On Sun, 28 Jun 2020, Simon Arlott wrote:

On 23/06/2020 21:42, Henrique de Moraes Holschuh wrote:

quoted

[1] I have long lost the will and energy to pursue this, so *this* is a
throw-away anecdote for anyone that cares: I reported here a few years
ago that many models of *SATA* based SSDs from Crucial/Micron, Samsung
and Intel were complaining (through their SMART attributes) that Linux
was causing unsafe shutdowns.

https://lkml.org/lkml/2017/4/10/1181

TL;DR: wait one *extra* second after the SSD acknowleged the STOP
command as complete before you trust the SSD device is safe to be
powered down (i.e. before reboot, suspend, poweroff/shutdown, and device
removal/detach).  This worked around the issue for every vendor and
model of SSD we tested.

Looking through that thread, it looks like a simple 1 second delay on
shutdown/reboot patch hasn't been proposed yet?

It should work, yes.  And it likely would help with whatever $RANDOM
other hardware that has the same issues but has no way to make itself
noticed, so *I* would appreciate it as something I could tell the kernel
to *always* do.

But for "sd" devices, it would be likely more complete to also ensure
the delay for device removal (not just on reboot and power off).

In my case none of the SSDs are recording unexpected power loss if they
are stopped before the reboot, but the reboot won't necessarily be
instantaneous after the last stop command returns.

Yes, it is a race.  If either the SSD happens to need less "extra" time,
or the computer takes a bit longer to reboot/power off, all is well.
Otherwise, the SSD loses the race, and gets powered down at an
inappropriate time.

-- 
  Henrique Holschuh