Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 0 insertions, 8025 deletions

diff --git a/ANDROID_3.4.5/fs/btrfs/extent-tree.c b/ANDROID_3.4.5/fs/btrfs/extent-tree.c
deleted file mode 100644
index 49fd7b66..00000000
--- a/ANDROID_3.4.5/fs/btrfs/extent-tree.c
+++ /dev/null
@@ -1,8025 +0,0 @@
-/*
- * Copyright (C) 2007 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-#include <linux/sched.h>
-#include <linux/pagemap.h>
-#include <linux/writeback.h>
-#include <linux/blkdev.h>
-#include <linux/sort.h>
-#include <linux/rcupdate.h>
-#include <linux/kthread.h>
-#include <linux/slab.h>
-#include <linux/ratelimit.h>
-#include "compat.h"
-#include "hash.h"
-#include "ctree.h"
-#include "disk-io.h"
-#include "print-tree.h"
-#include "transaction.h"
-#include "volumes.h"
-#include "locking.h"
-#include "free-space-cache.h"
-
-/*
- * control flags for do_chunk_alloc's force field
- * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
- * if we really need one.
- *
- * CHUNK_ALLOC_LIMITED means to only try and allocate one
- * if we have very few chunks already allocated.  This is
- * used as part of the clustering code to help make sure
- * we have a good pool of storage to cluster in, without
- * filling the FS with empty chunks
- *
- * CHUNK_ALLOC_FORCE means it must try to allocate one
- *
- */
-enum {
-	CHUNK_ALLOC_NO_FORCE = 0,
-	CHUNK_ALLOC_LIMITED = 1,
-	CHUNK_ALLOC_FORCE = 2,
-};
-
-/*
- * Control how reservations are dealt with.
- *
- * RESERVE_FREE - freeing a reservation.
- * RESERVE_ALLOC - allocating space and we need to update bytes_may_use for
- *   ENOSPC accounting
- * RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update
- *   bytes_may_use as the ENOSPC accounting is done elsewhere
- */
-enum {
-	RESERVE_FREE = 0,
-	RESERVE_ALLOC = 1,
-	RESERVE_ALLOC_NO_ACCOUNT = 2,
-};
-
-static int update_block_group(struct btrfs_trans_handle *trans,
-			      struct btrfs_root *root,
-			      u64 bytenr, u64 num_bytes, int alloc);
-static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root,
-				u64 bytenr, u64 num_bytes, u64 parent,
-				u64 root_objectid, u64 owner_objectid,
-				u64 owner_offset, int refs_to_drop,
-				struct btrfs_delayed_extent_op *extra_op);
-static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
-				    struct extent_buffer *leaf,
-				    struct btrfs_extent_item *ei);
-static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
-				      struct btrfs_root *root,
-				      u64 parent, u64 root_objectid,
-				      u64 flags, u64 owner, u64 offset,
-				      struct btrfs_key *ins, int ref_mod);
-static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
-				     struct btrfs_root *root,
-				     u64 parent, u64 root_objectid,
-				     u64 flags, struct btrfs_disk_key *key,
-				     int level, struct btrfs_key *ins);
-static int do_chunk_alloc(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *extent_root, u64 alloc_bytes,
-			  u64 flags, int force);
-static int find_next_key(struct btrfs_path *path, int level,
-			 struct btrfs_key *key);
-static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
-			    int dump_block_groups);
-static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
-				       u64 num_bytes, int reserve);
-
-static noinline int
-block_group_cache_done(struct btrfs_block_group_cache *cache)
-{
-	smp_mb();
-	return cache->cached == BTRFS_CACHE_FINISHED;
-}
-
-static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
-{
-	return (cache->flags & bits) == bits;
-}
-
-static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
-{
-	atomic_inc(&cache->count);
-}
-
-void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
-{
-	if (atomic_dec_and_test(&cache->count)) {
-		WARN_ON(cache->pinned > 0);
-		WARN_ON(cache->reserved > 0);
-		kfree(cache->free_space_ctl);
-		kfree(cache);
-	}
-}
-
-/*
- * this adds the block group to the fs_info rb tree for the block group
- * cache
- */
-static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
-				struct btrfs_block_group_cache *block_group)
-{
-	struct rb_node **p;
-	struct rb_node *parent = NULL;
-	struct btrfs_block_group_cache *cache;
-
-	spin_lock(&info->block_group_cache_lock);
-	p = &info->block_group_cache_tree.rb_node;
-
-	while (*p) {
-		parent = *p;
-		cache = rb_entry(parent, struct btrfs_block_group_cache,
-				 cache_node);
-		if (block_group->key.objectid < cache->key.objectid) {
-			p = &(*p)->rb_left;
-		} else if (block_group->key.objectid > cache->key.objectid) {
-			p = &(*p)->rb_right;
-		} else {
-			spin_unlock(&info->block_group_cache_lock);
-			return -EEXIST;
-		}
-	}
-
-	rb_link_node(&block_group->cache_node, parent, p);
-	rb_insert_color(&block_group->cache_node,
-			&info->block_group_cache_tree);
-	spin_unlock(&info->block_group_cache_lock);
-
-	return 0;
-}
-
-/*
- * This will return the block group at or after bytenr if contains is 0, else
- * it will return the block group that contains the bytenr
- */
-static struct btrfs_block_group_cache *
-block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
-			      int contains)
-{
-	struct btrfs_block_group_cache *cache, *ret = NULL;
-	struct rb_node *n;
-	u64 end, start;
-
-	spin_lock(&info->block_group_cache_lock);
-	n = info->block_group_cache_tree.rb_node;
-
-	while (n) {
-		cache = rb_entry(n, struct btrfs_block_group_cache,
-				 cache_node);
-		end = cache->key.objectid + cache->key.offset - 1;
-		start = cache->key.objectid;
-
-		if (bytenr < start) {
-			if (!contains && (!ret || start < ret->key.objectid))
-				ret = cache;
-			n = n->rb_left;
-		} else if (bytenr > start) {
-			if (contains && bytenr <= end) {
-				ret = cache;
-				break;
-			}
-			n = n->rb_right;
-		} else {
-			ret = cache;
-			break;
-		}
-	}
-	if (ret)
-		btrfs_get_block_group(ret);
-	spin_unlock(&info->block_group_cache_lock);
-
-	return ret;
-}
-
-static int add_excluded_extent(struct btrfs_root *root,
-			       u64 start, u64 num_bytes)
-{
-	u64 end = start + num_bytes - 1;
-	set_extent_bits(&root->fs_info->freed_extents[0],
-			start, end, EXTENT_UPTODATE, GFP_NOFS);
-	set_extent_bits(&root->fs_info->freed_extents[1],
-			start, end, EXTENT_UPTODATE, GFP_NOFS);
-	return 0;
-}
-
-static void free_excluded_extents(struct btrfs_root *root,
-				  struct btrfs_block_group_cache *cache)
-{
-	u64 start, end;
-
-	start = cache->key.objectid;
-	end = start + cache->key.offset - 1;
-
-	clear_extent_bits(&root->fs_info->freed_extents[0],
-			  start, end, EXTENT_UPTODATE, GFP_NOFS);
-	clear_extent_bits(&root->fs_info->freed_extents[1],
-			  start, end, EXTENT_UPTODATE, GFP_NOFS);
-}
-
-static int exclude_super_stripes(struct btrfs_root *root,
-				 struct btrfs_block_group_cache *cache)
-{
-	u64 bytenr;
-	u64 *logical;
-	int stripe_len;
-	int i, nr, ret;
-
-	if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
-		stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
-		cache->bytes_super += stripe_len;
-		ret = add_excluded_extent(root, cache->key.objectid,
-					  stripe_len);
-		BUG_ON(ret); /* -ENOMEM */
-	}
-
-	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
-		bytenr = btrfs_sb_offset(i);
-		ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
-				       cache->key.objectid, bytenr,
-				       0, &logical, &nr, &stripe_len);
-		BUG_ON(ret); /* -ENOMEM */
-
-		while (nr--) {
-			cache->bytes_super += stripe_len;
-			ret = add_excluded_extent(root, logical[nr],
-						  stripe_len);
-			BUG_ON(ret); /* -ENOMEM */
-		}
-
-		kfree(logical);
-	}
-	return 0;
-}
-
-static struct btrfs_caching_control *
-get_caching_control(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_caching_control *ctl;
-
-	spin_lock(&cache->lock);
-	if (cache->cached != BTRFS_CACHE_STARTED) {
-		spin_unlock(&cache->lock);
-		return NULL;
-	}
-
-	/* We're loading it the fast way, so we don't have a caching_ctl. */
-	if (!cache->caching_ctl) {
-		spin_unlock(&cache->lock);
-		return NULL;
-	}
-
-	ctl = cache->caching_ctl;
-	atomic_inc(&ctl->count);
-	spin_unlock(&cache->lock);
-	return ctl;
-}
-
-static void put_caching_control(struct btrfs_caching_control *ctl)
-{
-	if (atomic_dec_and_test(&ctl->count))
-		kfree(ctl);
-}
-
-/*
- * this is only called by cache_block_group, since we could have freed extents
- * we need to check the pinned_extents for any extents that can't be used yet
- * since their free space will be released as soon as the transaction commits.
- */
-static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
-			      struct btrfs_fs_info *info, u64 start, u64 end)
-{
-	u64 extent_start, extent_end, size, total_added = 0;
-	int ret;
-
-	while (start < end) {
-		ret = find_first_extent_bit(info->pinned_extents, start,
-					    &extent_start, &extent_end,
-					    EXTENT_DIRTY | EXTENT_UPTODATE);
-		if (ret)
-			break;
-
-		if (extent_start <= start) {
-			start = extent_end + 1;
-		} else if (extent_start > start && extent_start < end) {
-			size = extent_start - start;
-			total_added += size;
-			ret = btrfs_add_free_space(block_group, start,
-						   size);
-			BUG_ON(ret); /* -ENOMEM or logic error */
-			start = extent_end + 1;
-		} else {
-			break;
-		}
-	}
-
-	if (start < end) {
-		size = end - start;
-		total_added += size;
-		ret = btrfs_add_free_space(block_group, start, size);
-		BUG_ON(ret); /* -ENOMEM or logic error */
-	}
-
-	return total_added;
-}
-
-static noinline void caching_thread(struct btrfs_work *work)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_fs_info *fs_info;
-	struct btrfs_caching_control *caching_ctl;
-	struct btrfs_root *extent_root;
-	struct btrfs_path *path;
-	struct extent_buffer *leaf;
-	struct btrfs_key key;
-	u64 total_found = 0;
-	u64 last = 0;
-	u32 nritems;
-	int ret = 0;
-
-	caching_ctl = container_of(work, struct btrfs_caching_control, work);
-	block_group = caching_ctl->block_group;
-	fs_info = block_group->fs_info;
-	extent_root = fs_info->extent_root;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		goto out;
-
-	last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
-
-	/*
-	 * We don't want to deadlock with somebody trying to allocate a new
-	 * extent for the extent root while also trying to search the extent
-	 * root to add free space.  So we skip locking and search the commit
-	 * root, since its read-only
-	 */
-	path->skip_locking = 1;
-	path->search_commit_root = 1;
-	path->reada = 1;
-
-	key.objectid = last;
-	key.offset = 0;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-again:
-	mutex_lock(&caching_ctl->mutex);
-	/* need to make sure the commit_root doesn't disappear */
-	down_read(&fs_info->extent_commit_sem);
-
-	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
-	if (ret < 0)
-		goto err;
-
-	leaf = path->nodes[0];
-	nritems = btrfs_header_nritems(leaf);
-
-	while (1) {
-		if (btrfs_fs_closing(fs_info) > 1) {
-			last = (u64)-1;
-			break;
-		}
-
-		if (path->slots[0] < nritems) {
-			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-		} else {
-			ret = find_next_key(path, 0, &key);
-			if (ret)
-				break;
-
-			if (need_resched() ||
-			    btrfs_next_leaf(extent_root, path)) {
-				caching_ctl->progress = last;
-				btrfs_release_path(path);
-				up_read(&fs_info->extent_commit_sem);
-				mutex_unlock(&caching_ctl->mutex);
-				cond_resched();
-				goto again;
-			}
-			leaf = path->nodes[0];
-			nritems = btrfs_header_nritems(leaf);
-			continue;
-		}
-
-		if (key.objectid < block_group->key.objectid) {
-			path->slots[0]++;
-			continue;
-		}
-
-		if (key.objectid >= block_group->key.objectid +
-		    block_group->key.offset)
-			break;
-
-		if (key.type == BTRFS_EXTENT_ITEM_KEY) {
-			total_found += add_new_free_space(block_group,
-							  fs_info, last,
-							  key.objectid);
-			last = key.objectid + key.offset;
-
-			if (total_found > (1024 * 1024 * 2)) {
-				total_found = 0;
-				wake_up(&caching_ctl->wait);
-			}
-		}
-		path->slots[0]++;
-	}
-	ret = 0;
-
-	total_found += add_new_free_space(block_group, fs_info, last,
-					  block_group->key.objectid +
-					  block_group->key.offset);
-	caching_ctl->progress = (u64)-1;
-
-	spin_lock(&block_group->lock);
-	block_group->caching_ctl = NULL;
-	block_group->cached = BTRFS_CACHE_FINISHED;
-	spin_unlock(&block_group->lock);
-
-err:
-	btrfs_free_path(path);
-	up_read(&fs_info->extent_commit_sem);
-
-	free_excluded_extents(extent_root, block_group);
-
-	mutex_unlock(&caching_ctl->mutex);
-out:
-	wake_up(&caching_ctl->wait);
-
-	put_caching_control(caching_ctl);
-	btrfs_put_block_group(block_group);
-}
-
-static int cache_block_group(struct btrfs_block_group_cache *cache,
-			     struct btrfs_trans_handle *trans,
-			     struct btrfs_root *root,
-			     int load_cache_only)
-{
-	DEFINE_WAIT(wait);
-	struct btrfs_fs_info *fs_info = cache->fs_info;
-	struct btrfs_caching_control *caching_ctl;
-	int ret = 0;
-
-	caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
-	if (!caching_ctl)
-		return -ENOMEM;
-
-	INIT_LIST_HEAD(&caching_ctl->list);
-	mutex_init(&caching_ctl->mutex);
-	init_waitqueue_head(&caching_ctl->wait);
-	caching_ctl->block_group = cache;
-	caching_ctl->progress = cache->key.objectid;
-	atomic_set(&caching_ctl->count, 1);
-	caching_ctl->work.func = caching_thread;
-
-	spin_lock(&cache->lock);
-	/*
-	 * This should be a rare occasion, but this could happen I think in the
-	 * case where one thread starts to load the space cache info, and then
-	 * some other thread starts a transaction commit which tries to do an
-	 * allocation while the other thread is still loading the space cache
-	 * info.  The previous loop should have kept us from choosing this block
-	 * group, but if we've moved to the state where we will wait on caching
-	 * block groups we need to first check if we're doing a fast load here,
-	 * so we can wait for it to finish, otherwise we could end up allocating
-	 * from a block group who's cache gets evicted for one reason or
-	 * another.
-	 */
-	while (cache->cached == BTRFS_CACHE_FAST) {
-		struct btrfs_caching_control *ctl;
-
-		ctl = cache->caching_ctl;
-		atomic_inc(&ctl->count);
-		prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
-		spin_unlock(&cache->lock);
-
-		schedule();
-
-		finish_wait(&ctl->wait, &wait);
-		put_caching_control(ctl);
-		spin_lock(&cache->lock);
-	}
-
-	if (cache->cached != BTRFS_CACHE_NO) {
-		spin_unlock(&cache->lock);
-		kfree(caching_ctl);
-		return 0;
-	}
-	WARN_ON(cache->caching_ctl);
-	cache->caching_ctl = caching_ctl;
-	cache->cached = BTRFS_CACHE_FAST;
-	spin_unlock(&cache->lock);
-
-	/*
-	 * We can't do the read from on-disk cache during a commit since we need
-	 * to have the normal tree locking.  Also if we are currently trying to
-	 * allocate blocks for the tree root we can't do the fast caching since
-	 * we likely hold important locks.
-	 */
-	if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
-		ret = load_free_space_cache(fs_info, cache);
-
-		spin_lock(&cache->lock);
-		if (ret == 1) {
-			cache->caching_ctl = NULL;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			cache->last_byte_to_unpin = (u64)-1;
-		} else {
-			if (load_cache_only) {
-				cache->caching_ctl = NULL;
-				cache->cached = BTRFS_CACHE_NO;
-			} else {
-				cache->cached = BTRFS_CACHE_STARTED;
-			}
-		}
-		spin_unlock(&cache->lock);
-		wake_up(&caching_ctl->wait);
-		if (ret == 1) {
-			put_caching_control(caching_ctl);
-			free_excluded_extents(fs_info->extent_root, cache);
-			return 0;
-		}
-	} else {
-		/*
-		 * We are not going to do the fast caching, set cached to the
-		 * appropriate value and wakeup any waiters.
-		 */
-		spin_lock(&cache->lock);
-		if (load_cache_only) {
-			cache->caching_ctl = NULL;
-			cache->cached = BTRFS_CACHE_NO;
-		} else {
-			cache->cached = BTRFS_CACHE_STARTED;
-		}
-		spin_unlock(&cache->lock);
-		wake_up(&caching_ctl->wait);
-	}
-
-	if (load_cache_only) {
-		put_caching_control(caching_ctl);
-		return 0;
-	}
-
-	down_write(&fs_info->extent_commit_sem);
-	atomic_inc(&caching_ctl->count);
-	list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
-	up_write(&fs_info->extent_commit_sem);
-
-	btrfs_get_block_group(cache);
-
-	btrfs_queue_worker(&fs_info->caching_workers, &caching_ctl->work);
-
-	return ret;
-}
-
-/*
- * return the block group that starts at or after bytenr
- */
-static struct btrfs_block_group_cache *
-btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
-{
-	struct btrfs_block_group_cache *cache;
-
-	cache = block_group_cache_tree_search(info, bytenr, 0);
-
-	return cache;
-}
-
-/*
- * return the block group that contains the given bytenr
- */
-struct btrfs_block_group_cache *btrfs_lookup_block_group(
-						 struct btrfs_fs_info *info,
-						 u64 bytenr)
-{
-	struct btrfs_block_group_cache *cache;
-
-	cache = block_group_cache_tree_search(info, bytenr, 1);
-
-	return cache;
-}
-
-static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
-						  u64 flags)
-{
-	struct list_head *head = &info->space_info;
-	struct btrfs_space_info *found;
-
-	flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(found, head, list) {
-		if (found->flags & flags) {
-			rcu_read_unlock();
-			return found;
-		}
-	}
-	rcu_read_unlock();
-	return NULL;
-}
-
-/*
- * after adding space to the filesystem, we need to clear the full flags
- * on all the space infos.
- */
-void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
-{
-	struct list_head *head = &info->space_info;
-	struct btrfs_space_info *found;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(found, head, list)
-		found->full = 0;
-	rcu_read_unlock();
-}
-
-static u64 div_factor(u64 num, int factor)
-{
-	if (factor == 10)
-		return num;
-	num *= factor;
-	do_div(num, 10);
-	return num;
-}
-
-static u64 div_factor_fine(u64 num, int factor)
-{
-	if (factor == 100)
-		return num;
-	num *= factor;
-	do_div(num, 100);
-	return num;
-}
-
-u64 btrfs_find_block_group(struct btrfs_root *root,
-			   u64 search_start, u64 search_hint, int owner)
-{
-	struct btrfs_block_group_cache *cache;
-	u64 used;
-	u64 last = max(search_hint, search_start);
-	u64 group_start = 0;
-	int full_search = 0;
-	int factor = 9;
-	int wrapped = 0;
-again:
-	while (1) {
-		cache = btrfs_lookup_first_block_group(root->fs_info, last);
-		if (!cache)
-			break;
-
-		spin_lock(&cache->lock);
-		last = cache->key.objectid + cache->key.offset;
-		used = btrfs_block_group_used(&cache->item);
-
-		if ((full_search || !cache->ro) &&
-		    block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) {
-			if (used + cache->pinned + cache->reserved <
-			    div_factor(cache->key.offset, factor)) {
-				group_start = cache->key.objectid;
-				spin_unlock(&cache->lock);
-				btrfs_put_block_group(cache);
-				goto found;
-			}
-		}
-		spin_unlock(&cache->lock);
-		btrfs_put_block_group(cache);
-		cond_resched();
-	}
-	if (!wrapped) {
-		last = search_start;
-		wrapped = 1;
-		goto again;
-	}
-	if (!full_search && factor < 10) {
-		last = search_start;
-		full_search = 1;
-		factor = 10;
-		goto again;
-	}
-found:
-	return group_start;
-}
-
-/* simple helper to search for an existing extent at a given offset */
-int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
-{
-	int ret;
-	struct btrfs_key key;
-	struct btrfs_path *path;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	key.objectid = start;
-	key.offset = len;
-	btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
-	ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
-				0, 0);
-	btrfs_free_path(path);
-	return ret;
-}
-
-/*
- * helper function to lookup reference count and flags of extent.
- *
- * the head node for delayed ref is used to store the sum of all the
- * reference count modifications queued up in the rbtree. the head
- * node may also store the extent flags to set. This way you can check
- * to see what the reference count and extent flags would be if all of
- * the delayed refs are not processed.
- */
-int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
-			     struct btrfs_root *root, u64 bytenr,
-			     u64 num_bytes, u64 *refs, u64 *flags)
-{
-	struct btrfs_delayed_ref_head *head;
-	struct btrfs_delayed_ref_root *delayed_refs;
-	struct btrfs_path *path;
-	struct btrfs_extent_item *ei;
-	struct extent_buffer *leaf;
-	struct btrfs_key key;
-	u32 item_size;
-	u64 num_refs;
-	u64 extent_flags;
-	int ret;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	key.objectid = bytenr;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-	key.offset = num_bytes;
-	if (!trans) {
-		path->skip_locking = 1;
-		path->search_commit_root = 1;
-	}
-again:
-	ret = btrfs_search_slot(trans, root->fs_info->extent_root,
-				&key, path, 0, 0);
-	if (ret < 0)
-		goto out_free;
-
-	if (ret == 0) {
-		leaf = path->nodes[0];
-		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-		if (item_size >= sizeof(*ei)) {
-			ei = btrfs_item_ptr(leaf, path->slots[0],
-					    struct btrfs_extent_item);
-			num_refs = btrfs_extent_refs(leaf, ei);
-			extent_flags = btrfs_extent_flags(leaf, ei);
-		} else {
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-			struct btrfs_extent_item_v0 *ei0;
-			BUG_ON(item_size != sizeof(*ei0));
-			ei0 = btrfs_item_ptr(leaf, path->slots[0],
-					     struct btrfs_extent_item_v0);
-			num_refs = btrfs_extent_refs_v0(leaf, ei0);
-			/* FIXME: this isn't correct for data */
-			extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
-#else
-			BUG();
-#endif
-		}
-		BUG_ON(num_refs == 0);
-	} else {
-		num_refs = 0;
-		extent_flags = 0;
-		ret = 0;
-	}
-
-	if (!trans)
-		goto out;
-
-	delayed_refs = &trans->transaction->delayed_refs;
-	spin_lock(&delayed_refs->lock);
-	head = btrfs_find_delayed_ref_head(trans, bytenr);
-	if (head) {
-		if (!mutex_trylock(&head->mutex)) {
-			atomic_inc(&head->node.refs);
-			spin_unlock(&delayed_refs->lock);
-
-			btrfs_release_path(path);
-
-			/*
-			 * Mutex was contended, block until it's released and try
-			 * again
-			 */
-			mutex_lock(&head->mutex);
-			mutex_unlock(&head->mutex);
-			btrfs_put_delayed_ref(&head->node);
-			goto again;
-		}
-		if (head->extent_op && head->extent_op->update_flags)
-			extent_flags |= head->extent_op->flags_to_set;
-		else
-			BUG_ON(num_refs == 0);
-
-		num_refs += head->node.ref_mod;
-		mutex_unlock(&head->mutex);
-	}
-	spin_unlock(&delayed_refs->lock);
-out:
-	WARN_ON(num_refs == 0);
-	if (refs)
-		*refs = num_refs;
-	if (flags)
-		*flags = extent_flags;
-out_free:
-	btrfs_free_path(path);
-	return ret;
-}
-
-/*
- * Back reference rules.  Back refs have three main goals:
- *
- * 1) differentiate between all holders of references to an extent so that
- *    when a reference is dropped we can make sure it was a valid reference
- *    before freeing the extent.
- *
- * 2) Provide enough information to quickly find the holders of an extent
- *    if we notice a given block is corrupted or bad.
- *
- * 3) Make it easy to migrate blocks for FS shrinking or storage pool
- *    maintenance.  This is actually the same as #2, but with a slightly
- *    different use case.
- *
- * There are two kinds of back refs. The implicit back refs is optimized
- * for pointers in non-shared tree blocks. For a given pointer in a block,
- * back refs of this kind provide information about the block's owner tree
- * and the pointer's key. These information allow us to find the block by
- * b-tree searching. The full back refs is for pointers in tree blocks not
- * referenced by their owner trees. The location of tree block is recorded
- * in the back refs. Actually the full back refs is generic, and can be
- * used in all cases the implicit back refs is used. The major shortcoming
- * of the full back refs is its overhead. Every time a tree block gets
- * COWed, we have to update back refs entry for all pointers in it.
- *
- * For a newly allocated tree block, we use implicit back refs for
- * pointers in it. This means most tree related operations only involve
- * implicit back refs. For a tree block created in old transaction, the
- * only way to drop a reference to it is COW it. So we can detect the
- * event that tree block loses its owner tree's reference and do the
- * back refs conversion.
- *
- * When a tree block is COW'd through a tree, there are four cases:
- *
- * The reference count of the block is one and the tree is the block's
- * owner tree. Nothing to do in this case.
- *
- * The reference count of the block is one and the tree is not the
- * block's owner tree. In this case, full back refs is used for pointers
- * in the block. Remove these full back refs, add implicit back refs for
- * every pointers in the new block.
- *
- * The reference count of the block is greater than one and the tree is
- * the block's owner tree. In this case, implicit back refs is used for
- * pointers in the block. Add full back refs for every pointers in the
- * block, increase lower level extents' reference counts. The original
- * implicit back refs are entailed to the new block.
- *
- * The reference count of the block is greater than one and the tree is
- * not the block's owner tree. Add implicit back refs for every pointer in
- * the new block, increase lower level extents' reference count.
- *
- * Back Reference Key composing:
- *
- * The key objectid corresponds to the first byte in the extent,
- * The key type is used to differentiate between types of back refs.
- * There are different meanings of the key offset for different types
- * of back refs.
- *
- * File extents can be referenced by:
- *
- * - multiple snapshots, subvolumes, or different generations in one subvol
- * - different files inside a single subvolume
- * - different offsets inside a file (bookend extents in file.c)
- *
- * The extent ref structure for the implicit back refs has fields for:
- *
- * - Objectid of the subvolume root
- * - objectid of the file holding the reference
- * - original offset in the file
- * - how many bookend extents
- *
- * The key offset for the implicit back refs is hash of the first
- * three fields.
- *
- * The extent ref structure for the full back refs has field for:
- *
- * - number of pointers in the tree leaf
- *
- * The key offset for the implicit back refs is the first byte of
- * the tree leaf
- *
- * When a file extent is allocated, The implicit back refs is used.
- * the fields are filled in:
- *
- *     (root_key.objectid, inode objectid, offset in file, 1)
- *
- * When a file extent is removed file truncation, we find the
- * corresponding implicit back refs and check the following fields:
- *
- *     (btrfs_header_owner(leaf), inode objectid, offset in file)
- *
- * Btree extents can be referenced by:
- *
- * - Different subvolumes
- *
- * Both the implicit back refs and the full back refs for tree blocks
- * only consist of key. The key offset for the implicit back refs is
- * objectid of block's owner tree. The key offset for the full back refs
- * is the first byte of parent block.
- *
- * When implicit back refs is used, information about the lowest key and
- * level of the tree block are required. These information are stored in
- * tree block info structure.
- */
-
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
-				  struct btrfs_root *root,
-				  struct btrfs_path *path,
-				  u64 owner, u32 extra_size)
-{
-	struct btrfs_extent_item *item;
-	struct btrfs_extent_item_v0 *ei0;
-	struct btrfs_extent_ref_v0 *ref0;
-	struct btrfs_tree_block_info *bi;
-	struct extent_buffer *leaf;
-	struct btrfs_key key;
-	struct btrfs_key found_key;
-	u32 new_size = sizeof(*item);
-	u64 refs;
-	int ret;
-
-	leaf = path->nodes[0];
-	BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
-
-	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-	ei0 = btrfs_item_ptr(leaf, path->slots[0],
-			     struct btrfs_extent_item_v0);
-	refs = btrfs_extent_refs_v0(leaf, ei0);
-
-	if (owner == (u64)-1) {
-		while (1) {
-			if (path->slots[0] >= btrfs_header_nritems(leaf)) {
-				ret = btrfs_next_leaf(root, path);
-				if (ret < 0)
-					return ret;
-				BUG_ON(ret > 0); /* Corruption */
-				leaf = path->nodes[0];
-			}
-			btrfs_item_key_to_cpu(leaf, &found_key,
-					      path->slots[0]);
-			BUG_ON(key.objectid != found_key.objectid);
-			if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
-				path->slots[0]++;
-				continue;
-			}
-			ref0 = btrfs_item_ptr(leaf, path->slots[0],
-					      struct btrfs_extent_ref_v0);
-			owner = btrfs_ref_objectid_v0(leaf, ref0);
-			break;
-		}
-	}
-	btrfs_release_path(path);
-
-	if (owner < BTRFS_FIRST_FREE_OBJECTID)
-		new_size += sizeof(*bi);
-
-	new_size -= sizeof(*ei0);
-	ret = btrfs_search_slot(trans, root, &key, path,
-				new_size + extra_size, 1);
-	if (ret < 0)
-		return ret;
-	BUG_ON(ret); /* Corruption */
-
-	btrfs_extend_item(trans, root, path, new_size);
-
-	leaf = path->nodes[0];
-	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
-	btrfs_set_extent_refs(leaf, item, refs);
-	/* FIXME: get real generation */
-	btrfs_set_extent_generation(leaf, item, 0);
-	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		btrfs_set_extent_flags(leaf, item,
-				       BTRFS_EXTENT_FLAG_TREE_BLOCK |
-				       BTRFS_BLOCK_FLAG_FULL_BACKREF);
-		bi = (struct btrfs_tree_block_info *)(item + 1);
-		/* FIXME: get first key of the block */
-		memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
-		btrfs_set_tree_block_level(leaf, bi, (int)owner);
-	} else {
-		btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
-	}
-	btrfs_mark_buffer_dirty(leaf);
-	return 0;
-}
-#endif
-
-static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
-{
-	u32 high_crc = ~(u32)0;
-	u32 low_crc = ~(u32)0;
-	__le64 lenum;
-
-	lenum = cpu_to_le64(root_objectid);
-	high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
-	lenum = cpu_to_le64(owner);
-	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
-	lenum = cpu_to_le64(offset);
-	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
-
-	return ((u64)high_crc << 31) ^ (u64)low_crc;
-}
-
-static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
-				     struct btrfs_extent_data_ref *ref)
-{
-	return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
-				    btrfs_extent_data_ref_objectid(leaf, ref),
-				    btrfs_extent_data_ref_offset(leaf, ref));
-}
-
-static int match_extent_data_ref(struct extent_buffer *leaf,
-				 struct btrfs_extent_data_ref *ref,
-				 u64 root_objectid, u64 owner, u64 offset)
-{
-	if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
-	    btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
-	    btrfs_extent_data_ref_offset(leaf, ref) != offset)
-		return 0;
-	return 1;
-}
-
-static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
-					   struct btrfs_root *root,
-					   struct btrfs_path *path,
-					   u64 bytenr, u64 parent,
-					   u64 root_objectid,
-					   u64 owner, u64 offset)
-{
-	struct btrfs_key key;
-	struct btrfs_extent_data_ref *ref;
-	struct extent_buffer *leaf;
-	u32 nritems;
-	int ret;
-	int recow;
-	int err = -ENOENT;
-
-	key.objectid = bytenr;
-	if (parent) {
-		key.type = BTRFS_SHARED_DATA_REF_KEY;
-		key.offset = parent;
-	} else {
-		key.type = BTRFS_EXTENT_DATA_REF_KEY;
-		key.offset = hash_extent_data_ref(root_objectid,
-						  owner, offset);
-	}
-again:
-	recow = 0;
-	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-	if (ret < 0) {
-		err = ret;
-		goto fail;
-	}
-
-	if (parent) {
-		if (!ret)
-			return 0;
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-		key.type = BTRFS_EXTENT_REF_V0_KEY;
-		btrfs_release_path(path);
-		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-		if (ret < 0) {
-			err = ret;
-			goto fail;
-		}
-		if (!ret)
-			return 0;
-#endif
-		goto fail;
-	}
-
-	leaf = path->nodes[0];
-	nritems = btrfs_header_nritems(leaf);
-	while (1) {
-		if (path->slots[0] >= nritems) {
-			ret = btrfs_next_leaf(root, path);
-			if (ret < 0)
-				err = ret;
-			if (ret)
-				goto fail;
-
-			leaf = path->nodes[0];
-			nritems = btrfs_header_nritems(leaf);
-			recow = 1;
-		}
-
-		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-		if (key.objectid != bytenr ||
-		    key.type != BTRFS_EXTENT_DATA_REF_KEY)
-			goto fail;
-
-		ref = btrfs_item_ptr(leaf, path->slots[0],
-				     struct btrfs_extent_data_ref);
-
-		if (match_extent_data_ref(leaf, ref, root_objectid,
-					  owner, offset)) {
-			if (recow) {
-				btrfs_release_path(path);
-				goto again;
-			}
-			err = 0;
-			break;
-		}
-		path->slots[0]++;
-	}
-fail:
-	return err;
-}
-
-static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
-					   struct btrfs_root *root,
-					   struct btrfs_path *path,
-					   u64 bytenr, u64 parent,
-					   u64 root_objectid, u64 owner,
-					   u64 offset, int refs_to_add)
-{
-	struct btrfs_key key;
-	struct extent_buffer *leaf;
-	u32 size;
-	u32 num_refs;
-	int ret;
-
-	key.objectid = bytenr;
-	if (parent) {
-		key.type = BTRFS_SHARED_DATA_REF_KEY;
-		key.offset = parent;
-		size = sizeof(struct btrfs_shared_data_ref);
-	} else {
-		key.type = BTRFS_EXTENT_DATA_REF_KEY;
-		key.offset = hash_extent_data_ref(root_objectid,
-						  owner, offset);
-		size = sizeof(struct btrfs_extent_data_ref);
-	}
-
-	ret = btrfs_insert_empty_item(trans, root, path, &key, size);
-	if (ret && ret != -EEXIST)
-		goto fail;
-
-	leaf = path->nodes[0];
-	if (parent) {
-		struct btrfs_shared_data_ref *ref;
-		ref = btrfs_item_ptr(leaf, path->slots[0],
-				     struct btrfs_shared_data_ref);
-		if (ret == 0) {
-			btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
-		} else {
-			num_refs = btrfs_shared_data_ref_count(leaf, ref);
-			num_refs += refs_to_add;
-			btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
-		}
-	} else {
-		struct btrfs_extent_data_ref *ref;
-		while (ret == -EEXIST) {
-			ref = btrfs_item_ptr(leaf, path->slots[0],
-					     struct btrfs_extent_data_ref);
-			if (match_extent_data_ref(leaf, ref, root_objectid,
-						  owner, offset))
-				break;
-			btrfs_release_path(path);
-			key.offset++;
-			ret = btrfs_insert_empty_item(trans, root, path, &key,
-						      size);
-			if (ret && ret != -EEXIST)
-				goto fail;
-
-			leaf = path->nodes[0];
-		}
-		ref = btrfs_item_ptr(leaf, path->slots[0],
-				     struct btrfs_extent_data_ref);
-		if (ret == 0) {
-			btrfs_set_extent_data_ref_root(leaf, ref,
-						       root_objectid);
-			btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
-			btrfs_set_extent_data_ref_offset(leaf, ref, offset);
-			btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
-		} else {
-			num_refs = btrfs_extent_data_ref_count(leaf, ref);
-			num_refs += refs_to_add;
-			btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
-		}
-	}
-	btrfs_mark_buffer_dirty(leaf);
-	ret = 0;
-fail:
-	btrfs_release_path(path);
-	return ret;
-}
-
-static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
-					   struct btrfs_root *root,
-					   struct btrfs_path *path,
-					   int refs_to_drop)
-{
-	struct btrfs_key key;
-	struct btrfs_extent_data_ref *ref1 = NULL;
-	struct btrfs_shared_data_ref *ref2 = NULL;
-	struct extent_buffer *leaf;
-	u32 num_refs = 0;
-	int ret = 0;
-
-	leaf = path->nodes[0];
-	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-
-	if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
-		ref1 = btrfs_item_ptr(leaf, path->slots[0],
-				      struct btrfs_extent_data_ref);
-		num_refs = btrfs_extent_data_ref_count(leaf, ref1);
-	} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
-		ref2 = btrfs_item_ptr(leaf, path->slots[0],
-				      struct btrfs_shared_data_ref);
-		num_refs = btrfs_shared_data_ref_count(leaf, ref2);
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-	} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
-		struct btrfs_extent_ref_v0 *ref0;
-		ref0 = btrfs_item_ptr(leaf, path->slots[0],
-				      struct btrfs_extent_ref_v0);
-		num_refs = btrfs_ref_count_v0(leaf, ref0);
-#endif
-	} else {
-		BUG();
-	}
-
-	BUG_ON(num_refs < refs_to_drop);
-	num_refs -= refs_to_drop;
-
-	if (num_refs == 0) {
-		ret = btrfs_del_item(trans, root, path);
-	} else {
-		if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
-			btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
-		else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
-			btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-		else {
-			struct btrfs_extent_ref_v0 *ref0;
-			ref0 = btrfs_item_ptr(leaf, path->slots[0],
-					struct btrfs_extent_ref_v0);
-			btrfs_set_ref_count_v0(leaf, ref0, num_refs);
-		}
-#endif
-		btrfs_mark_buffer_dirty(leaf);
-	}
-	return ret;
-}
-
-static noinline u32 extent_data_ref_count(struct btrfs_root *root,
-					  struct btrfs_path *path,
-					  struct btrfs_extent_inline_ref *iref)
-{
-	struct btrfs_key key;
-	struct extent_buffer *leaf;
-	struct btrfs_extent_data_ref *ref1;
-	struct btrfs_shared_data_ref *ref2;
-	u32 num_refs = 0;
-
-	leaf = path->nodes[0];
-	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-	if (iref) {
-		if (btrfs_extent_inline_ref_type(leaf, iref) ==
-		    BTRFS_EXTENT_DATA_REF_KEY) {
-			ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
-			num_refs = btrfs_extent_data_ref_count(leaf, ref1);
-		} else {
-			ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
-			num_refs = btrfs_shared_data_ref_count(leaf, ref2);
-		}
-	} else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
-		ref1 = btrfs_item_ptr(leaf, path->slots[0],
-				      struct btrfs_extent_data_ref);
-		num_refs = btrfs_extent_data_ref_count(leaf, ref1);
-	} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
-		ref2 = btrfs_item_ptr(leaf, path->slots[0],
-				      struct btrfs_shared_data_ref);
-		num_refs = btrfs_shared_data_ref_count(leaf, ref2);
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-	} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
-		struct btrfs_extent_ref_v0 *ref0;
-		ref0 = btrfs_item_ptr(leaf, path->slots[0],
-				      struct btrfs_extent_ref_v0);
-		num_refs = btrfs_ref_count_v0(leaf, ref0);
-#endif
-	} else {
-		WARN_ON(1);
-	}
-	return num_refs;
-}
-
-static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
-					  struct btrfs_root *root,
-					  struct btrfs_path *path,
-					  u64 bytenr, u64 parent,
-					  u64 root_objectid)
-{
-	struct btrfs_key key;
-	int ret;
-
-	key.objectid = bytenr;
-	if (parent) {
-		key.type = BTRFS_SHARED_BLOCK_REF_KEY;
-		key.offset = parent;
-	} else {
-		key.type = BTRFS_TREE_BLOCK_REF_KEY;
-		key.offset = root_objectid;
-	}
-
-	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-	if (ret > 0)
-		ret = -ENOENT;
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-	if (ret == -ENOENT && parent) {
-		btrfs_release_path(path);
-		key.type = BTRFS_EXTENT_REF_V0_KEY;
-		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-		if (ret > 0)
-			ret = -ENOENT;
-	}
-#endif
-	return ret;
-}
-
-static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
-					  struct btrfs_root *root,
-					  struct btrfs_path *path,
-					  u64 bytenr, u64 parent,
-					  u64 root_objectid)
-{
-	struct btrfs_key key;
-	int ret;
-
-	key.objectid = bytenr;
-	if (parent) {
-		key.type = BTRFS_SHARED_BLOCK_REF_KEY;
-		key.offset = parent;
-	} else {
-		key.type = BTRFS_TREE_BLOCK_REF_KEY;
-		key.offset = root_objectid;
-	}
-
-	ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
-	btrfs_release_path(path);
-	return ret;
-}
-
-static inline int extent_ref_type(u64 parent, u64 owner)
-{
-	int type;
-	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		if (parent > 0)
-			type = BTRFS_SHARED_BLOCK_REF_KEY;
-		else
-			type = BTRFS_TREE_BLOCK_REF_KEY;
-	} else {
-		if (parent > 0)
-			type = BTRFS_SHARED_DATA_REF_KEY;
-		else
-			type = BTRFS_EXTENT_DATA_REF_KEY;
-	}
-	return type;
-}
-
-static int find_next_key(struct btrfs_path *path, int level,
-			 struct btrfs_key *key)
-
-{
-	for (; level < BTRFS_MAX_LEVEL; level++) {
-		if (!path->nodes[level])
-			break;
-		if (path->slots[level] + 1 >=
-		    btrfs_header_nritems(path->nodes[level]))
-			continue;
-		if (level == 0)
-			btrfs_item_key_to_cpu(path->nodes[level], key,
-					      path->slots[level] + 1);
-		else
-			btrfs_node_key_to_cpu(path->nodes[level], key,
-					      path->slots[level] + 1);
-		return 0;
-	}
-	return 1;
-}
-
-/*
- * look for inline back ref. if back ref is found, *ref_ret is set
- * to the address of inline back ref, and 0 is returned.
- *
- * if back ref isn't found, *ref_ret is set to the address where it
- * should be inserted, and -ENOENT is returned.
- *
- * if insert is true and there are too many inline back refs, the path
- * points to the extent item, and -EAGAIN is returned.
- *
- * NOTE: inline back refs are ordered in the same way that back ref
- *	 items in the tree are ordered.
- */
-static noinline_for_stack
-int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 struct btrfs_extent_inline_ref **ref_ret,
-				 u64 bytenr, u64 num_bytes,
-				 u64 parent, u64 root_objectid,
-				 u64 owner, u64 offset, int insert)
-{
-	struct btrfs_key key;
-	struct extent_buffer *leaf;
-	struct btrfs_extent_item *ei;
-	struct btrfs_extent_inline_ref *iref;
-	u64 flags;
-	u64 item_size;
-	unsigned long ptr;
-	unsigned long end;
-	int extra_size;
-	int type;
-	int want;
-	int ret;
-	int err = 0;
-
-	key.objectid = bytenr;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-	key.offset = num_bytes;
-
-	want = extent_ref_type(parent, owner);
-	if (insert) {
-		extra_size = btrfs_extent_inline_ref_size(want);
-		path->keep_locks = 1;
-	} else
-		extra_size = -1;
-	ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
-	if (ret < 0) {
-		err = ret;
-		goto out;
-	}
-	if (ret && !insert) {
-		err = -ENOENT;
-		goto out;
-	}
-	BUG_ON(ret); /* Corruption */
-
-	leaf = path->nodes[0];
-	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-	if (item_size < sizeof(*ei)) {
-		if (!insert) {
-			err = -ENOENT;
-			goto out;
-		}
-		ret = convert_extent_item_v0(trans, root, path, owner,
-					     extra_size);
-		if (ret < 0) {
-			err = ret;
-			goto out;
-		}
-		leaf = path->nodes[0];
-		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-	}
-#endif
-	BUG_ON(item_size < sizeof(*ei));
-
-	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
-	flags = btrfs_extent_flags(leaf, ei);
-
-	ptr = (unsigned long)(ei + 1);
-	end = (unsigned long)ei + item_size;
-
-	if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
-		ptr += sizeof(struct btrfs_tree_block_info);
-		BUG_ON(ptr > end);
-	} else {
-		BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
-	}
-
-	err = -ENOENT;
-	while (1) {
-		if (ptr >= end) {
-			WARN_ON(ptr > end);
-			break;
-		}
-		iref = (struct btrfs_extent_inline_ref *)ptr;
-		type = btrfs_extent_inline_ref_type(leaf, iref);
-		if (want < type)
-			break;
-		if (want > type) {
-			ptr += btrfs_extent_inline_ref_size(type);
-			continue;
-		}
-
-		if (type == BTRFS_EXTENT_DATA_REF_KEY) {
-			struct btrfs_extent_data_ref *dref;
-			dref = (struct btrfs_extent_data_ref *)(&iref->offset);
-			if (match_extent_data_ref(leaf, dref, root_objectid,
-						  owner, offset)) {
-				err = 0;
-				break;
-			}
-			if (hash_extent_data_ref_item(leaf, dref) <
-			    hash_extent_data_ref(root_objectid, owner, offset))
-				break;
-		} else {
-			u64 ref_offset;
-			ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
-			if (parent > 0) {
-				if (parent == ref_offset) {
-					err = 0;
-					break;
-				}
-				if (ref_offset < parent)
-					break;
-			} else {
-				if (root_objectid == ref_offset) {
-					err = 0;
-					break;
-				}
-				if (ref_offset < root_objectid)
-					break;
-			}
-		}
-		ptr += btrfs_extent_inline_ref_size(type);
-	}
-	if (err == -ENOENT && insert) {
-		if (item_size + extra_size >=
-		    BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
-			err = -EAGAIN;
-			goto out;
-		}
-		/*
-		 * To add new inline back ref, we have to make sure
-		 * there is no corresponding back ref item.
-		 * For simplicity, we just do not add new inline back
-		 * ref if there is any kind of item for this block
-		 */
-		if (find_next_key(path, 0, &key) == 0 &&
-		    key.objectid == bytenr &&
-		    key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
-			err = -EAGAIN;
-			goto out;
-		}
-	}
-	*ref_ret = (struct btrfs_extent_inline_ref *)ptr;
-out:
-	if (insert) {
-		path->keep_locks = 0;
-		btrfs_unlock_up_safe(path, 1);
-	}
-	return err;
-}
-
-/*
- * helper to add new inline back ref
- */
-static noinline_for_stack
-void setup_inline_extent_backref(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 struct btrfs_extent_inline_ref *iref,
-				 u64 parent, u64 root_objectid,
-				 u64 owner, u64 offset, int refs_to_add,
-				 struct btrfs_delayed_extent_op *extent_op)
-{
-	struct extent_buffer *leaf;
-	struct btrfs_extent_item *ei;
-	unsigned long ptr;
-	unsigned long end;
-	unsigned long item_offset;
-	u64 refs;
-	int size;
-	int type;
-
-	leaf = path->nodes[0];
-	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
-	item_offset = (unsigned long)iref - (unsigned long)ei;
-
-	type = extent_ref_type(parent, owner);
-	size = btrfs_extent_inline_ref_size(type);
-
-	btrfs_extend_item(trans, root, path, size);
-
-	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
-	refs = btrfs_extent_refs(leaf, ei);
-	refs += refs_to_add;
-	btrfs_set_extent_refs(leaf, ei, refs);
-	if (extent_op)
-		__run_delayed_extent_op(extent_op, leaf, ei);
-
-	ptr = (unsigned long)ei + item_offset;
-	end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
-	if (ptr < end - size)
-		memmove_extent_buffer(leaf, ptr + size, ptr,
-				      end - size - ptr);
-
-	iref = (struct btrfs_extent_inline_ref *)ptr;
-	btrfs_set_extent_inline_ref_type(leaf, iref, type);
-	if (type == BTRFS_EXTENT_DATA_REF_KEY) {
-		struct btrfs_extent_data_ref *dref;
-		dref = (struct btrfs_extent_data_ref *)(&iref->offset);
-		btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
-		btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
-		btrfs_set_extent_data_ref_offset(leaf, dref, offset);
-		btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
-	} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
-		struct btrfs_shared_data_ref *sref;
-		sref = (struct btrfs_shared_data_ref *)(iref + 1);
-		btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
-		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
-	} else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
-		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
-	} else {
-		btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
-	}
-	btrfs_mark_buffer_dirty(leaf);
-}
-
-static int lookup_extent_backref(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 struct btrfs_extent_inline_ref **ref_ret,
-				 u64 bytenr, u64 num_bytes, u64 parent,
-				 u64 root_objectid, u64 owner, u64 offset)
-{
-	int ret;
-
-	ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
-					   bytenr, num_bytes, parent,
-					   root_objectid, owner, offset, 0);
-	if (ret != -ENOENT)
-		return ret;
-
-	btrfs_release_path(path);
-	*ref_ret = NULL;
-
-	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
-					    root_objectid);
-	} else {
-		ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
-					     root_objectid, owner, offset);
-	}
-	return ret;
-}
-
-/*
- * helper to update/remove inline back ref
- */
-static noinline_for_stack
-void update_inline_extent_backref(struct btrfs_trans_handle *trans,
-				  struct btrfs_root *root,
-				  struct btrfs_path *path,
-				  struct btrfs_extent_inline_ref *iref,
-				  int refs_to_mod,
-				  struct btrfs_delayed_extent_op *extent_op)
-{
-	struct extent_buffer *leaf;
-	struct btrfs_extent_item *ei;
-	struct btrfs_extent_data_ref *dref = NULL;
-	struct btrfs_shared_data_ref *sref = NULL;
-	unsigned long ptr;
-	unsigned long end;
-	u32 item_size;
-	int size;
-	int type;
-	u64 refs;
-
-	leaf = path->nodes[0];
-	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
-	refs = btrfs_extent_refs(leaf, ei);
-	WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
-	refs += refs_to_mod;
-	btrfs_set_extent_refs(leaf, ei, refs);
-	if (extent_op)
-		__run_delayed_extent_op(extent_op, leaf, ei);
-
-	type = btrfs_extent_inline_ref_type(leaf, iref);
-
-	if (type == BTRFS_EXTENT_DATA_REF_KEY) {
-		dref = (struct btrfs_extent_data_ref *)(&iref->offset);
-		refs = btrfs_extent_data_ref_count(leaf, dref);
-	} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
-		sref = (struct btrfs_shared_data_ref *)(iref + 1);
-		refs = btrfs_shared_data_ref_count(leaf, sref);
-	} else {
-		refs = 1;
-		BUG_ON(refs_to_mod != -1);
-	}
-
-	BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
-	refs += refs_to_mod;
-
-	if (refs > 0) {
-		if (type == BTRFS_EXTENT_DATA_REF_KEY)
-			btrfs_set_extent_data_ref_count(leaf, dref, refs);
-		else
-			btrfs_set_shared_data_ref_count(leaf, sref, refs);
-	} else {
-		size =  btrfs_extent_inline_ref_size(type);
-		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-		ptr = (unsigned long)iref;
-		end = (unsigned long)ei + item_size;
-		if (ptr + size < end)
-			memmove_extent_buffer(leaf, ptr, ptr + size,
-					      end - ptr - size);
-		item_size -= size;
-		btrfs_truncate_item(trans, root, path, item_size, 1);
-	}
-	btrfs_mark_buffer_dirty(leaf);
-}
-
-static noinline_for_stack
-int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 u64 bytenr, u64 num_bytes, u64 parent,
-				 u64 root_objectid, u64 owner,
-				 u64 offset, int refs_to_add,
-				 struct btrfs_delayed_extent_op *extent_op)
-{
-	struct btrfs_extent_inline_ref *iref;
-	int ret;
-
-	ret = lookup_inline_extent_backref(trans, root, path, &iref,
-					   bytenr, num_bytes, parent,
-					   root_objectid, owner, offset, 1);
-	if (ret == 0) {
-		BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
-		update_inline_extent_backref(trans, root, path, iref,
-					     refs_to_add, extent_op);
-	} else if (ret == -ENOENT) {
-		setup_inline_extent_backref(trans, root, path, iref, parent,
-					    root_objectid, owner, offset,
-					    refs_to_add, extent_op);
-		ret = 0;
-	}
-	return ret;
-}
-
-static int insert_extent_backref(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 u64 bytenr, u64 parent, u64 root_objectid,
-				 u64 owner, u64 offset, int refs_to_add)
-{
-	int ret;
-	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		BUG_ON(refs_to_add != 1);
-		ret = insert_tree_block_ref(trans, root, path, bytenr,
-					    parent, root_objectid);
-	} else {
-		ret = insert_extent_data_ref(trans, root, path, bytenr,
-					     parent, root_objectid,
-					     owner, offset, refs_to_add);
-	}
-	return ret;
-}
-
-static int remove_extent_backref(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 struct btrfs_extent_inline_ref *iref,
-				 int refs_to_drop, int is_data)
-{
-	int ret = 0;
-
-	BUG_ON(!is_data && refs_to_drop != 1);
-	if (iref) {
-		update_inline_extent_backref(trans, root, path, iref,
-					     -refs_to_drop, NULL);
-	} else if (is_data) {
-		ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
-	} else {
-		ret = btrfs_del_item(trans, root, path);
-	}
-	return ret;
-}
-
-static int btrfs_issue_discard(struct block_device *bdev,
-				u64 start, u64 len)
-{
-	return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
-}
-
-static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
-				u64 num_bytes, u64 *actual_bytes)
-{
-	int ret;
-	u64 discarded_bytes = 0;
-	struct btrfs_bio *bbio = NULL;
-
-
-	/* Tell the block device(s) that the sectors can be discarded */
-	ret = btrfs_map_block(&root->fs_info->mapping_tree, REQ_DISCARD,
-			      bytenr, &num_bytes, &bbio, 0);
-	/* Error condition is -ENOMEM */
-	if (!ret) {
-		struct btrfs_bio_stripe *stripe = bbio->stripes;
-		int i;
-
-
-		for (i = 0; i < bbio->num_stripes; i++, stripe++) {
-			if (!stripe->dev->can_discard)
-				continue;
-
-			ret = btrfs_issue_discard(stripe->dev->bdev,
-						  stripe->physical,
-						  stripe->length);
-			if (!ret)
-				discarded_bytes += stripe->length;
-			else if (ret != -EOPNOTSUPP)
-				break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
-
-			/*
-			 * Just in case we get back EOPNOTSUPP for some reason,
-			 * just ignore the return value so we don't screw up
-			 * people calling discard_extent.
-			 */
-			ret = 0;
-		}
-		kfree(bbio);
-	}
-
-	if (actual_bytes)
-		*actual_bytes = discarded_bytes;
-
-
-	return ret;
-}
-
-/* Can return -ENOMEM */
-int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root,
-			 u64 bytenr, u64 num_bytes, u64 parent,
-			 u64 root_objectid, u64 owner, u64 offset, int for_cow)
-{
-	int ret;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-
-	BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
-	       root_objectid == BTRFS_TREE_LOG_OBJECTID);
-
-	if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
-					num_bytes,
-					parent, root_objectid, (int)owner,
-					BTRFS_ADD_DELAYED_REF, NULL, for_cow);
-	} else {
-		ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
-					num_bytes,
-					parent, root_objectid, owner, offset,
-					BTRFS_ADD_DELAYED_REF, NULL, for_cow);
-	}
-	return ret;
-}
-
-static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
-				  struct btrfs_root *root,
-				  u64 bytenr, u64 num_bytes,
-				  u64 parent, u64 root_objectid,
-				  u64 owner, u64 offset, int refs_to_add,
-				  struct btrfs_delayed_extent_op *extent_op)
-{
-	struct btrfs_path *path;
-	struct extent_buffer *leaf;
-	struct btrfs_extent_item *item;
-	u64 refs;
-	int ret;
-	int err = 0;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	path->reada = 1;
-	path->leave_spinning = 1;
-	/* this will setup the path even if it fails to insert the back ref */
-	ret = insert_inline_extent_backref(trans, root->fs_info->extent_root,
-					   path, bytenr, num_bytes, parent,
-					   root_objectid, owner, offset,
-					   refs_to_add, extent_op);
-	if (ret == 0)
-		goto out;
-
-	if (ret != -EAGAIN) {
-		err = ret;
-		goto out;
-	}
-
-	leaf = path->nodes[0];
-	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
-	refs = btrfs_extent_refs(leaf, item);
-	btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
-	if (extent_op)
-		__run_delayed_extent_op(extent_op, leaf, item);
-
-	btrfs_mark_buffer_dirty(leaf);
-	btrfs_release_path(path);
-
-	path->reada = 1;
-	path->leave_spinning = 1;
-
-	/* now insert the actual backref */
-	ret = insert_extent_backref(trans, root->fs_info->extent_root,
-				    path, bytenr, parent, root_objectid,
-				    owner, offset, refs_to_add);
-	if (ret)
-		btrfs_abort_transaction(trans, root, ret);
-out:
-	btrfs_free_path(path);
-	return err;
-}
-
-static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root,
-				struct btrfs_delayed_ref_node *node,
-				struct btrfs_delayed_extent_op *extent_op,
-				int insert_reserved)
-{
-	int ret = 0;
-	struct btrfs_delayed_data_ref *ref;
-	struct btrfs_key ins;
-	u64 parent = 0;
-	u64 ref_root = 0;
-	u64 flags = 0;
-
-	ins.objectid = node->bytenr;
-	ins.offset = node->num_bytes;
-	ins.type = BTRFS_EXTENT_ITEM_KEY;
-
-	ref = btrfs_delayed_node_to_data_ref(node);
-	if (node->type == BTRFS_SHARED_DATA_REF_KEY)
-		parent = ref->parent;
-	else
-		ref_root = ref->root;
-
-	if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
-		if (extent_op) {
-			BUG_ON(extent_op->update_key);
-			flags |= extent_op->flags_to_set;
-		}
-		ret = alloc_reserved_file_extent(trans, root,
-						 parent, ref_root, flags,
-						 ref->objectid, ref->offset,
-						 &ins, node->ref_mod);
-	} else if (node->action == BTRFS_ADD_DELAYED_REF) {
-		ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
-					     node->num_bytes, parent,
-					     ref_root, ref->objectid,
-					     ref->offset, node->ref_mod,
-					     extent_op);
-	} else if (node->action == BTRFS_DROP_DELAYED_REF) {
-		ret = __btrfs_free_extent(trans, root, node->bytenr,
-					  node->num_bytes, parent,
-					  ref_root, ref->objectid,
-					  ref->offset, node->ref_mod,
-					  extent_op);
-	} else {
-		BUG();
-	}
-	return ret;
-}
-
-static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
-				    struct extent_buffer *leaf,
-				    struct btrfs_extent_item *ei)
-{
-	u64 flags = btrfs_extent_flags(leaf, ei);
-	if (extent_op->update_flags) {
-		flags |= extent_op->flags_to_set;
-		btrfs_set_extent_flags(leaf, ei, flags);
-	}
-
-	if (extent_op->update_key) {
-		struct btrfs_tree_block_info *bi;
-		BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
-		bi = (struct btrfs_tree_block_info *)(ei + 1);
-		btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
-	}
-}
-
-static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_delayed_ref_node *node,
-				 struct btrfs_delayed_extent_op *extent_op)
-{
-	struct btrfs_key key;
-	struct btrfs_path *path;
-	struct btrfs_extent_item *ei;
-	struct extent_buffer *leaf;
-	u32 item_size;
-	int ret;
-	int err = 0;
-
-	if (trans->aborted)
-		return 0;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	key.objectid = node->bytenr;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-	key.offset = node->num_bytes;
-
-	path->reada = 1;
-	path->leave_spinning = 1;
-	ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
-				path, 0, 1);
-	if (ret < 0) {
-		err = ret;
-		goto out;
-	}
-	if (ret > 0) {
-		err = -EIO;
-		goto out;
-	}
-
-	leaf = path->nodes[0];
-	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-	if (item_size < sizeof(*ei)) {
-		ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
-					     path, (u64)-1, 0);
-		if (ret < 0) {
-			err = ret;
-			goto out;
-		}
-		leaf = path->nodes[0];
-		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-	}
-#endif
-	BUG_ON(item_size < sizeof(*ei));
-	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
-	__run_delayed_extent_op(extent_op, leaf, ei);
-
-	btrfs_mark_buffer_dirty(leaf);
-out:
-	btrfs_free_path(path);
-	return err;
-}
-
-static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root,
-				struct btrfs_delayed_ref_node *node,
-				struct btrfs_delayed_extent_op *extent_op,
-				int insert_reserved)
-{
-	int ret = 0;
-	struct btrfs_delayed_tree_ref *ref;
-	struct btrfs_key ins;
-	u64 parent = 0;
-	u64 ref_root = 0;
-
-	ins.objectid = node->bytenr;
-	ins.offset = node->num_bytes;
-	ins.type = BTRFS_EXTENT_ITEM_KEY;
-
-	ref = btrfs_delayed_node_to_tree_ref(node);
-	if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
-		parent = ref->parent;
-	else
-		ref_root = ref->root;
-
-	BUG_ON(node->ref_mod != 1);
-	if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
-		BUG_ON(!extent_op || !extent_op->update_flags ||
-		       !extent_op->update_key);
-		ret = alloc_reserved_tree_block(trans, root,
-						parent, ref_root,
-						extent_op->flags_to_set,
-						&extent_op->key,
-						ref->level, &ins);
-	} else if (node->action == BTRFS_ADD_DELAYED_REF) {
-		ret = __btrfs_inc_extent_ref(trans, root, node->bytenr,
-					     node->num_bytes, parent, ref_root,
-					     ref->level, 0, 1, extent_op);
-	} else if (node->action == BTRFS_DROP_DELAYED_REF) {
-		ret = __btrfs_free_extent(trans, root, node->bytenr,
-					  node->num_bytes, parent, ref_root,
-					  ref->level, 0, 1, extent_op);
-	} else {
-		BUG();
-	}
-	return ret;
-}
-
-/* helper function to actually process a single delayed ref entry */
-static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
-			       struct btrfs_root *root,
-			       struct btrfs_delayed_ref_node *node,
-			       struct btrfs_delayed_extent_op *extent_op,
-			       int insert_reserved)
-{
-	int ret = 0;
-
-	if (trans->aborted)
-		return 0;
-
-	if (btrfs_delayed_ref_is_head(node)) {
-		struct btrfs_delayed_ref_head *head;
-		/*
-		 * we've hit the end of the chain and we were supposed
-		 * to insert this extent into the tree.  But, it got
-		 * deleted before we ever needed to insert it, so all
-		 * we have to do is clean up the accounting
-		 */
-		BUG_ON(extent_op);
-		head = btrfs_delayed_node_to_head(node);
-		if (insert_reserved) {
-			btrfs_pin_extent(root, node->bytenr,
-					 node->num_bytes, 1);
-			if (head->is_data) {
-				ret = btrfs_del_csums(trans, root,
-						      node->bytenr,
-						      node->num_bytes);
-			}
-		}
-		mutex_unlock(&head->mutex);
-		return ret;
-	}
-
-	if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
-	    node->type == BTRFS_SHARED_BLOCK_REF_KEY)
-		ret = run_delayed_tree_ref(trans, root, node, extent_op,
-					   insert_reserved);
-	else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
-		 node->type == BTRFS_SHARED_DATA_REF_KEY)
-		ret = run_delayed_data_ref(trans, root, node, extent_op,
-					   insert_reserved);
-	else
-		BUG();
-	return ret;
-}
-
-static noinline struct btrfs_delayed_ref_node *
-select_delayed_ref(struct btrfs_delayed_ref_head *head)
-{
-	struct rb_node *node;
-	struct btrfs_delayed_ref_node *ref;
-	int action = BTRFS_ADD_DELAYED_REF;
-again:
-	/*
-	 * select delayed ref of type BTRFS_ADD_DELAYED_REF first.
-	 * this prevents ref count from going down to zero when
-	 * there still are pending delayed ref.
-	 */
-	node = rb_prev(&head->node.rb_node);
-	while (1) {
-		if (!node)
-			break;
-		ref = rb_entry(node, struct btrfs_delayed_ref_node,
-				rb_node);
-		if (ref->bytenr != head->node.bytenr)
-			break;
-		if (ref->action == action)
-			return ref;
-		node = rb_prev(node);
-	}
-	if (action == BTRFS_ADD_DELAYED_REF) {
-		action = BTRFS_DROP_DELAYED_REF;
-		goto again;
-	}
-	return NULL;
-}
-
-/*
- * Returns 0 on success or if called with an already aborted transaction.
- * Returns -ENOMEM or -EIO on failure and will abort the transaction.
- */
-static noinline int run_clustered_refs(struct btrfs_trans_handle *trans,
-				       struct btrfs_root *root,
-				       struct list_head *cluster)
-{
-	struct btrfs_delayed_ref_root *delayed_refs;
-	struct btrfs_delayed_ref_node *ref;
-	struct btrfs_delayed_ref_head *locked_ref = NULL;
-	struct btrfs_delayed_extent_op *extent_op;
-	int ret;
-	int count = 0;
-	int must_insert_reserved = 0;
-
-	delayed_refs = &trans->transaction->delayed_refs;
-	while (1) {
-		if (!locked_ref) {
-			/* pick a new head ref from the cluster list */
-			if (list_empty(cluster))
-				break;
-
-			locked_ref = list_entry(cluster->next,
-				     struct btrfs_delayed_ref_head, cluster);
-
-			/* grab the lock that says we are going to process
-			 * all the refs for this head */
-			ret = btrfs_delayed_ref_lock(trans, locked_ref);
-
-			/*
-			 * we may have dropped the spin lock to get the head
-			 * mutex lock, and that might have given someone else
-			 * time to free the head.  If that's true, it has been
-			 * removed from our list and we can move on.
-			 */
-			if (ret == -EAGAIN) {
-				locked_ref = NULL;
-				count++;
-				continue;
-			}
-		}
-
-		/*
-		 * locked_ref is the head node, so we have to go one
-		 * node back for any delayed ref updates
-		 */
-		ref = select_delayed_ref(locked_ref);
-
-		if (ref && ref->seq &&
-		    btrfs_check_delayed_seq(delayed_refs, ref->seq)) {
-			/*
-			 * there are still refs with lower seq numbers in the
-			 * process of being added. Don't run this ref yet.
-			 */
-			list_del_init(&locked_ref->cluster);
-			mutex_unlock(&locked_ref->mutex);
-			locked_ref = NULL;
-			delayed_refs->num_heads_ready++;
-			spin_unlock(&delayed_refs->lock);
-			cond_resched();
-			spin_lock(&delayed_refs->lock);
-			continue;
-		}
-
-		/*
-		 * record the must insert reserved flag before we
-		 * drop the spin lock.
-		 */
-		must_insert_reserved = locked_ref->must_insert_reserved;
-		locked_ref->must_insert_reserved = 0;
-
-		extent_op = locked_ref->extent_op;
-		locked_ref->extent_op = NULL;
-
-		if (!ref) {
-			/* All delayed refs have been processed, Go ahead
-			 * and send the head node to run_one_delayed_ref,
-			 * so that any accounting fixes can happen
-			 */
-			ref = &locked_ref->node;
-
-			if (extent_op && must_insert_reserved) {
-				kfree(extent_op);
-				extent_op = NULL;
-			}
-
-			if (extent_op) {
-				spin_unlock(&delayed_refs->lock);
-
-				ret = run_delayed_extent_op(trans, root,
-							    ref, extent_op);
-				kfree(extent_op);
-
-				if (ret) {
-					printk(KERN_DEBUG "btrfs: run_delayed_extent_op returned %d\n", ret);
-					spin_lock(&delayed_refs->lock);
-					return ret;
-				}
-
-				goto next;
-			}
-
-			list_del_init(&locked_ref->cluster);
-			locked_ref = NULL;
-		}
-
-		ref->in_tree = 0;
-		rb_erase(&ref->rb_node, &delayed_refs->root);
-		delayed_refs->num_entries--;
-		/*
-		 * we modified num_entries, but as we're currently running
-		 * delayed refs, skip
-		 *     wake_up(&delayed_refs->seq_wait);
-		 * here.
-		 */
-		spin_unlock(&delayed_refs->lock);
-
-		ret = run_one_delayed_ref(trans, root, ref, extent_op,
-					  must_insert_reserved);
-
-		btrfs_put_delayed_ref(ref);
-		kfree(extent_op);
-		count++;
-
-		if (ret) {
-			printk(KERN_DEBUG "btrfs: run_one_delayed_ref returned %d\n", ret);
-			spin_lock(&delayed_refs->lock);
-			return ret;
-		}
-
-next:
-		do_chunk_alloc(trans, root->fs_info->extent_root,
-			       2 * 1024 * 1024,
-			       btrfs_get_alloc_profile(root, 0),
-			       CHUNK_ALLOC_NO_FORCE);
-		cond_resched();
-		spin_lock(&delayed_refs->lock);
-	}
-	return count;
-}
-
-
-static void wait_for_more_refs(struct btrfs_delayed_ref_root *delayed_refs,
-			unsigned long num_refs)
-{
-	struct list_head *first_seq = delayed_refs->seq_head.next;
-
-	spin_unlock(&delayed_refs->lock);
-	pr_debug("waiting for more refs (num %ld, first %p)\n",
-		 num_refs, first_seq);
-	wait_event(delayed_refs->seq_wait,
-		   num_refs != delayed_refs->num_entries ||
-		   delayed_refs->seq_head.next != first_seq);
-	pr_debug("done waiting for more refs (num %ld, first %p)\n",
-		 delayed_refs->num_entries, delayed_refs->seq_head.next);
-	spin_lock(&delayed_refs->lock);
-}
-
-/*
- * this starts processing the delayed reference count updates and
- * extent insertions we have queued up so far.  count can be
- * 0, which means to process everything in the tree at the start
- * of the run (but not newly added entries), or it can be some target
- * number you'd like to process.
- *
- * Returns 0 on success or if called with an aborted transaction
- * Returns <0 on error and aborts the transaction
- */
-int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root, unsigned long count)
-{
-	struct rb_node *node;
-	struct btrfs_delayed_ref_root *delayed_refs;
-	struct btrfs_delayed_ref_node *ref;
-	struct list_head cluster;
-	int ret;
-	u64 delayed_start;
-	int run_all = count == (unsigned long)-1;
-	int run_most = 0;
-	unsigned long num_refs = 0;
-	int consider_waiting;
-
-	/* We'll clean this up in btrfs_cleanup_transaction */
-	if (trans->aborted)
-		return 0;
-
-	if (root == root->fs_info->extent_root)
-		root = root->fs_info->tree_root;
-
-	do_chunk_alloc(trans, root->fs_info->extent_root,
-		       2 * 1024 * 1024, btrfs_get_alloc_profile(root, 0),
-		       CHUNK_ALLOC_NO_FORCE);
-
-	delayed_refs = &trans->transaction->delayed_refs;
-	INIT_LIST_HEAD(&cluster);
-again:
-	consider_waiting = 0;
-	spin_lock(&delayed_refs->lock);
-	if (count == 0) {
-		count = delayed_refs->num_entries * 2;
-		run_most = 1;
-	}
-	while (1) {
-		if (!(run_all || run_most) &&
-		    delayed_refs->num_heads_ready < 64)
-			break;
-
-		/*
-		 * go find something we can process in the rbtree.  We start at
-		 * the beginning of the tree, and then build a cluster
-		 * of refs to process starting at the first one we are able to
-		 * lock
-		 */
-		delayed_start = delayed_refs->run_delayed_start;
-		ret = btrfs_find_ref_cluster(trans, &cluster,
-					     delayed_refs->run_delayed_start);
-		if (ret)
-			break;
-
-		if (delayed_start >= delayed_refs->run_delayed_start) {
-			if (consider_waiting == 0) {
-				/*
-				 * btrfs_find_ref_cluster looped. let's do one
-				 * more cycle. if we don't run any delayed ref
-				 * during that cycle (because we can't because
-				 * all of them are blocked) and if the number of
-				 * refs doesn't change, we avoid busy waiting.
-				 */
-				consider_waiting = 1;
-				num_refs = delayed_refs->num_entries;
-			} else {
-				wait_for_more_refs(delayed_refs, num_refs);
-				/*
-				 * after waiting, things have changed. we
-				 * dropped the lock and someone else might have
-				 * run some refs, built new clusters and so on.
-				 * therefore, we restart staleness detection.
-				 */
-				consider_waiting = 0;
-			}
-		}
-
-		ret = run_clustered_refs(trans, root, &cluster);
-		if (ret < 0) {
-			spin_unlock(&delayed_refs->lock);
-			btrfs_abort_transaction(trans, root, ret);
-			return ret;
-		}
-
-		count -= min_t(unsigned long, ret, count);
-
-		if (count == 0)
-			break;
-
-		if (ret || delayed_refs->run_delayed_start == 0) {
-			/* refs were run, let's reset staleness detection */
-			consider_waiting = 0;
-		}
-	}
-
-	if (run_all) {
-		node = rb_first(&delayed_refs->root);
-		if (!node)
-			goto out;
-		count = (unsigned long)-1;
-
-		while (node) {
-			ref = rb_entry(node, struct btrfs_delayed_ref_node,
-				       rb_node);
-			if (btrfs_delayed_ref_is_head(ref)) {
-				struct btrfs_delayed_ref_head *head;
-
-				head = btrfs_delayed_node_to_head(ref);
-				atomic_inc(&ref->refs);
-
-				spin_unlock(&delayed_refs->lock);
-				/*
-				 * Mutex was contended, block until it's
-				 * released and try again
-				 */
-				mutex_lock(&head->mutex);
-				mutex_unlock(&head->mutex);
-
-				btrfs_put_delayed_ref(ref);
-				cond_resched();
-				goto again;
-			}
-			node = rb_next(node);
-		}
-		spin_unlock(&delayed_refs->lock);
-		schedule_timeout(1);
-		goto again;
-	}
-out:
-	spin_unlock(&delayed_refs->lock);
-	return 0;
-}
-
-int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root,
-				u64 bytenr, u64 num_bytes, u64 flags,
-				int is_data)
-{
-	struct btrfs_delayed_extent_op *extent_op;
-	int ret;
-
-	extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
-	if (!extent_op)
-		return -ENOMEM;
-
-	extent_op->flags_to_set = flags;
-	extent_op->update_flags = 1;
-	extent_op->update_key = 0;
-	extent_op->is_data = is_data ? 1 : 0;
-
-	ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
-					  num_bytes, extent_op);
-	if (ret)
-		kfree(extent_op);
-	return ret;
-}
-
-static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
-				      struct btrfs_root *root,
-				      struct btrfs_path *path,
-				      u64 objectid, u64 offset, u64 bytenr)
-{
-	struct btrfs_delayed_ref_head *head;
-	struct btrfs_delayed_ref_node *ref;
-	struct btrfs_delayed_data_ref *data_ref;
-	struct btrfs_delayed_ref_root *delayed_refs;
-	struct rb_node *node;
-	int ret = 0;
-
-	ret = -ENOENT;
-	delayed_refs = &trans->transaction->delayed_refs;
-	spin_lock(&delayed_refs->lock);
-	head = btrfs_find_delayed_ref_head(trans, bytenr);
-	if (!head)
-		goto out;
-
-	if (!mutex_trylock(&head->mutex)) {
-		atomic_inc(&head->node.refs);
-		spin_unlock(&delayed_refs->lock);
-
-		btrfs_release_path(path);
-
-		/*
-		 * Mutex was contended, block until it's released and let
-		 * caller try again
-		 */
-		mutex_lock(&head->mutex);
-		mutex_unlock(&head->mutex);
-		btrfs_put_delayed_ref(&head->node);
-		return -EAGAIN;
-	}
-
-	node = rb_prev(&head->node.rb_node);
-	if (!node)
-		goto out_unlock;
-
-	ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
-
-	if (ref->bytenr != bytenr)
-		goto out_unlock;
-
-	ret = 1;
-	if (ref->type != BTRFS_EXTENT_DATA_REF_KEY)
-		goto out_unlock;
-
-	data_ref = btrfs_delayed_node_to_data_ref(ref);
-
-	node = rb_prev(node);
-	if (node) {
-		ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
-		if (ref->bytenr == bytenr)
-			goto out_unlock;
-	}
-
-	if (data_ref->root != root->root_key.objectid ||
-	    data_ref->objectid != objectid || data_ref->offset != offset)
-		goto out_unlock;
-
-	ret = 0;
-out_unlock:
-	mutex_unlock(&head->mutex);
-out:
-	spin_unlock(&delayed_refs->lock);
-	return ret;
-}
-
-static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
-					struct btrfs_root *root,
-					struct btrfs_path *path,
-					u64 objectid, u64 offset, u64 bytenr)
-{
-	struct btrfs_root *extent_root = root->fs_info->extent_root;
-	struct extent_buffer *leaf;
-	struct btrfs_extent_data_ref *ref;
-	struct btrfs_extent_inline_ref *iref;
-	struct btrfs_extent_item *ei;
-	struct btrfs_key key;
-	u32 item_size;
-	int ret;
-
-	key.objectid = bytenr;
-	key.offset = (u64)-1;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-
-	ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
-	if (ret < 0)
-		goto out;
-	BUG_ON(ret == 0); /* Corruption */
-
-	ret = -ENOENT;
-	if (path->slots[0] == 0)
-		goto out;
-
-	path->slots[0]--;
-	leaf = path->nodes[0];
-	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
-
-	if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
-		goto out;
-
-	ret = 1;
-	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-	if (item_size < sizeof(*ei)) {
-		WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
-		goto out;
-	}
-#endif
-	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
-
-	if (item_size != sizeof(*ei) +
-	    btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
-		goto out;
-
-	if (btrfs_extent_generation(leaf, ei) <=
-	    btrfs_root_last_snapshot(&root->root_item))
-		goto out;
-
-	iref = (struct btrfs_extent_inline_ref *)(ei + 1);
-	if (btrfs_extent_inline_ref_type(leaf, iref) !=
-	    BTRFS_EXTENT_DATA_REF_KEY)
-		goto out;
-
-	ref = (struct btrfs_extent_data_ref *)(&iref->offset);
-	if (btrfs_extent_refs(leaf, ei) !=
-	    btrfs_extent_data_ref_count(leaf, ref) ||
-	    btrfs_extent_data_ref_root(leaf, ref) !=
-	    root->root_key.objectid ||
-	    btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
-	    btrfs_extent_data_ref_offset(leaf, ref) != offset)
-		goto out;
-
-	ret = 0;
-out:
-	return ret;
-}
-
-int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root,
-			  u64 objectid, u64 offset, u64 bytenr)
-{
-	struct btrfs_path *path;
-	int ret;
-	int ret2;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOENT;
-
-	do {
-		ret = check_committed_ref(trans, root, path, objectid,
-					  offset, bytenr);
-		if (ret && ret != -ENOENT)
-			goto out;
-
-		ret2 = check_delayed_ref(trans, root, path, objectid,
-					 offset, bytenr);
-	} while (ret2 == -EAGAIN);
-
-	if (ret2 && ret2 != -ENOENT) {
-		ret = ret2;
-		goto out;
-	}
-
-	if (ret != -ENOENT || ret2 != -ENOENT)
-		ret = 0;
-out:
-	btrfs_free_path(path);
-	if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
-		WARN_ON(ret > 0);
-	return ret;
-}
-
-static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
-			   struct extent_buffer *buf,
-			   int full_backref, int inc, int for_cow)
-{
-	u64 bytenr;
-	u64 num_bytes;
-	u64 parent;
-	u64 ref_root;
-	u32 nritems;
-	struct btrfs_key key;
-	struct btrfs_file_extent_item *fi;
-	int i;
-	int level;
-	int ret = 0;
-	int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
-			    u64, u64, u64, u64, u64, u64, int);
-
-	ref_root = btrfs_header_owner(buf);
-	nritems = btrfs_header_nritems(buf);
-	level = btrfs_header_level(buf);
-
-	if (!root->ref_cows && level == 0)
-		return 0;
-
-	if (inc)
-		process_func = btrfs_inc_extent_ref;
-	else
-		process_func = btrfs_free_extent;
-
-	if (full_backref)
-		parent = buf->start;
-	else
-		parent = 0;
-
-	for (i = 0; i < nritems; i++) {
-		if (level == 0) {
-			btrfs_item_key_to_cpu(buf, &key, i);
-			if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
-				continue;
-			fi = btrfs_item_ptr(buf, i,
-					    struct btrfs_file_extent_item);
-			if (btrfs_file_extent_type(buf, fi) ==
-			    BTRFS_FILE_EXTENT_INLINE)
-				continue;
-			bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
-			if (bytenr == 0)
-				continue;
-
-			num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
-			key.offset -= btrfs_file_extent_offset(buf, fi);
-			ret = process_func(trans, root, bytenr, num_bytes,
-					   parent, ref_root, key.objectid,
-					   key.offset, for_cow);
-			if (ret)
-				goto fail;
-		} else {
-			bytenr = btrfs_node_blockptr(buf, i);
-			num_bytes = btrfs_level_size(root, level - 1);
-			ret = process_func(trans, root, bytenr, num_bytes,
-					   parent, ref_root, level - 1, 0,
-					   for_cow);
-			if (ret)
-				goto fail;
-		}
-	}
-	return 0;
-fail:
-	return ret;
-}
-
-int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		  struct extent_buffer *buf, int full_backref, int for_cow)
-{
-	return __btrfs_mod_ref(trans, root, buf, full_backref, 1, for_cow);
-}
-
-int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		  struct extent_buffer *buf, int full_backref, int for_cow)
-{
-	return __btrfs_mod_ref(trans, root, buf, full_backref, 0, for_cow);
-}
-
-static int write_one_cache_group(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 struct btrfs_block_group_cache *cache)
-{
-	int ret;
-	struct btrfs_root *extent_root = root->fs_info->extent_root;
-	unsigned long bi;
-	struct extent_buffer *leaf;
-
-	ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
-	if (ret < 0)
-		goto fail;
-	BUG_ON(ret); /* Corruption */
-
-	leaf = path->nodes[0];
-	bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
-	write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
-	btrfs_mark_buffer_dirty(leaf);
-	btrfs_release_path(path);
-fail:
-	if (ret) {
-		btrfs_abort_transaction(trans, root, ret);
-		return ret;
-	}
-	return 0;
-
-}
-
-static struct btrfs_block_group_cache *
-next_block_group(struct btrfs_root *root,
-		 struct btrfs_block_group_cache *cache)
-{
-	struct rb_node *node;
-	spin_lock(&root->fs_info->block_group_cache_lock);
-	node = rb_next(&cache->cache_node);
-	btrfs_put_block_group(cache);
-	if (node) {
-		cache = rb_entry(node, struct btrfs_block_group_cache,
-				 cache_node);
-		btrfs_get_block_group(cache);
-	} else
-		cache = NULL;
-	spin_unlock(&root->fs_info->block_group_cache_lock);
-	return cache;
-}
-
-static int cache_save_setup(struct btrfs_block_group_cache *block_group,
-			    struct btrfs_trans_handle *trans,
-			    struct btrfs_path *path)
-{
-	struct btrfs_root *root = block_group->fs_info->tree_root;
-	struct inode *inode = NULL;
-	u64 alloc_hint = 0;
-	int dcs = BTRFS_DC_ERROR;
-	int num_pages = 0;
-	int retries = 0;
-	int ret = 0;
-
-	/*
-	 * If this block group is smaller than 100 megs don't bother caching the
-	 * block group.
-	 */
-	if (block_group->key.offset < (100 * 1024 * 1024)) {
-		spin_lock(&block_group->lock);
-		block_group->disk_cache_state = BTRFS_DC_WRITTEN;
-		spin_unlock(&block_group->lock);
-		return 0;
-	}
-
-again:
-	inode = lookup_free_space_inode(root, block_group, path);
-	if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
-		ret = PTR_ERR(inode);
-		btrfs_release_path(path);
-		goto out;
-	}
-
-	if (IS_ERR(inode)) {
-		BUG_ON(retries);
-		retries++;
-
-		if (block_group->ro)
-			goto out_free;
-
-		ret = create_free_space_inode(root, trans, block_group, path);
-		if (ret)
-			goto out_free;
-		goto again;
-	}
-
-	/* We've already setup this transaction, go ahead and exit */
-	if (block_group->cache_generation == trans->transid &&
-	    i_size_read(inode)) {
-		dcs = BTRFS_DC_SETUP;
-		goto out_put;
-	}
-
-	/*
-	 * We want to set the generation to 0, that way if anything goes wrong
-	 * from here on out we know not to trust this cache when we load up next
-	 * time.
-	 */
-	BTRFS_I(inode)->generation = 0;
-	ret = btrfs_update_inode(trans, root, inode);
-	WARN_ON(ret);
-
-	if (i_size_read(inode) > 0) {
-		ret = btrfs_truncate_free_space_cache(root, trans, path,
-						      inode);
-		if (ret)
-			goto out_put;
-	}
-
-	spin_lock(&block_group->lock);
-	if (block_group->cached != BTRFS_CACHE_FINISHED) {
-		/* We're not cached, don't bother trying to write stuff out */
-		dcs = BTRFS_DC_WRITTEN;
-		spin_unlock(&block_group->lock);
-		goto out_put;
-	}
-	spin_unlock(&block_group->lock);
-
-	num_pages = (int)div64_u64(block_group->key.offset, 1024 * 1024 * 1024);
-	if (!num_pages)
-		num_pages = 1;
-
-	/*
-	 * Just to make absolutely sure we have enough space, we're going to
-	 * preallocate 12 pages worth of space for each block group.  In
-	 * practice we ought to use at most 8, but we need extra space so we can
-	 * add our header and have a terminator between the extents and the
-	 * bitmaps.
-	 */
-	num_pages *= 16;
-	num_pages *= PAGE_CACHE_SIZE;
-
-	ret = btrfs_check_data_free_space(inode, num_pages);
-	if (ret)
-		goto out_put;
-
-	ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
-					      num_pages, num_pages,
-					      &alloc_hint);
-	if (!ret)
-		dcs = BTRFS_DC_SETUP;
-	btrfs_free_reserved_data_space(inode, num_pages);
-
-out_put:
-	iput(inode);
-out_free:
-	btrfs_release_path(path);
-out:
-	spin_lock(&block_group->lock);
-	if (!ret && dcs == BTRFS_DC_SETUP)
-		block_group->cache_generation = trans->transid;
-	block_group->disk_cache_state = dcs;
-	spin_unlock(&block_group->lock);
-
-	return ret;
-}
-
-int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
-				   struct btrfs_root *root)
-{
-	struct btrfs_block_group_cache *cache;
-	int err = 0;
-	struct btrfs_path *path;
-	u64 last = 0;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-again:
-	while (1) {
-		cache = btrfs_lookup_first_block_group(root->fs_info, last);
-		while (cache) {
-			if (cache->disk_cache_state == BTRFS_DC_CLEAR)
-				break;
-			cache = next_block_group(root, cache);
-		}
-		if (!cache) {
-			if (last == 0)
-				break;
-			last = 0;
-			continue;
-		}
-		err = cache_save_setup(cache, trans, path);
-		last = cache->key.objectid + cache->key.offset;
-		btrfs_put_block_group(cache);
-	}
-
-	while (1) {
-		if (last == 0) {
-			err = btrfs_run_delayed_refs(trans, root,
-						     (unsigned long)-1);
-			if (err) /* File system offline */
-				goto out;
-		}
-
-		cache = btrfs_lookup_first_block_group(root->fs_info, last);
-		while (cache) {
-			if (cache->disk_cache_state == BTRFS_DC_CLEAR) {
-				btrfs_put_block_group(cache);
-				goto again;
-			}
-
-			if (cache->dirty)
-				break;
-			cache = next_block_group(root, cache);
-		}
-		if (!cache) {
-			if (last == 0)
-				break;
-			last = 0;
-			continue;
-		}
-
-		if (cache->disk_cache_state == BTRFS_DC_SETUP)
-			cache->disk_cache_state = BTRFS_DC_NEED_WRITE;
-		cache->dirty = 0;
-		last = cache->key.objectid + cache->key.offset;
-
-		err = write_one_cache_group(trans, root, path, cache);
-		if (err) /* File system offline */
-			goto out;
-
-		btrfs_put_block_group(cache);
-	}
-
-	while (1) {
-		/*
-		 * I don't think this is needed since we're just marking our
-		 * preallocated extent as written, but just in case it can't
-		 * hurt.
-		 */
-		if (last == 0) {
-			err = btrfs_run_delayed_refs(trans, root,
-						     (unsigned long)-1);
-			if (err) /* File system offline */
-				goto out;
-		}
-
-		cache = btrfs_lookup_first_block_group(root->fs_info, last);
-		while (cache) {
-			/*
-			 * Really this shouldn't happen, but it could if we
-			 * couldn't write the entire preallocated extent and
-			 * splitting the extent resulted in a new block.
-			 */
-			if (cache->dirty) {
-				btrfs_put_block_group(cache);
-				goto again;
-			}
-			if (cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
-				break;
-			cache = next_block_group(root, cache);
-		}
-		if (!cache) {
-			if (last == 0)
-				break;
-			last = 0;
-			continue;
-		}
-
-		err = btrfs_write_out_cache(root, trans, cache, path);
-
-		/*
-		 * If we didn't have an error then the cache state is still
-		 * NEED_WRITE, so we can set it to WRITTEN.
-		 */
-		if (!err && cache->disk_cache_state == BTRFS_DC_NEED_WRITE)
-			cache->disk_cache_state = BTRFS_DC_WRITTEN;
-		last = cache->key.objectid + cache->key.offset;
-		btrfs_put_block_group(cache);
-	}
-out:
-
-	btrfs_free_path(path);
-	return err;
-}
-
-int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
-{
-	struct btrfs_block_group_cache *block_group;
-	int readonly = 0;
-
-	block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
-	if (!block_group || block_group->ro)
-		readonly = 1;
-	if (block_group)
-		btrfs_put_block_group(block_group);
-	return readonly;
-}
-
-static int update_space_info(struct btrfs_fs_info *info, u64 flags,
-			     u64 total_bytes, u64 bytes_used,
-			     struct btrfs_space_info **space_info)
-{
-	struct btrfs_space_info *found;
-	int i;
-	int factor;
-
-	if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
-		     BTRFS_BLOCK_GROUP_RAID10))
-		factor = 2;
-	else
-		factor = 1;
-
-	found = __find_space_info(info, flags);
-	if (found) {
-		spin_lock(&found->lock);
-		found->total_bytes += total_bytes;
-		found->disk_total += total_bytes * factor;
-		found->bytes_used += bytes_used;
-		found->disk_used += bytes_used * factor;
-		found->full = 0;
-		spin_unlock(&found->lock);
-		*space_info = found;
-		return 0;
-	}
-	found = kzalloc(sizeof(*found), GFP_NOFS);
-	if (!found)
-		return -ENOMEM;
-
-	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
-		INIT_LIST_HEAD(&found->block_groups[i]);
-	init_rwsem(&found->groups_sem);
-	spin_lock_init(&found->lock);
-	found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
-	found->total_bytes = total_bytes;
-	found->disk_total = total_bytes * factor;
-	found->bytes_used = bytes_used;
-	found->disk_used = bytes_used * factor;
-	found->bytes_pinned = 0;
-	found->bytes_reserved = 0;
-	found->bytes_readonly = 0;
-	found->bytes_may_use = 0;
-	found->full = 0;
-	found->force_alloc = CHUNK_ALLOC_NO_FORCE;
-	found->chunk_alloc = 0;
-	found->flush = 0;
-	init_waitqueue_head(&found->wait);
-	*space_info = found;
-	list_add_rcu(&found->list, &info->space_info);
-	return 0;
-}
-
-static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 extra_flags = chunk_to_extended(flags) &
-				BTRFS_EXTENDED_PROFILE_MASK;
-
-	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		fs_info->avail_data_alloc_bits |= extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_METADATA)
-		fs_info->avail_metadata_alloc_bits |= extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		fs_info->avail_system_alloc_bits |= extra_flags;
-}
-
-/*
- * returns target flags in extended format or 0 if restripe for this
- * chunk_type is not in progress
- *
- * should be called with either volume_mutex or balance_lock held
- */
-static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
-	u64 target = 0;
-
-	if (!bctl)
-		return 0;
-
-	if (flags & BTRFS_BLOCK_GROUP_DATA &&
-	    bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
-	} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
-		   bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
-	} else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
-		   bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
-		target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
-	}
-
-	return target;
-}
-
-/*
- * @flags: available profiles in extended format (see ctree.h)
- *
- * Returns reduced profile in chunk format.  If profile changing is in
- * progress (either running or paused) picks the target profile (if it's
- * already available), otherwise falls back to plain reducing.
- */
-u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
-{
-	/*
-	 * we add in the count of missing devices because we want
-	 * to make sure that any RAID levels on a degraded FS
-	 * continue to be honored.
-	 */
-	u64 num_devices = root->fs_info->fs_devices->rw_devices +
-		root->fs_info->fs_devices->missing_devices;
-	u64 target;
-
-	/*
-	 * see if restripe for this chunk_type is in progress, if so
-	 * try to reduce to the target profile
-	 */
-	spin_lock(&root->fs_info->balance_lock);
-	target = get_restripe_target(root->fs_info, flags);
-	if (target) {
-		/* pick target profile only if it's already available */
-		if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
-			spin_unlock(&root->fs_info->balance_lock);
-			return extended_to_chunk(target);
-		}
-	}
-	spin_unlock(&root->fs_info->balance_lock);
-
-	if (num_devices == 1)
-		flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0);
-	if (num_devices < 4)
-		flags &= ~BTRFS_BLOCK_GROUP_RAID10;
-
-	if ((flags & BTRFS_BLOCK_GROUP_DUP) &&
-	    (flags & (BTRFS_BLOCK_GROUP_RAID1 |
-		      BTRFS_BLOCK_GROUP_RAID10))) {
-		flags &= ~BTRFS_BLOCK_GROUP_DUP;
-	}
-
-	if ((flags & BTRFS_BLOCK_GROUP_RAID1) &&
-	    (flags & BTRFS_BLOCK_GROUP_RAID10)) {
-		flags &= ~BTRFS_BLOCK_GROUP_RAID1;
-	}
-
-	if ((flags & BTRFS_BLOCK_GROUP_RAID0) &&
-	    ((flags & BTRFS_BLOCK_GROUP_RAID1) |
-	     (flags & BTRFS_BLOCK_GROUP_RAID10) |
-	     (flags & BTRFS_BLOCK_GROUP_DUP))) {
-		flags &= ~BTRFS_BLOCK_GROUP_RAID0;
-	}
-
-	return extended_to_chunk(flags);
-}
-
-static u64 get_alloc_profile(struct btrfs_root *root, u64 flags)
-{
-	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		flags |= root->fs_info->avail_data_alloc_bits;
-	else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		flags |= root->fs_info->avail_system_alloc_bits;
-	else if (flags & BTRFS_BLOCK_GROUP_METADATA)
-		flags |= root->fs_info->avail_metadata_alloc_bits;
-
-	return btrfs_reduce_alloc_profile(root, flags);
-}
-
-u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
-{
-	u64 flags;
-
-	if (data)
-		flags = BTRFS_BLOCK_GROUP_DATA;
-	else if (root == root->fs_info->chunk_root)
-		flags = BTRFS_BLOCK_GROUP_SYSTEM;
-	else
-		flags = BTRFS_BLOCK_GROUP_METADATA;
-
-	return get_alloc_profile(root, flags);
-}
-
-void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode)
-{
-	BTRFS_I(inode)->space_info = __find_space_info(root->fs_info,
-						       BTRFS_BLOCK_GROUP_DATA);
-}
-
-/*
- * This will check the space that the inode allocates from to make sure we have
- * enough space for bytes.
- */
-int btrfs_check_data_free_space(struct inode *inode, u64 bytes)
-{
-	struct btrfs_space_info *data_sinfo;
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 used;
-	int ret = 0, committed = 0, alloc_chunk = 1;
-
-	/* make sure bytes are sectorsize aligned */
-	bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
-
-	if (root == root->fs_info->tree_root ||
-	    BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID) {
-		alloc_chunk = 0;
-		committed = 1;
-	}
-
-	data_sinfo = BTRFS_I(inode)->space_info;
-	if (!data_sinfo)
-		goto alloc;
-
-again:
-	/* make sure we have enough space to handle the data first */
-	spin_lock(&data_sinfo->lock);
-	used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
-		data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
-		data_sinfo->bytes_may_use;
-
-	if (used + bytes > data_sinfo->total_bytes) {
-		struct btrfs_trans_handle *trans;
-
-		/*
-		 * if we don't have enough free bytes in this space then we need
-		 * to alloc a new chunk.
-		 */
-		if (!data_sinfo->full && alloc_chunk) {
-			u64 alloc_target;
-
-			data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
-			spin_unlock(&data_sinfo->lock);
-alloc:
-			alloc_target = btrfs_get_alloc_profile(root, 1);
-			trans = btrfs_join_transaction(root);
-			if (IS_ERR(trans))
-				return PTR_ERR(trans);
-
-			ret = do_chunk_alloc(trans, root->fs_info->extent_root,
-					     bytes + 2 * 1024 * 1024,
-					     alloc_target,
-					     CHUNK_ALLOC_NO_FORCE);
-			btrfs_end_transaction(trans, root);
-			if (ret < 0) {
-				if (ret != -ENOSPC)
-					return ret;
-				else
-					goto commit_trans;
-			}
-
-			if (!data_sinfo) {
-				btrfs_set_inode_space_info(root, inode);
-				data_sinfo = BTRFS_I(inode)->space_info;
-			}
-			goto again;
-		}
-
-		/*
-		 * If we have less pinned bytes than we want to allocate then
-		 * don't bother committing the transaction, it won't help us.
-		 */
-		if (data_sinfo->bytes_pinned < bytes)
-			committed = 1;
-		spin_unlock(&data_sinfo->lock);
-
-		/* commit the current transaction and try again */
-commit_trans:
-		if (!committed &&
-		    !atomic_read(&root->fs_info->open_ioctl_trans)) {
-			committed = 1;
-			trans = btrfs_join_transaction(root);
-			if (IS_ERR(trans))
-				return PTR_ERR(trans);
-			ret = btrfs_commit_transaction(trans, root);
-			if (ret)
-				return ret;
-			goto again;
-		}
-
-		return -ENOSPC;
-	}
-	data_sinfo->bytes_may_use += bytes;
-	trace_btrfs_space_reservation(root->fs_info, "space_info",
-				      data_sinfo->flags, bytes, 1);
-	spin_unlock(&data_sinfo->lock);
-
-	return 0;
-}
-
-/*
- * Called if we need to clear a data reservation for this inode.
- */
-void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
-{
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-	struct btrfs_space_info *data_sinfo;
-
-	/* make sure bytes are sectorsize aligned */
-	bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
-
-	data_sinfo = BTRFS_I(inode)->space_info;
-	spin_lock(&data_sinfo->lock);
-	data_sinfo->bytes_may_use -= bytes;
-	trace_btrfs_space_reservation(root->fs_info, "space_info",
-				      data_sinfo->flags, bytes, 0);
-	spin_unlock(&data_sinfo->lock);
-}
-
-static void force_metadata_allocation(struct btrfs_fs_info *info)
-{
-	struct list_head *head = &info->space_info;
-	struct btrfs_space_info *found;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(found, head, list) {
-		if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
-			found->force_alloc = CHUNK_ALLOC_FORCE;
-	}
-	rcu_read_unlock();
-}
-
-static int should_alloc_chunk(struct btrfs_root *root,
-			      struct btrfs_space_info *sinfo, u64 alloc_bytes,
-			      int force)
-{
-	struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
-	u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
-	u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
-	u64 thresh;
-
-	if (force == CHUNK_ALLOC_FORCE)
-		return 1;
-
-	/*
-	 * We need to take into account the global rsv because for all intents
-	 * and purposes it's used space.  Don't worry about locking the
-	 * global_rsv, it doesn't change except when the transaction commits.
-	 */
-	num_allocated += global_rsv->size;
-
-	/*
-	 * in limited mode, we want to have some free space up to
-	 * about 1% of the FS size.
-	 */
-	if (force == CHUNK_ALLOC_LIMITED) {
-		thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
-		thresh = max_t(u64, 64 * 1024 * 1024,
-			       div_factor_fine(thresh, 1));
-
-		if (num_bytes - num_allocated < thresh)
-			return 1;
-	}
-	thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
-
-	/* 256MB or 2% of the FS */
-	thresh = max_t(u64, 256 * 1024 * 1024, div_factor_fine(thresh, 2));
-	/* system chunks need a much small threshold */
-	if (sinfo->flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		thresh = 32 * 1024 * 1024;
-
-	if (num_bytes > thresh && sinfo->bytes_used < div_factor(num_bytes, 8))
-		return 0;
-	return 1;
-}
-
-static u64 get_system_chunk_thresh(struct btrfs_root *root, u64 type)
-{
-	u64 num_dev;
-
-	if (type & BTRFS_BLOCK_GROUP_RAID10 ||
-	    type & BTRFS_BLOCK_GROUP_RAID0)
-		num_dev = root->fs_info->fs_devices->rw_devices;
-	else if (type & BTRFS_BLOCK_GROUP_RAID1)
-		num_dev = 2;
-	else
-		num_dev = 1;	/* DUP or single */
-
-	/* metadata for updaing devices and chunk tree */
-	return btrfs_calc_trans_metadata_size(root, num_dev + 1);
-}
-
-static void check_system_chunk(struct btrfs_trans_handle *trans,
-			       struct btrfs_root *root, u64 type)
-{
-	struct btrfs_space_info *info;
-	u64 left;
-	u64 thresh;
-
-	info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
-	spin_lock(&info->lock);
-	left = info->total_bytes - info->bytes_used - info->bytes_pinned -
-		info->bytes_reserved - info->bytes_readonly;
-	spin_unlock(&info->lock);
-
-	thresh = get_system_chunk_thresh(root, type);
-	if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) {
-		printk(KERN_INFO "left=%llu, need=%llu, flags=%llu\n",
-		       left, thresh, type);
-		dump_space_info(info, 0, 0);
-	}
-
-	if (left < thresh) {
-		u64 flags;
-
-		flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0);
-		btrfs_alloc_chunk(trans, root, flags);
-	}
-}
-
-static int do_chunk_alloc(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *extent_root, u64 alloc_bytes,
-			  u64 flags, int force)
-{
-	struct btrfs_space_info *space_info;
-	struct btrfs_fs_info *fs_info = extent_root->fs_info;
-	int wait_for_alloc = 0;
-	int ret = 0;
-
-	space_info = __find_space_info(extent_root->fs_info, flags);
-	if (!space_info) {
-		ret = update_space_info(extent_root->fs_info, flags,
-					0, 0, &space_info);
-		BUG_ON(ret); /* -ENOMEM */
-	}
-	BUG_ON(!space_info); /* Logic error */
-
-again:
-	spin_lock(&space_info->lock);
-	if (force < space_info->force_alloc)
-		force = space_info->force_alloc;
-	if (space_info->full) {
-		spin_unlock(&space_info->lock);
-		return 0;
-	}
-
-	if (!should_alloc_chunk(extent_root, space_info, alloc_bytes, force)) {
-		spin_unlock(&space_info->lock);
-		return 0;
-	} else if (space_info->chunk_alloc) {
-		wait_for_alloc = 1;
-	} else {
-		space_info->chunk_alloc = 1;
-	}
-
-	spin_unlock(&space_info->lock);
-
-	mutex_lock(&fs_info->chunk_mutex);
-
-	/*
-	 * The chunk_mutex is held throughout the entirety of a chunk
-	 * allocation, so once we've acquired the chunk_mutex we know that the
-	 * other guy is done and we need to recheck and see if we should
-	 * allocate.
-	 */
-	if (wait_for_alloc) {
-		mutex_unlock(&fs_info->chunk_mutex);
-		wait_for_alloc = 0;
-		goto again;
-	}
-
-	/*
-	 * If we have mixed data/metadata chunks we want to make sure we keep
-	 * allocating mixed chunks instead of individual chunks.
-	 */
-	if (btrfs_mixed_space_info(space_info))
-		flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
-
-	/*
-	 * if we're doing a data chunk, go ahead and make sure that
-	 * we keep a reasonable number of metadata chunks allocated in the
-	 * FS as well.
-	 */
-	if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
-		fs_info->data_chunk_allocations++;
-		if (!(fs_info->data_chunk_allocations %
-		      fs_info->metadata_ratio))
-			force_metadata_allocation(fs_info);
-	}
-
-	/*
-	 * Check if we have enough space in SYSTEM chunk because we may need
-	 * to update devices.
-	 */
-	check_system_chunk(trans, extent_root, flags);
-
-	ret = btrfs_alloc_chunk(trans, extent_root, flags);
-	if (ret < 0 && ret != -ENOSPC)
-		goto out;
-
-	spin_lock(&space_info->lock);
-	if (ret)
-		space_info->full = 1;
-	else
-		ret = 1;
-
-	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
-	space_info->chunk_alloc = 0;
-	spin_unlock(&space_info->lock);
-out:
-	mutex_unlock(&extent_root->fs_info->chunk_mutex);
-	return ret;
-}
-
-/*
- * shrink metadata reservation for delalloc
- */
-static int shrink_delalloc(struct btrfs_root *root, u64 to_reclaim,
-			   bool wait_ordered)
-{
-	struct btrfs_block_rsv *block_rsv;
-	struct btrfs_space_info *space_info;
-	struct btrfs_trans_handle *trans;
-	u64 reserved;
-	u64 max_reclaim;
-	u64 reclaimed = 0;
-	long time_left;
-	unsigned long nr_pages = (2 * 1024 * 1024) >> PAGE_CACHE_SHIFT;
-	int loops = 0;
-	unsigned long progress;
-
-	trans = (struct btrfs_trans_handle *)current->journal_info;
-	block_rsv = &root->fs_info->delalloc_block_rsv;
-	space_info = block_rsv->space_info;
-
-	smp_mb();
-	reserved = space_info->bytes_may_use;
-	progress = space_info->reservation_progress;
-
-	if (reserved == 0)
-		return 0;
-
-	smp_mb();
-	if (root->fs_info->delalloc_bytes == 0) {
-		if (trans)
-			return 0;
-		btrfs_wait_ordered_extents(root, 0, 0);
-		return 0;
-	}
-
-	max_reclaim = min(reserved, to_reclaim);
-	nr_pages = max_t(unsigned long, nr_pages,
-			 max_reclaim >> PAGE_CACHE_SHIFT);
-	while (loops < 1024) {
-		/* have the flusher threads jump in and do some IO */
-		smp_mb();
-		nr_pages = min_t(unsigned long, nr_pages,
-		       root->fs_info->delalloc_bytes >> PAGE_CACHE_SHIFT);
-		writeback_inodes_sb_nr_if_idle(root->fs_info->sb, nr_pages,
-						WB_REASON_FS_FREE_SPACE);
-
-		spin_lock(&space_info->lock);
-		if (reserved > space_info->bytes_may_use)
-			reclaimed += reserved - space_info->bytes_may_use;
-		reserved = space_info->bytes_may_use;
-		spin_unlock(&space_info->lock);
-
-		loops++;
-
-		if (reserved == 0 || reclaimed >= max_reclaim)
-			break;
-
-		if (trans && trans->transaction->blocked)
-			return -EAGAIN;
-
-		if (wait_ordered && !trans) {
-			btrfs_wait_ordered_extents(root, 0, 0);
-		} else {
-			time_left = schedule_timeout_interruptible(1);
-
-			/* We were interrupted, exit */
-			if (time_left)
-				break;
-		}
-
-		/* we've kicked the IO a few times, if anything has been freed,
-		 * exit.  There is no sense in looping here for a long time
-		 * when we really need to commit the transaction, or there are
-		 * just too many writers without enough free space
-		 */
-
-		if (loops > 3) {
-			smp_mb();
-			if (progress != space_info->reservation_progress)
-				break;
-		}
-
-	}
-
-	return reclaimed >= to_reclaim;
-}
-
-/**
- * maybe_commit_transaction - possibly commit the transaction if its ok to
- * @root - the root we're allocating for
- * @bytes - the number of bytes we want to reserve
- * @force - force the commit
- *
- * This will check to make sure that committing the transaction will actually
- * get us somewhere and then commit the transaction if it does.  Otherwise it
- * will return -ENOSPC.
- */
-static int may_commit_transaction(struct btrfs_root *root,
-				  struct btrfs_space_info *space_info,
-				  u64 bytes, int force)
-{
-	struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv;
-	struct btrfs_trans_handle *trans;
-
-	trans = (struct btrfs_trans_handle *)current->journal_info;
-	if (trans)
-		return -EAGAIN;
-
-	if (force)
-		goto commit;
-
-	/* See if there is enough pinned space to make this reservation */
-	spin_lock(&space_info->lock);
-	if (space_info->bytes_pinned >= bytes) {
-		spin_unlock(&space_info->lock);
-		goto commit;
-	}
-	spin_unlock(&space_info->lock);
-
-	/*
-	 * See if there is some space in the delayed insertion reservation for
-	 * this reservation.
-	 */
-	if (space_info != delayed_rsv->space_info)
-		return -ENOSPC;
-
-	spin_lock(&space_info->lock);
-	spin_lock(&delayed_rsv->lock);
-	if (space_info->bytes_pinned + delayed_rsv->size < bytes) {
-		spin_unlock(&delayed_rsv->lock);
-		spin_unlock(&space_info->lock);
-		return -ENOSPC;
-	}
-	spin_unlock(&delayed_rsv->lock);
-	spin_unlock(&space_info->lock);
-
-commit:
-	trans = btrfs_join_transaction(root);
-	if (IS_ERR(trans))
-		return -ENOSPC;
-
-	return btrfs_commit_transaction(trans, root);
-}
-
-/**
- * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
- * @root - the root we're allocating for
- * @block_rsv - the block_rsv we're allocating for
- * @orig_bytes - the number of bytes we want
- * @flush - wether or not we can flush to make our reservation
- *
- * This will reserve orgi_bytes number of bytes from the space info associated
- * with the block_rsv.  If there is not enough space it will make an attempt to
- * flush out space to make room.  It will do this by flushing delalloc if
- * possible or committing the transaction.  If flush is 0 then no attempts to
- * regain reservations will be made and this will fail if there is not enough
- * space already.
- */
-static int reserve_metadata_bytes(struct btrfs_root *root,
-				  struct btrfs_block_rsv *block_rsv,
-				  u64 orig_bytes, int flush)
-{
-	struct btrfs_space_info *space_info = block_rsv->space_info;
-	u64 used;
-	u64 num_bytes = orig_bytes;
-	int retries = 0;
-	int ret = 0;
-	bool committed = false;
-	bool flushing = false;
-	bool wait_ordered = false;
-
-again:
-	ret = 0;
-	spin_lock(&space_info->lock);
-	/*
-	 * We only want to wait if somebody other than us is flushing and we are
-	 * actually alloed to flush.
-	 */
-	while (flush && !flushing && space_info->flush) {
-		spin_unlock(&space_info->lock);
-		/*
-		 * If we have a trans handle we can't wait because the flusher
-		 * may have to commit the transaction, which would mean we would
-		 * deadlock since we are waiting for the flusher to finish, but
-		 * hold the current transaction open.
-		 */
-		if (current->journal_info)
-			return -EAGAIN;
-		ret = wait_event_killable(space_info->wait, !space_info->flush);
-		/* Must have been killed, return */
-		if (ret)
-			return -EINTR;
-
-		spin_lock(&space_info->lock);
-	}
-
-	ret = -ENOSPC;
-	used = space_info->bytes_used + space_info->bytes_reserved +
-		space_info->bytes_pinned + space_info->bytes_readonly +
-		space_info->bytes_may_use;
-
-	/*
-	 * The idea here is that we've not already over-reserved the block group
-	 * then we can go ahead and save our reservation first and then start
-	 * flushing if we need to.  Otherwise if we've already overcommitted
-	 * lets start flushing stuff first and then come back and try to make
-	 * our reservation.
-	 */
-	if (used <= space_info->total_bytes) {
-		if (used + orig_bytes <= space_info->total_bytes) {
-			space_info->bytes_may_use += orig_bytes;
-			trace_btrfs_space_reservation(root->fs_info,
-				"space_info", space_info->flags, orig_bytes, 1);
-			ret = 0;
-		} else {
-			/*
-			 * Ok set num_bytes to orig_bytes since we aren't
-			 * overocmmitted, this way we only try and reclaim what
-			 * we need.
-			 */
-			num_bytes = orig_bytes;
-		}
-	} else {
-		/*
-		 * Ok we're over committed, set num_bytes to the overcommitted
-		 * amount plus the amount of bytes that we need for this
-		 * reservation.
-		 */
-		wait_ordered = true;
-		num_bytes = used - space_info->total_bytes +
-			(orig_bytes * (retries + 1));
-	}
-
-	if (ret) {
-		u64 profile = btrfs_get_alloc_profile(root, 0);
-		u64 avail;
-
-		/*
-		 * If we have a lot of space that's pinned, don't bother doing
-		 * the overcommit dance yet and just commit the transaction.
-		 */
-		avail = (space_info->total_bytes - space_info->bytes_used) * 8;
-		do_div(avail, 10);
-		if (space_info->bytes_pinned >= avail && flush && !committed) {
-			space_info->flush = 1;
-			flushing = true;
-			spin_unlock(&space_info->lock);
-			ret = may_commit_transaction(root, space_info,
-						     orig_bytes, 1);
-			if (ret)
-				goto out;
-			committed = true;
-			goto again;
-		}
-
-		spin_lock(&root->fs_info->free_chunk_lock);
-		avail = root->fs_info->free_chunk_space;
-
-		/*
-		 * If we have dup, raid1 or raid10 then only half of the free
-		 * space is actually useable.
-		 */
-		if (profile & (BTRFS_BLOCK_GROUP_DUP |
-			       BTRFS_BLOCK_GROUP_RAID1 |
-			       BTRFS_BLOCK_GROUP_RAID10))
-			avail >>= 1;
-
-		/*
-		 * If we aren't flushing don't let us overcommit too much, say
-		 * 1/8th of the space.  If we can flush, let it overcommit up to
-		 * 1/2 of the space.
-		 */
-		if (flush)
-			avail >>= 3;
-		else
-			avail >>= 1;
-		 spin_unlock(&root->fs_info->free_chunk_lock);
-
-		if (used + num_bytes < space_info->total_bytes + avail) {
-			space_info->bytes_may_use += orig_bytes;
-			trace_btrfs_space_reservation(root->fs_info,
-				"space_info", space_info->flags, orig_bytes, 1);
-			ret = 0;
-		} else {
-			wait_ordered = true;
-		}
-	}
-
-	/*
-	 * Couldn't make our reservation, save our place so while we're trying
-	 * to reclaim space we can actually use it instead of somebody else
-	 * stealing it from us.
-	 */
-	if (ret && flush) {
-		flushing = true;
-		space_info->flush = 1;
-	}
-
-	spin_unlock(&space_info->lock);
-
-	if (!ret || !flush)
-		goto out;
-
-	/*
-	 * We do synchronous shrinking since we don't actually unreserve
-	 * metadata until after the IO is completed.
-	 */
-	ret = shrink_delalloc(root, num_bytes, wait_ordered);
-	if (ret < 0)
-		goto out;
-
-	ret = 0;
-
-	/*
-	 * So if we were overcommitted it's possible that somebody else flushed
-	 * out enough space and we simply didn't have enough space to reclaim,
-	 * so go back around and try again.
-	 */
-	if (retries < 2) {
-		wait_ordered = true;
-		retries++;
-		goto again;
-	}
-
-	ret = -ENOSPC;
-	if (committed)
-		goto out;
-
-	ret = may_commit_transaction(root, space_info, orig_bytes, 0);
-	if (!ret) {
-		committed = true;
-		goto again;
-	}
-
-out:
-	if (flushing) {
-		spin_lock(&space_info->lock);
-		space_info->flush = 0;
-		wake_up_all(&space_info->wait);
-		spin_unlock(&space_info->lock);
-	}
-	return ret;
-}
-
-static struct btrfs_block_rsv *get_block_rsv(
-					const struct btrfs_trans_handle *trans,
-					const struct btrfs_root *root)
-{
-	struct btrfs_block_rsv *block_rsv = NULL;
-
-	if (root->ref_cows || root == root->fs_info->csum_root)
-		block_rsv = trans->block_rsv;
-
-	if (!block_rsv)
-		block_rsv = root->block_rsv;
-
-	if (!block_rsv)
-		block_rsv = &root->fs_info->empty_block_rsv;
-
-	return block_rsv;
-}
-
-static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
-			       u64 num_bytes)
-{
-	int ret = -ENOSPC;
-	spin_lock(&block_rsv->lock);
-	if (block_rsv->reserved >= num_bytes) {
-		block_rsv->reserved -= num_bytes;
-		if (block_rsv->reserved < block_rsv->size)
-			block_rsv->full = 0;
-		ret = 0;
-	}
-	spin_unlock(&block_rsv->lock);
-	return ret;
-}
-
-static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
-				u64 num_bytes, int update_size)
-{
-	spin_lock(&block_rsv->lock);
-	block_rsv->reserved += num_bytes;
-	if (update_size)
-		block_rsv->size += num_bytes;
-	else if (block_rsv->reserved >= block_rsv->size)
-		block_rsv->full = 1;
-	spin_unlock(&block_rsv->lock);
-}
-
-static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
-				    struct btrfs_block_rsv *block_rsv,
-				    struct btrfs_block_rsv *dest, u64 num_bytes)
-{
-	struct btrfs_space_info *space_info = block_rsv->space_info;
-
-	spin_lock(&block_rsv->lock);
-	if (num_bytes == (u64)-1)
-		num_bytes = block_rsv->size;
-	block_rsv->size -= num_bytes;
-	if (block_rsv->reserved >= block_rsv->size) {
-		num_bytes = block_rsv->reserved - block_rsv->size;
-		block_rsv->reserved = block_rsv->size;
-		block_rsv->full = 1;
-	} else {
-		num_bytes = 0;
-	}
-	spin_unlock(&block_rsv->lock);
-
-	if (num_bytes > 0) {
-		if (dest) {
-			spin_lock(&dest->lock);
-			if (!dest->full) {
-				u64 bytes_to_add;
-
-				bytes_to_add = dest->size - dest->reserved;
-				bytes_to_add = min(num_bytes, bytes_to_add);
-				dest->reserved += bytes_to_add;
-				if (dest->reserved >= dest->size)
-					dest->full = 1;
-				num_bytes -= bytes_to_add;
-			}
-			spin_unlock(&dest->lock);
-		}
-		if (num_bytes) {
-			spin_lock(&space_info->lock);
-			space_info->bytes_may_use -= num_bytes;
-			trace_btrfs_space_reservation(fs_info, "space_info",
-					space_info->flags, num_bytes, 0);
-			space_info->reservation_progress++;
-			spin_unlock(&space_info->lock);
-		}
-	}
-}
-
-static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
-				   struct btrfs_block_rsv *dst, u64 num_bytes)
-{
-	int ret;
-
-	ret = block_rsv_use_bytes(src, num_bytes);
-	if (ret)
-		return ret;
-
-	block_rsv_add_bytes(dst, num_bytes, 1);
-	return 0;
-}
-
-void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv)
-{
-	memset(rsv, 0, sizeof(*rsv));
-	spin_lock_init(&rsv->lock);
-}
-
-struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
-{
-	struct btrfs_block_rsv *block_rsv;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-
-	block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
-	if (!block_rsv)
-		return NULL;
-
-	btrfs_init_block_rsv(block_rsv);
-	block_rsv->space_info = __find_space_info(fs_info,
-						  BTRFS_BLOCK_GROUP_METADATA);
-	return block_rsv;
-}
-
-void btrfs_free_block_rsv(struct btrfs_root *root,
-			  struct btrfs_block_rsv *rsv)
-{
-	btrfs_block_rsv_release(root, rsv, (u64)-1);
-	kfree(rsv);
-}
-
-static inline int __block_rsv_add(struct btrfs_root *root,
-				  struct btrfs_block_rsv *block_rsv,
-				  u64 num_bytes, int flush)
-{
-	int ret;
-
-	if (num_bytes == 0)
-		return 0;
-
-	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
-	if (!ret) {
-		block_rsv_add_bytes(block_rsv, num_bytes, 1);
-		return 0;
-	}
-
-	return ret;
-}
-
-int btrfs_block_rsv_add(struct btrfs_root *root,
-			struct btrfs_block_rsv *block_rsv,
-			u64 num_bytes)
-{
-	return __block_rsv_add(root, block_rsv, num_bytes, 1);
-}
-
-int btrfs_block_rsv_add_noflush(struct btrfs_root *root,
-				struct btrfs_block_rsv *block_rsv,
-				u64 num_bytes)
-{
-	return __block_rsv_add(root, block_rsv, num_bytes, 0);
-}
-
-int btrfs_block_rsv_check(struct btrfs_root *root,
-			  struct btrfs_block_rsv *block_rsv, int min_factor)
-{
-	u64 num_bytes = 0;
-	int ret = -ENOSPC;
-
-	if (!block_rsv)
-		return 0;
-
-	spin_lock(&block_rsv->lock);
-	num_bytes = div_factor(block_rsv->size, min_factor);
-	if (block_rsv->reserved >= num_bytes)
-		ret = 0;
-	spin_unlock(&block_rsv->lock);
-
-	return ret;
-}
-
-static inline int __btrfs_block_rsv_refill(struct btrfs_root *root,
-					   struct btrfs_block_rsv *block_rsv,
-					   u64 min_reserved, int flush)
-{
-	u64 num_bytes = 0;
-	int ret = -ENOSPC;
-
-	if (!block_rsv)
-		return 0;
-
-	spin_lock(&block_rsv->lock);
-	num_bytes = min_reserved;
-	if (block_rsv->reserved >= num_bytes)
-		ret = 0;
-	else
-		num_bytes -= block_rsv->reserved;
-	spin_unlock(&block_rsv->lock);
-
-	if (!ret)
-		return 0;
-
-	ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
-	if (!ret) {
-		block_rsv_add_bytes(block_rsv, num_bytes, 0);
-		return 0;
-	}
-
-	return ret;
-}
-
-int btrfs_block_rsv_refill(struct btrfs_root *root,
-			   struct btrfs_block_rsv *block_rsv,
-			   u64 min_reserved)
-{
-	return __btrfs_block_rsv_refill(root, block_rsv, min_reserved, 1);
-}
-
-int btrfs_block_rsv_refill_noflush(struct btrfs_root *root,
-				   struct btrfs_block_rsv *block_rsv,
-				   u64 min_reserved)
-{
-	return __btrfs_block_rsv_refill(root, block_rsv, min_reserved, 0);
-}
-
-int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
-			    struct btrfs_block_rsv *dst_rsv,
-			    u64 num_bytes)
-{
-	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
-}
-
-void btrfs_block_rsv_release(struct btrfs_root *root,
-			     struct btrfs_block_rsv *block_rsv,
-			     u64 num_bytes)
-{
-	struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
-	if (global_rsv->full || global_rsv == block_rsv ||
-	    block_rsv->space_info != global_rsv->space_info)
-		global_rsv = NULL;
-	block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv,
-				num_bytes);
-}
-
-/*
- * helper to calculate size of global block reservation.
- * the desired value is sum of space used by extent tree,
- * checksum tree and root tree
- */
-static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_space_info *sinfo;
-	u64 num_bytes;
-	u64 meta_used;
-	u64 data_used;
-	int csum_size = btrfs_super_csum_size(fs_info->super_copy);
-
-	sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
-	spin_lock(&sinfo->lock);
-	data_used = sinfo->bytes_used;
-	spin_unlock(&sinfo->lock);
-
-	sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
-	spin_lock(&sinfo->lock);
-	if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
-		data_used = 0;
-	meta_used = sinfo->bytes_used;
-	spin_unlock(&sinfo->lock);
-
-	num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
-		    csum_size * 2;
-	num_bytes += div64_u64(data_used + meta_used, 50);
-
-	if (num_bytes * 3 > meta_used)
-		num_bytes = div64_u64(meta_used, 3);
-
-	return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
-}
-
-static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
-	struct btrfs_space_info *sinfo = block_rsv->space_info;
-	u64 num_bytes;
-
-	num_bytes = calc_global_metadata_size(fs_info);
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&block_rsv->lock);
-
-	block_rsv->size = num_bytes;
-
-	num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
-		    sinfo->bytes_reserved + sinfo->bytes_readonly +
-		    sinfo->bytes_may_use;
-
-	if (sinfo->total_bytes > num_bytes) {
-		num_bytes = sinfo->total_bytes - num_bytes;
-		block_rsv->reserved += num_bytes;
-		sinfo->bytes_may_use += num_bytes;
-		trace_btrfs_space_reservation(fs_info, "space_info",
-				      sinfo->flags, num_bytes, 1);
-	}
-
-	if (block_rsv->reserved >= block_rsv->size) {
-		num_bytes = block_rsv->reserved - block_rsv->size;
-		sinfo->bytes_may_use -= num_bytes;
-		trace_btrfs_space_reservation(fs_info, "space_info",
-				      sinfo->flags, num_bytes, 0);
-		sinfo->reservation_progress++;
-		block_rsv->reserved = block_rsv->size;
-		block_rsv->full = 1;
-	}
-
-	spin_unlock(&block_rsv->lock);
-	spin_unlock(&sinfo->lock);
-}
-
-static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_space_info *space_info;
-
-	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
-	fs_info->chunk_block_rsv.space_info = space_info;
-
-	space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
-	fs_info->global_block_rsv.space_info = space_info;
-	fs_info->delalloc_block_rsv.space_info = space_info;
-	fs_info->trans_block_rsv.space_info = space_info;
-	fs_info->empty_block_rsv.space_info = space_info;
-	fs_info->delayed_block_rsv.space_info = space_info;
-
-	fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
-	fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
-	fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
-	fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
-	fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
-
-	update_global_block_rsv(fs_info);
-}
-
-static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
-{
-	block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
-				(u64)-1);
-	WARN_ON(fs_info->delalloc_block_rsv.size > 0);
-	WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
-	WARN_ON(fs_info->trans_block_rsv.size > 0);
-	WARN_ON(fs_info->trans_block_rsv.reserved > 0);
-	WARN_ON(fs_info->chunk_block_rsv.size > 0);
-	WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
-	WARN_ON(fs_info->delayed_block_rsv.size > 0);
-	WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
-}
-
-void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
-				  struct btrfs_root *root)
-{
-	if (!trans->bytes_reserved)
-		return;
-
-	trace_btrfs_space_reservation(root->fs_info, "transaction",
-				      trans->transid, trans->bytes_reserved, 0);
-	btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
-	trans->bytes_reserved = 0;
-}
-
-/* Can only return 0 or -ENOSPC */
-int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
-				  struct inode *inode)
-{
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-	struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
-	struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
-
-	/*
-	 * We need to hold space in order to delete our orphan item once we've
-	 * added it, so this takes the reservation so we can release it later
-	 * when we are truly done with the orphan item.
-	 */
-	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
-	trace_btrfs_space_reservation(root->fs_info, "orphan",
-				      btrfs_ino(inode), num_bytes, 1);
-	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
-}
-
-void btrfs_orphan_release_metadata(struct inode *inode)
-{
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
-	trace_btrfs_space_reservation(root->fs_info, "orphan",
-				      btrfs_ino(inode), num_bytes, 0);
-	btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
-}
-
-int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
-				struct btrfs_pending_snapshot *pending)
-{
-	struct btrfs_root *root = pending->root;
-	struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
-	struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;
-	/*
-	 * two for root back/forward refs, two for directory entries
-	 * and one for root of the snapshot.
-	 */
-	u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
-	dst_rsv->space_info = src_rsv->space_info;
-	return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
-}
-
-/**
- * drop_outstanding_extent - drop an outstanding extent
- * @inode: the inode we're dropping the extent for
- *
- * This is called when we are freeing up an outstanding extent, either called
- * after an error or after an extent is written.  This will return the number of
- * reserved extents that need to be freed.  This must be called with
- * BTRFS_I(inode)->lock held.
- */
-static unsigned drop_outstanding_extent(struct inode *inode)
-{
-	unsigned drop_inode_space = 0;
-	unsigned dropped_extents = 0;
-
-	BUG_ON(!BTRFS_I(inode)->outstanding_extents);
-	BTRFS_I(inode)->outstanding_extents--;
-
-	if (BTRFS_I(inode)->outstanding_extents == 0 &&
-	    BTRFS_I(inode)->delalloc_meta_reserved) {
-		drop_inode_space = 1;
-		BTRFS_I(inode)->delalloc_meta_reserved = 0;
-	}
-
-	/*
-	 * If we have more or the same amount of outsanding extents than we have
-	 * reserved then we need to leave the reserved extents count alone.
-	 */
-	if (BTRFS_I(inode)->outstanding_extents >=
-	    BTRFS_I(inode)->reserved_extents)
-		return drop_inode_space;
-
-	dropped_extents = BTRFS_I(inode)->reserved_extents -
-		BTRFS_I(inode)->outstanding_extents;
-	BTRFS_I(inode)->reserved_extents -= dropped_extents;
-	return dropped_extents + drop_inode_space;
-}
-
-/**
- * calc_csum_metadata_size - return the amount of metada space that must be
- *	reserved/free'd for the given bytes.
- * @inode: the inode we're manipulating
- * @num_bytes: the number of bytes in question
- * @reserve: 1 if we are reserving space, 0 if we are freeing space
- *
- * This adjusts the number of csum_bytes in the inode and then returns the
- * correct amount of metadata that must either be reserved or freed.  We
- * calculate how many checksums we can fit into one leaf and then divide the
- * number of bytes that will need to be checksumed by this value to figure out
- * how many checksums will be required.  If we are adding bytes then the number
- * may go up and we will return the number of additional bytes that must be
- * reserved.  If it is going down we will return the number of bytes that must
- * be freed.
- *
- * This must be called with BTRFS_I(inode)->lock held.
- */
-static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
-				   int reserve)
-{
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 csum_size;
-	int num_csums_per_leaf;
-	int num_csums;
-	int old_csums;
-
-	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
-	    BTRFS_I(inode)->csum_bytes == 0)
-		return 0;
-
-	old_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
-	if (reserve)
-		BTRFS_I(inode)->csum_bytes += num_bytes;
-	else
-		BTRFS_I(inode)->csum_bytes -= num_bytes;
-	csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
-	num_csums_per_leaf = (int)div64_u64(csum_size,
-					    sizeof(struct btrfs_csum_item) +
-					    sizeof(struct btrfs_disk_key));
-	num_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
-	num_csums = num_csums + num_csums_per_leaf - 1;
-	num_csums = num_csums / num_csums_per_leaf;
-
-	old_csums = old_csums + num_csums_per_leaf - 1;
-	old_csums = old_csums / num_csums_per_leaf;
-
-	/* No change, no need to reserve more */
-	if (old_csums == num_csums)
-		return 0;
-
-	if (reserve)
-		return btrfs_calc_trans_metadata_size(root,
-						      num_csums - old_csums);
-
-	return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
-}
-
-int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
-{
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-	struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
-	u64 to_reserve = 0;
-	u64 csum_bytes;
-	unsigned nr_extents = 0;
-	int extra_reserve = 0;
-	int flush = 1;
-	int ret;
-
-	/* Need to be holding the i_mutex here if we aren't free space cache */
-	if (btrfs_is_free_space_inode(root, inode))
-		flush = 0;
-
-	if (flush && btrfs_transaction_in_commit(root->fs_info))
-		schedule_timeout(1);
-
-	mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
-	num_bytes = ALIGN(num_bytes, root->sectorsize);
-
-	spin_lock(&BTRFS_I(inode)->lock);
-	BTRFS_I(inode)->outstanding_extents++;
-
-	if (BTRFS_I(inode)->outstanding_extents >
-	    BTRFS_I(inode)->reserved_extents)
-		nr_extents = BTRFS_I(inode)->outstanding_extents -
-			BTRFS_I(inode)->reserved_extents;
-
-	/*
-	 * Add an item to reserve for updating the inode when we complete the
-	 * delalloc io.
-	 */
-	if (!BTRFS_I(inode)->delalloc_meta_reserved) {
-		nr_extents++;
-		extra_reserve = 1;
-	}
-
-	to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
-	to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
-	csum_bytes = BTRFS_I(inode)->csum_bytes;
-	spin_unlock(&BTRFS_I(inode)->lock);
-
-	ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
-	if (ret) {
-		u64 to_free = 0;
-		unsigned dropped;
-
-		spin_lock(&BTRFS_I(inode)->lock);
-		dropped = drop_outstanding_extent(inode);
-		/*
-		 * If the inodes csum_bytes is the same as the original
-		 * csum_bytes then we know we haven't raced with any free()ers
-		 * so we can just reduce our inodes csum bytes and carry on.
-		 * Otherwise we have to do the normal free thing to account for
-		 * the case that the free side didn't free up its reserve
-		 * because of this outstanding reservation.
-		 */
-		if (BTRFS_I(inode)->csum_bytes == csum_bytes)
-			calc_csum_metadata_size(inode, num_bytes, 0);
-		else
-			to_free = calc_csum_metadata_size(inode, num_bytes, 0);
-		spin_unlock(&BTRFS_I(inode)->lock);
-		if (dropped)
-			to_free += btrfs_calc_trans_metadata_size(root, dropped);
-
-		if (to_free) {
-			btrfs_block_rsv_release(root, block_rsv, to_free);
-			trace_btrfs_space_reservation(root->fs_info,
-						      "delalloc",
-						      btrfs_ino(inode),
-						      to_free, 0);
-		}
-		mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
-		return ret;
-	}
-
-	spin_lock(&BTRFS_I(inode)->lock);
-	if (extra_reserve) {
-		BTRFS_I(inode)->delalloc_meta_reserved = 1;
-		nr_extents--;
-	}
-	BTRFS_I(inode)->reserved_extents += nr_extents;
-	spin_unlock(&BTRFS_I(inode)->lock);
-	mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
-
-	if (to_reserve)
-		trace_btrfs_space_reservation(root->fs_info,"delalloc",
-					      btrfs_ino(inode), to_reserve, 1);
-	block_rsv_add_bytes(block_rsv, to_reserve, 1);
-
-	return 0;
-}
-
-/**
- * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
- * @inode: the inode to release the reservation for
- * @num_bytes: the number of bytes we're releasing
- *
- * This will release the metadata reservation for an inode.  This can be called
- * once we complete IO for a given set of bytes to release their metadata
- * reservations.
- */
-void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
-{
-	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 to_free = 0;
-	unsigned dropped;
-
-	num_bytes = ALIGN(num_bytes, root->sectorsize);
-	spin_lock(&BTRFS_I(inode)->lock);
-	dropped = drop_outstanding_extent(inode);
-
-	to_free = calc_csum_metadata_size(inode, num_bytes, 0);
-	spin_unlock(&BTRFS_I(inode)->lock);
-	if (dropped > 0)
-		to_free += btrfs_calc_trans_metadata_size(root, dropped);
-
-	trace_btrfs_space_reservation(root->fs_info, "delalloc",
-				      btrfs_ino(inode), to_free, 0);
-	btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
-				to_free);
-}
-
-/**
- * btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc
- * @inode: inode we're writing to
- * @num_bytes: the number of bytes we want to allocate
- *
- * This will do the following things
- *
- * o reserve space in the data space info for num_bytes
- * o reserve space in the metadata space info based on number of outstanding
- *   extents and how much csums will be needed
- * o add to the inodes ->delalloc_bytes
- * o add it to the fs_info's delalloc inodes list.
- *
- * This will return 0 for success and -ENOSPC if there is no space left.
- */
-int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
-{
-	int ret;
-
-	ret = btrfs_check_data_free_space(inode, num_bytes);
-	if (ret)
-		return ret;
-
-	ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
-	if (ret) {
-		btrfs_free_reserved_data_space(inode, num_bytes);
-		return ret;
-	}
-
-	return 0;
-}
-
-/**
- * btrfs_delalloc_release_space - release data and metadata space for delalloc
- * @inode: inode we're releasing space for
- * @num_bytes: the number of bytes we want to free up
- *
- * This must be matched with a call to btrfs_delalloc_reserve_space.  This is
- * called in the case that we don't need the metadata AND data reservations
- * anymore.  So if there is an error or we insert an inline extent.
- *
- * This function will release the metadata space that was not used and will
- * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
- * list if there are no delalloc bytes left.
- */
-void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
-{
-	btrfs_delalloc_release_metadata(inode, num_bytes);
-	btrfs_free_reserved_data_space(inode, num_bytes);
-}
-
-static int update_block_group(struct btrfs_trans_handle *trans,
-			      struct btrfs_root *root,
-			      u64 bytenr, u64 num_bytes, int alloc)
-{
-	struct btrfs_block_group_cache *cache = NULL;
-	struct btrfs_fs_info *info = root->fs_info;
-	u64 total = num_bytes;
-	u64 old_val;
-	u64 byte_in_group;
-	int factor;
-
-	/* block accounting for super block */
-	spin_lock(&info->delalloc_lock);
-	old_val = btrfs_super_bytes_used(info->super_copy);
-	if (alloc)
-		old_val += num_bytes;
-	else
-		old_val -= num_bytes;
-	btrfs_set_super_bytes_used(info->super_copy, old_val);
-	spin_unlock(&info->delalloc_lock);
-
-	while (total) {
-		cache = btrfs_lookup_block_group(info, bytenr);
-		if (!cache)
-			return -ENOENT;
-		if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
-				    BTRFS_BLOCK_GROUP_RAID1 |
-				    BTRFS_BLOCK_GROUP_RAID10))
-			factor = 2;
-		else
-			factor = 1;
-		/*
-		 * If this block group has free space cache written out, we
-		 * need to make sure to load it if we are removing space.  This
-		 * is because we need the unpinning stage to actually add the
-		 * space back to the block group, otherwise we will leak space.
-		 */
-		if (!alloc && cache->cached == BTRFS_CACHE_NO)
-			cache_block_group(cache, trans, NULL, 1);
-
-		byte_in_group = bytenr - cache->key.objectid;
-		WARN_ON(byte_in_group > cache->key.offset);
-
-		spin_lock(&cache->space_info->lock);
-		spin_lock(&cache->lock);
-
-		if (btrfs_test_opt(root, SPACE_CACHE) &&
-		    cache->disk_cache_state < BTRFS_DC_CLEAR)
-			cache->disk_cache_state = BTRFS_DC_CLEAR;
-
-		cache->dirty = 1;
-		old_val = btrfs_block_group_used(&cache->item);
-		num_bytes = min(total, cache->key.offset - byte_in_group);
-		if (alloc) {
-			old_val += num_bytes;
-			btrfs_set_block_group_used(&cache->item, old_val);
-			cache->reserved -= num_bytes;
-			cache->space_info->bytes_reserved -= num_bytes;
-			cache->space_info->bytes_used += num_bytes;
-			cache->space_info->disk_used += num_bytes * factor;
-			spin_unlock(&cache->lock);
-			spin_unlock(&cache->space_info->lock);
-		} else {
-			old_val -= num_bytes;
-			btrfs_set_block_group_used(&cache->item, old_val);
-			cache->pinned += num_bytes;
-			cache->space_info->bytes_pinned += num_bytes;
-			cache->space_info->bytes_used -= num_bytes;
-			cache->space_info->disk_used -= num_bytes * factor;
-			spin_unlock(&cache->lock);
-			spin_unlock(&cache->space_info->lock);
-
-			set_extent_dirty(info->pinned_extents,
-					 bytenr, bytenr + num_bytes - 1,
-					 GFP_NOFS | __GFP_NOFAIL);
-		}
-		btrfs_put_block_group(cache);
-		total -= num_bytes;
-		bytenr += num_bytes;
-	}
-	return 0;
-}
-
-static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
-{
-	struct btrfs_block_group_cache *cache;
-	u64 bytenr;
-
-	cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
-	if (!cache)
-		return 0;
-
-	bytenr = cache->key.objectid;
-	btrfs_put_block_group(cache);
-
-	return bytenr;
-}
-
-static int pin_down_extent(struct btrfs_root *root,
-			   struct btrfs_block_group_cache *cache,
-			   u64 bytenr, u64 num_bytes, int reserved)
-{
-	spin_lock(&cache->space_info->lock);
-	spin_lock(&cache->lock);
-	cache->pinned += num_bytes;
-	cache->space_info->bytes_pinned += num_bytes;
-	if (reserved) {
-		cache->reserved -= num_bytes;
-		cache->space_info->bytes_reserved -= num_bytes;
-	}
-	spin_unlock(&cache->lock);
-	spin_unlock(&cache->space_info->lock);
-
-	set_extent_dirty(root->fs_info->pinned_extents, bytenr,
-			 bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
-	return 0;
-}
-
-/*
- * this function must be called within transaction
- */
-int btrfs_pin_extent(struct btrfs_root *root,
-		     u64 bytenr, u64 num_bytes, int reserved)
-{
-	struct btrfs_block_group_cache *cache;
-
-	cache = btrfs_lookup_block_group(root->fs_info, bytenr);
-	BUG_ON(!cache); /* Logic error */
-
-	pin_down_extent(root, cache, bytenr, num_bytes, reserved);
-
-	btrfs_put_block_group(cache);
-	return 0;
-}
-
-/*
- * this function must be called within transaction
- */
-int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
-				    struct btrfs_root *root,
-				    u64 bytenr, u64 num_bytes)
-{
-	struct btrfs_block_group_cache *cache;
-
-	cache = btrfs_lookup_block_group(root->fs_info, bytenr);
-	BUG_ON(!cache); /* Logic error */
-
-	/*
-	 * pull in the free space cache (if any) so that our pin
-	 * removes the free space from the cache.  We have load_only set
-	 * to one because the slow code to read in the free extents does check
-	 * the pinned extents.
-	 */
-	cache_block_group(cache, trans, root, 1);
-
-	pin_down_extent(root, cache, bytenr, num_bytes, 0);
-
-	/* remove us from the free space cache (if we're there at all) */
-	btrfs_remove_free_space(cache, bytenr, num_bytes);
-	btrfs_put_block_group(cache);
-	return 0;
-}
-
-/**
- * btrfs_update_reserved_bytes - update the block_group and space info counters
- * @cache:	The cache we are manipulating
- * @num_bytes:	The number of bytes in question
- * @reserve:	One of the reservation enums
- *
- * This is called by the allocator when it reserves space, or by somebody who is
- * freeing space that was never actually used on disk.  For example if you
- * reserve some space for a new leaf in transaction A and before transaction A
- * commits you free that leaf, you call this with reserve set to 0 in order to
- * clear the reservation.
- *
- * Metadata reservations should be called with RESERVE_ALLOC so we do the proper
- * ENOSPC accounting.  For data we handle the reservation through clearing the
- * delalloc bits in the io_tree.  We have to do this since we could end up
- * allocating less disk space for the amount of data we have reserved in the
- * case of compression.
- *
- * If this is a reservation and the block group has become read only we cannot
- * make the reservation and return -EAGAIN, otherwise this function always
- * succeeds.
- */
-static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
-				       u64 num_bytes, int reserve)
-{
-	struct btrfs_space_info *space_info = cache->space_info;
-	int ret = 0;
-
-	spin_lock(&space_info->lock);
-	spin_lock(&cache->lock);
-	if (reserve != RESERVE_FREE) {
-		if (cache->ro) {
-			ret = -EAGAIN;
-		} else {
-			cache->reserved += num_bytes;
-			space_info->bytes_reserved += num_bytes;
-			if (reserve == RESERVE_ALLOC) {
-				trace_btrfs_space_reservation(cache->fs_info,
-						"space_info", space_info->flags,
-						num_bytes, 0);
-				space_info->bytes_may_use -= num_bytes;
-			}
-		}
-	} else {
-		if (cache->ro)
-			space_info->bytes_readonly += num_bytes;
-		cache->reserved -= num_bytes;
-		space_info->bytes_reserved -= num_bytes;
-		space_info->reservation_progress++;
-	}
-	spin_unlock(&cache->lock);
-	spin_unlock(&space_info->lock);
-	return ret;
-}
-
-void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_caching_control *next;
-	struct btrfs_caching_control *caching_ctl;
-	struct btrfs_block_group_cache *cache;
-
-	down_write(&fs_info->extent_commit_sem);
-
-	list_for_each_entry_safe(caching_ctl, next,
-				 &fs_info->caching_block_groups, list) {
-		cache = caching_ctl->block_group;
-		if (block_group_cache_done(cache)) {
-			cache->last_byte_to_unpin = (u64)-1;
-			list_del_init(&caching_ctl->list);
-			put_caching_control(caching_ctl);
-		} else {
-			cache->last_byte_to_unpin = caching_ctl->progress;
-		}
-	}
-
-	if (fs_info->pinned_extents == &fs_info->freed_extents[0])
-		fs_info->pinned_extents = &fs_info->freed_extents[1];
-	else
-		fs_info->pinned_extents = &fs_info->freed_extents[0];
-
-	up_write(&fs_info->extent_commit_sem);
-
-	update_global_block_rsv(fs_info);
-}
-
-static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_block_group_cache *cache = NULL;
-	u64 len;
-
-	while (start <= end) {
-		if (!cache ||
-		    start >= cache->key.objectid + cache->key.offset) {
-			if (cache)
-				btrfs_put_block_group(cache);
-			cache = btrfs_lookup_block_group(fs_info, start);
-			BUG_ON(!cache); /* Logic error */
-		}
-
-		len = cache->key.objectid + cache->key.offset - start;
-		len = min(len, end + 1 - start);
-
-		if (start < cache->last_byte_to_unpin) {
-			len = min(len, cache->last_byte_to_unpin - start);
-			btrfs_add_free_space(cache, start, len);
-		}
-
-		start += len;
-
-		spin_lock(&cache->space_info->lock);
-		spin_lock(&cache->lock);
-		cache->pinned -= len;
-		cache->space_info->bytes_pinned -= len;
-		if (cache->ro)
-			cache->space_info->bytes_readonly += len;
-		spin_unlock(&cache->lock);
-		spin_unlock(&cache->space_info->lock);
-	}
-
-	if (cache)
-		btrfs_put_block_group(cache);
-	return 0;
-}
-
-int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
-			       struct btrfs_root *root)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct extent_io_tree *unpin;
-	u64 start;
-	u64 end;
-	int ret;
-
-	if (trans->aborted)
-		return 0;
-
-	if (fs_info->pinned_extents == &fs_info->freed_extents[0])
-		unpin = &fs_info->freed_extents[1];
-	else
-		unpin = &fs_info->freed_extents[0];
-
-	while (1) {
-		ret = find_first_extent_bit(unpin, 0, &start, &end,
-					    EXTENT_DIRTY);
-		if (ret)
-			break;
-
-		if (btrfs_test_opt(root, DISCARD))
-			ret = btrfs_discard_extent(root, start,
-						   end + 1 - start, NULL);
-
-		clear_extent_dirty(unpin, start, end, GFP_NOFS);
-		unpin_extent_range(root, start, end);
-		cond_resched();
-	}
-
-	return 0;
-}
-
-static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root,
-				u64 bytenr, u64 num_bytes, u64 parent,
-				u64 root_objectid, u64 owner_objectid,
-				u64 owner_offset, int refs_to_drop,
-				struct btrfs_delayed_extent_op *extent_op)
-{
-	struct btrfs_key key;
-	struct btrfs_path *path;
-	struct btrfs_fs_info *info = root->fs_info;
-	struct btrfs_root *extent_root = info->extent_root;
-	struct extent_buffer *leaf;
-	struct btrfs_extent_item *ei;
-	struct btrfs_extent_inline_ref *iref;
-	int ret;
-	int is_data;
-	int extent_slot = 0;
-	int found_extent = 0;
-	int num_to_del = 1;
-	u32 item_size;
-	u64 refs;
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	path->reada = 1;
-	path->leave_spinning = 1;
-
-	is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
-	BUG_ON(!is_data && refs_to_drop != 1);
-
-	ret = lookup_extent_backref(trans, extent_root, path, &iref,
-				    bytenr, num_bytes, parent,
-				    root_objectid, owner_objectid,
-				    owner_offset);
-	if (ret == 0) {
-		extent_slot = path->slots[0];
-		while (extent_slot >= 0) {
-			btrfs_item_key_to_cpu(path->nodes[0], &key,
-					      extent_slot);
-			if (key.objectid != bytenr)
-				break;
-			if (key.type == BTRFS_EXTENT_ITEM_KEY &&
-			    key.offset == num_bytes) {
-				found_extent = 1;
-				break;
-			}
-			if (path->slots[0] - extent_slot > 5)
-				break;
-			extent_slot--;
-		}
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-		item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
-		if (found_extent && item_size < sizeof(*ei))
-			found_extent = 0;
-#endif
-		if (!found_extent) {
-			BUG_ON(iref);
-			ret = remove_extent_backref(trans, extent_root, path,
-						    NULL, refs_to_drop,
-						    is_data);
-			if (ret)
-				goto abort;
-			btrfs_release_path(path);
-			path->leave_spinning = 1;
-
-			key.objectid = bytenr;
-			key.type = BTRFS_EXTENT_ITEM_KEY;
-			key.offset = num_bytes;
-
-			ret = btrfs_search_slot(trans, extent_root,
-						&key, path, -1, 1);
-			if (ret) {
-				printk(KERN_ERR "umm, got %d back from search"
-				       ", was looking for %llu\n", ret,
-				       (unsigned long long)bytenr);
-				if (ret > 0)
-					btrfs_print_leaf(extent_root,
-							 path->nodes[0]);
-			}
-			if (ret < 0)
-				goto abort;
-			extent_slot = path->slots[0];
-		}
-	} else if (ret == -ENOENT) {
-		btrfs_print_leaf(extent_root, path->nodes[0]);
-		WARN_ON(1);
-		printk(KERN_ERR "btrfs unable to find ref byte nr %llu "
-		       "parent %llu root %llu  owner %llu offset %llu\n",
-		       (unsigned long long)bytenr,
-		       (unsigned long long)parent,
-		       (unsigned long long)root_objectid,
-		       (unsigned long long)owner_objectid,
-		       (unsigned long long)owner_offset);
-	} else {
-		goto abort;
-	}
-
-	leaf = path->nodes[0];
-	item_size = btrfs_item_size_nr(leaf, extent_slot);
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-	if (item_size < sizeof(*ei)) {
-		BUG_ON(found_extent || extent_slot != path->slots[0]);
-		ret = convert_extent_item_v0(trans, extent_root, path,
-					     owner_objectid, 0);
-		if (ret < 0)
-			goto abort;
-
-		btrfs_release_path(path);
-		path->leave_spinning = 1;
-
-		key.objectid = bytenr;
-		key.type = BTRFS_EXTENT_ITEM_KEY;
-		key.offset = num_bytes;
-
-		ret = btrfs_search_slot(trans, extent_root, &key, path,
-					-1, 1);
-		if (ret) {
-			printk(KERN_ERR "umm, got %d back from search"
-			       ", was looking for %llu\n", ret,
-			       (unsigned long long)bytenr);
-			btrfs_print_leaf(extent_root, path->nodes[0]);
-		}
-		if (ret < 0)
-			goto abort;
-		extent_slot = path->slots[0];
-		leaf = path->nodes[0];
-		item_size = btrfs_item_size_nr(leaf, extent_slot);
-	}
-#endif
-	BUG_ON(item_size < sizeof(*ei));
-	ei = btrfs_item_ptr(leaf, extent_slot,
-			    struct btrfs_extent_item);
-	if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) {
-		struct btrfs_tree_block_info *bi;
-		BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
-		bi = (struct btrfs_tree_block_info *)(ei + 1);
-		WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
-	}
-
-	refs = btrfs_extent_refs(leaf, ei);
-	BUG_ON(refs < refs_to_drop);
-	refs -= refs_to_drop;
-
-	if (refs > 0) {
-		if (extent_op)
-			__run_delayed_extent_op(extent_op, leaf, ei);
-		/*
-		 * In the case of inline back ref, reference count will
-		 * be updated by remove_extent_backref
-		 */
-		if (iref) {
-			BUG_ON(!found_extent);
-		} else {
-			btrfs_set_extent_refs(leaf, ei, refs);
-			btrfs_mark_buffer_dirty(leaf);
-		}
-		if (found_extent) {
-			ret = remove_extent_backref(trans, extent_root, path,
-						    iref, refs_to_drop,
-						    is_data);
-			if (ret)
-				goto abort;
-		}
-	} else {
-		if (found_extent) {
-			BUG_ON(is_data && refs_to_drop !=
-			       extent_data_ref_count(root, path, iref));
-			if (iref) {
-				BUG_ON(path->slots[0] != extent_slot);
-			} else {
-				BUG_ON(path->slots[0] != extent_slot + 1);
-				path->slots[0] = extent_slot;
-				num_to_del = 2;
-			}
-		}
-
-		ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
-				      num_to_del);
-		if (ret)
-			goto abort;
-		btrfs_release_path(path);
-
-		if (is_data) {
-			ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
-			if (ret)
-				goto abort;
-		}
-
-		ret = update_block_group(trans, root, bytenr, num_bytes, 0);
-		if (ret)
-			goto abort;
-	}
-out:
-	btrfs_free_path(path);
-	return ret;
-
-abort:
-	btrfs_abort_transaction(trans, extent_root, ret);
-	goto out;
-}
-
-/*
- * when we free an block, it is possible (and likely) that we free the last
- * delayed ref for that extent as well.  This searches the delayed ref tree for
- * a given extent, and if there are no other delayed refs to be processed, it
- * removes it from the tree.
- */
-static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
-				      struct btrfs_root *root, u64 bytenr)
-{
-	struct btrfs_delayed_ref_head *head;
-	struct btrfs_delayed_ref_root *delayed_refs;
-	struct btrfs_delayed_ref_node *ref;
-	struct rb_node *node;
-	int ret = 0;
-
-	delayed_refs = &trans->transaction->delayed_refs;
-	spin_lock(&delayed_refs->lock);
-	head = btrfs_find_delayed_ref_head(trans, bytenr);
-	if (!head)
-		goto out;
-
-	node = rb_prev(&head->node.rb_node);
-	if (!node)
-		goto out;
-
-	ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
-
-	/* there are still entries for this ref, we can't drop it */
-	if (ref->bytenr == bytenr)
-		goto out;
-
-	if (head->extent_op) {
-		if (!head->must_insert_reserved)
-			goto out;
-		kfree(head->extent_op);
-		head->extent_op = NULL;
-	}
-
-	/*
-	 * waiting for the lock here would deadlock.  If someone else has it
-	 * locked they are already in the process of dropping it anyway
-	 */
-	if (!mutex_trylock(&head->mutex))
-		goto out;
-
-	/*
-	 * at this point we have a head with no other entries.  Go
-	 * ahead and process it.
-	 */
-	head->node.in_tree = 0;
-	rb_erase(&head->node.rb_node, &delayed_refs->root);
-
-	delayed_refs->num_entries--;
-	if (waitqueue_active(&delayed_refs->seq_wait))
-		wake_up(&delayed_refs->seq_wait);
-
-	/*
-	 * we don't take a ref on the node because we're removing it from the
-	 * tree, so we just steal the ref the tree was holding.
-	 */
-	delayed_refs->num_heads--;
-	if (list_empty(&head->cluster))
-		delayed_refs->num_heads_ready--;
-
-	list_del_init(&head->cluster);
-	spin_unlock(&delayed_refs->lock);
-
-	BUG_ON(head->extent_op);
-	if (head->must_insert_reserved)
-		ret = 1;
-
-	mutex_unlock(&head->mutex);
-	btrfs_put_delayed_ref(&head->node);
-	return ret;
-out:
-	spin_unlock(&delayed_refs->lock);
-	return 0;
-}
-
-void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
-			   struct extent_buffer *buf,
-			   u64 parent, int last_ref, int for_cow)
-{
-	struct btrfs_block_group_cache *cache = NULL;
-	int ret;
-
-	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
-		ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
-					buf->start, buf->len,
-					parent, root->root_key.objectid,
-					btrfs_header_level(buf),
-					BTRFS_DROP_DELAYED_REF, NULL, for_cow);
-		BUG_ON(ret); /* -ENOMEM */
-	}
-
-	if (!last_ref)
-		return;
-
-	cache = btrfs_lookup_block_group(root->fs_info, buf->start);
-
-	if (btrfs_header_generation(buf) == trans->transid) {
-		if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
-			ret = check_ref_cleanup(trans, root, buf->start);
-			if (!ret)
-				goto out;
-		}
-
-		if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
-			pin_down_extent(root, cache, buf->start, buf->len, 1);
-			goto out;
-		}
-
-		WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
-
-		btrfs_add_free_space(cache, buf->start, buf->len);
-		btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE);
-	}
-out:
-	/*
-	 * Deleting the buffer, clear the corrupt flag since it doesn't matter
-	 * anymore.
-	 */
-	clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
-	btrfs_put_block_group(cache);
-}
-
-/* Can return -ENOMEM */
-int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		      u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
-		      u64 owner, u64 offset, int for_cow)
-{
-	int ret;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-
-	/*
-	 * tree log blocks never actually go into the extent allocation
-	 * tree, just update pinning info and exit early.
-	 */
-	if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
-		WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
-		/* unlocks the pinned mutex */
-		btrfs_pin_extent(root, bytenr, num_bytes, 1);
-		ret = 0;
-	} else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
-		ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
-					num_bytes,
-					parent, root_objectid, (int)owner,
-					BTRFS_DROP_DELAYED_REF, NULL, for_cow);
-	} else {
-		ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
-						num_bytes,
-						parent, root_objectid, owner,
-						offset, BTRFS_DROP_DELAYED_REF,
-						NULL, for_cow);
-	}
-	return ret;
-}
-
-static u64 stripe_align(struct btrfs_root *root, u64 val)
-{
-	u64 mask = ((u64)root->stripesize - 1);
-	u64 ret = (val + mask) & ~mask;
-	return ret;
-}
-
-/*
- * when we wait for progress in the block group caching, its because
- * our allocation attempt failed at least once.  So, we must sleep
- * and let some progress happen before we try again.
- *
- * This function will sleep at least once waiting for new free space to
- * show up, and then it will check the block group free space numbers
- * for our min num_bytes.  Another option is to have it go ahead
- * and look in the rbtree for a free extent of a given size, but this
- * is a good start.
- */
-static noinline int
-wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
-				u64 num_bytes)
-{
-	struct btrfs_caching_control *caching_ctl;
-	DEFINE_WAIT(wait);
-
-	caching_ctl = get_caching_control(cache);
-	if (!caching_ctl)
-		return 0;
-
-	wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
-		   (cache->free_space_ctl->free_space >= num_bytes));
-
-	put_caching_control(caching_ctl);
-	return 0;
-}
-
-static noinline int
-wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_caching_control *caching_ctl;
-	DEFINE_WAIT(wait);
-
-	caching_ctl = get_caching_control(cache);
-	if (!caching_ctl)
-		return 0;
-
-	wait_event(caching_ctl->wait, block_group_cache_done(cache));
-
-	put_caching_control(caching_ctl);
-	return 0;
-}
-
-static int __get_block_group_index(u64 flags)
-{
-	int index;
-
-	if (flags & BTRFS_BLOCK_GROUP_RAID10)
-		index = 0;
-	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
-		index = 1;
-	else if (flags & BTRFS_BLOCK_GROUP_DUP)
-		index = 2;
-	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
-		index = 3;
-	else
-		index = 4;
-
-	return index;
-}
-
-static int get_block_group_index(struct btrfs_block_group_cache *cache)
-{
-	return __get_block_group_index(cache->flags);
-}
-
-enum btrfs_loop_type {
-	LOOP_CACHING_NOWAIT = 0,
-	LOOP_CACHING_WAIT = 1,
-	LOOP_ALLOC_CHUNK = 2,
-	LOOP_NO_EMPTY_SIZE = 3,
-};
-
-/*
- * walks the btree of allocated extents and find a hole of a given size.
- * The key ins is changed to record the hole:
- * ins->objectid == block start
- * ins->flags = BTRFS_EXTENT_ITEM_KEY
- * ins->offset == number of blocks
- * Any available blocks before search_start are skipped.
- */
-static noinline int find_free_extent(struct btrfs_trans_handle *trans,
-				     struct btrfs_root *orig_root,
-				     u64 num_bytes, u64 empty_size,
-				     u64 hint_byte, struct btrfs_key *ins,
-				     u64 data)
-{
-	int ret = 0;
-	struct btrfs_root *root = orig_root->fs_info->extent_root;
-	struct btrfs_free_cluster *last_ptr = NULL;
-	struct btrfs_block_group_cache *block_group = NULL;
-	struct btrfs_block_group_cache *used_block_group;
-	u64 search_start = 0;
-	int empty_cluster = 2 * 1024 * 1024;
-	int allowed_chunk_alloc = 0;
-	int done_chunk_alloc = 0;
-	struct btrfs_space_info *space_info;
-	int loop = 0;
-	int index = 0;
-	int alloc_type = (data & BTRFS_BLOCK_GROUP_DATA) ?
-		RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
-	bool found_uncached_bg = false;
-	bool failed_cluster_refill = false;
-	bool failed_alloc = false;
-	bool use_cluster = true;
-	bool have_caching_bg = false;
-
-	WARN_ON(num_bytes < root->sectorsize);
-	btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
-	ins->objectid = 0;
-	ins->offset = 0;
-
-	trace_find_free_extent(orig_root, num_bytes, empty_size, data);
-
-	space_info = __find_space_info(root->fs_info, data);
-	if (!space_info) {
-		printk(KERN_ERR "No space info for %llu\n", data);
-		return -ENOSPC;
-	}
-
-	/*
-	 * If the space info is for both data and metadata it means we have a
-	 * small filesystem and we can't use the clustering stuff.
-	 */
-	if (btrfs_mixed_space_info(space_info))
-		use_cluster = false;
-
-	if (orig_root->ref_cows || empty_size)
-		allowed_chunk_alloc = 1;
-
-	if (data & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
-		last_ptr = &root->fs_info->meta_alloc_cluster;
-		if (!btrfs_test_opt(root, SSD))
-			empty_cluster = 64 * 1024;
-	}
-
-	if ((data & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
-	    btrfs_test_opt(root, SSD)) {
-		last_ptr = &root->fs_info->data_alloc_cluster;
-	}
-
-	if (last_ptr) {
-		spin_lock(&last_ptr->lock);
-		if (last_ptr->block_group)
-			hint_byte = last_ptr->window_start;
-		spin_unlock(&last_ptr->lock);
-	}
-
-	search_start = max(search_start, first_logical_byte(root, 0));
-	search_start = max(search_start, hint_byte);
-
-	if (!last_ptr)
-		empty_cluster = 0;
-
-	if (search_start == hint_byte) {
-		block_group = btrfs_lookup_block_group(root->fs_info,
-						       search_start);
-		used_block_group = block_group;
-		/*
-		 * we don't want to use the block group if it doesn't match our
-		 * allocation bits, or if its not cached.
-		 *
-		 * However if we are re-searching with an ideal block group
-		 * picked out then we don't care that the block group is cached.
-		 */
-		if (block_group && block_group_bits(block_group, data) &&
-		    block_group->cached != BTRFS_CACHE_NO) {
-			down_read(&space_info->groups_sem);
-			if (list_empty(&block_group->list) ||
-			    block_group->ro) {
-				/*
-				 * someone is removing this block group,
-				 * we can't jump into the have_block_group
-				 * target because our list pointers are not
-				 * valid
-				 */
-				btrfs_put_block_group(block_group);
-				up_read(&space_info->groups_sem);
-			} else {
-				index = get_block_group_index(block_group);
-				goto have_block_group;
-			}
-		} else if (block_group) {
-			btrfs_put_block_group(block_group);
-		}
-	}
-search:
-	have_caching_bg = false;
-	down_read(&space_info->groups_sem);
-	list_for_each_entry(block_group, &space_info->block_groups[index],
-			    list) {
-		u64 offset;
-		int cached;
-
-		used_block_group = block_group;
-		btrfs_get_block_group(block_group);
-		search_start = block_group->key.objectid;
-
-		/*
-		 * this can happen if we end up cycling through all the
-		 * raid types, but we want to make sure we only allocate
-		 * for the proper type.
-		 */
-		if (!block_group_bits(block_group, data)) {
-		    u64 extra = BTRFS_BLOCK_GROUP_DUP |
-				BTRFS_BLOCK_GROUP_RAID1 |
-				BTRFS_BLOCK_GROUP_RAID10;
-
-			/*
-			 * if they asked for extra copies and this block group
-			 * doesn't provide them, bail.  This does allow us to
-			 * fill raid0 from raid1.
-			 */
-			if ((data & extra) && !(block_group->flags & extra))
-				goto loop;
-		}
-
-have_block_group:
-		cached = block_group_cache_done(block_group);
-		if (unlikely(!cached)) {
-			found_uncached_bg = true;
-			ret = cache_block_group(block_group, trans,
-						orig_root, 0);
-			BUG_ON(ret < 0);
-			ret = 0;
-		}
-
-		if (unlikely(block_group->ro))
-			goto loop;
-
-		/*
-		 * Ok we want to try and use the cluster allocator, so
-		 * lets look there
-		 */
-		if (last_ptr) {
-			/*
-			 * the refill lock keeps out other
-			 * people trying to start a new cluster
-			 */
-			spin_lock(&last_ptr->refill_lock);
-			used_block_group = last_ptr->block_group;
-			if (used_block_group != block_group &&
-			    (!used_block_group ||
-			     used_block_group->ro ||
-			     !block_group_bits(used_block_group, data))) {
-				used_block_group = block_group;
-				goto refill_cluster;
-			}
-
-			if (used_block_group != block_group)
-				btrfs_get_block_group(used_block_group);
-
-			offset = btrfs_alloc_from_cluster(used_block_group,
-			  last_ptr, num_bytes, used_block_group->key.objectid);
-			if (offset) {
-				/* we have a block, we're done */
-				spin_unlock(&last_ptr->refill_lock);
-				trace_btrfs_reserve_extent_cluster(root,
-					block_group, search_start, num_bytes);
-				goto checks;
-			}
-
-			WARN_ON(last_ptr->block_group != used_block_group);
-			if (used_block_group != block_group) {
-				btrfs_put_block_group(used_block_group);
-				used_block_group = block_group;
-			}
-refill_cluster:
-			BUG_ON(used_block_group != block_group);
-			/* If we are on LOOP_NO_EMPTY_SIZE, we can't
-			 * set up a new clusters, so lets just skip it
-			 * and let the allocator find whatever block
-			 * it can find.  If we reach this point, we
-			 * will have tried the cluster allocator
-			 * plenty of times and not have found
-			 * anything, so we are likely way too
-			 * fragmented for the clustering stuff to find
-			 * anything.
-			 *
-			 * However, if the cluster is taken from the
-			 * current block group, release the cluster
-			 * first, so that we stand a better chance of
-			 * succeeding in the unclustered
-			 * allocation.  */
-			if (loop >= LOOP_NO_EMPTY_SIZE &&
-			    last_ptr->block_group != block_group) {
-				spin_unlock(&last_ptr->refill_lock);
-				goto unclustered_alloc;
-			}
-
-			/*
-			 * this cluster didn't work out, free it and
-			 * start over
-			 */
-			btrfs_return_cluster_to_free_space(NULL, last_ptr);
-
-			if (loop >= LOOP_NO_EMPTY_SIZE) {
-				spin_unlock(&last_ptr->refill_lock);
-				goto unclustered_alloc;
-			}
-
-			/* allocate a cluster in this block group */
-			ret = btrfs_find_space_cluster(trans, root,
-					       block_group, last_ptr,
-					       search_start, num_bytes,
-					       empty_cluster + empty_size);
-			if (ret == 0) {
-				/*
-				 * now pull our allocation out of this
-				 * cluster
-				 */
-				offset = btrfs_alloc_from_cluster(block_group,
-						  last_ptr, num_bytes,
-						  search_start);
-				if (offset) {
-					/* we found one, proceed */
-					spin_unlock(&last_ptr->refill_lock);
-					trace_btrfs_reserve_extent_cluster(root,
-						block_group, search_start,
-						num_bytes);
-					goto checks;
-				}
-			} else if (!cached && loop > LOOP_CACHING_NOWAIT
-				   && !failed_cluster_refill) {
-				spin_unlock(&last_ptr->refill_lock);
-
-				failed_cluster_refill = true;
-				wait_block_group_cache_progress(block_group,
-				       num_bytes + empty_cluster + empty_size);
-				goto have_block_group;
-			}
-
-			/*
-			 * at this point we either didn't find a cluster
-			 * or we weren't able to allocate a block from our
-			 * cluster.  Free the cluster we've been trying
-			 * to use, and go to the next block group
-			 */
-			btrfs_return_cluster_to_free_space(NULL, last_ptr);
-			spin_unlock(&last_ptr->refill_lock);
-			goto loop;
-		}
-
-unclustered_alloc:
-		spin_lock(&block_group->free_space_ctl->tree_lock);
-		if (cached &&
-		    block_group->free_space_ctl->free_space <
-		    num_bytes + empty_cluster + empty_size) {
-			spin_unlock(&block_group->free_space_ctl->tree_lock);
-			goto loop;
-		}
-		spin_unlock(&block_group->free_space_ctl->tree_lock);
-
-		offset = btrfs_find_space_for_alloc(block_group, search_start,
-						    num_bytes, empty_size);
-		/*
-		 * If we didn't find a chunk, and we haven't failed on this
-		 * block group before, and this block group is in the middle of
-		 * caching and we are ok with waiting, then go ahead and wait
-		 * for progress to be made, and set failed_alloc to true.
-		 *
-		 * If failed_alloc is true then we've already waited on this
-		 * block group once and should move on to the next block group.
-		 */
-		if (!offset && !failed_alloc && !cached &&
-		    loop > LOOP_CACHING_NOWAIT) {
-			wait_block_group_cache_progress(block_group,
-						num_bytes + empty_size);
-			failed_alloc = true;
-			goto have_block_group;
-		} else if (!offset) {
-			if (!cached)
-				have_caching_bg = true;
-			goto loop;
-		}
-checks:
-		search_start = stripe_align(root, offset);
-
-		/* move on to the next group */
-		if (search_start + num_bytes >
-		    used_block_group->key.objectid + used_block_group->key.offset) {
-			btrfs_add_free_space(used_block_group, offset, num_bytes);
-			goto loop;
-		}
-
-		if (offset < search_start)
-			btrfs_add_free_space(used_block_group, offset,
-					     search_start - offset);
-		BUG_ON(offset > search_start);
-
-		ret = btrfs_update_reserved_bytes(used_block_group, num_bytes,
-						  alloc_type);
-		if (ret == -EAGAIN) {
-			btrfs_add_free_space(used_block_group, offset, num_bytes);
-			goto loop;
-		}
-
-		/* we are all good, lets return */
-		ins->objectid = search_start;
-		ins->offset = num_bytes;
-
-		trace_btrfs_reserve_extent(orig_root, block_group,
-					   search_start, num_bytes);
-		if (offset < search_start)
-			btrfs_add_free_space(used_block_group, offset,
-					     search_start - offset);
-		BUG_ON(offset > search_start);
-		if (used_block_group != block_group)
-			btrfs_put_block_group(used_block_group);
-		btrfs_put_block_group(block_group);
-		break;
-loop:
-		failed_cluster_refill = false;
-		failed_alloc = false;
-		BUG_ON(index != get_block_group_index(block_group));
-		if (used_block_group != block_group)
-			btrfs_put_block_group(used_block_group);
-		btrfs_put_block_group(block_group);
-	}
-	up_read(&space_info->groups_sem);
-
-	if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
-		goto search;
-
-	if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
-		goto search;
-
-	/*
-	 * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
-	 *			caching kthreads as we move along
-	 * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
-	 * LOOP_ALLOC_CHUNK, force a chunk allocation and try again
-	 * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
-	 *			again
-	 */
-	if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
-		index = 0;
-		loop++;
-		if (loop == LOOP_ALLOC_CHUNK) {
-		       if (allowed_chunk_alloc) {
-				ret = do_chunk_alloc(trans, root, num_bytes +
-						     2 * 1024 * 1024, data,
-						     CHUNK_ALLOC_LIMITED);
-				if (ret < 0) {
-					btrfs_abort_transaction(trans,
-								root, ret);
-					goto out;
-				}
-				allowed_chunk_alloc = 0;
-				if (ret == 1)
-					done_chunk_alloc = 1;
-			} else if (!done_chunk_alloc &&
-				   space_info->force_alloc ==
-				   CHUNK_ALLOC_NO_FORCE) {
-				space_info->force_alloc = CHUNK_ALLOC_LIMITED;
-			}
-
-		       /*
-			* We didn't allocate a chunk, go ahead and drop the
-			* empty size and loop again.
-			*/
-		       if (!done_chunk_alloc)
-			       loop = LOOP_NO_EMPTY_SIZE;
-		}
-
-		if (loop == LOOP_NO_EMPTY_SIZE) {
-			empty_size = 0;
-			empty_cluster = 0;
-		}
-
-		goto search;
-	} else if (!ins->objectid) {
-		ret = -ENOSPC;
-	} else if (ins->objectid) {
-		ret = 0;
-	}
-out:
-
-	return ret;
-}
-
-static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
-			    int dump_block_groups)
-{
-	struct btrfs_block_group_cache *cache;
-	int index = 0;
-
-	spin_lock(&info->lock);
-	printk(KERN_INFO "space_info %llu has %llu free, is %sfull\n",
-	       (unsigned long long)info->flags,
-	       (unsigned long long)(info->total_bytes - info->bytes_used -
-				    info->bytes_pinned - info->bytes_reserved -
-				    info->bytes_readonly),
-	       (info->full) ? "" : "not ");
-	printk(KERN_INFO "space_info total=%llu, used=%llu, pinned=%llu, "
-	       "reserved=%llu, may_use=%llu, readonly=%llu\n",
-	       (unsigned long long)info->total_bytes,
-	       (unsigned long long)info->bytes_used,
-	       (unsigned long long)info->bytes_pinned,
-	       (unsigned long long)info->bytes_reserved,
-	       (unsigned long long)info->bytes_may_use,
-	       (unsigned long long)info->bytes_readonly);
-	spin_unlock(&info->lock);
-
-	if (!dump_block_groups)
-		return;
-
-	down_read(&info->groups_sem);
-again:
-	list_for_each_entry(cache, &info->block_groups[index], list) {
-		spin_lock(&cache->lock);
-		printk(KERN_INFO "block group %llu has %llu bytes, %llu used "
-		       "%llu pinned %llu reserved\n",
-		       (unsigned long long)cache->key.objectid,
-		       (unsigned long long)cache->key.offset,
-		       (unsigned long long)btrfs_block_group_used(&cache->item),
-		       (unsigned long long)cache->pinned,
-		       (unsigned long long)cache->reserved);
-		btrfs_dump_free_space(cache, bytes);
-		spin_unlock(&cache->lock);
-	}
-	if (++index < BTRFS_NR_RAID_TYPES)
-		goto again;
-	up_read(&info->groups_sem);
-}
-
-int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
-			 struct btrfs_root *root,
-			 u64 num_bytes, u64 min_alloc_size,
-			 u64 empty_size, u64 hint_byte,
-			 struct btrfs_key *ins, u64 data)
-{
-	bool final_tried = false;
-	int ret;
-
-	data = btrfs_get_alloc_profile(root, data);
-again:
-	/*
-	 * the only place that sets empty_size is btrfs_realloc_node, which
-	 * is not called recursively on allocations
-	 */
-	if (empty_size || root->ref_cows) {
-		ret = do_chunk_alloc(trans, root->fs_info->extent_root,
-				     num_bytes + 2 * 1024 * 1024, data,
-				     CHUNK_ALLOC_NO_FORCE);
-		if (ret < 0 && ret != -ENOSPC) {
-			btrfs_abort_transaction(trans, root, ret);
-			return ret;
-		}
-	}
-
-	WARN_ON(num_bytes < root->sectorsize);
-	ret = find_free_extent(trans, root, num_bytes, empty_size,
-			       hint_byte, ins, data);
-
-	if (ret == -ENOSPC) {
-		if (!final_tried) {
-			num_bytes = num_bytes >> 1;
-			num_bytes = num_bytes & ~(root->sectorsize - 1);
-			num_bytes = max(num_bytes, min_alloc_size);
-			ret = do_chunk_alloc(trans, root->fs_info->extent_root,
-				       num_bytes, data, CHUNK_ALLOC_FORCE);
-			if (ret < 0 && ret != -ENOSPC) {
-				btrfs_abort_transaction(trans, root, ret);
-				return ret;
-			}
-			if (num_bytes == min_alloc_size)
-				final_tried = true;
-			goto again;
-		} else if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
-			struct btrfs_space_info *sinfo;
-
-			sinfo = __find_space_info(root->fs_info, data);
-			printk(KERN_ERR "btrfs allocation failed flags %llu, "
-			       "wanted %llu\n", (unsigned long long)data,
-			       (unsigned long long)num_bytes);
-			if (sinfo)
-				dump_space_info(sinfo, num_bytes, 1);
-		}
-	}
-
-	trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
-
-	return ret;
-}
-
-static int __btrfs_free_reserved_extent(struct btrfs_root *root,
-					u64 start, u64 len, int pin)
-{
-	struct btrfs_block_group_cache *cache;
-	int ret = 0;
-
-	cache = btrfs_lookup_block_group(root->fs_info, start);
-	if (!cache) {
-		printk(KERN_ERR "Unable to find block group for %llu\n",
-		       (unsigned long long)start);
-		return -ENOSPC;
-	}
-
-	if (btrfs_test_opt(root, DISCARD))
-		ret = btrfs_discard_extent(root, start, len, NULL);
-
-	if (pin)
-		pin_down_extent(root, cache, start, len, 1);
-	else {
-		btrfs_add_free_space(cache, start, len);
-		btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
-	}
-	btrfs_put_block_group(cache);
-
-	trace_btrfs_reserved_extent_free(root, start, len);
-
-	return ret;
-}
-
-int btrfs_free_reserved_extent(struct btrfs_root *root,
-					u64 start, u64 len)
-{
-	return __btrfs_free_reserved_extent(root, start, len, 0);
-}
-
-int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
-				       u64 start, u64 len)
-{
-	return __btrfs_free_reserved_extent(root, start, len, 1);
-}
-
-static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
-				      struct btrfs_root *root,
-				      u64 parent, u64 root_objectid,
-				      u64 flags, u64 owner, u64 offset,
-				      struct btrfs_key *ins, int ref_mod)
-{
-	int ret;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_extent_item *extent_item;
-	struct btrfs_extent_inline_ref *iref;
-	struct btrfs_path *path;
-	struct extent_buffer *leaf;
-	int type;
-	u32 size;
-
-	if (parent > 0)
-		type = BTRFS_SHARED_DATA_REF_KEY;
-	else
-		type = BTRFS_EXTENT_DATA_REF_KEY;
-
-	size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	path->leave_spinning = 1;
-	ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
-				      ins, size);
-	if (ret) {
-		btrfs_free_path(path);
-		return ret;
-	}
-
-	leaf = path->nodes[0];
-	extent_item = btrfs_item_ptr(leaf, path->slots[0],
-				     struct btrfs_extent_item);
-	btrfs_set_extent_refs(leaf, extent_item, ref_mod);
-	btrfs_set_extent_generation(leaf, extent_item, trans->transid);
-	btrfs_set_extent_flags(leaf, extent_item,
-			       flags | BTRFS_EXTENT_FLAG_DATA);
-
-	iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
-	btrfs_set_extent_inline_ref_type(leaf, iref, type);
-	if (parent > 0) {
-		struct btrfs_shared_data_ref *ref;
-		ref = (struct btrfs_shared_data_ref *)(iref + 1);
-		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
-		btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
-	} else {
-		struct btrfs_extent_data_ref *ref;
-		ref = (struct btrfs_extent_data_ref *)(&iref->offset);
-		btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
-		btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
-		btrfs_set_extent_data_ref_offset(leaf, ref, offset);
-		btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
-	}
-
-	btrfs_mark_buffer_dirty(path->nodes[0]);
-	btrfs_free_path(path);
-
-	ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
-	if (ret) { /* -ENOENT, logic error */
-		printk(KERN_ERR "btrfs update block group failed for %llu "
-		       "%llu\n", (unsigned long long)ins->objectid,
-		       (unsigned long long)ins->offset);
-		BUG();
-	}
-	return ret;
-}
-
-static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
-				     struct btrfs_root *root,
-				     u64 parent, u64 root_objectid,
-				     u64 flags, struct btrfs_disk_key *key,
-				     int level, struct btrfs_key *ins)
-{
-	int ret;
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_extent_item *extent_item;
-	struct btrfs_tree_block_info *block_info;
-	struct btrfs_extent_inline_ref *iref;
-	struct btrfs_path *path;
-	struct extent_buffer *leaf;
-	u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref);
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	path->leave_spinning = 1;
-	ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
-				      ins, size);
-	if (ret) {
-		btrfs_free_path(path);
-		return ret;
-	}
-
-	leaf = path->nodes[0];
-	extent_item = btrfs_item_ptr(leaf, path->slots[0],
-				     struct btrfs_extent_item);
-	btrfs_set_extent_refs(leaf, extent_item, 1);
-	btrfs_set_extent_generation(leaf, extent_item, trans->transid);
-	btrfs_set_extent_flags(leaf, extent_item,
-			       flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
-	block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
-
-	btrfs_set_tree_block_key(leaf, block_info, key);
-	btrfs_set_tree_block_level(leaf, block_info, level);
-
-	iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
-	if (parent > 0) {
-		BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
-		btrfs_set_extent_inline_ref_type(leaf, iref,
-						 BTRFS_SHARED_BLOCK_REF_KEY);
-		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
-	} else {
-		btrfs_set_extent_inline_ref_type(leaf, iref,
-						 BTRFS_TREE_BLOCK_REF_KEY);
-		btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
-	}
-
-	btrfs_mark_buffer_dirty(leaf);
-	btrfs_free_path(path);
-
-	ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
-	if (ret) { /* -ENOENT, logic error */
-		printk(KERN_ERR "btrfs update block group failed for %llu "
-		       "%llu\n", (unsigned long long)ins->objectid,
-		       (unsigned long long)ins->offset);
-		BUG();
-	}
-	return ret;
-}
-
-int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
-				     struct btrfs_root *root,
-				     u64 root_objectid, u64 owner,
-				     u64 offset, struct btrfs_key *ins)
-{
-	int ret;
-
-	BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
-
-	ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
-					 ins->offset, 0,
-					 root_objectid, owner, offset,
-					 BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
-	return ret;
-}
-
-/*
- * this is used by the tree logging recovery code.  It records that
- * an extent has been allocated and makes sure to clear the free
- * space cache bits as well
- */
-int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
-				   struct btrfs_root *root,
-				   u64 root_objectid, u64 owner, u64 offset,
-				   struct btrfs_key *ins)
-{
-	int ret;
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_caching_control *caching_ctl;
-	u64 start = ins->objectid;
-	u64 num_bytes = ins->offset;
-
-	block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
-	cache_block_group(block_group, trans, NULL, 0);
-	caching_ctl = get_caching_control(block_group);
-
-	if (!caching_ctl) {
-		BUG_ON(!block_group_cache_done(block_group));
-		ret = btrfs_remove_free_space(block_group, start, num_bytes);
-		BUG_ON(ret); /* -ENOMEM */
-	} else {
-		mutex_lock(&caching_ctl->mutex);
-
-		if (start >= caching_ctl->progress) {
-			ret = add_excluded_extent(root, start, num_bytes);
-			BUG_ON(ret); /* -ENOMEM */
-		} else if (start + num_bytes <= caching_ctl->progress) {
-			ret = btrfs_remove_free_space(block_group,
-						      start, num_bytes);
-			BUG_ON(ret); /* -ENOMEM */
-		} else {
-			num_bytes = caching_ctl->progress - start;
-			ret = btrfs_remove_free_space(block_group,
-						      start, num_bytes);
-			BUG_ON(ret); /* -ENOMEM */
-
-			start = caching_ctl->progress;
-			num_bytes = ins->objectid + ins->offset -
-				    caching_ctl->progress;
-			ret = add_excluded_extent(root, start, num_bytes);
-			BUG_ON(ret); /* -ENOMEM */
-		}
-
-		mutex_unlock(&caching_ctl->mutex);
-		put_caching_control(caching_ctl);
-	}
-
-	ret = btrfs_update_reserved_bytes(block_group, ins->offset,
-					  RESERVE_ALLOC_NO_ACCOUNT);
-	BUG_ON(ret); /* logic error */
-	btrfs_put_block_group(block_group);
-	ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
-					 0, owner, offset, ins, 1);
-	return ret;
-}
-
-struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
-					    struct btrfs_root *root,
-					    u64 bytenr, u32 blocksize,
-					    int level)
-{
-	struct extent_buffer *buf;
-
-	buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
-	if (!buf)
-		return ERR_PTR(-ENOMEM);
-	btrfs_set_header_generation(buf, trans->transid);
-	btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
-	btrfs_tree_lock(buf);
-	clean_tree_block(trans, root, buf);
-	clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
-
-	btrfs_set_lock_blocking(buf);
-	btrfs_set_buffer_uptodate(buf);
-
-	if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
-		/*
-		 * we allow two log transactions at a time, use different
-		 * EXENT bit to differentiate dirty pages.
-		 */
-		if (root->log_transid % 2 == 0)
-			set_extent_dirty(&root->dirty_log_pages, buf->start,
-					buf->start + buf->len - 1, GFP_NOFS);
-		else
-			set_extent_new(&root->dirty_log_pages, buf->start,
-					buf->start + buf->len - 1, GFP_NOFS);
-	} else {
-		set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
-			 buf->start + buf->len - 1, GFP_NOFS);
-	}
-	trans->blocks_used++;
-	/* this returns a buffer locked for blocking */
-	return buf;
-}
-
-static struct btrfs_block_rsv *
-use_block_rsv(struct btrfs_trans_handle *trans,
-	      struct btrfs_root *root, u32 blocksize)
-{
-	struct btrfs_block_rsv *block_rsv;
-	struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
-	int ret;
-
-	block_rsv = get_block_rsv(trans, root);
-
-	if (block_rsv->size == 0) {
-		ret = reserve_metadata_bytes(root, block_rsv, blocksize, 0);
-		/*
-		 * If we couldn't reserve metadata bytes try and use some from
-		 * the global reserve.
-		 */
-		if (ret && block_rsv != global_rsv) {
-			ret = block_rsv_use_bytes(global_rsv, blocksize);
-			if (!ret)
-				return global_rsv;
-			return ERR_PTR(ret);
-		} else if (ret) {
-			return ERR_PTR(ret);
-		}
-		return block_rsv;
-	}
-
-	ret = block_rsv_use_bytes(block_rsv, blocksize);
-	if (!ret)
-		return block_rsv;
-	if (ret) {
-		static DEFINE_RATELIMIT_STATE(_rs,
-				DEFAULT_RATELIMIT_INTERVAL,
-				/*DEFAULT_RATELIMIT_BURST*/ 2);
-		if (__ratelimit(&_rs)) {
-			printk(KERN_DEBUG "btrfs: block rsv returned %d\n", ret);
-			WARN_ON(1);
-		}
-		ret = reserve_metadata_bytes(root, block_rsv, blocksize, 0);
-		if (!ret) {
-			return block_rsv;
-		} else if (ret && block_rsv != global_rsv) {
-			ret = block_rsv_use_bytes(global_rsv, blocksize);
-			if (!ret)
-				return global_rsv;
-		}
-	}
-
-	return ERR_PTR(-ENOSPC);
-}
-
-static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
-			    struct btrfs_block_rsv *block_rsv, u32 blocksize)
-{
-	block_rsv_add_bytes(block_rsv, blocksize, 0);
-	block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
-}
-
-/*
- * finds a free extent and does all the dirty work required for allocation
- * returns the key for the extent through ins, and a tree buffer for
- * the first block of the extent through buf.
- *
- * returns the tree buffer or NULL.
- */
-struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
-					struct btrfs_root *root, u32 blocksize,
-					u64 parent, u64 root_objectid,
-					struct btrfs_disk_key *key, int level,
-					u64 hint, u64 empty_size, int for_cow)
-{
-	struct btrfs_key ins;
-	struct btrfs_block_rsv *block_rsv;
-	struct extent_buffer *buf;
-	u64 flags = 0;
-	int ret;
-
-
-	block_rsv = use_block_rsv(trans, root, blocksize);
-	if (IS_ERR(block_rsv))
-		return ERR_CAST(block_rsv);
-
-	ret = btrfs_reserve_extent(trans, root, blocksize, blocksize,
-				   empty_size, hint, &ins, 0);
-	if (ret) {
-		unuse_block_rsv(root->fs_info, block_rsv, blocksize);
-		return ERR_PTR(ret);
-	}
-
-	buf = btrfs_init_new_buffer(trans, root, ins.objectid,
-				    blocksize, level);
-	BUG_ON(IS_ERR(buf)); /* -ENOMEM */
-
-	if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
-		if (parent == 0)
-			parent = ins.objectid;
-		flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
-	} else
-		BUG_ON(parent > 0);
-
-	if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
-		struct btrfs_delayed_extent_op *extent_op;
-		extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
-		BUG_ON(!extent_op); /* -ENOMEM */
-		if (key)
-			memcpy(&extent_op->key, key, sizeof(extent_op->key));
-		else
-			memset(&extent_op->key, 0, sizeof(extent_op->key));
-		extent_op->flags_to_set = flags;
-		extent_op->update_key = 1;
-		extent_op->update_flags = 1;
-		extent_op->is_data = 0;
-
-		ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
-					ins.objectid,
-					ins.offset, parent, root_objectid,
-					level, BTRFS_ADD_DELAYED_EXTENT,
-					extent_op, for_cow);
-		BUG_ON(ret); /* -ENOMEM */
-	}
-	return buf;
-}
-
-struct walk_control {
-	u64 refs[BTRFS_MAX_LEVEL];
-	u64 flags[BTRFS_MAX_LEVEL];
-	struct btrfs_key update_progress;
-	int stage;
-	int level;
-	int shared_level;
-	int update_ref;
-	int keep_locks;
-	int reada_slot;
-	int reada_count;
-	int for_reloc;
-};
-
-#define DROP_REFERENCE	1
-#define UPDATE_BACKREF	2
-
-static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
-				     struct btrfs_root *root,
-				     struct walk_control *wc,
-				     struct btrfs_path *path)
-{
-	u64 bytenr;
-	u64 generation;
-	u64 refs;
-	u64 flags;
-	u32 nritems;
-	u32 blocksize;
-	struct btrfs_key key;
-	struct extent_buffer *eb;
-	int ret;
-	int slot;
-	int nread = 0;
-
-	if (path->slots[wc->level] < wc->reada_slot) {
-		wc->reada_count = wc->reada_count * 2 / 3;
-		wc->reada_count = max(wc->reada_count, 2);
-	} else {
-		wc->reada_count = wc->reada_count * 3 / 2;
-		wc->reada_count = min_t(int, wc->reada_count,
-					BTRFS_NODEPTRS_PER_BLOCK(root));
-	}
-
-	eb = path->nodes[wc->level];
-	nritems = btrfs_header_nritems(eb);
-	blocksize = btrfs_level_size(root, wc->level - 1);
-
-	for (slot = path->slots[wc->level]; slot < nritems; slot++) {
-		if (nread >= wc->reada_count)
-			break;
-
-		cond_resched();
-		bytenr = btrfs_node_blockptr(eb, slot);
-		generation = btrfs_node_ptr_generation(eb, slot);
-
-		if (slot == path->slots[wc->level])
-			goto reada;
-
-		if (wc->stage == UPDATE_BACKREF &&
-		    generation <= root->root_key.offset)
-			continue;
-
-		/* We don't lock the tree block, it's OK to be racy here */
-		ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
-					       &refs, &flags);
-		/* We don't care about errors in readahead. */
-		if (ret < 0)
-			continue;
-		BUG_ON(refs == 0);
-
-		if (wc->stage == DROP_REFERENCE) {
-			if (refs == 1)
-				goto reada;
-
-			if (wc->level == 1 &&
-			    (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
-				continue;
-			if (!wc->update_ref ||
-			    generation <= root->root_key.offset)
-				continue;
-			btrfs_node_key_to_cpu(eb, &key, slot);
-			ret = btrfs_comp_cpu_keys(&key,
-						  &wc->update_progress);
-			if (ret < 0)
-				continue;
-		} else {
-			if (wc->level == 1 &&
-			    (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
-				continue;
-		}
-reada:
-		ret = readahead_tree_block(root, bytenr, blocksize,
-					   generation);
-		if (ret)
-			break;
-		nread++;
-	}
-	wc->reada_slot = slot;
-}
-
-/*
- * hepler to process tree block while walking down the tree.
- *
- * when wc->stage == UPDATE_BACKREF, this function updates
- * back refs for pointers in the block.
- *
- * NOTE: return value 1 means we should stop walking down.
- */
-static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
-				   struct btrfs_root *root,
-				   struct btrfs_path *path,
-				   struct walk_control *wc, int lookup_info)
-{
-	int level = wc->level;
-	struct extent_buffer *eb = path->nodes[level];
-	u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
-	int ret;
-
-	if (wc->stage == UPDATE_BACKREF &&
-	    btrfs_header_owner(eb) != root->root_key.objectid)
-		return 1;
-
-	/*
-	 * when reference count of tree block is 1, it won't increase
-	 * again. once full backref flag is set, we never clear it.
-	 */
-	if (lookup_info &&
-	    ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
-	     (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
-		BUG_ON(!path->locks[level]);
-		ret = btrfs_lookup_extent_info(trans, root,
-					       eb->start, eb->len,
-					       &wc->refs[level],
-					       &wc->flags[level]);
-		BUG_ON(ret == -ENOMEM);
-		if (ret)
-			return ret;
-		BUG_ON(wc->refs[level] == 0);
-	}
-
-	if (wc->stage == DROP_REFERENCE) {
-		if (wc->refs[level] > 1)
-			return 1;
-
-		if (path->locks[level] && !wc->keep_locks) {
-			btrfs_tree_unlock_rw(eb, path->locks[level]);
-			path->locks[level] = 0;
-		}
-		return 0;
-	}
-
-	/* wc->stage == UPDATE_BACKREF */
-	if (!(wc->flags[level] & flag)) {
-		BUG_ON(!path->locks[level]);
-		ret = btrfs_inc_ref(trans, root, eb, 1, wc->for_reloc);
-		BUG_ON(ret); /* -ENOMEM */
-		ret = btrfs_dec_ref(trans, root, eb, 0, wc->for_reloc);
-		BUG_ON(ret); /* -ENOMEM */
-		ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
-						  eb->len, flag, 0);
-		BUG_ON(ret); /* -ENOMEM */
-		wc->flags[level] |= flag;
-	}
-
-	/*
-	 * the block is shared by multiple trees, so it's not good to
-	 * keep the tree lock
-	 */
-	if (path->locks[level] && level > 0) {
-		btrfs_tree_unlock_rw(eb, path->locks[level]);
-		path->locks[level] = 0;
-	}
-	return 0;
-}
-
-/*
- * hepler to process tree block pointer.
- *
- * when wc->stage == DROP_REFERENCE, this function checks
- * reference count of the block pointed to. if the block
- * is shared and we need update back refs for the subtree
- * rooted at the block, this function changes wc->stage to
- * UPDATE_BACKREF. if the block is shared and there is no
- * need to update back, this function drops the reference
- * to the block.
- *
- * NOTE: return value 1 means we should stop walking down.
- */
-static noinline int do_walk_down(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 struct walk_control *wc, int *lookup_info)
-{
-	u64 bytenr;
-	u64 generation;
-	u64 parent;
-	u32 blocksize;
-	struct btrfs_key key;
-	struct extent_buffer *next;
-	int level = wc->level;
-	int reada = 0;
-	int ret = 0;
-
-	generation = btrfs_node_ptr_generation(path->nodes[level],
-					       path->slots[level]);
-	/*
-	 * if the lower level block was created before the snapshot
-	 * was created, we know there is no need to update back refs
-	 * for the subtree
-	 */
-	if (wc->stage == UPDATE_BACKREF &&
-	    generation <= root->root_key.offset) {
-		*lookup_info = 1;
-		return 1;
-	}
-
-	bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
-	blocksize = btrfs_level_size(root, level - 1);
-
-	next = btrfs_find_tree_block(root, bytenr, blocksize);
-	if (!next) {
-		next = btrfs_find_create_tree_block(root, bytenr, blocksize);
-		if (!next)
-			return -ENOMEM;
-		reada = 1;
-	}
-	btrfs_tree_lock(next);
-	btrfs_set_lock_blocking(next);
-
-	ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize,
-				       &wc->refs[level - 1],
-				       &wc->flags[level - 1]);
-	if (ret < 0) {
-		btrfs_tree_unlock(next);
-		return ret;
-	}
-
-	BUG_ON(wc->refs[level - 1] == 0);
-	*lookup_info = 0;
-
-	if (wc->stage == DROP_REFERENCE) {
-		if (wc->refs[level - 1] > 1) {
-			if (level == 1 &&
-			    (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
-				goto skip;
-
-			if (!wc->update_ref ||
-			    generation <= root->root_key.offset)
-				goto skip;
-
-			btrfs_node_key_to_cpu(path->nodes[level], &key,
-					      path->slots[level]);
-			ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
-			if (ret < 0)
-				goto skip;
-
-			wc->stage = UPDATE_BACKREF;
-			wc->shared_level = level - 1;
-		}
-	} else {
-		if (level == 1 &&
-		    (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
-			goto skip;
-	}
-
-	if (!btrfs_buffer_uptodate(next, generation, 0)) {
-		btrfs_tree_unlock(next);
-		free_extent_buffer(next);
-		next = NULL;
-		*lookup_info = 1;
-	}
-
-	if (!next) {
-		if (reada && level == 1)
-			reada_walk_down(trans, root, wc, path);
-		next = read_tree_block(root, bytenr, blocksize, generation);
-		if (!next)
-			return -EIO;
-		btrfs_tree_lock(next);
-		btrfs_set_lock_blocking(next);
-	}
-
-	level--;
-	BUG_ON(level != btrfs_header_level(next));
-	path->nodes[level] = next;
-	path->slots[level] = 0;
-	path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
-	wc->level = level;
-	if (wc->level == 1)
-		wc->reada_slot = 0;
-	return 0;
-skip:
-	wc->refs[level - 1] = 0;
-	wc->flags[level - 1] = 0;
-	if (wc->stage == DROP_REFERENCE) {
-		if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
-			parent = path->nodes[level]->start;
-		} else {
-			BUG_ON(root->root_key.objectid !=
-			       btrfs_header_owner(path->nodes[level]));
-			parent = 0;
-		}
-
-		ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
-				root->root_key.objectid, level - 1, 0, 0);
-		BUG_ON(ret); /* -ENOMEM */
-	}
-	btrfs_tree_unlock(next);
-	free_extent_buffer(next);
-	*lookup_info = 1;
-	return 1;
-}
-
-/*
- * hepler to process tree block while walking up the tree.
- *
- * when wc->stage == DROP_REFERENCE, this function drops
- * reference count on the block.
- *
- * when wc->stage == UPDATE_BACKREF, this function changes
- * wc->stage back to DROP_REFERENCE if we changed wc->stage
- * to UPDATE_BACKREF previously while processing the block.
- *
- * NOTE: return value 1 means we should stop walking up.
- */
-static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 struct walk_control *wc)
-{
-	int ret;
-	int level = wc->level;
-	struct extent_buffer *eb = path->nodes[level];
-	u64 parent = 0;
-
-	if (wc->stage == UPDATE_BACKREF) {
-		BUG_ON(wc->shared_level < level);
-		if (level < wc->shared_level)
-			goto out;
-
-		ret = find_next_key(path, level + 1, &wc->update_progress);
-		if (ret > 0)
-			wc->update_ref = 0;
-
-		wc->stage = DROP_REFERENCE;
-		wc->shared_level = -1;
-		path->slots[level] = 0;
-
-		/*
-		 * check reference count again if the block isn't locked.
-		 * we should start walking down the tree again if reference
-		 * count is one.
-		 */
-		if (!path->locks[level]) {
-			BUG_ON(level == 0);
-			btrfs_tree_lock(eb);
-			btrfs_set_lock_blocking(eb);
-			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
-
-			ret = btrfs_lookup_extent_info(trans, root,
-						       eb->start, eb->len,
-						       &wc->refs[level],
-						       &wc->flags[level]);
-			if (ret < 0) {
-				btrfs_tree_unlock_rw(eb, path->locks[level]);
-				return ret;
-			}
-			BUG_ON(wc->refs[level] == 0);
-			if (wc->refs[level] == 1) {
-				btrfs_tree_unlock_rw(eb, path->locks[level]);
-				return 1;
-			}
-		}
-	}
-
-	/* wc->stage == DROP_REFERENCE */
-	BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
-
-	if (wc->refs[level] == 1) {
-		if (level == 0) {
-			if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
-				ret = btrfs_dec_ref(trans, root, eb, 1,
-						    wc->for_reloc);
-			else
-				ret = btrfs_dec_ref(trans, root, eb, 0,
-						    wc->for_reloc);
-			BUG_ON(ret); /* -ENOMEM */
-		}
-		/* make block locked assertion in clean_tree_block happy */
-		if (!path->locks[level] &&
-		    btrfs_header_generation(eb) == trans->transid) {
-			btrfs_tree_lock(eb);
-			btrfs_set_lock_blocking(eb);
-			path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
-		}
-		clean_tree_block(trans, root, eb);
-	}
-
-	if (eb == root->node) {
-		if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
-			parent = eb->start;
-		else
-			BUG_ON(root->root_key.objectid !=
-			       btrfs_header_owner(eb));
-	} else {
-		if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
-			parent = path->nodes[level + 1]->start;
-		else
-			BUG_ON(root->root_key.objectid !=
-			       btrfs_header_owner(path->nodes[level + 1]));
-	}
-
-	btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1, 0);
-out:
-	wc->refs[level] = 0;
-	wc->flags[level] = 0;
-	return 0;
-}
-
-static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
-				   struct btrfs_root *root,
-				   struct btrfs_path *path,
-				   struct walk_control *wc)
-{
-	int level = wc->level;
-	int lookup_info = 1;
-	int ret;
-
-	while (level >= 0) {
-		ret = walk_down_proc(trans, root, path, wc, lookup_info);
-		if (ret > 0)
-			break;
-
-		if (level == 0)
-			break;
-
-		if (path->slots[level] >=
-		    btrfs_header_nritems(path->nodes[level]))
-			break;
-
-		ret = do_walk_down(trans, root, path, wc, &lookup_info);
-		if (ret > 0) {
-			path->slots[level]++;
-			continue;
-		} else if (ret < 0)
-			return ret;
-		level = wc->level;
-	}
-	return 0;
-}
-
-static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
-				 struct btrfs_root *root,
-				 struct btrfs_path *path,
-				 struct walk_control *wc, int max_level)
-{
-	int level = wc->level;
-	int ret;
-
-	path->slots[level] = btrfs_header_nritems(path->nodes[level]);
-	while (level < max_level && path->nodes[level]) {
-		wc->level = level;
-		if (path->slots[level] + 1 <
-		    btrfs_header_nritems(path->nodes[level])) {
-			path->slots[level]++;
-			return 0;
-		} else {
-			ret = walk_up_proc(trans, root, path, wc);
-			if (ret > 0)
-				return 0;
-
-			if (path->locks[level]) {
-				btrfs_tree_unlock_rw(path->nodes[level],
-						     path->locks[level]);
-				path->locks[level] = 0;
-			}
-			free_extent_buffer(path->nodes[level]);
-			path->nodes[level] = NULL;
-			level++;
-		}
-	}
-	return 1;
-}
-
-/*
- * drop a subvolume tree.
- *
- * this function traverses the tree freeing any blocks that only
- * referenced by the tree.
- *
- * when a shared tree block is found. this function decreases its
- * reference count by one. if update_ref is true, this function
- * also make sure backrefs for the shared block and all lower level
- * blocks are properly updated.
- */
-int btrfs_drop_snapshot(struct btrfs_root *root,
-			 struct btrfs_block_rsv *block_rsv, int update_ref,
-			 int for_reloc)
-{
-	struct btrfs_path *path;
-	struct btrfs_trans_handle *trans;
-	struct btrfs_root *tree_root = root->fs_info->tree_root;
-	struct btrfs_root_item *root_item = &root->root_item;
-	struct walk_control *wc;
-	struct btrfs_key key;
-	int err = 0;
-	int ret;
-	int level;
-
-	path = btrfs_alloc_path();
-	if (!path) {
-		err = -ENOMEM;
-		goto out;
-	}
-
-	wc = kzalloc(sizeof(*wc), GFP_NOFS);
-	if (!wc) {
-		btrfs_free_path(path);
-		err = -ENOMEM;
-		goto out;
-	}
-
-	trans = btrfs_start_transaction(tree_root, 0);
-	if (IS_ERR(trans)) {
-		err = PTR_ERR(trans);
-		goto out_free;
-	}
-
-	if (block_rsv)
-		trans->block_rsv = block_rsv;
-
-	if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
-		level = btrfs_header_level(root->node);
-		path->nodes[level] = btrfs_lock_root_node(root);
-		btrfs_set_lock_blocking(path->nodes[level]);
-		path->slots[level] = 0;
-		path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
-		memset(&wc->update_progress, 0,
-		       sizeof(wc->update_progress));
-	} else {
-		btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
-		memcpy(&wc->update_progress, &key,
-		       sizeof(wc->update_progress));
-
-		level = root_item->drop_level;
-		BUG_ON(level == 0);
-		path->lowest_level = level;
-		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-		path->lowest_level = 0;
-		if (ret < 0) {
-			err = ret;
-			goto out_end_trans;
-		}
-		WARN_ON(ret > 0);
-
-		/*
-		 * unlock our path, this is safe because only this
-		 * function is allowed to delete this snapshot
-		 */
-		btrfs_unlock_up_safe(path, 0);
-
-		level = btrfs_header_level(root->node);
-		while (1) {
-			btrfs_tree_lock(path->nodes[level]);
-			btrfs_set_lock_blocking(path->nodes[level]);
-
-			ret = btrfs_lookup_extent_info(trans, root,
-						path->nodes[level]->start,
-						path->nodes[level]->len,
-						&wc->refs[level],
-						&wc->flags[level]);
-			if (ret < 0) {
-				err = ret;
-				goto out_end_trans;
-			}
-			BUG_ON(wc->refs[level] == 0);
-
-			if (level == root_item->drop_level)
-				break;
-
-			btrfs_tree_unlock(path->nodes[level]);
-			WARN_ON(wc->refs[level] != 1);
-			level--;
-		}
-	}
-
-	wc->level = level;
-	wc->shared_level = -1;
-	wc->stage = DROP_REFERENCE;
-	wc->update_ref = update_ref;
-	wc->keep_locks = 0;
-	wc->for_reloc = for_reloc;
-	wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
-
-	while (1) {
-		ret = walk_down_tree(trans, root, path, wc);
-		if (ret < 0) {
-			err = ret;
-			break;
-		}
-
-		ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
-		if (ret < 0) {
-			err = ret;
-			break;
-		}
-
-		if (ret > 0) {
-			BUG_ON(wc->stage != DROP_REFERENCE);
-			break;
-		}
-
-		if (wc->stage == DROP_REFERENCE) {
-			level = wc->level;
-			btrfs_node_key(path->nodes[level],
-				       &root_item->drop_progress,
-				       path->slots[level]);
-			root_item->drop_level = level;
-		}
-
-		BUG_ON(wc->level == 0);
-		if (btrfs_should_end_transaction(trans, tree_root)) {
-			ret = btrfs_update_root(trans, tree_root,
-						&root->root_key,
-						root_item);
-			if (ret) {
-				btrfs_abort_transaction(trans, tree_root, ret);
-				err = ret;
-				goto out_end_trans;
-			}
-
-			btrfs_end_transaction_throttle(trans, tree_root);
-			trans = btrfs_start_transaction(tree_root, 0);
-			if (IS_ERR(trans)) {
-				err = PTR_ERR(trans);
-				goto out_free;
-			}
-			if (block_rsv)
-				trans->block_rsv = block_rsv;
-		}
-	}
-	btrfs_release_path(path);
-	if (err)
-		goto out_end_trans;
-
-	ret = btrfs_del_root(trans, tree_root, &root->root_key);
-	if (ret) {
-		btrfs_abort_transaction(trans, tree_root, ret);
-		goto out_end_trans;
-	}
-
-	if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
-		ret = btrfs_find_last_root(tree_root, root->root_key.objectid,
-					   NULL, NULL);
-		if (ret < 0) {
-			btrfs_abort_transaction(trans, tree_root, ret);
-			err = ret;
-			goto out_end_trans;
-		} else if (ret > 0) {
-			/* if we fail to delete the orphan item this time
-			 * around, it'll get picked up the next time.
-			 *
-			 * The most common failure here is just -ENOENT.
-			 */
-			btrfs_del_orphan_item(trans, tree_root,
-					      root->root_key.objectid);
-		}
-	}
-
-	if (root->in_radix) {
-		btrfs_free_fs_root(tree_root->fs_info, root);
-	} else {
-		free_extent_buffer(root->node);
-		free_extent_buffer(root->commit_root);
-		kfree(root);
-	}
-out_end_trans:
-	btrfs_end_transaction_throttle(trans, tree_root);
-out_free:
-	kfree(wc);
-	btrfs_free_path(path);
-out:
-	if (err)
-		btrfs_std_error(root->fs_info, err);
-	return err;
-}
-
-/*
- * drop subtree rooted at tree block 'node'.
- *
- * NOTE: this function will unlock and release tree block 'node'
- * only used by relocation code
- */
-int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root,
-			struct extent_buffer *node,
-			struct extent_buffer *parent)
-{
-	struct btrfs_path *path;
-	struct walk_control *wc;
-	int level;
-	int parent_level;
-	int ret = 0;
-	int wret;
-
-	BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
-
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	wc = kzalloc(sizeof(*wc), GFP_NOFS);
-	if (!wc) {
-		btrfs_free_path(path);
-		return -ENOMEM;
-	}
-
-	btrfs_assert_tree_locked(parent);
-	parent_level = btrfs_header_level(parent);
-	extent_buffer_get(parent);
-	path->nodes[parent_level] = parent;
-	path->slots[parent_level] = btrfs_header_nritems(parent);
-
-	btrfs_assert_tree_locked(node);
-	level = btrfs_header_level(node);
-	path->nodes[level] = node;
-	path->slots[level] = 0;
-	path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
-
-	wc->refs[parent_level] = 1;
-	wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
-	wc->level = level;
-	wc->shared_level = -1;
-	wc->stage = DROP_REFERENCE;
-	wc->update_ref = 0;
-	wc->keep_locks = 1;
-	wc->for_reloc = 1;
-	wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
-
-	while (1) {
-		wret = walk_down_tree(trans, root, path, wc);
-		if (wret < 0) {
-			ret = wret;
-			break;
-		}
-
-		wret = walk_up_tree(trans, root, path, wc, parent_level);
-		if (wret < 0)
-			ret = wret;
-		if (wret != 0)
-			break;
-	}
-
-	kfree(wc);
-	btrfs_free_path(path);
-	return ret;
-}
-
-static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
-{
-	u64 num_devices;
-	u64 stripped;
-
-	/*
-	 * if restripe for this chunk_type is on pick target profile and
-	 * return, otherwise do the usual balance
-	 */
-	stripped = get_restripe_target(root->fs_info, flags);
-	if (stripped)
-		return extended_to_chunk(stripped);
-
-	/*
-	 * we add in the count of missing devices because we want
-	 * to make sure that any RAID levels on a degraded FS
-	 * continue to be honored.
-	 */
-	num_devices = root->fs_info->fs_devices->rw_devices +
-		root->fs_info->fs_devices->missing_devices;
-
-	stripped = BTRFS_BLOCK_GROUP_RAID0 |
-		BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
-
-	if (num_devices == 1) {
-		stripped |= BTRFS_BLOCK_GROUP_DUP;
-		stripped = flags & ~stripped;
-
-		/* turn raid0 into single device chunks */
-		if (flags & BTRFS_BLOCK_GROUP_RAID0)
-			return stripped;
-
-		/* turn mirroring into duplication */
-		if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
-			     BTRFS_BLOCK_GROUP_RAID10))
-			return stripped | BTRFS_BLOCK_GROUP_DUP;
-	} else {
-		/* they already had raid on here, just return */
-		if (flags & stripped)
-			return flags;
-
-		stripped |= BTRFS_BLOCK_GROUP_DUP;
-		stripped = flags & ~stripped;
-
-		/* switch duplicated blocks with raid1 */
-		if (flags & BTRFS_BLOCK_GROUP_DUP)
-			return stripped | BTRFS_BLOCK_GROUP_RAID1;
-
-		/* this is drive concat, leave it alone */
-	}
-
-	return flags;
-}
-
-static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
-{
-	struct btrfs_space_info *sinfo = cache->space_info;
-	u64 num_bytes;
-	u64 min_allocable_bytes;
-	int ret = -ENOSPC;
-
-
-	/*
-	 * We need some metadata space and system metadata space for
-	 * allocating chunks in some corner cases until we force to set
-	 * it to be readonly.
-	 */
-	if ((sinfo->flags &
-	     (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
-	    !force)
-		min_allocable_bytes = 1 * 1024 * 1024;
-	else
-		min_allocable_bytes = 0;
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&cache->lock);
-
-	if (cache->ro) {
-		ret = 0;
-		goto out;
-	}
-
-	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
-		    cache->bytes_super - btrfs_block_group_used(&cache->item);
-
-	if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
-	    sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
-	    min_allocable_bytes <= sinfo->total_bytes) {
-		sinfo->bytes_readonly += num_bytes;
-		cache->ro = 1;
-		ret = 0;
-	}
-out:
-	spin_unlock(&cache->lock);
-	spin_unlock(&sinfo->lock);
-	return ret;
-}
-
-int btrfs_set_block_group_ro(struct btrfs_root *root,
-			     struct btrfs_block_group_cache *cache)
-
-{
-	struct btrfs_trans_handle *trans;
-	u64 alloc_flags;
-	int ret;
-
-	BUG_ON(cache->ro);
-
-	trans = btrfs_join_transaction(root);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
-
-	alloc_flags = update_block_group_flags(root, cache->flags);
-	if (alloc_flags != cache->flags) {
-		ret = do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
-				     CHUNK_ALLOC_FORCE);
-		if (ret < 0)
-			goto out;
-	}
-
-	ret = set_block_group_ro(cache, 0);
-	if (!ret)
-		goto out;
-	alloc_flags = get_alloc_profile(root, cache->space_info->flags);
-	ret = do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
-			     CHUNK_ALLOC_FORCE);
-	if (ret < 0)
-		goto out;
-	ret = set_block_group_ro(cache, 0);
-out:
-	btrfs_end_transaction(trans, root);
-	return ret;
-}
-
-int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
-			    struct btrfs_root *root, u64 type)
-{
-	u64 alloc_flags = get_alloc_profile(root, type);
-	return do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
-			      CHUNK_ALLOC_FORCE);
-}
-
-/*
- * helper to account the unused space of all the readonly block group in the
- * list. takes mirrors into account.
- */
-static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
-{
-	struct btrfs_block_group_cache *block_group;
-	u64 free_bytes = 0;
-	int factor;
-
-	list_for_each_entry(block_group, groups_list, list) {
-		spin_lock(&block_group->lock);
-
-		if (!block_group->ro) {
-			spin_unlock(&block_group->lock);
-			continue;
-		}
-
-		if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
-					  BTRFS_BLOCK_GROUP_RAID10 |
-					  BTRFS_BLOCK_GROUP_DUP))
-			factor = 2;
-		else
-			factor = 1;
-
-		free_bytes += (block_group->key.offset -
-			       btrfs_block_group_used(&block_group->item)) *
-			       factor;
-
-		spin_unlock(&block_group->lock);
-	}
-
-	return free_bytes;
-}
-
-/*
- * helper to account the unused space of all the readonly block group in the
- * space_info. takes mirrors into account.
- */
-u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
-{
-	int i;
-	u64 free_bytes = 0;
-
-	spin_lock(&sinfo->lock);
-
-	for(i = 0; i < BTRFS_NR_RAID_TYPES; i++)
-		if (!list_empty(&sinfo->block_groups[i]))
-			free_bytes += __btrfs_get_ro_block_group_free_space(
-						&sinfo->block_groups[i]);
-
-	spin_unlock(&sinfo->lock);
-
-	return free_bytes;
-}
-
-void btrfs_set_block_group_rw(struct btrfs_root *root,
-			      struct btrfs_block_group_cache *cache)
-{
-	struct btrfs_space_info *sinfo = cache->space_info;
-	u64 num_bytes;
-
-	BUG_ON(!cache->ro);
-
-	spin_lock(&sinfo->lock);
-	spin_lock(&cache->lock);
-	num_bytes = cache->key.offset - cache->reserved - cache->pinned -
-		    cache->bytes_super - btrfs_block_group_used(&cache->item);
-	sinfo->bytes_readonly -= num_bytes;
-	cache->ro = 0;
-	spin_unlock(&cache->lock);
-	spin_unlock(&sinfo->lock);
-}
-
-/*
- * checks to see if its even possible to relocate this block group.
- *
- * @return - -1 if it's not a good idea to relocate this block group, 0 if its
- * ok to go ahead and try.
- */
-int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_space_info *space_info;
-	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
-	struct btrfs_device *device;
-	u64 min_free;
-	u64 dev_min = 1;
-	u64 dev_nr = 0;
-	u64 target;
-	int index;
-	int full = 0;
-	int ret = 0;
-
-	block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
-
-	/* odd, couldn't find the block group, leave it alone */
-	if (!block_group)
-		return -1;
-
-	min_free = btrfs_block_group_used(&block_group->item);
-
-	/* no bytes used, we're good */
-	if (!min_free)
-		goto out;
-
-	space_info = block_group->space_info;
-	spin_lock(&space_info->lock);
-
-	full = space_info->full;
-
-	/*
-	 * if this is the last block group we have in this space, we can't
-	 * relocate it unless we're able to allocate a new chunk below.
-	 *
-	 * Otherwise, we need to make sure we have room in the space to handle
-	 * all of the extents from this block group.  If we can, we're good
-	 */
-	if ((space_info->total_bytes != block_group->key.offset) &&
-	    (space_info->bytes_used + space_info->bytes_reserved +
-	     space_info->bytes_pinned + space_info->bytes_readonly +
-	     min_free < space_info->total_bytes)) {
-		spin_unlock(&space_info->lock);
-		goto out;
-	}
-	spin_unlock(&space_info->lock);
-
-	/*
-	 * ok we don't have enough space, but maybe we have free space on our
-	 * devices to allocate new chunks for relocation, so loop through our
-	 * alloc devices and guess if we have enough space.  if this block
-	 * group is going to be restriped, run checks against the target
-	 * profile instead of the current one.
-	 */
-	ret = -1;
-
-	/*
-	 * index:
-	 *      0: raid10
-	 *      1: raid1
-	 *      2: dup
-	 *      3: raid0
-	 *      4: single
-	 */
-	target = get_restripe_target(root->fs_info, block_group->flags);
-	if (target) {
-		index = __get_block_group_index(extended_to_chunk(target));
-	} else {
-		/*
-		 * this is just a balance, so if we were marked as full
-		 * we know there is no space for a new chunk
-		 */
-		if (full)
-			goto out;
-
-		index = get_block_group_index(block_group);
-	}
-
-	if (index == 0) {
-		dev_min = 4;
-		/* Divide by 2 */
-		min_free >>= 1;
-	} else if (index == 1) {
-		dev_min = 2;
-	} else if (index == 2) {
-		/* Multiply by 2 */
-		min_free <<= 1;
-	} else if (index == 3) {
-		dev_min = fs_devices->rw_devices;
-		do_div(min_free, dev_min);
-	}
-
-	mutex_lock(&root->fs_info->chunk_mutex);
-	list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
-		u64 dev_offset;
-
-		/*
-		 * check to make sure we can actually find a chunk with enough
-		 * space to fit our block group in.
-		 */
-		if (device->total_bytes > device->bytes_used + min_free) {
-			ret = find_free_dev_extent(device, min_free,
-						   &dev_offset, NULL);
-			if (!ret)
-				dev_nr++;
-
-			if (dev_nr >= dev_min)
-				break;
-
-			ret = -1;
-		}
-	}
-	mutex_unlock(&root->fs_info->chunk_mutex);
-out:
-	btrfs_put_block_group(block_group);
-	return ret;
-}
-
-static int find_first_block_group(struct btrfs_root *root,
-		struct btrfs_path *path, struct btrfs_key *key)
-{
-	int ret = 0;
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
-	int slot;
-
-	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
-	if (ret < 0)
-		goto out;
-
-	while (1) {
-		slot = path->slots[0];
-		leaf = path->nodes[0];
-		if (slot >= btrfs_header_nritems(leaf)) {
-			ret = btrfs_next_leaf(root, path);
-			if (ret == 0)
-				continue;
-			if (ret < 0)
-				goto out;
-			break;
-		}
-		btrfs_item_key_to_cpu(leaf, &found_key, slot);
-
-		if (found_key.objectid >= key->objectid &&
-		    found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
-			ret = 0;
-			goto out;
-		}
-		path->slots[0]++;
-	}
-out:
-	return ret;
-}
-
-void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
-{
-	struct btrfs_block_group_cache *block_group;
-	u64 last = 0;
-
-	while (1) {
-		struct inode *inode;
-
-		block_group = btrfs_lookup_first_block_group(info, last);
-		while (block_group) {
-			spin_lock(&block_group->lock);
-			if (block_group->iref)
-				break;
-			spin_unlock(&block_group->lock);
-			block_group = next_block_group(info->tree_root,
-						       block_group);
-		}
-		if (!block_group) {
-			if (last == 0)
-				break;
-			last = 0;
-			continue;
-		}
-
-		inode = block_group->inode;
-		block_group->iref = 0;
-		block_group->inode = NULL;
-		spin_unlock(&block_group->lock);
-		iput(inode);
-		last = block_group->key.objectid + block_group->key.offset;
-		btrfs_put_block_group(block_group);
-	}
-}
-
-int btrfs_free_block_groups(struct btrfs_fs_info *info)
-{
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_space_info *space_info;
-	struct btrfs_caching_control *caching_ctl;
-	struct rb_node *n;
-
-	down_write(&info->extent_commit_sem);
-	while (!list_empty(&info->caching_block_groups)) {
-		caching_ctl = list_entry(info->caching_block_groups.next,
-					 struct btrfs_caching_control, list);
-		list_del(&caching_ctl->list);
-		put_caching_control(caching_ctl);
-	}
-	up_write(&info->extent_commit_sem);
-
-	spin_lock(&info->block_group_cache_lock);
-	while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
-		block_group = rb_entry(n, struct btrfs_block_group_cache,
-				       cache_node);
-		rb_erase(&block_group->cache_node,
-			 &info->block_group_cache_tree);
-		spin_unlock(&info->block_group_cache_lock);
-
-		down_write(&block_group->space_info->groups_sem);
-		list_del(&block_group->list);
-		up_write(&block_group->space_info->groups_sem);
-
-		if (block_group->cached == BTRFS_CACHE_STARTED)
-			wait_block_group_cache_done(block_group);
-
-		/*
-		 * We haven't cached this block group, which means we could
-		 * possibly have excluded extents on this block group.
-		 */
-		if (block_group->cached == BTRFS_CACHE_NO)
-			free_excluded_extents(info->extent_root, block_group);
-
-		btrfs_remove_free_space_cache(block_group);
-		btrfs_put_block_group(block_group);
-
-		spin_lock(&info->block_group_cache_lock);
-	}
-	spin_unlock(&info->block_group_cache_lock);
-
-	/* now that all the block groups are freed, go through and
-	 * free all the space_info structs.  This is only called during
-	 * the final stages of unmount, and so we know nobody is
-	 * using them.  We call synchronize_rcu() once before we start,
-	 * just to be on the safe side.
-	 */
-	synchronize_rcu();
-
-	release_global_block_rsv(info);
-
-	while(!list_empty(&info->space_info)) {
-		space_info = list_entry(info->space_info.next,
-					struct btrfs_space_info,
-					list);
-		if (space_info->bytes_pinned > 0 ||
-		    space_info->bytes_reserved > 0 ||
-		    space_info->bytes_may_use > 0) {
-			WARN_ON(1);
-			dump_space_info(space_info, 0, 0);
-		}
-		list_del(&space_info->list);
-		kfree(space_info);
-	}
-	return 0;
-}
-
-static void __link_block_group(struct btrfs_space_info *space_info,
-			       struct btrfs_block_group_cache *cache)
-{
-	int index = get_block_group_index(cache);
-
-	down_write(&space_info->groups_sem);
-	list_add_tail(&cache->list, &space_info->block_groups[index]);
-	up_write(&space_info->groups_sem);
-}
-
-int btrfs_read_block_groups(struct btrfs_root *root)
-{
-	struct btrfs_path *path;
-	int ret;
-	struct btrfs_block_group_cache *cache;
-	struct btrfs_fs_info *info = root->fs_info;
-	struct btrfs_space_info *space_info;
-	struct btrfs_key key;
-	struct btrfs_key found_key;
-	struct extent_buffer *leaf;
-	int need_clear = 0;
-	u64 cache_gen;
-
-	root = info->extent_root;
-	key.objectid = 0;
-	key.offset = 0;
-	btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-	path->reada = 1;
-
-	cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
-	if (btrfs_test_opt(root, SPACE_CACHE) &&
-	    btrfs_super_generation(root->fs_info->super_copy) != cache_gen)
-		need_clear = 1;
-	if (btrfs_test_opt(root, CLEAR_CACHE))
-		need_clear = 1;
-
-	while (1) {
-		ret = find_first_block_group(root, path, &key);
-		if (ret > 0)
-			break;
-		if (ret != 0)
-			goto error;
-		leaf = path->nodes[0];
-		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
-		cache = kzalloc(sizeof(*cache), GFP_NOFS);
-		if (!cache) {
-			ret = -ENOMEM;
-			goto error;
-		}
-		cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
-						GFP_NOFS);
-		if (!cache->free_space_ctl) {
-			kfree(cache);
-			ret = -ENOMEM;
-			goto error;
-		}
-
-		atomic_set(&cache->count, 1);
-		spin_lock_init(&cache->lock);
-		cache->fs_info = info;
-		INIT_LIST_HEAD(&cache->list);
-		INIT_LIST_HEAD(&cache->cluster_list);
-
-		if (need_clear)
-			cache->disk_cache_state = BTRFS_DC_CLEAR;
-
-		read_extent_buffer(leaf, &cache->item,
-				   btrfs_item_ptr_offset(leaf, path->slots[0]),
-				   sizeof(cache->item));
-		memcpy(&cache->key, &found_key, sizeof(found_key));
-
-		key.objectid = found_key.objectid + found_key.offset;
-		btrfs_release_path(path);
-		cache->flags = btrfs_block_group_flags(&cache->item);
-		cache->sectorsize = root->sectorsize;
-
-		btrfs_init_free_space_ctl(cache);
-
-		/*
-		 * We need to exclude the super stripes now so that the space
-		 * info has super bytes accounted for, otherwise we'll think
-		 * we have more space than we actually do.
-		 */
-		exclude_super_stripes(root, cache);
-
-		/*
-		 * check for two cases, either we are full, and therefore
-		 * don't need to bother with the caching work since we won't
-		 * find any space, or we are empty, and we can just add all
-		 * the space in and be done with it.  This saves us _alot_ of
-		 * time, particularly in the full case.
-		 */
-		if (found_key.offset == btrfs_block_group_used(&cache->item)) {
-			cache->last_byte_to_unpin = (u64)-1;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			free_excluded_extents(root, cache);
-		} else if (btrfs_block_group_used(&cache->item) == 0) {
-			cache->last_byte_to_unpin = (u64)-1;
-			cache->cached = BTRFS_CACHE_FINISHED;
-			add_new_free_space(cache, root->fs_info,
-					   found_key.objectid,
-					   found_key.objectid +
-					   found_key.offset);
-			free_excluded_extents(root, cache);
-		}
-
-		ret = update_space_info(info, cache->flags, found_key.offset,
-					btrfs_block_group_used(&cache->item),
-					&space_info);
-		BUG_ON(ret); /* -ENOMEM */
-		cache->space_info = space_info;
-		spin_lock(&cache->space_info->lock);
-		cache->space_info->bytes_readonly += cache->bytes_super;
-		spin_unlock(&cache->space_info->lock);
-
-		__link_block_group(space_info, cache);
-
-		ret = btrfs_add_block_group_cache(root->fs_info, cache);
-		BUG_ON(ret); /* Logic error */
-
-		set_avail_alloc_bits(root->fs_info, cache->flags);
-		if (btrfs_chunk_readonly(root, cache->key.objectid))
-			set_block_group_ro(cache, 1);
-	}
-
-	list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
-		if (!(get_alloc_profile(root, space_info->flags) &
-		      (BTRFS_BLOCK_GROUP_RAID10 |
-		       BTRFS_BLOCK_GROUP_RAID1 |
-		       BTRFS_BLOCK_GROUP_DUP)))
-			continue;
-		/*
-		 * avoid allocating from un-mirrored block group if there are
-		 * mirrored block groups.
-		 */
-		list_for_each_entry(cache, &space_info->block_groups[3], list)
-			set_block_group_ro(cache, 1);
-		list_for_each_entry(cache, &space_info->block_groups[4], list)
-			set_block_group_ro(cache, 1);
-	}
-
-	init_global_block_rsv(info);
-	ret = 0;
-error:
-	btrfs_free_path(path);
-	return ret;
-}
-
-int btrfs_make_block_group(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root, u64 bytes_used,
-			   u64 type, u64 chunk_objectid, u64 chunk_offset,
-			   u64 size)
-{
-	int ret;
-	struct btrfs_root *extent_root;
-	struct btrfs_block_group_cache *cache;
-
-	extent_root = root->fs_info->extent_root;
-
-	root->fs_info->last_trans_log_full_commit = trans->transid;
-
-	cache = kzalloc(sizeof(*cache), GFP_NOFS);
-	if (!cache)
-		return -ENOMEM;
-	cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
-					GFP_NOFS);
-	if (!cache->free_space_ctl) {
-		kfree(cache);
-		return -ENOMEM;
-	}
-
-	cache->key.objectid = chunk_offset;
-	cache->key.offset = size;
-	cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
-	cache->sectorsize = root->sectorsize;
-	cache->fs_info = root->fs_info;
-
-	atomic_set(&cache->count, 1);
-	spin_lock_init(&cache->lock);
-	INIT_LIST_HEAD(&cache->list);
-	INIT_LIST_HEAD(&cache->cluster_list);
-
-	btrfs_init_free_space_ctl(cache);
-
-	btrfs_set_block_group_used(&cache->item, bytes_used);
-	btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
-	cache->flags = type;
-	btrfs_set_block_group_flags(&cache->item, type);
-
-	cache->last_byte_to_unpin = (u64)-1;
-	cache->cached = BTRFS_CACHE_FINISHED;
-	exclude_super_stripes(root, cache);
-
-	add_new_free_space(cache, root->fs_info, chunk_offset,
-			   chunk_offset + size);
-
-	free_excluded_extents(root, cache);
-
-	ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
-				&cache->space_info);
-	BUG_ON(ret); /* -ENOMEM */
-	update_global_block_rsv(root->fs_info);
-
-	spin_lock(&cache->space_info->lock);
-	cache->space_info->bytes_readonly += cache->bytes_super;
-	spin_unlock(&cache->space_info->lock);
-
-	__link_block_group(cache->space_info, cache);
-
-	ret = btrfs_add_block_group_cache(root->fs_info, cache);
-	BUG_ON(ret); /* Logic error */
-
-	ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item,
-				sizeof(cache->item));
-	if (ret) {
-		btrfs_abort_transaction(trans, extent_root, ret);
-		return ret;
-	}
-
-	set_avail_alloc_bits(extent_root->fs_info, type);
-
-	return 0;
-}
-
-static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
-{
-	u64 extra_flags = chunk_to_extended(flags) &
-				BTRFS_EXTENDED_PROFILE_MASK;
-
-	if (flags & BTRFS_BLOCK_GROUP_DATA)
-		fs_info->avail_data_alloc_bits &= ~extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_METADATA)
-		fs_info->avail_metadata_alloc_bits &= ~extra_flags;
-	if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
-		fs_info->avail_system_alloc_bits &= ~extra_flags;
-}
-
-int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
-			     struct btrfs_root *root, u64 group_start)
-{
-	struct btrfs_path *path;
-	struct btrfs_block_group_cache *block_group;
-	struct btrfs_free_cluster *cluster;
-	struct btrfs_root *tree_root = root->fs_info->tree_root;
-	struct btrfs_key key;
-	struct inode *inode;
-	int ret;
-	int index;
-	int factor;
-
-	root = root->fs_info->extent_root;
-
-	block_group = btrfs_lookup_block_group(root->fs_info, group_start);
-	BUG_ON(!block_group);
-	BUG_ON(!block_group->ro);
-
-	/*
-	 * Free the reserved super bytes from this block group before
-	 * remove it.
-	 */
-	free_excluded_extents(root, block_group);
-
-	memcpy(&key, &block_group->key, sizeof(key));
-	index = get_block_group_index(block_group);
-	if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
-				  BTRFS_BLOCK_GROUP_RAID1 |
-				  BTRFS_BLOCK_GROUP_RAID10))
-		factor = 2;
-	else
-		factor = 1;
-
-	/* make sure this block group isn't part of an allocation cluster */
-	cluster = &root->fs_info->data_alloc_cluster;
-	spin_lock(&cluster->refill_lock);
-	btrfs_return_cluster_to_free_space(block_group, cluster);
-	spin_unlock(&cluster->refill_lock);
-
-	/*
-	 * make sure this block group isn't part of a metadata
-	 * allocation cluster
-	 */
-	cluster = &root->fs_info->meta_alloc_cluster;
-	spin_lock(&cluster->refill_lock);
-	btrfs_return_cluster_to_free_space(block_group, cluster);
-	spin_unlock(&cluster->refill_lock);
-
-	path = btrfs_alloc_path();
-	if (!path) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	inode = lookup_free_space_inode(tree_root, block_group, path);
-	if (!IS_ERR(inode)) {
-		ret = btrfs_orphan_add(trans, inode);
-		if (ret) {
-			btrfs_add_delayed_iput(inode);
-			goto out;
-		}
-		clear_nlink(inode);
-		/* One for the block groups ref */
-		spin_lock(&block_group->lock);
-		if (block_group->iref) {
-			block_group->iref = 0;
-			block_group->inode = NULL;
-			spin_unlock(&block_group->lock);
-			iput(inode);
-		} else {
-			spin_unlock(&block_group->lock);
-		}
-		/* One for our lookup ref */
-		btrfs_add_delayed_iput(inode);
-	}
-
-	key.objectid = BTRFS_FREE_SPACE_OBJECTID;
-	key.offset = block_group->key.objectid;
-	key.type = 0;
-
-	ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
-	if (ret < 0)
-		goto out;
-	if (ret > 0)
-		btrfs_release_path(path);
-	if (ret == 0) {
-		ret = btrfs_del_item(trans, tree_root, path);
-		if (ret)
-			goto out;
-		btrfs_release_path(path);
-	}
-
-	spin_lock(&root->fs_info->block_group_cache_lock);
-	rb_erase(&block_group->cache_node,
-		 &root->fs_info->block_group_cache_tree);
-	spin_unlock(&root->fs_info->block_group_cache_lock);
-
-	down_write(&block_group->space_info->groups_sem);
-	/*
-	 * we must use list_del_init so people can check to see if they
-	 * are still on the list after taking the semaphore
-	 */
-	list_del_init(&block_group->list);
-	if (list_empty(&block_group->space_info->block_groups[index]))
-		clear_avail_alloc_bits(root->fs_info, block_group->flags);
-	up_write(&block_group->space_info->groups_sem);
-
-	if (block_group->cached == BTRFS_CACHE_STARTED)
-		wait_block_group_cache_done(block_group);
-
-	btrfs_remove_free_space_cache(block_group);
-
-	spin_lock(&block_group->space_info->lock);
-	block_group->space_info->total_bytes -= block_group->key.offset;
-	block_group->space_info->bytes_readonly -= block_group->key.offset;
-	block_group->space_info->disk_total -= block_group->key.offset * factor;
-	spin_unlock(&block_group->space_info->lock);
-
-	memcpy(&key, &block_group->key, sizeof(key));
-
-	btrfs_clear_space_info_full(root->fs_info);
-
-	btrfs_put_block_group(block_group);
-	btrfs_put_block_group(block_group);
-
-	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-	if (ret > 0)
-		ret = -EIO;
-	if (ret < 0)
-		goto out;
-
-	ret = btrfs_del_item(trans, root, path);
-out:
-	btrfs_free_path(path);
-	return ret;
-}
-
-int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_space_info *space_info;
-	struct btrfs_super_block *disk_super;
-	u64 features;
-	u64 flags;
-	int mixed = 0;
-	int ret;
-
-	disk_super = fs_info->super_copy;
-	if (!btrfs_super_root(disk_super))
-		return 1;
-
-	features = btrfs_super_incompat_flags(disk_super);
-	if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
-		mixed = 1;
-
-	flags = BTRFS_BLOCK_GROUP_SYSTEM;
-	ret = update_space_info(fs_info, flags, 0, 0, &space_info);
-	if (ret)
-		goto out;
-
-	if (mixed) {
-		flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
-		ret = update_space_info(fs_info, flags, 0, 0, &space_info);
-	} else {
-		flags = BTRFS_BLOCK_GROUP_METADATA;
-		ret = update_space_info(fs_info, flags, 0, 0, &space_info);
-		if (ret)
-			goto out;
-
-		flags = BTRFS_BLOCK_GROUP_DATA;
-		ret = update_space_info(fs_info, flags, 0, 0, &space_info);
-	}
-out:
-	return ret;
-}
-
-int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
-{
-	return unpin_extent_range(root, start, end);
-}
-
-int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
-			       u64 num_bytes, u64 *actual_bytes)
-{
-	return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
-}
-
-int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct btrfs_block_group_cache *cache = NULL;
-	u64 group_trimmed;
-	u64 start;
-	u64 end;
-	u64 trimmed = 0;
-	u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
-	int ret = 0;
-
-	/*
-	 * try to trim all FS space, our block group may start from non-zero.
-	 */
-	if (range->len == total_bytes)
-		cache = btrfs_lookup_first_block_group(fs_info, range->start);
-	else
-		cache = btrfs_lookup_block_group(fs_info, range->start);
-
-	while (cache) {
-		if (cache->key.objectid >= (range->start + range->len)) {
-			btrfs_put_block_group(cache);
-			break;
-		}
-
-		start = max(range->start, cache->key.objectid);
-		end = min(range->start + range->len,
-				cache->key.objectid + cache->key.offset);
-
-		if (end - start >= range->minlen) {
-			if (!block_group_cache_done(cache)) {
-				ret = cache_block_group(cache, NULL, root, 0);
-				if (!ret)
-					wait_block_group_cache_done(cache);
-			}
-			ret = btrfs_trim_block_group(cache,
-						     &group_trimmed,
-						     start,
-						     end,
-						     range->minlen);
-
-			trimmed += group_trimmed;
-			if (ret) {
-				btrfs_put_block_group(cache);
-				break;
-			}
-		}
-
-		cache = next_block_group(fs_info->tree_root, cache);
-	}
-
-	range->len = trimmed;
-	return ret;
-}