On Thu, Dec 1, 2016 at 11:48 PM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > An overlayfs instance can be the lower layer of another stacked > overlayfs instance. > > This setup triggers a lockdep splat of possible recursive locking > of sb->s_type->i_mutex_key in iterate_dir(). > > Fix this by annotating stackable inode_lock() according to stack > level of the super block instance. > > Stackable fs inode_lock() is annotated at lockdep_class level, > so it is independent of the inner fs I_MUTEX subclass annotations. > > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx> > --- > fs/inode.c | 10 ++++++---- > include/linux/fs.h | 14 ++++++++++++-- > 2 files changed, 18 insertions(+), 6 deletions(-) > > diff --git a/fs/inode.c b/fs/inode.c > index 88110fd..f46b267 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -169,7 +169,8 @@ int inode_init_always(struct super_block *sb, struct inode *inode) > lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); > > init_rwsem(&inode->i_rwsem); > - lockdep_set_class(&inode->i_rwsem, &sb->s_type->i_mutex_key); > + lockdep_set_class(&inode->i_rwsem, > + &sb->s_type->i_mutex_key[FS_STACK_NESTING(sb)]); > NACK to self. This new annotated lock name looks ugly in lockdep stats. I'll move the annotation for the special nested case into the file system Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
