From: Ingo Molnar Teach special (recursive) locking code to the lock validator. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton --- drivers/usb/core/inode.c | 2 +- fs/namei.c | 24 ++++++++++++------------ include/linux/fs.h | 14 ++++++++++++++ 3 files changed, 27 insertions(+), 13 deletions(-) diff -puN drivers/usb/core/inode.c~lock-validator-special-locking-i_mutex drivers/usb/core/inode.c --- devel/drivers/usb/core/inode.c~lock-validator-special-locking-i_mutex 2006-05-29 18:13:12.000000000 -0700 +++ devel-akpm/drivers/usb/core/inode.c 2006-05-29 18:13:12.000000000 -0700 @@ -201,7 +201,7 @@ static void update_sb(struct super_block if (!root) return; - mutex_lock(&root->d_inode->i_mutex); + mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_PARENT); list_for_each_entry(bus, &root->d_subdirs, d_u.d_child) { if (bus->d_inode) { diff -puN fs/namei.c~lock-validator-special-locking-i_mutex fs/namei.c --- devel/fs/namei.c~lock-validator-special-locking-i_mutex 2006-05-29 18:13:12.000000000 -0700 +++ devel-akpm/fs/namei.c 2006-05-29 18:13:12.000000000 -0700 @@ -1422,7 +1422,7 @@ struct dentry *lock_rename(struct dentry struct dentry *p; if (p1 == p2) { - mutex_lock(&p1->d_inode->i_mutex); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); return NULL; } @@ -1430,30 +1430,30 @@ struct dentry *lock_rename(struct dentry for (p = p1; p->d_parent != p; p = p->d_parent) { if (p->d_parent == p2) { - mutex_lock(&p2->d_inode->i_mutex); - mutex_lock(&p1->d_inode->i_mutex); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD); return p; } } for (p = p2; p->d_parent != p; p = p->d_parent) { if (p->d_parent == p1) { - mutex_lock(&p1->d_inode->i_mutex); - mutex_lock(&p2->d_inode->i_mutex); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); return p; } } - mutex_lock(&p1->d_inode->i_mutex); - mutex_lock(&p2->d_inode->i_mutex); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); return NULL; } void unlock_rename(struct dentry *p1, struct dentry *p2) { - mutex_unlock(&p1->d_inode->i_mutex); + mutex_unlock_non_nested(&p1->d_inode->i_mutex); if (p1 != p2) { - mutex_unlock(&p2->d_inode->i_mutex); + mutex_unlock_non_nested(&p2->d_inode->i_mutex); mutex_unlock(&p1->d_inode->i_sb->s_vfs_rename_mutex); } } @@ -1750,7 +1750,7 @@ struct dentry *lookup_create(struct name { struct dentry *dentry = ERR_PTR(-EEXIST); - mutex_lock(&nd->dentry->d_inode->i_mutex); + mutex_lock_nested(&nd->dentry->d_inode->i_mutex, I_MUTEX_PARENT); /* * Yucky last component or no last component at all? * (foo/., foo/.., /////) @@ -2007,7 +2007,7 @@ static long do_rmdir(int dfd, const char error = -EBUSY; goto exit1; } - mutex_lock(&nd.dentry->d_inode->i_mutex); + mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); error = PTR_ERR(dentry); if (!IS_ERR(dentry)) { @@ -2081,7 +2081,7 @@ static long do_unlinkat(int dfd, const c error = -EISDIR; if (nd.last_type != LAST_NORM) goto exit1; - mutex_lock(&nd.dentry->d_inode->i_mutex); + mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); error = PTR_ERR(dentry); if (!IS_ERR(dentry)) { diff -puN include/linux/fs.h~lock-validator-special-locking-i_mutex include/linux/fs.h --- devel/include/linux/fs.h~lock-validator-special-locking-i_mutex 2006-05-29 18:13:12.000000000 -0700 +++ devel-akpm/include/linux/fs.h 2006-05-29 18:13:12.000000000 -0700 @@ -558,6 +558,20 @@ struct inode { }; /* + * inode->i_mutex nesting types for the LOCKDEP validator: + * + * 0: the object of the current VFS operation + * 1: parent + * 2: child/target + */ +enum inode_i_mutex_lock_type +{ + I_MUTEX_NORMAL, + I_MUTEX_PARENT, + I_MUTEX_CHILD +}; + +/* * NOTE: in a 32bit arch with a preemptable kernel and * an UP compile the i_size_read/write must be atomic * with respect to the local cpu (unlike with preempt disabled), _