Here's a comprehensive solution to the common Samba permissions issue where newly created files/directories don't inherit the desired 777 permissions:

The problem stems from Linux's default umask behavior interacting with Samba's permission settings. When users create files through Samba, the system applies both the user's umask and Samba's mask settings, often resulting in stricter permissions than desired.

Edit your /etc/samba/smb.conf to include these directives under the relevant share:

[shared_folder]
   path = /path/to/shared
   create mask = 0777
   directory mask = 0777
   force create mode = 0777
   force directory mode = 0777
   force user = shareduser
   force group = sharedgroup

Combine the Samba configuration with these system settings:

# Set default ACLs on the shared directory
sudo setfacl -R -d -m u::rwx,g::rwx,o::rwx /path/to/shared

# Verify with:
getfacl /path/to/shared

For more control, use inotify to watch for new files:

#!/bin/bash
inotifywait -m -r -e create --format '%w%f' /path/to/shared | while read NEWFILE
do
   if [ -d "$NEWFILE" ]; then
      chmod 777 "$NEWFILE"
   else
      chmod 666 "$NEWFILE"
   fi
done

Edit /etc/profile or create /etc/profile.d/set_umask.sh:

# Set system-wide umask
if [ "$(id -u)" -ge 1000 ]; then
    umask 000
fi

While 777 permissions solve access issues, they present security risks. Consider these alternatives:

• Use proper group permissions instead of world-writable
• Implement ACLs for finer-grained control
• Create a shared group and setgid on directories

When managing multi-user Samba shares, permission issues can become a recurring headache. The core issue manifests when different users create files/directories with restrictive default permissions (typically 755 for directories and 644 for files). This creates access problems when users from different systems (Windows, Mac, Linux) need to collaborate in the same shared folder.

Linux applies default permissions based on the umask value. The standard umask of 022 (resulting in 755 for dirs) gets applied even through Samba. What we need is to override this system-wide behavior specifically for our shared directory.

1. Setting Directory Defaults with setfacl

The modern approach uses Access Control Lists (ACLs):

# Install ACL support if needed
sudo apt-get install acl

# Set default ACLs on the shared folder
sudo setfacl -Rdm u::rwx,g::rwx,o::rwx /path/to/shared_folder
sudo setfacl -Rm u::rwx,g::rwx,o::rwx /path/to/shared_folder

2. Samba Configuration Tweaks /h2>

Add these parameters to your smb.conf:

[shared]
   path = /path/to/shared_folder
   create mask = 0777
   directory mask = 0777
   force create mode = 0777
   force directory mode = 0777
   inherit permissions = yes
   inherit acls = yes

3. Filesystem Mount Options

For ext4 filesystems, add these options to /etc/fstab:

/dev/sdX1  /path/to/shared_folder  ext4  defaults,acl,umask=000  0  2

As a temporary measure while implementing the permanent solution, you can use this incrontab entry:

*/5 * * * * find /path/to/shared_folder -type d -exec chmod 777 {} \;

While 777 permissions solve access issues, consider more secure alternatives:

• Create a common group for all users
• Set SGID bit to maintain group ownership
• Use finer-grained ACLs for specific needs

After implementing changes:

# Check directory permissions
ls -ld /path/to/shared_folder

# Verify ACL settings
getfacl /path/to/shared_folder

# Test file creation as different users
sudo -u user1 touch /path/to/shared_folder/testfile
ls -l /path/to/shared_folder/testfile