diff options
Diffstat (limited to 'fs/ocfs2/mmap.c')
| -rw-r--r-- | fs/ocfs2/mmap.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c new file mode 100644 index 000000000000..843cf9ddefe8 --- /dev/null +++ b/fs/ocfs2/mmap.c @@ -0,0 +1,98 @@ +/* -*- 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 inode *inode = area->vm_file->f_dentry->d_inode; + struct page *page = NOPAGE_SIGBUS; + sigset_t blocked, oldset; + int ret; + + mlog_entry("(inode %lu, address %lu)\n", inode->i_ino, address); + + /* 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; +} + |