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ccd979bd MF |
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> | |
ccd979bd MF |
28 | #include <linux/highmem.h> |
29 | #include <linux/pagemap.h> | |
30 | #include <linux/uio.h> | |
31 | #include <linux/signal.h> | |
32 | #include <linux/rbtree.h> | |
33 | ||
ccd979bd MF |
34 | #include <cluster/masklog.h> |
35 | ||
36 | #include "ocfs2.h" | |
37 | ||
7307de80 | 38 | #include "aops.h" |
ccd979bd MF |
39 | #include "dlmglue.h" |
40 | #include "file.h" | |
41 | #include "inode.h" | |
42 | #include "mmap.h" | |
e4b963f1 | 43 | #include "super.h" |
614a9e84 | 44 | #include "ocfs2_trace.h" |
ccd979bd | 45 | |
7307de80 | 46 | |
d0217ac0 | 47 | static int ocfs2_fault(struct vm_area_struct *area, struct vm_fault *vmf) |
ccd979bd | 48 | { |
e4b963f1 JB |
49 | sigset_t oldset; |
50 | int ret; | |
ccd979bd | 51 | |
e4b963f1 | 52 | ocfs2_block_signals(&oldset); |
d0217ac0 | 53 | ret = filemap_fault(area, vmf); |
e4b963f1 | 54 | ocfs2_unblock_signals(&oldset); |
ccd979bd | 55 | |
614a9e84 TM |
56 | trace_ocfs2_fault(OCFS2_I(area->vm_file->f_mapping->host)->ip_blkno, |
57 | area, vmf->page, vmf->pgoff); | |
d0217ac0 | 58 | return ret; |
ccd979bd MF |
59 | } |
60 | ||
0378da0f | 61 | static int __ocfs2_page_mkwrite(struct file *file, struct buffer_head *di_bh, |
7307de80 MF |
62 | struct page *page) |
63 | { | |
64 | int ret; | |
0378da0f | 65 | struct inode *inode = file->f_path.dentry->d_inode; |
7307de80 | 66 | struct address_space *mapping = inode->i_mapping; |
18336338 | 67 | loff_t pos = page_offset(page); |
7307de80 MF |
68 | unsigned int len = PAGE_CACHE_SIZE; |
69 | pgoff_t last_index; | |
70 | struct page *locked_page = NULL; | |
71 | void *fsdata; | |
72 | loff_t size = i_size_read(inode); | |
ccd979bd | 73 | |
7307de80 MF |
74 | /* |
75 | * Another node might have truncated while we were waiting on | |
76 | * cluster locks. | |
f63afdb2 TM |
77 | * We don't check size == 0 before the shift. This is borrowed |
78 | * from do_generic_file_read. | |
7307de80 | 79 | */ |
f63afdb2 TM |
80 | last_index = (size - 1) >> PAGE_CACHE_SHIFT; |
81 | if (unlikely(!size || page->index > last_index)) { | |
7307de80 MF |
82 | ret = -EINVAL; |
83 | goto out; | |
84 | } | |
85 | ||
86 | /* | |
87 | * The i_size check above doesn't catch the case where nodes | |
88 | * truncated and then re-extended the file. We'll re-check the | |
89 | * page mapping after taking the page lock inside of | |
90 | * ocfs2_write_begin_nolock(). | |
91 | */ | |
92 | if (!PageUptodate(page) || page->mapping != inode->i_mapping) { | |
4c1bbf1b TM |
93 | /* |
94 | * the page has been umapped in ocfs2_data_downconvert_worker. | |
95 | * So return 0 here and let VFS retry. | |
96 | */ | |
97 | ret = 0; | |
7307de80 MF |
98 | goto out; |
99 | } | |
100 | ||
101 | /* | |
102 | * Call ocfs2_write_begin() and ocfs2_write_end() to take | |
103 | * advantage of the allocation code there. We pass a write | |
104 | * length of the whole page (chopped to i_size) to make sure | |
105 | * the whole thing is allocated. | |
106 | * | |
107 | * Since we know the page is up to date, we don't have to | |
108 | * worry about ocfs2_write_begin() skipping some buffer reads | |
109 | * because the "write" would invalidate their data. | |
110 | */ | |
111 | if (page->index == last_index) | |
f63afdb2 | 112 | len = ((size - 1) & ~PAGE_CACHE_MASK) + 1; |
7307de80 | 113 | |
0378da0f | 114 | ret = ocfs2_write_begin_nolock(file, mapping, pos, len, 0, &locked_page, |
7307de80 MF |
115 | &fsdata, di_bh, page); |
116 | if (ret) { | |
117 | if (ret != -ENOSPC) | |
118 | mlog_errno(ret); | |
119 | goto out; | |
120 | } | |
121 | ||
122 | ret = ocfs2_write_end_nolock(mapping, pos, len, len, locked_page, | |
123 | fsdata); | |
124 | if (ret < 0) { | |
125 | mlog_errno(ret); | |
126 | goto out; | |
127 | } | |
128 | BUG_ON(ret != len); | |
129 | ret = 0; | |
130 | out: | |
131 | return ret; | |
132 | } | |
133 | ||
c2ec175c | 134 | static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
ccd979bd | 135 | { |
c2ec175c | 136 | struct page *page = vmf->page; |
7307de80 MF |
137 | struct inode *inode = vma->vm_file->f_path.dentry->d_inode; |
138 | struct buffer_head *di_bh = NULL; | |
e4b963f1 JB |
139 | sigset_t oldset; |
140 | int ret; | |
7307de80 | 141 | |
e4b963f1 | 142 | ocfs2_block_signals(&oldset); |
7307de80 MF |
143 | |
144 | /* | |
145 | * The cluster locks taken will block a truncate from another | |
146 | * node. Taking the data lock will also ensure that we don't | |
147 | * attempt page truncation as part of a downconvert. | |
148 | */ | |
e63aecb6 | 149 | ret = ocfs2_inode_lock(inode, &di_bh, 1); |
7307de80 MF |
150 | if (ret < 0) { |
151 | mlog_errno(ret); | |
152 | goto out; | |
153 | } | |
25899dee | 154 | |
89488984 | 155 | /* |
7307de80 MF |
156 | * The alloc sem should be enough to serialize with |
157 | * ocfs2_truncate_file() changing i_size as well as any thread | |
158 | * modifying the inode btree. | |
89488984 | 159 | */ |
7307de80 MF |
160 | down_write(&OCFS2_I(inode)->ip_alloc_sem); |
161 | ||
0378da0f | 162 | ret = __ocfs2_page_mkwrite(vma->vm_file, di_bh, page); |
7307de80 | 163 | |
7307de80 MF |
164 | up_write(&OCFS2_I(inode)->ip_alloc_sem); |
165 | ||
166 | brelse(di_bh); | |
e63aecb6 | 167 | ocfs2_inode_unlock(inode, 1); |
7307de80 MF |
168 | |
169 | out: | |
e4b963f1 | 170 | ocfs2_unblock_signals(&oldset); |
c2ec175c NP |
171 | if (ret) |
172 | ret = VM_FAULT_SIGBUS; | |
7307de80 MF |
173 | return ret; |
174 | } | |
175 | ||
f0f37e2f | 176 | static const struct vm_operations_struct ocfs2_file_vm_ops = { |
54cb8821 | 177 | .fault = ocfs2_fault, |
7307de80 MF |
178 | .page_mkwrite = ocfs2_page_mkwrite, |
179 | }; | |
180 | ||
181 | int ocfs2_mmap(struct file *file, struct vm_area_struct *vma) | |
182 | { | |
183 | int ret = 0, lock_level = 0; | |
184 | ||
e63aecb6 | 185 | ret = ocfs2_inode_lock_atime(file->f_dentry->d_inode, |
25899dee TY |
186 | file->f_vfsmnt, &lock_level); |
187 | if (ret < 0) { | |
188 | mlog_errno(ret); | |
189 | goto out; | |
190 | } | |
e63aecb6 | 191 | ocfs2_inode_unlock(file->f_dentry->d_inode, lock_level); |
25899dee | 192 | out: |
ccd979bd | 193 | vma->vm_ops = &ocfs2_file_vm_ops; |
d0217ac0 | 194 | vma->vm_flags |= VM_CAN_NONLINEAR; |
ccd979bd MF |
195 | return 0; |
196 | } | |
197 |