Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753580Ab3HVFKX (ORCPT ); Thu, 22 Aug 2013 01:10:23 -0400 Received: from mail-ob0-f181.google.com ([209.85.214.181]:61311 "EHLO mail-ob0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753555Ab3HVFKS (ORCPT ); Thu, 22 Aug 2013 01:10:18 -0400 From: "Nicholas A. Bellinger" To: target-devel Cc: lkml , linux-scsi , Christoph Hellwig , Hannes Reinecke , Martin Petersen , Chris Mason , Roland Dreier , James Bottomley , Nicholas Bellinger , Nicholas Bellinger Subject: [PATCH-v2 06/12] target: Add memory allocation for bidirectional commands Date: Thu, 22 Aug 2013 04:54:04 +0000 Message-Id: <1377147250-10125-7-git-send-email-nab@daterainc.com> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1377147250-10125-1-git-send-email-nab@daterainc.com> References: <1377147250-10125-1-git-send-email-nab@daterainc.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3219 Lines: 105 From: Nicholas Bellinger This adds transport_generic_get_mem_bidi() to perform scatterlist allocation for bidirectional commands. Also, update transport_generic_new_cmd() to call this new function when SCF_BIDI has been set. v2 Changes: - Use SCF_COMPARE_AND_WRITE instead of CDB based check for calculating length in transport_generic_get_mem_bidi(). - Use SCF_COMPARE_AND_WRITE in transport_generic_new_cmd() for determing when to call transport_generic_get_mem_bidi() Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Martin Petersen Cc: Chris Mason Cc: James Bottomley Cc: Nicholas Bellinger Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 54 ++++++++++++++++++++++++++++++++ 1 files changed, 54 insertions(+), 0 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 781859e..967dac7 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2092,6 +2092,53 @@ void transport_kunmap_data_sg(struct se_cmd *cmd) EXPORT_SYMBOL(transport_kunmap_data_sg); static int +transport_generic_get_mem_bidi(struct se_cmd *cmd) +{ + struct se_device *dev = cmd->se_dev; + struct page *page; + gfp_t zero_flag; + u32 length; + unsigned int nents; + int i = 0; + + if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) + length = cmd->t_task_nolb * dev->dev_attrib.block_size; + else + length = cmd->data_length; + + nents = DIV_ROUND_UP(length, PAGE_SIZE); + cmd->t_bidi_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL); + if (!cmd->t_bidi_data_sg) + return -ENOMEM; + + cmd->t_bidi_data_nents = nents; + sg_init_table(cmd->t_bidi_data_sg, nents); + + zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO; + + while (length) { + u32 page_len = min_t(u32, length, PAGE_SIZE); + page = alloc_page(GFP_KERNEL | zero_flag); + if (!page) + goto out; + + sg_set_page(&cmd->t_bidi_data_sg[i], page, page_len, 0); + length -= page_len; + i++; + } + return 0; + +out: + while (i > 0) { + i--; + __free_page(sg_page(&cmd->t_bidi_data_sg[i])); + } + kfree(cmd->t_bidi_data_sg); + cmd->t_bidi_data_sg = NULL; + return -ENOMEM; +} + +static int transport_generic_get_mem(struct se_cmd *cmd) { u32 length = cmd->data_length; @@ -2149,6 +2196,13 @@ transport_generic_new_cmd(struct se_cmd *cmd) */ if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) && cmd->data_length) { + if ((cmd->se_cmd_flags & SCF_BIDI) || + (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) { + ret = transport_generic_get_mem_bidi(cmd); + if (ret < 0) + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + } + ret = transport_generic_get_mem(cmd); if (ret < 0) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/