Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 2 | * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. |
| 3 | * All Rights Reserved. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License as |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * published by the Free Software Foundation. |
| 8 | * |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 9 | * This program is distributed in the hope that it would be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | * |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write the Free Software Foundation, |
| 16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <xfs.h> |
| 19 | |
| 20 | /* Read from kernel buffer at src to user/kernel buffer defined |
| 21 | * by the uio structure. Advance the pointer in the uio struct |
| 22 | * as we go. |
| 23 | */ |
| 24 | int |
| 25 | uio_read(caddr_t src, size_t len, struct uio *uio) |
| 26 | { |
| 27 | size_t count; |
| 28 | |
| 29 | if (!len || !uio->uio_resid) |
| 30 | return 0; |
| 31 | |
| 32 | count = uio->uio_iov->iov_len; |
| 33 | if (!count) |
| 34 | return 0; |
| 35 | if (count > len) |
| 36 | count = len; |
| 37 | |
| 38 | if (uio->uio_segflg == UIO_USERSPACE) { |
| 39 | if (copy_to_user(uio->uio_iov->iov_base, src, count)) |
| 40 | return EFAULT; |
| 41 | } else { |
| 42 | ASSERT(uio->uio_segflg == UIO_SYSSPACE); |
| 43 | memcpy(uio->uio_iov->iov_base, src, count); |
| 44 | } |
| 45 | |
| 46 | uio->uio_iov->iov_base = (void*)((char*)uio->uio_iov->iov_base + count); |
| 47 | uio->uio_iov->iov_len -= count; |
| 48 | uio->uio_offset += count; |
| 49 | uio->uio_resid -= count; |
| 50 | return 0; |
| 51 | } |