On Tue, Mar 30, 2021 at 04:36:37PM -0700, Dan Williams wrote:
> -static void cxlmdev_unregister(void *_cxlmd)
> +static void cxl_memdev_activate(struct cxl_memdev *cxlmd, struct cxl_mem
> *cxlm)
> {
> - struct cxl_memdev *cxlmd = _cxlmd;
> - struct device *dev = &cxlmd->dev;
> + cxlmd->cxlm = cxlm;
> + down_write(&cxl_memdev_rwsem);
> + up_write(&cxl_memdev_rwsem);
> +}
No reason not to put the assignment inside the lock. Though using the
lock at all is overkill as the pointer hasn't left the local stack
frame at this point.
> err_add:
> - ida_free(&cxl_memdev_ida, cxlmd->id);
> -err_id:
> /*
> - * Theoretically userspace could have already entered the fops,
> - * so flush ops_active.
> + * The cdev was briefly live, shutdown any ioctl operations that
> + * saw that state.
> */
Wow it is really subtle that cdev_device_add has this tiny hole where
it can fail but have already allowed open() :<
Other than the lock it looks OK
Reviewed-by: Jason Gunthorpe <[email protected]>
Jason
