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linux/fs/ocfs2/vote.c

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/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* vote.c
*
* description here
*
* Copyright (C) 2003, 2004 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/kthread.h>
#include <cluster/heartbeat.h>
#include <cluster/nodemanager.h>
#include <cluster/tcp.h>
#include <dlm/dlmapi.h>
#define MLOG_MASK_PREFIX ML_VOTE
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "heartbeat.h"
#include "inode.h"
#include "journal.h"
#include "slot_map.h"
#include "vote.h"
#include "buffer_head_io.h"
#define OCFS2_MESSAGE_TYPE_VOTE (0x1)
#define OCFS2_MESSAGE_TYPE_RESPONSE (0x2)
struct ocfs2_msg_hdr
{
__be32 h_response_id; /* used to lookup message handle on sending
* node. */
__be32 h_request;
__be64 h_blkno;
__be32 h_generation;
__be32 h_node_num; /* node sending this particular message. */
};
struct ocfs2_vote_msg
{
struct ocfs2_msg_hdr v_hdr;
__be32 v_reserved1;
} __attribute__ ((packed));
/* Responses are given these values to maintain backwards
* compatibility with older ocfs2 versions */
#define OCFS2_RESPONSE_OK (0)
#define OCFS2_RESPONSE_BUSY (-16)
#define OCFS2_RESPONSE_BAD_MSG (-22)
struct ocfs2_response_msg
{
struct ocfs2_msg_hdr r_hdr;
__be32 r_response;
} __attribute__ ((packed));
struct ocfs2_vote_work {
struct list_head w_list;
struct ocfs2_vote_msg w_msg;
};
enum ocfs2_vote_request {
OCFS2_VOTE_REQ_INVALID = 0,
OCFS2_VOTE_REQ_MOUNT,
OCFS2_VOTE_REQ_UMOUNT,
OCFS2_VOTE_REQ_LAST
};
static inline int ocfs2_is_valid_vote_request(int request)
{
return OCFS2_VOTE_REQ_INVALID < request &&
request < OCFS2_VOTE_REQ_LAST;
}
typedef void (*ocfs2_net_response_callback)(void *priv,
struct ocfs2_response_msg *resp);
struct ocfs2_net_response_cb {
ocfs2_net_response_callback rc_cb;
void *rc_priv;
};
struct ocfs2_net_wait_ctxt {
struct list_head n_list;
u32 n_response_id;
wait_queue_head_t n_event;
struct ocfs2_node_map n_node_map;
int n_response; /* an agreggate response. 0 if
* all nodes are go, < 0 on any
* negative response from any
* node or network error. */
struct ocfs2_net_response_cb *n_callback;
};
static void ocfs2_process_mount_request(struct ocfs2_super *osb,
unsigned int node_num)
{
mlog(0, "MOUNT vote from node %u\n", node_num);
/* The other node only sends us this message when he has an EX
* on the superblock, so our recovery threads (if having been
* launched) are waiting on it.*/
ocfs2_recovery_map_clear(osb, node_num);
ocfs2_node_map_set_bit(osb, &osb->mounted_map, node_num);
/* We clear the umount map here because a node may have been
* previously mounted, safely unmounted but never stopped
* heartbeating - in which case we'd have a stale entry. */
ocfs2_node_map_clear_bit(osb, &osb->umount_map, node_num);
}
static void ocfs2_process_umount_request(struct ocfs2_super *osb,
unsigned int node_num)
{
mlog(0, "UMOUNT vote from node %u\n", node_num);
ocfs2_node_map_clear_bit(osb, &osb->mounted_map, node_num);
ocfs2_node_map_set_bit(osb, &osb->umount_map, node_num);
}
static void ocfs2_process_vote(struct ocfs2_super *osb,
struct ocfs2_vote_msg *msg)
{
int net_status, vote_response;
unsigned int node_num;
u64 blkno;
enum ocfs2_vote_request request;
struct ocfs2_msg_hdr *hdr = &msg->v_hdr;
struct ocfs2_response_msg response;
/* decode the network mumbo jumbo into local variables. */
request = be32_to_cpu(hdr->h_request);
blkno = be64_to_cpu(hdr->h_blkno);
node_num = be32_to_cpu(hdr->h_node_num);
mlog(0, "processing vote: request = %u, blkno = %llu, node_num = %u\n",
request, (unsigned long long)blkno, node_num);
if (!ocfs2_is_valid_vote_request(request)) {
mlog(ML_ERROR, "Invalid vote request %d from node %u\n",
request, node_num);
vote_response = OCFS2_RESPONSE_BAD_MSG;
goto respond;
}
vote_response = OCFS2_RESPONSE_OK;
switch (request) {
case OCFS2_VOTE_REQ_UMOUNT:
ocfs2_process_umount_request(osb, node_num);
goto respond;
case OCFS2_VOTE_REQ_MOUNT:
ocfs2_process_mount_request(osb, node_num);
goto respond;
default:
/* avoids a gcc warning */
break;
}
respond:
/* Response struture is small so we just put it on the stack
* and stuff it inline. */
memset(&response, 0, sizeof(struct ocfs2_response_msg));
response.r_hdr.h_response_id = hdr->h_response_id;
response.r_hdr.h_blkno = hdr->h_blkno;
response.r_hdr.h_generation = hdr->h_generation;
response.r_hdr.h_node_num = cpu_to_be32(osb->node_num);
response.r_response = cpu_to_be32(vote_response);
net_status = o2net_send_message(OCFS2_MESSAGE_TYPE_RESPONSE,
osb->net_key,
&response,
sizeof(struct ocfs2_response_msg),
node_num,
NULL);
/* We still want to error print for ENOPROTOOPT here. The
* sending node shouldn't have unregistered his net handler
* without sending an unmount vote 1st */
if (net_status < 0
&& net_status != -ETIMEDOUT
&& net_status != -ENOTCONN)
mlog(ML_ERROR, "message to node %u fails with error %d!\n",
node_num, net_status);
}
static void ocfs2_vote_thread_do_work(struct ocfs2_super *osb)
{
unsigned long processed;
struct ocfs2_lock_res *lockres;
struct ocfs2_vote_work *work;
mlog_entry_void();
spin_lock(&osb->vote_task_lock);
/* grab this early so we know to try again if a state change and
* wake happens part-way through our work */
osb->vote_work_sequence = osb->vote_wake_sequence;
processed = osb->blocked_lock_count;
while (processed) {
BUG_ON(list_empty(&osb->blocked_lock_list));
lockres = list_entry(osb->blocked_lock_list.next,
struct ocfs2_lock_res, l_blocked_list);
list_del_init(&lockres->l_blocked_list);
osb->blocked_lock_count--;
spin_unlock(&osb->vote_task_lock);
BUG_ON(!processed);
processed--;
ocfs2_process_blocked_lock(osb, lockres);
spin_lock(&osb->vote_task_lock);
}
while (osb->vote_count) {
BUG_ON(list_empty(&osb->vote_list));
work = list_entry(osb->vote_list.next,
struct ocfs2_vote_work, w_list);
list_del(&work->w_list);
osb->vote_count--;
spin_unlock(&osb->vote_task_lock);
ocfs2_process_vote(osb, &work->w_msg);
kfree(work);
spin_lock(&osb->vote_task_lock);
}
spin_unlock(&osb->vote_task_lock);
mlog_exit_void();
}
static int ocfs2_vote_thread_lists_empty(struct ocfs2_super *osb)
{
int empty = 0;
spin_lock(&osb->vote_task_lock);
if (list_empty(&osb->blocked_lock_list) &&
list_empty(&osb->vote_list))
empty = 1;
spin_unlock(&osb->vote_task_lock);
return empty;
}
static int ocfs2_vote_thread_should_wake(struct ocfs2_super *osb)
{
int should_wake = 0;
spin_lock(&osb->vote_task_lock);
if (osb->vote_work_sequence != osb->vote_wake_sequence)
should_wake = 1;
spin_unlock(&osb->vote_task_lock);
return should_wake;
}
int ocfs2_vote_thread(void *arg)
{
int status = 0;
struct ocfs2_super *osb = arg;
/* only quit once we've been asked to stop and there is no more
* work available */
while (!(kthread_should_stop() &&
ocfs2_vote_thread_lists_empty(osb))) {
wait_event_interruptible(osb->vote_event,
ocfs2_vote_thread_should_wake(osb) ||
kthread_should_stop());
mlog(0, "vote_thread: awoken\n");
ocfs2_vote_thread_do_work(osb);
}
osb->vote_task = NULL;
return status;
}
static struct ocfs2_net_wait_ctxt *ocfs2_new_net_wait_ctxt(unsigned int response_id)
{
struct ocfs2_net_wait_ctxt *w;
w = kzalloc(sizeof(*w), GFP_NOFS);
if (!w) {
mlog_errno(-ENOMEM);
goto bail;
}
INIT_LIST_HEAD(&w->n_list);
init_waitqueue_head(&w->n_event);
ocfs2_node_map_init(&w->n_node_map);
w->n_response_id = response_id;
w->n_callback = NULL;
bail:
return w;
}
static unsigned int ocfs2_new_response_id(struct ocfs2_super *osb)
{
unsigned int ret;
spin_lock(&osb->net_response_lock);
ret = ++osb->net_response_ids;
spin_unlock(&osb->net_response_lock);
return ret;
}
static void ocfs2_dequeue_net_wait_ctxt(struct ocfs2_super *osb,
struct ocfs2_net_wait_ctxt *w)
{
spin_lock(&osb->net_response_lock);
list_del(&w->n_list);
spin_unlock(&osb->net_response_lock);
}
static void ocfs2_queue_net_wait_ctxt(struct ocfs2_super *osb,
struct ocfs2_net_wait_ctxt *w)
{
spin_lock(&osb->net_response_lock);
list_add_tail(&w->n_list,
&osb->net_response_list);
spin_unlock(&osb->net_response_lock);
}
static void __ocfs2_mark_node_responded(struct ocfs2_super *osb,
struct ocfs2_net_wait_ctxt *w,
int node_num)
{
assert_spin_locked(&osb->net_response_lock);
ocfs2_node_map_clear_bit(osb, &w->n_node_map, node_num);
if (ocfs2_node_map_is_empty(osb, &w->n_node_map))
wake_up(&w->n_event);
}
/* Intended to be called from the node down callback, we fake remove
* the node from all our response contexts */
void ocfs2_remove_node_from_vote_queues(struct ocfs2_super *osb,
int node_num)
{
struct list_head *p;
struct ocfs2_net_wait_ctxt *w = NULL;
spin_lock(&osb->net_response_lock);
list_for_each(p, &osb->net_response_list) {
w = list_entry(p, struct ocfs2_net_wait_ctxt, n_list);
__ocfs2_mark_node_responded(osb, w, node_num);
}
spin_unlock(&osb->net_response_lock);
}
static int ocfs2_broadcast_vote(struct ocfs2_super *osb,
struct ocfs2_vote_msg *request,
unsigned int response_id,
int *response,
struct ocfs2_net_response_cb *callback)
{
int status, i, remote_err;
struct ocfs2_net_wait_ctxt *w = NULL;
int dequeued = 0;
mlog_entry_void();
w = ocfs2_new_net_wait_ctxt(response_id);
if (!w) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
w->n_callback = callback;
/* we're pretty much ready to go at this point, and this fills
* in n_response which we need anyway... */
ocfs2_queue_net_wait_ctxt(osb, w);
i = ocfs2_node_map_iterate(osb, &osb->mounted_map, 0);
while (i != O2NM_INVALID_NODE_NUM) {
if (i != osb->node_num) {
mlog(0, "trying to send request to node %i\n", i);
ocfs2_node_map_set_bit(osb, &w->n_node_map, i);
remote_err = 0;
status = o2net_send_message(OCFS2_MESSAGE_TYPE_VOTE,
osb->net_key,
request,
sizeof(*request),
i,
&remote_err);
if (status == -ETIMEDOUT) {
mlog(0, "remote node %d timed out!\n", i);
status = -EAGAIN;
goto bail;
}
if (remote_err < 0) {
status = remote_err;
mlog(0, "remote error %d on node %d!\n",
remote_err, i);
mlog_errno(status);
goto bail;
}
if (status < 0) {
mlog_errno(status);
goto bail;
}
}
i++;
i = ocfs2_node_map_iterate(osb, &osb->mounted_map, i);
mlog(0, "next is %d, i am %d\n", i, osb->node_num);
}
mlog(0, "done sending, now waiting on responses...\n");
wait_event(w->n_event, ocfs2_node_map_is_empty(osb, &w->n_node_map));
ocfs2_dequeue_net_wait_ctxt(osb, w);
dequeued = 1;
*response = w->n_response;
status = 0;
bail:
if (w) {
if (!dequeued)
ocfs2_dequeue_net_wait_ctxt(osb, w);
kfree(w);
}
mlog_exit(status);
return status;
}
static struct ocfs2_vote_msg * ocfs2_new_vote_request(struct ocfs2_super *osb,
u64 blkno,
unsigned int generation,
enum ocfs2_vote_request type)
{
struct ocfs2_vote_msg *request;
struct ocfs2_msg_hdr *hdr;
BUG_ON(!ocfs2_is_valid_vote_request(type));
request = kzalloc(sizeof(*request), GFP_NOFS);
if (!request) {
mlog_errno(-ENOMEM);
} else {
hdr = &request->v_hdr;
hdr->h_node_num = cpu_to_be32(osb->node_num);
hdr->h_request = cpu_to_be32(type);
hdr->h_blkno = cpu_to_be64(blkno);
hdr->h_generation = cpu_to_be32(generation);
}
return request;
}
/* Complete the buildup of a new vote request and process the
* broadcast return value. */
static int ocfs2_do_request_vote(struct ocfs2_super *osb,
struct ocfs2_vote_msg *request,
struct ocfs2_net_response_cb *callback)
{
int status, response = -EBUSY;
unsigned int response_id;
struct ocfs2_msg_hdr *hdr;
response_id = ocfs2_new_response_id(osb);
hdr = &request->v_hdr;
hdr->h_response_id = cpu_to_be32(response_id);
status = ocfs2_broadcast_vote(osb, request, response_id, &response,
callback);
if (status < 0) {
mlog_errno(status);
goto bail;
}
status = response;
bail:
return status;
}
int ocfs2_request_mount_vote(struct ocfs2_super *osb)
{
int status;
struct ocfs2_vote_msg *request = NULL;
request = ocfs2_new_vote_request(osb, 0ULL, 0, OCFS2_VOTE_REQ_MOUNT);
if (!request) {
status = -ENOMEM;
goto bail;
}
status = -EAGAIN;
while (status == -EAGAIN) {
if (!(osb->s_mount_opt & OCFS2_MOUNT_NOINTR) &&
signal_pending(current)) {
status = -ERESTARTSYS;
goto bail;
}
if (ocfs2_node_map_is_only(osb, &osb->mounted_map,
osb->node_num)) {
status = 0;
goto bail;
}
status = ocfs2_do_request_vote(osb, request, NULL);
}
bail:
kfree(request);
return status;
}
int ocfs2_request_umount_vote(struct ocfs2_super *osb)
{
int status;
struct ocfs2_vote_msg *request = NULL;
request = ocfs2_new_vote_request(osb, 0ULL, 0, OCFS2_VOTE_REQ_UMOUNT);
if (!request) {
status = -ENOMEM;
goto bail;
}
status = -EAGAIN;
while (status == -EAGAIN) {
/* Do not check signals on this vote... We really want
* this one to go all the way through. */
if (ocfs2_node_map_is_only(osb, &osb->mounted_map,
osb->node_num)) {
status = 0;
goto bail;
}
status = ocfs2_do_request_vote(osb, request, NULL);
}
bail:
kfree(request);
return status;
}
/* TODO: This should eventually be a hash table! */
static struct ocfs2_net_wait_ctxt * __ocfs2_find_net_wait_ctxt(struct ocfs2_super *osb,
u32 response_id)
{
struct list_head *p;
struct ocfs2_net_wait_ctxt *w = NULL;
list_for_each(p, &osb->net_response_list) {
w = list_entry(p, struct ocfs2_net_wait_ctxt, n_list);
if (response_id == w->n_response_id)
break;
w = NULL;
}
return w;
}
/* Translate response codes into local node errno values */
static inline int ocfs2_translate_response(int response)
{
int ret;
switch (response) {
case OCFS2_RESPONSE_OK:
ret = 0;
break;
case OCFS2_RESPONSE_BUSY:
ret = -EBUSY;
break;
default:
ret = -EINVAL;
}
return ret;
}
static int ocfs2_handle_response_message(struct o2net_msg *msg,
u32 len,
void *data, void **ret_data)
{
unsigned int response_id, node_num;
int response_status;
struct ocfs2_super *osb = data;
struct ocfs2_response_msg *resp;
struct ocfs2_net_wait_ctxt * w;
struct ocfs2_net_response_cb *resp_cb;
resp = (struct ocfs2_response_msg *) msg->buf;
response_id = be32_to_cpu(resp->r_hdr.h_response_id);
node_num = be32_to_cpu(resp->r_hdr.h_node_num);
response_status =
ocfs2_translate_response(be32_to_cpu(resp->r_response));
mlog(0, "received response message:\n");
mlog(0, "h_response_id = %u\n", response_id);
mlog(0, "h_request = %u\n", be32_to_cpu(resp->r_hdr.h_request));
mlog(0, "h_blkno = %llu\n",
(unsigned long long)be64_to_cpu(resp->r_hdr.h_blkno));
mlog(0, "h_generation = %u\n", be32_to_cpu(resp->r_hdr.h_generation));
mlog(0, "h_node_num = %u\n", node_num);
mlog(0, "r_response = %d\n", response_status);
spin_lock(&osb->net_response_lock);
w = __ocfs2_find_net_wait_ctxt(osb, response_id);
if (!w) {
mlog(0, "request not found!\n");
goto bail;
}
resp_cb = w->n_callback;
if (response_status && (!w->n_response)) {
/* we only really need one negative response so don't
* set it twice. */
w->n_response = response_status;
}
if (resp_cb) {
spin_unlock(&osb->net_response_lock);
resp_cb->rc_cb(resp_cb->rc_priv, resp);
spin_lock(&osb->net_response_lock);
}
__ocfs2_mark_node_responded(osb, w, node_num);
bail:
spin_unlock(&osb->net_response_lock);
return 0;
}
static int ocfs2_handle_vote_message(struct o2net_msg *msg,
u32 len,
void *data, void **ret_data)
{
int status;
struct ocfs2_super *osb = data;
struct ocfs2_vote_work *work;
work = kmalloc(sizeof(struct ocfs2_vote_work), GFP_NOFS);
if (!work) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
INIT_LIST_HEAD(&work->w_list);
memcpy(&work->w_msg, msg->buf, sizeof(struct ocfs2_vote_msg));
mlog(0, "scheduling vote request:\n");
mlog(0, "h_response_id = %u\n",
be32_to_cpu(work->w_msg.v_hdr.h_response_id));
mlog(0, "h_request = %u\n", be32_to_cpu(work->w_msg.v_hdr.h_request));
mlog(0, "h_blkno = %llu\n",
(unsigned long long)be64_to_cpu(work->w_msg.v_hdr.h_blkno));
mlog(0, "h_generation = %u\n",
be32_to_cpu(work->w_msg.v_hdr.h_generation));
mlog(0, "h_node_num = %u\n",
be32_to_cpu(work->w_msg.v_hdr.h_node_num));
spin_lock(&osb->vote_task_lock);
list_add_tail(&work->w_list, &osb->vote_list);
osb->vote_count++;
spin_unlock(&osb->vote_task_lock);
ocfs2_kick_vote_thread(osb);
status = 0;
bail:
return status;
}
void ocfs2_unregister_net_handlers(struct ocfs2_super *osb)
{
if (!osb->net_key)
return;
o2net_unregister_handler_list(&osb->osb_net_handlers);
if (!list_empty(&osb->net_response_list))
mlog(ML_ERROR, "net response list not empty!\n");
osb->net_key = 0;
}
int ocfs2_register_net_handlers(struct ocfs2_super *osb)
{
int status = 0;
if (ocfs2_mount_local(osb))
return 0;
status = o2net_register_handler(OCFS2_MESSAGE_TYPE_RESPONSE,
osb->net_key,
sizeof(struct ocfs2_response_msg),
ocfs2_handle_response_message,
osb, NULL, &osb->osb_net_handlers);
if (status) {
mlog_errno(status);
goto bail;
}
status = o2net_register_handler(OCFS2_MESSAGE_TYPE_VOTE,
osb->net_key,
sizeof(struct ocfs2_vote_msg),
ocfs2_handle_vote_message,
osb, NULL, &osb->osb_net_handlers);
if (status) {
mlog_errno(status);
goto bail;
}
bail:
if (status < 0)
ocfs2_unregister_net_handlers(osb);
return status;
}
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