Commit 02a13674 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: account io_uring internal files as REQ_F_INFLIGHT 



We need to actively cancel anything that introduces a potential circular
loop, where io_uring holds a reference to itself. If the file in question
is an io_uring file, then add the request to the inflight list.

Cc: stable@vger.kernel.org # 5.9+
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9d5c8190

fs/io_uring.c

+26 −10
Original line number Diff line number Diff line
@@ -1075,8 +1075,11 @@ static bool io_match_task(struct io_kiocb *head, 
		return true;



	io_for_each_link(req, head) {

		if ((req->flags & REQ_F_WORK_INITIALIZED) &&

		    (req->work.flags & IO_WQ_WORK_FILES) &&

		if (!(req->flags & REQ_F_WORK_INITIALIZED))

			continue;

		if (req->file && req->file->f_op == &io_uring_fops)

			return true;

		if ((req->work.flags & IO_WQ_WORK_FILES) &&

		    req->work.identity->files == files)

			return true;

	}
@@ -1505,11 +1508,14 @@ static bool io_grab_identity(struct io_kiocb *req) 
			return false;

		atomic_inc(&id->files->count);

		get_nsproxy(id->nsproxy);



		if (!(req->flags & REQ_F_INFLIGHT)) {

			req->flags |= REQ_F_INFLIGHT;



			spin_lock_irq(&ctx->inflight_lock);

			list_add(&req->inflight_entry, &ctx->inflight_list);

			spin_unlock_irq(&ctx->inflight_lock);

		}

		req->work.flags |= IO_WQ_WORK_FILES;

	}

	if (!(req->work.flags & IO_WQ_WORK_MM) &&
@@ -6164,8 +6170,10 @@ static void io_req_drop_files(struct io_kiocb *req) 
	struct io_uring_task *tctx = req->task->io_uring;

	unsigned long flags;



	if (req->work.flags & IO_WQ_WORK_FILES) {

		put_files_struct(req->work.identity->files);

		put_nsproxy(req->work.identity->nsproxy);

	}

	spin_lock_irqsave(&ctx->inflight_lock, flags);

	list_del(&req->inflight_entry);

	spin_unlock_irqrestore(&ctx->inflight_lock, flags);
@@ -6450,6 +6458,15 @@ static struct file *io_file_get(struct io_submit_state *state, 
		file = __io_file_get(state, fd);

	}



	if (file && file->f_op == &io_uring_fops) {

		io_req_init_async(req);

		req->flags |= REQ_F_INFLIGHT;



		spin_lock_irq(&ctx->inflight_lock);

		list_add(&req->inflight_entry, &ctx->inflight_list);

		spin_unlock_irq(&ctx->inflight_lock);

	}



	return file;

}
@@ -8860,8 +8877,7 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, 


		spin_lock_irq(&ctx->inflight_lock);

		list_for_each_entry(req, &ctx->inflight_list, inflight_entry) {

			if (req->task != task ||

			    req->work.identity->files != files)

			if (!io_match_task(req, task, files))

				continue;

			found = true;

			break;