On Wed, Jun 18, 2008 at 02:31:34PM +0200, Louis Rilling wrote: > On Tue, Jun 17, 2008 at 03:41:00PM -0700, Joel Becker wrote: > > However, if the subsystem is made up of multiple modules, this may not > > pin the subsystem. Thus, it would be possible to unload the toplevel > > subsystem module while there is still a child item. Thus, we now > > try_module_get() the subsystem's module. This only really affects > > children of the toplevel subsystem group. Deeper children already have > > their parents pinned. > > Looks good to me. > > What about new item module pinning versus a concurrent sys_delete_module() in a > preemptible kernel? AFAICS new_item pinning is just done too late to protect > anybody against sys_delete_module(). Shouldn't we remove new item module pinning > and let the subsystem do it? Good catch. Preempt doesn't matter - it could just be another CPU. Certainly if there are multiple modules the make_item() will have to pin the submodule before calling it. But the common case isn't multiple modules. What we absolutely don't want is making the common case have to pin itself. Joel -- Life's Little Instruction Book #30 "Never buy a house without a fireplace." Joel Becker Principal Software Developer Oracle E-mail: joel.becker@xxxxxxxxxx Phone: (650) 506-8127 -- 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
