buf.c revision 1.16
1 /* $NetBSD: buf.c,v 1.16 2013/01/28 10:16:35 mlelstv 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 #if HAVE_NBTOOL_CONFIG_H 39 #include "nbtool_config.h" 40 #endif 41 42 #include <sys/cdefs.h> 43 #if defined(__RCSID) && !defined(__lint) 44 __RCSID("$NetBSD: buf.c,v 1.16 2013/01/28 10:16:35 mlelstv Exp $"); 45 #endif /* !__lint */ 46 47 #include <sys/param.h> 48 #include <sys/time.h> 49 50 #include <assert.h> 51 #include <errno.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <unistd.h> 55 56 #include "makefs.h" 57 58 #include <ufs/ufs/dinode.h> 59 #include <ufs/ffs/fs.h> 60 61 #include "ffs/buf.h" 62 #include "ffs/ufs_inode.h" 63 64 extern int sectorsize; /* XXX: from ffs.c & mkfs.c */ 65 66 TAILQ_HEAD(buftailhead,buf) buftail; 67 68 int 69 bread(struct vnode *vp, daddr_t blkno, int size, struct kauth_cred *u1 __unused, 70 int u2 __unused, struct buf **bpp) 71 { 72 off_t offset; 73 ssize_t rv; 74 struct fs *fs = vp->fs; 75 76 assert (fs != NULL); 77 assert (bpp != NULL); 78 79 if (debug & DEBUG_BUF_BREAD) 80 printf("bread: blkno %lld size %d\n", (long long)blkno, size); 81 *bpp = getblk(vp, blkno, size, 0, 0); 82 offset = (*bpp)->b_blkno * sectorsize; /* XXX */ 83 if (debug & DEBUG_BUF_BREAD) 84 printf("bread: blkno %lld offset %lld bcount %ld\n", 85 (long long)(*bpp)->b_blkno, (long long) offset, 86 (*bpp)->b_bcount); 87 if (lseek((*bpp)->b_fd, offset, SEEK_SET) == -1) 88 err(1, "bread: lseek %lld (%lld)", 89 (long long)(*bpp)->b_blkno, (long long)offset); 90 rv = read((*bpp)->b_fd, (*bpp)->b_data, (*bpp)->b_bcount); 91 if (debug & DEBUG_BUF_BREAD) 92 printf("bread: read %ld (%lld) returned %d\n", 93 (*bpp)->b_bcount, (long long)offset, (int)rv); 94 if (rv == -1) /* read error */ 95 err(1, "bread: read %ld (%lld) returned %d", 96 (*bpp)->b_bcount, (long long)offset, (int)rv); 97 else if (rv != (*bpp)->b_bcount) /* short read */ 98 err(1, "bread: read %ld (%lld) returned %d", 99 (*bpp)->b_bcount, (long long)offset, (int)rv); 100 else 101 return (0); 102 } 103 104 void 105 brelse(struct buf *bp, int u1 __unused) 106 { 107 108 assert (bp != NULL); 109 assert (bp->b_data != NULL); 110 111 if (bp->b_lblkno < 0) { 112 /* 113 * XXX don't remove any buffers with negative logical block 114 * numbers (lblkno), so that we retain the mapping 115 * of negative lblkno -> real blkno that ffs_balloc() 116 * sets up. 117 * 118 * if we instead released these buffers, and implemented 119 * ufs_strategy() (and ufs_bmaparray()) and called those 120 * from bread() and bwrite() to convert the lblkno to 121 * a real blkno, we'd add a lot more code & complexity 122 * and reading off disk, for little gain, because this 123 * simple hack works for our purpose. 124 */ 125 bp->b_bcount = 0; 126 return; 127 } 128 129 TAILQ_REMOVE(&buftail, bp, b_tailq); 130 free(bp->b_data); 131 free(bp); 132 } 133 134 int 135 bwrite(struct buf *bp) 136 { 137 off_t offset; 138 ssize_t rv; 139 int bytes; 140 141 assert (bp != NULL); 142 offset = bp->b_blkno * sectorsize; /* XXX */ 143 bytes = bp->b_bcount; 144 if (debug & DEBUG_BUF_BWRITE) 145 printf("bwrite: blkno %lld offset %lld bcount %d\n", 146 (long long)bp->b_blkno, (long long) offset, bytes); 147 if (lseek(bp->b_fd, offset, SEEK_SET) == -1) 148 return (errno); 149 rv = write(bp->b_fd, bp->b_data, bytes); 150 if (debug & DEBUG_BUF_BWRITE) 151 printf("bwrite: write %ld (offset %lld) returned %lld\n", 152 bp->b_bcount, (long long)offset, (long long)rv); 153 brelse(bp, 0); 154 if (rv == bytes) 155 return (0); 156 else if (rv == -1) /* write error */ 157 return (errno); 158 else /* short write ? */ 159 return (EAGAIN); 160 } 161 162 void 163 bcleanup(void) 164 { 165 struct buf *bp; 166 167 /* 168 * XXX this really shouldn't be necessary, but i'm curious to 169 * know why there's still some buffers lying around that 170 * aren't brelse()d 171 */ 172 173 if (TAILQ_EMPTY(&buftail)) 174 return; 175 176 printf("bcleanup: unflushed buffers:\n"); 177 TAILQ_FOREACH(bp, &buftail, b_tailq) { 178 printf("\tlblkno %10lld blkno %10lld count %6ld bufsize %6ld\n", 179 (long long)bp->b_lblkno, (long long)bp->b_blkno, 180 bp->b_bcount, bp->b_bufsize); 181 } 182 printf("bcleanup: done\n"); 183 } 184 185 struct buf * 186 getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused, 187 int u2 __unused) 188 { 189 static int buftailinitted; 190 struct buf *bp; 191 void *n; 192 int fd = vp->fd; 193 struct fs *fs = vp->fs; 194 195 assert (fs != NULL); 196 if (debug & DEBUG_BUF_GETBLK) 197 printf("getblk: blkno %lld size %d\n", (long long)blkno, size); 198 199 bp = NULL; 200 if (!buftailinitted) { 201 if (debug & DEBUG_BUF_GETBLK) 202 printf("getblk: initialising tailq\n"); 203 TAILQ_INIT(&buftail); 204 buftailinitted = 1; 205 } else { 206 TAILQ_FOREACH(bp, &buftail, b_tailq) { 207 if (bp->b_lblkno != blkno) 208 continue; 209 break; 210 } 211 } 212 if (bp == NULL) { 213 if ((bp = calloc(1, sizeof(struct buf))) == NULL) 214 err(1, "getblk: calloc"); 215 216 bp->b_bufsize = 0; 217 bp->b_blkno = bp->b_lblkno = blkno; 218 bp->b_fd = fd; 219 bp->b_fs = fs; 220 bp->b_data = NULL; 221 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq); 222 } 223 bp->b_bcount = size; 224 if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) { 225 n = realloc(bp->b_data, size); 226 if (n == NULL) 227 err(1, "getblk: realloc b_data %ld", bp->b_bcount); 228 memset(n, 0, size); 229 bp->b_data = n; 230 bp->b_bufsize = size; 231 } 232 233 return (bp); 234 } 235
Indexes created Fri Oct 03 02:09:57 GMT 2025