hdr->nops++;
}
+static u32 highest_slotid(struct nfsd4_session *ses)
+{
+ u32 idx;
+
+ spin_lock(&ses->se_lock);
+ idx = fls(~ses->se_cb_slot_avail);
+ if (idx > 0)
+ --idx;
+ idx = max(idx, ses->se_cb_highest_slot);
+ spin_unlock(&ses->se_lock);
+ return idx;
+}
+
/*
* CB_SEQUENCE4args
*
encode_sessionid4(xdr, session);
p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
- *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
- *p++ = xdr_zero; /* csa_slotid */
- *p++ = xdr_zero; /* csa_highest_slotid */
+ *p++ = cpu_to_be32(session->se_cb_seq_nr[cb->cb_held_slot]); /* csa_sequenceid */
+ *p++ = cpu_to_be32(cb->cb_held_slot); /* csa_slotid */
+ *p++ = cpu_to_be32(highest_slotid(session)); /* csa_highest_slotid */
*p++ = xdr_zero; /* csa_cachethis */
xdr_encode_empty_array(p); /* csa_referring_call_lists */
hdr->nops++;
}
+static void update_cb_slot_table(struct nfsd4_session *ses, u32 target)
+{
+ /* No need to do anything if nothing changed */
+ if (likely(target == READ_ONCE(ses->se_cb_highest_slot)))
+ return;
+
+ spin_lock(&ses->se_lock);
+ if (target > ses->se_cb_highest_slot) {
+ int i;
+
+ target = min(target, NFSD_BC_SLOT_TABLE_SIZE - 1);
+
+ /*
+ * Growing the slot table. Reset any new sequences to 1.
+ *
+ * NB: There is some debate about whether the RFC requires this,
+ * but the Linux client expects it.
+ */
+ for (i = ses->se_cb_highest_slot + 1; i <= target; ++i)
+ ses->se_cb_seq_nr[i] = 1;
+ }
+ ses->se_cb_highest_slot = target;
+ spin_unlock(&ses->se_lock);
+}
+
/*
* CB_SEQUENCE4resok
*
struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
int status = -ESERVERFAULT;
__be32 *p;
- u32 dummy;
+ u32 seqid, slotid, target;
/*
* If the server returns different values for sessionID, slotID or
}
p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
- dummy = be32_to_cpup(p++);
- if (dummy != session->se_cb_seq_nr) {
+ seqid = be32_to_cpup(p++);
+ if (seqid != session->se_cb_seq_nr[cb->cb_held_slot]) {
dprintk("NFS: %s Invalid sequence number\n", __func__);
goto out;
}
- dummy = be32_to_cpup(p++);
- if (dummy != 0) {
+ slotid = be32_to_cpup(p++);
+ if (slotid != cb->cb_held_slot) {
dprintk("NFS: %s Invalid slotid\n", __func__);
goto out;
}
- /*
- * FIXME: process highest slotid and target highest slotid
- */
+ p++; // ignore current highest slot value
+
+ target = be32_to_cpup(p++);
+ update_cb_slot_table(session, target);
status = 0;
out:
cb->cb_seq_status = status;
spin_unlock(&clp->cl_lock);
}
+static int grab_slot(struct nfsd4_session *ses)
+{
+ int idx;
+
+ spin_lock(&ses->se_lock);
+ idx = ffs(ses->se_cb_slot_avail) - 1;
+ if (idx < 0 || idx > ses->se_cb_highest_slot) {
+ spin_unlock(&ses->se_lock);
+ return -1;
+ }
+ /* clear the bit for the slot */
+ ses->se_cb_slot_avail &= ~BIT(idx);
+ spin_unlock(&ses->se_lock);
+ return idx;
+}
+
/*
* There's currently a single callback channel slot.
* If the slot is available, then mark it busy. Otherwise, set the
static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
{
struct nfs4_client *clp = cb->cb_clp;
+ struct nfsd4_session *ses = clp->cl_cb_session;
- if (!cb->cb_holds_slot &&
- test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
+ if (cb->cb_held_slot >= 0)
+ return true;
+ cb->cb_held_slot = grab_slot(ses);
+ if (cb->cb_held_slot < 0) {
rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
/* Race breaker */
- if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
- dprintk("%s slot is busy\n", __func__);
+ cb->cb_held_slot = grab_slot(ses);
+ if (cb->cb_held_slot < 0)
return false;
- }
rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
}
- cb->cb_holds_slot = true;
return true;
}
static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
+ struct nfsd4_session *ses = clp->cl_cb_session;
- if (cb->cb_holds_slot) {
- cb->cb_holds_slot = false;
- clear_bit(0, &clp->cl_cb_slot_busy);
+ if (cb->cb_held_slot >= 0) {
+ spin_lock(&ses->se_lock);
+ ses->se_cb_slot_avail |= BIT(cb->cb_held_slot);
+ spin_unlock(&ses->se_lock);
+ cb->cb_held_slot = -1;
rpc_wake_up_next(&clp->cl_cb_waitq);
}
}
}
/*
- * TODO: cb_sequence should support referring call lists, cachethis, multiple
- * slots, and mark callback channel down on communication errors.
+ * TODO: cb_sequence should support referring call lists, cachethis,
+ * and mark callback channel down on communication errors.
*/
static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
{
return true;
}
- if (!cb->cb_holds_slot)
+ if (cb->cb_held_slot < 0)
goto need_restart;
/* This is the operation status code for CB_SEQUENCE */
* If CB_SEQUENCE returns an error, then the state of the slot
* (sequence ID, cached reply) MUST NOT change.
*/
- ++session->se_cb_seq_nr;
+ ++session->se_cb_seq_nr[cb->cb_held_slot];
break;
case -ESERVERFAULT:
- ++session->se_cb_seq_nr;
+ ++session->se_cb_seq_nr[cb->cb_held_slot];
nfsd4_mark_cb_fault(cb->cb_clp);
ret = false;
break;
case -NFS4ERR_BADSLOT:
goto retry_nowait;
case -NFS4ERR_SEQ_MISORDERED:
- if (session->se_cb_seq_nr != 1) {
- session->se_cb_seq_nr = 1;
+ if (session->se_cb_seq_nr[cb->cb_held_slot] != 1) {
+ session->se_cb_seq_nr[cb->cb_held_slot] = 1;
goto retry_nowait;
}
break;
default:
nfsd4_mark_cb_fault(cb->cb_clp);
}
- nfsd41_cb_release_slot(cb);
-
trace_nfsd_cb_free_slot(task, cb);
+ nfsd41_cb_release_slot(cb);
if (RPC_SIGNALLED(task))
goto need_restart;
INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
cb->cb_status = 0;
cb->cb_need_restart = false;
- cb->cb_holds_slot = false;
+ cb->cb_held_slot = -1;
}
/**
}
memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs));
+ new->se_cb_slot_avail = ~0U;
+ new->se_cb_highest_slot = min(battrs->maxreqs - 1,
+ NFSD_BC_SLOT_TABLE_SIZE - 1);
+ spin_lock_init(&new->se_lock);
return new;
out_free:
while (i--)
INIT_LIST_HEAD(&new->se_conns);
- new->se_cb_seq_nr = 1;
+ atomic_set(&new->se_ref, 0);
new->se_dead = false;
new->se_cb_prog = cses->callback_prog;
new->se_cb_sec = cses->cb_sec;
- atomic_set(&new->se_ref, 0);
+
+ for (idx = 0; idx < NFSD_BC_SLOT_TABLE_SIZE; ++idx)
+ new->se_cb_seq_nr[idx] = 1;
+
idx = hash_sessionid(&new->se_sessionid);
list_add(&new->se_hash, &nn->sessionid_hashtbl[idx]);
spin_lock(&clp->cl_lock);
kref_init(&clp->cl_nfsdfs.cl_ref);
nfsd4_init_cb(&clp->cl_cb_null, clp, NULL, NFSPROC4_CLNT_CB_NULL);
clp->cl_time = ktime_get_boottime_seconds();
- clear_bit(0, &clp->cl_cb_slot_busy);
copy_verf(clp, verf);
memcpy(&clp->cl_addr, sa, sizeof(struct sockaddr_storage));
clp->cl_cb_session = NULL;
cr_ses->flags &= ~SESSION4_PERSIST;
/* Upshifting from TCP to RDMA is not supported */
cr_ses->flags &= ~SESSION4_RDMA;
+ /* Report the correct number of backchannel slots */
+ cr_ses->back_channel.maxreqs = new->se_cb_highest_slot + 1;
init_session(rqstp, new, conf, cr_ses);
nfsd4_get_session_locked(new);
projects / linux.git / commitdiff