On Thu, Sep 19, 2002 at 12:27:33AM -0700, Greg KH wrote: > On Thu, Sep 19, 2002 at 10:25:48AM +0200, yaelgilad wrote: > > Hi, > > I am building a kernel module which will probably need > > to access files, real or virtual. The module will be inserted > > to an "out-of-the-box" kernel. I have full control of which-boxes :-) > > > > Are there any obvious issues I should be aware of ? > > Yes, you should not ever access files from within the kernel. Do not do > this, change your design, it is broken. Well, you should avoid reading files from a disk. Make a utility to feed pre-parsed data to you. It reduces complexity of code in kernel and makes things more flexible. > > I need to create a kernel thread, which will loop > > on a blocking read from some something in /dev. > > Heh, if you're wanting to block on data from a device, do that in > userspace, not within the kernel. However, if it can be done in user-space, do it there. Remember, that doing things in kernel gives very limited speed advantage while it makes things complicated. If it for any reason can't be done in user-land, you probably could get the data without opening the device file. If end up with the need to open it, don't go through the filesystem. It's a waste of everything. You can get apropriate structure for the device the way generic device open does and mimic what it does (block devices can be accessed the way fs drivers do). ------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@ucw.cz> -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
