Commit 778ac324 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Fix deadlock on -ENOSPC w.r.t. partial open buckets 



Open buckets on the partial list should not count as allocated when
we're trying to allocate from the partial list.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent e0fafac5

fs/bcachefs/alloc_foreground.c

+15 −1
Original line number Diff line number Diff line
@@ -162,6 +162,10 @@ static void open_bucket_free_unused(struct bch_fs *c, struct open_bucket *ob) 
	       ARRAY_SIZE(c->open_buckets_partial));



	spin_lock(&c->freelist_lock);

	rcu_read_lock();

	bch2_dev_rcu(c, ob->dev)->nr_partial_buckets++;

	rcu_read_unlock();



	ob->on_partial_list = true;

	c->open_buckets_partial[c->open_buckets_partial_nr++] =

		ob - c->open_buckets;
@@ -972,7 +976,7 @@ static int bucket_alloc_set_partial(struct bch_fs *c, 
			u64 avail;



			bch2_dev_usage_read_fast(ca, &usage);

			avail = dev_buckets_free(ca, usage, watermark);

			avail = dev_buckets_free(ca, usage, watermark) + ca->nr_partial_buckets;

			if (!avail)

				continue;
@@ -981,6 +985,10 @@ static int bucket_alloc_set_partial(struct bch_fs *c, 
					  i);

			ob->on_partial_list = false;



			rcu_read_lock();

			bch2_dev_rcu(c, ob->dev)->nr_partial_buckets--;

			rcu_read_unlock();



			ret = add_new_bucket(c, ptrs, devs_may_alloc,

					     nr_replicas, nr_effective,

					     have_cache, ob);
@@ -1191,7 +1199,13 @@ void bch2_open_buckets_stop(struct bch_fs *c, struct bch_dev *ca, 
			--c->open_buckets_partial_nr;

			swap(c->open_buckets_partial[i],

			     c->open_buckets_partial[c->open_buckets_partial_nr]);



			ob->on_partial_list = false;



			rcu_read_lock();

			bch2_dev_rcu(c, ob->dev)->nr_partial_buckets--;

			rcu_read_unlock();



			spin_unlock(&c->freelist_lock);

			bch2_open_bucket_put(c, ob);

			spin_lock(&c->freelist_lock);

fs/bcachefs/bcachefs.h

+1 −0
Original line number Diff line number Diff line
@@ -555,6 +555,7 @@ struct bch_dev { 
	u64			alloc_cursor[3];



	unsigned		nr_open_buckets;

	unsigned		nr_partial_buckets;

	unsigned		nr_btree_reserve;



	size_t			inc_gen_needs_gc;