1 #include <linux/module.h>
3 #include <linux/blkdev.h>
4 #include <linux/crypto.h>
5 #include <linux/scatterlist.h>
6 #include <linux/swap.h>
9 #include "transaction.h"
11 static int check_tree_block(struct btrfs_root
*root
, struct buffer_head
*buf
)
13 struct btrfs_node
*node
= btrfs_buffer_node(buf
);
14 if (buf
->b_blocknr
!= btrfs_header_blocknr(&node
->header
)) {
17 if (root
->node
&& btrfs_header_parentid(&node
->header
) !=
18 btrfs_header_parentid(btrfs_buffer_header(root
->node
))) {
24 struct buffer_head
*btrfs_find_tree_block(struct btrfs_root
*root
, u64 blocknr
)
26 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
27 int blockbits
= root
->fs_info
->sb
->s_blocksize_bits
;
28 unsigned long index
= blocknr
>> (PAGE_CACHE_SHIFT
- blockbits
);
30 struct buffer_head
*bh
;
31 struct buffer_head
*head
;
32 struct buffer_head
*ret
= NULL
;
35 page
= find_lock_page(mapping
, index
);
39 if (!page_has_buffers(page
))
42 head
= page_buffers(page
);
45 if (buffer_mapped(bh
) && bh
->b_blocknr
== blocknr
) {
57 page_cache_release(page
);
61 struct buffer_head
*btrfs_find_create_tree_block(struct btrfs_root
*root
,
64 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
65 int blockbits
= root
->fs_info
->sb
->s_blocksize_bits
;
66 unsigned long index
= blocknr
>> (PAGE_CACHE_SHIFT
- blockbits
);
68 struct buffer_head
*bh
;
69 struct buffer_head
*head
;
70 struct buffer_head
*ret
= NULL
;
71 u64 first_block
= index
<< (PAGE_CACHE_SHIFT
- blockbits
);
73 page
= grab_cache_page(mapping
, index
);
77 if (!page_has_buffers(page
))
78 create_empty_buffers(page
, root
->fs_info
->sb
->s_blocksize
, 0);
79 head
= page_buffers(page
);
82 if (!buffer_mapped(bh
)) {
83 bh
->b_bdev
= root
->fs_info
->sb
->s_bdev
;
84 bh
->b_blocknr
= first_block
;
85 set_buffer_mapped(bh
);
87 if (bh
->b_blocknr
== blocknr
) {
99 page_cache_release(page
);
103 static sector_t
max_block(struct block_device
*bdev
)
105 sector_t retval
= ~((sector_t
)0);
106 loff_t sz
= i_size_read(bdev
->bd_inode
);
109 unsigned int size
= block_size(bdev
);
110 unsigned int sizebits
= blksize_bits(size
);
111 retval
= (sz
>> sizebits
);
116 static int btree_get_block(struct inode
*inode
, sector_t iblock
,
117 struct buffer_head
*bh
, int create
)
119 if (iblock
>= max_block(inode
->i_sb
->s_bdev
)) {
124 * for reads, we're just trying to fill a partial page.
125 * return a hole, they will have to call get_block again
126 * before they can fill it, and they will get -EIO at that
131 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
132 bh
->b_blocknr
= iblock
;
133 set_buffer_mapped(bh
);
137 int btrfs_csum_data(struct btrfs_root
* root
, char *data
, size_t len
,
140 struct scatterlist sg
;
141 struct crypto_hash
*tfm
= root
->fs_info
->hash_tfm
;
142 struct hash_desc desc
;
147 sg_init_one(&sg
, data
, len
);
148 spin_lock(&root
->fs_info
->hash_lock
);
149 ret
= crypto_hash_digest(&desc
, &sg
, 1, result
);
150 spin_unlock(&root
->fs_info
->hash_lock
);
152 printk("sha256 digest failed\n");
156 static int csum_tree_block(struct btrfs_root
*root
, struct buffer_head
*bh
,
159 char result
[BTRFS_CSUM_SIZE
];
161 struct btrfs_node
*node
;
163 ret
= btrfs_csum_data(root
, bh
->b_data
+ BTRFS_CSUM_SIZE
,
164 bh
->b_size
- BTRFS_CSUM_SIZE
, result
);
168 if (memcmp(bh
->b_data
, result
, BTRFS_CSUM_SIZE
)) {
169 printk("checksum verify failed on %lu\n",
174 node
= btrfs_buffer_node(bh
);
175 memcpy(node
->header
.csum
, result
, BTRFS_CSUM_SIZE
);
180 static int btree_writepage(struct page
*page
, struct writeback_control
*wbc
)
182 struct buffer_head
*bh
;
183 struct btrfs_root
*root
= btrfs_sb(page
->mapping
->host
->i_sb
);
184 struct buffer_head
*head
;
185 if (!page_has_buffers(page
)) {
186 create_empty_buffers(page
, root
->fs_info
->sb
->s_blocksize
,
187 (1 << BH_Dirty
)|(1 << BH_Uptodate
));
189 head
= page_buffers(page
);
192 if (buffer_dirty(bh
))
193 csum_tree_block(root
, bh
, 0);
194 bh
= bh
->b_this_page
;
195 } while (bh
!= head
);
196 return block_write_full_page(page
, btree_get_block
, wbc
);
199 static int btree_readpage(struct file
* file
, struct page
* page
)
201 return block_read_full_page(page
, btree_get_block
);
204 static struct address_space_operations btree_aops
= {
205 .readpage
= btree_readpage
,
206 .writepage
= btree_writepage
,
207 .sync_page
= block_sync_page
,
210 struct buffer_head
*read_tree_block(struct btrfs_root
*root
, u64 blocknr
)
212 struct buffer_head
*bh
= NULL
;
214 bh
= btrfs_find_create_tree_block(root
, blocknr
);
217 if (buffer_uptodate(bh
))
220 if (!buffer_uptodate(bh
)) {
222 bh
->b_end_io
= end_buffer_read_sync
;
225 if (!buffer_uptodate(bh
))
227 csum_tree_block(root
, bh
, 1);
232 if (check_tree_block(root
, bh
))
240 int dirty_tree_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
241 struct buffer_head
*buf
)
243 WARN_ON(atomic_read(&buf
->b_count
) == 0);
244 mark_buffer_dirty(buf
);
248 int clean_tree_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
249 struct buffer_head
*buf
)
251 WARN_ON(atomic_read(&buf
->b_count
) == 0);
252 clear_buffer_dirty(buf
);
256 static int __setup_root(int blocksize
,
257 struct btrfs_root
*root
,
258 struct btrfs_fs_info
*fs_info
,
262 root
->commit_root
= NULL
;
263 root
->blocksize
= blocksize
;
265 root
->fs_info
= fs_info
;
266 memset(&root
->root_key
, 0, sizeof(root
->root_key
));
267 memset(&root
->root_item
, 0, sizeof(root
->root_item
));
271 static int find_and_setup_root(int blocksize
,
272 struct btrfs_root
*tree_root
,
273 struct btrfs_fs_info
*fs_info
,
275 struct btrfs_root
*root
)
279 __setup_root(blocksize
, root
, fs_info
, objectid
);
280 ret
= btrfs_find_last_root(tree_root
, objectid
,
281 &root
->root_item
, &root
->root_key
);
284 root
->node
= read_tree_block(root
,
285 btrfs_root_blocknr(&root
->root_item
));
290 struct btrfs_root
*open_ctree(struct super_block
*sb
)
292 struct btrfs_root
*root
= kmalloc(sizeof(struct btrfs_root
),
294 struct btrfs_root
*extent_root
= kmalloc(sizeof(struct btrfs_root
),
296 struct btrfs_root
*tree_root
= kmalloc(sizeof(struct btrfs_root
),
298 struct btrfs_root
*inode_root
= kmalloc(sizeof(struct btrfs_root
),
300 struct btrfs_fs_info
*fs_info
= kmalloc(sizeof(*fs_info
),
303 struct btrfs_super_block
*disk_super
;
305 init_bit_radix(&fs_info
->pinned_radix
);
306 init_bit_radix(&fs_info
->pending_del_radix
);
307 sb_set_blocksize(sb
, 4096);
308 fs_info
->running_transaction
= NULL
;
309 fs_info
->fs_root
= root
;
310 fs_info
->tree_root
= tree_root
;
311 fs_info
->extent_root
= extent_root
;
312 fs_info
->inode_root
= inode_root
;
313 fs_info
->last_inode_alloc
= 0;
314 fs_info
->last_inode_alloc_dirid
= 0;
316 fs_info
->btree_inode
= new_inode(sb
);
317 fs_info
->btree_inode
->i_ino
= 1;
318 fs_info
->btree_inode
->i_nlink
= 1;
319 fs_info
->btree_inode
->i_size
= sb
->s_bdev
->bd_inode
->i_size
;
320 fs_info
->btree_inode
->i_mapping
->a_ops
= &btree_aops
;
321 insert_inode_hash(fs_info
->btree_inode
);
322 mapping_set_gfp_mask(fs_info
->btree_inode
->i_mapping
, GFP_NOFS
);
323 fs_info
->hash_tfm
= crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC
);
324 spin_lock_init(&fs_info
->hash_lock
);
325 if (!fs_info
->hash_tfm
|| IS_ERR(fs_info
->hash_tfm
)) {
326 printk("failed to allocate sha256 hash\n");
329 mutex_init(&fs_info
->trans_mutex
);
330 mutex_init(&fs_info
->fs_mutex
);
331 memset(&fs_info
->current_insert
, 0, sizeof(fs_info
->current_insert
));
332 memset(&fs_info
->last_insert
, 0, sizeof(fs_info
->last_insert
));
334 __setup_root(sb
->s_blocksize
, tree_root
,
335 fs_info
, BTRFS_ROOT_TREE_OBJECTID
);
336 fs_info
->sb_buffer
= read_tree_block(tree_root
,
337 BTRFS_SUPER_INFO_OFFSET
/
340 if (!fs_info
->sb_buffer
) {
344 disk_super
= (struct btrfs_super_block
*)fs_info
->sb_buffer
->b_data
;
345 if (!btrfs_super_root(disk_super
)) {
348 fs_info
->disk_super
= disk_super
;
349 tree_root
->node
= read_tree_block(tree_root
,
350 btrfs_super_root(disk_super
));
351 BUG_ON(!tree_root
->node
);
353 mutex_lock(&fs_info
->fs_mutex
);
354 ret
= find_and_setup_root(sb
->s_blocksize
, tree_root
, fs_info
,
355 BTRFS_EXTENT_TREE_OBJECTID
, extent_root
);
358 ret
= find_and_setup_root(sb
->s_blocksize
, tree_root
, fs_info
,
359 BTRFS_INODE_MAP_OBJECTID
, inode_root
);
362 ret
= find_and_setup_root(sb
->s_blocksize
, tree_root
, fs_info
,
363 BTRFS_FS_TREE_OBJECTID
, root
);
364 mutex_unlock(&fs_info
->fs_mutex
);
366 root
->commit_root
= root
->node
;
369 root
->fs_info
->generation
= root
->root_key
.offset
+ 1;
373 int write_ctree_super(struct btrfs_trans_handle
*trans
, struct btrfs_root
376 struct buffer_head
*bh
= root
->fs_info
->sb_buffer
;
378 btrfs_set_super_root(root
->fs_info
->disk_super
,
379 root
->fs_info
->tree_root
->node
->b_blocknr
);
381 WARN_ON(atomic_read(&bh
->b_count
) < 1);
382 clear_buffer_dirty(bh
);
383 csum_tree_block(root
, bh
, 0);
384 bh
->b_end_io
= end_buffer_write_sync
;
386 submit_bh(WRITE
, bh
);
388 if (!buffer_uptodate(bh
)) {
395 int close_ctree(struct btrfs_root
*root
)
398 struct btrfs_trans_handle
*trans
;
400 mutex_lock(&root
->fs_info
->fs_mutex
);
401 trans
= btrfs_start_transaction(root
, 1);
402 btrfs_commit_transaction(trans
, root
);
403 /* run commit again to drop the original snapshot */
404 trans
= btrfs_start_transaction(root
, 1);
405 btrfs_commit_transaction(trans
, root
);
406 ret
= btrfs_write_and_wait_transaction(NULL
, root
);
408 write_ctree_super(NULL
, root
);
409 mutex_unlock(&root
->fs_info
->fs_mutex
);
412 btrfs_block_release(root
, root
->node
);
413 if (root
->fs_info
->extent_root
->node
)
414 btrfs_block_release(root
->fs_info
->extent_root
,
415 root
->fs_info
->extent_root
->node
);
416 if (root
->fs_info
->inode_root
->node
)
417 btrfs_block_release(root
->fs_info
->inode_root
,
418 root
->fs_info
->inode_root
->node
);
419 if (root
->fs_info
->tree_root
->node
)
420 btrfs_block_release(root
->fs_info
->tree_root
,
421 root
->fs_info
->tree_root
->node
);
422 btrfs_block_release(root
, root
->commit_root
);
423 btrfs_block_release(root
, root
->fs_info
->sb_buffer
);
424 crypto_free_hash(root
->fs_info
->hash_tfm
);
425 truncate_inode_pages(root
->fs_info
->btree_inode
->i_mapping
, 0);
426 iput(root
->fs_info
->btree_inode
);
427 kfree(root
->fs_info
->extent_root
);
428 kfree(root
->fs_info
->inode_root
);
429 kfree(root
->fs_info
->tree_root
);
430 kfree(root
->fs_info
);
435 void btrfs_block_release(struct btrfs_root
*root
, struct buffer_head
*buf
)