net/smc: non blocking recvmsg() return -EAGAIN when no data and signal_pending

stable inclusion
from stable-v5.10.117
commit d5e1b41bf7e02bf2cdccf516adadb083abf4bd0c
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L66B

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d5e1b41bf7e02bf2cdccf516adadb083abf4bd0c



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[ Upstream commit f3c46e41 ]

Non blocking sendmsg will return -EAGAIN when any signal pending
and no send space left, while non blocking recvmsg return -EINTR
when signal pending and no data received. This may makes confused.
As TCP returns -EAGAIN in the conditions described above. Align the
behavior of smc with TCP.

Fixes: 846e344e ("net/smc: add receive timeout check")
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20220512030820.73848-1-guangguan.wang@linux.alibaba.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>