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 <linux/fs.h>
  17 #include <asm/semaphore.h>
  18 #include "sysfs.h"
  19
  20
  21 static void remove_files(struct dentry * dir,
  22                          const struct attribute_group * grp)
  23 {
  24         struct attribute *const* attr;
  25
  26         for (attr = grp->attrs; *attr; attr++)
  27                 sysfs_hash_and_remove(dir,(*attr)->name);
  28 }
  29
  30 static int create_files(struct dentry * dir,
  31                         const struct attribute_group * grp)
  32 {
  33         struct attribute *const* attr;
  34         int error = 0;
  35
  36         for (attr = grp->attrs; *attr && !error; attr++) {
  37                 error = sysfs_add_file(dir, *attr, SYSFS_KOBJ_ATTR);
  38         }
  39         if (error)
  40                 remove_files(dir,grp);
  41         return error;
  42 }
  43
  44
  45 int sysfs_create_group(struct kobject * kobj,
  46                        const struct attribute_group * grp)
  47 {
  48         struct dentry * dir;
  49         int error;
  50
  51         BUG_ON(!kobj || !kobj->dentry);
  52
  53         if (grp->name) {
  54                 error = sysfs_create_subdir(kobj,grp->name,&dir);
  55                 if (error)
  56                         return error;
  57         } else
  58                 dir = kobj->dentry;
  59         dir = dget(dir);
  60         if ((error = create_files(dir,grp))) {
  61                 if (grp->name)
  62                         sysfs_remove_subdir(dir);
  63         }
  64         dput(dir);
  65         return error;
  66 }
  67
  68 void sysfs_remove_group(struct kobject * kobj,
  69                         const struct attribute_group * grp)
  70 {
  71         struct dentry * dir;
  72
  73         if (grp->name) {
  74                 dir = lookup_one_len_kern(grp->name, kobj->dentry,
  75                                 strlen(grp->name));
  76                 BUG_ON(IS_ERR(dir));
  77         }
  78         else
  79                 dir = dget(kobj->dentry);
  80
  81         remove_files(dir,grp);
  82         if (grp->name)
  83                 sysfs_remove_subdir(dir);
  84         /* release the ref. taken in this routine */
  85         dput(dir);
  86 }
  87
  88
  89 EXPORT_SYMBOL_GPL(sysfs_create_group);
  90 EXPORT_SYMBOL_GPL(sysfs_remove_group);