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Diffstat (limited to 'Documentation/filesystems/nfs/nfs41-server.txt')
| -rw-r--r-- | Documentation/filesystems/nfs/nfs41-server.txt | 173 |
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diff --git a/Documentation/filesystems/nfs/nfs41-server.txt b/Documentation/filesystems/nfs/nfs41-server.txt new file mode 100644 index 000000000..682a59fab --- /dev/null +++ b/Documentation/filesystems/nfs/nfs41-server.txt @@ -0,0 +1,173 @@ +NFSv4.1 Server Implementation + +Server support for minorversion 1 can be controlled using the +/proc/fs/nfsd/versions control file. The string output returned +by reading this file will contain either "+4.1" or "-4.1" +correspondingly. + +Currently, server support for minorversion 1 is enabled by default. +It can be disabled at run time by writing the string "-4.1" to +the /proc/fs/nfsd/versions control file. Note that to write this +control file, the nfsd service must be taken down. You can use rpc.nfsd +for this; see rpc.nfsd(8). + +(Warning: older servers will interpret "+4.1" and "-4.1" as "+4" and +"-4", respectively. Therefore, code meant to work on both new and old +kernels must turn 4.1 on or off *before* turning support for version 4 +on or off; rpc.nfsd does this correctly.) + +The NFSv4 minorversion 1 (NFSv4.1) implementation in nfsd is based +on RFC 5661. + +From the many new features in NFSv4.1 the current implementation +focuses on the mandatory-to-implement NFSv4.1 Sessions, providing +"exactly once" semantics and better control and throttling of the +resources allocated for each client. + +The table below, taken from the NFSv4.1 document, lists +the operations that are mandatory to implement (REQ), optional +(OPT), and NFSv4.0 operations that are required not to implement (MNI) +in minor version 1. The first column indicates the operations that +are not supported yet by the linux server implementation. + +The OPTIONAL features identified and their abbreviations are as follows: + pNFS Parallel NFS + FDELG File Delegations + DDELG Directory Delegations + +The following abbreviations indicate the linux server implementation status. + I Implemented NFSv4.1 operations. + NS Not Supported. + NS* Unimplemented optional feature. + +Operations + + +----------------------+------------+--------------+----------------+ + | Operation | REQ, REC, | Feature | Definition | + | | OPT, or | (REQ, REC, | | + | | MNI | or OPT) | | + +----------------------+------------+--------------+----------------+ + | ACCESS | REQ | | Section 18.1 | +I | BACKCHANNEL_CTL | REQ | | Section 18.33 | +I | BIND_CONN_TO_SESSION | REQ | | Section 18.34 | + | CLOSE | REQ | | Section 18.2 | + | COMMIT | REQ | | Section 18.3 | + | CREATE | REQ | | Section 18.4 | +I | CREATE_SESSION | REQ | | Section 18.36 | +NS*| DELEGPURGE | OPT | FDELG (REQ) | Section 18.5 | + | DELEGRETURN | OPT | FDELG, | Section 18.6 | + | | | DDELG, pNFS | | + | | | (REQ) | | +I | DESTROY_CLIENTID | REQ | | Section 18.50 | +I | DESTROY_SESSION | REQ | | Section 18.37 | +I | EXCHANGE_ID | REQ | | Section 18.35 | +I | FREE_STATEID | REQ | | Section 18.38 | + | GETATTR | REQ | | Section 18.7 | +I | GETDEVICEINFO | OPT | pNFS (REQ) | Section 18.40 | +NS*| GETDEVICELIST | OPT | pNFS (OPT) | Section 18.41 | + | GETFH | REQ | | Section 18.8 | +NS*| GET_DIR_DELEGATION | OPT | DDELG (REQ) | Section 18.39 | +I | LAYOUTCOMMIT | OPT | pNFS (REQ) | Section 18.42 | +I | LAYOUTGET | OPT | pNFS (REQ) | Section 18.43 | +I | LAYOUTRETURN | OPT | pNFS (REQ) | Section 18.44 | + | LINK | OPT | | Section 18.9 | + | LOCK | REQ | | Section 18.10 | + | LOCKT | REQ | | Section 18.11 | + | LOCKU | REQ | | Section 18.12 | + | LOOKUP | REQ | | Section 18.13 | + | LOOKUPP | REQ | | Section 18.14 | + | NVERIFY | REQ | | Section 18.15 | + | OPEN | REQ | | Section 18.16 | +NS*| OPENATTR | OPT | | Section 18.17 | + | OPEN_CONFIRM | MNI | | N/A | + | OPEN_DOWNGRADE | REQ | | Section 18.18 | + | PUTFH | REQ | | Section 18.19 | + | PUTPUBFH | REQ | | Section 18.20 | + | PUTROOTFH | REQ | | Section 18.21 | + | READ | REQ | | Section 18.22 | + | READDIR | REQ | | Section 18.23 | + | READLINK | OPT | | Section 18.24 | + | RECLAIM_COMPLETE | REQ | | Section 18.51 | + | RELEASE_LOCKOWNER | MNI | | N/A | + | REMOVE | REQ | | Section 18.25 | + | RENAME | REQ | | Section 18.26 | + | RENEW | MNI | | N/A | + | RESTOREFH | REQ | | Section 18.27 | + | SAVEFH | REQ | | Section 18.28 | + | SECINFO | REQ | | Section 18.29 | +I | SECINFO_NO_NAME | REC | pNFS files | Section 18.45, | + | | | layout (REQ) | Section 13.12 | +I | SEQUENCE | REQ | | Section 18.46 | + | SETATTR | REQ | | Section 18.30 | + | SETCLIENTID | MNI | | N/A | + | SETCLIENTID_CONFIRM | MNI | | N/A | +NS | SET_SSV | REQ | | Section 18.47 | +I | TEST_STATEID | REQ | | Section 18.48 | + | VERIFY | REQ | | Section 18.31 | +NS*| WANT_DELEGATION | OPT | FDELG (OPT) | Section 18.49 | + | WRITE | REQ | | Section 18.32 | + +Callback Operations + + +-------------------------+-----------+-------------+---------------+ + | Operation | REQ, REC, | Feature | Definition | + | | OPT, or | (REQ, REC, | | + | | MNI | or OPT) | | + +-------------------------+-----------+-------------+---------------+ + | CB_GETATTR | OPT | FDELG (REQ) | Section 20.1 | +I | CB_LAYOUTRECALL | OPT | pNFS (REQ) | Section 20.3 | +NS*| CB_NOTIFY | OPT | DDELG (REQ) | Section 20.4 | +NS*| CB_NOTIFY_DEVICEID | OPT | pNFS (OPT) | Section 20.12 | +NS*| CB_NOTIFY_LOCK | OPT | | Section 20.11 | +NS*| CB_PUSH_DELEG | OPT | FDELG (OPT) | Section 20.5 | + | CB_RECALL | OPT | FDELG, | Section 20.2 | + | | | DDELG, pNFS | | + | | | (REQ) | | +NS*| CB_RECALL_ANY | OPT | FDELG, | Section 20.6 | + | | | DDELG, pNFS | | + | | | (REQ) | | +NS | CB_RECALL_SLOT | REQ | | Section 20.8 | +NS*| CB_RECALLABLE_OBJ_AVAIL | OPT | DDELG, pNFS | Section 20.7 | + | | | (REQ) | | +I | CB_SEQUENCE | OPT | FDELG, | Section 20.9 | + | | | DDELG, pNFS | | + | | | (REQ) | | +NS*| CB_WANTS_CANCELLED | OPT | FDELG, | Section 20.10 | + | | | DDELG, pNFS | | + | | | (REQ) | | + +-------------------------+-----------+-------------+---------------+ + +Implementation notes: + +SSV: +* The spec claims this is mandatory, but we don't actually know of any + implementations, so we're ignoring it for now. The server returns + NFS4ERR_ENCR_ALG_UNSUPP on EXCHANGE_ID, which should be future-proof. + +GSS on the backchannel: +* Again, theoretically required but not widely implemented (in + particular, the current Linux client doesn't request it). We return + NFS4ERR_ENCR_ALG_UNSUPP on CREATE_SESSION. + +DELEGPURGE: +* mandatory only for servers that support CLAIM_DELEGATE_PREV and/or + CLAIM_DELEG_PREV_FH (which allows clients to keep delegations that + persist across client reboots). Thus we need not implement this for + now. + +EXCHANGE_ID: +* implementation ids are ignored + +CREATE_SESSION: +* backchannel attributes are ignored + +SEQUENCE: +* no support for dynamic slot table renegotiation (optional) + +Nonstandard compound limitations: +* No support for a sessions fore channel RPC compound that requires both a + ca_maxrequestsize request and a ca_maxresponsesize reply, so we may + fail to live up to the promise we made in CREATE_SESSION fore channel + negotiation. + +See also http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues. |