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 "props.h"
8 #include "btrfs_inode.h"
9 #include "transaction.h"
10 #include "ctree.h"
11 #include "xattr.h"
12 #include "compression.h"
13
14 #define BTRFS_PROP_HANDLERS_HT_BITS 8
15 static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
16
17 struct prop_handler {
18 struct hlist_node node;
19 const char *xattr_name;
20 int (*validate)(const char *value, size_t len);
21 int (*apply)(struct inode *inode, const char *value, size_t len);
22 const char *(*extract)(struct inode *inode);
23 int inheritable;
24 };
25
26 static int prop_compression_validate(const char *value, size_t len);
27 static int prop_compression_apply(struct inode *inode,
28 const char *value,
29 size_t len);
30 static const char *prop_compression_extract(struct inode *inode);
31
32 static struct prop_handler prop_handlers[] = {
33 {
34 .xattr_name = XATTR_BTRFS_PREFIX "compression",
35 .validate = prop_compression_validate,
36 .apply = prop_compression_apply,
37 .extract = prop_compression_extract,
38 .inheritable = 1
39 },
40 };
41
btrfs_props_init(void)42 void __init btrfs_props_init(void)
43 {
44 int i;
45
46 hash_init(prop_handlers_ht);
47
48 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
49 struct prop_handler *p = &prop_handlers[i];
50 u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
51
52 hash_add(prop_handlers_ht, &p->node, h);
53 }
54 }
55
find_prop_handlers_by_hash(const u64 hash)56 static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
57 {
58 struct hlist_head *h;
59
60 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
61 if (hlist_empty(h))
62 return NULL;
63
64 return h;
65 }
66
67 static const struct prop_handler *
find_prop_handler(const char * name,const struct hlist_head * handlers)68 find_prop_handler(const char *name,
69 const struct hlist_head *handlers)
70 {
71 struct prop_handler *h;
72
73 if (!handlers) {
74 u64 hash = btrfs_name_hash(name, strlen(name));
75
76 handlers = find_prop_handlers_by_hash(hash);
77 if (!handlers)
78 return NULL;
79 }
80
81 hlist_for_each_entry(h, handlers, node)
82 if (!strcmp(h->xattr_name, name))
83 return h;
84
85 return NULL;
86 }
87
__btrfs_set_prop(struct btrfs_trans_handle * trans,struct inode * inode,const char * name,const char * value,size_t value_len,int flags)88 static int __btrfs_set_prop(struct btrfs_trans_handle *trans,
89 struct inode *inode,
90 const char *name,
91 const char *value,
92 size_t value_len,
93 int flags)
94 {
95 const struct prop_handler *handler;
96 int ret;
97
98 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
99 return -EINVAL;
100
101 handler = find_prop_handler(name, NULL);
102 if (!handler)
103 return -EINVAL;
104
105 if (value_len == 0) {
106 ret = btrfs_setxattr(trans, inode, handler->xattr_name,
107 NULL, 0, flags);
108 if (ret)
109 return ret;
110
111 ret = handler->apply(inode, NULL, 0);
112 ASSERT(ret == 0);
113
114 return ret;
115 }
116
117 ret = handler->validate(value, value_len);
118 if (ret)
119 return ret;
120 ret = btrfs_setxattr(trans, inode, handler->xattr_name,
121 value, value_len, flags);
122 if (ret)
123 return ret;
124 ret = handler->apply(inode, value, value_len);
125 if (ret) {
126 btrfs_setxattr(trans, inode, handler->xattr_name,
127 NULL, 0, flags);
128 return ret;
129 }
130
131 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
132
133 return 0;
134 }
135
btrfs_set_prop(struct inode * inode,const char * name,const char * value,size_t value_len,int flags)136 int btrfs_set_prop(struct inode *inode,
137 const char *name,
138 const char *value,
139 size_t value_len,
140 int flags)
141 {
142 return __btrfs_set_prop(NULL, inode, name, value, value_len, flags);
143 }
144
iterate_object_props(struct btrfs_root * root,struct btrfs_path * path,u64 objectid,void (* iterator)(void *,const struct prop_handler *,const char *,size_t),void * ctx)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(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(leaf, &key, 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(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_nr(leaf, slot);
193
194 while (cur < total_len) {
195 u32 name_len = btrfs_dir_name_len(leaf, di);
196 u32 data_len = btrfs_dir_data_len(leaf, 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(leaf, XATTR_BTRFS_PREFIX,
206 name_ptr,
207 XATTR_BTRFS_PREFIX_LEN))
208 goto next_dir_item;
209
210 if (name_len >= name_buf_len) {
211 kfree(name_buf);
212 name_buf_len = name_len + 1;
213 name_buf = kmalloc(name_buf_len, GFP_NOFS);
214 if (!name_buf) {
215 ret = -ENOMEM;
216 goto out;
217 }
218 }
219 read_extent_buffer(leaf, name_buf, name_ptr, name_len);
220 name_buf[name_len] = '\0';
221
222 handler = find_prop_handler(name_buf, handlers);
223 if (!handler)
224 goto next_dir_item;
225
226 if (data_len > value_buf_len) {
227 kfree(value_buf);
228 value_buf_len = data_len;
229 value_buf = kmalloc(data_len, GFP_NOFS);
230 if (!value_buf) {
231 ret = -ENOMEM;
232 goto out;
233 }
234 }
235 read_extent_buffer(leaf, value_buf, data_ptr, 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(path);
250 kfree(name_buf);
251 kfree(value_buf);
252
253 return ret;
254 }
255
inode_prop_iterator(void * ctx,const struct prop_handler * handler,const char * value,size_t len)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(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
273 }
274
btrfs_load_inode_props(struct inode * inode,struct btrfs_path * path)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(BTRFS_I(inode));
279 int ret;
280
281 ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode);
282
283 return ret;
284 }
285
inherit_props(struct btrfs_trans_handle * trans,struct inode * inode,struct inode * parent)286 static int inherit_props(struct btrfs_trans_handle *trans,
287 struct inode *inode,
288 struct inode *parent)
289 {
290 struct btrfs_root *root = BTRFS_I(inode)->root;
291 struct btrfs_fs_info *fs_info = root->fs_info;
292 int ret;
293 int i;
294
295 if (!test_bit(BTRFS_INODE_HAS_PROPS,
296 &BTRFS_I(parent)->runtime_flags))
297 return 0;
298
299 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
300 const struct prop_handler *h = &prop_handlers[i];
301 const char *value;
302 u64 num_bytes;
303
304 if (!h->inheritable)
305 continue;
306
307 value = h->extract(parent);
308 if (!value)
309 continue;
310
311 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
312 ret = btrfs_block_rsv_add(root, trans->block_rsv,
313 num_bytes, BTRFS_RESERVE_NO_FLUSH);
314 if (ret)
315 goto out;
316 ret = __btrfs_set_prop(trans, inode, h->xattr_name,
317 value, strlen(value), 0);
318 btrfs_block_rsv_release(fs_info, trans->block_rsv, num_bytes);
319 if (ret)
320 goto out;
321 }
322 ret = 0;
323 out:
324 return ret;
325 }
326
btrfs_inode_inherit_props(struct btrfs_trans_handle * trans,struct inode * inode,struct inode * dir)327 int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
328 struct inode *inode,
329 struct inode *dir)
330 {
331 if (!dir)
332 return 0;
333
334 return inherit_props(trans, inode, dir);
335 }
336
btrfs_subvol_inherit_props(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_root * parent_root)337 int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans,
338 struct btrfs_root *root,
339 struct btrfs_root *parent_root)
340 {
341 struct super_block *sb = root->fs_info->sb;
342 struct btrfs_key key;
343 struct inode *parent_inode, *child_inode;
344 int ret;
345
346 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
347 key.type = BTRFS_INODE_ITEM_KEY;
348 key.offset = 0;
349
350 parent_inode = btrfs_iget(sb, &key, parent_root, NULL);
351 if (IS_ERR(parent_inode))
352 return PTR_ERR(parent_inode);
353
354 child_inode = btrfs_iget(sb, &key, root, NULL);
355 if (IS_ERR(child_inode)) {
356 iput(parent_inode);
357 return PTR_ERR(child_inode);
358 }
359
360 ret = inherit_props(trans, child_inode, parent_inode);
361 iput(child_inode);
362 iput(parent_inode);
363
364 return ret;
365 }
366
prop_compression_validate(const char * value,size_t len)367 static int prop_compression_validate(const char *value, size_t len)
368 {
369 if (!strncmp("lzo", value, len))
370 return 0;
371 else if (!strncmp("zlib", value, len))
372 return 0;
373 else if (!strncmp("zstd", value, len))
374 return 0;
375
376 return -EINVAL;
377 }
378
prop_compression_apply(struct inode * inode,const char * value,size_t len)379 static int prop_compression_apply(struct inode *inode,
380 const char *value,
381 size_t len)
382 {
383 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
384 int type;
385
386 if (len == 0) {
387 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
388 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
389 BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
390
391 return 0;
392 }
393
394 if (!strncmp("lzo", value, 3)) {
395 type = BTRFS_COMPRESS_LZO;
396 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
397 } else if (!strncmp("zlib", value, 4)) {
398 type = BTRFS_COMPRESS_ZLIB;
399 } else if (!strncmp("zstd", value, len)) {
400 type = BTRFS_COMPRESS_ZSTD;
401 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
402 } else {
403 return -EINVAL;
404 }
405
406 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
407 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
408 BTRFS_I(inode)->prop_compress = type;
409
410 return 0;
411 }
412
prop_compression_extract(struct inode * inode)413 static const char *prop_compression_extract(struct inode *inode)
414 {
415 switch (BTRFS_I(inode)->prop_compress) {
416 case BTRFS_COMPRESS_ZLIB:
417 case BTRFS_COMPRESS_LZO:
418 case BTRFS_COMPRESS_ZSTD:
419 return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
420 default:
421 break;
422 }
423
424 return NULL;
425 }
426
427
428
