OSCL-LXR linux-6.0.1/​lib/​kobject.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * kobject.c - library routines for handling generic kernel objects
  *
  * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org>
  * Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com>
  * Copyright (c) 2006-2007 Novell Inc.
  *
  * Please see the file Documentation/core-api/kobject.rst for critical information
  * about using the kobject interface.
  */
 
 #include <linux/kobject.h>
 #include <linux/string.h>
 #include <linux/export.h>
 #include <linux/stat.h>
 #include <linux/slab.h>
 #include <linux/random.h>
 
 /**
  * kobject_namespace() - Return @kobj's namespace tag.
  * @kobj: kobject in question
  *
  * Returns namespace tag of @kobj if its parent has namespace ops enabled
  * and thus @kobj should have a namespace tag associated with it.  Returns
  * %NULL otherwise.
  */
 const void *kobject_namespace(struct kobject *kobj)
 {
     const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj);
 
     if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE)
         return NULL;
 
     return kobj->ktype->namespace(kobj);
 }
 
 /**
  * kobject_get_ownership() - Get sysfs ownership data for @kobj.
  * @kobj: kobject in question
  * @uid: kernel user ID for sysfs objects
  * @gid: kernel group ID for sysfs objects
  *
  * Returns initial uid/gid pair that should be used when creating sysfs
  * representation of given kobject. Normally used to adjust ownership of
  * objects in a container.
  */
 void kobject_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
 {
     *uid = GLOBAL_ROOT_UID;
     *gid = GLOBAL_ROOT_GID;
 
     if (kobj->ktype->get_ownership)
         kobj->ktype->get_ownership(kobj, uid, gid);
 }
 
 static int create_dir(struct kobject *kobj)
 {
     const struct kobj_type *ktype = get_ktype(kobj);
     const struct kobj_ns_type_operations *ops;
     int error;
 
     error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj));
     if (error)
         return error;
 
     if (ktype) {
         error = sysfs_create_groups(kobj, ktype->default_groups);
         if (error) {
             sysfs_remove_dir(kobj);
             return error;
         }
     }
 
     /*
      * @kobj->sd may be deleted by an ancestor going away.  Hold an
      * extra reference so that it stays until @kobj is gone.
      */
     sysfs_get(kobj->sd);
 
     /*
      * If @kobj has ns_ops, its children need to be filtered based on
      * their namespace tags.  Enable namespace support on @kobj->sd.
      */
     ops = kobj_child_ns_ops(kobj);
     if (ops) {
         BUG_ON(ops->type <= KOBJ_NS_TYPE_NONE);
         BUG_ON(ops->type >= KOBJ_NS_TYPES);
         BUG_ON(!kobj_ns_type_registered(ops->type));
 
         sysfs_enable_ns(kobj->sd);
     }
 
     return 0;
 }
 
 static int get_kobj_path_length(struct kobject *kobj)
 {
     int length = 1;
     struct kobject *parent = kobj;
 
     /* walk up the ancestors until we hit the one pointing to the
      * root.
      * Add 1 to strlen for leading '/' of each level.
      */
     do {
         if (kobject_name(parent) == NULL)
             return 0;
         length += strlen(kobject_name(parent)) + 1;
         parent = parent->parent;
     } while (parent);
     return length;
 }
 
 static void fill_kobj_path(struct kobject *kobj, char *path, int length)
 {
     struct kobject *parent;
 
     --length;
     for (parent = kobj; parent; parent = parent->parent) {
         int cur = strlen(kobject_name(parent));
         /* back up enough to print this name with '/' */
         length -= cur;
         memcpy(path + length, kobject_name(parent), cur);
         *(path + --length) = '/';
     }
 
     pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
          kobj, __func__, path);
 }
 
 /**
  * kobject_get_path() - Allocate memory and fill in the path for @kobj.
  * @kobj:   kobject in question, with which to build the path
  * @gfp_mask:   the allocation type used to allocate the path
  *
  * Return: The newly allocated memory, caller must free with kfree().
  */
 char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
 {
     char *path;
     int len;
 
     len = get_kobj_path_length(kobj);
     if (len == 0)
         return NULL;
     path = kzalloc(len, gfp_mask);
     if (!path)
         return NULL;
     fill_kobj_path(kobj, path, len);
 
     return path;
 }
 EXPORT_SYMBOL_GPL(kobject_get_path);
 
 /* add the kobject to its kset's list */
 static void kobj_kset_join(struct kobject *kobj)
 {
     if (!kobj->kset)
         return;
 
     kset_get(kobj->kset);
     spin_lock(&kobj->kset->list_lock);
     list_add_tail(&kobj->entry, &kobj->kset->list);
     spin_unlock(&kobj->kset->list_lock);
 }
 
 /* remove the kobject from its kset's list */
 static void kobj_kset_leave(struct kobject *kobj)
 {
     if (!kobj->kset)
         return;
 
     spin_lock(&kobj->kset->list_lock);
     list_del_init(&kobj->entry);
     spin_unlock(&kobj->kset->list_lock);
     kset_put(kobj->kset);
 }
 
 static void kobject_init_internal(struct kobject *kobj)
 {
     if (!kobj)
         return;
     kref_init(&kobj->kref);
     INIT_LIST_HEAD(&kobj->entry);
     kobj->state_in_sysfs = 0;
     kobj->state_add_uevent_sent = 0;
     kobj->state_remove_uevent_sent = 0;
     kobj->state_initialized = 1;
 }
 
 
 static int kobject_add_internal(struct kobject *kobj)
 {
     int error = 0;
     struct kobject *parent;
 
     if (!kobj)
         return -ENOENT;
 
     if (!kobj->name || !kobj->name[0]) {
         WARN(1,
              "kobject: (%p): attempted to be registered with empty name!\n",
              kobj);
         return -EINVAL;
     }
 
     parent = kobject_get(kobj->parent);
 
     /* join kset if set, use it as parent if we do not already have one */
     if (kobj->kset) {
         if (!parent)
             parent = kobject_get(&kobj->kset->kobj);
         kobj_kset_join(kobj);
         kobj->parent = parent;
     }
 
     pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
          kobject_name(kobj), kobj, __func__,
          parent ? kobject_name(parent) : "<NULL>",
          kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>");
 
     error = create_dir(kobj);
     if (error) {
         kobj_kset_leave(kobj);
         kobject_put(parent);
         kobj->parent = NULL;
 
         /* be noisy on error issues */
         if (error == -EEXIST)
             pr_err("%s failed for %s with -EEXIST, don't try to register things with the same name in the same directory.\n",
                    __func__, kobject_name(kobj));
         else
             pr_err("%s failed for %s (error: %d parent: %s)\n",
                    __func__, kobject_name(kobj), error,
                    parent ? kobject_name(parent) : "'none'");
     } else
         kobj->state_in_sysfs = 1;
 
     return error;
 }
 
 /**
  * kobject_set_name_vargs() - Set the name of a kobject.
  * @kobj: struct kobject to set the name of
  * @fmt: format string used to build the name
  * @vargs: vargs to format the string.
  */
 int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
                   va_list vargs)
 {
     const char *s;
 
     if (kobj->name && !fmt)
         return 0;
 
     s = kvasprintf_const(GFP_KERNEL, fmt, vargs);
     if (!s)
         return -ENOMEM;
 
     /*
      * ewww... some of these buggers have '/' in the name ... If
      * that's the case, we need to make sure we have an actual
      * allocated copy to modify, since kvasprintf_const may have
      * returned something from .rodata.
      */
     if (strchr(s, '/')) {
         char *t;
 
         t = kstrdup(s, GFP_KERNEL);
         kfree_const(s);
         if (!t)
             return -ENOMEM;
         strreplace(t, '/', '!');
         s = t;
     }
     kfree_const(kobj->name);
     kobj->name = s;
 
     return 0;
 }
 
 /**
  * kobject_set_name() - Set the name of a kobject.
  * @kobj: struct kobject to set the name of
  * @fmt: format string used to build the name
  *
  * This sets the name of the kobject.  If you have already added the
  * kobject to the system, you must call kobject_rename() in order to
  * change the name of the kobject.
  */
 int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
 {
     va_list vargs;
     int retval;
 
     va_start(vargs, fmt);
     retval = kobject_set_name_vargs(kobj, fmt, vargs);
     va_end(vargs);
 
     return retval;
 }
 EXPORT_SYMBOL(kobject_set_name);
 
 /**
  * kobject_init() - Initialize a kobject structure.
  * @kobj: pointer to the kobject to initialize
  * @ktype: pointer to the ktype for this kobject.
  *
  * This function will properly initialize a kobject such that it can then
  * be passed to the kobject_add() call.
  *
  * After this function is called, the kobject MUST be cleaned up by a call
  * to kobject_put(), not by a call to kfree directly to ensure that all of
  * the memory is cleaned up properly.
  */
 void kobject_init(struct kobject *kobj, const struct kobj_type *ktype)
 {
     char *err_str;
 
     if (!kobj) {
         err_str = "invalid kobject pointer!";
         goto error;
     }
     if (!ktype) {
         err_str = "must have a ktype to be initialized properly!\n";
         goto error;
     }
     if (kobj->state_initialized) {
         /* do not error out as sometimes we can recover */
         pr_err("kobject (%p): tried to init an initialized object, something is seriously wrong.\n",
                kobj);
         dump_stack();
     }
 
     kobject_init_internal(kobj);
     kobj->ktype = ktype;
     return;
 
 error:
     pr_err("kobject (%p): %s\n", kobj, err_str);
     dump_stack();
 }
 EXPORT_SYMBOL(kobject_init);
 
 static __printf(3, 0) int kobject_add_varg(struct kobject *kobj,
                        struct kobject *parent,
                        const char *fmt, va_list vargs)
 {
     int retval;
 
     retval = kobject_set_name_vargs(kobj, fmt, vargs);
     if (retval) {
         pr_err("kobject: can not set name properly!\n");
         return retval;
     }
     kobj->parent = parent;
     return kobject_add_internal(kobj);
 }
 
 /**
  * kobject_add() - The main kobject add function.
  * @kobj: the kobject to add
  * @parent: pointer to the parent of the kobject.
  * @fmt: format to name the kobject with.
  *
  * The kobject name is set and added to the kobject hierarchy in this
  * function.
  *
  * If @parent is set, then the parent of the @kobj will be set to it.
  * If @parent is NULL, then the parent of the @kobj will be set to the
  * kobject associated with the kset assigned to this kobject.  If no kset
  * is assigned to the kobject, then the kobject will be located in the
  * root of the sysfs tree.
  *
  * Note, no "add" uevent will be created with this call, the caller should set
  * up all of the necessary sysfs files for the object and then call
  * kobject_uevent() with the UEVENT_ADD parameter to ensure that
  * userspace is properly notified of this kobject's creation.
  *
  * Return: If this function returns an error, kobject_put() must be
  *         called to properly clean up the memory associated with the
  *         object.  Under no instance should the kobject that is passed
  *         to this function be directly freed with a call to kfree(),
  *         that can leak memory.
  *
  *         If this function returns success, kobject_put() must also be called
  *         in order to properly clean up the memory associated with the object.
  *
  *         In short, once this function is called, kobject_put() MUST be called
  *         when the use of the object is finished in order to properly free
  *         everything.
  */
 int kobject_add(struct kobject *kobj, struct kobject *parent,
         const char *fmt, ...)
 {
     va_list args;
     int retval;
 
     if (!kobj)
         return -EINVAL;
 
     if (!kobj->state_initialized) {
         pr_err("kobject '%s' (%p): tried to add an uninitialized object, something is seriously wrong.\n",
                kobject_name(kobj), kobj);
         dump_stack();
         return -EINVAL;
     }
     va_start(args, fmt);
     retval = kobject_add_varg(kobj, parent, fmt, args);
     va_end(args);
 
     return retval;
 }
 EXPORT_SYMBOL(kobject_add);
 
 /**
  * kobject_init_and_add() - Initialize a kobject structure and add it to
  *                          the kobject hierarchy.
  * @kobj: pointer to the kobject to initialize
  * @ktype: pointer to the ktype for this kobject.
  * @parent: pointer to the parent of this kobject.
  * @fmt: the name of the kobject.
  *
  * This function combines the call to kobject_init() and kobject_add().
  *
  * If this function returns an error, kobject_put() must be called to
  * properly clean up the memory associated with the object.  This is the
  * same type of error handling after a call to kobject_add() and kobject
  * lifetime rules are the same here.
  */
 int kobject_init_and_add(struct kobject *kobj, const struct kobj_type *ktype,
              struct kobject *parent, const char *fmt, ...)
 {
     va_list args;
     int retval;
 
     kobject_init(kobj, ktype);
 
     va_start(args, fmt);
     retval = kobject_add_varg(kobj, parent, fmt, args);
     va_end(args);
 
     return retval;
 }
 EXPORT_SYMBOL_GPL(kobject_init_and_add);
 
 /**
  * kobject_rename() - Change the name of an object.
  * @kobj: object in question.
  * @new_name: object's new name
  *
  * It is the responsibility of the caller to provide mutual
  * exclusion between two different calls of kobject_rename
  * on the same kobject and to ensure that new_name is valid and
  * won't conflict with other kobjects.
  */
 int kobject_rename(struct kobject *kobj, const char *new_name)
 {
     int error = 0;
     const char *devpath = NULL;
     const char *dup_name = NULL, *name;
     char *devpath_string = NULL;
     char *envp[2];
 
     kobj = kobject_get(kobj);
     if (!kobj)
         return -EINVAL;
     if (!kobj->parent) {
         kobject_put(kobj);
         return -EINVAL;
     }
 
     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;
 
     name = dup_name = kstrdup_const(new_name, GFP_KERNEL);
     if (!name) {
         error = -ENOMEM;
         goto out;
     }
 
     error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj));
     if (error)
         goto out;
 
     /* Install the new kobject name */
     dup_name = kobj->name;
     kobj->name = name;
 
     /* This function is mostly/only used for network interface.
      * Some hotplug package track interfaces by their name and
      * therefore want to know when the name is changed by the user. */
     kobject_uevent_env(kobj, KOBJ_MOVE, envp);
 
 out:
     kfree_const(dup_name);
     kfree(devpath_string);
     kfree(devpath);
     kobject_put(kobj);
 
     return error;
 }
 EXPORT_SYMBOL_GPL(kobject_rename);
 
 /**
  * kobject_move() - Move object to another parent.
  * @kobj: object in question.
  * @new_parent: object's new parent (can be NULL)
  */
 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) {
         if (kobj->kset)
             new_parent = kobject_get(&kobj->kset->kobj);
     }
 
     /* 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_ns(kobj, new_parent, kobject_namespace(kobj));
     if (error)
         goto out;
     old_parent = kobj->parent;
     kobj->parent = new_parent;
     new_parent = NULL;
     kobject_put(old_parent);
     kobject_uevent_env(kobj, KOBJ_MOVE, envp);
 out:
     kobject_put(new_parent);
     kobject_put(kobj);
     kfree(devpath_string);
     kfree(devpath);
     return error;
 }
 EXPORT_SYMBOL_GPL(kobject_move);
 
 static void __kobject_del(struct kobject *kobj)
 {
     struct kernfs_node *sd;
     const struct kobj_type *ktype;
 
     sd = kobj->sd;
     ktype = get_ktype(kobj);
 
     if (ktype)
         sysfs_remove_groups(kobj, ktype->default_groups);
 
     /* send "remove" if the caller did not do it but sent "add" */
     if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
         pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
              kobject_name(kobj), kobj);
         kobject_uevent(kobj, KOBJ_REMOVE);
     }
 
     sysfs_remove_dir(kobj);
     sysfs_put(sd);
 
     kobj->state_in_sysfs = 0;
     kobj_kset_leave(kobj);
     kobj->parent = NULL;
 }
 
 /**
  * kobject_del() - Unlink kobject from hierarchy.
  * @kobj: object.
  *
  * This is the function that should be called to delete an object
  * successfully added via kobject_add().
  */
 void kobject_del(struct kobject *kobj)
 {
     struct kobject *parent;
 
     if (!kobj)
         return;
 
     parent = kobj->parent;
     __kobject_del(kobj);
     kobject_put(parent);
 }
 EXPORT_SYMBOL(kobject_del);
 
 /**
  * kobject_get() - Increment refcount for object.
  * @kobj: object.
  */
 struct kobject *kobject_get(struct kobject *kobj)
 {
     if (kobj) {
         if (!kobj->state_initialized)
             WARN(1, KERN_WARNING
                 "kobject: '%s' (%p): is not initialized, yet kobject_get() is being called.\n",
                  kobject_name(kobj), kobj);
         kref_get(&kobj->kref);
     }
     return kobj;
 }
 EXPORT_SYMBOL(kobject_get);
 
 struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj)
 {
     if (!kobj)
         return NULL;
     if (!kref_get_unless_zero(&kobj->kref))
         kobj = NULL;
     return kobj;
 }
 EXPORT_SYMBOL(kobject_get_unless_zero);
 
 /*
  * kobject_cleanup - free kobject resources.
  * @kobj: object to cleanup
  */
 static void kobject_cleanup(struct kobject *kobj)
 {
     struct kobject *parent = kobj->parent;
     const struct kobj_type *t = get_ktype(kobj);
     const char *name = kobj->name;
 
     pr_debug("kobject: '%s' (%p): %s, parent %p\n",
          kobject_name(kobj), kobj, __func__, kobj->parent);
 
     if (t && !t->release)
         pr_debug("kobject: '%s' (%p): does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",
              kobject_name(kobj), kobj);
 
     /* remove from sysfs if the caller did not do it */
     if (kobj->state_in_sysfs) {
         pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
              kobject_name(kobj), kobj);
         __kobject_del(kobj);
     } else {
         /* avoid dropping the parent reference unnecessarily */
         parent = NULL;
     }
 
     if (t && t->release) {
         pr_debug("kobject: '%s' (%p): calling ktype release\n",
              kobject_name(kobj), kobj);
         t->release(kobj);
     }
 
     /* free name if we allocated it */
     if (name) {
         pr_debug("kobject: '%s': free name\n", name);
         kfree_const(name);
     }
 
     kobject_put(parent);
 }
 
 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
 static void kobject_delayed_cleanup(struct work_struct *work)
 {
     kobject_cleanup(container_of(to_delayed_work(work),
                      struct kobject, release));
 }
 #endif
 
 static void kobject_release(struct kref *kref)
 {
     struct kobject *kobj = container_of(kref, struct kobject, kref);
 #ifdef CONFIG_DEBUG_KOBJECT_RELEASE
     unsigned long delay = HZ + HZ * (get_random_int() & 0x3);
     pr_info("kobject: '%s' (%p): %s, parent %p (delayed %ld)\n",
          kobject_name(kobj), kobj, __func__, kobj->parent, delay);
     INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup);
 
     schedule_delayed_work(&kobj->release, delay);
 #else
     kobject_cleanup(kobj);
 #endif
 }
 
 /**
  * kobject_put() - Decrement refcount for object.
  * @kobj: object.
  *
  * Decrement the refcount, and if 0, call kobject_cleanup().
  */
 void kobject_put(struct kobject *kobj)
 {
     if (kobj) {
         if (!kobj->state_initialized)
             WARN(1, KERN_WARNING
                 "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called.\n",
                  kobject_name(kobj), kobj);
         kref_put(&kobj->kref, kobject_release);
     }
 }
 EXPORT_SYMBOL(kobject_put);
 
 static void dynamic_kobj_release(struct kobject *kobj)
 {
     pr_debug("kobject: (%p): %s\n", kobj, __func__);
     kfree(kobj);
 }
 
 static struct kobj_type dynamic_kobj_ktype = {
     .release    = dynamic_kobj_release,
     .sysfs_ops  = &kobj_sysfs_ops,
 };
 
 /**
  * kobject_create() - Create a struct kobject dynamically.
  *
  * This function creates a kobject structure dynamically and sets it up
  * to be a "dynamic" kobject with a default release function set up.
  *
  * If the kobject was not able to be created, NULL will be returned.
  * The kobject structure returned from here must be cleaned up with a
  * call to kobject_put() and not kfree(), as kobject_init() has
  * already been called on this structure.
  */
 static struct kobject *kobject_create(void)
 {
     struct kobject *kobj;
 
     kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
     if (!kobj)
         return NULL;
 
     kobject_init(kobj, &dynamic_kobj_ktype);
     return kobj;
 }
 
 /**
  * kobject_create_and_add() - Create a struct kobject dynamically and
  *                            register it with sysfs.
  * @name: the name for the kobject
  * @parent: the parent kobject of this kobject, if any.
  *
  * This function creates a kobject structure dynamically and registers it
  * with sysfs.  When you are finished with this structure, call
  * kobject_put() and the structure will be dynamically freed when
  * it is no longer being used.
  *
  * If the kobject was not able to be created, NULL will be returned.
  */
 struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
 {
     struct kobject *kobj;
     int retval;
 
     kobj = kobject_create();
     if (!kobj)
         return NULL;
 
     retval = kobject_add(kobj, parent, "%s", name);
     if (retval) {
         pr_warn("%s: kobject_add error: %d\n", __func__, retval);
         kobject_put(kobj);
         kobj = NULL;
     }
     return kobj;
 }
 EXPORT_SYMBOL_GPL(kobject_create_and_add);
 
 /**
  * kset_init() - Initialize a kset for use.
  * @k: kset
  */
 void kset_init(struct kset *k)
 {
     kobject_init_internal(&k->kobj);
     INIT_LIST_HEAD(&k->list);
     spin_lock_init(&k->list_lock);
 }
 
 /* default kobject attribute operations */
 static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
                   char *buf)
 {
     struct kobj_attribute *kattr;
     ssize_t ret = -EIO;
 
     kattr = container_of(attr, struct kobj_attribute, attr);
     if (kattr->show)
         ret = kattr->show(kobj, kattr, buf);
     return ret;
 }
 
 static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
                    const char *buf, size_t count)
 {
     struct kobj_attribute *kattr;
     ssize_t ret = -EIO;
 
     kattr = container_of(attr, struct kobj_attribute, attr);
     if (kattr->store)
         ret = kattr->store(kobj, kattr, buf, count);
     return ret;
 }
 
 const struct sysfs_ops kobj_sysfs_ops = {
     .show   = kobj_attr_show,
     .store  = kobj_attr_store,
 };
 EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
 
 /**
  * kset_register() - Initialize and add a kset.
  * @k: kset.
  */
 int kset_register(struct kset *k)
 {
     int err;
 
     if (!k)
         return -EINVAL;
 
     kset_init(k);
     err = kobject_add_internal(&k->kobj);
     if (err)
         return err;
     kobject_uevent(&k->kobj, KOBJ_ADD);
     return 0;
 }
 EXPORT_SYMBOL(kset_register);
 
 /**
  * kset_unregister() - Remove a kset.
  * @k: kset.
  */
 void kset_unregister(struct kset *k)
 {
     if (!k)
         return;
     kobject_del(&k->kobj);
     kobject_put(&k->kobj);
 }
 EXPORT_SYMBOL(kset_unregister);
 
 /**
  * kset_find_obj() - Search for object in kset.
  * @kset: kset we're looking in.
  * @name: object's name.
  *
  * Lock kset via @kset->subsys, and iterate over @kset->list,
  * looking for a matching kobject. If matching object is found
  * take a reference and return the object.
  */
 struct kobject *kset_find_obj(struct kset *kset, const char *name)
 {
     struct kobject *k;
     struct kobject *ret = NULL;
 
     spin_lock(&kset->list_lock);
 
     list_for_each_entry(k, &kset->list, entry) {
         if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
             ret = kobject_get_unless_zero(k);
             break;
         }
     }
 
     spin_unlock(&kset->list_lock);
     return ret;
 }
 EXPORT_SYMBOL_GPL(kset_find_obj);
 
 static void kset_release(struct kobject *kobj)
 {
     struct kset *kset = container_of(kobj, struct kset, kobj);
     pr_debug("kobject: '%s' (%p): %s\n",
          kobject_name(kobj), kobj, __func__);
     kfree(kset);
 }
 
 static void kset_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
 {
     if (kobj->parent)
         kobject_get_ownership(kobj->parent, uid, gid);
 }
 
 static struct kobj_type kset_ktype = {
     .sysfs_ops  = &kobj_sysfs_ops,
     .release    = kset_release,
     .get_ownership  = kset_get_ownership,
 };
 
 /**
  * kset_create() - Create a struct kset dynamically.
  *
  * @name: the name for the kset
  * @uevent_ops: a struct kset_uevent_ops for the kset
  * @parent_kobj: the parent kobject of this kset, if any.
  *
  * This function creates a kset structure dynamically.  This structure can
  * then be registered with the system and show up in sysfs with a call to
  * kset_register().  When you are finished with this structure, if
  * kset_register() has been called, call kset_unregister() and the
  * structure will be dynamically freed when it is no longer being used.
  *
  * If the kset was not able to be created, NULL will be returned.
  */
 static struct kset *kset_create(const char *name,
                 const struct kset_uevent_ops *uevent_ops,
                 struct kobject *parent_kobj)
 {
     struct kset *kset;
     int retval;
 
     kset = kzalloc(sizeof(*kset), GFP_KERNEL);
     if (!kset)
         return NULL;
     retval = kobject_set_name(&kset->kobj, "%s", name);
     if (retval) {
         kfree(kset);
         return NULL;
     }
     kset->uevent_ops = uevent_ops;
     kset->kobj.parent = parent_kobj;
 
     /*
      * The kobject of this kset will have a type of kset_ktype and belong to
      * no kset itself.  That way we can properly free it when it is
      * finished being used.
      */
     kset->kobj.ktype = &kset_ktype;
     kset->kobj.kset = NULL;
 
     return kset;
 }
 
 /**
  * kset_create_and_add() - Create a struct kset dynamically and add it to sysfs.
  *
  * @name: the name for the kset
  * @uevent_ops: a struct kset_uevent_ops for the kset
  * @parent_kobj: the parent kobject of this kset, if any.
  *
  * This function creates a kset structure dynamically and registers it
  * with sysfs.  When you are finished with this structure, call
  * kset_unregister() and the structure will be dynamically freed when it
  * is no longer being used.
  *
  * If the kset was not able to be created, NULL will be returned.
  */
 struct kset *kset_create_and_add(const char *name,
                  const struct kset_uevent_ops *uevent_ops,
                  struct kobject *parent_kobj)
 {
     struct kset *kset;
     int error;
 
     kset = kset_create(name, uevent_ops, parent_kobj);
     if (!kset)
         return NULL;
     error = kset_register(kset);
     if (error) {
         kfree(kset);
         return NULL;
     }
     return kset;
 }
 EXPORT_SYMBOL_GPL(kset_create_and_add);
 
 
 static DEFINE_SPINLOCK(kobj_ns_type_lock);
 static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
 
 int kobj_ns_type_register(const struct kobj_ns_type_operations *ops)
 {
     enum kobj_ns_type type = ops->type;
     int error;
 
     spin_lock(&kobj_ns_type_lock);
 
     error = -EINVAL;
     if (type >= KOBJ_NS_TYPES)
         goto out;
 
     error = -EINVAL;
     if (type <= KOBJ_NS_TYPE_NONE)
         goto out;
 
     error = -EBUSY;
     if (kobj_ns_ops_tbl[type])
         goto out;
 
     error = 0;
     kobj_ns_ops_tbl[type] = ops;
 
 out:
     spin_unlock(&kobj_ns_type_lock);
     return error;
 }
 
 int kobj_ns_type_registered(enum kobj_ns_type type)
 {
     int registered = 0;
 
     spin_lock(&kobj_ns_type_lock);
     if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES))
         registered = kobj_ns_ops_tbl[type] != NULL;
     spin_unlock(&kobj_ns_type_lock);
 
     return registered;
 }
 
 const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
 {
     const struct kobj_ns_type_operations *ops = NULL;
 
     if (parent && parent->ktype && parent->ktype->child_ns_type)
         ops = parent->ktype->child_ns_type(parent);
 
     return ops;
 }
 
 const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
 {
     return kobj_child_ns_ops(kobj->parent);
 }
 
 bool kobj_ns_current_may_mount(enum kobj_ns_type type)
 {
     bool may_mount = true;
 
     spin_lock(&kobj_ns_type_lock);
     if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
         kobj_ns_ops_tbl[type])
         may_mount = kobj_ns_ops_tbl[type]->current_may_mount();
     spin_unlock(&kobj_ns_type_lock);
 
     return may_mount;
 }
 
 void *kobj_ns_grab_current(enum kobj_ns_type type)
 {
     void *ns = NULL;
 
     spin_lock(&kobj_ns_type_lock);
     if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
         kobj_ns_ops_tbl[type])
         ns = kobj_ns_ops_tbl[type]->grab_current_ns();
     spin_unlock(&kobj_ns_type_lock);
 
     return ns;
 }
 EXPORT_SYMBOL_GPL(kobj_ns_grab_current);
 
 const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
 {
     const void *ns = NULL;
 
     spin_lock(&kobj_ns_type_lock);
     if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
         kobj_ns_ops_tbl[type])
         ns = kobj_ns_ops_tbl[type]->netlink_ns(sk);
     spin_unlock(&kobj_ns_type_lock);
 
     return ns;
 }
 
 const void *kobj_ns_initial(enum kobj_ns_type type)
 {
     const void *ns = NULL;
 
     spin_lock(&kobj_ns_type_lock);
     if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
         kobj_ns_ops_tbl[type])
         ns = kobj_ns_ops_tbl[type]->initial_ns();
     spin_unlock(&kobj_ns_type_lock);
 
     return ns;
 }
 
 void kobj_ns_drop(enum kobj_ns_type type, void *ns)
 {
     spin_lock(&kobj_ns_type_lock);
     if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) &&
         kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns)
         kobj_ns_ops_tbl[type]->drop_ns(ns);
     spin_unlock(&kobj_ns_type_lock);
 }
 EXPORT_SYMBOL_GPL(kobj_ns_drop);

This page was automatically generated by the 2.1.0 LXR engine. The LXR team