diff options
| -rw-r--r-- | fs/nfsd/nfs4state.c | 77 | ||||
| -rw-r--r-- | fs/nfsd/state.h | 1 |
2 files changed, 73 insertions, 5 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index d29737018f04..b38b3a1c0307 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1909,6 +1909,16 @@ gen_sessionid(struct nfsd4_session *ses) */ #define NFSD_MIN_HDR_SEQ_SZ (24 + 12 + 44) +static struct shrinker *nfsd_slot_shrinker; +static DEFINE_SPINLOCK(nfsd_session_list_lock); +static LIST_HEAD(nfsd_session_list); +/* The sum of "target_slots-1" on every session. The shrinker can push this + * down, though it can take a little while for the memory to actually + * be freed. The "-1" is because we can never free slot 0 while the + * session is active. + */ +static atomic_t nfsd_total_target_slots = ATOMIC_INIT(0); + static void free_session_slots(struct nfsd4_session *ses, int from) { @@ -1930,8 +1940,11 @@ free_session_slots(struct nfsd4_session *ses, int from) kfree(slot); } ses->se_fchannel.maxreqs = from; - if (ses->se_target_maxslots > from) - ses->se_target_maxslots = from; + if (ses->se_target_maxslots > from) { + int new_target = from ?: 1; + atomic_sub(ses->se_target_maxslots - new_target, &nfsd_total_target_slots); + ses->se_target_maxslots = new_target; + } } /** @@ -1949,7 +1962,7 @@ free_session_slots(struct nfsd4_session *ses, int from) * Return value: * The number of slots that the target was reduced by. */ -static int __maybe_unused +static int reduce_session_slots(struct nfsd4_session *ses, int dec) { struct nfsd_net *nn = net_generic(ses->se_client->net, @@ -1962,6 +1975,7 @@ reduce_session_slots(struct nfsd4_session *ses, int dec) return ret; ret = min(dec, ses->se_target_maxslots-1); ses->se_target_maxslots -= ret; + atomic_sub(ret, &nfsd_total_target_slots); ses->se_slot_gen += 1; if (ses->se_slot_gen == 0) { int i; @@ -2021,6 +2035,7 @@ static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs, fattrs->maxreqs = i; memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs)); new->se_target_maxslots = i; + atomic_add(i - 1, &nfsd_total_target_slots); new->se_cb_slot_avail = ~0U; new->se_cb_highest_slot = min(battrs->maxreqs - 1, NFSD_BC_SLOT_TABLE_SIZE - 1); @@ -2145,6 +2160,36 @@ static void free_session(struct nfsd4_session *ses) __free_session(ses); } +static unsigned long +nfsd_slot_count(struct shrinker *s, struct shrink_control *sc) +{ + unsigned long cnt = atomic_read(&nfsd_total_target_slots); + + return cnt ? cnt : SHRINK_EMPTY; +} + +static unsigned long +nfsd_slot_scan(struct shrinker *s, struct shrink_control *sc) +{ + struct nfsd4_session *ses; + unsigned long scanned = 0; + unsigned long freed = 0; + + spin_lock(&nfsd_session_list_lock); + list_for_each_entry(ses, &nfsd_session_list, se_all_sessions) { + freed += reduce_session_slots(ses, 1); + scanned += 1; + if (scanned >= sc->nr_to_scan) { + /* Move starting point for next scan */ + list_move(&nfsd_session_list, &ses->se_all_sessions); + break; + } + } + spin_unlock(&nfsd_session_list_lock); + sc->nr_scanned = scanned; + return freed; +} + static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, struct nfs4_client *clp, struct nfsd4_create_session *cses) { int idx; @@ -2169,6 +2214,10 @@ static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, stru list_add(&new->se_perclnt, &clp->cl_sessions); spin_unlock(&clp->cl_lock); + spin_lock(&nfsd_session_list_lock); + list_add_tail(&new->se_all_sessions, &nfsd_session_list); + spin_unlock(&nfsd_session_list_lock); + { struct sockaddr *sa = svc_addr(rqstp); /* @@ -2238,6 +2287,9 @@ unhash_session(struct nfsd4_session *ses) spin_lock(&ses->se_client->cl_lock); list_del(&ses->se_perclnt); spin_unlock(&ses->se_client->cl_lock); + spin_lock(&nfsd_session_list_lock); + list_del(&ses->se_all_sessions); + spin_unlock(&nfsd_session_list_lock); } /* SETCLIENTID and SETCLIENTID_CONFIRM Helper functions */ @@ -2373,8 +2425,12 @@ unhash_client_locked(struct nfs4_client *clp) } list_del_init(&clp->cl_lru); spin_lock(&clp->cl_lock); - list_for_each_entry(ses, &clp->cl_sessions, se_perclnt) + spin_lock(&nfsd_session_list_lock); + list_for_each_entry(ses, &clp->cl_sessions, se_perclnt) { list_del_init(&ses->se_hash); + list_del_init(&ses->se_all_sessions); + } + spin_unlock(&nfsd_session_list_lock); spin_unlock(&clp->cl_lock); } @@ -4380,6 +4436,8 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, GFP_NOWAIT))) { s += 1; session->se_fchannel.maxreqs = s; + atomic_add(s - session->se_target_maxslots, + &nfsd_total_target_slots); session->se_target_maxslots = s; } else { kfree(slot); @@ -8770,7 +8828,6 @@ skip_grace: } /* initialization to perform when the nfsd service is started: */ - int nfs4_state_start(void) { @@ -8780,6 +8837,15 @@ nfs4_state_start(void) if (ret) return ret; + nfsd_slot_shrinker = shrinker_alloc(0, "nfsd-DRC-slot"); + if (!nfsd_slot_shrinker) { + rhltable_destroy(&nfs4_file_rhltable); + return -ENOMEM; + } + nfsd_slot_shrinker->count_objects = nfsd_slot_count; + nfsd_slot_shrinker->scan_objects = nfsd_slot_scan; + shrinker_register(nfsd_slot_shrinker); + set_max_delegations(); return 0; } @@ -8821,6 +8887,7 @@ void nfs4_state_shutdown(void) { rhltable_destroy(&nfs4_file_rhltable); + shrinker_free(nfsd_slot_shrinker); } static void diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 2b0e6148a87a..b31a8523c8e5 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -325,6 +325,7 @@ struct nfsd4_session { u32 se_cb_prog; struct list_head se_hash; /* hash by sessionid */ struct list_head se_perclnt; + struct list_head se_all_sessions;/* global list of sessions */ struct nfs4_client *se_client; struct nfs4_sessionid se_sessionid; struct nfsd4_channel_attrs se_fchannel; |