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>
21 #include "btrfs_inode.h"
23 #include "transaction.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);
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);
39 static int prop_compression_validate(const char *value, size_t len);
40 static int prop_compression_apply(struct inode *inode,
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,
55 void __init btrfs_props_init(void)
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)
73 h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)];
80 static const struct prop_handler *
81 find_prop_handler(const char *name,
82 const struct hlist_head *handlers)
84 struct prop_handler *h;
87 u64 hash = btrfs_name_hash(name, strlen(name));
89 handlers = find_prop_handlers_by_hash(hash);
94 hlist_for_each_entry(h, handlers, node)
95 if (!strcmp(h->xattr_name, name))
101 static int __btrfs_set_prop(struct btrfs_trans_handle *trans,
108 const struct prop_handler *handler;
111 if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN)
114 handler = find_prop_handler(name, NULL);
118 if (value_len == 0) {
119 ret = __btrfs_setxattr(trans, inode, handler->xattr_name,
124 ret = handler->apply(inode, NULL, 0);
130 ret = handler->validate(value, value_len);
133 ret = __btrfs_setxattr(trans, inode, handler->xattr_name,
134 value, value_len, flags);
137 ret = handler->apply(inode, value, value_len);
139 __btrfs_setxattr(trans, inode, handler->xattr_name,
144 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
149 int btrfs_set_prop(struct inode *inode,
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,
161 void (*iterator)(void *,
162 const struct prop_handler *,
168 char *name_buf = NULL;
169 char *value_buf = NULL;
170 int name_buf_len = 0;
171 int value_buf_len = 0;
174 struct btrfs_key key;
175 struct btrfs_dir_item *di;
176 struct extent_buffer *leaf;
177 u32 total_len, cur, this_len;
179 const struct hlist_head *handlers;
181 slot = path->slots[0];
182 leaf = path->nodes[0];
184 if (slot >= btrfs_header_nritems(leaf)) {
185 ret = btrfs_next_leaf(root, path);
193 btrfs_item_key_to_cpu(leaf, &key, slot);
194 if (key.objectid != objectid)
196 if (key.type != BTRFS_XATTR_ITEM_KEY)
199 handlers = find_prop_handlers_by_hash(key.offset);
203 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
205 total_len = btrfs_item_size_nr(leaf, slot);
207 while (cur < total_len) {
208 u32 name_len = btrfs_dir_name_len(leaf, di);
209 u32 data_len = btrfs_dir_data_len(leaf, di);
210 unsigned long name_ptr, data_ptr;
211 const struct prop_handler *handler;
213 this_len = sizeof(*di) + name_len + data_len;
214 name_ptr = (unsigned long)(di + 1);
215 data_ptr = name_ptr + name_len;
217 if (name_len <= XATTR_BTRFS_PREFIX_LEN ||
218 memcmp_extent_buffer(leaf, XATTR_BTRFS_PREFIX,
220 XATTR_BTRFS_PREFIX_LEN))
223 if (name_len >= name_buf_len) {
225 name_buf_len = name_len + 1;
226 name_buf = kmalloc(name_buf_len, GFP_NOFS);
232 read_extent_buffer(leaf, name_buf, name_ptr, name_len);
233 name_buf[name_len] = '\0';
235 handler = find_prop_handler(name_buf, handlers);
239 if (data_len > value_buf_len) {
241 value_buf_len = data_len;
242 value_buf = kmalloc(data_len, GFP_NOFS);
248 read_extent_buffer(leaf, value_buf, data_ptr, data_len);
250 iterator(ctx, handler, value_buf, data_len);
253 di = (struct btrfs_dir_item *)((char *) di + this_len);
262 btrfs_release_path(path);
269 static void inode_prop_iterator(void *ctx,
270 const struct prop_handler *handler,
274 struct inode *inode = ctx;
275 struct btrfs_root *root = BTRFS_I(inode)->root;
278 ret = handler->apply(inode, value, len);
280 btrfs_warn(root->fs_info,
281 "error applying prop %s to ino %llu (root %llu): %d",
282 handler->xattr_name, btrfs_ino(inode),
283 root->root_key.objectid, ret);
285 set_bit(BTRFS_INODE_HAS_PROPS, &BTRFS_I(inode)->runtime_flags);
288 int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path)
290 struct btrfs_root *root = BTRFS_I(inode)->root;
291 u64 ino = btrfs_ino(inode);
294 ret = iterate_object_props(root, path, ino, inode_prop_iterator, inode);
299 static int inherit_props(struct btrfs_trans_handle *trans,
301 struct inode *parent)
303 struct btrfs_root *root = BTRFS_I(inode)->root;
307 if (!test_bit(BTRFS_INODE_HAS_PROPS,
308 &BTRFS_I(parent)->runtime_flags))
311 for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) {
312 const struct prop_handler *h = &prop_handlers[i];
319 value = h->extract(parent);
323 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
324 ret = btrfs_block_rsv_add(root, trans->block_rsv,
325 num_bytes, BTRFS_RESERVE_NO_FLUSH);
328 ret = __btrfs_set_prop(trans, inode, h->xattr_name,
329 value, strlen(value), 0);
330 btrfs_block_rsv_release(root, trans->block_rsv, num_bytes);
339 int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans,
346 return inherit_props(trans, inode, dir);
349 int btrfs_subvol_inherit_props(struct btrfs_trans_handle *trans,
350 struct btrfs_root *root,
351 struct btrfs_root *parent_root)
353 struct super_block *sb = root->fs_info->sb;
354 struct btrfs_key key;
355 struct inode *parent_inode, *child_inode;
358 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
359 key.type = BTRFS_INODE_ITEM_KEY;
362 parent_inode = btrfs_iget(sb, &key, parent_root, NULL);
363 if (IS_ERR(parent_inode))
364 return PTR_ERR(parent_inode);
366 child_inode = btrfs_iget(sb, &key, root, NULL);
367 if (IS_ERR(child_inode)) {
369 return PTR_ERR(child_inode);
372 ret = inherit_props(trans, child_inode, parent_inode);
379 static int prop_compression_validate(const char *value, size_t len)
381 if (!strncmp("lzo", value, len))
383 else if (!strncmp("zlib", value, len))
389 static int prop_compression_apply(struct inode *inode,
396 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
397 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
398 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
403 if (!strncmp("lzo", value, len))
404 type = BTRFS_COMPRESS_LZO;
405 else if (!strncmp("zlib", value, len))
406 type = BTRFS_COMPRESS_ZLIB;
410 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
411 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
412 BTRFS_I(inode)->force_compress = type;
417 static const char *prop_compression_extract(struct inode *inode)
419 switch (BTRFS_I(inode)->force_compress) {
420 case BTRFS_COMPRESS_ZLIB:
422 case BTRFS_COMPRESS_LZO: