108 lines
2.8 KiB
C
108 lines
2.8 KiB
C
/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* mmap.c
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*
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* Code to deal with the mess that is clustered mmap.
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*
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* Copyright (C) 2002, 2004 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include <linux/fs.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/highmem.h>
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#include <linux/pagemap.h>
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#include <linux/uio.h>
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#include <linux/signal.h>
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#include <linux/rbtree.h>
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#define MLOG_MASK_PREFIX ML_FILE_IO
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#include <cluster/masklog.h>
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#include "ocfs2.h"
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#include "dlmglue.h"
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#include "file.h"
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#include "inode.h"
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#include "mmap.h"
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static struct page *ocfs2_nopage(struct vm_area_struct * area,
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unsigned long address,
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int *type)
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{
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struct page *page = NOPAGE_SIGBUS;
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sigset_t blocked, oldset;
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int ret;
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mlog_entry("(area=%p, address=%lu, type=%p)\n", area, address,
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type);
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/* The best way to deal with signals in this path is
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* to block them upfront, rather than allowing the
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* locking paths to return -ERESTARTSYS. */
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sigfillset(&blocked);
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/* We should technically never get a bad ret return
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* from sigprocmask */
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ret = sigprocmask(SIG_BLOCK, &blocked, &oldset);
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if (ret < 0) {
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mlog_errno(ret);
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goto out;
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}
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page = filemap_nopage(area, address, type);
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ret = sigprocmask(SIG_SETMASK, &oldset, NULL);
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if (ret < 0)
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mlog_errno(ret);
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out:
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mlog_exit_ptr(page);
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return page;
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}
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static struct vm_operations_struct ocfs2_file_vm_ops = {
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.nopage = ocfs2_nopage,
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};
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int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
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{
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int ret = 0, lock_level = 0;
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/* We don't want to support shared writable mappings yet. */
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if (((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE))
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&& ((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) {
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mlog(0, "disallow shared writable mmaps %lx\n", vma->vm_flags);
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/* This is -EINVAL because generic_file_readonly_mmap
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* returns it in a similar situation. */
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return -EINVAL;
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}
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ret = ocfs2_meta_lock_atime(file->f_dentry->d_inode,
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file->f_vfsmnt, &lock_level);
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if (ret < 0) {
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mlog_errno(ret);
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goto out;
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}
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ocfs2_meta_unlock(file->f_dentry->d_inode, lock_level);
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out:
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vma->vm_ops = &ocfs2_file_vm_ops;
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return 0;
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}
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