30b4cb36b1
Andrii Nakryiko reports that sockmap_listen test suite is frequently
failing due to accept() calls erroring out with EAGAIN:
./test_progs:connect_accept_thread:733: accept: Resource temporarily unavailable
connect_accept_thread:FAIL:733
This is because we are using a non-blocking listening TCP socket to
accept() connections without polling on the socket.
While at first switching to blocking mode seems like the right thing to do,
this could lead to test process blocking indefinitely in face of a network
issue, like loopback interface being down, as Andrii pointed out.
Hence, stick to non-blocking mode for TCP listening sockets but with
polling for incoming connection for a limited time before giving up.
Apply this approach to all socket I/O calls in the test suite that we
expect to block indefinitely, that is accept() for TCP and recv() for UDP.
Fixes: 44d28be2b8d4 ("selftests/bpf: Tests for sockmap/sockhash holding listening sockets")
Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200313161049.677700-1-jakub@cloudflare.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.