xref: /openbmc/linux/fs/btrfs/disk-io.c (revision 70b2befd0c8a4064715d8b340270650cc9d15af8)
1 #include <linux/module.h>
2 #include <linux/fs.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>
8 #include "ctree.h"
9 #include "disk-io.h"
10 #include "transaction.h"
11 #include "btrfs_inode.h"
12 
13 struct dev_lookup {
14 	u64 block_start;
15 	u64 num_blocks;
16 	u64 device_id;
17 	struct block_device *bdev;
18 };
19 
20 int btrfs_insert_dev_radix(struct btrfs_root *root,
21 			   struct block_device *bdev,
22 			   u64 device_id,
23 			   u64 block_start,
24 			   u64 num_blocks)
25 {
26 	struct dev_lookup *lookup;
27 	int ret;
28 
29 	lookup = kmalloc(sizeof(*lookup), GFP_NOFS);
30 	if (!lookup)
31 		return -ENOMEM;
32 	lookup->block_start = block_start;
33 	lookup->num_blocks = num_blocks;
34 	lookup->bdev = bdev;
35 	lookup->device_id = device_id;
36 
37 	ret = radix_tree_insert(&root->fs_info->dev_radix, block_start +
38 				num_blocks - 1, lookup);
39 	return ret;
40 }
41 
42 u64 bh_blocknr(struct buffer_head *bh)
43 {
44 	int blkbits = bh->b_page->mapping->host->i_blkbits;
45 	u64 blocknr = bh->b_page->index << (PAGE_CACHE_SHIFT - blkbits);
46 	unsigned long offset;
47 
48 	if (PageHighMem(bh->b_page))
49 		offset = (unsigned long)bh->b_data;
50 	else
51 		offset = bh->b_data - (char *)page_address(bh->b_page);
52 	blocknr += offset >> (PAGE_CACHE_SHIFT - blkbits);
53 	return blocknr;
54 }
55 
56 static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
57 {
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));
62 		BUG();
63 	}
64 	return 0;
65 }
66 
67 struct buffer_head *btrfs_find_tree_block(struct btrfs_root *root, u64 blocknr)
68 {
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);
72 	struct page *page;
73 	struct buffer_head *bh;
74 	struct buffer_head *head;
75 	struct buffer_head *ret = NULL;
76 
77 
78 	page = find_lock_page(mapping, index);
79 	if (!page)
80 		return NULL;
81 
82 	if (!page_has_buffers(page))
83 		goto out_unlock;
84 
85 	head = page_buffers(page);
86 	bh = head;
87 	do {
88 		if (buffer_mapped(bh) && bh_blocknr(bh) == blocknr) {
89 			ret = bh;
90 			get_bh(bh);
91 			goto out_unlock;
92 		}
93 		bh = bh->b_this_page;
94 	} while (bh != head);
95 out_unlock:
96 	unlock_page(page);
97 	if (ret) {
98 		touch_buffer(ret);
99 	}
100 	page_cache_release(page);
101 	return ret;
102 }
103 
104 int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
105 			     u64 logical)
106 {
107 	struct dev_lookup *lookup[2];
108 
109 	int ret;
110 
111 	root = root->fs_info->dev_root;
112 	ret = radix_tree_gang_lookup(&root->fs_info->dev_radix,
113 				     (void **)lookup,
114 				     (unsigned long)logical,
115 				     ARRAY_SIZE(lookup));
116 	if (ret == 0 || lookup[0]->block_start > logical ||
117 	    lookup[0]->block_start + lookup[0]->num_blocks <= logical) {
118 		ret = -ENOENT;
119 		goto out;
120 	}
121 	bh->b_bdev = lookup[0]->bdev;
122 	bh->b_blocknr = logical - lookup[0]->block_start;
123 	set_buffer_mapped(bh);
124 	ret = 0;
125 out:
126 	return ret;
127 }
128 
129 struct buffer_head *btrfs_find_create_tree_block(struct btrfs_root *root,
130 						 u64 blocknr)
131 {
132 	struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
133 	int blockbits = root->fs_info->sb->s_blocksize_bits;
134 	unsigned long index = blocknr >> (PAGE_CACHE_SHIFT - blockbits);
135 	struct page *page;
136 	struct buffer_head *bh;
137 	struct buffer_head *head;
138 	struct buffer_head *ret = NULL;
139 	int err;
140 	u64 first_block = index << (PAGE_CACHE_SHIFT - blockbits);
141 
142 	page = grab_cache_page(mapping, index);
143 	if (!page)
144 		return NULL;
145 
146 	if (!page_has_buffers(page))
147 		create_empty_buffers(page, root->fs_info->sb->s_blocksize, 0);
148 	head = page_buffers(page);
149 	bh = head;
150 	do {
151 		if (!buffer_mapped(bh)) {
152 			err = btrfs_map_bh_to_logical(root, bh, first_block);
153 			BUG_ON(err);
154 		}
155 		if (bh_blocknr(bh) == blocknr) {
156 			ret = bh;
157 			get_bh(bh);
158 			goto out_unlock;
159 		}
160 		bh = bh->b_this_page;
161 		first_block++;
162 	} while (bh != head);
163 out_unlock:
164 	unlock_page(page);
165 	if (ret)
166 		touch_buffer(ret);
167 	page_cache_release(page);
168 	return ret;
169 }
170 
171 static int btree_get_block(struct inode *inode, sector_t iblock,
172 			   struct buffer_head *bh, int create)
173 {
174 	int err;
175 	struct btrfs_root *root = BTRFS_I(bh->b_page->mapping->host)->root;
176 	err = btrfs_map_bh_to_logical(root, bh, iblock);
177 	return err;
178 }
179 
180 int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
181 		    char *result)
182 {
183 	struct scatterlist sg;
184 	struct crypto_hash *tfm = root->fs_info->hash_tfm;
185 	struct hash_desc desc;
186 	int ret;
187 
188 	desc.tfm = tfm;
189 	desc.flags = 0;
190 	sg_init_one(&sg, data, len);
191 	spin_lock(&root->fs_info->hash_lock);
192 	ret = crypto_hash_digest(&desc, &sg, 1, result);
193 	spin_unlock(&root->fs_info->hash_lock);
194 	if (ret) {
195 		printk("sha256 digest failed\n");
196 	}
197 	return ret;
198 }
199 static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
200 			   int verify)
201 {
202 	char result[BTRFS_CSUM_SIZE];
203 	int ret;
204 	struct btrfs_node *node;
205 
206 	ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
207 			      bh->b_size - BTRFS_CSUM_SIZE, result);
208 	if (ret)
209 		return ret;
210 	if (verify) {
211 		if (memcmp(bh->b_data, result, BTRFS_CSUM_SIZE)) {
212 			printk("checksum verify failed on %Lu\n",
213 			       bh_blocknr(bh));
214 			return 1;
215 		}
216 	} else {
217 		node = btrfs_buffer_node(bh);
218 		memcpy(node->header.csum, result, BTRFS_CSUM_SIZE);
219 	}
220 	return 0;
221 }
222 
223 static int btree_writepage(struct page *page, struct writeback_control *wbc)
224 {
225 	struct buffer_head *bh;
226 	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
227 	struct buffer_head *head;
228 	if (!page_has_buffers(page)) {
229 		create_empty_buffers(page, root->fs_info->sb->s_blocksize,
230 					(1 << BH_Dirty)|(1 << BH_Uptodate));
231 	}
232 	head = page_buffers(page);
233 	bh = head;
234 	do {
235 		if (buffer_dirty(bh))
236 			csum_tree_block(root, bh, 0);
237 		bh = bh->b_this_page;
238 	} while (bh != head);
239 	return block_write_full_page(page, btree_get_block, wbc);
240 }
241 
242 static int btree_readpage(struct file * file, struct page * page)
243 {
244 	return block_read_full_page(page, btree_get_block);
245 }
246 
247 static struct address_space_operations btree_aops = {
248 	.readpage	= btree_readpage,
249 	.writepage	= btree_writepage,
250 	.sync_page	= block_sync_page,
251 };
252 
253 struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
254 {
255 	struct buffer_head *bh = NULL;
256 
257 	bh = btrfs_find_create_tree_block(root, blocknr);
258 	if (!bh)
259 		return bh;
260 	if (buffer_uptodate(bh))
261 		goto uptodate;
262 	lock_buffer(bh);
263 	if (!buffer_uptodate(bh)) {
264 		get_bh(bh);
265 		bh->b_end_io = end_buffer_read_sync;
266 		submit_bh(READ, bh);
267 		wait_on_buffer(bh);
268 		if (!buffer_uptodate(bh))
269 			goto fail;
270 		csum_tree_block(root, bh, 1);
271 	} else {
272 		unlock_buffer(bh);
273 	}
274 uptodate:
275 	if (check_tree_block(root, bh))
276 		BUG();
277 	return bh;
278 fail:
279 	brelse(bh);
280 	return NULL;
281 }
282 
283 int dirty_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
284 		     struct buffer_head *buf)
285 {
286 	WARN_ON(atomic_read(&buf->b_count) == 0);
287 	mark_buffer_dirty(buf);
288 	return 0;
289 }
290 
291 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
292 		     struct buffer_head *buf)
293 {
294 	WARN_ON(atomic_read(&buf->b_count) == 0);
295 	clear_buffer_dirty(buf);
296 	return 0;
297 }
298 
299 static int __setup_root(int blocksize,
300 			struct btrfs_root *root,
301 			struct btrfs_fs_info *fs_info,
302 			u64 objectid)
303 {
304 	root->node = NULL;
305 	root->inode = NULL;
306 	root->commit_root = NULL;
307 	root->blocksize = blocksize;
308 	root->ref_cows = 0;
309 	root->fs_info = fs_info;
310 	root->objectid = objectid;
311 	root->last_trans = 0;
312 	root->highest_inode = 0;
313 	root->last_inode_alloc = 0;
314 	memset(&root->root_key, 0, sizeof(root->root_key));
315 	memset(&root->root_item, 0, sizeof(root->root_item));
316 	return 0;
317 }
318 
319 static int find_and_setup_root(int blocksize,
320 			       struct btrfs_root *tree_root,
321 			       struct btrfs_fs_info *fs_info,
322 			       u64 objectid,
323 			       struct btrfs_root *root)
324 {
325 	int ret;
326 
327 	__setup_root(blocksize, root, fs_info, objectid);
328 	ret = btrfs_find_last_root(tree_root, objectid,
329 				   &root->root_item, &root->root_key);
330 	BUG_ON(ret);
331 
332 	root->node = read_tree_block(root,
333 				     btrfs_root_blocknr(&root->root_item));
334 	BUG_ON(!root->node);
335 	return 0;
336 }
337 
338 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
339 				      struct btrfs_key *location)
340 {
341 	struct btrfs_root *root;
342 	struct btrfs_root *tree_root = fs_info->tree_root;
343 	struct btrfs_path *path;
344 	struct btrfs_leaf *l;
345 	u64 highest_inode;
346 	int ret = 0;
347 
348 printk("read_fs_root looking for %Lu %Lu %u\n", location->objectid, location->offset, location->flags);
349 	root = radix_tree_lookup(&fs_info->fs_roots_radix,
350 				 (unsigned long)location->objectid);
351 	if (root) {
352 printk("found %p in cache\n", root);
353 		return root;
354 	}
355 	root = kmalloc(sizeof(*root), GFP_NOFS);
356 	if (!root) {
357 printk("failed1\n");
358 		return ERR_PTR(-ENOMEM);
359 	}
360 	if (location->offset == (u64)-1) {
361 		ret = find_and_setup_root(fs_info->sb->s_blocksize,
362 					  fs_info->tree_root, fs_info,
363 					  location->objectid, root);
364 		if (ret) {
365 printk("failed2\n");
366 			kfree(root);
367 			return ERR_PTR(ret);
368 		}
369 		goto insert;
370 	}
371 
372 	__setup_root(fs_info->sb->s_blocksize, root, fs_info,
373 		     location->objectid);
374 
375 	path = btrfs_alloc_path();
376 	BUG_ON(!path);
377 	ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
378 	if (ret != 0) {
379 printk("internal search_slot gives us %d\n", ret);
380 		if (ret > 0)
381 			ret = -ENOENT;
382 		goto out;
383 	}
384 	l = btrfs_buffer_leaf(path->nodes[0]);
385 	memcpy(&root->root_item,
386 	       btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
387 	       sizeof(root->root_item));
388 	memcpy(&root->root_key, location, sizeof(*location));
389 	ret = 0;
390 out:
391 	btrfs_release_path(root, path);
392 	btrfs_free_path(path);
393 	if (ret) {
394 		kfree(root);
395 		return ERR_PTR(ret);
396 	}
397 	root->node = read_tree_block(root,
398 				     btrfs_root_blocknr(&root->root_item));
399 	BUG_ON(!root->node);
400 insert:
401 printk("inserting %p\n", root);
402 	root->ref_cows = 1;
403 	ret = radix_tree_insert(&fs_info->fs_roots_radix,
404 				(unsigned long)root->root_key.objectid,
405 				root);
406 	if (ret) {
407 printk("radix_tree_insert gives us %d\n", ret);
408 		brelse(root->node);
409 		kfree(root);
410 		return ERR_PTR(ret);
411 	}
412 	ret = btrfs_find_highest_inode(root, &highest_inode);
413 	if (ret == 0) {
414 		root->highest_inode = highest_inode;
415 		root->last_inode_alloc = highest_inode;
416 printk("highest inode is %Lu\n", highest_inode);
417 	}
418 printk("all worked\n");
419 	return root;
420 }
421 
422 static int btrfs_open_disk(struct btrfs_root *root, u64 device_id,
423 			   u64 block_start, u64 num_blocks,
424 			   char *filename, int name_len)
425 {
426 	char *null_filename;
427 	struct block_device *bdev;
428 	int ret;
429 
430 	null_filename = kmalloc(name_len + 1, GFP_NOFS);
431 	if (!null_filename)
432 		return -ENOMEM;
433 	memcpy(null_filename, filename, name_len);
434 	null_filename[name_len] = '\0';
435 
436 	bdev = open_bdev_excl(null_filename, O_RDWR, root->fs_info->sb);
437 	if (IS_ERR(bdev)) {
438 		ret = PTR_ERR(bdev);
439 		goto out;
440 	}
441 	set_blocksize(bdev, root->fs_info->sb->s_blocksize);
442 	ret = btrfs_insert_dev_radix(root, bdev, device_id,
443 				     block_start, num_blocks);
444 	BUG_ON(ret);
445 	ret = 0;
446 out:
447 	kfree(null_filename);
448 	return ret;
449 }
450 
451 static int read_device_info(struct btrfs_root *root)
452 {
453 	struct btrfs_path *path;
454 	int ret;
455 	struct btrfs_key key;
456 	struct btrfs_leaf *leaf;
457 	struct btrfs_device_item *dev_item;
458 	int nritems;
459 	int slot;
460 
461 	root = root->fs_info->dev_root;
462 
463 	path = btrfs_alloc_path();
464 	if (!path)
465 		return -ENOMEM;
466 	key.objectid = 0;
467 	key.offset = 0;
468 	key.flags = 0;
469 	btrfs_set_key_type(&key, BTRFS_DEV_ITEM_KEY);
470 
471 	mutex_lock(&root->fs_info->fs_mutex);
472 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
473 	leaf = btrfs_buffer_leaf(path->nodes[0]);
474 	nritems = btrfs_header_nritems(&leaf->header);
475 	while(1) {
476 		slot = path->slots[0];
477 		if (slot >= nritems) {
478 			ret = btrfs_next_leaf(root, path);
479 			if (ret)
480 				break;
481 			leaf = btrfs_buffer_leaf(path->nodes[0]);
482 			nritems = btrfs_header_nritems(&leaf->header);
483 			slot = path->slots[0];
484 		}
485 		btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
486 		if (btrfs_key_type(&key) != BTRFS_DEV_ITEM_KEY) {
487 			path->slots[0]++;
488 			continue;
489 		}
490 		dev_item = btrfs_item_ptr(leaf, slot, struct btrfs_device_item);
491 printk("found key %Lu %Lu\n", key.objectid, key.offset);
492 		if (btrfs_device_id(dev_item) !=
493 		    btrfs_super_device_id(root->fs_info->disk_super)) {
494 			ret = btrfs_open_disk(root, btrfs_device_id(dev_item),
495 					      key.objectid, key.offset,
496 					      (char *)(dev_item + 1),
497 					      btrfs_device_pathlen(dev_item));
498 			BUG_ON(ret);
499 		}
500 		path->slots[0]++;
501 	}
502 	btrfs_free_path(path);
503 	mutex_unlock(&root->fs_info->fs_mutex);
504 	return 0;
505 }
506 
507 struct btrfs_root *open_ctree(struct super_block *sb)
508 {
509 	struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
510 						 GFP_NOFS);
511 	struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
512 						 GFP_NOFS);
513 	struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
514 					       GFP_NOFS);
515 	struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
516 						GFP_NOFS);
517 	int ret;
518 	struct btrfs_super_block *disk_super;
519 	struct dev_lookup *dev_lookup;
520 
521 	init_bit_radix(&fs_info->pinned_radix);
522 	init_bit_radix(&fs_info->pending_del_radix);
523 	INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
524 	INIT_RADIX_TREE(&fs_info->dev_radix, GFP_NOFS);
525 	sb_set_blocksize(sb, 4096);
526 	fs_info->running_transaction = NULL;
527 	fs_info->tree_root = tree_root;
528 	fs_info->extent_root = extent_root;
529 	fs_info->dev_root = dev_root;
530 	fs_info->sb = sb;
531 	fs_info->btree_inode = new_inode(sb);
532 	fs_info->btree_inode->i_ino = 1;
533 	fs_info->btree_inode->i_nlink = 1;
534 	fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
535 	fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
536 	BTRFS_I(fs_info->btree_inode)->root = tree_root;
537 	memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
538 	       sizeof(struct btrfs_key));
539 	insert_inode_hash(fs_info->btree_inode);
540 	mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
541 	fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
542 	spin_lock_init(&fs_info->hash_lock);
543 	if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
544 		printk("failed to allocate sha256 hash\n");
545 		return NULL;
546 	}
547 	mutex_init(&fs_info->trans_mutex);
548 	mutex_init(&fs_info->fs_mutex);
549 	memset(&fs_info->current_insert, 0, sizeof(fs_info->current_insert));
550 	memset(&fs_info->last_insert, 0, sizeof(fs_info->last_insert));
551 
552 	__setup_root(sb->s_blocksize, dev_root,
553 		     fs_info, BTRFS_DEV_TREE_OBJECTID);
554 
555 	__setup_root(sb->s_blocksize, tree_root,
556 		     fs_info, BTRFS_ROOT_TREE_OBJECTID);
557 
558 	dev_lookup = kmalloc(sizeof(*dev_lookup), GFP_NOFS);
559 	dev_lookup->block_start = 0;
560 	dev_lookup->num_blocks = (u32)-2;
561 	dev_lookup->bdev = sb->s_bdev;
562 	dev_lookup->device_id = 0;
563 	ret = radix_tree_insert(&fs_info->dev_radix, (u32)-2, dev_lookup);
564 	BUG_ON(ret);
565 	fs_info->sb_buffer = read_tree_block(tree_root,
566 					     BTRFS_SUPER_INFO_OFFSET /
567 					     sb->s_blocksize);
568 
569 	if (!fs_info->sb_buffer)
570 		return NULL;
571 	disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
572 	if (!btrfs_super_root(disk_super))
573 		return NULL;
574 
575 	i_size_write(fs_info->btree_inode,
576 		     btrfs_super_total_blocks(disk_super) <<
577 		     fs_info->btree_inode->i_blkbits);
578 
579 	radix_tree_delete(&fs_info->dev_radix, (u32)-2);
580 	dev_lookup->block_start = btrfs_super_device_block_start(disk_super);
581 	dev_lookup->num_blocks = btrfs_super_device_num_blocks(disk_super);
582 	dev_lookup->device_id = btrfs_super_device_id(disk_super);
583 
584 	ret = radix_tree_insert(&fs_info->dev_radix,
585 				dev_lookup->block_start +
586 				dev_lookup->num_blocks - 1, dev_lookup);
587 	BUG_ON(ret);
588 
589 	fs_info->disk_super = disk_super;
590 
591 	dev_root->node = read_tree_block(tree_root,
592 					  btrfs_super_device_root(disk_super));
593 
594 	ret = read_device_info(dev_root);
595 	BUG_ON(ret);
596 
597 	tree_root->node = read_tree_block(tree_root,
598 					  btrfs_super_root(disk_super));
599 	BUG_ON(!tree_root->node);
600 
601 	mutex_lock(&fs_info->fs_mutex);
602 	ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
603 				  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
604 	BUG_ON(ret);
605 
606 	fs_info->generation = btrfs_super_generation(disk_super) + 1;
607 	memset(&fs_info->kobj, 0, sizeof(fs_info->kobj));
608 	kobj_set_kset_s(fs_info, btrfs_subsys);
609 	kobject_set_name(&fs_info->kobj, "%s", sb->s_id);
610 	kobject_register(&fs_info->kobj);
611 	mutex_unlock(&fs_info->fs_mutex);
612 	return tree_root;
613 }
614 
615 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
616 		      *root)
617 {
618 	struct buffer_head *bh = root->fs_info->sb_buffer;
619 
620 	btrfs_set_super_root(root->fs_info->disk_super,
621 			     bh_blocknr(root->fs_info->tree_root->node));
622 	lock_buffer(bh);
623 	WARN_ON(atomic_read(&bh->b_count) < 1);
624 	clear_buffer_dirty(bh);
625 	csum_tree_block(root, bh, 0);
626 	bh->b_end_io = end_buffer_write_sync;
627 	get_bh(bh);
628 	submit_bh(WRITE, bh);
629 	wait_on_buffer(bh);
630 	if (!buffer_uptodate(bh)) {
631 		WARN_ON(1);
632 		return -EIO;
633 	}
634 	return 0;
635 }
636 
637 static int free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
638 {
639 	radix_tree_delete(&fs_info->fs_roots_radix,
640 			  (unsigned long)root->root_key.objectid);
641 	if (root->inode)
642 		iput(root->inode);
643 	if (root->node)
644 		brelse(root->node);
645 	if (root->commit_root)
646 		brelse(root->commit_root);
647 	kfree(root);
648 	return 0;
649 }
650 
651 int del_fs_roots(struct btrfs_fs_info *fs_info)
652 {
653 	int ret;
654 	struct btrfs_root *gang[8];
655 	int i;
656 
657 	while(1) {
658 		ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
659 					     (void **)gang, 0,
660 					     ARRAY_SIZE(gang));
661 		if (!ret)
662 			break;
663 		for (i = 0; i < ret; i++)
664 			free_fs_root(fs_info, gang[i]);
665 	}
666 	return 0;
667 }
668 
669 static int free_dev_radix(struct btrfs_fs_info *fs_info)
670 {
671 	struct dev_lookup *lookup[8];
672 	struct block_device *super_bdev = fs_info->sb->s_bdev;
673 	int ret;
674 	int i;
675 	while(1) {
676 		ret = radix_tree_gang_lookup(&fs_info->dev_radix,
677 					     (void **)lookup, 0,
678 					     ARRAY_SIZE(lookup));
679 		if (!ret)
680 			break;
681 		for (i = 0; i < ret; i++) {
682 			if (lookup[i]->bdev != super_bdev)
683 				close_bdev_excl(lookup[i]->bdev);
684 			radix_tree_delete(&fs_info->dev_radix,
685 					  lookup[i]->block_start +
686 					  lookup[i]->num_blocks - 1);
687 			kfree(lookup[i]);
688 		}
689 	}
690 	return 0;
691 }
692 
693 int close_ctree(struct btrfs_root *root)
694 {
695 	int ret;
696 	struct btrfs_trans_handle *trans;
697 	struct btrfs_fs_info *fs_info = root->fs_info;
698 
699 	mutex_lock(&fs_info->fs_mutex);
700 	trans = btrfs_start_transaction(root, 1);
701 	btrfs_commit_transaction(trans, root);
702 	/* run commit again to  drop the original snapshot */
703 	trans = btrfs_start_transaction(root, 1);
704 	btrfs_commit_transaction(trans, root);
705 	ret = btrfs_write_and_wait_transaction(NULL, root);
706 	BUG_ON(ret);
707 	write_ctree_super(NULL, root);
708 	mutex_unlock(&fs_info->fs_mutex);
709 
710 	if (fs_info->extent_root->node)
711 		btrfs_block_release(fs_info->extent_root,
712 				    fs_info->extent_root->node);
713 	if (fs_info->dev_root->node)
714 		btrfs_block_release(fs_info->dev_root,
715 				    fs_info->dev_root->node);
716 	if (fs_info->tree_root->node)
717 		btrfs_block_release(fs_info->tree_root,
718 				    fs_info->tree_root->node);
719 	btrfs_block_release(root, fs_info->sb_buffer);
720 	crypto_free_hash(fs_info->hash_tfm);
721 	truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
722 	iput(fs_info->btree_inode);
723 
724 	free_dev_radix(fs_info);
725 	del_fs_roots(fs_info);
726 	kfree(fs_info->extent_root);
727 	kfree(fs_info->tree_root);
728 	kobject_unregister(&fs_info->kobj);
729 	return 0;
730 }
731 
732 void btrfs_block_release(struct btrfs_root *root, struct buffer_head *buf)
733 {
734 	brelse(buf);
735 }
736 
737