target: Remove legacy t_fe_count + avoid t_state_lock access in transport_put_cmd

This patch removes legacy se_cmd->t_fe_count usage in order to avoid
se_cmd->t_state_lock access within transport_put_cmd() during normal
fast path se_cmd descriptor release.

Also drop the left-over parameter usage within core_tmr_handle_tas_abort()

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 2 insertions, 29 deletions

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index d0b4dd95b91e..0d7cacb91107 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -85,13 +85,8 @@ void core_tmr_release_req(
 static void core_tmr_handle_tas_abort(
         struct se_node_acl *tmr_nacl,
         struct se_cmd *cmd,
-        int tas,
-        int fe_count)
+        int tas)
 {
-        if (!fe_count) {
-                transport_cmd_finish_abort(cmd, 1);
-                return;
-        }
         /*
          * TASK ABORTED status (TAS) bit support
         */
@@ -253,7 +248,6 @@ static void core_tmr_drain_state_list(
         LIST_HEAD(drain_task_list);
         struct se_cmd *cmd, *next;
         unsigned long flags;
-        int fe_count;
 
         /*
          * Complete outstanding commands with TASK_ABORTED SAM status.
@@ -329,12 +323,10 @@ static void core_tmr_drain_state_list(
                 spin_lock_irqsave(&cmd->t_state_lock, flags);
                 target_stop_cmd(cmd, &flags);
 
-                fe_count = atomic_read(&cmd->t_fe_count);
-
                 cmd->transport_state |= CMD_T_ABORTED;
                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
-                core_tmr_handle_tas_abort(tmr_nacl, cmd, tas, fe_count);
+                core_tmr_handle_tas_abort(tmr_nacl, cmd, tas);
         }
 }
 
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index bc37666bc941..01cdee47f75e 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1968,21 +1968,6 @@ static int transport_release_cmd(struct se_cmd *cmd)
  */
 static int transport_put_cmd(struct se_cmd *cmd)
 {
-        unsigned long flags;
-
-        spin_lock_irqsave(&cmd->t_state_lock, flags);
-        if (atomic_read(&cmd->t_fe_count) &&
-            !atomic_dec_and_test(&cmd->t_fe_count)) {
-                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-                return 0;
-        }
-
-        if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
-                cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
-                target_remove_from_state_list(cmd);
-        }
-        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-
         transport_free_pages(cmd);
         return transport_release_cmd(cmd);
 }
@@ -2100,9 +2085,6 @@ transport_generic_new_cmd(struct se_cmd *cmd)
                 if (ret < 0)
                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
         }
-
-        atomic_inc(&cmd->t_fe_count);
-
         /*
          * If this command is not a write we can execute it right here,
          * for write buffers we need to notify the fabric driver first
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 8952ee9f7cef..891ea1f81832 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -454,7 +454,6 @@ struct se_cmd {
         unsigned char           *t_task_cdb;
         unsigned char           __t_task_cdb[TCM_MAX_COMMAND_SIZE];
         unsigned long long      t_task_lba;
-        atomic_t                t_fe_count;
         unsigned int            transport_state;
 #define CMD_T_ABORTED           (1 << 0)
 #define CMD_T_ACTIVE            (1 << 1)