Re: [PATCH for-4.2? v3 0/8] block: Fix resize (extending) of short overlays

[Max Reitz <mreitz@redhat.com>]

[-- Attachment #1.1: Type: text/plain, Size: 1019 bytes --]

On 22.11.19 17:05, Kevin Wolf wrote:
> See patch 4 for the description of the bug fixed.
> 
> v3:
> - Don't allow blocking the monitor for a zero write in block_resize
>   (even though we can already blockfor other reasons there). This is
>   mainly responsible for the increased complexity compared to v2.
>   Personally, I think this is not an improvement over v2, but if this is
>   what it takes to fix a corruption issue in 4.2... [Max]

I don’t find it so bad because the added complexity is:

(1) A mainly mechanical change of code to add another parameter to
{blk,bdrv}(_co)?_truncate(),

(2) qcow2 providing BDRV_REQ_NO_FALLBACK, and

(3) passing BDRV_REQ_NO_FALLBACK in bdrv_co_truncate() if the new
parameter is true.

(1) sees the most LoC changed, but it isn’t a complex change.  (2) and
(3) are both basically one-line changes each.


OTOH, as I’ve said on IRC, I believe you have a sufficient number of
R-bs on v2 to take it without mine, so the choice is yours.

Max


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]