Index: sys/compat/linprocfs/linprocfs.c
===================================================================
--- sys/compat/linprocfs/linprocfs.c
+++ sys/compat/linprocfs/linprocfs.c
@@ -340,7 +340,7 @@
 	error = namei(&nd);
 	lep = linux_emul_path;
 	if (error == 0) {
-		if (vn_fullpath(td, nd.ni_vp, &dlep, &flep) == 0)
+		if (vn_fullpath(td, nd.ni_vp, 0, &dlep, &flep) == 0)
 			lep = dlep;
 		vrele(nd.ni_vp);
 	}
@@ -884,7 +884,7 @@
 	char *fullpath = "unknown";
 	char *freepath = NULL;
 
-	vn_fullpath(td, p->p_fd->fd_cdir, &fullpath, &freepath);
+	vn_fullpath(td, p->p_fd->fd_cdir, 0, &fullpath, &freepath);
 	sbuf_printf(sb, "%s", fullpath);
 	if (freepath)
 		free(freepath, M_TEMP);
@@ -902,7 +902,7 @@
 	char *freepath = NULL;
 
 	rvp = jailed(p->p_ucred) ? p->p_fd->fd_jdir : p->p_fd->fd_rdir;
-	vn_fullpath(td, rvp, &fullpath, &freepath);
+	vn_fullpath(td, rvp, 0, &fullpath, &freepath);
 	sbuf_printf(sb, "%s", fullpath);
 	if (freepath)
 		free(freepath, M_TEMP);
@@ -1053,7 +1053,7 @@
 			shadow_count = obj->shadow_count;
 			VM_OBJECT_RUNLOCK(obj);
 			if (vp) {
-				vn_fullpath(td, vp, &name, &freename);
+				vn_fullpath(td, vp, 0, &name, &freename);
 				vn_lock(vp, LK_SHARED | LK_RETRY);
 				VOP_GETATTR(vp, &vat, td->td_ucred);
 				ino = vat.va_fileid;
Index: sys/dev/hwpmc/hwpmc_mod.c
===================================================================
--- sys/dev/hwpmc/hwpmc_mod.c
+++ sys/dev/hwpmc/hwpmc_mod.c
@@ -728,7 +728,7 @@
 
 	*fullpath = "unknown";
 	*freepath = NULL;
-	vn_fullpath(curthread, v, fullpath, freepath);
+	vn_fullpath(curthread, v, 0, fullpath, freepath);
 }
 
 /*
Index: sys/fs/procfs/procfs.c
===================================================================
--- sys/fs/procfs/procfs.c
+++ sys/fs/procfs/procfs.c
@@ -77,7 +77,7 @@
 	textvp = p->p_textvp;
 	vhold(textvp);
 	PROC_UNLOCK(p);
-	error = vn_fullpath(td, textvp, &fullpath, &freepath);
+	error = vn_fullpath(td, textvp, 0, &fullpath, &freepath);
 	vdrop(textvp);
 	if (error == 0)
 		sbuf_printf(sb, "%s", fullpath);
Index: sys/fs/procfs/procfs_map.c
===================================================================
--- sys/fs/procfs/procfs_map.c
+++ sys/fs/procfs/procfs_map.c
@@ -188,7 +188,7 @@
 			shadow_count = obj->shadow_count;
 			VM_OBJECT_RUNLOCK(obj);
 			if (vp != NULL) {
-				vn_fullpath(td, vp, &fullpath, &freepath);
+				vn_fullpath(td, vp, 0, &fullpath, &freepath);
 				vrele(vp);
 			}
 		} else {
Index: sys/kern/imgact_elf.c
===================================================================
--- sys/kern/imgact_elf.c
+++ sys/kern/imgact_elf.c
@@ -1870,7 +1870,7 @@
 		sbuf_set_drain(sb, sbuf_drain_count, &size);
 		sbuf_bcat(sb, &structsize, sizeof(structsize));
 		PROC_LOCK(p);
-		kern_proc_filedesc_out(p, sb, -1);
+		kern_proc_filedesc_out(p, sb, -1, LK_NOWAIT);
 		sbuf_finish(sb);
 		sbuf_delete(sb);
 		*sizep = size;
@@ -1878,7 +1878,7 @@
 		structsize = sizeof(struct kinfo_file);
 		sbuf_bcat(sb, &structsize, sizeof(structsize));
 		PROC_LOCK(p);
-		kern_proc_filedesc_out(p, sb, -1);
+		kern_proc_filedesc_out(p, sb, -1, LK_NOWAIT);
 	}
 }
 
Index: sys/kern/kern_descrip.c
===================================================================
--- sys/kern/kern_descrip.c
+++ sys/kern/kern_descrip.c
@@ -3090,7 +3090,7 @@
 
 static void
 export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp,
-    struct kinfo_file *kif, struct filedesc *fdp)
+    struct kinfo_file *kif, struct filedesc *fdp, int lkflags)
 {
 	int error;
 
@@ -3111,7 +3111,7 @@
 	 * This may drop the filedesc lock, so the 'fp' cannot be
 	 * accessed after this call.
 	 */
-	error = fo_fill_kinfo(fp, kif, fdp);
+	error = fo_fill_kinfo(fp, kif, fdp, lkflags);
 	if (error == 0)
 		kif->kf_status |= KF_ATTR_VALID;
 	pack_kinfo(kif);
@@ -3119,14 +3119,14 @@
 
 static void
 export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags,
-    struct kinfo_file *kif)
+    struct kinfo_file *kif, int lkflags)
 {
 	int error;
 
 	bzero(kif, sizeof(*kif));
 
 	kif->kf_type = KF_TYPE_VNODE;
-	error = vn_fill_kinfo_vnode(vp, kif);
+	error = vn_fill_kinfo_vnode(vp, kif, lkflags);
 	if (error == 0)
 		kif->kf_status |= KF_ATTR_VALID;
 	kif->kf_flags = xlate_fflags(fflags);
@@ -3164,13 +3164,13 @@
 
 static int
 export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp,
-    struct export_fd_buf *efbuf)
+    struct export_fd_buf *efbuf, int lkflags)
 {
 	int error;
 
 	if (efbuf->remainder == 0)
 		return (0);
-	export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp);
+	export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, lkflags);
 	FILEDESC_SUNLOCK(efbuf->fdp);
 	error = export_kinfo_to_sb(efbuf);
 	FILEDESC_SLOCK(efbuf->fdp);
@@ -3179,7 +3179,7 @@
 
 static int
 export_vnode_to_sb(struct vnode *vp, int fd, int fflags,
-    struct export_fd_buf *efbuf)
+    struct export_fd_buf *efbuf, int lkflags)
 {
 	int error;
 
@@ -3187,7 +3187,7 @@
 		return (0);
 	if (efbuf->fdp != NULL)
 		FILEDESC_SUNLOCK(efbuf->fdp);
-	export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif);
+	export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, lkflags);
 	error = export_kinfo_to_sb(efbuf);
 	if (efbuf->fdp != NULL)
 		FILEDESC_SLOCK(efbuf->fdp);
@@ -3198,9 +3198,12 @@
  * Store a process file descriptor information to sbuf.
  *
  * Takes a locked proc as argument, and returns with the proc unlocked.
+ *
+ * LK_NOWAIT may be passed in lkflags to avoid sleeping on vnode locks.
  */
 int
-kern_proc_filedesc_out(struct proc *p,  struct sbuf *sb, ssize_t maxlen)
+kern_proc_filedesc_out(struct proc *p,  struct sbuf *sb, ssize_t maxlen,
+    int lkflags)
 {
 	struct file *fp;
 	struct filedesc *fdp;
@@ -3234,12 +3237,13 @@
 	efbuf->remainder = maxlen;
 	if (tracevp != NULL)
 		export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE,
-		    efbuf);
+		    efbuf, lkflags);
 	if (textvp != NULL)
-		export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf);
+		export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf,
+		    lkflags);
 	if (cttyvp != NULL)
 		export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE,
-		    efbuf);
+		    efbuf, lkflags);
 	error = 0;
 	if (fdp == NULL)
 		goto fail;
@@ -3248,17 +3252,20 @@
 	/* working directory */
 	if (fdp->fd_cdir != NULL) {
 		vref(fdp->fd_cdir);
-		export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf);
+		export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf,
+		    lkflags);
 	}
 	/* root directory */
 	if (fdp->fd_rdir != NULL) {
 		vref(fdp->fd_rdir);
-		export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf);
+		export_vnode_to_sb(fdp->fd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf,
+		    lkflags);
 	}
 	/* jail directory */
 	if (fdp->fd_jdir != NULL) {
 		vref(fdp->fd_jdir);
-		export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf);
+		export_vnode_to_sb(fdp->fd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf,
+		    lkflags);
 	}
 	for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) {
 		if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
@@ -3274,7 +3281,7 @@
 		 * re-validate and re-evaluate its properties when the
 		 * loop continues.
 		 */
-		error = export_file_to_sb(fp, i, &rights, efbuf);
+		error = export_file_to_sb(fp, i, &rights, efbuf, lkflags);
 		if (error != 0 || efbuf->remainder == 0)
 			break;
 	}
@@ -3308,7 +3315,7 @@
 		return (error);
 	}
 	maxlen = req->oldptr != NULL ? req->oldlen : -1;
-	error = kern_proc_filedesc_out(p, &sb, maxlen);
+	error = kern_proc_filedesc_out(p, &sb, maxlen, 0);
 	error2 = sbuf_finish(&sb);
 	sbuf_delete(&sb);
 	return (error != 0 ? error : error2);
@@ -3348,7 +3355,7 @@
 
 	vref(vp);
 	FILEDESC_SUNLOCK(fdp);
-	export_vnode_to_kinfo(vp, type, 0, kif);
+	export_vnode_to_kinfo(vp, type, 0, kif, 0);
 	kinfo_to_okinfo(kif, okif);
 	error = SYSCTL_OUT(req, okif, sizeof(*okif));
 	FILEDESC_SLOCK(fdp);
@@ -3391,7 +3398,7 @@
 	for (i = 0; fdp->fd_refcnt > 0 && i <= fdp->fd_lastfile; i++) {
 		if ((fp = fdp->fd_ofiles[i].fde_file) == NULL)
 			continue;
-		export_file_to_kinfo(fp, i, NULL, kif, fdp);
+		export_file_to_kinfo(fp, i, NULL, kif, fdp, 0);
 		FILEDESC_SUNLOCK(fdp);
 		kinfo_to_okinfo(kif, okif);
 		error = SYSCTL_OUT(req, okif, sizeof(*okif));
@@ -3474,7 +3481,7 @@
 	else {
 		vref(fdp->fd_cdir);
 		error = export_vnode_to_sb(fdp->fd_cdir, KF_FD_TYPE_CWD,
-		    FREAD, efbuf);
+		    FREAD, efbuf, 0);
 	}
 	FILEDESC_SUNLOCK(fdp);
 	fddrop(fdp);
@@ -3730,7 +3737,8 @@
 }
 
 static int
-badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp,
+    int lkflags)
 {
 
 	return (0);
Index: sys/kern/kern_event.c
===================================================================
--- sys/kern/kern_event.c
+++ sys/kern/kern_event.c
@@ -1832,7 +1832,8 @@
 }
 
 static int
-kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+kqueue_fill_kinfo(struct file *fp, struct kinfo_file *kif,
+    struct filedesc *fdp, int lkflags)
 {
 
 	kif->kf_type = KF_TYPE_KQUEUE;
Index: sys/kern/kern_exec.c
===================================================================
--- sys/kern/kern_exec.c
+++ sys/kern/kern_exec.c
@@ -550,7 +550,7 @@
 	 */
 	if (imgp->auxargs != NULL &&
 	    ((args->fname != NULL && args->fname[0] == '/') ||
-	     vn_fullpath(td, imgp->vp, &imgp->execpath, &imgp->freepath) != 0))
+	     vn_fullpath(td, imgp->vp, 0, &imgp->execpath, &imgp->freepath) != 0))
 		imgp->execpath = args->fname;
 
 	if (disallow_high_osrel &&
Index: sys/kern/kern_proc.c
===================================================================
--- sys/kern/kern_proc.c
+++ sys/kern/kern_proc.c
@@ -1977,7 +1977,7 @@
 	vref(vp);
 	if (*pidp != -1)
 		PROC_UNLOCK(p);
-	error = vn_fullpath(req->td, vp, &retbuf, &freebuf);
+	error = vn_fullpath(req->td, vp, 0, &retbuf, &freebuf);
 	vrele(vp);
 	if (error)
 		return (error);
@@ -2138,7 +2138,7 @@
 			kve->kve_shadow_count = obj->shadow_count;
 			VM_OBJECT_RUNLOCK(obj);
 			if (vp != NULL) {
-				vn_fullpath(curthread, vp, &fullpath,
+				vn_fullpath(curthread, vp, 0, &fullpath,
 				    &freepath);
 				cred = curthread->td_ucred;
 				vn_lock(vp, LK_SHARED | LK_RETRY);
@@ -2367,7 +2367,7 @@
 			kve->kve_shadow_count = obj->shadow_count;
 			VM_OBJECT_RUNLOCK(obj);
 			if (vp != NULL) {
-				vn_fullpath(curthread, vp, &fullpath,
+				vn_fullpath(curthread, vp, 0, &fullpath,
 				    &freepath);
 				kve->kve_vn_type = vntype_to_kinfo(vp->v_type);
 				cred = curthread->td_ucred;
Index: sys/kern/sys_pipe.c
===================================================================
--- sys/kern/sys_pipe.c
+++ sys/kern/sys_pipe.c
@@ -1610,12 +1610,13 @@
 }
 
 static int
-pipe_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+pipe_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp,
+    int lkflags)
 {
 	struct pipe *pi;
 
 	if (fp->f_type == DTYPE_FIFO)
-		return (vn_fill_kinfo(fp, kif, fdp));
+		return (vn_fill_kinfo(fp, kif, fdp, lkflags));
 	kif->kf_type = KF_TYPE_PIPE;
 	pi = fp->f_data;
 	kif->kf_un.kf_pipe.kf_pipe_addr = (uintptr_t)pi;
Index: sys/kern/sys_procdesc.c
===================================================================
--- sys/kern/sys_procdesc.c
+++ sys/kern/sys_procdesc.c
@@ -536,7 +536,7 @@
 
 static int
 procdesc_fill_kinfo(struct file *fp, struct kinfo_file *kif,
-    struct filedesc *fdp)
+    struct filedesc *fdp, int lkflags)
 {
 	struct procdesc *pdp;
 
Index: sys/kern/sys_process.c
===================================================================
--- sys/kern/sys_process.c
+++ sys/kern/sys_process.c
@@ -412,7 +412,7 @@
 		if (vp != NULL) {
 			freepath = NULL;
 			fullpath = NULL;
-			vn_fullpath(td, vp, &fullpath, &freepath);
+			vn_fullpath(td, vp, 0, &fullpath, &freepath);
 			vn_lock(vp, LK_SHARED | LK_RETRY);
 			if (VOP_GETATTR(vp, &vattr, td->td_ucred) == 0) {
 				pve->pve_fileid = vattr.va_fileid;
Index: sys/kern/sys_socket.c
===================================================================
--- sys/kern/sys_socket.c
+++ sys/kern/sys_socket.c
@@ -310,7 +310,8 @@
 }
 
 static int
-soo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+soo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp,
+    int lkflags)
 {
 	struct sockaddr *sa;
 	struct inpcb *inpcb;
Index: sys/kern/tty_pts.c
===================================================================
--- sys/kern/tty_pts.c
+++ sys/kern/tty_pts.c
@@ -585,7 +585,8 @@
 }
 
 static int
-ptsdev_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+ptsdev_fill_kinfo(struct file *fp, struct kinfo_file *kif,
+    struct filedesc *fdp, int lkflags)
 {
 	struct tty *tp;
 
Index: sys/kern/uipc_mqueue.c
===================================================================
--- sys/kern/uipc_mqueue.c
+++ sys/kern/uipc_mqueue.c
@@ -2573,7 +2573,8 @@
 }
 
 static int
-mqf_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+mqf_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp,
+    int lkflags)
 {
 
 	kif->kf_type = KF_TYPE_MQUEUE;
Index: sys/kern/uipc_sem.c
===================================================================
--- sys/kern/uipc_sem.c
+++ sys/kern/uipc_sem.c
@@ -256,7 +256,8 @@
 }
 
 static int
-ksem_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+ksem_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp,
+    int lkflags)
 {
 	struct ksem *ks;
 
Index: sys/kern/uipc_shm.c
===================================================================
--- sys/kern/uipc_shm.c
+++ sys/kern/uipc_shm.c
@@ -1038,7 +1038,7 @@
 }
 
 static int
-shm_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+shm_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp, int lkflags)
 {
 	struct shmfd *shmfd;
 
Index: sys/kern/vfs_cache.c
===================================================================
--- sys/kern/vfs_cache.c
+++ sys/kern/vfs_cache.c
@@ -306,10 +306,10 @@
 
 
 static void cache_zap(struct namecache *ncp);
-static int vn_vptocnp_locked(struct vnode **vp, struct ucred *cred, char *buf,
-    u_int *buflen);
+static int vn_vptocnp_locked(struct vnode **vp, struct ucred *cred,
+    int lkflags, char *buf, u_int *buflen);
 static int vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir,
-    char *buf, char **retbuf, u_int buflen);
+    int lkflags, char *buf, char **retbuf, u_int buflen);
 
 static MALLOC_DEFINE(M_VFSCACHE, "vfscache", "VFS name cache entries");
 
@@ -1081,7 +1081,7 @@
 	rdir = fdp->fd_rdir;
 	VREF(rdir);
 	FILEDESC_SUNLOCK(fdp);
-	error = vn_fullpath1(td, cdir, rdir, tmpbuf, &bp, buflen);
+	error = vn_fullpath1(td, cdir, rdir, 0, tmpbuf, &bp, buflen);
 	vrele(rdir);
 	vrele(cdir);
 
@@ -1125,13 +1125,17 @@
  * cache (if available)
  */
 int
-vn_fullpath(struct thread *td, struct vnode *vn, char **retbuf, char **freebuf)
+vn_fullpath(struct thread *td, struct vnode *vn, int lkflags, char **retbuf,
+    char **freebuf)
 {
 	char *buf;
 	struct filedesc *fdp;
 	struct vnode *rdir;
 	int error;
 
+	KASSERT((lkflags & ~LK_NOWAIT) == 0,
+	    ("invalid lkflags: %08x", lkflags));
+
 	if (disablefullpath)
 		return (ENODEV);
 	if (vn == NULL)
@@ -1143,7 +1147,7 @@
 	rdir = fdp->fd_rdir;
 	VREF(rdir);
 	FILEDESC_SUNLOCK(fdp);
-	error = vn_fullpath1(td, vn, rdir, buf, retbuf, MAXPATHLEN);
+	error = vn_fullpath1(td, vn, rdir, lkflags, buf, retbuf, MAXPATHLEN);
 	vrele(rdir);
 
 	if (!error)
@@ -1171,7 +1175,7 @@
 	if (vn == NULL)
 		return (EINVAL);
 	buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
-	error = vn_fullpath1(td, vn, rootvnode, buf, retbuf, MAXPATHLEN);
+	error = vn_fullpath1(td, vn, rootvnode, 0, buf, retbuf, MAXPATHLEN);
 	if (!error)
 		*freebuf = buf;
 	else
@@ -1185,15 +1189,15 @@
 	int error;
 
 	CACHE_RLOCK();
-	error = vn_vptocnp_locked(vp, cred, buf, buflen);
+	error = vn_vptocnp_locked(vp, cred, 0, buf, buflen);
 	if (error == 0)
 		CACHE_RUNLOCK();
 	return (error);
 }
 
 static int
-vn_vptocnp_locked(struct vnode **vp, struct ucred *cred, char *buf,
-    u_int *buflen)
+vn_vptocnp_locked(struct vnode **vp, struct ucred *cred, int lkflags,
+    char *buf, u_int *buflen)
 {
 	struct vnode *dvp;
 	struct namecache *ncp;
@@ -1228,9 +1232,17 @@
 	SDT_PROBE(vfs, namecache, fullpath, miss, vp, 0, 0, 0, 0);
 
 	CACHE_RUNLOCK();
-	vn_lock(*vp, LK_SHARED | LK_RETRY);
-	error = VOP_VPTOCNP(*vp, &dvp, cred, buf, buflen);
-	vput(*vp);
+
+	lkflags |= LK_SHARED;
+	if ((lkflags & LK_NOWAIT) == 0)
+		lkflags |= LK_RETRY;
+	error = vn_lock(*vp, lkflags);
+	if (error)
+		vrele(*vp);
+	else {
+		error = VOP_VPTOCNP(*vp, &dvp, cred, buf, buflen);
+		vput(*vp);
+	}
 	if (error) {
 		numfullpathfail2++;
 		SDT_PROBE(vfs, namecache, fullpath, return,  error, vp,
@@ -1261,7 +1273,7 @@
  */
 static int
 vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir,
-    char *buf, char **retbuf, u_int buflen)
+    int lkflags, char *buf, char **retbuf, u_int buflen)
 {
 	int error, slash_prefixed;
 #ifdef KDTRACE_HOOKS
@@ -1279,7 +1291,7 @@
 	vref(vp);
 	CACHE_RLOCK();
 	if (vp->v_type != VDIR) {
-		error = vn_vptocnp_locked(&vp, td->td_ucred, buf, &buflen);
+		error = vn_vptocnp_locked(&vp, td->td_ucred, lkflags, buf, &buflen);
 		if (error)
 			return (error);
 		if (buflen == 0) {
@@ -1317,7 +1329,7 @@
 			    error, vp, NULL, 0, 0);
 			break;
 		}
-		error = vn_vptocnp_locked(&vp, td->td_ucred, buf, &buflen);
+		error = vn_vptocnp_locked(&vp, td->td_ucred, lkflags, buf, &buflen);
 		if (error)
 			break;
 		if (buflen == 0) {
Index: sys/kern/vfs_vnops.c
===================================================================
--- sys/kern/vfs_vnops.c
+++ sys/kern/vfs_vnops.c
@@ -2302,7 +2302,8 @@
 }
 
 int
-vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp,
+    int lkflags)
 {
 	struct vnode *vp;
 	int error;
@@ -2314,23 +2315,26 @@
 	vp = fp->f_vnode;
 	vref(vp);
 	FILEDESC_SUNLOCK(fdp);
-	error = vn_fill_kinfo_vnode(vp, kif);
+	error = vn_fill_kinfo_vnode(vp, kif, lkflags);
 	vrele(vp);
 	FILEDESC_SLOCK(fdp);
 	return (error);
 }
 
 int
-vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
+vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif, int lkflags)
 {
 	struct vattr va;
 	char *fullpath, *freepath;
 	int error;
 
+	KASSERT((lkflags & ~LK_NOWAIT) == 0,
+	    ("invalid lkflags: %08x", lkflags));
+
 	kif->kf_vnode_type = vntype_to_kinfo(vp->v_type);
 	freepath = NULL;
 	fullpath = "-";
-	error = vn_fullpath(curthread, vp, &fullpath, &freepath);
+	error = vn_fullpath(curthread, vp, lkflags, &fullpath, &freepath);
 	if (error == 0) {
 		strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
 	}
@@ -2342,7 +2346,14 @@
 	 */
 	va.va_fsid = VNOVAL;
 	va.va_rdev = NODEV;
-	vn_lock(vp, LK_SHARED | LK_RETRY);
+
+	lkflags |= LK_SHARED;
+	if ((lkflags & LK_NOWAIT) == 0)
+		lkflags |= LK_RETRY;
+
+	error = vn_lock(vp, lkflags);
+	if (error != 0)
+		return (error);
 	error = VOP_GETATTR(vp, &va, curthread->td_ucred);
 	VOP_UNLOCK(vp, 0);
 	if (error != 0)
Index: sys/ofed/include/linux/linux_compat.c
===================================================================
--- sys/ofed/include/linux/linux_compat.c
+++ sys/ofed/include/linux/linux_compat.c
@@ -590,7 +590,7 @@
 
 static int
 linux_file_fill_kinfo(struct file *fp, struct kinfo_file *kif,
-    struct filedesc *fdp)
+    struct filedesc *fdp, int lkflags)
 {
 
 	return (0);
Index: sys/opencrypto/cryptodev.c
===================================================================
--- sys/opencrypto/cryptodev.c
+++ sys/opencrypto/cryptodev.c
@@ -300,7 +300,7 @@
 		    struct ucred *, struct thread *);
 static	int cryptof_close(struct file *, struct thread *);
 static	int cryptof_fill_kinfo(struct file *, struct kinfo_file *,
-		    struct filedesc *);
+		    struct filedesc *, int);
 
 static struct fileops cryptofops = {
     .fo_read = invfo_rdwr,
@@ -1196,7 +1196,8 @@
 }
 
 static int
-cryptof_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+cryptof_fill_kinfo(struct file *fp, struct kinfo_file *kif,
+    struct filedesc *fdp, int lkflags)
 {
 
 	kif->kf_type = KF_TYPE_CRYPTO;
Index: sys/security/audit/audit_bsm_klib.c
===================================================================
--- sys/security/audit/audit_bsm_klib.c
+++ sys/security/audit/audit_bsm_klib.c
@@ -542,7 +542,7 @@
 		free(fbuf, M_TEMP);
 	}
 	if (cvnp != NULL) {
-		error = vn_fullpath(td, cvnp, &rbuf, &fbuf);
+		error = vn_fullpath(td, cvnp, 0, &rbuf, &fbuf);
 		vdrop(cvnp);
 		if (error) {
 			cpath[0] = '\0';
Index: sys/sys/file.h
===================================================================
--- sys/sys/file.h
+++ sys/sys/file.h
@@ -113,7 +113,7 @@
 typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
 		    struct thread *td);
 typedef int fo_fill_kinfo_t(struct file *fp, struct kinfo_file *kif,
-		    struct filedesc *fdp);
+		    struct filedesc *fdp, int lkflags);
 typedef	int fo_flags_t;
 
 struct fileops {
@@ -246,7 +246,7 @@
 fo_sendfile_t	vn_sendfile;
 fo_seek_t	vn_seek;
 fo_fill_kinfo_t	vn_fill_kinfo;
-int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
+int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif, int lkflags);
 
 void finit(struct file *, u_int, short, void *, struct fileops *);
 int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp,
@@ -384,10 +384,11 @@
 }
 
 static __inline int
-fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
+fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp,
+    int lkflags)
 {
 
-	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
+	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp, lkflags));
 }
 
 #endif /* _KERNEL */
Index: sys/sys/user.h
===================================================================
--- sys/sys/user.h
+++ sys/sys/user.h
@@ -529,7 +529,8 @@
  * to be locked on enter.  On return the process is unlocked.
  */
 
-int	kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen);
+int	kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen,
+	int lkflags);
 int	kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen);
 int	kern_proc_out(struct proc *p, struct sbuf *sb, int flags);
 int	kern_proc_vmmap_out(struct proc *p, struct sbuf *sb);
Index: sys/sys/vnode.h
===================================================================
--- sys/sys/vnode.h
+++ sys/sys/vnode.h
@@ -630,8 +630,8 @@
 int	vn_vptocnp(struct vnode **vp, struct ucred *cred, char *buf,
 	    u_int *buflen);
 #define textvp_fullpath(p, rb, rfb) \
-	vn_fullpath(FIRST_THREAD_IN_PROC(p), (p)->p_textvp, rb, rfb)
-int	vn_fullpath(struct thread *td, struct vnode *vn,
+	vn_fullpath(FIRST_THREAD_IN_PROC(p), (p)->p_textvp, 0, rb, rfb)
+int	vn_fullpath(struct thread *td, struct vnode *vn, int lkflags,
 	    char **retbuf, char **freebuf);
 int	vn_fullpath_global(struct thread *td, struct vnode *vn,
 	    char **retbuf, char **freebuf);