Re: [PATCH 1/4] fs, afs: convert afs_cell.usage from atomic_t to refcount_t
From: David Howells
Date: Wed Feb 22 2017 - 11:16:14 EST
Elena Reshetova <elena.reshetova@xxxxxxxxx> wrote:
> refcount_t type and corresponding API should be
> used instead of atomic_t when the variable is used as
> a reference counter. This allows to avoid accidental
> refcounter overflows that might lead to use-after-free
This causes an assertion failure because cells aren't immediately destroyed
when their refcount reaches 0, but may be resurrected provided the cache lock
is held. However, attempting to increment the 0 refcount does nothing, not
even giving a warning.
So please place a hold on this patch. I will check the other AFS patches also.