Re: [f2fs-dev] [PATCH v3] f2fs: do not support mmap write for large folio

Chao Yu via Linux-f2fs-devel
2026-04-13T11:28:11Z

On 4/9/2026 2:13 AM, Jaegeuk Kim via Linux-f2fs-devel wrote:
> Let's check mmap writes onto the large folio, since we don't support writing
> large folios.
>
> Reviewed-by: Daeho Jeong <daehojeong@google.com>
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
>
> - log v2:
> : add comments
>
> fs/f2fs/file.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 2c4880f24b54..c0220cd7b332 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -82,7 +82,12 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
> int err = 0;
> vm_fault_t ret;
>
> - if (unlikely(IS_IMMUTABLE(inode)))
> + /*
> + * We only support large folio on the read case.
> + * Don't make any dirty pages.
> + */
> + if (unlikely(IS_IMMUTABLE(inode)) ||
> + mapping_large_folio_support(inode->i_mapping))
> return VM_FAULT_SIGBUS;

The code itself looks good, since it's an impossible case, should we
use f2fs_bug_on(, mapping_large_folio_support()) to catch any bug case
rather than just returning error here w/o log?

Thanks,

>
> if (is_inode_flag_set(inode, FI_COMPRESS_RELEASED)) {