blob: 0387968e6f475e35426b3e241c17a14de44665f3 [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{
David Howells2b0143b2015-03-17 22:25:59 +000059 struct inode * inode = d_inode(dentry);
Joel Becker3d0f89b2006-01-25 13:31:07 -080060 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;
Deepa Dinamanib1f1a292016-02-22 07:17:50 -080078 sd_iattr->ia_atime = sd_iattr->ia_mtime =
79 sd_iattr->ia_ctime = current_fs_time(inode->i_sb);
Joel Becker3d0f89b2006-01-25 13:31:07 -080080 sd->s_iattr = sd_iattr;
81 }
Joel Becker3d0f89b2006-01-25 13:31:07 -080082 /* attributes were changed atleast once in past */
83
Nick Piggin75de46b2010-05-31 17:58:02 +100084 error = simple_setattr(dentry, iattr);
85 if (error)
86 return error;
87
Joel Becker3d0f89b2006-01-25 13:31:07 -080088 if (ia_valid & ATTR_UID)
89 sd_iattr->ia_uid = iattr->ia_uid;
90 if (ia_valid & ATTR_GID)
91 sd_iattr->ia_gid = iattr->ia_gid;
92 if (ia_valid & ATTR_ATIME)
93 sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
94 inode->i_sb->s_time_gran);
95 if (ia_valid & ATTR_MTIME)
96 sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
97 inode->i_sb->s_time_gran);
98 if (ia_valid & ATTR_CTIME)
99 sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
100 inode->i_sb->s_time_gran);
101 if (ia_valid & ATTR_MODE) {
102 umode_t mode = iattr->ia_mode;
103
104 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
105 mode &= ~S_ISGID;
106 sd_iattr->ia_mode = sd->s_mode = mode;
107 }
108
109 return error;
110}
111
Al Viro43947512011-07-25 00:05:26 -0400112static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
Joel Becker3d0f89b2006-01-25 13:31:07 -0800113{
114 inode->i_mode = mode;
Deepa Dinamanib1f1a292016-02-22 07:17:50 -0800115 inode->i_atime = inode->i_mtime =
116 inode->i_ctime = current_fs_time(inode->i_sb);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800117}
118
119static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
120{
121 inode->i_mode = iattr->ia_mode;
122 inode->i_uid = iattr->ia_uid;
123 inode->i_gid = iattr->ia_gid;
124 inode->i_atime = iattr->ia_atime;
125 inode->i_mtime = iattr->ia_mtime;
126 inode->i_ctime = iattr->ia_ctime;
127}
128
Al Virob7c177f2012-03-17 16:24:54 -0400129struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
130 struct super_block *s)
Joel Becker7063fbf2005-12-15 14:29:43 -0800131{
Al Virob7c177f2012-03-17 16:24:54 -0400132 struct inode * inode = new_inode(s);
Joel Becker7063fbf2005-12-15 14:29:43 -0800133 if (inode) {
Christoph Hellwig85fe4022010-10-23 11:19:54 -0400134 inode->i_ino = get_next_ino();
Joel Becker7063fbf2005-12-15 14:29:43 -0800135 inode->i_mapping->a_ops = &configfs_aops;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800136 inode->i_op = &configfs_inode_operations;
137
138 if (sd->s_iattr) {
139 /* sysfs_dirent has non-default attributes
140 * get them for the new inode from persistent copy
141 * in sysfs_dirent
142 */
143 set_inode_attr(inode, sd->s_iattr);
144 } else
145 set_default_inode_attr(inode, mode);
Joel Becker7063fbf2005-12-15 14:29:43 -0800146 }
147 return inode;
148}
149
Louis Rillinge74cc062009-01-28 19:18:32 +0100150#ifdef CONFIG_LOCKDEP
151
152static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
153 struct inode *inode)
154{
155 int depth = sd->s_depth;
156
157 if (depth > 0) {
158 if (depth <= ARRAY_SIZE(default_group_class)) {
Al Viro9902af72016-04-15 15:08:36 -0400159 lockdep_set_class(&inode->i_rwsem,
Louis Rillinge74cc062009-01-28 19:18:32 +0100160 &default_group_class[depth - 1]);
161 } else {
162 /*
163 * In practice the maximum level of locking depth is
164 * already reached. Just inform about possible reasons.
165 */
Fabian Frederick1d88aa42014-06-04 16:05:59 -0700166 pr_info("Too many levels of inodes for the locking correctness validator.\n");
Fabian Frederickc6686932014-06-04 16:05:58 -0700167 pr_info("Spurious warnings may appear.\n");
Louis Rillinge74cc062009-01-28 19:18:32 +0100168 }
169 }
170}
171
172#else /* CONFIG_LOCKDEP */
173
174static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
175 struct inode *inode)
176{
177}
178
179#endif /* CONFIG_LOCKDEP */
180
Al Viroc88b1e72015-01-29 00:17:57 -0500181int configfs_create(struct dentry * dentry, umode_t mode, void (*init)(struct inode *))
Joel Becker7063fbf2005-12-15 14:29:43 -0800182{
183 int error = 0;
Al Viro16d13b52012-03-17 16:41:55 -0400184 struct inode *inode = NULL;
185 struct configfs_dirent *sd;
186 struct inode *p_inode;
Joel Becker7063fbf2005-12-15 14:29:43 -0800187
Al Viro16d13b52012-03-17 16:41:55 -0400188 if (!dentry)
189 return -ENOENT;
190
David Howells2b0143b2015-03-17 22:25:59 +0000191 if (d_really_is_positive(dentry))
Al Viro16d13b52012-03-17 16:41:55 -0400192 return -EEXIST;
193
194 sd = dentry->d_fsdata;
195 inode = configfs_new_inode(mode, sd, dentry->d_sb);
196 if (!inode)
197 return -ENOMEM;
198
David Howells2b0143b2015-03-17 22:25:59 +0000199 p_inode = d_inode(dentry->d_parent);
Deepa Dinamanib1f1a292016-02-22 07:17:50 -0800200 p_inode->i_mtime = p_inode->i_ctime = current_fs_time(p_inode->i_sb);
Al Viro16d13b52012-03-17 16:41:55 -0400201 configfs_set_inode_lock_class(sd, inode);
202
Al Viroc88b1e72015-01-29 00:17:57 -0500203 init(inode);
Al Viro5cf3b562016-03-07 14:25:46 -0500204 if (S_ISDIR(mode) || S_ISLNK(mode)) {
205 /*
206 * ->symlink(), ->mkdir(), configfs_register_subsystem() or
207 * create_default_group() - already hashed.
208 */
209 d_instantiate(dentry, inode);
Al Viro16d13b52012-03-17 16:41:55 -0400210 dget(dentry); /* pin link and directory dentries in core */
Al Viro5cf3b562016-03-07 14:25:46 -0500211 } else {
212 /* ->lookup() */
213 d_add(dentry, inode);
214 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800215 return error;
216}
217
218/*
219 * Get the name for corresponding element represented by the given configfs_dirent
220 */
221const unsigned char * configfs_get_name(struct configfs_dirent *sd)
222{
Joel Becker3d0f89b2006-01-25 13:31:07 -0800223 struct configfs_attribute *attr;
Joel Becker7063fbf2005-12-15 14:29:43 -0800224
Eric Sesterhenn / snakebyte1a1974f2006-01-27 10:32:24 +0100225 BUG_ON(!sd || !sd->s_element);
Joel Becker7063fbf2005-12-15 14:29:43 -0800226
227 /* These always have a dentry, so use that */
228 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
229 return sd->s_dentry->d_name.name;
230
Pantelis Antoniou03607ac2015-10-22 23:30:04 +0300231 if (sd->s_type & (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)) {
Joel Becker7063fbf2005-12-15 14:29:43 -0800232 attr = sd->s_element;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800233 return attr->ca_name;
Joel Becker7063fbf2005-12-15 14:29:43 -0800234 }
235 return NULL;
236}
237
238
239/*
240 * Unhashes the dentry corresponding to given configfs_dirent
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800241 * Called with parent inode's i_mutex held.
Joel Becker7063fbf2005-12-15 14:29:43 -0800242 */
243void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
244{
245 struct dentry * dentry = sd->s_dentry;
246
247 if (dentry) {
Joel Becker3d0f89b2006-01-25 13:31:07 -0800248 spin_lock(&dentry->d_lock);
Al Virodc3f4192015-05-18 10:10:34 -0400249 if (simple_positive(dentry)) {
Nick Piggindc0474b2011-01-07 17:49:43 +1100250 dget_dlock(dentry);
Joel Becker7063fbf2005-12-15 14:29:43 -0800251 __d_drop(dentry);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800252 spin_unlock(&dentry->d_lock);
David Howells2b0143b2015-03-17 22:25:59 +0000253 simple_unlink(d_inode(parent), dentry);
Nick Pigginb5c84bf2011-01-07 17:49:38 +1100254 } else
Joel Becker3d0f89b2006-01-25 13:31:07 -0800255 spin_unlock(&dentry->d_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800256 }
257}
258
259void configfs_hash_and_remove(struct dentry * dir, const char * name)
260{
261 struct configfs_dirent * sd;
262 struct configfs_dirent * parent_sd = dir->d_fsdata;
263
David Howells2b0143b2015-03-17 22:25:59 +0000264 if (d_really_is_negative(dir))
Joel Becker3d0f89b2006-01-25 13:31:07 -0800265 /* no inode means this hasn't been made visible yet */
266 return;
267
Al Viro59551022016-01-22 15:40:57 -0500268 inode_lock(d_inode(dir));
Joel Becker7063fbf2005-12-15 14:29:43 -0800269 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
270 if (!sd->s_element)
271 continue;
272 if (!strcmp(configfs_get_name(sd), name)) {
Louis Rilling6f610762008-06-16 19:00:58 +0200273 spin_lock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800274 list_del_init(&sd->s_sibling);
Louis Rilling6f610762008-06-16 19:00:58 +0200275 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800276 configfs_drop_dentry(sd, dir);
277 configfs_put(sd);
278 break;
279 }
280 }
Al Viro59551022016-01-22 15:40:57 -0500281 inode_unlock(d_inode(dir));
Joel Becker7063fbf2005-12-15 14:29:43 -0800282}