bcachefs: Start journal reclaim thread earlier

Especially in userspace, we sometime run into resource exhaustion issues
with starting up threads after mark and sweep/fsck.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/journal.c

@@ -1044,7 +1044,7 @@ int bch2_fs_journal_start(struct journal *j, u64 cur_seq,
 	bch2_journal_space_available(j);
 	spin_unlock(&j->lock);
 
-	return 0;
+	return bch2_journal_reclaim_start(j);
 }
 
 /* init/exit: */

fs/bcachefs/super.c

@@ -276,7 +276,7 @@ static void bch2_writes_disabled(struct percpu_ref *writes)
 void bch2_fs_read_only(struct bch_fs *c)
 {
 	if (!test_bit(BCH_FS_RW, &c->flags)) {
-		BUG_ON(c->journal.reclaim_thread);
+		bch2_journal_reclaim_stop(&c->journal);
 		return;
 	}
 
@@ -431,12 +431,6 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 	for_each_rw_member(ca, c, i)
 		bch2_wake_allocator(ca);
 
-	ret = bch2_journal_reclaim_start(&c->journal);
-	if (ret) {
-		bch_err(c, "error starting journal reclaim: %i", ret);
-		return ret;
-	}
-
 	if (!early) {
 		ret = bch2_fs_read_write_late(c);
 		if (ret)