FAILED: patch "[PATCH] io_uring: fix tw losing poll events" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Possible dependencies:

539bcb57da2f ("io_uring: fix tw losing poll events")
329061d3e2f9 ("io_uring: move poll handling into its own file") cfd22e6b3319 ("io_uring: add opcode name to io_op_defs") c9f06aa7de15 ("io_uring: move io_uring_task (tctx) helpers into its own file") a4ad4f748ea9 ("io_uring: move fdinfo helpers to its own file") e5550a1447bf ("io_uring: use io_is_uring_fops() consistently") 17437f311490 ("io_uring: move SQPOLL related handling into its own file") 59915143e89f ("io_uring: move timeout opcodes and handling into its own file") e418bbc97bff ("io_uring: move our reference counting into a header") 36404b09aa60 ("io_uring: move msg_ring into its own file") f9ead18c1058 ("io_uring: split network related opcodes into its own file") e0da14def1ee ("io_uring: move statx handling to its own file") a9c210cebe13 ("io_uring: move epoll handler to its own file") 4cf90495281b ("io_uring: add a dummy -EOPNOTSUPP prep handler") 99f15d8d6136 ("io_uring: move uring_cmd handling to its own file") cd40cae29ef8 ("io_uring: split out open/close operations") 453b329be5ea ("io_uring: separate out file table handling code") f4c163dd7d4b ("io_uring: split out fadvise/madvise operations") 0d5847274037 ("io_uring: split out fs related sync/fallocate functions") 531113bbd5bf ("io_uring: split out splice related operations")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 539bcb57da2f58886d7d5c17134236b0ec9cd15d Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <[email protected]>
Date: Thu, 17 Nov 2022 18:40:15 +0000
Subject: [PATCH] io_uring: fix tw losing poll events

We may never try to process a poll wake and its mask if there was multiple wake ups racing for queueing up a tw. Force io_poll_check_events() to update the mask by vfs_poll().

index 90920abf91ff..c34019b18211 100644
@@ -228,6 +228,13 @@ static int io_poll_check_events(struct io_kiocb *req, bool *locked)
 			return IOU_POLL_DONE;
 		if (v & IO_POLL_CANCEL_FLAG)
 			return -ECANCELED;
+		/*
+		 * cqe.res contains only events of the first wake up
+		 * and all others are be lost. Redo vfs_poll() to get
+		 * up to date state.
+		 */
+		if ((v & IO_POLL_REF_MASK) != 1)
+			req->cqe.res = 0;
 
 		/* the mask was stashed in __io_poll_execute */
 		if (!req->cqe.res) {