@@ -191,6 +191,7 @@ struct nfsd_net {
siphash_key_t siphash_key;
atomic_t nfs4_client_count;
+ unsigned int nfs4_max_clients;
};
/* Simple check to find out if a given net was properly initialized */
@@ -126,6 +126,7 @@ static const struct nfsd4_callback_ops nfsd4_cb_recall_ops;
static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops;
static struct workqueue_struct *laundry_wq;
+#define NFSD_CLIENT_MAX_TRIM_PER_RUN 128
int nfsd4_create_laundry_wq(void)
{
@@ -2059,6 +2060,8 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name,
struct nfs4_client *clp;
int i;
+ if (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients)
+ return NULL;
clp = kmem_cache_zalloc(client_slab, GFP_KERNEL);
if (clp == NULL)
return NULL;
@@ -5796,9 +5799,12 @@ static void
nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist,
struct laundry_time *lt)
{
+ unsigned int maxreap = 0, reapcnt = 0;
struct list_head *pos, *next;
struct nfs4_client *clp;
+ if (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients)
+ maxreap = NFSD_CLIENT_MAX_TRIM_PER_RUN;
INIT_LIST_HEAD(reaplist);
spin_lock(&nn->client_lock);
list_for_each_safe(pos, next, &nn->client_lru) {
@@ -5809,14 +5815,17 @@ nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist,
break;
if (!atomic_read(&clp->cl_rpc_users))
clp->cl_state = NFSD4_COURTESY;
- if (!client_has_state(clp) ||
- ktime_get_boottime_seconds() >=
- (clp->cl_time + NFSD_COURTESY_CLIENT_TIMEOUT))
+ if (!client_has_state(clp))
goto exp_client;
if (nfs4_anylock_blockers(clp)) {
exp_client:
- if (!mark_client_expired_locked(clp))
+ if (!mark_client_expired_locked(clp)) {
list_add(&clp->cl_lru, reaplist);
+ reapcnt++;
+ }
+ } else {
+ if (reapcnt < maxreap)
+ goto exp_client;
}
}
spin_unlock(&nn->client_lock);
@@ -96,6 +96,8 @@ static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
#endif
};
+#define NFS4_MAX_CLIENTS_PER_4GB 4096
+
static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
{
ino_t ino = file_inode(file)->i_ino;
@@ -1462,6 +1464,8 @@ unsigned int nfsd_net_id;
static __net_init int nfsd_init_net(struct net *net)
{
int retval;
+ unsigned long lowmem;
+ struct sysinfo si;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
retval = nfsd_export_init(net);
@@ -1488,6 +1492,10 @@ static __net_init int nfsd_init_net(struct net *net)
seqlock_init(&nn->writeverf_lock);
atomic_set(&nn->nfs4_client_count, 0);
+ si_meminfo(&si);
+ lowmem = (si.totalram - si.totalhigh) * si.mem_unit;
+ nn->nfs4_max_clients = (((lowmem * 100) >> 32) *
+ NFS4_MAX_CLIENTS_PER_4GB) / 100;
return 0;
Currently there is no limit on how many v4 clients are supported by the system. This can be a problem in systems with small memory configuration to function properly when a very large number of clients exist that creates memory shortage conditions. This patch enforces a limit of 4096 NFSv4 clients, including courtesy clients, per 4GB of system memory. When the number of the clients reaches the limit, requests that create new clients are returned with NFS4ERR_DELAY. The laundromat detects this condition and removes older courtesy clients. Due to the overhead of the upcall to remove the client record, the maximun number of clients the laundromat removes on each run is limited to 128. This is done to ensure the laundromat can still process other tasks in a timely manner. Since there is now a limit of the number of clients, the 24-hr idle time limit of courtesy client is no longer needed and was removed. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> --- fs/nfsd/netns.h | 1 + fs/nfsd/nfs4state.c | 17 +++++++++++++---- fs/nfsd/nfsctl.c | 8 ++++++++ 3 files changed, 22 insertions(+), 4 deletions(-)