When some program on the same host enabled netlink support for target_core_user.ko, go-tcmu program hangs

[nak3]

description

When some program that uses target_core_user.ko enables netlink support (TCMU_ATTR_SUPP_KERN_CMD_REPLY), go-tcmu hangs.

reproduce steps

1. Run tcmu-runner (to enable netlink reply support).

  # ./tcmu-runner
  // You can stop tcmu-runner process as it keeps the netlink support enabled //

2. Start go-tcmu program

  # go run cmd/tcmufile/tcmufile.go /tmp/foo
  ... snip ...
  DEBU[0000] Setting /sys/kernel/config/target/core/user_30/foo/control: dev_config=go-tcmu//foo
  DEBU[0000] Setting /sys/kernel/config/target/core/user_30/foo/control: hw_block_size=1024
  DEBU[0000] Setting /sys/kernel/config/target/core/user_30/foo/control: async=1
  DEBU[0000] Setting /sys/kernel/config/target/core/user_30/foo/enable: 1
  //  hang forever //