xfs: use per-filesystem radix trees for dquot lookup

Replace the global hash tables for looking up in-memory dquot structures
with per-filesystem radix trees to allow scaling to a large number of
in-memory dquot structures.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 8 insertions, 87 deletions

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index a2579e1d687f..bb884e701cd9 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -54,9 +54,6 @@ struct xfs_qm	*xfs_Gqm;
 kmem_zone_t     *qm_dqzone;
 kmem_zone_t     *qm_dqtrxzone;
 
-STATIC void     xfs_qm_list_init(xfs_dqlist_t *, char *, int);
-STATIC void     xfs_qm_list_destroy(xfs_dqlist_t *);
-
 STATIC int      xfs_qm_init_quotainos(xfs_mount_t *);
 STATIC int      xfs_qm_init_quotainfo(xfs_mount_t *);
 STATIC int      xfs_qm_shake(struct shrinker *, struct shrink_control *);
@@ -68,37 +65,9 @@ STATIC int	xfs_qm_shake(struct shrinker *, struct shrink_control *);
 STATIC struct xfs_qm *
 xfs_Gqm_init(void)
 {
-        xfs_dqhash_t    *udqhash, *gdqhash;
         xfs_qm_t        *xqm;
-        size_t          hsize;
-        uint            i;
-
-        /*
-         * Initialize the dquot hash tables.
-         */
-        udqhash = kmem_zalloc_greedy(&hsize,
-                                     XFS_QM_HASHSIZE_LOW * sizeof(xfs_dqhash_t),
-                                     XFS_QM_HASHSIZE_HIGH * sizeof(xfs_dqhash_t));
-        if (!udqhash)
-                goto out;
-
-        gdqhash = kmem_zalloc_large(hsize);
-        if (!gdqhash)
-                goto out_free_udqhash;
-
-        hsize /= sizeof(xfs_dqhash_t);
 
         xqm = kmem_zalloc(sizeof(xfs_qm_t), KM_SLEEP);
-        xqm->qm_dqhashmask = hsize - 1;
-        xqm->qm_usr_dqhtable = udqhash;
-        xqm->qm_grp_dqhtable = gdqhash;
-        ASSERT(xqm->qm_usr_dqhtable != NULL);
-        ASSERT(xqm->qm_grp_dqhtable != NULL);
-
-        for (i = 0; i < hsize; i++) {
-                xfs_qm_list_init(&(xqm->qm_usr_dqhtable[i]), "uxdqh", i);
-                xfs_qm_list_init(&(xqm->qm_grp_dqhtable[i]), "gxdqh", i);
-        }
 
         /*
          * dquot zone. we register our own low-memory callback.
@@ -122,11 +91,6 @@ xfs_Gqm_init(void)
 
         xqm->qm_nrefs = 0;
         return xqm;
-
- out_free_udqhash:
-        kmem_free_large(udqhash);
- out:
-        return NULL;
 }
 
 /*
@@ -136,22 +100,9 @@ STATIC void
 xfs_qm_destroy(
         struct xfs_qm   *xqm)
 {
-        int             hsize, i;
-
         ASSERT(xqm != NULL);
         ASSERT(xqm->qm_nrefs == 0);
 
-        hsize = xqm->qm_dqhashmask + 1;
-        for (i = 0; i < hsize; i++) {
-                xfs_qm_list_destroy(&(xqm->qm_usr_dqhtable[i]));
-                xfs_qm_list_destroy(&(xqm->qm_grp_dqhtable[i]));
-        }
-        kmem_free_large(xqm->qm_usr_dqhtable);
-        kmem_free_large(xqm->qm_grp_dqhtable);
-        xqm->qm_usr_dqhtable = NULL;
-        xqm->qm_grp_dqhtable = NULL;
-        xqm->qm_dqhashmask = 0;
-
         kmem_free(xqm);
 }
 
@@ -762,14 +713,6 @@ xfs_qm_dqdetach(
 }
 
 /*
- * The hash chains and the mplist use the same xfs_dqhash structure as
- * their list head, but we can take the mplist qh_lock and one of the
- * hash qh_locks at the same time without any problem as they aren't
- * related.
- */
-static struct lock_class_key xfs_quota_mplist_class;
-
-/*
  * This initializes all the quota information that's kept in the
  * mount structure
  */
@@ -802,9 +745,12 @@ xfs_qm_init_quotainfo(
                 return error;
         }
 
+        INIT_RADIX_TREE(&qinf->qi_uquota_tree, GFP_NOFS);
+        INIT_RADIX_TREE(&qinf->qi_gquota_tree, GFP_NOFS);
+        mutex_init(&qinf->qi_tree_lock);
+
         INIT_LIST_HEAD(&qinf->qi_dqlist);
         mutex_init(&qinf->qi_dqlist_lock);
-        lockdep_set_class(&qinf->qi_dqlist_lock, &xfs_quota_mplist_class);
 
         INIT_LIST_HEAD(&qinf->qi_lru_list);
         qinf->qi_lru_count = 0;
@@ -924,30 +870,6 @@ xfs_qm_destroy_quotainfo(
         mp->m_quotainfo = NULL;
 }
 
-
-
-/* ------------------- PRIVATE STATIC FUNCTIONS ----------------------- */
-
-/* ARGSUSED */
-STATIC void
-xfs_qm_list_init(
-        xfs_dqlist_t    *list,
-        char            *str,
-        int             n)
-{
-        mutex_init(&list->qh_lock);
-        INIT_LIST_HEAD(&list->qh_list);
-        list->qh_version = 0;
-        list->qh_nelems = 0;
-}
-
-STATIC void
-xfs_qm_list_destroy(
-        xfs_dqlist_t    *list)
-{
-        mutex_destroy(&(list->qh_lock));
-}
-
 /*
  * Create an inode and return with a reference already taken, but unlocked
  * This is how we create quota inodes
@@ -1592,10 +1514,10 @@ xfs_qm_dqfree_one(
         struct xfs_mount        *mp = dqp->q_mount;
         struct xfs_quotainfo    *qi = mp->m_quotainfo;
 
-        mutex_lock(&dqp->q_hash->qh_lock);
-        list_del_init(&dqp->q_hashlist);
-        dqp->q_hash->qh_version++;
-        mutex_unlock(&dqp->q_hash->qh_lock);
+        mutex_lock(&qi->qi_tree_lock);
+        radix_tree_delete(XFS_DQUOT_TREE(qi, dqp->q_core.d_flags),
+                          be32_to_cpu(dqp->q_core.d_id));
+        mutex_unlock(&qi->qi_tree_lock);
 
         mutex_lock(&qi->qi_dqlist_lock);
         list_del_init(&dqp->q_mplist);
@@ -1634,7 +1556,6 @@ xfs_qm_dqreclaim_one(
                 return;
         }
 
-        ASSERT(dqp->q_hash);
         ASSERT(!list_empty(&dqp->q_mplist));
 
         /*