ocfs2/cluster: Reorganize o2hb debugfs init

o2hb debugfs handling is reorganized to allow for easy expansion.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>

1 files changed, 78 insertions, 23 deletions

diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index a8f10649674d..16e49765c853 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -62,8 +62,19 @@ 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_DB_TYPE_LIVENODES          0
+struct o2hb_debug_buf {
+        int db_type;
+        int db_size;
+        int db_len;
+        void *db_data;
+};
+
+static struct o2hb_debug_buf *o2hb_db_livenodes;
+
 #define O2HB_DEBUG_DIR                  "o2hb"
 #define O2HB_DEBUG_LIVENODES            "livenodes"
+
 static struct dentry *o2hb_debug_dir;
 static struct dentry *o2hb_debug_livenodes;
 
@@ -969,21 +980,35 @@ static int o2hb_thread(void *data)
 #ifdef CONFIG_DEBUG_FS
 static int o2hb_debug_open(struct inode *inode, struct file *file)
 {
+        struct o2hb_debug_buf *db = inode->i_private;
         unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)];
         char *buf = NULL;
         int i = -1;
         int out = 0;
 
+        /* max_nodes should be the largest bitmap we pass here */
+        BUG_ON(sizeof(map) < db->db_size);
+
         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
         if (!buf)
                 goto bail;
 
-        o2hb_fill_node_map(map, sizeof(map));
+        switch (db->db_type) {
+        case O2HB_DB_TYPE_LIVENODES:
+                spin_lock(&o2hb_live_lock);
+                memcpy(map, db->db_data, db->db_size);
+                spin_unlock(&o2hb_live_lock);
+                break;
+
+        default:
+                goto done;
+        }
 
-        while ((i = find_next_bit(map, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES)
+        while ((i = find_next_bit(map, db->db_len, i + 1)) < db->db_len)
                 out += snprintf(buf + out, PAGE_SIZE - out, "%d ", i);
         out += snprintf(buf + out, PAGE_SIZE - out, "\n");
 
+done:
         i_size_write(inode, out);
 
         file->private_data = buf;
@@ -1030,10 +1055,56 @@ static const struct file_operations o2hb_debug_fops = {
 
 void o2hb_exit(void)
 {
-        if (o2hb_debug_livenodes)
-                debugfs_remove(o2hb_debug_livenodes);
-        if (o2hb_debug_dir)
-                debugfs_remove(o2hb_debug_dir);
+        kfree(o2hb_db_livenodes);
+        debugfs_remove(o2hb_debug_livenodes);
+        debugfs_remove(o2hb_debug_dir);
+}
+
+static struct dentry *o2hb_debug_create(const char *name, struct dentry *dir,
+                                        struct o2hb_debug_buf **db, int db_len,
+                                        int type, int size, int len, void *data)
+{
+        *db = kmalloc(db_len, GFP_KERNEL);
+        if (!*db)
+                return NULL;
+
+        (*db)->db_type = type;
+        (*db)->db_size = size;
+        (*db)->db_len = len;
+        (*db)->db_data = data;
+
+        return debugfs_create_file(name, S_IFREG|S_IRUSR, dir, *db,
+                                   &o2hb_debug_fops);
+}
+
+static int o2hb_debug_init(void)
+{
+        int ret = -ENOMEM;
+
+        o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL);
+        if (!o2hb_debug_dir) {
+                mlog_errno(ret);
+                goto bail;
+        }
+
+        o2hb_debug_livenodes = o2hb_debug_create(O2HB_DEBUG_LIVENODES,
+                                                 o2hb_debug_dir,
+                                                 &o2hb_db_livenodes,
+                                                 sizeof(*o2hb_db_livenodes),
+                                                 O2HB_DB_TYPE_LIVENODES,
+                                                 sizeof(o2hb_live_node_bitmap),
+                                                 O2NM_MAX_NODES,
+                                                 o2hb_live_node_bitmap);
+        if (!o2hb_debug_livenodes) {
+                mlog_errno(ret);
+                goto bail;
+        }
+        ret = 0;
+bail:
+        if (ret)
+                o2hb_exit();
+
+        return ret;
 }
 
 int o2hb_init(void)
@@ -1050,23 +1121,7 @@ int o2hb_init(void)
 
         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;
+        return o2hb_debug_init();
 }
 
 /* if we're already in a callback then we're already serialized by the sem */