@@ -1909,6 +1909,16 @@ gen_sessionid(struct nfsd4_session *ses)
*/
#define NFSD_MIN_HDR_SEQ_SZ (24 + 12 + 44)
+static struct shrinker *nfsd_slot_shrinker;
+static DEFINE_SPINLOCK(nfsd_session_list_lock);
+static LIST_HEAD(nfsd_session_list);
+/* The sum of "target_slots-1" on every session. The shrinker can push this
+ * down, though it can take a little while for the memory to actually
+ * be freed. The "-1" is because we can never free slot 0 while the
+ * session is active.
+ */
+static atomic_t nfsd_total_target_slots = ATOMIC_INIT(0);
+
static void
free_session_slots(struct nfsd4_session *ses, int from)
{
@@ -1930,8 +1940,11 @@ free_session_slots(struct nfsd4_session *ses, int from)
kfree(slot);
}
ses->se_fchannel.maxreqs = from;
- if (ses->se_target_maxslots > from)
- ses->se_target_maxslots = from;
+ if (ses->se_target_maxslots > from) {
+ int new_target = from ?: 1;
+ atomic_sub(ses->se_target_maxslots - new_target, &nfsd_total_target_slots);
+ ses->se_target_maxslots = new_target;
+ }
}
/**
@@ -1949,7 +1962,7 @@ free_session_slots(struct nfsd4_session *ses, int from)
* Return value:
* The number of slots that the target was reduced by.
*/
-static int __maybe_unused
+static int
reduce_session_slots(struct nfsd4_session *ses, int dec)
{
struct nfsd_net *nn = net_generic(ses->se_client->net,
@@ -1962,6 +1975,7 @@ reduce_session_slots(struct nfsd4_session *ses, int dec)
return ret;
ret = min(dec, ses->se_target_maxslots-1);
ses->se_target_maxslots -= ret;
+ atomic_sub(ret, &nfsd_total_target_slots);
ses->se_slot_gen += 1;
if (ses->se_slot_gen == 0) {
int i;
@@ -2021,6 +2035,7 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs,
fattrs->maxreqs = i;
memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs));
new->se_target_maxslots = i;
+ atomic_add(i - 1, &nfsd_total_target_slots);
new->se_cb_slot_avail = ~0U;
new->se_cb_highest_slot = min(battrs->maxreqs - 1,
NFSD_BC_SLOT_TABLE_SIZE - 1);
@@ -2145,6 +2160,36 @@ static void free_session(struct nfsd4_session *ses)
__free_session(ses);
}
+static unsigned long
+nfsd_slot_count(struct shrinker *s, struct shrink_control *sc)
+{
+ unsigned long cnt = atomic_read(&nfsd_total_target_slots);
+
+ return cnt ? cnt : SHRINK_EMPTY;
+}
+
+static unsigned long
+nfsd_slot_scan(struct shrinker *s, struct shrink_control *sc)
+{
+ struct nfsd4_session *ses;
+ unsigned long scanned = 0;
+ unsigned long freed = 0;
+
+ spin_lock(&nfsd_session_list_lock);
+ list_for_each_entry(ses, &nfsd_session_list, se_all_sessions) {
+ freed += reduce_session_slots(ses, 1);
+ scanned += 1;
+ if (scanned >= sc->nr_to_scan) {
+ /* Move starting point for next scan */
+ list_move(&nfsd_session_list, &ses->se_all_sessions);
+ break;
+ }
+ }
+ spin_unlock(&nfsd_session_list_lock);
+ sc->nr_scanned = scanned;
+ return freed;
+}
+
static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, struct nfs4_client *clp, struct nfsd4_create_session *cses)
{
int idx;
@@ -2169,6 +2214,10 @@ static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, stru
list_add(&new->se_perclnt, &clp->cl_sessions);
spin_unlock(&clp->cl_lock);
+ spin_lock(&nfsd_session_list_lock);
+ list_add_tail(&new->se_all_sessions, &nfsd_session_list);
+ spin_unlock(&nfsd_session_list_lock);
+
{
struct sockaddr *sa = svc_addr(rqstp);
/*
@@ -2238,6 +2287,9 @@ unhash_session(struct nfsd4_session *ses)
spin_lock(&ses->se_client->cl_lock);
list_del(&ses->se_perclnt);
spin_unlock(&ses->se_client->cl_lock);
+ spin_lock(&nfsd_session_list_lock);
+ list_del(&ses->se_all_sessions);
+ spin_unlock(&nfsd_session_list_lock);
}
/* SETCLIENTID and SETCLIENTID_CONFIRM Helper functions */
@@ -2373,8 +2425,12 @@ unhash_client_locked(struct nfs4_client *clp)
}
list_del_init(&clp->cl_lru);
spin_lock(&clp->cl_lock);
- list_for_each_entry(ses, &clp->cl_sessions, se_perclnt)
+ spin_lock(&nfsd_session_list_lock);
+ list_for_each_entry(ses, &clp->cl_sessions, se_perclnt) {
list_del_init(&ses->se_hash);
+ list_del_init(&ses->se_all_sessions);
+ }
+ spin_unlock(&nfsd_session_list_lock);
spin_unlock(&clp->cl_lock);
}
@@ -4380,6 +4436,8 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
GFP_NOWAIT))) {
s += 1;
session->se_fchannel.maxreqs = s;
+ atomic_add(s - session->se_target_maxslots,
+ &nfsd_total_target_slots);
session->se_target_maxslots = s;
} else {
kfree(slot);
@@ -8776,7 +8834,6 @@ nfs4_state_start_net(struct net *net)
}
/* initialization to perform when the nfsd service is started: */
-
int
nfs4_state_start(void)
{
@@ -8786,6 +8843,15 @@ nfs4_state_start(void)
if (ret)
return ret;
+ nfsd_slot_shrinker = shrinker_alloc(0, "nfsd-DRC-slot");
+ if (!nfsd_slot_shrinker) {
+ rhltable_destroy(&nfs4_file_rhltable);
+ return -ENOMEM;
+ }
+ nfsd_slot_shrinker->count_objects = nfsd_slot_count;
+ nfsd_slot_shrinker->scan_objects = nfsd_slot_scan;
+ shrinker_register(nfsd_slot_shrinker);
+
set_max_delegations();
return 0;
}
@@ -8827,6 +8893,7 @@ void
nfs4_state_shutdown(void)
{
rhltable_destroy(&nfs4_file_rhltable);
+ shrinker_free(nfsd_slot_shrinker);
}
static void
@@ -325,6 +325,7 @@ struct nfsd4_session {
u32 se_cb_prog;
struct list_head se_hash; /* hash by sessionid */
struct list_head se_perclnt;
+ struct list_head se_all_sessions;/* global list of sessions */
struct nfs4_client *se_client;
struct nfs4_sessionid se_sessionid;
struct nfsd4_channel_attrs se_fchannel;