From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Stefan Bader <stefan.bader@canonical.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
"Jan Beulich" <jbeulich@suse.com>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH v3] xen-blk(front|back): Handle large physical sector disks
Date: Tue, 28 May 2013 08:47:56 -0400 [thread overview]
Message-ID: <20130528124756.GA3754@phenom.dumpdata.com> (raw)
In-Reply-To: <5193A38B.4080508@canonical.com>
On Wed, May 15, 2013 at 05:02:35PM +0200, Stefan Bader wrote:
> Changed the xenbus_gather but kept the xenbus_dev_error (without being fatal) as
> that seems closer to the style of the other calls.
Hm, could you rebase this on top of stable/for-jens-3.10 please?
I get this:
patching file drivers/block/xen-blkback/xenbus.c
Hunk #1 FAILED at 704.
1 out of 1 hunk FAILED -- saving rejects to file drivers/block/xen-blkback/xenbus.c.rej
patching file drivers/block/xen-blkfront.c
Hunk #1 FAILED at 542.
patch: **** malformed patch at line 133: 16
>
> -Stefan
>
> From cddea87d842cc5feb427f3eedefc0566d69fb9b6 Mon Sep 17 00:00:00 2001
> From: Stefan Bader <stefan.bader@canonical.com>
> Date: Mon, 13 May 2013 16:28:15 +0200
> Subject: [PATCH] xen/blk: Use physical sector size for setup
>
> Currently xen-blkback passes the logical sector size over xenbus and
> xen-blkfront sets up the paravirt disk with that logical block size.
> But newer drives usually have the logical sector size set to 512 for
> compatibility reasons and would show the actual sector size only in
> physical sector size.
> This results in the device being partitioned and accessed in dom0 with
> the correct sector size, but the guest thinks 512 bytes is the correct
> block size. And that results in poor performance.
>
> To fix this, blkback gets modified to pass also physical-sector-size
> over xenbus and blkfront to use both values to set up the paravirt
> disk. I did not just change the passed in sector-size because I am
> not sure having a bigger logical sector size than the physical one
> is valid (and that would happen if a newer dom0 kernel hits an older
> domU kernel). Also this way a domU set up before should still be
> accessible (just some tools might detect the unaligned setup).
>
> [v2: Make xenbus write failure non-fatal]
> [v3: Use xenbus_scanf instead of xenbus_gather]
>
> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
> ---
> drivers/block/xen-blkback/xenbus.c | 5 +++++
> drivers/block/xen-blkfront.c | 23 +++++++++++++++++++----
> 2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
> index 8bfd1bc..25463e3 100644
> --- a/drivers/block/xen-blkback/xenbus.c
> +++ b/drivers/block/xen-blkback/xenbus.c
> @@ -704,6 +704,11 @@ again:
> dev->nodename);
> goto abort;
> }
> + err = xenbus_printf(xbt, dev->nodename, "physical-sector-size", "%u",
> + bdev_physical_block_size(be->blkif->vbd.bdev));
> + if (err)
> + xenbus_dev_error(dev, err, "writing %s/physical-sector-size",
> + dev->nodename);
>
> err = xenbus_transaction_end(xbt, 0);
> if (err == -EAGAIN)
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index d89ef86..33b5618 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -542,7 +542,8 @@ wait:
> flush_requests(info);
> }
>
> -static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
> +static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
> + unsigned int physical_sector_size)
> {
> struct request_queue *rq;
> struct blkfront_info *info = gd->private_data;
> @@ -564,6 +565,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16
> sector_size)
>
> /* Hard sector size and max sectors impersonate the equiv. hardware. */
> blk_queue_logical_block_size(rq, sector_size);
> + blk_queue_physical_block_size(rq, physical_sector_size);
> blk_queue_max_hw_sectors(rq, 512);
>
> /* Each segment in a request is up to an aligned page in size. */
> @@ -667,7 +669,8 @@ static char *encode_disk_name(char *ptr, unsigned int n)
>
> static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
> struct blkfront_info *info,
> - u16 vdisk_info, u16 sector_size)
> + u16 vdisk_info, u16 sector_size,
> + unsigned int physical_sector_size)
> {
> struct gendisk *gd;
> int nr_minors = 1;
> @@ -734,7 +737,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
> gd->driverfs_dev = &(info->xbdev->dev);
> set_capacity(gd, capacity);
>
> - if (xlvbd_init_blk_queue(gd, sector_size)) {
> + if (xlvbd_init_blk_queue(gd, sector_size, physical_sector_size)) {
> del_gendisk(gd);
> goto release;
> }
> @@ -1395,6 +1398,7 @@ static void blkfront_connect(struct blkfront_info *info)
> {
> unsigned long long sectors;
> unsigned long sector_size;
> + unsigned int physical_sector_size;
> unsigned int binfo;
> int err;
> int barrier, flush, discard, persistent;
> @@ -1437,6 +1441,16 @@ static void blkfront_connect(struct blkfront_info *info)
> return;
> }
>
> + /*
> + * physcial-sector-size is a newer field, so old backends may not
> + * provide this. Assume physical sector size to be the same as
> + * sector_size in that case.
> + */
> + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
> + "physical-sector-size", "%u", &physical_sector_size);
> + if (err != 1)
> + physical_sector_size = sector_size;
> +
> info->feature_flush = 0;
> info->flush_op = 0;
>
> @@ -1483,7 +1497,8 @@ static void blkfront_connect(struct blkfront_info *info)
> else
> info->feature_persistent = persistent;
>
> - err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
> + err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size,
> + physical_sector_size);
> if (err) {
> xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s",
> info->xbdev->otherend);
> --
> 1.7.9.5
>
> From cddea87d842cc5feb427f3eedefc0566d69fb9b6 Mon Sep 17 00:00:00 2001
> From: Stefan Bader <stefan.bader@canonical.com>
> Date: Mon, 13 May 2013 16:28:15 +0200
> Subject: [PATCH] xen/blk: Use physical sector size for setup
>
> Currently xen-blkback passes the logical sector size over xenbus and
> xen-blkfront sets up the paravirt disk with that logical block size.
> But newer drives usually have the logical sector size set to 512 for
> compatibility reasons and would show the actual sector size only in
> physical sector size.
> This results in the device being partitioned and accessed in dom0 with
> the correct sector size, but the guest thinks 512 bytes is the correct
> block size. And that results in poor performance.
>
> To fix this, blkback gets modified to pass also physical-sector-size
> over xenbus and blkfront to use both values to set up the paravirt
> disk. I did not just change the passed in sector-size because I am
> not sure having a bigger logical sector size than the physical one
> is valid (and that would happen if a newer dom0 kernel hits an older
> domU kernel). Also this way a domU set up before should still be
> accessible (just some tools might detect the unaligned setup).
>
> [v2: Make xenbus write failure non-fatal]
> [v3: Use xenbus_scanf instead of xenbus_gather]
>
> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
> ---
> drivers/block/xen-blkback/xenbus.c | 5 +++++
> drivers/block/xen-blkfront.c | 23 +++++++++++++++++++----
> 2 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
> index 8bfd1bc..25463e3 100644
> --- a/drivers/block/xen-blkback/xenbus.c
> +++ b/drivers/block/xen-blkback/xenbus.c
> @@ -704,6 +704,11 @@ again:
> dev->nodename);
> goto abort;
> }
> + err = xenbus_printf(xbt, dev->nodename, "physical-sector-size", "%u",
> + bdev_physical_block_size(be->blkif->vbd.bdev));
> + if (err)
> + xenbus_dev_error(dev, err, "writing %s/physical-sector-size",
> + dev->nodename);
>
> err = xenbus_transaction_end(xbt, 0);
> if (err == -EAGAIN)
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index d89ef86..33b5618 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -542,7 +542,8 @@ wait:
> flush_requests(info);
> }
>
> -static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
> +static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
> + unsigned int physical_sector_size)
> {
> struct request_queue *rq;
> struct blkfront_info *info = gd->private_data;
> @@ -564,6 +565,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
>
> /* Hard sector size and max sectors impersonate the equiv. hardware. */
> blk_queue_logical_block_size(rq, sector_size);
> + blk_queue_physical_block_size(rq, physical_sector_size);
> blk_queue_max_hw_sectors(rq, 512);
>
> /* Each segment in a request is up to an aligned page in size. */
> @@ -667,7 +669,8 @@ static char *encode_disk_name(char *ptr, unsigned int n)
>
> static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
> struct blkfront_info *info,
> - u16 vdisk_info, u16 sector_size)
> + u16 vdisk_info, u16 sector_size,
> + unsigned int physical_sector_size)
> {
> struct gendisk *gd;
> int nr_minors = 1;
> @@ -734,7 +737,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
> gd->driverfs_dev = &(info->xbdev->dev);
> set_capacity(gd, capacity);
>
> - if (xlvbd_init_blk_queue(gd, sector_size)) {
> + if (xlvbd_init_blk_queue(gd, sector_size, physical_sector_size)) {
> del_gendisk(gd);
> goto release;
> }
> @@ -1395,6 +1398,7 @@ static void blkfront_connect(struct blkfront_info *info)
> {
> unsigned long long sectors;
> unsigned long sector_size;
> + unsigned int physical_sector_size;
> unsigned int binfo;
> int err;
> int barrier, flush, discard, persistent;
> @@ -1437,6 +1441,16 @@ static void blkfront_connect(struct blkfront_info *info)
> return;
> }
>
> + /*
> + * physcial-sector-size is a newer field, so old backends may not
> + * provide this. Assume physical sector size to be the same as
> + * sector_size in that case.
> + */
> + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
> + "physical-sector-size", "%u", &physical_sector_size);
> + if (err != 1)
> + physical_sector_size = sector_size;
> +
> info->feature_flush = 0;
> info->flush_op = 0;
>
> @@ -1483,7 +1497,8 @@ static void blkfront_connect(struct blkfront_info *info)
> else
> info->feature_persistent = persistent;
>
> - err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
> + err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size,
> + physical_sector_size);
> if (err) {
> xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s",
> info->xbdev->otherend);
> --
> 1.7.9.5
>
next prev parent reply other threads:[~2013-05-28 12:47 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-13 17:47 [PATCH] xen-blk(front|back): Handle large physical sector disks Stefan Bader
2013-05-14 8:04 ` Jan Beulich
2013-05-15 9:26 ` Stefan Bader
2013-05-15 9:47 ` Jan Beulich
2013-05-15 10:04 ` James Harper
2013-05-15 10:10 ` Stefan Bader
2013-05-15 12:23 ` Jan Beulich
2013-05-15 13:54 ` Konrad Rzeszutek Wilk
2013-05-15 10:58 ` Stefan Bader
2013-05-15 12:28 ` Jan Beulich
2013-05-14 14:49 ` Roger Pau Monné
2013-05-14 16:11 ` Stefan Bader
2013-05-15 15:02 ` [PATCH v3] " Stefan Bader
2013-05-22 11:48 ` Stefan Bader
2013-05-22 12:21 ` Jan Beulich
2013-05-22 13:15 ` Stefan Bader
2013-05-22 13:22 ` Jan Beulich
2013-05-22 13:02 ` Konrad Rzeszutek Wilk
2013-05-28 12:47 ` Konrad Rzeszutek Wilk [this message]
2013-05-28 12:55 ` Stefan Bader
2013-05-28 16:17 ` Konrad Rzeszutek Wilk
2013-05-28 18:03 ` Stefan Bader
2013-06-05 20:25 ` Konrad Rzeszutek Wilk
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