bcache and cluster filesystems? [LWN.net]

bcache and cluster filesystems?

Posted Jul 9, 2010 2:56 UTC (Fri) by skissane (subscriber, #38675)
Parent article: Bcache: Caching beyond just RAM

How would this interact with a cluster file system such as OCFS?
I assume it wouldn't work, unless the cluster file system was aware of the
bcache, and had some way to do cache invalidation of the blocks which had
been changed by other nodes in the cluster....

to post comments

bcache and cluster filesystems?

Posted Jul 9, 2010 3:28 UTC (Fri) by koverstreet (✭ supporter ✭, #4296) [Link] (2 responses)

Yeah, it'd quickly explode. Probably be fun to watch, though.

bcache and cluster filesystems?

Posted Jul 10, 2010 11:20 UTC (Sat) by skissane (subscriber, #38675) [Link] (1 responses)

it would be interesting to work out, what extra features would bcache need to provide so that a clustered filesystem could use it without issue... i assume just some API to tell bcache to invalidate some block...

bcache and cluster filesystems?

Posted Jul 11, 2010 3:22 UTC (Sun) by koverstreet (✭ supporter ✭, #4296) [Link]

Yeah, nothing more complicated than that. Make a new bio flag to invalidate a region of cache, and make sure everything that isn't a cache ignores it. Making bcache handle it would be trivial, it'd just be a matter of making sure ocfs2 always invalidates what it needs to.