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-rw-r--r--Documentation/filesystems/nfs/idmapper.txt28
1 files changed, 14 insertions, 14 deletions
diff --git a/Documentation/filesystems/nfs/idmapper.txt b/Documentation/filesystems/nfs/idmapper.txt
index c3852041a21f..b9b4192ea8b5 100644
--- a/Documentation/filesystems/nfs/idmapper.txt
+++ b/Documentation/filesystems/nfs/idmapper.txt
@@ -6,7 +6,7 @@ Id 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 6translate user and group names into ids. Part of this translation involves
7performing an upcall to userspace to request the information. Id mapper will 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 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 9/usr/sbin/nfs.idmap should be called by request-key, and will perform the
10translation and initialize a key with the resulting information. 10translation and initialize a key with the resulting information.
11 11
12 NFS_USE_NEW_IDMAPPER must be selected when configuring the kernel to use this 12 NFS_USE_NEW_IDMAPPER must be selected when configuring the kernel to use this
@@ -20,12 +20,12 @@ direct the upcall. The following line should be added:
20 20
21#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ... 21#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ...
22#====== ======= =============== =============== =============================== 22#====== ======= =============== =============== ===============================
23create id_resolver * * /usr/sbin/nfs.upcall %k %d 600 23create id_resolver * * /usr/sbin/nfs.idmap %k %d 600
24 24
25This will direct all id_resolver requests to the program /usr/sbin/nfs.upcall. 25This will direct all id_resolver requests to the program /usr/sbin/nfs.idmap.
26The last parameter, 600, defines how many seconds into the future the key will 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 27expire. This parameter is optional for /usr/sbin/nfs.idmap. When the timeout
28is not specified, nfs.upcall will default to 600 seconds. 28is not specified, nfs.idmap will default to 600 seconds.
29 29
30id mapper uses for key descriptions: 30id mapper uses for key descriptions:
31 uid: Find the UID for the given user 31 uid: Find the UID for the given user
@@ -39,29 +39,29 @@ would edit your request-key.conf so it look similar to this:
39 39
40#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ... 40#OP TYPE DESCRIPTION CALLOUT INFO PROGRAM ARG1 ARG2 ARG3 ...
41#====== ======= =============== =============== =============================== 41#====== ======= =============== =============== ===============================
42create id_resolver uid:* * /some/other/program %k %d 600 42create id_resolver uid:* * /some/other/program %k %d 600
43create id_resolver * * /usr/sbin/nfs.upcall %k %d 600 43create id_resolver * * /usr/sbin/nfs.idmap %k %d 600
44 44
45Notice that the new line was added above the line for the generic program. 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 46request-key will find the first matching line and corresponding program. In
47this case, /some/other/program will handle all uid lookups and 47this case, /some/other/program will handle all uid lookups and
48/usr/sbin/nfs.upcall will handle gid, user, and group lookups. 48/usr/sbin/nfs.idmap will handle gid, user, and group lookups.
49 49
50See <file:Documentation/keys-request-keys.txt> for more information about the 50See <file:Documentation/keys-request-keys.txt> for more information about the
51request-key function. 51request-key function.
52 52
53 53
54========== 54=========
55nfs.upcall 55nfs.idmap
56========== 56=========
57nfs.upcall is designed to be called by request-key, and should not be run "by 57nfs.idmap 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 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 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). 60then passed as an argument to keyctl_instantiate (both are part of keyutils.h).
61 61
62The actual lookups are performed by functions found in nfsidmap.h. nfs.upcall 62The actual lookups are performed by functions found in nfsidmap.h. nfs.idmap
63determines the correct function to call by looking at the first part of the 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 64description string. For example, a uid lookup description will appear as
65"uid:user@domain". 65"uid:user@domain".
66 66
67nfs.upcall will return 0 if the key was instantiated, and non-zero otherwise. 67nfs.idmap will return 0 if the key was instantiated, and non-zero otherwise.