+ struct group_info *ginfo;
+
+ LASSERT(ngroups <= NGROUPS_SMALL);
+
+ OBD_ALLOC(ginfo, sizeof(*ginfo) + 1 * sizeof(gid_t *));
+ if (!ginfo)
+ return NULL;
+ ginfo->ngroups = ngroups;
+ ginfo->nblocks = 1;
+ ginfo->blocks[0] = ginfo->small_block;
+ atomic_set(&ginfo->usage, 1);
+
+ return ginfo;
+}
+
+void groups_free(struct group_info *ginfo)
+{
+ LASSERT(ginfo->ngroups <= NGROUPS_SMALL);
+ LASSERT(ginfo->nblocks == 1);
+ LASSERT(ginfo->blocks[0] == ginfo->small_block);
+
+ OBD_FREE(ginfo, sizeof(*ginfo) + 1 * sizeof(gid_t *));
+}
+
+/* for 2.4 the group number is small, so simply search the
+ * whole array.
+ */
+int groups_search(struct group_info *ginfo, gid_t grp)
+{
+ int i;
+
+ if (!ginfo)
+ return 0;
+
+ for (i = 0; i < ginfo->ngroups; i++)
+ if (GROUP_AT(ginfo, i) == grp)
+ return 1;
+ return 0;
+}
+
+#else /* >= 2.6.4 */
+
+void groups_sort(struct group_info *ginfo)
+{
+ int base, max, stride;
+ int gidsetsize = ginfo->ngroups;
+
+ for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
+ ; /* nothing */
+ stride /= 3;
+
+ while (stride) {
+ max = gidsetsize - stride;
+ for (base = 0; base < max; base++) {
+ int left = base;
+ int right = left + stride;
+ gid_t tmp = GROUP_AT(ginfo, right);
+
+ while (left >= 0 && GROUP_AT(ginfo, left) > tmp) {
+ GROUP_AT(ginfo, right) =
+ GROUP_AT(ginfo, left);
+ right = left;
+ left -= stride;
+ }
+ GROUP_AT(ginfo, right) = tmp;
+ }
+ stride /= 3;
+ }
+}
+
+int groups_search(struct group_info *ginfo, gid_t grp)
+{
+ int left, right;
+
+ if (!ginfo)
+ return 0;
+
+ left = 0;
+ right = ginfo->ngroups;
+ while (left < right) {
+ int mid = (left + right) / 2;
+ int cmp = grp - GROUP_AT(ginfo, mid);
+ if (cmp > 0)
+ left = mid + 1;
+ else if (cmp < 0)
+ right = mid;
+ else
+ return 1;
+ }
+ return 0;
+}
+#endif
+
+void groups_from_buffer(struct group_info *ginfo, __u32 *gids)
+{
+ int i, ngroups = ginfo->ngroups;
+
+ for (i = 0; i < ginfo->nblocks; i++) {
+ int count = min(NGROUPS_PER_BLOCK, ngroups);
+
+ memcpy(ginfo->blocks[i], gids, count * sizeof(__u32));
+ gids += NGROUPS_PER_BLOCK;
+ ngroups -= count;
+ }
+}
+
+void mds_pack_dentry2id(struct obd_device *obd,
+ struct lustre_id *id,
+ struct dentry *dentry,
+ int read_fid)
+{
+ id_ino(id) = dentry->d_inum;
+ id_gen(id) = dentry->d_generation;
+
+ if (read_fid) {
+ id_fid(id) = dentry->d_fid;
+ id_group(id) = dentry->d_mdsnum;
+ }
+}
+
+void mds_pack_dentry2body(struct obd_device *obd,
+ struct mds_body *b,
+ struct dentry *dentry,
+ int read_fid)
+{
+ b->valid |= OBD_MD_FLID | OBD_MD_FLGENER |
+ OBD_MD_MDS;
+
+ if (read_fid)
+ b->valid |= OBD_MD_FID;
+
+ mds_pack_dentry2id(obd, &b->id1, dentry,
+ read_fid);
+}
+
+int mds_pack_inode2id(struct obd_device *obd,
+ struct lustre_id *id,
+ struct inode *inode,
+ int read_fid)
+{
+ int rc = 0;
+ ENTRY;
+
+ if (read_fid) {
+ /* we have to avoid deadlock. */
+ if (!down_trylock(&inode->i_sem)) {
+ rc = mds_read_inode_sid(obd, inode, id);
+ up(&inode->i_sem);
+ } else {
+ rc = mds_read_inode_sid(obd, inode, id);
+ }
+ }
+ if (rc == 0) {
+ id_ino(id) = inode->i_ino;
+ id_gen(id) = inode->i_generation;
+ id_type(id) = (S_IFMT & inode->i_mode);
+ }
+ RETURN(rc);