From: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Date: Sat, 28 Feb 2015 20:06:01 +0000 (+0900)
Subject: sbin/hammer: Don't show FLAG_BADMIRRORTID for root node in certain corner case situation
X-Git-Tag: v4.2.0rc~701
X-Git-Url: https://gitweb.dragonflybsd.org/~tuxillo/dragonfly.git/commitdiff_plain/44cd685c7ff64915c6067e9911cb9d6f03e2eaf8

sbin/hammer: Don't show FLAG_BADMIRRORTID for root node in certain corner case situation

- Make hammer show command stop showwing an error flag regarding
  mirror tid that isn't actually an error.

- newfs_hammer initializes the root node's mirror_tid with 0 along
  with its first two elements, but this mirror_tid is not updated
  till the third element is allocated (by creating a file, etc).
  Following result shows this situation.

- In this situation the root node's node->mirror_tid (==0) being
  smaller than elm->base.create_tid or elm->base.delete_tid is not
  an error. This only happens on the root node because all the other
  nodes get updated when they split from existing ones.

     NODE 8000000020800000 cnt=02 p=0000000000000000 type=L depth=0 mirror 0000000000000000 fill=z8:65=1% {
B-----M	ELM  0 R lo=00000001 obj=0000000000000001 rt=01 key=0000000000000000 ot=01
	         tids 0000000100000001:0000000000000000
		 <snip>
B-----M	ELM  1 R lo=00000002 obj=0000000000000001 rt=15 key=0000000000000000 ot=00
	         tids 0000000100000001:0000000000000000
		 <snip>
     }
---

diff --git a/sbin/hammer/cmd_show.c b/sbin/hammer/cmd_show.c
index 40fd4fac93..fc860a8250 100644
--- a/sbin/hammer/cmd_show.c
+++ b/sbin/hammer/cmd_show.c
@@ -355,11 +355,15 @@ get_elm_flags(hammer_node_ondisk_t node, hammer_off_t node_offset,
 		}
 		break;
 	case HAMMER_BTREE_TYPE_LEAF:
-		if (elm->base.create_tid &&
+		if (node->mirror_tid == 0 &&
+		    !(node->parent == 0 && node->count == 2)) {
+			flags |= FLAG_BADMIRRORTID;
+		}
+		if (elm->base.create_tid && node->mirror_tid &&
 		    elm->base.create_tid > node->mirror_tid) {
 			flags |= FLAG_BADMIRRORTID;
 		}
-		if (elm->base.delete_tid &&
+		if (elm->base.delete_tid && node->mirror_tid &&
 		    elm->base.delete_tid > node->mirror_tid) {
 			flags |= FLAG_BADMIRRORTID;
 		}
diff --git a/sbin/newfs_hammer/newfs_hammer.c b/sbin/newfs_hammer/newfs_hammer.c
index 6065baf35f..6bd72f3cd5 100644
--- a/sbin/newfs_hammer/newfs_hammer.c
+++ b/sbin/newfs_hammer/newfs_hammer.c
@@ -614,6 +614,9 @@ format_root(const char *label)
 	hammer_btree_elm_t elm;
 	u_int64_t xtime;
 
+	/*
+	 * Allocate zero-filled root btree node and data
+	 */
 	bnode = alloc_btree_element(&btree_off);
 	idata = alloc_data_element(&data_off, sizeof(*idata), &data_buffer1);
 	pfsd = alloc_data_element(&pfsd_off, sizeof(*pfsd), &data_buffer2);