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Communication Framework: Receiving

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1. receive status

   sender                         receiver                   receiver
   ACK:CR                          ACK:CR                     ACK:CR

2. sender get EX of TOKEN
   sender get EX of MESSAGE
   sender                          receiver                   receiver
   TOKEN:EX                         ACK:CR                     ACK:CR
   MESSAGE:EX
   ACK:CR

3. sender write LVB.
   sender down-convert MESSAGE from EX to CR
   sender try to get EX of ACK
   [ wait until all receiver has *processed* the MESSAGE ]

                                     [ triggered by bast of ACK ]
                                     receiver get CR of MESSAGE
                                     receiver read LVB
                                     receiver processes the message
				     [ wait finish ]
                                     receiver release ACK

   sender                         receiver                   receiver
   TOKEN:EX                       MESSAGE:CR                 MESSAGE:CR
   MESSAGE:CR
   ACK:EX

4. sender down-convert ACK from EX to CR
   sender release MESSAGE
   sender release TOKEN
				  receiver upconvert to EX of MESSAGE
                                  receiver get CR of ACK
				  receiver release MESSAGE

   sender                        receiver                   receiver
   ACK:CR                         ACK:CR                     ACK:CR

Signed-off-by: Lidong Zhong <lzhong@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
This commit is contained in:
Goldwyn Rodrigues 2014-06-07 01:08:29 -05:00
parent 4b26a08af9
commit 4664680c38
1 changed files with 102 additions and 0 deletions
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102
drivers/md/md-cluster.c
View File

@ -52,6 +52,23 @@ struct md_cluster_info {
spinlock_t suspend_lock;
struct md_thread *recovery_thread;
unsigned long recovery_map;
/* communication loc resources */
struct dlm_lock_resource *ack_lockres;
struct dlm_lock_resource *message_lockres;
struct dlm_lock_resource *token_lockres;
struct md_thread *recv_thread;
};
enum msg_type {
METADATA_UPDATED = 0,
RESYNCING,
};
struct cluster_msg {
int type;
int slot;
sector_t low;
sector_t high;
};
static void sync_ast(void *arg)
@ -283,6 +300,64 @@ static const struct dlm_lockspace_ops md_ls_ops = {
.recover_done = recover_done,
};
/*
* The BAST function for the ack lock resource
* This function wakes up the receive thread in
* order to receive and process the message.
*/
static void ack_bast(void *arg, int mode)
{
struct dlm_lock_resource *res = (struct dlm_lock_resource *)arg;
struct md_cluster_info *cinfo = res->mddev->cluster_info;
if (mode == DLM_LOCK_EX)
md_wakeup_thread(cinfo->recv_thread);
}
static void process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
{
switch (msg->type) {
case METADATA_UPDATED:
pr_info("%s: %d Received message: METADATA_UPDATE from %d\n",
__func__, __LINE__, msg->slot);
break;
case RESYNCING:
pr_info("%s: %d Received message: RESYNCING from %d\n",
__func__, __LINE__, msg->slot);
break;
};
}
/*
* thread for receiving message
*/
static void recv_daemon(struct md_thread *thread)
{
struct md_cluster_info *cinfo = thread->mddev->cluster_info;
struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
struct cluster_msg msg;
/*get CR on Message*/
if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
pr_err("md/raid1:failed to get CR on MESSAGE\n");
return;
}
/* read lvb and wake up thread to process this message_lockres */
memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
process_recvd_msg(thread->mddev, &msg);
/*release CR on ack_lockres*/
dlm_unlock_sync(ack_lockres);
/*up-convert to EX on message_lockres*/
dlm_lock_sync(message_lockres, DLM_LOCK_EX);
/*get CR on ack_lockres again*/
dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
/*release CR on message_lockres*/
dlm_unlock_sync(message_lockres);
}
static int gather_all_resync_info(struct mddev *mddev, int total_slots)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
@ -368,6 +443,26 @@ static int join(struct mddev *mddev, int nodes)
ret = -ENOMEM;
goto err;
}
/* Initiate the communication resources */
ret = -ENOMEM;
cinfo->recv_thread = md_register_thread(recv_daemon, mddev, "cluster_recv");
if (!cinfo->recv_thread) {
pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
goto err;
}
cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
if (!cinfo->message_lockres)
goto err;
cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
if (!cinfo->token_lockres)
goto err;
cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
if (!cinfo->ack_lockres)
goto err;
/* get sync CR lock on ACK. */
if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
ret);
pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
@ -389,6 +484,9 @@ static int join(struct mddev *mddev, int nodes)
return 0;
err:
lockres_free(cinfo->message_lockres);
lockres_free(cinfo->token_lockres);
lockres_free(cinfo->ack_lockres);
lockres_free(cinfo->bitmap_lockres);
lockres_free(cinfo->sb_lock);
if (cinfo->lockspace)
@ -406,6 +504,10 @@ static int leave(struct mddev *mddev)
if (!cinfo)
return 0;
md_unregister_thread(&cinfo->recovery_thread);
md_unregister_thread(&cinfo->recv_thread);
lockres_free(cinfo->message_lockres);
lockres_free(cinfo->token_lockres);
lockres_free(cinfo->ack_lockres);
lockres_free(cinfo->sb_lock);
lockres_free(cinfo->bitmap_lockres);
dlm_release_lockspace(cinfo->lockspace, 2);