When the lower file of a metacopy is inaccessible, -EIO is returned. For users not familiar with overlayfs internals, such as myself, the meaning of this error may not be apparent or easy to determine, since the (metacopy) file is present and open/stat succeed when accessed outside of the overlay. Add a rate-limited warning for invalid metacopy to give users a hint when investigating such errors, as discussed on linux-unionfs[0]. Use "orphan metacopy" terminology to match "orphan index entry" in ovl_verify_index. [0]: https://lore.kernel.org/linux-unionfs/CAOQ4uxi23Zsmfb4rCed1n=On0NNA5KZD74jjjeyz+et32sk-gg@xxxxxxxxxxxxxx/ Signed-off-by: Kevin Locke <kevin@xxxxxxxxxxxxxxx> --- fs/overlayfs/namei.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index f7d4358db637..30e1c10800ab 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -1000,6 +1000,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, * Just make sure a corresponding data dentry has been found. */ if (d.metacopy || (uppermetacopy && !ctr)) { + pr_warn_ratelimited("orphan metacopy (%pd2)\n", dentry); err = -EIO; goto out_put; } else if (!d.is_dir && upperdentry && !ctr && origin_path) { -- 2.28.0
