[Drbd-dev] DRBD-8 - next crash in bio_split()

[Graham, Simon]

> Index: drbd_req.c
> ===================================================================
> --- drbd_req.c	(revision 2415)
> +++ drbd_req.c	(working copy)
> @@ -1068,7 +1068,11 @@
>  	unsigned int bio_size = bio->bi_size;
>  	int max;
> 
> +#if 1
> +	max = DRBD_MAX_SEGMENT_SIZE - ((bio_offset &
> (DRBD_MAX_SEGMENT_SIZE-1)) + bio_size);
> +#else
>  	max = AL_EXTENT_SIZE - ((bio_offset & (AL_EXTENT_SIZE-1)) +
> bio_size);
> +#endif
>  	if (max < 0) max = 0;
>  	if (max <= bvec->bv_len && bio_size == 0)
>  		return bvec->bv_len;

I'm not sure to be honest - I take it the intent here is to ensure there
can only ever be one bio_vec in a bio that needs to be split? And the
way to do that is to ensure that the only way a request that is too
large can be passed to DRBD is if it is the first entry that is too
large?

I'll try this and let you know...