Commit d8b50597 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: fix restart handling in bch2_alloc_write_key() 



This is ugly:

We may discover in alloc_write_key that the data type we calculated is
wrong, because BCH_DATA_need_discard is checked/set elsewhere, and the
disk accounting counters we calculated need to be updated.

But bch2_alloc_key_to_dev_counters(..., BTREE_TRIGGER_gc) is not safe
w.r.t. transaction restarts, so we need to propagate the fixup back to
our gc state in case we take a transaction restart.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 7ee4be9c

fs/bcachefs/btree_gc.c

+11 −1
Original line number Diff line number Diff line
@@ -820,12 +820,22 @@ static int bch2_alloc_write_key(struct btree_trans *trans, 
	 * fix that here:

	 */

	alloc_data_type_set(&gc, gc.data_type);



	if (gc.data_type != old_gc.data_type ||

	    gc.dirty_sectors != old_gc.dirty_sectors) {

		ret = bch2_alloc_key_to_dev_counters(trans, ca, &old_gc, &gc, BTREE_TRIGGER_gc);

		if (ret)

			return ret;



		/*

		 * Ugly: alloc_key_to_dev_counters(..., BTREE_TRIGGER_gc) is not

		 * safe w.r.t. transaction restarts, so fixup the gc_bucket so

		 * we don't run it twice:

		 */

		percpu_down_read(&c->mark_lock);

		struct bucket *gc_m = gc_bucket(ca, iter->pos.offset);

		gc_m->data_type = gc.data_type;

		gc_m->dirty_sectors = gc.dirty_sectors;

		percpu_up_read(&c->mark_lock);

	}



	if (fsck_err_on(new.data_type != gc.data_type,