bcachefs: ec_stripe_delete_work() now takes ref on c->writes

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

fs/bcachefs/ec.c

@@ -672,9 +672,8 @@ void bch2_stripes_heap_update(struct bch_fs *c,
 
 	heap_verify_backpointer(c, idx);
 
-	if (stripe_idx_to_delete(c) >= 0 &&
-	    !percpu_ref_is_dying(&c->writes))
-		schedule_work(&c->ec_stripe_delete_work);
+	if (stripe_idx_to_delete(c) >= 0)
+		bch2_do_stripe_deletes(c);
 }
 
 /* stripe deletion */
@@ -707,6 +706,15 @@ static void ec_stripe_delete_work(struct work_struct *work)
 		if (ec_stripe_delete(c, idx))
 			break;
 	}
+
+	percpu_ref_put(&c->writes);
+}
+
+void bch2_do_stripe_deletes(struct bch_fs *c)
+{
+	if (percpu_ref_tryget_live(&c->writes) &&
+	    !schedule_work(&c->ec_stripe_delete_work))
+		percpu_ref_put(&c->writes);
 }
 
 /* stripe creation: */

fs/bcachefs/ec.h

@@ -213,6 +213,8 @@ void bch2_stripes_heap_update(struct bch_fs *, struct stripe *, size_t);
 void bch2_stripes_heap_del(struct bch_fs *, struct stripe *, size_t);
 void bch2_stripes_heap_insert(struct bch_fs *, struct stripe *, size_t);
 
+void bch2_do_stripe_deletes(struct bch_fs *);
+
 void bch2_ec_stop_dev(struct bch_fs *, struct bch_dev *);
 
 void bch2_ec_flush_new_stripes(struct bch_fs *);

fs/bcachefs/super.c

@@ -258,8 +258,6 @@ void bch2_fs_read_only(struct bch_fs *c)
 	 */
 	percpu_ref_kill(&c->writes);
 
-	cancel_work_sync(&c->ec_stripe_delete_work);
-
 	/*
 	 * If we're not doing an emergency shutdown, we want to wait on
 	 * outstanding writes to complete so they don't see spurious errors due
@@ -391,9 +389,6 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 		bch2_dev_allocator_add(c, ca);
 	bch2_recalc_capacity(c);
 
-	bch2_do_discards(c);
-	bch2_do_invalidates(c);
-
 	if (!early) {
 		ret = bch2_fs_read_write_late(c);
 		if (ret)
@@ -403,6 +398,10 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 	percpu_ref_reinit(&c->writes);
 	set_bit(BCH_FS_RW, &c->flags);
 	set_bit(BCH_FS_WAS_RW, &c->flags);
+
+	bch2_do_discards(c);
+	bch2_do_invalidates(c);
+	bch2_do_stripe_deletes(c);
 	return 0;
 err:
 	__bch2_fs_read_only(c);