Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932577AbdCaCfp (ORCPT ); Thu, 30 Mar 2017 22:35:45 -0400 Received: from cmccmta2.chinamobile.com ([221.176.66.80]:5964 "EHLO cmccmta2.chinamobile.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545AbdCaCfn (ORCPT ); Thu, 30 Mar 2017 22:35:43 -0400 X-RM-TRANSID: 2ee558ddc078b92-8bcbd X-RM-SPAM-FLAG: 00000000 X-RM-TRANSID: 2eea58ddc077fe9-47870 From: lixiubo@cmss.chinamobile.com To: nab@linux-iscsi.org Cc: mchristi@redhat.com, agrover@redhat.com, iliastsi@arrikto.com, namei.unix@gmail.com, sheng@yasker.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org, Xiubo Li Subject: [PATCH] tcmu: Skip Data-Out blocks before gathering Data-In buffer for BIDI case Date: Fri, 31 Mar 2017 10:35:25 +0800 Message-Id: <1490927725-25131-1-git-send-email-lixiubo@cmss.chinamobile.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3492 Lines: 101 From: Xiubo Li For the bidirectional case, the Data-Out buffer blocks will always at the head of the tcmu_cmd's bitmap, and before gathering the Data-In buffer, first of all it should skip the Data-Out ones, or the device supporting BIDI commands won't work. Fixed: 26418649eead ("target/user: Introduce data_bitmap, replace data_length/data_head/data_tail") Reported-by: Ilias Tsitsimpis Signed-off-by: Xiubo Li --- drivers/target/target_core_user.c | 48 +++++++++++++++++++++++++++------------ 1 file changed, 33 insertions(+), 15 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index ede815c..63e3a1b 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -311,24 +311,50 @@ static void free_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd) DATA_BLOCK_BITS); } -static void gather_data_area(struct tcmu_dev *udev, unsigned long *cmd_bitmap, - struct scatterlist *data_sg, unsigned int data_nents) +static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, + bool bidi) { + struct se_cmd *se_cmd = cmd->se_cmd; int i, block; int block_remaining = 0; void *from, *to; size_t copy_bytes, from_offset; - struct scatterlist *sg; + struct scatterlist *sg, *data_sg; + unsigned int data_nents; + DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS); + + bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS); + + if (!bidi) { + data_sg = se_cmd->t_data_sg; + data_nents = se_cmd->t_data_nents; + } else { + uint32_t count; + + /* + * For bidi case, the first count blocks are for Data-Out + * buffer blocks, and before gathering the Data-In buffer + * the Data-Out buffer blocks should be discarded. + */ + count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE); + while (count--) { + block = find_first_bit(bitmap, DATA_BLOCK_BITS); + clear_bit(block, bitmap); + } + + data_sg = se_cmd->t_bidi_data_sg; + data_nents = se_cmd->t_bidi_data_nents; + } for_each_sg(data_sg, sg, data_nents, i) { int sg_remaining = sg->length; to = kmap_atomic(sg_page(sg)) + sg->offset; while (sg_remaining > 0) { if (block_remaining == 0) { - block = find_first_bit(cmd_bitmap, + block = find_first_bit(bitmap, DATA_BLOCK_BITS); block_remaining = DATA_BLOCK_SIZE; - clear_bit(block, cmd_bitmap); + clear_bit(block, bitmap); } copy_bytes = min_t(size_t, sg_remaining, block_remaining); @@ -610,19 +636,11 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry * se_cmd->scsi_sense_length); free_data_area(udev, cmd); } else if (se_cmd->se_cmd_flags & SCF_BIDI) { - DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS); - /* Get Data-In buffer before clean up */ - bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS); - gather_data_area(udev, bitmap, - se_cmd->t_bidi_data_sg, se_cmd->t_bidi_data_nents); + gather_data_area(udev, cmd, true); free_data_area(udev, cmd); } else if (se_cmd->data_direction == DMA_FROM_DEVICE) { - DECLARE_BITMAP(bitmap, DATA_BLOCK_BITS); - - bitmap_copy(bitmap, cmd->data_bitmap, DATA_BLOCK_BITS); - gather_data_area(udev, bitmap, - se_cmd->t_data_sg, se_cmd->t_data_nents); + gather_data_area(udev, cmd, false); free_data_area(udev, cmd); } else if (se_cmd->data_direction == DMA_TO_DEVICE) { free_data_area(udev, cmd); -- 1.8.3.1