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sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation

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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>
This commit is contained in:
Tejun Heo
2013-11-28 14:54:29 -05:00
committed by Greg Kroah-Hartman
parent 2b25a62901
commit 517e64f578
4 changed files with 56 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
include/linux/kernfs.h
View File

@@ -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 @@ struct kernfs_ops {
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 kernfs_ops {
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 @@ kernfs_create_dir_ns(struct sysfs_dirent *parent, const char *name, void *priv,
{ 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 *
@@ -131,6 +138,20 @@ kernfs_create_dir(struct sysfs_dirent *parent, const char *name, void *priv)
return kernfs_create_dir_ns(parent, name, priv, NULL);
}
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)