nfsd4: make backchannel sequence number per-session
Currently we don't deal well with a client that has multiple sessions
associated with it (even simultaneously, or serially over the lifetime
of the client).
In particular, we don't attempt to keep the backchannel running after
the original session diseappears.
We will fix that soon.
Once we do that, we need the slot sequence number to be per-session;
otherwise, for example, we cannot correctly handle a case like this:
- All session 1 connections are lost.
- The client creates session 2. We use it for the backchannel
(since it's the only working choice).
- The client gives us a new connection to use with session 1.
- The client destroys session 2.
At this point our only choice is to go back to using session 1. When we
do so we must use the sequence number that is next for session 1. We
therefore need to maintain multiple sequence number streams.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 78ac779..5df9dda 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -260,7 +260,7 @@
WRITE32(OP_CB_SEQUENCE);
WRITEMEM(ses->se_sessionid.data, NFS4_MAX_SESSIONID_LEN);
- WRITE32(cb->cb_clp->cl_cb_seq_nr);
+ WRITE32(ses->se_cb_seq_nr);
WRITE32(0); /* slotid, always 0 */
WRITE32(0); /* highest slotid always 0 */
WRITE32(0); /* cachethis always 0 */
@@ -369,7 +369,7 @@
goto out;
}
READ32(dummy);
- if (dummy != cb->cb_clp->cl_cb_seq_nr) {
+ if (dummy != ses->se_cb_seq_nr) {
dprintk("%s Invalid sequence number\n", __func__);
goto out;
}
@@ -643,11 +643,11 @@
if (clp->cl_cb_conn.cb_minorversion) {
/* No need for lock, access serialized in nfsd4_cb_prepare */
- ++clp->cl_cb_seq_nr;
+ ++clp->cl_cb_session->se_cb_seq_nr;
clear_bit(0, &clp->cl_cb_slot_busy);
rpc_wake_up_next(&clp->cl_cb_waitq);
dprintk("%s: freed slot, new seqid=%d\n", __func__,
- clp->cl_cb_seq_nr);
+ clp->cl_cb_session->se_cb_seq_nr);
/* We're done looking into the sequence information */
task->tk_msg.rpc_resp = NULL;
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index c942511..6367c44 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -725,8 +725,7 @@
kfree(ses);
}
-
-static __be32 alloc_init_session(struct svc_rqst *rqstp, struct nfs4_client *clp, struct nfsd4_create_session *cses)
+static struct nfsd4_session *alloc_init_session(struct svc_rqst *rqstp, struct nfs4_client *clp, struct nfsd4_create_session *cses)
{
struct nfsd4_session *new;
struct nfsd4_channel_attrs *fchan = &cses->fore_channel;
@@ -747,7 +746,7 @@
new = alloc_session(slotsize, numslots);
if (!new) {
nfsd4_put_drc_mem(slotsize, fchan->maxreqs);
- return nfserr_jukebox;
+ return NULL;
}
init_forechannel_attrs(&new->se_fchannel, fchan, numslots, slotsize);
@@ -756,6 +755,7 @@
INIT_LIST_HEAD(&new->se_conns);
+ new->se_cb_seq_nr = 1;
new->se_flags = cses->flags;
kref_init(&new->se_ref);
idx = hash_sessionid(&new->se_sessionid);
@@ -765,9 +765,10 @@
spin_unlock(&client_lock);
status = nfsd4_new_conn(rqstp, new);
+ /* whoops: benny points out, status is ignored! (err, or bogus) */
if (status) {
free_session(&new->se_ref);
- return nfserr_jukebox;
+ return NULL;
}
if (!clp->cl_cb_session && (cses->flags & SESSION4_BACK_CHAN)) {
struct sockaddr *sa = svc_addr(rqstp);
@@ -779,10 +780,9 @@
clp->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
clp->cl_cb_conn.cb_minorversion = 1;
clp->cl_cb_conn.cb_prog = cses->callback_prog;
- clp->cl_cb_seq_nr = 1;
nfsd4_probe_callback(clp, &clp->cl_cb_conn);
}
- return nfs_ok;
+ return new;
}
/* caller must hold client_lock */
@@ -1485,6 +1485,7 @@
{
struct sockaddr *sa = svc_addr(rqstp);
struct nfs4_client *conf, *unconf;
+ struct nfsd4_session *new;
struct nfsd4_clid_slot *cs_slot = NULL;
int status = 0;
@@ -1538,11 +1539,12 @@
cr_ses->flags &= ~SESSION4_PERSIST;
cr_ses->flags &= ~SESSION4_RDMA;
- status = alloc_init_session(rqstp, conf, cr_ses);
- if (status)
+ status = nfserr_jukebox;
+ new = alloc_init_session(rqstp, conf, cr_ses);
+ if (!new)
goto out;
-
- memcpy(cr_ses->sessionid.data, conf->cl_cb_session->se_sessionid.data,
+ status = nfs_ok;
+ memcpy(cr_ses->sessionid.data, new->se_sessionid.data,
NFS4_MAX_SESSIONID_LEN);
cr_ses->seqid = cs_slot->sl_seqid;
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index cdce26a..7f5b267 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -172,6 +172,7 @@
struct nfsd4_channel_attrs se_fchannel;
struct nfsd4_channel_attrs se_bchannel;
struct list_head se_conns;
+ u32 se_cb_seq_nr;
struct nfsd4_slot *se_slots[]; /* forward channel slots */
};
@@ -249,7 +250,6 @@
/* for nfs41 callbacks */
/* We currently support a single back channel with a single slot */
unsigned long cl_cb_slot_busy;
- u32 cl_cb_seq_nr;
struct rpc_wait_queue cl_cb_waitq; /* backchannel callers may */
/* wait here for slots */
};