You should not apply them if you don't really know what you are doing. The patches are resonably benign. Converting your sdcard partition to ext4 is NOT NOT NOT benign and you can really hose yourself doing it.
I'm not going into great depth with these instructions. If you don't understand them, play around with building cyanogen, installing it, etc until they are crystal clear.
To swap your sdcard to ext4:
* Apply the patches and rebuild cyanogen. Rebuild it. They will change your recovery image and vold.
* Install vold and flash (and/or boot) the recovery image.
* Boot into recovery, mount your sdcard and back it up to your computer (i.e., not nandroid, copy the files.) Nandroid would be a good idea too.
* Format your media partition to ext4 (the one that is vfat, by-name is media, mine is partition 3) mkfs.ext4 can be found by googling, or you can use make_ext4fs from /system/bin. I used mkfs.ext4.
* You should be able to manually mount that.
* Push your files back.
* sync and reboot.
Et Voila, you should have an ext4 sdcard partition.
THIS IS VERY DANGEROUS.
YOU CAN REALLY HOSE YOURSELF DOING IT.
Here are the patches:
This one adds ext4 support to vold, thus allowing gingerbread to mount ext4 partitions for the sdcard (which on the Nexus S, is the 'media' partition.)
This is a change to recovery, making it seamlessly mount ext4 partitions for /sdcard.
# mount /dev/block/platform/s3c-sdhci.0/by-name/system on /system type ext4 (ro,noatime,barrier=1,data=ordered,noauto_da_alloc) /dev/block/platform/s3c-sdhci.0/by-name/userdata on /data type ext4 (rw,nosuid,nodev,noatime,barrier=0,data=ordered) /dev/block/vold/179:3 on /mnt/sdcard type ext4 (rw,nosuid,nodev,noexec,noatime,barrier=1,data=ordered,noauto_da_alloc) /dev/block/vold/179:3 on /mnt/secure/asec type ext4 (rw,nosuid,nodev,noexec,noatime,barrier=1,data=ordered,noauto_da_alloc) tmpfs on /mnt/sdcard/.android_secure type tmpfs (ro,relatime,size=0k,mode=000)