NEX-3165 need some dedup improvements
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
re #12611 rb4105 zpool import panic in ddt_zap_count()
re #12585 rb4049 ZFS++ work port - refactoring to improve separation of open/closed code, bug fixes, performance improvements - open code

@@ -18,10 +18,11 @@
  *
  * CDDL HEADER END
  */
 /*
  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2016 by Delphix. All rights reserved.
  */
 
 #ifndef _SYS_DDT_H
 #define _SYS_DDT_H

@@ -54,10 +55,21 @@
         DDT_CLASS_DUPLICATE,
         DDT_CLASS_UNIQUE,
         DDT_CLASSES
 };
 
+/*
+ * Tracks whether a DDE is loading or already loaded and
+ * which entries got removed from dedup path to support dedup ceiling
+ */
+enum dde_state {
+        DDE_LOADING     = (1 << 0),
+        DDE_LOADED      = (1 << 1),
+        DDE_NEW         = (1 << 2),
+        DDE_DONT_SYNC   = (1 << 3),
+};
+
 #define DDT_TYPE_CURRENT                0
 
 #define DDT_COMPRESS_BYTEORDER_MASK     0x80
 #define DDT_COMPRESS_FUNCTION_MASK      0x7f
 

@@ -109,25 +121,31 @@
  */
 struct ddt_entry {
         ddt_key_t       dde_key;
         ddt_phys_t      dde_phys[DDT_PHYS_TYPES];
         zio_t           *dde_lead_zio[DDT_PHYS_TYPES];
+        ddt_stat_t      dde_lkstat;
         struct abd      *dde_repair_abd;
         enum ddt_type   dde_type;
         enum ddt_class  dde_class;
-        uint8_t         dde_loading;
-        uint8_t         dde_loaded;
+        uint8_t         dde_state;
         kcondvar_t      dde_cv;
+        kmutex_t        dde_lock;
         avl_node_t      dde_node;
 };
 
+#define DDT_HASHSZ              0x100
+#define DDT_HASHFN(csum)        (*((uint8_t *)&(csum).zc_word[0]) & \
+            (DDT_HASHSZ - 1))
+
 /*
  * In-core ddt
  */
 struct ddt {
-        kmutex_t        ddt_lock;
-        avl_tree_t      ddt_tree;
+        kmutex_t        ddt_lock[DDT_HASHSZ];
+        avl_tree_t      ddt_tree[DDT_HASHSZ];
+        kmutex_t        ddt_repair_lock;
         avl_tree_t      ddt_repair_tree;
         enum zio_checksum ddt_checksum;
         spa_t           *ddt_spa;
         objset_t        *ddt_os;
         uint64_t        ddt_stat_object;

@@ -163,21 +181,21 @@
             dmu_tx_t *tx);
         int (*ddt_op_remove)(objset_t *os, uint64_t object, ddt_entry_t *dde,
             dmu_tx_t *tx);
         int (*ddt_op_walk)(objset_t *os, uint64_t object, ddt_entry_t *dde,
             uint64_t *walk);
-        uint64_t (*ddt_op_count)(objset_t *os, uint64_t object);
+        int (*ddt_op_count)(objset_t *os, uint64_t object, uint64_t *count);
 } ddt_ops_t;
 
 #define DDT_NAMELEN     80
 
 extern void ddt_object_name(ddt_t *ddt, enum ddt_type type,
     enum ddt_class class, char *name);
 extern int ddt_object_walk(ddt_t *ddt, enum ddt_type type,
     enum ddt_class class, uint64_t *walk, ddt_entry_t *dde);
-extern uint64_t ddt_object_count(ddt_t *ddt, enum ddt_type type,
-    enum ddt_class class);
+extern int ddt_object_count(ddt_t *ddt, enum ddt_type type,
+    enum ddt_class class, uint64_t *count);
 extern int ddt_object_info(ddt_t *ddt, enum ddt_type type,
     enum ddt_class class, dmu_object_info_t *);
 extern boolean_t ddt_object_exists(ddt_t *ddt, enum ddt_type type,
     enum ddt_class class);
 

@@ -215,12 +233,14 @@
 
 extern size_t ddt_compress(void *src, uchar_t *dst, size_t s_len, size_t d_len);
 extern void ddt_decompress(uchar_t *src, void *dst, size_t s_len, size_t d_len);
 
 extern ddt_t *ddt_select(spa_t *spa, const blkptr_t *bp);
-extern void ddt_enter(ddt_t *ddt);
-extern void ddt_exit(ddt_t *ddt);
+extern void ddt_enter(ddt_t *ddt, uint8_t hash);
+extern void ddt_exit(ddt_t *ddt, uint8_t hash);
+extern void dde_enter(ddt_entry_t *dde);
+extern void dde_exit(ddt_entry_t *dde);
 extern ddt_entry_t *ddt_lookup(ddt_t *ddt, const blkptr_t *bp, boolean_t add);
 extern void ddt_prefetch(spa_t *spa, const blkptr_t *bp);
 extern void ddt_remove(ddt_t *ddt, ddt_entry_t *dde);
 
 extern boolean_t ddt_class_contains(spa_t *spa, enum ddt_class max_class,

@@ -236,10 +256,12 @@
 extern void ddt_unload(spa_t *spa);
 extern void ddt_sync(spa_t *spa, uint64_t txg);
 extern int ddt_walk(spa_t *spa, ddt_bookmark_t *ddb, ddt_entry_t *dde);
 extern int ddt_object_update(ddt_t *ddt, enum ddt_type type,
     enum ddt_class class, ddt_entry_t *dde, dmu_tx_t *tx);
+extern void ddt_init(void);
+extern void ddt_fini(void);
 
 extern const ddt_ops_t ddt_zap_ops;
 
 #ifdef  __cplusplus
 }