On Mon, Nov 24, 2014 at 07:21:01AM -0800, Christoph Hellwig wrote: > On Fri, Nov 21, 2014 at 02:59:21PM -0500, Theodore Ts'o wrote: > > We needed to preserve update_time() because btrfs wants to have a > > special btrfs_root_readonly() check; otherwise we could drop the > > update_time() inode operation entirely. > > Can't btrfs just set the immutable flag on every inode that is read > when the root has the BTRFS_ROOT_SUBVOL_RDONLY flag? That would > cut down the places that need this check to the ioctl path so that > we prevent users from clearling the immutable flag. Sounds like a good plan to me, although I'm not sure I understand how BTRFS_ROOT_SUBVOL_RDONLY flag works, since I would have thought there are all sorts of places in the VFS layer where it is currently checking MS_RDONLY and MNT_READONLY and _not_ checking BTRFS_ROOT_SUBVOL_RDONLY isn't causing other problems. But unless there's something more subtle going on, it would seem to me that setting the immutable flag on each inode would be a better way to go in any case. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
