Hi, For v1, see: https://lore.kernel.org/linux-fsdevel/20210208221829.17247-1-axboe@xxxxxxxxx/ tldr; don't -EAGAIN IOCB_NOWAIT dio reads just because we have page cache entries for the given range. This causes unnecessary work from the callers side, when the IO could have been issued totally fine without blocking on writeback when there is none. fs/iomap/direct-io.c | 23 ++++++++++++++-------- include/linux/fs.h | 2 ++ mm/filemap.c | 47 ++++++++++++++++++++++++++++++++++++++++++-- 3 files changed, 62 insertions(+), 10 deletions(-) Since v1: - Simplify the filemap_range_needs_writeback() loop (Willy) - Drop the write side (Chinner) -- Jens Axboe
