nfsd: don't take nfsd4_copy ref for OP_OFFLOAD_STATUS

We're not doing any blocking operations for OP_OFFLOAD_STATUS, so taking
and putting a reference is a waste of effort. Take the client lock,
search for the copy and fetch the wr_bytes_written field and return.

Also, make find_async_copy a static function.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 9435136d7de6b8a0dfd54f363a0f8b1529574689..3b73e4d342bf9eef338f37531c03796aee528e17 100644 (file)
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1824,23 +1824,34 @@ out_err:
        goto out;
 }
 
-struct nfsd4_copy *
-find_async_copy(struct nfs4_client *clp, stateid_t *stateid)
+static struct nfsd4_copy *
+find_async_copy_locked(struct nfs4_client *clp, stateid_t *stateid)
 {
        struct nfsd4_copy *copy;
 
-       spin_lock(&clp->async_lock);
+       lockdep_assert_held(&clp->async_lock);
+
        list_for_each_entry(copy, &clp->async_copies, copies) {
                if (memcmp(&copy->cp_stateid.cs_stid, stateid, NFS4_STATEID_SIZE))
                        continue;
-               refcount_inc(&copy->refcount);
-               spin_unlock(&clp->async_lock);
                return copy;
        }
-       spin_unlock(&clp->async_lock);
        return NULL;
 }
 
+static struct nfsd4_copy *
+find_async_copy(struct nfs4_client *clp, stateid_t *stateid)
+{
+       struct nfsd4_copy *copy;
+
+       spin_lock(&clp->async_lock);
+       copy = find_async_copy_locked(clp, stateid);
+       if (copy)
+               refcount_inc(&copy->refcount);
+       spin_unlock(&clp->async_lock);
+       return copy;
+}
+
 static __be32
 nfsd4_offload_cancel(struct svc_rqst *rqstp,
                     struct nfsd4_compound_state *cstate,
@@ -1925,22 +1936,24 @@ nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        nfsd_file_put(nf);
        return status;
 }
+
 static __be32
 nfsd4_offload_status(struct svc_rqst *rqstp,
                     struct nfsd4_compound_state *cstate,
                     union nfsd4_op_u *u)
 {
        struct nfsd4_offload_status *os = &u->offload_status;
-       __be32 status = 0;
+       __be32 status = nfs_ok;
        struct nfsd4_copy *copy;
        struct nfs4_client *clp = cstate->clp;
 
-       copy = find_async_copy(clp, &os->stateid);
-       if (copy) {
+       spin_lock(&clp->async_lock);
+       copy = find_async_copy_locked(clp, &os->stateid);
+       if (copy)
                os->count = copy->cp_res.wr_bytes_written;
-               nfs4_put_copy(copy);
-       } else
+       else
                status = nfserr_bad_stateid;
+       spin_unlock(&clp->async_lock);
 
        return status;
 }

diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index e94634d3059127f2ca9f385ced1bd694b98ad501..d49d3060ed4f7cccd8e9607965c71a63aee9b992 100644 (file)
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -705,8 +705,6 @@ extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(struct xdr_netobj name
 extern bool nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn);
 
 void put_nfs4_file(struct nfs4_file *fi);
-extern struct nfsd4_copy *
-find_async_copy(struct nfs4_client *clp, stateid_t *staetid);
 extern void nfs4_put_cpntf_state(struct nfsd_net *nn,
                                 struct nfs4_cpntf_state *cps);
 extern __be32 manage_cpntf_state(struct nfsd_net *nn, stateid_t *st,