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Date:   Tue, 15 Sep 2020 13:38:09 -0400 (EDT)
From:   Mikulas Patocka <mpatocka@redhat.com>
To:     Dan Williams <dan.j.williams@intel.com>
cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
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Subject: Re: [RFC] nvfs: a filesystem for persistent memory
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On Tue, 15 Sep 2020, Mikulas Patocka wrote:

> > > - __copy_from_user_inatomic_nocache doesn't flush cache for leading and
> > > trailing bytes.
> > 
> > You want copy_user_flushcache(). See how fs/dax.c arranges for
> > dax_copy_from_iter() to route to pmem_copy_from_iter().
> 
> Is it something new for the kernel 5.10? I see only __copy_user_flushcache 
> that is implemented just for x86 and arm64.
> 
> There is __copy_from_user_flushcache implemented for x86, arm64 and power. 
> It is used in lib/iov_iter.c under
> #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE - so should I use this?
> 
> Mikulas

... and __copy_user_flushcache is not exported for modules. So, I am stuck 
with __copy_from_user_inatomic_nocache.

Mikulas