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 "sysfs.h"
  17
  18
  19 static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
  20                          const struct attribute_group *grp)
  21 {
  22         struct attribute *const* attr;
  23         int i;
  24
  25         for (i = 0, attr = grp->attrs; *attr; i++, attr++)
  26                 if (!grp->is_visible ||
  27                     grp->is_visible(kobj, *attr, i))
  28                         sysfs_hash_and_remove(dir_sd, (*attr)->name);
  29 }
  30
  31 static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
  32                         const struct attribute_group *grp)
  33 {
  34         struct attribute *const* attr;
  35         int error = 0, i;
  36
  37         for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++)
  38                 if (!grp->is_visible ||
  39                     grp->is_visible(kobj, *attr, i))
  40                         error |=
  41                                 sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
  42         if (error)
  43                 remove_files(dir_sd, kobj, grp);
  44         return error;
  45 }
  46
  47
  48 int sysfs_create_group(struct kobject * kobj,
  49                        const struct attribute_group * grp)
  50 {
  51         struct sysfs_dirent *sd;
  52         int error;
  53
  54         BUG_ON(!kobj || !kobj->sd);
  55
  56         if (grp->name) {
  57                 error = sysfs_create_subdir(kobj, grp->name, &sd);
  58                 if (error)
  59                         return error;
  60         } else
  61                 sd = kobj->sd;
  62         sysfs_get(sd);
  63         error = create_files(sd, kobj, grp);
  64         if (error) {
  65                 if (grp->name)
  66                         sysfs_remove_subdir(sd);
  67         }
  68         sysfs_put(sd);
  69         return error;
  70 }
  71
  72 void sysfs_remove_group(struct kobject * kobj,
  73                         const struct attribute_group * grp)
  74 {
  75         struct sysfs_dirent *dir_sd = kobj->sd;
  76         struct sysfs_dirent *sd;
  77
  78         if (grp->name) {
  79                 sd = sysfs_get_dirent(dir_sd, grp->name);
  80                 if (!sd) {
  81                         printk(KERN_WARNING "sysfs group %p not found for "
  82                                 "kobject '%s'\n", grp, kobject_name(kobj));
  83                         WARN_ON(!sd);
  84                         return;
  85                 }
  86         } else
  87                 sd = sysfs_get(dir_sd);
  88
  89         remove_files(sd, kobj, grp);
  90         if (grp->name)
  91                 sysfs_remove_subdir(sd);
  92
  93         sysfs_put(sd);
  94 }
  95
  96
  97 EXPORT_SYMBOL_GPL(sysfs_create_group);
  98 EXPORT_SYMBOL_GPL(sysfs_remove_group);