ia64/linux-2.6.18-xen.hg

view fs/ocfs2/mmap.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * mmap.c
5 *
6 * Code to deal with the mess that is clustered mmap.
7 *
8 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
26 #include <linux/fs.h>
27 #include <linux/types.h>
28 #include <linux/slab.h>
29 #include <linux/highmem.h>
30 #include <linux/pagemap.h>
31 #include <linux/uio.h>
32 #include <linux/signal.h>
33 #include <linux/rbtree.h>
35 #define MLOG_MASK_PREFIX ML_FILE_IO
36 #include <cluster/masklog.h>
38 #include "ocfs2.h"
40 #include "dlmglue.h"
41 #include "file.h"
42 #include "inode.h"
43 #include "mmap.h"
45 static struct page *ocfs2_nopage(struct vm_area_struct * area,
46 unsigned long address,
47 int *type)
48 {
49 struct page *page = NOPAGE_SIGBUS;
50 sigset_t blocked, oldset;
51 int ret;
53 mlog_entry("(area=%p, address=%lu, type=%p)\n", area, address,
54 type);
56 /* The best way to deal with signals in this path is
57 * to block them upfront, rather than allowing the
58 * locking paths to return -ERESTARTSYS. */
59 sigfillset(&blocked);
61 /* We should technically never get a bad ret return
62 * from sigprocmask */
63 ret = sigprocmask(SIG_BLOCK, &blocked, &oldset);
64 if (ret < 0) {
65 mlog_errno(ret);
66 goto out;
67 }
69 page = filemap_nopage(area, address, type);
71 ret = sigprocmask(SIG_SETMASK, &oldset, NULL);
72 if (ret < 0)
73 mlog_errno(ret);
74 out:
75 mlog_exit_ptr(page);
76 return page;
77 }
79 static struct vm_operations_struct ocfs2_file_vm_ops = {
80 .nopage = ocfs2_nopage,
81 };
83 int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
84 {
85 /* We don't want to support shared writable mappings yet. */
86 if (((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE))
87 && ((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) {
88 mlog(0, "disallow shared writable mmaps %lx\n", vma->vm_flags);
89 /* This is -EINVAL because generic_file_readonly_mmap
90 * returns it in a similar situation. */
91 return -EINVAL;
92 }
94 file_accessed(file);
95 vma->vm_ops = &ocfs2_file_vm_ops;
96 return 0;
97 }