ceph: use rbtree for snap_realms

Switch from radix tree to rbtree for snap realms.  This is much more
appropriate given that realm keys are few and far between.

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

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 81840d6b68a489cb5b3d3f522a665c06b7c74ed6..02834cecc3a0641773c9233b8c45fa0bc233826c 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2097,9 +2097,8 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds)
 {
        struct ceph_mds_session *session = NULL;
        struct ceph_msg *reply;
+       struct rb_node *p;
        int err;
-       int got;
-       u64 next_snap_ino = 0;
        struct ceph_pagelist *pagelist;
 
        pr_info("reconnect to recovering mds%d\n", mds);
@@ -2155,14 +2154,10 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds)
         * parent for all of our realms.  If the mds has any newer info,
         * it will tell us.
         */
-       next_snap_ino = 0;
-       while (1) {
-               struct ceph_snap_realm *realm;
+       for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
+               struct ceph_snap_realm *realm =
+                       rb_entry(p, struct ceph_snap_realm, node);
                struct ceph_mds_snaprealm_reconnect sr_rec;
-               got = radix_tree_gang_lookup(&mdsc->snap_realms,
-                                            (void **)&realm, next_snap_ino, 1);
-               if (!got)
-                       break;
 
                dout(" adding snap realm %llx seq %lld parent %llx\n",
                     realm->ino, realm->seq, realm->parent_ino);
@@ -2172,7 +2167,6 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds)
                err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
                if (err)
                        goto fail;
-               next_snap_ino = realm->ino + 1;
        }
 
 send:
@@ -2603,7 +2597,7 @@ int ceph_mdsc_init(struct ceph_mds_client *mdsc, struct ceph_client *client)
        mdsc->max_sessions = 0;
        mdsc->stopping = 0;
        init_rwsem(&mdsc->snap_rwsem);
-       INIT_RADIX_TREE(&mdsc->snap_realms, GFP_NOFS);
+       mdsc->snap_realms = RB_ROOT;
        INIT_LIST_HEAD(&mdsc->snap_empty);
        spin_lock_init(&mdsc->snap_empty_lock);
        mdsc->last_tid = 0;

diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 98f09cd0600699fc2df3fe0ce4b179403a096722..9d6b9017387989f409f541d792cf7a9d1deca720 100644 (file)
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -5,7 +5,6 @@
 #include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
-#include <linux/radix-tree.h>
 #include <linux/rbtree.h>
 #include <linux/spinlock.h>
 
@@ -246,7 +245,7 @@ struct ceph_mds_client {
         * should be destroyed.
         */
        struct rw_semaphore     snap_rwsem;
-       struct radix_tree_root  snap_realms;
+       struct rb_root          snap_realms;
        struct list_head        snap_empty;
        spinlock_t              snap_empty_lock;  /* protect snap_empty */
 

diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index dcf18d92130a2c56dba4f1d92453abdcff828cd1..49d0c4c59d81b6cdc919b1b088dd9e8db92c355d 100644 (file)
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -1,6 +1,5 @@
 #include "ceph_debug.h"
 
-#include <linux/radix-tree.h>
 #include <linux/sort.h>
 
 #include "super.h"
@@ -77,6 +76,28 @@ void ceph_get_snap_realm(struct ceph_mds_client *mdsc,
        atomic_inc(&realm->nref);
 }
 
+static void __insert_snap_realm(struct rb_root *root,
+                               struct ceph_snap_realm *new)
+{
+       struct rb_node **p = &root->rb_node;
+       struct rb_node *parent = NULL;
+       struct ceph_snap_realm *r = NULL;
+
+       while (*p) {
+               parent = *p;
+               r = rb_entry(parent, struct ceph_snap_realm, node);
+               if (new->ino < r->ino)
+                       p = &(*p)->rb_left;
+               else if (new->ino > r->ino)
+                       p = &(*p)->rb_right;
+               else
+                       BUG();
+       }
+
+       rb_link_node(&new->node, parent, p);
+       rb_insert_color(&new->node, root);
+}
+
 /*
  * create and get the realm rooted at @ino and bump its ref count.
  *
@@ -92,8 +113,6 @@ static struct ceph_snap_realm *ceph_create_snap_realm(
        if (!realm)
                return ERR_PTR(-ENOMEM);
 
-       radix_tree_insert(&mdsc->snap_realms, ino, realm);
-
        atomic_set(&realm->nref, 0);    /* tree does not take a ref */
        realm->ino = ino;
        INIT_LIST_HEAD(&realm->children);
@@ -101,24 +120,34 @@ static struct ceph_snap_realm *ceph_create_snap_realm(
        INIT_LIST_HEAD(&realm->empty_item);
        INIT_LIST_HEAD(&realm->inodes_with_caps);
        spin_lock_init(&realm->inodes_with_caps_lock);
+       __insert_snap_realm(&mdsc->snap_realms, realm);
        dout("create_snap_realm %llx %p\n", realm->ino, realm);
        return realm;
 }
 
 /*
- * find and get (if found) the realm rooted at @ino and bump its ref count.
+ * lookup the realm rooted at @ino.
  *
  * caller must hold snap_rwsem for write.
  */
 struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc,
                                               u64 ino)
 {
-       struct ceph_snap_realm *realm;
-
-       realm = radix_tree_lookup(&mdsc->snap_realms, ino);
-       if (realm)
-               dout("lookup_snap_realm %llx %p\n", realm->ino, realm);
-       return realm;
+       struct rb_node *n = mdsc->snap_realms.rb_node;
+       struct ceph_snap_realm *r;
+
+       while (n) {
+               r = rb_entry(n, struct ceph_snap_realm, node);
+               if (ino < r->ino)
+                       n = n->rb_left;
+               else if (ino > r->ino)
+                       n = n->rb_right;
+               else {
+                       dout("lookup_snap_realm %llx %p\n", r->ino, r);
+                       return r;
+               }
+       }
+       return NULL;
 }
 
 static void __put_snap_realm(struct ceph_mds_client *mdsc,
@@ -132,7 +161,7 @@ static void __destroy_snap_realm(struct ceph_mds_client *mdsc,
 {
        dout("__destroy_snap_realm %p %llx\n", realm, realm->ino);
 
-       radix_tree_delete(&mdsc->snap_realms, realm->ino);
+       rb_erase(&realm->node, &mdsc->snap_realms);
 
        if (realm->parent) {
                list_del_init(&realm->child_item);

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index b2adfccbab9882e6c1baa2429c4564d07e4d8e23..1f3928785e1277b6df0b1acbabcb61cedcc55f49 100644 (file)
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -656,6 +656,8 @@ static inline void ceph_put_snap_context(struct ceph_snap_context *sc)
 struct ceph_snap_realm {
        u64 ino;
        atomic_t nref;
+       struct rb_node node;
+
        u64 created, seq;
        u64 parent_ino;
        u64 parent_since;   /* snapid when our current parent became so */