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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 | */ | |
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 | ||
45 | static struct page *ocfs2_nopage(struct vm_area_struct * area, | |
46 | unsigned long address, | |
47 | int *type) | |
48 | { | |
49 | struct inode *inode = area->vm_file->f_dentry->d_inode; | |
50 | struct page *page = NOPAGE_SIGBUS; | |
51 | sigset_t blocked, oldset; | |
52 | int ret; | |
53 | ||
54 | mlog_entry("(inode %lu, address %lu)\n", inode->i_ino, address); | |
55 | ||
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); | |
74 | out: | |
75 | mlog_exit_ptr(page); | |
76 | return page; | |
77 | } | |
78 | ||
79 | static struct vm_operations_struct ocfs2_file_vm_ops = { | |
80 | .nopage = ocfs2_nopage, | |
81 | }; | |
82 | ||
83 | int ocfs2_mmap(struct file *file, | |
84 | struct vm_area_struct *vma) | |
85 | { | |
86 | struct address_space *mapping = file->f_dentry->d_inode->i_mapping; | |
87 | struct inode *inode = mapping->host; | |
88 | ||
89 | /* We don't want to support shared writable mappings yet. */ | |
90 | if (((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE)) | |
91 | && ((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) { | |
92 | mlog(0, "disallow shared writable mmaps %lx\n", vma->vm_flags); | |
93 | /* This is -EINVAL because generic_file_readonly_mmap | |
94 | * returns it in a similar situation. */ | |
95 | return -EINVAL; | |
96 | } | |
97 | ||
98 | update_atime(inode); | |
99 | vma->vm_ops = &ocfs2_file_vm_ops; | |
100 | return 0; | |
101 | } | |
102 |