nfsd: Add a mutex to protect the NFSv4.0 open owner replay cache

We don't want to rely on the client_mutex for protection in the case of
NFSv4 open owners. Instead, we add a mutex that will only be taken for
NFSv4.0 state mutating operations, and that will be released once the
entire compound is done.

Also, ensure that nfsd4_cstate_assign_replay/nfsd4_cstate_clear_replay
take a reference to the stateowner when they are using it for NFSv4.0
open and lock replay caching.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 8611585f739d0bfd0b2771adfcb41ae73f1b2daf..29cf395b694e4298ab48793b4c5ad8c26acf92a2 100644 (file)
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -469,12 +469,9 @@ out:
                fh_put(resfh);
                kfree(resfh);
        }
-       nfsd4_cleanup_open_state(open, status);
-       if (open->op_openowner && !nfsd4_has_session(cstate))
-               cstate->replay_owner = &open->op_openowner->oo_owner;
+       nfsd4_cleanup_open_state(cstate, open, status);
        nfsd4_bump_seqid(cstate, status);
-       if (!cstate->replay_owner)
-               nfs4_unlock_state();
+       nfs4_unlock_state();
        return status;
 }
 
@@ -1395,10 +1392,7 @@ encode_op:
                        args->ops, args->opcnt, resp->opcnt, op->opnum,
                        be32_to_cpu(status));
 
-               if (cstate->replay_owner) {
-                       nfs4_unlock_state();
-                       cstate->replay_owner = NULL;
-               }
+               nfsd4_cstate_clear_replay(cstate);
                /* XXX Ugh, we need to get rid of this kind of special case: */
                if (op->opnum == OP_READ && op->u.read.rd_filp)
                        fput(op->u.read.rd_filp);

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 5a93e5fafd4a30fae087b4cd58c3d45a442a6132..749608b914b4936b4d1e8e5a7fb27b3aa23e5dd7 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1069,7 +1069,7 @@ void nfsd4_bump_seqid(struct nfsd4_compound_state *cstate, __be32 nfserr)
                return;
 
        if (!seqid_mutating_err(ntohl(nfserr))) {
-               cstate->replay_owner = NULL;
+               nfsd4_cstate_clear_replay(cstate);
                return;
        }
        if (!so)
@@ -2940,6 +2940,28 @@ static void init_nfs4_replay(struct nfs4_replay *rp)
        rp->rp_status = nfserr_serverfault;
        rp->rp_buflen = 0;
        rp->rp_buf = rp->rp_ibuf;
+       mutex_init(&rp->rp_mutex);
+}
+
+static void nfsd4_cstate_assign_replay(struct nfsd4_compound_state *cstate,
+               struct nfs4_stateowner *so)
+{
+       if (!nfsd4_has_session(cstate)) {
+               mutex_lock(&so->so_replay.rp_mutex);
+               cstate->replay_owner = so;
+               atomic_inc(&so->so_count);
+       }
+}
+
+void nfsd4_cstate_clear_replay(struct nfsd4_compound_state *cstate)
+{
+       struct nfs4_stateowner *so = cstate->replay_owner;
+
+       if (so != NULL) {
+               cstate->replay_owner = NULL;
+               mutex_unlock(&so->so_replay.rp_mutex);
+               nfs4_put_stateowner(so);
+       }
 }
 
 static inline void *alloc_stateowner(struct kmem_cache *slab, struct xdr_netobj *owner, struct nfs4_client *clp)
@@ -3855,7 +3877,8 @@ out:
        return status;
 }
 
-void nfsd4_cleanup_open_state(struct nfsd4_open *open, __be32 status)
+void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
+                             struct nfsd4_open *open, __be32 status)
 {
        if (open->op_openowner) {
                struct nfs4_openowner *oo = open->op_openowner;
@@ -3869,6 +3892,8 @@ void nfsd4_cleanup_open_state(struct nfsd4_open *open, __be32 status)
                        } else
                                oo->oo_flags &= ~NFS4_OO_NEW;
                }
+               if (open->op_openowner)
+                       nfsd4_cstate_assign_replay(cstate, &oo->oo_owner);
        }
        if (open->op_file)
                nfsd4_free_file(open->op_file);
@@ -4399,8 +4424,7 @@ nfs4_preprocess_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
        if (status)
                return status;
        stp = openlockstateid(s);
-       if (!nfsd4_has_session(cstate))
-               cstate->replay_owner = stp->st_stateowner;
+       nfsd4_cstate_assign_replay(cstate, stp->st_stateowner);
 
        status = nfs4_seqid_op_checks(cstate, stateid, seqid, stp);
        if (!status)
@@ -4469,8 +4493,7 @@ put_stateid:
        nfs4_put_stid(&stp->st_stid);
 out:
        nfsd4_bump_seqid(cstate, status);
-       if (!cstate->replay_owner)
-               nfs4_unlock_state();
+       nfs4_unlock_state();
        return status;
 }
 
@@ -4544,8 +4567,7 @@ put_stateid:
        nfs4_put_stid(&stp->st_stid);
 out:
        nfsd4_bump_seqid(cstate, status);
-       if (!cstate->replay_owner)
-               nfs4_unlock_state();
+       nfs4_unlock_state();
        return status;
 }
 
@@ -4610,8 +4632,7 @@ nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        /* put reference from nfs4_preprocess_seqid_op */
        nfs4_put_stid(&stp->st_stid);
 out:
-       if (!cstate->replay_owner)
-               nfs4_unlock_state();
+       nfs4_unlock_state();
        return status;
 }
 
@@ -5071,8 +5092,7 @@ out:
        if (status && new_state)
                release_lock_stateid(lock_stp);
        nfsd4_bump_seqid(cstate, status);
-       if (!cstate->replay_owner)
-               nfs4_unlock_state();
+       nfs4_unlock_state();
        if (file_lock)
                locks_free_lock(file_lock);
        if (conflock)
@@ -5236,8 +5256,7 @@ put_stateid:
        nfs4_put_stid(&stp->st_stid);
 out:
        nfsd4_bump_seqid(cstate, status);
-       if (!cstate->replay_owner)
-               nfs4_unlock_state();
+       nfs4_unlock_state();
        if (file_lock)
                locks_free_lock(file_lock);
        return status;

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 628b430e743e470ae772f09af7b33574ba0471b2..72a2a82e11a467263bc543e5ea3be1786f1d398e 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3925,8 +3925,6 @@ status:
  * 
  * XDR note: do not encode rp->rp_buflen: the buffer contains the
  * previously sent already encoded operation.
- *
- * called with nfs4_lock_state() held
  */
 void
 nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index dc725deb4aa8a538dae9a1f4e42cfdeaf768360c..9cba295812f6da855a13ec3e190423db6206eda8 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -328,6 +328,7 @@ struct nfs4_replay {
        unsigned int            rp_buflen;
        char                    *rp_buf;
        struct knfsd_fh         rp_openfh;
+       struct mutex            rp_mutex;
        char                    rp_ibuf[NFSD4_REPLAY_ISIZE];
 };
 

diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 5abf6c942ddf9370b5827f8064676de5ae4d1409..465e7799742a399fe07878af06db0b3f35bc35df 100644 (file)
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -599,7 +599,9 @@ extern __be32 nfsd4_process_open1(struct nfsd4_compound_state *,
                struct nfsd4_open *open, struct nfsd_net *nn);
 extern __be32 nfsd4_process_open2(struct svc_rqst *rqstp,
                struct svc_fh *current_fh, struct nfsd4_open *open);
-extern void nfsd4_cleanup_open_state(struct nfsd4_open *open, __be32 status);
+extern void nfsd4_cstate_clear_replay(struct nfsd4_compound_state *cstate);
+extern void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
+               struct nfsd4_open *open, __be32 status);
 extern __be32 nfsd4_open_confirm(struct svc_rqst *rqstp,
                struct nfsd4_compound_state *, struct nfsd4_open_confirm *oc);
 extern __be32 nfsd4_close(struct svc_rqst *rqstp,
@@ -630,6 +632,7 @@ extern __be32 nfsd4_test_stateid(struct svc_rqst *rqstp,
 extern __be32 nfsd4_free_stateid(struct svc_rqst *rqstp,
                struct nfsd4_compound_state *, struct nfsd4_free_stateid *free_stateid);
 extern void nfsd4_bump_seqid(struct nfsd4_compound_state *, __be32 nfserr);
+
 #endif
 
 /*