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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-25 13:48:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-25 13:48:29 -0700
commit74eb94b218d087798a52c0b4f1379b635287a4b8 (patch)
tree4e467c3014c2b1169f6f71d88cf5d1598f3ce28e /Documentation/filesystems
parent7b6181e06841f5ad15c4ff708b967b4db65a64de (diff)
parent9a84d38031c258a17bb39beed1e500eadee67407 (diff)
Merge branch 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
* 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (67 commits) SUNRPC: Cleanup duplicate assignment in rpcauth_refreshcred nfs: fix unchecked value Ask for time_delta during fsinfo probe Revalidate caches on lock SUNRPC: After calling xprt_release(), we must restart from call_reserve NFSv4: Fix up the 'dircount' hint in encode_readdir NFSv4: Clean up nfs4_decode_dirent NFSv4: nfs4_decode_dirent must clear entry->fattr->valid NFSv4: Fix a regression in decode_getfattr NFSv4: Fix up decode_attr_filehandle() to handle the case of empty fh pointer NFS: Ensure we check all allocation return values in new readdir code NFS: Readdir plus in v4 NFS: introduce generic decode_getattr function NFS: check xdr_decode for errors NFS: nfs_readdir_filler catch all errors NFS: readdir with vmapped pages NFS: remove page size checking code NFS: decode_dirent should use an xdr_stream SUNRPC: Add a helper function xdr_inline_peek NFS: remove readdir plus limit ...
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/nfs/00-INDEX2
-rw-r--r--Documentation/filesystems/nfs/idmapper.txt67
-rw-r--r--Documentation/filesystems/nfs/nfsroot.txt22
3 files changed, 91 insertions, 0 deletions
diff --git a/Documentation/filesystems/nfs/00-INDEX b/Documentation/filesystems/nfs/00-INDEX
index 2f68cd68876..3225a566211 100644
--- a/Documentation/filesystems/nfs/00-INDEX
+++ b/Documentation/filesystems/nfs/00-INDEX
@@ -14,3 +14,5 @@ nfsroot.txt
- short guide on setting up a diskless box with NFS root filesystem.
rpc-cache.txt
- introduction to the caching mechanisms in the sunrpc layer.
+idmapper.txt
+ - 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 00000000000..c3852041a21
--- /dev/null
+++ b/Documentation/filesystems/nfs/idmapper.txt
@@ -0,0 +1,67 @@
+
+=========
+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. Id mapper will
+user request-key to perform this upcall and cache the result. The program
+/usr/sbin/nfs.upcall should be called by request-key, and will perform the
+translation and initialize a key with the resulting information.
+
+ NFS_USE_NEW_IDMAPPER must be selected when configuring the kernel to use this
+ feature.
+
+===========
+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.upcall %k %d 600
+
+This will direct all id_resolver requests to the program /usr/sbin/nfs.upcall.
+The last parameter, 600, defines how many seconds into the future the key will
+expire. This parameter is optional for /usr/sbin/nfs.upcall. When the timeout
+is not specified, nfs.upcall will default to 600 seconds.
+
+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
+ group: Find the group name for the given GID
+
+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.upcall %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.upcall will handle gid, user, and group lookups.
+
+See <file:Documentation/keys-request-keys.txt> for more information about the
+request-key function.
+
+
+==========
+nfs.upcall
+==========
+nfs.upcall 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
+then passed as an argument to keyctl_instantiate (both are part of keyutils.h).
+
+The actual lookups are performed by functions found in nfsidmap.h. nfs.upcall
+determines the correct function to call by looking at the first part of the
+description string. For example, a uid lookup description will appear as
+"uid:user@domain".
+
+nfs.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 f2430a7974e..90c71c6f0d0 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>
Default: any
+nfsrootdebug
+
+ This parameter enables debugging messages to appear in the kernel
+ log at boot time so that administrators can verify that the correct
+ NFS mount options, server address, and root path are passed to the
+ NFS client.
+
+
+rdinit=<executable file>
+
+ To specify which file contains the program that starts system
+ initialization, administrators can use this command line parameter.
+ The default value of this parameter is "/init". If the specified
+ file exists and the kernel can execute it, root filesystem related
+ kernel command line parameters, including `nfsroot=', are ignored.
+
+ A description of the process of mounting the root file system can be
+ found in:
+
+ Documentation/early-userspace/README
+
+
3.) Boot Loader