target: Avoid extra t_state_lock access in __target_execute_cmd

This patch makes target_execute_cmd() set CMD_T_BUSY|CMD_T_SENT while
holding se_cmd->t_state_lock, in order to avoid the extra aquire/release
in __target_execute_cmd().

It also clears these bits in case of a target_handle_task_attr()
failure.

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>

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 01cdee4..e9ba012 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1580,10 +1580,6 @@ static void __target_execute_cmd(struct se_cmd *cmd)
 {
        sense_reason_t ret;
 
-       spin_lock_irq(&cmd->t_state_lock);
-       cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
-       spin_unlock_irq(&cmd->t_state_lock);
-
        if (cmd->execute_cmd) {
                ret = cmd->execute_cmd(cmd);
                if (ret) {
@@ -1690,11 +1686,17 @@ void target_execute_cmd(struct se_cmd *cmd)
        }
 
        cmd->t_state = TRANSPORT_PROCESSING;
-       cmd->transport_state |= CMD_T_ACTIVE;
+       cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
        spin_unlock_irq(&cmd->t_state_lock);
 
-       if (!target_handle_task_attr(cmd))
-               __target_execute_cmd(cmd);
+       if (target_handle_task_attr(cmd)) {
+               spin_lock_irq(&cmd->t_state_lock);
+               cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
+               spin_unlock_irq(&cmd->t_state_lock);
+               return;
+       }
+
+       __target_execute_cmd(cmd);
 }
 EXPORT_SYMBOL(target_execute_cmd);