On Tue, Oct 19, 2010 at 02:42:35PM +1100, npiggin@xxxxxxxxx wrote: > + /* > + * We can walk the per-sb list of inodes here without worrying about > + * its consistency, because the list must not change during umount > + * anymore, and because iprune_sem keeps shrink_icache_memory() away. > + */ > fsnotify_unmount_inodes(&sb->s_inodes); OK, explain to me why is that safe. Note that fsnotify_destroy_mark() _can_ race with umount, dropping the last reference to inode before fsnotify_unmount_inodes() would get to it and kill it (along with the mark). With the current code it's just fine - we walk the list under lock and iput() won't mess with that list until it acquires the damn lock. And no matter who gets there first, the mark will be destroyed and reference to inode will be dropped. With your change, AFAICS, removal from the list can happen while we walk it. With obvious results. -- 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
