Date: Wed, 14 Jun 2017 12:56:35 +0200
From: Jan Kara <jack@suse.cz>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-nvdimm@lists.01.org, Jan Kara <jack@suse.cz>,
        dm-devel@redhat.com, Matthew Wilcox <mawilcox@microsoft.com>,
        x86@kernel.org, linux-kernel@vger.kernel.org,
        Jeff Moyer <jmoyer@redhat.com>, viro@zeniv.linux.org.uk,
        linux-fsdevel@vger.kernel.org,
        Ross Zwisler <ross.zwisler@linux.intel.com>, hch@lst.de
Subject: Re: [PATCH v3 06/14] filesystem-dax: convert to dax_flush()
Message-ID: <20170614105635.GF21506@quack2.suse.cz>
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On Fri 09-06-17 13:24:18, Dan Williams wrote:
> Filesystem-DAX flushes caches whenever it writes to the address returned
> through dax_direct_access() and when writing back dirty radix entries.
> That flushing is only required in the pmem case, so the dax_flush()
> helper skips cache management work when the underlying driver does not
> specify a flush method.
> 
> We still do all the dirty tracking since the radix entry will already be
> there for locking purposes. However, the work to clean the entry will be
> a nop for some dax drivers.
> 
> Cc: Jan Kara <jack@suse.cz>
> Cc: Jeff Moyer <jmoyer@redhat.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Matthew Wilcox <mawilcox@microsoft.com>
> Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/dax.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index b459948de427..0933fc460ada 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -784,7 +784,7 @@ static int dax_writeback_one(struct block_device *bdev,
>  	}
>  
>  	dax_mapping_entry_mkclean(mapping, index, pfn_t_to_pfn(pfn));
> -	wb_cache_pmem(kaddr, size);
> +	dax_flush(dax_dev, pgoff, kaddr, size);
>  	/*
>  	 * After we have flushed the cache, we can clear the dirty tag. There
>  	 * cannot be new dirty data in the pfn after the flush has completed as
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR