Subject: Re: linux-next: build failure after merge of the folio tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 2 Nov 2021 09:05:07 +1100

Hi all,

On Wed, 22 Sep 2021 14:19:10 +1000 Stephen Rothwell <[email-masked]> wrote:
>
> On Tue, 21 Sep 2021 14:26:28 +1000 Stephen Rothwell <[email-masked]> wrote:
> >
> > After merging the folio tree, today's linux-next build (x86_64
> > allmodconfig) failed like this:
> > 
> > fs/9p/vfs_file.c: In function 'v9fs_vm_page_mkwrite':
> > fs/9p/vfs_file.c:557:6: error: implicit declaration of function 'wait_on_page_bit_killable'; did you mean 'wait_on_page_locked_killable'? [-Werror=implicit-function-declaration]
> >   557 |      wait_on_page_bit_killable(page, PG_writeback) < 0)
> >       |      ^~~~~~~~~~~~~~~~~~~~~~~~~
> >       |      wait_on_page_locked_killable
> > 
> > Caused by commit
> > 
> >   be8f72914261 ("mm/filemap: Add folio_wait_bit()")
> > 
> > interacting with commit
> > 
> >   82766b47b26c ("9p: (untested) Convert to using the netfs helper lib to do reads and caching")
> > 
> > from the fscache tree.
> > 
> > I have applied the following merge fix patch.
> > 
> > From: Stephen Rothwell <[email-masked]>
> > Date: Tue, 21 Sep 2021 14:18:06 +1000
> > Subject: [PATCH] fix up for "9p: (untested) Convert to using the netfs helper
> >  lib to do reads and caching"
> > 
> > Signed-off-by: Stephen Rothwell <[email-masked]>
> > ---
> >  fs/9p/vfs_file.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
> > index 4b617d10cf28..68d05b2aa290 100644
> > --- a/fs/9p/vfs_file.c
> > +++ b/fs/9p/vfs_file.c
> > @@ -554,7 +554,7 @@ v9fs_vm_page_mkwrite(struct vm_fault *vmf)
> >  #endif
> >  
> >  	if (PageWriteback(page) &&
> > -	    wait_on_page_bit_killable(page, PG_writeback) < 0)
> > +	    folio_wait_bit_killable(page_folio(page), PG_writeback) < 0)
> >  		return VM_FAULT_RETRY;
> >  
> >  	/* Update file times before taking page lock */  
> 
> This fix patch now looks like this:
> 
> From: Stephen Rothwell <[email-masked]>
> Date: Wed, 22 Sep 2021 14:16:55 +1000
> Subject: [PATCH] fix up for "9p: Convert to using the netfs helper lib to do reads and caching"
> 
> Signed-off-by: Stephen Rothwell <[email-masked]>
> ---
>  fs/9p/vfs_file.c | 4 ++--
>  1 file changed, 2 insertion(+), 2 deletion(-)
> 
> diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
> index 7ed76a4c18f1..0f99ec49006e 100644
> --- a/fs/9p/vfs_file.c
> +++ b/fs/9p/vfs_file.c
> @@ -549,12 +549,12 @@ v9fs_vm_page_mkwrite(struct vm_fault *vmf)
>  	 */
>  #ifdef CONFIG_9P_FSCACHE
>  	if (PageFsCache(page) &&
> -	    wait_on_page_bit_killable(page, PG_fscache) < 0)
> +	    folio_wait_bit_killable(page_folio(page), PG_fscache) < 0)
>  		return VM_FAULT_RETRY;
>  #endif
>  
>  	if (PageWriteback(page) &&
> -	    wait_on_page_bit_killable(page, PG_writeback) < 0)
> +	    folio_wait_bit_killable(page_folio(page), PG_writeback) < 0)
>  		return VM_FAULT_RETRY;
>  
>  	/* Update file times before taking page lock */

This is now a conflict between Linus' tree and the fscache tree.

-- 
Cheers,
Stephen Rothwell