tree 7a040d749346cd1b34b5eaa35980c09a6a57399e
parent 509d7648135f914a3dd64c17484b33df5dd0a19c
author Magnus Karlsson <magnus.karlsson@intel.com> 1531296770 +0200
committer Daniel Borkmann <daniel@iogearbox.net> 1531488871 +0200

xsk: do not return EAGAIN from sendmsg when completion queue is full

This patch stops returning EAGAIN in TX copy mode when the completion
queue is full as zero-copy does not do this. Instead this situation
can be detected by comparing the head and tail pointers of the
completion queue in both modes. In any case, EAGAIN was not the
correct error code here since no amount of calling sendmsg will solve
the problem. Only consuming one or more messages on the completion
queue will fix this.

With this patch, the error reporting becomes consistent between copy
mode and zero-copy mode.

Fixes: 35fcde7f8deb ("xsk: support for Tx")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>