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a070a91cf1
This patch prepares hooks to redirect to the midcomms layer which will be used by the midcomms re-transmit handling. There exists the new concept of stateless buffers allocation and commits. This can be used to bypass the midcomms re-transmit handling. It is used by RCOM_STATUS and RCOM_NAMES messages, because they have their own ping-like re-transmit handling. As well these two messages will be used to determine the DLM version per node, because these two messages are per observation the first messages which are exchanged. Cluster manager events for node membership are added to add support for half-closed connections in cases that the peer connection get to an end of file but DLM still holds membership of the node. In this time DLM can still trigger new message which we should allow. After the cluster manager node removal event occurs it safe to close the connection. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
133 lines
3.3 KiB
C
133 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/******************************************************************************
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*******************************************************************************
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**
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** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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** Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
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**
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**
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*******************************************************************************
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******************************************************************************/
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/*
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* midcomms.c
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*
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* This is the appallingly named "mid-level" comms layer.
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*
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* Its purpose is to take packets from the "real" comms layer,
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* split them up into packets and pass them to the interested
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* part of the locking mechanism.
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*
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* It also takes messages from the locking layer, formats them
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* into packets and sends them to the comms layer.
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*/
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#include "dlm_internal.h"
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#include "lowcomms.h"
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#include "config.h"
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#include "lock.h"
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#include "midcomms.h"
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struct dlm_mhandle *dlm_midcomms_get_mhandle(int nodeid, int len,
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gfp_t allocation, char **ppc)
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{
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return dlm_lowcomms_get_buffer(nodeid, len, allocation, ppc);
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}
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void dlm_midcomms_commit_mhandle(struct dlm_mhandle *mh)
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{
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dlm_lowcomms_commit_buffer(mh);
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}
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void dlm_midcomms_add_member(int nodeid) { }
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void dlm_midcomms_remove_member(int nodeid) { }
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int dlm_midcomms_start(void)
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{
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return dlm_lowcomms_start();
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}
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void dlm_midcomms_shutdown(void)
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{
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dlm_lowcomms_shutdown();
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}
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int dlm_midcomms_close(int nodeid)
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{
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return dlm_lowcomms_close(nodeid);
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}
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/*
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* Called from the low-level comms layer to process a buffer of
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* commands.
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*/
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int dlm_process_incoming_buffer(int nodeid, unsigned char *buf, int len)
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{
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const unsigned char *ptr = buf;
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const struct dlm_header *hd;
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uint16_t msglen;
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int ret = 0;
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while (len >= sizeof(struct dlm_header)) {
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hd = (struct dlm_header *)ptr;
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/* no message should be more than DEFAULT_BUFFER_SIZE or
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* less than dlm_header size.
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*
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* Some messages does not have a 8 byte length boundary yet
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* which can occur in a unaligned memory access of some dlm
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* messages. However this problem need to be fixed at the
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* sending side, for now it seems nobody run into architecture
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* related issues yet but it slows down some processing.
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* Fixing this issue should be scheduled in future by doing
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* the next major version bump.
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*/
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msglen = le16_to_cpu(hd->h_length);
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if (msglen > DEFAULT_BUFFER_SIZE ||
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msglen < sizeof(struct dlm_header)) {
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log_print("received invalid length header: %u from node %d, will abort message parsing",
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msglen, nodeid);
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return -EBADMSG;
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}
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/* caller will take care that leftover
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* will be parsed next call with more data
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*/
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if (msglen > len)
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break;
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switch (hd->h_cmd) {
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case DLM_MSG:
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if (msglen < sizeof(struct dlm_message)) {
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log_print("dlm msg too small: %u, will skip this message",
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msglen);
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goto skip;
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}
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break;
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case DLM_RCOM:
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if (msglen < sizeof(struct dlm_rcom)) {
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log_print("dlm rcom msg too small: %u, will skip this message",
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msglen);
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goto skip;
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}
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break;
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default:
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log_print("unsupported h_cmd received: %u, will skip this message",
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hd->h_cmd);
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goto skip;
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}
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dlm_receive_buffer((union dlm_packet *)ptr, nodeid);
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skip:
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ret += msglen;
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len -= msglen;
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ptr += msglen;
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}
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return ret;
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}
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