freebsd-dev/lib/libufs/block.c
2011-12-08 12:31:47 +00:00

202 lines
4.9 KiB
C

/*
* Copyright (c) 2002 Juli Mallett. All rights reserved.
*
* This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
* FreeBSD project. Redistribution and use in source and binary forms, with
* or without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistribution 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 AUTHOR ``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 AUTHOR 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>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/stat.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libufs.h>
ssize_t
bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
{
void *p2;
ssize_t cnt;
ERROR(disk, NULL);
p2 = data;
/*
* XXX: various disk controllers require alignment of our buffer
* XXX: which is stricter than struct alignment.
* XXX: Bounce the buffer if not 64 byte aligned.
* XXX: this can be removed if/when the kernel is fixed
*/
if (((intptr_t)data) & 0x3f) {
p2 = malloc(size);
if (p2 == NULL) {
ERROR(disk, "allocate bounce buffer");
goto fail;
}
}
cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
if (cnt == -1) {
ERROR(disk, "read error from block device");
goto fail;
}
if (cnt == 0) {
ERROR(disk, "end of file from block device");
goto fail;
}
if ((size_t)cnt != size) {
ERROR(disk, "short read or read error from block device");
goto fail;
}
if (p2 != data) {
memcpy(data, p2, size);
free(p2);
}
return (cnt);
fail: memset(data, 0, size);
if (p2 != data) {
free(p2);
}
return (-1);
}
ssize_t
bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
{
ssize_t cnt;
int rv;
void *p2 = NULL;
ERROR(disk, NULL);
rv = ufs_disk_write(disk);
if (rv == -1) {
ERROR(disk, "failed to open disk for writing");
return (-1);
}
/*
* XXX: various disk controllers require alignment of our buffer
* XXX: which is stricter than struct alignment.
* XXX: Bounce the buffer if not 64 byte aligned.
* XXX: this can be removed if/when the kernel is fixed
*/
if (((intptr_t)data) & 0x3f) {
p2 = malloc(size);
if (p2 == NULL) {
ERROR(disk, "allocate bounce buffer");
return (-1);
}
memcpy(p2, data, size);
data = p2;
}
cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
if (p2 != NULL)
free(p2);
if (cnt == -1) {
ERROR(disk, "write error to block device");
return (-1);
}
if ((size_t)cnt != size) {
ERROR(disk, "short write to block device");
return (-1);
}
return (cnt);
}
#ifdef __FreeBSD_kernel__
static int
berase_helper(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
{
off_t ioarg[2];
ioarg[0] = blockno * disk->d_bsize;
ioarg[1] = size;
return (ioctl(disk->d_fd, DIOCGDELETE, ioarg));
}
#else
static int
berase_helper(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
{
char *zero_chunk;
off_t offset, zero_chunk_size, pwrite_size;
int rv;
offset = blockno * disk->d_bsize;
zero_chunk_size = 65536 * disk->d_bsize;
zero_chunk = calloc(1, zero_chunk_size);
if (zero_chunk == NULL) {
ERROR(disk, "failed to allocate memory");
return (-1);
}
while (size > 0) {
pwrite_size = size;
if (pwrite_size > zero_chunk_size)
pwrite_size = zero_chunk_size;
rv = pwrite(disk->d_fd, zero_chunk, pwrite_size, offset);
if (rv == -1) {
ERROR(disk, "failed writing to disk");
break;
}
size -= rv;
offset += rv;
rv = 0;
}
free(zero_chunk);
return (rv);
}
#endif
int
berase(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
{
int rv;
ERROR(disk, NULL);
rv = ufs_disk_write(disk);
if (rv == -1) {
ERROR(disk, "failed to open disk for writing");
return(rv);
}
return (berase_helper(disk, blockno, size));
}