[PATCH 2/3] io_uring: cleanup iowq cancellation files matching

[Pavel Begunkov <asml.silence@gmail.com>]

Clean up io_cancel_task_cb() and related io-wq cancellation after
renouncing from files cancellations. No need to drag files anymore, just
pass task directly.

io_match_task() guarantees to not walk through linked request when
files==NULL, so we can also get rid of ugly conditional synchronisation
there.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 24 +++---------------------
 1 file changed, 3 insertions(+), 21 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0c886ef49920..8d181ef44398 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8850,29 +8850,12 @@ static int io_uring_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-struct io_task_cancel {
-	struct task_struct *task;
-	struct files_struct *files;
-};
-
 static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
 {
 	struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-	struct io_task_cancel *cancel = data;
-	bool ret;
-
-	if (cancel->files && (req->flags & REQ_F_LINK_TIMEOUT)) {
-		unsigned long flags;
-		struct io_ring_ctx *ctx = req->ctx;
+	struct task_struct *tsk = data;
 
-		/* protect against races with linked timeouts */
-		spin_lock_irqsave(&ctx->completion_lock, flags);
-		ret = io_match_task(req, cancel->task, cancel->files);
-		spin_unlock_irqrestore(&ctx->completion_lock, flags);
-	} else {
-		ret = io_match_task(req, cancel->task, cancel->files);
-	}
-	return ret;
+	return io_match_task(req, tsk, NULL);
 }
 
 static void io_cancel_defer_files(struct io_ring_ctx *ctx,
@@ -8905,13 +8888,12 @@ static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
 					    struct task_struct *task)
 {
 	while (1) {
-		struct io_task_cancel cancel = { .task = task, .files = NULL, };
 		enum io_wq_cancel cret;
 		bool ret = false;
 
 		if (ctx->io_wq) {
 			cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb,
-					       &cancel, true);
+					       task, true);
 			ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
 		}
 
-- 
2.24.0