VOP_FSYNC() requires that it's vnode argument be locked, which nfs_link()

wasn't doing.  Rather than just lock and unlock the vnode around the call
to VOP_FSYNC(), implement rwatson's suggestion to lock the file vnode
in kern_link() before calling VOP_LINK(), since the other filesystems
also locked the file vnode right away in their link methods.  Remove the
locking and and unlocking from the leaf filesystem link methods.

Reviewed by:	rwatson, bde  (except for the unionfs_link() changes)

2 files changed, 8 insertions, 22 deletions

diff --git a/sys/gnu/ext2fs/ext2_vnops.c b/sys/gnu/ext2fs/ext2_vnops.c
index dd24a9d..c1fba78 100644
--- a/sys/gnu/ext2fs/ext2_vnops.c
+++ b/sys/gnu/ext2fs/ext2_vnops.c
@@ -827,7 +827,6 @@ ext2_link(ap)
 	struct vnode *vp = ap->a_vp;
 	struct vnode *tdvp = ap->a_tdvp;
 	struct componentname *cnp = ap->a_cnp;
-	struct thread *td = cnp->cn_thread;
 	struct inode *ip;
 	int error;
 
@@ -837,19 +836,16 @@ ext2_link(ap)
 #endif
 	if (tdvp->v_mount != vp->v_mount) {
 		error = EXDEV;
-		goto out2;
-	}
-	if (tdvp != vp && (error = vn_lock(vp, LK_EXCLUSIVE, td))) {
-		goto out2;
+		goto out;
 	}
 	ip = VTOI(vp);
 	if ((nlink_t)ip->i_nlink >= LINK_MAX) {
 		error = EMLINK;
-		goto out1;
+		goto out;
 	}
 	if (ip->i_flags & (IMMUTABLE | APPEND)) {
 		error = EPERM;
-		goto out1;
+		goto out;
 	}
 	ip->i_nlink++;
 	ip->i_flag |= IN_CHANGE;
@@ -860,10 +856,7 @@ ext2_link(ap)
 		ip->i_nlink--;
 		ip->i_flag |= IN_CHANGE;
 	}
-out1:
-	if (tdvp != vp)
-		VOP_UNLOCK(vp, 0, td);
-out2:
+out:
 	return (error);
 }
 
diff --git a/sys/gnu/fs/ext2fs/ext2_vnops.c b/sys/gnu/fs/ext2fs/ext2_vnops.c
index dd24a9d..c1fba78 100644
--- a/sys/gnu/fs/ext2fs/ext2_vnops.c
+++ b/sys/gnu/fs/ext2fs/ext2_vnops.c
@@ -827,7 +827,6 @@ ext2_link(ap)
 	struct vnode *vp = ap->a_vp;
 	struct vnode *tdvp = ap->a_tdvp;
 	struct componentname *cnp = ap->a_cnp;
-	struct thread *td = cnp->cn_thread;
 	struct inode *ip;
 	int error;
 
@@ -837,19 +836,16 @@ ext2_link(ap)
 #endif
 	if (tdvp->v_mount != vp->v_mount) {
 		error = EXDEV;
-		goto out2;
-	}
-	if (tdvp != vp && (error = vn_lock(vp, LK_EXCLUSIVE, td))) {
-		goto out2;
+		goto out;
 	}
 	ip = VTOI(vp);
 	if ((nlink_t)ip->i_nlink >= LINK_MAX) {
 		error = EMLINK;
-		goto out1;
+		goto out;
 	}
 	if (ip->i_flags & (IMMUTABLE | APPEND)) {
 		error = EPERM;
-		goto out1;
+		goto out;
 	}
 	ip->i_nlink++;
 	ip->i_flag |= IN_CHANGE;
@@ -860,10 +856,7 @@ ext2_link(ap)
 		ip->i_nlink--;
 		ip->i_flag |= IN_CHANGE;
 	}
-out1:
-	if (tdvp != vp)
-		VOP_UNLOCK(vp, 0, td);
-out2:
+out:
 	return (error);
 }