You're right, this is definitely what's missing:

>       linux-vdso.so.1 (0x00007ffeb2163000)
>        libfuse.so.2 => /lib/x86_64-linux-gnu/libfuse.so.2
> (0x00007ffb2d6b7000)
>        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0
> (0x00007ffb2d694000)
>        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007ffb2d4a3000)
>        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007ffb2d49d000)
>        /lib64/ld-linux-x86-64.so.2 (0x00007ffb2d728000)
>

And actually when running configure, I notice this:

> checking lz4.h usability... no
> checking lz4.h presence... no
> checking for lz4.h... no
>

Not sure what I'm missing here though...

$ apt list --installed | grep lz4
> liblz4-1/now 1.9.3-2 amd64 [installed,local]
> lz4/now 1.9.3-2 amd64 [installed,local]
>

On Fri, 20 Aug 2021 at 16:27, Gao Xiang <xiang@kernel.org> wrote:

> On Fri, Aug 20, 2021 at 04:16:20PM +0300, Igor Eisberg wrote:
> > You're quicker than expected, thanks for answering.
> > Not sure how to check if lz4 was builtin, but considering that erofsfuse
> is
> > only about 34.5KB (stripped) I would guess not?
> > Here's the output of erofsfuse -d (it prints this but never exists back
> to
> > shell unless I do Ctrl+C):
>
> Yeah, it will run erofsfuse in foreground, and you need to access the
> erofs compressed files, and then check the printed result.
>
> But I think there is a easier way to check if lz4 was linked, just type
> ldd <your erofsfuse program>
>
> if lz4 was linked, it will print some message like below:
>         linux-vdso.so.1 (0x00007ffee176e000)
>         libfuse.so.2 =&gt; /lib/x86_64-linux-gnu/libfuse.so.2
> (0x00007f8e21f24000)
>         liblz4.so.1 =&gt; /lib/x86_64-linux-gnu/liblz4.so.1
> (0x00007f8e21f01000)
>         libpthread.so.0 =&gt; /lib/x86_64-linux-gnu/libpthread.so.0
> (0x00007f8e21ee0000)
>         libc.so.6 =&gt; /lib/x86_64-linux-gnu/libc.so.6
> (0x00007f8e21d1f000)
>         libdl.so.2 =&gt; /lib/x86_64-linux-gnu/libdl.so.2
> (0x00007f8e21d1a000)
>         /lib64/ld-linux-x86-64.so.2 (0x00007f8e21f91000)
>
> Thanks,
> Gao Xiang
>
> >
> > erofsfuse 1.3
> > >
> > > disk: product.img
> > >
> > > mountpoint: product-mnt
> > >
> > > dbglevel: 7
> > >
> > > FUSE library version: 2.9.9
> > >
> > > nullpath_ok: 0
> > >
> > > nopath: 0
> > >
> > > utime_omit_ok: 0
> > >
> > > unique: 1, opcode: INIT (26), nodeid: 0, insize: 56, pid: 0
> > >
> > > INIT: 7.27
> > >
> > > flags=0x003ffffb
> > >
> > > max_readahead=0x00020000
> > >
> > > EROFS: erofsfuse_init() Line[23] Using FUSE protocol 7.27
> > >
> > >    INIT: 7.19
> > >
> > >    flags=0x00000011
> > >
> > >    max_readahead=0x00020000
> > >
> > >    max_write=0x00020000
> > >
> > >    max_background=0
> > >
> > >    congestion_threshold=0
> > >
> > >    unique: 1, success, outsize: 40
> > >
> > >
> > On Fri, 20 Aug 2021 at 15:49, Gao Xiang <xiang@kernel.org> wrote:
> >
> > > Hi Igor,
> > >
> > > On Fri, Aug 20, 2021 at 03:34:05PM +0300, Igor Eisberg wrote:
> > > > Hey there, getting straight to the point.
> > > > Our team is using Debian 10, in which erofs mounting is not
> supported and
> > > > we have no option of updating the kernel, nor do we have sudo
> permissions
> > > > on this server.
> > > >
> > > > Our only choice is to use erofsfuse to mount an Android image
> > > (compression
> > > > was used on that image), for the sole purpose of extracting its
> contents
> > > to
> > > > another folder for processing.
> > > > Tried on Debian 10, pop_OS! and even the latest Kubuntu (where native
> > > > mounting is supported), but on all of them I could not copy files
> which
> > > are
> > > > compressed from the mounted image to another location (ext4 file
> system).
> > > >
> > > > The error I'm getting is: "Operation not supported (95)"
> > > >
> > >
> > > Thanks for your feedback.
> > >
> > > Could you check if lz4 was built-in when building erofsfuse? I guess
> > > that is the reason (lack of lz4 support builtin).
> > >
> > > If not, could you add -d to erofsfuse when starting up?
> > >
> > > Thanks,
> > > Gao Xiang
> > >
> > > > Notes:
> > > > * Only extremely small (< 1 KB) files which are stored uncompressed
> are
> > > > copied successfully.
> > > > * Copying works perfectly when mounting the image with "sudo mount"
> on
> > > the
> > > > latest Kubuntu, so it has to be something with erofsfuse.
> > > >
> > > > Anything you can do to help resolve this?
> > > >
> > > > Best,
> > > > Igor.
> > >
>