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v7fs_io.c revision 1.1 
      1 /*	$NetBSD: v7fs_io.c,v 1.1 2011/06/27 11:52:25 uch 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 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: v7fs_io.c,v 1.1 2011/06/27 11:52:25 uch Exp $");
     34 #if defined _KERNEL_OPT
     35 #include "opt_v7fs.h"
     36 #endif
     37 
     38 #ifdef _KERNEL
     39 #include <sys/param.h>
     40 #else
     41 #include <stdio.h>
     42 #include <errno.h>
     43 #include <stdlib.h>
     44 #endif
     45 
     46 #include "v7fs.h"
     47 #include "v7fs_impl.h"
     48 
     49 #if defined _KERNEL
     50 #define	STATIC_BUFFER
     51 #endif
     52 
     53 #ifdef V7FS_IO_DEBUG
     54 #define	DPRINTF(fmt, args...)	printf("%s: " fmt, __func__, ##args)
     55 #else
     56 #define	DPRINTF(fmt, args...)	((void)0)
     57 #endif
     58 
     59 void *
     60 scratch_read(struct v7fs_self *fs, daddr_t blk)
     61 {
     62 #ifdef STATIC_BUFFER
     63 	int i;
     64 	MEM_LOCK(fs);
     65 	for (i = 0; i < V7FS_SELF_NSCRATCH; i++) {
     66 		if (fs->scratch_free & (1 << i)) {
     67 			fs->scratch_free &= ~(1 << i);
     68 			break;
     69 		}
     70 	}
     71 	if (i == V7FS_SELF_NSCRATCH) {
     72 		DPRINTF("No scratch area. increase V7FS_SELF_NSCRATCH\n");
     73 		assert(0);
     74 		MEM_UNLOCK(fs);
     75 		return NULL;
     76 	}
     77 
     78 	if (!fs->io.read(fs->io.cookie, fs->scratch[i], blk)) {
     79 		DPRINTF("*** I/O error block %ld\n", (long)blk);
     80 		fs->scratch_free |= (1 << i);
     81 		MEM_UNLOCK(fs);
     82 		return NULL;
     83 	}
     84 	MEM_UNLOCK(fs);
     85 	/* Statistic */
     86 	int n;
     87 	if ((n = scratch_remain(fs)) < fs->scratch_remain)
     88 		fs->scratch_remain = n;
     89 
     90 	return fs->scratch[i];
     91 #else
     92 	uint8_t *buf = malloc(V7FS_BSIZE);
     93 	if (!fs->io.read(fs->io.cookie, buf, blk)) {
     94 		DPRINTF("*** I/O error block %ld\n",(long)blk);
     95 		return NULL;
     96 	}
     97 	return buf;
     98 #endif
     99 }
    100 
    101 int
    102 scratch_remain(const struct v7fs_self *fs)
    103 {
    104 #ifdef STATIC_BUFFER
    105 	int nfree;
    106 	int i;
    107 	MEM_LOCK(fs);
    108 	for (i = 0, nfree = 0; i < V7FS_SELF_NSCRATCH; i++) {
    109 		if (fs->scratch_free & (1 << i)) {
    110 			nfree++;
    111 		}
    112 	}
    113 	MEM_UNLOCK(fs);
    114 	return nfree;
    115 #else
    116 	return -1;
    117 #endif
    118 }
    119 
    120 void
    121 scratch_free(struct v7fs_self *fs __unused, void *p)
    122 {
    123 #ifdef STATIC_BUFFER
    124 	int i;
    125 	MEM_LOCK(fs);
    126 	for (i = 0; i < V7FS_SELF_NSCRATCH; i++)
    127 		if (fs->scratch[i] == p) {
    128 			fs->scratch_free |= (1 << i);
    129 			break;
    130 		}
    131 	MEM_UNLOCK(fs);
    132 	assert(i != V7FS_SELF_NSCRATCH);
    133 #else
    134 	free(p);
    135 #endif
    136 }
    137