zfs diff output contains erroneous entries with (on_delete_queue) in name

[eharris]

System information

Type	Version/Name
Distribution Name	Debian
Distribution Version	12 (bookworm)
Kernel Version	6.1.0-30-amd64
Architecture	amd64
OpenZFS Version	zfs-2.2.7-1~bpo12+1

Describe the problem you're observing

When issuing zfs diff to compare snapshots, I am getting incorrect entries that appear to be generated by an unhandled condition in the zfs code. These entries are sorted by inode change time as reported by zfs diff, intervening records are omitted.

1702463177.984234053    +       F       /home(on_delete_queue)
1702463222.918242690    +       F       /home(on_delete_queue)
1702463230.678223263    +       F       /home(on_delete_queue)
1702463239.754202772    +       F       /home(on_delete_queue)
1702463242.678196671    +       F       /home(on_delete_queue)
1702463248.222185756    +       F       /home(on_delete_queue)
1702463250.194182077    +       F       /home(on_delete_queue)
1702463257.178169889    +       F       /home(on_delete_queue)
1702463275.406144059    +       F       /home(on_delete_queue)
1704072224.275433402    +       F       /home(on_delete_queue)

The only other reference I found to this (mentioning (on_delete_queue) was #12219, which was on a much older version of zfs. Apparently the problem remains.

Describe how to reproduce the problem

Not sure.

Include any warning/errors/backtraces from the system logs

None

[eharris]

Found another instance with a different but similar message in the zfs diff output.

M       F       /home/test/proj/pictures/2018-10-26T16_20_25Z-13-1.jpg    (+1)

This was a modification record, so should only have 3 fields, but it has a tab and 4th field, (+1).

The command line was zfs diff -HF

[dnelson-1901]

Found another instance with a different but similar message in the zfs diff output.

M       F       /home/test/proj/pictures/2018-10-26T16_20_25Z-13-1.jpg    (+1)

This was a modification record, so should only have 3 fields, but it has a tab and 4th field, (+1).

The command line was zfs diff -HF

I know what this line is - it's a link count change. It's mentioned in the manpage and shown in the example output: https://openzfs.github.io/openzfs-docs/man/v2.2/8/zfs-diff.8.html

[eharris]

Thank you @dnelson-1901 for that pointer, nice to have an explanation for those. The (on_delete_queue) issue remains.

[eadwu]

See it as well. It also may be taking up space? I pruned all snapshots and zfs diff only shows on_delete_queue so I'm just guessing that's the problem.

Rolling back to the initial snapshot reclaims the phantom space usage.