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>
7 #include <linux/radix-tree.h>
10 #include "transaction.h"
11 #include "btrfs_inode.h"
17 struct block_device *bdev;
20 int btrfs_insert_dev_radix(struct btrfs_root *root,
21 struct block_device *bdev,
26 struct dev_lookup *lookup;
29 lookup = kmalloc(sizeof(*lookup), GFP_NOFS);
32 lookup->block_start = block_start;
33 lookup->num_blocks = num_blocks;
35 lookup->device_id = device_id;
37 ret = radix_tree_insert(&root->fs_info->dev_radix, block_start +
38 num_blocks - 1, lookup);
42 u64 bh_blocknr(struct buffer_head *bh)
44 int blkbits = bh->b_page->mapping->host->i_blkbits;
45 u64 blocknr = bh->b_page->index << (PAGE_CACHE_SHIFT - blkbits);
48 if (PageHighMem(bh->b_page))
49 offset = (unsigned long)bh->b_data;
51 offset = bh->b_data - (char *)page_address(bh->b_page);
52 blocknr += offset >> (PAGE_CACHE_SHIFT - blkbits);
56 static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
58 struct btrfs_node *node = btrfs_buffer_node(buf);
59 if (bh_blocknr(buf) != btrfs_header_blocknr(&node->header)) {
60 printk(KERN_CRIT "bh_blocknr(buf) is %Lu, header is %Lu\n",
61 bh_blocknr(buf), btrfs_header_blocknr(&node->header));
67 struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
69 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
70 int blockbits = root->fs_info->sb->s_blocksize_bits;
71 unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
73 struct buffer_head *bh;
74 struct buffer_head *head;
75 struct buffer_head *ret = NULL;
78 page = find_lock_page(mapping, index);
82 if (!page_has_buffers(page))
85 head = page_buffers(page);
88 if (buffer_mapped(bh) && bh_blocknr(bh) == blocknr) {
97 page_cache_release(page);
101 int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
104 struct dev_lookup *lookup[2];
111 set_buffer_mapped(bh);
114 root = root->fs_info->dev_root;
115 ret = radix_tree_gang_lookup(&root->fs_info->dev_radix,
117 (unsigned long)logical,
119 if (ret == 0 || lookup[0]->block_start > logical ||
120 lookup[0]->block_start + lookup[0]->num_blocks <= logical) {
124 bh->b_bdev = lookup[0]->bdev;
125 bh->b_blocknr = logical - lookup[0]->block_start;
126 set_buffer_mapped(bh);
132 struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
135 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
136 int blockbits = root->fs_info->sb->s_blocksize_bits;
137 unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
139 struct buffer_head *bh;
140 struct buffer_head *head;
141 struct buffer_head *ret = NULL;
143 u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
145 page = grab_cache_page(mapping, index);
149 if (!page_has_buffers(page))
150 create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
151 head = page_buffers(page);
154 if (!buffer_mapped(bh)) {
155 err = btrfs_map_bh_to_logical(root, bh, first_block);
158 if (bh_blocknr(bh) == blocknr) {
163 bh = bh->b_this_page;
165 } while (bh != head);
170 page_cache_release(page);
174 static int btree_get_block(struct inode *inode, sector_t iblock,
175 struct buffer_head *bh, int create)
178 struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
179 err = btrfs_map_bh_to_logical(root, bh, iblock);
183 int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
186 struct scatterlist sg;
187 struct crypto_hash *tfm = root->fs_info->hash_tfm;
188 struct hash_desc desc;
193 sg_init_one(&sg, data, len);
194 spin_lock(&root->fs_info->hash_lock);
195 ret = crypto_hash_digest(&desc, &sg, 1, result);
196 spin_unlock(&root->fs_info->hash_lock);
198 printk("sha256 digest failed\n");
202 static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
205 char result[BTRFS_CSUM_SIZE];
207 struct btrfs_node *node;
209 ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
210 bh->b_size - BTRFS_CSUM_SIZE, result);
214 if (memcmp(bh->b_data, result, BTRFS_CSUM_SIZE)) {
215 printk("checksum verify failed on %Lu\n",
220 node = btrfs_buffer_node(bh);
221 memcpy(node->header.csum, result, BTRFS_CSUM_SIZE);
226 static int btree_writepage(struct page *page, struct writeback_control *wbc)
228 struct buffer_head *bh;
229 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
230 struct buffer_head *head;
231 if (!page_has_buffers(page)) {
232 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
233 (1 << BH_Dirty)|(1 << BH_Uptodate));
235 head = page_buffers(page);
238 if (buffer_dirty(bh))
239 csum_tree_block(root, bh, 0);
240 bh = bh->b_this_page;
241 } while (bh != head);
242 return block_write_full_page(page, btree_get_block, wbc);
245 static int btree_readpage(struct file * file, struct page * page)
247 return block_read_full_page(page, btree_get_block);
250 static struct address_space_operations btree_aops = {
251 .readpage = btree_readpage,
252 .writepage = btree_writepage,
253 .sync_page = block_sync_page,
256 struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
258 struct buffer_head *bh = NULL;
260 bh = btrfs_find_create_tree_block(root, blocknr);
263 if (buffer_uptodate(bh))
266 if (!buffer_uptodate(bh)) {
268 bh->b_end_io = end_buffer_read_sync;
271 if (!buffer_uptodate(bh))
273 csum_tree_block(root, bh, 1);
278 if (check_tree_block(root, bh))
286 int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
287 struct buffer_head *buf)
289 WARN_ON(atomic_read(&buf->b_count) == 0);
290 mark_buffer_dirty(buf);
294 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
295 struct buffer_head *buf)
297 WARN_ON(atomic_read(&buf->b_count) == 0);
298 clear_buffer_dirty(buf);
302 static int __setup_root(int blocksize,
303 struct btrfs_root *root,
304 struct btrfs_fs_info *fs_info,
309 root->commit_root = NULL;
310 root->blocksize = blocksize;
312 root->fs_info = fs_info;
313 root->objectid = objectid;
314 root->last_trans = 0;
315 root->highest_inode = 0;
316 root->last_inode_alloc = 0;
317 memset(&root->root_key, 0, sizeof(root->root_key));
318 memset(&root->root_item, 0, sizeof(root->root_item));
319 root->root_key.objectid = objectid;
323 static int find_and_setup_root(int blocksize,
324 struct btrfs_root *tree_root,
325 struct btrfs_fs_info *fs_info,
327 struct btrfs_root *root)
331 __setup_root(blocksize, root, fs_info, objectid);
332 ret = btrfs_find_last_root(tree_root, objectid,
333 &root->root_item, &root->root_key);
336 root->node = read_tree_block(root,
337 btrfs_root_blocknr(&root->root_item));
342 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
343 struct btrfs_key *location)
345 struct btrfs_root *root;
346 struct btrfs_root *tree_root = fs_info->tree_root;
347 struct btrfs_path *path;
348 struct btrfs_leaf *l;
352 printk("read_fs_root looking for %Lu %Lu %u\n", location->objectid, location->offset, location->flags);
353 root = radix_tree_lookup(&fs_info->fs_roots_radix,
354 (unsigned long)location->objectid);
356 printk("found %p in cache\n", root);
359 root = kmalloc(sizeof(*root), GFP_NOFS);
362 return ERR_PTR(-ENOMEM);
364 if (location->offset == (u64)-1) {
365 ret = find_and_setup_root(fs_info->sb->s_blocksize,
366 fs_info->tree_root, fs_info,
367 location->objectid, root);
376 __setup_root(fs_info->sb->s_blocksize, root, fs_info,
379 path = btrfs_alloc_path();
381 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
383 printk("internal search_slot gives us %d\n", ret);
388 l = btrfs_buffer_leaf(path->nodes[0]);
389 memcpy(&root->root_item,
390 btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
391 sizeof(root->root_item));
392 memcpy(&root->root_key, location, sizeof(*location));
395 btrfs_release_path(root, path);
396 btrfs_free_path(path);
401 root->node = read_tree_block(root,
402 btrfs_root_blocknr(&root->root_item));
405 printk("inserting %p\n", root);
407 ret = radix_tree_insert(&fs_info->fs_roots_radix,
408 (unsigned long)root->root_key.objectid,
411 printk("radix_tree_insert gives us %d\n", ret);
416 ret = btrfs_find_highest_inode(root, &highest_inode);
418 root->highest_inode = highest_inode;
419 root->last_inode_alloc = highest_inode;
420 printk("highest inode is %Lu\n", highest_inode);
422 printk("all worked\n");
426 static int btrfs_open_disk(struct btrfs_root *root, u64 device_id,
427 u64 block_start, u64 num_blocks,
428 char *filename, int name_len)
431 struct block_device *bdev;
434 null_filename = kmalloc(name_len + 1, GFP_NOFS);
437 memcpy(null_filename, filename, name_len);
438 null_filename[name_len] = '\0';
440 bdev = open_bdev_excl(null_filename, O_RDWR, root->fs_info->sb);
445 set_blocksize(bdev, root->fs_info->sb->s_blocksize);
446 ret = btrfs_insert_dev_radix(root, bdev, device_id,
447 block_start, num_blocks);
451 kfree(null_filename);
455 static int read_device_info(struct btrfs_root *root)
457 struct btrfs_path *path;
459 struct btrfs_key key;
460 struct btrfs_leaf *leaf;
461 struct btrfs_device_item *dev_item;
465 root = root->fs_info->dev_root;
467 path = btrfs_alloc_path();
473 btrfs_set_key_type(&key, BTRFS_DEV_ITEM_KEY);
475 mutex_lock(&root->fs_info->fs_mutex);
476 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
477 leaf = btrfs_buffer_leaf(path->nodes[0]);
478 nritems = btrfs_header_nritems(&leaf->header);
480 slot = path->slots[0];
481 if (slot >= nritems) {
482 ret = btrfs_next_leaf(root, path);
485 leaf = btrfs_buffer_leaf(path->nodes[0]);
486 nritems = btrfs_header_nritems(&leaf->header);
487 slot = path->slots[0];
489 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
490 if (btrfs_key_type(&key) != BTRFS_DEV_ITEM_KEY) {
494 dev_item = btrfs_item_ptr(leaf, slot, struct btrfs_device_item);
495 printk("found key %Lu %Lu\n", key.objectid, key.offset);
496 if (btrfs_device_id(dev_item) !=
497 btrfs_super_device_id(root->fs_info->disk_super)) {
498 ret = btrfs_open_disk(root, btrfs_device_id(dev_item),
499 key.objectid, key.offset,
500 (char *)(dev_item + 1),
501 btrfs_device_pathlen(dev_item));
506 btrfs_free_path(path);
507 mutex_unlock(&root->fs_info->fs_mutex);
511 struct btrfs_root *open_ctree(struct super_block *sb)
513 struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
515 struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
517 struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
519 struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
522 struct btrfs_super_block *disk_super;
523 struct dev_lookup *dev_lookup;
525 init_bit_radix(&fs_info->pinned_radix);
526 init_bit_radix(&fs_info->pending_del_radix);
527 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
528 INIT_RADIX_TREE(&fs_info->dev_radix, GFP_NOFS);
529 INIT_RADIX_TREE(&fs_info->block_group_radix, GFP_KERNEL);
530 INIT_LIST_HEAD(&fs_info->trans_list);
531 sb_set_blocksize(sb, 4096);
532 fs_info->running_transaction = NULL;
533 fs_info->tree_root = tree_root;
534 fs_info->extent_root = extent_root;
535 fs_info->dev_root = dev_root;
537 fs_info->btree_inode = new_inode(sb);
538 fs_info->btree_inode->i_ino = 1;
539 fs_info->btree_inode->i_nlink = 1;
540 fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
541 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
542 fs_info->do_barriers = 1;
543 fs_info->extent_tree_insert_nr = 0;
544 fs_info->extent_tree_prealloc_nr = 0;
545 BTRFS_I(fs_info->btree_inode)->root = tree_root;
546 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
547 sizeof(struct btrfs_key));
548 insert_inode_hash(fs_info->btree_inode);
549 mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
550 fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
551 spin_lock_init(&fs_info->hash_lock);
552 if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
553 printk("failed to allocate sha256 hash\n");
556 mutex_init(&fs_info->trans_mutex);
557 mutex_init(&fs_info->fs_mutex);
558 fs_info->block_group_cache = NULL;
560 __setup_root(sb->s_blocksize, dev_root,
561 fs_info, BTRFS_DEV_TREE_OBJECTID);
563 __setup_root(sb->s_blocksize, tree_root,
564 fs_info, BTRFS_ROOT_TREE_OBJECTID);
566 dev_lookup = kmalloc(sizeof(*dev_lookup), GFP_NOFS);
567 dev_lookup->block_start = 0;
568 dev_lookup->num_blocks = (u32)-2;
569 dev_lookup->bdev = sb->s_bdev;
570 dev_lookup->device_id = 0;
571 ret = radix_tree_insert(&fs_info->dev_radix, (u32)-2, dev_lookup);
573 fs_info->sb_buffer = read_tree_block(tree_root,
574 BTRFS_SUPER_INFO_OFFSET /
577 if (!fs_info->sb_buffer)
579 disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
580 if (!btrfs_super_root(disk_super))
583 i_size_write(fs_info->btree_inode,
584 btrfs_super_total_blocks(disk_super) <<
585 fs_info->btree_inode->i_blkbits);
587 radix_tree_delete(&fs_info->dev_radix, (u32)-2);
588 dev_lookup->block_start = btrfs_super_device_block_start(disk_super);
589 dev_lookup->num_blocks = btrfs_super_device_num_blocks(disk_super);
590 dev_lookup->device_id = btrfs_super_device_id(disk_super);
592 ret = radix_tree_insert(&fs_info->dev_radix,
593 dev_lookup->block_start +
594 dev_lookup->num_blocks - 1, dev_lookup);
597 fs_info->disk_super = disk_super;
599 dev_root->node = read_tree_block(tree_root,
600 btrfs_super_device_root(disk_super));
602 ret = read_device_info(dev_root);
605 tree_root->node = read_tree_block(tree_root,
606 btrfs_super_root(disk_super));
607 BUG_ON(!tree_root->node);
609 mutex_lock(&fs_info->fs_mutex);
610 ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
611 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
614 btrfs_read_block_groups(extent_root);
616 fs_info->generation = btrfs_super_generation(disk_super) + 1;
617 memset(&fs_info->kobj, 0, sizeof(fs_info->kobj));
618 kobj_set_kset_s(fs_info, btrfs_subsys);
619 kobject_set_name(&fs_info->kobj, "%s", sb->s_id);
620 kobject_register(&fs_info->kobj);
621 mutex_unlock(&fs_info->fs_mutex);
625 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
629 struct buffer_head *bh = root->fs_info->sb_buffer;
631 btrfs_set_super_root(root->fs_info->disk_super,
632 bh_blocknr(root->fs_info->tree_root->node));
634 WARN_ON(atomic_read(&bh->b_count) < 1);
635 clear_buffer_dirty(bh);
636 csum_tree_block(root, bh, 0);
637 bh->b_end_io = end_buffer_write_sync;
639 if (root->fs_info->do_barriers)
640 ret = submit_bh(WRITE_BARRIER, bh);
642 ret = submit_bh(WRITE, bh);
643 if (ret == -EOPNOTSUPP) {
644 set_buffer_uptodate(bh);
645 root->fs_info->do_barriers = 0;
646 ret = submit_bh(WRITE, bh);
649 if (!buffer_uptodate(bh)) {
656 static int free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
658 radix_tree_delete(&fs_info->fs_roots_radix,
659 (unsigned long)root->root_key.objectid);
664 if (root->commit_root)
665 brelse(root->commit_root);
670 int del_fs_roots(struct btrfs_fs_info *fs_info)
673 struct btrfs_root *gang[8];
677 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
682 for (i = 0; i < ret; i++)
683 free_fs_root(fs_info, gang[i]);
688 static int free_dev_radix(struct btrfs_fs_info *fs_info)
690 struct dev_lookup *lookup[8];
691 struct block_device *super_bdev = fs_info->sb->s_bdev;
695 ret = radix_tree_gang_lookup(&fs_info->dev_radix,
700 for (i = 0; i < ret; i++) {
701 if (lookup[i]->bdev != super_bdev)
702 close_bdev_excl(lookup[i]->bdev);
703 radix_tree_delete(&fs_info->dev_radix,
704 lookup[i]->block_start +
705 lookup[i]->num_blocks - 1);
712 int close_ctree(struct btrfs_root *root)
715 struct btrfs_trans_handle *trans;
716 struct btrfs_fs_info *fs_info = root->fs_info;
718 mutex_lock(&fs_info->fs_mutex);
719 trans = btrfs_start_transaction(root, 1);
720 btrfs_commit_transaction(trans, root);
721 /* run commit again to drop the original snapshot */
722 trans = btrfs_start_transaction(root, 1);
723 btrfs_commit_transaction(trans, root);
724 ret = btrfs_write_and_wait_transaction(NULL, root);
726 write_ctree_super(NULL, root);
727 mutex_unlock(&fs_info->fs_mutex);
729 if (fs_info->extent_root->node)
730 btrfs_block_release(fs_info->extent_root,
731 fs_info->extent_root->node);
732 if (fs_info->dev_root->node)
733 btrfs_block_release(fs_info->dev_root,
734 fs_info->dev_root->node);
735 if (fs_info->tree_root->node)
736 btrfs_block_release(fs_info->tree_root,
737 fs_info->tree_root->node);
738 btrfs_block_release(root, fs_info->sb_buffer);
739 crypto_free_hash(fs_info->hash_tfm);
740 truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
741 iput(fs_info->btree_inode);
743 free_dev_radix(fs_info);
744 btrfs_free_block_groups(root->fs_info);
745 del_fs_roots(fs_info);
746 kfree(fs_info->extent_root);
747 kfree(fs_info->tree_root);
748 kobject_unregister(&fs_info->kobj);
752 void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)