Re: Regression in squashfs mount option handling in v5.4

[Randy Dunlap]

[adding Cc-s]

On 11/30/19 10:15 AM, Jeremi Piotrowski wrote:
> Hi,
> 
> I'm working on an embedded project which uses 'rauc' as an updater. rauc mounts
> a squashfs image using
> 
>   mount -t squashfs -o ro,loop,sizelimit=xxx squashfs.img /mnt
> 
> On my system mount is busybox, and busybox does not know the sizelimit
> parameter, so it simply passes it on to the mount syscall. The syscall
> arguments end up being:
> 
>   mount("/dev/loop0", "dir", "squashfs", MS_RDONLY|MS_SILENT, "sizelimit=xxx")
> 
> Until kernel 5.4 this worked, since 5.4 this returns EINVAL and dmesg contains
> the line "squashfs: Unknown parameter 'sizelimit'". I believe this has to do
> with the conversion of squashfs to the new mount api. 
> 
> This is an unfortunate regression, and it does not seem like this can be simply
> reverted. What is the suggested course of action?
> 
> Please cc me on replies, I'm not subscribed to the list.
> 
> Thanks,
> Jeremi
> 


-- 
~Randy
Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>