3 files changed, 56 insertions, 3 deletions

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index b559221b2d34..4582d5efc01e 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -734,7 +734,7 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
 	type = ovl_path_type(dentry);
 
 	old_cred = ovl_override_creds(dentry->d_sb);
-	if (OVL_TYPE_PURE_UPPER(type))
+	if (!ovl_lower_positive(dentry))
 		err = ovl_remove_upper(dentry, is_dir);
 	else
 		err = ovl_remove_and_whiteout(dentry, is_dir);
@@ -841,7 +841,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
 	}
 
 	if (overwrite) {
-		if (old_opaque) {
+		if (ovl_lower_positive(old)) {
 			if (!ovl_dentry_is_whiteout(new)) {
 				/* Whiteout source */
 				flags |= RENAME_WHITEOUT;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 51e7d58276ce..2bd933aa622b 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -161,6 +161,7 @@ struct dentry *ovl_workdir(struct dentry *dentry);
 int ovl_want_write(struct dentry *dentry);
 void ovl_drop_write(struct dentry *dentry);
 bool ovl_dentry_is_opaque(struct dentry *dentry);
+bool ovl_lower_positive(struct dentry *dentry);
 bool ovl_dentry_is_whiteout(struct dentry *dentry);
 void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque);
 bool ovl_is_whiteout(struct dentry *dentry);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index aa0427dabea8..b58710b36157 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -429,7 +429,6 @@ static inline struct dentry *ovl_lookup_real(struct dentry *dir,
 	struct dentry *dentry;
 
 	dentry = lookup_one_len_unlocked(name->name, dir, name->len);
-
 	if (IS_ERR(dentry)) {
 		if (PTR_ERR(dentry) == -ENOENT)
 			dentry = NULL;
@@ -613,6 +612,59 @@ out:
 	return ERR_PTR(err);
 }
 
+bool ovl_lower_positive(struct dentry *dentry)
+{
+	struct ovl_entry *oe = dentry->d_fsdata;
+	struct ovl_entry *poe = dentry->d_parent->d_fsdata;
+	const struct qstr *name = &dentry->d_name;
+	unsigned int i;
+	bool positive = false;
+	bool done = false;
+
+	/*
+	 * If dentry is negative, then lower is positive iff this is a
+	 * whiteout.
+	 */
+	if (!dentry->d_inode)
+		return oe->opaque;
+
+	/* Negative upper -> positive lower */
+	if (!oe->__upperdentry)
+		return true;
+
+	/* Positive upper -> have to look up lower to see whether it exists */
+	for (i = 0; !done && !positive && i < poe->numlower; i++) {
+		struct dentry *this;
+		struct dentry *lowerdir = poe->lowerstack[i].dentry;
+
+		this = lookup_one_len_unlocked(name->name, lowerdir,
+					       name->len);
+		if (IS_ERR(this)) {
+			switch (PTR_ERR(this)) {
+			case -ENOENT:
+			case -ENAMETOOLONG:
+				break;
+
+			default:
+				/*
+				 * Assume something is there, we just couldn't
+				 * access it.
+				 */
+				positive = true;
+				break;
+			}
+		} else {
+			if (this->d_inode) {
+				positive = !ovl_is_whiteout(this);
+				done = true;
+			}
+			dput(this);
+		}
+	}
+
+	return positive;
+}
+
 struct file *ovl_path_open(struct path *path, int flags)
 {
 	return dentry_open(path, flags | O_NOATIME, current_cred());