[PATCHSET v2 0/3] Improve IOCB_NOWAIT O_DIRECT reads

Hi,

For v1, see:

https://lore.kernel.org/linux-fsdevel/20210208221829.17247-1-axboe@kernel.dk/ (local)

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