[PATCH 38/39] sysfs, kernfs: make sysfs_dirent definition public

Tejun Heo
2013-11-03T09:54:18Z

sysfs_dirent includes some information which should be available to
kernfs users - the type, name and parent pointer. This patch moves
sysfs_dirent definition from kernfs/kernfs-internal.h to
include/linux/kernfs.h so that kernfs users can access them.

The type part of flags is exported as enum kernfs_node_type and
sysfs_type() is moved to include/linux/kernfs.h and updated to return
the enum type. sysfs_dirent->s_parent and ->s_name are marked
explicitly as public.

This patch doesn't introduce any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/kernfs/kernfs-internal.h | 76 +---------------------------------------
include/linux/kernfs.h | 84 ++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 84 insertions(+), 76 deletions(-)

diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 933b7f8..ace0b81 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -13,88 +13,19 @@

#include <linux/lockdep.h>
#include <linux/fs.h>
-#include <linux/rbtree.h>
#include <linux/mutex.h>

#include <linux/kernfs.h>

-struct sysfs_open_dirent;
-
-/* type-specific structures for sysfs_dirent->s_* union members */
-struct sysfs_elem_dir {
- unsigned long subdirs;
- /* children rbtree starts here and goes through sd->s_rb */
- struct rb_root children;
-
- /*
- * The kernfs hierarchy this directory belongs to. This fits
- * better directly in sysfs_dirent but is here to save space.
- */
- struct kernfs_root *root;
-};
-
-struct sysfs_elem_symlink {
- struct sysfs_dirent *target_sd;
-};
-
-struct sysfs_elem_attr {
- const struct kernfs_ops *ops;
- struct sysfs_open_dirent *open;
- loff_t size;
-};
-
struct sysfs_inode_attrs {
struct iattr ia_iattr;
void *ia_secdata;
u32 ia_secdata_len;
};

-/*
- * sysfs_dirent - the building block of sysfs hierarchy. Each and
- * every sysfs node is represented by single sysfs_dirent.
- *
- * As long as s_count reference is held, the sysfs_dirent itself is
- * accessible. Dereferencing s_elem or any other outer entity
- * requires s_active reference.
- */
-struct sysfs_dirent {
- atomic_t s_count;
- atomic_t s_active;
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- struct lockdep_map dep_map;
-#endif
- struct sysfs_dirent *s_parent;
- const char *s_name;
-
- struct rb_node s_rb;
-
- union {
- struct completion *completion;
- struct sysfs_dirent *removed_list;
- } u;
-
- const void *s_ns; /* namespace tag */
- unsigned int s_hash; /* ns + name hash */
- union {
- struct sysfs_elem_dir s_dir;
- struct sysfs_elem_symlink s_symlink;
- struct sysfs_elem_attr s_attr;
- };
-
- void *priv;
-
- unsigned short s_flags;
- umode_t s_mode;
- unsigned int s_ino;
- struct sysfs_inode_attrs *s_iattr;
-};
-
#define SD_DEACTIVATED_BIAS INT_MIN

-#define SYSFS_TYPE_MASK 0x000f
-#define SYSFS_DIR 0x0001
-#define SYSFS_KOBJ_ATTR 0x0002
-#define SYSFS_KOBJ_LINK 0x0004
+/* SYSFS_TYPE_MASK and types are defined in include/linux/kernfs.h */
#define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK)
#define SYSFS_ACTIVE_REF SYSFS_KOBJ_ATTR

@@ -105,11 +36,6 @@ struct sysfs_dirent {
#define SYSFS_FLAG_HAS_MMAP 0x0080
#define SYSFS_FLAG_LOCKDEP 0x0100

-static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
-{
- return sd->s_flags & SYSFS_TYPE_MASK;
-}
-
/**
* kernfs_root - find out the kernfs_root a sysfs_dirent belongs to
* @sd: sysfs_dirent of interest
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 403cbc5..3084977 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -13,6 +13,9 @@
#include <linux/mutex.h>
#include <linux/idr.h>
#include <linux/lockdep.h>
+#include <linux/rbtree.h>
+#include <linux/atomic.h>
+#include <linux/completion.h>

struct file;
struct iattr;
@@ -21,7 +24,81 @@ struct vm_area_struct;
struct super_block;
struct file_system_type;

-struct sysfs_dirent;
+struct sysfs_open_dirent;
+struct sysfs_inode_attrs;
+
+#define SYSFS_TYPE_MASK 0x000f
+
+enum kernfs_node_type {
+ SYSFS_DIR = 0x0001,
+ SYSFS_KOBJ_ATTR = 0x0002,
+ SYSFS_KOBJ_LINK = 0x0004,
+};
+
+/* type-specific structures for sysfs_dirent->s_* union members */
+struct sysfs_elem_dir {
+ unsigned long subdirs;
+ /* children rbtree starts here and goes through sd->s_rb */
+ struct rb_root children;
+
+ /*
+ * The kernfs hierarchy this directory belongs to. This fits
+ * better directly in sysfs_dirent but is here to save space.
+ */
+ struct kernfs_root *root;
+};
+
+struct sysfs_elem_symlink {
+ struct sysfs_dirent *target_sd;
+};
+
+struct sysfs_elem_attr {
+ const struct kernfs_ops *ops;
+ struct sysfs_open_dirent *open;
+ loff_t size;
+};
+
+/*
+ * sysfs_dirent - the building block of sysfs hierarchy. Each and every
+ * sysfs node is represented by single sysfs_dirent. Most fields are
+ * private to kernfs and shouldn't be accessed directly by kernfs users.
+ *
+ * As long as s_count reference is held, the sysfs_dirent itself is
+ * accessible. Dereferencing s_elem or any other outer entity
+ * requires s_active reference.
+ */
+struct sysfs_dirent {
+ atomic_t s_count;
+ atomic_t s_active;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+ /* the following two fields are published */
+ struct sysfs_dirent *s_parent;
+ const char *s_name;
+
+ struct rb_node s_rb;
+
+ union {
+ struct completion *completion;
+ struct sysfs_dirent *removed_list;
+ } u;
+
+ const void *s_ns; /* namespace tag */
+ unsigned int s_hash; /* ns + name hash */
+ union {
+ struct sysfs_elem_dir s_dir;
+ struct sysfs_elem_symlink s_symlink;
+ struct sysfs_elem_attr s_attr;
+ };
+
+ void *priv;
+
+ unsigned short s_flags;
+ umode_t s_mode;
+ unsigned int s_ino;
+ struct sysfs_inode_attrs *s_iattr;
+};

struct kernfs_root {
/* published fields */
@@ -80,6 +157,11 @@ struct kernfs_ops {
#endif
};

+static inline enum kernfs_node_type sysfs_type(struct sysfs_dirent *sd)
+{
+ return sd->s_flags & SYSFS_TYPE_MASK;
+}
+
#ifdef CONFIG_SYSFS

struct sysfs_dirent *kernfs_find_and_get_ns(struct sysfs_dirent *parent,
--
1.8.3.1