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 <string.h> 49 #include <unistd.h> 50 51 #include "makefs.h" 52 53 #include <ufs/ufs/dinode.h> 54 #include <ufs/ffs/fs.h> 55 56 #include "ffs/buf.h" 57 #include "ffs/ufs_inode.h" 58 59 extern int sectorsize; /* XXX: from ffs.c & mkfs.c */ 60 61 TAILQ_HEAD(buftailhead,buf) buftail; 62 63 int 64 bread(struct vnode *vp, daddr_t blkno, int size, struct ucred *u1 __unused, 65 struct buf **bpp) 66 { 67 off_t offset; 68 ssize_t rv; 69 struct fs *fs = vp->fs; 70 71 assert (fs != NULL); 72 assert (bpp != NULL); 73 74 if (debug & DEBUG_BUF_BREAD) 75 printf("%s: blkno %lld size %d\n", __func__, (long long)blkno, 76 size); 77 *bpp = getblk(vp, blkno, size, 0, 0, 0); 78 offset = (*bpp)->b_blkno * sectorsize; /* XXX */ 79 if (debug & DEBUG_BUF_BREAD) 80 printf("%s: blkno %lld offset %lld bcount %ld\n", __func__, 81 (long long)(*bpp)->b_blkno, (long long) offset, 82 (*bpp)->b_bcount); 83 if (lseek((*bpp)->b_fd, offset, SEEK_SET) == -1) 84 err(1, "%s: lseek %lld (%lld)", __func__, 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("%s: read %ld (%lld) returned %d\n", __func__, 89 (*bpp)->b_bcount, (long long)offset, (int)rv); 90 if (rv == -1) /* read error */ 91 err(1, "%s: read %ld (%lld) returned %d", __func__, 92 (*bpp)->b_bcount, (long long)offset, (int)rv); 93 else if (rv != (*bpp)->b_bcount) /* short read */ 94 err(1, "%s: read %ld (%lld) returned %d", __func__, 95 (*bpp)->b_bcount, (long long)offset, (int)rv); 96 else 97 return (0); 98 } 99 100 void 101 brelse(struct buf *bp, int u1 __unused) 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: blkno %lld offset %lld bcount %ld\n", 140 (long long)bp->b_blkno, (long long) offset, 141 bp->b_bcount); 142 if (lseek(bp->b_fd, offset, SEEK_SET) == -1) 143 return (errno); 144 rv = write(bp->b_fd, bp->b_data, bp->b_bcount); 145 if (debug & DEBUG_BUF_BWRITE) 146 printf("bwrite: write %ld (offset %lld) returned %lld\n", 147 bp->b_bcount, (long long)offset, (long long)rv); 148 if (rv == bp->b_bcount) 149 return (0); 150 else if (rv == -1) /* write error */ 151 return (errno); 152 else /* short write ? */ 153 return (EAGAIN); 154 } 155 156 void 157 bcleanup(void) 158 { 159 struct buf *bp; 160 161 /* 162 * XXX this really shouldn't be necessary, but i'm curious to 163 * know why there's still some buffers lying around that 164 * aren't brelse()d 165 */ 166 167 if (TAILQ_EMPTY(&buftail)) 168 return; 169 170 printf("bcleanup: unflushed buffers:\n"); 171 TAILQ_FOREACH(bp, &buftail, b_tailq) { 172 printf("\tlblkno %10lld blkno %10lld count %6ld bufsize %6ld\n", 173 (long long)bp->b_lblkno, (long long)bp->b_blkno, 174 bp->b_bcount, bp->b_bufsize); 175 } 176 printf("bcleanup: done\n"); 177 } 178 179 struct buf * 180 getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused, 181 int u2 __unused, int u3 __unused) 182 { 183 static int buftailinitted; 184 struct buf *bp; 185 void *n; 186 int fd = vp->fd; 187 struct fs *fs = vp->fs; 188 189 blkno += vp->offset; 190 assert (fs != NULL); 191 if (debug & DEBUG_BUF_GETBLK) 192 printf("getblk: blkno %lld size %d\n", (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 memset(n, 0, size); 224 bp->b_data = n; 225 bp->b_bufsize = size; 226 } 227 228 return (bp); 229 } 230