On Fri, Nov 18, 2016 at 02:52:22PM -0700, Andreas Dilger wrote: > > > Yes, this would be a much nicer way to detect fast symlinks. > > > > The only thing I'd be concerned about is the possibility of pre-existing > > "slow" symlinks that actually have targets short enough to be "fast" > > symlinks, perhaps in filesystems created by old drivers or by external > > tools. If such links happened to work before, then a change to check > > i_size would break them. > > > > This may not be an issue in practice. I checked some old ext4 versions, > > ext2 from Linux 0.99.7, e2fsprogs, Android's ext4_utils, and FreeBSD's > > ext2 driver. > > They all create "fast" symlinks if the length of the symlink target length > > excluding the terminating null (i_size) is < 60. > > I did a similar analysis with similar results. > Ted, what would you say about Andreas' suggestion to use i_size to distinguish fast symlinks from slow symlinks? It looks like this was discussed some years ago but the discussion died out and no change was made: see https://www.spinics.net/lists/linux-ext4/msg05693.html Given the investigation I did it seems it would very likely be safe, but we can never be 100% sure it won't break some obscure tool or (version of a tool) to create symlinks on ext2/ext3/ext4 filesystems we don't know about. Eric -- 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
