From a3f349071eb0ae2aa18ac2da55060865d8190cf0 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Wed, 15 Sep 2021 12:04:20 +0100
Subject: [PATCH] io_uring: remove ctx referencing from complete_post
Git-commit: a3f349071eb0ae2aa18ac2da55060865d8190cf0
Patch-mainline: v5.16-rc1
References: bsc#1205205

Now completions are done from task context, that means that it's either
the task itself, task_work or io-wq worker. In all those cases the ctx
will be staying alive by mutexing, explicit referencing or req references
by iowq. Remove extra ctx pinning from io_req_complete_post().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/60a0e96434c16ab4fe587651448290d61ec9a113.1631703756.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 fs/io_uring.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 323ef0bb4bc1..027ca7a6df44 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1809,17 +1809,11 @@ static void io_req_complete_post(struct io_kiocb *req, long res,
 		io_put_task(req->task, 1);
 		list_add(&req->inflight_entry, &ctx->locked_free_list);
 		ctx->locked_free_nr++;
-	} else {
-		if (!percpu_ref_tryget(&ctx->refs))
-			req = NULL;
+		percpu_ref_put(&ctx->refs);
 	}
 	io_commit_cqring(ctx);
 	spin_unlock(&ctx->completion_lock);
-
-	if (req) {
-		io_cqring_ev_posted(ctx);
-		percpu_ref_put(&ctx->refs);
-	}
+	io_cqring_ev_posted(ctx);
 }
 
 static inline bool io_req_needs_clean(struct io_kiocb *req)
-- 
2.35.3