Some filesystems, like configfs, need to lock more than two regular inodes recursively in a tree, which i_mutex lockdep subclasses do not permit. This patch reorders the definitions (but not the semantics) of i_mutex lockdep sub-classes so that nested i_mutex locking can be done with sub-classes I_MUTEX_PARENT -> I_MUTEX_CHILD -> I_MUTEX_CHILD + 1 -> I_MUTEX_CHILD + 2 -> ... until MAX_LOCKDEP_SUBCLASSES - 1. Signed-off-by: Louis Rilling --- include/linux/fs.h | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) Index: b/include/linux/fs.h =================================================================== --- a/include/linux/fs.h 2008-05-21 09:40:28.000000000 +0200 +++ b/include/linux/fs.h 2008-05-22 12:20:20.000000000 +0200 @@ -660,20 +660,23 @@ struct inode { * inode->i_mutex nesting subclasses for the lock validator: * * 0: the object of the current VFS operation - * 1: parent - * 2: child/target - * 3: quota file + * 1: xattrs + * 2: quota file + * 3: parent + * 4: child/target + * ...: lower-level children * * The locking order between these classes is - * parent -> child -> normal -> xattr -> quota + * parent -> child -> sub-children... -> normal -> xattr -> quota */ enum inode_i_mutex_lock_class { I_MUTEX_NORMAL, + I_MUTEX_XATTR, + I_MUTEX_QUOTA, I_MUTEX_PARENT, I_MUTEX_CHILD, - I_MUTEX_XATTR, - I_MUTEX_QUOTA + /* Reserved for variable paths of nested inode locks */ }; extern void inode_double_lock(struct inode *inode1, struct inode *inode2); -- Dr Louis Rilling Kerlabs Skype: louis.rilling Batiment Germanium Phone: (+33|0) 6 80 89 08 23 80 avenue des Buttes de Coesmes http://www.kerlabs.com/ 35700 Rennes -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/