On 9/22/23 8:50 PM, Ming Lei wrote: > diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h > index ae08d6f66e62..a0307289bdc7 100644 > --- a/include/linux/io_uring.h > +++ b/include/linux/io_uring.h > @@ -20,9 +20,13 @@ enum io_uring_cmd_flags { > IO_URING_F_SQE128 = (1 << 8), > IO_URING_F_CQE32 = (1 << 9), > IO_URING_F_IOPOLL = (1 << 10), > + > + /* set when uring wants to cancel one issued command */ > + IO_URING_F_CANCEL = (1 << 11), > }; I'd make that comment: /* set when uring wants to cancel a previously issued command */ > @@ -125,6 +132,15 @@ static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd, > { > return -EOPNOTSUPP; > } > +static inline int io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd, > + unsigned int issue_flags) > +{ > + return -EOPNOTSUPP; > +} Do we need this to return an error? Presumably this will never get called if IO_URING isn't defined, but if it does, it obviously doesn't need to do anything anyway. Seems like it should just be a void, and ditto for the enabled version which can't return an error anyway. > return ret; > } > > +static bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx, > + struct task_struct *task, bool cancel_all) > +{ > + struct hlist_node *tmp; > + struct io_kiocb *req; > + bool ret = false; > + > + lockdep_assert_held(&ctx->uring_lock); > + > + hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd, > + hash_node) { > + struct io_uring_cmd *cmd = io_kiocb_to_cmd(req, > + struct io_uring_cmd); > + struct file *file = req->file; > + > + if (WARN_ON_ONCE(!file->f_op->uring_cmd)) > + continue; That check belongs in the function that marks it cancelable and adds it to the list. Outside of those minor nits, looks fine to me, and patch 1 does too. -- Jens Axboe