LS not working by probability

[dura0ok]

OS: Linux Mint 21.2 x86_64
Kernel: 5.15.0-88-generic
version: master commit #1479669
config like in example

[errinj_noop]
op_regexp    = .*
path_regexp  = .*
probability  = 30

i try run ls /tmp/fs 100 times, but there was always a result ls: Unable to access /tmp/fs': I/O error