1 #include <linux/module.h>
3 #include <linux/blkdev.h>
4 #include <linux/crypto.h>
5 #include <linux/scatterlist.h>
8 #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
;
34 page
= find_lock_page(mapping
, index
);
38 if (!page_has_buffers(page
))
41 head
= page_buffers(page
);
44 if (buffer_mapped(bh
) && bh
->b_blocknr
== blocknr
) {
53 page_cache_release(page
);
57 struct buffer_head
*btrfs_find_create_tree_block(struct btrfs_root
*root
,
60 struct address_space
*mapping
= root
->fs_info
->btree_inode
->i_mapping
;
61 int blockbits
= root
->fs_info
->sb
->s_blocksize_bits
;
62 unsigned long index
= blocknr
>> (PAGE_CACHE_SHIFT
- blockbits
);
64 struct buffer_head
*bh
;
65 struct buffer_head
*head
;
66 struct buffer_head
*ret
= NULL
;
67 u64 first_block
= index
<< (PAGE_CACHE_SHIFT
- blockbits
);
68 page
= grab_cache_page(mapping
, index
);
72 if (!page_has_buffers(page
))
73 create_empty_buffers(page
, root
->fs_info
->sb
->s_blocksize
, 0);
74 head
= page_buffers(page
);
77 if (!buffer_mapped(bh
)) {
78 bh
->b_bdev
= root
->fs_info
->sb
->s_bdev
;
79 bh
->b_blocknr
= first_block
;
80 set_buffer_mapped(bh
);
82 if (bh
->b_blocknr
== blocknr
) {
92 page_cache_release(page
);
96 static sector_t
max_block(struct block_device
*bdev
)
98 sector_t retval
= ~((sector_t
)0);
99 loff_t sz
= i_size_read(bdev
->bd_inode
);
102 unsigned int size
= block_size(bdev
);
103 unsigned int sizebits
= blksize_bits(size
);
104 retval
= (sz
>> sizebits
);
109 static int btree_get_block(struct inode
*inode
, sector_t iblock
,
110 struct buffer_head
*bh
, int create
)
112 if (iblock
>= max_block(inode
->i_sb
->s_bdev
)) {
117 * for reads, we're just trying to fill a partial page.
118 * return a hole, they will have to call get_block again
119 * before they can fill it, and they will get -EIO at that
124 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
125 bh
->b_blocknr
= iblock
;
126 set_buffer_mapped(bh
);
130 int btrfs_csum_data(struct btrfs_root
* root
, char *data
, size_t len
,
133 struct scatterlist sg
;
134 struct crypto_hash
*tfm
= root
->fs_info
->hash_tfm
;
135 struct hash_desc desc
;
140 sg_init_one(&sg
, data
, len
);
141 spin_lock(&root
->fs_info
->hash_lock
);
142 ret
= crypto_hash_digest(&desc
, &sg
, len
, result
);
143 spin_unlock(&root
->fs_info
->hash_lock
);
145 printk("sha256 digest failed\n");
149 static int csum_tree_block(struct btrfs_root
*root
, struct buffer_head
*bh
,
152 char result
[BTRFS_CSUM_SIZE
];
154 struct btrfs_node
*node
;
156 ret
= btrfs_csum_data(root
, bh
->b_data
+ BTRFS_CSUM_SIZE
,
157 bh
->b_size
- BTRFS_CSUM_SIZE
, result
);
161 if (memcmp(bh
->b_data
, result
, BTRFS_CSUM_SIZE
)) {
162 printk("checksum verify failed on %lu\n",
167 node
= btrfs_buffer_node(bh
);
168 memcpy(&node
->header
.csum
, result
, BTRFS_CSUM_SIZE
);
173 static int btree_writepage(struct page
*page
, struct writeback_control
*wbc
)
175 struct buffer_head
*bh
;
176 struct btrfs_root
*root
= btrfs_sb(page
->mapping
->host
->i_sb
);
177 struct buffer_head
*head
;
179 if (!page_has_buffers(page
)) {
180 create_empty_buffers(page
, root
->fs_info
->sb
->s_blocksize
,
181 (1 << BH_Dirty
)|(1 << BH_Uptodate
));
183 head
= page_buffers(page
);
186 if (buffer_dirty(bh
))
187 csum_tree_block(root
, bh
, 0);
188 bh
= bh
->b_this_page
;
189 } while (bh
!= head
);
190 return block_write_full_page(page
, btree_get_block
, wbc
);
193 static int btree_readpage(struct file
* file
, struct page
* page
)
195 return block_read_full_page(page
, btree_get_block
);
198 static struct address_space_operations btree_aops
= {
199 .readpage
= btree_readpage
,
200 .writepage
= btree_writepage
,
201 .sync_page
= block_sync_page
,
204 struct buffer_head
*read_tree_block(struct btrfs_root
*root
, u64 blocknr
)
206 struct buffer_head
*bh
= NULL
;
208 bh
= btrfs_find_create_tree_block(root
, blocknr
);
212 if (!buffer_uptodate(bh
)) {
214 bh
->b_end_io
= end_buffer_read_sync
;
217 if (!buffer_uptodate(bh
))
219 csum_tree_block(root
, bh
, 1);
223 if (check_tree_block(root
, bh
))
232 int dirty_tree_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
233 struct buffer_head
*buf
)
235 mark_buffer_dirty(buf
);
239 int clean_tree_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
240 struct buffer_head
*buf
)
242 clear_buffer_dirty(buf
);
246 static int __setup_root(struct btrfs_super_block
*super
,
247 struct btrfs_root
*root
,
248 struct btrfs_fs_info
*fs_info
,
252 root
->commit_root
= NULL
;
253 root
->blocksize
= btrfs_super_blocksize(super
);
255 root
->fs_info
= fs_info
;
256 memset(&root
->root_key
, 0, sizeof(root
->root_key
));
257 memset(&root
->root_item
, 0, sizeof(root
->root_item
));
261 static int find_and_setup_root(struct btrfs_super_block
*super
,
262 struct btrfs_root
*tree_root
,
263 struct btrfs_fs_info
*fs_info
,
265 struct btrfs_root
*root
)
269 __setup_root(super
, root
, fs_info
, objectid
);
270 ret
= btrfs_find_last_root(tree_root
, objectid
,
271 &root
->root_item
, &root
->root_key
);
274 root
->node
= read_tree_block(root
,
275 btrfs_root_blocknr(&root
->root_item
));
280 struct btrfs_root
*open_ctree(struct super_block
*sb
,
281 struct buffer_head
*sb_buffer
,
282 struct btrfs_super_block
*disk_super
)
284 struct btrfs_root
*root
= kmalloc(sizeof(struct btrfs_root
),
286 struct btrfs_root
*extent_root
= kmalloc(sizeof(struct btrfs_root
),
288 struct btrfs_root
*tree_root
= kmalloc(sizeof(struct btrfs_root
),
290 struct btrfs_root
*inode_root
= kmalloc(sizeof(struct btrfs_root
),
292 struct btrfs_fs_info
*fs_info
= kmalloc(sizeof(*fs_info
),
296 if (!btrfs_super_root(disk_super
)) {
299 init_bit_radix(&fs_info
->pinned_radix
);
300 init_bit_radix(&fs_info
->pending_del_radix
);
301 sb_set_blocksize(sb
, sb_buffer
->b_size
);
302 fs_info
->running_transaction
= NULL
;
303 fs_info
->fs_root
= root
;
304 fs_info
->tree_root
= tree_root
;
305 fs_info
->extent_root
= extent_root
;
306 fs_info
->inode_root
= inode_root
;
307 fs_info
->last_inode_alloc
= 0;
308 fs_info
->last_inode_alloc_dirid
= 0;
309 fs_info
->disk_super
= disk_super
;
311 fs_info
->btree_inode
= new_inode(sb
);
312 fs_info
->btree_inode
->i_ino
= 1;
313 fs_info
->btree_inode
->i_size
= sb
->s_bdev
->bd_inode
->i_size
;
314 fs_info
->btree_inode
->i_mapping
->a_ops
= &btree_aops
;
315 mapping_set_gfp_mask(fs_info
->btree_inode
->i_mapping
, GFP_NOFS
);
316 fs_info
->hash_tfm
= crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC
);
317 spin_lock_init(&fs_info
->hash_lock
);
319 if (!fs_info
->hash_tfm
|| IS_ERR(fs_info
->hash_tfm
)) {
320 printk("failed to allocate sha256 hash\n");
324 mutex_init(&fs_info
->trans_mutex
);
325 mutex_init(&fs_info
->fs_mutex
);
326 memset(&fs_info
->current_insert
, 0, sizeof(fs_info
->current_insert
));
327 memset(&fs_info
->last_insert
, 0, sizeof(fs_info
->last_insert
));
329 __setup_root(disk_super
, tree_root
, fs_info
, BTRFS_ROOT_TREE_OBJECTID
);
331 fs_info
->sb_buffer
= read_tree_block(tree_root
, sb_buffer
->b_blocknr
);
333 if (!fs_info
->sb_buffer
) {
339 disk_super
= (struct btrfs_super_block
*)fs_info
->sb_buffer
->b_data
;
340 fs_info
->disk_super
= disk_super
;
342 tree_root
->node
= read_tree_block(tree_root
,
343 btrfs_super_root(disk_super
));
344 BUG_ON(!tree_root
->node
);
346 ret
= find_and_setup_root(disk_super
, tree_root
, fs_info
,
347 BTRFS_EXTENT_TREE_OBJECTID
, extent_root
);
350 ret
= find_and_setup_root(disk_super
, tree_root
, fs_info
,
351 BTRFS_INODE_MAP_OBJECTID
, inode_root
);
354 ret
= find_and_setup_root(disk_super
, tree_root
, fs_info
,
355 BTRFS_FS_TREE_OBJECTID
, root
);
357 root
->commit_root
= root
->node
;
360 root
->fs_info
->generation
= root
->root_key
.offset
+ 1;
364 int write_ctree_super(struct btrfs_trans_handle
*trans
, struct btrfs_root
367 struct buffer_head
*bh
= root
->fs_info
->sb_buffer
;
368 btrfs_set_super_root(root
->fs_info
->disk_super
,
369 root
->fs_info
->tree_root
->node
->b_blocknr
);
371 clear_buffer_dirty(bh
);
372 csum_tree_block(root
, bh
, 0);
373 bh
->b_end_io
= end_buffer_write_sync
;
375 submit_bh(WRITE
, bh
);
377 if (!buffer_uptodate(bh
)) {
384 int close_ctree(struct btrfs_root
*root
)
387 struct btrfs_trans_handle
*trans
;
389 trans
= btrfs_start_transaction(root
, 1);
390 btrfs_commit_transaction(trans
, root
);
391 /* run commit again to drop the original snapshot */
392 trans
= btrfs_start_transaction(root
, 1);
393 btrfs_commit_transaction(trans
, root
);
394 ret
= btrfs_write_and_wait_transaction(NULL
, root
);
396 write_ctree_super(NULL
, root
);
399 btrfs_block_release(root
, root
->node
);
400 if (root
->fs_info
->extent_root
->node
)
401 btrfs_block_release(root
->fs_info
->extent_root
,
402 root
->fs_info
->extent_root
->node
);
403 if (root
->fs_info
->inode_root
->node
)
404 btrfs_block_release(root
->fs_info
->inode_root
,
405 root
->fs_info
->inode_root
->node
);
406 if (root
->fs_info
->tree_root
->node
)
407 btrfs_block_release(root
->fs_info
->tree_root
,
408 root
->fs_info
->tree_root
->node
);
409 btrfs_block_release(root
, root
->commit_root
);
410 btrfs_block_release(root
, root
->fs_info
->sb_buffer
);
411 crypto_free_hash(root
->fs_info
->hash_tfm
);
412 truncate_inode_pages(root
->fs_info
->btree_inode
->i_mapping
, 0);
413 iput(root
->fs_info
->btree_inode
);
414 kfree(root
->fs_info
->extent_root
);
415 kfree(root
->fs_info
->inode_root
);
416 kfree(root
->fs_info
->tree_root
);
417 kfree(root
->fs_info
);
422 void btrfs_block_release(struct btrfs_root
*root
, struct buffer_head
*buf
)