[PATCHSET,0/2] Multishot read tweaks

Message

Jens Axboe April 1, 2024, 5:49 p.m. UTC

Hi,

We can't properly support multishot reads unless one of the following
conditions are true:

1) The file supports proper FMODE_NOWAIT
2) Barring proper FMODE_NOWAIT support, the file must be opened in
   non-blocking O_NONBLOCK mode

Without either one of those, non-blocking retries cannot be attempted.
And without that, it's pointless to support multishot reads.

If this is attempted, fall back to singleshot mode. This will properly
do the initial CQE posting, but will not set IORING_CQE_F_MORE as we
can't reliably perform the retries that multishot requires.

 io_uring/io_uring.c | 13 +++++++++----
 io_uring/rw.c       |  9 ++++++++-
 2 files changed, 17 insertions(+), 5 deletions(-)