[PATCH v2 27/29] docs: filesystems: convert sysfs-tagging.txt to ReST

From: Mauro Carvalho Chehab
Date: Tue Apr 21 2020 - 12:55:20 EST


- Add a SPDX header;
- Adjust document title;
- Some whitespace fixes and new line breaks;
- Mark literal blocks as such;
- Add it to filesystems/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---
Documentation/filesystems/index.rst | 1 +
.../{sysfs-tagging.txt => sysfs-tagging.rst} | 22 ++++++++++++-------
2 files changed, 15 insertions(+), 8 deletions(-)
rename Documentation/filesystems/{sysfs-tagging.txt => sysfs-tagging.rst} (72%)

diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index 65719684295e..11852bf3e758 100644
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -35,6 +35,7 @@ algorithms work.
seq_file
sharedsubtree
sysfs-pci
+ sysfs-tagging

automount-support

diff --git a/Documentation/filesystems/sysfs-tagging.txt b/Documentation/filesystems/sysfs-tagging.rst
similarity index 72%
rename from Documentation/filesystems/sysfs-tagging.txt
rename to Documentation/filesystems/sysfs-tagging.rst
index c7c8e6438958..8888a05c398e 100644
--- a/Documentation/filesystems/sysfs-tagging.txt
+++ b/Documentation/filesystems/sysfs-tagging.rst
@@ -1,5 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=============
Sysfs tagging
--------------
+=============

(Taken almost verbatim from Eric Biederman's netns tagging patch
commit msg)
@@ -18,25 +21,28 @@ in the directories and applications only see a limited set of
the network devices.

Each sysfs directory entry may be tagged with a namespace via the
-void *ns member of its kernfs_node. If a directory entry is tagged,
-then kernfs_node->flags will have a flag between KOBJ_NS_TYPE_NONE
+``void *ns member`` of its ``kernfs_node``. If a directory entry is tagged,
+then ``kernfs_node->flags`` will have a flag between KOBJ_NS_TYPE_NONE
and KOBJ_NS_TYPES, and ns will point to the namespace to which it
belongs.

-Each sysfs superblock's kernfs_super_info contains an array void
-*ns[KOBJ_NS_TYPES]. When a task in a tagging namespace
+Each sysfs superblock's kernfs_super_info contains an array
+``void *ns[KOBJ_NS_TYPES]``. When a task in a tagging namespace
kobj_nstype first mounts sysfs, a new superblock is created. It
will be differentiated from other sysfs mounts by having its
-s_fs_info->ns[kobj_nstype] set to the new namespace. Note that
+``s_fs_info->ns[kobj_nstype]`` set to the new namespace. Note that
through bind mounting and mounts propagation, a task can easily view
the contents of other namespaces' sysfs mounts. Therefore, when a
namespace exits, it will call kobj_ns_exit() to invalidate any
kernfs_node->ns pointers pointing to it.

Users of this interface:
-- define a type in the kobj_ns_type enumeration.
-- call kobj_ns_type_register() with its kobj_ns_type_operations which has
+
+- define a type in the ``kobj_ns_type`` enumeration.
+- call kobj_ns_type_register() with its ``kobj_ns_type_operations`` which has
+
- current_ns() which returns current's namespace
- netlink_ns() which returns a socket's namespace
- initial_ns() which returns the initial namesapce
+
- call kobj_ns_exit() when an individual tag is no longer valid
--
2.25.2