bcachefs: check the invalid parameter for perf test

The perf_test does not check the number of iterations and threads
when it is zero. If nr_thread is 0, the perf test will keep
waiting for wakekup. If iteration is 0, it will cause exception
of division by zero. This can be reproduced by:
  echo "rand_insert 0 1" > /sys/fs/bcachefs/${uuid}/perf_test
or
  echo "rand_insert 1 0" > /sys/fs/bcachefs/${uuid}/perf_test

Fixes: 1c6fdbd8f246 ("bcachefs: Initial commit")
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/tests.c b/fs/bcachefs/tests.c
index 315038a0a92d4df9c945d59c82dbf77889496205..fb5c1543e52f096f4da7e43fb00c6aac9550bc59 100644 (file)
--- a/fs/bcachefs/tests.c
+++ b/fs/bcachefs/tests.c
@@ -809,6 +809,11 @@ int bch2_btree_perf_test(struct bch_fs *c, const char *testname,
        unsigned i;
        u64 time;
 
+       if (nr == 0 || nr_threads == 0) {
+               pr_err("nr of iterations or threads is not allowed to be 0");
+               return -EINVAL;
+       }
+
        atomic_set(&j.ready, nr_threads);
        init_waitqueue_head(&j.ready_wait);