ocfs2/hb: Expose the list of heartbeating nodes via debugfs

This patch creates a debugfs file, o2hb/livesnodes, which exposes the
aggregate list of heartbeating node across all heartbeat regions.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 04697ba..4f85ece 100644 (file)
--- 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 +911,77 @@ static int o2hb_thread(void *data)
        return 0;
 }
 
-void o2hb_init(void)
+#ifdef CONFIG_DEBUG_FS
+static int o2hb_debug_open(struct inode *inode, struct file *file)
+{
+       unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)];
+       char *buf = NULL;
+       int i = -1;
+       int out = 0;
+
+       buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+       if (!buf)
+               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(buf + out, PAGE_SIZE - out, "%d ", i);
+       out += snprintf(buf + out, PAGE_SIZE - out, "\n");
+
+       i_size_write(inode, out);
+
+       file->private_data = buf;
+
+       return 0;
+bail:
+       return -ENOMEM;
+}
+
+static int o2hb_debug_release(struct inode *inode, struct file *file)
+{
+       kfree(file->private_data);
+       return 0;
+}
+
+static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
+                                size_t nbytes, loff_t *ppos)
+{
+       return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
+                                      i_size_read(file->f_mapping->host));
+}
+#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;
+}
+#endif  /* CONFIG_DEBUG_FS */
+
+static struct file_operations o2hb_debug_fops = {
+       .open =         o2hb_debug_open,
+       .release =      o2hb_debug_release,
+       .read =         o2hb_debug_read,
+       .llseek =       generic_file_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 +994,24 @@ 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 (file)
--- 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 70e8fa9..7ee6188 100644 (file)
--- 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;
 }