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63541927 FDBM |
1 | /* |
2 | * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
19 | #include <linux/hashtable.h> | |
20 | #include "props.h" | |
21 | #include "btrfs_inode.h" | |
22 | #include "hash.h" | |
23 | #include "transaction.h" | |
24 | #include "xattr.h" | |
25 | ||
26 | #define BTRFS_PROP_HANDLERS_HT_BITS 8 | |
27 | static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); | |
28 | ||
29 | struct prop_handler { | |
30 | struct hlist_node node; | |
31 | const char *xattr_name; | |
32 | int (*validate)(const char *value, size_t len); | |
33 | int (*apply)(struct inode *inode, const char *value, size_t len); | |
34 | const char *(*extract)(struct inode *inode); | |
35 | int inheritable; | |
36 | }; | |
37 | ||
38 | static int prop_compression_validate(const char *value, size_t len); | |
39 | static int prop_compression_apply(struct inode *inode, | |
40 | const char *value, | |
41 | size_t len); | |
42 | static const char *prop_compression_extract(struct inode *inode); | |
43 | ||
44 | static struct prop_handler prop_handlers[] = { | |
45 | { | |
46 | .xattr_name = XATTR_BTRFS_PREFIX "compression", | |
47 | .validate = prop_compression_validate, | |
48 | .apply = prop_compression_apply, | |
49 | .extract = prop_compression_extract, | |
50 | .inheritable = 1 | |
51 | }, | |
63541927 FDBM |
52 | }; |
53 | ||
54 | void __init btrfs_props_init(void) | |
55 | { | |
619ed392 | 56 | int i; |
63541927 FDBM |
57 | |
58 | hash_init(prop_handlers_ht); | |
59 | ||
619ed392 BL |
60 | for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { |
61 | struct prop_handler *p = &prop_handlers[i]; | |
63541927 FDBM |
62 | u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name)); |
63 | ||
64 | hash_add(prop_handlers_ht, &p->node, h); | |
65 | } | |
66 | } | |
67 | ||
68 | static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash) | |
69 | { | |
70 | struct hlist_head *h; | |
71 | ||
72 | h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)]; | |
73 | if (hlist_empty(h)) | |
74 | return NULL; | |
75 | ||
76 | return h; | |
77 | } | |
78 | ||
79 | static const struct prop_handler * | |
80 | find_prop_handler(const char *name, | |
81 | const struct hlist_head *handlers) | |
82 | { | |
83 | struct prop_handler *h; | |
84 | ||
85 | if (!handlers) { | |
86 | u64 hash = btrfs_name_hash(name, strlen(name)); | |
87 | ||
88 | handlers = find_prop_handlers_by_hash(hash); | |
89 | if (!handlers) | |
90 | return NULL; | |
91 | } | |
92 | ||
93 | hlist_for_each_entry(h, handlers, node) | |
94 | if (!strcmp(h->xattr_name, name)) | |
95 | return h; | |
96 | ||
97 | return NULL; | |
98 | } | |
99 | ||
100 | static int __btrfs_set_prop(struct btrfs_trans_handle *trans, | |
101 | struct inode *inode, | |
102 | const char *name, | |
103 | const char *value, | |
104 | size_t value_len, | |
105 | int flags) | |
106 | { | |
107 | const struct prop_handler *handler; | |
108 | int ret; | |
109 | ||
110 | if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN) | |
111 | return -EINVAL; | |
112 | ||
113 | handler = find_prop_handler(name, NULL); | |
114 | if (!handler) | |
115 | return -EINVAL; | |
116 | ||
117 | if (value_len == 0) { | |
118 | ret = __btrfs_setxattr(trans, inode, handler->xattr_name, | |
119 | NULL, 0, flags); | |
120 | if (ret) | |
121 | return ret; | |
122 | ||
123 | ret = handler->apply(inode, NULL, 0); | |
124 | ASSERT(ret == 0); | |
125 | ||
126 | return ret; | |
127 | } | |
128 | ||
129 | ret = handler->validate(value, value_len); | |
130 | if (ret) | |
131 | return ret; | |
132 | ret = __btrfs_setxattr(trans, inode, handler->xattr_name, | |
133 | value, value_len, flags); | |
134 | if (ret) | |
135 | return ret; | |
136 | ret = handler->apply(inode, value, value_len); | |
137 | if (ret) { | |
138 | __btrfs_setxattr(trans, inode, handler->xattr_name, | |
139 | NULL, 0, flags); | |
140 | return ret; | |
141 | } | |
142 | ||
143 | set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | int btrfs_set_prop(struct inode *inode, | |
149 | const char *name, | |
150 | const char *value, | |
151 | size_t value_len, | |
152 | int flags) | |
153 | { | |
154 | return __btrfs_set_prop(NULL, inode, name, value, value_len, flags); | |
155 | } | |
156 | ||
157 | static int iterate_object_props(struct btrfs_root *root, | |
158 | struct btrfs_path *path, | |
159 | u64 objectid, | |
160 | void (*iterator)(void *, | |
161 | const struct prop_handler *, | |
162 | const char *, | |
163 | size_t), | |
164 | void *ctx) | |
165 | { | |
166 | int ret; | |
167 | char *name_buf = NULL; | |
168 | char *value_buf = NULL; | |
169 | int name_buf_len = 0; | |
170 | int value_buf_len = 0; | |
171 | ||
172 | while (1) { | |
173 | struct btrfs_key key; | |
174 | struct btrfs_dir_item *di; | |
175 | struct extent_buffer *leaf; | |
176 | u32 total_len, cur, this_len; | |
177 | int slot; | |
178 | const struct hlist_head *handlers; | |
179 | ||
180 | slot = path->slots[0]; | |
181 | leaf = path->nodes[0]; | |
182 | ||
183 | if (slot >= btrfs_header_nritems(leaf)) { | |
184 | ret = btrfs_next_leaf(root, path); | |
185 | if (ret < 0) | |
186 | goto out; | |
187 | else if (ret > 0) | |
188 | break; | |
189 | continue; | |
190 | } | |
191 | ||
192 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
193 | if (key.objectid != objectid) | |
194 | break; | |
195 | if (key.type != BTRFS_XATTR_ITEM_KEY) | |
196 | break; | |
197 | ||
198 | handlers = find_prop_handlers_by_hash(key.offset); | |
199 | if (!handlers) | |
200 | goto next_slot; | |
201 | ||
202 | di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); | |
203 | cur = 0; | |
204 | total_len = btrfs_item_size_nr(leaf, slot); | |
205 | ||
206 | while (cur < total_len) { | |
207 | u32 name_len = btrfs_dir_name_len(leaf, di); | |
208 | u32 data_len = btrfs_dir_data_len(leaf, di); | |
209 | unsigned long name_ptr, data_ptr; | |
210 | const struct prop_handler *handler; | |
211 | ||
212 | this_len = sizeof(*di) + name_len + data_len; | |
213 | name_ptr = (unsigned long)(di + 1); | |
214 | data_ptr = name_ptr + name_len; | |
215 | ||
216 | if (name_len <= XATTR_BTRFS_PREFIX_LEN || | |
217 | memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX, | |
218 | name_ptr, | |
219 | XATTR_BTRFS_PREFIX_LEN)) | |
220 | goto next_dir_item; | |
221 | ||
222 | if (name_len >= name_buf_len) { | |
223 | kfree(name_buf); | |
224 | name_buf_len = name_len + 1; | |
225 | name_buf = kmalloc(name_buf_len, GFP_NOFS); | |
226 | if (!name_buf) { | |
227 | ret = -ENOMEM; | |
228 | goto out; | |
229 | } | |
230 | } | |
231 | read_extent_buffer(leaf, name_buf, name_ptr, name_len); | |
232 | name_buf[name_len] = '\0'; | |
233 | ||
234 | handler = find_prop_handler(name_buf, handlers); | |
235 | if (!handler) | |
236 | goto next_dir_item; | |
237 | ||
238 | if (data_len > value_buf_len) { | |
239 | kfree(value_buf); | |
240 | value_buf_len = data_len; | |
241 | value_buf = kmalloc(data_len, GFP_NOFS); | |
242 | if (!value_buf) { | |
243 | ret = -ENOMEM; | |
244 | goto out; | |
245 | } | |
246 | } | |
247 | read_extent_buffer(leaf, value_buf, data_ptr, data_len); | |
248 | ||
249 | iterator(ctx, handler, value_buf, data_len); | |
250 | next_dir_item: | |
251 | cur += this_len; | |
252 | di = (struct btrfs_dir_item *)((char *) di + this_len); | |
253 | } | |
254 | ||
255 | next_slot: | |
256 | path->slots[0]++; | |
257 | } | |
258 | ||
259 | ret = 0; | |
260 | out: | |
261 | btrfs_release_path(path); | |
262 | kfree(name_buf); | |
263 | kfree(value_buf); | |
264 | ||
265 | return ret; | |
266 | } | |
267 | ||
268 | static void inode_prop_iterator(void *ctx, | |
269 | const struct prop_handler *handler, | |
270 | const char *value, | |
271 | size_t len) | |
272 | { | |
273 | struct inode *inode = ctx; | |
274 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
275 | int ret; | |
276 | ||
277 | ret = handler->apply(inode, value, len); | |
278 | if (unlikely(ret)) | |
279 | btrfs_warn(root->fs_info, | |
280 | "error applying prop %s to ino %llu (root %llu): %d", | |
281 | handler->xattr_name, btrfs_ino(inode), | |
282 | root->root_key.objectid, ret); | |
283 | else | |
284 | set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags); | |
285 | } | |
286 | ||
287 | int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path) | |
288 | { | |
289 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
290 | u64 ino = btrfs_ino(inode); | |
291 | int ret; | |
292 | ||
293 | ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode); | |
294 | ||
295 | return ret; | |
296 | } | |
297 | ||
298 | static int inherit_props(struct btrfs_trans_handle *trans, | |
299 | struct inode *inode, | |
300 | struct inode *parent) | |
301 | { | |
63541927 FDBM |
302 | struct btrfs_root *root = BTRFS_I(inode)->root; |
303 | int ret; | |
619ed392 | 304 | int i; |
63541927 FDBM |
305 | |
306 | if (!test_bit(BTRFS_INODE_HAS_PROPS, | |
307 | &BTRFS_I(parent)->runtime_flags)) | |
308 | return 0; | |
309 | ||
619ed392 BL |
310 | for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { |
311 | const struct prop_handler *h = &prop_handlers[i]; | |
63541927 FDBM |
312 | const char *value; |
313 | u64 num_bytes; | |
314 | ||
315 | if (!h->inheritable) | |
316 | continue; | |
317 | ||
318 | value = h->extract(parent); | |
319 | if (!value) | |
320 | continue; | |
321 | ||
322 | num_bytes = btrfs_calc_trans_metadata_size(root, 1); | |
323 | ret = btrfs_block_rsv_add(root, trans->block_rsv, | |
324 | num_bytes, BTRFS_RESERVE_NO_FLUSH); | |
325 | if (ret) | |
326 | goto out; | |
327 | ret = __btrfs_set_prop(trans, inode, h->xattr_name, | |
328 | value, strlen(value), 0); | |
329 | btrfs_block_rsv_release(root, trans->block_rsv, num_bytes); | |
330 | if (ret) | |
331 | goto out; | |
332 | } | |
333 | ret = 0; | |
334 | out: | |
335 | return ret; | |
336 | } | |
337 | ||
338 | int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans, | |
339 | struct inode *inode, | |
340 | struct inode *dir) | |
341 | { | |
342 | if (!dir) | |
343 | return 0; | |
344 | ||
345 | return inherit_props(trans, inode, dir); | |
346 | } | |
347 | ||
348 | int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans, | |
349 | struct btrfs_root *root, | |
350 | struct btrfs_root *parent_root) | |
351 | { | |
352 | struct btrfs_key key; | |
353 | struct inode *parent_inode, *child_inode; | |
354 | int ret; | |
355 | ||
356 | key.objectid = BTRFS_FIRST_FREE_OBJECTID; | |
357 | key.type = BTRFS_INODE_ITEM_KEY; | |
358 | key.offset = 0; | |
359 | ||
360 | parent_inode = btrfs_iget(parent_root->fs_info->sb, &key, | |
361 | parent_root, NULL); | |
362 | if (IS_ERR(parent_inode)) | |
363 | return PTR_ERR(parent_inode); | |
364 | ||
365 | child_inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); | |
366 | if (IS_ERR(child_inode)) { | |
367 | iput(parent_inode); | |
368 | return PTR_ERR(child_inode); | |
369 | } | |
370 | ||
371 | ret = inherit_props(trans, child_inode, parent_inode); | |
372 | iput(child_inode); | |
373 | iput(parent_inode); | |
374 | ||
375 | return ret; | |
376 | } | |
377 | ||
378 | static int prop_compression_validate(const char *value, size_t len) | |
379 | { | |
380 | if (!strncmp("lzo", value, len)) | |
381 | return 0; | |
382 | else if (!strncmp("zlib", value, len)) | |
383 | return 0; | |
384 | ||
385 | return -EINVAL; | |
386 | } | |
387 | ||
388 | static int prop_compression_apply(struct inode *inode, | |
389 | const char *value, | |
390 | size_t len) | |
391 | { | |
392 | int type; | |
393 | ||
394 | if (len == 0) { | |
395 | BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; | |
396 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; | |
397 | BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE; | |
398 | ||
399 | return 0; | |
400 | } | |
401 | ||
402 | if (!strncmp("lzo", value, len)) | |
403 | type = BTRFS_COMPRESS_LZO; | |
404 | else if (!strncmp("zlib", value, len)) | |
405 | type = BTRFS_COMPRESS_ZLIB; | |
406 | else | |
407 | return -EINVAL; | |
408 | ||
409 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; | |
410 | BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; | |
411 | BTRFS_I(inode)->force_compress = type; | |
412 | ||
413 | return 0; | |
414 | } | |
415 | ||
416 | static const char *prop_compression_extract(struct inode *inode) | |
417 | { | |
418 | switch (BTRFS_I(inode)->force_compress) { | |
419 | case BTRFS_COMPRESS_ZLIB: | |
420 | return "zlib"; | |
421 | case BTRFS_COMPRESS_LZO: | |
422 | return "lzo"; | |
423 | } | |
424 | ||
425 | return NULL; | |
426 | } | |
e8c9f186 DS |
427 | |
428 |