From 97118d11db99484338915c391830f5e9ad423dc2 Mon Sep 17 00:00:00 2001
From: rwatson <rwatson@FreeBSD.org>
Date: Wed, 26 Jul 2000 20:29:20 +0000
Subject: [PATCH] o Lock vnode before calling extattr_* VOP's, and modify vnode
 spec to   allow for that. o Remember to call NDFREE() if exiting as a result
 of a failed   vn_start_write() when snapshotting.

Reviewed by:	mckusick
Obtained from:	TrustedBSD Project
---
 sys/kern/vfs_extattr.c  | 17 +++++++++++------
 sys/kern/vfs_syscalls.c | 17 +++++++++++------
 sys/kern/vnode_if.src   |  2 +-
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/sys/kern/vfs_extattr.c b/sys/kern/vfs_extattr.c
index e8b6b250e7f4..d305c39f1159 100644
--- a/sys/kern/vfs_extattr.c
+++ b/sys/kern/vfs_extattr.c
@@ -3548,11 +3548,14 @@ extattr_set_file(p, uap)
 	error = copyin(SCARG(uap, attrname), attrname, EXTATTR_MAXNAMELEN);
 	if (error)
 		return (error);
-	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
+	    SCARG(uap, path), p);
 	if ((error = namei(&nd)) != 0)
 		return(error);
-	if ((error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH)) != 0)
-		goto done;
+	if ((error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH)) != 0) {
+		NDFREE(&nd, 0);
+		return (error);
+	}
 	iovlen = uap->iovcnt * sizeof(struct iovec);
 	if (uap->iovcnt > UIO_SMALLIOV) {
 		if (uap->iovcnt > UIO_MAXIOV) {
@@ -3617,7 +3620,8 @@ extattr_get_file(p, uap)
 	error = copyin(SCARG(uap, attrname), attrname, EXTATTR_MAXNAMELEN);
 	if (error)
 		return (error);
-	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
+	    SCARG(uap, path), p);
 	if ((error = namei(&nd)) != 0)
 		return (error);
 	iovlen = uap->iovcnt * sizeof (struct iovec);
@@ -3681,11 +3685,12 @@ extattr_delete_file(p, uap)
 	error = copyin(SCARG(uap, attrname), attrname, EXTATTR_MAXNAMELEN);
 	if (error)
 		return(error);
-	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	NDINIT(&nd, LOOKUP | LOCKLEAF, FOLLOW, UIO_USERSPACE,
+	    SCARG(uap, path), p);
 	if ((error = namei(&nd)) != 0)
 		return(error);
 	if ((error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH)) != 0) {
-		vrele(nd.ni_vp);
+		NDFREE(&nd, 0);
 		return (error);
 	}
 	error = VOP_SETEXTATTR(nd.ni_vp, attrname, NULL, p->p_cred->pc_ucred,
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index e8b6b250e7f4..d305c39f1159 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -3548,11 +3548,14 @@ extattr_set_file(p, uap)
 	error = copyin(SCARG(uap, attrname), attrname, EXTATTR_MAXNAMELEN);
 	if (error)
 		return (error);
-	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
+	    SCARG(uap, path), p);
 	if ((error = namei(&nd)) != 0)
 		return(error);
-	if ((error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH)) != 0)
-		goto done;
+	if ((error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH)) != 0) {
+		NDFREE(&nd, 0);
+		return (error);
+	}
 	iovlen = uap->iovcnt * sizeof(struct iovec);
 	if (uap->iovcnt > UIO_SMALLIOV) {
 		if (uap->iovcnt > UIO_MAXIOV) {
@@ -3617,7 +3620,8 @@ extattr_get_file(p, uap)
 	error = copyin(SCARG(uap, attrname), attrname, EXTATTR_MAXNAMELEN);
 	if (error)
 		return (error);
-	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
+	    SCARG(uap, path), p);
 	if ((error = namei(&nd)) != 0)
 		return (error);
 	iovlen = uap->iovcnt * sizeof (struct iovec);
@@ -3681,11 +3685,12 @@ extattr_delete_file(p, uap)
 	error = copyin(SCARG(uap, attrname), attrname, EXTATTR_MAXNAMELEN);
 	if (error)
 		return(error);
-	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	NDINIT(&nd, LOOKUP | LOCKLEAF, FOLLOW, UIO_USERSPACE,
+	    SCARG(uap, path), p);
 	if ((error = namei(&nd)) != 0)
 		return(error);
 	if ((error = vn_start_write(nd.ni_vp, &mp, V_WAIT | PCATCH)) != 0) {
-		vrele(nd.ni_vp);
+		NDFREE(&nd, 0);
 		return (error);
 	}
 	error = VOP_SETEXTATTR(nd.ni_vp, attrname, NULL, p->p_cred->pc_ucred,
diff --git a/sys/kern/vnode_if.src b/sys/kern/vnode_if.src
index bda7e98e763a..866abfbc309c 100644
--- a/sys/kern/vnode_if.src
+++ b/sys/kern/vnode_if.src
@@ -535,7 +535,7 @@ vop_aclcheck {
 };
 
 #
-#% getextattr	vp	= = =
+#% getextattr	vp	L L L
 #
 vop_getextattr {
 	IN struct vnode *vp;