mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 00:52:01 +00:00
2522fe45a1
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 45 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528170027.342746075@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
136 lines
3.6 KiB
C
136 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/******************************************************************************
|
|
*******************************************************************************
|
|
**
|
|
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
|
|
** Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
|
|
**
|
|
**
|
|
*******************************************************************************
|
|
******************************************************************************/
|
|
|
|
/*
|
|
* midcomms.c
|
|
*
|
|
* This is the appallingly named "mid-level" comms layer.
|
|
*
|
|
* Its purpose is to take packets from the "real" comms layer,
|
|
* split them up into packets and pass them to the interested
|
|
* part of the locking mechanism.
|
|
*
|
|
* It also takes messages from the locking layer, formats them
|
|
* into packets and sends them to the comms layer.
|
|
*/
|
|
|
|
#include "dlm_internal.h"
|
|
#include "lowcomms.h"
|
|
#include "config.h"
|
|
#include "lock.h"
|
|
#include "midcomms.h"
|
|
|
|
|
|
static void copy_from_cb(void *dst, const void *base, unsigned offset,
|
|
unsigned len, unsigned limit)
|
|
{
|
|
unsigned copy = len;
|
|
|
|
if ((copy + offset) > limit)
|
|
copy = limit - offset;
|
|
memcpy(dst, base + offset, copy);
|
|
len -= copy;
|
|
if (len)
|
|
memcpy(dst + copy, base, len);
|
|
}
|
|
|
|
/*
|
|
* Called from the low-level comms layer to process a buffer of
|
|
* commands.
|
|
*
|
|
* Only complete messages are processed here, any "spare" bytes from
|
|
* the end of a buffer are saved and tacked onto the front of the next
|
|
* message that comes in. I doubt this will happen very often but we
|
|
* need to be able to cope with it and I don't want the task to be waiting
|
|
* for packets to come in when there is useful work to be done.
|
|
*/
|
|
|
|
int dlm_process_incoming_buffer(int nodeid, const void *base,
|
|
unsigned offset, unsigned len, unsigned limit)
|
|
{
|
|
union {
|
|
unsigned char __buf[DLM_INBUF_LEN];
|
|
/* this is to force proper alignment on some arches */
|
|
union dlm_packet p;
|
|
} __tmp;
|
|
union dlm_packet *p = &__tmp.p;
|
|
int ret = 0;
|
|
int err = 0;
|
|
uint16_t msglen;
|
|
uint32_t lockspace;
|
|
|
|
while (len > sizeof(struct dlm_header)) {
|
|
|
|
/* Copy just the header to check the total length. The
|
|
message may wrap around the end of the buffer back to the
|
|
start, so we need to use a temp buffer and copy_from_cb. */
|
|
|
|
copy_from_cb(p, base, offset, sizeof(struct dlm_header),
|
|
limit);
|
|
|
|
msglen = le16_to_cpu(p->header.h_length);
|
|
lockspace = p->header.h_lockspace;
|
|
|
|
err = -EINVAL;
|
|
if (msglen < sizeof(struct dlm_header))
|
|
break;
|
|
if (p->header.h_cmd == DLM_MSG) {
|
|
if (msglen < sizeof(struct dlm_message))
|
|
break;
|
|
} else {
|
|
if (msglen < sizeof(struct dlm_rcom))
|
|
break;
|
|
}
|
|
err = -E2BIG;
|
|
if (msglen > dlm_config.ci_buffer_size) {
|
|
log_print("message size %d from %d too big, buf len %d",
|
|
msglen, nodeid, len);
|
|
break;
|
|
}
|
|
err = 0;
|
|
|
|
/* If only part of the full message is contained in this
|
|
buffer, then do nothing and wait for lowcomms to call
|
|
us again later with more data. We return 0 meaning
|
|
we've consumed none of the input buffer. */
|
|
|
|
if (msglen > len)
|
|
break;
|
|
|
|
/* Allocate a larger temp buffer if the full message won't fit
|
|
in the buffer on the stack (which should work for most
|
|
ordinary messages). */
|
|
|
|
if (msglen > sizeof(__tmp) && p == &__tmp.p) {
|
|
p = kmalloc(dlm_config.ci_buffer_size, GFP_NOFS);
|
|
if (p == NULL)
|
|
return ret;
|
|
}
|
|
|
|
copy_from_cb(p, base, offset, msglen, limit);
|
|
|
|
BUG_ON(lockspace != p->header.h_lockspace);
|
|
|
|
ret += msglen;
|
|
offset += msglen;
|
|
offset &= (limit - 1);
|
|
len -= msglen;
|
|
|
|
dlm_receive_buffer(p, nodeid);
|
|
}
|
|
|
|
if (p != &__tmp.p)
|
|
kfree(p);
|
|
|
|
return err ? err : ret;
|
|
}
|
|
|