From 8a82472f86bf693b8e91ed56c9ca4f62fbbdcfa3 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Mon, 20 Nov 2006 17:07:51 +0100 Subject: [PATCH] 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: Cornelia Huck Acked-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 92 +++++++++++++++++++++++++++++++++++++++++ fs/sysfs/dir.c | 45 ++++++++++++++++++++ include/linux/device.h | 1 + include/linux/kobject.h | 8 ++++ include/linux/sysfs.h | 8 ++++ lib/kobject.c | 50 ++++++++++++++++++++++ lib/kobject_uevent.c | 28 +++++++++++-- 7 files changed, 228 insertions(+), 4 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 75b45a10935..e4eaf46c4d9 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -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); diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 3aa3434621c..a5782e8c7f0 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -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; diff --git a/include/linux/device.h b/include/linux/device.h index 0a0370c7418..583a341e016 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -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 diff --git a/include/linux/kobject.h b/include/linux/kobject.h index bcd9cd173c2..d1c8d28fa92 100644 --- a/include/linux/kobject.h +++ b/include/linux/kobject.h @@ -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, diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 6d5c43d31de..2129d1b6c87 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -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; diff --git a/lib/kobject.c b/lib/kobject.c index 7dd5c0e9d99..744a4b102c7 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -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. diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 7f20e7b857c..a1922765ff3 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -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 @@ exit: 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); /** -- 2.41.0