today something happened and I lost access to '/data' in rom slot 3, and on a reboot it complains about encryption failing. I can boot the stock image just fine, but rom slot 3 (eclipse) was my daily driver, and, of course, I don't have a recent backup. I tried mounting the userdata img on my linux machine and got
EXT3-fs error (device loop0): ext3_check_descriptors: Block bitmap for group 0 not in group (block 2553887680)!
EXT3-fs (loop0): error: group descriptors corrupted
I'm going to try using fsck to fix it, but while I'm waiting to get the chance, I'm wondering if there are any other options. this is safestrap 3.05.
okay, got a chance to try this, and it worked! here's what I did:
switch to the stock slot (you could probably use any other working slot; not entirely sure)
mount the internal sd card on a linux box. for me, when I plug it in to the computer with the USB cable, the internal card is auto-mounted as /media/MOT .
look in the appropriate rom slot. I was using rom slot 3, so I looked in '/media/MOT/safestrap/rom-slot3'.
I then copied 'userdata.img' to my local disk; you could attempt the repair in place, but I didn't want to take a chance of messing things up any further. so
cp /media/MOT/safestrap/rom-slot3/userdata.img /scratch/droid4
cd /scratch/droid4
at least on my linux system, fsck won't run on a file, so you have to mount the image as a device:
losetup /dev/loop0 userdata.img
fsck -y /dev/loop0
I don't usually like '-y', which gives fsck permission to make all repairs without asking, but there seemed to be a lot of problems, and since this is just a copy...
then umount the device
losetup -d /dev/loop0
I then made yet another copy of the 'bad' img, just in case, after which I copied the repaired image back onto the phone
cp /scratch/droid4/userdata.img /media/MOT/safestrap/rom-slot3
powered the phone up, switched back to rom slot 3, rebooted, and everything looks just like it did before. even the time-keeping application that had been running when the phone crashed was correct!
I'm not sure why I had this problem: I was getting some strange behavior from swype in google voice, and was experimenting with removing/re-installing those apps, and wham!