Commit d396f89d authored by Jeff Layton's avatar Jeff Layton Committed by Ilya Dryomov
Browse files

libceph: add sparse read support to msgr1 



Add 2 new fields to ceph_connection_v1_info to track the necessary info
in sparse reads. Skip initializing the cursor for a sparse read.

Break out read_partial_message_section into a wrapper around a new
read_partial_message_chunk function that doesn't zero out the crc first.

Add new helper functions to drive receiving into the destinations
provided by the sparse_read state machine.

Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Reviewed-by: default avatarXiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: default avatarLuís Henriques <lhenriques@suse.de>
Reviewed-by: default avatarMilind Changire <mchangir@redhat.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent f36217e3

include/linux/ceph/messenger.h

+4 −0
Original line number Diff line number Diff line
@@ -336,6 +336,10 @@ struct ceph_connection_v1_info { 


	int in_base_pos;     /* bytes read */



	/* sparse reads */

	struct kvec in_sr_kvec; /* current location to receive into */

	u64 in_sr_len;		/* amount of data in this extent */



	/* message in temps */

	u8 in_tag;           /* protocol control byte */

	struct ceph_msg_header in_hdr;

net/ceph/messenger_v1.c

+90 −8
Original line number Diff line number Diff line
@@ -159,8 +159,8 @@ static size_t sizeof_footer(struct ceph_connection *con) 


static void prepare_message_data(struct ceph_msg *msg, u32 data_len)

{

	/* Initialize data cursor */



	/* Initialize data cursor if it's not a sparse read */

	if (!msg->sparse_read)

		ceph_msg_data_cursor_init(&msg->cursor, msg, data_len);

}
@@ -960,7 +960,7 @@ static void process_ack(struct ceph_connection *con) 
	prepare_read_tag(con);

}



static int read_partial_message_section(struct ceph_connection *con,

static int read_partial_message_chunk(struct ceph_connection *con,

				      struct kvec *section,

				      unsigned int sec_len, u32 *crc)

{
@@ -978,11 +978,91 @@ static int read_partial_message_section(struct ceph_connection *con, 
		section->iov_len += ret;

	}

	if (section->iov_len == sec_len)

		*crc = crc32c(0, section->iov_base, section->iov_len);

		*crc = crc32c(*crc, section->iov_base, section->iov_len);



	return 1;

}



static inline int read_partial_message_section(struct ceph_connection *con,

					       struct kvec *section,

					       unsigned int sec_len, u32 *crc)

{

	*crc = 0;

	return read_partial_message_chunk(con, section, sec_len, crc);

}



static int read_sparse_msg_extent(struct ceph_connection *con, u32 *crc)

{

	struct ceph_msg_data_cursor *cursor = &con->in_msg->cursor;

	bool do_bounce = ceph_test_opt(from_msgr(con->msgr), RXBOUNCE);



	if (do_bounce && unlikely(!con->bounce_page)) {

		con->bounce_page = alloc_page(GFP_NOIO);

		if (!con->bounce_page) {

			pr_err("failed to allocate bounce page\n");

			return -ENOMEM;

		}

	}



	while (cursor->sr_resid > 0) {

		struct page *page, *rpage;

		size_t off, len;

		int ret;



		page = ceph_msg_data_next(cursor, &off, &len);

		rpage = do_bounce ? con->bounce_page : page;



		/* clamp to what remains in extent */

		len = min_t(int, len, cursor->sr_resid);

		ret = ceph_tcp_recvpage(con->sock, rpage, (int)off, len);

		if (ret <= 0)

			return ret;

		*crc = ceph_crc32c_page(*crc, rpage, off, ret);

		ceph_msg_data_advance(cursor, (size_t)ret);

		cursor->sr_resid -= ret;

		if (do_bounce)

			memcpy_page(page, off, rpage, off, ret);

	}

	return 1;

}



static int read_sparse_msg_data(struct ceph_connection *con)

{

	struct ceph_msg_data_cursor *cursor = &con->in_msg->cursor;

	bool do_datacrc = !ceph_test_opt(from_msgr(con->msgr), NOCRC);

	u32 crc = 0;

	int ret = 1;



	if (do_datacrc)

		crc = con->in_data_crc;



	do {

		if (con->v1.in_sr_kvec.iov_base)

			ret = read_partial_message_chunk(con,

							 &con->v1.in_sr_kvec,

							 con->v1.in_sr_len,

							 &crc);

		else if (cursor->sr_resid > 0)

			ret = read_sparse_msg_extent(con, &crc);



		if (ret <= 0) {

			if (do_datacrc)

				con->in_data_crc = crc;

			return ret;

		}



		memset(&con->v1.in_sr_kvec, 0, sizeof(con->v1.in_sr_kvec));

		ret = con->ops->sparse_read(con, cursor,

				(char **)&con->v1.in_sr_kvec.iov_base);

		con->v1.in_sr_len = ret;

	} while (ret > 0);



	if (do_datacrc)

		con->in_data_crc = crc;



	return ret < 0 ? ret : 1;  /* must return > 0 to indicate success */

}



static int read_partial_msg_data(struct ceph_connection *con)

{

	struct ceph_msg_data_cursor *cursor = &con->in_msg->cursor;
@@ -1173,7 +1253,9 @@ static int read_partial_message(struct ceph_connection *con) 
		if (!m->num_data_items)

			return -EIO;



		if (ceph_test_opt(from_msgr(con->msgr), RXBOUNCE))

		if (m->sparse_read)

			ret = read_sparse_msg_data(con);

		else if (ceph_test_opt(from_msgr(con->msgr), RXBOUNCE))

			ret = read_partial_msg_data_bounce(con);

		else

			ret = read_partial_msg_data(con);