提交 8a82472f 编写于 作者: C Cornelia Huck 提交者: Greg Kroah-Hartman

driver core: Introduce device_move(): move a device to a new parent.

Provide a function device_move() to move a device to a new parent device. Add
auxilliary functions kobject_move() and sysfs_move_dir().
kobject_move() generates a new uevent of type KOBJ_MOVE, containing the
previous path (DEVPATH_OLD) in addition to the usual values. For this, a new
interface kobject_uevent_env() is created that allows to add further
environmental data to the uevent at the kobject layer.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
上级 af9e0765
......@@ -955,3 +955,95 @@ int device_rename(struct device *dev, char *new_name)
return error;
}
static int device_move_class_links(struct device *dev,
struct device *old_parent,
struct device *new_parent)
{
#ifdef CONFIG_SYSFS_DEPRECATED
int error;
char *class_name;
class_name = make_class_name(dev->class->name, &dev->kobj);
if (!class_name) {
error = PTR_ERR(class_name);
class_name = NULL;
goto out;
}
if (old_parent) {
sysfs_remove_link(&dev->kobj, "device");
sysfs_remove_link(&old_parent->kobj, class_name);
}
error = sysfs_create_link(&dev->kobj, &new_parent->kobj, "device");
if (error)
goto out;
error = sysfs_create_link(&new_parent->kobj, &dev->kobj, class_name);
if (error)
sysfs_remove_link(&dev->kobj, "device");
out:
kfree(class_name);
return error;
#else
return 0;
#endif
}
/**
* device_move - moves a device to a new parent
* @dev: the pointer to the struct device to be moved
* @new_parent: the new parent of the device
*/
int device_move(struct device *dev, struct device *new_parent)
{
int error;
struct device *old_parent;
dev = get_device(dev);
if (!dev)
return -EINVAL;
if (!device_is_registered(dev)) {
error = -EINVAL;
goto out;
}
new_parent = get_device(new_parent);
if (!new_parent) {
error = -EINVAL;
goto out;
}
pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
new_parent->bus_id);
error = kobject_move(&dev->kobj, &new_parent->kobj);
if (error) {
put_device(new_parent);
goto out;
}
old_parent = dev->parent;
dev->parent = new_parent;
if (old_parent)
klist_del(&dev->knode_parent);
klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
if (!dev->class)
goto out_put;
error = device_move_class_links(dev, old_parent, new_parent);
if (error) {
/* We ignore errors on cleanup since we're hosed anyway... */
device_move_class_links(dev, new_parent, old_parent);
if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
klist_del(&dev->knode_parent);
if (old_parent)
klist_add_tail(&dev->knode_parent,
&old_parent->klist_children);
}
put_device(new_parent);
goto out;
}
out_put:
put_device(old_parent);
out:
put_device(dev);
return error;
}
EXPORT_SYMBOL_GPL(device_move);
......@@ -372,6 +372,51 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
return error;
}
int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent)
{
struct dentry *old_parent_dentry, *new_parent_dentry, *new_dentry;
struct sysfs_dirent *new_parent_sd, *sd;
int error;
if (!new_parent)
return -EINVAL;
old_parent_dentry = kobj->parent ?
kobj->parent->dentry : sysfs_mount->mnt_sb->s_root;
new_parent_dentry = new_parent->dentry;
again:
mutex_lock(&old_parent_dentry->d_inode->i_mutex);
if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) {
mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
goto again;
}
new_parent_sd = new_parent_dentry->d_fsdata;
sd = kobj->dentry->d_fsdata;
new_dentry = lookup_one_len(kobj->name, new_parent_dentry,
strlen(kobj->name));
if (IS_ERR(new_dentry)) {
error = PTR_ERR(new_dentry);
goto out;
} else
error = 0;
d_add(new_dentry, NULL);
d_move(kobj->dentry, new_dentry);
dput(new_dentry);
/* Remove from old parent's list and insert into new parent's list. */
list_del_init(&sd->s_sibling);
list_add(&sd->s_sibling, &new_parent_sd->s_children);
out:
mutex_unlock(&new_parent_dentry->d_inode->i_mutex);
mutex_unlock(&old_parent_dentry->d_inode->i_mutex);
return error;
}
static int sysfs_dir_open(struct inode *inode, struct file *file)
{
struct dentry * dentry = file->f_dentry;
......
......@@ -424,6 +424,7 @@ extern int device_for_each_child(struct device *, void *,
extern struct device *device_find_child(struct device *, void *data,
int (*match)(struct device *, void *));
extern int device_rename(struct device *dev, char *new_name);
extern int device_move(struct device *dev, struct device *new_parent);
/*
* Manual binding of a device to driver. See drivers/base/bus.c
......
......@@ -47,6 +47,7 @@ enum kobject_action {
KOBJ_UMOUNT = (__force kobject_action_t) 0x05, /* umount event for block devices (broken) */
KOBJ_OFFLINE = (__force kobject_action_t) 0x06, /* device offline */
KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device online */
KOBJ_MOVE = (__force kobject_action_t) 0x08, /* device move */
};
struct kobject {
......@@ -76,6 +77,7 @@ extern int __must_check kobject_add(struct kobject *);
extern void kobject_del(struct kobject *);
extern int __must_check kobject_rename(struct kobject *, const char *new_name);
extern int __must_check kobject_move(struct kobject *, struct kobject *);
extern int __must_check kobject_register(struct kobject *);
extern void kobject_unregister(struct kobject *);
......@@ -264,6 +266,8 @@ extern int __must_check subsys_create_file(struct subsystem * ,
#if defined(CONFIG_HOTPLUG)
void kobject_uevent(struct kobject *kobj, enum kobject_action action);
void kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
char *envp[]);
int add_uevent_var(char **envp, int num_envp, int *cur_index,
char *buffer, int buffer_size, int *cur_len,
......@@ -271,6 +275,10 @@ int add_uevent_var(char **envp, int num_envp, int *cur_index,
__attribute__((format (printf, 7, 8)));
#else
static inline void kobject_uevent(struct kobject *kobj, enum kobject_action action) { }
static inline void kobject_uevent_env(struct kobject *kobj,
enum kobject_action action,
char *envp[])
{ }
static inline int add_uevent_var(char **envp, int num_envp, int *cur_index,
char *buffer, int buffer_size, int *cur_len,
......
......@@ -96,6 +96,9 @@ sysfs_remove_dir(struct kobject *);
extern int __must_check
sysfs_rename_dir(struct kobject *, const char *new_name);
extern int __must_check
sysfs_move_dir(struct kobject *, struct kobject *);
extern int __must_check
sysfs_create_file(struct kobject *, const struct attribute *);
......@@ -142,6 +145,11 @@ static inline int sysfs_rename_dir(struct kobject * k, const char *new_name)
return 0;
}
static inline int sysfs_move_dir(struct kobject * k, struct kobject * new_parent)
{
return 0;
}
static inline int sysfs_create_file(struct kobject * k, const struct attribute * a)
{
return 0;
......
......@@ -310,6 +310,56 @@ int kobject_rename(struct kobject * kobj, const char *new_name)
return error;
}
/**
* kobject_move - move object to another parent
* @kobj: object in question.
* @new_parent: object's new parent
*/
int kobject_move(struct kobject *kobj, struct kobject *new_parent)
{
int error;
struct kobject *old_parent;
const char *devpath = NULL;
char *devpath_string = NULL;
char *envp[2];
kobj = kobject_get(kobj);
if (!kobj)
return -EINVAL;
new_parent = kobject_get(new_parent);
if (!new_parent) {
error = -EINVAL;
goto out;
}
/* old object path */
devpath = kobject_get_path(kobj, GFP_KERNEL);
if (!devpath) {
error = -ENOMEM;
goto out;
}
devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
if (!devpath_string) {
error = -ENOMEM;
goto out;
}
sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
envp[0] = devpath_string;
envp[1] = NULL;
error = sysfs_move_dir(kobj, new_parent);
if (error)
goto out;
old_parent = kobj->parent;
kobj->parent = new_parent;
kobject_put(old_parent);
kobject_uevent_env(kobj, KOBJ_MOVE, envp);
out:
kobject_put(kobj);
kfree(devpath_string);
kfree(devpath);
return error;
}
/**
* kobject_del - unlink kobject from hierarchy.
* @kobj: object.
......
......@@ -50,18 +50,22 @@ static char *action_to_string(enum kobject_action action)
return "offline";
case KOBJ_ONLINE:
return "online";
case KOBJ_MOVE:
return "move";
default:
return NULL;
}
}
/**
* kobject_uevent - notify userspace by ending an uevent
* kobject_uevent_env - send an uevent with environmental data
*
* @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
* @action: action that is happening (usually KOBJ_MOVE)
* @kobj: struct kobject that the action is happening to
* @envp_ext: pointer to environmental data
*/
void kobject_uevent(struct kobject *kobj, enum kobject_action action)
void kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
char *envp_ext[])
{
char **envp;
char *buffer;
......@@ -76,6 +80,7 @@ void kobject_uevent(struct kobject *kobj, enum kobject_action action)
char *seq_buff;
int i = 0;
int retval;
int j;
pr_debug("%s\n", __FUNCTION__);
......@@ -134,7 +139,8 @@ void kobject_uevent(struct kobject *kobj, enum kobject_action action)
scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1;
envp [i++] = scratch;
scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1;
for (j = 0; envp_ext && envp_ext[j]; j++)
envp[i++] = envp_ext[j];
/* just reserve the space, overwrite it after kset call has returned */
envp[i++] = seq_buff = scratch;
scratch += strlen("SEQNUM=18446744073709551616") + 1;
......@@ -200,6 +206,20 @@ void kobject_uevent(struct kobject *kobj, enum kobject_action action)
kfree(envp);
return;
}
EXPORT_SYMBOL_GPL(kobject_uevent_env);
/**
* kobject_uevent - notify userspace by ending an uevent
*
* @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
* @kobj: struct kobject that the action is happening to
*/
void kobject_uevent(struct kobject *kobj, enum kobject_action action)
{
kobject_uevent_env(kobj, action, NULL);
}
EXPORT_SYMBOL_GPL(kobject_uevent);
/**
......
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