From: Mark Fasheh <mfasheh@suse.com>
Date: Mon, 29 Aug 2011 21:30:39 +0000 (-0700)
Subject: btrfs: Don't BUG_ON errors from update_ref_for_cow()
X-Git-Tag: v3.4-rc3~11^2~20^2~10
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b68dc2a93e794c8507338c91577a277efa4555d5;p=platform%2Fkernel%2Flinux-stable.git

btrfs: Don't BUG_ON errors from update_ref_for_cow()

__btrfs_cow_block(), the only caller of update_ref_for_cow() will BUG_ON()
any error return.  Instead, we can go read-only fs as update_ref_for_cow()
manipulates disk data in a way which doesn't look like it's easily rolled
back.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
---

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 3b767d2..36e16bd 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -474,7 +474,10 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 			    BTRFS_FSID_SIZE);
 
 	ret = update_ref_for_cow(trans, root, buf, cow, &last_ref);
-	BUG_ON(ret);
+	if (ret) {
+		btrfs_std_error(root->fs_info, ret);
+		return ret;
+	}
 
 	if (root->ref_cows)
 		btrfs_reloc_cow_block(trans, root, buf, cow);