Re: [Qemu-devel] [PATCH v3 3/6] nbd/client: Report offsets in bdrv_block_status

[Vladimir Sementsov-Ogievskiy]

29.03.2019 7:27, Eric Blake wrote:
> It is desirable for 'qemu-img map' to have the same output for a file
> whether it is served over file or nbd protocols. However, ever since
> we implemented block status for NBD (2.12), the NBD protocol forgot to
> inform the block layer that as the final layer in the chain, the
> offset is valid; without an offset, the human-readable form of
> qemu-img map gives up with the unhelpful:
> 
> $ nbdkit -U - data data="1" size=512 --run 'qemu-img map $nbd'
> Offset          Length          Mapped to       File
> qemu-img: File contains external, encrypted or compressed clusters.
> 
> The --output=json form always works, because it is reporting the
> lower-level bdrv_block_status results directly rather than trying to
> filter out sparse ranges for human consumption.
> 
> With this patch, the output changes to:
> 
> Offset          Length          Mapped to       File
> 0               0x200           0               
> nbd+unix://?socket=/tmp/nbdkitOxeoLa/socket
> 
> This change is observable to several iotests.
> 
> Fixes: 78a33ab5
> Reported-by: Richard W.M. Jones<address@hidden>
> Signed-off-by: Eric Blake<address@hidden>


Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>

-- 
Best regards,
Vladimir