diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index e00189aebbf4..3eff92450fd5 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -108,6 +108,12 @@ int debugfs_file_get(struct dentry *dentry) kfree(fsd); fsd = READ_ONCE(dentry->d_fsdata); } +#ifdef CONFIG_LOCKDEP + fsd->lock_name = kasprintf(GFP_KERNEL, "debugfs:%pd", dentry); + lockdep_register_key(&fsd->key); + lockdep_init_map(&fsd->lockdep_map, fsd->lock_name ?: "debugfs", + &fsd->key, 0); +#endif } /* @@ -124,6 +130,8 @@ int debugfs_file_get(struct dentry *dentry) if (!refcount_inc_not_zero(&fsd->active_users)) return -EIO; + lock_map_acquire_read(&fsd->lockdep_map); + return 0; } EXPORT_SYMBOL_GPL(debugfs_file_get); @@ -141,6 +149,8 @@ void debugfs_file_put(struct dentry *dentry) { struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata); + lock_map_release(&fsd->lockdep_map); + if (refcount_dec_and_test(&fsd->active_users)) complete(&fsd->active_users_drained); } diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index dcde4199a625..80f4f000dcc1 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -241,6 +241,14 @@ static void debugfs_release_dentry(struct dentry *dentry) if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) return; + /* check it wasn't a dir (no fsdata) or automount (no real_fops) */ + if (fsd && fsd->real_fops) { +#ifdef CONFIG_LOCKDEP + lockdep_unregister_key(&fsd->key); + kfree(fsd->lock_name); +#endif + } + kfree(fsd); } @@ -744,6 +752,10 @@ static void __debugfs_file_removed(struct dentry *dentry) fsd = READ_ONCE(dentry->d_fsdata); if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) return; + + lock_map_acquire(&fsd->lockdep_map); + lock_map_release(&fsd->lockdep_map); + if (!refcount_dec_and_test(&fsd->active_users)) wait_for_completion(&fsd->active_users_drained); } diff --git a/fs/debugfs/internal.h b/fs/debugfs/internal.h index f7c489b5a368..c7d61cfc97d2 100644 --- a/fs/debugfs/internal.h +++ b/fs/debugfs/internal.h @@ -7,6 +7,7 @@ #ifndef _DEBUGFS_INTERNAL_H_ #define _DEBUGFS_INTERNAL_H_ +#include struct file_operations; @@ -23,6 +24,11 @@ struct debugfs_fsdata { struct { refcount_t active_users; struct completion active_users_drained; +#ifdef CONFIG_LOCKDEP + struct lockdep_map lockdep_map; + struct lock_class_key key; + char *lock_name; +#endif }; }; };