On Tue 15-03-22 20:40:07, Stephen Rothwell wrote:
> Hi all,
>
> Today's linux-next merge of the folio tree got a conflict in:
>
> fs/ext4/inode.c
>
> between commit:
>
> 2bb8dd401a4f ("ext4: warn when dirtying page w/o buffers in data=journal mode")
>
> from the ext4 tree and commit:
>
> 821405cf3ebb ("fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio")
>
> from the folio tree.
>
> I didn't know how to complete this fix up ans so just commented out the
> new WARN_ON().
Thanks for the notice Stephen! The resolution should be like:
- WARN_ON_ONCE(!page_has_buffers(page));
+ WARN_ON_ONCE(!folio_buffers(folio));
How are we going to handle this conflict Ted? Just tell Linus about the
conflict and resolution?
Honza
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging. You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
>
> --
> Cheers,
> Stephen Rothwell
>
> diff --cc fs/ext4/inode.c
> index 3d0ca48d20c8,436efd31cc27..000000000000
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@@ -3573,31 -3541,30 +3573,32 @@@ const struct iomap_ops ext4_iomap_repor
> };
>
> /*
> - * Whenever the page is being dirtied, corresponding buffers should already be
> - * Folios can be marked dirty completely asynchronously from ext4's
> - * journalling activity. By filemap_sync_pte(), try_to_unmap_one(), etc.
> - * We cannot do much here because ->dirty_folio may be called with the
> - * page table lock held. The folio is not necessarily locked.
> ++ * Whenever the folio is being dirtied, corresponding buffers should already be
> + * attached to the transaction (we take care of this in ext4_page_mkwrite() and
> + * ext4_write_begin()). However we cannot move buffers to dirty transaction
> - * lists here because ->set_page_dirty is called under VFS locks and the page
> ++ * lists here because ->dirty_folio is called under VFS locks and the folio
> + * is not necessarily locked.
> *
> - * We cannot just dirty the page and leave attached buffers clean, because the
> + * We cannot just dirty the folio and leave attached buffers clean, because the
> * buffers' dirty state is "definitive". We cannot just set the buffers dirty
> * or jbddirty because all the journalling code will explode.
> *
> - * So what we do is to mark the page "pending dirty" and next time writepage
> + * So what we do is to mark the folio "pending dirty" and next time writepage
> * is called, propagate that into the buffers appropriately.
> */
> - static int ext4_journalled_set_page_dirty(struct page *page)
> + static bool ext4_journalled_dirty_folio(struct address_space *mapping,
> + struct folio *folio)
> {
> - WARN_ON_ONCE(!page_has_buffers(page));
> - SetPageChecked(page);
> - return __set_page_dirty_nobuffers(page);
> ++/* WARN_ON_ONCE(!page_has_buffers(page)); */
> + folio_set_checked(folio);
> + return filemap_dirty_folio(mapping, folio);
> }
>
> - static int ext4_set_page_dirty(struct page *page)
> + static bool ext4_dirty_folio(struct address_space *mapping, struct folio *folio)
> {
> - WARN_ON_ONCE(!PageLocked(page) && !PageDirty(page));
> - WARN_ON_ONCE(!page_has_buffers(page));
> - return __set_page_dirty_buffers(page);
> + WARN_ON_ONCE(!folio_test_locked(folio) && !folio_test_dirty(folio));
> + WARN_ON_ONCE(!folio_buffers(folio));
> + return block_dirty_folio(mapping, folio);
> }
>
> static int ext4_iomap_swap_activate(struct swap_info_struct *sis,
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
