Image 2.7b4 Fails to Mount Rootfs Due to ext3 vs. ext4 Mount Option

I updated to the SOM to the image 2.7b4 from an older image version.

The Linux kernel boots but is not able to mount the rootfs with the following output which is then followed by a backtrace:

[    3.109371] EXT4-fs (mmcblk0p2): couldn't mount as ext3 due to feature incompatibilities
[    3.117676] List of all partitions:
[    3.121229] 0100           65536 ram0  (driver?)
[    3.125959] 0101           65536 ram1  (driver?)
[    3.130647] 0102           65536 ram2  (driver?)
[    3.135373] 0103           65536 ram3  (driver?)
[    3.140061] 0104           65536 ram4  (driver?)
[    3.144767] 0105           65536 ram5  (driver?)
[    3.149462] 0106           65536 ram6  (driver?)
[    3.154176] 0107           65536 ram7  (driver?)
[    3.158864] 0108           65536 ram8  (driver?)
[    3.166761] 0109           65536 ram9  (driver?)
[    3.174673] 010a           65536 ram10  (driver?)
[    3.182604] 010b           65536 ram11  (driver?)
[    3.190512] 010c           65536 ram12  (driver?)
[    3.198368] 010d           65536 ram13  (driver?)
[    3.206155] 010e           65536 ram14  (driver?)
[    3.213965] 010f           65536 ram15  (driver?)
[    3.221690] b300         3866624 mmcblk0  driver: mmcblk
[    3.230011]   b301           16384 mmcblk0p1 ded30c96-01
[    3.238343]   b302         3846144 mmcblk0p2 ded30c96-02
[    3.246676] b310            2048 mmcblk0boot1  (driver?)
[    3.255014] b308            2048 mmcblk0boot0  (driver?)
[    3.263310] 0800        29313144 sda  driver: sd
[    3.270890]   0801         1002708 sda1 2c1c6762-01
[    3.278710]   0802        28308892 sda2 2c1c6762-02
[    3.286506] No filesystem could mount root, tried:  ext3
[    3.294735] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179,2)

How can I make the kernel mount the rootfs again?

With the image 2.7b4 we changed from using ext3 to using ext4 for the root file system.

The U-Boot environment must be changed to take that into account, but, to not override settings you might have in the environment we do not reset it automatically.

If you do not want to keep the environment set it to the new defaults as follows:

env default -a
saveenv

If you want to keep your environment, first print the two affected variables for your records, then set them to their new values:

printenv emmcargs sdargs
env default emmcargs sdargs
saveenv