Re: Anti-critical-section assertion failure in mcxt.c reached by walsender

I wrote:
> Thomas Munro <thomas(dot)munro(at)gmail(dot)com> writes:
>> Oh, and I see that 13 has 9989d37d "Remove XLogFileNameP() from the
>> tree" to fix this exact problem.

> Hah, so that maybe explains why thorntail has only shown this in
> the v12 branch. Should we consider back-patching that?

Realizing that 9989d37d prevents the assertion failure, I went
to see if thorntail had shown EIO failures without assertions.
Looking back 180 days, I found these:

sysname | branch | snapshot | stage | l
-----------+---------------+---------------------+--------------------+------------------------------------------------------------------------------------------------------------------------------------------------
thorntail | HEAD | 2021-03-19 21:28:15 | recoveryCheck | 2021-03-20 00:48:48.117 MSK [4089174:11] 008_fsm_truncation.pl PANIC: could not fdatasync file "000000010000000000000002": Input/output error
thorntail | HEAD | 2021-04-06 16:08:10 | recoveryCheck | 2021-04-06 19:30:54.103 MSK [3355008:11] 008_fsm_truncation.pl PANIC: could not fdatasync file "000000010000000000000002": Input/output error
thorntail | REL9_6_STABLE | 2021-04-12 02:38:04 | pg_basebackupCheck | pg_basebackup: could not fsync file "000000010000000000000013": Input/output error

So indeed the kernel-or-hardware problem is affecting other branches.
I suspect that the lack of reports in the pre-v12 branches is mostly
down to there having been many fewer runs on those branches within
the past couple months.

regards, tom lane