NetBSD/sys/fs/sysvbfs/bfs_sysvbfs.c
hannken 5d2bff060a Make sure all cached buffers with valid, not yet written data have been
run through copy-on-write.  Call fscow_run() with valid data where possible.

The LP_UFSCOW hack is no longer needed to protect ffs_copyonwrite() against
endless recursion.

- Add a flag B_MODIFY to bread(), breada() and breadn().  If set the caller
  intends to modify the buffer returned.

- Always run copy-on-write on buffers returned from ffs_balloc().

- Add new function ffs_getblk() that gets a buffer, assigns a new blkno,
  may clear the buffer and runs copy-on-write.  Process possible errors
  from getblk() or fscow_run().  Part of PR kern/38664.

Welcome to 4.99.63

Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>
2008-05-16 09:21:59 +00:00

158 lines
3.9 KiB
C

/* $NetBSD: bfs_sysvbfs.c,v 1.10 2008/05/16 09:21:59 hannken Exp $ */
/*-
* Copyright (c) 2004 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by UCHIYAMA Yasushi.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 THE FOUNDATION OR CONTRIBUTORS
* 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: bfs_sysvbfs.c,v 1.10 2008/05/16 09:21:59 hannken Exp $");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/kauth.h>
#include <fs/sysvbfs/bfs.h>
struct bc_io_ops {
struct sector_io_ops io;
struct vnode *vp;
kauth_cred_t cred;
};
#define STATIC
STATIC bool bc_read_n(void *, uint8_t *, daddr_t, int);
STATIC bool bc_read(void *, uint8_t *, daddr_t);
STATIC bool bc_write_n(void *, uint8_t *, daddr_t, int);
STATIC bool bc_write(void *, uint8_t *, daddr_t);
int
sysvbfs_bfs_init(struct bfs **bfsp, struct vnode *vp)
{
struct bc_io_ops *bio;
if ((bio = malloc(sizeof(*bio), M_TEMP, M_WAITOK | M_ZERO)) == NULL) {
printf("can't allocate I/O ops.\n");
return ENOMEM;
}
bio->io.read = bc_read;
bio->io.read_n = bc_read_n;
bio->io.write = bc_write;
bio->io.write_n = bc_write_n;
bio->vp = vp;
bio->cred = NOCRED; /* sysvbfs layer check cred. */
return bfs_init2(bfsp, 0, (struct sector_io_ops *)bio, false);
}
void
sysvbfs_bfs_fini(struct bfs *bfs)
{
free(bfs->io, M_TEMP);
bfs_fini(bfs);
}
STATIC bool
bc_read_n(void *self, uint8_t *buf, daddr_t block, int count)
{
int i;
for (i = 0; i < count; i++) {
if (!bc_read(self, buf, block))
return false;
buf += DEV_BSIZE;
block++;
}
return true;
}
STATIC bool
bc_read(void *self, uint8_t *buf, daddr_t block)
{
struct bc_io_ops *bio = self;
struct buf *bp = NULL;
if (bread(bio->vp, block, DEV_BSIZE, bio->cred, 0, &bp) != 0)
goto error_exit;
memcpy(buf, bp->b_data, DEV_BSIZE);
brelse(bp, 0);
return true;
error_exit:
printf("%s: block %lld read failed.\n", __func__,
(long long int)block);
if (bp != NULL)
brelse(bp, 0);
return false;
}
STATIC bool
bc_write_n(void *self, uint8_t *buf, daddr_t block, int count)
{
int i;
for (i = 0; i < count; i++) {
if (!bc_write(self, buf, block))
return false;
buf += DEV_BSIZE;
block++;
}
return true;
}
STATIC bool
bc_write(void *self, uint8_t *buf, daddr_t block)
{
struct bc_io_ops *bio = self;
struct buf *bp;
#if 0
printf("%s: block=%lld\n", __func__, block);
#endif
if ((bp = getblk(bio->vp, block, DEV_BSIZE, 0, 0)) == 0) {
printf("getblk failed.\n");
return false;
}
memcpy(bp->b_data, buf, DEV_BSIZE);
if (bwrite(bp) != 0) {
printf("bwrite failed.\n");
return false;
}
return true;
}