[SCSI] iscsi tcp: fix iscsi xmit state machine
If iscsi_tcp partially sends a header, it would recalculate the
header size and readd the size of the digest (if header digests
are used).This would cause us to send sizeof(digest) extra bytes
when we sent the rest of the header.
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 1e722f5..0afdca2 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -109,7 +109,7 @@
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
crypto_hash_digest(&tcp_conn->tx_hash, &buf->sg, buf->sg.length, crc);
- buf->sg.length = tcp_conn->hdr_size;
+ buf->sg.length += sizeof(u32);
}
static inline int
@@ -423,7 +423,7 @@
tcp_ctask->exp_datasn = r2tsn + 1;
__kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
- tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
+ tcp_ctask->xmstate |= XMSTATE_SOL_HDR_INIT;
list_move_tail(&ctask->running, &conn->xmitqueue);
scsi_queue_work(session->host, &conn->xmitwork);
@@ -1284,41 +1284,10 @@
static void
iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
{
- struct scsi_cmnd *sc = ctask->sc;
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
-
- 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;
- BUG_ON(sc->request_bufflen == 0);
-
- if (sc->use_sg) {
- struct scatterlist *sg = sc->request_buffer;
-
- iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
- tcp_ctask->sg = sg + 1;
- tcp_ctask->bad_sg = sg + sc->use_sg;
- } else {
- iscsi_buf_init_iov(&tcp_ctask->sendbuf,
- sc->request_buffer,
- sc->request_bufflen);
- tcp_ctask->sg = NULL;
- tcp_ctask->bad_sg = NULL;
- }
- debug_scsi("cmd [itt 0x%x total %d imm_data %d "
- "unsol count %d, unsol offset %d]\n",
- ctask->itt, sc->request_bufflen, ctask->imm_count,
- ctask->unsol_count, ctask->unsol_offset);
- } else
- tcp_ctask->xmstate = XMSTATE_R_HDR;
-
- iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
- sizeof(struct iscsi_hdr));
+ tcp_ctask->xmstate = XMSTATE_CMD_HDR_INIT;
}
/**
@@ -1331,9 +1300,11 @@
* call it again later, or recover. '0' return code means successful
* xmit.
*
- * Management xmit state machine consists of two states:
- * IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
- * IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
+ * Management xmit state machine consists of these states:
+ * XMSTATE_IMM_HDR_INIT - calculate digest of PDU Header
+ * XMSTATE_IMM_HDR - PDU Header xmit in progress
+ * XMSTATE_IMM_DATA - PDU Data xmit in progress
+ * XMSTATE_IDLE - management PDU is done
**/
static int
iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
@@ -1344,23 +1315,34 @@
debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
conn->id, tcp_mtask->xmstate, mtask->itt);
- if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
- tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
- if (mtask->data_count)
+ if (tcp_mtask->xmstate & XMSTATE_IMM_HDR_INIT) {
+ iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
+ sizeof(struct iscsi_hdr));
+
+ if (mtask->data_count) {
tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
+ iscsi_buf_init_iov(&tcp_mtask->sendbuf,
+ (char*)mtask->data,
+ mtask->data_count);
+ }
+
if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
conn->stop_stage != STOP_CONN_RECOVER &&
conn->hdrdgst_en)
iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
(u8*)tcp_mtask->hdrext);
+
+ tcp_mtask->sent = 0;
+ tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR_INIT;
+ tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
+ }
+
+ if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
mtask->data_count);
- if (rc) {
- tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
- if (mtask->data_count)
- tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
+ if (rc)
return rc;
- }
+ tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
}
if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
@@ -1394,55 +1376,75 @@
return 0;
}
-static inline int
-iscsi_send_read_hdr(struct iscsi_conn *conn,
- struct iscsi_tcp_cmd_task *tcp_ctask)
+static int
+iscsi_send_cmd_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
- int rc;
-
- tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
- if (conn->hdrdgst_en)
- iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
- (u8*)tcp_ctask->hdrext);
- rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
- if (!rc) {
- BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
- return 0; /* wait for Data-In */
- }
- tcp_ctask->xmstate |= XMSTATE_R_HDR;
- return rc;
-}
-
-static inline int
-iscsi_send_write_hdr(struct iscsi_conn *conn,
- struct iscsi_cmd_task *ctask)
-{
+ struct scsi_cmnd *sc = ctask->sc;
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
- int rc;
+ int rc = 0;
- tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
- if (conn->hdrdgst_en)
- iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
- (u8*)tcp_ctask->hdrext);
- rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
- if (rc) {
- tcp_ctask->xmstate |= XMSTATE_W_HDR;
- return rc;
- }
+ if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_INIT) {
+ tcp_ctask->sent = 0;
+ tcp_ctask->sg_count = 0;
+ tcp_ctask->exp_datasn = 0;
- if (ctask->imm_count) {
- tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
- iscsi_set_padding(tcp_ctask, ctask->imm_count);
+ if (sc->sc_data_direction == DMA_TO_DEVICE) {
+ if (sc->use_sg) {
+ struct scatterlist *sg = sc->request_buffer;
- if (ctask->conn->datadgst_en) {
- iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
- tcp_ctask->immdigest = 0;
+ iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
+ tcp_ctask->sg = sg + 1;
+ tcp_ctask->bad_sg = sg + sc->use_sg;
+ } else {
+ iscsi_buf_init_iov(&tcp_ctask->sendbuf,
+ sc->request_buffer,
+ sc->request_bufflen);
+ tcp_ctask->sg = NULL;
+ tcp_ctask->bad_sg = NULL;
+ }
+
+ debug_scsi("cmd [itt 0x%x total %d imm_data %d "
+ "unsol count %d, unsol offset %d]\n",
+ ctask->itt, sc->request_bufflen,
+ ctask->imm_count, ctask->unsol_count,
+ ctask->unsol_offset);
}
+
+ iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
+ sizeof(struct iscsi_hdr));
+
+ if (conn->hdrdgst_en)
+ iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
+ (u8*)tcp_ctask->hdrext);
+ tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_INIT;
+ tcp_ctask->xmstate |= XMSTATE_CMD_HDR_XMIT;
}
- if (ctask->unsol_count)
- tcp_ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
- return 0;
+ if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_XMIT) {
+ rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
+ if (rc)
+ return rc;
+ tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_XMIT;
+
+ if (sc->sc_data_direction != DMA_TO_DEVICE)
+ return 0;
+
+ if (ctask->imm_count) {
+ tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
+ iscsi_set_padding(tcp_ctask, ctask->imm_count);
+
+ if (ctask->conn->datadgst_en) {
+ iscsi_data_digest_init(ctask->conn->dd_data,
+ tcp_ctask);
+ tcp_ctask->immdigest = 0;
+ }
+ }
+
+ if (ctask->unsol_count)
+ tcp_ctask->xmstate |=
+ XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
+ }
+ return rc;
}
static int
@@ -1631,9 +1633,7 @@
struct iscsi_data_task *dtask;
int left, rc;
- if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
- tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
- tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
+ if (tcp_ctask->xmstate & XMSTATE_SOL_HDR_INIT) {
if (!tcp_ctask->r2t) {
spin_lock_bh(&session->lock);
__kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
@@ -1647,12 +1647,19 @@
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &r2t->headbuf,
(u8*)dtask->hdrext);
+ tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR_INIT;
+ tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
+ }
+
+ if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
+ r2t = tcp_ctask->r2t;
+ dtask = &r2t->dtask;
+
rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
- if (rc) {
- tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
- tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
+ if (rc)
return rc;
- }
+ tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
+ tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
if (conn->datadgst_en) {
iscsi_data_digest_init(conn->dd_data, tcp_ctask);
@@ -1684,8 +1691,6 @@
left = r2t->data_length - r2t->sent;
if (left) {
iscsi_solicit_data_cont(conn, ctask, r2t, left);
- tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
- tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
goto send_hdr;
}
@@ -1700,8 +1705,6 @@
if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t,
sizeof(void*))) {
tcp_ctask->r2t = r2t;
- tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
- tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
spin_unlock_bh(&session->lock);
goto send_hdr;
}
@@ -1710,6 +1713,46 @@
return 0;
}
+/**
+ * iscsi_tcp_ctask_xmit - xmit normal PDU task
+ * @conn: iscsi connection
+ * @ctask: iscsi command task
+ *
+ * Notes:
+ * The function can return -EAGAIN in which case caller must
+ * call it again later, or recover. '0' return code means successful
+ * xmit.
+ * The function is devided to logical helpers (above) for the different
+ * xmit stages.
+ *
+ *iscsi_send_cmd_hdr()
+ * XMSTATE_CMD_HDR_INIT - prepare Header and Data buffers Calculate
+ * Header Digest
+ * XMSTATE_CMD_HDR_XMIT - Transmit header in progress
+ *
+ *iscsi_send_padding
+ * XMSTATE_W_PAD - Prepare and send pading
+ * XMSTATE_W_RESEND_PAD - retry send pading
+ *
+ *iscsi_send_digest
+ * XMSTATE_W_RESEND_DATA_DIGEST - Finalize and send Data Digest
+ * XMSTATE_W_RESEND_DATA_DIGEST - retry sending digest
+ *
+ *iscsi_send_unsol_hdr
+ * XMSTATE_UNS_INIT - prepare un-solicit data header and digest
+ * XMSTATE_UNS_HDR - send un-solicit header
+ *
+ *iscsi_send_unsol_pdu
+ * XMSTATE_UNS_DATA - send un-solicit data in progress
+ *
+ *iscsi_send_sol_pdu
+ * XMSTATE_SOL_HDR_INIT - solicit data header and digest initialize
+ * XMSTATE_SOL_HDR - send solicit header
+ * XMSTATE_SOL_DATA - send solicit data
+ *
+ *iscsi_tcp_ctask_xmit
+ * XMSTATE_IMM_DATA - xmit managment data (??)
+ **/
static int
iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
{
@@ -1725,14 +1768,11 @@
if (ctask->mtask)
return rc;
- if (tcp_ctask->xmstate & XMSTATE_R_HDR)
- return iscsi_send_read_hdr(conn, tcp_ctask);
-
- if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
- rc = iscsi_send_write_hdr(conn, ctask);
- if (rc)
- return rc;
- }
+ rc = iscsi_send_cmd_hdr(conn, ctask);
+ if (rc)
+ return rc;
+ if (ctask->sc->sc_data_direction != DMA_TO_DEVICE)
+ return 0;
if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
@@ -1913,15 +1953,7 @@
char *data, uint32_t data_size)
{
struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
-
- iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
- sizeof(struct iscsi_hdr));
- tcp_mtask->xmstate = XMSTATE_IMM_HDR;
- tcp_mtask->sent = 0;
-
- if (mtask->data_count)
- iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
- mtask->data_count);
+ tcp_mtask->xmstate = XMSTATE_IMM_HDR_INIT;
}
static int