Fix for bug #2406 (autodetect supported relayfs versions)

1 files changed, 50 insertions, 2 deletions

diff --git a/runtime/transport/procfs.c b/runtime/transport/procfs.c
index 96337466..22b14046 100644
--- a/runtime/transport/procfs.c
+++ b/runtime/transport/procfs.c
@@ -31,13 +31,13 @@ _stp_proc_read (struct file *file, char __user *buf, size_t count, loff_t *ppos)
 		return -EINVAL;
 
 	out.cpu = cpu;
-#ifdef RELAYFS_VERSION_GE_4
+#if RELAYFS_VERSION_GE_4 || defined (CONFIG_RELAY)
 	out.produced = _stp_chan->buf[cpu]->subbufs_produced;
 	out.consumed = _stp_chan->buf[cpu]->subbufs_consumed;
 #else
 	out.produced = atomic_read(&_stp_chan->buf[cpu]->subbufs_produced);
 	out.consumed = atomic_read(&_stp_chan->buf[cpu]->subbufs_consumed);
-#endif /* RELAYFS_VERSION_GE_4 */
+#endif  /* RELAYFS_VERSION_GE_4 || CONFIG_RELAY */
 
 	num = sizeof(out);
 	if (copy_to_user(buf, &out, num))
@@ -262,6 +262,38 @@ err:
 	return _stp_current_buffers;
 }
 
+#if defined (STP_RELAYFS) && defined(CONFIG_RELAY)
+struct dentry *module_dir_dentry;
+
+static inline struct dentry *_stp_get_proc_root(void)
+{
+	struct file_system_type *procfs_type;
+	struct super_block *procfs_sb;
+
+	procfs_type = get_fs_type("proc");
+	if (!procfs_type || list_empty(&procfs_type->fs_supers))
+		return NULL;
+	procfs_sb = list_entry(procfs_type->fs_supers.next,
+			       struct super_block, s_instances);
+	return procfs_sb->s_root;
+}
+
+static inline struct dentry *_stp_force_dir_creation(const char *dirname, struct dentry *parent)
+{
+	struct dentry *dir_dentry;
+
+	mutex_lock(&parent->d_inode->i_mutex);
+	dir_dentry = lookup_one_len(dirname, parent, strlen(dirname));
+	mutex_unlock(&parent->d_inode->i_mutex);
+	if (IS_ERR(dir_dentry)) {
+		dir_dentry = NULL;
+		remove_proc_entry(dirname, NULL);
+	}
+	
+	return dir_dentry;
+}
+#endif  /* STP_RELAYFS && CONFIG_RELAY */
+
 static int _stp_register_procfs (void)
 {
 	int i;
@@ -270,6 +302,10 @@ static int _stp_register_procfs (void)
 	int j;
 	char buf[8];
 #endif
+#if defined (CONFIG_RELAY)
+	struct dentry *proc_root_dentry;
+	struct dentry *systemtap_dir_dentry;
+#endif /* CONFIG_RELAY */
 	struct proc_dir_entry *de;
 	struct list_head *p, *tmp;
 
@@ -301,11 +337,23 @@ static int _stp_register_procfs (void)
 			goto err0;
 	}
 
+#if defined (STP_RELAYFS) && defined (CONFIG_RELAY)
+	proc_root_dentry = _stp_get_proc_root();
+	systemtap_dir_dentry = _stp_force_dir_creation(dirname, proc_root_dentry);
+	if (!systemtap_dir_dentry)
+		goto err0;
+#endif /* STP_RELAYFS && CONFIG_RELAY */
 	/* now create /proc/systemtap/module_name */
 	_stp_proc_mod = proc_mkdir (THIS_MODULE->name, _stp_proc_root);
 	if (_stp_proc_mod == NULL)
 		goto err0;
 
+#if defined (STP_RELAYFS) && defined (CONFIG_RELAY)
+	module_dir_dentry = _stp_force_dir_creation(THIS_MODULE->name, systemtap_dir_dentry);
+	if (!module_dir_dentry)
+		goto err0;
+#endif /* STP_RELAYFS && CONFIG_RELAY */
+
 #ifdef STP_RELAYFS	
 	/* now for each cpu "n", create /proc/systemtap/module_name/n  */
 	for_each_cpu(i) {