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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(BTRFS_I(inode)),
51 name, 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_fs_info *fs_info = root->fs_info;
98 struct btrfs_path *path;
99 size_t name_len = strlen(name);
100 int ret = 0;
101
102 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root->fs_info))
103 return -ENOSPC;
104
105 path = btrfs_alloc_path();
106 if (!path)
107 return -ENOMEM;
108 path->skip_release_on_error = 1;
109
110 if (!value) {
111 di = btrfs_lookup_xattr(trans, root, path,
112 btrfs_ino(BTRFS_I(inode)), name, name_len, -1);
113 if (!di && (flags & XATTR_REPLACE))
114 ret = -ENODATA;
115 else if (IS_ERR(di))
116 ret = PTR_ERR(di);
117 else if (di)
118 ret = btrfs_delete_one_dir_name(trans, root, path, di);
119 goto out;
120 }
121
122
123
124
125
126
127
128
129 if (flags & XATTR_REPLACE) {
130 ASSERT(inode_is_locked(inode));
131 di = btrfs_lookup_xattr(NULL, root, path,
132 btrfs_ino(BTRFS_I(inode)), name, name_len, 0);
133 if (!di)
134 ret = -ENODATA;
135 else if (IS_ERR(di))
136 ret = PTR_ERR(di);
137 if (ret)
138 goto out;
139 btrfs_release_path(path);
140 di = NULL;
141 }
142
143 ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(BTRFS_I(inode)),
144 name, name_len, value, size);
145 if (ret == -EOVERFLOW) {
146
147
148
149
150
151 ret = 0;
152 btrfs_assert_tree_locked(path->nodes[0]);
153 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
154 if (!di && !(flags & XATTR_REPLACE)) {
155 ret = -ENOSPC;
156 goto out;
157 }
158 } else if (ret == -EEXIST) {
159 ret = 0;
160 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
161 ASSERT(di);
162 } else if (ret) {
163 goto out;
164 }
165
166 if (di && (flags & XATTR_CREATE)) {
167 ret = -EEXIST;
168 goto out;
169 }
170
171 if (di) {
172
173
174
175
176
177
178
179 const int slot = path->slots[0];
180 struct extent_buffer *leaf = path->nodes[0];
181 const u16 old_data_len = btrfs_dir_data_len(leaf, di);
182 const u32 item_size = btrfs_item_size_nr(leaf, slot);
183 const u32 data_size = sizeof(*di) + name_len + size;
184 struct btrfs_item *item;
185 unsigned long data_ptr;
186 char *ptr;
187
188 if (size > old_data_len) {
189 if (btrfs_leaf_free_space(fs_info, leaf) <
190 (size - old_data_len)) {
191 ret = -ENOSPC;
192 goto out;
193 }
194 }
195
196 if (old_data_len + name_len + sizeof(*di) == item_size) {
197
198 if (size > old_data_len)
199 btrfs_extend_item(fs_info, path,
200 size - old_data_len);
201 else if (size < old_data_len)
202 btrfs_truncate_item(fs_info, path,
203 data_size, 1);
204 } else {
205
206 ret = btrfs_delete_one_dir_name(trans, root, path, di);
207 if (ret)
208 goto out;
209 btrfs_extend_item(fs_info, path, data_size);
210 }
211
212 item = btrfs_item_nr(slot);
213 ptr = btrfs_item_ptr(leaf, slot, char);
214 ptr += btrfs_item_size(leaf, item) - data_size;
215 di = (struct btrfs_dir_item *)ptr;
216 btrfs_set_dir_data_len(leaf, di, size);
217 data_ptr = ((unsigned long)(di + 1)) + name_len;
218 write_extent_buffer(leaf, value, data_ptr, size);
219 btrfs_mark_buffer_dirty(leaf);
220 } else {
221
222
223
224
225
226 }
227out:
228 btrfs_free_path(path);
229 return ret;
230}
231
232
233
234
235int __btrfs_setxattr(struct btrfs_trans_handle *trans,
236 struct inode *inode, const char *name,
237 const void *value, size_t size, int flags)
238{
239 struct btrfs_root *root = BTRFS_I(inode)->root;
240 int ret;
241
242 if (btrfs_root_readonly(root))
243 return -EROFS;
244
245 if (trans)
246 return do_setxattr(trans, inode, name, value, size, flags);
247
248 trans = btrfs_start_transaction(root, 2);
249 if (IS_ERR(trans))
250 return PTR_ERR(trans);
251
252 ret = do_setxattr(trans, inode, name, value, size, flags);
253 if (ret)
254 goto out;
255
256 inode_inc_iversion(inode);
257 inode->i_ctime = current_time(inode);
258 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
259 ret = btrfs_update_inode(trans, root, inode);
260 BUG_ON(ret);
261out:
262 btrfs_end_transaction(trans);
263 return ret;
264}
265
266ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
267{
268 struct btrfs_key key;
269 struct inode *inode = d_inode(dentry);
270 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
271 struct btrfs_root *root = BTRFS_I(inode)->root;
272 struct btrfs_path *path;
273 int ret = 0;
274 size_t total_size = 0, size_left = size;
275
276
277
278
279
280
281 key.objectid = btrfs_ino(BTRFS_I(inode));
282 key.type = BTRFS_XATTR_ITEM_KEY;
283 key.offset = 0;
284
285 path = btrfs_alloc_path();
286 if (!path)
287 return -ENOMEM;
288 path->reada = READA_FORWARD;
289
290
291 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
292 if (ret < 0)
293 goto err;
294
295 while (1) {
296 struct extent_buffer *leaf;
297 int slot;
298 struct btrfs_dir_item *di;
299 struct btrfs_key found_key;
300 u32 item_size;
301 u32 cur;
302
303 leaf = path->nodes[0];
304 slot = path->slots[0];
305
306
307 if (slot >= btrfs_header_nritems(leaf)) {
308
309
310
311
312 ret = btrfs_next_leaf(root, path);
313 if (ret < 0)
314 goto err;
315 else if (ret > 0)
316 break;
317 continue;
318 }
319
320 btrfs_item_key_to_cpu(leaf, &found_key, slot);
321
322
323 if (found_key.objectid != key.objectid)
324 break;
325 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
326 break;
327 if (found_key.type < BTRFS_XATTR_ITEM_KEY)
328 goto next_item;
329
330 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
331 item_size = btrfs_item_size_nr(leaf, slot);
332 cur = 0;
333 while (cur < item_size) {
334 u16 name_len = btrfs_dir_name_len(leaf, di);
335 u16 data_len = btrfs_dir_data_len(leaf, di);
336 u32 this_len = sizeof(*di) + name_len + data_len;
337 unsigned long name_ptr = (unsigned long)(di + 1);
338
339 if (verify_dir_item(fs_info, leaf, di)) {
340 ret = -EIO;
341 goto err;
342 }
343
344 total_size += name_len + 1;
345
346
347
348
349 if (!size)
350 goto next;
351
352 if (!buffer || (name_len + 1) > size_left) {
353 ret = -ERANGE;
354 goto err;
355 }
356
357 read_extent_buffer(leaf, buffer, name_ptr, name_len);
358 buffer[name_len] = '\0';
359
360 size_left -= name_len + 1;
361 buffer += name_len + 1;
362next:
363 cur += this_len;
364 di = (struct btrfs_dir_item *)((char *)di + this_len);
365 }
366next_item:
367 path->slots[0]++;
368 }
369 ret = total_size;
370
371err:
372 btrfs_free_path(path);
373
374 return ret;
375}
376
377static int btrfs_xattr_handler_get(const struct xattr_handler *handler,
378 struct dentry *unused, struct inode *inode,
379 const char *name, void *buffer, size_t size)
380{
381 name = xattr_full_name(handler, name);
382 return __btrfs_getxattr(inode, name, buffer, size);
383}
384
385static int btrfs_xattr_handler_set(const struct xattr_handler *handler,
386 struct dentry *unused, struct inode *inode,
387 const char *name, const void *buffer,
388 size_t size, int flags)
389{
390 name = xattr_full_name(handler, name);
391 return __btrfs_setxattr(NULL, inode, name, buffer, size, flags);
392}
393
394static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
395 struct dentry *unused, struct inode *inode,
396 const char *name, const void *value,
397 size_t size, int flags)
398{
399 name = xattr_full_name(handler, name);
400 return btrfs_set_prop(inode, name, value, size, flags);
401}
402
403static const struct xattr_handler btrfs_security_xattr_handler = {
404 .prefix = XATTR_SECURITY_PREFIX,
405 .get = btrfs_xattr_handler_get,
406 .set = btrfs_xattr_handler_set,
407};
408
409static const struct xattr_handler btrfs_trusted_xattr_handler = {
410 .prefix = XATTR_TRUSTED_PREFIX,
411 .get = btrfs_xattr_handler_get,
412 .set = btrfs_xattr_handler_set,
413};
414
415static const struct xattr_handler btrfs_user_xattr_handler = {
416 .prefix = XATTR_USER_PREFIX,
417 .get = btrfs_xattr_handler_get,
418 .set = btrfs_xattr_handler_set,
419};
420
421static const struct xattr_handler btrfs_btrfs_xattr_handler = {
422 .prefix = XATTR_BTRFS_PREFIX,
423 .get = btrfs_xattr_handler_get,
424 .set = btrfs_xattr_handler_set_prop,
425};
426
427const struct xattr_handler *btrfs_xattr_handlers[] = {
428 &btrfs_security_xattr_handler,
429#ifdef CONFIG_BTRFS_FS_POSIX_ACL
430 &posix_acl_access_xattr_handler,
431 &posix_acl_default_xattr_handler,
432#endif
433 &btrfs_trusted_xattr_handler,
434 &btrfs_user_xattr_handler,
435 &btrfs_btrfs_xattr_handler,
436 NULL,
437};
438
439static int btrfs_initxattrs(struct inode *inode,
440 const struct xattr *xattr_array, void *fs_info)
441{
442 const struct xattr *xattr;
443 struct btrfs_trans_handle *trans = fs_info;
444 char *name;
445 int err = 0;
446
447 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
448 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
449 strlen(xattr->name) + 1, GFP_KERNEL);
450 if (!name) {
451 err = -ENOMEM;
452 break;
453 }
454 strcpy(name, XATTR_SECURITY_PREFIX);
455 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
456 err = __btrfs_setxattr(trans, inode, name,
457 xattr->value, xattr->value_len, 0);
458 kfree(name);
459 if (err < 0)
460 break;
461 }
462 return err;
463}
464
465int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
466 struct inode *inode, struct inode *dir,
467 const struct qstr *qstr)
468{
469 return security_inode_init_security(inode, dir, qstr,
470 &btrfs_initxattrs, trans);
471}
472