afs: Support the AFS dynamic root
Support the AFS dynamic root which is a pseudo-volume that doesn't connect
to any server resource, but rather is just a root directory that
dynamically creates mountpoint directories where the name of such a
directory is the name of the cell.
Such a mount can be created thus:
mount -t afs none /afs -o dyn
Dynamic root superblocks aren't shared except by bind mounts and
propagation. Cell root volumes can then be mounted by referring to them by
name, e.g.:
ls /afs/grand.central.org/
ls /afs/.grand.central.org/
The kernel will upcall to consult the DNS if the address wasn't supplied
directly.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/Documentation/filesystems/afs.txt b/Documentation/filesystems/afs.txt
index ba99b5a..c5254f6 100644
--- a/Documentation/filesystems/afs.txt
+++ b/Documentation/filesystems/afs.txt
@@ -7,6 +7,7 @@
- Overview.
- Usage.
- Mountpoints.
+ - Dynamic root.
- Proc filesystem.
- The cell database.
- Security.
@@ -127,6 +128,22 @@
umount /afs
+============
+DYNAMIC ROOT
+============
+
+A mount option is available to create a serverless mount that is only usable
+for dynamic lookup. Creating such a mount can be done by, for example:
+
+ mount -t afs none /afs -o dyn
+
+This creates a mount that just has an empty directory at the root. Attempting
+to look up a name in this directory will cause a mountpoint to be created that
+looks up a cell of the same name, for example:
+
+ ls /afs/grand.central.org/
+
+
===============
PROC FILESYSTEM
===============