Function cache_fplookup_impl

freebsd/kern/vfs_cache.c:5606–5675

}

static int
cache_fplookup_impl(struct vnode *dvp, struct cache_fpl *fpl)
{
	struct nameidata *ndp;
	struct componentname *cnp;
	struct mount *mp;
	int error;

	ndp = fpl->ndp;
	cnp = fpl->cnp;

	cache_fpl_checkpoint(fpl);

	/*
	 * The vnode at hand is almost always stable, skip checking for it.
	 * Worst case this postpones the check towards the end of the iteration
	 * of the main loop.
	 */
	fpl->dvp = dvp;
	fpl->dvp_seqc = vn_seqc_read_notmodify(fpl->dvp);

	mp = atomic_load_ptr(&dvp->v_mount);
	if (__predict_false(mp == NULL || !cache_fplookup_mp_supported(mp))) {
		return (cache_fpl_aborted(fpl));
	}

	MPASS(fpl->tvp == NULL);

	for (;;) {
		cache_fplookup_parse(fpl);

		error = VOP_FPLOOKUP_VEXEC(fpl->dvp, cnp->cn_cred);
		if (__predict_false(error != 0)) {
			error = cache_fplookup_failed_vexec(fpl, error);
			break;
		}

		error = cache_fplookup_next(fpl);
		if (__predict_false(cache_fpl_terminated(fpl))) {
			break;
		}

		VNPASS(!seqc_in_modify(fpl->tvp_seqc), fpl->tvp);

		if (fpl->tvp->v_type == VLNK) {
			error = cache_fplookup_symlink(fpl);
			if (cache_fpl_terminated(fpl)) {
				break;
			}
		} else {
			if (cache_fpl_islastcn(ndp)) {
				error = cache_fplookup_final(fpl);
				break;
			}

			if (!vn_seqc_consistent(fpl->dvp, fpl->dvp_seqc)) {
				error = cache_fpl_aborted(fpl);
				break;