Commit f0747ebf authored by Alexander Aring's avatar Alexander Aring Committed by David Teigland
Browse files

fs: dlm: simplify writequeue handling 



This patch cleans up the current dlm sending allocator handling by using
some named macros, list functionality and removes some goto statements.

Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent e1a7cbce

fs/dlm/lowcomms.c

+43 −40
Original line number Diff line number Diff line
@@ -102,6 +102,9 @@ struct listen_connection { 
	struct work_struct rwork;

};



#define DLM_WQ_REMAIN_BYTES(e) (PAGE_SIZE - e->end)

#define DLM_WQ_LENGTH_BYTES(e) (e->end - e->offset)



/* An entry waiting to be sent */

struct writequeue_entry {

	struct list_head list;
@@ -1351,7 +1354,7 @@ static struct writequeue_entry *new_writequeue_entry(struct connection *con, 
{

	struct writequeue_entry *entry;



	entry = kmalloc(sizeof(struct writequeue_entry), allocation);

	entry = kzalloc(sizeof(*entry), allocation);

	if (!entry)

		return NULL;
@@ -1361,62 +1364,62 @@ static struct writequeue_entry *new_writequeue_entry(struct connection *con, 
		return NULL;

	}



	entry->offset = 0;

	entry->len = 0;

	entry->end = 0;

	entry->users = 0;

	entry->con = con;

	entry->users = 1;



	return entry;

}



void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)

static struct writequeue_entry *new_wq_entry(struct connection *con, int len,

					     gfp_t allocation, char **ppc)

{

	struct connection *con;

	struct writequeue_entry *e;

	int offset = 0;



	if (len > DEFAULT_BUFFER_SIZE ||

	    len < sizeof(struct dlm_header)) {

		BUILD_BUG_ON(PAGE_SIZE < DEFAULT_BUFFER_SIZE);

		log_print("failed to allocate a buffer of size %d", len);

		WARN_ON(1);

		return NULL;

	}



	con = nodeid2con(nodeid, allocation);

	if (!con)

		return NULL;



	spin_lock(&con->writequeue_lock);

	e = list_entry(con->writequeue.prev, struct writequeue_entry, list);

	if ((&e->list == &con->writequeue) ||

	    (PAGE_SIZE - e->end < len)) {

		e = NULL;

	} else {

		offset = e->end;

	if (!list_empty(&con->writequeue)) {

		e = list_last_entry(&con->writequeue, struct writequeue_entry, list);

		if (DLM_WQ_REMAIN_BYTES(e) >= len) {

			*ppc = page_address(e->page) + e->end;

			e->end += len;

			e->users++;

	}

			spin_unlock(&con->writequeue_lock);



	if (e) {

	got_one:

		*ppc = page_address(e->page) + offset;

			return e;

		}

	}

	spin_unlock(&con->writequeue_lock);



	e = new_writequeue_entry(con, allocation);

	if (e) {

		spin_lock(&con->writequeue_lock);

		offset = e->end;

	if (!e)

		return NULL;



	*ppc = page_address(e->page);

	e->end += len;

		e->users++;



	spin_lock(&con->writequeue_lock);

	list_add_tail(&e->list, &con->writequeue);

	spin_unlock(&con->writequeue_lock);

		goto got_one;



	return e;

};



void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)

{

	struct connection *con;



	if (len > DEFAULT_BUFFER_SIZE ||

	    len < sizeof(struct dlm_header)) {

		BUILD_BUG_ON(PAGE_SIZE < DEFAULT_BUFFER_SIZE);

		log_print("failed to allocate a buffer of size %d", len);

		WARN_ON(1);

		return NULL;

	}



	con = nodeid2con(nodeid, allocation);

	if (!con)

		return NULL;



	return new_wq_entry(con, len, allocation, ppc);

}



void dlm_lowcomms_commit_buffer(void *mh)
@@ -1429,7 +1432,8 @@ void dlm_lowcomms_commit_buffer(void *mh) 
	users = --e->users;

	if (users)

		goto out;

	e->len = e->end - e->offset;



	e->len = DLM_WQ_LENGTH_BYTES(e);

	spin_unlock(&con->writequeue_lock);



	queue_work(send_workqueue, &con->swork);
@@ -1455,11 +1459,10 @@ static void send_to_sock(struct connection *con) 


	spin_lock(&con->writequeue_lock);

	for (;;) {

		e = list_entry(con->writequeue.next, struct writequeue_entry,

			       list);

		if ((struct list_head *) e == &con->writequeue)

		if (list_empty(&con->writequeue))

			break;



		e = list_first_entry(&con->writequeue, struct writequeue_entry, list);

		len = e->len;

		offset = e->offset;

		BUG_ON(len == 0 && e->users == 0);