hi,
I try to know why output following error? I found that "disable_ifindex" file do not set read function, so return -EINVAL when do read. Is it a bug in test_offload.py?
test output: selftests: bpf: test_offload.py Test destruction of generic XDP... ...... raise Exception("Command failed: %s\n%s" % (proc.args, stderr)) Exception: Command failed: cat /sys/kernel/debug/netdevsim/netdevsim0//ports/0/dev/hwstats/l3/disable_ifindex
cat: /sys/kernel/debug/netdevsim/netdevsim0//ports/0/dev/hwstats/l3/disable_ifindex: Invalid argument not ok 20 selftests: bpf: test_offload.py # exit=1
source code: In drivers/net/netdevsim/hwstats.c: define NSIM_DEV_HWSTATS_FOPS(ACTION, TYPE) \ { \ .fops = { \ .open = simple_open, \ .write = nsim_dev_hwstats_do_write, \ .llseek = generic_file_llseek, \ .owner = THIS_MODULE, \ }, \ .action = ACTION, \ .type = TYPE, \ }
static const struct nsim_dev_hwstats_fops nsim_dev_hwstats_l3_disable_fops = NSIM_DEV_HWSTATS_FOPS(NSIM_DEV_HWSTATS_DO_DISABLE, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
debugfs_create_file("disable_ifindex", 0600, hwstats->l3_ddir, hwstats, &nsim_dev_hwstats_l3_disable_fops.fops);
In fs/read_write.c: ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos) { ...... if (file->f_op->read) ret = file->f_op->read(file, buf, count, pos); else if (file->f_op->read_iter) ret = new_sync_read(file, buf, count, pos); else ret = -EINVAL; ...... }
best regards,