本文档翻译自NFSv4.1 Server Implementation，翻译时文件的最新提交是04f81fb08d067f79c59fe132929a9c81eb9cb74b Documentation: nfs: nfs41-server: convert to ReST，大部分借助于ChatGPT。仅作为我个人的参考，如果你想查阅，建议看英文文档，因为我不确定我记录的中文翻译是否完整和正确。
服务器对 minorversion 1 的支持可以通过 /proc/fs/nfsd/versions 控制文件进行控制。读取该文件返回的字符串将分别包含 "+4.1" 或 "-4.1"。
目前，服务器对 minorversion 1 的支持是默认启用的。可以在运行时通过将字符串 "-4.1" 写入 /proc/fs/nfsd/versions 控制文件来禁用它。请注意，要写入该控制文件，必须先停止 nfsd 服务。您可以使用 rpc.nfsd 来完成此操作；参见 rpc.nfsd(8)。
（警告: 较旧的服务器会将 "+4.1" 和 "-4.1" 解释为 "+4" 和 "-4"。因此，旨在同时适用于新旧内核的代码必须在打开或关闭版本 4 的支持之前先打开或关闭 4.1 的支持；rpc.nfsd 可以正确处理这一点。）
nfsd 中的 NFSv4 minorversion 1 (NFSv4.1) 实现基于 RFC 5661。
在 NFSv4.1 的众多新特性中，当前实现侧重于强制实施的 NFSv4.1 Sessions，提供“仅一次”语义以及更好的资源分配控制和限制。
下表摘自 NFSv4.1 文档，列出了在 minor version 1 中强制实现的操作（REQ）、可选操作（OPT）和 NFSv4.0 操作（MNI）。第一列表示 linux 服务器实现尚未支持的操作。
可选功能及其缩写如下:
- **pNFS** Parallel NFS
- **FDELG** File Delegations
- **DDELG** Directory Delegations
以下缩写表示 Linux 服务器实现的状态。
- **I** Implemented NFSv4.1 operations.
- **NS** Not Supported.
- **NS\*** Unimplemented optional feature.
+-----------------------+----------------------+---------------------+---------------------------+----------------+
| Implementation status | Operation | REQ,REC, OPT or NMI | Feature (REQ, REC or OPT) | Definition |
+=======================+======================+=====================+===========================+================+
| | 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 |
+-----------------------+----------------------+---------------------+---------------------------+----------------++-----------------------+-------------------------+---------------------+---------------------------+---------------+
| Implementation status | Operation | REQ,REC, OPT or NMI | Feature (REQ, REC or OPT) | Definition |
+=======================+=========================+=====================+===========================+===============+
| | 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) | |
+-----------------------+-------------------------+---------------------+---------------------------+---------------+SSV:
规范声称这是强制性的，但我们实际上不知道任何实现，所以我们现在忽略它。服务器在 EXCHANGE_ID 上返回 NFS4ERR_ENCR_ALG_UNSUPP，这应该是面向未来的。
后通道上的 GSS:
同样，理论上是强制性的，但没有广泛实现（特别是当前的 Linux 客户端不请求它）。我们在 CREATE_SESSION 上返回 NFS4ERR_ENCR_ALG_UNSUPP。
DELEGPURGE:
仅对支持 CLAIM_DELEGATE_PREV 和/或 CLAIM_DELEG_PREV_FH 的服务器是强制性的（这允许客户端在重启后保留委托）。因此，我们目前不需要实现它。
EXCHANGE_ID:
忽略实现 ID。
CREATE_SESSION:
忽略后通道属性。
SEQUENCE:
不支持动态槽表重新协商（可选）。
非标准复合限制:
不支持会话前通道 RPC 复合，该复合要求同时具有 ca_maxrequestsize 请求和 ca_maxresponsesize 响应，因此我们可能无法履行在 CREATE_SESSION 前通道协商中做出的承诺。
另见: http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues。