[PATCH 05/29] nfsd41: create_session cache hold client reference

andros
2009-04-23T16:43:16Z

expire_client can be called on a confirmed or unconfirmed client while
processing the create session operation and accessing the clientid slot.

Signed-off-by: Andy Adamson <andros@netapp.com>
---
fs/nfsd/nfs4state.c | 14 ++++++++++----
1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index a585a58..accad58 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1355,6 +1355,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
conf = find_confirmed_client(&cr_ses->clientid);

if (conf) {
+ atomic_inc(&conf->cl_count);
slot = &conf->cl_slot;
status = check_slot_seqid(cr_ses->seqid, slot);
if (status == nfserr_replay_cache) {
@@ -1363,27 +1364,30 @@ nfsd4_create_session(struct svc_rqst *rqstp,
cstate->status = nfserr_replay_clientid_cache;
/* Return the cached reply status */
status = nfsd4_replay_create_session(resp, slot);
- goto out;
+ goto out_put;
} else if (cr_ses->seqid != conf->cl_slot.sl_seqid + 1) {
status = nfserr_seq_misordered;
dprintk("Sequence misordered!\n");
dprintk("Expected seqid= %d but got seqid= %d\n",
slot->sl_seqid, cr_ses->seqid);
- goto out;
+ goto out_put;
}
conf->cl_slot.sl_seqid++;
} else if (unconf) {
+ atomic_inc(&unconf->cl_count);
slot = &unconf->cl_slot;
status = check_slot_seqid(cr_ses->seqid, slot);
if (status) {
/* an unconfirmed replay returns misordered */
status = nfserr_seq_misordered;
- goto out;
+ conf = unconf; /* for put_nfs4_client */
+ goto out_put;
}

if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) ||
(ip_addr != unconf->cl_addr)) {
status = nfserr_clid_inuse;
+ conf = unconf; /* for put_nfs4_client */
goto out_cache;
}

@@ -1413,7 +1417,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,

status = alloc_init_session(rqstp, conf, cr_ses);
if (status)
- goto out;
+ goto out_put;

memcpy(cr_ses->sessionid.data, conf->cl_sessionid.data,
NFS4_MAX_SESSIONID_LEN);
@@ -1423,6 +1427,8 @@ out_cache:
/* cache solo and embedded create sessions under the state lock */
nfsd4_cache_create_session(cr_ses, slot, status);

+out_put:
+ put_nfs4_client(conf);
out:
nfs4_unlock_state();
dprintk("%s returns %d\n", __func__, ntohl(status));
--
1.5.4.3