Am 15.02.2017 um 17:48 hat Max Reitz geschrieben: > On 15.02.2017 17:44, Kevin Wolf wrote: > > Am 15.02.2017 um 14:42 hat Max Reitz geschrieben: > >> On 14.02.2017 10:52, Alberto Garcia wrote: > >>> On Mon 13 Feb 2017 06:13:38 PM CET, Max Reitz wrote: > >>> > >>>>>> -#define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \ > >>>>>> - INT_MAX >> BDRV_SECTOR_BITS) > >>>>>> -#define BDRV_REQUEST_MAX_BYTES (BDRV_REQUEST_MAX_SECTORS << > >>>>>> BDRV_SECTOR_BITS) > >>>>>> +#define BDRV_REQUEST_MAX_BYTES MIN(SIZE_MAX, INT_MAX) > >>>>>> +#define BDRV_REQUEST_MAX_SECTORS (BDRV_REQUEST_MAX_BYTES >> > >>>>>> BDRV_SECTOR_BITS) > >>>>> > >>>>> I'm just pointing it out because I don't know if this can cause > >>>>> problems, but this patch would make BDRV_REQUEST_MAX_BYTES not a > >>>>> multiple of the sector size (INT_MAX is actually a prime number). > >>>> > >>>> Very good point. I don't think this could be an issue, though. For one > >>>> thing, the use of BDRV_REQUEST_MAX_BYTES is very limited. > >>> > >>> Ok, but then I wonder what's the benefit of increasing > >>> BDRV_REQUEST_MAX_BYTES. > >> > >> The benefit is that the definition looks cleaner. > > > > Whatever way we want to write it, I think MAX_BYTES = MAX_SECTORS * 512 > > should be a given. Everything else is bound to confuse people and > > introduce bugs sooner or later. > > Probably only sooner and not later, considering we are switching to byte > granularity overall anyway. And if something confuses people, I'd argue > it's the fact that we still have sector granularity all over the place > and not that your requests can be a bit bigger if you submit them in > bytes than if you submit them in sectors. > > Anyway, if MAX_BYTES should be a multiple of the sector size, then I > can't think of a much better way to write this than what we currently > have and this patch is unneeded.
Maybe we can just get rid of BDRV_REQUEST_MAX_SECTORS? Or do we need to do a few more conversion before that? Kevin
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