On Fri, Sep 06, 2013 at 02:48:32PM -0700, Linus Torvalds wrote: > On Fri, Sep 6, 2013 at 2:05 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > > > I can take that, but I'm really not convinced that we need writer lock > > there at all. After all, if we really can get livelocks on that one, > > we would be getting them on d_lookup()... > > d_lookup() does a _single_ path component. That's a *big* difference. > > Sure, the hash chain that d_lookup() (well, __d_lookup()) ends up > walking is a bit more complicated than just following the dentry > parent pointer, but that's much harder to trigger than just creating a > really deep directory structure of single-letter nested directories, > and then doing a "getcwd()" that walks 1024+ parents, while another > thread is looping renaming things.. > > So I personally do feel a lot safer with the fallback to write locking here. > > Especially since it's pretty simple, so there isn't really much downside. Er... what will happen if you have done just what you've described and have a process call d_lookup()? -- 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
