svn commit: r316719 - head/sys/fs/nfsclient

[Rick Macklem]

Author: rmacklem
Date: Tue Apr 11 22:47:02 2017
New Revision: 316719
URL: https://svnweb.freebsd.org/changeset/base/316719

Log:
  Don't throw away Open state when a NFSv4.1 client recovery fails.
  
  If the ExchangeID/CreateSession operations done by an NFSv4.1 client
  after the server crashes/reboots fails, it is possible that some process/thread
  is waiting for an open_owner lock. If the client state is free'd, this
  can cause a crash.
  This would not normally happen, but has been observed on a mount of the
  AmazonEFS service.
  
  Reported by:	cperciva
  Tested by:	cperciva
  PR:		216086
  MFC after:	2 weeks

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

Modified: head/sys/fs/nfsclient/nfs_clstate.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clstate.c	Tue Apr 11 21:55:39 2017	(r316718)
+++ head/sys/fs/nfsclient/nfs_clstate.c	Tue Apr 11 22:47:02 2017	(r316719)
@@ -1934,10 +1934,9 @@ nfscl_recover(struct nfsclclient *clp, s
 	     error == NFSERR_BADSESSION ||
 	     error == NFSERR_STALEDONTRECOVER) && --trycnt > 0);
 	if (error) {
-		nfscl_cleanclient(clp);
 		NFSLOCKCLSTATE();
-		clp->nfsc_flags &= ~(NFSCLFLAGS_HASCLIENTID |
-		    NFSCLFLAGS_RECOVER | NFSCLFLAGS_RECVRINPROG);
+		clp->nfsc_flags &= ~(NFSCLFLAGS_RECOVER |
+		    NFSCLFLAGS_RECVRINPROG);
 		wakeup(&clp->nfsc_flags);
 		nfsv4_unlock(&clp->nfsc_lock, 0);
 		NFSUNLOCKCLSTATE();
@@ -2254,13 +2253,8 @@ nfscl_hasexpired(struct nfsclclient *clp
 	     error == NFSERR_BADSESSION ||
 	     error == NFSERR_STALEDONTRECOVER) && --trycnt > 0);
 	if (error) {
-		/*
-		 * Clear out any state.
-		 */
-		nfscl_cleanclient(clp);
 		NFSLOCKCLSTATE();
-		clp->nfsc_flags &= ~(NFSCLFLAGS_HASCLIENTID |
-		    NFSCLFLAGS_RECOVER);
+		clp->nfsc_flags &= ~NFSCLFLAGS_RECOVER;
 	} else {
 		/*
 		 * Expire the state for the client.