On Wed, Jun 12, 2024 at 08:41:01AM +0700, Shaun Tancheff wrote: > On 6/11/24 23:13, Christoph Hellwig wrote: > >> On Tue, Jun 11, 2024 at 05:47:12PM +0700, Shaun Tancheff wrote: >>>> const struct address_space_operations *a_ops = mapping->a_ops; >>>> + size_t chunk = mapping_max_folio_size(mapping); >>> Better to default chunk to PAGE_SIZE for backward compat >>> + size_t chunk = PAGE_SIZE; >>> >>>> long status = 0; >>>> ssize_t written = 0; >>>> >>> Have fs opt in to large folio support: >>> >>> + if (mapping_large_folio_support(mapping)) >>> + chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER; >> I don't think you've actually read the code, have you? > > I checked from 6.6 to linux-next with this patch and my ext4 VM does not boot without the opt-in. Please take a look at the definition of mapping_max_folio_size, which is called above in the quoted patch.
