/****************************************************************************** ******************************************************************************* ** ** Copyright (C) 2005-2007 Red Hat, Inc. All rights reserved. ** ** This copyrighted material is made available to anyone wishing to use, ** modify, copy, or redistribute it subject to the terms and conditions ** of the GNU General Public License v.2. ** ******************************************************************************* ******************************************************************************/ #include "dlm_internal.h" #include "member.h" #include "lock.h" #include "dir.h" #include "config.h" #include "requestqueue.h" struct rq_entry { struct list_head list; int nodeid; struct dlm_message request; }; /* * Requests received while the lockspace is in recovery get added to the * request queue and processed when recovery is complete. This happens when * the lockspace is suspended on some nodes before it is on others, or the * lockspace is enabled on some while still suspended on others. */ void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_message *ms) { struct rq_entry *e; int length = ms->m_header.h_length - sizeof(struct dlm_message); e = kmalloc(sizeof(struct rq_entry) + length, GFP_NOFS); if (!e) { log_print("dlm_add_requestqueue: out of memory len %d", length); return; } e->nodeid = nodeid; memcpy(&e->request, ms, ms->m_header.h_length); mutex_lock(&ls->ls_requestqueue_mutex); list_add_tail(&e->list, &ls->ls_requestqueue); mutex_unlock(&ls->ls_requestqueue_mutex); } /* * Called by dlm_recoverd to process normal messages saved while recovery was * happening. Normal locking has been enabled before this is called. dlm_recv * upon receiving a message, will wait for all saved messages to be drained * here before processing the message it got. If a new dlm_ls_stop() arrives * while we're processing these saved messages, it may block trying to suspend * dlm_recv if dlm_recv is waiting for us in dlm_wait_requestqueue. In that * case, we don't abort since locking_stopped is still 0. If dlm_recv is not * waiting for us, then this processing may be aborted due to locking_stopped. */ int dlm_process_requestqueue(struct dlm_ls *ls) { struct rq_entry *e; int error = 0; mutex_lock(&ls->ls_requestqueue_mutex); for (;;) { if (list_empty(&ls->ls_requestqueue)) { mutex_unlock(&ls->ls_requestqueue_mutex); error = 0; break; } e = list_entry(ls->ls_requestqueue.next, struct rq_entry, list); mutex_unlock(&ls->ls_requestqueue_mutex); dlm_receive_message_saved(ls, &e->request); mutex_lock(&ls->ls_requestqueue_mutex); list_del(&e->list); kfree(e); if (dlm_locking_stopped(ls)) { log_debug(ls, "process_requestqueue abort running"); mutex_unlock(&ls->ls_requestqueue_mutex); error = -EINTR; break; } schedule(); } return error; } /* * After recovery is done, locking is resumed and dlm_recoverd takes all the * saved requests and processes them as they would have been by dlm_recv. At * the same time, dlm_recv will start receiving new requests from remote nodes. * We want to delay dlm_recv processing new requests until dlm_recoverd has * finished processing the old saved requests. We don't check for locking * stopped here because dlm_ls_stop won't stop locking until it's suspended us * (dlm_recv). */ void dlm_wait_requestqueue(struct dlm_ls *ls) { for (;;) { mutex_lock(&ls->ls_requestqueue_mutex); if (list_empty(&ls->ls_requestqueue)) break; mutex_unlock(&ls->ls_requestqueue_mutex); schedule(); } mutex_unlock(&ls->ls_requestqueue_mutex); } static int purge_request(struct dlm_ls *ls, struct dlm_message *ms, int nodeid) { uint32_t type = ms->m_type; /* the ls is being cleaned up and freed by release_lockspace */ if (!ls->ls_count) return 1; if (dlm_is_removed(ls, nodeid)) return 1; /* directory operations are always purged because the directory is always rebuilt during recovery and the lookups resent */ if (type == DLM_MSG_REMOVE || type == DLM_MSG_LOOKUP || type == DLM_MSG_LOOKUP_REPLY) return 1; if (!dlm_no_directory(ls)) return 0; /* with no directory, the master is likely to change as a part of recovery; requests to/from the defunct master need to be purged */ switch (type) { case DLM_MSG_REQUEST: case DLM_MSG_CONVERT: case DLM_MSG_UNLOCK: case DLM_MSG_CANCEL: /* we're no longer the master of this resource, the sender will resend to the new master (see waiter_needs_recovery) */ if (dlm_hash2nodeid(ls, ms->m_hash) != dlm_our_nodeid()) return 1; break; case DLM_MSG_REQUEST_REPLY: case DLM_MSG_CONVERT_REPLY: case DLM_MSG_UNLOCK_REPLY: case DLM_MSG_CANCEL_REPLY: case DLM_MSG_GRANT: /* this reply is from the former master of the resource, we'll resend to the new master if needed */ if (dlm_hash2nodeid(ls, ms->m_hash) != nodeid) return 1; break; } return 0; } void dlm_purge_requestqueue(struct dlm_ls *ls) { struct dlm_message *ms; struct rq_entry *e, *safe; mutex_lock(&ls->ls_requestqueue_mutex); list_for_each_entry_safe(e, safe, &ls->ls_requestqueue, list) { ms = &e->request; if (purge_request(ls, ms, e->nodeid)) { list_del(&e->list); kfree(e); } } mutex_unlock(&ls->ls_requestqueue_mutex); }