fs: dlm: add functionality to re-transmit a message

This patch introduces a retransmit functionality for a lowcomms message
handle. It's just allocates a new buffer and transmit it again, no
special handling about prioritize it because keeping bytestream in order.

To avoid another connection look some refactor was done to make a new
buffer allocation with a preexisting connection pointer.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This commit is contained in:
Alexander Aring 2021-05-21 15:08:43 -04:00 committed by David Teigland
parent 8f2dc78dbc
commit 2874d1a68c
2 changed files with 67 additions and 19 deletions

View File

@ -126,6 +126,8 @@ struct writequeue_entry {
struct dlm_msg {
struct writequeue_entry *entry;
struct dlm_msg *orig_msg;
bool retransmit;
void *ppc;
int len;
int idx; /* new()/commit() idx exchange */
@ -1055,6 +1057,10 @@ static void free_entry(struct writequeue_entry *e)
struct dlm_msg *msg, *tmp;
list_for_each_entry_safe(msg, tmp, &e->msgs, list) {
if (msg->orig_msg) {
msg->orig_msg->retransmit = false;
kref_put(&msg->orig_msg->ref, dlm_msg_release);
}
list_del(&msg->list);
kref_put(&msg->ref, dlm_msg_release);
}
@ -1494,11 +1500,37 @@ static struct writequeue_entry *new_wq_entry(struct connection *con, int len,
return e;
};
static struct dlm_msg *dlm_lowcomms_new_msg_con(struct connection *con, int len,
gfp_t allocation, char **ppc,
void (*cb)(struct dlm_mhandle *mh),
struct dlm_mhandle *mh)
{
struct writequeue_entry *e;
struct dlm_msg *msg;
msg = kzalloc(sizeof(*msg), allocation);
if (!msg)
return NULL;
kref_init(&msg->ref);
e = new_wq_entry(con, len, allocation, ppc, cb, mh);
if (!e) {
kfree(msg);
return NULL;
}
msg->ppc = *ppc;
msg->len = len;
msg->entry = e;
return msg;
}
struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation,
char **ppc, void (*cb)(struct dlm_mhandle *mh),
struct dlm_mhandle *mh)
{
struct writequeue_entry *e;
struct connection *con;
struct dlm_msg *msg;
int idx;
@ -1518,32 +1550,18 @@ struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation,
return NULL;
}
msg = kzalloc(sizeof(*msg), allocation);
msg = dlm_lowcomms_new_msg_con(con, len, allocation, ppc, cb, mh);
if (!msg) {
srcu_read_unlock(&connections_srcu, idx);
return NULL;
}
kref_init(&msg->ref);
e = new_wq_entry(con, len, allocation, ppc, cb, mh);
if (!e) {
srcu_read_unlock(&connections_srcu, idx);
kfree(msg);
return NULL;
}
msg->ppc = *ppc;
msg->len = len;
msg->entry = e;
/* we assume if successful commit must called */
msg->idx = idx;
return msg;
}
void dlm_lowcomms_commit_msg(struct dlm_msg *msg)
static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg)
{
struct writequeue_entry *e = msg->entry;
struct connection *con = e->con;
@ -1561,20 +1579,49 @@ void dlm_lowcomms_commit_msg(struct dlm_msg *msg)
spin_unlock(&con->writequeue_lock);
queue_work(send_workqueue, &con->swork);
srcu_read_unlock(&connections_srcu, msg->idx);
return;
out:
spin_unlock(&con->writequeue_lock);
srcu_read_unlock(&connections_srcu, msg->idx);
return;
}
void dlm_lowcomms_commit_msg(struct dlm_msg *msg)
{
_dlm_lowcomms_commit_msg(msg);
srcu_read_unlock(&connections_srcu, msg->idx);
}
void dlm_lowcomms_put_msg(struct dlm_msg *msg)
{
kref_put(&msg->ref, dlm_msg_release);
}
/* does not held connections_srcu, usage workqueue only */
int dlm_lowcomms_resend_msg(struct dlm_msg *msg)
{
struct dlm_msg *msg_resend;
char *ppc;
if (msg->retransmit)
return 1;
msg_resend = dlm_lowcomms_new_msg_con(msg->entry->con, msg->len,
GFP_ATOMIC, &ppc, NULL, NULL);
if (!msg_resend)
return -ENOMEM;
msg->retransmit = true;
kref_get(&msg->ref);
msg_resend->orig_msg = msg;
memcpy(ppc, msg->ppc, msg->len);
_dlm_lowcomms_commit_msg(msg_resend);
dlm_lowcomms_put_msg(msg_resend);
return 0;
}
/* Send a message */
static void send_to_sock(struct connection *con)
{

View File

@ -27,6 +27,7 @@ struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation,
struct dlm_mhandle *mh);
void dlm_lowcomms_commit_msg(struct dlm_msg *msg);
void dlm_lowcomms_put_msg(struct dlm_msg *msg);
int dlm_lowcomms_resend_msg(struct dlm_msg *msg);
int dlm_lowcomms_connect_node(int nodeid);
int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark);
int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len);