I have a router with a USB stick attached, with some data on it.

I wanted to save some space, and as I won't edit some of the files, I created a squashfs image (in a file).

However, mounting this squashfs image fails:

# mount -t squashfs -o loop unattended.sqfs unattended
mount: Mounting /home/samba/unattended.sqfs on /home/samba/unattended failed: Invalid argument

dmesg gives me this output:

SQUASHFS error: lzma returned unexpected result 0x1
SQUASHFS error: Unable to read cache block [53c:18]
SQUASHFS error: Unable to read inode [53c:18]
SQUASHFS error: Root inode create failed

I tried creating the image on a x86 machine, and on a router itself; mounting fails in both cases.

I noticed that the image is mounted properly only if I disable the compression completly:

mksquashfs samba/ smb.sqfs -noI -noD -noF

However, id rather have compression enabled.

Any ideas?

It seems that OpenWRT's squashfs is patched with lzma and it won't mount normal squashfs images.

To make a squashfs image that will work under OpenWRT one needs a patched mksquashfs - one can be found here: http://wl500g.dyndns.org/lzma/mksquashfs-lzma

even with patched_kernel_squashfs-lzma ,mounting loopback could get into trouble if
the squashfs_image was created with "nopad,noappend" as showned in target/linux/image/squashfs.mk.
So the universal way is to :
dd if=image.squashfs of=/dev/mtdblock0
mount -tsquashfs /dev/mtdblock0 /mnt