Imported Upstream version 0.6.5.3

[mirror_zfs-debian.git] / include / sys / dnode.h

diff --git a/include/sys/dnode.h b/include/sys/dnode.h
index b63549b4675320199e3644f87d2e6f2c081e49eb..50e01155903aa3e2b7b1be879dd31e62ddcba5e6 100644 (file)
--- a/include/sys/dnode.h
+++ b/include/sys/dnode.h
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
+ * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  */
 
 #ifndef        _SYS_DNODE_H
@@ -233,7 +234,18 @@ typedef struct dnode {
        refcount_t dn_holds;
 
        kmutex_t dn_dbufs_mtx;
-       list_t dn_dbufs;                /* descendent dbufs */
+       /*
+        * Descendent dbufs, ordered by dbuf_compare. Note that dn_dbufs
+        * can contain multiple dbufs of the same (level, blkid) when a
+        * dbuf is marked DB_EVICTING without being removed from
+        * dn_dbufs. To maintain the avl invariant that there cannot be
+        * duplicate entries, we order the dbufs by an arbitrary value -
+        * their address in memory. This means that dn_dbufs cannot be used to
+        * directly look up a dbuf. Instead, callers must use avl_walk, have
+        * a reference to the dbuf, or look up a non-existant node with
+        * db_state = DB_SEARCH (see dbuf_free_range for an example).
+        */
+       avl_tree_t dn_dbufs;
 
        /* protected by dn_struct_rwlock */
        struct dmu_buf_impl *dn_bonus;  /* bonus buffer dbuf */
@@ -266,8 +278,9 @@ typedef struct dnode_handle {
 } dnode_handle_t;
 
 typedef struct dnode_children {
+       dmu_buf_user_t dnc_dbu;         /* User evict data */
        size_t dnc_count;               /* number of children */
-       dnode_handle_t dnc_children[1]; /* sized dynamically */
+       dnode_handle_t dnc_children[];  /* sized dynamically */
 } dnode_children_t;
 
 typedef struct free_range {
@@ -276,7 +289,7 @@ typedef struct free_range {
        uint64_t fr_nblks;
 } free_range_t;
 
-dnode_t *dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
+void dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
     uint64_t object, dnode_handle_t *dnh);
 void dnode_special_close(dnode_handle_t *dnh);