[Ocfs2-devel] [PATCH 1/4] ocfs2/hb: Exposes list of heartbeating nodes via debugfs

Sunil Mushran
Thu, 11 Sep 2008 03:05:54 -0000

Patch creates a debugfs file, o2hb/livesnodes, which when read will expose
the aggregate list of heartbeating node across all heartbeat regions.

Signed-off-by: Sunil Mushran <sunil.mushran at oracle.com>
---
 fs/ocfs2/cluster/heartbeat.c   |  140 +++++++++++++++++++++++++++++++++++++++-
 fs/ocfs2/cluster/heartbeat.h   |    3 +-
 fs/ocfs2/cluster/nodemanager.c |    9 ++-
 3 files changed, 148 insertions(+), 4 deletions(-)

diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 7dce161..1ea87ee 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -33,6 +33,7 @@
 #include <linux/random.h>
 #include <linux/crc32.h>
 #include <linux/time.h>
+#include <linux/debugfs.h>

 #include "heartbeat.h"
 #include "tcp.h"
@@ -60,6 +61,11 @@ static unsigned long
o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
 static LIST_HEAD(o2hb_node_events);
 static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue);

+#define O2HB_DEBUG_DIR			"o2hb"
+#define O2HB_DEBUG_LIVENODES		"livenodes"
+static struct dentry *o2hb_debug_dir;
+static struct dentry *o2hb_debug_livenodes;
+
 static LIST_HEAD(o2hb_all_regions);

 static struct o2hb_callback {
@@ -905,7 +911,121 @@ static int o2hb_thread(void *data)
 	return 0;
 }

-void o2hb_init(void)
+#ifdef CONFIG_DEBUG_FS
+struct o2hb_debug_buffer {
+	int len;
+	char *buf;
+};
+
+static int o2hb_debug_open(struct inode *inode, struct file *file)
+{
+	unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)];
+	struct o2hb_debug_buffer *odb = NULL;
+	int i = -1;
+	int out = 0;
+
+	odb = kzalloc(sizeof(struct o2hb_debug_buffer), GFP_KERNEL);
+	if (!odb)
+		goto bail;
+
+	odb->len = PAGE_SIZE;
+	odb->buf = kmalloc(odb->len, GFP_KERNEL);
+	if (!odb->buf) {
+		kfree(odb);
+		goto bail;
+	}
+
+	o2hb_fill_node_map(map, sizeof(map));
+
+	while ((i = find_next_bit(map, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES)
+		out += snprintf(odb->buf + out, odb->len - out, "%d ", i);
+	out += snprintf(odb->buf + out, odb->len - out, "\n");
+
+	odb->len = out;
+
+	file->private_data = odb;
+
+	return 0;
+bail:
+	return -ENOMEM;
+}
+
+static int o2hb_debug_release(struct inode *inode, struct file *file)
+{
+	struct o2hb_debug_buffer *odb +			(struct o2hb_debug_buffer
*)file->private_data;
+
+	kfree(odb->buf);
+	kfree(odb);
+
+	return 0;
+}
+
+static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
+				 size_t nbytes, loff_t *ppos)
+{
+	struct o2hb_debug_buffer *odb +			(struct o2hb_debug_buffer
*)file->private_data;
+
+	return simple_read_from_buffer(buf, nbytes, ppos, odb->buf, odb->len);
+}
+
+static loff_t o2hb_debug_llseek(struct file *file, loff_t off, int whence)
+{
+	struct o2hb_debug_buffer *odb +			(struct o2hb_debug_buffer
*)file->private_data;
+	loff_t new = -1;
+
+	switch (whence) {
+	case 0:
+		new = off;
+		break;
+	case 1:
+		new = file->f_pos + off;
+		break;
+	}
+
+	if (new < 0 || new > odb->len)
+		return -EINVAL;
+
+	return (file->f_pos = new);
+}
+#else
+static int o2hb_debug_open(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+static int o2hb_debug_release(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
+			       size_t nbytes, loff_t *ppos)
+{
+	return 0;
+}
+static loff_t o2hb_debug_llseek(struct file *file, loff_t off, int whence)
+{
+	return 0;
+}
+#endif  /* CONFIG_DEBUG_FS */
+
+static struct file_operations o2hb_debug_fops = {
+	.open =		o2hb_debug_open,
+	.release =	o2hb_debug_release,
+	.read =		o2hb_debug_read,
+	.llseek =	o2hb_debug_llseek,
+};
+
+void o2hb_exit(void)
+{
+	if (o2hb_debug_livenodes)
+		debugfs_remove(o2hb_debug_livenodes);
+	if (o2hb_debug_dir)
+		debugfs_remove(o2hb_debug_dir);
+}
+
+int o2hb_init(void)
 {
 	int i;

@@ -918,6 +1038,24 @@ void o2hb_init(void)
 	INIT_LIST_HEAD(&o2hb_node_events);

 	memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap));
+
+	o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL);
+	if (!o2hb_debug_dir) {
+		 mlog_errno(-ENOMEM);
+		 return -ENOMEM;
+	}
+
+	o2hb_debug_livenodes = debugfs_create_file(O2HB_DEBUG_LIVENODES,
+						   S_IFREG|S_IRUSR,
+						   o2hb_debug_dir, NULL,
+						   &o2hb_debug_fops);
+	if (!o2hb_debug_livenodes) {
+		mlog_errno(-ENOMEM);
+		debugfs_remove(o2hb_debug_dir);
+		return -ENOMEM;
+	}
+
+	return 0;
 }

 /* if we're already in a callback then we're already serialized by the
sem */
diff --git a/fs/ocfs2/cluster/heartbeat.h b/fs/ocfs2/cluster/heartbeat.h
index e511339..2f16492 100644
--- a/fs/ocfs2/cluster/heartbeat.h
+++ b/fs/ocfs2/cluster/heartbeat.h
@@ -75,7 +75,8 @@ void o2hb_unregister_callback(const char *region_uuid,
 			      struct o2hb_callback_func *hc);
 void o2hb_fill_node_map(unsigned long *map,
 			unsigned bytes);
-void o2hb_init(void);
+void o2hb_exit(void);
+int o2hb_init(void);
 int o2hb_check_node_heartbeating(u8 node_num);
 int o2hb_check_node_heartbeating_from_callback(u8 node_num);
 int o2hb_check_local_node_heartbeating(void);
diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c
index 816a3f6..2ce28d7 100644
--- a/fs/ocfs2/cluster/nodemanager.c
+++ b/fs/ocfs2/cluster/nodemanager.c
@@ -881,6 +881,7 @@ static void __exit exit_o2nm(void)
 	o2cb_sys_shutdown();

 	o2net_exit();
+	o2hb_exit();
 }

 static int __init init_o2nm(void)
@@ -889,11 +890,13 @@ static int __init init_o2nm(void)

 	cluster_print_version();

-	o2hb_init();
+	ret = o2hb_init();
+	if (ret)
+		goto out;

 	ret = o2net_init();
 	if (ret)
-		goto out;
+		goto out_o2hb;

 	ret = o2net_register_hb_callbacks();
 	if (ret)
@@ -916,6 +919,8 @@ out_callbacks:
 	o2net_unregister_hb_callbacks();
 out_o2net:
 	o2net_exit();
+out_o2hb:
+	o2hb_exit();
 out:
 	return ret;
 }
--
1.5.4.3