On 2024/9/19 16:25, alexjlzheng@xxxxxxxxx wrote:
> From: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
>
> The commit 91562895f803 ("ext4: properly sync file size update after O_SYNC
> direct IO") causes confusion about the meaning of the return value of
> ext4_dio_write_end_io().
>
> Specifically, when the ext4_handle_inode_extension() operation succeeds,
> ext4_dio_write_end_io() directly returns count instead of 0.
>
> This does not cause a bug in the current kernel, but the semantics of the
> return value of the ext4_dio_write_end_io() function are wrong, which is
> likely to introduce bugs in the future code evolution.
>
> Signed-off-by: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
Make sense to me,
Reviewed-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
> ---
> Changelog: Just RESEND
>
> v1: https://lore.kernel.org/linux-ext4/20240815112746.18570-1-alexjlzheng@xxxxxxxxxxx/
> ---
> fs/ext4/file.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index c89e434db6b7..6df5a92cec2b 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -392,8 +392,9 @@ static int ext4_dio_write_end_io(struct kiocb *iocb, ssize_t size,
> */
> if (pos + size <= READ_ONCE(EXT4_I(inode)->i_disksize) &&
> pos + size <= i_size_read(inode))
> - return size;
> - return ext4_handle_inode_extension(inode, pos, size);
> + return 0;
> + error = ext4_handle_inode_extension(inode, pos, size);
> + return error < 0 ? error : 0;
> }
>
> static const struct iomap_dio_ops ext4_dio_write_ops = {
