Line data Source code
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 :
19 : #define BTRFS_PROP_HANDLERS_HT_BITS 8
20 : static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
21 :
22 : struct prop_handler {
23 : struct hlist_node node;
24 : const char *xattr_name;
25 : int (*validate)(const struct btrfs_inode *inode, const char *value,
26 : size_t len);
27 : int (*apply)(struct inode *inode, const char *value, size_t len);
28 : const char *(*extract)(struct inode *inode);
29 : bool (*ignore)(const struct btrfs_inode *inode);
30 : int inheritable;
31 : };
32 :
33 : static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
34 : {
35 0 : struct hlist_head *h;
36 :
37 0 : h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
38 0 : if (hlist_empty(h))
39 : return NULL;
40 :
41 : return h;
42 : }
43 :
44 : static const struct prop_handler *
45 0 : find_prop_handler(const char *name,
46 : const struct hlist_head *handlers)
47 : {
48 0 : struct prop_handler *h;
49 :
50 0 : if (!handlers) {
51 0 : u64 hash = btrfs_name_hash(name, strlen(name));
52 :
53 0 : handlers = find_prop_handlers_by_hash(hash);
54 : if (!handlers)
55 : return NULL;
56 : }
57 :
58 0 : hlist_for_each_entry(h, handlers, node)
59 0 : if (!strcmp(h->xattr_name, name))
60 0 : return h;
61 :
62 : return NULL;
63 : }
64 :
65 0 : int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name,
66 : const char *value, size_t value_len)
67 : {
68 0 : const struct prop_handler *handler;
69 :
70 0 : if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
71 : return -EINVAL;
72 :
73 0 : handler = find_prop_handler(name, NULL);
74 0 : if (!handler)
75 : return -EINVAL;
76 :
77 0 : if (value_len == 0)
78 : return 0;
79 :
80 0 : return handler->validate(inode, value, value_len);
81 : }
82 :
83 : /*
84 : * Check if a property should be ignored (not set) for an inode.
85 : *
86 : * @inode: The target inode.
87 : * @name: The property's name.
88 : *
89 : * The caller must be sure the given property name is valid, for example by
90 : * having previously called btrfs_validate_prop().
91 : *
92 : * Returns: true if the property should be ignored for the given inode
93 : * false if the property must not be ignored for the given inode
94 : */
95 0 : bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name)
96 : {
97 0 : const struct prop_handler *handler;
98 :
99 0 : handler = find_prop_handler(name, NULL);
100 0 : ASSERT(handler != NULL);
101 :
102 0 : return handler->ignore(inode);
103 : }
104 :
105 0 : int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
106 : const char *name, const char *value, size_t value_len,
107 : int flags)
108 : {
109 0 : const struct prop_handler *handler;
110 0 : int ret;
111 :
112 0 : handler = find_prop_handler(name, NULL);
113 0 : if (!handler)
114 : return -EINVAL;
115 :
116 0 : if (value_len == 0) {
117 0 : ret = btrfs_setxattr(trans, inode, handler->xattr_name,
118 : NULL, 0, flags);
119 0 : if (ret)
120 : return ret;
121 :
122 0 : ret = handler->apply(inode, NULL, 0);
123 0 : ASSERT(ret == 0);
124 :
125 0 : return ret;
126 : }
127 :
128 0 : ret = btrfs_setxattr(trans, inode, handler->xattr_name, value,
129 : value_len, flags);
130 0 : if (ret)
131 : return ret;
132 0 : ret = handler->apply(inode, value, value_len);
133 0 : if (ret) {
134 0 : btrfs_setxattr(trans, inode, handler->xattr_name, NULL,
135 : 0, flags);
136 0 : return ret;
137 : }
138 :
139 0 : set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
140 :
141 : return 0;
142 : }
143 :
144 0 : static int iterate_object_props(struct btrfs_root *root,
145 : struct btrfs_path *path,
146 : u64 objectid,
147 : void (*iterator)(void *,
148 : const struct prop_handler *,
149 : const char *,
150 : size_t),
151 : void *ctx)
152 : {
153 0 : int ret;
154 0 : char *name_buf = NULL;
155 0 : char *value_buf = NULL;
156 0 : int name_buf_len = 0;
157 0 : int value_buf_len = 0;
158 :
159 0 : while (1) {
160 0 : struct btrfs_key key;
161 0 : struct btrfs_dir_item *di;
162 0 : struct extent_buffer *leaf;
163 0 : u32 total_len, cur, this_len;
164 0 : int slot;
165 0 : const struct hlist_head *handlers;
166 :
167 0 : slot = path->slots[0];
168 0 : leaf = path->nodes[0];
169 :
170 0 : if (slot >= btrfs_header_nritems(leaf)) {
171 0 : ret = btrfs_next_leaf(root, path);
172 0 : if (ret < 0)
173 0 : goto out;
174 0 : else if (ret > 0)
175 : break;
176 0 : continue;
177 : }
178 :
179 0 : btrfs_item_key_to_cpu(leaf, &key, slot);
180 0 : if (key.objectid != objectid)
181 : break;
182 0 : if (key.type != BTRFS_XATTR_ITEM_KEY)
183 : break;
184 :
185 0 : handlers = find_prop_handlers_by_hash(key.offset);
186 0 : if (!handlers)
187 0 : goto next_slot;
188 :
189 0 : di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
190 0 : cur = 0;
191 0 : total_len = btrfs_item_size(leaf, slot);
192 :
193 0 : while (cur < total_len) {
194 0 : u32 name_len = btrfs_dir_name_len(leaf, di);
195 0 : u32 data_len = btrfs_dir_data_len(leaf, di);
196 0 : unsigned long name_ptr, data_ptr;
197 0 : const struct prop_handler *handler;
198 :
199 0 : this_len = sizeof(*di) + name_len + data_len;
200 0 : name_ptr = (unsigned long)(di + 1);
201 0 : data_ptr = name_ptr + name_len;
202 :
203 0 : if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
204 0 : memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
205 : name_ptr,
206 : XATTR_BTRFS_PREFIX_LEN))
207 0 : goto next_dir_item;
208 :
209 0 : if (name_len >= name_buf_len) {
210 0 : kfree(name_buf);
211 0 : name_buf_len = name_len + 1;
212 0 : name_buf = kmalloc(name_buf_len, GFP_NOFS);
213 0 : if (!name_buf) {
214 0 : ret = -ENOMEM;
215 0 : goto out;
216 : }
217 : }
218 0 : read_extent_buffer(leaf, name_buf, name_ptr, name_len);
219 0 : name_buf[name_len] = '\0';
220 :
221 0 : handler = find_prop_handler(name_buf, handlers);
222 0 : if (!handler)
223 0 : goto next_dir_item;
224 :
225 0 : if (data_len > value_buf_len) {
226 0 : kfree(value_buf);
227 0 : value_buf_len = data_len;
228 0 : value_buf = kmalloc(data_len, GFP_NOFS);
229 0 : if (!value_buf) {
230 0 : ret = -ENOMEM;
231 0 : goto out;
232 : }
233 : }
234 0 : read_extent_buffer(leaf, value_buf, data_ptr, data_len);
235 :
236 0 : iterator(ctx, handler, value_buf, data_len);
237 0 : next_dir_item:
238 0 : cur += this_len;
239 0 : di = (struct btrfs_dir_item *)((char *) di + this_len);
240 : }
241 :
242 0 : next_slot:
243 0 : path->slots[0]++;
244 : }
245 :
246 0 : ret = 0;
247 0 : out:
248 0 : btrfs_release_path(path);
249 0 : kfree(name_buf);
250 0 : kfree(value_buf);
251 :
252 0 : return ret;
253 : }
254 :
255 0 : static void inode_prop_iterator(void *ctx,
256 : const struct prop_handler *handler,
257 : const char *value,
258 : size_t len)
259 : {
260 0 : struct inode *inode = ctx;
261 0 : struct btrfs_root *root = BTRFS_I(inode)->root;
262 0 : int ret;
263 :
264 0 : ret = handler->apply(inode, value, len);
265 0 : if (unlikely(ret))
266 0 : btrfs_warn(root->fs_info,
267 : "error applying prop %s to ino %llu (root %llu): %d",
268 : handler->xattr_name, btrfs_ino(BTRFS_I(inode)),
269 : root->root_key.objectid, ret);
270 : else
271 0 : set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
272 0 : }
273 :
274 0 : int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
275 : {
276 0 : struct btrfs_root *root = BTRFS_I(inode)->root;
277 0 : u64 ino = btrfs_ino(BTRFS_I(inode));
278 :
279 0 : return iterate_object_props(root, path, ino, inode_prop_iterator, inode);
280 : }
281 :
282 0 : static int prop_compression_validate(const struct btrfs_inode *inode,
283 : const char *value, size_t len)
284 : {
285 0 : if (!btrfs_inode_can_compress(inode))
286 : return -EINVAL;
287 :
288 0 : if (!value)
289 : return 0;
290 :
291 0 : if (btrfs_compress_is_valid_type(value, len))
292 : return 0;
293 :
294 0 : if ((len == 2 && strncmp("no", value, 2) == 0) ||
295 0 : (len == 4 && strncmp("none", value, 4) == 0))
296 0 : return 0;
297 :
298 : return -EINVAL;
299 : }
300 :
301 0 : static int prop_compression_apply(struct inode *inode, const char *value,
302 : size_t len)
303 : {
304 0 : struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
305 0 : int type;
306 :
307 : /* Reset to defaults */
308 0 : if (len == 0) {
309 0 : BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
310 0 : BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
311 0 : BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
312 0 : return 0;
313 : }
314 :
315 : /* Set NOCOMPRESS flag */
316 0 : if ((len == 2 && strncmp("no", value, 2) == 0) ||
317 0 : (len == 4 && strncmp("none", value, 4) == 0)) {
318 0 : BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
319 0 : BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
320 0 : BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
321 :
322 0 : return 0;
323 : }
324 :
325 0 : if (!strncmp("lzo", value, 3)) {
326 0 : type = BTRFS_COMPRESS_LZO;
327 0 : btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
328 0 : } else if (!strncmp("zlib", value, 4)) {
329 : type = BTRFS_COMPRESS_ZLIB;
330 0 : } else if (!strncmp("zstd", value, 4)) {
331 0 : type = BTRFS_COMPRESS_ZSTD;
332 0 : btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
333 : } else {
334 : return -EINVAL;
335 : }
336 :
337 0 : BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
338 0 : BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
339 0 : BTRFS_I(inode)->prop_compress = type;
340 :
341 0 : return 0;
342 : }
343 :
344 0 : static bool prop_compression_ignore(const struct btrfs_inode *inode)
345 : {
346 : /*
347 : * Compression only has effect for regular files, and for directories
348 : * we set it just to propagate it to new files created inside them.
349 : * Everything else (symlinks, devices, sockets, fifos) is pointless as
350 : * it will do nothing, so don't waste metadata space on a compression
351 : * xattr for anything that is neither a file nor a directory.
352 : */
353 0 : if (!S_ISREG(inode->vfs_inode.i_mode) &&
354 : !S_ISDIR(inode->vfs_inode.i_mode))
355 0 : return true;
356 :
357 : return false;
358 : }
359 :
360 0 : static const char *prop_compression_extract(struct inode *inode)
361 : {
362 0 : switch (BTRFS_I(inode)->prop_compress) {
363 : case BTRFS_COMPRESS_ZLIB:
364 : case BTRFS_COMPRESS_LZO:
365 : case BTRFS_COMPRESS_ZSTD:
366 0 : return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
367 : default:
368 : break;
369 : }
370 :
371 : return NULL;
372 : }
373 :
374 : static struct prop_handler prop_handlers[] = {
375 : {
376 : .xattr_name = XATTR_BTRFS_PREFIX "compression",
377 : .validate = prop_compression_validate,
378 : .apply = prop_compression_apply,
379 : .extract = prop_compression_extract,
380 : .ignore = prop_compression_ignore,
381 : .inheritable = 1
382 : },
383 : };
384 :
385 0 : int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
386 : struct inode *inode, struct inode *parent)
387 : {
388 0 : struct btrfs_root *root = BTRFS_I(inode)->root;
389 0 : struct btrfs_fs_info *fs_info = root->fs_info;
390 0 : int ret;
391 0 : int i;
392 0 : bool need_reserve = false;
393 :
394 0 : if (!test_bit(BTRFS_INODE_HAS_PROPS,
395 : &BTRFS_I(parent)->runtime_flags))
396 : return 0;
397 :
398 0 : for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
399 0 : const struct prop_handler *h = &prop_handlers[i];
400 0 : const char *value;
401 0 : u64 num_bytes = 0;
402 :
403 0 : if (!h->inheritable)
404 0 : continue;
405 :
406 0 : if (h->ignore(BTRFS_I(inode)))
407 0 : continue;
408 :
409 0 : value = h->extract(parent);
410 0 : if (!value)
411 0 : continue;
412 :
413 : /*
414 : * This is not strictly necessary as the property should be
415 : * valid, but in case it isn't, don't propagate it further.
416 : */
417 0 : ret = h->validate(BTRFS_I(inode), value, strlen(value));
418 0 : if (ret)
419 0 : continue;
420 :
421 : /*
422 : * Currently callers should be reserving 1 item for properties,
423 : * since we only have 1 property that we currently support. If
424 : * we add more in the future we need to try and reserve more
425 : * space for them. But we should also revisit how we do space
426 : * reservations if we do add more properties in the future.
427 : */
428 0 : if (need_reserve) {
429 0 : num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
430 0 : ret = btrfs_block_rsv_add(fs_info, trans->block_rsv,
431 : num_bytes,
432 : BTRFS_RESERVE_NO_FLUSH);
433 0 : if (ret)
434 0 : return ret;
435 : }
436 :
437 0 : ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
438 : strlen(value), 0);
439 0 : if (!ret) {
440 0 : ret = h->apply(inode, value, strlen(value));
441 0 : if (ret)
442 0 : btrfs_setxattr(trans, inode, h->xattr_name,
443 : NULL, 0, 0);
444 : else
445 0 : set_bit(BTRFS_INODE_HAS_PROPS,
446 0 : &BTRFS_I(inode)->runtime_flags);
447 : }
448 :
449 0 : if (need_reserve) {
450 0 : btrfs_block_rsv_release(fs_info, trans->block_rsv,
451 : num_bytes, NULL);
452 0 : if (ret)
453 0 : return ret;
454 : }
455 : need_reserve = true;
456 : }
457 :
458 : return 0;
459 : }
460 :
461 2 : int __init btrfs_props_init(void)
462 : {
463 2 : int i;
464 :
465 4 : for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
466 2 : struct prop_handler *p = &prop_handlers[i];
467 2 : u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
468 :
469 2 : hash_add(prop_handlers_ht, &p->node, h);
470 : }
471 2 : return 0;
472 : }
473 :
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