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Commit 6df19a79 authored by Mike Christie's avatar Mike Christie Committed by James Bottomley
Browse files

[SCSI] libiscsi_tcp: support padding offload 



cxgb3i does not offload the processing of the header,
but it will always process the padding. This patch
adds a padding offload flag to detect when the LLD
supports this.

The patch also modifies the header processing so that
we do not try to read/bypass the header dugest in the
skb. cxgb3i will not include it with the header like
with other offload cards.

Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent ae15f801

drivers/scsi/iscsi_tcp.c

+5 −4
Original line number Diff line number Diff line
@@ -194,7 +194,7 @@ iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_sw_tcp_conn *tcp_sw_conn) 


/**

 * iscsi_sw_tcp_xmit_segment - transmit segment

 * @tcp_sw_conn: the iSCSI TCP connection

 * @tcp_conn: the iSCSI TCP connection

 * @segment: the buffer to transmnit

 *

 * This function transmits as much of the buffer as
@@ -205,14 +205,15 @@ iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_sw_tcp_conn *tcp_sw_conn) 
 * hash as it goes. When the entire segment has been transmitted,

 * it will retrieve the hash value and send it as well.

 */

static int iscsi_sw_tcp_xmit_segment(struct iscsi_sw_tcp_conn *tcp_sw_conn,

static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,

				     struct iscsi_segment *segment)

{

	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;

	struct socket *sk = tcp_sw_conn->sock;

	unsigned int copied = 0;

	int r = 0;



	while (!iscsi_tcp_segment_done(segment, 0, r)) {

	while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {

		struct scatterlist *sg;

		unsigned int offset, copy;

		int flags = 0;
@@ -263,7 +264,7 @@ static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn) 
	int rc = 0;



	while (1) {

		rc = iscsi_sw_tcp_xmit_segment(tcp_sw_conn, segment);

		rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment);

		if (rc < 0) {

			rc = ISCSI_ERR_XMIT_FAILED;

			goto error;

drivers/scsi/libiscsi_tcp.c

+20 −17
Original line number Diff line number Diff line
@@ -159,6 +159,7 @@ iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest) 


/**

 * iscsi_tcp_segment_done - check whether the segment is complete

 * @tcp_conn: iscsi tcp connection

 * @segment: iscsi segment to check

 * @recv: set to one of this is called from the recv path

 * @copied: number of bytes copied
@@ -172,7 +173,8 @@ iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest) 
 *

 * This function must be re-entrant.

 */

int iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv,

int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,

			   struct iscsi_segment *segment, int recv,

			   unsigned copied)

{

	static unsigned char padbuf[ISCSI_PAD_LEN];
@@ -225,6 +227,7 @@ int iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv, 
	}



	/* Do we need to handle padding? */

	if (!(tcp_conn->iscsi_conn->session->tt->caps & CAP_PADDING_OFFLOAD)) {

		pad = iscsi_padding(segment->total_copied);

		if (pad != 0) {

			debug_tcp("consume %d pad bytes\n", pad);
@@ -233,6 +236,7 @@ int iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv, 
			segment->data = padbuf;

			return 0;

		}

	}



	/*

	 * Set us up for transferring the data digest. hdr digest
@@ -273,7 +277,7 @@ iscsi_tcp_segment_recv(struct iscsi_tcp_conn *tcp_conn, 
{

	unsigned int copy = 0, copied = 0;



	while (!iscsi_tcp_segment_done(segment, 1, copy)) {

	while (!iscsi_tcp_segment_done(tcp_conn, segment, 1, copy)) {

		if (copied == len) {

			debug_tcp("iscsi_tcp_segment_recv copied %d bytes\n",

				  len);
@@ -794,7 +798,8 @@ iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn, 
	/* We're done processing the header. See if we're doing

	 * header digests; if so, set up the recv_digest buffer

	 * and go back for more. */

	if (conn->hdrdgst_en) {

	if (conn->hdrdgst_en &&

	    !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) {

		if (segment->digest_len == 0) {

			/*

			 * Even if we offload the digest processing we
@@ -806,7 +811,6 @@ iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn, 
			return 0;

		}



		if (!(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) {

		iscsi_tcp_dgst_header(tcp_conn->rx_hash, hdr,

				      segment->total_copied - ISCSI_DIGEST_SIZE,

				      segment->digest);
@@ -814,7 +818,6 @@ iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn, 
		if (!iscsi_tcp_dgst_verify(tcp_conn, segment))

			return ISCSI_ERR_HDR_DGST;

	}

	}



	tcp_conn->in.hdr = hdr;

	return iscsi_tcp_hdr_dissect(conn, hdr);

include/scsi/iscsi_if.h

+2 −0
Original line number Diff line number Diff line
@@ -336,6 +336,8 @@ enum iscsi_host_param { 
#define CAP_SENDTARGETS_OFFLOAD	0x400	/* offload discovery process */

#define CAP_DATA_PATH_OFFLOAD	0x800	/* offload entire IO path */

#define CAP_DIGEST_OFFLOAD	0x1000	/* offload hdr and data digests */

#define CAP_PADDING_OFFLOAD	0x2000	/* offload padding insertion, removal,

					 and verification */



/*

 * These flags describes reason of stop_conn() call

include/scsi/libiscsi_tcp.h

+2 −1
Original line number Diff line number Diff line
@@ -99,7 +99,8 @@ extern int iscsi_tcp_task_xmit(struct iscsi_task *task); 


/* segment helpers */

extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);

extern int iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv,

extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,

				  struct iscsi_segment *segment, int recv,

				  unsigned copied);

extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);