From patchwork Thu Jul 2 03:13:14 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandra Seetharaman X-Patchwork-Id: 33600 Received: from hormel.redhat.com (hormel1.redhat.com [209.132.177.33]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n623B3m5002911 for ; Thu, 2 Jul 2009 03:11:03 GMT Received: from listman.util.phx.redhat.com (listman.util.phx.redhat.com [10.8.4.110]) by hormel.redhat.com (Postfix) with ESMTP id 31D106192B3; Wed, 1 Jul 2009 23:11:03 -0400 (EDT) Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by listman.util.phx.redhat.com (8.13.1/8.13.1) with ESMTP id n623B0Xk029749 for ; Wed, 1 Jul 2009 23:11:01 -0400 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n623B0D1009270 for ; Wed, 1 Jul 2009 23:11:00 -0400 Received: from e39.co.us.ibm.com (e39.co.us.ibm.com [32.97.110.160]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id n623Aid0030134 for ; Wed, 1 Jul 2009 23:10:44 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e39.co.us.ibm.com (8.13.1/8.13.1) with ESMTP id n6236OQc030444 for ; Wed, 1 Jul 2009 21:06:24 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n623Ahci200090 for ; Wed, 1 Jul 2009 21:10:43 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n623Ahmt028090 for ; Wed, 1 Jul 2009 21:10:43 -0600 Received: from [127.0.1.1] (chandra-ubuntu.beaverton.ibm.com [9.47.17.98]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id n623Ah49028057; Wed, 1 Jul 2009 21:10:43 -0600 From: Chandra Seetharaman To: linux-scsi@vger.kernel.org Date: Wed, 01 Jul 2009 20:13:14 -0700 Message-Id: <20090702031314.28354.41987.sendpatchset@chandra-ubuntu> In-Reply-To: <20090702031308.28354.73353.sendpatchset@chandra-ubuntu> References: <20090702031308.28354.73353.sendpatchset@chandra-ubuntu> X-RedHat-Spam-Score: -1.771 X-Scanned-By: MIMEDefang 2.58 on 172.16.52.254 X-Scanned-By: MIMEDefang 2.63 on 172.16.48.32 X-loop: dm-devel@redhat.com Cc: michaelc@cs.wisc.edu, asson_ronald@emc.com, James.Bottomley@HansenPartnership.com, dm-devel@redhat.com, Benoit_Arthur@emc.com, Eddie.Williams@steeleye.com, agk@redhat.com Subject: [dm-devel] [PATCH 1/3] scsi_dh: add the interface scsi_dh_set_params() X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.5 Precedence: junk Reply-To: device-mapper development List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com When we moved the device handler functionality from dm layer to SCSI layer we dropped the paramaeter functionality. This path adds an interface to scsi dh layer to set device handler parameters. Basically, multipath layer need to create a string with all the parameters and call scsi_dh_set_params() after it called scsi_dh_attach() on a device. If a device handler provides such an interface it will handle the parameters as it expects them. Signed-off-by: Chandra Seetharaman --- drivers/scsi/device_handler/scsi_dh.c | 33 +++++++++++++++++++++++++++++++++ include/scsi/scsi_device.h | 1 + include/scsi/scsi_dh.h | 5 +++++ 3 files changed, 39 insertions(+) -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel Index: linux-2.6.31-rc1/include/scsi/scsi_device.h =================================================================== --- linux-2.6.31-rc1.orig/include/scsi/scsi_device.h +++ linux-2.6.31-rc1/include/scsi/scsi_device.h @@ -187,6 +187,7 @@ struct scsi_device_handler { void (*detach)(struct scsi_device *); int (*activate)(struct scsi_device *); int (*prep_fn)(struct scsi_device *, struct request *); + int (*set_params)(struct scsi_device *, const char *); }; struct scsi_dh_data { Index: linux-2.6.31-rc1/include/scsi/scsi_dh.h =================================================================== --- linux-2.6.31-rc1.orig/include/scsi/scsi_dh.h +++ linux-2.6.31-rc1/include/scsi/scsi_dh.h @@ -60,6 +60,7 @@ extern int scsi_dh_activate(struct reque extern int scsi_dh_handler_exist(const char *); extern int scsi_dh_attach(struct request_queue *, const char *); extern void scsi_dh_detach(struct request_queue *); +extern int scsi_dh_set_params(struct request_queue *, const char *); #else static inline int scsi_dh_activate(struct request_queue *req) { @@ -77,4 +78,8 @@ static inline void scsi_dh_detach(struct { return; } +static inline int scsi_dh_set_params(struct request_queue *req, const char *params) +{ + return -SCSI_DH_NOSYS; +} #endif Index: linux-2.6.31-rc1/drivers/scsi/device_handler/scsi_dh.c =================================================================== --- linux-2.6.31-rc1.orig/drivers/scsi/device_handler/scsi_dh.c +++ linux-2.6.31-rc1/drivers/scsi/device_handler/scsi_dh.c @@ -449,6 +449,39 @@ int scsi_dh_activate(struct request_queu EXPORT_SYMBOL_GPL(scsi_dh_activate); /* + * scsi_dh_set_params - set the parameters for the device as per the + * string specified in params. + * @q - Request queue that is associated with the scsi_device for + * which the parameters to be set. + * @params - parameters in the following format + * "no_of_params\0param1\0param2\0param3\0...\0" + * for example, string for 2 parameters with value 10 and 21 + * is specified as "2\010\021\0". + */ +int scsi_dh_set_params(struct request_queue *q, const char *params) +{ + int err = -SCSI_DH_NOSYS; + unsigned long flags; + struct scsi_device *sdev; + struct scsi_device_handler *scsi_dh = NULL; + + spin_lock_irqsave(q->queue_lock, flags); + sdev = q->queuedata; + if (sdev && sdev->scsi_dh_data) + scsi_dh = sdev->scsi_dh_data->scsi_dh; + if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev)) + err = 0; + spin_unlock_irqrestore(q->queue_lock, flags); + + if (err) + return err; + err = scsi_dh->set_params(sdev, params); + put_device(&sdev->sdev_gendev); + return err; +} +EXPORT_SYMBOL_GPL(scsi_dh_set_params); + +/* * scsi_dh_handler_exist - Return TRUE(1) if a device handler exists for * the given name. FALSE(0) otherwise. * @name - name of the device handler.