1 files changed, 16 insertions, 4 deletions

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index a619addecafc..321511ed8c42 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -598,18 +598,30 @@ static bool ovl_verify_inode(struct inode *inode, struct dentry *lowerdentry,
         return true;
 }
 
-struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry)
+struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry,
+                            struct dentry *index)
 {
         struct dentry *lowerdentry = ovl_dentry_lower(dentry);
         struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
         struct inode *inode;
+        /* Already indexed or could be indexed on copy up? */
+        bool indexed = (index || (ovl_indexdir(dentry->d_sb) && !upperdentry));
+
+        if (WARN_ON(upperdentry && indexed && !lowerdentry))
+                return ERR_PTR(-EIO);
 
         if (!realinode)
                 realinode = d_inode(lowerdentry);
 
-        if (!S_ISDIR(realinode->i_mode) &&
-            (upperdentry || (lowerdentry && ovl_indexdir(dentry->d_sb)))) {
-                struct inode *key = d_inode(lowerdentry ?: upperdentry);
+        /*
+         * Copy up origin (lower) may exist for non-indexed upper, but we must
+         * not use lower as hash key in that case.
+         * Hash inodes that are or could be indexed by origin inode and
+         * non-indexed upper inodes that could be hard linked by upper inode.
+         */
+        if (!S_ISDIR(realinode->i_mode) && (upperdentry || indexed)) {
+                struct inode *key = d_inode(indexed ? lowerdentry :
+                                                      upperdentry);
                 unsigned int nlink;
 
                 inode = iget5_locked(dentry->d_sb, (unsigned long) key,