[PATCH] Avoid CTDB daemon deadlock while reading db sequence number (bug 13021)

[Volker Lendecke]

On Mon, Sep 11, 2017 at 01:59:02PM +1000, Amitay Isaacs via samba-technical wrote:
> Once the recovery starts and databases are frozen, then all the record
> access is postponed till the recovery is complete except reading the
> database sequence number.  Database access for reading sequence number
> is done via a control which does not check if the databases are frozen
> or not.

Doesn't this depends on the lock helper process to go away in time
when being asked to? Chouldn't we also do a tdb_chainlock_nonblock in
the parent to avoid any problems with races?

Thanks,

Volker

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