summaryrefslogtreecommitdiffstats
path: root/usr.sbin/makefs/ffs/buf.c
blob: c6ee039d38cca69dc6c0326034b15e18bbe383cb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/*	$OpenBSD: buf.c,v 1.5 2016/10/26 15:31:13 natano Exp $	*/
/*	$NetBSD: buf.c,v 1.24 2016/06/24 19:24:11 christos Exp $	*/

/*
 * Copyright (c) 2001 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Luke Mewburn for Wasabi Systems, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed for the NetBSD Project by
 *      Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/time.h>

#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <util.h>

#include "makefs.h"
#include "buf.h"

TAILQ_HEAD(buftailhead,mkfsbuf) buftail;

int
bread(struct mkfsvnode *vp, daddr_t blkno, int size, int u2 __unused,
	struct mkfsbuf **bpp)
{
	off_t	offset;
	ssize_t	rv;
	fsinfo_t *fs = vp->fs;

	assert (bpp != NULL);

	*bpp = getblk(vp, blkno, size, 0, 0);
	offset = (*bpp)->b_blkno * fs->sectorsize + fs->offset;
	if (lseek((*bpp)->b_fs->fd, offset, SEEK_SET) == -1)
		err(1, "%s: lseek %lld (%lld)", __func__,
		    (long long)(*bpp)->b_blkno, (long long)offset);
	rv = read((*bpp)->b_fs->fd, (*bpp)->b_data, (size_t)(*bpp)->b_bcount);
	if (rv == -1)				/* read error */
		err(1, "%s: read %ld (%lld) returned %zd", __func__,
		    (*bpp)->b_bcount, (long long)offset, rv);
	else if (rv != (*bpp)->b_bcount)	/* short read */
		errx(1, "%s: read %ld (%lld) returned %zd", __func__,
		    (*bpp)->b_bcount, (long long)offset, rv);
	else
		return (0);
}

void
brelse(struct mkfsbuf *bp, int u1 __unused)
{

	assert (bp != NULL);
	assert (bp->b_data != NULL);

	if (bp->b_lblkno < 0) {
		/*
		 * XXX	don't remove any buffers with negative logical block
		 *	numbers (lblkno), so that we retain the mapping
		 *	of negative lblkno -> real blkno that ffs_balloc()
		 *	sets up.
		 *
		 *	if we instead released these buffers, and implemented
		 *	ufs_strategy() (and ufs_bmaparray()) and called those
		 *	from bread() and bwrite() to convert the lblkno to
		 *	a real blkno, we'd add a lot more code & complexity
		 *	and reading off disk, for little gain, because this
		 *	simple hack works for our purpose.
		 */
		bp->b_bcount = 0;
		return;
	}
		
	TAILQ_REMOVE(&buftail, bp, b_tailq);
	free(bp->b_data);
	free(bp);
}

int
bwrite(struct mkfsbuf *bp)
{
	off_t	offset;
	ssize_t	rv;
	size_t	bytes;
	fsinfo_t *fs = bp->b_fs;

	assert (bp != NULL);
	offset = bp->b_blkno * fs->sectorsize + fs->offset;
	bytes  = (size_t)bp->b_bcount;
	if (lseek(bp->b_fs->fd, offset, SEEK_SET) == -1)
		return (errno);
	rv = write(bp->b_fs->fd, bp->b_data, bytes);
	brelse(bp, 0);
	if (rv == (ssize_t)bytes)
		return (0);
	else if (rv == -1)		/* write error */
		return (errno);
	else				/* short write ? */
		return (EAGAIN);
}

void
bcleanup(void)
{
#if DEBUG_BUFFERS
	struct mkfsbuf *bp;

	/*
	 * XXX	this really shouldn't be necessary, but i'm curious to
	 *	know why there's still some buffers lying around that
	 *	aren't brelse()d
	 */
	
	if (TAILQ_EMPTY(&buftail))
		return;

	printf("bcleanup: unflushed buffers:\n");
	TAILQ_FOREACH(bp, &buftail, b_tailq) {
		printf("\tlblkno %10lld  blkno %10lld  count %6ld  bufsize %6ld\n",
		    (long long)bp->b_lblkno, (long long)bp->b_blkno,
		    bp->b_bcount, bp->b_bufsize);
	}
	printf("bcleanup: done\n");
#endif
}

struct mkfsbuf *
getblk(struct mkfsvnode *vp, daddr_t blkno, int size, int u1 __unused,
    int u2 __unused)
{
	static int buftailinitted;
	struct mkfsbuf *bp;
	void *n;

	bp = NULL;
	if (!buftailinitted) {
		TAILQ_INIT(&buftail);
		buftailinitted = 1;
	} else {
		TAILQ_FOREACH(bp, &buftail, b_tailq) {
			if (bp->b_lblkno != blkno)
				continue;
			break;
		}
	}
	if (bp == NULL) {
		bp = ecalloc(1, sizeof(*bp));
		bp->b_bufsize = 0;
		bp->b_blkno = bp->b_lblkno = blkno;
		bp->b_fs = vp->fs;
		bp->b_data = NULL;
		TAILQ_INSERT_HEAD(&buftail, bp, b_tailq);
	}
	bp->b_bcount = size;
	if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) {
		n = erealloc(bp->b_data, (size_t)size);
		memset(n, 0, (size_t)size);
		bp->b_data = n;
		bp->b_bufsize = size;
	}

	return (bp);
}