From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965096AbdDSPLG (ORCPT ); Wed, 19 Apr 2017 11:11:06 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:47164 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762393AbdDSOoq (ORCPT ); Wed, 19 Apr 2017 10:44:46 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ilias Tsitsimpis , Xiubo Li , Nicholas Bellinger Subject: [PATCH 4.9 04/69] tcmu: Skip Data-Out blocks before gathering Data-In buffer for BIDI case Date: Wed, 19 Apr 2017 16:42:20 +0200 Message-Id: <20170419141617.101777798@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170419141616.919951169@linuxfoundation.org> References: <20170419141616.919951169@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xiubo Li commit a5d68ba85801a78c892a0eb8efb711e293ed314b upstream. 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 Tested-by: Ilias Tsitsimpis Signed-off-by: Xiubo Li Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/target_core_user.c | 48 ++++++++++++++++++++++++++------------ 1 file changed, 33 insertions(+), 15 deletions(-) --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -306,24 +306,50 @@ static void free_data_area(struct tcmu_d 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); @@ -600,19 +626,11 @@ static void tcmu_handle_completion(struc 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);