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@xxxxxxx> > Cc: Jeff Moyer <jmoyer@xxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> > Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@xxxxxxx> 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@xxxxxxxx> SUSE Labs, CR
