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29#undef DEBUG
30
31#include <linux/pagemap.h>
32#include <linux/namei.h>
33#include <linux/backing-dev.h>
34#include <linux/capability.h>
35#include <linux/sched.h>
36#include <linux/lockdep.h>
37
38#include <linux/configfs.h>
39#include "configfs_internal.h"
40
41#ifdef CONFIG_LOCKDEP
42static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
43#endif
44
45extern struct super_block * configfs_sb;
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 struct backing_dev_info configfs_backing_dev_info = {
54 .name = "configfs",
55 .ra_pages = 0,
56 .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
57};
58
59static const struct inode_operations configfs_inode_operations ={
60 .setattr = configfs_setattr,
61};
62
63int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
64{
65 struct inode * inode = dentry->d_inode;
66 struct configfs_dirent * sd = dentry->d_fsdata;
67 struct iattr * sd_iattr;
68 unsigned int ia_valid = iattr->ia_valid;
69 int error;
70
71 if (!sd)
72 return -EINVAL;
73
74 sd_iattr = sd->s_iattr;
75
76 error = inode_change_ok(inode, iattr);
77 if (error)
78 return error;
79
80 error = inode_setattr(inode, iattr);
81 if (error)
82 return error;
83
84 if (!sd_iattr) {
85
86 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
87 if (!sd_iattr)
88 return -ENOMEM;
89
90 sd_iattr->ia_mode = sd->s_mode;
91 sd_iattr->ia_uid = 0;
92 sd_iattr->ia_gid = 0;
93 sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME;
94 sd->s_iattr = sd_iattr;
95 }
96
97
98
99 if (ia_valid & ATTR_UID)
100 sd_iattr->ia_uid = iattr->ia_uid;
101 if (ia_valid & ATTR_GID)
102 sd_iattr->ia_gid = iattr->ia_gid;
103 if (ia_valid & ATTR_ATIME)
104 sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime,
105 inode->i_sb->s_time_gran);
106 if (ia_valid & ATTR_MTIME)
107 sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime,
108 inode->i_sb->s_time_gran);
109 if (ia_valid & ATTR_CTIME)
110 sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime,
111 inode->i_sb->s_time_gran);
112 if (ia_valid & ATTR_MODE) {
113 umode_t mode = iattr->ia_mode;
114
115 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
116 mode &= ~S_ISGID;
117 sd_iattr->ia_mode = sd->s_mode = mode;
118 }
119
120 return error;
121}
122
123static inline void set_default_inode_attr(struct inode * inode, mode_t mode)
124{
125 inode->i_mode = mode;
126 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
127}
128
129static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
130{
131 inode->i_mode = iattr->ia_mode;
132 inode->i_uid = iattr->ia_uid;
133 inode->i_gid = iattr->ia_gid;
134 inode->i_atime = iattr->ia_atime;
135 inode->i_mtime = iattr->ia_mtime;
136 inode->i_ctime = iattr->ia_ctime;
137}
138
139struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd)
140{
141 struct inode * inode = new_inode(configfs_sb);
142 if (inode) {
143 inode->i_mapping->a_ops = &configfs_aops;
144 inode->i_mapping->backing_dev_info = &configfs_backing_dev_info;
145 inode->i_op = &configfs_inode_operations;
146
147 if (sd->s_iattr) {
148
149
150
151
152 set_inode_attr(inode, sd->s_iattr);
153 } else
154 set_default_inode_attr(inode, mode);
155 }
156 return inode;
157}
158
159#ifdef CONFIG_LOCKDEP
160
161static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
162 struct inode *inode)
163{
164 int depth = sd->s_depth;
165
166 if (depth > 0) {
167 if (depth <= ARRAY_SIZE(default_group_class)) {
168 lockdep_set_class(&inode->i_mutex,
169 &default_group_class[depth - 1]);
170 } else {
171
172
173
174
175 printk(KERN_INFO "configfs: Too many levels of inodes"
176 " for the locking correctness validator.\n");
177 printk(KERN_INFO "Spurious warnings may appear.\n");
178 }
179 }
180}
181
182#else
183
184static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
185 struct inode *inode)
186{
187}
188
189#endif
190
191int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *))
192{
193 int error = 0;
194 struct inode * inode = NULL;
195 if (dentry) {
196 if (!dentry->d_inode) {
197 struct configfs_dirent *sd = dentry->d_fsdata;
198 if ((inode = configfs_new_inode(mode, sd))) {
199 if (dentry->d_parent && dentry->d_parent->d_inode) {
200 struct inode *p_inode = dentry->d_parent->d_inode;
201 p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
202 }
203 configfs_set_inode_lock_class(sd, inode);
204 goto Proceed;
205 }
206 else
207 error = -ENOMEM;
208 } else
209 error = -EEXIST;
210 } else
211 error = -ENOENT;
212 goto Done;
213
214 Proceed:
215 if (init)
216 error = init(inode);
217 if (!error) {
218 d_instantiate(dentry, inode);
219 if (S_ISDIR(mode) || S_ISLNK(mode))
220 dget(dentry);
221 } else
222 iput(inode);
223 Done:
224 return error;
225}
226
227
228
229
230const unsigned char * configfs_get_name(struct configfs_dirent *sd)
231{
232 struct configfs_attribute *attr;
233
234 BUG_ON(!sd || !sd->s_element);
235
236
237 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
238 return sd->s_dentry->d_name.name;
239
240 if (sd->s_type & CONFIGFS_ITEM_ATTR) {
241 attr = sd->s_element;
242 return attr->ca_name;
243 }
244 return NULL;
245}
246
247
248
249
250
251
252void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
253{
254 struct dentry * dentry = sd->s_dentry;
255
256 if (dentry) {
257 spin_lock(&dcache_lock);
258 spin_lock(&dentry->d_lock);
259 if (!(d_unhashed(dentry) && dentry->d_inode)) {
260 dget_locked(dentry);
261 __d_drop(dentry);
262 spin_unlock(&dentry->d_lock);
263 spin_unlock(&dcache_lock);
264 simple_unlink(parent->d_inode, dentry);
265 } else {
266 spin_unlock(&dentry->d_lock);
267 spin_unlock(&dcache_lock);
268 }
269 }
270}
271
272void configfs_hash_and_remove(struct dentry * dir, const char * name)
273{
274 struct configfs_dirent * sd;
275 struct configfs_dirent * parent_sd = dir->d_fsdata;
276
277 if (dir->d_inode == NULL)
278
279 return;
280
281 mutex_lock(&dir->d_inode->i_mutex);
282 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
283 if (!sd->s_element)
284 continue;
285 if (!strcmp(configfs_get_name(sd), name)) {
286 spin_lock(&configfs_dirent_lock);
287 list_del_init(&sd->s_sibling);
288 spin_unlock(&configfs_dirent_lock);
289 configfs_drop_dentry(sd, dir);
290 configfs_put(sd);
291 break;
292 }
293 }
294 mutex_unlock(&dir->d_inode->i_mutex);
295}
296
297int __init configfs_inode_init(void)
298{
299 return bdi_init(&configfs_backing_dev_info);
300}
301
302void __exit configfs_inode_exit(void)
303{
304 bdi_destroy(&configfs_backing_dev_info);
305}
306