On Tue, 19 May 2009, Valerie Aurora wrote: > On Tue, May 19, 2009 at 06:15:52PM +0200, Miklos Szeredi wrote: > > Worse, it looks like there are still i_mutex lock ordering issues > > (__hash_lookup_topmost()/__hash_lookup_build_union()). What happens > > if two separate unions of two filesystems are built where the order of > > branches is reversed? > > We have a similar problem in union_copyup_dir(). Hm, thinking about > this, only one of the file systems can actually change while we are > doing work. That might help us get out of the lock ordering problems. > Thoughts? Right, we talked about this with Jan, and came basically to the same conclusion. The lookup on the lower branches needs to be separate from the atomic lookup/create on the top branch. Which means some restructuring in the callers... I'm not sure how all this could be simplified, I don't yet even understand what all these different lookup functions are meant to do (header comments might help). Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
