SUSE LINUX Documentation - Index of

mask::rwx
other::---
148 Reference
In addition to the entries initiated for the user geeko and the group mascots, a mask
entry has been generated. This mask entry is set automatically so that all permissions
are effective. setfacl automatically adapts existing mask entries to the settings
modified, unless you deactivate this feature with -n. mask defines the maximum effective
access permissions for all entries in the group class. This includes named user,
named group, and owning group. The group class permission bits displayed by ls -dl
mydir now correspond to the mask entry.
drwxrwx---+ ... tux project3 ... mydir
The first column of the output contains an additional + to indicate that there is an extended
ACL for this item.
According to the output of the ls command, the permissions for the mask entry include
write access. Traditionally, such permission bits would mean that the owning group
(here project3) also has write access to the directory mydir. However, the effective
access permissions for the owning group correspond to the overlapping portion of the
permissions defined for the owning group and for the mask—which is r-x in our example
(see Table 5.2, “Masking Access Permissions” (page 145)). As far as the effective
permissions of the owning group in this example are concerned, nothing has changed
even after the addition of the ACL entries.
Edit the mask entry with setfacl or chmod. For example, use chmod g-w mydir.
ls -dl mydir then shows:
drwxr-x---+ ... tux project3 ... mydir
getfacl mydir provides the following output:
# file: mydir
# owner: tux
# group: project3
user::rwx
user:geeko:rwx # effective: r-x
group::r-x
group:mascots:rwx # effective: r-x
mask::r-x
other::---
After executing the chmod command to remove the write permission from the group
class bits, the output of the ls command is sufficient to see that the mask bits must
have changed accordingly: write permission is again limited to the owner of mydir.