From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chandra Seetharaman Subject: [PATCH] Retry mode select in rdac device handler Date: Wed, 05 Nov 2008 20:06:37 -0800 Message-ID: <1225944397.14830.1111.camel@chandra-ubuntu> Reply-To: sekharan@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Sender: linux-scsi-owner@vger.kernel.org To: Linux SCSI Mailing list Cc: dm-devel List-Id: dm-devel.ids When the mode select sent to the controller fails with the retryable error, it is better to retry the mode_select from the hardware handler itself, instead of propagating the failure to dm-multipath. Signed-off-by: Chandra Seetharaman --- Index: linux-2.6.28-rc3/drivers/scsi/device_handler/scsi_dh_rdac.c =================================================================== --- linux-2.6.28-rc3.orig/drivers/scsi/device_handler/scsi_dh_rdac.c +++ linux-2.6.28-rc3/drivers/scsi/device_handler/scsi_dh_rdac.c @@ -24,6 +24,7 @@ #include #define RDAC_NAME "rdac" +#define RDAC_RETRY_COUNT 5 /* * LSI mode page stuff @@ -477,21 +478,27 @@ static int send_mode_select(struct scsi_ { struct request *rq; struct request_queue *q = sdev->request_queue; - int err = SCSI_DH_RES_TEMP_UNAVAIL; + int err, retry_cnt = RDAC_RETRY_COUNT; +retry: + err = SCSI_DH_RES_TEMP_UNAVAIL; rq = rdac_failover_get(sdev, h); if (!rq) goto done; - sdev_printk(KERN_INFO, sdev, "queueing MODE_SELECT command.\n"); + sdev_printk(KERN_INFO, sdev, "%s MODE_SELECT command.\n", + (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying"); err = blk_execute_rq(q, NULL, rq, 1); - if (err != SCSI_DH_OK) + blk_put_request(rq); + if (err != SCSI_DH_OK) { err = mode_select_handle_sense(sdev, h->sense); + if (err == SCSI_DH_RETRY && retry_cnt--) + goto retry; + } if (err == SCSI_DH_OK) h->state = RDAC_STATE_ACTIVE; - blk_put_request(rq); done: return err; }