Hi Sven, On Thu, Jan 14, 2010 at 07:18:50PM +0100, Sven Eschenberg wrote: > Hi Arno, > > Agreed. > > Concerning the actual problem: This should not go into cryptsetup, it's > not the right place. Well, it is actually already in there, just at the moment it gives you the first it finds. I think it is acceptable to have it in there, as cryptsetup already is a frontend. Writing a frontend for a frontend is a bit redundant. > If we talk convetions, then the convention is: > There is only ONE inode representing the device under /dev. If your > hotplug manager (and it's configuration) creates multiple such entries, > it is an indication for misconfiguration (imho). I.E.: Each device > should have one physical identification (the inode carrying major:minor, > together with the pathname) and as many logical names (via softlinks) as > wanted. This guarantees that the right pathname can be found (not only > for dmcrypt btw) and the device is yet useable via it's symbolic names > (i.e. UUIDs, volume labels etc.). > > If the preference of the system administrator is on UUID names, then > those should be created as device files, and the 'traditional names' as > softlinks. If yet there is a need to know all device names that link to > a certain major:minor, then this can and should be done in a simple > shell script, where it belongs in my opinion. > > Just my 2 cents I agree to that. It came when I added udev to my system, which I do not like, and it creating devices under /dev/scsi/ is the default under Debian. Clearly this has not been thought through. As such broken configs can happen and it seems easily, it seems they need to be expected. Arno > Regards > > -Sven > > > > Arno Wagner schrieb: >> Well, I think listing all in /dev/ would be an improvement to >> the current behaviour. Of course people can put their device >> spceials somewhere else, but that is a pretty big break of >> convention that IMO does not need to be supported. >> >> Arno >> >> On Wed, Jan 13, 2010 at 05:18:27PM +0100, Sven Eschenberg wrote: >>> Hi Arno, >>> >>> Indeed cryyptsetup traverses /dev stating each file for major:minor >>> and stops on the first match - at least a trace suggests this. The >>> question is though, if this is an appropriated approach. One thing >>> that annoys me when doing this: There's no guarantee that device >>> inodes are in /dev, nor links to it. In theory it cann be any place >>> in the filesystem. there can be as many links as you want and as >>> many inodes for the same device, as you want. >>> >>> Regards >>> >>> -Sven >>> >>> >>> Arno Wagner schrieb: >>>> Having had a bit of time to think about it, it seems that >>>> it would indeed be necessary to store the device name. >>>> >>>> A possible alternative is to traverse all of /dev/ and >>>> report all devices that match major/minor. This may be >>>> the solution causing the least effort, as cryptsetup >>>> is doing something like it already, just that it currently >>>> stops after the first match. >>>> >>>> In fact, I think I prefer for it to report all devices >>>> that match. >>>> >>>> Arno >>>> >>>> >>>> On Wed, Jan 13, 2010 at 11:20:36AM +0100, Sven Eschenberg wrote: >>>>> Hi Luca, >>>>> >>>>> I doubt this is possible. The only possible thing would be: Modify DM, >>>>> when a device name is passed in, to keep the passed in name alongside >>>>> the actual major:minor and provide an IOCTL, to access the information. >>>>> >>>>> Regards >>>>> >>>>> -Sven >>>>> >>>>> >>>>> On Wed, 2010-01-13 at 08:01 +0100, Luca Berra wrote: >>>>>> On Sun, Jan 10, 2010 at 09:33:13PM +0100, Milan Broz wrote: >>>>>>> The algorithm is very simple (and was probably written before >>>>>>> udev was used so these special links in /dev did not exist). >>>>>>> >>>>>>> So it need to add some preferred names and not print the first entry. >>>>>>> >>>>>>> Please can you add an issue to project pages to not forget about this? >>>>>>> Probably good idea to fix it in next minor release. >>>>>> it could be useful to have the functionality in device-mapper itself, >>>>>> instead of duplicating in dm-crypt, lvm, dmraid, whatever ? >>>>>> >>>>>> Regards, >>>>>> L. >>>>>> >>>>> _______________________________________________ >>>>> dm-crypt mailing list >>>>> dm-crypt@xxxxxxxx >>>>> http://www.saout.de/mailman/listinfo/dm-crypt >>>>> >>> _______________________________________________ >>> dm-crypt mailing list >>> dm-crypt@xxxxxxxx >>> http://www.saout.de/mailman/listinfo/dm-crypt >>> >> > > _______________________________________________ > dm-crypt mailing list > dm-crypt@xxxxxxxx > http://www.saout.de/mailman/listinfo/dm-crypt > -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@xxxxxxxxxxx GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
