[Qemu-devel] [PATCH] raw: Fix BlockLimits passthrough

[Qemu-devel] [PATCH] raw: Fix BlockLimits passthrough

[Kevin Wolf]

raw copies over the BlockLimits of bs->file during bdrv_open().
However, since commit d34682cd it is immediately overwritten during
bdrv_refresh_limits(). This caused all fields except for
opt_transfer_length and opt_mem_alignment (which happen to be correctly
inherited in generic code) to be zeroed.

Move the BlockLimit assignment to a .bdrv_refresh_limits() callback to
make it work again for all fields.

Reported-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/raw_bsd.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/block/raw_bsd.c b/block/raw_bsd.c
index 978ae7a..af8706d 100644
--- a/block/raw_bsd.c
+++ b/block/raw_bsd.c
@@ -90,6 +90,12 @@ static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
     return bdrv_get_info(bs->file, bdi);
 }
 
+static int raw_refresh_limits(BlockDriverState *bs)
+{
+    bs->bl = bs->file->bl;
+    return 0;
+}
+
 static int raw_truncate(BlockDriverState *bs, int64_t offset)
 {
     return bdrv_truncate(bs->file, offset);
@@ -150,7 +156,6 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
                     Error **errp)
 {
     bs->sg = bs->file->sg;
-    bs->bl = bs->file->bl;
     return 0;
 }
 
@@ -182,6 +187,7 @@ static BlockDriver bdrv_raw = {
     .bdrv_getlength       = &raw_getlength,
     .has_variable_length  = true,
     .bdrv_get_info        = &raw_get_info,
+    .bdrv_refresh_limits  = &raw_refresh_limits,
     .bdrv_is_inserted     = &raw_is_inserted,
     .bdrv_media_changed   = &raw_media_changed,
     .bdrv_eject           = &raw_eject,
-- 
1.8.1.4

Re: [Qemu-devel] [PATCH] raw: Fix BlockLimits passthrough

[Laszlo Ersek]

On 02/04/14 12:01, Kevin Wolf wrote:
> raw copies over the BlockLimits of bs->file during bdrv_open().
> However, since commit d34682cd it is immediately overwritten during
> bdrv_refresh_limits(). This caused all fields except for
> opt_transfer_length and opt_mem_alignment (which happen to be correctly
> inherited in generic code) to be zeroed.
> 
> Move the BlockLimit assignment to a .bdrv_refresh_limits() callback to
> make it work again for all fields.
> 
> Reported-by: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/raw_bsd.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/block/raw_bsd.c b/block/raw_bsd.c
> index 978ae7a..af8706d 100644
> --- a/block/raw_bsd.c
> +++ b/block/raw_bsd.c
> @@ -90,6 +90,12 @@ static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>      return bdrv_get_info(bs->file, bdi);
>  }
>  
> +static int raw_refresh_limits(BlockDriverState *bs)
> +{
> +    bs->bl = bs->file->bl;
> +    return 0;
> +}
> +
>  static int raw_truncate(BlockDriverState *bs, int64_t offset)
>  {
>      return bdrv_truncate(bs->file, offset);
> @@ -150,7 +156,6 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
>                      Error **errp)
>  {
>      bs->sg = bs->file->sg;
> -    bs->bl = bs->file->bl;
>      return 0;
>  }
>  
> @@ -182,6 +187,7 @@ static BlockDriver bdrv_raw = {
>      .bdrv_getlength       = &raw_getlength,
>      .has_variable_length  = true,
>      .bdrv_get_info        = &raw_get_info,
> +    .bdrv_refresh_limits  = &raw_refresh_limits,
>      .bdrv_is_inserted     = &raw_is_inserted,
>      .bdrv_media_changed   = &raw_media_changed,
>      .bdrv_eject           = &raw_eject,
> 

Reviewed-by: Laszlo Ersek <lersek@redhat.com>