From 74f4cf290918f05b6489aa732dfb08aa5606b9d6 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Thu, 16 Aug 2012 17:06:41 -0700 Subject: [PATCH] target: Fix regression bug with handling of zero-length data CDBs This patch fixes a regression bug with the handling of zero-length data CDBs within transport_generic_new_cmd() code. The bug was introduced with the following commit as part of the single task conversion work: commit 4101f0a89d4eb13f04cb0344d59a335b862ca5f9 Author: Christoph Hellwig Date: Tue Apr 24 00:25:03 2012 -0400 target: always allocate a single task where the zero-length check for SCF_SCSI_DATA_SG_IO_CDB was incorrectly changed to SCF_SCSI_CONTROL_SG_IO_CDB because of the seperate comment in transport_generic_new_cmd() wrt to control CDBs zero-length handling introduced in: commit 91ec1d3535b2acf12c599045cc19ad9be3c6a47b Author: Nicholas Bellinger Date: Fri Jan 13 12:01:34 2012 -0800 target: Add workaround for zero-length control CDB handling So go ahead and change transport_generic_new_cmd() to handle control+data zero-length CDBs in the same manner for this special case. Tested with iscsi-target + loopback fabric port LUNs on 3.6-rc0 code. This patch will also need to be picked up for 3.5-stable. (hch: Add proper comment in transport_generic_new_cmd) Cc: Christoph Hellwig Cc: Roland Dreier Cc: Andy Grover Cc: stable@vger.kernel.org Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index a7589ccdb6f..ea9a3d2e4f5 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2323,9 +2323,12 @@ int transport_generic_new_cmd(struct se_cmd *cmd) if (ret < 0) goto out_fail; } - - /* Workaround for handling zero-length control CDBs */ - if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->data_length) { + /* + * If this command doesn't have any payload and we don't have to call + * into the fabric for data transfers, go ahead and complete it right + * away. + */ + if (!cmd->data_length) { spin_lock_irq(&cmd->t_state_lock); cmd->t_state = TRANSPORT_COMPLETE; cmd->transport_state |= CMD_T_ACTIVE; -- 2.41.0