lib/kobject.c

   1 /*
   2  * kobject.c - library routines for handling generic kernel objects
   3  *
   4  * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org>
   5  * Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com>
   6  * Copyright (c) 2006-2007 Novell Inc.
   7  *
   8  * This file is released under the GPLv2.
   9  *
  10  *
  11  * Please see the file Documentation/kobject.txt for critical information
  12  * about using the kobject interface.
  13  */
  14
  15 #include <linux/kobject.h>
  16 #include <linux/string.h>
  17 #include <linux/module.h>
  18 #include <linux/stat.h>
  19 #include <linux/slab.h>
  20
  21 /**
  22  *      populate_dir - populate directory with attributes.
  23  *      @kobj:  object we're working on.
  24  *
  25  *      Most subsystems have a set of default attributes that
  26  *      are associated with an object that registers with them.
  27  *      This is a helper called during object registration that
  28  *      loops through the default attributes of the subsystem
  29  *      and creates attributes files for them in sysfs.
  30  *
  31  */
  32
  33 static int populate_dir(struct kobject * kobj)
  34 {
  35         struct kobj_type * t = get_ktype(kobj);
  36         struct attribute * attr;
  37         int error = 0;
  38         int i;
  39
  40         if (t && t->default_attrs) {
  41                 for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) {
  42                         if ((error = sysfs_create_file(kobj,attr)))
  43                                 break;
  44                 }
  45         }
  46         return error;
  47 }
  48
  49 static int create_dir(struct kobject * kobj)
  50 {
  51         int error = 0;
  52         if (kobject_name(kobj)) {
  53                 error = sysfs_create_dir(kobj);
  54                 if (!error) {
  55                         if ((error = populate_dir(kobj)))
  56                                 sysfs_remove_dir(kobj);
  57                 }
  58         }
  59         return error;
  60 }
  61
  62 static inline struct kobject * to_kobj(struct list_head * entry)
  63 {
  64         return container_of(entry,struct kobject,entry);
  65 }
  66
  67 static int get_kobj_path_length(struct kobject *kobj)
  68 {
  69         int length = 1;
  70         struct kobject * parent = kobj;
  71
  72         /* walk up the ancestors until we hit the one pointing to the
  73          * root.
  74          * Add 1 to strlen for leading '/' of each level.
  75          */
  76         do {
  77                 if (kobject_name(parent) == NULL)
  78                         return 0;
  79                 length += strlen(kobject_name(parent)) + 1;
  80                 parent = parent->parent;
  81         } while (parent);
  82         return length;
  83 }
  84
  85 static void fill_kobj_path(struct kobject *kobj, char *path, int length)
  86 {
  87         struct kobject * parent;
  88
  89         --length;
  90         for (parent = kobj; parent; parent = parent->parent) {
  91                 int cur = strlen(kobject_name(parent));
  92                 /* back up enough to print this name with '/' */
  93                 length -= cur;
  94                 strncpy (path + length, kobject_name(parent), cur);
  95                 *(path + --length) = '/';
  96         }
  97
  98         pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
  99                  kobj, __FUNCTION__,path);
 100 }
 101
 102 /**
 103  * kobject_get_path - generate and return the path associated with a given kobj and kset pair.
 104  *
 105  * @kobj:       kobject in question, with which to build the path
 106  * @gfp_mask:   the allocation type used to allocate the path
 107  *
 108  * The result must be freed by the caller with kfree().
 109  */
 110 char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
 111 {
 112         char *path;
 113         int len;
 114
 115         len = get_kobj_path_length(kobj);
 116         if (len == 0)
 117                 return NULL;
 118         path = kzalloc(len, gfp_mask);
 119         if (!path)
 120                 return NULL;
 121         fill_kobj_path(kobj, path, len);
 122
 123         return path;
 124 }
 125 EXPORT_SYMBOL_GPL(kobject_get_path);
 126
 127 /**
 128  *      kobject_init - initialize object.
 129  *      @kobj:  object in question.
 130  */
 131 void kobject_init(struct kobject * kobj)
 132 {
 133         if (!kobj)
 134                 return;
 135         kref_init(&kobj->kref);
 136         INIT_LIST_HEAD(&kobj->entry);
 137 }
 138
 139
 140 /**
 141  *      unlink - remove kobject from kset list.
 142  *      @kobj:  kobject.
 143  *
 144  *      Remove the kobject from the kset list and decrement
 145  *      its parent's refcount.
 146  *      This is separated out, so we can use it in both
 147  *      kobject_del() and kobject_add() on error.
 148  */
 149
 150 static void unlink(struct kobject * kobj)
 151 {
 152         struct kobject *parent = kobj->parent;
 153
 154         if (kobj->kset) {
 155                 spin_lock(&kobj->kset->list_lock);
 156                 list_del_init(&kobj->entry);
 157                 spin_unlock(&kobj->kset->list_lock);
 158         }
 159         kobj->parent = NULL;
 160         kobject_put(kobj);
 161         kobject_put(parent);
 162 }
 163
 164 /**
 165  *      kobject_add - add an object to the hierarchy.
 166  *      @kobj:  object.
 167  */
 168
 169 int kobject_add(struct kobject * kobj)
 170 {
 171         int error = 0;
 172         struct kobject * parent;
 173
 174         if (!(kobj = kobject_get(kobj)))
 175                 return -ENOENT;
 176         if (!kobj->k_name)
 177                 kobject_set_name(kobj, "NO_NAME");
 178         if (!*kobj->k_name) {
 179                 pr_debug("kobject (%p) attempted to be registered with no "
 180                          "name!\n", kobj);
 181                 WARN_ON(1);
 182                 kobject_put(kobj);
 183                 return -EINVAL;
 184         }
 185         parent = kobject_get(kobj->parent);
 186
 187         pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
 188                  kobject_name(kobj), kobj, __FUNCTION__,
 189                  parent ? kobject_name(parent) : "<NULL>",
 190                  kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>" );
 191
 192         if (kobj->kset) {
 193                 kobj->kset = kset_get(kobj->kset);
 194
 195                 if (!parent) {
 196                         parent = kobject_get(&kobj->kset->kobj);
 197                         /*
 198                          * If the kset is our parent, get a second
 199                          * reference, we drop both the kset and the
 200                          * parent ref on cleanup
 201                          */
 202                         kobject_get(parent);
 203                 }
 204
 205                 spin_lock(&kobj->kset->list_lock);
 206                 list_add_tail(&kobj->entry, &kobj->kset->list);
 207                 spin_unlock(&kobj->kset->list_lock);
 208                 kobj->parent = parent;
 209         }
 210
 211         error = create_dir(kobj);
 212         if (error) {
 213                 /* unlink does the kobject_put() for us */
 214                 unlink(kobj);
 215
 216                 /* be noisy on error issues */
 217                 if (error == -EEXIST)
 218                         printk(KERN_ERR "kobject_add failed for %s with "
 219                                "-EEXIST, don't try to register things with "
 220                                "the same name in the same directory.\n",
 221                                kobject_name(kobj));
 222                 else
 223                         printk(KERN_ERR "kobject_add failed for %s (%d)\n",
 224                                kobject_name(kobj), error);
 225                 dump_stack();
 226         }
 227
 228         return error;
 229 }
 230
 231 /**
 232  *      kobject_register - initialize and add an object.
 233  *      @kobj:  object in question.
 234  */
 235
 236 int kobject_register(struct kobject * kobj)
 237 {
 238         int error = -EINVAL;
 239         if (kobj) {
 240                 kobject_init(kobj);
 241                 error = kobject_add(kobj);
 242                 if (!error)
 243                         kobject_uevent(kobj, KOBJ_ADD);
 244         }
 245         return error;
 246 }
 247
 248 /**
 249  * kobject_set_name_vargs - Set the name of an kobject
 250  * @kobj: struct kobject to set the name of
 251  * @fmt: format string used to build the name
 252  * @vargs: vargs to format the string.
 253  */
 254 static int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
 255                                   va_list vargs)
 256 {
 257         va_list aq;
 258         char *name;
 259
 260         va_copy(aq, vargs);
 261         name = kvasprintf(GFP_KERNEL, fmt, vargs);
 262         va_end(aq);
 263
 264         if (!name)
 265                 return -ENOMEM;
 266
 267         /* Free the old name, if necessary. */
 268         kfree(kobj->k_name);
 269
 270         /* Now, set the new name */
 271         kobj->k_name = name;
 272
 273         return 0;
 274 }
 275
 276 /**
 277  * kobject_set_name - Set the name of a kobject
 278  * @kobj: struct kobject to set the name of
 279  * @fmt: format string used to build the name
 280  *
 281  * This sets the name of the kobject.  If you have already added the
 282  * kobject to the system, you must call kobject_rename() in order to
 283  * change the name of the kobject.
 284  */
 285 int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
 286 {
 287         va_list args;
 288         int retval;
 289
 290         va_start(args, fmt);
 291         retval = kobject_set_name_vargs(kobj, fmt, args);
 292         va_end(args);
 293
 294         return retval;
 295 }
 296 EXPORT_SYMBOL(kobject_set_name);
 297
 298 /**
 299  * kobject_init_ng - initialize a kobject structure
 300  * @kobj: pointer to the kobject to initialize
 301  * @ktype: pointer to the ktype for this kobject.
 302  *
 303  * This function will properly initialize a kobject such that it can then
 304  * be passed to the kobject_add() call.
 305  *
 306  * After this function is called, the kobject MUST be cleaned up by a call
 307  * to kobject_put(), not by a call to kfree directly to ensure that all of
 308  * the memory is cleaned up properly.
 309  */
 310 void kobject_init_ng(struct kobject *kobj, struct kobj_type *ktype)
 311 {
 312         char *err_str;
 313
 314         if (!kobj) {
 315                 err_str = "invalid kobject pointer!";
 316                 goto error;
 317         }
 318         if (!ktype) {
 319                 err_str = "must have a ktype to be initialized properly!\n";
 320                 goto error;
 321         }
 322         if (atomic_read(&kobj->kref.refcount)) {
 323                 /* do not error out as sometimes we can recover */
 324                 printk(KERN_ERR "kobject: reference count is already set, "
 325                        "something is seriously wrong.\n");
 326                 dump_stack();
 327         }
 328
 329         kref_init(&kobj->kref);
 330         INIT_LIST_HEAD(&kobj->entry);
 331         kobj->ktype = ktype;
 332         return;
 333
 334 error:
 335         printk(KERN_ERR "kobject: %s\n", err_str);
 336         dump_stack();
 337 }
 338 EXPORT_SYMBOL(kobject_init_ng);
 339
 340 static int kobject_add_varg(struct kobject *kobj, struct kobject *parent,
 341                             const char *fmt, va_list vargs)
 342 {
 343         va_list aq;
 344         int retval;
 345
 346         va_copy(aq, vargs);
 347         retval = kobject_set_name_vargs(kobj, fmt, aq);
 348         va_end(aq);
 349         if (retval) {
 350                 printk(KERN_ERR "kobject: can not set name properly!\n");
 351                 return retval;
 352         }
 353         kobj->parent = parent;
 354         return kobject_add(kobj);
 355 }
 356
 357 /**
 358  * kobject_add_ng - the main kobject add function
 359  * @kobj: the kobject to add
 360  * @parent: pointer to the parent of the kobject.
 361  * @fmt: format to name the kobject with.
 362  *
 363  * The kobject name is set and added to the kobject hierarchy in this
 364  * function.
 365  *
 366  * If @parent is set, then the parent of the @kobj will be set to it.
 367  * If @parent is NULL, then the parent of the @kobj will be set to the
 368  * kobject associted with the kset assigned to this kobject.  If no kset
 369  * is assigned to the kobject, then the kobject will be located in the
 370  * root of the sysfs tree.
 371  *
 372  * If this function returns an error, kobject_put() must be called to
 373  * properly clean up the memory associated with the object.
 374  *
 375  * If the function is successful, the only way to properly clean up the
 376  * memory is with a call to kobject_del(), in which case, a call to
 377  * kobject_put() is not necessary (kobject_del() does the final
 378  * kobject_put() to call the release function in the ktype's release
 379  * pointer.)
 380  *
 381  * Under no instance should the kobject that is passed to this function
 382  * be directly freed with a call to kfree(), that can leak memory.
 383  *
 384  * Note, no uevent will be created with this call, the caller should set
 385  * up all of the necessary sysfs files for the object and then call
 386  * kobject_uevent() with the UEVENT_ADD parameter to ensure that
 387  * userspace is properly notified of this kobject's creation.
 388  */
 389 int kobject_add_ng(struct kobject *kobj, struct kobject *parent,
 390                    const char *fmt, ...)
 391 {
 392         va_list args;
 393         int retval;
 394
 395         if (!kobj)
 396                 return -EINVAL;
 397
 398         va_start(args, fmt);
 399         retval = kobject_add_varg(kobj, parent, fmt, args);
 400         va_end(args);
 401
 402         return retval;
 403 }
 404 EXPORT_SYMBOL(kobject_add_ng);
 405
 406 /**
 407  * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
 408  * @kobj: pointer to the kobject to initialize
 409  * @ktype: pointer to the ktype for this kobject.
 410  * @parent: pointer to the parent of this kobject.
 411  * @fmt: the name of the kobject.
 412  *
 413  * This function combines the call to kobject_init_ng() and
 414  * kobject_add_ng().  The same type of error handling after a call to
 415  * kobject_add_ng() and kobject lifetime rules are the same here.
 416  */
 417 int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
 418                          struct kobject *parent, const char *fmt, ...)
 419 {
 420         va_list args;
 421         int retval;
 422
 423         kobject_init_ng(kobj, ktype);
 424
 425         va_start(args, fmt);
 426         retval = kobject_add_varg(kobj, parent, fmt, args);
 427         va_end(args);
 428
 429         return retval;
 430 }
 431 EXPORT_SYMBOL_GPL(kobject_init_and_add);
 432
 433 /**
 434  *      kobject_rename - change the name of an object
 435  *      @kobj:  object in question.
 436  *      @new_name: object's new name
 437  */
 438
 439 int kobject_rename(struct kobject * kobj, const char *new_name)
 440 {
 441         int error = 0;
 442         const char *devpath = NULL;
 443         char *devpath_string = NULL;
 444         char *envp[2];
 445
 446         kobj = kobject_get(kobj);
 447         if (!kobj)
 448                 return -EINVAL;
 449         if (!kobj->parent)
 450                 return -EINVAL;
 451
 452         /* see if this name is already in use */
 453         if (kobj->kset) {
 454                 struct kobject *temp_kobj;
 455                 temp_kobj = kset_find_obj(kobj->kset, new_name);
 456                 if (temp_kobj) {
 457                         printk(KERN_WARNING "kobject '%s' cannot be renamed "
 458                                "to '%s' as '%s' is already in existence.\n",
 459                                kobject_name(kobj), new_name, new_name);
 460                         kobject_put(temp_kobj);
 461                         return -EINVAL;
 462                 }
 463         }
 464
 465         devpath = kobject_get_path(kobj, GFP_KERNEL);
 466         if (!devpath) {
 467                 error = -ENOMEM;
 468                 goto out;
 469         }
 470         devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
 471         if (!devpath_string) {
 472                 error = -ENOMEM;
 473                 goto out;
 474         }
 475         sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
 476         envp[0] = devpath_string;
 477         envp[1] = NULL;
 478
 479         error = sysfs_rename_dir(kobj, new_name);
 480
 481         /* This function is mostly/only used for network interface.
 482          * Some hotplug package track interfaces by their name and
 483          * therefore want to know when the name is changed by the user. */
 484         if (!error)
 485                 kobject_uevent_env(kobj, KOBJ_MOVE, envp);
 486
 487 out:
 488         kfree(devpath_string);
 489         kfree(devpath);
 490         kobject_put(kobj);
 491
 492         return error;
 493 }
 494
 495 /**
 496  *      kobject_move - move object to another parent
 497  *      @kobj:  object in question.
 498  *      @new_parent: object's new parent (can be NULL)
 499  */
 500
 501 int kobject_move(struct kobject *kobj, struct kobject *new_parent)
 502 {
 503         int error;
 504         struct kobject *old_parent;
 505         const char *devpath = NULL;
 506         char *devpath_string = NULL;
 507         char *envp[2];
 508
 509         kobj = kobject_get(kobj);
 510         if (!kobj)
 511                 return -EINVAL;
 512         new_parent = kobject_get(new_parent);
 513         if (!new_parent) {
 514                 if (kobj->kset)
 515                         new_parent = kobject_get(&kobj->kset->kobj);
 516         }
 517         /* old object path */
 518         devpath = kobject_get_path(kobj, GFP_KERNEL);
 519         if (!devpath) {
 520                 error = -ENOMEM;
 521                 goto out;
 522         }
 523         devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL);
 524         if (!devpath_string) {
 525                 error = -ENOMEM;
 526                 goto out;
 527         }
 528         sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
 529         envp[0] = devpath_string;
 530         envp[1] = NULL;
 531         error = sysfs_move_dir(kobj, new_parent);
 532         if (error)
 533                 goto out;
 534         old_parent = kobj->parent;
 535         kobj->parent = new_parent;
 536         new_parent = NULL;
 537         kobject_put(old_parent);
 538         kobject_uevent_env(kobj, KOBJ_MOVE, envp);
 539 out:
 540         kobject_put(new_parent);
 541         kobject_put(kobj);
 542         kfree(devpath_string);
 543         kfree(devpath);
 544         return error;
 545 }
 546
 547 /**
 548  *      kobject_del - unlink kobject from hierarchy.
 549  *      @kobj:  object.
 550  */
 551
 552 void kobject_del(struct kobject * kobj)
 553 {
 554         if (!kobj)
 555                 return;
 556         sysfs_remove_dir(kobj);
 557         unlink(kobj);
 558 }
 559
 560 /**
 561  *      kobject_unregister - remove object from hierarchy and decrement refcount.
 562  *      @kobj:  object going away.
 563  */
 564
 565 void kobject_unregister(struct kobject * kobj)
 566 {
 567         if (!kobj)
 568                 return;
 569         pr_debug("kobject: '%s' (%p): %s\n",
 570                  kobject_name(kobj), kobj, __FUNCTION__);
 571         kobject_uevent(kobj, KOBJ_REMOVE);
 572         kobject_del(kobj);
 573         kobject_put(kobj);
 574 }
 575
 576 /**
 577  *      kobject_get - increment refcount for object.
 578  *      @kobj:  object.
 579  */
 580
 581 struct kobject * kobject_get(struct kobject * kobj)
 582 {
 583         if (kobj)
 584                 kref_get(&kobj->kref);
 585         return kobj;
 586 }
 587
 588 /*
 589  * kobject_cleanup - free kobject resources.
 590  * @kobj: object to cleanup
 591  */
 592 static void kobject_cleanup(struct kobject *kobj)
 593 {
 594         struct kobj_type * t = get_ktype(kobj);
 595         struct kset * s = kobj->kset;
 596         const char *name = kobj->k_name;
 597
 598         pr_debug("kobject: '%s' (%p): %s\n",
 599                  kobject_name(kobj), kobj, __FUNCTION__);
 600         if (t && t->release) {
 601                 t->release(kobj);
 602                 /* If we have a release function, we can guess that this was
 603                  * not a statically allocated kobject, so we should be safe to
 604                  * free the name */
 605                 kfree(name);
 606         }
 607         if (s)
 608                 kset_put(s);
 609 }
 610
 611 static void kobject_release(struct kref *kref)
 612 {
 613         kobject_cleanup(container_of(kref, struct kobject, kref));
 614 }
 615
 616 /**
 617  *      kobject_put - decrement refcount for object.
 618  *      @kobj:  object.
 619  *
 620  *      Decrement the refcount, and if 0, call kobject_cleanup().
 621  */
 622 void kobject_put(struct kobject * kobj)
 623 {
 624         if (kobj)
 625                 kref_put(&kobj->kref, kobject_release);
 626 }
 627
 628 static void dynamic_kobj_release(struct kobject *kobj)
 629 {
 630         pr_debug("kobject: '%s' (%p): %s\n",
 631                  kobject_name(kobj), kobj, __FUNCTION__);
 632         kfree(kobj);
 633 }
 634
 635 static struct kobj_type dynamic_kobj_ktype = {
 636         .release        = dynamic_kobj_release,
 637         .sysfs_ops      = &kobj_sysfs_ops,
 638 };
 639
 640 /**
 641  * kobject_create - create a struct kobject dynamically
 642  *
 643  * This function creates a kobject structure dynamically and sets it up
 644  * to be a "dynamic" kobject with a default release function set up.
 645  *
 646  * If the kobject was not able to be created, NULL will be returned.
 647  * The kobject structure returned from here must be cleaned up with a
 648  * call to kobject_put() and not kfree(), as kobject_init_ng() has
 649  * already been called on this structure.
 650  */
 651 struct kobject *kobject_create(void)
 652 {
 653         struct kobject *kobj;
 654
 655         kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
 656         if (!kobj)
 657                 return NULL;
 658
 659         kobject_init_ng(kobj, &dynamic_kobj_ktype);
 660         return kobj;
 661 }
 662
 663 /**
 664  * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
 665  *
 666  * @name: the name for the kset
 667  * @parent: the parent kobject of this kobject, if any.
 668  *
 669  * This function creates a kset structure dynamically and registers it
 670  * with sysfs.  When you are finished with this structure, call
 671  * kobject_unregister() and the structure will be dynamically freed when
 672  * it is no longer being used.
 673  *
 674  * If the kobject was not able to be created, NULL will be returned.
 675  */
 676 struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
 677 {
 678         struct kobject *kobj;
 679         int retval;
 680
 681         kobj = kobject_create();
 682         if (!kobj)
 683                 return NULL;
 684
 685         retval = kobject_add_ng(kobj, parent, "%s", name);
 686         if (retval) {
 687                 printk(KERN_WARNING "%s: kobject_add error: %d\n",
 688                        __FUNCTION__, retval);
 689                 kobject_put(kobj);
 690                 kobj = NULL;
 691         }
 692         return kobj;
 693 }
 694 EXPORT_SYMBOL_GPL(kobject_create_and_add);
 695
 696 /**
 697  *      kset_init - initialize a kset for use
 698  *      @k:     kset
 699  */
 700
 701 void kset_init(struct kset * k)
 702 {
 703         kobject_init(&k->kobj);
 704         INIT_LIST_HEAD(&k->list);
 705         spin_lock_init(&k->list_lock);
 706 }
 707
 708 /* default kobject attribute operations */
 709 static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
 710                               char *buf)
 711 {
 712         struct kobj_attribute *kattr;
 713         ssize_t ret = -EIO;
 714
 715         kattr = container_of(attr, struct kobj_attribute, attr);
 716         if (kattr->show)
 717                 ret = kattr->show(kobj, kattr, buf);
 718         return ret;
 719 }
 720
 721 static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
 722                                const char *buf, size_t count)
 723 {
 724         struct kobj_attribute *kattr;
 725         ssize_t ret = -EIO;
 726
 727         kattr = container_of(attr, struct kobj_attribute, attr);
 728         if (kattr->store)
 729                 ret = kattr->store(kobj, kattr, buf, count);
 730         return ret;
 731 }
 732
 733 struct sysfs_ops kobj_sysfs_ops = {
 734         .show   = kobj_attr_show,
 735         .store  = kobj_attr_store,
 736 };
 737
 738 /**
 739  *      kset_add - add a kset object to the hierarchy.
 740  *      @k:     kset.
 741  */
 742
 743 int kset_add(struct kset * k)
 744 {
 745         return kobject_add(&k->kobj);
 746 }
 747
 748
 749 /**
 750  *      kset_register - initialize and add a kset.
 751  *      @k:     kset.
 752  */
 753
 754 int kset_register(struct kset * k)
 755 {
 756         int err;
 757
 758         if (!k)
 759                 return -EINVAL;
 760
 761         kset_init(k);
 762         err = kset_add(k);
 763         if (err)
 764                 return err;
 765         kobject_uevent(&k->kobj, KOBJ_ADD);
 766         return 0;
 767 }
 768
 769
 770 /**
 771  *      kset_unregister - remove a kset.
 772  *      @k:     kset.
 773  */
 774
 775 void kset_unregister(struct kset * k)
 776 {
 777         if (!k)
 778                 return;
 779         kobject_unregister(&k->kobj);
 780 }
 781
 782
 783 /**
 784  *      kset_find_obj - search for object in kset.
 785  *      @kset:  kset we're looking in.
 786  *      @name:  object's name.
 787  *
 788  *      Lock kset via @kset->subsys, and iterate over @kset->list,
 789  *      looking for a matching kobject. If matching object is found
 790  *      take a reference and return the object.
 791  */
 792
 793 struct kobject * kset_find_obj(struct kset * kset, const char * name)
 794 {
 795         struct list_head * entry;
 796         struct kobject * ret = NULL;
 797
 798         spin_lock(&kset->list_lock);
 799         list_for_each(entry,&kset->list) {
 800                 struct kobject * k = to_kobj(entry);
 801                 if (kobject_name(k) && !strcmp(kobject_name(k),name)) {
 802                         ret = kobject_get(k);
 803                         break;
 804                 }
 805         }
 806         spin_unlock(&kset->list_lock);
 807         return ret;
 808 }
 809
 810 static void kset_release(struct kobject *kobj)
 811 {
 812         struct kset *kset = container_of(kobj, struct kset, kobj);
 813         pr_debug("kobject: '%s' (%p): %s\n",
 814                  kobject_name(kobj), kobj, __FUNCTION__);
 815         kfree(kset);
 816 }
 817
 818 static struct kobj_type kset_ktype = {
 819         .sysfs_ops      = &kobj_sysfs_ops,
 820         .release = kset_release,
 821 };
 822
 823 /**
 824  * kset_create - create a struct kset dynamically
 825  *
 826  * @name: the name for the kset
 827  * @uevent_ops: a struct kset_uevent_ops for the kset
 828  * @parent_kobj: the parent kobject of this kset, if any.
 829  *
 830  * This function creates a kset structure dynamically.  This structure can
 831  * then be registered with the system and show up in sysfs with a call to
 832  * kset_register().  When you are finished with this structure, if
 833  * kset_register() has been called, call kset_unregister() and the
 834  * structure will be dynamically freed when it is no longer being used.
 835  *
 836  * If the kset was not able to be created, NULL will be returned.
 837  */
 838 static struct kset *kset_create(const char *name,
 839                                 struct kset_uevent_ops *uevent_ops,
 840                                 struct kobject *parent_kobj)
 841 {
 842         struct kset *kset;
 843
 844         kset = kzalloc(sizeof(*kset), GFP_KERNEL);
 845         if (!kset)
 846                 return NULL;
 847         kobject_set_name(&kset->kobj, name);
 848         kset->uevent_ops = uevent_ops;
 849         kset->kobj.parent = parent_kobj;
 850
 851         /*
 852          * The kobject of this kset will have a type of kset_ktype and belong to
 853          * no kset itself.  That way we can properly free it when it is
 854          * finished being used.
 855          */
 856         kset->kobj.ktype = &kset_ktype;
 857         kset->kobj.kset = NULL;
 858
 859         return kset;
 860 }
 861
 862 /**
 863  * kset_create_and_add - create a struct kset dynamically and add it to sysfs
 864  *
 865  * @name: the name for the kset
 866  * @uevent_ops: a struct kset_uevent_ops for the kset
 867  * @parent_kobj: the parent kobject of this kset, if any.
 868  *
 869  * This function creates a kset structure dynamically and registers it
 870  * with sysfs.  When you are finished with this structure, call
 871  * kset_unregister() and the structure will be dynamically freed when it
 872  * is no longer being used.
 873  *
 874  * If the kset was not able to be created, NULL will be returned.
 875  */
 876 struct kset *kset_create_and_add(const char *name,
 877                                  struct kset_uevent_ops *uevent_ops,
 878                                  struct kobject *parent_kobj)
 879 {
 880         struct kset *kset;
 881         int error;
 882
 883         kset = kset_create(name, uevent_ops, parent_kobj);
 884         if (!kset)
 885                 return NULL;
 886         error = kset_register(kset);
 887         if (error) {
 888                 kfree(kset);
 889                 return NULL;
 890         }
 891         return kset;
 892 }
 893 EXPORT_SYMBOL_GPL(kset_create_and_add);
 894
 895 EXPORT_SYMBOL(kobject_init);
 896 EXPORT_SYMBOL(kobject_register);
 897 EXPORT_SYMBOL(kobject_unregister);
 898 EXPORT_SYMBOL(kobject_get);
 899 EXPORT_SYMBOL(kobject_put);
 900 EXPORT_SYMBOL(kobject_add);
 901 EXPORT_SYMBOL(kobject_del);
 902
 903 EXPORT_SYMBOL(kset_register);
 904 EXPORT_SYMBOL(kset_unregister);