[PATCH v2 15/15] docs: fs: proc.rst: convert a new chapter to ReST

From: Mauro Carvalho Chehab
Date: Tue Jun 23 2020 - 03:09:57 EST


A new chapter was added to proc.rst. Adjust the markups
to avoid this warning:

Documentation/filesystems/proc.rst:2194: WARNING: Inconsistent literal block quoting.

And to properly mark the code-blocks there.

Fixes: 37e7647a7212 ("docs: proc: add documentation for "hidepid=4" and "subset=pid" options and new mount behavior")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
Documentation/filesystems/proc.rst | 44 ++++++++++++++----------------
1 file changed, 21 insertions(+), 23 deletions(-)

diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 53a0230a08e2..cc0fd2685562 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -2179,46 +2179,44 @@ subset=pid hides all top level files and directories in the procfs that
are not related to tasks.

5 Filesystem behavior
-----------------------------
+---------------------------

Originally, before the advent of pid namepsace, procfs was a global file
system. It means that there was only one procfs instance in the system.

When pid namespace was added, a separate procfs instance was mounted in
each pid namespace. So, procfs mount options are global among all
-mountpoints within the same namespace.
+mountpoints within the same namespace::

-::
+ # grep ^proc /proc/mounts
+ proc /proc proc rw,relatime,hidepid=2 0 0

-# grep ^proc /proc/mounts
-proc /proc proc rw,relatime,hidepid=2 0 0
+ # strace -e mount mount -o hidepid=1 -t proc proc /tmp/proc
+ mount("proc", "/tmp/proc", "proc", 0, "hidepid=1") = 0
+ +++ exited with 0 +++

-# strace -e mount mount -o hidepid=1 -t proc proc /tmp/proc
-mount("proc", "/tmp/proc", "proc", 0, "hidepid=1") = 0
-+++ exited with 0 +++
-
-# grep ^proc /proc/mounts
-proc /proc proc rw,relatime,hidepid=2 0 0
-proc /tmp/proc proc rw,relatime,hidepid=2 0 0
+ # grep ^proc /proc/mounts
+ proc /proc proc rw,relatime,hidepid=2 0 0
+ proc /tmp/proc proc rw,relatime,hidepid=2 0 0

and only after remounting procfs mount options will change at all
-mountpoints.
+mountpoints::

-# mount -o remount,hidepid=1 -t proc proc /tmp/proc
+ # mount -o remount,hidepid=1 -t proc proc /tmp/proc

-# grep ^proc /proc/mounts
-proc /proc proc rw,relatime,hidepid=1 0 0
-proc /tmp/proc proc rw,relatime,hidepid=1 0 0
+ # grep ^proc /proc/mounts
+ proc /proc proc rw,relatime,hidepid=1 0 0
+ proc /tmp/proc proc rw,relatime,hidepid=1 0 0

This behavior is different from the behavior of other filesystems.

The new procfs behavior is more like other filesystems. Each procfs mount
creates a new procfs instance. Mount options affect own procfs instance.
It means that it became possible to have several procfs instances
-displaying tasks with different filtering options in one pid namespace.
+displaying tasks with different filtering options in one pid namespace::

-# mount -o hidepid=invisible -t proc proc /proc
-# mount -o hidepid=noaccess -t proc proc /tmp/proc
-# grep ^proc /proc/mounts
-proc /proc proc rw,relatime,hidepid=invisible 0 0
-proc /tmp/proc proc rw,relatime,hidepid=noaccess 0 0
+ # mount -o hidepid=invisible -t proc proc /proc
+ # mount -o hidepid=noaccess -t proc proc /tmp/proc
+ # grep ^proc /proc/mounts
+ proc /proc proc rw,relatime,hidepid=invisible 0 0
+ proc /tmp/proc proc rw,relatime,hidepid=noaccess 0 0
--
2.26.2