From: Yan Zheng <zheng.yan@oracle.com>
Date: Fri, 24 Jul 2009 15:06:53 +0000 (-0400)
Subject: Btrfs: find_free_dev_extent doesn't handle holes at the start of the device
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1fcbac581be375ca0a686f72ee2b7fd1dbf386e7;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

Btrfs: find_free_dev_extent doesn't handle holes at the start of the device

find_free_dev_extent does not properly handle the case where
the device is not complete free, and there is a free extent
at the beginning of the device.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 55c37276a29f..074c1c56d8c4 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -758,9 +758,13 @@ static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans,
 	ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
 	if (ret < 0)
 		goto error;
-	ret = btrfs_previous_item(root, path, 0, key.type);
-	if (ret < 0)
-		goto error;
+	if (ret > 0) {
+		ret = btrfs_previous_item(root, path, key.objectid, key.type);
+		if (ret < 0)
+			goto error;
+		if (ret > 0)
+			start_found = 1;
+	}
 	l = path->nodes[0];
 	btrfs_item_key_to_cpu(l, &key, path->slots[0]);
 	while (1) {