/* -*- 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) { /* We don't want to support shared writable mappings yet. */ if (((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; } file_accessed(file); vma->vm_ops = &ocfs2_file_vm_ops; return 0; }