Bcache hang

Bcache hang

[Ross Anderson]

Current bcache and bcache-testing cause kernel panic on bcache add. 
These are on existing devices, Echo 1 to unregistered, remove existing 
cache device replace with new, make-bcache -C, then echo to register. 
Register hangs and following kernel output and hang occurs.



The following is debug info for the hang
http://pastebin.com/87iYygdw

Re: Bcache hang

[Kent Overstreet]

On Wed, Jan 09, 2013 at 01:17:39PM -0600, Ross Anderson wrote:
> Current bcache and bcache-testing cause kernel panic on bcache add.
> These are on existing devices, Echo 1 to unregistered, remove
> existing cache device replace with new, make-bcache -C, then echo to
> register. Register hangs and following kernel output and hang
> occurs.

We already talked about this on irc, but for anyone following on the
list - fixed this a couple days ago.