ovl: Do not expose metacopy only dentry from d_real()
Metacopy dentry/inode is internal to overlay and is never exposed outside
of it. Exception is metacopy upper file used for fsync(). Modify d_real()
to look for dentries/inode which have data, but also allow matching upper
inode without data for the fsync case.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 6d22bbd..2e0fc93 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -95,10 +95,13 @@ static struct dentry *ovl_d_real(struct dentry *dentry,
}
real = ovl_dentry_upper(dentry);
- if (real && (!inode || inode == d_inode(real)))
+ if (real && (inode == d_inode(real)))
return real;
- real = ovl_dentry_lower(dentry);
+ if (real && !inode && ovl_has_upperdata(d_inode(dentry)))
+ return real;
+
+ real = ovl_dentry_lowerdata(dentry);
if (!real)
goto bug;