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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * mmap.c
6 *
7 * Code to deal with the mess that is clustered mmap.
8 *
9 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
10 */
11
12#include <linux/fs.h>
13#include <linux/types.h>
14#include <linux/highmem.h>
15#include <linux/pagemap.h>
16#include <linux/uio.h>
17#include <linux/signal.h>
18#include <linux/rbtree.h>
19
20#include <cluster/masklog.h>
21
22#include "ocfs2.h"
23
24#include "aops.h"
25#include "dlmglue.h"
26#include "file.h"
27#include "inode.h"
28#include "mmap.h"
29#include "super.h"
30#include "ocfs2_trace.h"
31
32
33static vm_fault_t ocfs2_fault(struct vm_fault *vmf)
34{
35 struct vm_area_struct *vma = vmf->vma;
36 sigset_t oldset;
37 vm_fault_t ret;
38
39 ocfs2_block_signals(&oldset);
40 ret = filemap_fault(vmf);
41 ocfs2_unblock_signals(&oldset);
42
43 trace_ocfs2_fault(OCFS2_I(vma->vm_file->f_mapping->host)->ip_blkno,
44 vma, vmf->page, vmf->pgoff);
45 return ret;
46}
47
48static vm_fault_t __ocfs2_page_mkwrite(struct file *file,
49 struct buffer_head *di_bh, struct page *page)
50{
51 int err;
52 vm_fault_t ret = VM_FAULT_NOPAGE;
53 struct inode *inode = file_inode(file);
54 struct address_space *mapping = inode->i_mapping;
55 loff_t pos = page_offset(page);
56 unsigned int len = PAGE_SIZE;
57 pgoff_t last_index;
58 struct page *locked_page = NULL;
59 void *fsdata;
60 loff_t size = i_size_read(inode);
61
62 last_index = (size - 1) >> PAGE_SHIFT;
63
64 /*
65 * There are cases that lead to the page no longer bebongs to the
66 * mapping.
67 * 1) pagecache truncates locally due to memory pressure.
68 * 2) pagecache truncates when another is taking EX lock against
69 * inode lock. see ocfs2_data_convert_worker.
70 *
71 * The i_size check doesn't catch the case where nodes truncated and
72 * then re-extended the file. We'll re-check the page mapping after
73 * taking the page lock inside of ocfs2_write_begin_nolock().
74 *
75 * Let VM retry with these cases.
76 */
77 if ((page->mapping != inode->i_mapping) ||
78 (!PageUptodate(page)) ||
79 (page_offset(page) >= size))
80 goto out;
81
82 /*
83 * Call ocfs2_write_begin() and ocfs2_write_end() to take
84 * advantage of the allocation code there. We pass a write
85 * length of the whole page (chopped to i_size) to make sure
86 * the whole thing is allocated.
87 *
88 * Since we know the page is up to date, we don't have to
89 * worry about ocfs2_write_begin() skipping some buffer reads
90 * because the "write" would invalidate their data.
91 */
92 if (page->index == last_index)
93 len = ((size - 1) & ~PAGE_MASK) + 1;
94
95 err = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_MMAP,
96 &locked_page, &fsdata, di_bh, page);
97 if (err) {
98 if (err != -ENOSPC)
99 mlog_errno(err);
100 ret = vmf_error(err);
101 goto out;
102 }
103
104 if (!locked_page) {
105 ret = VM_FAULT_NOPAGE;
106 goto out;
107 }
108 err = ocfs2_write_end_nolock(mapping, pos, len, len, fsdata);
109 BUG_ON(err != len);
110 ret = VM_FAULT_LOCKED;
111out:
112 return ret;
113}
114
115static vm_fault_t ocfs2_page_mkwrite(struct vm_fault *vmf)
116{
117 struct page *page = vmf->page;
118 struct inode *inode = file_inode(vmf->vma->vm_file);
119 struct buffer_head *di_bh = NULL;
120 sigset_t oldset;
121 int err;
122 vm_fault_t ret;
123
124 sb_start_pagefault(inode->i_sb);
125 ocfs2_block_signals(&oldset);
126
127 /*
128 * The cluster locks taken will block a truncate from another
129 * node. Taking the data lock will also ensure that we don't
130 * attempt page truncation as part of a downconvert.
131 */
132 err = ocfs2_inode_lock(inode, &di_bh, 1);
133 if (err < 0) {
134 mlog_errno(err);
135 ret = vmf_error(err);
136 goto out;
137 }
138
139 /*
140 * The alloc sem should be enough to serialize with
141 * ocfs2_truncate_file() changing i_size as well as any thread
142 * modifying the inode btree.
143 */
144 down_write(&OCFS2_I(inode)->ip_alloc_sem);
145
146 ret = __ocfs2_page_mkwrite(vmf->vma->vm_file, di_bh, page);
147
148 up_write(&OCFS2_I(inode)->ip_alloc_sem);
149
150 brelse(di_bh);
151 ocfs2_inode_unlock(inode, 1);
152
153out:
154 ocfs2_unblock_signals(&oldset);
155 sb_end_pagefault(inode->i_sb);
156 return ret;
157}
158
159static const struct vm_operations_struct ocfs2_file_vm_ops = {
160 .fault = ocfs2_fault,
161 .page_mkwrite = ocfs2_page_mkwrite,
162};
163
164int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
165{
166 int ret = 0, lock_level = 0;
167
168 ret = ocfs2_inode_lock_atime(file_inode(file),
169 file->f_path.mnt, &lock_level, 1);
170 if (ret < 0) {
171 mlog_errno(ret);
172 goto out;
173 }
174 ocfs2_inode_unlock(file_inode(file), lock_level);
175out:
176 vma->vm_ops = &ocfs2_file_vm_ops;
177 return 0;
178}
179
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/highmem.h>
29#include <linux/pagemap.h>
30#include <linux/uio.h>
31#include <linux/signal.h>
32#include <linux/rbtree.h>
33
34#include <cluster/masklog.h>
35
36#include "ocfs2.h"
37
38#include "aops.h"
39#include "dlmglue.h"
40#include "file.h"
41#include "inode.h"
42#include "mmap.h"
43#include "super.h"
44#include "ocfs2_trace.h"
45
46
47static int ocfs2_fault(struct vm_area_struct *area, struct vm_fault *vmf)
48{
49 sigset_t oldset;
50 int ret;
51
52 ocfs2_block_signals(&oldset);
53 ret = filemap_fault(area, vmf);
54 ocfs2_unblock_signals(&oldset);
55
56 trace_ocfs2_fault(OCFS2_I(area->vm_file->f_mapping->host)->ip_blkno,
57 area, vmf->page, vmf->pgoff);
58 return ret;
59}
60
61static int __ocfs2_page_mkwrite(struct file *file, struct buffer_head *di_bh,
62 struct page *page)
63{
64 int ret;
65 struct inode *inode = file->f_path.dentry->d_inode;
66 struct address_space *mapping = inode->i_mapping;
67 loff_t pos = page_offset(page);
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);
73
74 /*
75 * Another node might have truncated while we were waiting on
76 * cluster locks.
77 * We don't check size == 0 before the shift. This is borrowed
78 * from do_generic_file_read.
79 */
80 last_index = (size - 1) >> PAGE_CACHE_SHIFT;
81 if (unlikely(!size || page->index > last_index)) {
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) {
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;
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)
112 len = ((size - 1) & ~PAGE_CACHE_MASK) + 1;
113
114 ret = ocfs2_write_begin_nolock(file, mapping, pos, len, 0, &locked_page,
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;
130out:
131 return ret;
132}
133
134static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
135{
136 struct page *page = vmf->page;
137 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
138 struct buffer_head *di_bh = NULL;
139 sigset_t oldset;
140 int ret;
141
142 ocfs2_block_signals(&oldset);
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 */
149 ret = ocfs2_inode_lock(inode, &di_bh, 1);
150 if (ret < 0) {
151 mlog_errno(ret);
152 goto out;
153 }
154
155 /*
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.
159 */
160 down_write(&OCFS2_I(inode)->ip_alloc_sem);
161
162 ret = __ocfs2_page_mkwrite(vma->vm_file, di_bh, page);
163
164 up_write(&OCFS2_I(inode)->ip_alloc_sem);
165
166 brelse(di_bh);
167 ocfs2_inode_unlock(inode, 1);
168
169out:
170 ocfs2_unblock_signals(&oldset);
171 if (ret)
172 ret = VM_FAULT_SIGBUS;
173 return ret;
174}
175
176static const struct vm_operations_struct ocfs2_file_vm_ops = {
177 .fault = ocfs2_fault,
178 .page_mkwrite = ocfs2_page_mkwrite,
179};
180
181int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
182{
183 int ret = 0, lock_level = 0;
184
185 ret = ocfs2_inode_lock_atime(file->f_dentry->d_inode,
186 file->f_vfsmnt, &lock_level);
187 if (ret < 0) {
188 mlog_errno(ret);
189 goto out;
190 }
191 ocfs2_inode_unlock(file->f_dentry->d_inode, lock_level);
192out:
193 vma->vm_ops = &ocfs2_file_vm_ops;
194 vma->vm_flags |= VM_CAN_NONLINEAR;
195 return 0;
196}
197