/* $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.
*/
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(__lint)
__RCSID("$NetBSD: buf.c,v 1.24 2016/06/24 19:24:11 christos Exp $");
#endif /* !__lint */
#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,buf) buftail;
int
bread(struct vnode *vp, daddr_t blkno, int size, int u2 __unused,
struct buf **bpp)
{
off_t offset;
ssize_t rv;
fsinfo_t *fs = vp->fs;
assert (bpp != NULL);
if (debug & DEBUG_BUF_BREAD)
printf("bread: blkno %lld size %d\n", (long long)blkno, size);
*bpp = getblk(vp, blkno, size, 0, 0);
offset = (*bpp)->b_blkno * fs->sectorsize + fs->offset;
if (debug & DEBUG_BUF_BREAD)
printf("bread: blkno %lld offset %lld bcount %ld\n",
(long long)(*bpp)->b_blkno, (long long) offset,
(*bpp)->b_bcount);
if (lseek((*bpp)->b_fs->fd, offset, SEEK_SET) == -1)
err(EXIT_FAILURE, "%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 (debug & DEBUG_BUF_BREAD)
printf("bread: read %ld (%lld) returned %zd\n",
(*bpp)->b_bcount, (long long)offset, rv);
if (rv == -1) /* read error */
err(EXIT_FAILURE, "%s: read %ld (%lld) returned %zd", __func__,
(*bpp)->b_bcount, (long long)offset, rv);
else if (rv != (*bpp)->b_bcount) /* short read */
errx(EXIT_FAILURE, "%s: read %ld (%lld) returned %zd", __func__,
(*bpp)->b_bcount, (long long)offset, rv);
else
return (0);
}
void
brelse(struct buf *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 buf *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 (debug & DEBUG_BUF_BWRITE)
printf("bwrite: blkno %lld offset %lld bcount %zu\n",
(long long)bp->b_blkno, (long long) offset, bytes);
if (lseek(bp->b_fs->fd, offset, SEEK_SET) == -1)
return (errno);
rv = write(bp->b_fs->fd, bp->b_data, bytes);
if (debug & DEBUG_BUF_BWRITE)
printf("bwrite: write %ld (offset %lld) returned %lld\n",
bp->b_bcount, (long long)offset, (long long)rv);
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)
{
struct buf *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");
}
struct buf *
getblk(struct vnode *vp, daddr_t blkno, int size, int u1 __unused,
int u2 __unused)
{
static int buftailinitted;
struct buf *bp;
void *n;
if (debug & DEBUG_BUF_GETBLK)
printf("getblk: blkno %lld size %d\n", (long long)blkno, size);
bp = NULL;
if (!buftailinitted) {
if (debug & DEBUG_BUF_GETBLK)
printf("getblk: initialising tailq\n");
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);
}