On Mon, Dec 02, 2013 at 09:33:18AM +0100, Jan Kara wrote: > > Indeed, XIP could make use of the structures we already > > have in the struct inode/address space to behave more like a normal > > filesystem. We already use the mapping tree to store > > per-page information that is used to serialise truncate vs page > > faults, so why not make XIP do exactly the same thing? > I believe that grabbing mmap_sem for writing during truncate (in case of > ext2 around xip_truncate_page() & truncate_setsize() calls should do the > trick. But I need to verify with lockdep that it doesn't introduce new > locking problems. Umm ... mmap_sem for write? On each of the tasks that have a file mmaped? I know we have double_down that orders by memory address, but I don't think we have an N_down_write(). -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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
