From: "Ewan D. Milne" <emilne@redhat.com>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Subject: Re: [PATCH v2] sd: Fix excessive capacity printing on devices with blocks bigger than 512 bytes
Date: Wed, 30 Mar 2016 12:34:42 -0400 [thread overview]
Message-ID: <1459355682.30035.29.camel@localhost.localdomain> (raw)
In-Reply-To: <1459214336-12668-1-git-send-email-martin.petersen@oracle.com>
On Mon, 2016-03-28 at 21:18 -0400, Martin K. Petersen wrote:
> During revalidate we check whether device capacity has changed before we
> decide whether to output disk information or not.
>
> The check for old capacity failed to take into account that we scaled
> sdkp->capacity based on the reported logical block size. And therefore
> the capacity test would always fail for devices with sectors bigger than
> 512 bytes and we would print several copies of the same discovery
> information.
>
> Avoid scaling sdkp->capacity and instead adjust the value on the fly
> when setting the block device capacity and generating fake C/H/S
> geometry.
>
> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
> Reported-by: Hannes Reinecke <hare@suse.de>
> ---
> drivers/scsi/sd.c | 28 ++++++++--------------------
> drivers/scsi/sd.h | 7 ++++++-
> 2 files changed, 14 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 5a5457ac9cdb..8401697ff6aa 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -1275,18 +1275,19 @@ static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
> struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
> struct scsi_device *sdp = sdkp->device;
> struct Scsi_Host *host = sdp->host;
> + sector_t capacity = logical_to_sectors(sdp, sdkp->capacity);
> int diskinfo[4];
>
> /* default to most commonly used values */
> - diskinfo[0] = 0x40; /* 1 << 6 */
> - diskinfo[1] = 0x20; /* 1 << 5 */
> - diskinfo[2] = sdkp->capacity >> 11;
> -
> + diskinfo[0] = 0x40; /* 1 << 6 */
> + diskinfo[1] = 0x20; /* 1 << 5 */
> + diskinfo[2] = capacity >> 11;
> +
> /* override with calculated, extended default, or driver values */
> if (host->hostt->bios_param)
> - host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
> + host->hostt->bios_param(sdp, bdev, capacity, diskinfo);
> else
> - scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
> + scsicam_bios_param(bdev, capacity, diskinfo);
>
> geo->heads = diskinfo[0];
> geo->sectors = diskinfo[1];
> @@ -2337,14 +2338,6 @@ got_data:
> if (sdkp->capacity > 0xffffffff)
> sdp->use_16_for_rw = 1;
>
> - /* Rescale capacity to 512-byte units */
> - if (sector_size == 4096)
> - sdkp->capacity <<= 3;
> - else if (sector_size == 2048)
> - sdkp->capacity <<= 2;
> - else if (sector_size == 1024)
> - sdkp->capacity <<= 1;
> -
> blk_queue_physical_block_size(sdp->request_queue,
> sdkp->physical_block_size);
> sdkp->device->sector_size = sector_size;
> @@ -2812,11 +2805,6 @@ static int sd_try_extended_inquiry(struct scsi_device *sdp)
> return 0;
> }
>
> -static inline u32 logical_to_sectors(struct scsi_device *sdev, u32 blocks)
> -{
> - return blocks << (ilog2(sdev->sector_size) - 9);
> -}
> -
> /**
> * sd_revalidate_disk - called the first time a new disk is seen,
> * performs disk spin up, read_capacity, etc.
> @@ -2900,7 +2888,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
> /* Combine with controller limits */
> q->limits.max_sectors = min(rw_max, queue_max_hw_sectors(q));
>
> - set_capacity(disk, sdkp->capacity);
> + set_capacity(disk, logical_to_sectors(sdp, sdkp->capacity));
> sd_config_write_same(sdkp);
> kfree(buffer);
>
> diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
> index 5f2a84aff29f..654630bb7d0e 100644
> --- a/drivers/scsi/sd.h
> +++ b/drivers/scsi/sd.h
> @@ -65,7 +65,7 @@ struct scsi_disk {
> struct device dev;
> struct gendisk *disk;
> atomic_t openers;
> - sector_t capacity; /* size in 512-byte sectors */
> + sector_t capacity; /* size in logical blocks */
> u32 max_xfer_blocks;
> u32 opt_xfer_blocks;
> u32 max_ws_blocks;
> @@ -146,6 +146,11 @@ static inline int scsi_medium_access_command(struct scsi_cmnd *scmd)
> return 0;
> }
>
> +static inline sector_t logical_to_sectors(struct scsi_device *sdev, sector_t blocks)
> +{
> + return blocks << (ilog2(sdev->sector_size) - 9);
> +}
> +
> /*
> * A DIF-capable target device can be formatted with different
> * protection schemes. Currently 0 through 3 are defined:
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
prev parent reply other threads:[~2016-03-30 16:34 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-21 12:27 [PATCH] sd: fixup capacity calculation for 4k drives Hannes Reinecke
2016-03-21 14:31 ` Christoph Hellwig
2016-03-22 1:16 ` Martin K. Petersen
2016-03-22 6:55 ` Christoph Hellwig
2016-03-22 7:14 ` Hannes Reinecke
2016-03-22 14:16 ` Ewan D. Milne
2016-03-29 1:14 ` Martin K. Petersen
2016-03-29 1:18 ` [PATCH v2] sd: Fix excessive capacity printing on devices with blocks bigger than 512 bytes Martin K. Petersen
2016-03-30 8:06 ` Hannes Reinecke
2016-03-30 16:34 ` Ewan D. Milne [this message]
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