Commit 7cae5159 authored by Mike Christie's avatar Mike Christie Committed by James Bottomley
Browse files

[SCSI] iscsi: add high mem support 



From Mike Christie <michaelc@cs.wisc.edu> and FUJITA Tomonori <tomof@acm.org>:

We cannot use page_address becuase some pages could be highmem.
Instead, we can use sock_no_sendpage which does kmap for us.

Signed-off-by: default avatarAlex Aizman <itn780@yahoo.com>
Signed-off-by: default avatarDmitry Yusupov <dmitry_yus@yahoo.com>
Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 56851698

drivers/scsi/iscsi_tcp.c

+30 −54
Original line number Diff line number Diff line
@@ -87,35 +87,32 @@ iscsi_buf_init_virt(struct iscsi_buf *ibuf, char *vbuf, int size) 
{

	sg_init_one(&ibuf->sg, (u8 *)vbuf, size);

	ibuf->sent = 0;

	ibuf->use_sendmsg = 0;

}



static inline void

iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)

{

	ibuf->sg.page = (void*)vbuf;

	ibuf->sg.offset = (unsigned int)-1;

	ibuf->sg.page = virt_to_page(vbuf);

	ibuf->sg.offset = offset_in_page(vbuf);

	ibuf->sg.length = size;

	ibuf->sent = 0;

}



static inline void*

iscsi_buf_iov_base(struct iscsi_buf *ibuf)

{

	return (char*)ibuf->sg.page + ibuf->sent;

	ibuf->use_sendmsg = 1;

}



static inline void

iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)

{

	/*

	 * Fastpath: sg element fits into single page

	 */

	if (sg->length + sg->offset <= PAGE_SIZE && page_count(sg->page) >= 2) {

	ibuf->sg.page = sg->page;

	ibuf->sg.offset = sg->offset;

	ibuf->sg.length = sg->length;

	} else

		iscsi_buf_init_iov(ibuf, page_address(sg->page), sg->length);

	/*

	 * Fastpath: sg element fits into single page

	 */

	if (sg->length + sg->offset <= PAGE_SIZE && page_count(sg->page) >= 2)

		ibuf->use_sendmsg = 0;

	else

		ibuf->use_sendmsg = 1;

	ibuf->sent = 0;

}
@@ -1311,35 +1308,25 @@ iscsi_conn_restore_callbacks(struct iscsi_conn *conn) 
 * @buf: buffer to write from

 * @size: actual size to write

 * @flags: socket's flags

 *

 * Notes:

 *	depending on buffer will use tcp_sendpage() or tcp_sendmsg().

 *	buf->sg.offset == -1 tells us that buffer is non S/G and forces

 *	to use tcp_sendmsg().

 */

static inline int

iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags)

{

	struct socket *sk = conn->sock;

	int res;



	if ((int)buf->sg.offset >= 0) {

	int offset = buf->sg.offset + buf->sent;



		res = conn->sendpage(sk, buf->sg.page, offset, size, flags);

	} else {

		struct msghdr msg;



		buf->iov.iov_base = iscsi_buf_iov_base(buf);

		buf->iov.iov_len = size;



		memset(&msg, 0, sizeof(struct msghdr));



		/* tcp_sendmsg */

		res = kernel_sendmsg(sk, &msg, &buf->iov, 1, size);

	}



	return res;

	/*

	 * if we got use_sg=0 or are sending something we kmallocd

	 * then we did not have to do kmap (kmap returns page_address)

	 *

	 * if we got use_sg > 0, but had to drop down, we do not

	 * set clustering so this should only happen for that

	 * slab case.

	 */

	if (buf->use_sendmsg)

		return sock_no_sendpage(sk, buf->sg.page, offset, size, flags);

	else

		return conn->sendpage(sk, buf->sg.page, offset, size, flags);

}



/**
@@ -1431,19 +1418,6 @@ iscsi_data_digest_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) 
	ctask->digest_count = 4;

}



static inline void

iscsi_buf_data_digest_update(struct iscsi_conn *conn, struct iscsi_buf *buf)

{

	struct scatterlist sg;



	if (buf->sg.offset != -1)

		crypto_digest_update(conn->data_tx_tfm, &buf->sg, 1);

	else {

		sg_init_one(&sg, (char *)buf->sg.page, buf->sg.length);

		crypto_digest_update(conn->data_tx_tfm, &sg, 1);

	}

}



static inline int

iscsi_digest_final_send(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,

			struct iscsi_buf *buf, uint32_t *digest, int final)
@@ -1806,7 +1780,8 @@ handle_xmstate_imm_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) 
			return -EAGAIN;

		}

		if (conn->datadgst_en)

			iscsi_buf_data_digest_update(conn, &ctask->sendbuf);

			crypto_digest_update(conn->data_tx_tfm,

					     &ctask->sendbuf.sg, 1);



		if (!ctask->imm_count)

			break;
@@ -1891,7 +1866,8 @@ handle_xmstate_uns_data(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) 
		 * so pass it

		 */

		if (conn->datadgst_en && ctask->sent - start > 0)

			iscsi_buf_data_digest_update(conn, &ctask->sendbuf);

			crypto_digest_update(conn->data_tx_tfm,

					     &ctask->sendbuf.sg, 1);



		if (!ctask->data_count)

			break;
@@ -1969,7 +1945,7 @@ solicit_again: 


	BUG_ON(r2t->data_count < 0);

	if (conn->datadgst_en)

		iscsi_buf_data_digest_update(conn, &r2t->sendbuf);

		crypto_digest_update(conn->data_tx_tfm, &r2t->sendbuf.sg, 1);



	if (r2t->data_count) {

		BUG_ON(ctask->sc->use_sg == 0);
@@ -2051,7 +2027,7 @@ handle_xmstate_w_pad(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) 
	}



	if (conn->datadgst_en) {

		iscsi_buf_data_digest_update(conn, &ctask->sendbuf);

		crypto_digest_update(conn->data_tx_tfm, &ctask->sendbuf.sg, 1);

		/* imm data? */

		if (!dtask) {

			if (iscsi_digest_final_send(conn, ctask, &ctask->immbuf,

drivers/scsi/iscsi_tcp.h

+1 −1
Original line number Diff line number Diff line
@@ -242,8 +242,8 @@ struct iscsi_session { 


struct iscsi_buf {

	struct scatterlist	sg;

	struct kvec		iov;

	unsigned int		sent;

	char			use_sendmsg;

};



struct iscsi_data_task {

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