diff options
author | Pavel Begunkov <asml.silence@gmail.com> | 2024-04-05 16:50:03 +0100 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2024-04-15 08:10:26 -0600 |
commit | de96e9ae69a134c009a6d9a7ca182fa67067ecac (patch) | |
tree | 54313a2b311bddaea262206a63408e309c65349c | |
parent | f39130004d3a9155d113284c19b5a7c2eccb43fe (diff) |
io_uring: turn implicit assumptions into a warning
io_req_complete_post() is now io-wq only and shouldn't be used outside
of it, i.e. it relies that io-wq holds a ref for the request as
explained in a comment below. Let's add a warning to enforce the
assumption and make sure nobody would try to do anything weird.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1013b60c35d431d0698cafbc53c06f5917348c20.1712331455.git.asml.silence@gmail.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r-- | io_uring/io_uring.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 8bd5db2056ee..8078d6944411 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -930,6 +930,13 @@ static void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags) struct io_ring_ctx *ctx = req->ctx; /* + * All execution paths but io-wq use the deferred completions by + * passing IO_URING_F_COMPLETE_DEFER and thus should not end up here. + */ + if (WARN_ON_ONCE(!(issue_flags & IO_URING_F_IOWQ))) + return; + + /* * Handle special CQ sync cases via task_work. DEFER_TASKRUN requires * the submitter task context, IOPOLL protects with uring_lock. */ @@ -946,7 +953,10 @@ static void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags) } io_cq_unlock_post(ctx); - /* called from io-wq submit work only, the ref won't drop to zero */ + /* + * We don't free the request here because we know it's called from + * io-wq only, which holds a reference, so it cannot be the last put. + */ req_ref_put(req); } |