Create new user with home directory inside another user's existing home directory -- both users must own the sub-directory

Question

Here's my situation:

• I have a user storageUser with a home directory of /storage
• storageUser owns /storage with full (RWE) rights
• Within /storage I have a directory media
• I'd like to create a new user mediaUser who's home directory is /storage/media with read-only permissions while maintaining storageUser's full RWE permissions

When using FTP or SSH to sign into the server, I'd like storageUser to be in control of /storage with full RWE permissions, while mediaUser only being able to read /storage/media. I'd like to give access to mediaUser in the future to share my media folder without people being able to make any changes.

Here's what I tried:

• Created mediaUser and set their password

useradd mediaUser
passwd mediaUser
...

• Created a new group storageGroup

groupadd storageGroup

• Added both storageUser and mediaUser to the group

usermod -a -G storageGroup storageUser
usermod -a -G storageGroup mediaUser

• Changed ownership permissions so that storageUser would have permission level 7 (read-write-execute) and storageGroup would have permission level 4 (read-only)

chown -R storageUser:storageGroup media
chmod -R 740 Media

• Changed the home directory of mediaUser

usermod -d /storage/media mediaUser

Permissions for storageUser seem to working OK, but when I SSH into the server as mediaUser, I get this error:

Could not chdir to home directory /storage/media: Permission denied

mediaUser also cannot read directory contents with ls

ls: cannot access '/storage/media': Permission denied

What am I doing wrong?

Answer 1

Create Users

1. useradd mediaUser
2. useradd storageUser

Setup Users

1. passwd mediaUser
2. passwd storageUser

Create Group

1. groupadd storageGroup

Create Directory

1. mkdir /storage/media

Assign Users to Group

1. usermod -a -G storageGroup {mediaUser,storageUser}

Change Owner of Directory to Group

1. chgrp storageGroup /storage/media

Now everyone in group storageGroup owns the particular directory. Removing a user from storageGroup also removes access to that directory. See also man chgrp This method also removes the need for storageUser, unless you're using that user for some other reason.

Answer 2

Beside users, groups, permissions and physical folders you can create soft or hard link with command ln which should make folders work as you expect. Entering the folder provided by link (shortcut) should work as it was real folder.

By default ln creates hard link, with option -s it creates soft link. Look into manual by man ln.