* [PATCH v7 0/2] NFSD: memory shrinker for NFSv4 clients
@ 2022-09-14 15:54 Dai Ngo
2022-09-14 15:54 ` [PATCH v7 1/2] NFSD: keep track of the number of courtesy clients in the system Dai Ngo
2022-09-14 15:54 ` [PATCH v7 2/2] NFSD: add shrinker to reap courtesy clients on low memory condition Dai Ngo
0 siblings, 2 replies; 5+ messages in thread
From: Dai Ngo @ 2022-09-14 15:54 UTC (permalink / raw)
To: chuck.lever, jlayton; +Cc: linux-nfs
This patch series implements the memory shrinker for NFSv4 clients
to react to system low memory condition.
The first patch adds a counter to keep track of the number of
courtesy clients in the system.
The second patch implements the courtesy_client_reaper used to
expiring the courtesy clients.
By destroying the courtesy clients, all states associated with
these clients are also released.
v2:
. fix kernel test robot errors in nfsd.h when CONFIG_NFSD_V4 not defined.
v3:
. add mod_delayed_work in nfsd_courtesy_client_scan to kick start
the laundromat.
v4:
. replace the use of xchg() with vanilla '=' in patch 1.
v5:
. rename nfsd_courtesy_client_count to nfsd_courtesy_clients
. add helper nfsd4_update_courtesy_client_count
. move nfsd_register_client_shrinker into nfsd4_init_leases_net
. move nfsd4_leases_net_shutdown from nfsd.h to nfs4state.c
. do away with shrinker 'scan' callback, just return SHRINK_STOP
. remove unused nfsd_client_shrinker_reapcount
v6:
. create courtesy_client_reaper and a separate delayed_work for it
using the laundromat_wq.
I tried merging nfs4_get_courtesy_client_reaplist and
nfs4_get_client_reaplist but it make the code looks ugly and
hard to read so I leave them as separate for now.
v7:
. patch1: rename nfsd4_decr_courtesy_client_count to
nfsd4_dec_courtesy_client_count
. patch 2: get rid of nfsd_client_shrinker_cb_count and do not
reschedule courtesy_client_reaper
---
Dai Ngo (2):
NFSD: keep track of the number of courtesy clients in the system
NFSD: add shrinker to reap courtesy clients on low memory condition
fs/nfsd/netns.h | 4 ++
fs/nfsd/nfs4state.c | 111 +++++++++++++++++++++++++++++++++++++++++++----
fs/nfsd/nfsctl.c | 6 ++-
fs/nfsd/nfsd.h | 7 ++-
4 files changed, 115 insertions(+), 13 deletions(-)
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v7 1/2] NFSD: keep track of the number of courtesy clients in the system 2022-09-14 15:54 [PATCH v7 0/2] NFSD: memory shrinker for NFSv4 clients Dai Ngo @ 2022-09-14 15:54 ` Dai Ngo 2022-09-14 15:54 ` [PATCH v7 2/2] NFSD: add shrinker to reap courtesy clients on low memory condition Dai Ngo 1 sibling, 0 replies; 5+ messages in thread From: Dai Ngo @ 2022-09-14 15:54 UTC (permalink / raw) To: chuck.lever, jlayton; +Cc: linux-nfs Add counter nfs4_courtesy_client_count to nfsd_net to keep track of the number of courtesy clients in the system. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> --- fs/nfsd/netns.h | 2 ++ fs/nfsd/nfs4state.c | 17 ++++++++++++++++- 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index ffe17743cc74..55c7006d6109 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -192,6 +192,8 @@ struct nfsd_net { atomic_t nfs4_client_count; int nfs4_max_clients; + + atomic_t nfsd_courtesy_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 c5d199d7e6b4..2827329704ea 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -160,6 +160,13 @@ static bool is_client_expired(struct nfs4_client *clp) return clp->cl_time == 0; } +static void nfsd4_dec_courtesy_client_count(struct nfsd_net *nn, + struct nfs4_client *clp) +{ + if (clp->cl_state != NFSD4_ACTIVE) + atomic_add_unless(&nn->nfsd_courtesy_clients, -1, 0); +} + static __be32 get_client_locked(struct nfs4_client *clp) { struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); @@ -169,6 +176,7 @@ static __be32 get_client_locked(struct nfs4_client *clp) if (is_client_expired(clp)) return nfserr_expired; atomic_inc(&clp->cl_rpc_users); + nfsd4_dec_courtesy_client_count(nn, clp); clp->cl_state = NFSD4_ACTIVE; return nfs_ok; } @@ -190,6 +198,7 @@ renew_client_locked(struct nfs4_client *clp) list_move_tail(&clp->cl_lru, &nn->client_lru); clp->cl_time = ktime_get_boottime_seconds(); + nfsd4_dec_courtesy_client_count(nn, clp); clp->cl_state = NFSD4_ACTIVE; } @@ -2233,6 +2242,7 @@ __destroy_client(struct nfs4_client *clp) if (clp->cl_cb_conn.cb_xprt) svc_xprt_put(clp->cl_cb_conn.cb_xprt); atomic_add_unless(&nn->nfs4_client_count, -1, 0); + nfsd4_dec_courtesy_client_count(nn, clp); free_client(clp); wake_up_all(&expiry_wq); } @@ -4356,6 +4366,8 @@ void nfsd4_init_leases_net(struct nfsd_net *nn) 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); + + atomic_set(&nn->nfsd_courtesy_clients, 0); } static void init_nfs4_replay(struct nfs4_replay *rp) @@ -5878,8 +5890,11 @@ nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist, goto exp_client; if (!state_expired(lt, clp->cl_time)) break; - if (!atomic_read(&clp->cl_rpc_users)) + if (!atomic_read(&clp->cl_rpc_users)) { + if (clp->cl_state == NFSD4_ACTIVE) + atomic_inc(&nn->nfsd_courtesy_clients); clp->cl_state = NFSD4_COURTESY; + } if (!client_has_state(clp)) goto exp_client; if (!nfs4_anylock_blockers(clp)) -- 2.9.5 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v7 2/2] NFSD: add shrinker to reap courtesy clients on low memory condition 2022-09-14 15:54 [PATCH v7 0/2] NFSD: memory shrinker for NFSv4 clients Dai Ngo 2022-09-14 15:54 ` [PATCH v7 1/2] NFSD: keep track of the number of courtesy clients in the system Dai Ngo @ 2022-09-14 15:54 ` Dai Ngo 2022-09-14 18:32 ` Chuck Lever III 1 sibling, 1 reply; 5+ messages in thread From: Dai Ngo @ 2022-09-14 15:54 UTC (permalink / raw) To: chuck.lever, jlayton; +Cc: linux-nfs 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> --- fs/nfsd/netns.h | 2 ++ fs/nfsd/nfs4state.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++----- fs/nfsd/nfsctl.c | 6 ++-- fs/nfsd/nfsd.h | 7 ++-- 4 files changed, 97 insertions(+), 12 deletions(-) diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index 55c7006d6109..8c854ba3285b 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -194,6 +194,8 @@ struct nfsd_net { int nfs4_max_clients; atomic_t nfsd_courtesy_clients; + struct shrinker nfsd_client_shrinker; + struct delayed_work nfsd_shrinker_work; }; /* 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 2827329704ea..62b848bb55df 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4347,7 +4347,27 @@ nfsd4_init_slabs(void) 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; @@ -4368,6 +4388,16 @@ 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) @@ -5909,10 +5939,49 @@ nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist, 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; @@ -5941,12 +6010,8 @@ 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); @@ -6029,6 +6094,18 @@ 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)) @@ -7845,6 +7922,7 @@ 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; diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 917fa1892fd2..597a26ad4183 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1481,11 +1481,12 @@ static __net_init int nfsd_init_net(struct net *net) goto out_idmap_error; nn->nfsd_versions = NULL; nn->nfsd4_minorversions = NULL; + retval = nfsd4_init_leases_net(nn); + if (retval) + goto out_drc_error; retval = nfsd_reply_cache_init(nn); if (retval) goto out_drc_error; - nfsd4_init_leases_net(nn); - get_random_bytes(&nn->siphash_key, sizeof(nn->siphash_key)); seqlock_init(&nn->writeverf_lock); @@ -1507,6 +1508,7 @@ static __net_exit void nfsd_exit_net(struct net *net) nfsd_idmap_shutdown(net); nfsd_export_shutdown(net); nfsd_netns_free_versions(net_generic(net, nfsd_net_id)); + nfsd4_leases_net_shutdown(nn); } static struct pernet_operations nfsd_net_ops = { diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 57a468ed85c3..cd92f615faa3 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -343,6 +343,7 @@ void nfsd_lockd_shutdown(void); #define NFSD_COURTESY_CLIENT_TIMEOUT (24 * 60 * 60) /* seconds */ #define NFSD_CLIENT_MAX_TRIM_PER_RUN 128 #define NFS4_CLIENTS_PER_GB 1024 +#define NFSD_CLIENT_SHRINKER_MINTIMEOUT 1 /* seconds */ /* * The following attributes are currently not supported by the NFSv4 server: @@ -498,7 +499,8 @@ extern void unregister_cld_notifier(void); extern void nfsd4_ssc_init_umount_work(struct nfsd_net *nn); #endif -extern void nfsd4_init_leases_net(struct nfsd_net *nn); +extern int nfsd4_init_leases_net(struct nfsd_net *nn); +extern void nfsd4_leases_net_shutdown(struct nfsd_net *nn); #else /* CONFIG_NFSD_V4 */ static inline int nfsd4_is_junction(struct dentry *dentry) @@ -506,7 +508,8 @@ static inline int nfsd4_is_junction(struct dentry *dentry) return 0; } -static inline void nfsd4_init_leases_net(struct nfsd_net *nn) {}; +static inline int nfsd4_init_leases_net(struct nfsd_net *nn) { return 0; }; +static inline void nfsd4_leases_net_shutdown(struct nfsd_net *nn) {}; #define register_cld_notifier() 0 #define unregister_cld_notifier() do { } while(0) -- 2.9.5 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v7 2/2] NFSD: add shrinker to reap courtesy clients on low memory condition 2022-09-14 15:54 ` [PATCH v7 2/2] NFSD: add shrinker to reap courtesy clients on low memory condition Dai Ngo @ 2022-09-14 18:32 ` Chuck Lever III 2022-09-14 18:37 ` dai.ngo 0 siblings, 1 reply; 5+ messages in thread From: Chuck Lever III @ 2022-09-14 18:32 UTC (permalink / raw) To: Dai Ngo; +Cc: Jeff Layton, Linux NFS Mailing List > On Sep 14, 2022, at 8:54 AM, Dai Ngo <dai.ngo@oracle.com> wrote: > > 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> > --- > fs/nfsd/netns.h | 2 ++ > fs/nfsd/nfs4state.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++----- > fs/nfsd/nfsctl.c | 6 ++-- > fs/nfsd/nfsd.h | 7 ++-- > 4 files changed, 97 insertions(+), 12 deletions(-) > > diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h > index 55c7006d6109..8c854ba3285b 100644 > --- a/fs/nfsd/netns.h > +++ b/fs/nfsd/netns.h > @@ -194,6 +194,8 @@ struct nfsd_net { > int nfs4_max_clients; > > atomic_t nfsd_courtesy_clients; > + struct shrinker nfsd_client_shrinker; > + struct delayed_work nfsd_shrinker_work; > }; > > /* 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 2827329704ea..62b848bb55df 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -4347,7 +4347,27 @@ nfsd4_init_slabs(void) > 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; > @@ -4368,6 +4388,16 @@ 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) > @@ -5909,10 +5939,49 @@ nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist, > 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; > @@ -5941,12 +6010,8 @@ 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); > @@ -6029,6 +6094,18 @@ 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)) > @@ -7845,6 +7922,7 @@ 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; > diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c > index 917fa1892fd2..597a26ad4183 100644 > --- a/fs/nfsd/nfsctl.c > +++ b/fs/nfsd/nfsctl.c > @@ -1481,11 +1481,12 @@ static __net_init int nfsd_init_net(struct net *net) > goto out_idmap_error; > nn->nfsd_versions = NULL; > nn->nfsd4_minorversions = NULL; > + retval = nfsd4_init_leases_net(nn); > + if (retval) > + goto out_drc_error; > retval = nfsd_reply_cache_init(nn); > if (retval) > goto out_drc_error; > - nfsd4_init_leases_net(nn); > - > get_random_bytes(&nn->siphash_key, sizeof(nn->siphash_key)); > seqlock_init(&nn->writeverf_lock); > > @@ -1507,6 +1508,7 @@ static __net_exit void nfsd_exit_net(struct net *net) > nfsd_idmap_shutdown(net); > nfsd_export_shutdown(net); > nfsd_netns_free_versions(net_generic(net, nfsd_net_id)); > + nfsd4_leases_net_shutdown(nn); > } > > static struct pernet_operations nfsd_net_ops = { > diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h > index 57a468ed85c3..cd92f615faa3 100644 > --- a/fs/nfsd/nfsd.h > +++ b/fs/nfsd/nfsd.h > @@ -343,6 +343,7 @@ void nfsd_lockd_shutdown(void); > #define NFSD_COURTESY_CLIENT_TIMEOUT (24 * 60 * 60) /* seconds */ > #define NFSD_CLIENT_MAX_TRIM_PER_RUN 128 > #define NFS4_CLIENTS_PER_GB 1024 > +#define NFSD_CLIENT_SHRINKER_MINTIMEOUT 1 /* seconds */ You don't need this definition any more. I can remove it when I apply the patch. Otherwise, these patches look great. I will give a few more days for more review comments. > /* > * The following attributes are currently not supported by the NFSv4 server: > @@ -498,7 +499,8 @@ extern void unregister_cld_notifier(void); > extern void nfsd4_ssc_init_umount_work(struct nfsd_net *nn); > #endif > > -extern void nfsd4_init_leases_net(struct nfsd_net *nn); > +extern int nfsd4_init_leases_net(struct nfsd_net *nn); > +extern void nfsd4_leases_net_shutdown(struct nfsd_net *nn); > > #else /* CONFIG_NFSD_V4 */ > static inline int nfsd4_is_junction(struct dentry *dentry) > @@ -506,7 +508,8 @@ static inline int nfsd4_is_junction(struct dentry *dentry) > return 0; > } > > -static inline void nfsd4_init_leases_net(struct nfsd_net *nn) {}; > +static inline int nfsd4_init_leases_net(struct nfsd_net *nn) { return 0; }; > +static inline void nfsd4_leases_net_shutdown(struct nfsd_net *nn) {}; > > #define register_cld_notifier() 0 > #define unregister_cld_notifier() do { } while(0) > -- > 2.9.5 > -- Chuck Lever ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v7 2/2] NFSD: add shrinker to reap courtesy clients on low memory condition 2022-09-14 18:32 ` Chuck Lever III @ 2022-09-14 18:37 ` dai.ngo 0 siblings, 0 replies; 5+ messages in thread From: dai.ngo @ 2022-09-14 18:37 UTC (permalink / raw) To: Chuck Lever III; +Cc: Jeff Layton, Linux NFS Mailing List On 9/14/22 11:32 AM, Chuck Lever III wrote: > >> On Sep 14, 2022, at 8:54 AM, Dai Ngo <dai.ngo@oracle.com> wrote: >> >> 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> >> --- >> fs/nfsd/netns.h | 2 ++ >> fs/nfsd/nfs4state.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++----- >> fs/nfsd/nfsctl.c | 6 ++-- >> fs/nfsd/nfsd.h | 7 ++-- >> 4 files changed, 97 insertions(+), 12 deletions(-) >> >> diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h >> index 55c7006d6109..8c854ba3285b 100644 >> --- a/fs/nfsd/netns.h >> +++ b/fs/nfsd/netns.h >> @@ -194,6 +194,8 @@ struct nfsd_net { >> int nfs4_max_clients; >> >> atomic_t nfsd_courtesy_clients; >> + struct shrinker nfsd_client_shrinker; >> + struct delayed_work nfsd_shrinker_work; >> }; >> >> /* 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 2827329704ea..62b848bb55df 100644 >> --- a/fs/nfsd/nfs4state.c >> +++ b/fs/nfsd/nfs4state.c >> @@ -4347,7 +4347,27 @@ nfsd4_init_slabs(void) >> 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; >> @@ -4368,6 +4388,16 @@ 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) >> @@ -5909,10 +5939,49 @@ nfs4_get_client_reaplist(struct nfsd_net *nn, struct list_head *reaplist, >> 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; >> @@ -5941,12 +6010,8 @@ 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); >> @@ -6029,6 +6094,18 @@ 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)) >> @@ -7845,6 +7922,7 @@ 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; >> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c >> index 917fa1892fd2..597a26ad4183 100644 >> --- a/fs/nfsd/nfsctl.c >> +++ b/fs/nfsd/nfsctl.c >> @@ -1481,11 +1481,12 @@ static __net_init int nfsd_init_net(struct net *net) >> goto out_idmap_error; >> nn->nfsd_versions = NULL; >> nn->nfsd4_minorversions = NULL; >> + retval = nfsd4_init_leases_net(nn); >> + if (retval) >> + goto out_drc_error; >> retval = nfsd_reply_cache_init(nn); >> if (retval) >> goto out_drc_error; >> - nfsd4_init_leases_net(nn); >> - >> get_random_bytes(&nn->siphash_key, sizeof(nn->siphash_key)); >> seqlock_init(&nn->writeverf_lock); >> >> @@ -1507,6 +1508,7 @@ static __net_exit void nfsd_exit_net(struct net *net) >> nfsd_idmap_shutdown(net); >> nfsd_export_shutdown(net); >> nfsd_netns_free_versions(net_generic(net, nfsd_net_id)); >> + nfsd4_leases_net_shutdown(nn); >> } >> >> static struct pernet_operations nfsd_net_ops = { >> diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h >> index 57a468ed85c3..cd92f615faa3 100644 >> --- a/fs/nfsd/nfsd.h >> +++ b/fs/nfsd/nfsd.h >> @@ -343,6 +343,7 @@ void nfsd_lockd_shutdown(void); >> #define NFSD_COURTESY_CLIENT_TIMEOUT (24 * 60 * 60) /* seconds */ >> #define NFSD_CLIENT_MAX_TRIM_PER_RUN 128 >> #define NFS4_CLIENTS_PER_GB 1024 >> +#define NFSD_CLIENT_SHRINKER_MINTIMEOUT 1 /* seconds */ > You don't need this definition any more. I can remove it > when I apply the patch. Oh yes, I missed this. > > Otherwise, these patches look great. I will give a few > more days for more review comments. Thank you Chuck, -Dai > > >> /* >> * The following attributes are currently not supported by the NFSv4 server: >> @@ -498,7 +499,8 @@ extern void unregister_cld_notifier(void); >> extern void nfsd4_ssc_init_umount_work(struct nfsd_net *nn); >> #endif >> >> -extern void nfsd4_init_leases_net(struct nfsd_net *nn); >> +extern int nfsd4_init_leases_net(struct nfsd_net *nn); >> +extern void nfsd4_leases_net_shutdown(struct nfsd_net *nn); >> >> #else /* CONFIG_NFSD_V4 */ >> static inline int nfsd4_is_junction(struct dentry *dentry) >> @@ -506,7 +508,8 @@ static inline int nfsd4_is_junction(struct dentry *dentry) >> return 0; >> } >> >> -static inline void nfsd4_init_leases_net(struct nfsd_net *nn) {}; >> +static inline int nfsd4_init_leases_net(struct nfsd_net *nn) { return 0; }; >> +static inline void nfsd4_leases_net_shutdown(struct nfsd_net *nn) {}; >> >> #define register_cld_notifier() 0 >> #define unregister_cld_notifier() do { } while(0) >> -- >> 2.9.5 >> > -- > Chuck Lever > > > ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-09-14 18:37 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-09-14 15:54 [PATCH v7 0/2] NFSD: memory shrinker for NFSv4 clients Dai Ngo 2022-09-14 15:54 ` [PATCH v7 1/2] NFSD: keep track of the number of courtesy clients in the system Dai Ngo 2022-09-14 15:54 ` [PATCH v7 2/2] NFSD: add shrinker to reap courtesy clients on low memory condition Dai Ngo 2022-09-14 18:32 ` Chuck Lever III 2022-09-14 18:37 ` dai.ngo
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