Messages in this thread |  | | Subject | Re: [PATCH v6 02/16] chardev: introduce cdev_get_by_path() | From | Sagi Grimberg <> | Date | Thu, 25 Jul 2019 21:29:40 -0700 |
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>>>>>>> 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.
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