bcachefs: extent_ptr_durability() -> bch2_dev_rcu()

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Author: Kent Overstreet

fs/bcachefs/data_update.c

@@ -203,6 +203,8 @@ static int __bch2_data_update_index_update(struct btree_trans *trans,
 
 		/* Now, drop excess replicas: */
 restart_drop_extra_replicas:
+
+		rcu_read_lock();
 		bkey_for_each_ptr_decode(old.k, bch2_bkey_ptrs(bkey_i_to_s(insert)), p, entry) {
 			unsigned ptr_durability = bch2_extent_ptr_durability(c, &p);
 
@@ -214,6 +216,7 @@ static int __bch2_data_update_index_update(struct btree_trans *trans,
 				goto restart_drop_extra_replicas;
 			}
 		}
+		rcu_read_unlock();
 
 		/* Finally, add the pointers we just wrote: */
 		extent_for_each_ptr_decode(extent_i_to_s(new), p, entry)
@@ -552,6 +555,7 @@ int bch2_data_update_init(struct btree_trans *trans,
 		struct bpos bucket = PTR_BUCKET_POS(ca, &p.ptr);
 		bool locked;
 
+		rcu_read_lock();
 		if (((1U << i) & m->data_opts.rewrite_ptrs)) {
 			BUG_ON(p.ptr.cached);
 
@@ -565,6 +569,7 @@ int bch2_data_update_init(struct btree_trans *trans,
 			bch2_dev_list_add_dev(&m->op.devs_have, p.ptr.dev);
 			durability_have += bch2_extent_ptr_durability(c, &p);
 		}
+		rcu_read_unlock();
 
 		/*
 		 * op->csum_type is normally initialized from the fs/file's

fs/bcachefs/extents.c

@@ -675,16 +675,16 @@ static inline unsigned __extent_ptr_durability(struct bch_dev *ca, struct extent
 
 unsigned bch2_extent_ptr_desired_durability(struct bch_fs *c, struct extent_ptr_decoded *p)
 {
-	struct bch_dev *ca = bch2_dev_bkey_exists(c, p->ptr.dev);
+	struct bch_dev *ca = bch2_dev_rcu(c, p->ptr.dev);
 
-	return __extent_ptr_durability(ca, p);
+	return ca ? __extent_ptr_durability(ca, p) : 0;
 }
 
 unsigned bch2_extent_ptr_durability(struct bch_fs *c, struct extent_ptr_decoded *p)
 {
-	struct bch_dev *ca = bch2_dev_bkey_exists(c, p->ptr.dev);
+	struct bch_dev *ca = bch2_dev_rcu(c, p->ptr.dev);
 
-	if (ca->mi.state == BCH_MEMBER_STATE_failed)
+	if (!ca || ca->mi.state == BCH_MEMBER_STATE_failed)
 		return 0;
 
 	return __extent_ptr_durability(ca, p);
@@ -697,8 +697,10 @@ unsigned bch2_bkey_durability(struct bch_fs *c, struct bkey_s_c k)
 	struct extent_ptr_decoded p;
 	unsigned durability = 0;
 
+	rcu_read_lock();
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
 		durability += bch2_extent_ptr_durability(c, &p);
+	rcu_read_unlock();
 
 	return durability;
 }
@@ -710,9 +712,11 @@ static unsigned bch2_bkey_durability_safe(struct bch_fs *c, struct bkey_s_c k)
 	struct extent_ptr_decoded p;
 	unsigned durability = 0;
 
+	rcu_read_lock();
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
 		if (p.ptr.dev < c->sb.nr_devices && c->devs[p.ptr.dev])
 			durability += bch2_extent_ptr_durability(c, &p);
+	rcu_read_unlock();
 
 	return durability;
 }

fs/bcachefs/io_write.c

@@ -1099,12 +1099,17 @@ static bool bch2_extent_is_writeable(struct bch_write_op *op,
 		return false;
 
 	e = bkey_s_c_to_extent(k);
+
+	rcu_read_lock();
 	extent_for_each_ptr_decode(e, p, entry) {
-		if (crc_is_encoded(p.crc) || p.has_ec)
+		if (crc_is_encoded(p.crc) || p.has_ec) {
+			rcu_read_unlock();
 			return false;
+		}
 
 		replicas += bch2_extent_ptr_durability(c, &p);
 	}
+	rcu_read_unlock();
 
 	return replicas >= op->opts.data_replicas;
 }

fs/bcachefs/move.c

@@ -1033,6 +1033,7 @@ static bool drop_extra_replicas_pred(struct bch_fs *c, void *arg,
 	struct extent_ptr_decoded p;
 	unsigned i = 0;
 
+	rcu_read_lock();
 	bkey_for_each_ptr_decode(k.k, bch2_bkey_ptrs_c(k), p, entry) {
 		unsigned d = bch2_extent_ptr_durability(c, &p);
 
@@ -1043,6 +1044,7 @@ static bool drop_extra_replicas_pred(struct bch_fs *c, void *arg,
 
 		i++;
 	}
+	rcu_read_unlock();
 
 	return data_opts->kill_ptrs != 0;
 }