From: Pavel Begunkov <asml.silence@gmail.com>
Date: Sun, 22 Mar 2020 16:14:26 +0000 (+0300)
Subject: io-wq: close cancel gap for hashed linked work
X-Git-Tag: v5.7-rc1~201^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f2cf11492b8b30d89b2fbf525c9ea5e8c4ccc842;p=thirdparty%2Flinux.git

io-wq: close cancel gap for hashed linked work

After io_assign_current_work() of a linked work, it can be decided to
offloaded to another thread so doing io_wqe_enqueue(). However, until
next io_assign_current_work() it can be cancelled, that isn't handled.

Don't assign it, if it's not going to be executed.

Fixes: 60cf46ae6054 ("io-wq: hash dependent work")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 9541df2729de0..b3fb61ec08708 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -485,7 +485,7 @@ static void io_worker_handle_work(struct io_worker *worker)
 	struct io_wq *wq = wqe->wq;
 
 	do {
-		struct io_wq_work *work;
+		struct io_wq_work *work, *assign_work;
 		unsigned int hash;
 get_next:
 		/*
@@ -522,10 +522,14 @@ get_next:
 			hash = io_get_work_hash(work);
 			work->func(&work);
 			work = (old_work == work) ? NULL : work;
-			io_assign_current_work(worker, work);
+
+			assign_work = work;
+			if (work && io_wq_is_hashed(work))
+				assign_work = NULL;
+			io_assign_current_work(worker, assign_work);
 			wq->free_work(old_work);
 
-			if (work && io_wq_is_hashed(work)) {
+			if (work && !assign_work) {
 				io_wqe_enqueue(wqe, work);
 				work = NULL;
 			}