Messages in this thread | | | Date | Thu, 30 May 2002 00:53:53 +0200 | From | Martin Dalecki <> | Subject | Re: [PATCH] 2.5.18 IDE 73 |
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Andries.Brouwer@cwi.nl wrote: >>>About scanning for partitions: >>>Several partitioning schemes exist, and reading partition tables is not >>>something a driver should do without getting explicit requests. >>>For all we know the disk contents may be completely random. >> > >>You are right but the fact is right now we have to do it this way. > > > That is OK - I just write to make sure we all agree that this must > only be an intermediate stage. Scanning for partitions must not be > something obscure that happens deep down in some driver. > > >>>You should offer the list of disks seen to user space, and user space >>>should decide which disks have to be investigated, and tell the kernel >>>about the partitions it wants to have on these disks. >>>That way all knowledge about partitioning, dynamic disks, disk managers >>>and the like is removed from the kernel, and moved into partx-type code. >> > >>But there is one thing, which isn't prette about the above sheme: races >>and atomicity of operations... Well this could be solved >>by making the mount system call passing this information as a parameters. >>You wouldn't even need to pass any list of disks to user land - we don't >>do it right now. > > > You see, some disks belong to RAIDs, some disks are in reality very > slow objects, like compact flash cards or so, some disk have some foreign > partitioning scheme. There can be all kinds of reasons why we do not > want to start reading and interpreting any random disk-like device.
Ahhh... wait a moment you are the one who is responsible for util-linux - wouldn't you care to take a bunch of patches?!
> I know that we used to do this, but it was wrong, so we must slowly move > to a setup where we do no longer do this. > > So, user space is started on a ramdisk or so, and gets parameters > rootdev=, rootpttype=, rootpartition=, rootfstype=. > Now it can use rootpttype to scan rootdev, find the partitions, > find rootpartition, mount it as type rootfstype on /. > > Afterwards the existence of more devices, possibly with partitions, > becomes of interest, for example because there is a "mount -a" somewhere. > Here userspace needs a list of available devices. Maybe /proc/partitions.
/etc/vfstab, /etc/mtab - are conceptually just fine.
No need to inevent here. No need to do the book keeping in kernel. passwd doesn't need /proc/users too and many people just forget that we are still on a UNIX like system. The only case which deserves special treatment is the parition where / resides.
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