From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:41926 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752295AbeFGBv3 (ORCPT ); Wed, 6 Jun 2018 21:51:29 -0400 From: "Martin K. Petersen" To: linux-scsi@vger.kernel.org, Christoph Anton Mitterer Cc: "Martin K. Petersen" , stable@vger.kernel.org Subject: [PATCH] scsi: sd: Optimal I/O size should be a multiple of physical block size Date: Wed, 6 Jun 2018 21:51:23 -0400 Message-Id: <20180607015123.17862-1-martin.petersen@oracle.com> In-Reply-To: <207561f82d5638c8f513f9aaf970a07098bfbb0f.camel@scientia.net> References: <207561f82d5638c8f513f9aaf970a07098bfbb0f.camel@scientia.net> Sender: stable-owner@vger.kernel.org List-ID: It was reported that some devices report an OPTIMAL TRANSFER LENGTH of 0xFFFF blocks. That looks bogus, especially for a device with a 4096-byte physical block size. Ignore OPTIMAL TRANSFER LENGTH if it is not a multiple of the device's reported physical block size. Cc: Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199759 Reported-by: Christoph Anton Mitterer Signed-off-by: Martin K. Petersen --- Before: NAME ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCHED RQ-SIZE RA WSAME sda 0 4096 33553920 4096 512 0 mq-deadline 256 128 32M After: NAME ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCHED RQ-SIZE RA WSAME sda 0 4096 0 4096 512 0 mq-deadline 256 4096 32M --- drivers/scsi/sd.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 9421d9877730..2d19eed3dfbc 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3067,7 +3067,7 @@ static int sd_revalidate_disk(struct gendisk *disk) struct request_queue *q = sdkp->disk->queue; sector_t old_capacity = sdkp->capacity; unsigned char *buffer; - unsigned int dev_max, rw_max; + unsigned int dev_max, rw_max, opt_xfer_bytes; SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_revalidate_disk\n")); @@ -3126,13 +3126,16 @@ static int sd_revalidate_disk(struct gendisk *disk) /* * Determine the device's preferred I/O size for reads and writes - * unless the reported value is unreasonably small, large, or - * garbage. + * unless the reported value is unreasonably small, large, not a + * multiple of the physical block size, or simply garbage. */ + opt_xfer_bytes = logical_to_bytes(sdp, sdkp->opt_xfer_blocks); + if (sdkp->opt_xfer_blocks && sdkp->opt_xfer_blocks <= dev_max && sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS && - logical_to_bytes(sdp, sdkp->opt_xfer_blocks) >= PAGE_SIZE) { + opt_xfer_bytes >= PAGE_SIZE && + (opt_xfer_bytes & (sdkp->physical_block_size - 1)) != 0) { q->limits.io_opt = logical_to_bytes(sdp, sdkp->opt_xfer_blocks); rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks); } else -- 2.17.1