Author: rmacklem
Date: Wed Apr 26 22:04:55 2017
New Revision: 317466
URL: https://svnweb.freebsd.org/changeset/base/317466
Log:
MFC: r316694
Fix a crash during unmount of an NFSv4.1 mount.
Larry Rosenman reported a crash on freebsd-current@ which was caused by
a premature release of the krpc backchannel socket structure.
I believe this was caused by a race between the SVC_RELEASE() in clnt_vc.c
and the xprt_unregister() in the higher layer (clnt_rc.c), which tried
to lock the mutex in the xprt structure and crashed.
This patch fixes this by removing the xprt_unregister() in the clnt_vc
layer and allowing this to always be done by the clnt_rc (higher reconnect
layer).
Modified:
stable/11/sys/rpc/clnt_rc.c
stable/11/sys/rpc/clnt_vc.c
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/sys/rpc/clnt_rc.c
==============================================================================
--- stable/11/sys/rpc/clnt_rc.c Wed Apr 26 21:54:53 2017 (r317465)
+++ stable/11/sys/rpc/clnt_rc.c Wed Apr 26 22:04:55 2017 (r317466)
@@ -450,7 +450,6 @@ clnt_reconnect_control(CLIENT *cl, u_int
case CLSET_BACKCHANNEL:
xprt = (SVCXPRT *)info;
- SVC_ACQUIRE(xprt);
xprt_register(xprt);
rc->rc_backchannel = info;
break;
Modified: stable/11/sys/rpc/clnt_vc.c
==============================================================================
--- stable/11/sys/rpc/clnt_vc.c Wed Apr 26 21:54:53 2017 (r317465)
+++ stable/11/sys/rpc/clnt_vc.c Wed Apr 26 22:04:55 2017 (r317466)
@@ -790,7 +790,7 @@ clnt_vc_destroy(CLIENT *cl)
sx_xlock(&xprt->xp_lock);
mtx_lock(&ct->ct_lock);
xprt->xp_p2 = NULL;
- xprt_unregister(xprt);
+ sx_xunlock(&xprt->xp_lock);
}
if (ct->ct_socket) {
@@ -800,10 +800,6 @@ clnt_vc_destroy(CLIENT *cl)
}
mtx_unlock(&ct->ct_lock);
- if (xprt != NULL) {
- sx_xunlock(&xprt->xp_lock);
- SVC_RELEASE(xprt);
- }
mtx_destroy(&ct->ct_lock);
if (so) {
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
