Add DEXITCODE plumbing to NFS.

Isilon has the concept of an in-memory exit-code ring that saves the last exit
code of a function and allows for stack tracing. This is very helpful when
debugging tough issues.

This patch is essentially a no-op for BSD at this point, until we upstream
the dexitcode logic itself. The patch adds DEXITCODE calls to every NFS
function that returns an errno error code. A number of code paths were also
reorganized to have single exit paths, to reduce code duplication.

Submitted by:   David Kwan <dkwan@isilon.com>
Reviewed by:    rmacklem
Approved by:    zml (mentor)
MFC after:      2 weeks

1 files changed, 12 insertions, 4 deletions

diff --git a/sys/fs/nfs/nfs_commonport.c b/sys/fs/nfs/nfs_commonport.c
index 2853854..4935b70 100644
--- a/sys/fs/nfs/nfs_commonport.c
+++ b/sys/fs/nfs/nfs_commonport.c
@@ -329,6 +329,7 @@ nfsvno_pathconf(struct vnode *vp, int flag, register_t *retf,
 		};
 		error = 0;
 	}
+	NFSEXITCODE(error);
 	return (error);
 }
 
@@ -427,6 +428,7 @@ nfssvc_nfscommon(struct thread *td, struct nfssvc_args *uap)
 	int error;
 
 	error = nfssvc_call(td, uap, td->td_ucred);
+	NFSEXITCODE(error);
 	return (error);
 }
 
@@ -439,9 +441,9 @@ nfssvc_call(struct thread *p, struct nfssvc_args *uap, struct ucred *cred)
 	if (uap->flag & NFSSVC_IDNAME) {
 		error = copyin(uap->argp, (caddr_t)&nid, sizeof (nid));
 		if (error)
-			return (error);
+			goto out;
 		error = nfssvc_idname(&nid);
-		return (error);
+		goto out;
 	} else if (uap->flag & NFSSVC_GETSTATS) {
 		error = copyout(&newnfsstats,
 		    CAST_USER_ADDR_T(uap->argp), sizeof (newnfsstats));
@@ -503,7 +505,7 @@ nfssvc_call(struct thread *p, struct nfssvc_args *uap, struct ucred *cred)
 				    sizeof(newnfsstats.cbrpccnt));
 			}
 		}
-		return (error);
+		goto out;
 	} else if (uap->flag & NFSSVC_NFSUSERDPORT) {
 		u_short sockport;
 
@@ -515,6 +517,9 @@ nfssvc_call(struct thread *p, struct nfssvc_args *uap, struct ucred *cred)
 		nfsrv_nfsuserddelport();
 		error = 0;
 	}
+
+out:
+	NFSEXITCODE(error);
 	return (error);
 }
 
@@ -569,7 +574,7 @@ nfscommon_modevent(module_t mod, int type, void *data)
 	switch (type) {
 	case MOD_LOAD:
 		if (loaded)
-			return (0);
+			goto out;
 		newnfs_portinit();
 		mtx_init(&nfs_nameid_mutex, "nfs_nameid_mutex", NULL, MTX_DEF);
 		mtx_init(&nfs_sockl_mutex, "nfs_sockl_mutex", NULL, MTX_DEF);
@@ -606,6 +611,9 @@ nfscommon_modevent(module_t mod, int type, void *data)
 		error = EOPNOTSUPP;
 		break;
 	}
+
+out:
+	NFSEXITCODE(error);
 	return error;
 }
 static moduledata_t nfscommon_mod = {