Fixed MTP to work with TWRP

fs/dlm/requestqueue.c

@@ -0,0 +1,171 @@
+/******************************************************************************
+*******************************************************************************
+**
+**  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;
+	uint32_t recover_seq;
+	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->recover_seq = ls->ls_recover_seq & 0xFFFFFFFF;
+	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;
+	struct dlm_message *ms;
+	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);
+
+		ms = &e->request;
+
+		log_limit(ls, "dlm_process_requestqueue msg %d from %d "
+			  "lkid %x remid %x result %d seq %u",
+			  ms->m_type, ms->m_header.h_nodeid,
+			  ms->m_lkid, ms->m_remid, ms->m_result,
+			  e->recover_seq);
+
+		dlm_receive_message_saved(ls, &e->request, e->recover_seq);
+
+		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;
+
+	return 1;
+}
+
+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);
+}
+