iscsi-target: Refactor ISCSI_OP_TEXT RX handling

This patch refactors ISCSI_OP_TEXT handling within iscsi-target in
order to handle iscsi_text payloads in a transport specific manner.

This includes splitting current iscsit_handle_text_cmd() into
iscsit_setup_text_cmd() and iscsit_process_text_cmd() calls, and
makes iscsit_handle_text_cmd be only used internally by traditional
iscsi socket calls.

Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 90 insertions, 68 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index f684627244bf..ae312c5d8a45 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1960,45 +1960,93 @@ attach:
 EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);
 
 /* #warning FIXME: Support Text Command parameters besides SendTargets */
-static int iscsit_handle_text_cmd(
-        struct iscsi_conn *conn,
-        unsigned char *buf)
+int
+iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
+                      struct iscsi_text *hdr)
 {
-        char *text_ptr, *text_in;
-        int cmdsn_ret, niov = 0, rx_got, rx_size;
-        u32 checksum = 0, data_crc = 0, payload_length;
-        u32 padding = 0, pad_bytes = 0, text_length = 0;
-        struct iscsi_cmd *cmd;
-        struct kvec iov[3];
-        struct iscsi_text *hdr;
-
-        hdr                     = (struct iscsi_text *) buf;
-        payload_length          = ntoh24(hdr->dlength);
+        u32 payload_length = ntoh24(hdr->dlength);
 
         if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
                 pr_err("Unable to accept text parameter length: %u"
                         "greater than MaxXmitDataSegmentLength %u.\n",
                        payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
-                return iscsit_add_reject(ISCSI_REASON_PROTOCOL_ERROR, 1,
-                                        buf, conn);
+                return iscsit_add_reject_from_cmd(ISCSI_REASON_PROTOCOL_ERROR,
+                                        1, 0, (unsigned char *)hdr, cmd);
         }
 
         pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
                 " ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
                 hdr->exp_statsn, payload_length);
 
-        rx_size = text_length = payload_length;
-        if (text_length) {
-                text_in = kzalloc(text_length, GFP_KERNEL);
+        cmd->iscsi_opcode       = ISCSI_OP_TEXT;
+        cmd->i_state            = ISTATE_SEND_TEXTRSP;
+        cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
+        conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
+        cmd->targ_xfer_tag      = 0xFFFFFFFF;
+        cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
+        cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
+        cmd->data_direction     = DMA_NONE;
+
+        return 0;
+}
+EXPORT_SYMBOL(iscsit_setup_text_cmd);
+
+int
+iscsit_process_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
+                        struct iscsi_text *hdr)
+{
+        int cmdsn_ret;
+
+        spin_lock_bh(&conn->cmd_lock);
+        list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
+        spin_unlock_bh(&conn->cmd_lock);
+
+        iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
+
+        if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
+                cmdsn_ret = iscsit_sequence_cmd(conn, cmd, hdr->cmdsn);
+                if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
+                        return iscsit_add_reject_from_cmd(
+                                        ISCSI_REASON_PROTOCOL_ERROR,
+                                        1, 0, (unsigned char *)hdr, cmd);
+                return 0;
+        }
+
+        return iscsit_execute_cmd(cmd, 0);
+}
+EXPORT_SYMBOL(iscsit_process_text_cmd);
+
+static int
+iscsit_handle_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
+                       unsigned char *buf)
+{
+        struct iscsi_text *hdr = (struct iscsi_text *)buf;
+        char *text_in = NULL;
+        u32 payload_length = ntoh24(hdr->dlength);
+        int rx_size, rc;
+
+        rc = iscsit_setup_text_cmd(conn, cmd, hdr);
+        if (rc < 0)
+                return rc;
+
+        rx_size = payload_length;
+        if (payload_length) {
+                char *text_ptr;
+                u32 checksum = 0, data_crc = 0;
+                u32 padding = 0, pad_bytes = 0;
+                int niov = 0, rx_got;
+                struct kvec iov[3];
+
+                text_in = kzalloc(payload_length, GFP_KERNEL);
                 if (!text_in) {
                         pr_err("Unable to allocate memory for"
                                 " incoming text parameters\n");
-                        return -1;
+                        goto reject;
                 }
 
                 memset(iov, 0, 3 * sizeof(struct kvec));
                 iov[niov].iov_base      = text_in;
-                iov[niov++].iov_len     = text_length;
+                iov[niov++].iov_len     = payload_length;
 
                 padding = ((-payload_length) & 3);
                 if (padding != 0) {
@@ -2015,14 +2063,12 @@ static int iscsit_handle_text_cmd(
                 }
 
                 rx_got = rx_data(conn, &iov[0], niov, rx_size);
-                if (rx_got != rx_size) {
-                        kfree(text_in);
-                        return -1;
-                }
+                if (rx_got != rx_size)
+                        goto reject;
 
                 if (conn->conn_ops->DataDigest) {
                         iscsit_do_crypto_hash_buf(&conn->conn_rx_hash,
-                                        text_in, text_length,
+                                        text_in, payload_length,
                                         padding, (u8 *)&pad_bytes,
                                         (u8 *)&data_crc);
 
@@ -2034,8 +2080,7 @@ static int iscsit_handle_text_cmd(
                                         pr_err("Unable to recover from"
                                         " Text Data digest failure while in"
                                                 " ERL=0.\n");
-                                        kfree(text_in);
-                                        return -1;
+                                        goto reject;
                                 } else {
                                         /*
                                          * Silently drop this PDU and let the
@@ -2050,68 +2095,40 @@ static int iscsit_handle_text_cmd(
                         } else {
                                 pr_debug("Got CRC32C DataDigest"
                                         " 0x%08x for %u bytes of text data.\n",
-                                                checksum, text_length);
+                                                checksum, payload_length);
                         }
                 }
-                text_in[text_length - 1] = '\0';
+                text_in[payload_length - 1] = '\0';
                 pr_debug("Successfully read %d bytes of text"
-                                " data.\n", text_length);
+                                " data.\n", payload_length);
 
                 if (strncmp("SendTargets", text_in, 11) != 0) {
                         pr_err("Received Text Data that is not"
                                 " SendTargets, cannot continue.\n");
-                        kfree(text_in);
-                        return -1;
+                        goto reject;
                 }
                 text_ptr = strchr(text_in, '=');
                 if (!text_ptr) {
                         pr_err("No \"=\" separator found in Text Data,"
                                 "  cannot continue.\n");
-                        kfree(text_in);
-                        return -1;
+                        goto reject;
                 }
                 if (strncmp("=All", text_ptr, 4) != 0) {
                         pr_err("Unable to locate All value for"
                                 " SendTargets key,  cannot continue.\n");
-                        kfree(text_in);
-                        return -1;
+                        goto reject;
                 }
-/*#warning Support SendTargets=(iSCSI Target Name/Nothing) values. */
                 kfree(text_in);
         }
 
-        cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
-        if (!cmd)
-                return iscsit_add_reject(ISCSI_REASON_BOOKMARK_NO_RESOURCES,
-                                        1, buf, conn);
-
-        cmd->iscsi_opcode       = ISCSI_OP_TEXT;
-        cmd->i_state            = ISTATE_SEND_TEXTRSP;
-        cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
-        conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
-        cmd->targ_xfer_tag      = 0xFFFFFFFF;
-        cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
-        cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
-        cmd->data_direction     = DMA_NONE;
-
-        spin_lock_bh(&conn->cmd_lock);
-        list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
-        spin_unlock_bh(&conn->cmd_lock);
-
-        iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
+        return iscsit_process_text_cmd(conn, cmd, hdr);
 
-        if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
-                cmdsn_ret = iscsit_sequence_cmd(conn, cmd, hdr->cmdsn);
-                if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
-                        return iscsit_add_reject_from_cmd(
-                                        ISCSI_REASON_PROTOCOL_ERROR,
-                                        1, 0, buf, cmd);
-
-                return 0;
-        }
-
-        return iscsit_execute_cmd(cmd, 0);
+reject:
+        kfree(text_in);
+        return iscsit_add_reject_from_cmd(ISCSI_REASON_PROTOCOL_ERROR,
+                                          0, 0, buf, cmd);
 }
+EXPORT_SYMBOL(iscsit_handle_text_cmd);
 
 int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
 {
@@ -3947,7 +3964,12 @@ static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
                 ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
                 break;
         case ISCSI_OP_TEXT:
-                ret = iscsit_handle_text_cmd(conn, buf);
+                cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
+                if (!cmd)
+                        return iscsit_add_reject(ISCSI_REASON_BOOKMARK_NO_RESOURCES,
+                                                1, buf, conn);
+
+                ret = iscsit_handle_text_cmd(conn, cmd, buf);
                 break;
         case ISCSI_OP_LOGOUT:
                 cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);