1 files changed, 117 insertions, 148 deletions

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index a5ae5b4620d0..aed3cb6bf865 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -62,7 +62,6 @@ static struct nfsd_fcache_bucket	*nfsd_file_hashtbl;
 static struct list_lru			nfsd_file_lru;
 static unsigned long			nfsd_file_flags;
 static struct fsnotify_group		*nfsd_file_fsnotify_group;
-static atomic_long_t			nfsd_filecache_count;
 static struct delayed_work		nfsd_filecache_laundrette;
 static struct rhashtable		nfsd_file_rhash_tbl
 						____cacheline_aligned_in_smp;
@@ -198,7 +197,7 @@ static const struct rhashtable_params nfsd_file_rhash_params = {
 static void
 nfsd_file_schedule_laundrette(void)
 {
-	if ((atomic_long_read(&nfsd_filecache_count) == 0) ||
+	if ((atomic_read(&nfsd_file_rhash_tbl.nelems) == 0) ||
 	    test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 0)
 		return;
 
@@ -298,7 +297,7 @@ nfsd_file_mark_find_or_create(struct nfsd_file *nf)
 }
 
 static struct nfsd_file *
-nfsd_file_alloc(struct inode *inode, unsigned int may, struct net *net)
+nfsd_file_alloc(struct nfsd_file_lookup_key *key, unsigned int may)
 {
 	struct nfsd_file *nf;
 
@@ -309,11 +308,14 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, struct net *net)
 		nf->nf_birthtime = ktime_get();
 		nf->nf_file = NULL;
 		nf->nf_cred = get_current_cred();
-		nf->nf_net = net;
+		nf->nf_net = key->net;
 		nf->nf_flags = 0;
-		nf->nf_inode = inode;
-		refcount_set(&nf->nf_ref, 1);
-		nf->nf_may = may & NFSD_FILE_MAY_MASK;
+		__set_bit(NFSD_FILE_HASHED, &nf->nf_flags);
+		__set_bit(NFSD_FILE_PENDING, &nf->nf_flags);
+		nf->nf_inode = key->inode;
+		/* nf_ref is pre-incremented for hash table */
+		refcount_set(&nf->nf_ref, 2);
+		nf->nf_may = key->need;
 		nf->nf_mark = NULL;
 		trace_nfsd_file_alloc(nf);
 	}
@@ -399,40 +401,21 @@ static void nfsd_file_lru_remove(struct nfsd_file *nf)
 }
 
 static void
-nfsd_file_do_unhash(struct nfsd_file *nf)
+nfsd_file_hash_remove(struct nfsd_file *nf)
 {
-	struct inode *inode = nf->nf_inode;
-	unsigned int hashval = (unsigned int)hash_long(inode->i_ino,
-				NFSD_FILE_HASH_BITS);
-
-	lockdep_assert_held(&nfsd_file_hashtbl[hashval].nfb_lock);
-
 	trace_nfsd_file_unhash(nf);
 
 	if (nfsd_file_check_write_error(nf))
 		nfsd_reset_write_verifier(net_generic(nf->nf_net, nfsd_net_id));
-	--nfsd_file_hashtbl[hashval].nfb_count;
-	hlist_del_rcu(&nf->nf_node);
-	atomic_long_dec(&nfsd_filecache_count);
-}
-
-static void
-nfsd_file_hash_remove(struct nfsd_file *nf)
-{
-	struct inode *inode = nf->nf_inode;
-	unsigned int hashval = (unsigned int)hash_long(inode->i_ino,
-				NFSD_FILE_HASH_BITS);
-
-	spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock);
-	nfsd_file_do_unhash(nf);
-	spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
+	rhashtable_remove_fast(&nfsd_file_rhash_tbl, &nf->nf_rhash,
+			       nfsd_file_rhash_params);
 }
 
 static bool
 nfsd_file_unhash(struct nfsd_file *nf)
 {
 	if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
-		nfsd_file_do_unhash(nf);
+		nfsd_file_hash_remove(nf);
 		return true;
 	}
 	return false;
@@ -442,9 +425,9 @@ nfsd_file_unhash(struct nfsd_file *nf)
  * Return true if the file was unhashed.
  */
 static bool
-nfsd_file_unhash_and_release_locked(struct nfsd_file *nf, struct list_head *dispose)
+nfsd_file_unhash_and_dispose(struct nfsd_file *nf, struct list_head *dispose)
 {
-	trace_nfsd_file_unhash_and_release_locked(nf);
+	trace_nfsd_file_unhash_and_dispose(nf);
 	if (!nfsd_file_unhash(nf))
 		return false;
 	/* keep final reference for nfsd_file_lru_dispose */
@@ -703,20 +686,23 @@ static struct shrinker	nfsd_file_shrinker = {
 static unsigned int
 __nfsd_file_close_inode(struct inode *inode, struct list_head *dispose)
 {
-	unsigned int		hashval = (unsigned int)hash_long(inode->i_ino,
-						NFSD_FILE_HASH_BITS);
-	unsigned int		count = 0;
-	struct nfsd_file	*nf;
-	struct hlist_node	*tmp;
-
-	spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock);
-	hlist_for_each_entry_safe(nf, tmp, &nfsd_file_hashtbl[hashval].nfb_head, nf_node) {
-		if (inode == nf->nf_inode) {
-			nfsd_file_unhash_and_release_locked(nf, dispose);
-			count++;
-		}
-	}
-	spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
+	struct nfsd_file_lookup_key key = {
+		.type	= NFSD_FILE_KEY_INODE,
+		.inode	= inode,
+	};
+	unsigned int count = 0;
+	struct nfsd_file *nf;
+
+	rcu_read_lock();
+	do {
+		nf = rhashtable_lookup(&nfsd_file_rhash_tbl, &key,
+				       nfsd_file_rhash_params);
+		if (!nf)
+			break;
+		nfsd_file_unhash_and_dispose(nf, dispose);
+		count++;
+	} while (1);
+	rcu_read_unlock();
 	return count;
 }
 
@@ -924,30 +910,35 @@ out_err:
 static void
 __nfsd_file_cache_purge(struct net *net)
 {
-	unsigned int		i;
-	struct nfsd_file	*nf;
-	struct hlist_node	*next;
+	struct rhashtable_iter iter;
+	struct nfsd_file *nf;
 	LIST_HEAD(dispose);
 	bool del;
 
-	for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) {
-		struct nfsd_fcache_bucket *nfb = &nfsd_file_hashtbl[i];
+	rhashtable_walk_enter(&nfsd_file_rhash_tbl, &iter);
+	do {
+		rhashtable_walk_start(&iter);
 
-		spin_lock(&nfb->nfb_lock);
-		hlist_for_each_entry_safe(nf, next, &nfb->nfb_head, nf_node) {
+		nf = rhashtable_walk_next(&iter);
+		while (!IS_ERR_OR_NULL(nf)) {
 			if (net && nf->nf_net != net)
 				continue;
-			del = nfsd_file_unhash_and_release_locked(nf, &dispose);
+			del = nfsd_file_unhash_and_dispose(nf, &dispose);
 
 			/*
 			 * Deadlock detected! Something marked this entry as
 			 * unhased, but hasn't removed it from the hash list.
 			 */
 			WARN_ON_ONCE(!del);
+
+			nf = rhashtable_walk_next(&iter);
 		}
-		spin_unlock(&nfb->nfb_lock);
-		nfsd_file_dispose_list(&dispose);
-	}
+
+		rhashtable_walk_stop(&iter);
+	} while (nf == ERR_PTR(-EAGAIN));
+	rhashtable_walk_exit(&iter);
+
+	nfsd_file_dispose_list(&dispose);
 }
 
 static struct nfsd_fcache_disposal *
@@ -1052,56 +1043,29 @@ nfsd_file_cache_shutdown(void)
 	}
 }
 
-static struct nfsd_file *
-nfsd_file_find_locked(struct inode *inode, unsigned int may_flags,
-			unsigned int hashval, struct net *net)
-{
-	struct nfsd_file *nf;
-	unsigned char need = may_flags & NFSD_FILE_MAY_MASK;
-
-	hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head,
-				 nf_node, lockdep_is_held(&nfsd_file_hashtbl[hashval].nfb_lock)) {
-		if (nf->nf_may != need)
-			continue;
-		if (nf->nf_inode != inode)
-			continue;
-		if (nf->nf_net != net)
-			continue;
-		if (!nfsd_match_cred(nf->nf_cred, current_cred()))
-			continue;
-		if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags))
-			continue;
-		if (nfsd_file_get(nf) != NULL)
-			return nf;
-	}
-	return NULL;
-}
-
 /**
- * nfsd_file_is_cached - are there any cached open files for this fh?
- * @inode: inode of the file to check
+ * nfsd_file_is_cached - are there any cached open files for this inode?
+ * @inode: inode to check
+ *
+ * The lookup matches inodes in all net namespaces and is atomic wrt
+ * nfsd_file_acquire().
  *
- * Scan the hashtable for open files that match this fh. Returns true if there
- * are any, and false if not.
+ * Return values:
+ *   %true: filecache contains at least one file matching this inode
+ *   %false: filecache contains no files matching this inode
  */
 bool
 nfsd_file_is_cached(struct inode *inode)
 {
-	bool			ret = false;
-	struct nfsd_file	*nf;
-	unsigned int		hashval;
-
-        hashval = (unsigned int)hash_long(inode->i_ino, NFSD_FILE_HASH_BITS);
-
-	rcu_read_lock();
-	hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head,
-				 nf_node) {
-		if (inode == nf->nf_inode) {
-			ret = true;
-			break;
-		}
-	}
-	rcu_read_unlock();
+	struct nfsd_file_lookup_key key = {
+		.type	= NFSD_FILE_KEY_INODE,
+		.inode	= inode,
+	};
+	bool ret = false;
+
+	if (rhashtable_lookup_fast(&nfsd_file_rhash_tbl, &key,
+				   nfsd_file_rhash_params) != NULL)
+		ret = true;
 	trace_nfsd_file_is_cached(inode, (int)ret);
 	return ret;
 }
@@ -1110,39 +1074,51 @@ static __be32
 nfsd_do_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		     unsigned int may_flags, struct nfsd_file **pnf, bool open)
 {
-	__be32	status;
-	struct net *net = SVC_NET(rqstp);
+	struct nfsd_file_lookup_key key = {
+		.type	= NFSD_FILE_KEY_FULL,
+		.need	= may_flags & NFSD_FILE_MAY_MASK,
+		.net	= SVC_NET(rqstp),
+	};
 	struct nfsd_file *nf, *new;
-	struct inode *inode;
-	unsigned int hashval;
 	bool retry = true;
+	__be32 status;
 
-	/* FIXME: skip this if fh_dentry is already set? */
 	status = fh_verify(rqstp, fhp, S_IFREG,
 				may_flags|NFSD_MAY_OWNER_OVERRIDE);
 	if (status != nfs_ok)
 		return status;
+	key.inode = d_inode(fhp->fh_dentry);
+	key.cred = get_current_cred();
 
-	inode = d_inode(fhp->fh_dentry);
-	hashval = (unsigned int)hash_long(inode->i_ino, NFSD_FILE_HASH_BITS);
 retry:
-	rcu_read_lock();
-	nf = nfsd_file_find_locked(inode, may_flags, hashval, net);
-	rcu_read_unlock();
+	/* Avoid allocation if the item is already in cache */
+	nf = rhashtable_lookup_fast(&nfsd_file_rhash_tbl, &key,
+				    nfsd_file_rhash_params);
+	if (nf)
+		nf = nfsd_file_get(nf);
 	if (nf)
 		goto wait_for_construction;
 
-	new = nfsd_file_alloc(inode, may_flags, net);
+	new = nfsd_file_alloc(&key, may_flags);
 	if (!new) {
 		status = nfserr_jukebox;
 		goto out_status;
 	}
 
-	spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock);
-	nf = nfsd_file_find_locked(inode, may_flags, hashval, net);
-	if (nf == NULL)
+	nf = rhashtable_lookup_get_insert_key(&nfsd_file_rhash_tbl,
+					      &key, &new->nf_rhash,
+					      nfsd_file_rhash_params);
+	if (!nf) {
+		nf = new;
+		goto open_file;
+	}
+	if (IS_ERR(nf))
+		goto insert_err;
+	nf = nfsd_file_get(nf);
+	if (nf == NULL) {
+		nf = new;
 		goto open_file;
-	spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
+	}
 	nfsd_file_slab_free(&new->nf_rcu);
 
 wait_for_construction:
@@ -1150,6 +1126,7 @@ wait_for_construction:
 
 	/* Did construction of this file fail? */
 	if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
+		trace_nfsd_file_cons_err(rqstp, key.inode, may_flags, nf);
 		if (!retry) {
 			status = nfserr_jukebox;
 			goto out;
@@ -1174,22 +1151,11 @@ out:
 	}
 
 out_status:
-	trace_nfsd_file_acquire(rqstp, inode, may_flags, nf, status);
+	put_cred(key.cred);
+	trace_nfsd_file_acquire(rqstp, key.inode, may_flags, nf, status);
 	return status;
 
 open_file:
-	nf = new;
-	/* Take reference for the hashtable */
-	refcount_inc(&nf->nf_ref);
-	__set_bit(NFSD_FILE_HASHED, &nf->nf_flags);
-	__set_bit(NFSD_FILE_PENDING, &nf->nf_flags);
-	hlist_add_head_rcu(&nf->nf_node, &nfsd_file_hashtbl[hashval].nfb_head);
-	++nfsd_file_hashtbl[hashval].nfb_count;
-	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);
-
 	nf->nf_mark = nfsd_file_mark_find_or_create(nf);
 	if (nf->nf_mark) {
 		if (open) {
@@ -1204,19 +1170,20 @@ open_file:
 	 * If construction failed, or we raced with a call to unlink()
 	 * then unhash.
 	 */
-	if (status != nfs_ok || inode->i_nlink == 0) {
-		bool do_free;
-		nfsd_file_lru_remove(nf);
-		spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock);
-		do_free = nfsd_file_unhash(nf);
-		spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
-		if (do_free)
+	if (status != nfs_ok || key.inode->i_nlink == 0)
+		if (nfsd_file_unhash(nf))
 			nfsd_file_put_noref(nf);
-	}
 	clear_bit_unlock(NFSD_FILE_PENDING, &nf->nf_flags);
 	smp_mb__after_atomic();
 	wake_up_bit(&nf->nf_flags, NFSD_FILE_PENDING);
 	goto out;
+
+insert_err:
+	nfsd_file_slab_free(&new->nf_rcu);
+	trace_nfsd_file_insert_err(rqstp, key.inode, may_flags, PTR_ERR(nf));
+	nf = NULL;
+	status = nfserr_jukebox;
+	goto out_status;
 }
 
 /**
@@ -1262,21 +1229,23 @@ static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 {
 	unsigned long releases = 0, pages_flushed = 0, evictions = 0;
 	unsigned long hits = 0, acquisitions = 0;
-	unsigned int i, count = 0, longest = 0;
+	unsigned int i, count = 0, buckets = 0;
 	unsigned long lru = 0, total_age = 0;
 
-	/*
-	 * No need for spinlocks here since we're not terribly interested in
-	 * accuracy. We do take the nfsd_mutex simply to ensure that we
-	 * don't end up racing with server shutdown
-	 */
+	/* Serialize with server shutdown */
 	mutex_lock(&nfsd_mutex);
 	if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 1) {
-		for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) {
-			count += nfsd_file_hashtbl[i].nfb_count;
-			longest = max(longest, nfsd_file_hashtbl[i].nfb_count);
-		}
+		struct bucket_table *tbl;
+		struct rhashtable *ht;
+
 		lru = list_lru_count(&nfsd_file_lru);
+
+		rcu_read_lock();
+		ht = &nfsd_file_rhash_tbl;
+		count = atomic_read(&ht->nelems);
+		tbl = rht_dereference_rcu(ht->tbl, ht);
+		buckets = tbl->size;
+		rcu_read_unlock();
 	}
 	mutex_unlock(&nfsd_mutex);
 
@@ -1290,7 +1259,7 @@ static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
 	}
 
 	seq_printf(m, "total entries: %u\n", count);
-	seq_printf(m, "longest chain: %u\n", longest);
+	seq_printf(m, "hash buckets:  %u\n", buckets);
 	seq_printf(m, "lru entries:   %lu\n", lru);
 	seq_printf(m, "cache hits:    %lu\n", hits);
 	seq_printf(m, "acquisitions:  %lu\n", acquisitions);