From 12a404837097f346ac09c977f021390fdc55ea71 Mon Sep 17 00:00:00 2001
From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Wed, 7 Jan 2009 15:26:04 -0800
Subject: [PATCH] Enable zfs_create_fs to operate without the VFS

---
 module/zfs/zfs_znode.c | 51 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/module/zfs/zfs_znode.c b/module/zfs/zfs_znode.c
index 4a1820940c..114eee682f 100644
--- a/module/zfs/zfs_znode.c
+++ b/module/zfs/zfs_znode.c
@@ -87,6 +87,7 @@
  * (such as VFS logic) that will not compile easily in userland.
  */
 #ifdef _KERNEL
+#ifdef HAVE_ZPL
 static kmem_cache_t *znode_cache = NULL;
 
 /*ARGSUSED*/
@@ -1473,20 +1474,28 @@ log:
 	dmu_tx_commit(tx);
 	return (0);
 }
+#endif /* HAVE_ZPL */
 
 void
 zfs_create_fs(objset_t *os, cred_t *cr, nvlist_t *zplprops, dmu_tx_t *tx)
 {
-	zfsvfs_t	zfsvfs;
 	uint64_t	moid, doid, version;
 	uint64_t	sense = ZFS_CASE_SENSITIVE;
 	uint64_t	norm = 0;
 	nvpair_t	*elem;
 	int		error;
+#ifdef HAVE_ZPL
+	zfsvfs_t	zfsvfs;
 	znode_t		*rootzp = NULL;
 	vnode_t		*vp;
 	vattr_t		vattr;
 	znode_t		*zp;
+#else
+	uint64_t	obj;
+	timestruc_t	now;
+	dmu_buf_t	*db;
+	znode_phys_t	*pzp;
+#endif /* HAVE_ZPL */
 
 	/*
 	 * First attempt to create master node.
@@ -1541,6 +1550,7 @@ zfs_create_fs(objset_t *os, cred_t *cr, nvlist_t *zplprops, dmu_tx_t *tx)
 	error = zap_add(os, moid, ZFS_UNLINKED_SET, 8, 1, &doid, tx);
 	ASSERT(error == 0);
 
+#ifdef HAVE_ZPL
 	/*
 	 * Create root znode.  Create minimal znode/vnode/zfsvfs
 	 * to allow zfs_mknode to work.
@@ -1593,6 +1603,45 @@ zfs_create_fs(objset_t *os, cred_t *cr, nvlist_t *zplprops, dmu_tx_t *tx)
 	dmu_buf_rele(rootzp->z_dbuf, NULL);
 	rootzp->z_dbuf = NULL;
 	kmem_cache_free(znode_cache, rootzp);
+#else
+	/*
+	 * Create root znode with code free of VFS dependencies
+	 */
+	obj = zap_create_norm(os, norm, DMU_OT_DIRECTORY_CONTENTS,
+	                      DMU_OT_ZNODE, sizeof (znode_phys_t), tx);
+
+	VERIFY(0 == dmu_bonus_hold(os, obj, FTAG, &db));
+	dmu_buf_will_dirty(db, tx);
+
+	/*
+	 * Initialize the znode physical data to zero.
+	 */
+	ASSERT(db->db_size >= sizeof (znode_phys_t));
+	bzero(db->db_data, db->db_size);
+	pzp = db->db_data;
+
+	if (USE_FUIDS(version, os))
+		pzp->zp_flags = ZFS_ARCHIVE | ZFS_AV_MODIFIED;
+
+	pzp->zp_size = 2; /* "." and ".." */
+	pzp->zp_links = 2;
+	pzp->zp_parent = obj;
+	pzp->zp_gen = dmu_tx_get_txg(tx);
+	pzp->zp_mode = S_IFDIR | 0755;
+	pzp->zp_flags = ZFS_ACL_TRIVIAL;
+
+	gethrestime(&now);
+
+	ZFS_TIME_ENCODE(&now, pzp->zp_crtime);
+	ZFS_TIME_ENCODE(&now, pzp->zp_ctime);
+	ZFS_TIME_ENCODE(&now, pzp->zp_atime);
+	ZFS_TIME_ENCODE(&now, pzp->zp_mtime);
+
+	error = zap_add(os, moid, ZFS_ROOT_OBJ, 8, 1, &obj, tx);
+	ASSERT(error == 0);
+
+	dmu_buf_rele(db, FTAG);
+#endif /* HAVE_ZPL */
 }
 
 #endif /* _KERNEL */