From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Roland Dreier , Giridhar Malavali , Chad Dupuis , Nicholas Bellinger , Kamal Mostafa Subject: [PATCH 048/105] tcm_qla2xxx: Fix residual for underrun commands that fail Date: Fri, 28 Jun 2013 11:51:10 -0700 Message-Id: <1372445527-24414-49-git-send-email-kamal@canonical.com> In-Reply-To: <1372445527-24414-1-git-send-email-kamal@canonical.com> References: <1372445527-24414-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8.13.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Roland Dreier commit b5aff3d2747bea08b386edd070941a45611ffe51 upstream. Suppose an initiator sends a DATA IN command with an allocation length shorter than the FC transfer length -- we get a target message like TARGET_CORE[qla2xxx]: Expected Transfer Length: 256 does not match SCSI CDB Length: 0 for SAM Opcode: 0x12 In that case, the target core adjusts the data_length and sets se_cmd->residual_count for the underrun. But now suppose that command fails and we end up in tcm_qla2xxx_queue_status() -- that function unconditionally overwrites residual_count with the already adjusted data_length, and the initiator will burp with a message like qla2xxx [0000:00:06.0]-301d:0: Dropped frame(s) detected (0x100 of 0x100 bytes). Fix this by adding on to the existing underflow residual count instead. Signed-off-by: Roland Dreier Cc: Giridhar Malavali Cc: Chad Dupuis Signed-off-by: Nicholas Bellinger Signed-off-by: Kamal Mostafa --- drivers/scsi/qla2xxx/tcm_qla2xxx.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c index d182c96..0c58bd1 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c @@ -688,8 +688,12 @@ static int tcm_qla2xxx_queue_status(struct se_cmd *se_cmd) * For FCP_READ with CHECK_CONDITION status, clear cmd->bufflen * for qla_tgt_xmit_response LLD code */ + if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) { + se_cmd->se_cmd_flags &= ~SCF_OVERFLOW_BIT; + se_cmd->residual_count = 0; + } se_cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT; - se_cmd->residual_count = se_cmd->data_length; + se_cmd->residual_count += se_cmd->data_length; cmd->bufflen = 0; } -- 1.8.1.2