On Tue, Dec 11, 2012 at 06:50:40PM -0700, Liu Bo wrote: > On Tue, Dec 11, 2012 at 09:57:50AM -0500, Josef Bacik wrote: > > On Fri, Nov 30, 2012 at 04:24:43AM -0700, Liu Bo wrote: > > > This can save us a dynamic memory allocation/free. > > > > > > > You can have multiple outstanding delayed iputs per inode, so this will result > > in inodes still being in use on unmount, so this isn't going to work. > > Yeah, you're right, but what if we add a check > > if (list_empty(&bi->iput_list)) > list_add(&bi->iput_list, &fs_info->iput_list)); > > Am I missing something? > Yes, we have the delayed iput stuff to keep us from running the actual iput stuff where we are for locking reasons. If we do the if (list_empty) check then we have to do something for the case wehre the list isn't empty so we don't leak references to the inode, which would basically mean doing an iput which is what we don't want to do. We could do a hybrid approach where we do your list and then allocate if we're already on the list, or add a counter so we know how many references to drop. But this as it is won't work. (Keep in mind I've been buried in tree logging for 3 months so if I'm wrong bear with me). Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
