nfsd: clean up lockowner refcounting when finding them

Ensure that when finding or creating a lockowner, that we get a
reference to it. For now, we also take an extra reference when a
lockowner is created that can be put when release_lockowner is called,
but we'll remove that in a later patch once we change how references are
held.

Since we no longer destroy lockowners in the event of an error in
nfsd4_lock, we must change how the seqid gets bumped in the lk_is_new
case. Instead of doing so on creation, do it manually in nfsd4_lock.

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

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 749608b914b4936b4d1e8e5a7fb27b3aa23e5dd7..eaa5f9ebf4441e60316243e56bddbc3bcf701f39 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4754,6 +4754,7 @@ find_lockowner_str(clientid_t *clid, struct xdr_netobj *owner,
                        continue;
                if (!same_owner_str(so, owner, clid))
                        continue;
+               atomic_inc(&so->so_count);
                return lockowner(so);
        }
        return NULL;
@@ -4787,9 +4788,7 @@ alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, str
                return NULL;
        INIT_LIST_HEAD(&lo->lo_owner.so_stateids);
        lo->lo_owner.so_is_open_owner = 0;
-       /* It is the openowner seqid that will be incremented in encode in the
-        * case of new lockowners; so increment the lock seqid manually: */
-       lo->lo_owner.so_seqid = lock->lk_new_lock_seqid + 1;
+       lo->lo_owner.so_seqid = lock->lk_new_lock_seqid;
        lo->lo_owner.so_ops = &lockowner_ops;
        list_add(&lo->lo_owner.so_strhash, &nn->ownerstr_hashtbl[strhashval]);
        return lo;
@@ -4895,6 +4894,7 @@ lookup_or_create_lock_state(struct nfsd4_compound_state *cstate,
                            struct nfsd4_lock *lock,
                            struct nfs4_ol_stateid **lst, bool *new)
 {
+       __be32 status;
        struct nfs4_file *fi = ost->st_stid.sc_file;
        struct nfs4_openowner *oo = openowner(ost->st_stateowner);
        struct nfs4_client *cl = oo->oo_owner.so_client;
@@ -4910,19 +4910,26 @@ lookup_or_create_lock_state(struct nfsd4_compound_state *cstate,
                lo = alloc_init_lock_stateowner(strhashval, cl, ost, lock);
                if (lo == NULL)
                        return nfserr_jukebox;
+               /* FIXME: extra reference for new lockowners for the client */
+               atomic_inc(&lo->lo_owner.so_count);
        } else {
                /* with an existing lockowner, seqids must be the same */
+               status = nfserr_bad_seqid;
                if (!cstate->minorversion &&
                    lock->lk_new_lock_seqid != lo->lo_owner.so_seqid)
-                       return nfserr_bad_seqid;
+                       goto out;
        }
 
        *lst = find_or_create_lock_stateid(lo, fi, inode, ost, new);
        if (*lst == NULL) {
                release_lockowner_if_empty(lo);
-               return nfserr_jukebox;
+               status = nfserr_jukebox;
+               goto out;
        }
-       return nfs_ok;
+       status = nfs_ok;
+out:
+       nfs4_put_stateowner(&lo->lo_owner);
+       return status;
 }
 
 /*
@@ -4941,9 +4948,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        struct file_lock *file_lock = NULL;
        struct file_lock *conflock = NULL;
        __be32 status = 0;
-       bool new_state = false;
        int lkflg;
        int err;
+       bool new = false;
        struct net *net = SVC_NET(rqstp);
        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
@@ -4986,7 +4993,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                                                &lock->v.new.clientid))
                        goto out;
                status = lookup_or_create_lock_state(cstate, open_stp, lock,
-                                                       &lock_stp, &new_state);
+                                                       &lock_stp, &new);
        } else {
                status = nfs4_preprocess_seqid_op(cstate,
                                       lock->lk_old_lock_seqid,
@@ -5085,12 +5092,24 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 out:
        if (filp)
                fput(filp);
-       if (lock_stp)
+       if (lock_stp) {
+               /* Bump seqid manually if the 4.0 replay owner is openowner */
+               if (cstate->replay_owner &&
+                   cstate->replay_owner != &lock_sop->lo_owner &&
+                   seqid_mutating_err(ntohl(status)))
+                       lock_sop->lo_owner.so_seqid++;
+
+               /*
+                * If this is a new, never-before-used stateid, and we are
+                * returning an error, then just go ahead and release it.
+                */
+               if (status && new)
+                       release_lock_stateid(lock_stp);
+
                nfs4_put_stid(&lock_stp->st_stid);
+       }
        if (open_stp)
                nfs4_put_stid(&open_stp->st_stid);
-       if (status && new_state)
-               release_lock_stateid(lock_stp);
        nfsd4_bump_seqid(cstate, status);
        nfs4_unlock_state();
        if (file_lock)
@@ -5125,7 +5144,7 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
            struct nfsd4_lockt *lockt)
 {
        struct file_lock *file_lock = NULL;
-       struct nfs4_lockowner *lo;
+       struct nfs4_lockowner *lo = NULL;
        __be32 status;
        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 
@@ -5188,6 +5207,8 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                nfs4_set_lock_denied(file_lock, &lockt->lt_denied);
        }
 out:
+       if (lo)
+               nfs4_put_stateowner(&lo->lo_owner);
        nfs4_unlock_state();
        if (file_lock)
                locks_free_lock(file_lock);