svn commit: r197048 - in head/sys: fs/nfsclient nfsclient

[Rick Macklem]

Author: rmacklem
Date: Wed Sep  9 20:37:49 2009
New Revision: 197048
URL: http://svn.freebsd.org/changeset/base/197048

Log:
  Add LK_NOWITNESS to the vn_lock() calls done on newly created nfs
  vnodes, since these nodes are not linked into the mount queue and,
  as such, the vn_lock() cannot cause a deadlock so LORs are harmless.
  
  Suggested by:	kib
  Approved by:	kib (mentor)
  MFC after:	3 days

Modified:
  head/sys/fs/nfsclient/nfs_clnode.c
  head/sys/fs/nfsclient/nfs_clport.c
  head/sys/nfsclient/nfs_node.c

Modified: head/sys/fs/nfsclient/nfs_clnode.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clnode.c	Wed Sep  9 20:28:58 2009	(r197047)
+++ head/sys/fs/nfsclient/nfs_clnode.c	Wed Sep  9 20:37:49 2009	(r197048)
@@ -157,7 +157,7 @@ ncl_nget(struct mount *mntp, u_int8_t *f
 	    M_NFSFH, M_WAITOK);
 	bcopy(fhp, np->n_fhp->nfh_fh, fhsize);
 	np->n_fhp->nfh_len = fhsize;
-	lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
+	lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_NOWITNESS, NULL);
 	error = insmntque(vp, mntp);
 	if (error != 0) {
 		*npp = NULL;

Modified: head/sys/fs/nfsclient/nfs_clport.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clport.c	Wed Sep  9 20:28:58 2009	(r197047)
+++ head/sys/fs/nfsclient/nfs_clport.c	Wed Sep  9 20:37:49 2009	(r197048)
@@ -232,7 +232,7 @@ nfscl_nget(struct mount *mntp, struct vn
 	 */
 	VN_LOCK_AREC(vp);
 	VN_LOCK_ASHARE(vp);
-	lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
+	lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_NOWITNESS, NULL);
 	error = insmntque(vp, mntp);
 	if (error != 0) {
 		*npp = NULL;

Modified: head/sys/nfsclient/nfs_node.c
==============================================================================
--- head/sys/nfsclient/nfs_node.c	Wed Sep  9 20:28:58 2009	(r197047)
+++ head/sys/nfsclient/nfs_node.c	Wed Sep  9 20:37:49 2009	(r197048)
@@ -158,7 +158,7 @@ nfs_nget(struct mount *mntp, nfsfh_t *fh
 		np->n_fhp = &np->n_fh;
 	bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize);
 	np->n_fhsize = fhsize;
-	lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
+	lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_NOWITNESS, NULL);
 	error = insmntque(vp, mntp);
 	if (error != 0) {
 		*npp = NULL;