On Apr 23, 2009, at 7:21 PM, J. Bruce Fields wrote:
On Thu, Apr 23, 2009 at 12:42:41PM -0400, andros@xxxxxxxxxx wrote:
From: Andy Adamson <andros@xxxxxxxxxx>
CREATE_SESSION can be preceeded by a SEQUENCE operation and the
create session single slot cache must be maintained. Encode the
results of
a create session call into the cache at the end of processing.
The create session result will also be encoded into the RPC
response, and if
it is preceeded by a SEQUENCE operation, will also be encoded into
the
session slot table cache.
Errors that do not change the create session cache:
A create session NFS4ERR_STALE_CLIENTID error means that a client
record
(and associated create session slot) could not be found and
therefore can't
be changed. NFSERR_SEQ_MISORDERED errors do not change the slot
cache.
All other errors get cached.
Thanks, this all sounds sensible. (One simple thing I think I was
confused about: the create_session sequencing is done at a layer above
sessions; so in the case of a create_session preceded by a sequence,
if
we discover at the point of processing the sequence that this is a
replay, we use the sequence replay cache and never even get to any
create_session processing. OK!)
Yes! The double DRC of a sequence:create_session is a bit confusing.
It works correctly because the create session or clientid cache is a
single slot. So if there is a sequence replay of a compound with a
create session it's safe to replay the create session stored in the
sequence slot cache because: sequence replay -> client did not get
the response -> create session slot sequence # was not incremented.
-->Andy
Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 6 +++++-
fs/nfsd/nfs4xdr.c | 19 +++++++++++++++++++
include/linux/nfsd/xdr4.h | 2 ++
3 files changed, 26 insertions(+), 1 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 27ad37f..279b47e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1377,7 +1377,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) ||
(ip_addr != unconf->cl_addr)) {
Could we apply the patch removing these ip_addr checks before any of
these patches? Also I seem to recall expressing some other doubts
about
the correctness of exchange_id and create_session--I'd like to see
those
addressed first, as this builds on those.
status = nfserr_clid_inuse;
- goto out;
+ goto out_cache;
}
slot = &unconf->cl_slot;
@@ -1424,6 +1424,10 @@ nfsd4_create_session(struct svc_rqst *rqstp,
cstate->slot = slot;
/* Ensure a page is used for the cache */
slot->sl_cache_entry.ce_cachethis = 1;
Is this still needed?
--b.
+out_cache:
+ /* cache solo and embedded create sessions under the state lock */
+ nfsd4_cache_create_session(cr_ses, slot, status);
+
out:
nfs4_unlock_state();
dprintk("%s returns %d\n", __func__, ntohl(status));
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index b2f8d74..6b34fac 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3046,6 +3046,25 @@ nfsd4_encode_create_session(struct
nfsd4_compoundres *resp, int nfserr,
return 0;
}
+/*
+ * Encode the create_session result into the create session single
DRC
+ * slot cache. Do this for solo or embedded create session
operations.
+ */
+void
+nfsd4_cache_create_session(struct nfsd4_create_session *cr_ses,
+ struct nfsd4_slot *slot, int nfserr)
+{
+ struct nfsd4_cache_entry *entry = &slot->sl_cache_entry;
+ __be32 *p = (__be32 *)entry->ce_datav.iov_base;
+ struct nfsd4_compoundres tmp = {
+ .p = p,
+ .end = p + XDR_QUADLEN(CS_MAX_ENC_SZ),
+ }, *resp = &tmp;
+
+ entry->ce_status = nfsd4_encode_create_session(resp, nfserr,
cr_ses);
+ entry->ce_datav.iov_len = (char *)resp->p - (char *)p;
+}
+
static __be32
nfsd4_encode_destroy_session(struct nfsd4_compoundres *resp, int
nfserr,
struct nfsd4_destroy_session *destroy_session)
diff --git a/include/linux/nfsd/xdr4.h b/include/linux/nfsd/xdr4.h
index afd4464..cc50ca0 100644
--- a/include/linux/nfsd/xdr4.h
+++ b/include/linux/nfsd/xdr4.h
@@ -517,6 +517,8 @@ extern __be32 nfsd4_setclientid_confirm(struct
svc_rqst *rqstp,
extern void nfsd4_store_cache_entry(struct nfsd4_compoundres *resp);
extern __be32 nfsd4_replay_cache_entry(struct nfsd4_compoundres
*resp,
struct nfsd4_sequence *seq);
+extern void nfsd4_cache_create_session(struct nfsd4_create_session
*cr_ses,
+ struct nfsd4_slot *slot, int nfserr);
extern __be32 nfsd4_exchange_id(struct svc_rqst *rqstp,
struct nfsd4_compound_state *,
struct nfsd4_exchange_id *);
--
1.5.4.3
--
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