Re: [Qemu-devel] [PATCH v3 00/14] block: Remove "growable", add blk_new_open()

[Kevin Wolf <kwolf@redhat.com>]

Am 26.01.2015 um 16:00 hat Max Reitz geschrieben:
> This series removes the "growable" field from the BlockDriverState
> object. Its use was to clamp guest requests against the limits of the
> BDS; however, this can now be done more easily by moving those checks
> into the BlockBackend functions.
> 
> In a future series, "growable" may be reintroduced (maybe with a
> different name); it will then signify whether a BDS is able to grow (in
> contrast to the current "growable", which signifies whether it is
> allowed to). Maybe I will add it to the BlockDriver instead of the BDS,
> though.
> 
> To be able to remove that field, qemu-io needs to be converted to
> BlockBackend, which is done by this series as well. While working on
> that I decided to convert blk_new_with_bs()+bdrv_open() to
> blk_new_open(). I was skeptical about that decision at first, but it
> seems good now that I was able to replace nearly every blk_new_with_bs()
> call by blk_new_open(). In a future series I may try to convert some
> remaining bdrv_open() calls to blk_new_open() as well. (And, in fact, in
> a future series I *will* replace the last remaining blk_new_with_bs()
> outside of blk_new_open() by blk_new_open().)
> 
> Finally, the question needs to be asked: If, after this series, every
> BDS is allowed to grow, are there any users which do not use BB, but
> should still be disallowed from reading/writing beyond a BDS's limits?
> The only users I could see were the block jobs. Some of them should
> indeed be converted to BB; but none of them takes a user-supplied offset
> or size, all work on the full BDS (or only on parts which have been
> modified, etc.). Therefore, it is by design impossible for them to
> exceed the BDS's limits, which makes making all BDS's growable safe.

Patches that I didn't comment on (all except 4, 5, 6, 9, 10, 13) are,
assuming that you address Eric's comments, if any:

Reviewed-by: Kevin Wolf <kwolf@redhat.com>