Re: [PATCH v3 0/5] Store overlay real upper file in ovl_file

[Al Viro <viro@zeniv.linux.org.uk>]

On Mon, Oct 07, 2024 at 04:19:20PM +0200, Amir Goldstein wrote:
> Hi all,
> 
> This is v3 of the code to avoid temporary backing file opens in
> overlayfs, taking into account Al's and Miklos' comments on v2 [1].
> 
> If no further comments, this is going for overlayfs-next.

BTW, looking through the vicinity of that stuff:

int ovl_cleanup(struct ovl_fs *ofs, struct inode *wdir, struct dentry *wdentry)
{
        int err;

        dget(wdentry);
        if (d_is_dir(wdentry))
                err = ovl_do_rmdir(ofs, wdir, wdentry);
        else
                err = ovl_do_unlink(ofs, wdir, wdentry);
        dput(wdentry);

        if (err) {
                pr_err("cleanup of '%pd2' failed (%i)\n",
                       wdentry, err);
        }

        return err;
}

What the hell are those dget()/dput() doing there?  Not to mention an
access after dput(), both vfs_rmdir() and vfs_unlink() expect the
reference to dentry argument to be held by the caller and leave it
for the caller to dispose of.  What am I missing here?