Re: [PATCH v2 6.6] io_uring/rw: ensure reissue path is correctly handled for IOPOLL

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: bcb0fda3c2da9fe4721d3e73d80e778c038e7d27

WARNING: Author mismatch between patch and upstream commit:
Backport author: Sumanth Gavini <sumanth.gavini@yahoo.com>
Commit author: Jens Axboe <axboe@kernel.dk>

Status in newer kernel trees:
6.15.y | Present (exact SHA1)
6.12.y | Not found

Note: The patch differs from the upstream commit:
---
1:  bcb0fda3c2da ! 1:  941165821178 io_uring/rw: ensure reissue path is correctly handled for IOPOLL
    @@
      ## Metadata ##
    -Author: Jens Axboe <axboe@kernel.dk>
    +Author: Sumanth Gavini <sumanth.gavini@yahoo.com>
     
      ## Commit message ##
         io_uring/rw: ensure reissue path is correctly handled for IOPOLL
     
    +    commit bcb0fda3c2da9fe4721d3e73d80e778c038e7d27 upstream.
    +
         The IOPOLL path posts CQEs when the io_kiocb is marked as completed,
         so it cannot rely on the usual retry that non-IOPOLL requests do for
         read/write requests.
    @@ Commit message
         Reported-by: John Garry <john.g.garry@oracle.com>
         Link: https://lore.kernel.org/io-uring/2b43ccfa-644d-4a09-8f8f-39ad71810f41@oracle.com/
         Signed-off-by: Jens Axboe <axboe@kernel.dk>
    +    Signed-off-by: Sumanth Gavini <sumanth.gavini@yahoo.com>
     
      ## io_uring/rw.c ##
     @@ io_uring/rw.c: static void io_complete_rw_iopoll(struct kiocb *kiocb, long res)
    @@ io_uring/rw.c: static void io_complete_rw_iopoll(struct kiocb *kiocb, long res)
      	if (unlikely(res != req->cqe.res)) {
     -		if (res == -EAGAIN && io_rw_should_reissue(req)) {
     +		if (res == -EAGAIN && io_rw_should_reissue(req))
    - 			req->flags |= REQ_F_REISSUE | REQ_F_BL_NO_RECYCLE;
    + 			req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO;
     -			return;
     -		}
     -		req->cqe.res = res;

---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| origin/linux-6.6.y        | Success     | Success    |