On Sun 30-10-16 10:44:37, Jan Kara wrote: > On Sat 29-10-16 13:09:25, Linus Torvalds wrote: > > On Sat, Oct 29, 2016 at 12:17 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > > > > > AFAICS, the possibility of dropping the last reference to struct file > > > before ->write_iter() has returned is fundamentally broken. I might be > > > missing something subtle here, but... > > > > Ok, let's add a get_file(); fput(); around that whole iter call sequence. > > > > And that's a separate issue from "we should hold the fs freezer lock > > around the whole operation". So I think we need both. > > Yup, these are two separate issues. I'm fine with adding get_file(); fput() > around the iter call sequence. Then, when we have struct file available for > the whole time ->write_iter runs, I'd prefer to keep the call to fool > lockdep where original file_end_write() call was - that gives us proper > lockdep coverage for all the code behind iter_op(). The downside is we > cannot keep helpers as elegant as you suggested in your patch but I believe > it's bearable and worth the additional lockdep coverage. I'll send patches > shortly... Hum, the additional refcount patch oopses on me when running generic/323, I'll have to board to my flight to US shortly so I won't be able to send it soon - maybe when I'm transferring in Denver ;). Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR -- 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
