From 63bf975936c02ff7010513305068008d835686c1 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 21 Jan 2023 10:39:22 -0700 Subject: [PATCH] UPSTREAM: io_uring: allow re-poll if we made progress commit 10c873334febaeea9aa0c25c10b5ac0951b77a5f upstream. We currently check REQ_F_POLLED before arming async poll for a notification to retry. If it's set, then we don't allow poll and will punt to io-wq instead. This is done to prevent a situation where a buggy driver will repeatedly return that there's space/data available yet we get -EAGAIN. However, if we already transferred data, then it should be safe to rely on poll again. Gate the check on whether or not REQ_F_PARTIAL_IO is also set. Change-Id: I36b6d16ac43202fdf9ae5eea64f9dfbcfbe7fee5 Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Bug: 268174392 (cherry picked from commit 4bc17e6381bdbe7373ffccbda94db56631061a4a) Signed-off-by: Greg Kroah-Hartman --- io_uring/io_uring.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index ec8f05f27260..91a177a2e7da 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -5704,7 +5704,7 @@ static int io_arm_poll_handler(struct io_kiocb *req) if (!req->file || !file_can_poll(req->file)) return IO_APOLL_ABORTED; - if (req->flags & REQ_F_POLLED) + if ((req->flags & (REQ_F_POLLED|REQ_F_PARTIAL_IO)) == REQ_F_POLLED) return IO_APOLL_ABORTED; if (!def->pollin && !def->pollout) return IO_APOLL_ABORTED; @@ -5720,7 +5720,10 @@ static int io_arm_poll_handler(struct io_kiocb *req) mask |= POLLOUT | POLLWRNORM; } - apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC); + if (req->flags & REQ_F_POLLED) + apoll = req->apoll; + else + apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC); if (unlikely(!apoll)) return IO_APOLL_ABORTED; apoll->double_poll = NULL;