From: Josef Bacik <jbacik@fusionio.com>
Date: Tue, 23 Apr 2013 15:30:14 +0000 (-0400)
Subject: Btrfs: add tree block level sanity check
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1c24c3ce6a8022ab225f44160bfddc92a5a6e435;p=linux-beck.git

Btrfs: add tree block level sanity check

With a users corrupted fs I was getting weird behavior and panics and it turns
out it was because one of his tree blocks had a bogus header level.  So add this
to the sanity checks in the endio handler for tree blocks.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index bb6cdbda4f56..c7d8fb0dbff6 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -613,6 +613,12 @@ static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 		goto err;
 	}
 	found_level = btrfs_header_level(eb);
+	if (found_level >= BTRFS_MAX_LEVEL) {
+		btrfs_info(root->fs_info, "bad tree block level %d\n",
+			   (int)btrfs_header_level(eb));
+		ret = -EIO;
+		goto err;
+	}
 
 	btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
 				       eb, found_level);