blob: 39737613424a2c073c21c540e7b022b96e344da9 [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
Mark Fasheh7307de82007-05-09 15:16:19 -070040#include "aops.h"
Mark Fashehccd979b2005-12-15 14:31:24 -080041#include "dlmglue.h"
42#include "file.h"
43#include "inode.h"
44#include "mmap.h"
45
Mark Fasheh7307de82007-05-09 15:16:19 -070046static inline int ocfs2_vm_op_block_sigs(sigset_t *blocked, sigset_t *oldset)
47{
48 /* The best way to deal with signals in the vm path is
49 * to block them upfront, rather than allowing the
50 * locking paths to return -ERESTARTSYS. */
51 sigfillset(blocked);
52
53 /* We should technically never get a bad return value
54 * from sigprocmask */
55 return sigprocmask(SIG_BLOCK, blocked, oldset);
56}
57
58static inline int ocfs2_vm_op_unblock_sigs(sigset_t *oldset)
59{
60 return sigprocmask(SIG_SETMASK, oldset, NULL);
61}
62
Nick Piggind0217ac2007-07-19 01:47:03 -070063static int ocfs2_fault(struct vm_area_struct *area, struct vm_fault *vmf)
Mark Fashehccd979b2005-12-15 14:31:24 -080064{
Mark Fashehccd979b2005-12-15 14:31:24 -080065 sigset_t blocked, oldset;
Nick Piggind0217ac2007-07-19 01:47:03 -070066 int error, ret;
Mark Fashehccd979b2005-12-15 14:31:24 -080067
Nick Piggind0217ac2007-07-19 01:47:03 -070068 mlog_entry("(area=%p, page offset=%lu)\n", area, vmf->pgoff);
Mark Fashehccd979b2005-12-15 14:31:24 -080069
Nick Piggind0217ac2007-07-19 01:47:03 -070070 error = ocfs2_vm_op_block_sigs(&blocked, &oldset);
71 if (error < 0) {
72 mlog_errno(error);
73 ret = VM_FAULT_SIGBUS;
Mark Fashehccd979b2005-12-15 14:31:24 -080074 goto out;
75 }
76
Nick Piggind0217ac2007-07-19 01:47:03 -070077 ret = filemap_fault(area, vmf);
Mark Fashehccd979b2005-12-15 14:31:24 -080078
Nick Piggind0217ac2007-07-19 01:47:03 -070079 error = ocfs2_vm_op_unblock_sigs(&oldset);
80 if (error < 0)
81 mlog_errno(error);
Mark Fashehccd979b2005-12-15 14:31:24 -080082out:
Nick Piggind0217ac2007-07-19 01:47:03 -070083 mlog_exit_ptr(vmf->page);
84 return ret;
Mark Fashehccd979b2005-12-15 14:31:24 -080085}
86
Mark Fasheh7307de82007-05-09 15:16:19 -070087static int __ocfs2_page_mkwrite(struct inode *inode, struct buffer_head *di_bh,
88 struct page *page)
89{
90 int ret;
91 struct address_space *mapping = inode->i_mapping;
Nick Piggin18336332007-07-20 00:31:45 -070092 loff_t pos = page_offset(page);
Mark Fasheh7307de82007-05-09 15:16:19 -070093 unsigned int len = PAGE_CACHE_SIZE;
94 pgoff_t last_index;
95 struct page *locked_page = NULL;
96 void *fsdata;
97 loff_t size = i_size_read(inode);
98
99 /*
100 * Another node might have truncated while we were waiting on
101 * cluster locks.
102 */
103 last_index = size >> PAGE_CACHE_SHIFT;
104 if (page->index > last_index) {
105 ret = -EINVAL;
106 goto out;
107 }
108
109 /*
110 * The i_size check above doesn't catch the case where nodes
111 * truncated and then re-extended the file. We'll re-check the
112 * page mapping after taking the page lock inside of
113 * ocfs2_write_begin_nolock().
114 */
115 if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
Tao Ma4c1bbf12008-10-06 16:59:55 +0800116 /*
117 * the page has been umapped in ocfs2_data_downconvert_worker.
118 * So return 0 here and let VFS retry.
119 */
120 ret = 0;
Mark Fasheh7307de82007-05-09 15:16:19 -0700121 goto out;
122 }
123
124 /*
125 * Call ocfs2_write_begin() and ocfs2_write_end() to take
126 * advantage of the allocation code there. We pass a write
127 * length of the whole page (chopped to i_size) to make sure
128 * the whole thing is allocated.
129 *
130 * Since we know the page is up to date, we don't have to
131 * worry about ocfs2_write_begin() skipping some buffer reads
132 * because the "write" would invalidate their data.
133 */
134 if (page->index == last_index)
135 len = size & ~PAGE_CACHE_MASK;
136
137 ret = ocfs2_write_begin_nolock(mapping, pos, len, 0, &locked_page,
138 &fsdata, di_bh, page);
139 if (ret) {
140 if (ret != -ENOSPC)
141 mlog_errno(ret);
142 goto out;
143 }
144
145 ret = ocfs2_write_end_nolock(mapping, pos, len, len, locked_page,
146 fsdata);
147 if (ret < 0) {
148 mlog_errno(ret);
149 goto out;
150 }
151 BUG_ON(ret != len);
152 ret = 0;
153out:
154 return ret;
155}
156
Nick Pigginc2ec1752009-03-31 15:23:21 -0700157static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
Mark Fasheh7307de82007-05-09 15:16:19 -0700158{
Nick Pigginc2ec1752009-03-31 15:23:21 -0700159 struct page *page = vmf->page;
Mark Fasheh7307de82007-05-09 15:16:19 -0700160 struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
161 struct buffer_head *di_bh = NULL;
162 sigset_t blocked, oldset;
163 int ret, ret2;
164
165 ret = ocfs2_vm_op_block_sigs(&blocked, &oldset);
166 if (ret < 0) {
167 mlog_errno(ret);
168 return ret;
169 }
170
171 /*
172 * The cluster locks taken will block a truncate from another
173 * node. Taking the data lock will also ensure that we don't
174 * attempt page truncation as part of a downconvert.
175 */
Mark Fashehe63aecb62007-10-18 15:30:42 -0700176 ret = ocfs2_inode_lock(inode, &di_bh, 1);
Mark Fasheh7307de82007-05-09 15:16:19 -0700177 if (ret < 0) {
178 mlog_errno(ret);
179 goto out;
180 }
181
182 /*
183 * The alloc sem should be enough to serialize with
184 * ocfs2_truncate_file() changing i_size as well as any thread
185 * modifying the inode btree.
186 */
187 down_write(&OCFS2_I(inode)->ip_alloc_sem);
188
Mark Fasheh7307de82007-05-09 15:16:19 -0700189 ret = __ocfs2_page_mkwrite(inode, di_bh, page);
190
Mark Fasheh7307de82007-05-09 15:16:19 -0700191 up_write(&OCFS2_I(inode)->ip_alloc_sem);
192
193 brelse(di_bh);
Mark Fashehe63aecb62007-10-18 15:30:42 -0700194 ocfs2_inode_unlock(inode, 1);
Mark Fasheh7307de82007-05-09 15:16:19 -0700195
196out:
197 ret2 = ocfs2_vm_op_unblock_sigs(&oldset);
198 if (ret2 < 0)
199 mlog_errno(ret2);
Nick Pigginc2ec1752009-03-31 15:23:21 -0700200 if (ret)
201 ret = VM_FAULT_SIGBUS;
Mark Fasheh7307de82007-05-09 15:16:19 -0700202 return ret;
203}
204
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +0400205static const struct vm_operations_struct ocfs2_file_vm_ops = {
Nick Piggin54cb8822007-07-19 01:46:59 -0700206 .fault = ocfs2_fault,
Mark Fasheh7307de82007-05-09 15:16:19 -0700207 .page_mkwrite = ocfs2_page_mkwrite,
Mark Fashehccd979b2005-12-15 14:31:24 -0800208};
209
Christoph Hellwig870f4812006-01-09 20:52:01 -0800210int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
Mark Fashehccd979b2005-12-15 14:31:24 -0800211{
Tiger Yang25899de2006-11-15 15:49:02 +0800212 int ret = 0, lock_level = 0;
Mark Fashehccd979b2005-12-15 14:31:24 -0800213
Mark Fashehe63aecb62007-10-18 15:30:42 -0700214 ret = ocfs2_inode_lock_atime(file->f_dentry->d_inode,
Tiger Yang25899de2006-11-15 15:49:02 +0800215 file->f_vfsmnt, &lock_level);
216 if (ret < 0) {
217 mlog_errno(ret);
218 goto out;
219 }
Mark Fashehe63aecb62007-10-18 15:30:42 -0700220 ocfs2_inode_unlock(file->f_dentry->d_inode, lock_level);
Tiger Yang25899de2006-11-15 15:49:02 +0800221out:
Mark Fashehccd979b2005-12-15 14:31:24 -0800222 vma->vm_ops = &ocfs2_file_vm_ops;
Nick Piggind0217ac2007-07-19 01:47:03 -0700223 vma->vm_flags |= VM_CAN_NONLINEAR;
Mark Fashehccd979b2005-12-15 14:31:24 -0800224 return 0;
225}
226