Rebase master to b117

[zfs.git] / module / zfs / zap.c

diff --git a/module/zfs/zap.c b/module/zfs/zap.c
index ca859ec..2dc2705 100644 (file)
--- a/module/zfs/zap.c
+++ b/module/zfs/zap.c
@@ -19,13 +19,10 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma ident  "%Z%%M% %I%     %E% SMI"
-
-
 /*
  * This file contains the top half of the zfs directory structure
  * implementation. The bottom half is in zap_leaf.c.
@@ -45,6 +42,7 @@
 #include <sys/dmu.h>
 #include <sys/zfs_context.h>
 #include <sys/zfs_znode.h>
+#include <sys/fs/zfs.h>
 #include <sys/zap.h>
 #include <sys/refcount.h>
 #include <sys/zap_impl.h>
@@ -1134,3 +1132,58 @@ fzap_get_stats(zap_t *zap, zap_stats_t *zs)
                }
        }
 }
+
+int
+fzap_count_write(zap_name_t *zn, int add, uint64_t *towrite,
+    uint64_t *tooverwrite)
+{
+       zap_t *zap = zn->zn_zap;
+       zap_leaf_t *l;
+       int err;
+
+       /*
+        * Account for the header block of the fatzap.
+        */
+       if (!add && dmu_buf_freeable(zap->zap_dbuf)) {
+               tooverwrite += zap->zap_dbuf->db_size;
+       } else {
+               towrite += zap->zap_dbuf->db_size;
+       }
+
+       /*
+        * Account for the pointer table blocks.
+        * If we are adding we need to account for the following cases :
+        * - If the pointer table is embedded, this operation could force an
+        *   external pointer table.
+        * - If this already has an external pointer table this operation
+        *   could extend the table.
+        */
+       if (add) {
+               if (zap->zap_f.zap_phys->zap_ptrtbl.zt_blk == 0)
+                       towrite += zap->zap_dbuf->db_size;
+               else
+                       towrite += (zap->zap_dbuf->db_size * 3);
+       }
+
+       /*
+        * Now, check if the block containing leaf is freeable
+        * and account accordingly.
+        */
+       err = zap_deref_leaf(zap, zn->zn_hash, NULL, RW_READER, &l);
+       if (err != 0) {
+               return (err);
+       }
+
+       if (!add && dmu_buf_freeable(l->l_dbuf)) {
+               tooverwrite += l->l_dbuf->db_size;
+       } else {
+               /*
+                * If this an add operation, the leaf block could split.
+                * Hence, we need to account for an additional leaf block.
+                */
+               towrite += (add ? 2 : 1) * l->l_dbuf->db_size;
+       }
+
+       zap_put_leaf(l);
+       return (0);
+}