[SCSI] iscsi: Some fixes in preparation for bidirectional support - exp_datasn
This patch fixes handling of expected datasn/r2tsn as received from
target. It is done according to: T10 rfc3720 section 3.2.2.3. Data Sequencing.
. unify expected datasn/r2tsn into one counter
. calculate than check expected datasn/r2tsn. On error print a message
and fail the request. (TODO use iscsi retransmits)
. remove the FIXME ;)
. avoid zero length memset
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 8201e6c..17fc79c 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -229,10 +229,13 @@
if (tcp_conn->in.datalen == 0)
return 0;
- if (ctask->datasn != datasn)
+ if (tcp_ctask->exp_datasn != datasn) {
+ debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->datasn(%d)\n",
+ __FUNCTION__, tcp_ctask->exp_datasn, datasn);
return ISCSI_ERR_DATASN;
+ }
- ctask->datasn++;
+ tcp_ctask->exp_datasn++;
tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
@@ -365,15 +368,16 @@
return ISCSI_ERR_DATALEN;
}
- if (tcp_ctask->exp_r2tsn && tcp_ctask->exp_r2tsn != r2tsn)
+ if (tcp_ctask->exp_datasn != r2tsn){
+ debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->r2tsn(%d)\n",
+ __FUNCTION__, tcp_ctask->exp_datasn, r2tsn);
return ISCSI_ERR_R2TSN;
+ }
rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
if (rc)
return rc;
- /* FIXME: use R2TSN to detect missing R2T */
-
/* fill-in new R2T associated with the task */
spin_lock(&session->lock);
if (!ctask->sc || ctask->mtask ||
@@ -414,7 +418,7 @@
iscsi_solicit_data_init(conn, ctask, r2t);
- tcp_ctask->exp_r2tsn = r2tsn + 1;
+ tcp_ctask->exp_datasn = r2tsn + 1;
__kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
list_move_tail(&ctask->running, &conn->xmitqueue);
@@ -1284,10 +1288,10 @@
tcp_ctask->sent = 0;
tcp_ctask->sg_count = 0;
+ tcp_ctask->exp_datasn = 0;
if (sc->sc_data_direction == DMA_TO_DEVICE) {
tcp_ctask->xmstate = XMSTATE_W_HDR;
- tcp_ctask->exp_r2tsn = 0;
BUG_ON(ctask->total_length == 0);
if (sc->use_sg) {
diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index 3273683..f909edb 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -152,7 +152,7 @@
struct scatterlist *sg; /* per-cmd SG list */
struct scatterlist *bad_sg; /* assert statement */
int sg_count; /* SG's to process */
- uint32_t exp_r2tsn;
+ uint32_t exp_datasn; /* expected target's R2TSN/DataSN */
int data_offset;
struct iscsi_r2t_info *r2t; /* in progress R2T */
struct iscsi_queue r2tpool;
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 5e6a424..eb51136 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -120,7 +120,9 @@
session->cmdsn++;
hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
memcpy(hdr->cdb, sc->cmnd, sc->cmd_len);
- memset(&hdr->cdb[sc->cmd_len], 0, MAX_COMMAND_SIZE - sc->cmd_len);
+ if (sc->cmd_len < MAX_COMMAND_SIZE)
+ memset(&hdr->cdb[sc->cmd_len], 0,
+ MAX_COMMAND_SIZE - sc->cmd_len);
ctask->data_count = 0;
if (sc->sc_data_direction == DMA_TO_DEVICE) {
@@ -165,7 +167,6 @@
/* No unsolicit Data-Out's */
ctask->hdr->flags |= ISCSI_FLAG_CMD_FINAL;
} else {
- ctask->datasn = 0;
hdr->flags |= ISCSI_FLAG_CMD_FINAL;
zero_data(hdr->dlength);
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index deae90a..61e0692 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -99,7 +99,6 @@
*/
struct iscsi_cmd *hdr;
int itt; /* this ITT */
- int datasn; /* DataSN */
uint32_t unsol_datasn;
int imm_count; /* imm-data (bytes) */