io_uring: properly mark async work as bounded vs unbounded

mainline inclusion
from mainline-5.5-rc1
commit 5f8fd2d3
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27
CVE: NA
---------------------------

Now that io-wq supports separating the two request lifetime types, mark
the following IO as having unbounded runtimes:

- Any read/write to a non-regular file
- Any specific networked IO
- Any poll command
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NZhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Nyangerkun <yangerkun@huawei.com>
Reviewed-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>

fs/io_uring.c

@@ -505,6 +505,20 @@ static inline bool io_prep_async_work(struct io_kiocb *req)
 		case IORING_OP_WRITEV:
 		case IORING_OP_WRITE_FIXED:
 			do_hashed = true;
+			/* fall-through */
+		case IORING_OP_READV:
+		case IORING_OP_READ_FIXED:
+		case IORING_OP_SENDMSG:
+		case IORING_OP_RECVMSG:
+		case IORING_OP_ACCEPT:
+		case IORING_OP_POLL_ADD:
+			/*
+			 * We know REQ_F_ISREG is not set on some of these
+			 * opcodes, but this enables us to keep the check in
+			 * just one place.
+			 */
+			if (!(req->flags & REQ_F_ISREG))
+				req->work.flags |= IO_WQ_WORK_UNBOUND;
 			break;
 		}
 		if (io_sqe_needs_user(req->submit.sqe))
@@ -3745,7 +3759,7 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
 
 	/* Do QD, or 4 * CPUS, whatever is smallest */
 	concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
-	ctx->io_wq = io_wq_create(concurrency, ctx->sqo_mm, NULL);
+	ctx->io_wq = io_wq_create(concurrency, ctx->sqo_mm, ctx->user);
 	if (IS_ERR(ctx->io_wq)) {
 		ret = PTR_ERR(ctx->io_wq);
 		ctx->io_wq = NULL;