usr.sbin/makefs/ffs/buf.c

   1 /*      $NetBSD: buf.c,v 1.22 2015/03/29 05:52:59 agc 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 1.22 2015/03/29 05:52:59 agc 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 #include <util.h>
  56
  57 #include "makefs.h"
  58 #include "buf.h"
  59
  60 TAILQ_HEAD(buftailhead,buf) buftail;
  61
  62 int
  63 bread(struct vnode *vp, daddr_t blkno, int size, int u2 __unused,
  64         struct buf **bpp)
  65 {
  66         off_t   offset;
  67         ssize_t rv;
  68         fsinfo_t *fs = vp->fs;
  69
  70         assert (bpp != NULL);
  71
  72         if (debug & DEBUG_BUF_BREAD)
  73                 printf("bread: blkno %lld size %d\n", (long long)blkno, size);
  74         *bpp = getblk(vp, blkno, size, 0, 0);
  75         offset = (*bpp)->b_blkno * fs->sectorsize + fs->offset;
  76         if (debug & DEBUG_BUF_BREAD)
  77                 printf("bread: blkno %lld offset %lld bcount %ld\n",
  78                     (long long)(*bpp)->b_blkno, (long long) offset,
  79                     (*bpp)->b_bcount);
  80         if (lseek((*bpp)->b_fs->fd, offset, SEEK_SET) == -1)
  81                 err(1, "%s: lseek %lld (%lld)", __func__,
  82                     (long long)(*bpp)->b_blkno, (long long)offset);
  83         rv = read((*bpp)->b_fs->fd, (*bpp)->b_data, (*bpp)->b_bcount);
  84         if (debug & DEBUG_BUF_BREAD)
  85                 printf("bread: read %ld (%lld) returned %zd\n",
  86                     (*bpp)->b_bcount, (long long)offset, rv);
  87         if (rv == -1)                           /* read error */
  88                 err(1, "%s: read %ld (%lld) returned %zd", __func__,
  89                     (*bpp)->b_bcount, (long long)offset, rv);
  90         else if (rv != (*bpp)->b_bcount)        /* short read */
  91                 err(1, "%s: read %ld (%lld) returned %zd", __func__,
  92                     (*bpp)->b_bcount, (long long)offset, rv);
  93         else
  94                 return (0);
  95 }
  96
  97 void
  98 brelse(struct buf *bp, int u1 __unused)
  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         int     bytes;
 133         fsinfo_t *fs = bp->b_fs;
 134
 135         assert (bp != NULL);
 136         offset = bp->b_blkno * fs->sectorsize + fs->offset;
 137         bytes  = bp->b_bcount;
 138         if (debug & DEBUG_BUF_BWRITE)
 139                 printf("bwrite: blkno %lld offset %lld bcount %d\n",
 140                     (long long)bp->b_blkno, (long long) offset, bytes);
 141         if (lseek(bp->b_fs->fd, offset, SEEK_SET) == -1)
 142                 return (errno);
 143         rv = write(bp->b_fs->fd, bp->b_data, bytes);
 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         brelse(bp, 0);
 148         if (rv == bytes)
 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)
 182 {
 183         static int buftailinitted;
 184         struct buf *bp;
 185         void *n;
 186
 187         if (debug & DEBUG_BUF_GETBLK)
 188                 printf("getblk: blkno %lld size %d\n", (long long)blkno, size);
 189
 190         bp = NULL;
 191         if (!buftailinitted) {
 192                 if (debug & DEBUG_BUF_GETBLK)
 193                         printf("getblk: initialising tailq\n");
 194                 TAILQ_INIT(&buftail);
 195                 buftailinitted = 1;
 196         } else {
 197                 TAILQ_FOREACH(bp, &buftail, b_tailq) {
 198                         if (bp->b_lblkno != blkno)
 199                                 continue;
 200                         break;
 201                 }
 202         }
 203         if (bp == NULL) {
 204                 bp = ecalloc(1, sizeof(*bp));
 205                 bp->b_bufsize = 0;
 206                 bp->b_blkno = bp->b_lblkno = blkno;
 207                 bp->b_fs = vp->fs;
 208                 bp->b_data = NULL;
 209                 TAILQ_INSERT_HEAD(&buftail, bp, b_tailq);
 210         }
 211         bp->b_bcount = size;
 212         if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) {
 213                 n = erealloc(bp->b_data, size);
 214                 memset(n, 0, size);
 215                 bp->b_data = n;
 216                 bp->b_bufsize = size;
 217         }
 218
 219         return (bp);
 220 }