MiSTer FPGA Forum

Hi all,

Today I was trying to troubleshoot something into my Mister and I saw this:

/root# dmesg
[...]
[ 17.776454] loop0: detected capacity change from 0 to 4096
[ 17.831561] EXT4-fs (loop0): ext4_check_descriptors: Checksum for group 0 fai led (55124!=0)
[ 17.839965] EXT4-fs (loop0): group descriptors corrupted!
[ 42.866893] EXT4-fs (loop8): re-mounted. Opts: (null). Quota mode: disabled.
[ 42.866929] ext4 filesystem being remounted at / supports timestamps until 20 38 (0x7fffffff)

I saw no other errors and filesystems seem to mount properly:

/root# fdisk -l
Disk /dev/ram0: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Disk /dev/ram1: 8 MiB, 8388608 bytes, 16384 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Disk /dev/mmcblk0: 476.71 GiB, 511868665856 bytes, 999743488 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x03a0c925

Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 2048 999738966 999736919 476.7G 7 HPFS/NTFS/exFAT
/dev/mmcblk0p2 999738967 999741014 2048 1M a2 unknown

Disk /dev/loop8: 375 MiB, 393216000 bytes, 768000 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

/root# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/loop8 348M 296M 26M 93% /
/dev/root 477G 466G 12G 98% /media/fat
devtmpfs 247M 0 247M 0% /dev
tmpfs 247M 0 247M 0% /dev/shm
tmpfs 247M 72K 247M 1% /tmp
tmpfs 247M 204K 247M 1% /run
tmpfs 247M 0 247M 0% /var/lib/samba

Is there any way to check (and/orfix) the filesystem propely?

Thank you very much in advance...

Since it's only loop0 that seems to have an issue and it's not the root filesystem,
you can do an losetup -a to find that loop 0 points to /media/fat/linux/bluetooth
So you can then do a umount /dev/loop0, followed by a fsck.ext4 /media/fat/linux/bluetooth.
Once it's done, reboot mister and if the sd card itself doesn't have issues, then the filesystem should be fine.

Thank you so much!!!

I followed the steps that you described and it looks good now:

dmesg
[..]
[ 20.778790] loop0: detected capacity change from 0 to 4096
[ 20.869208] EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null). Quota mode: disabled.
[ 25.001888] EXT4-fs (loop8): re-mounted. Opts: (null). Quota mode: disabled.

Thanks again!

Glad it worked out for you