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: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index c083e539e898ba6593bc0d6185ccb8692aae6a95..94479483c3d6b6294eaa7d48e356aa33fce5614b 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -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)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 741b9449f727defc794347f1b116c955d715e691..9fbf7c8f0a3eebd78fc70134b405d1940299d585 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -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,
-                                             RP_UNLOCKED, RP_LOCKED) != RP_LOCKED);
-               if (atomic_read(&so->so_replay.rp_locked) == RP_UNHASHED)
+                              cmpxchg(&so->so_replay.rp_locked,
+                                      RP_UNLOCKED, RP_LOCKED) != RP_LOCKED);
+               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);

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index e16bb3717fb9bb4725b9498c70dd3da72552845a..ba30b2335b667e40e3bc1aed1384c72c7b62b311 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -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];
 };