> IOW, mark_mounts_for_expiry() should do the following: > grabbing namespace_sem exclusive > grab vfsmount_lock > walk the list as it does now, except that it should do the right > check from the very beginning (propagate_mount_busy()) > without dropping the vfsmount_lock, go through the collected list, > calling umount_tree() > drop the locks > do release_mounts() > The second pass is needed since umount_tree() might do interesting things > to expiry list, so we make life easier for ourselves by leaving that to > second pass when we just want to drain the resulting list until it's empty. > > Does anybody see holes in the above? > > shrink_submounts() is _probably_ similar (lock/collect/umount_tree on all/ > unlock/release_mounts), but I'm not sure if I understand WTF is really > attempted in there. > > Is there any reason why we do that in ->umount_begin() and not *after* > it, unconditionally, straight from do_umount()? AFAICS, the only reason > why it's done from fs-specific code is figuring out which mount-list > should the stuff go back to, and that's both broken *and* not needed > with sanitized locking as above. While we are at it, I'd rather return > ->umount_begin() to its previous prototype, TYVM - the less filesystem > sees vfsmounts, the better off we all are... All of that seems sane to me. Miklos -- 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
