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nfsd41: create_session operation

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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 <eshel@almaden.ibm.com>
Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com>
[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 <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[use sessionid_lock spin lock]
[nfsd41: use bool inuse for slot state]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41 remove sl_session from alloc_init_session]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[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 <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Andy Adamson
2009-04-03 08:28:28 +03:00
committed by J. Bruce Fields
parent 14778a133e
commit ec6b5d7b50
4 changed files with 358 additions and 6 deletions
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21
include/linux/nfsd/xdr4.h
View File

@@ -359,8 +359,27 @@ struct nfsd4_exchange_id {
int spa_how;
};
struct nfsd4_channel_attrs {
u32 headerpadsz;
u32 maxreq_sz;
u32 maxresp_sz;
u32 maxresp_cached;
u32 maxops;
u32 maxreqs;
u32 nr_rdma_attrs;
u32 rdma_attrs;
};
struct nfsd4_create_session {
int foo; /* stub */
clientid_t clientid;
struct nfs4_sessionid sessionid;
u32 seqid;
u32 flags;
struct nfsd4_channel_attrs fore_channel;
struct nfsd4_channel_attrs back_channel;
u32 callback_prog;
u32 uid;
u32 gid;
};
struct nfsd4_sequence {