nfs: new subdir Documentation/filesystems/nfs

We're adding enough nfs documentation that it may as well have its own
subdirectory.

Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

1 files changed, 0 insertions, 222 deletions

diff --git a/Documentation/filesystems/nfs41-server.txt b/Documentation/filesystems/nfs41-server.txt
deleted file mode 100644
index 1bd0d0c0517..00000000000
--- a/Documentation/filesystems/nfs41-server.txt
+++ /dev/null
@@ -1,222 +0,0 @@
-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 disabled by default.
-It can be enabled 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.  Use your user-mode
-nfs-utils to set this up; 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 the latest NFSv4.1 Internet Draft:
-http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-29
-
-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.
-
-Other NFSv4.1 features, Parallel NFS operations in particular,
-are still under development out of tree.
-See http://wiki.linux-nfs.org/wiki/index.php/PNFS_prototype_design
-for more information.
-
-The current implementation is intended for developers only: while it
-does support ordinary file operations on clients we have tested against
-(including the linux client), it is incomplete in ways which may limit
-features unexpectedly, cause known bugs in rare cases, or cause
-interoperability problems with future clients.  Known issues:
-
-	- gss support is questionable: currently mounts with kerberos
-	  from a linux client are possible, but we aren't really
-	  conformant with the spec (for example, we don't use kerberos
-	  on the backchannel correctly).
-	- no trunking support: no clients currently take advantage of
-	  trunking, but this is a mandatory feature, and its use is
-	  recommended to clients in a number of places.  (E.g. to ensure
-	  timely renewal in case an existing connection's retry timeouts
-	  have gotten too long; see section 8.3 of the draft.)
-	  Therefore, lack of this feature may cause future clients to
-	  fail.
-	- Incomplete backchannel support: incomplete backchannel gss
-	  support and no support for BACKCHANNEL_CTL mean that
-	  callbacks (hence delegations and layouts) may not be
-	  available and clients confused by the incomplete
-	  implementation may fail.
-	- Server reboot recovery is unsupported; if the server reboots,
-	  clients may fail.
-	- We do not support SSV, which provides security for shared
-	  client-server state (thus preventing unauthorized tampering
-	  with locks and opens, for example).  It is mandatory for
-	  servers to support this, though no clients use it yet.
-	- Mandatory operations which we do not support, such as
-	  DESTROY_CLIENTID, FREE_STATEID, SECINFO_NO_NAME, and
-	  TEST_STATEID, are not currently used by clients, but will be
-	  (and the spec recommends their uses in common cases), and
-	  clients should not be expected to know how to recover from the
-	  case where they are not supported.  This will eventually cause
-	  interoperability failures.
-
-In addition, some limitations are inherited from the current NFSv4
-implementation:
-
-	- Incomplete delegation enforcement: if a file is renamed or
-	  unlinked, a client holding a delegation may continue to
-	  indefinitely allow opens of the file under the old name.
-
-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.
-	P	pNFS features implemented out of tree.
-	PNS	pNFS features that are not supported yet (out of tree).
-
-Operations
-
-   +----------------------+------------+--------------+----------------+
-   | Operation            | REQ, REC,  | Feature      | Definition     |
-   |                      | OPT, or    | (REQ, REC,   |                |
-   |                      | MNI        | or OPT)      |                |
-   +----------------------+------------+--------------+----------------+
-   | ACCESS               | REQ        |              | Section 18.1   |
-NS | BACKCHANNEL_CTL      | REQ        |              | Section 18.33  |
-NS | 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)        |                |
-NS | DESTROY_CLIENTID     | REQ        |              | Section 18.50  |
-I  | DESTROY_SESSION      | REQ        |              | Section 18.37  |
-I  | EXCHANGE_ID          | REQ        |              | Section 18.35  |
-NS | FREE_STATEID         | REQ        |              | Section 18.38  |
-   | GETATTR              | REQ        |              | Section 18.7   |
-P  | GETDEVICEINFO        | OPT        | pNFS (REQ)   | Section 18.40  |
-P  | GETDEVICELIST        | OPT        | pNFS (OPT)   | Section 18.41  |
-   | GETFH                | REQ        |              | Section 18.8   |
-NS*| GET_DIR_DELEGATION   | OPT        | DDELG (REQ)  | Section 18.39  |
-P  | LAYOUTCOMMIT         | OPT        | pNFS (REQ)   | Section 18.42  |
-P  | LAYOUTGET            | OPT        | pNFS (REQ)   | Section 18.43  |
-P  | 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  |
-NS | 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  |
-NS | 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  |
-NS | 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  |
-P  | CB_LAYOUTRECALL         | OPT       | pNFS (REQ)  | Section 20.3  |
-NS*| CB_NOTIFY               | OPT       | DDELG (REQ) | Section 20.4  |
-P  | 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:
-
-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:
-* only SP4_NONE state protection supported
-* implementation ids are ignored
-
-CREATE_SESSION:
-* backchannel attributes are ignored
-* backchannel security parameters are ignored
-
-SEQUENCE:
-* no support for dynamic slot table renegotiation (optional)
-
-nfsv4.1 COMPOUND rules:
-The following cases aren't supported yet:
-* Enforcing of NFS4ERR_NOT_ONLY_OP for: BIND_CONN_TO_SESSION, CREATE_SESSION,
-  DESTROY_CLIENTID, DESTROY_SESSION, EXCHANGE_ID.
-* DESTROY_SESSION MUST be the final operation in the COMPOUND request.
-
-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.
-* No more than one IO operation (read, write, readdir) allowed per
-  compound.