Re: [Qemu-block] [PATCH for-3.1? v2 1/3] block: Always abort reopen after prepare succeeded

[Alberto Garcia]

On Fri 16 Nov 2018 05:45:24 PM CET, Max Reitz wrote:
> bdrv_reopen_multiple() does not invoke bdrv_reopen_abort() for the
> element of the reopen queue for which bdrv_reopen_prepare() failed,
> because it assumes that the prepare function will have rolled back all
> changes already.
>
> However, bdrv_reopen_prepare() does not do this in every case: It may
> notice an error after BlockDriver.bdrv_reopen_prepare() succeeded, and
> it will not invoke BlockDriver.bdrv_reopen_abort() then; and neither
> will bdrv_reopen_multiple(), as explained above.
>
> This is wrong because we must always call .bdrv_reopen_commit() or
> .bdrv_reopen_abort() after .bdrv_reopen_prepare() has succeeded.
> Otherwise, the block driver has no chance to undo what it has done in
> its implementation of .bdrv_reopen_prepare().
>
> To fix this, bdrv_reopen_prepare() has to call .bdrv_reopen_abort() if
> it wants to return an error after .bdrv_reopen_prepare() has succeeded.
>
> Signed-off-by: Max Reitz <address@hidden>

Reviewed-by: Alberto Garcia <address@hidden>

Berto