How to access sdcard?

[lapsio]

I'm trying to find a way to access sd card but I'm getting Permission Denied everywhere. Even with fake root. /data is inaccessible, there's no /sdcard and most of directories in /mnt return Permission Denied as well.

I gave UserLAnd permission to Storage on Android permissions level. Tried reinstalling multiple times. Didn't help.

[lapsio]

also where are stored UserLAnd files in Android storage? Are they still located in some "public" location like sdcard or somewhere in system files, inaccessible by Android file browsers?

[thedward]

Android's /sdcard appears to be mounted at /host-rootfs/sdcard/.

[lapsio]

Could you add some symlink somewhere? Because listing /host-rootfs itself gives Permission denied so it's a bit hard to guess what's inside and that you can jump over it to /host-rootfs/sdcard/

[corbinlc]

We can add a binding

[corbinlc]

We had this on gnuroot debian and will do it here too. The path for the sdcard is not always the same, so the binding will not always be /sdcard -> /host-rootfs/sdcard

A proot binding is conceptually similar to a symbolic link, but different.

[AdamMatthewLTM]

@lapsio ,

Thank you for your report and request. I have organized this reply into two parts, the first being related to permissions and the second being related to UserLAnd file locations.

Part 1:
Even as root, some directories in Android will return a 'permission denied' error if you attempt to perform certain tasks within them. For example, I can confirm that in the "data" folder the ls command will return a permission denied error. This is actually intended behavior in Android. However, you may be able to perform the same command within certain sub-directories.

"ls /data/data/tech.ula" should not return an error. If you can confirm this works for you @lapsio , please reply to this thread.

In regards to sdcard permissions , Android implements a different method of accessing it. As @thedward stated, the directory /host-rootfs/sdcard is the correct method to access that location. Furthermore, I do not believe any subdirectories within /host-rootfs should be met with permissions errors if you are accessing it as root.

Part 2:
UserLAnd undergoes a somewhat complex installation procedure, and the short version (from my limited understanding - if this is incorrect please correct this statement) is that the majority of installation files for debian will be found in the /data folder and subfolders for Android.

Any downloaded files will be stored in the Android download manager default location (folder "Downloads" for Android 7.0).

Thank you for filing this issue,
-Adam

[lapsio]

Yeah i know proot will give Permission Denied in lots of cases because it's fake root so it's not an issue. Issue is that there are some files somewhere which are accessible after going through "denied wall of obscurity". I think listing them in documentation or some README file in default user's home would be sufficient solution if they're not that much predictable. Well I just added ln -s /host-rootfs/sdcard / and it's fine but I wouldn't guess it without help. Here are my permissions after sudo su:

root@localhost:/home/lapsio# ls /data                                                  
ls: cannot open directory '/data': Permission denied                                   
root@localhost:/home/lapsio# ls /data/                                                 
ls: cannot open directory '/data/': Permission denied                                  
root@localhost:/home/lapsio# ls /data/data                                             
ls: cannot open directory '/data/data': Permission denied                              
root@localhost:/home/lapsio# ls /data/data/                                            
ls: cannot open directory '/data/data/': Permission denied                             
root@localhost:/home/lapsio# ls /data/data/tech.ula                                    
cache  code_cache  databases  files  shared_prefs                                      
root@localhost:/home/lapsio# ls /host-rootfs                                           
ls: cannot open directory '/host-rootfs': Permission denied                            
root@localhost:/home/lapsio# ls /host-rootfs/                                          
ls: cannot open directory '/host-rootfs/': Permission denied                           
root@localhost:/home/lapsio# ls /host-rootfs/sdcard                                    
ASUS                    Music               Downloads.... etc                                
root@localhost:/home/lapsio#

[lapsio]

This is another thing that worries me a bit but I don't know if it's okay:

lapsio@localhost ~> ls /mnt/                                                           
ls: cannot access '/mnt/media_rw': Permission denied                                   
appfuse/  asec/  expand/  media_rw/  obb/  runtime/  sdcard@  secure/  user/           
lapsio@localhost ~> file /mnt/sdcard                                                   
/mnt/sdcard: broken symbolic link to /storage/self/primary                             
lapsio@localhost ~>

I mean broken symbolic links is not really something you expect on fresh system i guess... Besides, for now this version seems to have superior compatibility comparing to old one in terms of files permissions handling. I compiled and installed without any issues some programs that required manual install scripts modification under old GNURoot in order to not crash in the middle.

[Root-voidX]

So i would like to add, I can definitely ls /host-rootfs and most of the other sub directories here except for /host-rootfs/data. And yes I can ls /host-rootfs/mnt. I assume at least for my device (S9+) that root directory is in /host-rootfs.