-/*
- * Helper function for ost_punch(): if asked by client, acquire [size, EOF]
- * lock on the file being truncated.
- */
-static int ost_punch_lock_get(struct obd_export *exp, struct obdo *oa,
- struct lustre_handle *lh)
-{
- int flags;
- struct ldlm_res_id res_id;
- ldlm_policy_data_t policy;
- __u64 start;
- __u64 finis;
-
- ENTRY;
-
- osc_build_res_name(oa->o_id, oa->o_gr, &res_id);
- LASSERT(!lustre_handle_is_used(lh));
-
- if (!(oa->o_valid & OBD_MD_FLFLAGS) ||
- !(oa->o_flags & OBD_FL_TRUNCLOCK))
- RETURN(0);
-
- CDEBUG(D_INODE, "OST-side truncate lock.\n");
-
- start = oa->o_size;
- finis = start + oa->o_blocks;
-
- /*
- * standard truncate optimization: if file body is completely
- * destroyed, don't send data back to the server.
- */
- flags = (start == 0) ? LDLM_AST_DISCARD_DATA : 0;
-
- policy.l_extent.start = start & CFS_PAGE_MASK;
-
- /*
- * If ->o_blocks is EOF it means "lock till the end of the
- * file". Otherwise, it's size of a hole being punched (in bytes)
- */
- if (oa->o_blocks == OBD_OBJECT_EOF || finis < start)
- policy.l_extent.end = OBD_OBJECT_EOF;
- else
- policy.l_extent.end = finis | ~CFS_PAGE_MASK;
-
- RETURN(ldlm_cli_enqueue_local(exp->exp_obd->obd_namespace, &res_id,
- LDLM_EXTENT, &policy, LCK_PW, &flags,
- ldlm_blocking_ast, ldlm_completion_ast,
- ldlm_glimpse_ast, NULL, 0, NULL,
- NULL, lh));
-}
-
-/*
- * Helper function for ost_punch(): release lock acquired by
- * ost_punch_lock_get(), if any.
- */
-static void ost_punch_lock_put(struct obd_export *exp, struct obdo *oa,
- struct lustre_handle *lh)
-{
- ENTRY;
- if (lustre_handle_is_used(lh))
- ldlm_lock_decref(lh, LCK_PW);
- EXIT;
-}
-