svn commit: r228827 - head/sys/fs/nfsclient

[Rick Macklem]

Author: rmacklem
Date: Fri Dec 23 02:04:35 2011
New Revision: 228827
URL: http://svn.freebsd.org/changeset/base/228827

Log:
  During investigation of an NFSv4 client crash reported by glebius@,
  jhb@ spotted that nfscl_getstateid() might modify credentials when
  called from nfsrpc_read() for the case where p != NULL, whereas
  nfsrpc_read() only did a crdup() to get new credentials for p == NULL.
  This bug was introduced by r195510, since pre-r195510 nfscl_getstateid()
  only modified credentials for the p == NULL case. This patch modifies
  nfsrpc_read()/nfsrpc_write() so that they do crdup() for the p != NULL case.
  It is conceivable that this bug caused the crash reported by glebius@, but
  that will not be determined for some time, since the crash occurred after
  about 1month of operation.
  
  Tested by:	glebius
  Reviewed by:	jhb
  MFC after:	2 weeks

Modified:
  head/sys/fs/nfsclient/nfs_clrpcops.c

Modified: head/sys/fs/nfsclient/nfs_clrpcops.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clrpcops.c	Fri Dec 23 01:56:25 2011	(r228826)
+++ head/sys/fs/nfsclient/nfs_clrpcops.c	Fri Dec 23 02:04:35 2011	(r228827)
@@ -1232,8 +1232,7 @@ nfsrpc_read(vnode_t vp, struct uio *uiop
 	newcred = cred;
 	if (NFSHASNFSV4(nmp)) {
 		nfhp = np->n_fhp;
-		if (p == NULL)
-			newcred = NFSNEWCRED(cred);
+		newcred = NFSNEWCRED(cred);
 	}
 	retrycnt = 0;
 	do {
@@ -1263,7 +1262,7 @@ nfsrpc_read(vnode_t vp, struct uio *uiop
 	     expireret == 0 && clidrev != 0 && retrycnt < 4));
 	if (error && retrycnt >= 4)
 		error = EIO;
-	if (NFSHASNFSV4(nmp) && p == NULL)
+	if (NFSHASNFSV4(nmp))
 		NFSFREECRED(newcred);
 	return (error);
 }
@@ -1384,8 +1383,7 @@ nfsrpc_write(vnode_t vp, struct uio *uio
 		clidrev = nmp->nm_clp->nfsc_clientidrev;
 	newcred = cred;
 	if (NFSHASNFSV4(nmp)) {
-		if (p == NULL)
-			newcred = NFSNEWCRED(cred);
+		newcred = NFSNEWCRED(cred);
 		nfhp = np->n_fhp;
 	}
 	retrycnt = 0;
@@ -1435,7 +1433,7 @@ nfsrpc_write(vnode_t vp, struct uio *uio
 	    ((error == NFSERR_STALESTATEID ||
 	      error == NFSERR_STALEDONTRECOVER) && called_from_strategy != 0)))
 		error = EIO;
-	if (NFSHASNFSV4(nmp) && p == NULL)
+	if (NFSHASNFSV4(nmp))
 		NFSFREECRED(newcred);
 	return (error);
 }