Re: ext3/ext4 fsync hack

[Hallvard Breien Furuseth <h.b.furuseth@usit.uio.no>]

Sorry, forgot this one.

On 01/06/2015 03:18 PM, Howard Chu wrote:
> Hallvard Breien Furuseth wrote:
> > Another issue: After an MDB_NOSYNC commit, mdb_env_sync()
> > only fdatasync()s.  It does not know when the file grew.
>
> I suppose we can change the FORCE flag to also cause fsync() to be used.

Insufficient if the user commits with MDB_NOSYNC (maybe when creating
the DB), then turns off MDB_NOSYNC and does mdb_env_sync(env, 0).
Or another process without MDB_NOSYNC doing mdb_env_sync(env, 0).

The lockfile could track what has been synced how, though.
Except it won't know at init, so if someone does a lot of
<open env, commit, close env> they'll end up fsync'ing each time.

--
Hallvard