dc6140013ae8194739a8aa6a387f12c35794bdf9
[sfrench/cifs-2.6.git] / fs / btrfs / props.c
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
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
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 *
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
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
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
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
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
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
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
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
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
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
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
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