uml: make hostfs_setattr() support operations on unlinked open files
[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, 
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);