Re: [PATCH 0/20 v3] dax: Clear dirty bits after flushing caches

On Fri 30-09-16 02:14:18, Christoph Hellwig wrote:

On Tue, Sep 27, 2016 at 06:08:04PM +0200, Jan Kara wrote:

quoted

Hello,

this is a third revision of my patches to clear dirty bits from radix tree of
DAX inodes when caches for corresponding pfns have been flushed. This patch set
is significantly larger than the previous version because I'm changing how
->fault, ->page_mkwrite, and ->pfn_mkwrite handlers may choose to handle the
fault

Btw, is there ny good reason to keep ->fault, ->pmd_fault, page->mkwrite
and pfn_mkwrite separate these days?  All of them now take a struct
vm_fault, and the differences aren't exactly obvious for callers and
users.

IMO ->fault and ->pmd_fault can be merged, ->page_mkwrite and ->pfn_mkwrite
can be merged. There were even patches flying around for that. I want to do
that but it's not a priority now as the patch set it already large enough.

I'm not sure whether merging ->fault and ->page_mkwrite would be really
helpful and it would certainly require some non-trivial changes in the
fault path. For example currently a write fault of a file mapping will
result in first ->fault being called which handles the read part of the
fault and then ->page_mkwrite is called to handle write-enabling of the
PTE. When the handlers would be merged, calling one handler twice would be
really strange.

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR

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