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30#undef DEBUG
31
32#include <linux/pagemap.h>
33#include <linux/namei.h>
34#include <linux/backing-dev.h>
35#include <linux/capability.h>
36#include <linux/sched.h>
37#include <linux/lockdep.h>
38#include <linux/slab.h>
39
40#include <linux/configfs.h>
41#include "configfs_internal.h"
42
43#ifdef CONFIG_LOCKDEP
44static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
45#endif
46
47static const struct address_space_operations configfs_aops = {
48 .readpage = simple_readpage,
49 .write_begin = simple_write_begin,
50 .write_end = simple_write_end,
51};
52
53static const struct inode_operations configfs_inode_operations ={
54 .setattr = configfs_setattr,
55};
56
57int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
58{
59 struct inode * inode = d_inode(dentry);
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;
69 if (!sd_iattr) {
70
71 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
72 if (!sd_iattr)
73 return -ENOMEM;
74
75 sd_iattr->ia_mode = sd->s_mode;
76 sd_iattr->ia_uid = GLOBAL_ROOT_UID;
77 sd_iattr->ia_gid = GLOBAL_ROOT_GID;
78 sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
79 sd->s_iattr = sd_iattr;
80 }
81
82
83 error = simple_setattr(dentry, iattr);
84 if (error)
85 return error;
86
87 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
111static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
112{
113 inode->i_mode = mode;
114 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
127struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
128 struct super_block *s)
129{
130 struct inode * inode = new_inode(s);
131 if (inode) {
132 inode->i_ino = get_next_ino();
133 inode->i_mapping->a_ops = &configfs_aops;
134 inode->i_op = &configfs_inode_operations;
135
136 if (sd->s_iattr) {
137
138
139
140
141 set_inode_attr(inode, sd->s_iattr);
142 } else
143 set_default_inode_attr(inode, mode);
144 }
145 return inode;
146}
147
148#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
162
163
164 pr_info("Too many levels of inodes for the locking correctness validator.\n");
165 pr_info("Spurious warnings may appear.\n");
166 }
167 }
168}
169
170#else
171
172static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
173 struct inode *inode)
174{
175}
176
177#endif
178
179int configfs_create(struct dentry * dentry, umode_t mode, void (*init)(struct inode *))
180{
181 int error = 0;
182 struct inode *inode = NULL;
183 struct configfs_dirent *sd;
184 struct inode *p_inode;
185
186 if (!dentry)
187 return -ENOENT;
188
189 if (d_really_is_positive(dentry))
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 = d_inode(dentry->d_parent);
198 p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
199 configfs_set_inode_lock_class(sd, inode);
200
201 init(inode);
202 d_instantiate(dentry, inode);
203 if (S_ISDIR(mode) || S_ISLNK(mode))
204 dget(dentry);
205 return error;
206}
207
208
209
210
211const unsigned char * configfs_get_name(struct configfs_dirent *sd)
212{
213 struct configfs_attribute *attr;
214
215 BUG_ON(!sd || !sd->s_element);
216
217
218 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
219 return sd->s_dentry->d_name.name;
220
221 if (sd->s_type & CONFIGFS_ITEM_ATTR) {
222 attr = sd->s_element;
223 return attr->ca_name;
224 }
225 return NULL;
226}
227
228
229
230
231
232
233void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
234{
235 struct dentry * dentry = sd->s_dentry;
236
237 if (dentry) {
238 spin_lock(&dentry->d_lock);
239 if (simple_positive(dentry)) {
240 dget_dlock(dentry);
241 __d_drop(dentry);
242 spin_unlock(&dentry->d_lock);
243 simple_unlink(d_inode(parent), dentry);
244 } else
245 spin_unlock(&dentry->d_lock);
246 }
247}
248
249void configfs_hash_and_remove(struct dentry * dir, const char * name)
250{
251 struct configfs_dirent * sd;
252 struct configfs_dirent * parent_sd = dir->d_fsdata;
253
254 if (d_really_is_negative(dir))
255
256 return;
257
258 mutex_lock(&d_inode(dir)->i_mutex);
259 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
260 if (!sd->s_element)
261 continue;
262 if (!strcmp(configfs_get_name(sd), name)) {
263 spin_lock(&configfs_dirent_lock);
264 list_del_init(&sd->s_sibling);
265 spin_unlock(&configfs_dirent_lock);
266 configfs_drop_dentry(sd, dir);
267 configfs_put(sd);
268 break;
269 }
270 }
271 mutex_unlock(&d_inode(dir)->i_mutex);
272}
273