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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
15static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
16
17struct 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
26static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
27{
28 struct hlist_head *h;
29
30 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
31 if (hlist_empty(h))
32 return NULL;
33
34 return h;
35}
36
37static const struct prop_handler *
38find_prop_handler(const char *name,
39 const struct hlist_head *handlers)
40{
41 struct prop_handler *h;
42
43 if (!handlers) {
44 u64 hash = btrfs_name_hash(name, strlen(name));
45
46 handlers = find_prop_handlers_by_hash(hash);
47 if (!handlers)
48 return NULL;
49 }
50
51 hlist_for_each_entry(h, handlers, node)
52 if (!strcmp(h->xattr_name, name))
53 return h;
54
55 return NULL;
56}
57
58int btrfs_validate_prop(const char *name, const char *value, size_t value_len)
59{
60 const struct prop_handler *handler;
61
62 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
63 return -EINVAL;
64
65 handler = find_prop_handler(name, NULL);
66 if (!handler)
67 return -EINVAL;
68
69 if (value_len == 0)
70 return 0;
71
72 return handler->validate(value, value_len);
73}
74
75int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
76 const char *name, const char *value, size_t value_len,
77 int flags)
78{
79 const struct prop_handler *handler;
80 int ret;
81
82 handler = find_prop_handler(name, NULL);
83 if (!handler)
84 return -EINVAL;
85
86 if (value_len == 0) {
87 ret = btrfs_setxattr(trans, inode, handler->xattr_name,
88 NULL, 0, flags);
89 if (ret)
90 return ret;
91
92 ret = handler->apply(inode, NULL, 0);
93 ASSERT(ret == 0);
94
95 return ret;
96 }
97
98 ret = btrfs_setxattr(trans, inode, handler->xattr_name, value,
99 value_len, flags);
100 if (ret)
101 return ret;
102 ret = handler->apply(inode, value, value_len);
103 if (ret) {
104 btrfs_setxattr(trans, inode, handler->xattr_name, NULL,
105 0, flags);
106 return ret;
107 }
108
109 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
110
111 return 0;
112}
113
114static int iterate_object_props(struct btrfs_root *root,
115 struct btrfs_path *path,
116 u64 objectid,
117 void (*iterator)(void *,
118 const struct prop_handler *,
119 const char *,
120 size_t),
121 void *ctx)
122{
123 int ret;
124 char *name_buf = NULL;
125 char *value_buf = NULL;
126 int name_buf_len = 0;
127 int value_buf_len = 0;
128
129 while (1) {
130 struct btrfs_key key;
131 struct btrfs_dir_item *di;
132 struct extent_buffer *leaf;
133 u32 total_len, cur, this_len;
134 int slot;
135 const struct hlist_head *handlers;
136
137 slot = path->slots[0];
138 leaf = path->nodes[0];
139
140 if (slot >= btrfs_header_nritems(leaf)) {
141 ret = btrfs_next_leaf(root, path);
142 if (ret < 0)
143 goto out;
144 else if (ret > 0)
145 break;
146 continue;
147 }
148
149 btrfs_item_key_to_cpu(leaf, &key, slot);
150 if (key.objectid != objectid)
151 break;
152 if (key.type != BTRFS_XATTR_ITEM_KEY)
153 break;
154
155 handlers = find_prop_handlers_by_hash(key.offset);
156 if (!handlers)
157 goto next_slot;
158
159 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
160 cur = 0;
161 total_len = btrfs_item_size_nr(leaf, slot);
162
163 while (cur < total_len) {
164 u32 name_len = btrfs_dir_name_len(leaf, di);
165 u32 data_len = btrfs_dir_data_len(leaf, di);
166 unsigned long name_ptr, data_ptr;
167 const struct prop_handler *handler;
168
169 this_len = sizeof(*di) + name_len + data_len;
170 name_ptr = (unsigned long)(di + 1);
171 data_ptr = name_ptr + name_len;
172
173 if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
174 memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
175 name_ptr,
176 XATTR_BTRFS_PREFIX_LEN))
177 goto next_dir_item;
178
179 if (name_len >= name_buf_len) {
180 kfree(name_buf);
181 name_buf_len = name_len + 1;
182 name_buf = kmalloc(name_buf_len, GFP_NOFS);
183 if (!name_buf) {
184 ret = -ENOMEM;
185 goto out;
186 }
187 }
188 read_extent_buffer(leaf, name_buf, name_ptr, name_len);
189 name_buf[name_len] = '\0';
190
191 handler = find_prop_handler(name_buf, handlers);
192 if (!handler)
193 goto next_dir_item;
194
195 if (data_len > value_buf_len) {
196 kfree(value_buf);
197 value_buf_len = data_len;
198 value_buf = kmalloc(data_len, GFP_NOFS);
199 if (!value_buf) {
200 ret = -ENOMEM;
201 goto out;
202 }
203 }
204 read_extent_buffer(leaf, value_buf, data_ptr, data_len);
205
206 iterator(ctx, handler, value_buf, data_len);
207next_dir_item:
208 cur += this_len;
209 di = (struct btrfs_dir_item *)((char *) di + this_len);
210 }
211
212next_slot:
213 path->slots[0]++;
214 }
215
216 ret = 0;
217out:
218 btrfs_release_path(path);
219 kfree(name_buf);
220 kfree(value_buf);
221
222 return ret;
223}
224
225static void inode_prop_iterator(void *ctx,
226 const struct prop_handler *handler,
227 const char *value,
228 size_t len)
229{
230 struct inode *inode = ctx;
231 struct btrfs_root *root = BTRFS_I(inode)->root;
232 int ret;
233
234 ret = handler->apply(inode, value, len);
235 if (unlikely(ret))
236 btrfs_warn(root->fs_info,
237 "error applying prop %s to ino %llu (root %llu): %d",
238 handler->xattr_name, btrfs_ino(BTRFS_I(inode)),
239 root->root_key.objectid, ret);
240 else
241 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
242}
243
244int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
245{
246 struct btrfs_root *root = BTRFS_I(inode)->root;
247 u64 ino = btrfs_ino(BTRFS_I(inode));
248 int ret;
249
250 ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode);
251
252 return ret;
253}
254
255static int prop_compression_validate(const char *value, size_t len)
256{
257 if (!value)
258 return 0;
259
260 if (btrfs_compress_is_valid_type(value, len))
261 return 0;
262
263 return -EINVAL;
264}
265
266static int prop_compression_apply(struct inode *inode, const char *value,
267 size_t len)
268{
269 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
270 int type;
271
272 if (len == 0) {
273 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
274 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
275 BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
276
277 return 0;
278 }
279
280 if (!strncmp("lzo", value, 3)) {
281 type = BTRFS_COMPRESS_LZO;
282 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
283 } else if (!strncmp("zlib", value, 4)) {
284 type = BTRFS_COMPRESS_ZLIB;
285 } else if (!strncmp("zstd", value, 4)) {
286 type = BTRFS_COMPRESS_ZSTD;
287 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
288 } else {
289 return -EINVAL;
290 }
291
292 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
293 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
294 BTRFS_I(inode)->prop_compress = type;
295
296 return 0;
297}
298
299static const char *prop_compression_extract(struct inode *inode)
300{
301 switch (BTRFS_I(inode)->prop_compress) {
302 case BTRFS_COMPRESS_ZLIB:
303 case BTRFS_COMPRESS_LZO:
304 case BTRFS_COMPRESS_ZSTD:
305 return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
306 default:
307 break;
308 }
309
310 return NULL;
311}
312
313static struct prop_handler prop_handlers[] = {
314 {
315 .xattr_name = XATTR_BTRFS_PREFIX "compression",
316 .validate = prop_compression_validate,
317 .apply = prop_compression_apply,
318 .extract = prop_compression_extract,
319 .inheritable = 1
320 },
321};
322
323static int inherit_props(struct btrfs_trans_handle *trans,
324 struct inode *inode,
325 struct inode *parent)
326{
327 struct btrfs_root *root = BTRFS_I(inode)->root;
328 struct btrfs_fs_info *fs_info = root->fs_info;
329 int ret;
330 int i;
331 bool need_reserve = false;
332
333 if (!test_bit(BTRFS_INODE_HAS_PROPS,
334 &BTRFS_I(parent)->runtime_flags))
335 return 0;
336
337 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
338 const struct prop_handler *h = &prop_handlers[i];
339 const char *value;
340 u64 num_bytes = 0;
341
342 if (!h->inheritable)
343 continue;
344
345 value = h->extract(parent);
346 if (!value)
347 continue;
348
349 /*
350 * This is not strictly necessary as the property should be
351 * valid, but in case it isn't, don't propagate it futher.
352 */
353 ret = h->validate(value, strlen(value));
354 if (ret)
355 continue;
356
357 /*
358 * Currently callers should be reserving 1 item for properties,
359 * since we only have 1 property that we currently support. If
360 * we add more in the future we need to try and reserve more
361 * space for them. But we should also revisit how we do space
362 * reservations if we do add more properties in the future.
363 */
364 if (need_reserve) {
365 num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
366 ret = btrfs_block_rsv_add(root, trans->block_rsv,
367 num_bytes, BTRFS_RESERVE_NO_FLUSH);
368 if (ret)
369 return ret;
370 }
371
372 ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
373 strlen(value), 0);
374 if (!ret) {
375 ret = h->apply(inode, value, strlen(value));
376 if (ret)
377 btrfs_setxattr(trans, inode, h->xattr_name,
378 NULL, 0, 0);
379 else
380 set_bit(BTRFS_INODE_HAS_PROPS,
381 &BTRFS_I(inode)->runtime_flags);
382 }
383
384 if (need_reserve) {
385 btrfs_block_rsv_release(fs_info, trans->block_rsv,
386 num_bytes);
387 if (ret)
388 return ret;
389 }
390 need_reserve = true;
391 }
392
393 return 0;
394}
395
396int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
397 struct inode *inode,
398 struct inode *dir)
399{
400 if (!dir)
401 return 0;
402
403 return inherit_props(trans, inode, dir);
404}
405
406int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans,
407 struct btrfs_root *root,
408 struct btrfs_root *parent_root)
409{
410 struct super_block *sb = root->fs_info->sb;
411 struct btrfs_key key;
412 struct inode *parent_inode, *child_inode;
413 int ret;
414
415 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
416 key.type = BTRFS_INODE_ITEM_KEY;
417 key.offset = 0;
418
419 parent_inode = btrfs_iget(sb, &key, parent_root, NULL);
420 if (IS_ERR(parent_inode))
421 return PTR_ERR(parent_inode);
422
423 child_inode = btrfs_iget(sb, &key, root, NULL);
424 if (IS_ERR(child_inode)) {
425 iput(parent_inode);
426 return PTR_ERR(child_inode);
427 }
428
429 ret = inherit_props(trans, child_inode, parent_inode);
430 iput(child_inode);
431 iput(parent_inode);
432
433 return ret;
434}
435
436void __init btrfs_props_init(void)
437{
438 int i;
439
440 hash_init(prop_handlers_ht);
441
442 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
443 struct prop_handler *p = &prop_handlers[i];
444 u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
445
446 hash_add(prop_handlers_ht, &p->node, h);
447 }
448}
449
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 <linux/xattr.h>
8#include "messages.h"
9#include "props.h"
10#include "btrfs_inode.h"
11#include "transaction.h"
12#include "ctree.h"
13#include "xattr.h"
14#include "compression.h"
15#include "space-info.h"
16#include "fs.h"
17#include "accessors.h"
18#include "super.h"
19#include "dir-item.h"
20
21#define BTRFS_PROP_HANDLERS_HT_BITS 8
22static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
23
24struct prop_handler {
25 struct hlist_node node;
26 const char *xattr_name;
27 int (*validate)(const struct btrfs_inode *inode, const char *value,
28 size_t len);
29 int (*apply)(struct inode *inode, const char *value, size_t len);
30 const char *(*extract)(struct inode *inode);
31 bool (*ignore)(const struct btrfs_inode *inode);
32 int inheritable;
33};
34
35static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
36{
37 struct hlist_head *h;
38
39 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
40 if (hlist_empty(h))
41 return NULL;
42
43 return h;
44}
45
46static const struct prop_handler *
47find_prop_handler(const char *name,
48 const struct hlist_head *handlers)
49{
50 struct prop_handler *h;
51
52 if (!handlers) {
53 u64 hash = btrfs_name_hash(name, strlen(name));
54
55 handlers = find_prop_handlers_by_hash(hash);
56 if (!handlers)
57 return NULL;
58 }
59
60 hlist_for_each_entry(h, handlers, node)
61 if (!strcmp(h->xattr_name, name))
62 return h;
63
64 return NULL;
65}
66
67int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name,
68 const char *value, size_t value_len)
69{
70 const struct prop_handler *handler;
71
72 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
73 return -EINVAL;
74
75 handler = find_prop_handler(name, NULL);
76 if (!handler)
77 return -EINVAL;
78
79 if (value_len == 0)
80 return 0;
81
82 return handler->validate(inode, value, value_len);
83}
84
85/*
86 * Check if a property should be ignored (not set) for an inode.
87 *
88 * @inode: The target inode.
89 * @name: The property's name.
90 *
91 * The caller must be sure the given property name is valid, for example by
92 * having previously called btrfs_validate_prop().
93 *
94 * Returns: true if the property should be ignored for the given inode
95 * false if the property must not be ignored for the given inode
96 */
97bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name)
98{
99 const struct prop_handler *handler;
100
101 handler = find_prop_handler(name, NULL);
102 ASSERT(handler != NULL);
103
104 return handler->ignore(inode);
105}
106
107int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode,
108 const char *name, const char *value, size_t value_len,
109 int flags)
110{
111 const struct prop_handler *handler;
112 int ret;
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 = btrfs_setxattr(trans, inode, handler->xattr_name, value,
131 value_len, flags);
132 if (ret)
133 return ret;
134 ret = handler->apply(inode, value, value_len);
135 if (ret) {
136 btrfs_setxattr(trans, inode, handler->xattr_name, NULL,
137 0, flags);
138 return ret;
139 }
140
141 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
142
143 return 0;
144}
145
146static int iterate_object_props(struct btrfs_root *root,
147 struct btrfs_path *path,
148 u64 objectid,
149 void (*iterator)(void *,
150 const struct prop_handler *,
151 const char *,
152 size_t),
153 void *ctx)
154{
155 int ret;
156 char *name_buf = NULL;
157 char *value_buf = NULL;
158 int name_buf_len = 0;
159 int value_buf_len = 0;
160
161 while (1) {
162 struct btrfs_key key;
163 struct btrfs_dir_item *di;
164 struct extent_buffer *leaf;
165 u32 total_len, cur, this_len;
166 int slot;
167 const struct hlist_head *handlers;
168
169 slot = path->slots[0];
170 leaf = path->nodes[0];
171
172 if (slot >= btrfs_header_nritems(leaf)) {
173 ret = btrfs_next_leaf(root, path);
174 if (ret < 0)
175 goto out;
176 else if (ret > 0)
177 break;
178 continue;
179 }
180
181 btrfs_item_key_to_cpu(leaf, &key, slot);
182 if (key.objectid != objectid)
183 break;
184 if (key.type != BTRFS_XATTR_ITEM_KEY)
185 break;
186
187 handlers = find_prop_handlers_by_hash(key.offset);
188 if (!handlers)
189 goto next_slot;
190
191 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
192 cur = 0;
193 total_len = btrfs_item_size(leaf, slot);
194
195 while (cur < total_len) {
196 u32 name_len = btrfs_dir_name_len(leaf, di);
197 u32 data_len = btrfs_dir_data_len(leaf, di);
198 unsigned long name_ptr, data_ptr;
199 const struct prop_handler *handler;
200
201 this_len = sizeof(*di) + name_len + data_len;
202 name_ptr = (unsigned long)(di + 1);
203 data_ptr = name_ptr + name_len;
204
205 if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
206 memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
207 name_ptr,
208 XATTR_BTRFS_PREFIX_LEN))
209 goto next_dir_item;
210
211 if (name_len >= name_buf_len) {
212 kfree(name_buf);
213 name_buf_len = name_len + 1;
214 name_buf = kmalloc(name_buf_len, GFP_NOFS);
215 if (!name_buf) {
216 ret = -ENOMEM;
217 goto out;
218 }
219 }
220 read_extent_buffer(leaf, name_buf, name_ptr, name_len);
221 name_buf[name_len] = '\0';
222
223 handler = find_prop_handler(name_buf, handlers);
224 if (!handler)
225 goto next_dir_item;
226
227 if (data_len > value_buf_len) {
228 kfree(value_buf);
229 value_buf_len = data_len;
230 value_buf = kmalloc(data_len, GFP_NOFS);
231 if (!value_buf) {
232 ret = -ENOMEM;
233 goto out;
234 }
235 }
236 read_extent_buffer(leaf, value_buf, data_ptr, data_len);
237
238 iterator(ctx, handler, value_buf, data_len);
239next_dir_item:
240 cur += this_len;
241 di = (struct btrfs_dir_item *)((char *) di + this_len);
242 }
243
244next_slot:
245 path->slots[0]++;
246 }
247
248 ret = 0;
249out:
250 btrfs_release_path(path);
251 kfree(name_buf);
252 kfree(value_buf);
253
254 return ret;
255}
256
257static void inode_prop_iterator(void *ctx,
258 const struct prop_handler *handler,
259 const char *value,
260 size_t len)
261{
262 struct inode *inode = ctx;
263 struct btrfs_root *root = BTRFS_I(inode)->root;
264 int ret;
265
266 ret = handler->apply(inode, value, len);
267 if (unlikely(ret))
268 btrfs_warn(root->fs_info,
269 "error applying prop %s to ino %llu (root %llu): %d",
270 handler->xattr_name, btrfs_ino(BTRFS_I(inode)),
271 root->root_key.objectid, ret);
272 else
273 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
274}
275
276int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
277{
278 struct btrfs_root *root = BTRFS_I(inode)->root;
279 u64 ino = btrfs_ino(BTRFS_I(inode));
280
281 return iterate_object_props(root, path, ino, inode_prop_iterator, inode);
282}
283
284static int prop_compression_validate(const struct btrfs_inode *inode,
285 const char *value, size_t len)
286{
287 if (!btrfs_inode_can_compress(inode))
288 return -EINVAL;
289
290 if (!value)
291 return 0;
292
293 if (btrfs_compress_is_valid_type(value, len))
294 return 0;
295
296 if ((len == 2 && strncmp("no", value, 2) == 0) ||
297 (len == 4 && strncmp("none", value, 4) == 0))
298 return 0;
299
300 return -EINVAL;
301}
302
303static int prop_compression_apply(struct inode *inode, const char *value,
304 size_t len)
305{
306 struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
307 int type;
308
309 /* Reset to defaults */
310 if (len == 0) {
311 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
312 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
313 BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
314 return 0;
315 }
316
317 /* Set NOCOMPRESS flag */
318 if ((len == 2 && strncmp("no", value, 2) == 0) ||
319 (len == 4 && strncmp("none", value, 4) == 0)) {
320 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
321 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
322 BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
323
324 return 0;
325 }
326
327 if (!strncmp("lzo", value, 3)) {
328 type = BTRFS_COMPRESS_LZO;
329 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
330 } else if (!strncmp("zlib", value, 4)) {
331 type = BTRFS_COMPRESS_ZLIB;
332 } else if (!strncmp("zstd", value, 4)) {
333 type = BTRFS_COMPRESS_ZSTD;
334 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
335 } else {
336 return -EINVAL;
337 }
338
339 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
340 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
341 BTRFS_I(inode)->prop_compress = type;
342
343 return 0;
344}
345
346static bool prop_compression_ignore(const struct btrfs_inode *inode)
347{
348 /*
349 * Compression only has effect for regular files, and for directories
350 * we set it just to propagate it to new files created inside them.
351 * Everything else (symlinks, devices, sockets, fifos) is pointless as
352 * it will do nothing, so don't waste metadata space on a compression
353 * xattr for anything that is neither a file nor a directory.
354 */
355 if (!S_ISREG(inode->vfs_inode.i_mode) &&
356 !S_ISDIR(inode->vfs_inode.i_mode))
357 return true;
358
359 return false;
360}
361
362static const char *prop_compression_extract(struct inode *inode)
363{
364 switch (BTRFS_I(inode)->prop_compress) {
365 case BTRFS_COMPRESS_ZLIB:
366 case BTRFS_COMPRESS_LZO:
367 case BTRFS_COMPRESS_ZSTD:
368 return btrfs_compress_type2str(BTRFS_I(inode)->prop_compress);
369 default:
370 break;
371 }
372
373 return NULL;
374}
375
376static struct prop_handler prop_handlers[] = {
377 {
378 .xattr_name = XATTR_BTRFS_PREFIX "compression",
379 .validate = prop_compression_validate,
380 .apply = prop_compression_apply,
381 .extract = prop_compression_extract,
382 .ignore = prop_compression_ignore,
383 .inheritable = 1
384 },
385};
386
387int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
388 struct inode *inode, struct inode *parent)
389{
390 struct btrfs_root *root = BTRFS_I(inode)->root;
391 struct btrfs_fs_info *fs_info = root->fs_info;
392 int ret;
393 int i;
394 bool need_reserve = false;
395
396 if (!test_bit(BTRFS_INODE_HAS_PROPS,
397 &BTRFS_I(parent)->runtime_flags))
398 return 0;
399
400 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
401 const struct prop_handler *h = &prop_handlers[i];
402 const char *value;
403 u64 num_bytes = 0;
404
405 if (!h->inheritable)
406 continue;
407
408 if (h->ignore(BTRFS_I(inode)))
409 continue;
410
411 value = h->extract(parent);
412 if (!value)
413 continue;
414
415 /*
416 * This is not strictly necessary as the property should be
417 * valid, but in case it isn't, don't propagate it further.
418 */
419 ret = h->validate(BTRFS_I(inode), value, strlen(value));
420 if (ret)
421 continue;
422
423 /*
424 * Currently callers should be reserving 1 item for properties,
425 * since we only have 1 property that we currently support. If
426 * we add more in the future we need to try and reserve more
427 * space for them. But we should also revisit how we do space
428 * reservations if we do add more properties in the future.
429 */
430 if (need_reserve) {
431 num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
432 ret = btrfs_block_rsv_add(fs_info, trans->block_rsv,
433 num_bytes,
434 BTRFS_RESERVE_NO_FLUSH);
435 if (ret)
436 return ret;
437 }
438
439 ret = btrfs_setxattr(trans, inode, h->xattr_name, value,
440 strlen(value), 0);
441 if (!ret) {
442 ret = h->apply(inode, value, strlen(value));
443 if (ret)
444 btrfs_setxattr(trans, inode, h->xattr_name,
445 NULL, 0, 0);
446 else
447 set_bit(BTRFS_INODE_HAS_PROPS,
448 &BTRFS_I(inode)->runtime_flags);
449 }
450
451 if (need_reserve) {
452 btrfs_block_rsv_release(fs_info, trans->block_rsv,
453 num_bytes, NULL);
454 if (ret)
455 return ret;
456 }
457 need_reserve = true;
458 }
459
460 return 0;
461}
462
463int __init btrfs_props_init(void)
464{
465 int i;
466
467 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
468 struct prop_handler *p = &prop_handlers[i];
469 u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
470
471 hash_add(prop_handlers_ht, &p->node, h);
472 }
473 return 0;
474}
475