Patchwork [2/2] Allow xen guests to plug disks of 1 TiB or more

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Submitter Felipe Franciosi
Date April 3, 2013, 2:01 p.m.
Message ID <1364997672-29579-3-git-send-email-felipe.franciosi@citrix.com>
Download mbox | patch
Permalink /patch/233489/
State New
Headers show

Comments

Felipe Franciosi - April 3, 2013, 2:01 p.m.
The current xen backend driver implementation uses int64_t variables
to store the size of the corresponding backend disk/file. It also uses
an int64_t variable to store the block size of that image. When writing
the number of sectors (file_size/block_size) to xenstore, however, it
passes these values as 32 bit signed integers. This will cause an
overflow for any disk of 1 TiB or more.

This patch changes the xen backend driver to use a 64 bit integer write
xenstore function.

Signed-off-by: Felipe Franciosi <felipe@paradoxo.org>
---
 hw/xen_disk.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
Stefano Stabellini - April 3, 2013, 3:20 p.m.
On Wed, 3 Apr 2013, Felipe Franciosi wrote:
> The current xen backend driver implementation uses int64_t variables
> to store the size of the corresponding backend disk/file. It also uses
> an int64_t variable to store the block size of that image. When writing
> the number of sectors (file_size/block_size) to xenstore, however, it
> passes these values as 32 bit signed integers. This will cause an
> overflow for any disk of 1 TiB or more.
> 
> This patch changes the xen backend driver to use a 64 bit integer write
> xenstore function.
> 
> Signed-off-by: Felipe Franciosi <felipe@paradoxo.org>

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>


>  hw/xen_disk.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/xen_disk.c b/hw/xen_disk.c
> index 83329e2..6255075 100644
> --- a/hw/xen_disk.c
> +++ b/hw/xen_disk.c
> @@ -797,8 +797,8 @@ static int blk_init(struct XenDevice *xendev)
>      xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1);
>      xenstore_write_be_int(&blkdev->xendev, "info",            info);
>      xenstore_write_be_int(&blkdev->xendev, "sector-size",     blkdev->file_blk);
> -    xenstore_write_be_int(&blkdev->xendev, "sectors",
> -                          blkdev->file_size / blkdev->file_blk);
> +    xenstore_write_be_int64(&blkdev->xendev, "sectors",
> +                            blkdev->file_size / blkdev->file_blk);
>      return 0;
>  
>  out_error:
> -- 
> 1.7.10.4
>

Patch

diff --git a/hw/xen_disk.c b/hw/xen_disk.c
index 83329e2..6255075 100644
--- a/hw/xen_disk.c
+++ b/hw/xen_disk.c
@@ -797,8 +797,8 @@  static int blk_init(struct XenDevice *xendev)
     xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1);
     xenstore_write_be_int(&blkdev->xendev, "info",            info);
     xenstore_write_be_int(&blkdev->xendev, "sector-size",     blkdev->file_blk);
-    xenstore_write_be_int(&blkdev->xendev, "sectors",
-                          blkdev->file_size / blkdev->file_blk);
+    xenstore_write_be_int64(&blkdev->xendev, "sectors",
+                            blkdev->file_size / blkdev->file_blk);
     return 0;
 
 out_error: