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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 10 Jan 2019 14:56:47 -0000 Received: from b03ledav006.gho.boulder.ibm.com (b03ledav006.gho.boulder.ibm.com [9.17.130.237]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x0AEukFT6881392 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 10 Jan 2019 14:56:46 GMT Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 766B1C605A; Thu, 10 Jan 2019 14:56:46 +0000 (GMT) Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1C6FDC6059; Thu, 10 Jan 2019 14:56:46 +0000 (GMT) Received: from oc6034535106.ibm.com (unknown [9.10.86.125]) by b03ledav006.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 10 Jan 2019 14:56:45 +0000 (GMT) Subject: Re: [PATCH] ibmvscsi: use GFP_ATOMIC with dma_alloc_coherent in map_sg_data To: Tyrel Datwyler , james.bottomley@hansenpartnership.com References: <1547089136-20264-1-git-send-email-tyreld@linux.vnet.ibm.com> From: Brian King Date: Thu, 10 Jan 2019 08:56:45 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1547089136-20264-1-git-send-email-tyreld@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19011014-0004-0000-0000-000014D03050 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010379; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000274; SDB=6.01144486; UDB=6.00595915; IPR=6.00924750; MB=3.00025068; MTD=3.00000008; XFM=3.00000015; UTC=2019-01-10 14:56:49 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19011014-0005-0000-0000-00008A2AEA82 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-01-10_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901100118 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stable@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-scsi@vger.kernel.org, martin.petersen@oracle.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 01/09/2019 08:58 PM, Tyrel Datwyler wrote: > While mapping DMA for scatter list when a scsi command is queued the > existing call to dma_alloc_coherent() in our map_sg_data() function > passes zero for the gfp_flags parameter. We are most definitly in atomic > context at this point as queue_command() is called in softirq context > and further we have a spinlock holding the scsi host lock. > > Fix this by passing GFP_ATOMIC to dma_alloc_coherent() to prevent any > sort of sleeping in atomic context deadlock. > > Fixes: 4dddbc26c389 ("[SCSI] ibmvscsi: handle large scatter/gather lists") > Cc: stable@vger.kernel.org > Signed-off-by: Tyrel Datwyler > --- > drivers/scsi/ibmvscsi/ibmvscsi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c > index 1135e74..cb8535e 100644 > --- a/drivers/scsi/ibmvscsi/ibmvscsi.c > +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c > @@ -731,7 +731,7 @@ static int map_sg_data(struct scsi_cmnd *cmd, > evt_struct->ext_list = (struct srp_direct_buf *) > dma_alloc_coherent(dev, > SG_ALL * sizeof(struct srp_direct_buf), > - &evt_struct->ext_list_token, 0); > + &evt_struct->ext_list_token, GFP_ATOMIC); > if (!evt_struct->ext_list) { > if (!firmware_has_feature(FW_FEATURE_CMO)) > sdev_printk(KERN_ERR, cmd->device, > Reviewed-by: Brian King -- Brian King Power Linux I/O IBM Linux Technology Center