fs/sysfs/group.c

   1 /*
   2  * fs/sysfs/group.c - Operations for adding/removing multiple files at once.
   3  *
   4  * Copyright (c) 2003 Patrick Mochel
   5  * Copyright (c) 2003 Open Source Development Lab
   6  *
   7  * This file is released undert the GPL v2.
   8  *
   9  */
  10
  11 #include <linux/kobject.h>
  12 #include <linux/module.h>
  13 #include <linux/dcache.h>
  14 #include <linux/namei.h>
  15 #include <linux/err.h>
  16 #include <asm/semaphore.h>
  17 #include "sysfs.h"
  18
  19
  20 static void remove_files(struct dentry * dir,
  21                          const struct attribute_group * grp)
  22 {
  23         struct attribute *const* attr;
  24
  25         for (attr = grp->attrs; *attr; attr++)
  26                 sysfs_hash_and_remove(dir,(*attr)->name);
  27 }
  28
  29 static int create_files(struct dentry * dir,
  30                         const struct attribute_group * grp)
  31 {
  32         struct attribute *const* attr;
  33         int error = 0;
  34
  35         for (attr = grp->attrs; *attr && !error; attr++) {
  36                 error = sysfs_add_file(dir, *attr, SYSFS_KOBJ_ATTR);
  37         }
  38         if (error)
  39                 remove_files(dir,grp);
  40         return error;
  41 }
  42
  43
  44 int sysfs_create_group(struct kobject * kobj,
  45                        const struct attribute_group * grp)
  46 {
  47         struct dentry * dir;
  48         int error;
  49
  50         BUG_ON(!kobj || !kobj->dentry);
  51
  52         if (grp->name) {
  53                 error = sysfs_create_subdir(kobj,grp->name,&dir);
  54                 if (error)
  55                         return error;
  56         } else
  57                 dir = kobj->dentry;
  58         dir = dget(dir);
  59         if ((error = create_files(dir,grp))) {
  60                 if (grp->name)
  61                         sysfs_remove_subdir(dir);
  62         }
  63         dput(dir);
  64         return error;
  65 }
  66
  67 void sysfs_remove_group(struct kobject * kobj,
  68                         const struct attribute_group * grp)
  69 {
  70         struct dentry * dir;
  71
  72         if (grp->name)
  73                 dir = lookup_one_len(grp->name, kobj->dentry,
  74                                 strlen(grp->name));
  75         else
  76                 dir = dget(kobj->dentry);
  77
  78         remove_files(dir,grp);
  79         if (grp->name)
  80                 sysfs_remove_subdir(dir);
  81         /* release the ref. taken in this routine */
  82         dput(dir);
  83 }
  84
  85
  86 EXPORT_SYMBOL_GPL(sysfs_create_group);
  87 EXPORT_SYMBOL_GPL(sysfs_remove_group);