Update bcachefs sources to 661faf58db bcachefs: fix a deadlock in journal replay error path

.bcachefs_revision

@@ -1 +1 @@
-6a361fb68c8b0b7cd3bc0085b8d21b808fdc13eb
+661faf58dbcab87e512e64e7cb164905689e64c8

libbcachefs/alloc.c

@@ -1153,6 +1153,7 @@ static enum bucket_alloc_ret __bch2_bucket_alloc_set(struct bch_fs *c,
 		 * open_bucket_add_buckets expects new pointers at the head of
 		 * the list:
 		 */
+		BUG_ON(ob->nr_ptrs >= BCH_REPLICAS_MAX);
 		memmove(&ob->ptrs[1],
 			&ob->ptrs[0],
 			ob->nr_ptrs * sizeof(ob->ptrs[0]));
@@ -1239,12 +1240,15 @@ static int bch2_bucket_alloc_set(struct bch_fs *c, struct write_point *wp,
  * reference _after_ doing the index update that makes its allocation reachable.
  */
 
-static void __bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob)
+void bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob)
 {
 	const struct bch_extent_ptr *ptr;
+	u8 new_ob;
 
-	lockdep_assert_held(&c->open_buckets_lock);
+	if (!atomic_dec_and_test(&ob->pin))
+		return;
 
+	spin_lock(&c->open_buckets_lock);
 	open_bucket_for_each_ptr(ob, ptr) {
 		struct bch_dev *ca = c->devs[ptr->dev];
 
@@ -1252,19 +1256,17 @@ static void __bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob)
 	}
 
 	ob->nr_ptrs = 0;
+	new_ob = ob->new_ob;
+	ob->new_ob = 0;
 
 	list_move(&ob->list, &c->open_buckets_free);
 	c->open_buckets_nr_free++;
-	closure_wake_up(&c->open_buckets_wait);
-}
+	spin_unlock(&c->open_buckets_lock);
 
-void bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *b)
-{
-	if (atomic_dec_and_test(&b->pin)) {
-		spin_lock(&c->open_buckets_lock);
-		__bch2_open_bucket_put(c, b);
-		spin_unlock(&c->open_buckets_lock);
-	}
+	closure_wake_up(&c->open_buckets_wait);
+
+	if (new_ob)
+		bch2_open_bucket_put(c, c->open_buckets + new_ob);
 }
 
 static struct open_bucket *bch2_open_bucket_get(struct bch_fs *c,
@@ -1285,6 +1287,9 @@ static struct open_bucket *bch2_open_bucket_get(struct bch_fs *c,
 		atomic_set(&ret->pin, 1); /* XXX */
 		ret->has_full_ptrs	= false;
 
+		BUG_ON(ret->new_ob);
+		BUG_ON(ret->nr_ptrs);
+
 		c->open_buckets_nr_free--;
 		trace_open_bucket_alloc(c, cl);
 	} else {
@@ -1333,17 +1338,34 @@ static void open_bucket_copy_unused_ptrs(struct bch_fs *c,
 					 struct open_bucket *new,
 					 struct open_bucket *old)
 {
-	unsigned i;
+	bool moved_ptr = false;
+	int i;
 
-	for (i = 0; i < old->nr_ptrs; i++)
+	for (i = old->nr_ptrs - 1; i >= 0; --i)
 		if (ob_ptr_sectors_free(c, old, &old->ptrs[i])) {
-			struct bch_extent_ptr tmp = old->ptrs[i];
+			BUG_ON(new->nr_ptrs >= BCH_REPLICAS_MAX);
 
-			tmp.offset += old->ptr_offset[i];
-			new->ptrs[new->nr_ptrs] = tmp;
-			new->ptr_offset[new->nr_ptrs] = 0;
+			new->ptrs[new->nr_ptrs]		= old->ptrs[i];
+			new->ptr_offset[new->nr_ptrs]	= old->ptr_offset[i];
 			new->nr_ptrs++;
+
+			old->nr_ptrs--;
+			memmove(&old->ptrs[i],
+				&old->ptrs[i + 1],
+				(old->nr_ptrs - i) * sizeof(old->ptrs[0]));
+			memmove(&old->ptr_offset[i],
+				&old->ptr_offset[i + 1],
+				(old->nr_ptrs - i) * sizeof(old->ptr_offset[0]));
+
+			moved_ptr = true;
 		}
+
+	if (moved_ptr) {
+		BUG_ON(old->new_ob);
+
+		atomic_inc(&new->pin);
+		old->new_ob = new - c->open_buckets;
+	}
 }
 
 static void verify_not_stale(struct bch_fs *c, const struct open_bucket *ob)

libbcachefs/alloc_types.h

@@ -52,6 +52,8 @@ struct open_bucket {
 	struct mutex		lock;
 	atomic_t		pin;
 	bool			has_full_ptrs;
+	u8			new_ob;
+
 	/*
 	 * recalculated every time we allocate from this open_bucket based on
 	 * how many pointers we're actually going to use:

libbcachefs/btree_cache.c

@@ -216,9 +216,6 @@ static unsigned long bch2_mca_scan(struct shrinker *shrink,
 	if (btree_shrinker_disabled(c))
 		return SHRINK_STOP;
 
-	if (c->btree_cache_alloc_lock)
-		return SHRINK_STOP;
-
 	/* Return -1 if we can't do anything right now */
 	if (sc->gfp_mask & __GFP_IO)
 		mutex_lock(&c->btree_cache_lock);
@@ -302,9 +299,6 @@ static unsigned long bch2_mca_count(struct shrinker *shrink,
 	if (btree_shrinker_disabled(c))
 		return 0;
 
-	if (c->btree_cache_alloc_lock)
-		return 0;
-
 	return mca_can_free(c) * btree_pages(c);
 }
 

libbcachefs/btree_io.c

@@ -1198,8 +1198,13 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct btree *b, bool have_retry
 			goto err;
 		}
 
-		if (ret)
-			continue;
+		if (ret) {
+			btree_err_on(!b->written,
+				     BTREE_ERR_FIXABLE, c, b, i,
+				     "first btree node bset has blacklisted journal seq");
+			if (b->written)
+				continue;
+		}
 
 		__bch2_btree_node_iter_push(iter, b,
 					   i->start,
@@ -1267,6 +1272,7 @@ static void btree_node_read_work(struct work_struct *work)
 
 	goto start;
 	do {
+		bch_info(c, "retrying read");
 		bio_reset(bio);
 		bio->bi_opf		= REQ_OP_READ|REQ_SYNC|REQ_META;
 		bio->bi_bdev		= rb->pick.ca->disk_sb.bdev;

libbcachefs/journal.c

@@ -1496,6 +1496,8 @@ int bch2_journal_replay(struct bch_fs *c, struct list_head *list)
 
 	j->replay_pin_list = NULL;
 
+	bch2_journal_set_replay_done(j);
+
 	if (did_replay) {
 		bch2_journal_flush_pins(&c->journal, U64_MAX);
 
@@ -1511,8 +1513,6 @@ int bch2_journal_replay(struct bch_fs *c, struct list_head *list)
 			goto err;
 		}
 	}
-
-	bch2_journal_set_replay_done(j);
 err:
 	bch2_journal_entries_free(list);
 	return ret;
@@ -1834,6 +1834,14 @@ void bch2_journal_flush_pins(struct journal *j, u64 seq_to_flush)
 	while ((pin = journal_get_next_pin(j, seq_to_flush, &pin_seq)))
 		pin->flush(j, pin, pin_seq);
 
+	/*
+	 * If journal replay hasn't completed, the unreplayed journal entries
+	 * hold refs on their corresponding sequence numbers and thus this would
+	 * deadlock:
+	 */
+	if (!test_bit(JOURNAL_REPLAY_DONE, &j->flags))
+		return;
+
 	wait_event(j->wait,
 		   journal_flush_done(j, seq_to_flush) ||
 		   bch2_journal_error(j));

libbcachefs/super.c

@@ -395,6 +395,7 @@ static void bch2_fs_free(struct bch_fs *c)
 	mempool_exit(&c->btree_reserve_pool);
 	mempool_exit(&c->fill_iter);
 	percpu_ref_exit(&c->writes);
+	kfree(c->replicas);
 
 	if (c->copygc_wq)
 		destroy_workqueue(c->copygc_wq);