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* nfsdcltrack: fetch NFSDCLTRACK_GRACE_START out of environmentJeff Layton2014-09-191-1/+71
| | | | | | | | | | | | | Allow the fetching of NFSDCLTRACK_GRACE_START out of environment variables. If it's present in the "create" or "init" upcalls, then we can use that to query the database to see whether there are any clients that have not issued a RECLAIM_COMPLETE since that time. If there aren't any, then we know that all reclaim activity is now done and we can then cue the kernel to lift the grace period. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Steve Dickson <steved@redhat.com>
* nfsdcltrack: grab the NFSDCLTRACK_CLIENT_HAS_SESSION env var if it's presentJeff Layton2014-09-191-5/+26
| | | | | | | | | | ...and set the has_session field in the DB based on whether it's true or not. Since we no longer set the timestamp for v4.1+ clients on a check operation, we must be careful to set the timestamp to zero for v4.1+ clients found via the legacy tracker. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Steve Dickson <steved@redhat.com>
* nfsdcltrack: overhaul database initializtionJeff Layton2014-09-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have some possibility for races with nfsdcltrack when the DB schema is upgraded. Suppose we update the nfs-utils package on a machine after the DB has been initialized. With the current scheme of initializing the DB only during the "init" phase, we could end up with a new program that expects a new schema with an old database. We could try to do a one-time update when the package is installed, but that could be racy. We could get an upcall between when the program is installed and when we run the update. Also, relying on packaging to get that right is tricky at best. To fix this, change how the database initialization and checking of the schema revision works. On every upcall, attempt to open the db as we normally would. If that fails, then try to create the directory if it doesn't exist and then retry the open. If it fails again, then give up. If we get a successful open, then query the DB for the schema version. If it matches what we expect, then declare success and move on. If the query fails then assume that the DB isn't set up yet. Start an exclusive transaction, check the schema version again and then set up the DB if no one raced in to create it in the meantime. This should only add a tiny bit of overhead on most upcalls (just an extra select of the parameters table), and should improve the performance of the "init" upcall. It'll also make it possible to handle DB schema changes sanely. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Signed-off-by: Steve Dickson <steved@redhat.com>
* nfsdcltrack: skip "." and ".." when trying to clean out legacy recdirJeff Layton2012-11-281-0/+11
| | | | | | | | readdir picks up these two entries as "normal" dentries, but rmdir'ing them won't work (and we wouldn't want to remove them anyway). Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve Dickson <steved@redhat.com>
* nfsdcltrack: add a legacy transition mechanismJeff Layton2012-11-111-0/+85
| | | | | | | | | | | | | | | | | | | | | | | | | | If the kernel passes the legacy recdir path in the environment, then we can use that to transition from the old legacy tracker to the new one. On a "check" operation, if there is no record of the client in the database, check to see if there is a matching recoverydir. If there isn't then just refuse the reclaim. If there is, then insert a new record for this client into the db, and remove the legacy recoverydir. If either of those operations fail, then refuse the reclaim. On a "gracedone" operation, clean out the entire legacy recoverydir after purging any unreclaimed records from the db. There's not much we can do if this fails, so just log a warning if it does. Note that this is a one-way conversion. If the user later boots back into an older kernel, it will have no knowledge of the new database. In principle, we could create a tool that would walk the clients table, md5 hash the clientids and create directories in the v4recovery dir. Doing that automatically would be pretty difficult however. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve Dickson <steved@redhat.com>
* nfsdcltrack: add a new "one-shot" program for manipulating the client ↵Jeff Layton2012-11-111-0/+436
tracking db Usermode helper upcalls are all the rage these days for infrequent upcalls, since they make it rather idiot-proof. No running daemon is required, so there's really no setup beyond ensuring that the callout exists and is runnable. This program adds a callout program to nfs-utils for that purpose. The storage engine on the backend is identical to the one used by nfsdcld. This just adds a new frontend for it. For now, building with --enable-nfsdcltrack gives you both nfsdcld and nfsdcltrack programs. A later patch will remove nfsdcld altogether. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve Dickson <steved@redhat.com>