diff options
Diffstat (limited to 'fs/nfsd/nfscache.c')
| -rw-r--r-- | fs/nfsd/nfscache.c | 215 |
1 files changed, 124 insertions, 91 deletions
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index 96352ab7bd81..3e64a3d50a1c 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -20,8 +20,7 @@ #include "nfsd.h" #include "cache.h" - -#define NFSDDBG_FACILITY NFSDDBG_REPCACHE +#include "trace.h" /* * We use this value to determine the number of hash buckets from the max @@ -36,6 +35,8 @@ struct nfsd_drc_bucket { spinlock_t cache_lock; }; +static struct kmem_cache *drc_slab; + static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec); static unsigned long nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc); @@ -83,19 +84,13 @@ nfsd_hashsize(unsigned int limit) return roundup_pow_of_two(limit / TARGET_BUCKET_SIZE); } -static u32 -nfsd_cache_hash(__be32 xid, struct nfsd_net *nn) -{ - return hash_32(be32_to_cpu(xid), nn->maskbits); -} - static struct svc_cacherep * nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum, struct nfsd_net *nn) { struct svc_cacherep *rp; - rp = kmem_cache_alloc(nn->drc_slab, GFP_KERNEL); + rp = kmem_cache_alloc(drc_slab, GFP_KERNEL); if (rp) { rp->c_state = RC_UNUSED; rp->c_type = RC_NOCACHE; @@ -120,16 +115,16 @@ nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp, struct nfsd_net *nn) { if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) { - nn->drc_mem_usage -= rp->c_replvec.iov_len; + nfsd_stats_drc_mem_usage_sub(nn, rp->c_replvec.iov_len); kfree(rp->c_replvec.iov_base); } if (rp->c_state != RC_UNUSED) { rb_erase(&rp->c_node, &b->rb_head); list_del(&rp->c_lru); atomic_dec(&nn->num_drc_entries); - nn->drc_mem_usage -= sizeof(*rp); + nfsd_stats_drc_mem_usage_sub(nn, sizeof(*rp)); } - kmem_cache_free(nn->drc_slab, rp); + kmem_cache_free(drc_slab, rp); } static void @@ -141,6 +136,28 @@ nfsd_reply_cache_free(struct nfsd_drc_bucket *b, struct svc_cacherep *rp, spin_unlock(&b->cache_lock); } +int nfsd_drc_slab_create(void) +{ + drc_slab = kmem_cache_create("nfsd_drc", + sizeof(struct svc_cacherep), 0, 0, NULL); + return drc_slab ? 0: -ENOMEM; +} + +void nfsd_drc_slab_free(void) +{ + kmem_cache_destroy(drc_slab); +} + +static int nfsd_reply_cache_stats_init(struct nfsd_net *nn) +{ + return nfsd_percpu_counters_init(nn->counter, NFSD_NET_COUNTERS_NUM); +} + +static void nfsd_reply_cache_stats_destroy(struct nfsd_net *nn) +{ + nfsd_percpu_counters_destroy(nn->counter, NFSD_NET_COUNTERS_NUM); +} + int nfsd_reply_cache_init(struct nfsd_net *nn) { unsigned int hashsize; @@ -152,27 +169,23 @@ int nfsd_reply_cache_init(struct nfsd_net *nn) hashsize = nfsd_hashsize(nn->max_drc_entries); nn->maskbits = ilog2(hashsize); + status = nfsd_reply_cache_stats_init(nn); + if (status) + goto out_nomem; + nn->nfsd_reply_cache_shrinker.scan_objects = nfsd_reply_cache_scan; nn->nfsd_reply_cache_shrinker.count_objects = nfsd_reply_cache_count; nn->nfsd_reply_cache_shrinker.seeks = 1; - status = register_shrinker(&nn->nfsd_reply_cache_shrinker); + status = register_shrinker(&nn->nfsd_reply_cache_shrinker, + "nfsd-reply:%s", nn->nfsd_name); if (status) - goto out_nomem; + goto out_stats_destroy; - nn->drc_slab = kmem_cache_create("nfsd_drc", - sizeof(struct svc_cacherep), 0, 0, NULL); - if (!nn->drc_slab) + nn->drc_hashtbl = kvzalloc(array_size(hashsize, + sizeof(*nn->drc_hashtbl)), GFP_KERNEL); + if (!nn->drc_hashtbl) goto out_shrinker; - nn->drc_hashtbl = kcalloc(hashsize, - sizeof(*nn->drc_hashtbl), GFP_KERNEL); - if (!nn->drc_hashtbl) { - nn->drc_hashtbl = vzalloc(array_size(hashsize, - sizeof(*nn->drc_hashtbl))); - if (!nn->drc_hashtbl) - goto out_slab; - } - for (i = 0; i < hashsize; i++) { INIT_LIST_HEAD(&nn->drc_hashtbl[i].lru_head); spin_lock_init(&nn->drc_hashtbl[i].cache_lock); @@ -180,10 +193,10 @@ int nfsd_reply_cache_init(struct nfsd_net *nn) nn->drc_hashsize = hashsize; return 0; -out_slab: - kmem_cache_destroy(nn->drc_slab); out_shrinker: unregister_shrinker(&nn->nfsd_reply_cache_shrinker); +out_stats_destroy: + nfsd_reply_cache_stats_destroy(nn); out_nomem: printk(KERN_ERR "nfsd: failed to allocate reply cache\n"); return -ENOMEM; @@ -204,13 +217,12 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn) rp, nn); } } + nfsd_reply_cache_stats_destroy(nn); kvfree(nn->drc_hashtbl); nn->drc_hashtbl = NULL; nn->drc_hashsize = 0; - kmem_cache_destroy(nn->drc_slab); - nn->drc_slab = NULL; } /* @@ -224,8 +236,16 @@ lru_put_end(struct nfsd_drc_bucket *b, struct svc_cacherep *rp) list_move_tail(&rp->c_lru, &b->lru_head); } -static long -prune_bucket(struct nfsd_drc_bucket *b, struct nfsd_net *nn) +static noinline struct nfsd_drc_bucket * +nfsd_cache_bucket_find(__be32 xid, struct nfsd_net *nn) +{ + unsigned int hash = hash_32((__force u32)xid, nn->maskbits); + + return &nn->drc_hashtbl[hash]; +} + +static long prune_bucket(struct nfsd_drc_bucket *b, struct nfsd_net *nn, + unsigned int max) { struct svc_cacherep *rp, *tmp; long freed = 0; @@ -241,11 +261,17 @@ prune_bucket(struct nfsd_drc_bucket *b, struct nfsd_net *nn) time_before(jiffies, rp->c_timestamp + RC_EXPIRE)) break; nfsd_reply_cache_free_locked(b, rp, nn); - freed++; + if (max && freed++ > max) + break; } return freed; } +static long nfsd_prune_bucket(struct nfsd_drc_bucket *b, struct nfsd_net *nn) +{ + return prune_bucket(b, nn, 3); +} + /* * Walk the LRU list and prune off entries that are older than RC_EXPIRE. * Also prune the oldest ones when the total exceeds the max number of entries. @@ -262,7 +288,7 @@ prune_cache_entries(struct nfsd_net *nn) if (list_empty(&b->lru_head)) continue; spin_lock(&b->cache_lock); - freed += prune_bucket(b, nn); + freed += prune_bucket(b, nn, 0); spin_unlock(&b->cache_lock); } return freed; @@ -323,8 +349,10 @@ nfsd_cache_key_cmp(const struct svc_cacherep *key, const struct svc_cacherep *rp, struct nfsd_net *nn) { if (key->c_key.k_xid == rp->c_key.k_xid && - key->c_key.k_csum != rp->c_key.k_csum) - ++nn->payload_misses; + key->c_key.k_csum != rp->c_key.k_csum) { + nfsd_stats_payload_misses_inc(nn); + trace_nfsd_drc_mismatch(nn, key, rp); + } return memcmp(&key->c_key, &rp->c_key, sizeof(key->c_key)); } @@ -377,29 +405,34 @@ out: return ret; } -/* +/** + * nfsd_cache_lookup - Find an entry in the duplicate reply cache + * @rqstp: Incoming Call to find + * * Try to find an entry matching the current call in the cache. When none * is found, we try to grab the oldest expired entry off the LRU list. If * a suitable one isn't there, then drop the cache_lock and allocate a * new one, then search again in case one got inserted while this thread * didn't hold the lock. + * + * Return values: + * %RC_DOIT: Process the request normally + * %RC_REPLY: Reply from cache + * %RC_DROPIT: Do not process the request further */ -int -nfsd_cache_lookup(struct svc_rqst *rqstp) +int nfsd_cache_lookup(struct svc_rqst *rqstp) { - struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); + struct nfsd_net *nn; struct svc_cacherep *rp, *found; - __be32 xid = rqstp->rq_xid; __wsum csum; - u32 hash = nfsd_cache_hash(xid, nn); - struct nfsd_drc_bucket *b = &nn->drc_hashtbl[hash]; + struct nfsd_drc_bucket *b; int type = rqstp->rq_cachetype; int rtn = RC_DOIT; rqstp->rq_cacherep = NULL; if (type == RC_NOCACHE) { - nfsdstats.rcnocache++; - return rtn; + nfsd_stats_rc_nocache_inc(); + goto out; } csum = nfsd_cache_csum(rqstp); @@ -408,47 +441,47 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) * Since the common case is a cache miss followed by an insert, * preallocate an entry. */ + nn = net_generic(SVC_NET(rqstp), nfsd_net_id); rp = nfsd_reply_cache_alloc(rqstp, csum, nn); - if (!rp) { - dprintk("nfsd: unable to allocate DRC entry!\n"); - return rtn; - } + if (!rp) + goto out; + b = nfsd_cache_bucket_find(rqstp->rq_xid, nn); spin_lock(&b->cache_lock); found = nfsd_cache_insert(b, rp, nn); - if (found != rp) { - nfsd_reply_cache_free_locked(NULL, rp, nn); - rp = found; + if (found != rp) goto found_entry; - } - nfsdstats.rcmisses++; + nfsd_stats_rc_misses_inc(); rqstp->rq_cacherep = rp; rp->c_state = RC_INPROG; atomic_inc(&nn->num_drc_entries); - nn->drc_mem_usage += sizeof(*rp); + nfsd_stats_drc_mem_usage_add(nn, sizeof(*rp)); - /* go ahead and prune the cache */ - prune_bucket(b, nn); - out: + nfsd_prune_bucket(b, nn); + +out_unlock: spin_unlock(&b->cache_lock); +out: return rtn; found_entry: /* We found a matching entry which is either in progress or done. */ - nfsdstats.rchits++; + nfsd_reply_cache_free_locked(NULL, rp, nn); + nfsd_stats_rc_hits_inc(); rtn = RC_DROPIT; + rp = found; /* Request being processed */ if (rp->c_state == RC_INPROG) - goto out; + goto out_trace; /* From the hall of fame of impractical attacks: * Is this a user who tries to snoop on the cache? */ rtn = RC_DOIT; if (!test_bit(RQ_SECURE, &rqstp->rq_flags) && rp->c_secure) - goto out; + goto out_trace; /* Compose RPC reply header */ switch (rp->c_type) { @@ -460,21 +493,26 @@ found_entry: break; case RC_REPLBUFF: if (!nfsd_cache_append(rqstp, &rp->c_replvec)) - goto out; /* should not happen */ + goto out_unlock; /* should not happen */ rtn = RC_REPLY; break; default: - printk(KERN_WARNING "nfsd: bad repcache type %d\n", rp->c_type); - nfsd_reply_cache_free_locked(b, rp, nn); + WARN_ONCE(1, "nfsd: bad repcache type %d\n", rp->c_type); } - goto out; +out_trace: + trace_nfsd_drc_found(nn, rqstp, rtn); + goto out_unlock; } -/* - * Update a cache entry. This is called from nfsd_dispatch when - * the procedure has been executed and the complete reply is in - * rqstp->rq_res. +/** + * nfsd_cache_update - Update an entry in the duplicate reply cache. + * @rqstp: svc_rqst with a finished Reply + * @cachetype: which cache to update + * @statp: Reply's status code + * + * This is called from nfsd_dispatch when the procedure has been + * executed and the complete reply is in rqstp->rq_res. * * We're copying around data here rather than swapping buffers because * the toplevel loop requires max-sized buffers, which would be a waste @@ -487,13 +525,11 @@ found_entry: * nfsd failed to encode a reply that otherwise would have been cached. * In this case, nfsd_cache_update is called with statp == NULL. */ -void -nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp) +void nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp) { struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); struct svc_cacherep *rp = rqstp->rq_cacherep; struct kvec *resv = &rqstp->rq_res.head[0], *cachv; - u32 hash; struct nfsd_drc_bucket *b; int len; size_t bufsize = 0; @@ -501,8 +537,7 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp) if (!rp) return; - hash = nfsd_cache_hash(rp->c_key.k_xid, nn); - b = &nn->drc_hashtbl[hash]; + b = nfsd_cache_bucket_find(rp->c_key.k_xid, nn); len = resv->iov_len - ((char*)statp - (char*)resv->iov_base); len >>= 2; @@ -535,7 +570,7 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp) return; } spin_lock(&b->cache_lock); - nn->drc_mem_usage += bufsize; + nfsd_stats_drc_mem_usage_add(nn, bufsize); lru_put_end(b, rp); rp->c_secure = test_bit(RQ_SECURE, &rqstp->rq_flags); rp->c_type = cachetype; @@ -569,28 +604,26 @@ nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data) * scraping this file for info should test the labels to ensure they're * getting the correct field. */ -static int nfsd_reply_cache_stats_show(struct seq_file *m, void *v) +int nfsd_reply_cache_stats_show(struct seq_file *m, void *v) { - struct nfsd_net *nn = m->private; + struct nfsd_net *nn = net_generic(file_inode(m->file)->i_sb->s_fs_info, + nfsd_net_id); seq_printf(m, "max entries: %u\n", nn->max_drc_entries); seq_printf(m, "num entries: %u\n", - atomic_read(&nn->num_drc_entries)); + atomic_read(&nn->num_drc_entries)); seq_printf(m, "hash buckets: %u\n", 1 << nn->maskbits); - seq_printf(m, "mem usage: %u\n", nn->drc_mem_usage); - seq_printf(m, "cache hits: %u\n", nfsdstats.rchits); - seq_printf(m, "cache misses: %u\n", nfsdstats.rcmisses); - seq_printf(m, "not cached: %u\n", nfsdstats.rcnocache); - seq_printf(m, "payload misses: %u\n", nn->payload_misses); + seq_printf(m, "mem usage: %lld\n", + percpu_counter_sum_positive(&nn->counter[NFSD_NET_DRC_MEM_USAGE])); + seq_printf(m, "cache hits: %lld\n", + percpu_counter_sum_positive(&nfsdstats.counter[NFSD_STATS_RC_HITS])); + seq_printf(m, "cache misses: %lld\n", + percpu_counter_sum_positive(&nfsdstats.counter[NFSD_STATS_RC_MISSES])); + seq_printf(m, "not cached: %lld\n", + percpu_counter_sum_positive(&nfsdstats.counter[NFSD_STATS_RC_NOCACHE])); + seq_printf(m, "payload misses: %lld\n", + percpu_counter_sum_positive(&nn->counter[NFSD_NET_PAYLOAD_MISSES])); seq_printf(m, "longest chain len: %u\n", nn->longest_chain); seq_printf(m, "cachesize at longest: %u\n", nn->longest_chain_cachesize); return 0; } - -int nfsd_reply_cache_stats_open(struct inode *inode, struct file *file) -{ - struct nfsd_net *nn = net_generic(file_inode(file)->i_sb->s_fs_info, - nfsd_net_id); - - return single_open(file, nfsd_reply_cache_stats_show, nn); -} |