nfsd: move the confirmed and unconfirmed hlists to a rbtree
authorJeff Layton <jlayton@redhat.com>
Mon, 12 Nov 2012 20:00:56 +0000 (15:00 -0500)
committerJ. Bruce Fields <bfields@redhat.com>
Mon, 12 Nov 2012 23:55:11 +0000 (18:55 -0500)
The current code requires that we md5 hash the name in order to store
the client in the confirmed and unconfirmed trees. Change it instead
to store the clients in a pair of rbtrees, and simply compare the
cl_names directly instead of hashing them. This also necessitates that
we add a new flag to the clp->cl_flags field to indicate which tree
the client is currently in.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
fs/nfsd/nfs4state.c
fs/nfsd/state.h

index 559ab574d46b2c25f0dbb99579314ab416529a62..99998a1eb42653120abcac06697914a0368ba94e 100644 (file)
@@ -412,10 +412,10 @@ static unsigned int clientstr_hashval(const char *name)
  * reclaim_str_hashtbl[] holds known client info from previous reset/reboot
  * used in reboot/reset lease grace period processing
  *
- * conf_id_hashtbl[], and conf_str_hashtbl[] hold confirmed
+ * conf_id_hashtbl[], and conf_name_tree hold confirmed
  * setclientid_confirmed info. 
  *
- * unconf_str_hastbl[] and unconf_id_hashtbl[] hold unconfirmed 
+ * unconf_id_hashtbl[] and unconf_name_tree hold unconfirmed
  * setclientid info.
  *
  * client_lru holds client queue ordered by nfs4_client.cl_time
@@ -423,13 +423,15 @@ static unsigned int clientstr_hashval(const char *name)
  *
  * close_lru holds (open) stateowner queue ordered by nfs4_stateowner.so_time
  * for last close replay.
+ *
+ * All of the above fields are protected by the client_mutex.
  */
 static struct list_head        reclaim_str_hashtbl[CLIENT_HASH_SIZE];
 static int reclaim_str_hashtbl_size = 0;
 static struct list_head        conf_id_hashtbl[CLIENT_HASH_SIZE];
-static struct list_head        conf_str_hashtbl[CLIENT_HASH_SIZE];
-static struct list_head        unconf_str_hashtbl[CLIENT_HASH_SIZE];
 static struct list_head        unconf_id_hashtbl[CLIENT_HASH_SIZE];
+static struct rb_root conf_name_tree;
+static struct rb_root unconf_name_tree;
 static struct list_head client_lru;
 static struct list_head close_lru;
 
@@ -1144,7 +1146,10 @@ destroy_client(struct nfs4_client *clp)
        if (clp->cl_cb_conn.cb_xprt)
                svc_xprt_put(clp->cl_cb_conn.cb_xprt);
        list_del(&clp->cl_idhash);
-       list_del(&clp->cl_strhash);
+       if (test_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags))
+               rb_erase(&clp->cl_namenode, &conf_name_tree);
+       else
+               rb_erase(&clp->cl_namenode, &unconf_name_tree);
        spin_lock(&client_lock);
        unhash_client_locked(clp);
        if (atomic_read(&clp->cl_refcount) == 0)
@@ -1187,6 +1192,17 @@ static int copy_cred(struct svc_cred *target, struct svc_cred *source)
        return 0;
 }
 
+static long long
+compare_blob(const struct xdr_netobj *o1, const struct xdr_netobj *o2)
+{
+       long long res;
+
+       res = o1->len - o2->len;
+       if (res)
+               return res;
+       return (long long)memcmp(o1->data, o2->data, o1->len);
+}
+
 static int same_name(const char *n1, const char *n2)
 {
        return 0 == memcmp(n1, n2, HEXDIR_LEN);
@@ -1307,7 +1323,6 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
        atomic_set(&clp->cl_refcount, 0);
        clp->cl_cb_state = NFSD4_CB_UNKNOWN;
        INIT_LIST_HEAD(&clp->cl_idhash);
-       INIT_LIST_HEAD(&clp->cl_strhash);
        INIT_LIST_HEAD(&clp->cl_openowners);
        INIT_LIST_HEAD(&clp->cl_delegations);
        INIT_LIST_HEAD(&clp->cl_lru);
@@ -1325,11 +1340,52 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
 }
 
 static void
-add_to_unconfirmed(struct nfs4_client *clp, unsigned int strhashval)
+add_clp_to_name_tree(struct nfs4_client *new_clp, struct rb_root *root)
+{
+       struct rb_node **new = &(root->rb_node), *parent = NULL;
+       struct nfs4_client *clp;
+
+       while (*new) {
+               clp = rb_entry(*new, struct nfs4_client, cl_namenode);
+               parent = *new;
+
+               if (compare_blob(&clp->cl_name, &new_clp->cl_name) > 0)
+                       new = &((*new)->rb_left);
+               else
+                       new = &((*new)->rb_right);
+       }
+
+       rb_link_node(&new_clp->cl_namenode, parent, new);
+       rb_insert_color(&new_clp->cl_namenode, root);
+}
+
+static struct nfs4_client *
+find_clp_in_name_tree(struct xdr_netobj *name, struct rb_root *root)
+{
+       long long cmp;
+       struct rb_node *node = root->rb_node;
+       struct nfs4_client *clp;
+
+       while (node) {
+               clp = rb_entry(node, struct nfs4_client, cl_namenode);
+               cmp = compare_blob(&clp->cl_name, name);
+               if (cmp > 0)
+                       node = node->rb_left;
+               else if (cmp < 0)
+                       node = node->rb_right;
+               else
+                       return clp;
+       }
+       return NULL;
+}
+
+static void
+add_to_unconfirmed(struct nfs4_client *clp)
 {
        unsigned int idhashval;
 
-       list_add(&clp->cl_strhash, &unconf_str_hashtbl[strhashval]);
+       clear_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
+       add_clp_to_name_tree(clp, &unconf_name_tree);
        idhashval = clientid_hashval(clp->cl_clientid.cl_id);
        list_add(&clp->cl_idhash, &unconf_id_hashtbl[idhashval]);
        renew_client(clp);
@@ -1339,12 +1395,12 @@ static void
 move_to_confirmed(struct nfs4_client *clp)
 {
        unsigned int idhashval = clientid_hashval(clp->cl_clientid.cl_id);
-       unsigned int strhashval;
 
        dprintk("NFSD: move_to_confirm nfs4_client %p\n", clp);
        list_move(&clp->cl_idhash, &conf_id_hashtbl[idhashval]);
-       strhashval = clientstr_hashval(clp->cl_recdir);
-       list_move(&clp->cl_strhash, &conf_str_hashtbl[strhashval]);
+       rb_erase(&clp->cl_namenode, &unconf_name_tree);
+       add_clp_to_name_tree(clp, &conf_name_tree);
+       set_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
        renew_client(clp);
 }
 
@@ -1387,27 +1443,15 @@ static bool clp_used_exchangeid(struct nfs4_client *clp)
 } 
 
 static struct nfs4_client *
-find_confirmed_client_by_str(const char *dname, unsigned int hashval)
+find_confirmed_client_by_name(struct xdr_netobj *name)
 {
-       struct nfs4_client *clp;
-
-       list_for_each_entry(clp, &conf_str_hashtbl[hashval], cl_strhash) {
-               if (same_name(clp->cl_recdir, dname))
-                       return clp;
-       }
-       return NULL;
+       return find_clp_in_name_tree(name, &conf_name_tree);
 }
 
 static struct nfs4_client *
-find_unconfirmed_client_by_str(const char *dname, unsigned int hashval)
+find_unconfirmed_client_by_name(struct xdr_netobj *name)
 {
-       struct nfs4_client *clp;
-
-       list_for_each_entry(clp, &unconf_str_hashtbl[hashval], cl_strhash) {
-               if (same_name(clp->cl_recdir, dname))
-                       return clp;
-       }
-       return NULL;
+       return find_clp_in_name_tree(name, &unconf_name_tree);
 }
 
 static void
@@ -1572,7 +1616,6 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
 {
        struct nfs4_client *unconf, *conf, *new;
        __be32 status;
-       unsigned int            strhashval;
        char                    dname[HEXDIR_LEN];
        char                    addr_str[INET6_ADDRSTRLEN];
        nfs4_verifier           verf = exid->verifier;
@@ -1605,11 +1648,9 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
        if (status)
                return status;
 
-       strhashval = clientstr_hashval(dname);
-
        /* Cases below refer to rfc 5661 section 18.35.4: */
        nfs4_lock_state();
-       conf = find_confirmed_client_by_str(dname, strhashval);
+       conf = find_confirmed_client_by_name(&exid->clname);
        if (conf) {
                bool creds_match = same_creds(&conf->cl_cred, &rqstp->rq_cred);
                bool verfs_match = same_verf(&verf, &conf->cl_verifier);
@@ -1654,7 +1695,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
                goto out;
        }
 
-       unconf  = find_unconfirmed_client_by_str(dname, strhashval);
+       unconf  = find_unconfirmed_client_by_name(&exid->clname);
        if (unconf) /* case 4, possible retry or client restart */
                expire_client(unconf);
 
@@ -1668,7 +1709,7 @@ out_new:
        new->cl_minorversion = 1;
 
        gen_clid(new);
-       add_to_unconfirmed(new, strhashval);
+       add_to_unconfirmed(new);
 out_copy:
        exid->clientid.cl_boot = new->cl_clientid.cl_boot;
        exid->clientid.cl_id = new->cl_clientid.cl_id;
@@ -1789,7 +1830,6 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                        goto out_free_conn;
                }
        } else if (unconf) {
-               unsigned int hash;
                struct nfs4_client *old;
                if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) ||
                    !rpc_cmp_addr(sa, (struct sockaddr *) &unconf->cl_addr)) {
@@ -1803,8 +1843,7 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                        status = nfserr_seq_misordered;
                        goto out_free_conn;
                }
-               hash = clientstr_hashval(unconf->cl_recdir);
-               old = find_confirmed_client_by_str(unconf->cl_recdir, hash);
+               old = find_confirmed_client_by_name(&unconf->cl_name);
                if (old)
                        expire_client(old);
                move_to_confirmed(unconf);
@@ -2195,7 +2234,6 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 {
        struct xdr_netobj       clname = setclid->se_name;
        nfs4_verifier           clverifier = setclid->se_verf;
-       unsigned int            strhashval;
        struct nfs4_client      *conf, *unconf, *new;
        __be32                  status;
        char                    dname[HEXDIR_LEN];
@@ -2204,11 +2242,9 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        if (status)
                return status;
 
-       strhashval = clientstr_hashval(dname);
-
        /* Cases below refer to rfc 3530 section 14.2.33: */
        nfs4_lock_state();
-       conf = find_confirmed_client_by_str(dname, strhashval);
+       conf = find_confirmed_client_by_name(&clname);
        if (conf) {
                /* case 0: */
                status = nfserr_clid_inuse;
@@ -2223,7 +2259,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                        goto out;
                }
        }
-       unconf = find_unconfirmed_client_by_str(dname, strhashval);
+       unconf = find_unconfirmed_client_by_name(&clname);
        if (unconf)
                expire_client(unconf);
        status = nfserr_jukebox;
@@ -2237,7 +2273,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                gen_clid(new);
        new->cl_minorversion = 0;
        gen_callback(new, setclid, rqstp);
-       add_to_unconfirmed(new, strhashval);
+       add_to_unconfirmed(new);
        setclid->se_clientid.cl_boot = new->cl_clientid.cl_boot;
        setclid->se_clientid.cl_id = new->cl_clientid.cl_id;
        memcpy(setclid->se_confirm.data, new->cl_confirm.data, sizeof(setclid->se_confirm.data));
@@ -2290,9 +2326,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
                nfsd4_probe_callback(conf);
                expire_client(unconf);
        } else { /* case 3: normal case; new or rebooted client */
-               unsigned int hash = clientstr_hashval(unconf->cl_recdir);
-
-               conf = find_confirmed_client_by_str(unconf->cl_recdir, hash);
+               conf = find_confirmed_client_by_name(&unconf->cl_name);
                if (conf)
                        expire_client(conf);
                move_to_confirmed(unconf);
@@ -4706,11 +4740,11 @@ nfs4_state_init(void)
 
        for (i = 0; i < CLIENT_HASH_SIZE; i++) {
                INIT_LIST_HEAD(&conf_id_hashtbl[i]);
-               INIT_LIST_HEAD(&conf_str_hashtbl[i]);
-               INIT_LIST_HEAD(&unconf_str_hashtbl[i]);
                INIT_LIST_HEAD(&unconf_id_hashtbl[i]);
                INIT_LIST_HEAD(&reclaim_str_hashtbl[i]);
        }
+       conf_name_tree = RB_ROOT;
+       unconf_name_tree = RB_ROOT;
        for (i = 0; i < SESSION_HASH_SIZE; i++)
                INIT_LIST_HEAD(&sessionid_hashtbl[i]);
        for (i = 0; i < FILE_HASH_SIZE; i++) {
@@ -4795,6 +4829,7 @@ out_recovery:
        return ret;
 }
 
+/* should be called with the state lock held */
 static void
 __nfs4_state_shutdown(void)
 {
@@ -4802,17 +4837,24 @@ __nfs4_state_shutdown(void)
        struct nfs4_client *clp = NULL;
        struct nfs4_delegation *dp = NULL;
        struct list_head *pos, *next, reaplist;
+       struct rb_node *node, *tmp;
 
        for (i = 0; i < CLIENT_HASH_SIZE; i++) {
                while (!list_empty(&conf_id_hashtbl[i])) {
                        clp = list_entry(conf_id_hashtbl[i].next, struct nfs4_client, cl_idhash);
                        destroy_client(clp);
                }
-               while (!list_empty(&unconf_str_hashtbl[i])) {
-                       clp = list_entry(unconf_str_hashtbl[i].next, struct nfs4_client, cl_strhash);
-                       destroy_client(clp);
-               }
        }
+
+       node = rb_first(&unconf_name_tree);
+       while (node != NULL) {
+               tmp = node;
+               node = rb_next(tmp);
+               clp = rb_entry(tmp, struct nfs4_client, cl_namenode);
+               rb_erase(tmp, &unconf_name_tree);
+               destroy_client(clp);
+       }
+
        INIT_LIST_HEAD(&reaplist);
        spin_lock(&recall_lock);
        list_for_each_safe(pos, next, &del_recall_lru) {
index cf9f7ba4df8d83a9e993b0dc1dc02fa6ebbc5b1f..6c342bd806e5ca24729ea30caa17b89d8d8d8ac8 100644 (file)
@@ -232,7 +232,7 @@ struct nfsd4_sessionid {
  */
 struct nfs4_client {
        struct list_head        cl_idhash;      /* hash by cl_clientid.id */
-       struct list_head        cl_strhash;     /* hash by cl_name */
+       struct rb_node          cl_namenode;    /* link into by-name trees */
        struct list_head        cl_openowners;
        struct idr              cl_stateids;    /* stateid lookup */
        struct list_head        cl_delegations;
@@ -253,6 +253,7 @@ struct nfs4_client {
 #define NFSD4_CLIENT_CB_KILL           (1)
 #define NFSD4_CLIENT_STABLE            (2)     /* client on stable storage */
 #define NFSD4_CLIENT_RECLAIM_COMPLETE  (3)     /* reclaim_complete done */
+#define NFSD4_CLIENT_CONFIRMED         (4)     /* client is confirmed */
 #define NFSD4_CLIENT_CB_FLAG_MASK      (1 << NFSD4_CLIENT_CB_UPDATE | \
                                         1 << NFSD4_CLIENT_CB_KILL)
        unsigned long           cl_flags;