Greg KH <[EMAIL PROTECTED]> writes: > >> Also fun is that the dev file implementation needs to be able to >> report different major:minor numbers based on which mount of >> sysfs we are dealing with. > > Um, no, that's not going to happen. /dev/sda will _always_ have the > same major:minor number, as defined by the LSB spec. You can not break > that at all. So while you might not want to show all mounts > /sys/devices/block/sda/ the ones that you do, will all have the LSB > defined major:minor number assigned to it.
Hmm. If that is in the LSB it must come from Documentation/devices.txt I'm not after changing the user visible major/minor assignments. Let me see if a concrete example will help. Suppose I have have a SAN with two disks: disk-1 and disk-2. I have two machines A and B. On machine A I get the mapping: sda -> disk-1, sdb ->disk-2. On machine B I wind up with a different probe order so I get the mapping: sda -> disk-2 sdb ->disk-1. To be very clear by sda I mean the block device with major 8 and minor 0, and by sdb I mean the block device with major 8 and minor 16. So I decide I want an environment on machine B that looks just like the environment on machine A, so I can bring transfer over a running program or whatever. So I run around looking at UUID labels and what not and I discover that the machine B knows disk-1 as sdb and that machine A knows disk-1 as sda. So I want to say: /sys/devices/block/sdb show up in this other device namespace as /sys/devices/block/sda. In that instance a running program won't notice the difference. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
