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-rw-r--r--fs/sysfs/dir.c207
-rw-r--r--fs/sysfs/group.c1
-rw-r--r--fs/sysfs/inode.c10
-rw-r--r--fs/sysfs/mount.c2
-rw-r--r--fs/sysfs/sysfs.h5
-rw-r--r--include/linux/kobject.h4
-rw-r--r--include/linux/sysfs.h23
-rw-r--r--lib/kobject.c42
8 files changed, 249 insertions, 45 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 9ff0449..9dcdf55 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -33,8 +33,7 @@ static struct dentry_operations sysfs_dentry_ops = {
/*
* Allocates a new sysfs_dirent and links it to the parent sysfs_dirent
*/
-static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
- void * element)
+static struct sysfs_dirent * __sysfs_new_dirent(void * element)
{
struct sysfs_dirent * sd;
@@ -46,12 +45,28 @@ static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
atomic_set(&sd->s_count, 1);
atomic_set(&sd->s_event, 1);
INIT_LIST_HEAD(&sd->s_children);
- list_add(&sd->s_sibling, &parent_sd->s_children);
+ INIT_LIST_HEAD(&sd->s_sibling);
sd->s_element = element;
return sd;
}
+static void __sysfs_list_dirent(struct sysfs_dirent *parent_sd,
+ struct sysfs_dirent *sd)
+{
+ if (sd)
+ list_add(&sd->s_sibling, &parent_sd->s_children);
+}
+
+static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent *parent_sd,
+ void * element)
+{
+ struct sysfs_dirent *sd;
+ sd = __sysfs_new_dirent(element);
+ __sysfs_list_dirent(parent_sd, sd);
+ return sd;
+}
+
/*
*
* Return -EEXIST if there is already a sysfs element with the same name for
@@ -78,14 +93,14 @@ int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
}
-int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
- void * element, umode_t mode, int type)
+static struct sysfs_dirent *
+__sysfs_make_dirent(struct dentry *dentry, void *element, mode_t mode, int type)
{
struct sysfs_dirent * sd;
- sd = sysfs_new_dirent(parent_sd, element);
+ sd = __sysfs_new_dirent(element);
if (!sd)
- return -ENOMEM;
+ goto out;
sd->s_mode = mode;
sd->s_type = type;
@@ -95,7 +110,19 @@ int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
dentry->d_op = &sysfs_dentry_ops;
}
- return 0;
+out:
+ return sd;
+}
+
+int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
+ void * element, umode_t mode, int type)
+{
+ struct sysfs_dirent *sd;
+
+ sd = __sysfs_make_dirent(dentry, element, mode, type);
+ __sysfs_list_dirent(parent_sd, sd);
+
+ return sd ? 0 : -ENOMEM;
}
static int init_dir(struct inode * inode)
@@ -166,11 +193,11 @@ int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d)
/**
* sysfs_create_dir - create a directory for an object.
- * @parent: parent parent object.
* @kobj: object we're creating directory for.
+ * @shadow_parent: parent parent object.
*/
-int sysfs_create_dir(struct kobject * kobj)
+int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent)
{
struct dentry * dentry = NULL;
struct dentry * parent;
@@ -178,7 +205,9 @@ int sysfs_create_dir(struct kobject * kobj)
BUG_ON(!kobj);
- if (kobj->parent)
+ if (shadow_parent)
+ parent = shadow_parent;
+ else if (kobj->parent)
parent = kobj->parent->dentry;
else if (sysfs_mount && sysfs_mount->mnt_sb)
parent = sysfs_mount->mnt_sb->s_root;
@@ -299,21 +328,12 @@ void sysfs_remove_subdir(struct dentry * d)
}
-/**
- * sysfs_remove_dir - remove an object's directory.
- * @kobj: object.
- *
- * The only thing special about this is that we remove any files in
- * the directory before we remove the directory, and we've inlined
- * what used to be sysfs_rmdir() below, instead of calling separately.
- */
-
-void sysfs_remove_dir(struct kobject * kobj)
+static void __sysfs_remove_dir(struct dentry *dentry)
{
- struct dentry * dentry = dget(kobj->dentry);
struct sysfs_dirent * parent_sd;
struct sysfs_dirent * sd, * tmp;
+ dget(dentry);
if (!dentry)
return;
@@ -334,32 +354,60 @@ void sysfs_remove_dir(struct kobject * kobj)
* Drop reference from dget() on entrance.
*/
dput(dentry);
+}
+
+/**
+ * sysfs_remove_dir - remove an object's directory.
+ * @kobj: object.
+ *
+ * The only thing special about this is that we remove any files in
+ * the directory before we remove the directory, and we've inlined
+ * what used to be sysfs_rmdir() below, instead of calling separately.
+ */
+
+void sysfs_remove_dir(struct kobject * kobj)
+{
+ __sysfs_remove_dir(kobj->dentry);
kobj->dentry = NULL;
}
-int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
+int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent,
+ const char *new_name)
{
int error = 0;
- struct dentry * new_dentry, * parent;
+ struct dentry * new_dentry;
- if (!strcmp(kobject_name(kobj), new_name))
- return -EINVAL;
-
- if (!kobj->parent)
- return -EINVAL;
+ if (!new_parent)
+ return -EFAULT;
down_write(&sysfs_rename_sem);
- parent = kobj->parent->dentry;
+ mutex_lock(&new_parent->d_inode->i_mutex);
- mutex_lock(&parent->d_inode->i_mutex);
-
- new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
+ new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
if (!IS_ERR(new_dentry)) {
- if (!new_dentry->d_inode) {
+ /* By allowing two different directories with the
+ * same d_parent we allow this routine to move
+ * between different shadows of the same directory
+ */
+ if (kobj->dentry->d_parent->d_inode != new_parent->d_inode)
+ return -EINVAL;
+ else if (new_dentry->d_parent->d_inode != new_parent->d_inode)
+ error = -EINVAL;
+ else if (new_dentry == kobj->dentry)
+ error = -EINVAL;
+ else if (!new_dentry->d_inode) {
error = kobject_set_name(kobj, "%s", new_name);
if (!error) {
+ struct sysfs_dirent *sd, *parent_sd;
+
d_add(new_dentry, NULL);
d_move(kobj->dentry, new_dentry);
+
+ sd = kobj->dentry->d_fsdata;
+ parent_sd = new_parent->d_fsdata;
+
+ list_del_init(&sd->s_sibling);
+ list_add(&sd->s_sibling, &parent_sd->s_children);
}
else
d_drop(new_dentry);
@@ -367,7 +415,7 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
error = -EEXIST;
dput(new_dentry);
}
- mutex_unlock(&parent->d_inode->i_mutex);
+ mutex_unlock(&new_parent->d_inode->i_mutex);
up_write(&sysfs_rename_sem);
return error;
@@ -546,6 +594,95 @@ static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
return offset;
}
+
+/**
+ * sysfs_make_shadowed_dir - Setup so a directory can be shadowed
+ * @kobj: object we're creating shadow of.
+ */
+
+int sysfs_make_shadowed_dir(struct kobject *kobj,
+ void * (*follow_link)(struct dentry *, struct nameidata *))
+{
+ struct inode *inode;
+ struct inode_operations *i_op;
+
+ inode = kobj->dentry->d_inode;
+ if (inode->i_op != &sysfs_dir_inode_operations)
+ return -EINVAL;
+
+ i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
+ if (!i_op)
+ return -ENOMEM;
+
+ memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op));
+ i_op->follow_link = follow_link;
+
+ /* Locking of inode->i_op?
+ * Since setting i_op is a single word write and they
+ * are atomic we should be ok here.
+ */
+ inode->i_op = i_op;
+ return 0;
+}
+
+/**
+ * sysfs_create_shadow_dir - create a shadow directory for an object.
+ * @kobj: object we're creating directory for.
+ *
+ * sysfs_make_shadowed_dir must already have been called on this
+ * directory.
+ */
+
+struct dentry *sysfs_create_shadow_dir(struct kobject *kobj)
+{
+ struct sysfs_dirent *sd;
+ struct dentry *parent, *dir, *shadow;
+ struct inode *inode;
+
+ dir = kobj->dentry;
+ inode = dir->d_inode;
+ parent = dir->d_parent;
+ shadow = ERR_PTR(-EINVAL);
+ if (!sysfs_is_shadowed_inode(inode))
+ goto out;
+
+ shadow = d_alloc(parent, &dir->d_name);
+ if (!shadow)
+ goto nomem;
+
+ sd = __sysfs_make_dirent(shadow, kobj, inode->i_mode, SYSFS_DIR);
+ if (!sd)
+ goto nomem;
+
+ d_instantiate(shadow, igrab(inode));
+ inc_nlink(inode);
+ inc_nlink(parent->d_inode);
+ shadow->d_op = &sysfs_dentry_ops;
+
+ dget(shadow); /* Extra count - pin the dentry in core */
+
+out:
+ return shadow;
+nomem:
+ dput(shadow);
+ shadow = ERR_PTR(-ENOMEM);
+ goto out;
+}
+
+/**
+ * sysfs_remove_shadow_dir - remove an object's directory.
+ * @shadow: dentry of shadow directory
+ *
+ * The only thing special about this is that we remove any files in
+ * the directory before we remove the directory, and we've inlined
+ * what used to be sysfs_rmdir() below, instead of calling separately.
+ */
+
+void sysfs_remove_shadow_dir(struct dentry *shadow)
+{
+ __sysfs_remove_dir(shadow);
+}
+
const struct file_operations sysfs_dir_operations = {
.open = sysfs_dir_open,
.release = sysfs_dir_close,
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 46a277b..b20951c 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -13,6 +13,7 @@
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/err.h>
+#include <linux/fs.h>
#include <asm/semaphore.h>
#include "sysfs.h"
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index dbd820f..542d2bc 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -33,6 +33,16 @@ static struct inode_operations sysfs_inode_operations ={
.setattr = sysfs_setattr,
};
+void sysfs_delete_inode(struct inode *inode)
+{
+ /* Free the shadowed directory inode operations */
+ if (sysfs_is_shadowed_inode(inode)) {
+ kfree(inode->i_op);
+ inode->i_op = NULL;
+ }
+ return generic_delete_inode(inode);
+}
+
int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
{
struct inode * inode = dentry->d_inode;
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index a1a58b9..f6a87a8 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -23,7 +23,7 @@ static void sysfs_clear_inode(struct inode *inode);
static struct super_operations sysfs_ops = {
.statfs = simple_statfs,
- .drop_inode = generic_delete_inode,
+ .drop_inode = sysfs_delete_inode,
.clear_inode = sysfs_clear_inode,
};
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 39c623f..fe1cbfd 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -2,6 +2,7 @@
extern struct vfsmount * sysfs_mount;
extern struct kmem_cache *sysfs_dir_cachep;
+extern void sysfs_delete_inode(struct inode *inode);
extern struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent *);
extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *));
@@ -112,3 +113,7 @@ static inline void sysfs_put(struct sysfs_dirent * sd)
release_sysfs_dirent(sd);
}
+static inline int sysfs_is_shadowed_inode(struct inode *inode)
+{
+ return S_ISDIR(inode->i_mode) && inode->i_op->follow_link;
+}
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index 76538fc..b850e03 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -74,9 +74,13 @@ extern void kobject_init(struct kobject *);
extern void kobject_cleanup(struct kobject *);
extern int __must_check kobject_add(struct kobject *);
+extern int __must_check kobject_shadow_add(struct kobject *, struct dentry *);
extern void kobject_del(struct kobject *);
extern int __must_check kobject_rename(struct kobject *, const char *new_name);
+extern int __must_check kobject_shadow_rename(struct kobject *kobj,
+ struct dentry *new_parent,
+ const char *new_name);
extern int __must_check kobject_move(struct kobject *, struct kobject *);
extern int __must_check kobject_register(struct kobject *);
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index eee4859..192de3a 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -16,6 +16,7 @@
struct kobject;
struct module;
+struct nameidata;
struct attribute {
const char * name;
@@ -89,13 +90,13 @@ struct sysfs_dirent {
#ifdef CONFIG_SYSFS
extern int __must_check
-sysfs_create_dir(struct kobject *);
+sysfs_create_dir(struct kobject *, struct dentry *);
extern void
sysfs_remove_dir(struct kobject *);
extern int __must_check
-sysfs_rename_dir(struct kobject *, const char *new_name);
+sysfs_rename_dir(struct kobject *, struct dentry *, const char *new_name);
extern int __must_check
sysfs_move_dir(struct kobject *, struct kobject *);
@@ -127,11 +128,17 @@ int __must_check sysfs_create_group(struct kobject *,
void sysfs_remove_group(struct kobject *, const struct attribute_group *);
void sysfs_notify(struct kobject * k, char *dir, char *attr);
+
+extern int sysfs_make_shadowed_dir(struct kobject *kobj,
+ void * (*follow_link)(struct dentry *, struct nameidata *));
+extern struct dentry *sysfs_create_shadow_dir(struct kobject *kobj);
+extern void sysfs_remove_shadow_dir(struct dentry *dir);
+
extern int __must_check sysfs_init(void);
#else /* CONFIG_SYSFS */
-static inline int sysfs_create_dir(struct kobject * k)
+static inline int sysfs_create_dir(struct kobject * k, struct dentry *shadow)
{
return 0;
}
@@ -141,7 +148,9 @@ static inline void sysfs_remove_dir(struct kobject * k)
;
}
-static inline int sysfs_rename_dir(struct kobject * k, const char *new_name)
+static inline int sysfs_rename_dir(struct kobject * k,
+ struct dentry *new_parent,
+ const char *new_name)
{
return 0;
}
@@ -205,6 +214,12 @@ static inline void sysfs_notify(struct kobject * k, char *dir, char *attr)
{
}
+static inline int sysfs_make_shadowed_dir(struct kobject *kobj,
+ void * (*follow_link)(struct dentry *, struct nameidata *))
+{
+ return 0;
+}
+
static inline int __must_check sysfs_init(void)
{
return 0;
diff --git a/lib/kobject.c b/lib/kobject.c
index 74b8dbc..c2917ffe 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -44,11 +44,11 @@ static int populate_dir(struct kobject * kobj)
return error;
}
-static int create_dir(struct kobject * kobj)
+static int create_dir(struct kobject * kobj, struct dentry *shadow_parent)
{
int error = 0;
if (kobject_name(kobj)) {
- error = sysfs_create_dir(kobj);
+ error = sysfs_create_dir(kobj, shadow_parent);
if (!error) {
if ((error = populate_dir(kobj)))
sysfs_remove_dir(kobj);
@@ -158,9 +158,10 @@ static void unlink(struct kobject * kobj)
/**
* kobject_add - add an object to the hierarchy.
* @kobj: object.
+ * @shadow_parent: sysfs directory to add to.
*/
-int kobject_add(struct kobject * kobj)
+int kobject_shadow_add(struct kobject * kobj, struct dentry *shadow_parent)
{
int error = 0;
struct kobject * parent;
@@ -191,7 +192,7 @@ int kobject_add(struct kobject * kobj)
}
kobj->parent = parent;
- error = create_dir(kobj);
+ error = create_dir(kobj, shadow_parent);
if (error) {
/* unlink does the kobject_put() for us */
unlink(kobj);
@@ -212,6 +213,15 @@ int kobject_add(struct kobject * kobj)
return error;
}
+/**
+ * kobject_add - add an object to the hierarchy.
+ * @kobj: object.
+ */
+int kobject_add(struct kobject * kobj)
+{
+ return kobject_shadow_add(kobj, NULL);
+}
+
/**
* kobject_register - initialize and add an object.
@@ -304,7 +314,29 @@ int kobject_rename(struct kobject * kobj, const char *new_name)
kobj = kobject_get(kobj);
if (!kobj)
return -EINVAL;
- error = sysfs_rename_dir(kobj, new_name);
+ if (!kobj->parent)
+ return -EINVAL;
+ error = sysfs_rename_dir(kobj, kobj->parent->dentry, new_name);
+ kobject_put(kobj);
+
+ return error;
+}
+
+/**
+ * kobject_rename - change the name of an object
+ * @kobj: object in question.
+ * @new_name: object's new name
+ */
+
+int kobject_shadow_rename(struct kobject * kobj, struct dentry *new_parent,
+ const char *new_name)
+{
+ int error = 0;
+
+ kobj = kobject_get(kobj);
+ if (!kobj)
+ return -EINVAL;
+ error = sysfs_rename_dir(kobj, new_parent, new_name);
kobject_put(kobj);
return error;
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