1 files changed, 19 insertions, 17 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 277bd1be21f..668dcabc569 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -56,29 +56,28 @@ static void configfs_d_iput(struct dentry * dentry,
 	struct configfs_dirent *sd = dentry->d_fsdata;
 
 	if (sd) {
-		BUG_ON(sd->s_dentry != dentry);
 		/* Coordinate with configfs_readdir */
 		spin_lock(&configfs_dirent_lock);
-		sd->s_dentry = NULL;
+		/* Coordinate with configfs_attach_attr where will increase
+		 * sd->s_count and update sd->s_dentry to new allocated one.
+		 * Only set sd->dentry to null when this dentry is the only
+		 * sd owner.
+		 * If not do so, configfs_d_iput may run just after
+		 * configfs_attach_attr and set sd->s_dentry to null
+		 * even it's still in use.
+		 */
+		if (atomic_read(&sd->s_count) <= 2)
+			sd->s_dentry = NULL;
+
 		spin_unlock(&configfs_dirent_lock);
 		configfs_put(sd);
 	}
 	iput(inode);
 }
 
-/*
- * We _must_ delete our dentries on last dput, as the chain-to-parent
- * behavior is required to clear the parents of default_groups.
- */
-static int configfs_d_delete(const struct dentry *dentry)
-{
-	return 1;
-}
-
 const struct dentry_operations configfs_dentry_ops = {
 	.d_iput		= configfs_d_iput,
-	/* simple_delete_dentry() isn't exported */
-	.d_delete	= configfs_d_delete,
+	.d_delete	= always_delete_dentry,
 };
 
 #ifdef CONFIG_LOCKDEP
@@ -426,8 +425,11 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
 	struct configfs_attribute * attr = sd->s_element;
 	int error;
 
+	spin_lock(&configfs_dirent_lock);
 	dentry->d_fsdata = configfs_get(sd);
 	sd->s_dentry = dentry;
+	spin_unlock(&configfs_dirent_lock);
+
 	error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
 				configfs_init_file);
 	if (error) {
@@ -938,9 +940,9 @@ static void client_drop_item(struct config_item *parent_item,
 #ifdef DEBUG
 static void configfs_dump_one(struct configfs_dirent *sd, int level)
 {
-	printk(KERN_INFO "%*s\"%s\":\n", level, " ", configfs_get_name(sd));
+	pr_info("%*s\"%s\":\n", level, " ", configfs_get_name(sd));
 
-#define type_print(_type) if (sd->s_type & _type) printk(KERN_INFO "%*s %s\n", level, " ", #_type);
+#define type_print(_type) if (sd->s_type & _type) pr_info("%*s %s\n", level, " ", #_type);
 	type_print(CONFIGFS_ROOT);
 	type_print(CONFIGFS_DIR);
 	type_print(CONFIGFS_ITEM_ATTR);
@@ -1697,7 +1699,7 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
 	struct dentry *root = dentry->d_sb->s_root;
 
 	if (dentry->d_parent != root) {
-		printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n");
+		pr_err("Tried to unregister non-subsystem!\n");
 		return;
 	}
 
@@ -1707,7 +1709,7 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
 	mutex_lock(&configfs_symlink_mutex);
 	spin_lock(&configfs_dirent_lock);
 	if (configfs_detach_prep(dentry, NULL)) {
-		printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n");
+		pr_err("Tried to unregister non-empty subsystem!\n");
 	}
 	spin_unlock(&configfs_dirent_lock);
 	mutex_unlock(&configfs_symlink_mutex);