[SCSI] scsi_tcp: rm data rx and tx tfms

We currently allocated seperate tfms for data and header digests. There
is no reason for this since we can never calculate a rx header and
digest at the same time. Same for sends. So this patch removes the data
tfms and has the send and recv sides use the rx_tfm or tx_tfm.

I also made the connection creation code preallocate the tfms because I
thought I hit a bug where I changed the digests settings during a
relogin but could not allocate the tfm and then we just failed.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 38 insertions, 72 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 290c1d76cd40..82399f71028d 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -693,7 +693,7 @@ iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
         struct scatterlist tmp;
 
         sg_init_one(&tmp, buf, len);
-        crypto_digest_update(tcp_conn->data_rx_tfm, &tmp, 1);
+        crypto_digest_update(tcp_conn->rx_tfm, &tmp, 1);
 }
 
 static int iscsi_scsi_data_in(struct iscsi_conn *conn)
@@ -748,11 +748,11 @@ static int iscsi_scsi_data_in(struct iscsi_conn *conn)
                         if (conn->datadgst_en) {
                                 if (!offset)
                                         crypto_digest_update(
-                                                        tcp_conn->data_rx_tfm,
+                                                        tcp_conn->rx_tfm,
                                                         &sg[i], 1);
                                 else
                                         partial_sg_digest_update(
-                                                        tcp_conn->data_rx_tfm,
+                                                        tcp_conn->rx_tfm,
                                                         &sg[i],
                                                         sg[i].offset + offset,
                                                         sg[i].length - offset);
@@ -766,7 +766,7 @@ static int iscsi_scsi_data_in(struct iscsi_conn *conn)
                                 /*
                                  * data-in is complete, but buffer not...
                                  */
-                                partial_sg_digest_update(tcp_conn->data_rx_tfm,
+                                partial_sg_digest_update(tcp_conn->rx_tfm,
                                                 &sg[i],
                                                 sg[i].offset, sg[i].length-rc);
                         rc = 0;
@@ -885,10 +885,8 @@ more:
                  */
                 rc = iscsi_tcp_hdr_recv(conn);
                 if (!rc && tcp_conn->in.datalen) {
-                        if (conn->datadgst_en) {
-                                BUG_ON(!tcp_conn->data_rx_tfm);
-                                crypto_digest_init(tcp_conn->data_rx_tfm);
-                        }
+                        if (conn->datadgst_en)
+                                crypto_digest_init(tcp_conn->rx_tfm);
                         tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
                 } else if (rc) {
                         iscsi_conn_failure(conn, rc);
@@ -940,10 +938,10 @@ more:
                                           tcp_conn->in.padding);
                                 memset(pad, 0, tcp_conn->in.padding);
                                 sg_init_one(&sg, pad, tcp_conn->in.padding);
-                                crypto_digest_update(tcp_conn->data_rx_tfm,
+                                crypto_digest_update(tcp_conn->rx_tfm,
                                                      &sg, 1);
                         }
-                        crypto_digest_final(tcp_conn->data_rx_tfm,
+                        crypto_digest_final(tcp_conn->rx_tfm,
                                             (u8 *) & tcp_conn->in.datadgst);
                         debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
                         tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
@@ -1188,7 +1186,7 @@ static inline void
 iscsi_data_digest_init(struct iscsi_tcp_conn *tcp_conn,
                       struct iscsi_tcp_cmd_task *tcp_ctask)
 {
-        crypto_digest_init(tcp_conn->data_tx_tfm);
+        crypto_digest_init(tcp_conn->tx_tfm);
         tcp_ctask->digest_count = 4;
 }
 
@@ -1444,7 +1442,7 @@ iscsi_send_padding(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
                 iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
                                    tcp_ctask->pad_count);
                 if (conn->datadgst_en)
-                        crypto_digest_update(tcp_conn->data_tx_tfm,
+                        crypto_digest_update(tcp_conn->tx_tfm,
                                              &tcp_ctask->sendbuf.sg, 1);
         } else if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_PAD))
                 return 0;
@@ -1477,7 +1475,7 @@ iscsi_send_digest(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
         tcp_conn = conn->dd_data;
 
         if (!(tcp_ctask->xmstate & XMSTATE_W_RESEND_DATA_DIGEST)) {
-                crypto_digest_final(tcp_conn->data_tx_tfm, (u8*)digest);
+                crypto_digest_final(tcp_conn->tx_tfm, (u8*)digest);
                 iscsi_buf_init_iov(buf, (char*)digest, 4);
         }
         tcp_ctask->xmstate &= ~XMSTATE_W_RESEND_DATA_DIGEST;
@@ -1511,7 +1509,7 @@ iscsi_send_data(struct iscsi_cmd_task *ctask, struct iscsi_buf *sendbuf,
                 rc = iscsi_sendpage(conn, sendbuf, count, &buf_sent);
                 *sent = *sent + buf_sent;
                 if (buf_sent && conn->datadgst_en)
-                        partial_sg_digest_update(tcp_conn->data_tx_tfm,
+                        partial_sg_digest_update(tcp_conn->tx_tfm,
                                 &sendbuf->sg, sendbuf->sg.offset + offset,
                                 buf_sent);
                 if (!iscsi_buf_left(sendbuf) && *sg != tcp_ctask->bad_sg) {
@@ -1547,10 +1545,6 @@ iscsi_send_unsol_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
                 if (conn->hdrdgst_en)
                         iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
                                         (u8*)dtask->hdrext);
-                if (conn->datadgst_en) {
-                        iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
-                        dtask->digest = 0;
-                }
 
                 tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
                 iscsi_set_padding(tcp_ctask, ctask->data_count);
@@ -1563,6 +1557,12 @@ iscsi_send_unsol_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
                 return rc;
         }
 
+        if (conn->datadgst_en) {
+                dtask = &tcp_ctask->unsol_dtask;
+                iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
+                dtask->digest = 0;
+        }
+
         debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
                    ctask->itt, ctask->unsol_count, tcp_ctask->sent);
         return 0;
@@ -1629,12 +1629,6 @@ send_hdr:
                 if (conn->hdrdgst_en)
                         iscsi_hdr_digest(conn, &r2t->headbuf,
                                         (u8*)dtask->hdrext);
-
-                if (conn->datadgst_en) {
-                        iscsi_data_digest_init(conn->dd_data, tcp_ctask);
-                        dtask->digest = 0;
-                }
-
                 rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
                 if (rc) {
                         tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
@@ -1642,6 +1636,11 @@ send_hdr:
                         return rc;
                 }
 
+                if (conn->datadgst_en) {
+                        iscsi_data_digest_init(conn->dd_data, tcp_ctask);
+                        dtask->digest = 0;
+                }
+
                 iscsi_set_padding(tcp_ctask, r2t->data_count);
                 debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",
                         r2t->solicit_datasn - 1, ctask->itt, r2t->data_count,
@@ -1764,8 +1763,20 @@ iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
         /* initial operational parameters */
         tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
 
+        tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c", 0);
+        if (!tcp_conn->tx_tfm)
+                goto free_tcp_conn;
+
+        tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c", 0);
+        if (!tcp_conn->rx_tfm)
+                goto free_tx_tfm;
+
         return cls_conn;
 
+free_tx_tfm:
+        crypto_free_tfm(tcp_conn->tx_tfm);
+free_tcp_conn:
+        kfree(tcp_conn);
 tcp_conn_alloc_fail:
         iscsi_conn_teardown(cls_conn);
         return NULL;
@@ -1807,10 +1818,6 @@ iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn)
                         crypto_free_tfm(tcp_conn->tx_tfm);
                 if (tcp_conn->rx_tfm)
                         crypto_free_tfm(tcp_conn->rx_tfm);
-                if (tcp_conn->data_tx_tfm)
-                        crypto_free_tfm(tcp_conn->data_tx_tfm);
-                if (tcp_conn->data_rx_tfm)
-                        crypto_free_tfm(tcp_conn->data_rx_tfm);
         }
 
         kfree(tcp_conn);
@@ -1968,48 +1975,11 @@ iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param,
         case ISCSI_PARAM_HDRDGST_EN:
                 iscsi_set_param(cls_conn, param, buf, buflen);
                 tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
-                if (conn->hdrdgst_en) {
+                if (conn->hdrdgst_en)
                         tcp_conn->hdr_size += sizeof(__u32);
-                        if (!tcp_conn->tx_tfm)
-                                tcp_conn->tx_tfm = crypto_alloc_tfm("crc32c",
-                                                                    0);
-                        if (!tcp_conn->tx_tfm)
-                                return -ENOMEM;
-                        if (!tcp_conn->rx_tfm)
-                                tcp_conn->rx_tfm = crypto_alloc_tfm("crc32c",
-                                                                    0);
-                        if (!tcp_conn->rx_tfm) {
-                                crypto_free_tfm(tcp_conn->tx_tfm);
-                                return -ENOMEM;
-                        }
-                } else {
-                        if (tcp_conn->tx_tfm)
-                                crypto_free_tfm(tcp_conn->tx_tfm);
-                        if (tcp_conn->rx_tfm)
-                                crypto_free_tfm(tcp_conn->rx_tfm);
-                }
                 break;
         case ISCSI_PARAM_DATADGST_EN:
                 iscsi_set_param(cls_conn, param, buf, buflen);
-                if (conn->datadgst_en) {
-                        if (!tcp_conn->data_tx_tfm)
-                                tcp_conn->data_tx_tfm =
-                                    crypto_alloc_tfm("crc32c", 0);
-                        if (!tcp_conn->data_tx_tfm)
-                                return -ENOMEM;
-                        if (!tcp_conn->data_rx_tfm)
-                                tcp_conn->data_rx_tfm =
-                                    crypto_alloc_tfm("crc32c", 0);
-                        if (!tcp_conn->data_rx_tfm) {
-                                crypto_free_tfm(tcp_conn->data_tx_tfm);
-                                return -ENOMEM;
-                        }
-                } else {
-                        if (tcp_conn->data_tx_tfm)
-                                crypto_free_tfm(tcp_conn->data_tx_tfm);
-                        if (tcp_conn->data_rx_tfm)
-                                crypto_free_tfm(tcp_conn->data_rx_tfm);
-                }
                 tcp_conn->sendpage = conn->datadgst_en ?
                         sock_no_sendpage : tcp_conn->sock->ops->sendpage;
                 break;
diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index 7e40e94d9fdc..609f4778d125 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -81,10 +81,6 @@ struct iscsi_tcp_conn {
                                                  * stop to terminate */
         /* iSCSI connection-wide sequencing */
         int                     hdr_size;       /* PDU header size */
-
-        struct crypto_tfm       *rx_tfm;        /* CRC32C (Rx) */
-        struct crypto_tfm       *data_rx_tfm;   /* CRC32C (Rx) for data */
-
         /* control data */
         struct iscsi_tcp_recv   in;             /* TCP receive context */
         int                     in_progress;    /* connection state machine */
@@ -94,9 +90,9 @@ struct iscsi_tcp_conn {
         void                    (*old_state_change)(struct sock *);
         void                    (*old_write_space)(struct sock *);
 
-        /* xmit */
+        /* data and header digests */
         struct crypto_tfm       *tx_tfm;        /* CRC32C (Tx) */
-        struct crypto_tfm       *data_tx_tfm;   /* CRC32C (Tx) for data */
+        struct crypto_tfm       *rx_tfm;        /* CRC32C (Rx) */
 
         /* MIB custom statistics */
         uint32_t                sendpage_failures_cnt;