[SCSI] iscsi: preemt fix and cleanup

From: zhenyu.z.wang@intel.com

Delay the head digest update until xmit time, like data digest update.
[To make things cleaner and avoid prempt bug]

Signed-off-by: Alex Aizman <itn780@yahoo.com>
Signed-off-by: Dmitry Yusupov <dmitry_yus@yahoo.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 28 insertions, 24 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 584e51024fd6..8751f6015559 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -129,14 +129,11 @@ iscsi_buf_left(struct iscsi_buf *ibuf)
 }
 
 static inline void
-iscsi_buf_init_hdr(struct iscsi_conn *conn, struct iscsi_buf *ibuf,
-                   char *vbuf, u8 *crc)
+iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
+                 u8* crc)
 {
-        iscsi_buf_init_virt(ibuf, vbuf, sizeof(struct iscsi_hdr));
-        if (conn->hdrdgst_en) {
-                crypto_digest_digest(conn->tx_tfm, &ibuf->sg, 1, crc);
-                ibuf->sg.length += sizeof(uint32_t);
-        }
+        crypto_digest_digest(conn->tx_tfm, &buf->sg, 1, crc);
+        buf->sg.length += sizeof(uint32_t);
 }
 
 static void
@@ -427,8 +424,8 @@ iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 
         r2t->sent = 0;
 
-        iscsi_buf_init_hdr(conn, &r2t->headbuf, (char*)hdr,
-                           (u8 *)dtask->hdrext);
+        iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
+                           sizeof(struct iscsi_hdr));
 
         r2t->dtask = dtask;
 
@@ -1494,8 +1491,8 @@ iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
         }
         conn->dataout_pdus_cnt++;
 
-        iscsi_buf_init_hdr(conn, &r2t->headbuf, (char*)hdr,
-                           (u8 *)dtask->hdrext);
+        iscsi_buf_init_virt(&r2t->headbuf, (char*)hdr,
+                           sizeof(struct iscsi_hdr));
 
         r2t->dtask = dtask;
 
@@ -1541,8 +1538,8 @@ iscsi_unsolicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
         }
 
-        iscsi_buf_init_hdr(conn, &ctask->headbuf, (char*)hdr,
-                           (u8 *)dtask->hdrext);
+        iscsi_buf_init_virt(&ctask->headbuf, (char*)hdr,
+                           sizeof(struct iscsi_hdr));
 
         list_add(&dtask->item, &ctask->dataqueue);
 
@@ -1662,8 +1659,8 @@ iscsi_cmd_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
                 zero_data(ctask->hdr.dlength);
         }
 
-        iscsi_buf_init_hdr(conn, &ctask->headbuf, (char*)&ctask->hdr,
-                            (u8 *)ctask->hdrext);
+        iscsi_buf_init_virt(&ctask->headbuf, (char*)&ctask->hdr, 
+                            sizeof(struct iscsi_hdr));
         conn->scsicmd_pdus_cnt++;
 }
 
@@ -1692,6 +1689,11 @@ iscsi_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
                 mtask->xmstate &= ~XMSTATE_IMM_HDR;
                 if (mtask->data_count)
                         mtask->xmstate |= XMSTATE_IMM_DATA;
+                if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
+                    conn->stop_stage != STOP_CONN_RECOVER &&
+                    conn->hdrdgst_en)
+                        iscsi_hdr_digest(conn, &mtask->headbuf,
+                                        (u8*)mtask->hdrext);
                 if (iscsi_sendhdr(conn, &mtask->headbuf, mtask->data_count)) {
                         mtask->xmstate |= XMSTATE_IMM_HDR;
                         if (mtask->data_count)
@@ -1723,6 +1725,8 @@ static inline int
 handle_xmstate_r_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 {
         ctask->xmstate &= ~XMSTATE_R_HDR;
+        if (conn->hdrdgst_en) 
+                iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
         if (!iscsi_sendhdr(conn, &ctask->headbuf, 0)) {
                 BUG_ON(ctask->xmstate != XMSTATE_IDLE);
                 return 0; /* wait for Data-In */
@@ -1735,6 +1739,8 @@ static inline int
 handle_xmstate_w_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 {
         ctask->xmstate &= ~XMSTATE_W_HDR;
+        if (conn->hdrdgst_en) 
+                iscsi_hdr_digest(conn, &ctask->headbuf, (u8*)ctask->hdrext);
         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->imm_count)) {
                 ctask->xmstate |= XMSTATE_W_HDR;
                 return -EAGAIN;
@@ -1813,7 +1819,9 @@ handle_xmstate_uns_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
                 iscsi_unsolicit_data_init(conn, ctask);
                 BUG_ON(!ctask->dtask);
                 dtask = ctask->dtask;
-
+                if (conn->hdrdgst_en)
+                        iscsi_hdr_digest(conn, &ctask->headbuf,
+                                        (u8*)dtask->hdrext);
                 ctask->xmstate &= ~XMSTATE_UNS_INIT;
         }
         if (iscsi_sendhdr(conn, &ctask->headbuf, ctask->data_count)) {
@@ -2118,7 +2126,9 @@ unsolicit_head_again:
                                     sizeof(void*));
 solicit_head_again:
                 r2t = ctask->r2t;
-
+                if (conn->hdrdgst_en)
+                        iscsi_hdr_digest(conn, &r2t->headbuf, 
+                                        (u8*)r2t->dtask->hdrext);
                 if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
                         ctask->xmstate &= ~XMSTATE_SOL_DATA;
                         ctask->xmstate |= XMSTATE_SOL_HDR;
@@ -2889,14 +2899,8 @@ iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 
         memcpy(&mtask->hdr, hdr, sizeof(struct iscsi_hdr));
 
-        if (conn->c_stage == ISCSI_CONN_INITIAL_STAGE ||
-            conn->stop_stage == STOP_CONN_RECOVER)
-                iscsi_buf_init_virt(&mtask->headbuf, (char*)&mtask->hdr,
+        iscsi_buf_init_virt(&mtask->headbuf, (char*)&mtask->hdr,
                                     sizeof(struct iscsi_hdr));
-        else
-                /* this will update header digest */
-                iscsi_buf_init_hdr(conn, &mtask->headbuf, (char*)&mtask->hdr,
-                                    (u8 *)mtask->hdrext);
 
         spin_unlock_bh(&session->lock);