Commit 61f00590 authored by Jonathan Corbet's avatar Jonathan Corbet
Browse files

Merge branch 'nfs' into docs-next 

Daniel W. S. Almeida writes:

  This series converts a few docs in Documentation/filesystems/nfs to RST.
  The docs were also moved into admin-guide because they contain
  information that might be useful for system administrators

  Most changes are related to aesthetics and presentation, i.e. the content
  itself remains mostly untouched. The use of markup was limited in order
  not to negatively impact the plain-text reading experience.
parents a1986433 6996e8ca

Documentation/admin-guide/index.rst

+1 −0
Original line number Diff line number Diff line
@@ -76,6 +76,7 @@ configure specific aspects of kernel behavior to your liking. 
   device-mapper/index

   efi-stub

   ext4

   nfs/index

   gpio/index

   highuid

   hw_random

Documentation/filesystems/nfs/fault_injection.txt→Documentation/admin-guide/nfs/fault_injection.rst

+3 −2
Original line number Diff line number Diff line 
===================

NFS Fault Injection

===================



Fault Injection

===============

Fault injection is a method for forcing errors that may not normally occur, or

may be difficult to reproduce.  Forcing these errors in a controlled environment

can help the developer find and fix bugs before their code is shipped in a

Documentation/admin-guide/nfs/index.rst

0 → 100644
+15 −0
Original line number Diff line number Diff line 
=============

NFS

=============



.. toctree::

    :maxdepth: 1



    nfs-client

    nfsroot

    nfs-rdma

    nfsd-admin-interfaces

    nfs-idmapper

    pnfs-block-server

    pnfs-scsi-server

    fault_injection

Documentation/filesystems/nfs/nfs.txt→Documentation/admin-guide/nfs/nfs-client.rst

+45 −40
Original line number Diff line number Diff line 
==========

NFS Client

==========



The NFS client

==============
@@ -59,10 +62,11 @@ The DNS resolver 


NFSv4 allows for one server to refer the NFS client to data that has been

migrated onto another server by means of the special "fs_locations"

attribute. See

	http://tools.ietf.org/html/rfc3530#section-6

and

	http://tools.ietf.org/html/draft-ietf-nfsv4-referrals-00

attribute. See `RFC3530 Section 6: Filesystem Migration and Replication`_ and

`Implementation Guide for Referrals in NFSv4`_.



.. _RFC3530 Section 6\: Filesystem Migration and Replication: http://tools.ietf.org/html/rfc3530#section-6

.. _Implementation Guide for Referrals in NFSv4: http://tools.ietf.org/html/draft-ietf-nfsv4-referrals-00



The fs_locations information can take the form of either an ip address and

a path, or a DNS hostname and a path. The latter requires the NFS client to
@@ -94,7 +98,8 @@ Assuming that the user has the 'rpc_pipefs' filesystem mounted in the usual 
       script, and <ttl> is the 'time to live' of this cache entry (in

       units of seconds).



       Note: If <ip address> is invalid, say the string "0", then a negative

       .. note::

            If <ip address> is invalid, say the string "0", then a negative

            entry is created, which will cause the kernel to treat the hostname

            as having no valid DNS translation.
@@ -103,6 +108,7 @@ Assuming that the user has the 'rpc_pipefs' filesystem mounted in the usual 


A basic sample /sbin/nfs_cache_getent

=====================================

.. code-block:: sh



    #!/bin/bash

    #
@@ -133,4 +139,3 @@ case "${cachename}" in 
            ;;

    esac

    echo "${result} ${name} ${ttl}" >${cache_path}

Documentation/filesystems/nfs/idmapper.txt→Documentation/admin-guide/nfs/nfs-idmapper.rst

+17 −14
Original line number Diff line number Diff line 
=============

NFS ID Mapper

=============



=========

ID Mapper

=========

Id mapper is used by NFS to translate user and group ids into names, and to

translate user and group names into ids.  Part of this translation involves

performing an upcall to userspace to request the information.  There are two
@@ -20,22 +20,24 @@ legacy rpc.idmap daemon for the id mapping. This result will be stored 
in a custom NFS idmap cache.





===========

Configuring

===========



The file /etc/request-key.conf will need to be modified so /sbin/request-key can

direct the upcall.  The following line should be added:



#OP	TYPE	DESCRIPTION	CALLOUT INFO	PROGRAM ARG1 ARG2 ARG3 ...

#======	=======	===============	===============	===============================

create	id_resolver	*	*		/usr/sbin/nfs.idmap %k %d 600

``#OP	TYPE	DESCRIPTION	CALLOUT INFO	PROGRAM ARG1 ARG2 ARG3 ...``

``#======	=======	===============	===============	===============================``

``create	id_resolver	*	*		/usr/sbin/nfs.idmap %k %d 600``





This will direct all id_resolver requests to the program /usr/sbin/nfs.idmap.

The last parameter, 600, defines how many seconds into the future the key will

expire.  This parameter is optional for /usr/sbin/nfs.idmap.  When the timeout

is not specified, nfs.idmap will default to 600 seconds.



id mapper uses for key descriptions:

id mapper uses for key descriptions::



	  uid:  Find the UID for the given user

	  gid:  Find the GID for the given group

	 user:  Find the user  name for the given UID
@@ -45,23 +47,24 @@ You can handle any of these individually, rather than using the generic upcall 
program.  If you would like to use your own program for a uid lookup then you

would edit your request-key.conf so it look similar to this:



#OP	TYPE	DESCRIPTION	CALLOUT INFO	PROGRAM ARG1 ARG2 ARG3 ...

#======	=======	===============	===============	===============================

create	id_resolver	uid:*	*		/some/other/program %k %d 600

create	id_resolver	*	*		/usr/sbin/nfs.idmap %k %d 600

``#OP	TYPE	DESCRIPTION	CALLOUT INFO	PROGRAM ARG1 ARG2 ARG3 ...``

``#======	=======	===============	===============	===============================``

``create	id_resolver	uid:*	*		/some/other/program %k %d 600``

``create	id_resolver	*	*		/usr/sbin/nfs.idmap %k %d 600``





Notice that the new line was added above the line for the generic program.

request-key will find the first matching line and corresponding program.  In

this case, /some/other/program will handle all uid lookups and

/usr/sbin/nfs.idmap will handle gid, user, and group lookups.



See <file:Documentation/security/keys/request-key.rst> for more information

See Documentation/security/keys/request-key.rst for more information

about the request-key function.





=========

nfs.idmap

=========



nfs.idmap is designed to be called by request-key, and should not be run "by

hand".  This program takes two arguments, a serialized key and a key

description.  The serialized key is first converted into a key_serial_t, and

CRA Git | Maintained and supported by SUSTech CRA and CCSE