Commit b7391f44 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

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: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 6411bd4a

fs/nfs/delegation.c

+42 −0
Original line number Diff line number Diff line
@@ -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<<NFS_DELEGATION_REFERENCED;

	spin_lock_init(&delegation->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!

 */

fs/nfs/delegation.h

+4 −13
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ struct nfs_delegation { 
enum {

	NFS_DELEGATION_NEED_RECLAIM = 0,

	NFS_DELEGATION_RETURN,

	NFS_DELEGATION_REFERENCED,

};



int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res);
@@ -39,6 +40,7 @@ void nfs_inode_return_delegation_noreclaim(struct inode *inode); 
struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle);

void nfs_super_return_all_delegations(struct super_block *sb);

void nfs_expire_all_delegations(struct nfs_client *clp);

void nfs_expire_unreferenced_delegations(struct nfs_client *clp);

void nfs_handle_cb_pathdown(struct nfs_client *clp);

void nfs_client_return_marked_delegations(struct nfs_client *clp);
@@ -51,19 +53,8 @@ int nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs4_state 
int nfs4_lock_delegation_recall(struct nfs4_state *state, struct file_lock *fl);

int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode);



static inline 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)

		ret = 1;

	rcu_read_unlock();

	return ret;

}

void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);

int nfs_have_delegation(struct inode *inode, int flags);



#else

static inline int nfs_have_delegation(struct inode *inode, int flags)

fs/nfs/nfs4proc.c

+2 −0
Original line number Diff line number Diff line
@@ -421,6 +421,7 @@ static int can_open_delegated(struct nfs_delegation *delegation, mode_t open_fla 
		return 0;

	if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags))

		return 0;

	nfs_mark_delegation_referenced(delegation);

	return 1;

}
@@ -505,6 +506,7 @@ static int update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stat 
	else if (memcmp(deleg_cur->stateid.data, delegation->data, NFS4_STATEID_SIZE) != 0)

		goto no_delegation_unlock;



	nfs_mark_delegation_referenced(deleg_cur);

	__update_open_stateid(state, open_stateid, &deleg_cur->stateid, open_flags);

	ret = 1;

no_delegation_unlock:

fs/nfs/nfs4renewd.c

+1 −0
Original line number Diff line number Diff line
@@ -101,6 +101,7 @@ nfs4_renew_state(struct work_struct *work) 
	cancel_delayed_work(&clp->cl_renewd);

	schedule_delayed_work(&clp->cl_renewd, timeout);

	spin_unlock(&clp->cl_lock);

	nfs_expire_unreferenced_delegations(clp);

out:

	dprintk("%s: done\n", __func__);

}

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