On Fri, Feb 09, 2007 at 02:09:54AM -0800, Andrew Morton wrote: > On Fri, 9 Feb 2007 10:54:05 +0100 Nick Piggin <npiggin@xxxxxxx> wrote: > > > > > That's still got a deadlock, > > It does? Yes, PG_lock vs mm->mmap_sem. > > and also it doesn't work if we want to lock > > the page when performing a minor fault (which I want to fix fault vs > > invalidate), > > It's hard to discuss this without a description of what you want to fix > there, and a description of how you plan to fix it. http://marc.theaimsgroup.com/?l=linux-mm&m=116865911432667&w=2 > > and also assumes nobody's ->nopage locks the page or > > requires any resources that are held by prepare_write (something not > > immediately clear to me with the cluster filesystems, at least). > > The nopage handler is filemap_nopage(). Are there any exceptions to that? OCFS2 and GFS2. > > But that all becomes legacy path, so do we really care? Supposing fs > > maintainers like perform_write, then after the main ones have implementations > > we could switch over to the slow-but-correct prepare_write legacy path. > > Or we could leave it, or we could use Linus's slightly-less-buggy scheme... > > by that point I expect I'd be sick of arguing about it ;) > > It's worth "arguing" about. This is write(). What matters more?? That's the legacy path that uses prepare/commit (ie. supposing that all major filesystems did get converted to perform_write). Of course I would still want my correct-but-slow version in that case, but I just wouldn't care to argue if you still wanted to keep it fast. - 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
