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

From: Stephen Rothwell <[email-masked]>
Date: Wed, 22 Sep 2021 14:19:10 +1000

Hi all,

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 */

-- 
Cheers,
Stephen Rothwell