1 /* -*- 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 40 #include "dlmglue.h" 41 #include "file.h" 42 #include "inode.h" 43 #include "mmap.h" 44 45 static struct page *ocfs2_nopage(struct vm_area_struct * area, 46 unsigned long address, 47 int *type) 48 { 49 struct inode *inode = area->vm_file->f_dentry->d_inode; 50 struct page *page = NOPAGE_SIGBUS; 51 sigset_t blocked, oldset; 52 int ret; 53 54 mlog_entry("(inode %lu, address %lu)\n", inode->i_ino, address); 55 56 /* The best way to deal with signals in this path is 57 * to block them upfront, rather than allowing the 58 * locking paths to return -ERESTARTSYS. */ 59 sigfillset(&blocked); 60 61 /* We should technically never get a bad ret return 62 * from sigprocmask */ 63 ret = sigprocmask(SIG_BLOCK, &blocked, &oldset); 64 if (ret < 0) { 65 mlog_errno(ret); 66 goto out; 67 } 68 69 page = filemap_nopage(area, address, type); 70 71 ret = sigprocmask(SIG_SETMASK, &oldset, NULL); 72 if (ret < 0) 73 mlog_errno(ret); 74 out: 75 mlog_exit_ptr(page); 76 return page; 77 } 78 79 static struct vm_operations_struct ocfs2_file_vm_ops = { 80 .nopage = ocfs2_nopage, 81 }; 82 83 int ocfs2_mmap(struct file *file, struct vm_area_struct *vma) 84 { 85 /* We don't want to support shared writable mappings yet. */ 86 if (((vma->vm_flags & VM_SHARED) || (vma->vm_flags & VM_MAYSHARE)) 87 && ((vma->vm_flags & VM_WRITE) || (vma->vm_flags & VM_MAYWRITE))) { 88 mlog(0, "disallow shared writable mmaps %lx\n", vma->vm_flags); 89 /* This is -EINVAL because generic_file_readonly_mmap 90 * returns it in a similar situation. */ 91 return -EINVAL; 92 } 93 94 file_accessed(file); 95 vma->vm_ops = &ocfs2_file_vm_ops; 96 return 0; 97 } 98 99