Commit d7682988 authored by Benny Halevy's avatar Benny Halevy Committed by J. Bruce Fields
Browse files

nfsd4: keep a reference count on client while in use 



Get a refcount on the client on SEQUENCE,
Release the refcount and renew the client when all respective compounds completed.
Do not expire the client by the laundromat while in use.
If the client was expired via another path, free it when the compounds
complete and the refcount reaches 0.

Note that unhash_client_locked must call list_del_init on cl_lru as
it may be called twice for the same client (once from nfs4_laundromat
and then from expire_client)

Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 07cd4909

fs/nfsd/nfs4state.c

+24 −3
Original line number Diff line number Diff line
@@ -701,6 +701,22 @@ free_client(struct nfs4_client *clp) 
	kfree(clp);

}



void

release_session_client(struct nfsd4_session *session)

{

	struct nfs4_client *clp = session->se_client;



	if (!atomic_dec_and_lock(&clp->cl_refcount, &client_lock))

		return;

	if (is_client_expired(clp)) {

		free_client(clp);

		session->se_client = NULL;

	} else

		renew_client_locked(clp);

	spin_unlock(&client_lock);

	nfsd4_put_session(session);

}



/* must be called under the client_lock */

static inline void

unhash_client_locked(struct nfs4_client *clp)
@@ -1476,8 +1492,7 @@ out: 
	/* Hold a session reference until done processing the compound. */

	if (cstate->session) {

		nfsd4_get_session(cstate->session);

		/* Renew the clientid on success and on replay */

		renew_client_locked(session->se_client);

		atomic_inc(&session->se_client->cl_refcount);

	}

	spin_unlock(&client_lock);

	dprintk("%s: return %d\n", __func__, ntohl(status));
@@ -2598,7 +2613,13 @@ nfs4_laundromat(void) 
				clientid_val = t;

			break;

		}

		list_move(&clp->cl_lru, &reaplist);

		if (atomic_read(&clp->cl_refcount)) {

			dprintk("NFSD: client in use (clientid %08x)\n",

				clp->cl_clientid.cl_id);

			continue;

		}

		unhash_client_locked(clp);

		list_add(&clp->cl_lru, &reaplist);

	}

	spin_unlock(&client_lock);

	list_for_each_safe(pos, next, &reaplist) {

fs/nfsd/nfs4xdr.c

+2 −1
Original line number Diff line number Diff line
@@ -3313,7 +3313,8 @@ nfs4svc_encode_compoundres(struct svc_rqst *rqstp, __be32 *p, struct nfsd4_compo 
			dprintk("%s: SET SLOT STATE TO AVAILABLE\n", __func__);

			cs->slot->sl_inuse = false;

		}

		nfsd4_put_session(cs->session);

		/* Renew the clientid on success and on replay */

		release_session_client(cs->session);

	}

	return 1;

}

fs/nfsd/state.h

+1 −0
Original line number Diff line number Diff line
@@ -420,6 +420,7 @@ extern int nfs4_has_reclaimed_state(const char *name, bool use_exchange_id); 
extern void nfsd4_recdir_purge_old(void);

extern int nfsd4_create_clid_dir(struct nfs4_client *clp);

extern void nfsd4_remove_clid_dir(struct nfs4_client *clp);

extern void release_session_client(struct nfsd4_session *);



static inline void

nfs4_put_stateowner(struct nfs4_stateowner *so)

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