tcm_fc: Fix ft_send_tm LUN lookup OOPs

This patch fixes a bug in ft_send_tm() that was incorrectly calling
ft_get_lun_for_cmd() -> transport_get_lun_for_cmd(), instead of using
transport_get_lun_for_tmr() for the proper struct se_lun lookup
that was triggering an OOPs in the se_cmd->tmr_req failure path.

This patch fixes the issue by re-arranging the codepath where
transport_get_lun_for_tmr() is called after tmr request is allocated and
made it available as part of se_cmd.

It also drops the now unnecessary ft_get_lun_for_cmd() unpacking code, and
uses scsilun_to_int() directly ahead of transport_get_lun_for_cmd() and
transport_get_lun_for_tmr() usage.

Signed-off-by: Patil, Kiran <kiran.patil@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>

2 files changed, 34 insertions, 32 deletions

diff --git a/drivers/target/tcm_fc/tcm_fc.h b/drivers/target/tcm_fc/tcm_fc.h
index defff32b7880..7b82f1b7fef8 100644
--- a/drivers/target/tcm_fc/tcm_fc.h
+++ b/drivers/target/tcm_fc/tcm_fc.h
@@ -144,7 +144,7 @@ enum ft_cmd_state {
  */
 struct ft_cmd {
         enum ft_cmd_state state;
-        u16 lun;                        /* LUN from request */
+        u32 lun;                        /* LUN from request */
         struct ft_sess *sess;           /* session held for cmd */
         struct fc_seq *seq;             /* sequence in exchange mgr */
         struct se_cmd se_cmd;           /* Local TCM I/O descriptor */
diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index c056a1132ae1..b2a106729d49 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -94,29 +94,6 @@ void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
                 16, 4, cmd->cdb, MAX_COMMAND_SIZE, 0);
 }
 
-/*
- * Get LUN from CDB.
- */
-static int ft_get_lun_for_cmd(struct ft_cmd *cmd, u8 *lunp)
-{
-        u64 lun;
-
-        lun = lunp[1];
-        switch (lunp[0] >> 6) {
-        case 0:
-                break;
-        case 1:
-                lun |= (lunp[0] & 0x3f) << 8;
-                break;
-        default:
-                return -1;
-        }
-        if (lun >= TRANSPORT_MAX_LUNS_PER_TPG)
-                return -1;
-        cmd->lun = lun;
-        return transport_get_lun_for_cmd(&cmd->se_cmd, NULL, lun);
-}
-
 static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd)
 {
         struct se_queue_obj *qobj;
@@ -418,6 +395,7 @@ static void ft_send_tm(struct ft_cmd *cmd)
 {
         struct se_tmr_req *tmr;
         struct fcp_cmnd *fcp;
+        struct ft_sess *sess;
         u8 tm_func;
 
         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
@@ -425,13 +403,6 @@ static void ft_send_tm(struct ft_cmd *cmd)
         switch (fcp->fc_tm_flags) {
         case FCP_TMF_LUN_RESET:
                 tm_func = TMR_LUN_RESET;
-                if (ft_get_lun_for_cmd(cmd, fcp->fc_lun) < 0) {
-                        ft_dump_cmd(cmd, __func__);
-                        transport_send_check_condition_and_sense(&cmd->se_cmd,
-                                cmd->se_cmd.scsi_sense_reason, 0);
-                        ft_sess_put(cmd->sess);
-                        return;
-                }
                 break;
         case FCP_TMF_TGT_RESET:
                 tm_func = TMR_TARGET_WARM_RESET;
@@ -463,6 +434,36 @@ static void ft_send_tm(struct ft_cmd *cmd)
                 return;
         }
         cmd->se_cmd.se_tmr_req = tmr;
+
+        switch (fcp->fc_tm_flags) {
+        case FCP_TMF_LUN_RESET:
+                cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
+                if (transport_get_lun_for_tmr(&cmd->se_cmd, cmd->lun) < 0) {
+                        /*
+                         * Make sure to clean up newly allocated TMR request
+                         * since "unable to  handle TMR request because failed
+                         * to get to LUN"
+                         */
+                        FT_TM_DBG("Failed to get LUN for TMR func %d, "
+                                  "se_cmd %p, unpacked_lun %d\n",
+                                  tm_func, &cmd->se_cmd, cmd->lun);
+                        ft_dump_cmd(cmd, __func__);
+                        sess = cmd->sess;
+                        transport_send_check_condition_and_sense(&cmd->se_cmd,
+                                cmd->se_cmd.scsi_sense_reason, 0);
+                        transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
+                        ft_sess_put(sess);
+                        return;
+                }
+                break;
+        case FCP_TMF_TGT_RESET:
+        case FCP_TMF_CLR_TASK_SET:
+        case FCP_TMF_ABT_TASK_SET:
+        case FCP_TMF_CLR_ACA:
+                break;
+        default:
+                return;
+        }
         transport_generic_handle_tmr(&cmd->se_cmd);
 }
 
@@ -635,7 +636,8 @@ static void ft_send_cmd(struct ft_cmd *cmd)
 
         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
 
-        ret = ft_get_lun_for_cmd(cmd, fcp->fc_lun);
+        cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
+        ret = transport_get_lun_for_cmd(&cmd->se_cmd, NULL, cmd->lun);
         if (ret < 0) {
                 ft_dump_cmd(cmd, __func__);
                 transport_send_check_condition_and_sense(&cmd->se_cmd,