From f2eace23e924bd3f05aedea4fc505eb5508d2d93 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:25:05 -0700 Subject: [PATCH] [PATCH] lockdep: annotate i_mutex 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 Signed-off-by: Linus Torvalds --- drivers/usb/core/inode.c | 2 +- fs/namei.c | 20 ++++++++++---------- include/linux/fs.h | 19 +++++++++++++++++++ 3 files changed, 30 insertions(+), 11 deletions(-) diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c index e47e3a8ed6e4..cf11196e012d 100644 --- a/drivers/usb/core/inode.c +++ b/drivers/usb/core/inode.c @@ -200,7 +200,7 @@ static void update_sb(struct super_block *sb) 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 --git a/fs/namei.c b/fs/namei.c index c784e8bb57a3..c9750d755aff 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1423,7 +1423,7 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) 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; } @@ -1431,22 +1431,22 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) 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; } @@ -1751,7 +1751,7 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir) { 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/.., /////) @@ -2008,7 +2008,7 @@ static long do_rmdir(int dfd, const char __user *pathname) 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)) { @@ -2082,7 +2082,7 @@ static long do_unlinkat(int dfd, const char __user *pathname) 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 --git a/include/linux/fs.h b/include/linux/fs.h index e04a5cfe874f..05ded9e76b23 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -542,6 +542,25 @@ struct inode { #endif }; +/* + * inode->i_mutex nesting subclasses for the lock validator: + * + * 0: the object of the current VFS operation + * 1: parent + * 2: child/target + * 3: quota file + * + * The locking order between these classes is + * parent -> child -> normal -> quota + */ +enum inode_i_mutex_lock_class +{ + I_MUTEX_NORMAL, + I_MUTEX_PARENT, + I_MUTEX_CHILD, + I_MUTEX_QUOTA +}; + /* * NOTE: in a 32bit arch with a preemptable kernel and * an UP compile the i_size_read/write must be atomic -- 2.20.1