xenbus: Fix memory leak on release
[pandora-kernel.git] / Documentation / filesystems / nfs41-server.txt
1 NFSv4.1 Server Implementation
2
3 Server support for minorversion 1 can be controlled using the
4 /proc/fs/nfsd/versions control file.  The string output returned
5 by reading this file will contain either "+4.1" or "-4.1"
6 correspondingly.
7
8 Currently, server support for minorversion 1 is disabled by default.
9 It can be enabled at run time by writing the string "+4.1" to
10 the /proc/fs/nfsd/versions control file.  Note that to write this
11 control file, the nfsd service must be taken down.  Use your user-mode
12 nfs-utils to set this up; see rpc.nfsd(8)
13
14 The NFSv4 minorversion 1 (NFSv4.1) implementation in nfsd is based
15 on the latest NFSv4.1 Internet Draft:
16 http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-29
17
18 From the many new features in NFSv4.1 the current implementation
19 focuses on the mandatory-to-implement NFSv4.1 Sessions, providing
20 "exactly once" semantics and better control and throttling of the
21 resources allocated for each client.
22
23 Other NFSv4.1 features, Parallel NFS operations in particular,
24 are still under development out of tree.
25 See http://wiki.linux-nfs.org/wiki/index.php/PNFS_prototype_design
26 for more information.
27
28 The table below, taken from the NFSv4.1 document, lists
29 the operations that are mandatory to implement (REQ), optional
30 (OPT), and NFSv4.0 operations that are required not to implement (MNI)
31 in minor version 1.  The first column indicates the operations that
32 are not supported yet by the linux server implementation.
33
34 The OPTIONAL features identified and their abbreviations are as follows:
35         pNFS    Parallel NFS
36         FDELG   File Delegations
37         DDELG   Directory Delegations
38
39 The following abbreviations indicate the linux server implementation status.
40         I       Implemented NFSv4.1 operations.
41         NS      Not Supported.
42         NS*     unimplemented optional feature.
43         P       pNFS features implemented out of tree.
44         PNS     pNFS features that are not supported yet (out of tree).
45
46 Operations
47
48    +----------------------+------------+--------------+----------------+
49    | Operation            | REQ, REC,  | Feature      | Definition     |
50    |                      | OPT, or    | (REQ, REC,   |                |
51    |                      | MNI        | or OPT)      |                |
52    +----------------------+------------+--------------+----------------+
53    | ACCESS               | REQ        |              | Section 18.1   |
54 NS | BACKCHANNEL_CTL      | REQ        |              | Section 18.33  |
55 NS | BIND_CONN_TO_SESSION | REQ        |              | Section 18.34  |
56    | CLOSE                | REQ        |              | Section 18.2   |
57    | COMMIT               | REQ        |              | Section 18.3   |
58    | CREATE               | REQ        |              | Section 18.4   |
59 I  | CREATE_SESSION       | REQ        |              | Section 18.36  |
60 NS*| DELEGPURGE           | OPT        | FDELG (REQ)  | Section 18.5   |
61    | DELEGRETURN          | OPT        | FDELG,       | Section 18.6   |
62    |                      |            | DDELG, pNFS  |                |
63    |                      |            | (REQ)        |                |
64 NS | DESTROY_CLIENTID     | REQ        |              | Section 18.50  |
65 I  | DESTROY_SESSION      | REQ        |              | Section 18.37  |
66 I  | EXCHANGE_ID          | REQ        |              | Section 18.35  |
67 NS | FREE_STATEID         | REQ        |              | Section 18.38  |
68    | GETATTR              | REQ        |              | Section 18.7   |
69 P  | GETDEVICEINFO        | OPT        | pNFS (REQ)   | Section 18.40  |
70 P  | GETDEVICELIST        | OPT        | pNFS (OPT)   | Section 18.41  |
71    | GETFH                | REQ        |              | Section 18.8   |
72 NS*| GET_DIR_DELEGATION   | OPT        | DDELG (REQ)  | Section 18.39  |
73 P  | LAYOUTCOMMIT         | OPT        | pNFS (REQ)   | Section 18.42  |
74 P  | LAYOUTGET            | OPT        | pNFS (REQ)   | Section 18.43  |
75 P  | LAYOUTRETURN         | OPT        | pNFS (REQ)   | Section 18.44  |
76    | LINK                 | OPT        |              | Section 18.9   |
77    | LOCK                 | REQ        |              | Section 18.10  |
78    | LOCKT                | REQ        |              | Section 18.11  |
79    | LOCKU                | REQ        |              | Section 18.12  |
80    | LOOKUP               | REQ        |              | Section 18.13  |
81    | LOOKUPP              | REQ        |              | Section 18.14  |
82    | NVERIFY              | REQ        |              | Section 18.15  |
83    | OPEN                 | REQ        |              | Section 18.16  |
84 NS*| OPENATTR             | OPT        |              | Section 18.17  |
85    | OPEN_CONFIRM         | MNI        |              | N/A            |
86    | OPEN_DOWNGRADE       | REQ        |              | Section 18.18  |
87    | PUTFH                | REQ        |              | Section 18.19  |
88    | PUTPUBFH             | REQ        |              | Section 18.20  |
89    | PUTROOTFH            | REQ        |              | Section 18.21  |
90    | READ                 | REQ        |              | Section 18.22  |
91    | READDIR              | REQ        |              | Section 18.23  |
92    | READLINK             | OPT        |              | Section 18.24  |
93 NS | RECLAIM_COMPLETE     | REQ        |              | Section 18.51  |
94    | RELEASE_LOCKOWNER    | MNI        |              | N/A            |
95    | REMOVE               | REQ        |              | Section 18.25  |
96    | RENAME               | REQ        |              | Section 18.26  |
97    | RENEW                | MNI        |              | N/A            |
98    | RESTOREFH            | REQ        |              | Section 18.27  |
99    | SAVEFH               | REQ        |              | Section 18.28  |
100    | SECINFO              | REQ        |              | Section 18.29  |
101 NS | SECINFO_NO_NAME      | REC        | pNFS files   | Section 18.45, |
102    |                      |            | layout (REQ) | Section 13.12  |
103 I  | SEQUENCE             | REQ        |              | Section 18.46  |
104    | SETATTR              | REQ        |              | Section 18.30  |
105    | SETCLIENTID          | MNI        |              | N/A            |
106    | SETCLIENTID_CONFIRM  | MNI        |              | N/A            |
107 NS | SET_SSV              | REQ        |              | Section 18.47  |
108 NS | TEST_STATEID         | REQ        |              | Section 18.48  |
109    | VERIFY               | REQ        |              | Section 18.31  |
110 NS*| WANT_DELEGATION      | OPT        | FDELG (OPT)  | Section 18.49  |
111    | WRITE                | REQ        |              | Section 18.32  |
112
113 Callback Operations
114
115    +-------------------------+-----------+-------------+---------------+
116    | Operation               | REQ, REC, | Feature     | Definition    |
117    |                         | OPT, or   | (REQ, REC,  |               |
118    |                         | MNI       | or OPT)     |               |
119    +-------------------------+-----------+-------------+---------------+
120    | CB_GETATTR              | OPT       | FDELG (REQ) | Section 20.1  |
121 P  | CB_LAYOUTRECALL         | OPT       | pNFS (REQ)  | Section 20.3  |
122 NS*| CB_NOTIFY               | OPT       | DDELG (REQ) | Section 20.4  |
123 P  | CB_NOTIFY_DEVICEID      | OPT       | pNFS (OPT)  | Section 20.12 |
124 NS*| CB_NOTIFY_LOCK          | OPT       |             | Section 20.11 |
125 NS*| CB_PUSH_DELEG           | OPT       | FDELG (OPT) | Section 20.5  |
126    | CB_RECALL               | OPT       | FDELG,      | Section 20.2  |
127    |                         |           | DDELG, pNFS |               |
128    |                         |           | (REQ)       |               |
129 NS*| CB_RECALL_ANY           | OPT       | FDELG,      | Section 20.6  |
130    |                         |           | DDELG, pNFS |               |
131    |                         |           | (REQ)       |               |
132 NS | CB_RECALL_SLOT          | REQ       |             | Section 20.8  |
133 NS*| CB_RECALLABLE_OBJ_AVAIL | OPT       | DDELG, pNFS | Section 20.7  |
134    |                         |           | (REQ)       |               |
135 I  | CB_SEQUENCE             | OPT       | FDELG,      | Section 20.9  |
136    |                         |           | DDELG, pNFS |               |
137    |                         |           | (REQ)       |               |
138 NS*| CB_WANTS_CANCELLED      | OPT       | FDELG,      | Section 20.10 |
139    |                         |           | DDELG, pNFS |               |
140    |                         |           | (REQ)       |               |
141    +-------------------------+-----------+-------------+---------------+
142
143 Implementation notes:
144
145 EXCHANGE_ID:
146 * only SP4_NONE state protection supported
147 * implementation ids are ignored
148
149 CREATE_SESSION:
150 * backchannel attributes are ignored
151 * backchannel security parameters are ignored
152
153 SEQUENCE:
154 * no support for dynamic slot table renegotiation (optional)
155
156 nfsv4.1 COMPOUND rules:
157 The following cases aren't supported yet:
158 * Enforcing of NFS4ERR_NOT_ONLY_OP for: BIND_CONN_TO_SESSION, CREATE_SESSION,
159   DESTROY_CLIENTID, DESTROY_SESSION, EXCHANGE_ID.
160 * DESTROY_SESSION MUST be the final operation in the COMPOUND request.
161