Create a root znode without VFS dependencies

For portability reasons it's handy to be able to create a root
znode and basic filesystem components without requiring the full
cooperation of the VFS.  We are committing to this to simply the
filesystem creations code.

diff --git a/module/zfs/zfs_znode.c b/module/zfs/zfs_znode.c
index 61eb877..283b4d5 100644 (file)
--- a/module/zfs/zfs_znode.c
+++ b/module/zfs/zfs_znode.c
@@ -1484,23 +1484,12 @@ void
 zfs_create_fs(objset_t *os, cred_t *cr, nvlist_t *zplprops, dmu_tx_t *tx)
 {
        uint64_t        moid, obj, sa_obj, version;
-       uint64_t        sense = ZFS_CASE_SENSITIVE;
        uint64_t        norm = 0;
        nvpair_t        *elem;
        int             error;
-#ifdef HAVE_ZPL
-       zfsvfs_t        zfsvfs;
-       int             i;
-       znode_t         *rootzp = NULL;
-       vnode_t         *vp;
-       vattr_t         vattr;
-       znode_t         *zp;
-       zfs_acl_ids_t   acl_ids;
-#else
        timestruc_t     now;
        dmu_buf_t       *db;
        znode_phys_t    *pzp;
-#endif /* HAVE_ZPL */
 
        /*
         * First attempt to create master node.
@@ -1536,8 +1525,6 @@ zfs_create_fs(objset_t *os, cred_t *cr, nvlist_t *zplprops, dmu_tx_t *tx)
                ASSERT(error == 0);
                if (strcmp(name, zfs_prop_to_name(ZFS_PROP_NORMALIZE)) == 0)
                        norm = val;
-               else if (strcmp(name, zfs_prop_to_name(ZFS_PROP_CASE)) == 0)
-                       sense = val;
        }
        ASSERT(version != 0);
        error = zap_update(os, moid, ZPL_VERSION_STR, 8, 1, &version, tx);
@@ -1562,79 +1549,11 @@ 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, &obj, tx);
        ASSERT(error == 0);
 
-#ifdef HAVE_ZPL
-       /*
-        * Create root znode.  Create minimal znode/vnode/zfsvfs
-        * to allow zfs_mknode to work.
-        */
-       vattr.va_mask = AT_MODE|AT_UID|AT_GID|AT_TYPE;
-       vattr.va_type = VDIR;
-       vattr.va_mode = S_IFDIR|0755;
-       vattr.va_uid = crgetuid(cr);
-       vattr.va_gid = crgetgid(cr);
-
-       rootzp = kmem_cache_alloc(znode_cache, KM_SLEEP);
-       ASSERT(!POINTER_IS_VALID(rootzp->z_zfsvfs));
-       rootzp->z_moved = 0;
-       rootzp->z_unlinked = 0;
-       rootzp->z_atime_dirty = 0;
-       rootzp->z_is_sa = USE_SA(version, os);
-
-       vp = ZTOV(rootzp);
-       vn_reinit(vp);
-       vp->v_type = VDIR;
-
-       bzero(&zfsvfs, sizeof (zfsvfs_t));
-
-       zfsvfs.z_os = os;
-       zfsvfs.z_parent = &zfsvfs;
-       zfsvfs.z_version = version;
-       zfsvfs.z_use_fuids = USE_FUIDS(version, os);
-       zfsvfs.z_use_sa = USE_SA(version, os);
-       zfsvfs.z_norm = norm;
-
-       error = sa_setup(os, sa_obj, zfs_attr_table, ZPL_END,
-           &zfsvfs.z_attr_table);
-
-       ASSERT(error == 0);
-
-       /*
-        * Fold case on file systems that are always or sometimes case
-        * insensitive.
-        */
-       if (sense == ZFS_CASE_INSENSITIVE || sense == ZFS_CASE_MIXED)
-               zfsvfs.z_norm |= U8_TEXTPREP_TOUPPER;
-
-       /* XXX - This must be destroyed but I'm not quite sure yet so
-        * I'm just annotating that fact when it's an issue.  -Brian */
-       mutex_init(&zfsvfs.z_znodes_lock, NULL, MUTEX_DEFAULT, NULL);
-       list_create(&zfsvfs.z_all_znodes, sizeof (znode_t),
-           offsetof(znode_t, z_link_node));
-
-       for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
-               mutex_init(&zfsvfs.z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL);
-
-       rootzp->z_zfsvfs = &zfsvfs;
-       VERIFY(0 == zfs_acl_ids_create(rootzp, IS_ROOT_NODE, &vattr,
-           cr, NULL, &acl_ids));
-       zfs_mknode(rootzp, &vattr, tx, cr, IS_ROOT_NODE, &zp, &acl_ids);
-       ASSERT3P(zp, ==, rootzp);
-       ASSERT(!vn_in_dnlc(ZTOV(rootzp))); /* not valid to move */
-       error = zap_add(os, moid, ZFS_ROOT_OBJ, 8, 1, &rootzp->z_id, tx);
-       ASSERT(error == 0);
-       zfs_acl_ids_free(&acl_ids);
-       POINTER_INVALIDATE(&rootzp->z_zfsvfs);
-
-       ZTOV(rootzp)->v_count = 0;
-       sa_handle_destroy(rootzp->z_sa_hdl);
-       kmem_cache_free(znode_cache, rootzp);
-       error = zfs_create_share_dir(&zfsvfs, tx);
-
-       for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
-               mutex_destroy(&zfsvfs.z_hold_mtx[i]);
-#else
        /*
-        * Create root znode with code free of VFS dependencies
+        * Create root znode with code free of VFS dependencies.  This
+        * is important because without a registered filesystem and super
+        * block all the required VFS hooks will be missing.  The critical
+        * thing is to just crete the required root znode.
         */
        obj = zap_create_norm(os, norm, DMU_OT_DIRECTORY_CONTENTS,
                              DMU_OT_ZNODE, sizeof (znode_phys_t), tx);