1 files changed, 10 insertions, 7 deletions

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 910553f..4e9d7c1 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -21,9 +21,10 @@ struct ovl_cache_entry {
 	unsigned int len;
 	unsigned int type;
 	u64 ino;
-	bool is_whiteout;
 	struct list_head l_node;
 	struct rb_node node;
+	bool is_whiteout;
+	bool is_cursor;
 	char name[];
 };
 
@@ -92,6 +93,7 @@ static struct ovl_cache_entry *ovl_cache_entry_new(const char *name, int len,
 		p->type = d_type;
 		p->ino = ino;
 		p->is_whiteout = false;
+		p->is_cursor = false;
 	}
 
 	return p;
@@ -251,7 +253,7 @@ static int ovl_dir_mark_whiteouts(struct dentry *dir,
 
 	mutex_lock(&dir->d_inode->i_mutex);
 	list_for_each_entry(p, rdd->list, l_node) {
-		if (!p->name)
+		if (p->is_cursor)
 			continue;
 
 		if (p->type != DT_CHR)
@@ -307,7 +309,6 @@ static inline int ovl_dir_read_merged(struct path *upperpath,
 	}
 out:
 	return err;
-
 }
 
 static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
@@ -316,7 +317,7 @@ static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
 	loff_t off = 0;
 
 	list_for_each_entry(p, &od->cache->entries, l_node) {
-		if (!p->name)
+		if (p->is_cursor)
 			continue;
 		if (off >= pos)
 			break;
@@ -389,7 +390,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
 
 		p = list_entry(od->cursor.l_node.next, struct ovl_cache_entry, l_node);
 		/* Skip cursors */
-		if (p->name) {
+		if (!p->is_cursor) {
 			if (!p->is_whiteout) {
 				if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
 					break;
@@ -454,12 +455,13 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
 	if (!od->is_upper && ovl_path_type(dentry) == OVL_PATH_MERGE) {
 		struct inode *inode = file_inode(file);
 
-		realfile = od->upperfile;
+		realfile =lockless_dereference(od->upperfile);
 		if (!realfile) {
 			struct path upperpath;
 
 			ovl_path_upper(dentry, &upperpath);
 			realfile = ovl_path_open(&upperpath, O_RDONLY);
+			smp_mb__before_spinlock();
 			mutex_lock(&inode->i_mutex);
 			if (!od->upperfile) {
 				if (IS_ERR(realfile)) {
@@ -518,6 +520,7 @@ static int ovl_dir_open(struct inode *inode, struct file *file)
 	od->realfile = realfile;
 	od->is_real = (type != OVL_PATH_MERGE);
 	od->is_upper = (type != OVL_PATH_LOWER);
+	od->cursor.is_cursor = true;
 	file->private_data = od;
 
 	return 0;
@@ -569,7 +572,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
 {
 	struct ovl_cache_entry *p;
 
-	mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_PARENT);
+	mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_CHILD);
 	list_for_each_entry(p, list, l_node) {
 		struct dentry *dentry;