Re: [Qemu-devel] [PULL 08/17] block: Assert no write requests under BDRV_O_INCOMING

[Laurent Vivier]

Hi,

this commit breaks incoming migration case:

qemu-system-ppc64 XXX -incoming tcp:0:4444
qemu-system-ppc64: .../qemu/block/io.c:1304: bdrv_co_do_pwritev:
Assertion `!(bs->open_flags & 0x0800)' failed.

Without "-incoming", the same command line boots fine.

Are you aware of the problem?

Laurent

On 20/01/2016 17:24, Kevin Wolf wrote:
> As long as BDRV_O_INCOMING is set, the image file is only opened so we
> have a file descriptor for it. We're definitely not supposed to modify
> the image, it's still owned by the migration source.
> 
> Signed-off-by: Kevin Wolf <address@hidden>
> Reviewed-by: Eric Blake <address@hidden>
> ---
>  block/io.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/block/io.c b/block/io.c
> index 707c04b..2372994 100644
> --- a/block/io.c
> +++ b/block/io.c
> @@ -1301,6 +1301,7 @@ static int coroutine_fn 
> bdrv_co_do_pwritev(BlockDriverState *bs,
>      if (bs->read_only) {
>          return -EPERM;
>      }
> +    assert(!(bs->open_flags & BDRV_O_INCOMING));
>  
>      ret = bdrv_check_byte_request(bs, offset, bytes);
>      if (ret < 0) {
> @@ -2462,6 +2463,7 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, 
> int64_t sector_num,
>      } else if (bs->read_only) {
>          return -EPERM;
>      }
> +    assert(!(bs->open_flags & BDRV_O_INCOMING));
>  
>      /* Do nothing if disabled.  */
>      if (!(bs->open_flags & BDRV_O_UNMAP)) {
>