mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / fs / btrfs / props.c
blobb9c7d8508e35116259666052b9d4c54d3496cb0d
1 /*
2 * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
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.
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.
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.
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"
27 #define BTRFS_PROP_HANDLERS_HT_BITS 8
28 static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS);
30 struct 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;
39 static int prop_compression_validate(const char *value, size_t len);
40 static int prop_compression_apply(struct inode *inode,
41 const char *value,
42 size_t len);
43 static const char *prop_compression_extract(struct inode *inode);
45 static struct prop_handler prop_handlers[] = {
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
55 void __init btrfs_props_init(void)
57 int i;
59 hash_init(prop_handlers_ht);
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));
65 hash_add(prop_handlers_ht, &p->node, h);
69 static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash)
71 struct hlist_head *h;
73 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
74 if (hlist_empty(h))
75 return NULL;
77 return h;
80 static const struct prop_handler *
81 find_prop_handler(const char *name,
82 const struct hlist_head *handlers)
84 struct prop_handler *h;
86 if (!handlers) {
87 u64 hash = btrfs_name_hash(name, strlen(name));
89 handlers = find_prop_handlers_by_hash(hash);
90 if (!handlers)
91 return NULL;
94 hlist_for_each_entry(h, handlers, node)
95 if (!strcmp(h->xattr_name, name))
96 return h;
98 return NULL;
101 static 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)
108 const struct prop_handler *handler;
109 int ret;
111 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
112 return -EINVAL;
114 handler = find_prop_handler(name, NULL);
115 if (!handler)
116 return -EINVAL;
118 if (value_len == 0) {
119 ret = __btrfs_setxattr(trans, inode, handler->xattr_name,
120 NULL, 0, flags);
121 if (ret)
122 return ret;
124 ret = handler->apply(inode, NULL, 0);
125 ASSERT(ret == 0);
127 return ret;
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;
144 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
146 return 0;
149 int btrfs_set_prop(struct inode *inode,
150 const char *name,
151 const char *value,
152 size_t value_len,
153 int flags)
155 return __btrfs_set_prop(NULL, inode, name, value, value_len, flags);
158 static 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)
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;
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;
182 slot = path->slots[0];
183 leaf = path->nodes[0];
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;
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;
200 handlers = find_prop_handlers_by_hash(key.offset);
201 if (!handlers)
202 goto next_slot;
204 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
205 cur = 0;
206 total_len = btrfs_item_size_nr(leaf, slot);
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;
214 this_len = sizeof(*di) + name_len + data_len;
215 name_ptr = (unsigned long)(di + 1);
216 data_ptr = name_ptr + name_len;
218 if (verify_dir_item(fs_info, leaf,
219 path->slots[0], di)) {
220 ret = -EIO;
221 goto out;
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;
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;
239 read_extent_buffer(leaf, name_buf, name_ptr, name_len);
240 name_buf[name_len] = '\0';
242 handler = find_prop_handler(name_buf, handlers);
243 if (!handler)
244 goto next_dir_item;
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;
255 read_extent_buffer(leaf, value_buf, data_ptr, data_len);
257 iterator(ctx, handler, value_buf, data_len);
258 next_dir_item:
259 cur += this_len;
260 di = (struct btrfs_dir_item *)((char *) di + this_len);
263 next_slot:
264 path->slots[0]++;
267 ret = 0;
268 out:
269 btrfs_release_path(path);
270 kfree(name_buf);
271 kfree(value_buf);
273 return ret;
276 static void inode_prop_iterator(void *ctx,
277 const struct prop_handler *handler,
278 const char *value,
279 size_t len)
281 struct inode *inode = ctx;
282 struct btrfs_root *root = BTRFS_I(inode)->root;
283 int ret;
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);
295 int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
297 struct btrfs_root *root = BTRFS_I(inode)->root;
298 u64 ino = btrfs_ino(BTRFS_I(inode));
299 int ret;
301 ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode);
303 return ret;
306 static int inherit_props(struct btrfs_trans_handle *trans,
307 struct inode *inode,
308 struct inode *parent)
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;
315 if (!test_bit(BTRFS_INODE_HAS_PROPS,
316 &BTRFS_I(parent)->runtime_flags))
317 return 0;
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;
324 if (!h->inheritable)
325 continue;
327 value = h->extract(parent);
328 if (!value)
329 continue;
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;
342 ret = 0;
343 out:
344 return ret;
347 int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
348 struct inode *inode,
349 struct inode *dir)
351 if (!dir)
352 return 0;
354 return inherit_props(trans, inode, dir);
357 int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans,
358 struct btrfs_root *root,
359 struct btrfs_root *parent_root)
361 struct super_block *sb = root->fs_info->sb;
362 struct btrfs_key key;
363 struct inode *parent_inode, *child_inode;
364 int ret;
366 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
367 key.type = BTRFS_INODE_ITEM_KEY;
368 key.offset = 0;
370 parent_inode = btrfs_iget(sb, &key, parent_root, NULL);
371 if (IS_ERR(parent_inode))
372 return PTR_ERR(parent_inode);
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);
380 ret = inherit_props(trans, child_inode, parent_inode);
381 iput(child_inode);
382 iput(parent_inode);
384 return ret;
387 static int prop_compression_validate(const char *value, size_t len)
389 if (btrfs_compress_is_valid_type(value, len))
390 return 0;
392 return -EINVAL;
395 static int prop_compression_apply(struct inode *inode,
396 const char *value,
397 size_t len)
399 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
400 int type;
402 if (len == 0) {
403 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
404 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
405 BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE;
407 return 0;
410 if (!strncmp("lzo", value, 3)) {
411 type = BTRFS_COMPRESS_LZO;
412 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
413 } else if (!strncmp("zlib", value, 4)) {
414 type = BTRFS_COMPRESS_ZLIB;
415 } else if (!strncmp("zstd", value, 4)) {
416 type = BTRFS_COMPRESS_ZSTD;
417 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
418 } else {
419 return -EINVAL;
422 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
423 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
424 BTRFS_I(inode)->prop_compress = type;
426 return 0;
429 static const char *prop_compression_extract(struct inode *inode)
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";
440 return NULL;