From 66fa44e7a3111d837743cb11af67100a0cd8b8c6 Mon Sep 17 00:00:00 2001
From: Venkatesh Srinivas <me@endeavour.zapto.org>
Date: Tue, 31 Jan 2012 00:15:24 -0500
Subject: [PATCH] tmpfs: Support NFS export of tmpfs filesystems.

* Implement vop_mountctl and MOUNTCTL_SET_EXPORT interfaces to allow mountd
  to export a tmpfs filesystem.

* Implement vfs_checkexp to allow NFS to function.

Closes: Bug 2277
---
 sys/vfs/tmpfs/tmpfs.h        |  2 ++
 sys/vfs/tmpfs/tmpfs_vfsops.c | 23 ++++++++++++++++++++++-
 sys/vfs/tmpfs/tmpfs_vnops.c  | 29 +++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/sys/vfs/tmpfs/tmpfs.h b/sys/vfs/tmpfs/tmpfs.h
index 4404cc6588..609b1c18e9 100644
--- a/sys/vfs/tmpfs/tmpfs.h
+++ b/sys/vfs/tmpfs/tmpfs.h
@@ -399,6 +399,8 @@ struct tmpfs_mount {
 	struct objcache		*tm_node_pool;
 
 	int			tm_flags;
+
+	struct netexport	tm_export;
 };
 
 #define TMPFS_LOCK(tm) lockmgr(&(tm)->allnode_lock, LK_EXCLUSIVE|LK_RETRY)
diff --git a/sys/vfs/tmpfs/tmpfs_vfsops.c b/sys/vfs/tmpfs/tmpfs_vfsops.c
index 940643a569..55b2ffc770 100644
--- a/sys/vfs/tmpfs/tmpfs_vfsops.c
+++ b/sys/vfs/tmpfs/tmpfs_vfsops.c
@@ -518,6 +518,26 @@ tmpfs_vptofh(struct vnode *vp, struct fid *fhp)
 
 /* --------------------------------------------------------------------- */
 
+static int 
+tmpfs_checkexp(struct mount *mp, struct sockaddr *nam, int *exflagsp, 
+	       struct ucred **credanonp) 
+{ 
+	struct tmpfs_mount *tmp; 
+	struct netcred *nc; 
+ 
+	tmp = (struct tmpfs_mount *) mp->mnt_data;
+	nc = vfs_export_lookup(mp, &tmp->tm_export, nam); 
+	if (nc == NULL) 
+		return (EACCES); 
+
+	*exflagsp = nc->netc_exflags; 
+	*credanonp = &nc->netc_anon; 
+ 
+	return (0); 
+} 
+
+/* --------------------------------------------------------------------- */ 
+
 /*
  * tmpfs vfs operations.
  */
@@ -529,7 +549,8 @@ static struct vfsops tmpfs_vfsops = {
 	.vfs_statfs =			tmpfs_statfs,
 	.vfs_fhtovp =			tmpfs_fhtovp,
 	.vfs_vptofh =			tmpfs_vptofh, 
-	.vfs_sync =			vfs_stdsync
+	.vfs_sync =			vfs_stdsync,
+	.vfs_checkexp =			tmpfs_checkexp,
 };
 
 VFS_SET(tmpfs_vfsops, tmpfs, 0);
diff --git a/sys/vfs/tmpfs/tmpfs_vnops.c b/sys/vfs/tmpfs/tmpfs_vnops.c
index 3a5d7a09dd..c30b8fa70c 100644
--- a/sys/vfs/tmpfs/tmpfs_vnops.c
+++ b/sys/vfs/tmpfs/tmpfs_vnops.c
@@ -48,6 +48,7 @@
 #include <sys/unistd.h>
 #include <sys/vfsops.h>
 #include <sys/vnode.h>
+#include <sys/mountctl.h>
 
 #include <vm/vm.h>
 #include <vm/vm_object.h>
@@ -1498,6 +1499,33 @@ tmpfs_reclaim(struct vop_reclaim_args *v)
 	return 0;
 }
 
+/* --------------------------------------------------------------------- */ 
+
+static int 
+tmpfs_mountctl(struct vop_mountctl_args *ap) 
+{ 
+	struct tmpfs_mount *tmp; 
+	struct mount *mp; 
+	int rc; 
+
+	switch (ap->a_op) { 
+	case (MOUNTCTL_SET_EXPORT): 
+		mp = ap->a_head.a_ops->head.vv_mount; 
+		tmp = (struct tmpfs_mount *) mp->mnt_data; 
+ 
+		if (ap->a_ctllen != sizeof(struct export_args)) 
+			rc = (EINVAL); 
+		else 
+			rc = vfs_export(mp, &tmp->tm_export, 
+					(const struct export_args *) ap->a_ctl); 
+		break; 
+	default: 
+		rc = vop_stdmountctl(ap); 
+		break; 
+	} 
+	return (rc); 
+} 
+
 /* --------------------------------------------------------------------- */
 
 static int
@@ -1699,6 +1727,7 @@ struct vop_ops tmpfs_vnode_vops = {
 	.vop_read =			tmpfs_read,
 	.vop_write =			tmpfs_write,
 	.vop_fsync =			tmpfs_fsync,
+	.vop_mountctl =			tmpfs_mountctl,
 	.vop_nremove =			tmpfs_nremove,
 	.vop_nlink =			tmpfs_nlink,
 	.vop_nrename =			tmpfs_nrename,
-- 
2.41.0