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Commit bae6acd9 authored by Alex Elder's avatar Alex Elder Committed by Sage Weil
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libceph: use local variables for message positions 

There are several places where a message's out_msg_pos or in_msg_pos
field is used repeatedly within a function.  Use a local pointer
variable for this purpose to unclutter the code.

This and the upcoming cleanup patches are related to:
    http://tracker.ceph.com/issues/4403



Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent 98a03708

net/ceph/messenger.c

+46 −39
Original line number Original line Diff line number Diff line
@@ -725,22 +725,23 @@ static void iter_bio_next(struct bio **bio_iter, unsigned int *seg) 
static void prepare_write_message_data(struct ceph_connection *con)

static void prepare_write_message_data(struct ceph_connection *con)

{

{

	struct ceph_msg *msg = con->out_msg;

	struct ceph_msg *msg = con->out_msg;

	struct ceph_msg_pos *msg_pos = &con->out_msg_pos;





	BUG_ON(!msg);

	BUG_ON(!msg);

	BUG_ON(!msg->hdr.data_len);

	BUG_ON(!msg->hdr.data_len);





	/* initialize page iterator */

	/* initialize page iterator */

	con->out_msg_pos.page = 0;

	msg_pos->page = 0;

	if (msg->pages)

	if (msg->pages)

		con->out_msg_pos.page_pos = msg->page_alignment;

		msg_pos->page_pos = msg->page_alignment;

	else

	else

		con->out_msg_pos.page_pos = 0;

		msg_pos->page_pos = 0;

#ifdef CONFIG_BLOCK

#ifdef CONFIG_BLOCK

	if (msg->bio)

	if (msg->bio)

		init_bio_iter(msg->bio, &msg->bio_iter, &msg->bio_seg);

		init_bio_iter(msg->bio, &msg->bio_iter, &msg->bio_seg);

#endif

#endif

	con->out_msg_pos.data_pos = 0;

	msg_pos->data_pos = 0;

	con->out_msg_pos.did_page_crc = false;

	msg_pos->did_page_crc = false;

	con->out_more = 1;  /* data + footer will follow */

	con->out_more = 1;  /* data + footer will follow */

}

}
@@ -1022,19 +1023,20 @@ static void out_msg_pos_next(struct ceph_connection *con, struct page *page, 
			size_t len, size_t sent, bool in_trail)

			size_t len, size_t sent, bool in_trail)

{

{

	struct ceph_msg *msg = con->out_msg;

	struct ceph_msg *msg = con->out_msg;

	struct ceph_msg_pos *msg_pos = &con->out_msg_pos;





	BUG_ON(!msg);

	BUG_ON(!msg);

	BUG_ON(!sent);

	BUG_ON(!sent);





	con->out_msg_pos.data_pos += sent;

	msg_pos->data_pos += sent;

	con->out_msg_pos.page_pos += sent;

	msg_pos->page_pos += sent;

	if (sent < len)

	if (sent < len)

		return;

		return;





	BUG_ON(sent != len);

	BUG_ON(sent != len);

	con->out_msg_pos.page_pos = 0;

	msg_pos->page_pos = 0;

	con->out_msg_pos.page++;

	msg_pos->page++;

	con->out_msg_pos.did_page_crc = false;

	msg_pos->did_page_crc = false;

	if (in_trail)

	if (in_trail)

		list_rotate_left(&msg->trail->head);

		list_rotate_left(&msg->trail->head);

	else if (msg->pagelist)

	else if (msg->pagelist)
@@ -1049,18 +1051,19 @@ static void in_msg_pos_next(struct ceph_connection *con, size_t len, 
				size_t received)

				size_t received)

{

{

	struct ceph_msg *msg = con->in_msg;

	struct ceph_msg *msg = con->in_msg;

	struct ceph_msg_pos *msg_pos = &con->in_msg_pos;





	BUG_ON(!msg);

	BUG_ON(!msg);

	BUG_ON(!received);

	BUG_ON(!received);





	con->in_msg_pos.data_pos += received;

	msg_pos->data_pos += received;

	con->in_msg_pos.page_pos += received;

	msg_pos->page_pos += received;

	if (received < len)

	if (received < len)

		return;

		return;





	BUG_ON(received != len);

	BUG_ON(received != len);

	con->in_msg_pos.page_pos = 0;

	msg_pos->page_pos = 0;

	con->in_msg_pos.page++;

	msg_pos->page++;

#ifdef CONFIG_BLOCK

#ifdef CONFIG_BLOCK

	if (msg->bio)

	if (msg->bio)

		iter_bio_next(&msg->bio_iter, &msg->bio_seg);

		iter_bio_next(&msg->bio_iter, &msg->bio_seg);
@@ -1077,6 +1080,7 @@ static void in_msg_pos_next(struct ceph_connection *con, size_t len, 
static int write_partial_msg_pages(struct ceph_connection *con)

static int write_partial_msg_pages(struct ceph_connection *con)

{

{

	struct ceph_msg *msg = con->out_msg;

	struct ceph_msg *msg = con->out_msg;

	struct ceph_msg_pos *msg_pos = &con->out_msg_pos;

	unsigned int data_len = le32_to_cpu(msg->hdr.data_len);

	unsigned int data_len = le32_to_cpu(msg->hdr.data_len);

	size_t len;

	size_t len;

	bool do_datacrc = !con->msgr->nocrc;

	bool do_datacrc = !con->msgr->nocrc;
@@ -1087,7 +1091,7 @@ static int write_partial_msg_pages(struct ceph_connection *con) 
	const size_t trail_off = data_len - trail_len;

	const size_t trail_off = data_len - trail_len;





	dout("write_partial_msg_pages %p msg %p page %d offset %d\n",

	dout("write_partial_msg_pages %p msg %p page %d offset %d\n",

	     con, msg, con->out_msg_pos.page, con->out_msg_pos.page_pos);

	     con, msg, msg_pos->page, msg_pos->page_pos);





	/*

	/*

	 * Iterate through each page that contains data to be

	 * Iterate through each page that contains data to be
@@ -1097,22 +1101,22 @@ static int write_partial_msg_pages(struct ceph_connection *con) 
	 * need to map the page.  If we have no pages, they have

	 * need to map the page.  If we have no pages, they have

	 * been revoked, so use the zero page.

	 * been revoked, so use the zero page.

	 */

	 */

	while (data_len > con->out_msg_pos.data_pos) {

	while (data_len > msg_pos->data_pos) {

		struct page *page = NULL;

		struct page *page = NULL;

		int max_write = PAGE_SIZE;

		int max_write = PAGE_SIZE;

		int bio_offset = 0;

		int bio_offset = 0;





		in_trail = in_trail || con->out_msg_pos.data_pos >= trail_off;

		in_trail = in_trail || msg_pos->data_pos >= trail_off;

		if (!in_trail)

		if (!in_trail)

			total_max_write = trail_off - con->out_msg_pos.data_pos;

			total_max_write = trail_off - msg_pos->data_pos;





		if (in_trail) {

		if (in_trail) {

			total_max_write = data_len - con->out_msg_pos.data_pos;

			total_max_write = data_len - msg_pos->data_pos;





			page = list_first_entry(&msg->trail->head,

			page = list_first_entry(&msg->trail->head,

						struct page, lru);

						struct page, lru);

		} else if (msg->pages) {

		} else if (msg->pages) {

			page = msg->pages[con->out_msg_pos.page];

			page = msg->pages[msg_pos->page];

		} else if (msg->pagelist) {

		} else if (msg->pagelist) {

			page = list_first_entry(&msg->pagelist->head,

			page = list_first_entry(&msg->pagelist->head,

						struct page, lru);

						struct page, lru);
@@ -1128,24 +1132,24 @@ static int write_partial_msg_pages(struct ceph_connection *con) 
		} else {

		} else {

			page = zero_page;

			page = zero_page;

		}

		}

		len = min_t(int, max_write - con->out_msg_pos.page_pos,

		len = min_t(int, max_write - msg_pos->page_pos,

			    total_max_write);

			    total_max_write);





		if (do_datacrc && !con->out_msg_pos.did_page_crc) {

		if (do_datacrc && !msg_pos->did_page_crc) {

			void *base;

			void *base;

			u32 crc = le32_to_cpu(msg->footer.data_crc);

			u32 crc = le32_to_cpu(msg->footer.data_crc);

			char *kaddr;

			char *kaddr;





			kaddr = kmap(page);

			kaddr = kmap(page);

			BUG_ON(kaddr == NULL);

			BUG_ON(kaddr == NULL);

			base = kaddr + con->out_msg_pos.page_pos + bio_offset;

			base = kaddr + msg_pos->page_pos + bio_offset;

			crc = crc32c(crc, base, len);

			crc = crc32c(crc, base, len);

			kunmap(page);

			kunmap(page);

			msg->footer.data_crc = cpu_to_le32(crc);

			msg->footer.data_crc = cpu_to_le32(crc);

			con->out_msg_pos.did_page_crc = true;

			msg_pos->did_page_crc = true;

		}

		}

		ret = ceph_tcp_sendpage(con->sock, page,

		ret = ceph_tcp_sendpage(con->sock, page,

				      con->out_msg_pos.page_pos + bio_offset,

				      msg_pos->page_pos + bio_offset,

				      len, true);

				      len, true);

		if (ret <= 0)

		if (ret <= 0)

			goto out;

			goto out;
@@ -1803,22 +1807,23 @@ static int read_partial_message_pages(struct ceph_connection *con, 
				      struct page **pages,

				      struct page **pages,

				      unsigned int data_len, bool do_datacrc)

				      unsigned int data_len, bool do_datacrc)

{

{

	struct ceph_msg_pos *msg_pos = &con->in_msg_pos;

	struct page *page;

	struct page *page;

	void *p;

	void *p;

	int ret;

	int ret;

	int left;

	int left;





	left = min((int)(data_len - con->in_msg_pos.data_pos),

	left = min((int)(data_len - msg_pos->data_pos),

		   (int)(PAGE_SIZE - con->in_msg_pos.page_pos));

		   (int)(PAGE_SIZE - msg_pos->page_pos));

	/* (page) data */

	/* (page) data */

	BUG_ON(pages == NULL);

	BUG_ON(pages == NULL);

	page = pages[con->in_msg_pos.page];

	page = pages[msg_pos->page];

	p = kmap(page);

	p = kmap(page);

	ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos, left);

	ret = ceph_tcp_recvmsg(con->sock, p + msg_pos->page_pos, left);

	if (ret > 0 && do_datacrc)

	if (ret > 0 && do_datacrc)

		con->in_data_crc =

		con->in_data_crc =

			crc32c(con->in_data_crc,

			crc32c(con->in_data_crc,

				  p + con->in_msg_pos.page_pos, ret);

				  p + msg_pos->page_pos, ret);

	kunmap(page);

	kunmap(page);

	if (ret <= 0)

	if (ret <= 0)

		return ret;

		return ret;
@@ -1833,6 +1838,7 @@ static int read_partial_message_bio(struct ceph_connection *con, 
				    unsigned int data_len, bool do_datacrc)

				    unsigned int data_len, bool do_datacrc)

{

{

	struct ceph_msg *msg = con->in_msg;

	struct ceph_msg *msg = con->in_msg;

	struct ceph_msg_pos *msg_pos = &con->in_msg_pos;

	struct bio_vec *bv;

	struct bio_vec *bv;

	struct page *page;

	struct page *page;

	void *p;

	void *p;
@@ -1842,17 +1848,17 @@ static int read_partial_message_bio(struct ceph_connection *con, 
	BUG_ON(!msg->bio_iter);

	BUG_ON(!msg->bio_iter);

	bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg);

	bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg);





	left = min((int)(data_len - con->in_msg_pos.data_pos),

	left = min((int)(data_len - msg_pos->data_pos),

		   (int)(bv->bv_len - con->in_msg_pos.page_pos));

		   (int)(bv->bv_len - msg_pos->page_pos));





	page = bv->bv_page;

	page = bv->bv_page;

	p = kmap(page) + bv->bv_offset;

	p = kmap(page) + bv->bv_offset;





	ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos, left);

	ret = ceph_tcp_recvmsg(con->sock, p + msg_pos->page_pos, left);

	if (ret > 0 && do_datacrc)

	if (ret > 0 && do_datacrc)

		con->in_data_crc =

		con->in_data_crc =

			crc32c(con->in_data_crc,

			crc32c(con->in_data_crc,

				  p + con->in_msg_pos.page_pos, ret);

				  p + msg_pos->page_pos, ret);

	kunmap(page);

	kunmap(page);

	if (ret <= 0)

	if (ret <= 0)

		return ret;

		return ret;
@@ -1869,6 +1875,7 @@ static int read_partial_message_bio(struct ceph_connection *con, 
static int read_partial_message(struct ceph_connection *con)

static int read_partial_message(struct ceph_connection *con)

{

{

	struct ceph_msg *m = con->in_msg;

	struct ceph_msg *m = con->in_msg;

	struct ceph_msg_pos *msg_pos = &con->in_msg_pos;

	int size;

	int size;

	int end;

	int end;

	int ret;

	int ret;
@@ -1949,12 +1956,12 @@ static int read_partial_message(struct ceph_connection *con) 
		if (m->middle)

		if (m->middle)

			m->middle->vec.iov_len = 0;

			m->middle->vec.iov_len = 0;





		con->in_msg_pos.page = 0;

		msg_pos->page = 0;

		if (m->pages)

		if (m->pages)

			con->in_msg_pos.page_pos = m->page_alignment;

			msg_pos->page_pos = m->page_alignment;

		else

		else

			con->in_msg_pos.page_pos = 0;

			msg_pos->page_pos = 0;

		con->in_msg_pos.data_pos = 0;

		msg_pos->data_pos = 0;





#ifdef CONFIG_BLOCK

#ifdef CONFIG_BLOCK

		if (m->bio)

		if (m->bio)
@@ -1978,7 +1985,7 @@ static int read_partial_message(struct ceph_connection *con) 
	}

	}





	/* (page) data */

	/* (page) data */

	while (con->in_msg_pos.data_pos < data_len) {

	while (msg_pos->data_pos < data_len) {

		if (m->pages) {

		if (m->pages) {

			ret = read_partial_message_pages(con, m->pages,

			ret = read_partial_message_pages(con, m->pages,

						 data_len, do_datacrc);

						 data_len, do_datacrc);