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19#include <linux/init.h>
20#include <linux/fs.h>
21#include <linux/slab.h>
22#include <linux/rwsem.h>
23#include <linux/xattr.h>
24#include <linux/security.h>
25#include <linux/posix_acl_xattr.h>
26#include "ctree.h"
27#include "btrfs_inode.h"
28#include "transaction.h"
29#include "xattr.h"
30#include "disk-io.h"
31#include "props.h"
32#include "locking.h"
33
34
35ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
36 void *buffer, size_t size)
37{
38 struct btrfs_dir_item *di;
39 struct btrfs_root *root = BTRFS_I(inode)->root;
40 struct btrfs_path *path;
41 struct extent_buffer *leaf;
42 int ret = 0;
43 unsigned long data_ptr;
44
45 path = btrfs_alloc_path();
46 if (!path)
47 return -ENOMEM;
48
49
50 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name,
51 strlen(name), 0);
52 if (!di) {
53 ret = -ENODATA;
54 goto out;
55 } else if (IS_ERR(di)) {
56 ret = PTR_ERR(di);
57 goto out;
58 }
59
60 leaf = path->nodes[0];
61
62 if (!size) {
63 ret = btrfs_dir_data_len(leaf, di);
64 goto out;
65 }
66
67
68 if (btrfs_dir_data_len(leaf, di) > size) {
69 ret = -ERANGE;
70 goto out;
71 }
72
73
74
75
76
77
78
79
80 data_ptr = (unsigned long)((char *)(di + 1) +
81 btrfs_dir_name_len(leaf, di));
82 read_extent_buffer(leaf, buffer, data_ptr,
83 btrfs_dir_data_len(leaf, di));
84 ret = btrfs_dir_data_len(leaf, di);
85
86out:
87 btrfs_free_path(path);
88 return ret;
89}
90
91static int do_setxattr(struct btrfs_trans_handle *trans,
92 struct inode *inode, const char *name,
93 const void *value, size_t size, int flags)
94{
95 struct btrfs_dir_item *di = NULL;
96 struct btrfs_root *root = BTRFS_I(inode)->root;
97 struct btrfs_path *path;
98 size_t name_len = strlen(name);
99 int ret = 0;
100
101 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root))
102 return -ENOSPC;
103
104 path = btrfs_alloc_path();
105 if (!path)
106 return -ENOMEM;
107 path->skip_release_on_error = 1;
108
109 if (!value) {
110 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
111 name, name_len, -1);
112 if (!di && (flags & XATTR_REPLACE))
113 ret = -ENODATA;
114 else if (IS_ERR(di))
115 ret = PTR_ERR(di);
116 else if (di)
117 ret = btrfs_delete_one_dir_name(trans, root, path, di);
118 goto out;
119 }
120
121
122
123
124
125
126
127
128 if (flags & XATTR_REPLACE) {
129 ASSERT(inode_is_locked(inode));
130 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode),
131 name, name_len, 0);
132 if (!di)
133 ret = -ENODATA;
134 else if (IS_ERR(di))
135 ret = PTR_ERR(di);
136 if (ret)
137 goto out;
138 btrfs_release_path(path);
139 di = NULL;
140 }
141
142 ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
143 name, name_len, value, size);
144 if (ret == -EOVERFLOW) {
145
146
147
148
149
150 ret = 0;
151 btrfs_assert_tree_locked(path->nodes[0]);
152 di = btrfs_match_dir_item_name(root, path, name, name_len);
153 if (!di && !(flags & XATTR_REPLACE)) {
154 ret = -ENOSPC;
155 goto out;
156 }
157 } else if (ret == -EEXIST) {
158 ret = 0;
159 di = btrfs_match_dir_item_name(root, path, name, name_len);
160 ASSERT(di);
161 } else if (ret) {
162 goto out;
163 }
164
165 if (di && (flags & XATTR_CREATE)) {
166 ret = -EEXIST;
167 goto out;
168 }
169
170 if (di) {
171
172
173
174
175
176
177
178 const int slot = path->slots[0];
179 struct extent_buffer *leaf = path->nodes[0];
180 const u16 old_data_len = btrfs_dir_data_len(leaf, di);
181 const u32 item_size = btrfs_item_size_nr(leaf, slot);
182 const u32 data_size = sizeof(*di) + name_len + size;
183 struct btrfs_item *item;
184 unsigned long data_ptr;
185 char *ptr;
186
187 if (size > old_data_len) {
188 if (btrfs_leaf_free_space(root, leaf) <
189 (size - old_data_len)) {
190 ret = -ENOSPC;
191 goto out;
192 }
193 }
194
195 if (old_data_len + name_len + sizeof(*di) == item_size) {
196
197 if (size > old_data_len)
198 btrfs_extend_item(root, path,
199 size - old_data_len);
200 else if (size < old_data_len)
201 btrfs_truncate_item(root, path, data_size, 1);
202 } else {
203
204 ret = btrfs_delete_one_dir_name(trans, root, path, di);
205 if (ret)
206 goto out;
207 btrfs_extend_item(root, path, data_size);
208 }
209
210 item = btrfs_item_nr(slot);
211 ptr = btrfs_item_ptr(leaf, slot, char);
212 ptr += btrfs_item_size(leaf, item) - data_size;
213 di = (struct btrfs_dir_item *)ptr;
214 btrfs_set_dir_data_len(leaf, di, size);
215 data_ptr = ((unsigned long)(di + 1)) + name_len;
216 write_extent_buffer(leaf, value, data_ptr, size);
217 btrfs_mark_buffer_dirty(leaf);
218 } else {
219
220
221
222
223
224 }
225out:
226 btrfs_free_path(path);
227 return ret;
228}
229
230
231
232
233int __btrfs_setxattr(struct btrfs_trans_handle *trans,
234 struct inode *inode, const char *name,
235 const void *value, size_t size, int flags)
236{
237 struct btrfs_root *root = BTRFS_I(inode)->root;
238 int ret;
239
240 if (btrfs_root_readonly(root))
241 return -EROFS;
242
243 if (trans)
244 return do_setxattr(trans, inode, name, value, size, flags);
245
246 trans = btrfs_start_transaction(root, 2);
247 if (IS_ERR(trans))
248 return PTR_ERR(trans);
249
250 ret = do_setxattr(trans, inode, name, value, size, flags);
251 if (ret)
252 goto out;
253
254 inode_inc_iversion(inode);
255 inode->i_ctime = current_time(inode);
256 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
257 ret = btrfs_update_inode(trans, root, inode);
258 BUG_ON(ret);
259out:
260 btrfs_end_transaction(trans, root);
261 return ret;
262}
263
264ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
265{
266 struct btrfs_key key;
267 struct inode *inode = d_inode(dentry);
268 struct btrfs_root *root = BTRFS_I(inode)->root;
269 struct btrfs_path *path;
270 int ret = 0;
271 size_t total_size = 0, size_left = size;
272
273
274
275
276
277
278 key.objectid = btrfs_ino(inode);
279 key.type = BTRFS_XATTR_ITEM_KEY;
280 key.offset = 0;
281
282 path = btrfs_alloc_path();
283 if (!path)
284 return -ENOMEM;
285 path->reada = READA_FORWARD;
286
287
288 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
289 if (ret < 0)
290 goto err;
291
292 while (1) {
293 struct extent_buffer *leaf;
294 int slot;
295 struct btrfs_dir_item *di;
296 struct btrfs_key found_key;
297 u32 item_size;
298 u32 cur;
299
300 leaf = path->nodes[0];
301 slot = path->slots[0];
302
303
304 if (slot >= btrfs_header_nritems(leaf)) {
305
306
307
308
309 ret = btrfs_next_leaf(root, path);
310 if (ret < 0)
311 goto err;
312 else if (ret > 0)
313 break;
314 continue;
315 }
316
317 btrfs_item_key_to_cpu(leaf, &found_key, slot);
318
319
320 if (found_key.objectid != key.objectid)
321 break;
322 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
323 break;
324 if (found_key.type < BTRFS_XATTR_ITEM_KEY)
325 goto next_item;
326
327 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
328 item_size = btrfs_item_size_nr(leaf, slot);
329 cur = 0;
330 while (cur < item_size) {
331 u16 name_len = btrfs_dir_name_len(leaf, di);
332 u16 data_len = btrfs_dir_data_len(leaf, di);
333 u32 this_len = sizeof(*di) + name_len + data_len;
334 unsigned long name_ptr = (unsigned long)(di + 1);
335
336 if (verify_dir_item(root, leaf, di)) {
337 ret = -EIO;
338 goto err;
339 }
340
341 total_size += name_len + 1;
342
343
344
345
346 if (!size)
347 goto next;
348
349 if (!buffer || (name_len + 1) > size_left) {
350 ret = -ERANGE;
351 goto err;
352 }
353
354 read_extent_buffer(leaf, buffer, name_ptr, name_len);
355 buffer[name_len] = '\0';
356
357 size_left -= name_len + 1;
358 buffer += name_len + 1;
359next:
360 cur += this_len;
361 di = (struct btrfs_dir_item *)((char *)di + this_len);
362 }
363next_item:
364 path->slots[0]++;
365 }
366 ret = total_size;
367
368err:
369 btrfs_free_path(path);
370
371 return ret;
372}
373
374static int btrfs_xattr_handler_get(const struct xattr_handler *handler,
375 struct dentry *unused, struct inode *inode,
376 const char *name, void *buffer, size_t size)
377{
378 name = xattr_full_name(handler, name);
379 return __btrfs_getxattr(inode, name, buffer, size);
380}
381
382static int btrfs_xattr_handler_set(const struct xattr_handler *handler,
383 struct dentry *unused, struct inode *inode,
384 const char *name, const void *buffer,
385 size_t size, int flags)
386{
387 name = xattr_full_name(handler, name);
388 return __btrfs_setxattr(NULL, inode, name, buffer, size, flags);
389}
390
391static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
392 struct dentry *unused, struct inode *inode,
393 const char *name, const void *value,
394 size_t size, int flags)
395{
396 name = xattr_full_name(handler, name);
397 return btrfs_set_prop(inode, name, value, size, flags);
398}
399
400static const struct xattr_handler btrfs_security_xattr_handler = {
401 .prefix = XATTR_SECURITY_PREFIX,
402 .get = btrfs_xattr_handler_get,
403 .set = btrfs_xattr_handler_set,
404};
405
406static const struct xattr_handler btrfs_trusted_xattr_handler = {
407 .prefix = XATTR_TRUSTED_PREFIX,
408 .get = btrfs_xattr_handler_get,
409 .set = btrfs_xattr_handler_set,
410};
411
412static const struct xattr_handler btrfs_user_xattr_handler = {
413 .prefix = XATTR_USER_PREFIX,
414 .get = btrfs_xattr_handler_get,
415 .set = btrfs_xattr_handler_set,
416};
417
418static const struct xattr_handler btrfs_btrfs_xattr_handler = {
419 .prefix = XATTR_BTRFS_PREFIX,
420 .get = btrfs_xattr_handler_get,
421 .set = btrfs_xattr_handler_set_prop,
422};
423
424const struct xattr_handler *btrfs_xattr_handlers[] = {
425 &btrfs_security_xattr_handler,
426#ifdef CONFIG_BTRFS_FS_POSIX_ACL
427 &posix_acl_access_xattr_handler,
428 &posix_acl_default_xattr_handler,
429#endif
430 &btrfs_trusted_xattr_handler,
431 &btrfs_user_xattr_handler,
432 &btrfs_btrfs_xattr_handler,
433 NULL,
434};
435
436static int btrfs_initxattrs(struct inode *inode,
437 const struct xattr *xattr_array, void *fs_info)
438{
439 const struct xattr *xattr;
440 struct btrfs_trans_handle *trans = fs_info;
441 char *name;
442 int err = 0;
443
444 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
445 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
446 strlen(xattr->name) + 1, GFP_KERNEL);
447 if (!name) {
448 err = -ENOMEM;
449 break;
450 }
451 strcpy(name, XATTR_SECURITY_PREFIX);
452 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
453 err = __btrfs_setxattr(trans, inode, name,
454 xattr->value, xattr->value_len, 0);
455 kfree(name);
456 if (err < 0)
457 break;
458 }
459 return err;
460}
461
462int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
463 struct inode *inode, struct inode *dir,
464 const struct qstr *qstr)
465{
466 return security_inode_init_security(inode, dir, qstr,
467 &btrfs_initxattrs, trans);
468}
469