diff options
Diffstat (limited to 'fs/nfsd/filecache.c')
-rw-r--r-- | fs/nfsd/filecache.c | 313 |
1 files changed, 237 insertions, 76 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 32a9bf22ac08..22e77ede9f14 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -27,7 +27,6 @@ #define NFSD_FILE_HASH_SIZE (1 << NFSD_FILE_HASH_BITS) #define NFSD_LAUNDRETTE_DELAY (2 * HZ) -#define NFSD_FILE_LRU_RESCAN (0) #define NFSD_FILE_SHUTDOWN (1) #define NFSD_FILE_LRU_THRESHOLD (4096UL) #define NFSD_FILE_LRU_LIMIT (NFSD_FILE_LRU_THRESHOLD << 2) @@ -44,6 +43,17 @@ struct nfsd_fcache_bucket { static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits); +struct nfsd_fcache_disposal { + struct list_head list; + struct work_struct work; + struct net *net; + spinlock_t lock; + struct list_head freeme; + struct rcu_head rcu; +}; + +static struct workqueue_struct *nfsd_filecache_wq __read_mostly; + static struct kmem_cache *nfsd_file_slab; static struct kmem_cache *nfsd_file_mark_slab; static struct nfsd_fcache_bucket *nfsd_file_hashtbl; @@ -52,32 +62,21 @@ static long nfsd_file_lru_flags; static struct fsnotify_group *nfsd_file_fsnotify_group; static atomic_long_t nfsd_filecache_count; static struct delayed_work nfsd_filecache_laundrette; +static DEFINE_SPINLOCK(laundrette_lock); +static LIST_HEAD(laundrettes); -enum nfsd_file_laundrette_ctl { - NFSD_FILE_LAUNDRETTE_NOFLUSH = 0, - NFSD_FILE_LAUNDRETTE_MAY_FLUSH -}; +static void nfsd_file_gc(void); static void -nfsd_file_schedule_laundrette(enum nfsd_file_laundrette_ctl ctl) +nfsd_file_schedule_laundrette(void) { long count = atomic_long_read(&nfsd_filecache_count); if (count == 0 || test_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags)) return; - /* Be more aggressive about scanning if over the threshold */ - if (count > NFSD_FILE_LRU_THRESHOLD) - mod_delayed_work(system_wq, &nfsd_filecache_laundrette, 0); - else - schedule_delayed_work(&nfsd_filecache_laundrette, NFSD_LAUNDRETTE_DELAY); - - if (ctl == NFSD_FILE_LAUNDRETTE_NOFLUSH) - return; - - /* ...and don't delay flushing if we're out of control */ - if (count >= NFSD_FILE_LRU_LIMIT) - flush_delayed_work(&nfsd_filecache_laundrette); + queue_delayed_work(system_wq, &nfsd_filecache_laundrette, + NFSD_LAUNDRETTE_DELAY); } static void @@ -101,7 +100,7 @@ nfsd_file_mark_free(struct fsnotify_mark *mark) static struct nfsd_file_mark * nfsd_file_mark_get(struct nfsd_file_mark *nfm) { - if (!atomic_inc_not_zero(&nfm->nfm_ref)) + if (!refcount_inc_not_zero(&nfm->nfm_ref)) return NULL; return nfm; } @@ -109,8 +108,7 @@ nfsd_file_mark_get(struct nfsd_file_mark *nfm) static void nfsd_file_mark_put(struct nfsd_file_mark *nfm) { - if (atomic_dec_and_test(&nfm->nfm_ref)) { - + if (refcount_dec_and_test(&nfm->nfm_ref)) { fsnotify_destroy_mark(&nfm->nfm_mark, nfsd_file_fsnotify_group); fsnotify_put_mark(&nfm->nfm_mark); } @@ -133,9 +131,13 @@ nfsd_file_mark_find_or_create(struct nfsd_file *nf) struct nfsd_file_mark, nfm_mark)); mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex); - fsnotify_put_mark(mark); - if (likely(nfm)) + if (nfm) { + fsnotify_put_mark(mark); break; + } + /* Avoid soft lockup race with nfsd_file_mark_put() */ + fsnotify_destroy_mark(mark, nfsd_file_fsnotify_group); + fsnotify_put_mark(mark); } else mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex); @@ -145,7 +147,7 @@ nfsd_file_mark_find_or_create(struct nfsd_file *nf) return NULL; fsnotify_init_mark(&new->nfm_mark, nfsd_file_fsnotify_group); new->nfm_mark.mask = FS_ATTRIB|FS_DELETE_SELF; - atomic_set(&new->nfm_ref, 1); + refcount_set(&new->nfm_ref, 1); err = fsnotify_add_inode_mark(&new->nfm_mark, inode, 0); @@ -183,7 +185,7 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval, nf->nf_flags = 0; nf->nf_inode = inode; nf->nf_hashval = hashval; - atomic_set(&nf->nf_ref, 1); + refcount_set(&nf->nf_ref, 1); nf->nf_may = may & NFSD_FILE_MAY_MASK; if (may & NFSD_MAY_NOT_BREAK_LEASE) { if (may & NFSD_MAY_WRITE) @@ -192,6 +194,7 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval, __set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags); } nf->nf_mark = NULL; + init_rwsem(&nf->nf_rwsem); trace_nfsd_file_alloc(nf); } return nf; @@ -238,13 +241,6 @@ nfsd_file_check_write_error(struct nfsd_file *nf) return filemap_check_wb_err(file->f_mapping, READ_ONCE(file->f_wb_err)); } -static bool -nfsd_file_in_use(struct nfsd_file *nf) -{ - return nfsd_file_check_writeback(nf) || - nfsd_file_check_write_error(nf); -} - static void nfsd_file_do_unhash(struct nfsd_file *nf) { @@ -256,8 +252,6 @@ nfsd_file_do_unhash(struct nfsd_file *nf) nfsd_reset_boot_verifier(net_generic(nf->nf_net, nfsd_net_id)); --nfsd_file_hashtbl[nf->nf_hashval].nfb_count; hlist_del_rcu(&nf->nf_node); - if (!list_empty(&nf->nf_lru)) - list_lru_del(&nfsd_file_lru, &nf->nf_lru); atomic_long_dec(&nfsd_filecache_count); } @@ -266,6 +260,8 @@ nfsd_file_unhash(struct nfsd_file *nf) { if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { nfsd_file_do_unhash(nf); + if (!list_empty(&nf->nf_lru)) + list_lru_del(&nfsd_file_lru, &nf->nf_lru); return true; } return false; @@ -283,42 +279,48 @@ nfsd_file_unhash_and_release_locked(struct nfsd_file *nf, struct list_head *disp if (!nfsd_file_unhash(nf)) return false; /* keep final reference for nfsd_file_lru_dispose */ - if (atomic_add_unless(&nf->nf_ref, -1, 1)) + if (refcount_dec_not_one(&nf->nf_ref)) return true; list_add(&nf->nf_lru, dispose); return true; } -static int +static void nfsd_file_put_noref(struct nfsd_file *nf) { - int count; trace_nfsd_file_put(nf); - count = atomic_dec_return(&nf->nf_ref); - if (!count) { + if (refcount_dec_and_test(&nf->nf_ref)) { WARN_ON(test_bit(NFSD_FILE_HASHED, &nf->nf_flags)); nfsd_file_free(nf); } - return count; } void nfsd_file_put(struct nfsd_file *nf) { - bool is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0; - bool unused = !nfsd_file_in_use(nf); + bool is_hashed; set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); - if (nfsd_file_put_noref(nf) == 1 && is_hashed && unused) - nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_MAY_FLUSH); + if (refcount_read(&nf->nf_ref) > 2 || !nf->nf_file) { + nfsd_file_put_noref(nf); + return; + } + + filemap_flush(nf->nf_file->f_mapping); + is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0; + nfsd_file_put_noref(nf); + if (is_hashed) + nfsd_file_schedule_laundrette(); + if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT) + nfsd_file_gc(); } struct nfsd_file * nfsd_file_get(struct nfsd_file *nf) { - if (likely(atomic_inc_not_zero(&nf->nf_ref))) + if (likely(refcount_inc_not_zero(&nf->nf_ref))) return nf; return NULL; } @@ -344,7 +346,7 @@ nfsd_file_dispose_list_sync(struct list_head *dispose) while(!list_empty(dispose)) { nf = list_first_entry(dispose, struct nfsd_file, nf_lru); list_del(&nf->nf_lru); - if (!atomic_dec_and_test(&nf->nf_ref)) + if (!refcount_dec_and_test(&nf->nf_ref)) continue; if (nfsd_file_free(nf)) flush = true; @@ -353,6 +355,58 @@ nfsd_file_dispose_list_sync(struct list_head *dispose) flush_delayed_fput(); } +static void +nfsd_file_list_remove_disposal(struct list_head *dst, + struct nfsd_fcache_disposal *l) +{ + spin_lock(&l->lock); + list_splice_init(&l->freeme, dst); + spin_unlock(&l->lock); +} + +static void +nfsd_file_list_add_disposal(struct list_head *files, struct net *net) +{ + struct nfsd_fcache_disposal *l; + + rcu_read_lock(); + list_for_each_entry_rcu(l, &laundrettes, list) { + if (l->net == net) { + spin_lock(&l->lock); + list_splice_tail_init(files, &l->freeme); + spin_unlock(&l->lock); + queue_work(nfsd_filecache_wq, &l->work); + break; + } + } + rcu_read_unlock(); +} + +static void +nfsd_file_list_add_pernet(struct list_head *dst, struct list_head *src, + struct net *net) +{ + struct nfsd_file *nf, *tmp; + + list_for_each_entry_safe(nf, tmp, src, nf_lru) { + if (nf->nf_net == net) + list_move_tail(&nf->nf_lru, dst); + } +} + +static void +nfsd_file_dispose_list_delayed(struct list_head *dispose) +{ + LIST_HEAD(list); + struct nfsd_file *nf; + + while(!list_empty(dispose)) { + nf = list_first_entry(dispose, struct nfsd_file, nf_lru); + nfsd_file_list_add_pernet(&list, dispose, nf->nf_net); + nfsd_file_list_add_disposal(&list, nf->nf_net); + } +} + /* * Note this can deadlock with nfsd_file_cache_purge. */ @@ -375,7 +429,7 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, * counter. Here we check the counter and then test and clear the flag. * That order is deliberate to ensure that we can do this locklessly. */ - if (atomic_read(&nf->nf_ref) > 1) + if (refcount_read(&nf->nf_ref) > 1) goto out_skip; /* @@ -386,31 +440,51 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, goto out_skip; if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) - goto out_rescan; + goto out_skip; if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) goto out_skip; list_lru_isolate_move(lru, &nf->nf_lru, head); return LRU_REMOVED; -out_rescan: - set_bit(NFSD_FILE_LRU_RESCAN, &nfsd_file_lru_flags); out_skip: return LRU_SKIP; } -static void -nfsd_file_lru_dispose(struct list_head *head) +static unsigned long +nfsd_file_lru_walk_list(struct shrink_control *sc) { - while(!list_empty(head)) { - struct nfsd_file *nf = list_first_entry(head, - struct nfsd_file, nf_lru); - list_del_init(&nf->nf_lru); + LIST_HEAD(head); + struct nfsd_file *nf; + unsigned long ret; + + if (sc) + ret = list_lru_shrink_walk(&nfsd_file_lru, sc, + nfsd_file_lru_cb, &head); + else + ret = list_lru_walk(&nfsd_file_lru, + nfsd_file_lru_cb, + &head, LONG_MAX); + list_for_each_entry(nf, &head, nf_lru) { spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); nfsd_file_do_unhash(nf); spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); - nfsd_file_put_noref(nf); } + nfsd_file_dispose_list_delayed(&head); + return ret; +} + +static void +nfsd_file_gc(void) +{ + nfsd_file_lru_walk_list(NULL); +} + +static void +nfsd_file_gc_worker(struct work_struct *work) +{ + nfsd_file_gc(); + nfsd_file_schedule_laundrette(); } static unsigned long @@ -422,12 +496,7 @@ nfsd_file_lru_count(struct shrinker *s, struct shrink_control *sc) static unsigned long nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc) { - LIST_HEAD(head); - unsigned long ret; - - ret = list_lru_shrink_walk(&nfsd_file_lru, sc, nfsd_file_lru_cb, &head); - nfsd_file_lru_dispose(&head); - return ret; + return nfsd_file_lru_walk_list(sc); } static struct shrinker nfsd_file_shrinker = { @@ -489,7 +558,7 @@ nfsd_file_close_inode(struct inode *inode) __nfsd_file_close_inode(inode, hashval, &dispose); trace_nfsd_file_close_inode(inode, hashval, !list_empty(&dispose)); - nfsd_file_dispose_list(&dispose); + nfsd_file_dispose_list_delayed(&dispose); } /** @@ -505,16 +574,11 @@ static void nfsd_file_delayed_close(struct work_struct *work) { LIST_HEAD(head); + struct nfsd_fcache_disposal *l = container_of(work, + struct nfsd_fcache_disposal, work); - list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb, &head, LONG_MAX); - - if (test_and_clear_bit(NFSD_FILE_LRU_RESCAN, &nfsd_file_lru_flags)) - nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_NOFLUSH); - - if (!list_empty(&head)) { - nfsd_file_lru_dispose(&head); - flush_delayed_fput(); - } + nfsd_file_list_remove_disposal(&head, l); + nfsd_file_dispose_list(&head); } static int @@ -575,6 +639,10 @@ nfsd_file_cache_init(void) if (nfsd_file_hashtbl) return 0; + nfsd_filecache_wq = alloc_workqueue("nfsd_filecache", 0, 0); + if (!nfsd_filecache_wq) + goto out; + nfsd_file_hashtbl = kcalloc(NFSD_FILE_HASH_SIZE, sizeof(*nfsd_file_hashtbl), GFP_KERNEL); if (!nfsd_file_hashtbl) { @@ -628,7 +696,7 @@ nfsd_file_cache_init(void) spin_lock_init(&nfsd_file_hashtbl[i].nfb_lock); } - INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_delayed_close); + INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_gc_worker); out: return ret; out_notifier: @@ -644,6 +712,8 @@ out_err: nfsd_file_mark_slab = NULL; kfree(nfsd_file_hashtbl); nfsd_file_hashtbl = NULL; + destroy_workqueue(nfsd_filecache_wq); + nfsd_filecache_wq = NULL; goto out; } @@ -682,6 +752,88 @@ nfsd_file_cache_purge(struct net *net) } } +static struct nfsd_fcache_disposal * +nfsd_alloc_fcache_disposal(struct net *net) +{ + struct nfsd_fcache_disposal *l; + + l = kmalloc(sizeof(*l), GFP_KERNEL); + if (!l) + return NULL; + INIT_WORK(&l->work, nfsd_file_delayed_close); + l->net = net; + spin_lock_init(&l->lock); + INIT_LIST_HEAD(&l->freeme); + return l; +} + +static void +nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l) +{ + rcu_assign_pointer(l->net, NULL); + cancel_work_sync(&l->work); + nfsd_file_dispose_list(&l->freeme); + kfree_rcu(l, rcu); +} + +static void +nfsd_add_fcache_disposal(struct nfsd_fcache_disposal *l) +{ + spin_lock(&laundrette_lock); + list_add_tail_rcu(&l->list, &laundrettes); + spin_unlock(&laundrette_lock); +} + +static void +nfsd_del_fcache_disposal(struct nfsd_fcache_disposal *l) +{ + spin_lock(&laundrette_lock); + list_del_rcu(&l->list); + spin_unlock(&laundrette_lock); +} + +static int +nfsd_alloc_fcache_disposal_net(struct net *net) +{ + struct nfsd_fcache_disposal *l; + + l = nfsd_alloc_fcache_disposal(net); + if (!l) + return -ENOMEM; + nfsd_add_fcache_disposal(l); + return 0; +} + +static void +nfsd_free_fcache_disposal_net(struct net *net) +{ + struct nfsd_fcache_disposal *l; + + rcu_read_lock(); + list_for_each_entry_rcu(l, &laundrettes, list) { + if (l->net != net) + continue; + nfsd_del_fcache_disposal(l); + rcu_read_unlock(); + nfsd_free_fcache_disposal(l); + return; + } + rcu_read_unlock(); +} + +int +nfsd_file_cache_start_net(struct net *net) +{ + return nfsd_alloc_fcache_disposal_net(net); +} + +void +nfsd_file_cache_shutdown_net(struct net *net) +{ + nfsd_file_cache_purge(net); + nfsd_free_fcache_disposal_net(net); +} + void nfsd_file_cache_shutdown(void) { @@ -706,6 +858,8 @@ nfsd_file_cache_shutdown(void) nfsd_file_mark_slab = NULL; kfree(nfsd_file_hashtbl); nfsd_file_hashtbl = NULL; + destroy_workqueue(nfsd_filecache_wq); + nfsd_filecache_wq = NULL; } static bool @@ -789,6 +943,7 @@ nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, *new; struct inode *inode; unsigned int hashval; + bool retry = true; /* FIXME: skip this if fh_dentry is already set? */ status = fh_verify(rqstp, fhp, S_IFREG, @@ -824,6 +979,11 @@ wait_for_construction: /* Did construction of this file fail? */ if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { + if (!retry) { + status = nfserr_jukebox; + goto out; + } + retry = false; nfsd_file_put_noref(nf); goto retry; } @@ -858,7 +1018,7 @@ out: open_file: nf = new; /* Take reference for the hashtable */ - atomic_inc(&nf->nf_ref); + refcount_inc(&nf->nf_ref); __set_bit(NFSD_FILE_HASHED, &nf->nf_flags); __set_bit(NFSD_FILE_PENDING, &nf->nf_flags); list_lru_add(&nfsd_file_lru, &nf->nf_lru); @@ -867,7 +1027,8 @@ open_file: nfsd_file_hashtbl[hashval].nfb_maxcount = max(nfsd_file_hashtbl[hashval].nfb_maxcount, nfsd_file_hashtbl[hashval].nfb_count); spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); - atomic_long_inc(&nfsd_filecache_count); + if (atomic_long_inc_return(&nfsd_filecache_count) >= NFSD_FILE_LRU_THRESHOLD) + nfsd_file_gc(); nf->nf_mark = nfsd_file_mark_find_or_create(nf); if (nf->nf_mark) |