On Tue, Jan 07, 2003 at 11:55:00AM +0100, [EMAIL PROTECTED] wrote: > > But, we don't have to truncate, we should just allocate as many bytes as > > we need, and store the information. > > > And, the sysfs name should not store the id.
> > OK. It seems that we are in total agreement. > Time for the next question. > > An id is constructed, that in many cases identifies something. > How do you plan to use this? Is it already in use somewhere? It's not in use in the main-line kernel. I forgot to mention that I'm using the id in scsi mid-level multi-path code, it has the same problem (the id is not always unique, plus other major issues to deal with). I'm not working on any device naming/persistence code, although I have given thought to solutions. Any solution there might apply to multi-path usage. But the multi-path cannot easily be moved to user space until we have complete user level scsi scanning. Is anyone currently writing device name solutions based on the scsi id? > The sysfs tree does not contain device nodes. > Do you plan a user space utility that figures out that > the ID "SHP CD-Writer+ 8200 [" belongs to /dev/hdd > which also is /dev/sr0? With the current code, any utility would be scsi specific (it could only name scsi devices based on an id, others would get a default name), so it would only cover /dev/sr0. I don't know much about IDE capabilities. > The id is not suitable as a user space name. Moreover, > it is a heuristic only, and user space needs unambiguous names. If we had a complete white/black list of devices with/without a unique id, there would be no ambiguity. Such a list could be generated by asking the user/administrator each time an unknown device is added to the system (or have a safe default); we could also have a white/black somewhere (for use from user space), much like we have with scsi_static_device_list in scsi_scan.c today. A user level white/black list is also useful for scanning, especially for user level scanning, and for kernel scanning if we can access it before starting the scan (via ramdisk at boot time). > What user space names do you want to use? Maybe have a configurable starting point (like /devnames, maybe something that does not collide with /dev, perhaps we can generate a /dev matching exactly what we have today), much like a mount point, or like devfs. I don't know of any good reasons for a file system. In any case, right now we should fix the scsi sysfs name, and add (and not truncate) a uid to scsi_device. -- Patrick Mansfield ------------------------------------------------------- This SF.NET email is sponsored by: SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See! http://www.vasoftware.com _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
