autofs-5.1.8 - allow -null map in indirect maps
We have had reports of GUI programs (such as Nautilus) probing for files
such as .hidden in the parent directory of the directory being accessed.
If using an indirect mount map with a wildcard map entry autofs is duty
bound to try and mount these which usually results in a mount failure but
can also cause lengthy delays in some cases.
There are some challenges to modifying application code and even if it
can be done it's always open to being broken later by developers that
aren't aware of the reasoning behind the original changes.
Now, there is a machanism in autofs that can be used to ignore certain
map entries, the "builtin map -null", see auto.master(5). Currently it
can be used only in the master map but this change extends it to be used
in indirect mount maps as well. In this way it can be used to handle
problematic entries by simply adding a map entry that uses the builtin
-null map.
For example:
.hidden -null
* someserver:/remote/home/&
This mechanism is not standard so if one is using systems other than
those with Linux autofs and central map storage, such as LDAP, then
it would be necessary to configure nsswitch to ensure the files map
source is consulted first followed by the remote map source. Then the
-null map entries included in a local file map that uses plus map
inclusion to move on the the central map source if there is no match.
For example, in /etc/auto.home we can have:
.hidden -null
+auto.home
Signed-off-by: Ian Kent <raven@themaw.net>
6 files changed
