[Nexus 7 Q&A, Help & Troubleshooting] bftb0:
I'll look at your kernel log in a little bit, but here's what sticks out.

1) Your userdata filesystem (mmcblk0p9) is corrupted - mildly. That shouldn't happen (although when it is bad you get pages and pages and pages of error output).

2) Your cache filesystem was mounted rw, but that doesn't necessarily mean that it was clean. You never ran a "e2fsck" check on either mmcblk0p3 or mmcblk0p4 (system and cache, respectively). Either that or they were clean and you didn't show the output. Which was it?

You should run the e2fsck checks on those as well and report back.

The recommendation that I will make for flashing the factory image is as follows:

1) Skip the bootloader flashing if you already have the matching bootloader version installed

2) Using fastboot, erase and format all three partitions cache, system, userdata:

fastboot erase cache
fastboot erase system
fastboot erase userdata **
fastboot format cache
fastboot format system
fastboot format userdata

** note this destroys all your data (but it sounds like you have either backed up your device or have moved beyond caring about this). I don't believe there is any reason for doing a fastboot erase of the boot partition (although I suppose if the bootloader understands "TRIM" behaviors, it would be possible that a "fastboot erase boot" operation changes the availability of pages in that partition for use in the wear-leveling free pool during subsequent writing operations. In the interest of safety, I would never allow the 4 sequential letters "boot" to appear in a "fastboot erase" command - to avoid accidentally doing something horrific like "fastboot erase bootloader". Better to simply skip erasing of the boot partition ("fastboot erase boot") than to run the risk of making a typing error and accidentally nuke the bootloader. (I don't even understand why the unlocked bootloader should allow erasure of the bootloader partition.)

3) Repeat the steps in my previous posts to check that the filesystems are being created cleanly by the fastboot format operation:

(3a) Soft-boot into a custom recovery and

umount /cache
umount /system
umount /data
e2fsck -f -n /dev/block/mmcblk0p3 [color=grey]# (system)[/color]
e2fsck -f -n /dev/block/mmcblk0p4 [color=grey]# (cache)[/color]
e2fsck -f -n /dev/block/mmcblk0p9 [color=grey]# (userdata [b][color=red]Grouper Only![/color][/b])[/color]
e2fsck -f -n /dev/block/mmcblk0p10 [color=grey]# (userdata [b][color=red]Tilapia Only![/color][/b])[/color]

They should all be clean, other than a complaint about lost+found being missing.

4) Now, perform the flashing of the factory boot.img & system.img - NOTHING ELSE. The important point here is to NOT FLASH "userdata.img" from the factory image.

fastboot flash system system.img
fastboot flash boot boot.img

5) Repeat the steps in my previous posts to check that the /system filesystem is clean, e.g.

umount /system
e2fsck -f -n /dev/block/mmcblk0p3

.

If everything is clean, go ahead and try booting the tablet into the normal OS

[Edit] I looked through your (recovery) kernel boot log.

I didn't see anything terribly unusual, except some indications of EXT4 filesystem repair. That shouldn't be happening, but could have been caused by:

- a kernel crash or maybe bootlooping

- you hard-crashing the device by holding the power button down > 15 seconds.

The good news is that I don't see anything unusual happening where the kernel reads the device partitioning information

---------- Post added at 10:53 AM ---------- Previous post was at 10:25 AM ----------

PS

I the post above - after step 3a - you can manually check to be sure that everything has really been erased from those three partitions by mounting each of /cache, /data, and /system, and then running a "df" command. The usage should be pretty close to 0% for all 3 of them.

BTW, I was a little sloppy above about giving the recovery terminal commands without prefixing them with "adb shell". I assumed that you know that you can just

adb shell
... (linux commands)
exit

with the custom recovery (soft-)booted, and then you will be sort of "logged in" to the device. You can tell the difference because of the command prompt you get. "Logged in" to the android device's recovery, it will be a "#" character. If you are on the PC you'll have the DOS/cygwin prompt, .e.g "C:\some-path-or-other>". You might already know that, but I thought I should mention it.