blob: 65af861471541924525bcd9c04ab32a931296ba8 [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 *
Paul Bolle395cf962011-08-15 02:02:26 +020026 * Please see Documentation/filesystems/configfs/configfs.txt for more
27 * information.
Joel Becker7063fbf2005-12-15 14:29:43 -080028 */
29
30#undef DEBUG
31
32#include <linux/pagemap.h>
33#include <linux/namei.h>
34#include <linux/backing-dev.h>
Joel Becker3d0f89b2006-01-25 13:31:07 -080035#include <linux/capability.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040036#include <linux/sched.h>
Louis Rillinge74cc062009-01-28 19:18:32 +010037#include <linux/lockdep.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090038#include <linux/slab.h>
Joel Becker7063fbf2005-12-15 14:29:43 -080039
40#include <linux/configfs.h>
41#include "configfs_internal.h"
42
Louis Rillinge74cc062009-01-28 19:18:32 +010043#ifdef CONFIG_LOCKDEP
44static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
45#endif
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
Arjan van de Ven754661f2007-02-12 00:55:38 -080053static const struct inode_operations configfs_inode_operations ={
Joel Becker3d0f89b2006-01-25 13:31:07 -080054 .setattr = configfs_setattr,
55};
56
57int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
58{
59 struct inode * inode = dentry->d_inode;
60 struct configfs_dirent * sd = dentry->d_fsdata;
61 struct iattr * sd_iattr;
62 unsigned int ia_valid = iattr->ia_valid;
63 int error;
64
65 if (!sd)
66 return -EINVAL;
67
68 sd_iattr = sd->s_iattr;
Joel Becker3d0f89b2006-01-25 13:31:07 -080069 if (!sd_iattr) {
70 /* setting attributes for the first time, allocate now */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -070071 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
Joel Becker3d0f89b2006-01-25 13:31:07 -080072 if (!sd_iattr)
73 return -ENOMEM;
74 /* assign default attributes */
Joel Becker3d0f89b2006-01-25 13:31:07 -080075 sd_iattr->ia_mode = sd->s_mode;
Eric W. Biederman69552c02012-02-07 16:28:09 -080076 sd_iattr->ia_uid = GLOBAL_ROOT_UID;
77 sd_iattr->ia_gid = GLOBAL_ROOT_GID;
Joel Becker3d0f89b2006-01-25 13:31:07 -080078 sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
79 sd->s_iattr = sd_iattr;
80 }
Joel Becker3d0f89b2006-01-25 13:31:07 -080081 /* attributes were changed atleast once in past */
82
Nick Piggin75de46b2010-05-31 17:58:02 +100083 error = simple_setattr(dentry, iattr);
84 if (error)
85 return error;
86
Joel Becker3d0f89b2006-01-25 13:31:07 -080087 if (ia_valid & ATTR_UID)
88 sd_iattr->ia_uid = iattr->ia_uid;
89 if (ia_valid & ATTR_GID)
90 sd_iattr->ia_gid = iattr->ia_gid;
91 if (ia_valid & ATTR_ATIME)
92 sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
93 inode->i_sb->s_time_gran);
94 if (ia_valid & ATTR_MTIME)
95 sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
96 inode->i_sb->s_time_gran);
97 if (ia_valid & ATTR_CTIME)
98 sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
99 inode->i_sb->s_time_gran);
100 if (ia_valid & ATTR_MODE) {
101 umode_t mode = iattr->ia_mode;
102
103 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
104 mode &= ~S_ISGID;
105 sd_iattr->ia_mode = sd->s_mode = mode;
106 }
107
108 return error;
109}
110
Al Viro43947512011-07-25 00:05:26 -0400111static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
Joel Becker3d0f89b2006-01-25 13:31:07 -0800112{
113 inode->i_mode = mode;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800114 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
115}
116
117static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
118{
119 inode->i_mode = iattr->ia_mode;
120 inode->i_uid = iattr->ia_uid;
121 inode->i_gid = iattr->ia_gid;
122 inode->i_atime = iattr->ia_atime;
123 inode->i_mtime = iattr->ia_mtime;
124 inode->i_ctime = iattr->ia_ctime;
125}
126
Al Virob7c177f2012-03-17 16:24:54 -0400127struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
128 struct super_block *s)
Joel Becker7063fbf2005-12-15 14:29:43 -0800129{
Al Virob7c177f2012-03-17 16:24:54 -0400130 struct inode * inode = new_inode(s);
Joel Becker7063fbf2005-12-15 14:29:43 -0800131 if (inode) {
Christoph Hellwig85fe4022010-10-23 11:19:54 -0400132 inode->i_ino = get_next_ino();
Joel Becker7063fbf2005-12-15 14:29:43 -0800133 inode->i_mapping->a_ops = &configfs_aops;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800134 inode->i_op = &configfs_inode_operations;
135
136 if (sd->s_iattr) {
137 /* sysfs_dirent has non-default attributes
138 * get them for the new inode from persistent copy
139 * in sysfs_dirent
140 */
141 set_inode_attr(inode, sd->s_iattr);
142 } else
143 set_default_inode_attr(inode, mode);
Joel Becker7063fbf2005-12-15 14:29:43 -0800144 }
145 return inode;
146}
147
Louis Rillinge74cc062009-01-28 19:18:32 +0100148#ifdef CONFIG_LOCKDEP
149
150static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
151 struct inode *inode)
152{
153 int depth = sd->s_depth;
154
155 if (depth > 0) {
156 if (depth <= ARRAY_SIZE(default_group_class)) {
157 lockdep_set_class(&inode->i_mutex,
158 &default_group_class[depth - 1]);
159 } else {
160 /*
161 * In practice the maximum level of locking depth is
162 * already reached. Just inform about possible reasons.
163 */
Fabian Frederick1d88aa42014-06-04 16:05:59 -0700164 pr_info("Too many levels of inodes for the locking correctness validator.\n");
Fabian Frederickc6686932014-06-04 16:05:58 -0700165 pr_info("Spurious warnings may appear.\n");
Louis Rillinge74cc062009-01-28 19:18:32 +0100166 }
167 }
168}
169
170#else /* CONFIG_LOCKDEP */
171
172static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
173 struct inode *inode)
174{
175}
176
177#endif /* CONFIG_LOCKDEP */
178
Al Viro43947512011-07-25 00:05:26 -0400179int configfs_create(struct dentry * dentry, umode_t mode, int (*init)(struct inode *))
Joel Becker7063fbf2005-12-15 14:29:43 -0800180{
181 int error = 0;
Al Viro16d13b52012-03-17 16:41:55 -0400182 struct inode *inode = NULL;
183 struct configfs_dirent *sd;
184 struct inode *p_inode;
Joel Becker7063fbf2005-12-15 14:29:43 -0800185
Al Viro16d13b52012-03-17 16:41:55 -0400186 if (!dentry)
187 return -ENOENT;
188
189 if (dentry->d_inode)
190 return -EEXIST;
191
192 sd = dentry->d_fsdata;
193 inode = configfs_new_inode(mode, sd, dentry->d_sb);
194 if (!inode)
195 return -ENOMEM;
196
197 p_inode = dentry->d_parent->d_inode;
198 p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
199 configfs_set_inode_lock_class(sd, inode);
200
201 if (init) {
Joel Becker7063fbf2005-12-15 14:29:43 -0800202 error = init(inode);
Al Viro16d13b52012-03-17 16:41:55 -0400203 if (error) {
204 iput(inode);
205 return error;
206 }
207 }
208 d_instantiate(dentry, inode);
209 if (S_ISDIR(mode) || S_ISLNK(mode))
210 dget(dentry); /* pin link and directory dentries in core */
Joel Becker7063fbf2005-12-15 14:29:43 -0800211 return error;
212}
213
214/*
215 * Get the name for corresponding element represented by the given configfs_dirent
216 */
217const unsigned char * configfs_get_name(struct configfs_dirent *sd)
218{
Joel Becker3d0f89b2006-01-25 13:31:07 -0800219 struct configfs_attribute *attr;
Joel Becker7063fbf2005-12-15 14:29:43 -0800220
Eric Sesterhenn / snakebyte1a1974f2006-01-27 10:32:24 +0100221 BUG_ON(!sd || !sd->s_element);
Joel Becker7063fbf2005-12-15 14:29:43 -0800222
223 /* These always have a dentry, so use that */
224 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
225 return sd->s_dentry->d_name.name;
226
227 if (sd->s_type & CONFIGFS_ITEM_ATTR) {
228 attr = sd->s_element;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800229 return attr->ca_name;
Joel Becker7063fbf2005-12-15 14:29:43 -0800230 }
231 return NULL;
232}
233
234
235/*
236 * Unhashes the dentry corresponding to given configfs_dirent
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800237 * Called with parent inode's i_mutex held.
Joel Becker7063fbf2005-12-15 14:29:43 -0800238 */
239void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
240{
241 struct dentry * dentry = sd->s_dentry;
242
243 if (dentry) {
Joel Becker3d0f89b2006-01-25 13:31:07 -0800244 spin_lock(&dentry->d_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800245 if (!(d_unhashed(dentry) && dentry->d_inode)) {
Nick Piggindc0474b2011-01-07 17:49:43 +1100246 dget_dlock(dentry);
Joel Becker7063fbf2005-12-15 14:29:43 -0800247 __d_drop(dentry);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800248 spin_unlock(&dentry->d_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800249 simple_unlink(parent->d_inode, dentry);
Nick Pigginb5c84bf2011-01-07 17:49:38 +1100250 } else
Joel Becker3d0f89b2006-01-25 13:31:07 -0800251 spin_unlock(&dentry->d_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800252 }
253}
254
255void configfs_hash_and_remove(struct dentry * dir, const char * name)
256{
257 struct configfs_dirent * sd;
258 struct configfs_dirent * parent_sd = dir->d_fsdata;
259
Joel Becker3d0f89b2006-01-25 13:31:07 -0800260 if (dir->d_inode == NULL)
261 /* no inode means this hasn't been made visible yet */
262 return;
263
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800264 mutex_lock(&dir->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800265 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
266 if (!sd->s_element)
267 continue;
268 if (!strcmp(configfs_get_name(sd), name)) {
Louis Rilling6f610762008-06-16 19:00:58 +0200269 spin_lock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800270 list_del_init(&sd->s_sibling);
Louis Rilling6f610762008-06-16 19:00:58 +0200271 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800272 configfs_drop_dentry(sd, dir);
273 configfs_put(sd);
274 break;
275 }
276 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800277 mutex_unlock(&dir->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800278}