On Thu, Jul 25, 2019 at 09:29:40PM -0700, 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. That is good, that solves the "/dev/random/" issue I was talking about earlier as well. Odds are you all can do the same for the blockdev interface as well. thanks, greg k-h