release/src-rt-6.x/linux/linux-2.6/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, struct kobject *kobj,
  22                          const struct attribute_group *grp)
  23 {
  24         struct attribute *const* attr;
  25         int i;
  26
  27         for (i = 0, attr = grp->attrs; *attr; i++, attr++)
  28                 if (!grp->is_visible ||
  29                     grp->is_visible(kobj, *attr, i))
  30                         sysfs_hash_and_remove(dir, (*attr)->name);
  31 }
  32
  33 static int create_files(struct dentry *dir, struct kobject *kobj,
  34                         const struct attribute_group *grp)
  35 {
  36         struct attribute *const* attr;
  37         int error = 0, i;
  38
  39         for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++)
  40                 if (!grp->is_visible ||
  41                     grp->is_visible(kobj, *attr, i))
  42                         error |=
  43                                 sysfs_add_file(dir, *attr, SYSFS_KOBJ_ATTR);
  44         if (error)
  45                 remove_files(dir, kobj, grp);
  46         return error;
  47 }
  48
  49
  50 int sysfs_create_group(struct kobject * kobj,
  51                        const struct attribute_group * grp)
  52 {
  53         struct dentry * dir;
  54         int error;
  55
  56         BUG_ON(!kobj || !kobj->dentry);
  57
  58         if (grp->name) {
  59                 error = sysfs_create_subdir(kobj,grp->name,&dir);
  60                 if (error)
  61                         return error;
  62         } else
  63                 dir = kobj->dentry;
  64         dir = dget(dir);
  65         error = create_files(dir, kobj, grp);
  66         if (error) {
  67                 if (grp->name)
  68                         sysfs_remove_subdir(dir);
  69         }
  70         dput(dir);
  71         return error;
  72 }
  73
  74 void sysfs_remove_group(struct kobject * kobj,
  75                         const struct attribute_group * grp)
  76 {
  77         struct dentry * dir;
  78
  79         if (grp->name) {
  80                 dir = lookup_one_len_kern(grp->name, kobj->dentry,
  81                                 strlen(grp->name));
  82                 BUG_ON(IS_ERR(dir));
  83         }
  84         else
  85                 dir = dget(kobj->dentry);
  86
  87         remove_files(dir, kobj, grp);
  88         if (grp->name)
  89                 sysfs_remove_subdir(dir);
  90         /* release the ref. taken in this routine */
  91         dput(dir);
  92 }
  93
  94
  95 EXPORT_SYMBOL_GPL(sysfs_create_group);
  96 EXPORT_SYMBOL_GPL(sysfs_remove_group);