fsck updating but not fixing filesystem

[David Brownlee <abs%absd.org@localhost>]

I have a reasonably large ffs filesystem (7.4GB, 35,459,874 files)
used as a dirvish backup target (dirvish creates a hardlink tree copy
of the previous backup, and then runs rsync over it to provide
relatively space efficient backups).

One of the rsync processes hung, and upon reboot fsck checked the
filesystem and marked it clean, but after a while it happened again,
and then again a third time.

This time I've run fsck -f repeatedly and each time it marks the
filesystem as clean, but the next run finds another issue.

This is netbsd-9 amd64 stable from nyftp, DELL, PERC H710P controller,
running RAID1.

filesystem was mounted -o log, which could have contributed to getting
into this state, but presumably fsck should be able to get it out?
(Waves hands and mumbles "triple indirect blocks")

Each fsck run takes a little over 2 hours to complete (hence the
desire to run with -o log)

A sample is below.

** /dev/rdk5
** File system is already clean
** Last Mounted on /home/media
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
DIRECTORY CORRUPTED  I=112567242  OWNER=1000 MODE=40775
SIZE=1536 MTIME=Jun  8 17:11 2020
DIR=?

SALVAGE? yes

MISSING '.'  I=112567242  OWNER=1000 MODE=40775
SIZE=1536 MTIME=Jun  8 17:11 2020
DIR=?

FIX? yes

MISSING '..'  I=112567242  OWNER=1000 MODE=40775
SIZE=1536 MTIME=Jun  8 17:11 2020
DIR=/.backup/server1/20200628/tree/opt/server/backup/source/e7/0154904991e70000bc764e08dbcd93b5/8c

FIX? yes

** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
LINK COUNT FILE I=67564638  OWNER=1000 MODE=100664
SIZE=14190 MTIME=May 13 03:14 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564639  OWNER=1000 MODE=100664
SIZE=45384 MTIME=May 13 03:19 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564640  OWNER=1000 MODE=100664
SIZE=52785 MTIME=May 13 03:18 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564641  OWNER=1000 MODE=100664
SIZE=56018 MTIME=May 13 03:24 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564642  OWNER=1000 MODE=100664
SIZE=34840 MTIME=May 13 03:34 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564643  OWNER=1000 MODE=100664
SIZE=87961 MTIME=May 13 03:31 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564644  OWNER=1000 MODE=100664
SIZE=24847 MTIME=May 13 03:42 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564645  OWNER=1000 MODE=100664
SIZE=43803 MTIME=May 13 03:44 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564646  OWNER=1000 MODE=100664
SIZE=55538 MTIME=May 13 03:50 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564647  OWNER=1000 MODE=100664
SIZE=64131 MTIME=May 13 04:05 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564648  OWNER=1000 MODE=100664
SIZE=32730 MTIME=May 13 04:00 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564649  OWNER=1000 MODE=100664
SIZE=35156 MTIME=May 13 04:50 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564650  OWNER=1000 MODE=100664
SIZE=91008 MTIME=May 13 05:04 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=67564651  OWNER=1000 MODE=100664
SIZE=15127 MTIME=Jun  8 17:11 2020   COUNT 10 SHOULD BE 9
ADJUST? yes

LINK COUNT FILE I=103736490  OWNER=1000 MODE=100664
SIZE=12134 MTIME=Mar 17 01:08 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736491  OWNER=1000 MODE=100664
SIZE=12007 MTIME=Mar 17 01:08 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736492  OWNER=1000 MODE=100664
SIZE=13711 MTIME=Mar 17 01:13 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736493  OWNER=1000 MODE=100664
SIZE=5313 MTIME=Mar 17 01:14 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736494  OWNER=1000 MODE=100664
SIZE=9659 MTIME=Mar 17 01:14 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736495  OWNER=1000 MODE=100664
SIZE=32231 MTIME=Mar 17 01:19 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736496  OWNER=1000 MODE=100664
SIZE=50302 MTIME=Mar 17 01:19 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736497  OWNER=1000 MODE=100664
SIZE=56209 MTIME=Mar 17 01:20 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736498  OWNER=1000 MODE=100664
SIZE=18932 MTIME=Mar 17 01:20 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736499  OWNER=1000 MODE=100664
SIZE=47033 MTIME=Mar 17 01:21 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736500  OWNER=1000 MODE=100664
SIZE=20355 MTIME=Mar 17 01:21 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736501  OWNER=1000 MODE=100664
SIZE=5218 MTIME=Mar 17 01:22 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736502  OWNER=1000 MODE=100664
SIZE=12071 MTIME=Mar 17 01:24 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736503  OWNER=1000 MODE=100664
SIZE=51133 MTIME=Mar 17 01:25 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

LINK COUNT FILE I=103736504  OWNER=1000 MODE=100664
SIZE=33834 MTIME=Mar 17 01:25 2020   COUNT 12 SHOULD BE 11
ADJUST? yes

** Phase 5 - Check Cyl groups
35459874 files, 573829791 used, 152957069 free (3939685 frags,
18627173 blocks, 0.5% fragmentation)