blob: af01158b39f553fd7f04f7970ce0a88d4293953c [file] [log] [blame]
Mark Fashehccd979b2005-12-15 14:31:24 -08001/* -*- 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 */
25
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>
34
35#define MLOG_MASK_PREFIX ML_FILE_IO
36#include <cluster/masklog.h>
37
38#include "ocfs2.h"
39
40#include "dlmglue.h"
41#include "file.h"
42#include "inode.h"
43#include "mmap.h"
44
45static struct page *ocfs2_nopage(struct vm_area_struct * area,
46 unsigned long address,
47 int *type)
48{
Mark Fashehccd979b2005-12-15 14:31:24 -080049 struct page *page = NOPAGE_SIGBUS;
50 sigset_t blocked, oldset;
51 int ret;
52
Joel Becker2b388c62006-05-10 18:28:59 -070053 mlog_entry("(area=%p, address=%lu, type=%p)\n", area, address,
54 type);
Mark Fashehccd979b2005-12-15 14:31:24 -080055
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);
60
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 }
68
69 page = filemap_nopage(area, address, type);
70
71 ret = sigprocmask(SIG_SETMASK, &oldset, NULL);
72 if (ret < 0)
73 mlog_errno(ret);
74out:
75 mlog_exit_ptr(page);
76 return page;
77}
78
79static struct vm_operations_struct ocfs2_file_vm_ops = {
80 .nopage = ocfs2_nopage,
81};
82
Christoph Hellwig870f4812006-01-09 20:52:01 -080083int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
Mark Fashehccd979b2005-12-15 14:31:24 -080084{
Tiger Yang25899de2006-11-15 15:49:02 +080085 int ret = 0, lock_level = 0;
Sunil Mushranc271c5c2006-12-05 17:56:35 -080086 struct ocfs2_super *osb = OCFS2_SB(file->f_dentry->d_inode->i_sb);
Tiger Yang25899de2006-11-15 15:49:02 +080087
Mark Fasheh89488982007-01-17 13:10:55 -080088 /*
89 * Only support shared writeable mmap for local mounts which
90 * don't know about holes.
91 */
92 if ((!ocfs2_mount_local(osb) || ocfs2_sparse_alloc(osb)) &&
Sunil Mushranc271c5c2006-12-05 17:56:35 -080093 ((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE)) &&
94 ((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) {
Mark Fashehccd979b2005-12-15 14:31:24 -080095 mlog(0, "disallow shared writable mmaps %lx\n", vma->vm_flags);
96 /* This is -EINVAL because generic_file_readonly_mmap
97 * returns it in a similar situation. */
98 return -EINVAL;
99 }
100
Tiger Yang25899de2006-11-15 15:49:02 +0800101 ret = ocfs2_meta_lock_atime(file->f_dentry->d_inode,
102 file->f_vfsmnt, &lock_level);
103 if (ret < 0) {
104 mlog_errno(ret);
105 goto out;
106 }
107 ocfs2_meta_unlock(file->f_dentry->d_inode, lock_level);
108out:
Mark Fashehccd979b2005-12-15 14:31:24 -0800109 vma->vm_ops = &ocfs2_file_vm_ops;
110 return 0;
111}
112