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af48b85b JK |
1 | /** |
2 | * fs/f2fs/xattr.c | |
3 | * | |
4 | * Copyright (c) 2012 Samsung Electronics Co., Ltd. | |
5 | * http://www.samsung.com/ | |
6 | * | |
7 | * Portions of this code from linux/fs/ext2/xattr.c | |
8 | * | |
9 | * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de> | |
10 | * | |
11 | * Fix by Harrison Xing <harrison@mountainviewdata.com>. | |
12 | * Extended attributes for symlinks and special files added per | |
13 | * suggestion of Luka Renko <luka.renko@hermes.si>. | |
14 | * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, | |
15 | * Red Hat Inc. | |
16 | * | |
17 | * This program is free software; you can redistribute it and/or modify | |
18 | * it under the terms of the GNU General Public License version 2 as | |
19 | * published by the Free Software Foundation. | |
20 | */ | |
21 | #include <linux/rwsem.h> | |
22 | #include <linux/f2fs_fs.h> | |
23 | #include "f2fs.h" | |
24 | #include "xattr.h" | |
25 | ||
26 | static size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list, | |
27 | size_t list_size, const char *name, size_t name_len, int type) | |
28 | { | |
29 | struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb); | |
30 | int total_len, prefix_len = 0; | |
31 | const char *prefix = NULL; | |
32 | ||
33 | switch (type) { | |
34 | case F2FS_XATTR_INDEX_USER: | |
35 | if (!test_opt(sbi, XATTR_USER)) | |
36 | return -EOPNOTSUPP; | |
37 | prefix = XATTR_USER_PREFIX; | |
38 | prefix_len = XATTR_USER_PREFIX_LEN; | |
39 | break; | |
40 | case F2FS_XATTR_INDEX_TRUSTED: | |
41 | if (!capable(CAP_SYS_ADMIN)) | |
42 | return -EPERM; | |
43 | prefix = XATTR_TRUSTED_PREFIX; | |
44 | prefix_len = XATTR_TRUSTED_PREFIX_LEN; | |
45 | break; | |
46 | default: | |
47 | return -EINVAL; | |
48 | } | |
49 | ||
50 | total_len = prefix_len + name_len + 1; | |
51 | if (list && total_len <= list_size) { | |
52 | memcpy(list, prefix, prefix_len); | |
53 | memcpy(list+prefix_len, name, name_len); | |
54 | list[prefix_len + name_len] = '\0'; | |
55 | } | |
56 | return total_len; | |
57 | } | |
58 | ||
59 | static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name, | |
60 | void *buffer, size_t size, int type) | |
61 | { | |
62 | struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb); | |
63 | ||
64 | switch (type) { | |
65 | case F2FS_XATTR_INDEX_USER: | |
66 | if (!test_opt(sbi, XATTR_USER)) | |
67 | return -EOPNOTSUPP; | |
68 | break; | |
69 | case F2FS_XATTR_INDEX_TRUSTED: | |
70 | if (!capable(CAP_SYS_ADMIN)) | |
71 | return -EPERM; | |
72 | break; | |
73 | default: | |
74 | return -EINVAL; | |
75 | } | |
76 | if (strcmp(name, "") == 0) | |
77 | return -EINVAL; | |
78 | return f2fs_getxattr(dentry->d_inode, type, name, | |
79 | buffer, size); | |
80 | } | |
81 | ||
82 | static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name, | |
83 | const void *value, size_t size, int flags, int type) | |
84 | { | |
85 | struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb); | |
86 | ||
87 | switch (type) { | |
88 | case F2FS_XATTR_INDEX_USER: | |
89 | if (!test_opt(sbi, XATTR_USER)) | |
90 | return -EOPNOTSUPP; | |
91 | break; | |
92 | case F2FS_XATTR_INDEX_TRUSTED: | |
93 | if (!capable(CAP_SYS_ADMIN)) | |
94 | return -EPERM; | |
95 | break; | |
96 | default: | |
97 | return -EINVAL; | |
98 | } | |
99 | if (strcmp(name, "") == 0) | |
100 | return -EINVAL; | |
101 | ||
102 | return f2fs_setxattr(dentry->d_inode, type, name, value, size); | |
103 | } | |
104 | ||
105 | const struct xattr_handler f2fs_xattr_user_handler = { | |
106 | .prefix = XATTR_USER_PREFIX, | |
107 | .flags = F2FS_XATTR_INDEX_USER, | |
108 | .list = f2fs_xattr_generic_list, | |
109 | .get = f2fs_xattr_generic_get, | |
110 | .set = f2fs_xattr_generic_set, | |
111 | }; | |
112 | ||
113 | const struct xattr_handler f2fs_xattr_trusted_handler = { | |
114 | .prefix = XATTR_TRUSTED_PREFIX, | |
115 | .flags = F2FS_XATTR_INDEX_TRUSTED, | |
116 | .list = f2fs_xattr_generic_list, | |
117 | .get = f2fs_xattr_generic_get, | |
118 | .set = f2fs_xattr_generic_set, | |
119 | }; | |
120 | ||
121 | static const struct xattr_handler *f2fs_xattr_handler_map[] = { | |
122 | [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler, | |
123 | #ifdef CONFIG_F2FS_FS_POSIX_ACL | |
124 | [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &f2fs_xattr_acl_access_handler, | |
125 | [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &f2fs_xattr_acl_default_handler, | |
126 | #endif | |
127 | [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler, | |
128 | [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler, | |
129 | }; | |
130 | ||
131 | const struct xattr_handler *f2fs_xattr_handlers[] = { | |
132 | &f2fs_xattr_user_handler, | |
133 | #ifdef CONFIG_F2FS_FS_POSIX_ACL | |
134 | &f2fs_xattr_acl_access_handler, | |
135 | &f2fs_xattr_acl_default_handler, | |
136 | #endif | |
137 | &f2fs_xattr_trusted_handler, | |
138 | &f2fs_xattr_advise_handler, | |
139 | NULL, | |
140 | }; | |
141 | ||
142 | static inline const struct xattr_handler *f2fs_xattr_handler(int name_index) | |
143 | { | |
144 | const struct xattr_handler *handler = NULL; | |
145 | ||
146 | if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map)) | |
147 | handler = f2fs_xattr_handler_map[name_index]; | |
148 | return handler; | |
149 | } | |
150 | ||
151 | int f2fs_getxattr(struct inode *inode, int name_index, const char *name, | |
152 | void *buffer, size_t buffer_size) | |
153 | { | |
154 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
155 | struct f2fs_inode_info *fi = F2FS_I(inode); | |
156 | struct f2fs_xattr_entry *entry; | |
157 | struct page *page; | |
158 | void *base_addr; | |
159 | int error = 0, found = 0; | |
160 | int value_len, name_len; | |
161 | ||
162 | if (name == NULL) | |
163 | return -EINVAL; | |
164 | name_len = strlen(name); | |
165 | ||
166 | if (!fi->i_xattr_nid) | |
167 | return -ENODATA; | |
168 | ||
169 | page = get_node_page(sbi, fi->i_xattr_nid); | |
170 | base_addr = page_address(page); | |
171 | ||
172 | list_for_each_xattr(entry, base_addr) { | |
173 | if (entry->e_name_index != name_index) | |
174 | continue; | |
175 | if (entry->e_name_len != name_len) | |
176 | continue; | |
177 | if (!memcmp(entry->e_name, name, name_len)) { | |
178 | found = 1; | |
179 | break; | |
180 | } | |
181 | } | |
182 | if (!found) { | |
183 | error = -ENODATA; | |
184 | goto cleanup; | |
185 | } | |
186 | ||
187 | value_len = le16_to_cpu(entry->e_value_size); | |
188 | ||
189 | if (buffer && value_len > buffer_size) { | |
190 | error = -ERANGE; | |
191 | goto cleanup; | |
192 | } | |
193 | ||
194 | if (buffer) { | |
195 | char *pval = entry->e_name + entry->e_name_len; | |
196 | memcpy(buffer, pval, value_len); | |
197 | } | |
198 | error = value_len; | |
199 | ||
200 | cleanup: | |
201 | f2fs_put_page(page, 1); | |
202 | return error; | |
203 | } | |
204 | ||
205 | ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) | |
206 | { | |
207 | struct inode *inode = dentry->d_inode; | |
208 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
209 | struct f2fs_inode_info *fi = F2FS_I(inode); | |
210 | struct f2fs_xattr_entry *entry; | |
211 | struct page *page; | |
212 | void *base_addr; | |
213 | int error = 0; | |
214 | size_t rest = buffer_size; | |
215 | ||
216 | if (!fi->i_xattr_nid) | |
217 | return 0; | |
218 | ||
219 | page = get_node_page(sbi, fi->i_xattr_nid); | |
220 | base_addr = page_address(page); | |
221 | ||
222 | list_for_each_xattr(entry, base_addr) { | |
223 | const struct xattr_handler *handler = | |
224 | f2fs_xattr_handler(entry->e_name_index); | |
225 | size_t size; | |
226 | ||
227 | if (!handler) | |
228 | continue; | |
229 | ||
230 | size = handler->list(dentry, buffer, rest, entry->e_name, | |
231 | entry->e_name_len, handler->flags); | |
232 | if (buffer && size > rest) { | |
233 | error = -ERANGE; | |
234 | goto cleanup; | |
235 | } | |
236 | ||
237 | if (buffer) | |
238 | buffer += size; | |
239 | rest -= size; | |
240 | } | |
241 | error = buffer_size - rest; | |
242 | cleanup: | |
243 | f2fs_put_page(page, 1); | |
244 | return error; | |
245 | } | |
246 | ||
247 | int f2fs_setxattr(struct inode *inode, int name_index, const char *name, | |
248 | const void *value, size_t value_len) | |
249 | { | |
250 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
251 | struct f2fs_inode_info *fi = F2FS_I(inode); | |
252 | struct f2fs_xattr_header *header = NULL; | |
253 | struct f2fs_xattr_entry *here, *last; | |
254 | struct page *page; | |
255 | void *base_addr; | |
256 | int error, found, free, name_len, newsize; | |
257 | char *pval; | |
258 | ||
259 | if (name == NULL) | |
260 | return -EINVAL; | |
261 | name_len = strlen(name); | |
262 | ||
263 | if (value == NULL) | |
264 | value_len = 0; | |
265 | ||
266 | if (name_len > 255 || value_len > MAX_VALUE_LEN) | |
267 | return -ERANGE; | |
268 | ||
269 | mutex_lock_op(sbi, NODE_NEW); | |
270 | if (!fi->i_xattr_nid) { | |
271 | /* Allocate new attribute block */ | |
272 | struct dnode_of_data dn; | |
273 | ||
274 | if (!alloc_nid(sbi, &fi->i_xattr_nid)) { | |
275 | mutex_unlock_op(sbi, NODE_NEW); | |
276 | return -ENOSPC; | |
277 | } | |
278 | set_new_dnode(&dn, inode, NULL, NULL, fi->i_xattr_nid); | |
279 | mark_inode_dirty(inode); | |
280 | ||
281 | page = new_node_page(&dn, XATTR_NODE_OFFSET); | |
282 | if (IS_ERR(page)) { | |
283 | alloc_nid_failed(sbi, fi->i_xattr_nid); | |
284 | fi->i_xattr_nid = 0; | |
285 | mutex_unlock_op(sbi, NODE_NEW); | |
286 | return PTR_ERR(page); | |
287 | } | |
288 | ||
289 | alloc_nid_done(sbi, fi->i_xattr_nid); | |
290 | base_addr = page_address(page); | |
291 | header = XATTR_HDR(base_addr); | |
292 | header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC); | |
293 | header->h_refcount = cpu_to_le32(1); | |
294 | } else { | |
295 | /* The inode already has an extended attribute block. */ | |
296 | page = get_node_page(sbi, fi->i_xattr_nid); | |
297 | if (IS_ERR(page)) { | |
298 | mutex_unlock_op(sbi, NODE_NEW); | |
299 | return PTR_ERR(page); | |
300 | } | |
301 | ||
302 | base_addr = page_address(page); | |
303 | header = XATTR_HDR(base_addr); | |
304 | } | |
305 | ||
306 | if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) { | |
307 | error = -EIO; | |
308 | goto cleanup; | |
309 | } | |
310 | ||
311 | /* find entry with wanted name. */ | |
312 | found = 0; | |
313 | list_for_each_xattr(here, base_addr) { | |
314 | if (here->e_name_index != name_index) | |
315 | continue; | |
316 | if (here->e_name_len != name_len) | |
317 | continue; | |
318 | if (!memcmp(here->e_name, name, name_len)) { | |
319 | found = 1; | |
320 | break; | |
321 | } | |
322 | } | |
323 | ||
324 | last = here; | |
325 | ||
326 | while (!IS_XATTR_LAST_ENTRY(last)) | |
327 | last = XATTR_NEXT_ENTRY(last); | |
328 | ||
329 | newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + | |
330 | name_len + value_len); | |
331 | ||
332 | /* 1. Check space */ | |
333 | if (value) { | |
334 | /* If value is NULL, it is remove operation. | |
335 | * In case of update operation, we caculate free. | |
336 | */ | |
337 | free = MIN_OFFSET - ((char *)last - (char *)header); | |
338 | if (found) | |
339 | free = free - ENTRY_SIZE(here); | |
340 | ||
341 | if (free < newsize) { | |
342 | error = -ENOSPC; | |
343 | goto cleanup; | |
344 | } | |
345 | } | |
346 | ||
347 | /* 2. Remove old entry */ | |
348 | if (found) { | |
349 | /* If entry is found, remove old entry. | |
350 | * If not found, remove operation is not needed. | |
351 | */ | |
352 | struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here); | |
353 | int oldsize = ENTRY_SIZE(here); | |
354 | ||
355 | memmove(here, next, (char *)last - (char *)next); | |
356 | last = (struct f2fs_xattr_entry *)((char *)last - oldsize); | |
357 | memset(last, 0, oldsize); | |
358 | } | |
359 | ||
360 | /* 3. Write new entry */ | |
361 | if (value) { | |
362 | /* Before we come here, old entry is removed. | |
363 | * We just write new entry. */ | |
364 | memset(last, 0, newsize); | |
365 | last->e_name_index = name_index; | |
366 | last->e_name_len = name_len; | |
367 | memcpy(last->e_name, name, name_len); | |
368 | pval = last->e_name + name_len; | |
369 | memcpy(pval, value, value_len); | |
370 | last->e_value_size = cpu_to_le16(value_len); | |
371 | } | |
372 | ||
373 | set_page_dirty(page); | |
374 | f2fs_put_page(page, 1); | |
375 | ||
376 | if (is_inode_flag_set(fi, FI_ACL_MODE)) { | |
377 | inode->i_mode = fi->i_acl_mode; | |
378 | inode->i_ctime = CURRENT_TIME; | |
379 | clear_inode_flag(fi, FI_ACL_MODE); | |
380 | } | |
381 | f2fs_write_inode(inode, NULL); | |
382 | mutex_unlock_op(sbi, NODE_NEW); | |
383 | ||
384 | return 0; | |
385 | cleanup: | |
386 | f2fs_put_page(page, 1); | |
387 | mutex_unlock_op(sbi, NODE_NEW); | |
388 | return error; | |
389 | } |