lockdep: per filesystem inode lock class

Give each filesystem its own inode lock class. The various filesystems have
different locking order wrt the inode locks; esp. the pseudo filesystems differ
from the rest.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>

2 files changed, 14 insertions, 3 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 29f5068f819b..bf6adf122c68 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -142,6 +142,15 @@ static struct inode *alloc_inode(struct super_block *sb)
                         return NULL;
                 }
 
+                spin_lock_init(&inode->i_lock);
+                lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key);
+
+                mutex_init(&inode->i_mutex);
+                lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key);
+
+                init_rwsem(&inode->i_alloc_sem);
+                lockdep_set_class(&inode->i_alloc_sem, &sb->s_type->i_alloc_sem_key);
+
                 mapping->a_ops = &empty_aops;
                 mapping->host = inode;
                 mapping->flags = 0;
@@ -190,8 +199,6 @@ void inode_init_once(struct inode *inode)
         INIT_HLIST_NODE(&inode->i_hash);
         INIT_LIST_HEAD(&inode->i_dentry);
         INIT_LIST_HEAD(&inode->i_devices);
-        mutex_init(&inode->i_mutex);
-        init_rwsem(&inode->i_alloc_sem);
         INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
         rwlock_init(&inode->i_data.tree_lock);
         spin_lock_init(&inode->i_data.i_mmap_lock);
@@ -199,7 +206,6 @@ void inode_init_once(struct inode *inode)
         spin_lock_init(&inode->i_data.private_lock);
         INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap);
         INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
-        spin_lock_init(&inode->i_lock);
         i_size_ordered_init(inode);
 #ifdef CONFIG_INOTIFY
         INIT_LIST_HEAD(&inode->inotify_watches);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 16421f662a7a..0cad20e12585 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1302,8 +1302,13 @@ struct file_system_type {
         struct module *owner;
         struct file_system_type * next;
         struct list_head fs_supers;
+
         struct lock_class_key s_lock_key;
         struct lock_class_key s_umount_key;
+
+        struct lock_class_key i_lock_key;
+        struct lock_class_key i_mutex_key;
+        struct lock_class_key i_alloc_sem_key;
 };
 
 extern int get_sb_bdev(struct file_system_type *fs_type,