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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 mnt_idmap *idmap, 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(idmap, 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 simple_inode_init_ts(inode);
92}
93
94static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
95{
96 inode->i_mode = iattr->ia_mode;
97 inode->i_uid = iattr->ia_uid;
98 inode->i_gid = iattr->ia_gid;
99 inode_set_atime_to_ts(inode, iattr->ia_atime);
100 inode_set_mtime_to_ts(inode, iattr->ia_mtime);
101 inode_set_ctime_to_ts(inode, iattr->ia_ctime);
102}
103
104struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
105 struct super_block *s)
106{
107 struct inode * inode = new_inode(s);
108 if (inode) {
109 inode->i_ino = get_next_ino();
110 inode->i_mapping->a_ops = &ram_aops;
111 inode->i_op = &configfs_inode_operations;
112
113 if (sd->s_iattr) {
114 /* sysfs_dirent has non-default attributes
115 * get them for the new inode from persistent copy
116 * in sysfs_dirent
117 */
118 set_inode_attr(inode, sd->s_iattr);
119 } else
120 set_default_inode_attr(inode, mode);
121 }
122 return inode;
123}
124
125#ifdef CONFIG_LOCKDEP
126
127static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
128 struct inode *inode)
129{
130 int depth = sd->s_depth;
131
132 if (depth > 0) {
133 if (depth <= ARRAY_SIZE(default_group_class)) {
134 lockdep_set_class(&inode->i_rwsem,
135 &default_group_class[depth - 1]);
136 } else {
137 /*
138 * In practice the maximum level of locking depth is
139 * already reached. Just inform about possible reasons.
140 */
141 pr_info("Too many levels of inodes for the locking correctness validator.\n");
142 pr_info("Spurious warnings may appear.\n");
143 }
144 }
145}
146
147#else /* CONFIG_LOCKDEP */
148
149static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
150 struct inode *inode)
151{
152}
153
154#endif /* CONFIG_LOCKDEP */
155
156struct inode *configfs_create(struct dentry *dentry, umode_t mode)
157{
158 struct inode *inode = NULL;
159 struct configfs_dirent *sd;
160 struct inode *p_inode;
161
162 if (!dentry)
163 return ERR_PTR(-ENOENT);
164
165 if (d_really_is_positive(dentry))
166 return ERR_PTR(-EEXIST);
167
168 sd = dentry->d_fsdata;
169 inode = configfs_new_inode(mode, sd, dentry->d_sb);
170 if (!inode)
171 return ERR_PTR(-ENOMEM);
172
173 p_inode = d_inode(dentry->d_parent);
174 inode_set_mtime_to_ts(p_inode, inode_set_ctime_current(p_inode));
175 configfs_set_inode_lock_class(sd, inode);
176 return inode;
177}
178
179/*
180 * Get the name for corresponding element represented by the given configfs_dirent
181 */
182const unsigned char * configfs_get_name(struct configfs_dirent *sd)
183{
184 struct configfs_attribute *attr;
185
186 BUG_ON(!sd || !sd->s_element);
187
188 /* These always have a dentry, so use that */
189 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
190 return sd->s_dentry->d_name.name;
191
192 if (sd->s_type & (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)) {
193 attr = sd->s_element;
194 return attr->ca_name;
195 }
196 return NULL;
197}
198
199
200/*
201 * Unhashes the dentry corresponding to given configfs_dirent
202 * Called with parent inode's i_mutex held.
203 */
204void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
205{
206 struct dentry * dentry = sd->s_dentry;
207
208 if (dentry) {
209 spin_lock(&dentry->d_lock);
210 if (simple_positive(dentry)) {
211 dget_dlock(dentry);
212 __d_drop(dentry);
213 spin_unlock(&dentry->d_lock);
214 simple_unlink(d_inode(parent), dentry);
215 } else
216 spin_unlock(&dentry->d_lock);
217 }
218}
219
220void configfs_hash_and_remove(struct dentry * dir, const char * name)
221{
222 struct configfs_dirent * sd;
223 struct configfs_dirent * parent_sd = dir->d_fsdata;
224
225 if (d_really_is_negative(dir))
226 /* no inode means this hasn't been made visible yet */
227 return;
228
229 inode_lock(d_inode(dir));
230 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
231 if (!sd->s_element)
232 continue;
233 if (!strcmp(configfs_get_name(sd), name)) {
234 spin_lock(&configfs_dirent_lock);
235 list_del_init(&sd->s_sibling);
236 spin_unlock(&configfs_dirent_lock);
237 configfs_drop_dentry(sd, dir);
238 configfs_put(sd);
239 break;
240 }
241 }
242 inode_unlock(d_inode(dir));
243}
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.rst 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 = iattr->ia_atime;
80 if (ia_valid & ATTR_MTIME)
81 sd_iattr->ia_mtime = iattr->ia_mtime;
82 if (ia_valid & ATTR_CTIME)
83 sd_iattr->ia_ctime = iattr->ia_ctime;
84 if (ia_valid & ATTR_MODE) {
85 umode_t mode = iattr->ia_mode;
86
87 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
88 mode &= ~S_ISGID;
89 sd_iattr->ia_mode = sd->s_mode = mode;
90 }
91
92 return error;
93}
94
95static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
96{
97 inode->i_mode = mode;
98 inode->i_atime = inode->i_mtime =
99 inode->i_ctime = current_time(inode);
100}
101
102static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
103{
104 inode->i_mode = iattr->ia_mode;
105 inode->i_uid = iattr->ia_uid;
106 inode->i_gid = iattr->ia_gid;
107 inode->i_atime = iattr->ia_atime;
108 inode->i_mtime = iattr->ia_mtime;
109 inode->i_ctime = iattr->ia_ctime;
110}
111
112struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
113 struct super_block *s)
114{
115 struct inode * inode = new_inode(s);
116 if (inode) {
117 inode->i_ino = get_next_ino();
118 inode->i_mapping->a_ops = &configfs_aops;
119 inode->i_op = &configfs_inode_operations;
120
121 if (sd->s_iattr) {
122 /* sysfs_dirent has non-default attributes
123 * get them for the new inode from persistent copy
124 * in sysfs_dirent
125 */
126 set_inode_attr(inode, sd->s_iattr);
127 } else
128 set_default_inode_attr(inode, mode);
129 }
130 return inode;
131}
132
133#ifdef CONFIG_LOCKDEP
134
135static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
136 struct inode *inode)
137{
138 int depth = sd->s_depth;
139
140 if (depth > 0) {
141 if (depth <= ARRAY_SIZE(default_group_class)) {
142 lockdep_set_class(&inode->i_rwsem,
143 &default_group_class[depth - 1]);
144 } else {
145 /*
146 * In practice the maximum level of locking depth is
147 * already reached. Just inform about possible reasons.
148 */
149 pr_info("Too many levels of inodes for the locking correctness validator.\n");
150 pr_info("Spurious warnings may appear.\n");
151 }
152 }
153}
154
155#else /* CONFIG_LOCKDEP */
156
157static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
158 struct inode *inode)
159{
160}
161
162#endif /* CONFIG_LOCKDEP */
163
164struct inode *configfs_create(struct dentry *dentry, umode_t mode)
165{
166 struct inode *inode = NULL;
167 struct configfs_dirent *sd;
168 struct inode *p_inode;
169
170 if (!dentry)
171 return ERR_PTR(-ENOENT);
172
173 if (d_really_is_positive(dentry))
174 return ERR_PTR(-EEXIST);
175
176 sd = dentry->d_fsdata;
177 inode = configfs_new_inode(mode, sd, dentry->d_sb);
178 if (!inode)
179 return ERR_PTR(-ENOMEM);
180
181 p_inode = d_inode(dentry->d_parent);
182 p_inode->i_mtime = p_inode->i_ctime = current_time(p_inode);
183 configfs_set_inode_lock_class(sd, inode);
184 return inode;
185}
186
187/*
188 * Get the name for corresponding element represented by the given configfs_dirent
189 */
190const unsigned char * configfs_get_name(struct configfs_dirent *sd)
191{
192 struct configfs_attribute *attr;
193
194 BUG_ON(!sd || !sd->s_element);
195
196 /* These always have a dentry, so use that */
197 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
198 return sd->s_dentry->d_name.name;
199
200 if (sd->s_type & (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)) {
201 attr = sd->s_element;
202 return attr->ca_name;
203 }
204 return NULL;
205}
206
207
208/*
209 * Unhashes the dentry corresponding to given configfs_dirent
210 * Called with parent inode's i_mutex held.
211 */
212void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
213{
214 struct dentry * dentry = sd->s_dentry;
215
216 if (dentry) {
217 spin_lock(&dentry->d_lock);
218 if (simple_positive(dentry)) {
219 dget_dlock(dentry);
220 __d_drop(dentry);
221 spin_unlock(&dentry->d_lock);
222 simple_unlink(d_inode(parent), dentry);
223 } else
224 spin_unlock(&dentry->d_lock);
225 }
226}
227
228void configfs_hash_and_remove(struct dentry * dir, const char * name)
229{
230 struct configfs_dirent * sd;
231 struct configfs_dirent * parent_sd = dir->d_fsdata;
232
233 if (d_really_is_negative(dir))
234 /* no inode means this hasn't been made visible yet */
235 return;
236
237 inode_lock(d_inode(dir));
238 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
239 if (!sd->s_element)
240 continue;
241 if (!strcmp(configfs_get_name(sd), name)) {
242 spin_lock(&configfs_dirent_lock);
243 list_del_init(&sd->s_sibling);
244 spin_unlock(&configfs_dirent_lock);
245 configfs_drop_dentry(sd, dir);
246 configfs_put(sd);
247 break;
248 }
249 }
250 inode_unlock(d_inode(dir));
251}