On 2019-07-25 10:29 p.m., Sagi Grimberg wrote: > >>>>>>>> NVMe-OF is configured using configfs. The target is specified by >>>>>>>> the >>>>>>>> user writing a path to a configfs attribute. This is the way it >>>>>>>> works >>>>>>>> today but with blkdev_get_by_path()[1]. For the passthru code, >>>>>>>> we need >>>>>>>> to get a nvme_ctrl instead of a block_device, but the principal >>>>>>>> is the same. >>>>>>> >>>>>>> Why isn't a fd being passed in there instead of a random string? >>>>>> >>>>>> I suppose we could echo a string of the file descriptor number there, >>>>>> and look up the fd in the process' file descriptor table ... >>>>> >>>>> Assuming that there is a open handle somewhere out there... >>> >>> Yes, that would be a step backwards from an interface. The user would >>> then need a special process to open the fd and pass it through configfs. >>> They couldn't just do it with basic bash commands. >> >> First of all, they can, but... WTF not have filp_open() done right there? >> Yes, by name. With permission checks done. And pick your object from >> the >> sodding struct file you'll get. >> >> What's the problem? Why do you need cdev lookups, etc., when you are >> dealing with files under your full control? Just open them and use >> ->private_data or whatever you set in ->open() to access the damn thing. >> All there is to it... > Oh this is so much simpler. There is really no point in using anything > else. Just need to remember to compare f->f_op to what we expect to make > sure that it is indeed the same device class. Yes, that sounds like a good idea. I'll do this for v2. Thanks, Logan