From 60ea68129942dc36cd1a3a9bdaec783369ee5a6d Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Thu, 17 Oct 2013 14:13:47 -0400 Subject: [PATCH] NFS: Migration support for RELEASE_LOCKOWNER Currently the Linux NFS client ignores the operation status code for the RELEASE_LOCKOWNER operation. Like NFSv3's UMNT operation, RELEASE_LOCKOWNER is a courtesy to help servers manage their resources, and the outcome is not consequential for the client. During a migration, a server may report NFS4ERR_LEASE_MOVED, in which case the client really should retry, since typically LEASE_MOVED has nothing to do with the current operation, but does prevent it from going forward. Also, it's important for a client to respond as soon as possible to a moved lease condition, since the client's lease could expire on the destination without further action by the client. NFS4ERR_DELAY is not included in the list of valid status codes for RELEASE_LOCKOWNER in RFC 3530bis. However, rfc3530-migration-update does permit migration-capable servers to return DELAY to clients, but only in the context of an ongoing migration. In this case the server has frozen lock state in preparation for migration, and a client retry would help the destination server purge unneeded state once migration recovery is complete. Interestly, NFS4ERR_MOVED is not valid for RELEASE_LOCKOWNER, even though lock owners can be migrated with Transparent State Migration. Note that RFC 3530bis section 9.5 includes RELEASE_LOCKOWNER in the list of operations that renew a client's lease on the server if they succeed. Now that our client pays attention to the operation's status code, we can note that renewal appropriately. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 2564e1c89f56..9f2ccf7471ee 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5800,6 +5800,7 @@ struct nfs_release_lockowner_data { struct nfs_release_lockowner_args args; struct nfs4_sequence_args seq_args; struct nfs4_sequence_res seq_res; + unsigned long timestamp; }; static void nfs4_release_lockowner_prepare(struct rpc_task *task, void *calldata) @@ -5807,12 +5808,27 @@ static void nfs4_release_lockowner_prepare(struct rpc_task *task, void *calldata struct nfs_release_lockowner_data *data = calldata; nfs40_setup_sequence(data->server, &data->seq_args, &data->seq_res, task); + data->timestamp = jiffies; } static void nfs4_release_lockowner_done(struct rpc_task *task, void *calldata) { struct nfs_release_lockowner_data *data = calldata; + struct nfs_server *server = data->server; + nfs40_sequence_done(task, &data->seq_res); + + switch (task->tk_status) { + case 0: + renew_lease(server, data->timestamp); + break; + case -NFS4ERR_STALE_CLIENTID: + case -NFS4ERR_EXPIRED: + case -NFS4ERR_LEASE_MOVED: + case -NFS4ERR_DELAY: + if (nfs4_async_handle_error(task, server, NULL) == -EAGAIN) + rpc_restart_call_prepare(task); + } } static void nfs4_release_lockowner_release(void *calldata)