diff options
author | Dai Ngo <dai.ngo@oracle.com> | 2022-09-14 18:54:26 +0300 |
---|---|---|
committer | Chuck Lever <chuck.lever@oracle.com> | 2022-09-26 21:02:41 +0300 |
commit | 7746b32f467b3813fb61faaab3258de35806a7ac (patch) | |
tree | 22ace645fe5c97affbe517c0f36395cdc2e898cf /fs/nfsd/nfs4state.c | |
parent | 3a4ea23d86a317c4b68b9a69d51f7e84e1e04357 (diff) | |
download | linux-7746b32f467b3813fb61faaab3258de35806a7ac.tar.xz |
NFSD: add shrinker to reap courtesy clients on low memory condition
Add courtesy_client_reaper to react to low memory condition triggered
by the system memory shrinker.
The delayed_work for the courtesy_client_reaper is scheduled on
the shrinker's count callback using the laundry_wq.
The shrinker's scan callback is not used for expiring the courtesy
clients due to potential deadlocks.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs/nfsd/nfs4state.c')
-rw-r--r-- | fs/nfsd/nfs4state.c | 94 |
1 files changed, 86 insertions, 8 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index a248ecfe89c8..56b50210da38 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4349,7 +4349,27 @@ out: return -ENOMEM; } -void nfsd4_init_leases_net(struct nfsd_net *nn) +static unsigned long +nfsd_courtesy_client_count(struct shrinker *shrink, struct shrink_control *sc) +{ + int cnt; + struct nfsd_net *nn = container_of(shrink, + struct nfsd_net, nfsd_client_shrinker); + + cnt = atomic_read(&nn->nfsd_courtesy_clients); + if (cnt > 0) + mod_delayed_work(laundry_wq, &nn->nfsd_shrinker_work, 0); + return (unsigned long)cnt; +} + +static unsigned long +nfsd_courtesy_client_scan(struct shrinker *shrink, struct shrink_control *sc) +{ + return SHRINK_STOP; +} + +int +nfsd4_init_leases_net(struct nfsd_net *nn) { struct sysinfo si; u64 max_clients; @@ -4370,6 +4390,16 @@ void nfsd4_init_leases_net(struct nfsd_net *nn) nn->nfs4_max_clients = max_t(int, max_clients, NFS4_CLIENTS_PER_GB); atomic_set(&nn->nfsd_courtesy_clients, 0); + nn->nfsd_client_shrinker.scan_objects = nfsd_courtesy_client_scan; + nn->nfsd_client_shrinker.count_objects = nfsd_courtesy_client_count; + nn->nfsd_client_shrinker.seeks = DEFAULT_SEEKS; + return register_shrinker(&nn->nfsd_client_shrinker, "nfsd-client"); +} + +void +nfsd4_leases_net_shutdown(struct nfsd_net *nn) +{ + unregister_shrinker(&nn->nfsd_client_shrinker); } static void init_nfs4_replay(struct nfs4_replay *rp) @@ -5942,10 +5972,49 @@ exp_client: spin_unlock(&nn->client_lock); } +static void +nfs4_get_courtesy_client_reaplist(struct nfsd_net *nn, + struct list_head *reaplist) +{ + unsigned int maxreap = 0, reapcnt = 0; + struct list_head *pos, *next; + struct nfs4_client *clp; + + 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) { + clp = list_entry(pos, struct nfs4_client, cl_lru); + if (clp->cl_state == NFSD4_ACTIVE) + break; + if (reapcnt >= maxreap) + break; + if (!mark_client_expired_locked(clp)) { + list_add(&clp->cl_lru, reaplist); + reapcnt++; + } + } + spin_unlock(&nn->client_lock); +} + +static void +nfs4_process_client_reaplist(struct list_head *reaplist) +{ + struct list_head *pos, *next; + struct nfs4_client *clp; + + list_for_each_safe(pos, next, reaplist) { + clp = list_entry(pos, struct nfs4_client, cl_lru); + trace_nfsd_clid_purged(&clp->cl_clientid); + list_del_init(&clp->cl_lru); + expire_client(clp); + } +} + static time64_t nfs4_laundromat(struct nfsd_net *nn) { - struct nfs4_client *clp; struct nfs4_openowner *oo; struct nfs4_delegation *dp; struct nfs4_ol_stateid *stp; @@ -5974,12 +6043,8 @@ nfs4_laundromat(struct nfsd_net *nn) } spin_unlock(&nn->s2s_cp_lock); nfs4_get_client_reaplist(nn, &reaplist, <); - list_for_each_safe(pos, next, &reaplist) { - clp = list_entry(pos, struct nfs4_client, cl_lru); - trace_nfsd_clid_purged(&clp->cl_clientid); - list_del_init(&clp->cl_lru); - expire_client(clp); - } + nfs4_process_client_reaplist(&reaplist); + spin_lock(&state_lock); list_for_each_safe(pos, next, &nn->del_recall_lru) { dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru); @@ -6062,6 +6127,18 @@ laundromat_main(struct work_struct *laundry) queue_delayed_work(laundry_wq, &nn->laundromat_work, t*HZ); } +static void +courtesy_client_reaper(struct work_struct *reaper) +{ + struct list_head reaplist; + struct delayed_work *dwork = to_delayed_work(reaper); + struct nfsd_net *nn = container_of(dwork, struct nfsd_net, + nfsd_shrinker_work); + + nfs4_get_courtesy_client_reaplist(nn, &reaplist); + nfs4_process_client_reaplist(&reaplist); +} + static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stid *stp) { if (!fh_match(&fhp->fh_handle, &stp->sc_file->fi_fhandle)) @@ -7879,6 +7956,7 @@ static int nfs4_state_create_net(struct net *net) INIT_LIST_HEAD(&nn->blocked_locks_lru); INIT_DELAYED_WORK(&nn->laundromat_work, laundromat_main); + INIT_DELAYED_WORK(&nn->nfsd_shrinker_work, courtesy_client_reaper); get_net(net); return 0; |