1 files changed, 59 insertions, 0 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 8e93341f3e82..9c2358391147 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -553,12 +553,24 @@ static void detach_groups(struct config_group *group)
 
                 child = sd->s_dentry;
 
+                /*
+                 * Note: we hide this from lockdep since we have no way
+                 * to teach lockdep about recursive
+                 * I_MUTEX_PARENT -> I_MUTEX_CHILD patterns along a path
+                 * in an inode tree, which are valid as soon as
+                 * I_MUTEX_PARENT -> I_MUTEX_CHILD is valid from a
+                 * parent inode to one of its children.
+                 */
+                lockdep_off();
                 mutex_lock(&child->d_inode->i_mutex);
+                lockdep_on();
 
                 configfs_detach_group(sd->s_element);
                 child->d_inode->i_flags |= S_DEAD;
 
+                lockdep_off();
                 mutex_unlock(&child->d_inode->i_mutex);
+                lockdep_on();
 
                 d_delete(child);
                 dput(child);
@@ -748,11 +760,22 @@ static int configfs_attach_item(struct config_item *parent_item,
                          * We are going to remove an inode and its dentry but
                          * the VFS may already have hit and used them. Thus,
                          * we must lock them as rmdir() would.
+                         *
+                         * Note: we hide this from lockdep since we have no way
+                         * to teach lockdep about recursive
+                         * I_MUTEX_PARENT -> I_MUTEX_CHILD patterns along a path
+                         * in an inode tree, which are valid as soon as
+                         * I_MUTEX_PARENT -> I_MUTEX_CHILD is valid from a
+                         * parent inode to one of its children.
                          */
+                        lockdep_off();
                         mutex_lock(&dentry->d_inode->i_mutex);
+                        lockdep_on();
                         configfs_remove_dir(item);
                         dentry->d_inode->i_flags |= S_DEAD;
+                        lockdep_off();
                         mutex_unlock(&dentry->d_inode->i_mutex);
+                        lockdep_on();
                         d_delete(dentry);
                 }
         }
@@ -787,14 +810,25 @@ static int configfs_attach_group(struct config_item *parent_item,
                  *
                  * We must also lock the inode to remove it safely in case of
                  * error, as rmdir() would.
+                 *
+                 * Note: we hide this from lockdep since we have no way
+                 * to teach lockdep about recursive
+                 * I_MUTEX_PARENT -> I_MUTEX_CHILD patterns along a path
+                 * in an inode tree, which are valid as soon as
+                 * I_MUTEX_PARENT -> I_MUTEX_CHILD is valid from a
+                 * parent inode to one of its children.
                  */
+                lockdep_off();
                 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
+                lockdep_on();
                 ret = populate_groups(to_config_group(item));
                 if (ret) {
                         configfs_detach_item(item);
                         dentry->d_inode->i_flags |= S_DEAD;
                 }
+                lockdep_off();
                 mutex_unlock(&dentry->d_inode->i_mutex);
+                lockdep_on();
                 if (ret)
                         d_delete(dentry);
         }
@@ -956,7 +990,17 @@ static int configfs_depend_prep(struct dentry *origin,
         BUG_ON(!origin || !sd);
 
         /* Lock this guy on the way down */
+        /*
+         * Note: we hide this from lockdep since we have no way
+         * to teach lockdep about recursive
+         * I_MUTEX_PARENT -> I_MUTEX_CHILD patterns along a path
+         * in an inode tree, which are valid as soon as
+         * I_MUTEX_PARENT -> I_MUTEX_CHILD is valid from a
+         * parent inode to one of its children.
+         */
+        lockdep_off();
         mutex_lock(&sd->s_dentry->d_inode->i_mutex);
+        lockdep_on();
         if (sd->s_element == target)  /* Boo-yah */
                 goto out;
 
@@ -970,7 +1014,9 @@ static int configfs_depend_prep(struct dentry *origin,
         }
 
         /* We looped all our children and didn't find target */
+        lockdep_off();
         mutex_unlock(&sd->s_dentry->d_inode->i_mutex);
+        lockdep_on();
         ret = -ENOENT;
 
 out:
@@ -990,11 +1036,16 @@ static void configfs_depend_rollback(struct dentry *origin,
         struct dentry *dentry = item->ci_dentry;
 
         while (dentry != origin) {
+                /* See comments in configfs_depend_prep() */
+                lockdep_off();
                 mutex_unlock(&dentry->d_inode->i_mutex);
+                lockdep_on();
                 dentry = dentry->d_parent;
         }
 
+        lockdep_off();
         mutex_unlock(&origin->d_inode->i_mutex);
+        lockdep_on();
 }
 
 int configfs_depend_item(struct configfs_subsystem *subsys,
@@ -1329,8 +1380,16 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
                         }
 
                         /* Wait until the racing operation terminates */
+                        /*
+                         * Note: we hide this from lockdep since we are locked
+                         * with subclass I_MUTEX_NORMAL from vfs_rmdir() (why
+                         * not I_MUTEX_CHILD?), and I_MUTEX_XATTR or
+                         * I_MUTEX_QUOTA are not relevant for the locked inode.
+                         */
+                        lockdep_off();
                         mutex_lock(wait_mutex);
                         mutex_unlock(wait_mutex);
+                        lockdep_on();
                 }
         } while (ret == -EAGAIN);