+
+/**
+ * Helper function to open llog or create it if doesn't exist.
+ * It hides all transaction handling from caller.
+ */
+int llog_open_create(const struct lu_env *env, struct llog_ctxt *ctxt,
+ struct llog_handle **res, struct llog_logid *logid,
+ char *name)
+{
+ struct thandle *th;
+ int rc;
+
+ ENTRY;
+
+ rc = llog_open(env, ctxt, res, logid, name, LLOG_OPEN_NEW);
+ if (rc)
+ RETURN(rc);
+
+ if (llog_exist(*res))
+ RETURN(0);
+
+ if ((*res)->lgh_obj != NULL) {
+ struct dt_device *d;
+
+ d = lu2dt_dev((*res)->lgh_obj->do_lu.lo_dev);
+
+ th = dt_trans_create(env, d);
+ if (IS_ERR(th))
+ GOTO(out, rc = PTR_ERR(th));
+
+ rc = llog_declare_create(env, *res, th);
+ if (rc == 0) {
+ rc = dt_trans_start_local(env, d, th);
+ if (rc == 0)
+ rc = llog_create(env, *res, th);
+ }
+ dt_trans_stop(env, d, th);
+ } else {
+ /* lvfs compat code */
+ LASSERT((*res)->lgh_file == NULL);
+ rc = llog_create(env, *res, NULL);
+ }
+out:
+ if (rc)
+ llog_close(env, *res);
+ RETURN(rc);
+}
+EXPORT_SYMBOL(llog_open_create);
+
+/**
+ * Helper function to delete existent llog.
+ */
+int llog_erase(const struct lu_env *env, struct llog_ctxt *ctxt,
+ struct llog_logid *logid, char *name)
+{
+ struct llog_handle *handle;
+ int rc = 0, rc2;
+
+ ENTRY;
+
+ /* nothing to erase */
+ if (name == NULL && logid == NULL)
+ RETURN(0);
+
+ rc = llog_open(env, ctxt, &handle, logid, name, LLOG_OPEN_EXISTS);
+ if (rc < 0)
+ RETURN(rc);
+
+ rc = llog_init_handle(env, handle, LLOG_F_IS_PLAIN, NULL);
+ if (rc == 0)
+ rc = llog_destroy(env, handle);
+
+ rc2 = llog_close(env, handle);
+ if (rc == 0)
+ rc = rc2;
+ RETURN(rc);
+}
+EXPORT_SYMBOL(llog_erase);
+
+int llog_open(const struct lu_env *env, struct llog_ctxt *ctxt,
+ struct llog_handle **lgh, struct llog_logid *logid,
+ char *name, enum llog_open_param open_param)
+{
+ int raised;
+ int rc;
+
+ ENTRY;
+
+ LASSERT(ctxt);
+ LASSERT(ctxt->loc_logops);
+
+ if (ctxt->loc_logops->lop_open == NULL) {
+ *lgh = NULL;
+ RETURN(-EOPNOTSUPP);
+ }
+
+ *lgh = llog_alloc_handle();
+ if (*lgh == NULL)
+ RETURN(-ENOMEM);
+ (*lgh)->lgh_ctxt = ctxt;
+ (*lgh)->lgh_logops = ctxt->loc_logops;
+
+ raised = cfs_cap_raised(CFS_CAP_SYS_RESOURCE);
+ if (!raised)
+ cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
+ rc = ctxt->loc_logops->lop_open(env, *lgh, logid, name, open_param);
+ if (!raised)
+ cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
+ if (rc) {
+ llog_free_handle(*lgh);
+ *lgh = NULL;
+ }
+ RETURN(rc);
+}
+EXPORT_SYMBOL(llog_open);
+
+int llog_close(const struct lu_env *env, struct llog_handle *loghandle)
+{
+ struct llog_operations *lop;
+ int rc;
+
+ ENTRY;
+
+ rc = llog_handle2ops(loghandle, &lop);
+ if (rc)
+ GOTO(out, rc);
+ if (lop->lop_close == NULL)
+ GOTO(out, -EOPNOTSUPP);
+ rc = lop->lop_close(env, loghandle);
+out:
+ llog_free_handle(loghandle);
+ RETURN(rc);
+}
+EXPORT_SYMBOL(llog_close);