releng/13 release/13.0.0 : odd/incorrect diff result over nfs (in a zfs file systems context) [RPi4B genet0 involved in problem]

[Mark Millard]

[Looks like the RPi4B genet0 handling is involved.]

On 2021-May-20, at 22:56, Mark Millard <marklmi at yahoo.com> wrote:
> 
> On 2021-May-20, at 22:19, Rick Macklem <rmacklem at uoguelph.ca> wrote:
> 
>> Ok, so it isn't related to "soft".
>> I am wondering if it is something specific to what
>> "diff -r" does?
>> 
>> Could you try:
>> # cd /usr/ports
>> # ls -R > /tmp/x
>> # cd /mnt
>> # ls -R > /tmp/y
>> # cd /tmp
>> # diff -u -p x y
>> --> To see if "ls -R" finds any difference?
>> 
> 
> # diff -u -p x y 
> --- x   2021-05-20 22:35:48.021663000 -0700
> +++ y   2021-05-20 22:39:03.691936000 -0700
> @@ -227209,10 +227209,10 @@ patch-chrome_browser_background_background__mode__mana
> patch-chrome_browser_background_background__mode__optimizer.cc
> patch-chrome_browser_browser__resources.grd
> patch-chrome_browser_browsing__data_chrome__browsing__data__remover__delegate.cc
> +patch-chrome_browser_chrome__browser
> patch-chrome_browser_chrome__browser__interface__binders.cc
> patch-chrome_browser_chrome__browser__main.cc
> patch-chrome_browser_chrome__browser__main__linux.cc
> -patch-chrome_browser_chrome__browser__main__posix.cc
> patch-chrome_browser_chrome__content__browser__client.cc
> patch-chrome_browser_chrome__content__browser__client.h
> patch-chrome_browser_crash__upload__list_crash__upload__list.cc
> 
> # find /usr/ports/ -name 'patch-chrome_browser_chrome__browser*' -print | more
> /usr/ports/devel/electron12/files/patch-chrome_browser_chrome__browser__main__linux.cc
> /usr/ports/devel/electron12/files/patch-chrome_browser_chrome__browser__main.cc
> /usr/ports/devel/electron12/files/patch-chrome_browser_chrome__browser__main__posix.cc
> /usr/ports/devel/electron12/files/patch-chrome_browser_chrome__browser__interface__binders.cc
> /usr/ports/www/chromium/files/patch-chrome_browser_chrome__browser__main__posix.cc
> /usr/ports/www/chromium/files/patch-chrome_browser_chrome__browser__main.cc
> /usr/ports/www/chromium/files/patch-chrome_browser_chrome__browser__main__linux.cc
> /usr/ports/www/chromium/files/patch-chrome_browser_chrome__browser__interface__binders.cc
> 
> find /mnt/ -name 'patch-chrome_browser_chrome__browser*' -print | more
> /mnt/devel/electron12/files/patch-chrome_browser_chrome__browser__main__linux.cc
> /mnt/devel/electron12/files/patch-chrome_browser_chrome__browser__main.cc
> /mnt/devel/electron12/files/patch-chrome_browser_chrome__browser__main__posix.cc
> /mnt/devel/electron12/files/patch-chrome_browser_chrome__browser__interface__binders.cc
> /mnt/www/chromium/files/patch-chrome_browser_chrome__browser
> /mnt/www/chromium/files/patch-chrome_browser_chrome__browser__main.cc
> /mnt/www/chromium/files/patch-chrome_browser_chrome__browser__main__linux.cc
> /mnt/www/chromium/files/patch-chrome_browser_chrome__browser__interface__binders.cc
> 
> So: patch-chrome_browser_chrome__browser appears to be a
> truncated: patch-chrome_browser_chrome__browser__main__posix.cc
> file name and find also gets the same oddity.
> 
> (Note: This had /usr/ports in a main context and /mnt/
> referring to a release/13.0.0 context.)
> 
>> ps: I do not think that r367492 could cause this, but it would be
>>    nice if you try a kernel with the r367492 patch reverted.
>>    It is currently in all of releng13, stable13 and main, although
>>    the patch to fix this is was just reviewed and may hit main soon.
> 
> Do you want a debug kernel to be used? Do you have a preference
> for main vs. stable/13 vs. release/13.0.0 based? Is it okay to
> stick to the base version things are now based on --or do you
> want me to update to more recent? (That last only applies if
> main or stable/13 is to be put to use.)
> 
>> . . . old history deleted . . .

I reversed the roles of the faster vs. somewhat slower
machine and so far my diff -r attempts for this found
no differences. The machines were using different types
of EtherNet devices.

So I've substituted a different EtherNet device onto
the slower machine: the same type of USB3 EtherNet
device in use on the faster machine (instead of
using the RPi4B's builtin EtherNet). So the below
testing is with both machines having a:

ugen0.6: <Realtek USB 10/100/1000 LAN> at usbus0
ure0 on uhub0
ure0: <Realtek USB 10/100/1000 LAN, class 0/0, rev 3.00/30.00, addr 5> on usbus0
miibus1: <MII bus> on ure0
rgephy0: <RTL8251/8153 1000BASE-T media interface> PHY 0 on miibus1
rgephy0:  none, 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT-FDX, 1000baseT-FDX-master, auto

in use.

I rebooted with this connected instead of the genet0
interface.

Mounting the slower machine's /usr/ports/ as /mnt/ from the faster machine:
No differences found by diff -r this way (expected result).

Mounting the faster machine's /usr/ports/ as /mnt/ from the slower machine:
No differences found by diff -r this way (expected result).

Doing diff -r's from both sides at the same time:
No differences found by diff -r this way (expected result).


So it looks like genet0 or its supporting software
is contributing to the problems that I had reported.

It is interesting that there were no examples of the
content of files reporting a mismatch, just some file
names/paths not finding matches, some with truncated
names or obvious-garbage bytes in names.


Note: The faster machine is a MACCCHIATObin Double
Shot. The slower machine is a RPi4B 8 GiByte.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)