I’ve just discovered that the magic database for the file(1) command in Debian/Unstable has no support for Linux Software RAID and that it’s support for BTRFS is lacking (no reporting of space used, number of devices, or the UUID). Below is my first draft of a change to fix these problems. I would appreciate it if someone with a big-endian system could test these out and let me know how they go, I suspect that I will have to change the “lelong” types to “long” but I’m not sure.
4096 lelong 0xa92b4efc Linux Software RAID
>4100 lelong x version 1.2 (%d)
>4112 belong x UUID=%8x:
>4116 belong x \b%8x:
>4120 belong x \b%8x:
>4124 belong x \b%8x
>4128 string x name=%s
>4168 lelong x level=%d
>4188 lelong x disks=%d
0 lelong 0xa92b4efc Linux Software RAID
>4 lelong x version 1.1 (%d)
>16 belong x UUID=%8x:
>20 belong x \b%8x:
>24 belong x \b%8x:
>28 belong x \b%8x
>32 string x name=%s
>72 lelong x level=%d
>92 lelong x disks=%d
# BTRFS
0x10040 string _BHRfS_M BTRFS Filesystem
>0x1012b string >\0 label "%s",
>0x10090 lelong x sectorsize %d,
>0x10094 lelong x nodesize %d,
>0x10098 lelong x leafsize %d,
>0x10020 belong x UUID=%8x-
>0x10024 beshort x \b%4x-
>0x10026 beshort x \b%4x-
>0x10028 beshort x \b%4x-
>0x1002a beshort x \b%4x
>0x1002c belong x \b%8x,
>0x10078 lequad x %lld/
>0x10070 lequad x \b%lld bytes used,
>0x10088 lequad x %lld devices