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) {
100 page_cache_release(page);
104 int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
107 struct dev_lookup *lookup[2];
114 set_buffer_mapped(bh);
117 root = root->fs_info->dev_root;
118 ret = radix_tree_gang_lookup(&root->fs_info->dev_radix,
120 (unsigned long)logical,
122 if (ret == 0 || lookup[0]->block_start > logical ||
123 lookup[0]->block_start + lookup[0]->num_blocks <= logical) {
127 bh->b_bdev = lookup[0]->bdev;
128 bh->b_blocknr = logical - lookup[0]->block_start;
129 set_buffer_mapped(bh);
135 struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
138 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
139 int blockbits = root->fs_info->sb->s_blocksize_bits;
140 unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
142 struct buffer_head *bh;
143 struct buffer_head *head;
144 struct buffer_head *ret = NULL;
146 u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
148 page = grab_cache_page(mapping, index);
152 if (!page_has_buffers(page))
153 create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
154 head = page_buffers(page);
157 if (!buffer_mapped(bh)) {
158 err = btrfs_map_bh_to_logical(root, bh, first_block);
161 if (bh_blocknr(bh) == blocknr) {
166 bh = bh->b_this_page;
168 } while (bh != head);
173 page_cache_release(page);
177 static int btree_get_block(struct inode *inode, sector_t iblock,
178 struct buffer_head *bh, int create)
181 struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
182 err = btrfs_map_bh_to_logical(root, bh, iblock);
186 int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
189 struct scatterlist sg;
190 struct crypto_hash *tfm = root->fs_info->hash_tfm;
191 struct hash_desc desc;
196 sg_init_one(&sg, data, len);
197 spin_lock(&root->fs_info->hash_lock);
198 ret = crypto_hash_digest(&desc, &sg, 1, result);
199 spin_unlock(&root->fs_info->hash_lock);
201 printk("sha256 digest failed\n");
205 static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
208 char result[BTRFS_CSUM_SIZE];
210 struct btrfs_node *node;
212 ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
213 bh->b_size - BTRFS_CSUM_SIZE, result);
217 if (memcmp(bh->b_data, result, BTRFS_CSUM_SIZE)) {
218 printk("checksum verify failed on %Lu\n",
223 node = btrfs_buffer_node(bh);
224 memcpy(node->header.csum, result, BTRFS_CSUM_SIZE);
229 static int btree_writepage(struct page *page, struct writeback_control *wbc)
231 struct buffer_head *bh;
232 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
233 struct buffer_head *head;
234 if (!page_has_buffers(page)) {
235 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
236 (1 << BH_Dirty)|(1 << BH_Uptodate));
238 head = page_buffers(page);
241 if (buffer_dirty(bh))
242 csum_tree_block(root, bh, 0);
243 bh = bh->b_this_page;
244 } while (bh != head);
245 return block_write_full_page(page, btree_get_block, wbc);
248 static int btree_readpage(struct file * file, struct page * page)
250 return block_read_full_page(page, btree_get_block);
253 static struct address_space_operations btree_aops = {
254 .readpage = btree_readpage,
255 .writepage = btree_writepage,
256 .sync_page = block_sync_page,
259 struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
261 struct buffer_head *bh = NULL;
263 bh = btrfs_find_create_tree_block(root, blocknr);
266 if (buffer_uptodate(bh))
269 if (!buffer_uptodate(bh)) {
271 bh->b_end_io = end_buffer_read_sync;
274 if (!buffer_uptodate(bh))
276 csum_tree_block(root, bh, 1);
281 if (check_tree_block(root, bh))
289 int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
290 struct buffer_head *buf)
292 WARN_ON(atomic_read(&buf->b_count) == 0);
293 mark_buffer_dirty(buf);
297 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
298 struct buffer_head *buf)
300 WARN_ON(atomic_read(&buf->b_count) == 0);
301 clear_buffer_dirty(buf);
305 static int __setup_root(int blocksize,
306 struct btrfs_root *root,
307 struct btrfs_fs_info *fs_info,
312 root->commit_root = NULL;
313 root->blocksize = blocksize;
315 root->fs_info = fs_info;
316 root->objectid = objectid;
317 root->last_trans = 0;
318 root->highest_inode = 0;
319 root->last_inode_alloc = 0;
320 memset(&root->root_key, 0, sizeof(root->root_key));
321 memset(&root->root_item, 0, sizeof(root->root_item));
322 root->root_key.objectid = objectid;
326 static int find_and_setup_root(int blocksize,
327 struct btrfs_root *tree_root,
328 struct btrfs_fs_info *fs_info,
330 struct btrfs_root *root)
334 __setup_root(blocksize, root, fs_info, objectid);
335 ret = btrfs_find_last_root(tree_root, objectid,
336 &root->root_item, &root->root_key);
339 root->node = read_tree_block(root,
340 btrfs_root_blocknr(&root->root_item));
345 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
346 struct btrfs_key *location)
348 struct btrfs_root *root;
349 struct btrfs_root *tree_root = fs_info->tree_root;
350 struct btrfs_path *path;
351 struct btrfs_leaf *l;
355 printk("read_fs_root looking for %Lu %Lu %u\n", location->objectid, location->offset, location->flags);
356 root = radix_tree_lookup(&fs_info->fs_roots_radix,
357 (unsigned long)location->objectid);
359 printk("found %p in cache\n", root);
362 root = kmalloc(sizeof(*root), GFP_NOFS);
365 return ERR_PTR(-ENOMEM);
367 if (location->offset == (u64)-1) {
368 ret = find_and_setup_root(fs_info->sb->s_blocksize,
369 fs_info->tree_root, fs_info,
370 location->objectid, root);
379 __setup_root(fs_info->sb->s_blocksize, root, fs_info,
382 path = btrfs_alloc_path();
384 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
386 printk("internal search_slot gives us %d\n", ret);
391 l = btrfs_buffer_leaf(path->nodes[0]);
392 memcpy(&root->root_item,
393 btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
394 sizeof(root->root_item));
395 memcpy(&root->root_key, location, sizeof(*location));
398 btrfs_release_path(root, path);
399 btrfs_free_path(path);
404 root->node = read_tree_block(root,
405 btrfs_root_blocknr(&root->root_item));
408 printk("inserting %p\n", root);
410 ret = radix_tree_insert(&fs_info->fs_roots_radix,
411 (unsigned long)root->root_key.objectid,
414 printk("radix_tree_insert gives us %d\n", ret);
419 ret = btrfs_find_highest_inode(root, &highest_inode);
421 root->highest_inode = highest_inode;
422 root->last_inode_alloc = highest_inode;
423 printk("highest inode is %Lu\n", highest_inode);
425 printk("all worked\n");
429 static int btrfs_open_disk(struct btrfs_root *root, u64 device_id,
430 u64 block_start, u64 num_blocks,
431 char *filename, int name_len)
434 struct block_device *bdev;
437 null_filename = kmalloc(name_len + 1, GFP_NOFS);
440 memcpy(null_filename, filename, name_len);
441 null_filename[name_len] = '\0';
443 bdev = open_bdev_excl(null_filename, O_RDWR, root->fs_info->sb);
448 set_blocksize(bdev, root->fs_info->sb->s_blocksize);
449 ret = btrfs_insert_dev_radix(root, bdev, device_id,
450 block_start, num_blocks);
454 kfree(null_filename);
458 static int read_device_info(struct btrfs_root *root)
460 struct btrfs_path *path;
462 struct btrfs_key key;
463 struct btrfs_leaf *leaf;
464 struct btrfs_device_item *dev_item;
468 root = root->fs_info->dev_root;
470 path = btrfs_alloc_path();
476 btrfs_set_key_type(&key, BTRFS_DEV_ITEM_KEY);
478 mutex_lock(&root->fs_info->fs_mutex);
479 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
480 leaf = btrfs_buffer_leaf(path->nodes[0]);
481 nritems = btrfs_header_nritems(&leaf->header);
483 slot = path->slots[0];
484 if (slot >= nritems) {
485 ret = btrfs_next_leaf(root, path);
488 leaf = btrfs_buffer_leaf(path->nodes[0]);
489 nritems = btrfs_header_nritems(&leaf->header);
490 slot = path->slots[0];
492 btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
493 if (btrfs_key_type(&key) != BTRFS_DEV_ITEM_KEY) {
497 dev_item = btrfs_item_ptr(leaf, slot, struct btrfs_device_item);
498 printk("found key %Lu %Lu\n", key.objectid, key.offset);
499 if (btrfs_device_id(dev_item) !=
500 btrfs_super_device_id(root->fs_info->disk_super)) {
501 ret = btrfs_open_disk(root, btrfs_device_id(dev_item),
502 key.objectid, key.offset,
503 (char *)(dev_item + 1),
504 btrfs_device_pathlen(dev_item));
509 btrfs_free_path(path);
510 mutex_unlock(&root->fs_info->fs_mutex);
514 struct btrfs_root *open_ctree(struct super_block *sb)
516 struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
518 struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
520 struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
522 struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
525 struct btrfs_super_block *disk_super;
526 struct dev_lookup *dev_lookup;
528 init_bit_radix(&fs_info->pinned_radix);
529 init_bit_radix(&fs_info->pending_del_radix);
530 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
531 INIT_RADIX_TREE(&fs_info->dev_radix, GFP_NOFS);
532 INIT_LIST_HEAD(&fs_info->trans_list);
533 sb_set_blocksize(sb, 4096);
534 fs_info->running_transaction = NULL;
535 fs_info->tree_root = tree_root;
536 fs_info->extent_root = extent_root;
537 fs_info->dev_root = dev_root;
539 fs_info->btree_inode = new_inode(sb);
540 fs_info->btree_inode->i_ino = 1;
541 fs_info->btree_inode->i_nlink = 1;
542 fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
543 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
544 fs_info->do_barriers = 1;
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 memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
559 memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
561 __setup_root(sb->s_blocksize, dev_root,
562 fs_info, BTRFS_DEV_TREE_OBJECTID);
564 __setup_root(sb->s_blocksize, tree_root,
565 fs_info, BTRFS_ROOT_TREE_OBJECTID);
567 dev_lookup = kmalloc(sizeof(*dev_lookup), GFP_NOFS);
568 dev_lookup->block_start = 0;
569 dev_lookup->num_blocks = (u32)-2;
570 dev_lookup->bdev = sb->s_bdev;
571 dev_lookup->device_id = 0;
572 ret = radix_tree_insert(&fs_info->dev_radix, (u32)-2, dev_lookup);
574 fs_info->sb_buffer = read_tree_block(tree_root,
575 BTRFS_SUPER_INFO_OFFSET /
578 if (!fs_info->sb_buffer)
580 disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
581 if (!btrfs_super_root(disk_super))
584 i_size_write(fs_info->btree_inode,
585 btrfs_super_total_blocks(disk_super) <<
586 fs_info->btree_inode->i_blkbits);
588 radix_tree_delete(&fs_info->dev_radix, (u32)-2);
589 dev_lookup->block_start = btrfs_super_device_block_start(disk_super);
590 dev_lookup->num_blocks = btrfs_super_device_num_blocks(disk_super);
591 dev_lookup->device_id = btrfs_super_device_id(disk_super);
593 ret = radix_tree_insert(&fs_info->dev_radix,
594 dev_lookup->block_start +
595 dev_lookup->num_blocks - 1, dev_lookup);
598 fs_info->disk_super = disk_super;
600 dev_root->node = read_tree_block(tree_root,
601 btrfs_super_device_root(disk_super));
603 ret = read_device_info(dev_root);
606 tree_root->node = read_tree_block(tree_root,
607 btrfs_super_root(disk_super));
608 BUG_ON(!tree_root->node);
610 mutex_lock(&fs_info->fs_mutex);
611 ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
612 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
615 fs_info->generation = btrfs_super_generation(disk_super) + 1;
616 memset(&fs_info->kobj, 0, sizeof(fs_info->kobj));
617 kobj_set_kset_s(fs_info, btrfs_subsys);
618 kobject_set_name(&fs_info->kobj, "%s", sb->s_id);
619 kobject_register(&fs_info->kobj);
620 mutex_unlock(&fs_info->fs_mutex);
624 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
628 struct buffer_head *bh = root->fs_info->sb_buffer;
630 btrfs_set_super_root(root->fs_info->disk_super,
631 bh_blocknr(root->fs_info->tree_root->node));
633 WARN_ON(atomic_read(&bh->b_count) < 1);
634 clear_buffer_dirty(bh);
635 csum_tree_block(root, bh, 0);
636 bh->b_end_io = end_buffer_write_sync;
638 if (root->fs_info->do_barriers)
639 ret = submit_bh(WRITE_BARRIER, bh);
641 ret = submit_bh(WRITE, bh);
642 if (ret == -EOPNOTSUPP) {
643 set_buffer_uptodate(bh);
644 root->fs_info->do_barriers = 0;
645 ret = submit_bh(WRITE, bh);
648 if (!buffer_uptodate(bh)) {
655 static int free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
657 radix_tree_delete(&fs_info->fs_roots_radix,
658 (unsigned long)root->root_key.objectid);
663 if (root->commit_root)
664 brelse(root->commit_root);
669 int del_fs_roots(struct btrfs_fs_info *fs_info)
672 struct btrfs_root *gang[8];
676 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
681 for (i = 0; i < ret; i++)
682 free_fs_root(fs_info, gang[i]);
687 static int free_dev_radix(struct btrfs_fs_info *fs_info)
689 struct dev_lookup *lookup[8];
690 struct block_device *super_bdev = fs_info->sb->s_bdev;
694 ret = radix_tree_gang_lookup(&fs_info->dev_radix,
699 for (i = 0; i < ret; i++) {
700 if (lookup[i]->bdev != super_bdev)
701 close_bdev_excl(lookup[i]->bdev);
702 radix_tree_delete(&fs_info->dev_radix,
703 lookup[i]->block_start +
704 lookup[i]->num_blocks - 1);
711 int close_ctree(struct btrfs_root *root)
714 struct btrfs_trans_handle *trans;
715 struct btrfs_fs_info *fs_info = root->fs_info;
717 mutex_lock(&fs_info->fs_mutex);
718 trans = btrfs_start_transaction(root, 1);
719 btrfs_commit_transaction(trans, root);
720 /* run commit again to drop the original snapshot */
721 trans = btrfs_start_transaction(root, 1);
722 btrfs_commit_transaction(trans, root);
723 ret = btrfs_write_and_wait_transaction(NULL, root);
725 write_ctree_super(NULL, root);
726 mutex_unlock(&fs_info->fs_mutex);
728 if (fs_info->extent_root->node)
729 btrfs_block_release(fs_info->extent_root,
730 fs_info->extent_root->node);
731 if (fs_info->dev_root->node)
732 btrfs_block_release(fs_info->dev_root,
733 fs_info->dev_root->node);
734 if (fs_info->tree_root->node)
735 btrfs_block_release(fs_info->tree_root,
736 fs_info->tree_root->node);
737 btrfs_block_release(root, fs_info->sb_buffer);
738 crypto_free_hash(fs_info->hash_tfm);
739 truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
740 iput(fs_info->btree_inode);
742 free_dev_radix(fs_info);
743 del_fs_roots(fs_info);
744 kfree(fs_info->extent_root);
745 kfree(fs_info->tree_root);
746 kobject_unregister(&fs_info->kobj);
750 void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)