From b7391f44f26b17ad25c7183a3d6ad50f0a9305ff Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 23 Dec 2008 15:21:52 -0500 Subject: NFSv4: Return unreferenced delegations more promptly If the client is not using a delegation, the right thing to do is to return it as soon as possible. This helps reduce the amount of state the server has to track, as well as reducing the potential for conflicts with other clients. Signed-off-by: Trond Myklebust --- fs/nfs/delegation.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'fs/nfs/delegation.c') diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 00c350c031b..e75f2f8c524 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -43,6 +43,27 @@ static void nfs_free_delegation(struct nfs_delegation *delegation) put_rpccred(cred); } +void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) +{ + set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags); +} + +int nfs_have_delegation(struct inode *inode, int flags) +{ + struct nfs_delegation *delegation; + int ret = 0; + + flags &= FMODE_READ|FMODE_WRITE; + rcu_read_lock(); + delegation = rcu_dereference(NFS_I(inode)->delegation); + if (delegation != NULL && (delegation->type & flags) == flags) { + nfs_mark_delegation_referenced(delegation); + ret = 1; + } + rcu_read_unlock(); + return ret; +} + static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state) { struct inode *inode = state->inode; @@ -188,6 +209,7 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct delegation->change_attr = nfsi->change_attr; delegation->cred = get_rpccred(cred); delegation->inode = inode; + delegation->flags = 1<lock); spin_lock(&clp->cl_lock); @@ -382,6 +404,26 @@ void nfs_handle_cb_pathdown(struct nfs_client *clp) nfs_client_mark_return_all_delegations(clp); } +static void nfs_client_mark_return_unreferenced_delegations(struct nfs_client *clp) +{ + struct nfs_delegation *delegation; + + rcu_read_lock(); + list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) { + if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) + continue; + set_bit(NFS_DELEGATION_RETURN, &delegation->flags); + set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); + } + rcu_read_unlock(); +} + +void nfs_expire_unreferenced_delegations(struct nfs_client *clp) +{ + nfs_client_mark_return_unreferenced_delegations(clp); + nfs_delegation_run_state_manager(clp); +} + /* * Asynchronous delegation recall! */ -- cgit v1.2.3