The patch titled
Subject: mm: use filemap_range_needs_writeback() for O_DIRECT reads
has been added to the -mm tree. Its filename is
mm-use-filemap_range_needs_writeback-for-o_direct-reads.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-use-filemap_range_needs_writeback-for-o_direct-reads.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-use-filemap_range_needs_writeback-for-o_direct-reads.patch
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------------------------------------------------------
From: Jens Axboe <axboe@xxxxxxxxx>
Subject: 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@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/filemap.c~mm-use-filemap_range_needs_writeback-for-o_direct-reads
+++ a/mm/filemap.c
@@ -2614,8 +2614,8 @@ generic_file_read_iter(struct kiocb *ioc
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,
_
Patches currently in -mm which might be from axboe@xxxxxxxxx are
swap-fix-swapfile-read-write-offset.patch
mm-provide-filemap_range_needs_writeback-helper.patch
mm-use-filemap_range_needs_writeback-for-o_direct-reads.patch
iomap-use-filemap_range_needs_writeback-for-o_direct-reads.patch
