linux-stable.git/include/linux/nfsd/state.h, branch v2.6.30

nfsd41: stateid handling

2009-04-04T00:41:19+00:00

When sessions are used, stateful operation sequenceid and stateid handling
are not used. When sessions are used,  on the first open set the seqid to 1,
mark state confirmed and skip seqid processing.

When sessionas are used the stateid generation number is ignored when it is zero
whereas without sessions bad_stateid or stale stateid is returned.

Add flags to propagate session use to all stateful ops and down to
check_stateid_generation.

Signed-off-by: Benny Halevy 
Signed-off-by: Andy Adamson 
[nfsd4_has_session should return a boolean, not u32]
Signed-off-by: Benny Halevy 
[nfsd41: pass nfsd4_compoundres * to nfsd4_process_open1]
[nfsd41: calculate HAS_SESSION in nfs4_preprocess_stateid_op]
[nfsd41: calculate HAS_SESSION in nfs4_preprocess_seqid_op]
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd: pass nfsd4_compound_state* to nfs4_preprocess_{state,seq}id_op

2009-04-04T00:41:19+00:00

Currently we only use cstate->current_fh,
will also be used by nfsd41 code.

Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd41: non-page DRC for solo sequence responses

2009-04-04T00:41:19+00:00

A session inactivity time compound (lease renewal) or a compound where the
sequence operation has sa_cachethis set to FALSE do not require any pages
to be held in the v4.1 DRC. This is because struct nfsd4_slot is already
caching the session information.

Add logic to the nfs41 server to not cache response pages for solo sequence
responses.

Return nfserr_replay_uncached_rep on the operation following the sequence
operation when sa_cachethis is FALSE.

Signed-off-by: Andy Adamson 
Signed-off-by: Benny Halevy 
[nfsd41: use cstate session in nfsd4_replay_cache_entry]
[nfsd41: rename nfsd4_no_page_in_cache]
[nfsd41 rename nfsd4_enc_no_page_replay]
[nfsd41 nfsd4_is_solo_sequence]
[nfsd41 change nfsd4_not_cached return]
Signed-off-by: Andy Adamson 
[changed return type to bool]
Signed-off-by: Benny Halevy 
[nfsd41 drop parens in nfsd4_is_solo_sequence call]
Signed-off-by: Andy Adamson 
[changed "== 0" to "!"]
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd41: Add a create session replay cache

2009-04-04T00:41:18+00:00

Replace the nfs4_client cl_seqid field with a single struct nfs41_slot used
for the create session replay cache.

The CREATE_SESSION slot sets the sl_session pointer to NULL. Otherwise, the
slot and it's replay cache are used just like the session slots.

Fix unconfirmed create_session replay response by initializing the
create_session slot sequence id to 0.

A future patch will set the CREATE_SESSION cache when a SEQUENCE operation
preceeds the CREATE_SESSION operation. This compound is currently only cached
in the session slot table.

Signed-off-by: Andy Adamson
Signed-off-by: Benny Halevy 
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy 
[nfsd41: revert portion of nfsd4_set_cache_entry]
Signed-off-by: Andy Adamson 
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd41: create_session operation

2009-04-04T00:41:18+00:00

Implement the create_session operation confoming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-26

Look up the client id (generated by the server on exchange_id,
given by the client on create_session).
If neither a confirmed or unconfirmed client is found
then the client id is stale
If a confirmed cilent is found (i.e. we already received
create_session for it) then compare the sequence id
to determine if it's a replay or possibly a mis-ordered rpc.
If the seqid is in order, update the confirmed client seqid
and procedd with updating the session parameters.

If an unconfirmed client_id is found then verify the creds
and seqid.  If both match move the client id to confirmed state
and proceed with processing the create_session.

Currently, we do not support persistent sessions, and RDMA.

alloc_init_session generates a new sessionid and creates
a session structure.

NFSD_PAGES_PER_SLOT is used for the max response cached calculation, and for
the counting of DRC pages using the hard limits set in struct srv_serv.

A note on NFSD_PAGES_PER_SLOT:

Other patches in this series allow for NFSD_PAGES_PER_SLOT + 1 pages to be
cached in a DRC slot when the response size is less than NFSD_PAGES_PER_SLOT *
PAGE_SIZE but xdr_buf pages are used. e.g. a READDIR operation will encode a
small amount of data in the xdr_buf head, and then the READDIR in the xdr_buf
pages.  So, the hard limit calculation use of pages by a session is
underestimated by the number of cached operations using the xdr_buf pages.

Yet another patch caches no pages for the solo sequence operation, or any
compound where cache_this is False.  So the hard limit calculation use of
pages by a session is overestimated by the number of these operations in the
cache.

TODO: improve resource pre-allocation and negotiate session
parameters accordingly.  Respect and possibly adjust
backchannel attributes.

Signed-off-by: Marc Eshel 
Signed-off-by: Dean Hildebrand 
[nfsd41: remove headerpadsz from channel attributes]
Our client and server only support a headerpadsz of 0.
[nfsd41: use DRC limits in fore channel init]
[nfsd41: do not change CREATE_SESSION back channel attrs]
Signed-off-by: Andy Adamson 
Signed-off-by: Benny Halevy 
[use sessionid_lock spin lock]
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy 
[nfsd41 remove sl_session from alloc_init_session]
Signed-off-by: Andy Adamson 
Signed-off-by: Benny Halevy 
[simplify nfsd4_encode_create_session error handling]
[nfsd41: fix comment style in init_forechannel_attrs]
[nfsd41: allocate struct nfsd4_session and slot table in one piece]
[nfsd41: no need to INIT_LIST_HEAD in alloc_init_session just prior to list_add]
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd41: DRC save, restore, and clear functions

2009-04-04T00:41:17+00:00

Cache all the result pages, including the rpc header in rq_respages[0],
for a request in the slot table cache entry.

Cache the statp pointer from nfsd_dispatch which points into rq_respages[0]
just past the rpc header. When setting a cache entry, calculate and save the
length of the nfs data minus the rpc header for rq_respages[0].

When replaying a cache entry, replace the cached rpc header with the
replayed request rpc result header, unless there is not enough room in the
cached results first page. In that case, use the cached rpc header.

The sessions fore channel maxresponse size cached is set to NFSD_PAGES_PER_SLOT
* PAGE_SIZE. For compounds we are cacheing with operations such as READDIR
that use the xdr_buf->pages to hold data, we choose to cache the extra page of
data rather than copying data from xdr_buf->pages into the xdr_buf->head page.

[nfsd41: limit cache to maxresponsesize_cached]
[nfsd41: mv nfsd4_set_statp under CONFIG_NFSD_V4_1]
[nfsd41: rename nfsd4_move_pages]
[nfsd41: rename page_no variable]
[nfsd41: rename nfsd4_set_cache_entry]
[nfsd41: fix nfsd41_copy_replay_data comment]
[nfsd41: add to nfsd4_set_cache_entry]
Signed-off-by: Andy Adamson 
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd41: match clientid establishment method

2009-04-04T00:41:15+00:00

We need to distinguish between client names provided by NFSv4.0 clients
SETCLIENTID and those provided by NFSv4.1 via EXCHANGE_ID when looking
up the clientid by string.

Signed-off-by: Benny Halevy 
Signed-off-by: Andy Adamson 
[nfsd41: use boolean values for use_exchange_id argument]
Signed-off-by: Benny Halevy 
[nfsd41: simplify match_clientid_establishment logic]
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd41: exchange_id operation

2009-04-04T00:41:15+00:00

Implement the exchange_id operation confoming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-28

Based on the client provided name, hash a client id.
If a confirmed one is found, compare the op's creds and
verifier.  If the creds match and the verifier is different
then expire the old client (client re-incarnated), otherwise,
if both match, assume it's a replay and ignore it.

If an unconfirmed client is found, then copy the new creds
and verifer if need update, otherwise assume replay.

The client is moved to a confirmed state on create_session.

In the nfs41 branch set the exchange_id flags to
EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_SUPP_MOVED_REFER
(pNFS is not supported, Referrals are supported,
Migration is not.).

Address various scenarios from section 18.35 of the spec:

1. Check for EXCHGID4_FLAG_UPD_CONFIRMED_REC_A and set
   EXCHGID4_FLAG_CONFIRMED_R as appropriate.

2. Return error codes per 18.35.4 scenarios.

3. Update client records or generate new client ids depending on
   scenario.

Note: 18.35.4 case 3 probably still needs revisiting.  The handling
seems not quite right.

Signed-off-by: Benny Halevy 
Signed-off-by: Andy Adamosn 
Signed-off-by: Benny Halevy 
[nfsd41: use utsname for major_id (and copy to server_scope)]
[nfsd41: fix handling of various exchange id scenarios]
Signed-off-by: Mike Sager 
Signed-off-by: Benny Halevy 
[nfsd41: reverse use of EXCHGID4_INVAL_FLAG_MASK_A]
[simplify nfsd4_encode_exchange_id error handling]
[nfsd41: embed an xdr_netobj in nfsd4_exchange_id]
[nfsd41: return nfserr_serverfault for spa_how == SP4_MACH_CRED]
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd41: sessionid hashing

2009-04-04T00:41:14+00:00

Simple sessionid hashing using its monotonically increasing sequence number.

Locking considerations:
sessionid_hashtbl access is controlled by the sessionid_lock spin lock.
It must be taken for insert, delete, and lookup.
nfsd4_sequence looks up the session id and if the session is found,
it calls nfsd4_get_session (still under the sessionid_lock).
nfsd4_destroy_session calls nfsd4_put_session after unhashing
it, so when the session's kref reaches zero it's going to get freed.

Signed-off-by: Benny Halevy 
[we don't use a prime for sessionid hash table size]
[use sessionid_lock spin lock]
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields

nfsd41: introduce nfs4_client cl_sessions list

2009-04-04T00:41:13+00:00

[get rid of CONFIG_NFSD_V4_1]
Signed-off-by: Benny Halevy 
Signed-off-by: J. Bruce Fields