/* -*- 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/slab.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/signal.h>
#include <linux/rbtree.h>
#define MLOG_MASK_PREFIX ML_FILE_IO
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "dlmglue.h"
#include "file.h"
#include "inode.h"
#include "mmap.h"
static struct page *ocfs2_nopage(struct vm_area_struct * area,
unsigned long address,
int *type)
{
struct page *page = NOPAGE_SIGBUS;
sigset_t blocked, oldset;
int ret;
mlog_entry("(area=%p, address=%lu, type=%p)\n", area, address,
type);
/* The best way to deal with signals in this path is
* to block them upfront, rather than allowing the
* locking paths to return -ERESTARTSYS. */
sigfillset(&blocked);
/* We should technically never get a bad ret return
* from sigprocmask */
ret = sigprocmask(SIG_BLOCK, &blocked, &oldset);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
page = filemap_nopage(area, address, type);
ret = sigprocmask(SIG_SETMASK, &oldset, NULL);
if (ret < 0)
mlog_errno(ret);
out:
mlog_exit_ptr(page);
return page;
}
static struct vm_operations_struct ocfs2_file_vm_ops = {
.nopage = ocfs2_nopage,
};
int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
int ret = 0, lock_level = 0;
struct ocfs2_super *osb = OCFS2_SB(file->f_dentry->d_inode->i_sb);
/*
* Only support shared writeable mmap for local mounts which
* don't know about holes.
*/
if ((!ocfs2_mount_local(osb) || ocfs2_sparse_alloc(osb)) &&
((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE)) &&
((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) {
mlog(0, "disallow shared writable mmaps %lx\n", vma->vm_flags);
/* This is -EINVAL because generic_file_readonly_mmap
* returns it in a similar situation. */
return -EINVAL;
}
ret = ocfs2_meta_lock_atime(file->f_dentry->d_inode,
file->f_vfsmnt, &lock_level);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
ocfs2_meta_unlock(file->f_dentry->d_inode, lock_level);
out:
vma->vm_ops = &ocfs2_file_vm_ops;
return 0;
}
