[PATCH] Properly handle signals on interruptible NFS mounts

[John Baldwin]

When the new RPC layer was brought in, the RPC_INTR return value (to indicate 
an RPC request was interrupted by a signal) was not handled in the NFS client.  
As a result, if an NFS request is interrupted by a signal (on a mount with the 
"intr" option), then the nfs_request() functions would fall through to the 
default case and return EACCES rather than EINTR.  While here, I noticed that 
the new RPC layer also lost all of the RPC statistics the old client used to 
keep (but that are still reported in 'nfsstat -c').  I've added back as many 
of the statistics as I could, but retries are not easy to do as only the RPC 
layer knows about them and not the NFS client.

Index: fs/nfs/nfs_commonkrpc.c
===================================================================
--- fs/nfs/nfs_commonkrpc.c	(revision 245225)
+++ fs/nfs/nfs_commonkrpc.c	(working copy)
@@ -767,12 +767,18 @@
 	if (stat == RPC_SUCCESS) {
 		error = 0;
 	} else if (stat == RPC_TIMEDOUT) {
+		NFSINCRGLOBAL(newnfsstats.rpctimeouts);
 		error = ETIMEDOUT;
 	} else if (stat == RPC_VERSMISMATCH) {
+		NFSINCRGLOBAL(newnfsstats.rpcinvalid);
 		error = EOPNOTSUPP;
 	} else if (stat == RPC_PROGVERSMISMATCH) {
+		NFSINCRGLOBAL(newnfsstats.rpcinvalid);
 		error = EPROTONOSUPPORT;
+	} else if (stat == RPC_INTR) {
+		error = EINTR;
 	} else {
+		NFSINCRGLOBAL(newnfsstats.rpcinvalid);
 		error = EACCES;
 	}
 	if (error) {
Index: nfsclient/nfs_krpc.c
===================================================================
--- nfsclient/nfs_krpc.c	(revision 245225)
+++ nfsclient/nfs_krpc.c	(working copy)
@@ -549,14 +549,21 @@
 	 */
 	if (stat == RPC_SUCCESS)
 		error = 0;
-	else if (stat == RPC_TIMEDOUT)
+	else if (stat == RPC_TIMEDOUT) {
+		nfsstats.rpctimeouts++;
 		error = ETIMEDOUT;
-	else if (stat == RPC_VERSMISMATCH)
+	} else if (stat == RPC_VERSMISMATCH) {
+		nfsstats.rpcinvalid++;
 		error = EOPNOTSUPP;
-	else if (stat == RPC_PROGVERSMISMATCH)
+	} else if (stat == RPC_PROGVERSMISMATCH) {
+		nfsstats.rpcinvalid++;
 		error = EPROTONOSUPPORT;
-	else
+	} else if (stat == RPC_INTR) {
+		error = EINTR;
+	} else {
+		nfsstats.rpcinvalid++;
 		error = EACCES;
+	}
 	if (error)
 		goto nfsmout;
 
@@ -572,6 +579,7 @@
 	if (error == ENOMEM) {
 		m_freem(mrep);
 		AUTH_DESTROY(auth);
+		nfsstats.rpcinvalid++;
 		return (error);
 	}
 

-- 
John Baldwin