On Fri, Jan 26, 2024 at 03:49:30PM +0000, Matthew Wilcox wrote: > This doesn't quite make sense to me. Do you mean: > > * If the caller modifies data in the folio, it must call folio_mark_dirty() > * before unlocking the folio to ensure that the folio is not reclaimed. > * There is no equivalent to write_begin/write_end for shmem. > > (also this should go before the Return: section; the return section > should be the last thing in the kernel-doc) So the first sentence and moving the section makes total sense. The second sentence I don't think is very useful. write_begin/write_end are relaly just a way for generic_perform_write to do the space reservation and extending i_size and not really methods in the classic sense. They should go away from a_ops and certainly don't end up being mentioned in shmem.c. What I have now is this: If the caller modifies data in the folio, it must call folio_mark_dirty() before unlocking the folio to ensure that the folio is not reclaimed. These is no need to reserve space before calling folio_mark_dirty(). but I'm open to further improvements.
