1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> |
4 | */ |
5 | |
6 | #include <linux/hashtable.h> |
7 | #include "messages.h" |
8 | #include "props.h" |
9 | #include "btrfs_inode.h" |
10 | #include "transaction.h" |
11 | #include "ctree.h" |
12 | #include "xattr.h" |
13 | #include "compression.h" |
14 | #include "space-info.h" |
15 | #include "fs.h" |
16 | #include "accessors.h" |
17 | #include "super.h" |
18 | #include "dir-item.h" |
19 | |
20 | #define BTRFS_PROP_HANDLERS_HT_BITS 8 |
21 | static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); |
22 | |
23 | struct prop_handler { |
24 | struct hlist_node node; |
25 | const char *xattr_name; |
26 | int (*validate)(const struct btrfs_inode *inode, const char *value, |
27 | size_t len); |
28 | int (*apply)(struct inode *inode, const char *value, size_t len); |
29 | const char *(*extract)(struct inode *inode); |
30 | bool (*ignore)(const struct btrfs_inode *inode); |
31 | int inheritable; |
32 | }; |
33 | |
34 | static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash) |
35 | { |
36 | struct hlist_head *h; |
37 | |
38 | h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)]; |
39 | if (hlist_empty(h)) |
40 | return NULL; |
41 | |
42 | return h; |
43 | } |
44 | |
45 | static const struct prop_handler * |
46 | find_prop_handler(const char *name, |
47 | const struct hlist_head *handlers) |
48 | { |
49 | struct prop_handler *h; |
50 | |
51 | if (!handlers) { |
52 | u64 hash = btrfs_name_hash(name, strlen(name)); |
53 | |
54 | handlers = find_prop_handlers_by_hash(hash); |
55 | if (!handlers) |
56 | return NULL; |
57 | } |
58 | |
59 | hlist_for_each_entry(h, handlers, node) |
60 | if (!strcmp(h->xattr_name, name)) |
61 | return h; |
62 | |
63 | return NULL; |
64 | } |
65 | |
66 | int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name, |
67 | const char *value, size_t value_len) |
68 | { |
69 | const struct prop_handler *handler; |
70 | |
71 | if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN) |
72 | return -EINVAL; |
73 | |
74 | handler = find_prop_handler(name, NULL); |
75 | if (!handler) |
76 | return -EINVAL; |
77 | |
78 | if (value_len == 0) |
79 | return 0; |
80 | |
81 | return handler->validate(inode, value, value_len); |
82 | } |
83 | |
84 | /* |
85 | * Check if a property should be ignored (not set) for an inode. |
86 | * |
87 | * @inode: The target inode. |
88 | * @name: The property's name. |
89 | * |
90 | * The caller must be sure the given property name is valid, for example by |
91 | * having previously called btrfs_validate_prop(). |
92 | * |
93 | * Returns: true if the property should be ignored for the given inode |
94 | * false if the property must not be ignored for the given inode |
95 | */ |
96 | bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name) |
97 | { |
98 | const struct prop_handler *handler; |
99 | |
100 | handler = find_prop_handler(name, NULL); |
101 | ASSERT(handler != NULL); |
102 | |
103 | return handler->ignore(inode); |
104 | } |
105 | |
106 | int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode, |
107 | const char *name, const char *value, size_t value_len, |
108 | int flags) |
109 | { |
110 | const struct prop_handler *handler; |
111 | int ret; |
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, name: handler->xattr_name, |
119 | NULL, size: 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 = btrfs_setxattr(trans, inode, name: handler->xattr_name, value, |
130 | size: value_len, flags); |
131 | if (ret) |
132 | return ret; |
133 | ret = handler->apply(inode, value, value_len); |
134 | if (ret) { |
135 | btrfs_setxattr(trans, inode, name: handler->xattr_name, NULL, |
136 | size: 0, flags); |
137 | return ret; |
138 | } |
139 | |
140 | set_bit(nr: BTRFS_INODE_HAS_PROPS, addr: &BTRFS_I(inode)->runtime_flags); |
141 | |
142 | return 0; |
143 | } |
144 | |
145 | static int iterate_object_props(struct btrfs_root *root, |
146 | struct btrfs_path *path, |
147 | u64 objectid, |
148 | void (*iterator)(void *, |
149 | const struct prop_handler *, |
150 | const char *, |
151 | size_t), |
152 | void *ctx) |
153 | { |
154 | int ret; |
155 | char *name_buf = NULL; |
156 | char *value_buf = NULL; |
157 | int name_buf_len = 0; |
158 | int value_buf_len = 0; |
159 | |
160 | while (1) { |
161 | struct btrfs_key key; |
162 | struct btrfs_dir_item *di; |
163 | struct extent_buffer *leaf; |
164 | u32 total_len, cur, this_len; |
165 | int slot; |
166 | const struct hlist_head *handlers; |
167 | |
168 | slot = path->slots[0]; |
169 | leaf = path->nodes[0]; |
170 | |
171 | if (slot >= btrfs_header_nritems(eb: leaf)) { |
172 | ret = btrfs_next_leaf(root, path); |
173 | if (ret < 0) |
174 | goto out; |
175 | else if (ret > 0) |
176 | break; |
177 | continue; |
178 | } |
179 | |
180 | btrfs_item_key_to_cpu(eb: leaf, cpu_key: &key, nr: slot); |
181 | if (key.objectid != objectid) |
182 | break; |
183 | if (key.type != BTRFS_XATTR_ITEM_KEY) |
184 | break; |
185 | |
186 | handlers = find_prop_handlers_by_hash(hash: key.offset); |
187 | if (!handlers) |
188 | goto next_slot; |
189 | |
190 | di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); |
191 | cur = 0; |
192 | total_len = btrfs_item_size(eb: leaf, slot); |
193 | |
194 | while (cur < total_len) { |
195 | u32 name_len = btrfs_dir_name_len(eb: leaf, s: di); |
196 | u32 data_len = btrfs_dir_data_len(eb: leaf, s: di); |
197 | unsigned long name_ptr, data_ptr; |
198 | const struct prop_handler *handler; |
199 | |
200 | this_len = sizeof(*di) + name_len + data_len; |
201 | name_ptr = (unsigned long)(di + 1); |
202 | data_ptr = name_ptr + name_len; |
203 | |
204 | if (name_len <= XATTR_BTRFS_PREFIX_LEN || |
205 | memcmp_extent_buffer(eb: leaf, XATTR_BTRFS_PREFIX, |
206 | start: name_ptr, |
207 | XATTR_BTRFS_PREFIX_LEN)) |
208 | goto next_dir_item; |
209 | |
210 | if (name_len >= name_buf_len) { |
211 | kfree(objp: name_buf); |
212 | name_buf_len = name_len + 1; |
213 | name_buf = kmalloc(size: name_buf_len, GFP_NOFS); |
214 | if (!name_buf) { |
215 | ret = -ENOMEM; |
216 | goto out; |
217 | } |
218 | } |
219 | read_extent_buffer(eb: leaf, dst: name_buf, start: name_ptr, len: name_len); |
220 | name_buf[name_len] = '\0'; |
221 | |
222 | handler = find_prop_handler(name: name_buf, handlers); |
223 | if (!handler) |
224 | goto next_dir_item; |
225 | |
226 | if (data_len > value_buf_len) { |
227 | kfree(objp: value_buf); |
228 | value_buf_len = data_len; |
229 | value_buf = kmalloc(size: data_len, GFP_NOFS); |
230 | if (!value_buf) { |
231 | ret = -ENOMEM; |
232 | goto out; |
233 | } |
234 | } |
235 | read_extent_buffer(eb: leaf, dst: value_buf, start: data_ptr, len: data_len); |
236 | |
237 | iterator(ctx, handler, value_buf, data_len); |
238 | next_dir_item: |
239 | cur += this_len; |
240 | di = (struct btrfs_dir_item *)((char *) di + this_len); |
241 | } |
242 | |
243 | next_slot: |
244 | path->slots[0]++; |
245 | } |
246 | |
247 | ret = 0; |
248 | out: |
249 | btrfs_release_path(p: path); |
250 | kfree(objp: name_buf); |
251 | kfree(objp: value_buf); |
252 | |
253 | return ret; |
254 | } |
255 | |
256 | static void inode_prop_iterator(void *ctx, |
257 | const struct prop_handler *handler, |
258 | const char *value, |
259 | size_t len) |
260 | { |
261 | struct inode *inode = ctx; |
262 | struct btrfs_root *root = BTRFS_I(inode)->root; |
263 | int ret; |
264 | |
265 | ret = handler->apply(inode, value, len); |
266 | if (unlikely(ret)) |
267 | btrfs_warn(root->fs_info, |
268 | "error applying prop %s to ino %llu (root %llu): %d" , |
269 | handler->xattr_name, btrfs_ino(BTRFS_I(inode)), |
270 | root->root_key.objectid, ret); |
271 | else |
272 | set_bit(nr: BTRFS_INODE_HAS_PROPS, addr: &BTRFS_I(inode)->runtime_flags); |
273 | } |
274 | |
275 | int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path) |
276 | { |
277 | struct btrfs_root *root = BTRFS_I(inode)->root; |
278 | u64 ino = btrfs_ino(inode: BTRFS_I(inode)); |
279 | |
280 | return iterate_object_props(root, path, objectid: ino, iterator: inode_prop_iterator, ctx: inode); |
281 | } |
282 | |
283 | static int prop_compression_validate(const struct btrfs_inode *inode, |
284 | const char *value, size_t len) |
285 | { |
286 | if (!btrfs_inode_can_compress(inode)) |
287 | return -EINVAL; |
288 | |
289 | if (!value) |
290 | return 0; |
291 | |
292 | if (btrfs_compress_is_valid_type(str: value, len)) |
293 | return 0; |
294 | |
295 | if ((len == 2 && strncmp("no" , value, 2) == 0) || |
296 | (len == 4 && strncmp("none" , value, 4) == 0)) |
297 | return 0; |
298 | |
299 | return -EINVAL; |
300 | } |
301 | |
302 | static int prop_compression_apply(struct inode *inode, const char *value, |
303 | size_t len) |
304 | { |
305 | struct btrfs_fs_info *fs_info = btrfs_sb(sb: inode->i_sb); |
306 | int type; |
307 | |
308 | /* Reset to defaults */ |
309 | if (len == 0) { |
310 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; |
311 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; |
312 | BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE; |
313 | return 0; |
314 | } |
315 | |
316 | /* Set NOCOMPRESS flag */ |
317 | if ((len == 2 && strncmp("no" , value, 2) == 0) || |
318 | (len == 4 && strncmp("none" , value, 4) == 0)) { |
319 | BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; |
320 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; |
321 | BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE; |
322 | |
323 | return 0; |
324 | } |
325 | |
326 | if (!strncmp("lzo" , value, 3)) { |
327 | type = BTRFS_COMPRESS_LZO; |
328 | btrfs_set_fs_incompat(fs_info, COMPRESS_LZO); |
329 | } else if (!strncmp("zlib" , value, 4)) { |
330 | type = BTRFS_COMPRESS_ZLIB; |
331 | } else if (!strncmp("zstd" , value, 4)) { |
332 | type = BTRFS_COMPRESS_ZSTD; |
333 | btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD); |
334 | } else { |
335 | return -EINVAL; |
336 | } |
337 | |
338 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; |
339 | BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; |
340 | BTRFS_I(inode)->prop_compress = type; |
341 | |
342 | return 0; |
343 | } |
344 | |
345 | static bool prop_compression_ignore(const struct btrfs_inode *inode) |
346 | { |
347 | /* |
348 | * Compression only has effect for regular files, and for directories |
349 | * we set it just to propagate it to new files created inside them. |
350 | * Everything else (symlinks, devices, sockets, fifos) is pointless as |
351 | * it will do nothing, so don't waste metadata space on a compression |
352 | * xattr for anything that is neither a file nor a directory. |
353 | */ |
354 | if (!S_ISREG(inode->vfs_inode.i_mode) && |
355 | !S_ISDIR(inode->vfs_inode.i_mode)) |
356 | return true; |
357 | |
358 | return false; |
359 | } |
360 | |
361 | static const char *(struct inode *inode) |
362 | { |
363 | switch (BTRFS_I(inode)->prop_compress) { |
364 | case BTRFS_COMPRESS_ZLIB: |
365 | case BTRFS_COMPRESS_LZO: |
366 | case BTRFS_COMPRESS_ZSTD: |
367 | return btrfs_compress_type2str(type: BTRFS_I(inode)->prop_compress); |
368 | default: |
369 | break; |
370 | } |
371 | |
372 | return NULL; |
373 | } |
374 | |
375 | static struct prop_handler prop_handlers[] = { |
376 | { |
377 | .xattr_name = XATTR_BTRFS_PREFIX "compression" , |
378 | .validate = prop_compression_validate, |
379 | .apply = prop_compression_apply, |
380 | .extract = prop_compression_extract, |
381 | .ignore = prop_compression_ignore, |
382 | .inheritable = 1 |
383 | }, |
384 | }; |
385 | |
386 | int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans, |
387 | struct inode *inode, struct inode *parent) |
388 | { |
389 | struct btrfs_root *root = BTRFS_I(inode)->root; |
390 | struct btrfs_fs_info *fs_info = root->fs_info; |
391 | int ret; |
392 | int i; |
393 | bool need_reserve = false; |
394 | |
395 | if (!test_bit(BTRFS_INODE_HAS_PROPS, |
396 | &BTRFS_I(parent)->runtime_flags)) |
397 | return 0; |
398 | |
399 | for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { |
400 | const struct prop_handler *h = &prop_handlers[i]; |
401 | const char *value; |
402 | u64 num_bytes = 0; |
403 | |
404 | if (!h->inheritable) |
405 | continue; |
406 | |
407 | if (h->ignore(BTRFS_I(inode))) |
408 | continue; |
409 | |
410 | value = h->extract(parent); |
411 | if (!value) |
412 | continue; |
413 | |
414 | /* |
415 | * This is not strictly necessary as the property should be |
416 | * valid, but in case it isn't, don't propagate it further. |
417 | */ |
418 | ret = h->validate(BTRFS_I(inode), value, strlen(value)); |
419 | if (ret) |
420 | continue; |
421 | |
422 | /* |
423 | * Currently callers should be reserving 1 item for properties, |
424 | * since we only have 1 property that we currently support. If |
425 | * we add more in the future we need to try and reserve more |
426 | * space for them. But we should also revisit how we do space |
427 | * reservations if we do add more properties in the future. |
428 | */ |
429 | if (need_reserve) { |
430 | num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items: 1); |
431 | ret = btrfs_block_rsv_add(fs_info, block_rsv: trans->block_rsv, |
432 | num_bytes, |
433 | flush: BTRFS_RESERVE_NO_FLUSH); |
434 | if (ret) |
435 | return ret; |
436 | } |
437 | |
438 | ret = btrfs_setxattr(trans, inode, name: h->xattr_name, value, |
439 | strlen(value), flags: 0); |
440 | if (!ret) { |
441 | ret = h->apply(inode, value, strlen(value)); |
442 | if (ret) |
443 | btrfs_setxattr(trans, inode, name: h->xattr_name, |
444 | NULL, size: 0, flags: 0); |
445 | else |
446 | set_bit(nr: BTRFS_INODE_HAS_PROPS, |
447 | addr: &BTRFS_I(inode)->runtime_flags); |
448 | } |
449 | |
450 | if (need_reserve) { |
451 | btrfs_block_rsv_release(fs_info, block_rsv: trans->block_rsv, |
452 | num_bytes, NULL); |
453 | if (ret) |
454 | return ret; |
455 | } |
456 | need_reserve = true; |
457 | } |
458 | |
459 | return 0; |
460 | } |
461 | |
462 | int __init btrfs_props_init(void) |
463 | { |
464 | int i; |
465 | |
466 | for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { |
467 | struct prop_handler *p = &prop_handlers[i]; |
468 | u64 h = btrfs_name_hash(name: p->xattr_name, strlen(p->xattr_name)); |
469 | |
470 | hash_add(prop_handlers_ht, &p->node, h); |
471 | } |
472 | return 0; |
473 | } |
474 | |
475 | |