[GFS2] The core of GFS2

This patch contains all the core files for GFS2.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
new file mode 100644
index 0000000..5c61861
--- /dev/null
+++ b/fs/gfs2/ops_dentry.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License v.2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/smp_lock.h>
+#include <asm/semaphore.h>
+
+#include "gfs2.h"
+#include "dir.h"
+#include "glock.h"
+#include "ops_dentry.h"
+
+/**
+ * gfs2_drevalidate - Check directory lookup consistency
+ * @dentry: the mapping to check
+ * @nd:
+ *
+ * Check to make sure the lookup necessary to arrive at this inode from its
+ * parent is still good.
+ *
+ * Returns: 1 if the dentry is ok, 0 if it isn't
+ */
+
+static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	struct dentry *parent = dget_parent(dentry);
+	struct gfs2_inode *dip = get_v2ip(parent->d_inode);
+	struct gfs2_sbd *sdp = dip->i_sbd;
+	struct inode *inode;
+	struct gfs2_holder d_gh;
+	struct gfs2_inode *ip;
+	struct gfs2_inum inum;
+	unsigned int type;
+	int error;
+
+	lock_kernel();
+
+	atomic_inc(&sdp->sd_ops_dentry);
+
+	inode = dentry->d_inode;
+	if (inode && is_bad_inode(inode))
+		goto invalid;
+
+	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
+	if (error)
+		goto fail;
+
+	error = gfs2_dir_search(dip, &dentry->d_name, &inum, &type);
+	switch (error) {
+	case 0:
+		if (!inode)
+			goto invalid_gunlock;
+		break;
+	case -ENOENT:
+		if (!inode)
+			goto valid_gunlock;
+		goto invalid_gunlock;
+	default:
+		goto fail_gunlock;
+	}
+
+	ip = get_v2ip(inode);
+
+	if (!gfs2_inum_equal(&ip->i_num, &inum))
+		goto invalid_gunlock;
+
+	if (IF2DT(ip->i_di.di_mode) != type) {
+		gfs2_consist_inode(dip);
+		goto fail_gunlock;
+	}
+
+ valid_gunlock:
+	gfs2_glock_dq_uninit(&d_gh);
+
+ valid:
+	unlock_kernel();
+	dput(parent);
+	return 1;
+
+ invalid_gunlock:
+	gfs2_glock_dq_uninit(&d_gh);
+
+ invalid:
+	if (inode && S_ISDIR(inode->i_mode)) {
+		if (have_submounts(dentry))
+			goto valid;
+		shrink_dcache_parent(dentry);
+	}
+	d_drop(dentry);
+
+	unlock_kernel();
+	dput(parent);
+	return 0;
+
+ fail_gunlock:
+	gfs2_glock_dq_uninit(&d_gh);
+
+ fail:
+	unlock_kernel();
+	dput(parent);
+	return 0;
+}
+
+struct dentry_operations gfs2_dops = {
+	.d_revalidate = gfs2_drevalidate,
+};
+