From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Thu, 6 Jun 2013 08:58:49 +0000 (-0700)
Subject: iscsi-target: Avoid unnecessary t_state_lock during unsolicited data-out check
X-Git-Tag: next-20130617~71^2~4
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c119b67de763de7629967881502f933b6af31fbd;p=karo-tx-linux.git

iscsi-target: Avoid unnecessary t_state_lock during unsolicited data-out check

In modern iscsi-target code, the setup and I/O submission is done within a
single process context, so there is no need to acquire se_cmd->t_state_lock while
checking SCF_SUPPORTED_SAM_OPCODE for determining when unsolicited data-out
should be dumped.

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/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index d7705e5824fb..cc43d4163adc 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1277,7 +1277,6 @@ iscsit_check_dataout_hdr(struct iscsi_conn *conn, unsigned char *buf,
 	struct iscsi_data *hdr = (struct iscsi_data *)buf;
 	struct iscsi_cmd *cmd = NULL;
 	struct se_cmd *se_cmd;
-	unsigned long flags;
 	u32 payload_length = ntoh24(hdr->dlength);
 	int rc;
 
@@ -1356,14 +1355,9 @@ iscsit_check_dataout_hdr(struct iscsi_conn *conn, unsigned char *buf,
 		 */
 
 		/* Something's amiss if we're not in WRITE_PENDING state... */
-		spin_lock_irqsave(&se_cmd->t_state_lock, flags);
 		WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
-		spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
-
-		spin_lock_irqsave(&se_cmd->t_state_lock, flags);
 		if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE))
 			dump_unsolicited_data = 1;
-		spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
 
 		if (dump_unsolicited_data) {
 			/*