[PATCH] fscrypt,f2fs: introduce fscrypt_finalize_bounce_folio() for cleanup

[PATCH] fscrypt,f2fs: introduce fscrypt_finalize_bounce_folio() for cleanup

[Chao Yu]

As part of the linux kernel's migration to folio-based APIs, introduce
fscrypt_finalize_bounce_folio() as the folio equivalent of
fscrypt_finalize_bounce_page(), and clean up f2fs codes with this new
helper.

Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Chao Yu <chao@kernel.org>
---

Is it worth to introduce fscrypt_finalize_bounce_folio(), then try to
do clean in f2fs_write_end_bio() first, and then replace
fscrypt_finalize_bounce_page() later?

 fs/f2fs/data.c          |  7 +------
 include/linux/fscrypt.h | 11 +++++++++++
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index ac1cf4de3d62..e0fca6c60e34 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -362,12 +362,7 @@ static void f2fs_write_end_bio(struct bio *bio)
 		struct folio *folio = fi.folio;
 		enum count_type type;
 
-		if (fscrypt_is_bounce_folio(folio)) {
-			struct folio *io_folio = folio;
-
-			folio = fscrypt_pagecache_folio(io_folio);
-			fscrypt_free_bounce_page(&io_folio->page);
-		}
+		fscrypt_finalize_bounce_folio(&folio);
 
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 		if (f2fs_is_compressed_page(folio)) {
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 54712ec61ffb..20b59b021c94 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -1132,4 +1132,15 @@ static inline void fscrypt_finalize_bounce_page(struct page **pagep)
 	}
 }
 
+/* If *foliop is a bounce folio, free it and set *foliop to the pagecache folio */
+static inline void fscrypt_finalize_bounce_folio(struct folio **foliop)
+{
+	struct folio *folio = *foliop;
+
+	if (fscrypt_is_bounce_folio(folio)) {
+		*foliop = fscrypt_pagecache_folio(folio);
+		fscrypt_free_bounce_page(&folio->page);
+	}
+}
+
 #endif	/* _LINUX_FSCRYPT_H */
-- 
2.49.0

Re: [PATCH] fscrypt,f2fs: introduce fscrypt_finalize_bounce_folio() for cleanup

[Eric Biggers]

On Mon, Jun 22, 2026 at 01:15:39AM +0000, Chao Yu wrote:
> As part of the linux kernel's migration to folio-based APIs, introduce
> fscrypt_finalize_bounce_folio() as the folio equivalent of
> fscrypt_finalize_bounce_page(), and clean up f2fs codes with this new
> helper.
> 
> Suggested-by: Matthew Wilcox <willy@infradead.org>
> Cc: Eric Biggers <ebiggers@kernel.org>
> Signed-off-by: Chao Yu <chao@kernel.org>
> ---
> 
> Is it worth to introduce fscrypt_finalize_bounce_folio(), then try to
> do clean in f2fs_write_end_bio() first, and then replace
> fscrypt_finalize_bounce_page() later?

I'm working on making ext4 and f2fs always do file contents
en/decryption using fscrypt_set_bio_crypt_ctx(), which already supports
large folios and doesn't require the filesystem to manage bounce
buffers.  I don't think these minor tweaks to the other implementation
(which don't actually make it support large folios) accomplish anything
useful, and we should focus on removing it instead.

- Eric