On Wed 24-02-21 09:44:54, Jens Axboe wrote:
> For the generic page cache read helper, use the better variant of checking
> for the need to call filemap_write_and_wait_range() when doing O_DIRECT
> reads. This avoids falling back to the slow path for IOCB_NOWAIT, if there
> are no pages to wait for (or write out).
>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> ---
> mm/filemap.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
Looks good to me. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
>
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 13338f877677..77f1b527541e 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -2645,8 +2645,8 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
>
> size = i_size_read(inode);
> if (iocb->ki_flags & IOCB_NOWAIT) {
> - if (filemap_range_has_page(mapping, iocb->ki_pos,
> - iocb->ki_pos + count - 1))
> + if (filemap_range_needs_writeback(mapping, iocb->ki_pos,
> + iocb->ki_pos + count - 1))
> return -EAGAIN;
> } else {
> retval = filemap_write_and_wait_range(mapping,
> --
> 2.30.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
