bcachefs: Kill BCH_FS_HOLD_BTREE_WRITES

This was just dead code.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/bcachefs.h

@@ -534,7 +534,6 @@ enum {
 	BCH_FS_NEED_ANOTHER_GC,
 	BCH_FS_DELETED_NODES,
 	BCH_FS_REBUILD_REPLICAS,
-	BCH_FS_HOLD_BTREE_WRITES,
 };
 
 struct btree_debug {

fs/bcachefs/btree_cache.c

@@ -223,8 +223,7 @@ static int __btree_node_reclaim(struct bch_fs *c, struct btree *b, bool flush)
 		goto out_unlock;
 
 	if (btree_node_dirty(b)) {
-		if (!flush ||
-		    test_bit(BCH_FS_HOLD_BTREE_WRITES, &c->flags))
+		if (!flush)
 			goto out_unlock;
 		/*
 		 * Using the underscore version because we don't want to compact

fs/bcachefs/btree_io.c

@@ -1772,9 +1772,6 @@ void __bch2_btree_node_write(struct bch_fs *c, struct btree *b, bool already_sta
 	if (already_started)
 		goto do_write;
 
-	if (test_bit(BCH_FS_HOLD_BTREE_WRITES, &c->flags))
-		return;
-
 	/*
 	 * We may only have a read lock on the btree node - the dirty bit is our
 	 * "lock" against racing with other threads that may be trying to start

fs/bcachefs/btree_update_interior.c

@@ -1104,8 +1104,7 @@ static void bch2_btree_set_root(struct btree_update *as,
 	struct btree *old;
 
 	trace_btree_set_root(c, b);
-	BUG_ON(!b->written &&
-	       !test_bit(BCH_FS_HOLD_BTREE_WRITES, &c->flags));
+	BUG_ON(!b->written);
 
 	old = btree_node_root(c, b);