Messages in this thread | | | Date | Wed, 13 Oct 2010 19:36:48 -0400 | From | Christoph Hellwig <> | Subject | Re: fs: Inode cache scalability V3 |
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On Wed, Oct 13, 2010 at 05:46:09PM -0400, Christoph Hellwig wrote: > On Wed, Oct 13, 2010 at 11:58:45AM -0400, Christoph Hellwig wrote: > > > > It's 100% reproducible on my kvm VM. The bug is the assert_spin_locked > > in redirty_tail. I really can't find a way how we reach it without > > d_lock so this really confuses me. > > We are for some reason getting a block device inode that is on the > dirty list of a bdi that it doesn't point to. Still trying to figure > out how exactly that happens.
It's because __blkdev_put reset the bdi on the mapping, and bdev inodes are still special cased to not use s_bdi unlike everybody else. So we keep switch between different bdis that get locked.
I wonder what's a good workaround for that. Just flushing out all dirty state of a block device inode on last close would fix, but we'd still have all the dragons hidden underneath until we finally sort out the bdi reference mess.
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