+ mpage-convert-do_mpage_readpage-to-return-int-type.patch added to mm-new branch

+ mpage-convert-do_mpage_readpage-to-return-int-type.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mpage: convert do_mpage_readpage() to return int type
has been added to the -mm mm-new branch.  Its filename is
     mpage-convert-do_mpage_readpage-to-return-int-type.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mpage-convert-do_mpage_readpage-to-return-int-type.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

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------------------------------------------------------
From: Chi Zhiling <chizhiling@kylinos.cn>
Subject: mpage: convert do_mpage_readpage() to return int type
Date: Tue, 12 Aug 2025 15:22:25 +0800

The return value of do_mpage_readpage() is arg->bio, which is already set
in the arg structure.  Returning it again is redundant.

This patch changes the return type to int and always returns 0 since the
caller does not care about the return value.

Link: https://lkml.kernel.org/r/20250812072225.181798-3-chizhiling@163.com
Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Sungjong Seo <sj1557.seo@samsung.com>
Cc: Yuezhang Mo <Yuezhang.Mo@sony.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/mpage.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/fs/mpage.c~mpage-convert-do_mpage_readpage-to-return-int-type
+++ a/fs/mpage.c
@@ -148,7 +148,7 @@ struct mpage_readpage_args {
  * represent the validity of its disk mapping and to decide when to do the next
  * get_block() call.
  */
-static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
+static int do_mpage_readpage(struct mpage_readpage_args *args)
 {
 	struct folio *folio = args->folio;
 	struct inode *inode = folio->mapping->host;
@@ -297,7 +297,7 @@ alloc_new:
 	else
 		args->last_block_in_bio = first_block + blocks_per_folio - 1;
 out:
-	return args->bio;
+	return 0;
 
 confused:
 	if (args->bio)
@@ -360,7 +360,7 @@ void mpage_readahead(struct readahead_co
 		prefetchw(&folio->flags);
 		args.folio = folio;
 		args.nr_pages = readahead_count(rac);
-		args.bio = do_mpage_readpage(&args);
+		do_mpage_readpage(&args);
 		if (!folio_test_locked(folio) &&
 		    !folio_test_uptodate(folio))
 			break;
@@ -381,7 +381,7 @@ int mpage_read_folio(struct folio *folio
 		.get_block = get_block,
 	};
 
-	args.bio = do_mpage_readpage(&args);
+	do_mpage_readpage(&args);
 	if (args.bio)
 		mpage_bio_submit_read(args.bio);
 	return 0;
_

Patches currently in -mm which might be from chizhiling@kylinos.cn are

mm-filemap-do-not-use-is_partially_uptodate-for-entire-folio.patch
mm-filemap-skip-non-uptodate-folio-if-there-are-available-folios.patch
mpage-terminate-read-ahead-on-read-error.patch
mpage-clean-up-do_mpage_readpage.patch
mpage-convert-do_mpage_readpage-to-return-int-type.patch

Re: + mpage-convert-do_mpage_readpage-to-return-int-type.patch added to mm-new branch

[Matthew Wilcox]

On Sun, Aug 17, 2025 at 07:46:03PM -0700, Andrew Morton wrote:
> From: Chi Zhiling <chizhiling@kylinos.cn>
> Subject: mpage: convert do_mpage_readpage() to return int type
> Date: Tue, 12 Aug 2025 15:22:25 +0800
> 
> The return value of do_mpage_readpage() is arg->bio, which is already set
> in the arg structure.  Returning it again is redundant.
> 
> This patch changes the return type to int and always returns 0 since the
> caller does not care about the return value.

This makes no sense.  If the caller doesn't care, then it should return
void.

Re: + mpage-convert-do_mpage_readpage-to-return-int-type.patch added to mm-new branch

[Chi Zhiling]

On 2025/8/18 11:07, Matthew Wilcox wrote:
> On Sun, Aug 17, 2025 at 07:46:03PM -0700, Andrew Morton wrote:
>> From: Chi Zhiling <chizhiling@kylinos.cn>
>> Subject: mpage: convert do_mpage_readpage() to return int type
>> Date: Tue, 12 Aug 2025 15:22:25 +0800
>>
>> The return value of do_mpage_readpage() is arg->bio, which is already set
>> in the arg structure.  Returning it again is redundant.
>>
>> This patch changes the return type to int and always returns 0 since the
>> caller does not care about the return value.
> 
> This makes no sense.  If the caller doesn't care, then it should return
> void.

Okay, I will change that.


Thanks,
Chi Zhiling