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1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
1da177e4 | 4 | * |
7b718769 NS |
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 | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
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. | |
1da177e4 | 13 | * |
7b718769 NS |
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 | |
1da177e4 | 17 | */ |
1da177e4 LT |
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 | } |