[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>

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 584e51024fd61bb1f792ca59efe74a0ab9afadb2..8751f60155597d8377fbb15de4ab8a47e6c2617a 100644 (file)
--- 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);