From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: [GIT PULL] SCSI fixes for 4.4-rc8 Date: Sat, 09 Jan 2016 09:51:24 -0800 Message-ID: <1452361884.2361.20.camel@HansenPartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Andrew Morton , Linus Torvalds Cc: linux-scsi , linux-kernel List-Id: linux-scsi@vger.kernel.org Single fix for machines with pages > 4k (PPC mostly). There's a bug in our optimal transfer size code where we don't account for pages > 4k and can set the transfer size to be less than the page size causing nasty failures. The patch is available here: git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes The short changelog is: Martin K. Petersen (1): sd: Reject optimal transfer length smaller than page size And the diffstat: drivers/scsi/sd.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) With full diff below. James --- diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 3d22fc3..4e08d1cd 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2885,10 +2885,13 @@ static int sd_revalidate_disk(struct gendisk *disk) /* * Use the device's preferred I/O size for reads and writes - * unless the reported value is unreasonably large (or garbage). + * unless the reported value is unreasonably small, large, or + * garbage. */ - if (sdkp->opt_xfer_blocks && sdkp->opt_xfer_blocks <= dev_max && - sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS) + if (sdkp->opt_xfer_blocks && + sdkp->opt_xfer_blocks <= dev_max && + sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS && + sdkp->opt_xfer_blocks * sdp->sector_size >= PAGE_CACHE_SIZE) rw_max = q->limits.io_opt = logical_to_sectors(sdp, sdkp->opt_xfer_blocks); else