This is a note to let you know that I've just added the patch titled
NFSD: limit the number of v4 clients to 1024 per 1GB of system memory
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsd-limit-the-number-of-v4-clients-to-1024-per-1gb-.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7bee796e56b88fab0a5d9cadefda792d623e5b02
Author: Dai Ngo <dai.ngo@xxxxxxxxxx>
Date: Fri Jul 15 16:54:53 2022 -0700
NFSD: limit the number of v4 clients to 1024 per 1GB of system memory
[ Upstream commit 4271c2c0887562318a0afef97d32d8a71cbe0743 ]
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 1024 NFSv4 clients, including courtesy
clients, per 1GB of system memory. When the number of the clients
reaches the limit, requests that create new clients are returned
with NFS4ERR_DELAY and the laundromat is kicked start to trim old
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 the 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@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index ce864f001a3ee..ffe17743cc74b 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -191,6 +191,7 @@ struct nfsd_net {
siphash_key_t siphash_key;
atomic_t nfs4_client_count;
+ int nfs4_max_clients;
};
/* Simple check to find out if a given net was properly initialized */
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 5003d73fa9287..1babc08fcb88f 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2072,6 +2072,10 @@ 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) {
+ mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);
+ return NULL;
+ }
clp = kmem_cache_zalloc(client_slab, GFP_KERNEL);
if (clp == NULL)
return NULL;
@@ -4353,6 +4357,9 @@ nfsd4_init_slabs(void)
void nfsd4_init_leases_net(struct nfsd_net *nn)
{
+ struct sysinfo si;
+ u64 max_clients;
+
nn->nfsd4_lease = 90; /* default lease time */
nn->nfsd4_grace = 90;
nn->somebody_reclaimed = false;
@@ -4363,6 +4370,10 @@ void nfsd4_init_leases_net(struct nfsd_net *nn)
nn->s2s_cp_cl_id = nn->clientid_counter++;
atomic_set(&nn->nfs4_client_count, 0);
+ si_meminfo(&si);
+ max_clients = (u64)si.totalram * si.mem_unit / (1024 * 1024 * 1024);
+ max_clients *= NFS4_CLIENTS_PER_GB;
+ nn->nfs4_max_clients = max_t(int, max_clients, NFS4_CLIENTS_PER_GB);
}
static void init_nfs4_replay(struct nfs4_replay *rp)
@@ -5828,9 +5839,12 @@ static void
nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist,
struct laundry_time *lt)
{
+ unsigned int maxreap, reapcnt = 0;
struct list_head *pos, *next;
struct nfs4_client *clp;
+ maxreap = (atomic_read(&nn->nfs4_client_count) >= nn->nfs4_max_clients) ?
+ NFSD_CLIENT_MAX_TRIM_PER_RUN : 0;
INIT_LIST_HEAD(reaplist);
spin_lock(&nn->client_lock);
list_for_each_safe(pos, next, &nn->client_lru) {
@@ -5841,14 +5855,15 @@ 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)) {
+ if (!nfs4_anylock_blockers(clp))
+ if (reapcnt >= maxreap)
+ continue;
exp_client:
- if (!mark_client_expired_locked(clp))
- list_add(&clp->cl_lru, reaplist);
+ if (!mark_client_expired_locked(clp)) {
+ list_add(&clp->cl_lru, reaplist);
+ reapcnt++;
}
}
spin_unlock(&nn->client_lock);
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index ef8087691138a..57a468ed85c35 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -341,6 +341,8 @@ void nfsd_lockd_shutdown(void);
#define NFSD_LAUNDROMAT_MINTIMEOUT 1 /* seconds */
#define NFSD_COURTESY_CLIENT_TIMEOUT (24 * 60 * 60) /* seconds */
+#define NFSD_CLIENT_MAX_TRIM_PER_RUN 128
+#define NFS4_CLIENTS_PER_GB 1024
/*
* The following attributes are currently not supported by the NFSv4 server:
