Merge change from vendor to reduce diff only.
ZFS dtrace probes are not supported on FreeBSD yet.
Illumos ZFS issues:
3598 want to dtrace when errors are generated in zfs
MFC after: 3 weeks
the underlying zap_count() to return no errors. However, it is possible
that the pool reaches to such a state where zap_count would return error,
leading to panics when a pool is imported.
This commit changes the ddt_zap_count to return error returned from
zap_count and handle the error appropriately. With this change, it's now
possible to let zpool rollback damaged transaction groups and import the
pool.
Obtained from: ZFS on Linux github (e8fd45a0f9)
MFC after: 1 month
Few new things available from now on:
- Data deduplication.
- Triple parity RAIDZ (RAIDZ3).
- zfs diff.
- zpool split.
- Snapshot holds.
- zpool import -F. Allows to rewind corrupted pool to earlier
transaction group.
- Possibility to import pool in read-only mode.
MFC after: 1 month