Commit 4d6128dc authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Guard against insufficient devices to create stripes 



We can't create stripes if we don't have enough devices - this
manifested as an integer underflow bug later.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 03cc1e67

fs/bcachefs/ec.c

+14 −2
Original line number Diff line number Diff line
@@ -1373,6 +1373,15 @@ ec_new_stripe_head_alloc(struct bch_fs *c, unsigned target, 
			h->nr_active_devs++;



	rcu_read_unlock();



	/*

	 * If we only have redundancy + 1 devices, we're better off with just

	 * replication:

	 */

	if (h->nr_active_devs < h->redundancy + 2)

		bch_err(c, "insufficient devices available to create stripe (have %u, need %u) - mismatched bucket sizes?",

			h->nr_active_devs, h->redundancy + 2);



	list_add(&h->list, &c->ec_stripe_head_list);

	return h;

}
@@ -1424,6 +1433,11 @@ __bch2_ec_stripe_head_get(struct btree_trans *trans, 


	h = ec_new_stripe_head_alloc(c, target, algo, redundancy, watermark);

found:

	if (!IS_ERR_OR_NULL(h) &&

	    h->nr_active_devs < h->redundancy + 2) {

		mutex_unlock(&h->lock);

		h = NULL;

	}

	mutex_unlock(&c->ec_stripe_head_lock);

	return h;

}
@@ -1681,8 +1695,6 @@ struct ec_stripe_head *bch2_ec_stripe_head_get(struct btree_trans *trans, 
	int ret;



	h = __bch2_ec_stripe_head_get(trans, target, algo, redundancy, watermark);

	if (!h)

		bch_err(c, "no stripe head");

	if (IS_ERR_OR_NULL(h))

		return h;