Commit 6318770a authored May 29, 2017 by Dan Williams

filesystem-dax: convert to dax_flush()



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: 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>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

parent abebfbe2

fs/dax.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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

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