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, 11 deletions

diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index c236bba9bfab..8f4b117823cc 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -31,12 +31,6 @@ extern kmem_zone_t	*qm_dqzone;
 extern kmem_zone_t      *qm_dqtrxzone;
 
 /*
- * Dquot hashtable constants/threshold values.
- */
-#define XFS_QM_HASHSIZE_LOW             (PAGE_SIZE / sizeof(xfs_dqhash_t))
-#define XFS_QM_HASHSIZE_HIGH            ((PAGE_SIZE * 4) / sizeof(xfs_dqhash_t))
-
-/*
  * This defines the unit of allocation of dquots.
  * Currently, it is just one file system block, and a 4K blk contains 30
  * (136 * 30 = 4080) dquots. It's probably not worth trying to make
@@ -47,15 +41,10 @@ extern kmem_zone_t	*qm_dqtrxzone;
  */
 #define XFS_DQUOT_CLUSTER_SIZE_FSB      (xfs_filblks_t)1
 
-typedef xfs_dqhash_t    xfs_dqlist_t;
-
 /*
  * Quota Manager (global) structure. Lives only in core.
  */
 typedef struct xfs_qm {
-        xfs_dqlist_t    *qm_usr_dqhtable;/* udquot hash table */
-        xfs_dqlist_t    *qm_grp_dqhtable;/* gdquot hash table */
-        uint             qm_dqhashmask;  /* # buckets in dq hashtab - 1 */
         uint             qm_nrefs;       /* file systems with quota on */
         kmem_zone_t     *qm_dqzone;      /* dquot mem-alloc zone */
         kmem_zone_t     *qm_dqtrxzone;   /* t_dqinfo of transactions */
@@ -66,6 +55,9 @@ typedef struct xfs_qm {
  * The mount structure keeps a pointer to this.
  */
 typedef struct xfs_quotainfo {
+        struct radix_tree_root qi_uquota_tree;
+        struct radix_tree_root qi_gquota_tree;
+        struct mutex qi_tree_lock;
         xfs_inode_t     *qi_uquotaip;    /* user quota inode */
         xfs_inode_t     *qi_gquotaip;    /* group quota inode */
         struct list_head qi_lru_list;
@@ -94,6 +86,11 @@ typedef struct xfs_quotainfo {
         struct shrinker  qi_shrinker;
 } xfs_quotainfo_t;
 
+#define XFS_DQUOT_TREE(qi, type) \
+        ((type & XFS_DQ_USER) ? \
+         &((qi)->qi_uquota_tree) : \
+         &((qi)->qi_gquota_tree))
+
 
 extern void     xfs_trans_mod_dquot(xfs_trans_t *, xfs_dquot_t *, uint, long);
 extern int      xfs_trans_reserve_quota_bydquots(xfs_trans_t *, xfs_mount_t *,