On 2/9/21 12:48 AM, Christoph Hellwig wrote:
> On Mon, Feb 08, 2021 at 07:30:07PM -0700, 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(-)
>>
>> diff --git a/mm/filemap.c b/mm/filemap.c
>> index 6a58d50fbd31..c80acb80e8f7 100644
>> --- a/mm/filemap.c
>> +++ b/mm/filemap.c
>> @@ -2643,8 +2643,8 @@ 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))
>
> Please avoid the overy long line, which is trivial to do by using the
> normal two tab indent for the continuation.
Sure, fixed.
--
Jens Axboe
