linux/fs/xfs/support/move.c

67 lines
2.0 KiB
C

/*
* Copyright (c) 2000-2003 Silicon Graphics, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 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.
*
* Further, this software is distributed without any warranty that it is
* free of the rightful claim of any third person regarding infringement
* or the like. Any license provided herein, whether implied or
* otherwise, applies only to this software file. Patent licenses, if
* any, provided herein do not apply to combinations of this program with
* other software, or any other product whatsoever.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
* Mountain View, CA 94043, or:
*
* http://www.sgi.com
*
* For further information regarding this notice, see:
*
* http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
*/
#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;
}