sys/fs/v7fs/v7fs_io.c

   1 /*      $NetBSD: v7fs_io.c,v 1.3 2013/06/28 14:49:14 christos Exp $     */
   2
   3 /*-
   4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by UCHIYAMA Yasushi.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #if HAVE_NBTOOL_CONFIG_H
  33 #include "nbtool_config.h"
  34 #endif
  35
  36 #include <sys/cdefs.h>
  37 __KERNEL_RCSID(0, "$NetBSD: v7fs_io.c,v 1.3 2013/06/28 14:49:14 christos Exp $");
  38 #if defined _KERNEL_OPT
  39 #include "opt_v7fs.h"
  40 #endif
  41
  42 #ifdef _KERNEL
  43 #include <sys/param.h>
  44 #else
  45 #include <stdio.h>
  46 #include <errno.h>
  47 #include <stdlib.h>
  48 #endif
  49
  50 #include "v7fs.h"
  51 #include "v7fs_impl.h"
  52
  53 #if defined _KERNEL
  54 #define STATIC_BUFFER
  55 #endif
  56
  57 #ifdef V7FS_IO_DEBUG
  58 #define DPRINTF(fmt, args...)   printf("%s: " fmt, __func__, ##args)
  59 #else
  60 #define DPRINTF(fmt, args...)   ((void)0)
  61 #endif
  62
  63 void *
  64 scratch_read(struct v7fs_self *fs, daddr_t blk)
  65 {
  66 #ifdef STATIC_BUFFER
  67         int i;
  68         MEM_LOCK(fs);
  69         for (i = 0; i < V7FS_SELF_NSCRATCH; i++) {
  70                 if (fs->scratch_free & (1 << i)) {
  71                         fs->scratch_free &= ~(1 << i);
  72                         break;
  73                 }
  74         }
  75         if (i == V7FS_SELF_NSCRATCH) {
  76                 DPRINTF("No scratch area. increase V7FS_SELF_NSCRATCH\n");
  77                 assert(0);
  78                 MEM_UNLOCK(fs);
  79                 return NULL;
  80         }
  81
  82         if (!fs->io.read(fs->io.cookie, fs->scratch[i], blk)) {
  83                 DPRINTF("*** I/O error block %ld\n", (long)blk);
  84                 fs->scratch_free |= (1 << i);
  85                 MEM_UNLOCK(fs);
  86                 return NULL;
  87         }
  88         MEM_UNLOCK(fs);
  89         /* Statistic */
  90         int n;
  91         if ((n = scratch_remain(fs)) < fs->scratch_remain)
  92                 fs->scratch_remain = n;
  93
  94         return fs->scratch[i];
  95 #else
  96         uint8_t *buf = malloc(V7FS_BSIZE);
  97         if (!fs->io.read(fs->io.cookie, buf, blk)) {
  98                 DPRINTF("*** I/O error block %ld\n",(long)blk);
  99                 free(buf);
 100                 return NULL;
 101         }
 102         return buf;
 103 #endif
 104 }
 105
 106 int
 107 scratch_remain(const struct v7fs_self *fs)
 108 {
 109 #ifdef STATIC_BUFFER
 110         int nfree;
 111         int i;
 112         MEM_LOCK(fs);
 113         for (i = 0, nfree = 0; i < V7FS_SELF_NSCRATCH; i++) {
 114                 if (fs->scratch_free & (1 << i)) {
 115                         nfree++;
 116                 }
 117         }
 118         MEM_UNLOCK(fs);
 119         return nfree;
 120 #else
 121         return -1;
 122 #endif
 123 }
 124
 125 void
 126 scratch_free(struct v7fs_self *fs __unused, void *p)
 127 {
 128 #ifdef STATIC_BUFFER
 129         int i;
 130         MEM_LOCK(fs);
 131         for (i = 0; i < V7FS_SELF_NSCRATCH; i++)
 132                 if (fs->scratch[i] == p) {
 133                         fs->scratch_free |= (1 << i);
 134                         break;
 135                 }
 136         MEM_UNLOCK(fs);
 137         assert(i != V7FS_SELF_NSCRATCH);
 138 #else
 139         free(p);
 140 #endif
 141 }