--- /dev/null
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) 2005 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;
+ char request[1];
+};
+
+/*
+ * 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.
+ */
+
+int dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_header *hd)
+{
+ struct rq_entry *e;
+ int length = hd->h_length;
+ int rv = 0;
+
+ e = kmalloc(sizeof(struct rq_entry) + length, GFP_KERNEL);
+ if (!e) {
+ log_print("dlm_add_requestqueue: out of memory\n");
+ return 0;
+ }
+
+ e->nodeid = nodeid;
+ memcpy(e->request, hd, length);
+
+ /* We need to check dlm_locking_stopped() after taking the mutex to
+ avoid a race where dlm_recoverd enables locking and runs
+ process_requestqueue between our earlier dlm_locking_stopped check
+ and this addition to the requestqueue. */
+
+ mutex_lock(&ls->ls_requestqueue_mutex);
+ if (dlm_locking_stopped(ls))
+ list_add_tail(&e->list, &ls->ls_requestqueue);
+ else {
+ log_debug(ls, "dlm_add_requestqueue skip from %d", nodeid);
+ kfree(e);
+ rv = -EAGAIN;
+ }
+ mutex_unlock(&ls->ls_requestqueue_mutex);
+ return rv;
+}
+
+int dlm_process_requestqueue(struct dlm_ls *ls)
+{
+ struct rq_entry *e;
+ struct dlm_header *hd;
+ 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);
+
+ hd = (struct dlm_header *) e->request;
+ error = dlm_receive_message(hd, e->nodeid, 1);
+
+ if (error == -EINTR) {
+ /* entry is left on requestqueue */
+ log_debug(ls, "process_requestqueue abort eintr");
+ break;
+ }
+
+ 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_recvd. At
+ * the same time, dlm_recvd will start receiving new requests from remote
+ * nodes. We want to delay dlm_recvd processing new requests until
+ * dlm_recoverd has finished processing the old saved requests.
+ */
+
+void dlm_wait_requestqueue(struct dlm_ls *ls)
+{
+ for (;;) {
+ mutex_lock(&ls->ls_requestqueue_mutex);
+ if (list_empty(&ls->ls_requestqueue))
+ break;
+ if (dlm_locking_stopped(ls))
+ 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 = (struct dlm_message *) e->request;
+
+ if (purge_request(ls, ms, e->nodeid)) {
+ list_del(&e->list);
+ kfree(e);
+ }
+ }
+ mutex_unlock(&ls->ls_requestqueue_mutex);
+}
+
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