5.15-stable review patch. If anyone has any objections, please let me know.
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From: Dai Ngo dai.ngo@oracle.com
[ 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@oracle.com Signed-off-by: Chuck Lever chuck.lever@oracle.com --- fs/nfsd/netns.h | 1 + fs/nfsd/nfs4state.c | 27 +++++++++++++++++++++------ fs/nfsd/nfsd.h | 2 ++ 3 files changed, 24 insertions(+), 6 deletions(-)
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 3d5ef021632b9..340d533dcafd3 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: