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Filipe David Borba Manana63541922014-01-07 11:47:46 +00001/*
2 * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
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
26#define BTRFS_PROP_HANDLERS_HT_BITS 8
27static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
28
29struct prop_handler {
30 struct hlist_node node;
31 const char *xattr_name;
32 int (*validate)(const char *value, size_t len);
33 int (*apply)(struct inode *inode, const char *value, size_t len);
34 const char *(*extract)(struct inode *inode);
35 int inheritable;
36};
37
38static int prop_compression_validate(const char *value, size_t len);
39static int prop_compression_apply(struct inode *inode,
40 const char *value,
41 size_t len);
42static const char *prop_compression_extract(struct inode *inode);
43
44static struct prop_handler prop_handlers[] = {
45 {
46 .xattr_name = XATTR_BTRFS_PREFIX "compression",
47 .validate = prop_compression_validate,
48 .apply = prop_compression_apply,
49 .extract = prop_compression_extract,
50 .inheritable = 1
51 },
Filipe David Borba Manana63541922014-01-07 11:47:46 +000052};
53
54void __init btrfs_props_init(void)
55{
Byongho Lee619ed392015-10-08 20:49:34 +090056 int i;
Filipe David Borba Manana63541922014-01-07 11:47:46 +000057
58 hash_init(prop_handlers_ht);
59
Byongho Lee619ed392015-10-08 20:49:34 +090060 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
61 struct prop_handler *p = &prop_handlers[i];
Filipe David Borba Manana63541922014-01-07 11:47:46 +000062 u64 h = btrfs_name_hash(p->xattr_name, strlen(p->xattr_name));
63
64 hash_add(prop_handlers_ht, &p->node, h);
65 }
66}
67
68static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
69{
70 struct hlist_head *h;
71
72 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
73 if (hlist_empty(h))
74 return NULL;
75
76 return h;
77}
78
79static const struct prop_handler *
80find_prop_handler(const char *name,
81 const struct hlist_head *handlers)
82{
83 struct prop_handler *h;
84
85 if (!handlers) {
86 u64 hash = btrfs_name_hash(name, strlen(name));
87
88 handlers = find_prop_handlers_by_hash(hash);
89 if (!handlers)
90 return NULL;
91 }
92
93 hlist_for_each_entry(h, handlers, node)
94 if (!strcmp(h->xattr_name, name))
95 return h;
96
97 return NULL;
98}
99
100static int __btrfs_set_prop(struct btrfs_trans_handle *trans,
101 struct inode *inode,
102 const char *name,
103 const char *value,
104 size_t value_len,
105 int flags)
106{
107 const struct prop_handler *handler;
108 int ret;
109
110 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
111 return -EINVAL;
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, handler->xattr_name,
119 NULL, 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 = handler->validate(value, value_len);
130 if (ret)
131 return ret;
132 ret = __btrfs_setxattr(trans, inode, handler->xattr_name,
133 value, value_len, flags);
134 if (ret)
135 return ret;
136 ret = handler->apply(inode, value, value_len);
137 if (ret) {
138 __btrfs_setxattr(trans, inode, handler->xattr_name,
139 NULL, 0, flags);
140 return ret;
141 }
142
143 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
144
145 return 0;
146}
147
148int btrfs_set_prop(struct inode *inode,
149 const char *name,
150 const char *value,
151 size_t value_len,
152 int flags)
153{
154 return __btrfs_set_prop(NULL, inode, name, value, value_len, flags);
155}
156
157static int iterate_object_props(struct btrfs_root *root,
158 struct btrfs_path *path,
159 u64 objectid,
160 void (*iterator)(void *,
161 const struct prop_handler *,
162 const char *,
163 size_t),
164 void *ctx)
165{
166 int ret;
167 char *name_buf = NULL;
168 char *value_buf = NULL;
169 int name_buf_len = 0;
170 int value_buf_len = 0;
171
172 while (1) {
173 struct btrfs_key key;
174 struct btrfs_dir_item *di;
175 struct extent_buffer *leaf;
176 u32 total_len, cur, this_len;
177 int slot;
178 const struct hlist_head *handlers;
179
180 slot = path->slots[0];
181 leaf = path->nodes[0];
182
183 if (slot >= btrfs_header_nritems(leaf)) {
184 ret = btrfs_next_leaf(root, path);
185 if (ret < 0)
186 goto out;
187 else if (ret > 0)
188 break;
189 continue;
190 }
191
192 btrfs_item_key_to_cpu(leaf, &key, slot);
193 if (key.objectid != objectid)
194 break;
195 if (key.type != BTRFS_XATTR_ITEM_KEY)
196 break;
197
198 handlers = find_prop_handlers_by_hash(key.offset);
199 if (!handlers)
200 goto next_slot;
201
202 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
203 cur = 0;
204 total_len = btrfs_item_size_nr(leaf, slot);
205
206 while (cur < total_len) {
207 u32 name_len = btrfs_dir_name_len(leaf, di);
208 u32 data_len = btrfs_dir_data_len(leaf, di);
209 unsigned long name_ptr, data_ptr;
210 const struct prop_handler *handler;
211
212 this_len = sizeof(*di) + name_len + data_len;
213 name_ptr = (unsigned long)(di + 1);
214 data_ptr = name_ptr + name_len;
215
216 if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
217 memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
218 name_ptr,
219 XATTR_BTRFS_PREFIX_LEN))
220 goto next_dir_item;
221
222 if (name_len >= name_buf_len) {
223 kfree(name_buf);
224 name_buf_len = name_len + 1;
225 name_buf = kmalloc(name_buf_len, GFP_NOFS);
226 if (!name_buf) {
227 ret = -ENOMEM;
228 goto out;
229 }
230 }
231 read_extent_buffer(leaf, name_buf, name_ptr, name_len);
232 name_buf[name_len] = '\0';
233
234 handler = find_prop_handler(name_buf, handlers);
235 if (!handler)
236 goto next_dir_item;
237
238 if (data_len > value_buf_len) {
239 kfree(value_buf);
240 value_buf_len = data_len;
241 value_buf = kmalloc(data_len, GFP_NOFS);
242 if (!value_buf) {
243 ret = -ENOMEM;
244 goto out;
245 }
246 }
247 read_extent_buffer(leaf, value_buf, data_ptr, data_len);
248
249 iterator(ctx, handler, value_buf, data_len);
250next_dir_item:
251 cur += this_len;
252 di = (struct btrfs_dir_item *)((char *) di + this_len);
253 }
254
255next_slot:
256 path->slots[0]++;
257 }
258
259 ret = 0;
260out:
261 btrfs_release_path(path);
262 kfree(name_buf);
263 kfree(value_buf);
264
265 return ret;
266}
267
268static void inode_prop_iterator(void *ctx,
269 const struct prop_handler *handler,
270 const char *value,
271 size_t len)
272{
273 struct inode *inode = ctx;
274 struct btrfs_root *root = BTRFS_I(inode)->root;
275 int ret;
276
277 ret = handler->apply(inode, value, len);
278 if (unlikely(ret))
279 btrfs_warn(root->fs_info,
280 "error applying prop %s to ino %llu (root %llu): %d",
281 handler->xattr_name, btrfs_ino(inode),
282 root->root_key.objectid, ret);
283 else
284 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
285}
286
287int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
288{
289 struct btrfs_root *root = BTRFS_I(inode)->root;
290 u64 ino = btrfs_ino(inode);
291 int ret;
292
293 ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode);
294
295 return ret;
296}
297
298static int inherit_props(struct btrfs_trans_handle *trans,
299 struct inode *inode,
300 struct inode *parent)
301{
Filipe David Borba Manana63541922014-01-07 11:47:46 +0000302 struct btrfs_root *root = BTRFS_I(inode)->root;
303 int ret;
Byongho Lee619ed392015-10-08 20:49:34 +0900304 int i;
Filipe David Borba Manana63541922014-01-07 11:47:46 +0000305
306 if (!test_bit(BTRFS_INODE_HAS_PROPS,
307 &BTRFS_I(parent)->runtime_flags))
308 return 0;
309
Byongho Lee619ed392015-10-08 20:49:34 +0900310 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
311 const struct prop_handler *h = &prop_handlers[i];
Filipe David Borba Manana63541922014-01-07 11:47:46 +0000312 const char *value;
313 u64 num_bytes;
314
315 if (!h->inheritable)
316 continue;
317
318 value = h->extract(parent);
319 if (!value)
320 continue;
321
322 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
323 ret = btrfs_block_rsv_add(root, trans->block_rsv,
324 num_bytes, BTRFS_RESERVE_NO_FLUSH);
325 if (ret)
326 goto out;
327 ret = __btrfs_set_prop(trans, inode, h->xattr_name,
328 value, strlen(value), 0);
329 btrfs_block_rsv_release(root, trans->block_rsv, num_bytes);
330 if (ret)
331 goto out;
332 }
333 ret = 0;
334out:
335 return ret;
336}
337
338int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
339 struct inode *inode,
340 struct inode *dir)
341{
342 if (!dir)
343 return 0;
344
345 return inherit_props(trans, inode, dir);
346}
347
348int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans,
349 struct btrfs_root *root,
350 struct btrfs_root *parent_root)
351{
352 struct btrfs_key key;
353 struct inode *parent_inode, *child_inode;
354 int ret;
355
356 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
357 key.type = BTRFS_INODE_ITEM_KEY;
358 key.offset = 0;
359
360 parent_inode = btrfs_iget(parent_root->fs_info->sb, &key,
361 parent_root, NULL);
362 if (IS_ERR(parent_inode))
363 return PTR_ERR(parent_inode);
364
365 child_inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
366 if (IS_ERR(child_inode)) {
367 iput(parent_inode);
368 return PTR_ERR(child_inode);
369 }
370
371 ret = inherit_props(trans, child_inode, parent_inode);
372 iput(child_inode);
373 iput(parent_inode);
374
375 return ret;
376}
377
378static int prop_compression_validate(const char *value, size_t len)
379{
380 if (!strncmp("lzo", value, len))
381 return 0;
382 else if (!strncmp("zlib", value, len))
383 return 0;
384
385 return -EINVAL;
386}
387
388static int prop_compression_apply(struct inode *inode,
389 const char *value,
390 size_t len)
391{
392 int type;
393
394 if (len == 0) {
395 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
396 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
397 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
398
399 return 0;
400 }
401
402 if (!strncmp("lzo", value, len))
403 type = BTRFS_COMPRESS_LZO;
404 else if (!strncmp("zlib", value, len))
405 type = BTRFS_COMPRESS_ZLIB;
406 else
407 return -EINVAL;
408
409 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
410 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
411 BTRFS_I(inode)->force_compress = type;
412
413 return 0;
414}
415
416static const char *prop_compression_extract(struct inode *inode)
417{
418 switch (BTRFS_I(inode)->force_compress) {
419 case BTRFS_COMPRESS_ZLIB:
420 return "zlib";
421 case BTRFS_COMPRESS_LZO:
422 return "lzo";
423 }
424
425 return NULL;
426}
David Sterbae8c9f182015-01-02 18:23:10 +0100427
428