From a6df93e354d8150ab4b055289fbea5eccb9a8cc7 Mon Sep 17 00:00:00 2001
From: trasz <trasz@FreeBSD.org>
Date: Fri, 7 Nov 2014 15:47:22 +0000
Subject: MFC r272512:

Make autofs use shared vnode locks.

Sponsored by:	The FreeBSD Foundation
---
 sys/fs/autofs/autofs.h        |  2 +-
 sys/fs/autofs/autofs_vfsops.c |  6 +++++-
 sys/fs/autofs/autofs_vnops.c  | 17 ++++++++++-------
 3 files changed, 16 insertions(+), 9 deletions(-)

(limited to 'sys/fs')

diff --git a/sys/fs/autofs/autofs.h b/sys/fs/autofs/autofs.h
index 0713307..dc33eef 100644
--- a/sys/fs/autofs/autofs.h
+++ b/sys/fs/autofs/autofs.h
@@ -138,6 +138,6 @@ int	autofs_node_find(struct autofs_node *parent,
 	    const char *name, int namelen, struct autofs_node **anpp);
 void	autofs_node_delete(struct autofs_node *anp);
 int	autofs_node_vn(struct autofs_node *anp, struct mount *mp,
-	    struct vnode **vpp);
+	    int flags, struct vnode **vpp);
 
 #endif /* !AUTOFS_H */
diff --git a/sys/fs/autofs/autofs_vfsops.c b/sys/fs/autofs/autofs_vfsops.c
index 21a49d9..13a5a89 100644
--- a/sys/fs/autofs/autofs_vfsops.c
+++ b/sys/fs/autofs/autofs_vfsops.c
@@ -88,6 +88,10 @@ autofs_mount(struct mount *mp)
 
 	vfs_getnewfsid(mp);
 
+	MNT_ILOCK(mp);
+	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED;
+	MNT_IUNLOCK(mp);
+
 	AUTOFS_XLOCK(amp);
 	error = autofs_node_new(NULL, amp, ".", -1, &amp->am_root);
 	if (error != 0) {
@@ -177,7 +181,7 @@ autofs_root(struct mount *mp, int flags, struct vnode **vpp)
 
 	amp = VFSTOAUTOFS(mp);
 
-	error = autofs_node_vn(amp->am_root, mp, vpp);
+	error = autofs_node_vn(amp->am_root, mp, flags, vpp);
 
 	return (error);
 }
diff --git a/sys/fs/autofs/autofs_vnops.c b/sys/fs/autofs/autofs_vnops.c
index 53490b3..72d6bff 100644
--- a/sys/fs/autofs/autofs_vnops.c
+++ b/sys/fs/autofs/autofs_vnops.c
@@ -198,12 +198,12 @@ mounted:
 }
 
 static int
-autofs_vget_callback(struct mount *mp, void *arg, int lkflags __unused,
+autofs_vget_callback(struct mount *mp, void *arg, int flags,
     struct vnode **vpp)
 {
 
 
-	return (autofs_node_vn(arg, mp, vpp));
+	return (autofs_node_vn(arg, mp, flags, vpp));
 }
 
 static int
@@ -233,7 +233,7 @@ autofs_lookup(struct vop_lookup_args *ap)
 		 * use vn_vget_ino_gen() which takes care of all that.
 		 */
 		error = vn_vget_ino_gen(dvp, autofs_vget_callback,
-		    anp->an_parent, 0, vpp);
+		    anp->an_parent, cnp->cn_lkflags, vpp);
 		if (error != 0) {
 			AUTOFS_WARN("vn_vget_ino_gen() failed with error %d",
 			    error);
@@ -294,7 +294,7 @@ autofs_lookup(struct vop_lookup_args *ap)
 	 */
 	AUTOFS_SUNLOCK(amp);
 
-	error = autofs_node_vn(child, mp, vpp);
+	error = autofs_node_vn(child, mp, cnp->cn_lkflags, vpp);
 	if (error != 0) {
 		if ((cnp->cn_flags & ISLASTCN) && cnp->cn_nameiop == CREATE)
 			return (EJUSTRETURN);
@@ -334,7 +334,7 @@ autofs_mkdir(struct vop_mkdir_args *ap)
 	}
 	AUTOFS_XUNLOCK(amp);
 
-	error = autofs_node_vn(child, vp->v_mount, ap->a_vpp);
+	error = autofs_node_vn(child, vp->v_mount, LK_EXCLUSIVE, ap->a_vpp);
 
 	return (error);
 }
@@ -581,7 +581,8 @@ autofs_node_delete(struct autofs_node *anp)
 }
 
 int
-autofs_node_vn(struct autofs_node *anp, struct mount *mp, struct vnode **vpp)
+autofs_node_vn(struct autofs_node *anp, struct mount *mp, int flags,
+    struct vnode **vpp)
 {
 	struct vnode *vp;
 	int error;
@@ -592,7 +593,7 @@ autofs_node_vn(struct autofs_node *anp, struct mount *mp, struct vnode **vpp)
 
 	vp = anp->an_vnode;
 	if (vp != NULL) {
-		error = vget(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
+		error = vget(vp, flags | LK_RETRY, curthread);
 		if (error != 0) {
 			AUTOFS_WARN("vget failed with error %d", error);
 			sx_xunlock(&anp->an_vnode_lock);
@@ -632,6 +633,8 @@ autofs_node_vn(struct autofs_node *anp, struct mount *mp, struct vnode **vpp)
 		vp->v_vflag |= VV_ROOT;
 	vp->v_data = anp;
 
+	VN_LOCK_ASHARE(vp);
+
 	error = insmntque(vp, mp);
 	if (error != 0) {
 		AUTOFS_WARN("insmntque() failed with error %d", error);
-- 
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