Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751905AbbKIPF6 (ORCPT ); Mon, 9 Nov 2015 10:05:58 -0500 Received: from mx2.suse.de ([195.135.220.15]:51594 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751555AbbKIPFz (ORCPT ); Mon, 9 Nov 2015 10:05:55 -0500 Message-ID: <5640B651.1010506@suse.de> Date: Mon, 09 Nov 2015 16:05:53 +0100 From: Hannes Reinecke User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Laurent Vivier CC: martin.petersen@oracle.com, brking@linux.vnet.ibm.com, tyreld@linux.vnet.ibm.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 3/3] ibmvscsi: Allow to configure maximum LUN References: <1447080465-17858-1-git-send-email-lvivier@redhat.com> <1447080465-17858-4-git-send-email-lvivier@redhat.com> <5640B2A6.20401@suse.de> <5640B4DC.9010706@redhat.com> In-Reply-To: <5640B4DC.9010706@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3882 Lines: 102 On 11/09/2015 03:59 PM, Laurent Vivier wrote: > > > On 09/11/2015 15:50, Hannes Reinecke wrote: >> On 11/09/2015 03:47 PM, Laurent Vivier wrote: >>> This patch allows to define the maximum LUN numbers. >>> As defined in 4.6.9 of SAM-4, the encoding of LUN is >>> on 5 bits (max_lun=32) and the current value is only 8. >>> >>> Signed-off-by: Laurent Vivier >>> --- >>> drivers/scsi/ibmvscsi/ibmvscsi.c | 9 ++++++++- >>> drivers/scsi/ibmvscsi/ibmvscsi.h | 1 + >>> 2 files changed, 9 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c >>> index 04de287..adcd5e8 100644 >>> --- a/drivers/scsi/ibmvscsi/ibmvscsi.c >>> +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c >>> @@ -84,6 +84,7 @@ >>> */ >>> static int max_id = 64; >>> static int max_channel = 3; >>> +static int max_lun = 8; >>> static int init_timeout = 300; >>> static int login_timeout = 60; >>> static int info_timeout = 30; >>> @@ -117,6 +118,9 @@ module_param_named(fast_fail, fast_fail, int, S_IRUGO | S_IWUSR); >>> MODULE_PARM_DESC(fast_fail, "Enable fast fail. [Default=1]"); >>> module_param_named(client_reserve, client_reserve, int, S_IRUGO ); >>> MODULE_PARM_DESC(client_reserve, "Attempt client managed reserve/release"); >>> +module_param(max_lun, int, S_IRUGO); >>> +MODULE_PARM_DESC(max_lun, "Maximum allowed LUN " >>> + "[Default=8,Max="__stringify(IBMVSCSI_MAX_LUN)"]"); >>> >>> static void ibmvscsi_handle_crq(struct viosrp_crq *crq, >>> struct ibmvscsi_host_data *hostdata); >>> @@ -2289,7 +2293,7 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id) >>> goto init_pool_failed; >>> } >>> >>> - host->max_lun = 8; >>> + host->max_lun = max_lun; >>> host->max_id = max_id; >>> host->max_channel = max_channel; >>> host->max_cmd_len = 16; >>> @@ -2414,6 +2418,9 @@ int __init ibmvscsi_module_init(void) >>> { >>> int ret; >>> >>> + if (max_lun > IBMVSCSI_MAX_LUN) >>> + return -EINVAL; >>> + >>> /* Ensure we have two requests to do error recovery */ >>> driver_template.can_queue = max_requests; >>> max_events = max_requests + 2; >>> diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.h b/drivers/scsi/ibmvscsi/ibmvscsi.h >>> index 7d64867..1067367 100644 >>> --- a/drivers/scsi/ibmvscsi/ibmvscsi.h >>> +++ b/drivers/scsi/ibmvscsi/ibmvscsi.h >>> @@ -48,6 +48,7 @@ struct Scsi_Host; >>> #define IBMVSCSI_CMDS_PER_LUN_DEFAULT 16 >>> #define IBMVSCSI_MAX_SECTORS_DEFAULT 256 /* 32 * 8 = default max I/O 32 pages */ >>> #define IBMVSCSI_MAX_CMDS_PER_LUN 64 >>> +#define IBMVSCSI_MAX_LUN 32 >>> >>> /* ------------------------------------------------------------ >>> * Data Structures >>> >> Please set max_lun to 31, and remove everything else. >> As discussed, max_lun is the max number of LUNs supported by the >> hardware/HBA. There is no point in restricting it further. > > You mean no module parameter and a simple "host->max_lun = 31" ? > Yes. > I'm wondering if it should be "host->max_lun = 32". What about this ? > 'max_lun' is used as the stopping condition while scanning LUNs sequentially in drivers/scsi/scsi_scan.c: for (lun = 1; lun < max_dev_lun; ++lun) if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL) != SCSI_SCAN_LUN_PRESENT) && so indeed it needs to be set to '32'. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N?rnberg GF: F. Imend?rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG N?rnberg) -- 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/