[lkml]   [2012]   [Aug]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [dm-devel] [PATCH v5 12/12] block: Only clone bio vecs that are in use
On Wed, Aug 8, 2012 at 8:19 PM, Kent Overstreet <> wrote:
> In particular, if this change breaks anything then the new bio_split()
> _will_ break things.
> We need to be clear about our interfaces; in this case bi_idx and
> bi_vcnt, in particular. Either this is a safe change, or it's not. If
> no one knows... that's a bigger problem, and not just for this patch...
> Fortunately this code actually has been tested quite a bit (and the bio
> splitting code for even longer), and (somewhat to my surprise) I haven't
> run into any bugs caused by it.

Oh, it's worse than that - remember how bio_kmalloc() works for up to
1024 pages, but bio_alloc_bioset() only up to 256?

We can already have situations where bios are allocated that are
impossible to clone (or if we don't, it's only because of
queue_limits. That's not sketchy at all.)

 \ /
  Last update: 2012-08-09 06:01    [W:0.123 / U:15.952 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site