bcachefs: Add error handling to unit & perf tests

This way, these tests can be used with tests that inject IO errors and
shut down the filesystem.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/sysfs.c

@@ -503,10 +503,11 @@ STORE(bch2_fs)
 		if (threads_str &&
 		    !(ret = kstrtouint(threads_str, 10, &threads)) &&
 		    !(ret = bch2_strtoull_h(nr_str, &nr)))
-			bch2_btree_perf_test(c, test, nr, threads);
-		else
-			size = ret;
+			ret = bch2_btree_perf_test(c, test, nr, threads);
 		kfree(tmp);
+
+		if (ret)
+			size = ret;
 	}
 #endif
 	return size;

fs/bcachefs/tests.h

@@ -6,7 +6,7 @@ struct bch_fs;
 
 #ifdef CONFIG_BCACHEFS_TESTS
 
-void bch2_btree_perf_test(struct bch_fs *, const char *, u64, unsigned);
+int bch2_btree_perf_test(struct bch_fs *, const char *, u64, unsigned);
 
 #else