From 7a60d6d7b34ebf9290d495e8bb4cd57c784ffb22 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 29 Apr 2021 22:55:21 -0700 Subject: [PATCH] mm: use filemap_range_needs_writeback() for O_DIRECT reads 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). Link: https://lkml.kernel.org/r/20210224164455.1096727-3-axboe@kernel.dk Signed-off-by: Jens Axboe Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/filemap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 1750742..16aea94 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2681,8 +2681,8 @@ 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, -- 2.7.4