Release 4.18 fs/ocfs2/mmap.c

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * mmap.c
 *
 * Code to deal with the mess that is clustered mmap.
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/types.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/signal.h>
#include <linux/rbtree.h>

#include <cluster/masklog.h>

#include "ocfs2.h"

#include "aops.h"
#include "dlmglue.h"
#include "file.h"
#include "inode.h"
#include "mmap.h"
#include "super.h"
#include "ocfs2_trace.h"




static vm_fault_t ocfs2_fault(struct vm_fault *vmf)
{
	struct vm_area_struct *vma = vmf->vma;
	sigset_t oldset;
	vm_fault_t ret;

	ocfs2_block_signals(&oldset);
	ret = filemap_fault(vmf);
	ocfs2_unblock_signals(&oldset);

	trace_ocfs2_fault(OCFS2_I(vma->vm_file->f_mapping->host)->ip_blkno,
			  vma, vmf->page, vmf->pgoff);
	return ret;
}

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Mark Fasheh
32
43.24%
1
12.50%
Tao Ma
18
24.32%
2
25.00%
Dave Jiang
11
14.86%
1
12.50%
Nicholas Piggin
9
12.16%
2
25.00%
Souptick Joarder
2
2.70%
1
12.50%
Joel Becker
2
2.70%
1
12.50%
Total
74
100.00%
8
100.00%



static vm_fault_t __ocfs2_page_mkwrite(struct file *file,
			struct buffer_head *di_bh, struct page *page)
{
	int err;
	vm_fault_t ret = VM_FAULT_NOPAGE;
	struct inode *inode = file_inode(file);
	struct address_space *mapping = inode->i_mapping;
	loff_t pos = page_offset(page);
	unsigned int len = PAGE_SIZE;
	pgoff_t last_index;
	struct page *locked_page = NULL;
	void *fsdata;
	loff_t size = i_size_read(inode);

	last_index = (size - 1) >> PAGE_SHIFT;

	/*
         * There are cases that lead to the page no longer bebongs to the
         * mapping.
         * 1) pagecache truncates locally due to memory pressure.
         * 2) pagecache truncates when another is taking EX lock against 
         * inode lock. see ocfs2_data_convert_worker.
         * 
         * The i_size check doesn't catch the case where nodes truncated and
         * then re-extended the file. We'll re-check the page mapping after
         * taking the page lock inside of ocfs2_write_begin_nolock().
         *
         * Let VM retry with these cases.
         */
	if ((page->mapping != inode->i_mapping) ||
	    (!PageUptodate(page)) ||
	    (page_offset(page) >= size))
		goto out;

	/*
         * Call ocfs2_write_begin() and ocfs2_write_end() to take
         * advantage of the allocation code there. We pass a write
         * length of the whole page (chopped to i_size) to make sure
         * the whole thing is allocated.
         *
         * Since we know the page is up to date, we don't have to
         * worry about ocfs2_write_begin() skipping some buffer reads
         * because the "write" would invalidate their data.
         */
	if (page->index == last_index)
		len = ((size - 1) & ~PAGE_MASK) + 1;

	err = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_MMAP,
				       &locked_page, &fsdata, di_bh, page);
	if (err) {
		if (err != -ENOSPC)
			mlog_errno(err);
		ret = vmf_error(err);
		goto out;
	}

	if (!locked_page) {
		ret = VM_FAULT_NOPAGE;
		goto out;
	}
	err = ocfs2_write_end_nolock(mapping, pos, len, len, fsdata);
	BUG_ON(err != len);
	ret = VM_FAULT_LOCKED;
out:
	return ret;
}

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Mark Fasheh
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3
23.08%
Wengang Wang
38
15.38%
1
7.69%
Tao Ma
21
8.50%
2
15.38%
Souptick Joarder
14
5.67%
1
7.69%
Sunil Mushran
9
3.64%
1
7.69%
Tiger Yang
5
2.02%
1
7.69%
Nicholas Piggin
3
1.21%
1
7.69%
Kirill A. Shutemov
3
1.21%
1
7.69%
Al Viro
3
1.21%
1
7.69%
Ryan Ding
1
0.40%
1
7.69%
Total
247
100.00%
13
100.00%



static vm_fault_t ocfs2_page_mkwrite(struct vm_fault *vmf)
{
	struct page *page = vmf->page;
	struct inode *inode = file_inode(vmf->vma->vm_file);
	struct buffer_head *di_bh = NULL;
	sigset_t oldset;
	int err;
	vm_fault_t ret;

	sb_start_pagefault(inode->i_sb);
	ocfs2_block_signals(&oldset);

	/*
         * The cluster locks taken will block a truncate from another
         * node. Taking the data lock will also ensure that we don't
         * attempt page truncation as part of a downconvert.
         */
	err = ocfs2_inode_lock(inode, &di_bh, 1);
	if (err < 0) {
		mlog_errno(err);
		ret = vmf_error(err);
		goto out;
	}

	/*
         * The alloc sem should be enough to serialize with
         * ocfs2_truncate_file() changing i_size as well as any thread
         * modifying the inode btree.
         */
	down_write(&OCFS2_I(inode)->ip_alloc_sem);

	ret = __ocfs2_page_mkwrite(vmf->vma->vm_file, di_bh, page);

	up_write(&OCFS2_I(inode)->ip_alloc_sem);

	brelse(di_bh);
	ocfs2_inode_unlock(inode, 1);

out:
	ocfs2_unblock_signals(&oldset);
	sb_end_pagefault(inode->i_sb);
	return ret;
}

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Mark Fasheh
116
69.46%
3
27.27%
Jan Kara
17
10.18%
2
18.18%
Souptick Joarder
11
6.59%
1
9.09%
Nicholas Piggin
11
6.59%
1
9.09%
Dave Jiang
4
2.40%
1
9.09%
Al Viro
3
1.80%
1
9.09%
Tao Ma
3
1.80%
1
9.09%
Joel Becker
2
1.20%
1
9.09%
Total
167
100.00%
11
100.00%


static const struct vm_operations_struct ocfs2_file_vm_ops = {
	.fault		= ocfs2_fault,
	.page_mkwrite	= ocfs2_page_mkwrite,
};



int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
	int ret = 0, lock_level = 0;

	ret = ocfs2_inode_lock_atime(file_inode(file),
				    file->f_path.mnt, &lock_level, 1);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}
	ocfs2_inode_unlock(file_inode(file), lock_level);
out:
	vma->vm_ops = &ocfs2_file_vm_ops;
	return 0;
}

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Mark Fasheh
39
46.99%
3
37.50%
Tiger Yang
32
38.55%
1
12.50%
Al Viro
9
10.84%
2
25.00%
Gang He
2
2.41%
1
12.50%
Christoph Hellwig
1
1.20%
1
12.50%
Total
83
100.00%
8
100.00%

Overall Contributors
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Mark Fasheh
395
61.91%
4
14.81%
Tao Ma
45
7.05%
4
14.81%
Wengang Wang
38
5.96%
1
3.70%
Tiger Yang
37
5.80%
1
3.70%
Souptick Joarder
27
4.23%
1
3.70%
Nicholas Piggin
25
3.92%
4
14.81%
Jan Kara
17
2.66%
2
7.41%
Dave Jiang
15
2.35%
1
3.70%
Al Viro
15
2.35%
2
7.41%
Sunil Mushran
9
1.41%
1
3.70%
Joel Becker
7
1.10%
1
3.70%
Kirill A. Shutemov
3
0.47%
1
3.70%
Gang He
2
0.31%
1
3.70%
Christoph Hellwig
1
0.16%
1
3.70%
Alexey Dobriyan
1
0.16%
1
3.70%
Ryan Ding
1
0.16%
1
3.70%
Total
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27
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Directory: fs/ocfs2

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