sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation
Currently, sysfs_dirent active_ref lockdep annotation uses
attribute->[s]key as the lockdep key, which forces
kernfs_create_file_ns() to assume that sysfs_dirent->priv is pointing
to a struct attribute which may not be true for non-sysfs users. This
patch restructures the lockdep annotation such that
* kernfs_ops contains lockdep_key which is used by default for files
created kernfs_create_file_ns().
* kernfs_create_file_ns_key() is introduced which takes an extra @key
argument. The created file will use the specified key for
active_ref lockdep annotation. If NULL is specified, lockdep for
the file is disabled.
* sysfs_add_file_mode_ns() is updated to use
kernfs_create_file_ns_key() with the appropriate key from the
attribute or NULL if ignore_lockdep is set.
This makes the lockdep annotation properly contained in kernfs while
allowing sysfs to cleanly keep its current behavior. This patch
doesn't introduce any behavior differences.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index f20796e..105d09d 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -11,6 +11,7 @@
#include <linux/err.h>
#include <linux/list.h>
#include <linux/mutex.h>
+#include <linux/lockdep.h>
struct file;
struct iattr;
@@ -62,6 +63,10 @@
loff_t off);
int (*mmap)(struct sysfs_open_file *of, struct vm_area_struct *vma);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lock_class_key lockdep_key;
+#endif
};
#ifdef CONFIG_SYSFS
@@ -69,11 +74,12 @@
struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
const char *name, void *priv,
const void *ns);
-struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent,
- const char *name,
- umode_t mode, loff_t size,
- const struct kernfs_ops *ops,
- void *priv, const void *ns);
+struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent,
+ const char *name,
+ umode_t mode, loff_t size,
+ const struct kernfs_ops *ops,
+ void *priv, const void *ns,
+ struct lock_class_key *key);
struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,
const char *name,
struct sysfs_dirent *target);
@@ -94,9 +100,10 @@
{ return ERR_PTR(-ENOSYS); }
static inline struct sysfs_dirent *
-kernfs_create_file_ns(struct sysfs_dirent *parent, const char *name,
- umode_t mode, loff_t size, const struct kernfs_ops *ops,
- void *priv, const void *ns)
+kernfs_create_file_ns_key(struct sysfs_dirent *parent, const char *name,
+ umode_t mode, loff_t size,
+ const struct kernfs_ops *ops, void *priv,
+ const void *ns, struct lock_class_key *key)
{ return ERR_PTR(-ENOSYS); }
static inline struct sysfs_dirent *
@@ -132,6 +139,20 @@
}
static inline struct sysfs_dirent *
+kernfs_create_file_ns(struct sysfs_dirent *parent, const char *name,
+ umode_t mode, loff_t size, const struct kernfs_ops *ops,
+ void *priv, const void *ns)
+{
+ struct lock_class_key *key = NULL;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ key = (struct lock_class_key *)&ops->lockdep_key;
+#endif
+ return kernfs_create_file_ns_key(parent, name, mode, size, ops, priv,
+ ns, key);
+}
+
+static inline struct sysfs_dirent *
kernfs_create_file(struct sysfs_dirent *parent, const char *name, umode_t mode,
loff_t size, const struct kernfs_ops *ops, void *priv)
{