From 1a398b973184342f30ab97711b9c38fd75df0384 Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Thu, 6 Jun 2013 01:40:27 -0700
Subject: [PATCH] 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>
---
drivers/target/target_core_transport.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 01cdee47f75e..e9ba012e82a9 100644
--- 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);
--
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