Re: [PATCH] md/raid5-ppl: convert pending_flushes from atomic_t to refcount_t

[Sajal Gupta <sajal2005gupta@gmail.com>]

Hi Dan,

> Have you tested this at all because it doesn't seem at all correct to
> me...

I have only done compile test, sorry, I forgot to mention that.

> How I imagined this would work would be:
> patch 1: add a break statement to fix the use after free
> patch 2: s/atomic_t/recount_t/

> The difference between atomic_t and refcount_t is that refount_t warns
> about overflows and underflows.

I did it like this because that is the pattern mostly used in the codebase.
Simple s/atomic_t/recount_t/ would have
refcount_set(&io->pending_flushes, 0) in init
and then later refcount_set(&io->pending_flushes, raid_disks) in
ppl_do_flush, which is not the usual way. I am treating it as a proper reference
counter rather than a mechanical type swap.

If that is too invasive, I’ll rework it into the break fix first, and do
s/atomic_t/recount_t cleanup separately.

Thanks,
Sajal