Commit 935fee5d authored by NeilBrown's avatar NeilBrown Committed by Chuck Lever
Browse files

nfsd: use new wake_up_var interfaces. 



The wake_up_var interface is fragile as barriers are sometimes needed.
There are now new interfaces so that most wake-ups can use an interface
that is guaranteed to have all barriers needed.

This patch changes the wake up on cl_cb_inflight to use
atomic_dec_and_wake_up().

It also changes the wake up on rp_locked to use store_release_wake_up().
This involves changing rp_locked from atomic_t to int.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 19d97ac5

fs/nfsd/nfs4callback.c

+1 −2
Original line number Diff line number Diff line
@@ -1036,8 +1036,7 @@ static void nfsd41_cb_inflight_begin(struct nfs4_client *clp) 
static void nfsd41_cb_inflight_end(struct nfs4_client *clp)

{



	if (atomic_dec_and_test(&clp->cl_cb_inflight))

		wake_up_var(&clp->cl_cb_inflight);

	atomic_dec_and_wake_up(&clp->cl_cb_inflight);

}



static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)

fs/nfsd/nfs4state.c

+6 −10
Original line number Diff line number Diff line
@@ -4739,7 +4739,7 @@ static void init_nfs4_replay(struct nfs4_replay *rp) 
	rp->rp_status = nfserr_serverfault;

	rp->rp_buflen = 0;

	rp->rp_buf = rp->rp_ibuf;

	atomic_set(&rp->rp_locked, RP_UNLOCKED);

	rp->rp_locked = RP_UNLOCKED;

}



static int nfsd4_cstate_assign_replay(struct nfsd4_compound_state *cstate,
@@ -4747,9 +4747,9 @@ static int nfsd4_cstate_assign_replay(struct nfsd4_compound_state *cstate, 
{

	if (!nfsd4_has_session(cstate)) {

		wait_var_event(&so->so_replay.rp_locked,

			       atomic_cmpxchg(&so->so_replay.rp_locked,

			       cmpxchg(&so->so_replay.rp_locked,

				       RP_UNLOCKED, RP_LOCKED) != RP_LOCKED);

		if (atomic_read(&so->so_replay.rp_locked) == RP_UNHASHED)

		if (so->so_replay.rp_locked == RP_UNHASHED)

			return -EAGAIN;

		cstate->replay_owner = nfs4_get_stateowner(so);

	}
@@ -4762,9 +4762,7 @@ void nfsd4_cstate_clear_replay(struct nfsd4_compound_state *cstate) 


	if (so != NULL) {

		cstate->replay_owner = NULL;

		atomic_set(&so->so_replay.rp_locked, RP_UNLOCKED);

		smp_mb__after_atomic();

		wake_up_var(&so->so_replay.rp_locked);

		store_release_wake_up(&so->so_replay.rp_locked, RP_UNLOCKED);

		nfs4_put_stateowner(so);

	}

}
@@ -5069,9 +5067,7 @@ move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net) 
	 * Some threads with a reference might be waiting for rp_locked,

	 * so tell them to stop waiting.

	 */

	atomic_set(&oo->oo_owner.so_replay.rp_locked, RP_UNHASHED);

	smp_mb__after_atomic();

	wake_up_var(&oo->oo_owner.so_replay.rp_locked);

	store_release_wake_up(&oo->oo_owner.so_replay.rp_locked, RP_UNHASHED);

	wait_event(close_wq, refcount_read(&s->st_stid.sc_count) == 2);



	release_all_access(s);

fs/nfsd/state.h

+1 −1
Original line number Diff line number Diff line
@@ -505,7 +505,7 @@ struct nfs4_replay { 
	unsigned int		rp_buflen;

	char			*rp_buf;

	struct knfsd_fh		rp_openfh;

	atomic_t		rp_locked;

	int			rp_locked;

	char			rp_ibuf[NFSD4_REPLAY_ISIZE];

};