> On 2021/01/27 9:36, Changheun Lee wrote:
> >>> +
> >>> /**
> >>> * bio_reset - reinitialize a bio
> >>> * @bio: bio to reset
> >>> @@ -877,7 +892,7 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page,
> >>> struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
> >>>
> >>> if (page_is_mergeable(bv, page, len, off, same_page)) {
> >>> - if (bio->bi_iter.bi_size > UINT_MAX - len) {
> >>> + if (bio->bi_iter.bi_size > bio_max_size(bio) - len) {
> >>> *same_page = false;
> >>> return false;
> >>> }
> >>> diff --git a/include/linux/bio.h b/include/linux/bio.h
> >>> index 1edda614f7ce..cdb134ca7bf5 100644
> >>> --- a/include/linux/bio.h
> >>> +++ b/include/linux/bio.h
> >>> @@ -100,6 +100,8 @@ static inline void *bio_data(struct bio *bio)
> >>> return NULL;
> >>> }
> >>>
> >>> +extern unsigned int bio_max_size(struct bio *);
> >>
> >> No need for extern.
> >
> > It's just for compile warning in my test environment.
> > I'll remove it too. But I think compile warning could be in the other
> > .c file which includes bio.h. Is it OK?
>
> Hmmm... not having extern should not generate a compilation warning. There are
> tons of functions declared without extern in header files in the kernel. What
> compiler are you using ?
>
Compiler imformation is below.
CROSS_COMPILE: android/prebuilts/gcc/linux-x86/aarch64/aarch64-linux-android-4.9/bin/aarch64-linux-android-
CC: android/prebuilts/clang/host/linux-x86/clang-r383902/bin/clang
CLANG_TRIPLE: android/prebuilts/clang/host/linux-x86/clang-r383902/bin/aarch64-linux-gnu-
CROSS_COMPILE_COMPAT: android/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/bin/arm-linux-androideabi-
>
> --
> Damien Le Moal
> Western Digital Research
>
---
Changheun Lee
Samsung Electronics
