docs: filesystems: convert automount-support.txt to ReST

- Add a SPDX header;
- Add a document title;
- Adjust section titles;
- Mark literal blocks as such;
- Add it to filesystems/index.rst.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/ba7e2f2bf9aa2c7096772f5e7e8e609cb5fce07c.1588021877.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/filesystems/automount-support.txt → Documentation/filesystems/automount-support.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+Automount Support
+=================
+
+
 Support is available for filesystems that wish to do automounting
 support (such as kAFS which can be found in fs/afs/ and NFS in
 fs/nfs/). This facility includes allowing in-kernel mounts to be
@@ -5,13 +12,12 @@ performed and mountpoint degradation to be requested. The latter can
 also be requested by userspace.
 
 
-======================
-IN-KERNEL AUTOMOUNTING
+In-Kernel Automounting
 ======================
 
 See section "Mount Traps" of  Documentation/filesystems/autofs.rst
 
-Then from userspace, you can just do something like:
+Then from userspace, you can just do something like::
 
 	[root@andromeda root]# mount -t afs \#root.afs. /afs
 	[root@andromeda root]# ls /afs
@@ -21,7 +27,7 @@ Then from userspace, you can just do something like:
 	[root@andromeda root]# ls /afs/cambridge/afsdoc/
 	ChangeLog  html  LICENSE  pdf  RELNOTES-1.2.2
 
-And then if you look in the mountpoint catalogue, you'll see something like:
+And then if you look in the mountpoint catalogue, you'll see something like::
 
 	[root@andromeda root]# cat /proc/mounts
 	...
@@ -30,8 +36,7 @@ And then if you look in the mountpoint catalogue, you'll see something like:
 	#afsdoc. /afs/cambridge.redhat.com/afsdoc afs rw 0 0
 
 
-===========================
-AUTOMATIC MOUNTPOINT EXPIRY
+Automatic Mountpoint Expiry
 ===========================
 
 Automatic expiration of mountpoints is easy, provided you've mounted the
@@ -43,7 +48,8 @@ To do expiration, you need to follow these steps:
      hung.
 
  (2) When a new mountpoint is created in the ->d_automount method, add
-     the mnt to the list using mnt_set_expiry()
+     the mnt to the list using mnt_set_expiry()::
+
              mnt_set_expiry(newmnt, &afs_vfsmounts);
 
  (3) When you want mountpoints to be expired, call mark_mounts_for_expiry()
@@ -70,8 +76,7 @@ and the copies of those that are on an expiration list will be added to the
 same expiration list.
 
 
-=======================
-USERSPACE DRIVEN EXPIRY
+Userspace Driven Expiry
 =======================
 
 As an alternative, it is possible for userspace to request expiry of any

Documentation/filesystems/index.rst

@@ -25,6 +25,8 @@ algorithms work.
    locking
    directory-locking
 
+   automount-support
+
    caching/index
 
    porting