52 строки
1.5 KiB
C
52 строки
1.5 KiB
C
/*
|
|
* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
|
|
* All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it would be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write the Free Software Foundation,
|
|
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
#include <xfs.h>
|
|
|
|
/* Read from kernel buffer at src to user/kernel buffer defined
|
|
* by the uio structure. Advance the pointer in the uio struct
|
|
* as we go.
|
|
*/
|
|
int
|
|
uio_read(caddr_t src, size_t len, struct uio *uio)
|
|
{
|
|
size_t count;
|
|
|
|
if (!len || !uio->uio_resid)
|
|
return 0;
|
|
|
|
count = uio->uio_iov->iov_len;
|
|
if (!count)
|
|
return 0;
|
|
if (count > len)
|
|
count = len;
|
|
|
|
if (uio->uio_segflg == UIO_USERSPACE) {
|
|
if (copy_to_user(uio->uio_iov->iov_base, src, count))
|
|
return EFAULT;
|
|
} else {
|
|
ASSERT(uio->uio_segflg == UIO_SYSSPACE);
|
|
memcpy(uio->uio_iov->iov_base, src, count);
|
|
}
|
|
|
|
uio->uio_iov->iov_base = (void*)((char*)uio->uio_iov->iov_base + count);
|
|
uio->uio_iov->iov_len -= count;
|
|
uio->uio_offset += count;
|
|
uio->uio_resid -= count;
|
|
return 0;
|
|
}
|