Re: loopback device HANGS

C. Scott Ananian (
Fri, 15 May 1998 05:57:57 -0400 (EDT)

On Fri, 15 May 1998, Stefan Ring <> wrote:

> I have tracked it down and found that the problem was introduced with
> version 2.1.95. [...]
> It is the two lines changed in drivers/block/ll_rw_blk.c
> After undoing the change, 2.1.95 worked fine for me. [...]

The changes Stefan are referring to are spinlocks added to the general
block IO subsystem, not loopback device changes.
Apparently, what is happening is that the loopback device hangs because it
invokes the block device subsystem recursively, deadlocking on the
spinlocks. I remember someone was working on this recently, but I don't
recall whom. The correct solution is to unlock the spinlocks before
loopback recurses into the block device subsystem, right? Did someone
have a patch for this? [I seem to recall that there were unresolved

[I'm not biting on the 'internationalized kernel messages' troll... =)
I thought we have put that to rest months ago! ]
@ @
C. Scott Ananian: / Declare the Truth boldly and
Laboratory for Computer Science/Crypto / without hindrance.
Massachusetts Institute of Technology /META-PARRESIAS AKOLUTOS:Acts 28:31
-.-. .-.. .. ..-. ..-. --- .-. -.. ... -.-. --- - - .- -. .- -. .. .- -.
PGP key available via finger and from

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to