Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * inode.c - basic inode and dentry operations.
4 *
5 * Based on sysfs:
6 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
7 *
8 * configfs Copyright (C) 2005 Oracle. All rights reserved.
9 *
10 * Please see Documentation/filesystems/configfs.rst for more
11 * information.
12 */
13
14#undef DEBUG
15
16#include <linux/pagemap.h>
17#include <linux/namei.h>
18#include <linux/backing-dev.h>
19#include <linux/capability.h>
20#include <linux/sched.h>
21#include <linux/lockdep.h>
22#include <linux/slab.h>
23
24#include <linux/configfs.h>
25#include "configfs_internal.h"
26
27#ifdef CONFIG_LOCKDEP
28static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
29#endif
30
31static const struct inode_operations configfs_inode_operations ={
32 .setattr = configfs_setattr,
33};
34
35int configfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
36 struct iattr *iattr)
37{
38 struct inode * inode = d_inode(dentry);
39 struct configfs_dirent * sd = dentry->d_fsdata;
40 struct iattr * sd_iattr;
41 unsigned int ia_valid = iattr->ia_valid;
42 int error;
43
44 if (!sd)
45 return -EINVAL;
46
47 sd_iattr = sd->s_iattr;
48 if (!sd_iattr) {
49 /* setting attributes for the first time, allocate now */
50 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
51 if (!sd_iattr)
52 return -ENOMEM;
53 /* assign default attributes */
54 sd_iattr->ia_mode = sd->s_mode;
55 sd_iattr->ia_uid = GLOBAL_ROOT_UID;
56 sd_iattr->ia_gid = GLOBAL_ROOT_GID;
57 sd_iattr->ia_atime = sd_iattr->ia_mtime =
58 sd_iattr->ia_ctime = current_time(inode);
59 sd->s_iattr = sd_iattr;
60 }
61 /* attributes were changed atleast once in past */
62
63 error = simple_setattr(mnt_userns, dentry, iattr);
64 if (error)
65 return error;
66
67 if (ia_valid & ATTR_UID)
68 sd_iattr->ia_uid = iattr->ia_uid;
69 if (ia_valid & ATTR_GID)
70 sd_iattr->ia_gid = iattr->ia_gid;
71 if (ia_valid & ATTR_ATIME)
72 sd_iattr->ia_atime = iattr->ia_atime;
73 if (ia_valid & ATTR_MTIME)
74 sd_iattr->ia_mtime = iattr->ia_mtime;
75 if (ia_valid & ATTR_CTIME)
76 sd_iattr->ia_ctime = iattr->ia_ctime;
77 if (ia_valid & ATTR_MODE) {
78 umode_t mode = iattr->ia_mode;
79
80 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
81 mode &= ~S_ISGID;
82 sd_iattr->ia_mode = sd->s_mode = mode;
83 }
84
85 return error;
86}
87
88static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
89{
90 inode->i_mode = mode;
91 inode->i_atime = inode->i_mtime =
92 inode->i_ctime = current_time(inode);
93}
94
95static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
96{
97 inode->i_mode = iattr->ia_mode;
98 inode->i_uid = iattr->ia_uid;
99 inode->i_gid = iattr->ia_gid;
100 inode->i_atime = iattr->ia_atime;
101 inode->i_mtime = iattr->ia_mtime;
102 inode->i_ctime = iattr->ia_ctime;
103}
104
105struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
106 struct super_block *s)
107{
108 struct inode * inode = new_inode(s);
109 if (inode) {
110 inode->i_ino = get_next_ino();
111 inode->i_mapping->a_ops = &ram_aops;
112 inode->i_op = &configfs_inode_operations;
113
114 if (sd->s_iattr) {
115 /* sysfs_dirent has non-default attributes
116 * get them for the new inode from persistent copy
117 * in sysfs_dirent
118 */
119 set_inode_attr(inode, sd->s_iattr);
120 } else
121 set_default_inode_attr(inode, mode);
122 }
123 return inode;
124}
125
126#ifdef CONFIG_LOCKDEP
127
128static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
129 struct inode *inode)
130{
131 int depth = sd->s_depth;
132
133 if (depth > 0) {
134 if (depth <= ARRAY_SIZE(default_group_class)) {
135 lockdep_set_class(&inode->i_rwsem,
136 &default_group_class[depth - 1]);
137 } else {
138 /*
139 * In practice the maximum level of locking depth is
140 * already reached. Just inform about possible reasons.
141 */
142 pr_info("Too many levels of inodes for the locking correctness validator.\n");
143 pr_info("Spurious warnings may appear.\n");
144 }
145 }
146}
147
148#else /* CONFIG_LOCKDEP */
149
150static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
151 struct inode *inode)
152{
153}
154
155#endif /* CONFIG_LOCKDEP */
156
157struct inode *configfs_create(struct dentry *dentry, umode_t mode)
158{
159 struct inode *inode = NULL;
160 struct configfs_dirent *sd;
161 struct inode *p_inode;
162
163 if (!dentry)
164 return ERR_PTR(-ENOENT);
165
166 if (d_really_is_positive(dentry))
167 return ERR_PTR(-EEXIST);
168
169 sd = dentry->d_fsdata;
170 inode = configfs_new_inode(mode, sd, dentry->d_sb);
171 if (!inode)
172 return ERR_PTR(-ENOMEM);
173
174 p_inode = d_inode(dentry->d_parent);
175 p_inode->i_mtime = p_inode->i_ctime = current_time(p_inode);
176 configfs_set_inode_lock_class(sd, inode);
177 return inode;
178}
179
180/*
181 * Get the name for corresponding element represented by the given configfs_dirent
182 */
183const unsigned char * configfs_get_name(struct configfs_dirent *sd)
184{
185 struct configfs_attribute *attr;
186
187 BUG_ON(!sd || !sd->s_element);
188
189 /* These always have a dentry, so use that */
190 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
191 return sd->s_dentry->d_name.name;
192
193 if (sd->s_type & (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)) {
194 attr = sd->s_element;
195 return attr->ca_name;
196 }
197 return NULL;
198}
199
200
201/*
202 * Unhashes the dentry corresponding to given configfs_dirent
203 * Called with parent inode's i_mutex held.
204 */
205void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
206{
207 struct dentry * dentry = sd->s_dentry;
208
209 if (dentry) {
210 spin_lock(&dentry->d_lock);
211 if (simple_positive(dentry)) {
212 dget_dlock(dentry);
213 __d_drop(dentry);
214 spin_unlock(&dentry->d_lock);
215 simple_unlink(d_inode(parent), dentry);
216 } else
217 spin_unlock(&dentry->d_lock);
218 }
219}
220
221void configfs_hash_and_remove(struct dentry * dir, const char * name)
222{
223 struct configfs_dirent * sd;
224 struct configfs_dirent * parent_sd = dir->d_fsdata;
225
226 if (d_really_is_negative(dir))
227 /* no inode means this hasn't been made visible yet */
228 return;
229
230 inode_lock(d_inode(dir));
231 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
232 if (!sd->s_element)
233 continue;
234 if (!strcmp(configfs_get_name(sd), name)) {
235 spin_lock(&configfs_dirent_lock);
236 list_del_init(&sd->s_sibling);
237 spin_unlock(&configfs_dirent_lock);
238 configfs_drop_dentry(sd, dir);
239 configfs_put(sd);
240 break;
241 }
242 }
243 inode_unlock(d_inode(dir));
244}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * inode.c - basic inode and dentry operations.
6 *
7 * Based on sysfs:
8 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
9 *
10 * configfs Copyright (C) 2005 Oracle. All rights reserved.
11 *
12 * Please see Documentation/filesystems/configfs/configfs.txt for more
13 * information.
14 */
15
16#undef DEBUG
17
18#include <linux/pagemap.h>
19#include <linux/namei.h>
20#include <linux/backing-dev.h>
21#include <linux/capability.h>
22#include <linux/sched.h>
23#include <linux/lockdep.h>
24#include <linux/slab.h>
25
26#include <linux/configfs.h>
27#include "configfs_internal.h"
28
29#ifdef CONFIG_LOCKDEP
30static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
31#endif
32
33static const struct address_space_operations configfs_aops = {
34 .readpage = simple_readpage,
35 .write_begin = simple_write_begin,
36 .write_end = simple_write_end,
37};
38
39static const struct inode_operations configfs_inode_operations ={
40 .setattr = configfs_setattr,
41};
42
43int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
44{
45 struct inode * inode = d_inode(dentry);
46 struct configfs_dirent * sd = dentry->d_fsdata;
47 struct iattr * sd_iattr;
48 unsigned int ia_valid = iattr->ia_valid;
49 int error;
50
51 if (!sd)
52 return -EINVAL;
53
54 sd_iattr = sd->s_iattr;
55 if (!sd_iattr) {
56 /* setting attributes for the first time, allocate now */
57 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
58 if (!sd_iattr)
59 return -ENOMEM;
60 /* assign default attributes */
61 sd_iattr->ia_mode = sd->s_mode;
62 sd_iattr->ia_uid = GLOBAL_ROOT_UID;
63 sd_iattr->ia_gid = GLOBAL_ROOT_GID;
64 sd_iattr->ia_atime = sd_iattr->ia_mtime =
65 sd_iattr->ia_ctime = current_time(inode);
66 sd->s_iattr = sd_iattr;
67 }
68 /* attributes were changed atleast once in past */
69
70 error = simple_setattr(dentry, iattr);
71 if (error)
72 return error;
73
74 if (ia_valid & ATTR_UID)
75 sd_iattr->ia_uid = iattr->ia_uid;
76 if (ia_valid & ATTR_GID)
77 sd_iattr->ia_gid = iattr->ia_gid;
78 if (ia_valid & ATTR_ATIME)
79 sd_iattr->ia_atime = timestamp_truncate(iattr->ia_atime,
80 inode);
81 if (ia_valid & ATTR_MTIME)
82 sd_iattr->ia_mtime = timestamp_truncate(iattr->ia_mtime,
83 inode);
84 if (ia_valid & ATTR_CTIME)
85 sd_iattr->ia_ctime = timestamp_truncate(iattr->ia_ctime,
86 inode);
87 if (ia_valid & ATTR_MODE) {
88 umode_t mode = iattr->ia_mode;
89
90 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
91 mode &= ~S_ISGID;
92 sd_iattr->ia_mode = sd->s_mode = mode;
93 }
94
95 return error;
96}
97
98static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
99{
100 inode->i_mode = mode;
101 inode->i_atime = inode->i_mtime =
102 inode->i_ctime = current_time(inode);
103}
104
105static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
106{
107 inode->i_mode = iattr->ia_mode;
108 inode->i_uid = iattr->ia_uid;
109 inode->i_gid = iattr->ia_gid;
110 inode->i_atime = iattr->ia_atime;
111 inode->i_mtime = iattr->ia_mtime;
112 inode->i_ctime = iattr->ia_ctime;
113}
114
115struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
116 struct super_block *s)
117{
118 struct inode * inode = new_inode(s);
119 if (inode) {
120 inode->i_ino = get_next_ino();
121 inode->i_mapping->a_ops = &configfs_aops;
122 inode->i_op = &configfs_inode_operations;
123
124 if (sd->s_iattr) {
125 /* sysfs_dirent has non-default attributes
126 * get them for the new inode from persistent copy
127 * in sysfs_dirent
128 */
129 set_inode_attr(inode, sd->s_iattr);
130 } else
131 set_default_inode_attr(inode, mode);
132 }
133 return inode;
134}
135
136#ifdef CONFIG_LOCKDEP
137
138static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
139 struct inode *inode)
140{
141 int depth = sd->s_depth;
142
143 if (depth > 0) {
144 if (depth <= ARRAY_SIZE(default_group_class)) {
145 lockdep_set_class(&inode->i_rwsem,
146 &default_group_class[depth - 1]);
147 } else {
148 /*
149 * In practice the maximum level of locking depth is
150 * already reached. Just inform about possible reasons.
151 */
152 pr_info("Too many levels of inodes for the locking correctness validator.\n");
153 pr_info("Spurious warnings may appear.\n");
154 }
155 }
156}
157
158#else /* CONFIG_LOCKDEP */
159
160static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
161 struct inode *inode)
162{
163}
164
165#endif /* CONFIG_LOCKDEP */
166
167struct inode *configfs_create(struct dentry *dentry, umode_t mode)
168{
169 struct inode *inode = NULL;
170 struct configfs_dirent *sd;
171 struct inode *p_inode;
172
173 if (!dentry)
174 return ERR_PTR(-ENOENT);
175
176 if (d_really_is_positive(dentry))
177 return ERR_PTR(-EEXIST);
178
179 sd = dentry->d_fsdata;
180 inode = configfs_new_inode(mode, sd, dentry->d_sb);
181 if (!inode)
182 return ERR_PTR(-ENOMEM);
183
184 p_inode = d_inode(dentry->d_parent);
185 p_inode->i_mtime = p_inode->i_ctime = current_time(p_inode);
186 configfs_set_inode_lock_class(sd, inode);
187 return inode;
188}
189
190/*
191 * Get the name for corresponding element represented by the given configfs_dirent
192 */
193const unsigned char * configfs_get_name(struct configfs_dirent *sd)
194{
195 struct configfs_attribute *attr;
196
197 BUG_ON(!sd || !sd->s_element);
198
199 /* These always have a dentry, so use that */
200 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
201 return sd->s_dentry->d_name.name;
202
203 if (sd->s_type & (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)) {
204 attr = sd->s_element;
205 return attr->ca_name;
206 }
207 return NULL;
208}
209
210
211/*
212 * Unhashes the dentry corresponding to given configfs_dirent
213 * Called with parent inode's i_mutex held.
214 */
215void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
216{
217 struct dentry * dentry = sd->s_dentry;
218
219 if (dentry) {
220 spin_lock(&dentry->d_lock);
221 if (simple_positive(dentry)) {
222 dget_dlock(dentry);
223 __d_drop(dentry);
224 spin_unlock(&dentry->d_lock);
225 simple_unlink(d_inode(parent), dentry);
226 } else
227 spin_unlock(&dentry->d_lock);
228 }
229}
230
231void configfs_hash_and_remove(struct dentry * dir, const char * name)
232{
233 struct configfs_dirent * sd;
234 struct configfs_dirent * parent_sd = dir->d_fsdata;
235
236 if (d_really_is_negative(dir))
237 /* no inode means this hasn't been made visible yet */
238 return;
239
240 inode_lock(d_inode(dir));
241 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
242 if (!sd->s_element)
243 continue;
244 if (!strcmp(configfs_get_name(sd), name)) {
245 spin_lock(&configfs_dirent_lock);
246 list_del_init(&sd->s_sibling);
247 spin_unlock(&configfs_dirent_lock);
248 configfs_drop_dentry(sd, dir);
249 configfs_put(sd);
250 break;
251 }
252 }
253 inode_unlock(d_inode(dir));
254}