From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41314 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751930AbbJRBAu (ORCPT ); Sat, 17 Oct 2015 21:00:50 -0400 Subject: Patch "3w-9xxx: don't unmap bounce buffered commands" has been added to the 4.2-stable tree To: hch@lst.de, JBottomley@Odin.com, aradford@gmail.com, atoth@atoth.sote.hu, gregkh@linuxfoundation.org Cc: , From: Date: Sat, 17 Oct 2015 18:00:49 -0700 Message-ID: <1445130049211219@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled 3w-9xxx: don't unmap bounce buffered commands to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: 3w-9xxx-don-t-unmap-bounce-buffered-commands.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 15e3d5a285ab9283136dba34bbf72886d9146706 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 3 Oct 2015 19:16:07 +0200 Subject: 3w-9xxx: don't unmap bounce buffered commands MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Christoph Hellwig commit 15e3d5a285ab9283136dba34bbf72886d9146706 upstream. 3w controller don't dma map small single SGL entry commands but instead bounce buffer them. Add a helper to identify these commands and don't call scsi_dma_unmap for them. Based on an earlier patch from James Bottomley. Fixes: 118c85 ("3w-9xxx: fix command completion race") Reported-by: Tóth Attila Tested-by: Tóth Attila Signed-off-by: Christoph Hellwig Acked-by: Adam Radford Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/3w-9xxx.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) --- a/drivers/scsi/3w-9xxx.c +++ b/drivers/scsi/3w-9xxx.c @@ -212,6 +212,17 @@ static const struct file_operations twa_ .llseek = noop_llseek, }; +/* + * The controllers use an inline buffer instead of a mapped SGL for small, + * single entry buffers. Note that we treat a zero-length transfer like + * a mapped SGL. + */ +static bool twa_command_mapped(struct scsi_cmnd *cmd) +{ + return scsi_sg_count(cmd) != 1 || + scsi_bufflen(cmd) >= TW_MIN_SGL_LENGTH; +} + /* This function will complete an aen request from the isr */ static int twa_aen_complete(TW_Device_Extension *tw_dev, int request_id) { @@ -1339,7 +1350,8 @@ static irqreturn_t twa_interrupt(int irq } /* Now complete the io */ - scsi_dma_unmap(cmd); + if (twa_command_mapped(cmd)) + scsi_dma_unmap(cmd); cmd->scsi_done(cmd); tw_dev->state[request_id] = TW_S_COMPLETED; twa_free_request_id(tw_dev, request_id); @@ -1582,7 +1594,8 @@ static int twa_reset_device_extension(TW struct scsi_cmnd *cmd = tw_dev->srb[i]; cmd->result = (DID_RESET << 16); - scsi_dma_unmap(cmd); + if (twa_command_mapped(cmd)) + scsi_dma_unmap(cmd); cmd->scsi_done(cmd); } } @@ -1765,12 +1778,14 @@ static int twa_scsi_queue_lck(struct scs retval = twa_scsiop_execute_scsi(tw_dev, request_id, NULL, 0, NULL); switch (retval) { case SCSI_MLQUEUE_HOST_BUSY: - scsi_dma_unmap(SCpnt); + if (twa_command_mapped(SCpnt)) + scsi_dma_unmap(SCpnt); twa_free_request_id(tw_dev, request_id); break; case 1: SCpnt->result = (DID_ERROR << 16); - scsi_dma_unmap(SCpnt); + if (twa_command_mapped(SCpnt)) + scsi_dma_unmap(SCpnt); done(SCpnt); tw_dev->state[request_id] = TW_S_COMPLETED; twa_free_request_id(tw_dev, request_id); @@ -1831,8 +1846,7 @@ static int twa_scsiop_execute_scsi(TW_De /* Map sglist from scsi layer to cmd packet */ if (scsi_sg_count(srb)) { - if ((scsi_sg_count(srb) == 1) && - (scsi_bufflen(srb) < TW_MIN_SGL_LENGTH)) { + if (!twa_command_mapped(srb)) { if (srb->sc_data_direction == DMA_TO_DEVICE || srb->sc_data_direction == DMA_BIDIRECTIONAL) scsi_sg_copy_to_buffer(srb, @@ -1905,7 +1919,7 @@ static void twa_scsiop_execute_scsi_comp { struct scsi_cmnd *cmd = tw_dev->srb[request_id]; - if (scsi_bufflen(cmd) < TW_MIN_SGL_LENGTH && + if (!twa_command_mapped(cmd) && (cmd->sc_data_direction == DMA_FROM_DEVICE || cmd->sc_data_direction == DMA_BIDIRECTIONAL)) { if (scsi_sg_count(cmd) == 1) { Patches currently in stable-queue which might be from hch@lst.de are queue-4.2/3w-9xxx-don-t-unmap-bounce-buffered-commands.patch queue-4.2/nfs-fix-pg_test-page-count-calculation.patch queue-4.2/target-attach-extended_copy-local-i-o-descriptors-to-xcopy_pt_sess.patch queue-4.2/target-fix-pr-registration-aptpl-rcu-conversion-regression.patch queue-4.2/blk-mq-avoid-setting-hctx-tags-cpumask-before-allocation.patch