io_uring: don't mark S_ISBLK async work as unbounded

stable inclusion
from stable-5.10.31
commit 6fbdce3cde97896ff4c2fb99e5d4bba45297a178
bugzilla: 51792

--------------------------------

[ Upstream commit 4b982bd0 ]

S_ISBLK is marked as unbounded work for async preparation, because it
doesn't match S_ISREG. That is incorrect, as any read/write to a block
device is also a bounded operation. Fix it up and ensure that S_ISBLK
isn't marked unbounded.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/io_uring.c

@@ -1440,7 +1440,7 @@ static void io_prep_async_work(struct io_kiocb *req)
 	if (req->flags & REQ_F_ISREG) {
 		if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
 			io_wq_hash_work(&req->work, file_inode(req->file));
-	} else {
+	} else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) {
 		if (def->unbound_nonreg_file)
 			req->work.flags |= IO_WQ_WORK_UNBOUND;
 	}