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-rw-r--r--Documentation/filesystems/nfs/00-INDEX2
-rw-r--r--Documentation/filesystems/nfs/idmapper.txt67
-rw-r--r--Documentation/filesystems/nfs/nfsroot.txt22
-rw-r--r--Documentation/kernel-parameters.txt5
4 files changed, 95 insertions, 1 deletions
diff --git a/Documentation/filesystems/nfs/00-INDEX b/Documentation/filesystems/nfs/00-INDEX
index 2f68cd688769..3225a5662114 100644
--- a/Documentation/filesystems/nfs/00-INDEX
+++ b/Documentation/filesystems/nfs/00-INDEX
@@ -14,3 +14,5 @@ nfsroot.txt
14 - short guide on setting up a diskless box with NFS root filesystem. 14 - short guide on setting up a diskless box with NFS root filesystem.
15rpc-cache.txt 15rpc-cache.txt
16 - introduction to the caching mechanisms in the sunrpc layer. 16 - introduction to the caching mechanisms in the sunrpc layer.
17idmapper.txt
18 - information for configuring request-keys to be used by idmapper
diff --git a/Documentation/filesystems/nfs/idmapper.txt b/Documentation/filesystems/nfs/idmapper.txt
new file mode 100644
index 000000000000..c3852041a21f
--- /dev/null
+++ b/Documentation/filesystems/nfs/idmapper.txt
@@ -0,0 +1,67 @@
1
2=========
3ID Mapper
4=========
5Id mapper is used by NFS to translate user and group ids into names, and to
6translate user and group names into ids. Part of this translation involves
7performing an upcall to userspace to request the information. Id mapper will
8user request-key to perform this upcall and cache the result. The program
9/usr/sbin/nfs.upcall should be called by request-key, and will perform the
10translation and initialize a key with the resulting information.
11
12 NFS_USE_NEW_IDMAPPER must be selected when configuring the kernel to use this
13 feature.
14
15===========
16Configuring
17===========
18The file /etc/request-key.conf will need to be modified so /sbin/request-key can
19direct the upcall. The following line should be added:
20
21#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ...
22#====== ======= =============== =============== ===============================
23create id_resolver * * /usr/sbin/nfs.upcall %k %d 600
24
25This will direct all id_resolver requests to the program /usr/sbin/nfs.upcall.
26The last parameter, 600, defines how many seconds into the future the key will
27expire. This parameter is optional for /usr/sbin/nfs.upcall. When the timeout
28is not specified, nfs.upcall will default to 600 seconds.
29
30id mapper uses for key descriptions:
31 uid: Find the UID for the given user
32 gid: Find the GID for the given group
33 user: Find the user name for the given UID
34 group: Find the group name for the given GID
35
36You can handle any of these individually, rather than using the generic upcall
37program. If you would like to use your own program for a uid lookup then you
38would edit your request-key.conf so it look similar to this:
39
40#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ...
41#====== ======= =============== =============== ===============================
42create id_resolver uid:* * /some/other/program %k %d 600
43create id_resolver * * /usr/sbin/nfs.upcall %k %d 600
44
45Notice that the new line was added above the line for the generic program.
46request-key will find the first matching line and corresponding program. In
47this case, /some/other/program will handle all uid lookups and
48/usr/sbin/nfs.upcall will handle gid, user, and group lookups.
49
50See <file:Documentation/keys-request-keys.txt> for more information about the
51request-key function.
52
53
54==========
55nfs.upcall
56==========
57nfs.upcall is designed to be called by request-key, and should not be run "by
58hand". This program takes two arguments, a serialized key and a key
59description. The serialized key is first converted into a key_serial_t, and
60then passed as an argument to keyctl_instantiate (both are part of keyutils.h).
61
62The actual lookups are performed by functions found in nfsidmap.h. nfs.upcall
63determines the correct function to call by looking at the first part of the
64description string. For example, a uid lookup description will appear as
65"uid:user@domain".
66
67nfs.upcall will return 0 if the key was instantiated, and non-zero otherwise.
diff --git a/Documentation/filesystems/nfs/nfsroot.txt b/Documentation/filesystems/nfs/nfsroot.txt
index f2430a7974e1..90c71c6f0d00 100644
--- a/Documentation/filesystems/nfs/nfsroot.txt
+++ b/Documentation/filesystems/nfs/nfsroot.txt
@@ -159,6 +159,28 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>
159 Default: any 159 Default: any
160 160
161 161
162nfsrootdebug
163
164 This parameter enables debugging messages to appear in the kernel
165 log at boot time so that administrators can verify that the correct
166 NFS mount options, server address, and root path are passed to the
167 NFS client.
168
169
170rdinit=<executable file>
171
172 To specify which file contains the program that starts system
173 initialization, administrators can use this command line parameter.
174 The default value of this parameter is "/init". If the specified
175 file exists and the kernel can execute it, root filesystem related
176 kernel command line parameters, including `nfsroot=', are ignored.
177
178 A description of the process of mounting the root file system can be
179 found in:
180
181 Documentation/early-userspace/README
182
183
162 184
163 185
1643.) Boot Loader 1863.) Boot Loader
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index b660085dcc69..4bc2f3c3da5b 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1541,12 +1541,15 @@ and is between 256 and 4096 characters. It is defined in the file
1541 1 to enable accounting 1541 1 to enable accounting
1542 Default value is 0. 1542 Default value is 0.
1543 1543
1544 nfsaddrs= [NFS] 1544 nfsaddrs= [NFS] Deprecated. Use ip= instead.
1545 See Documentation/filesystems/nfs/nfsroot.txt. 1545 See Documentation/filesystems/nfs/nfsroot.txt.
1546 1546
1547 nfsroot= [NFS] nfs root filesystem for disk-less boxes. 1547 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
1548 See Documentation/filesystems/nfs/nfsroot.txt. 1548 See Documentation/filesystems/nfs/nfsroot.txt.
1549 1549
1550 nfsrootdebug [NFS] enable nfsroot debugging messages.
1551 See Documentation/filesystems/nfs/nfsroot.txt.
1552
1550 nfs.callback_tcpport= 1553 nfs.callback_tcpport=
1551 [NFS] set the TCP port on which the NFSv4 callback 1554 [NFS] set the TCP port on which the NFSv4 callback
1552 channel should listen. 1555 channel should listen.