blob: 4921e7426d95b4d3aed71a1dc0e0d7c89d1e2100 [file] [log] [blame]
Joel Becker7063fbf2005-12-15 14:29:43 -08001/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * inode.c - basic inode and dentry operations.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public
17 * License along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA.
20 *
21 * Based on sysfs:
22 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
23 *
24 * configfs Copyright (C) 2005 Oracle. All rights reserved.
25 *
26 * Please see Documentation/filesystems/configfs.txt for more information.
27 */
28
29#undef DEBUG
30
31#include <linux/pagemap.h>
32#include <linux/namei.h>
33#include <linux/backing-dev.h>
Joel Becker3d0f89b2006-01-25 13:31:07 -080034#include <linux/capability.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040035#include <linux/sched.h>
Louis Rillinge74cc062009-01-28 19:18:32 +010036#include <linux/lockdep.h>
Joel Becker7063fbf2005-12-15 14:29:43 -080037
38#include <linux/configfs.h>
39#include "configfs_internal.h"
40
Louis Rillinge74cc062009-01-28 19:18:32 +010041#ifdef CONFIG_LOCKDEP
42static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
43#endif
44
Joel Becker7063fbf2005-12-15 14:29:43 -080045extern struct super_block * configfs_sb;
46
Christoph Hellwigf5e54d62006-06-28 04:26:44 -070047static const struct address_space_operations configfs_aops = {
Joel Becker7063fbf2005-12-15 14:29:43 -080048 .readpage = simple_readpage,
Nick Piggin800d15a2007-10-16 01:25:03 -070049 .write_begin = simple_write_begin,
50 .write_end = simple_write_end,
Joel Becker7063fbf2005-12-15 14:29:43 -080051};
52
53static struct backing_dev_info configfs_backing_dev_info = {
54 .ra_pages = 0, /* No readahead */
Miklos Szeredie4ad08f2008-04-30 00:54:37 -070055 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
Joel Becker7063fbf2005-12-15 14:29:43 -080056};
57
Arjan van de Ven754661f2007-02-12 00:55:38 -080058static const struct inode_operations configfs_inode_operations ={
Joel Becker3d0f89b2006-01-25 13:31:07 -080059 .setattr = configfs_setattr,
60};
61
62int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
63{
64 struct inode * inode = dentry->d_inode;
65 struct configfs_dirent * sd = dentry->d_fsdata;
66 struct iattr * sd_iattr;
67 unsigned int ia_valid = iattr->ia_valid;
68 int error;
69
70 if (!sd)
71 return -EINVAL;
72
73 sd_iattr = sd->s_iattr;
74
75 error = inode_change_ok(inode, iattr);
76 if (error)
77 return error;
78
79 error = inode_setattr(inode, iattr);
80 if (error)
81 return error;
82
83 if (!sd_iattr) {
84 /* setting attributes for the first time, allocate now */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -070085 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
Joel Becker3d0f89b2006-01-25 13:31:07 -080086 if (!sd_iattr)
87 return -ENOMEM;
88 /* assign default attributes */
Joel Becker3d0f89b2006-01-25 13:31:07 -080089 sd_iattr->ia_mode = sd->s_mode;
90 sd_iattr->ia_uid = 0;
91 sd_iattr->ia_gid = 0;
92 sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
93 sd->s_iattr = sd_iattr;
94 }
95
96 /* attributes were changed atleast once in past */
97
98 if (ia_valid & ATTR_UID)
99 sd_iattr->ia_uid = iattr->ia_uid;
100 if (ia_valid & ATTR_GID)
101 sd_iattr->ia_gid = iattr->ia_gid;
102 if (ia_valid & ATTR_ATIME)
103 sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
104 inode->i_sb->s_time_gran);
105 if (ia_valid & ATTR_MTIME)
106 sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
107 inode->i_sb->s_time_gran);
108 if (ia_valid & ATTR_CTIME)
109 sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
110 inode->i_sb->s_time_gran);
111 if (ia_valid & ATTR_MODE) {
112 umode_t mode = iattr->ia_mode;
113
114 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
115 mode &= ~S_ISGID;
116 sd_iattr->ia_mode = sd->s_mode = mode;
117 }
118
119 return error;
120}
121
122static inline void set_default_inode_attr(struct inode * inode, mode_t mode)
123{
124 inode->i_mode = mode;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800125 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
126}
127
128static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
129{
130 inode->i_mode = iattr->ia_mode;
131 inode->i_uid = iattr->ia_uid;
132 inode->i_gid = iattr->ia_gid;
133 inode->i_atime = iattr->ia_atime;
134 inode->i_mtime = iattr->ia_mtime;
135 inode->i_ctime = iattr->ia_ctime;
136}
137
138struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd)
Joel Becker7063fbf2005-12-15 14:29:43 -0800139{
140 struct inode * inode = new_inode(configfs_sb);
141 if (inode) {
Joel Becker7063fbf2005-12-15 14:29:43 -0800142 inode->i_mapping->a_ops = &configfs_aops;
143 inode->i_mapping->backing_dev_info = &configfs_backing_dev_info;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800144 inode->i_op = &configfs_inode_operations;
145
146 if (sd->s_iattr) {
147 /* sysfs_dirent has non-default attributes
148 * get them for the new inode from persistent copy
149 * in sysfs_dirent
150 */
151 set_inode_attr(inode, sd->s_iattr);
152 } else
153 set_default_inode_attr(inode, mode);
Joel Becker7063fbf2005-12-15 14:29:43 -0800154 }
155 return inode;
156}
157
Louis Rillinge74cc062009-01-28 19:18:32 +0100158#ifdef CONFIG_LOCKDEP
159
160static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
161 struct inode *inode)
162{
163 int depth = sd->s_depth;
164
165 if (depth > 0) {
166 if (depth <= ARRAY_SIZE(default_group_class)) {
167 lockdep_set_class(&inode->i_mutex,
168 &default_group_class[depth - 1]);
169 } else {
170 /*
171 * In practice the maximum level of locking depth is
172 * already reached. Just inform about possible reasons.
173 */
174 printk(KERN_INFO "configfs: Too many levels of inodes"
175 " for the locking correctness validator.\n");
176 printk(KERN_INFO "Spurious warnings may appear.\n");
177 }
178 }
179}
180
181#else /* CONFIG_LOCKDEP */
182
183static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
184 struct inode *inode)
185{
186}
187
188#endif /* CONFIG_LOCKDEP */
189
Joel Becker7063fbf2005-12-15 14:29:43 -0800190int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
191{
192 int error = 0;
193 struct inode * inode = NULL;
194 if (dentry) {
195 if (!dentry->d_inode) {
Joel Becker3d0f89b2006-01-25 13:31:07 -0800196 struct configfs_dirent *sd = dentry->d_fsdata;
197 if ((inode = configfs_new_inode(mode, sd))) {
Joel Becker7063fbf2005-12-15 14:29:43 -0800198 if (dentry->d_parent && dentry->d_parent->d_inode) {
199 struct inode *p_inode = dentry->d_parent->d_inode;
200 p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
201 }
Louis Rillinge74cc062009-01-28 19:18:32 +0100202 configfs_set_inode_lock_class(sd, inode);
Joel Becker7063fbf2005-12-15 14:29:43 -0800203 goto Proceed;
204 }
205 else
206 error = -ENOMEM;
207 } else
208 error = -EEXIST;
209 } else
210 error = -ENOENT;
211 goto Done;
212
213 Proceed:
214 if (init)
215 error = init(inode);
216 if (!error) {
217 d_instantiate(dentry, inode);
218 if (S_ISDIR(mode) || S_ISLNK(mode))
219 dget(dentry); /* pin link and directory dentries in core */
220 } else
221 iput(inode);
222 Done:
223 return error;
224}
225
226/*
227 * Get the name for corresponding element represented by the given configfs_dirent
228 */
229const unsigned char * configfs_get_name(struct configfs_dirent *sd)
230{
Joel Becker3d0f89b2006-01-25 13:31:07 -0800231 struct configfs_attribute *attr;
Joel Becker7063fbf2005-12-15 14:29:43 -0800232
Eric Sesterhenn / snakebyte1a1974f2006-01-27 10:32:24 +0100233 BUG_ON(!sd || !sd->s_element);
Joel Becker7063fbf2005-12-15 14:29:43 -0800234
235 /* These always have a dentry, so use that */
236 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
237 return sd->s_dentry->d_name.name;
238
239 if (sd->s_type & CONFIGFS_ITEM_ATTR) {
240 attr = sd->s_element;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800241 return attr->ca_name;
Joel Becker7063fbf2005-12-15 14:29:43 -0800242 }
243 return NULL;
244}
245
246
247/*
248 * Unhashes the dentry corresponding to given configfs_dirent
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800249 * Called with parent inode's i_mutex held.
Joel Becker7063fbf2005-12-15 14:29:43 -0800250 */
251void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
252{
253 struct dentry * dentry = sd->s_dentry;
254
255 if (dentry) {
256 spin_lock(&dcache_lock);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800257 spin_lock(&dentry->d_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800258 if (!(d_unhashed(dentry) && dentry->d_inode)) {
259 dget_locked(dentry);
260 __d_drop(dentry);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800261 spin_unlock(&dentry->d_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800262 spin_unlock(&dcache_lock);
263 simple_unlink(parent->d_inode, dentry);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800264 } else {
265 spin_unlock(&dentry->d_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800266 spin_unlock(&dcache_lock);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800267 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800268 }
269}
270
271void configfs_hash_and_remove(struct dentry * dir, const char * name)
272{
273 struct configfs_dirent * sd;
274 struct configfs_dirent * parent_sd = dir->d_fsdata;
275
Joel Becker3d0f89b2006-01-25 13:31:07 -0800276 if (dir->d_inode == NULL)
277 /* no inode means this hasn't been made visible yet */
278 return;
279
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800280 mutex_lock(&dir->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800281 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
282 if (!sd->s_element)
283 continue;
284 if (!strcmp(configfs_get_name(sd), name)) {
Louis Rilling6f610762008-06-16 19:00:58 +0200285 spin_lock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800286 list_del_init(&sd->s_sibling);
Louis Rilling6f610762008-06-16 19:00:58 +0200287 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800288 configfs_drop_dentry(sd, dir);
289 configfs_put(sd);
290 break;
291 }
292 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800293 mutex_unlock(&dir->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800294}
295
Peter Zijlstrae0bf68d2007-10-16 23:25:46 -0700296int __init configfs_inode_init(void)
297{
298 return bdi_init(&configfs_backing_dev_info);
299}
Joel Becker7063fbf2005-12-15 14:29:43 -0800300
Peter Zijlstrae0bf68d2007-10-16 23:25:46 -0700301void __exit configfs_inode_exit(void)
302{
303 bdi_destroy(&configfs_backing_dev_info);
304}