Re: xfs mr_lock vs mmap_sem lock inversion?

From: Christoph Hellwig
Date: Fri Jul 17 2009 - 11:09:30 EST



It's a problem in the VM code, which we already discussed a while
ago. The problem is that the VMA manipultation code calls fput
under the mmap_sem, while we can take mmap_sem ue to a page fault
from inside generic_file_aio_read/write. So any filesystem
that nees the same lock held over read/write also in release is
crewed.

Now on the positive side I think we can actually get rid of taking
the iolock in ->release in XFS, but I'm sure other filesystems
might continue hitting similar issues.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/