ovl: fix value of i_ino for lower hardlink corner case

Commit 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more
cases"), relaxed the condition nfs_export=on in order to set the value of
i_ino to xino map of real ino.

Specifically, it also relaxed the pre-condition that index=on for
consistent i_ino. This opened the corner case of lower hardlink in
ovl_get_inode(), which calls ovl_fill_inode() with ino=0 and then
ovl_init_inode() is called to set i_ino to lower real ino without the xino
mapping.

Pass the correct values of ino;fsid in this case to ovl_fill_inode(), so it
can initialize i_ino correctly.

Fixes: 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more ...")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 79e8994..3f993c1 100644 (file)
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -891,7 +891,7 @@ struct inode *ovl_get_inode(struct super_block *sb,
        struct dentry *lowerdentry = lowerpath ? lowerpath->dentry : NULL;
        bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry,
                                        oip->index);
-       int fsid = bylower ? oip->lowerpath->layer->fsid : 0;
+       int fsid = bylower ? lowerpath->layer->fsid : 0;
        bool is_dir, metacopy = false;
        unsigned long ino = 0;
        int err = oip->newinode ? -EEXIST : -ENOMEM;
@@ -941,6 +941,8 @@ struct inode *ovl_get_inode(struct super_block *sb,
                        err = -ENOMEM;
                        goto out_err;
                }
+               ino = realinode->i_ino;
+               fsid = lowerpath->layer->fsid;
        }
        ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
        ovl_inode_init(inode, upperdentry, lowerdentry, oip->lowerdata);