ceph: use rbtree for mon statfs requests

An rbtree is lighter weight, particularly given we will generally have
very few in-flight statfs requests.

Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
index cd5dd805e4be03048f79c06cdbe6ac0ffc453e78..b58bd9188692311067de7417f0c906d95475d95f 100644 (file)
--- a/fs/ceph/debugfs.c
+++ b/fs/ceph/debugfs.c
@@ -112,9 +112,8 @@ static int monc_show(struct seq_file *s, void *p)
 {
        struct ceph_client *client = s->private;
        struct ceph_mon_statfs_request *req;
-       u64 nexttid = 0;
-       int got;
        struct ceph_mon_client *monc = &client->monc;
+       struct rb_node *rp;
 
        mutex_lock(&monc->mutex);
 
@@ -125,17 +124,12 @@ static int monc_show(struct seq_file *s, void *p)
        if (monc->want_next_osdmap)
                seq_printf(s, "want next osdmap\n");
 
-       while (nexttid < monc->last_tid) {
-               got = radix_tree_gang_lookup(&monc->statfs_request_tree,
-                                            (void **)&req, nexttid, 1);
-               if (got == 0)
-                       break;
-               nexttid = req->tid + 1;
-
+       for (rp = rb_first(&monc->statfs_request_tree); rp; rp = rb_next(rp)) {
+               req = rb_entry(rp, struct ceph_mon_statfs_request, node);
                seq_printf(s, "%lld statfs\n", req->tid);
        }
-       mutex_unlock(&monc->mutex);
 
+       mutex_unlock(&monc->mutex);
        return 0;
 }
 

diff --git a/fs/ceph/mon_client.c b/fs/ceph/mon_client.c
index fec41a0eff8615d993576ca125e51133d2616811..542276e60798af19c8acdc31c024175c9e23091f 100644 (file)
--- a/fs/ceph/mon_client.c
+++ b/fs/ceph/mon_client.c
@@ -343,6 +343,46 @@ out:
 /*
  * statfs
  */
+static struct ceph_mon_statfs_request *__lookup_statfs(
+       struct ceph_mon_client *monc, u64 tid)
+{
+       struct ceph_mon_statfs_request *req;
+       struct rb_node *n = monc->statfs_request_tree.rb_node;
+
+       while (n) {
+               req = rb_entry(n, struct ceph_mon_statfs_request, node);
+               if (tid < req->tid)
+                       n = n->rb_left;
+               else if (tid > req->tid)
+                       n = n->rb_right;
+               else
+                       return req;
+       }
+       return NULL;
+}
+
+static void __insert_statfs(struct ceph_mon_client *monc,
+                           struct ceph_mon_statfs_request *new)
+{
+       struct rb_node **p = &monc->statfs_request_tree.rb_node;
+       struct rb_node *parent = NULL;
+       struct ceph_mon_statfs_request *req = NULL;
+
+       while (*p) {
+               parent = *p;
+               req = rb_entry(parent, struct ceph_mon_statfs_request, node);
+               if (new->tid < req->tid)
+                       p = &(*p)->rb_left;
+               else if (new->tid > req->tid)
+                       p = &(*p)->rb_right;
+               else
+                       BUG();
+       }
+
+       rb_link_node(&new->node, parent, p);
+       rb_insert_color(&new->node, &monc->statfs_request_tree);
+}
+
 static void handle_statfs_reply(struct ceph_mon_client *monc,
                                struct ceph_msg *msg)
 {
@@ -356,7 +396,7 @@ static void handle_statfs_reply(struct ceph_mon_client *monc,
        dout("handle_statfs_reply %p tid %llu\n", msg, tid);
 
        mutex_lock(&monc->mutex);
-       req = radix_tree_lookup(&monc->statfs_request_tree, tid);
+       req = __lookup_statfs(monc, tid);
        if (req) {
                *req->buf = reply->st;
                req->result = 0;
@@ -416,11 +456,7 @@ int ceph_monc_do_statfs(struct ceph_mon_client *monc, struct ceph_statfs *buf)
        req.tid = ++monc->last_tid;
        req.last_attempt = jiffies;
        req.delay = BASE_DELAY_INTERVAL;
-       if (radix_tree_insert(&monc->statfs_request_tree, req.tid, &req) < 0) {
-               mutex_unlock(&monc->mutex);
-               pr_err("ENOMEM in do_statfs\n");
-               return -ENOMEM;
-       }
+       __insert_statfs(monc, &req);
        monc->num_statfs_requests++;
        mutex_unlock(&monc->mutex);
 
@@ -430,7 +466,7 @@ int ceph_monc_do_statfs(struct ceph_mon_client *monc, struct ceph_statfs *buf)
                err = wait_for_completion_interruptible(&req.completion);
 
        mutex_lock(&monc->mutex);
-       radix_tree_delete(&monc->statfs_request_tree, req.tid);
+       rb_erase(&req.node, &monc->statfs_request_tree);
        monc->num_statfs_requests--;
        ceph_msgpool_resv(&monc->msgpool_statfs_reply, -1);
        mutex_unlock(&monc->mutex);
@@ -445,20 +481,11 @@ int ceph_monc_do_statfs(struct ceph_mon_client *monc, struct ceph_statfs *buf)
  */
 static void __resend_statfs(struct ceph_mon_client *monc)
 {
-       u64 next_tid = 0;
-       int got;
-       int did = 0;
        struct ceph_mon_statfs_request *req;
+       struct rb_node *p;
 
-       while (1) {
-               got = radix_tree_gang_lookup(&monc->statfs_request_tree,
-                                            (void **)&req,
-                                            next_tid, 1);
-               if (got == 0)
-                       break;
-               did++;
-               next_tid = req->tid + 1;
-
+       for (p = rb_first(&monc->statfs_request_tree); p; p = rb_next(p)) {
+               req = rb_entry(p, struct ceph_mon_statfs_request, node);
                send_statfs(monc, req);
        }
 }
@@ -578,7 +605,7 @@ int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
        monc->sub_sent = 0;
 
        INIT_DELAYED_WORK(&monc->delayed_work, delayed_work);
-       INIT_RADIX_TREE(&monc->statfs_request_tree, GFP_NOFS);
+       monc->statfs_request_tree = RB_ROOT;
        monc->num_statfs_requests = 0;
        monc->last_tid = 0;
 

diff --git a/fs/ceph/mon_client.h b/fs/ceph/mon_client.h
index 5ca8e48d4379fa0e4f6ab80bdd8a2d1a99c99c70..b958ad5afa061e92a0031a0fd03ac77433dbd17d 100644 (file)
--- a/fs/ceph/mon_client.h
+++ b/fs/ceph/mon_client.h
@@ -2,7 +2,7 @@
 #define _FS_CEPH_MON_CLIENT_H
 
 #include <linux/completion.h>
-#include <linux/radix-tree.h>
+#include <linux/rbtree.h>
 
 #include "messenger.h"
 #include "msgpool.h"
@@ -45,6 +45,7 @@ struct ceph_mon_request {
  */
 struct ceph_mon_statfs_request {
        u64 tid;
+       struct rb_node node;
        int result;
        struct ceph_statfs *buf;
        struct completion completion;
@@ -75,7 +76,7 @@ struct ceph_mon_client {
        struct ceph_msgpool msgpool_auth_reply;
 
        /* pending statfs requests */
-       struct radix_tree_root statfs_request_tree;
+       struct rb_root statfs_request_tree;
        int num_statfs_requests;
        u64 last_tid;