buf.c revision 329099 
1/*	$NetBSD: buf.c,v 1.13 2004/06/20 22:20:18 jmc 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#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: stable/11/usr.sbin/makefs/ffs/buf.c 329099 2018-02-10 04:37:44Z kevans $");
40
41#include <sys/param.h>
42#include <sys/time.h>
43
44#include <assert.h>
45#include <errno.h>
46#include <stdio.h>
47#include <stdlib.h>
48#include <unistd.h>
49
50#include "makefs.h"
51
52#include <ufs/ufs/dinode.h>
53#include <ufs/ffs/fs.h>
54
55#include "ffs/buf.h"
56#include "ffs/ufs_inode.h"
57
58extern int sectorsize;		/* XXX: from ffs.c & mkfs.c */
59
60TAILQ_HEAD(buftailhead,buf) buftail;
61
62int
63bread(struct vnode *vp, daddr_t blkno, int size, struct ucred *u1 __unused,
64    struct buf **bpp)
65{
66	off_t	offset;
67	ssize_t	rv;
68	struct fs *fs = vp->fs;
69
70	assert (fs != NULL);
71	assert (bpp != NULL);
72
73	if (debug & DEBUG_BUF_BREAD)
74		printf("bread: fs %p blkno %lld size %d\n",
75		    fs, (long long)blkno, size);
76	*bpp = getblk(vp, blkno, size, 0, 0, 0);
77	offset = (*bpp)->b_blkno * sectorsize;	/* XXX */
78	if (debug & DEBUG_BUF_BREAD)
79		printf("bread: bp %p blkno %lld offset %lld bcount %ld\n",
80		    (*bpp), (long long)(*bpp)->b_blkno, (long long) offset,
81		    (*bpp)->b_bcount);
82	if (lseek((*bpp)->b_fd, offset, SEEK_SET) == -1)
83		err(1, "bread: lseek %lld (%lld)",
84		    (long long)(*bpp)->b_blkno, (long long)offset);
85	rv = read((*bpp)->b_fd, (*bpp)->b_data, (*bpp)->b_bcount);
86	if (debug & DEBUG_BUF_BREAD)
87		printf("bread: read %ld (%lld) returned %d\n",
88		    (*bpp)->b_bcount, (long long)offset, (int)rv);
89	if (rv == -1)				/* read error */
90		err(1, "bread: read %ld (%lld) returned %d",
91		    (*bpp)->b_bcount, (long long)offset, (int)rv);
92	else if (rv != (*bpp)->b_bcount)	/* short read */
93		err(1, "bread: read %ld (%lld) returned %d",
94		    (*bpp)->b_bcount, (long long)offset, (int)rv);
95	else
96		return (0);
97}
98
99void
100brelse(struct buf *bp, int u1 __unused)
101{
102
103	assert (bp != NULL);
104	assert (bp->b_data != NULL);
105
106	if (bp->b_lblkno < 0) {
107		/*
108		 * XXX	don't remove any buffers with negative logical block
109		 *	numbers (lblkno), so that we retain the mapping
110		 *	of negative lblkno -> real blkno that ffs_balloc()
111		 *	sets up.
112		 *
113		 *	if we instead released these buffers, and implemented
114		 *	ufs_strategy() (and ufs_bmaparray()) and called those
115		 *	from bread() and bwrite() to convert the lblkno to
116		 *	a real blkno, we'd add a lot more code & complexity
117		 *	and reading off disk, for little gain, because this
118		 *	simple hack works for our purpose.
119		 */
120		bp->b_bcount = 0;
121		return;
122	}
123
124	TAILQ_REMOVE(&buftail, bp, b_tailq);
125	free(bp->b_data);
126	free(bp);
127}
128
129int
130bwrite(struct buf *bp)
131{
132	off_t	offset;
133	ssize_t	rv;
134
135	assert (bp != NULL);
136	offset = bp->b_blkno * sectorsize;	/* XXX */
137	if (debug & DEBUG_BUF_BWRITE)
138		printf("bwrite: bp %p blkno %lld offset %lld bcount %ld\n",
139		    bp, (long long)bp->b_blkno, (long long) offset,
140		    bp->b_bcount);
141	if (lseek(bp->b_fd, offset, SEEK_SET) == -1)
142		return (errno);
143	rv = write(bp->b_fd, bp->b_data, bp->b_bcount);
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	if (rv == bp->b_bcount)
148		return (0);
149	else if (rv == -1)		/* write error */
150		return (errno);
151	else				/* short write ? */
152		return (EAGAIN);
153}
154
155void
156bcleanup(void)
157{
158	struct buf *bp;
159
160	/*
161	 * XXX	this really shouldn't be necessary, but i'm curious to
162	 *	know why there's still some buffers lying around that
163	 *	aren't brelse()d
164	 */
165
166	if (TAILQ_EMPTY(&buftail))
167		return;
168
169	printf("bcleanup: unflushed buffers:\n");
170	TAILQ_FOREACH(bp, &buftail, b_tailq) {
171		printf("\tlblkno %10lld  blkno %10lld  count %6ld  bufsize %6ld\n",
172		    (long long)bp->b_lblkno, (long long)bp->b_blkno,
173		    bp->b_bcount, bp->b_bufsize);
174	}
175	printf("bcleanup: done\n");
176}
177
178struct buf *
179getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused,
180    int u2 __unused, int u3 __unused)
181{
182	static int buftailinitted;
183	struct buf *bp;
184	void *n;
185	int fd = vp->fd;
186	struct fs *fs = vp->fs;
187
188	blkno += vp->offset;
189	assert (fs != NULL);
190	if (debug & DEBUG_BUF_GETBLK)
191		printf("getblk: fs %p blkno %lld size %d\n", fs,
192		    (long long)blkno, size);
193
194	bp = NULL;
195	if (!buftailinitted) {
196		if (debug & DEBUG_BUF_GETBLK)
197			printf("getblk: initialising tailq\n");
198		TAILQ_INIT(&buftail);
199		buftailinitted = 1;
200	} else {
201		TAILQ_FOREACH(bp, &buftail, b_tailq) {
202			if (bp->b_lblkno != blkno)
203				continue;
204			break;
205		}
206	}
207	if (bp == NULL) {
208		if ((bp = calloc(1, sizeof(struct buf))) == NULL)
209			err(1, "getblk: calloc");
210
211		bp->b_bufsize = 0;
212		bp->b_blkno = bp->b_lblkno = blkno;
213		bp->b_fd = fd;
214		bp->b_fs = fs;
215		bp->b_data = NULL;
216		TAILQ_INSERT_HEAD(&buftail, bp, b_tailq);
217	}
218	bp->b_bcount = size;
219	if (bp->b_data == NULL || bp->b_bcount > bp->b_bufsize) {
220		n = realloc(bp->b_data, size);
221		if (n == NULL)
222			err(1, "getblk: realloc b_data %ld", bp->b_bcount);
223		bp->b_data = n;
224		bp->b_bufsize = size;
225	}
226
227	return (bp);
228}
229