[LTP] [PATCH v6] lib: Use backoff polling to wait for loop device nodes

[Avinesh Kumar]

Hi,


d90d2004657b ("lib: Use backoff polling to wait for loop
   device nodes")

This patch introduces a regression in few old API based tests which
call tst_acquire_device() -> tst_find_free_loopdev()/tst_attach_device()):

     - linkat02
     - mknodat02
     - rename11
     - renameat01
     - umount2_01

these fail with
tst_kconfig.c:90: TINFO: Parsing kernel config '/proc/config.gz'
linkat02    1  TBROK  :  tst_sig.c:232: unexpected signal SIGCHLD(17) 
received (pid = 122504).
linkat02    2  TBROK  :  Remaining cases broken

which comes from def_handler(int sig) in lib/tst_sig.c

The old API treats SIGCHLD as fatal, which is now being generated while
reading the kconfig file. So we need to address this until we convert
these tests to new API, maybe by intentionally avoiding
TST_RETRY_FN_EXP_BACKOFF()/tst_multiply_timeout() for now.


Regards,
Avinesh