorsize; /* XXX: from ffs.c & mkfs.c */ 59 60 TAILQ_HEAD(buftailhead,buf) buftail; 61 62 int 63 bread(int fd, struct fs *fs, daddr_t blkno, int size, struct buf **bpp) 64 { 65 off_t offset; 66 ssize_t rv; 67 68 assert (fs != NULL); 69 assert (bpp != NULL); 70 71 if (debug & DEBUG_BUF_BREAD) 72 printf("bread: fs %p blkno %lld size %d\n", 73 fs, (long long)blkno, size); 74 *bpp = getblk(fd, fs, blkno, size); 75 offset = (*bpp)->b_blkno * sectorsize; /* XXX */ 76 if (debug & DEBUG_BUF_BREAD) 77 printf("bread: bp %p blkno %lld offset %lld bcount %ld\n", 78 (*bpp), (long long)(*bpp)->b_blkno, (long long) offset, 79 (*bpp)->b_bcount); 80 if (lseek((*bpp)->b_fd, offset, SEEK_SET) == -1) 81 err(1, "bread: lseek %lld (%lld)", 82 (long long)(*bpp)->b_blkno, (long long)offset); 83 rv = read((*bpp)->b_fd, (*bpp)->b_data, (*bpp)->b_bcount); 84 if (debug & DEBUG_BUF_BREAD) 85 printf("bread: read %ld (%lld) returned %d\n", 86 (*bpp)->b_bcount, (long long)offset, (int)rv); 87 if (rv == -1) /* read error */ 88 err(1, "bread: read %ld (%lld) returned %d", 89 (*bpp)->b_bcount, (long long)offset, (int)rv); 90 else if (rv != (*bpp)->b_bcount) /* short read */ 91 err(1, "bread: read %ld (%lld) returned %d", 92 (*bpp)->b_bcount, (long long)offset, (int)rv); 93 else 94 return (0); 95 } 96 97 void 98 brelse(struct buf *bp) 99 { 100 101 assert (bp != NULL); 102 assert (bp->b_data != NULL); 103 104 if (bp->b_lblkno < 0) { 105 /* 106 * XXX don't remove any buffers with negative logical block 107 * numbers (lblkno), so that we retain the mapping 108 * of negative lblkno -> real blkno that ffs_balloc() 109 * sets up. 110 * 111 * if we instead released these buffers, and implemented 112 * ufs_strategy() (and ufs_bmaparray()) and called those 113 * from bread() and bwrite() to convert the lblkno to 114 * a real blkno, we'd add a lot more code & complexity 115 * and reading off disk, for little gain, because this 116 * simple hack works for our purpose. 117 */ 118 bp->b_bcount = 0; 119 return; 120 } 121 122 TAILQ_REMOVE(&buftail, bp, b_tailq); 123 free(bp->b_data); 124 free(bp); 125 } 126 127 int 128 bwrite(struct buf *bp) 129 { 130 off_t offset; 131 ssize_t rv; 132 133 assert (bp != NULL); 134 offset = bp->b_blkno * sectorsize; /* XXX */ 135 if (debug & DEBUG_BUF_BWRITE) 136 printf("bwrite: bp %p blkno %lld offset %lld bcount %ld\n", 137 bp, (long long)bp->b_blkno, (long long) offset, 138 bp->b_bcount); 139 if (lseek(bp->b_fd, offset, SEEK_SET) == -1) 140 return (errno); 141 rv = write(bp->b_fd, bp->b_data, bp->b_bcount); 142 if (debug & DEBUG_BUF_BWRITE) 143 printf("bwrite: write %ld (offset %lld) returned %lld\n", 144 bp->b_bcount, (long long)offset, (long long)rv); 145 if (rv == bp->b_bcount) 146 return (0); 147 else if (rv == -1) /* write error */ 148 return (errno); 149 else /* short write ? */ 150 return (EAGAIN); 151 } 152 153 void 154 bcleanup(void) 155 { 156 struct buf *bp; 157 158 /* 159 * XXX this really shouldn't be necessary, but i'm curious to 160 * know why there's still some buffers lying around that 161 * aren't brelse()d 162 */ 163 164 if (TAILQ_EMPTY(&buftail)) 165 return; 166 167 printf("bcleanup: unflushed buffers:\n"); 168 TAILQ_FOREACH(bp, &buftail, b_tailq) { 169 printf("\tlblkno %10lld blkno %10lld count %6ld bufsize %6ld\n", 170 (long long)bp->b_lblkno, (long long)bp->b_blkno, 171 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 void *n; 182 183 assert (fs != NULL); 184 if (debug & DEBUG_BUF_GETBLK) 185 printf("getblk: fs %p blkno %lld size %d\n", fs, 186 (long long)blkno, size); 187 188 bp = NULL; 189 if (!buftailinitted) { 190 if (debug & DEBUG_BUF_GETBLK) 191 printf("getblk: initialising tailq\n"); 192 TAILQ_INIT(&buftail); 193 buftailinitted = 1; 194 } else { 195 TAILQ_FOREACH(bp, &buftail, b_tailq) { 196 if (bp->b_lblkno != blkno) 197 continue; 198 break; 199 } 200 } 201 if (bp == NULL) { 202 if ((bp = calloc(1, sizeof(struct buf))) == NULL) 203 err(1, "getblk: calloc"); 204 205 bp->b_bufsize = 0; 206 bp->b_blkno = bp->b_lblkno = blkno; 207 bp->b_fd = fd; 208 bp->b_fs = fs; 209 bp->b_data = NULL; 210 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq); 211 } 212 bp->b_bcount = size; 213 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) { 214 n = realloc(bp->b_data, size); 215 if (n == NULL) 216 err(1, "getblk: realloc b_data %ld", bp->b_bcount); 217 bp->b_data = n; 218 bp->b_bufsize = size; 219 } 220 221 return (bp); 222 } 223