xref: /netbsd-src/sys/fs/v7fs/v7fs_io.c (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
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