1 /* $NetBSD: buf.c,v 1.13 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(struct vnode *vp, daddr_t blkno, int size, struct ucred *u1 __unused, 64 struct buf **bpp) 65 { 66 off_t offset; 67 ssize_t rv; 68 struct fs *fs = vp->fs; 69 70 assert (fs != NULL); 71 assert (bpp != NULL); 72 73 if (debug & DEBUG_BUF_BREAD) 74 printf("bread: fs %p blkno %lld size %d\n", 75 fs, (long long)blkno, size); 76 *bpp = getblk(vp, blkno, size, 0, 0, 0); 77 offset = (*bpp)->b_blkno * sectorsize; /* XXX */ 78 if (debug & DEBUG_BUF_BREAD) 79 printf("bread: bp %p blkno %lld offset %lld bcount %ld\n", 80 (*bpp), (long long)(*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, int u1 __unused) 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 %lld offset %lld bcount %ld\n", 139 bp, (long long)bp->b_blkno, (long long) offset, 140 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 %10lld blkno %10lld count %6ld bufsize %6ld\n", 172 (long long)bp->b_lblkno, (long long)bp->b_blkno, 173 bp->b_bcount, bp->b_bufsize); 174 } 175 printf("bcleanup: done\n"); 176 } 177 178 struct buf * 179 getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused, 180 int u2 __unused, int u3 __unused) 181 { 182 static int buftailinitted; 183 struct buf *bp; 184 void *n; 185 int fd = vp->fd; 186 struct fs *fs = vp->fs; 187 188 blkno += vp->offset; 189 assert (fs != NULL); 190 if (debug & DEBUG_BUF_GETBLK) 191 printf("getblk: fs %p blkno %lld size %d\n", fs, 192 (long long)blkno, size); 193 194 bp = NULL; 195 if (!buftailinitted) { 196 if (debug & DEBUG_BUF_GETBLK) 197 printf("getblk: initialising tailq\n"); 198 TAILQ_INIT(&buftail); 199 buftailinitted = 1; 200 } else { 201 TAILQ_FOREACH(bp, &buftail, b_tailq) { 202 if (bp->b_lblkno != blkno) 203 continue; 204 break; 205 } 206 } 207 if (bp == NULL) { 208 if ((bp = calloc(1, sizeof(struct buf))) == NULL) 209 err(1, "getblk: calloc"); 210 211 bp->b_bufsize = 0; 212 bp->b_blkno = bp->b_lblkno = blkno; 213 bp->b_fd = fd; 214 bp->b_fs = fs; 215 bp->b_data = NULL; 216 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq); 217 } 218 bp->b_bcount = size; 219 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) { 220 n = realloc(bp->b_data, size); 221 if (n == NULL) 222 err(1, "getblk: realloc b_data %ld", bp->b_bcount); 223 bp->b_data = n; 224 bp->b_bufsize = size; 225 } 226 227 return (bp); 228 } 229