We punt close to async for the final fput(), but we log the completion
even before that even in that case. We rely on the request not having
a files table assigned to detect what the final async close should do.
However, if we punt the async queue to __io_queue_sqe(), we'll get
->files assigned and this makes io_close_finish() think it should both
close the filp again (which does no harm) AND log a new CQE event for
this request. This causes duplicate CQEs.
Queue the request up for async manually so we don't grab files
needlessly and trigger this condition.
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
diff --git a/fs/io_uring.c b/fs/io_uring.c
index cb3c0a803b46..fb5c5b3e23f4 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2841,16 +2841,13 @@ static void io_close_finish(struct io_wq_work **workptr)
int ret;
ret = filp_close(req->close.put_file, req->work.files);
- if (ret < 0) {
+ if (ret < 0)
req_set_fail_links(req);
- }
io_cqring_add_event(req, ret);
}
fput(req->close.put_file);
- /* we bypassed the re-issue, drop the submission reference */
- io_put_req(req);
io_put_req_find_next(req, &nxt);
if (nxt)
io_wq_assign_next(workptr, nxt);
@@ -2892,7 +2889,13 @@ static int io_close(struct io_kiocb *req, struct io_kiocb **nxt,
eagain:
req->work.func = io_close_finish;
- return -EAGAIN;
+ /*
+ * Do manual async queue here to avoid grabbing files - we don't
+ * need the files, and it'll cause io_close_finish() to close
+ * the file again and cause a double CQE entry for this request
+ */
+ io_queue_async_work(req);
+ return 0;
}
static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--
Jens Axboe
