From: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Date: Fri, 3 Nov 2017 08:28:05 +0000 (+0800)
Subject: btrfs-progs: lowmem check: Fix false alert about referencer count mismatch
X-Git-Tag: upstream/4.16.1~279
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=29379da543da18f40f0a780bd61823316968607c;p=platform%2Fupstream%2Fbtrfs-progs.git

btrfs-progs: lowmem check: Fix false alert about referencer count mismatch

The normal back reference counting doesn't care about the extent referred
by the extent data in the shared leaf. The check_extent_data_backref
function need to skip the leaf that owner mismatch with the root_id.

Reported-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/cmds-check.c b/cmds-check.c
index 5750bb7..a93ac2c 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -12468,7 +12468,8 @@ static int check_extent_data_backref(struct btrfs_fs_info *fs_info,
 		leaf = path.nodes[0];
 		slot = path.slots[0];
 
-		if (slot >= btrfs_header_nritems(leaf))
+		if (slot >= btrfs_header_nritems(leaf) ||
+		    btrfs_header_owner(leaf) != root_id)
 			goto next;
 		btrfs_item_key_to_cpu(leaf, &key, slot);
 		if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)