This is a note to let you know that I've just added the patch titled io_uring: don't mark S_ISBLK async work as unbounded to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-don-t-mark-s_isblk-async-work-as-unbounded.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 84a1b3ba9db39e2603176b4fd2be63ae6c222d74 Author: Jens Axboe <axboe@xxxxxxxxx> Date: Thu Apr 1 08:38:34 2021 -0600 io_uring: don't mark S_ISBLK async work as unbounded [ Upstream commit 4b982bd0f383db9132e892c0c5144117359a6289 ] 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: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/io_uring.c b/fs/io_uring.c index 0de27e75460d..dc1b0f6fd49b 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1439,7 +1439,7 @@ 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; }