After looking at Liu Bo's recent patch (titled "Btrfs: fix comp_oper to get right order") I realized the search made by qgroup_oper_exists() was buggy because its tree navigation comparison function, comp_oper_exist(), only looks at the fields bytenr and ref_root of a tree node, ignoring the seq field completely. This was wrong because when we insert a node into the tree we use comp_oper(), which takes a decision based first on bytenr, then on seq and then on the ref_root field. That means qgroup_oper_exists() could miss the fact that at least one operation with given bytenr and ref_root exists. Fix this by changing the insertion navigation function to use the ref_root field right after using the bytenr field and before using the seq field.
This patch applies on top of the patch mentioned above from Liu. Signed-off-by: Filipe Manana <[email protected]> --- fs/btrfs/qgroup.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 058c79e..683862a 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1256,14 +1256,14 @@ static int comp_oper(struct btrfs_qgroup_operation *oper1, return -1; if (oper1->bytenr > oper2->bytenr) return 1; - if (oper1->seq < oper2->seq) - return -1; - if (oper1->seq > oper2->seq) - return 1; if (oper1->ref_root < oper2->ref_root) return -1; if (oper1->ref_root > oper2->ref_root) return 1; + if (oper1->seq < oper2->seq) + return -1; + if (oper1->seq > oper2->seq) + return 1; if (oper1->type < oper2->type) return -1; if (oper1->type > oper2->type) -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
