| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2000-2003 Silicon Graphics, Inc. All Rights Reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of version 2 of the GNU General Public License as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it would be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 11 | * |
| 12 | * Further, this software is distributed without any warranty that it is |
| 13 | * free of the rightful claim of any third person regarding infringement |
| 14 | * or the like. Any license provided herein, whether implied or |
| 15 | * otherwise, applies only to this software file. Patent licenses, if |
| 16 | * any, provided herein do not apply to combinations of this program with |
| 17 | * other software, or any other product whatsoever. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License along |
| 20 | * with this program; if not, write the Free Software Foundation, Inc., 59 |
| 21 | * Temple Place - Suite 330, Boston MA 02111-1307, USA. |
| 22 | * |
| 23 | * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, |
| 24 | * Mountain View, CA 94043, or: |
| 25 | * |
| 26 | * http://www.sgi.com |
| 27 | * |
| 28 | * For further information regarding this notice, see: |
| 29 | * |
| 30 | * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ |
| 31 | */ |
| 32 | |
| 33 | #include <xfs.h> |
| 34 | |
| 35 | /* Read from kernel buffer at src to user/kernel buffer defined |
| 36 | * by the uio structure. Advance the pointer in the uio struct |
| 37 | * as we go. |
| 38 | */ |
| 39 | int |
| 40 | uio_read(caddr_t src, size_t len, struct uio *uio) |
| 41 | { |
| 42 | size_t count; |
| 43 | |
| 44 | if (!len || !uio->uio_resid) |
| 45 | return 0; |
| 46 | |
| 47 | count = uio->uio_iov->iov_len; |
| 48 | if (!count) |
| 49 | return 0; |
| 50 | if (count > len) |
| 51 | count = len; |
| 52 | |
| 53 | if (uio->uio_segflg == UIO_USERSPACE) { |
| 54 | if (copy_to_user(uio->uio_iov->iov_base, src, count)) |
| 55 | return EFAULT; |
| 56 | } else { |
| 57 | ASSERT(uio->uio_segflg == UIO_SYSSPACE); |
| 58 | memcpy(uio->uio_iov->iov_base, src, count); |
| 59 | } |
| 60 | |
| 61 | uio->uio_iov->iov_base = (void*)((char*)uio->uio_iov->iov_base + count); |
| 62 | uio->uio_iov->iov_len -= count; |
| 63 | uio->uio_offset += count; |
| 64 | uio->uio_resid -= count; |
| 65 | return 0; |
| 66 | } |