[PATCH] OCFS2: The Second Oracle Cluster Filesystem

The OCFS2 file system module.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>

1 files changed, 102 insertions, 0 deletions

diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
new file mode 100644
index 0000000..afdeec4
--- /dev/null
+++ b/fs/ocfs2/mmap.c
@@ -0,0 +1,102 @@
+/* -*- 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)
+{
+	struct address_space *mapping = file->f_dentry->d_inode->i_mapping;
+	struct inode *inode = mapping->host;
+
+	/* 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;
+	}
+
+	update_atime(inode);
+	vma->vm_ops = &ocfs2_file_vm_ops;
+	return 0;
+}
+