[Ocfs2-tools-devel] [PATCH 15/22] tunefs rework: Add feature_local.c

[Joel Becker]

Enables and disables the local filesystem feature.  This transfers an
ocfs2 filesystem between a single-node local filesystem and a
cluster-aware one.

This is the 'local' key to the tunefs option '--fs-features', as well as
the tunefs option '-M'.

Signed-off-by: Joel Becker <joel.becker at oracle.com>
---
 tunefs.ocfs2/feature_local.c |  134 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 134 insertions(+), 0 deletions(-)
 create mode 100644 tunefs.ocfs2/feature_local.c

diff --git a/tunefs.ocfs2/feature_local.c b/tunefs.ocfs2/feature_local.c
new file mode 100644
index 0000000..40a483d
--- /dev/null
+++ b/tunefs.ocfs2/feature_local.c
@@ -0,0 +1,134 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * feature_local.c
+ *
+ * ocfs2 tune utility for updating the mount type.
+ *
+ * Copyright (C) 2004, 2008 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 version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <inttypes.h>
+
+#include "ocfs2/ocfs2.h"
+
+#include "libocfs2ne.h"
+
+static int disable_local(ocfs2_filesys *fs, int flags)
+{
+	errcode_t ret = 0;
+	struct ocfs2_super_block *sb = OCFS2_RAW_SB(fs->fs_super);
+	struct o2cb_cluster_desc desc;
+
+	if (!ocfs2_mount_local(fs)) {
+		verbosef(VL_APP,
+			 "Device \"%s\" is already a cluster-aware "
+			 "filesystem; nothing to do\n",
+			 fs->fs_devname);
+		goto out;
+	}
+
+	if (!tunefs_interact("Make device \"%s\" a cluster-aware "
+			     "filesystem? ",
+			     fs->fs_devname))
+		goto out;
+
+	/*
+	 * Since it was a local device, tunefs_open() will not
+	 * have connected to o2cb.
+	 */
+	ret = o2cb_init();
+	if (ret) {
+		tcom_err(ret, "while connecting to the cluster stack");
+		goto out;
+	}
+	ret = o2cb_running_cluster_desc(&desc);
+	if (ret) {
+		tcom_err(ret, "while trying to determine the running cluster");
+		goto out;
+	}
+	if (desc.c_stack)
+		verbosef(VL_APP,
+			 "Cluster stack: %s\n"
+			 "Cluster name: %s\n",
+			 desc.c_stack, desc.c_cluster);
+	else
+		verbosef(VL_APP, "Cluster stack: classic o2cb\n");
+
+	sb->s_feature_incompat &=
+		~OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT;
+	tunefs_block_signals();
+	ret = ocfs2_set_cluster_desc(fs, &desc);
+	tunefs_block_signals();
+	o2cb_free_cluster_desc(&desc);
+	if (ret)
+		tcom_err(ret, "while writing setting the cluster descriptor");
+
+out:
+	if (ret)
+		errorf("Unable to disable the local mount feature on "
+		       "device \"%s\"\n",
+		       fs->fs_devname);
+	return ret;
+}
+
+static int enable_local(ocfs2_filesys *fs, int flags)
+{
+	errcode_t ret = 0;
+	struct ocfs2_super_block *sb = OCFS2_RAW_SB(fs->fs_super);
+
+	if (ocfs2_mount_local(fs)) {
+		verbosef(VL_APP,
+			 "Device \"%s\" is already a single-node "
+			 "filesystem; nothing to do\n",
+			 fs->fs_devname);
+		goto out;
+	}
+
+	if (!tunefs_interact("Make device \"%s\" a single-node "
+			     "(non-clustered) filesystem? ",
+			     fs->fs_devname))
+		goto out;
+
+	sb->s_feature_incompat |=
+		OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT;
+	sb->s_feature_incompat &=
+		~OCFS2_FEATURE_INCOMPAT_USERSPACE_STACK;
+
+	tunefs_block_signals();
+	ret = ocfs2_write_super(fs);
+	tunefs_unblock_signals();
+	if (ret)
+		tcom_err(ret,
+			 "while writing out the superblock; Unable to "
+			 "enable the local mount feature on device \"%s\"",
+			 fs->fs_devname);
+
+out:
+	return ret;
+}
+
+DEFINE_TUNEFS_FEATURE_INCOMPAT(local,
+			       OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT,
+			       TUNEFS_FLAG_RW,
+			       enable_local,
+			       disable_local);
+
+#ifdef DEBUG_EXE
+int main(int argc, char *argv[])
+{
+	return tunefs_feature_main(argc, argv, &local_feature);
+}
+#endif
-- 
1.5.6.3