[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 <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c
index e47e3a8..cf11196 100644
--- a/drivers/usb/core/inode.c
+++ b/drivers/usb/core/inode.c
@@ -200,7 +200,7 @@
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 c784e8b..c9750d7 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1423,7 +1423,7 @@
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 @@
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 *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 @@
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 @@
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 e04a5cf..05ded9e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -543,6 +543,25 @@
};
/*
+ * 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
* with respect to the local cpu (unlike with preempt disabled),