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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#include "compression.h"
26
27#define BTRFS_PROP_HANDLERS_HT_BITS 8
28static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
29
30struct prop_handler {
31 struct hlist_node node;
32 const char *xattr_name;
33 int (*validate)(const char *value, size_t len);
34 int (*apply)(struct inode *inode, const char *value, size_t len);
35 const char *(*extract)(struct inode *inode);
36 int inheritable;
37};
38
39static int prop_compression_validate(const char *value, size_t len);
40static int prop_compression_apply(struct inode *inode,
41 const char *value,
42 size_t len);
43static const char *prop_compression_extract(struct inode *inode);
44
45static struct prop_handler prop_handlers[] = {
46 {
47 .xattr_name = XATTR_BTRFS_PREFIX "compression",
48 .validate = prop_compression_validate,
49 .apply = prop_compression_apply,
50 .extract = prop_compression_extract,
51 .inheritable = 1
52 },
53};
54
55void __init btrfs_props_init(void)
56{
57 int i;
58
59 hash_init(prop_handlers_ht);
60
61 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
62 struct prop_handler *p = &prop_handlers[i];
63 u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
64
65 hash_add(prop_handlers_ht, &p->node, h);
66 }
67}
68
69static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
70{
71 struct hlist_head *h;
72
73 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
74 if (hlist_empty(h))
75 return NULL;
76
77 return h;
78}
79
80static const struct prop_handler *
81find_prop_handler(const char *name,
82 const struct hlist_head *handlers)
83{
84 struct prop_handler *h;
85
86 if (!handlers) {
87 u64 hash = btrfs_name_hash(name, strlen(name));
88
89 handlers = find_prop_handlers_by_hash(hash);
90 if (!handlers)
91 return NULL;
92 }
93
94 hlist_for_each_entry(h, handlers, node)
95 if (!strcmp(h->xattr_name, name))
96 return h;
97
98 return NULL;
99}
100
101static int __btrfs_set_prop(struct btrfs_trans_handle *trans,
102 struct inode *inode,
103 const char *name,
104 const char *value,
105 size_t value_len,
106 int flags)
107{
108 const struct prop_handler *handler;
109 int ret;
110
111 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
112 return -EINVAL;
113
114 handler = find_prop_handler(name, NULL);
115 if (!handler)
116 return -EINVAL;
117
118 if (value_len == 0) {
119 ret = __btrfs_setxattr(trans, inode, handler->xattr_name,
120 NULL, 0, flags);
121 if (ret)
122 return ret;
123
124 ret = handler->apply(inode, NULL, 0);
125 ASSERT(ret == 0);
126
127 return ret;
128 }
129
130 ret = handler->validate(value, value_len);
131 if (ret)
132 return ret;
133 ret = __btrfs_setxattr(trans, inode, handler->xattr_name,
134 value, value_len, flags);
135 if (ret)
136 return ret;
137 ret = handler->apply(inode, value, value_len);
138 if (ret) {
139 __btrfs_setxattr(trans, inode, handler->xattr_name,
140 NULL, 0, flags);
141 return ret;
142 }
143
144 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
145
146 return 0;
147}
148
149int btrfs_set_prop(struct inode *inode,
150 const char *name,
151 const char *value,
152 size_t value_len,
153 int flags)
154{
155 return __btrfs_set_prop(NULL, inode, name, value, value_len, flags);
156}
157
158static int iterate_object_props(struct btrfs_root *root,
159 struct btrfs_path *path,
160 u64 objectid,
161 void (*iterator)(void *,
162 const struct prop_handler *,
163 const char *,
164 size_t),
165 void *ctx)
166{
167 struct btrfs_fs_info *fs_info = root->fs_info;
168 int ret;
169 char *name_buf = NULL;
170 char *value_buf = NULL;
171 int name_buf_len = 0;
172 int value_buf_len = 0;
173
174 while (1) {
175 struct btrfs_key key;
176 struct btrfs_dir_item *di;
177 struct extent_buffer *leaf;
178 u32 total_len, cur, this_len;
179 int slot;
180 const struct hlist_head *handlers;
181
182 slot = path->slots[0];
183 leaf = path->nodes[0];
184
185 if (slot >= btrfs_header_nritems(leaf)) {
186 ret = btrfs_next_leaf(root, path);
187 if (ret < 0)
188 goto out;
189 else if (ret > 0)
190 break;
191 continue;
192 }
193
194 btrfs_item_key_to_cpu(leaf, &key, slot);
195 if (key.objectid != objectid)
196 break;
197 if (key.type != BTRFS_XATTR_ITEM_KEY)
198 break;
199
200 handlers = find_prop_handlers_by_hash(key.offset);
201 if (!handlers)
202 goto next_slot;
203
204 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
205 cur = 0;
206 total_len = btrfs_item_size_nr(leaf, slot);
207
208 while (cur < total_len) {
209 u32 name_len = btrfs_dir_name_len(leaf, di);
210 u32 data_len = btrfs_dir_data_len(leaf, di);
211 unsigned long name_ptr, data_ptr;
212 const struct prop_handler *handler;
213
214 this_len = sizeof(*di) + name_len + data_len;
215 name_ptr = (unsigned long)(di + 1);
216 data_ptr = name_ptr + name_len;
217
218 if (verify_dir_item(fs_info, leaf,
219 path->slots[0], di)) {
220 ret = -EIO;
221 goto out;
222 }
223
224 if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
225 memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
226 name_ptr,
227 XATTR_BTRFS_PREFIX_LEN))
228 goto next_dir_item;
229
230 if (name_len >= name_buf_len) {
231 kfree(name_buf);
232 name_buf_len = name_len + 1;
233 name_buf = kmalloc(name_buf_len, GFP_NOFS);
234 if (!name_buf) {
235 ret = -ENOMEM;
236 goto out;
237 }
238 }
239 read_extent_buffer(leaf, name_buf, name_ptr, name_len);
240 name_buf[name_len] = '\0';
241
242 handler = find_prop_handler(name_buf, handlers);
243 if (!handler)
244 goto next_dir_item;
245
246 if (data_len > value_buf_len) {
247 kfree(value_buf);
248 value_buf_len = data_len;
249 value_buf = kmalloc(data_len, GFP_NOFS);
250 if (!value_buf) {
251 ret = -ENOMEM;
252 goto out;
253 }
254 }
255 read_extent_buffer(leaf, value_buf, data_ptr, data_len);
256
257 iterator(ctx, handler, value_buf, data_len);
258next_dir_item:
259 cur += this_len;
260 di = (struct btrfs_dir_item *)((char *) di + this_len);
261 }
262
263next_slot:
264 path->slots[0]++;
265 }
266
267 ret = 0;
268out:
269 btrfs_release_path(path);
270 kfree(name_buf);
271 kfree(value_buf);
272
273 return ret;
274}
275
276static void inode_prop_iterator(void *ctx,
277 const struct prop_handler *handler,
278 const char *value,
279 size_t len)
280{
281 struct inode *inode = ctx;
282 struct btrfs_root *root = BTRFS_I(inode)->root;
283 int ret;
284
285 ret = handler->apply(inode, value, len);
286 if (unlikely(ret))
287 btrfs_warn(root->fs_info,
288 "error applying prop %s to ino %llu (root %llu): %d",
289 handler->xattr_name, btrfs_ino(BTRFS_I(inode)),
290 root->root_key.objectid, ret);
291 else
292 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
293}
294
295int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
296{
297 struct btrfs_root *root = BTRFS_I(inode)->root;
298 u64 ino = btrfs_ino(BTRFS_I(inode));
299 int ret;
300
301 ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode);
302
303 return ret;
304}
305
306static int inherit_props(struct btrfs_trans_handle *trans,
307 struct inode *inode,
308 struct inode *parent)
309{
310 struct btrfs_root *root = BTRFS_I(inode)->root;
311 struct btrfs_fs_info *fs_info = root->fs_info;
312 int ret;
313 int i;
314
315 if (!test_bit(BTRFS_INODE_HAS_PROPS,
316 &BTRFS_I(parent)->runtime_flags))
317 return 0;
318
319 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
320 const struct prop_handler *h = &prop_handlers[i];
321 const char *value;
322 u64 num_bytes;
323
324 if (!h->inheritable)
325 continue;
326
327 value = h->extract(parent);
328 if (!value)
329 continue;
330
331 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
332 ret = btrfs_block_rsv_add(root, trans->block_rsv,
333 num_bytes, BTRFS_RESERVE_NO_FLUSH);
334 if (ret)
335 goto out;
336 ret = __btrfs_set_prop(trans, inode, h->xattr_name,
337 value, strlen(value), 0);
338 btrfs_block_rsv_release(fs_info, trans->block_rsv, num_bytes);
339 if (ret)
340 goto out;
341 }
342 ret = 0;
343out:
344 return ret;
345}
346
347int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
348 struct inode *inode,
349 struct inode *dir)
350{
351 if (!dir)
352 return 0;
353
354 return inherit_props(trans, inode, dir);
355}
356
357int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans,
358 struct btrfs_root *root,
359 struct btrfs_root *parent_root)
360{
361 struct super_block *sb = root->fs_info->sb;
362 struct btrfs_key key;
363 struct inode *parent_inode, *child_inode;
364 int ret;
365
366 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
367 key.type = BTRFS_INODE_ITEM_KEY;
368 key.offset = 0;
369
370 parent_inode = btrfs_iget(sb, &key, parent_root, NULL);
371 if (IS_ERR(parent_inode))
372 return PTR_ERR(parent_inode);
373
374 child_inode = btrfs_iget(sb, &key, root, NULL);
375 if (IS_ERR(child_inode)) {
376 iput(parent_inode);
377 return PTR_ERR(child_inode);
378 }
379
380 ret = inherit_props(trans, child_inode, parent_inode);
381 iput(child_inode);
382 iput(parent_inode);
383
384 return ret;
385}
386
387static int prop_compression_validate(const char *value, size_t len)
388{
389 if (!strncmp("lzo", value, len))
390 return 0;
391 else if (!strncmp("zlib", value, len))
392 return 0;
393 else if (!strncmp("zstd", value, len))
394 return 0;
395
396 return -EINVAL;
397}
398
399static int prop_compression_apply(struct inode *inode,
400 const char *value,
401 size_t len)
402{
403 int type;
404
405 if (len == 0) {
406 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
407 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
408 BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
409
410 return 0;
411 }
412
413 if (!strncmp("lzo", value, 3))
414 type = BTRFS_COMPRESS_LZO;
415 else if (!strncmp("zlib", value, 4))
416 type = BTRFS_COMPRESS_ZLIB;
417 else if (!strncmp("zstd", value, len))
418 type = BTRFS_COMPRESS_ZSTD;
419 else
420 return -EINVAL;
421
422 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
423 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
424 BTRFS_I(inode)->prop_compress = type;
425
426 return 0;
427}
428
429static const char *prop_compression_extract(struct inode *inode)
430{
431 switch (BTRFS_I(inode)->prop_compress) {
432 case BTRFS_COMPRESS_ZLIB:
433 return "zlib";
434 case BTRFS_COMPRESS_LZO:
435 return "lzo";
436 case BTRFS_COMPRESS_ZSTD:
437 return "zstd";
438 }
439
440 return NULL;
441}
442
443
444
