On Wed 21-03-18 15:57:37, Dan Williams wrote: > In preparation for the dax implementation to start associating dax pages > to inodes via page->mapping, we need to provide a 'struct > address_space_operations' instance for dax. Otherwise, direct-I/O > triggers incorrect page cache assumptions and warnings. > > Cc: "Theodore Ts'o" <tytso@xxxxxxx> > Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx> > Cc: linux-ext4@xxxxxxxxxxxxxxx > Cc: Jan Kara <jack@xxxxxxx> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Looks good, just one nit below. > @@ -3946,6 +3961,13 @@ static const struct address_space_operations ext4_da_aops = { > .error_remove_page = generic_error_remove_page, > }; > > +static const struct address_space_operations ext4_dax_aops = { > + .direct_IO = ext4_direct_IO, So ext4_direct_IO() for IS_DAX() files will just bail out. So could you just provide ext4_dax_direct_IO() which will bail out and use it here? With a similar comment as in xfs_vm_direct_IO() that open still needs this method set... Thanks! Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR