On Tue, Jan 07 2014 at 3:16pm -0500, Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote: > On Tue, 7 Jan 2014, Mike Snitzer wrote: > > > I've staged your patch in linux-next for 3.14, see: > > http://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=for-next&id=af7b1e5c767fc895788c971c8f4686402ac8344f > > Looking at this patch, I realize that it is buggy too. If module unload > happens at this point (after the completion is signaled, but before the > release function returns), it crashes. > > static void dm_kobject_release(struct kobject *kobj) > { > complete(dm_get_completion_from_kobject(kobj)); > >========== module unload here ===============< > } That race isn't a surprise, thought you pointed it out earlier in this thread? Anyway, I'm inclined to keep the racey patch staged in linux-dm.git until the stalemate with gregkh is resolved. DM is no worse than other code that follows this same wait for completion pattern. > The patch that I sent initially in this thread doesn't have this bug > because the completion is signaled in non-module code. > > That goes back to my initial claim - it is impossible to use the kobject > interface correctly! But if Greg doesn't want a patch that fixes the > kobject interface, I don't really know what to do about it. Right, I'm missing what is wrong with your proposed kobject_put_wait interface. Greg, can you please establish that you understand the problem, and existing kobject patterns, before you dismiss a fix? -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
