Rooting Samsung Galaxy S II GT-i9100

How does one root a Samsung Galaxy S II GT-i9100 (with its original Android 2.3 Gingerbread), preferably under Linux Mint? This questions pertains specifically the GT-i9100 version (not GT-i9100G nor GT-i9100T, et cetera), which currently has no entry under the rooting index . I am particularly looking for a rooting method which does not wipe the data on the phone, as [I am hoping to recover data afterwards](https://android.stackexchange.com/questions/89133/data-recovery-on-boot-looped-samsung-galaxy-s-ii-gt-i9100) . I have an 8GB external SD card.