1 files changed, 360 insertions, 139 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 3efe1c3877b..a684086c3c8 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -315,12 +315,6 @@ 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;
@@ -491,7 +485,7 @@ next:
 							  key.objectid);
 			if (key.type == BTRFS_METADATA_ITEM_KEY)
 				last = key.objectid +
-					fs_info->tree_root->leafsize;
+					fs_info->tree_root->nodesize;
 			else
 				last = key.objectid + key.offset;
 
@@ -594,6 +588,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
 	spin_unlock(&cache->lock);
 
 	if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
+		mutex_lock(&caching_ctl->mutex);
 		ret = load_free_space_cache(fs_info, cache);
 
 		spin_lock(&cache->lock);
@@ -601,15 +596,19 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
 			cache->caching_ctl = NULL;
 			cache->cached = BTRFS_CACHE_FINISHED;
 			cache->last_byte_to_unpin = (u64)-1;
+			caching_ctl->progress = (u64)-1;
 		} else {
 			if (load_cache_only) {
 				cache->caching_ctl = NULL;
 				cache->cached = BTRFS_CACHE_NO;
 			} else {
 				cache->cached = BTRFS_CACHE_STARTED;
+				cache->has_caching_ctl = 1;
 			}
 		}
 		spin_unlock(&cache->lock);
+		mutex_unlock(&caching_ctl->mutex);
+
 		wake_up(&caching_ctl->wait);
 		if (ret == 1) {
 			put_caching_control(caching_ctl);
@@ -627,6 +626,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
 			cache->cached = BTRFS_CACHE_NO;
 		} else {
 			cache->cached = BTRFS_CACHE_STARTED;
+			cache->has_caching_ctl = 1;
 		}
 		spin_unlock(&cache->lock);
 		wake_up(&caching_ctl->wait);
@@ -710,8 +710,8 @@ void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
 	rcu_read_unlock();
 }
 
-/* simple helper to search for an existing extent at a given offset */
-int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
+/* simple helper to search for an existing data extent at a given offset */
+int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len)
 {
 	int ret;
 	struct btrfs_key key;
@@ -726,12 +726,6 @@ int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
 	key.type = BTRFS_EXTENT_ITEM_KEY;
 	ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
 				0, 0);
-	if (ret > 0) {
-		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
-		if (key.objectid == start &&
-		    key.type == BTRFS_METADATA_ITEM_KEY)
-			ret = 0;
-	}
 	btrfs_free_path(path);
 	return ret;
 }
@@ -765,7 +759,7 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 	 * different
 	 */
 	if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
-		offset = root->leafsize;
+		offset = root->nodesize;
 		metadata = 0;
 	}
 
@@ -786,7 +780,6 @@ search_again:
 	else
 		key.type = BTRFS_EXTENT_ITEM_KEY;
 
-again:
 	ret = btrfs_search_slot(trans, root->fs_info->extent_root,
 				&key, path, 0, 0);
 	if (ret < 0)
@@ -799,16 +792,9 @@ again:
 					      path->slots[0]);
 			if (key.objectid == bytenr &&
 			    key.type == BTRFS_EXTENT_ITEM_KEY &&
-			    key.offset == root->leafsize)
+			    key.offset == root->nodesize)
 				ret = 0;
 		}
-		if (ret) {
-			key.objectid = bytenr;
-			key.type = BTRFS_EXTENT_ITEM_KEY;
-			key.offset = root->leafsize;
-			btrfs_release_path(path);
-			goto again;
-		}
 	}
 
 	if (ret == 0) {
@@ -1903,8 +1889,8 @@ static int btrfs_issue_discard(struct block_device *bdev,
 	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 btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
+			 u64 num_bytes, u64 *actual_bytes)
 {
 	int ret;
 	u64 discarded_bytes = 0;
@@ -2651,7 +2637,7 @@ int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
 	num_bytes = btrfs_calc_trans_metadata_size(root, 1);
 	num_heads = heads_to_leaves(root, num_heads);
 	if (num_heads > 1)
-		num_bytes += (num_heads - 1) * root->leafsize;
+		num_bytes += (num_heads - 1) * root->nodesize;
 	num_bytes <<= 1;
 	global_rsv = &root->fs_info->global_block_rsv;
 
@@ -3073,10 +3059,10 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
 	int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
 			    u64, u64, u64, u64, u64, u64, int);
 
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-	if (unlikely(test_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state)))
+
+	if (btrfs_test_is_dummy_root(root))
 		return 0;
-#endif
+
 	ref_root = btrfs_header_owner(buf);
 	nritems = btrfs_header_nritems(buf);
 	level = btrfs_header_level(buf);
@@ -3097,7 +3083,7 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
 	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)
+			if (key.type != BTRFS_EXTENT_DATA_KEY)
 				continue;
 			fi = btrfs_item_ptr(buf, i,
 					    struct btrfs_file_extent_item);
@@ -3117,7 +3103,7 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
 				goto fail;
 		} else {
 			bytenr = btrfs_node_blockptr(buf, i);
-			num_bytes = btrfs_level_size(root, level - 1);
+			num_bytes = root->nodesize;
 			ret = process_func(trans, root, bytenr, num_bytes,
 					   parent, ref_root, level - 1, 0,
 					   1);
@@ -3153,9 +3139,11 @@ static int write_one_cache_group(struct btrfs_trans_handle *trans,
 	struct extent_buffer *leaf;
 
 	ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
-	if (ret < 0)
+	if (ret) {
+		if (ret > 0)
+			ret = -ENOENT;
 		goto fail;
-	BUG_ON(ret); /* Corruption */
+	}
 
 	leaf = path->nodes[0];
 	bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
@@ -3163,11 +3151,9 @@ static int write_one_cache_group(struct btrfs_trans_handle *trans,
 	btrfs_mark_buffer_dirty(leaf);
 	btrfs_release_path(path);
 fail:
-	if (ret) {
+	if (ret)
 		btrfs_abort_transaction(trans, root, ret);
-		return ret;
-	}
-	return 0;
+	return ret;
 
 }
 
@@ -3176,7 +3162,19 @@ 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);
+
+	/* If our block group was removed, we need a full search. */
+	if (RB_EMPTY_NODE(&cache->cache_node)) {
+		const u64 next_bytenr = cache->key.objectid + cache->key.offset;
+
+		spin_unlock(&root->fs_info->block_group_cache_lock);
+		btrfs_put_block_group(cache);
+		cache = btrfs_lookup_first_block_group(root->fs_info,
+						       next_bytenr);
+		return cache;
+	}
 	node = rb_next(&cache->cache_node);
 	btrfs_put_block_group(cache);
 	if (node) {
@@ -3494,7 +3492,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
 	if (!found)
 		return -ENOMEM;
 
-	ret = percpu_counter_init(&found->total_bytes_pinned, 0);
+	ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL);
 	if (ret) {
 		kfree(found);
 		return ret;
@@ -3518,6 +3516,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
 	found->chunk_alloc = 0;
 	found->flush = 0;
 	init_waitqueue_head(&found->wait);
+	INIT_LIST_HEAD(&found->ro_bgs);
 
 	ret = kobject_init_and_add(&found->kobj, &space_info_ktype,
 				    info->space_info_kobj, "%s",
@@ -4343,11 +4342,21 @@ static inline int need_do_async_reclaim(struct btrfs_space_info *space_info,
 }
 
 static int btrfs_need_do_async_reclaim(struct btrfs_space_info *space_info,
-				       struct btrfs_fs_info *fs_info)
+				       struct btrfs_fs_info *fs_info,
+				       int flush_state)
 {
 	u64 used;
 
 	spin_lock(&space_info->lock);
+	/*
+	 * We run out of space and have not got any free space via flush_space,
+	 * so don't bother doing async reclaim.
+	 */
+	if (flush_state > COMMIT_TRANS && space_info->full) {
+		spin_unlock(&space_info->lock);
+		return 0;
+	}
+
 	used = space_info->bytes_used + space_info->bytes_reserved +
 	       space_info->bytes_pinned + space_info->bytes_readonly +
 	       space_info->bytes_may_use;
@@ -4380,11 +4389,12 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
 		flush_space(fs_info->fs_root, space_info, to_reclaim,
 			    to_reclaim, flush_state);
 		flush_state++;
-		if (!btrfs_need_do_async_reclaim(space_info, fs_info))
+		if (!btrfs_need_do_async_reclaim(space_info, fs_info,
+						 flush_state))
 			return;
 	} while (flush_state <= COMMIT_TRANS);
 
-	if (btrfs_need_do_async_reclaim(space_info, fs_info))
+	if (btrfs_need_do_async_reclaim(space_info, fs_info, flush_state))
 		queue_work(system_unbound_wq, work);
 }
 
@@ -4502,7 +4512,13 @@ again:
 		space_info->flush = 1;
 	} else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
 		used += orig_bytes;
-		if (need_do_async_reclaim(space_info, root->fs_info, used) &&
+		/*
+		 * We will do the space reservation dance during log replay,
+		 * which means we won't have fs_info->fs_root set, so don't do
+		 * the async reclaim as we will panic.
+		 */
+		if (!root->fs_info->log_root_recovering &&
+		    need_do_async_reclaim(space_info, root->fs_info, used) &&
 		    !work_busy(&root->fs_info->async_reclaim_work))
 			queue_work(system_unbound_wq,
 				   &root->fs_info->async_reclaim_work);
@@ -4839,7 +4855,7 @@ static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
 	if (num_bytes * 3 > meta_used)
 		num_bytes = div64_u64(meta_used, 3);
 
-	return ALIGN(num_bytes, fs_info->extent_root->leafsize << 10);
+	return ALIGN(num_bytes, fs_info->extent_root->nodesize << 10);
 }
 
 static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
@@ -4988,7 +5004,7 @@ int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
 
 	if (root->fs_info->quota_enabled) {
 		/* One for parent inode, two for dir entries */
-		num_bytes = 3 * root->leafsize;
+		num_bytes = 3 * root->nodesize;
 		ret = btrfs_qgroup_reserve(root, num_bytes);
 		if (ret)
 			return ret;
@@ -5176,7 +5192,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 
 	if (root->fs_info->quota_enabled) {
 		ret = btrfs_qgroup_reserve(root, num_bytes +
-					   nr_extents * root->leafsize);
+					   nr_extents * root->nodesize);
 		if (ret)
 			goto out_fail;
 	}
@@ -5185,7 +5201,7 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 	if (unlikely(ret)) {
 		if (root->fs_info->quota_enabled)
 			btrfs_qgroup_free(root, num_bytes +
-						nr_extents * root->leafsize);
+						nr_extents * root->nodesize);
 		goto out_fail;
 	}
 
@@ -5301,7 +5317,7 @@ void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
 				      btrfs_ino(inode), to_free, 0);
 	if (root->fs_info->quota_enabled) {
 		btrfs_qgroup_free(root, num_bytes +
-					dropped * root->leafsize);
+					dropped * root->nodesize);
 	}
 
 	btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
@@ -5433,6 +5449,19 @@ static int update_block_group(struct btrfs_root *root,
 			set_extent_dirty(info->pinned_extents,
 					 bytenr, bytenr + num_bytes - 1,
 					 GFP_NOFS | __GFP_NOFAIL);
+			/*
+			 * No longer have used bytes in this block group, queue
+			 * it for deletion.
+			 */
+			if (old_val == 0) {
+				spin_lock(&info->unused_bgs_lock);
+				if (list_empty(&cache->bg_list)) {
+					btrfs_get_block_group(cache);
+					list_add_tail(&cache->bg_list,
+						      &info->unused_bgs);
+				}
+				spin_unlock(&info->unused_bgs_lock);
+			}
 		}
 		btrfs_put_block_group(cache);
 		total -= num_bytes;
@@ -5698,7 +5727,8 @@ void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
 	update_global_block_rsv(fs_info);
 }
 
-static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
+static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end,
+			      const bool return_free_space)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_block_group_cache *cache = NULL;
@@ -5722,7 +5752,8 @@ static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
 
 		if (start < cache->last_byte_to_unpin) {
 			len = min(len, cache->last_byte_to_unpin - start);
-			btrfs_add_free_space(cache, start, len);
+			if (return_free_space)
+				btrfs_add_free_space(cache, start, len);
 		}
 
 		start += len;
@@ -5786,7 +5817,7 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
 						   end + 1 - start, NULL);
 
 		clear_extent_dirty(unpin, start, end, GFP_NOFS);
-		unpin_extent_range(root, start, end);
+		unpin_extent_range(root, start, end, true);
 		cond_resched();
 	}
 
@@ -6233,10 +6264,9 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	int ret;
 	struct btrfs_fs_info *fs_info = root->fs_info;
 
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-	if (unlikely(test_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state)))
+	if (btrfs_test_is_dummy_root(root))
 		return 0;
-#endif
+
 	add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid);
 
 	/*
@@ -6263,14 +6293,6 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	return ret;
 }
 
-static u64 stripe_align(struct btrfs_root *root,
-			struct btrfs_block_group_cache *cache,
-			u64 val, u64 num_bytes)
-{
-	u64 ret = ALIGN(val, root->stripesize);
-	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
@@ -6464,7 +6486,7 @@ static noinline int find_free_extent(struct btrfs_root *orig_root,
 	bool have_caching_bg = false;
 
 	WARN_ON(num_bytes < root->sectorsize);
-	btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
+	ins->type = BTRFS_EXTENT_ITEM_KEY;
 	ins->objectid = 0;
 	ins->offset = 0;
 
@@ -6751,8 +6773,7 @@ unclustered_alloc:
 			goto loop;
 		}
 checks:
-		search_start = stripe_align(root, block_group,
-					    offset, num_bytes);
+		search_start = ALIGN(offset, root->stripesize);
 
 		/* move on to the next group */
 		if (search_start + num_bytes >
@@ -7077,7 +7098,7 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 	path = btrfs_alloc_path();
 	if (!path) {
 		btrfs_free_and_pin_reserved_extent(root, ins->objectid,
-						   root->leafsize);
+						   root->nodesize);
 		return -ENOMEM;
 	}
 
@@ -7086,7 +7107,7 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 				      ins, size);
 	if (ret) {
 		btrfs_free_and_pin_reserved_extent(root, ins->objectid,
-						   root->leafsize);
+						   root->nodesize);
 		btrfs_free_path(path);
 		return ret;
 	}
@@ -7101,7 +7122,7 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 
 	if (skinny_metadata) {
 		iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
-		num_bytes = root->leafsize;
+		num_bytes = root->nodesize;
 	} else {
 		block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
 		btrfs_set_tree_block_key(leaf, block_info, key);
@@ -7131,14 +7152,14 @@ static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
 			return ret;
 	}
 
-	ret = update_block_group(root, ins->objectid, root->leafsize, 1);
+	ret = update_block_group(root, ins->objectid, root->nodesize, 1);
 	if (ret) { /* -ENOENT, logic error */
 		btrfs_err(fs_info, "update block group failed for %llu %llu",
 			ins->objectid, ins->offset);
 		BUG();
 	}
 
-	trace_btrfs_reserved_extent_alloc(root, ins->objectid, root->leafsize);
+	trace_btrfs_reserved_extent_alloc(root, ins->objectid, root->nodesize);
 	return ret;
 }
 
@@ -7213,17 +7234,19 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	btrfs_set_buffer_uptodate(buf);
 
 	if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+		buf->log_index = root->log_transid % 2;
 		/*
 		 * we allow two log transactions at a time, use different
 		 * EXENT bit to differentiate dirty pages.
 		 */
-		if (root->log_transid % 2 == 0)
+		if (buf->log_index == 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 {
+		buf->log_index = -1;
 		set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
 			 buf->start + buf->len - 1, GFP_NOFS);
 	}
@@ -7300,8 +7323,8 @@ static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
  *
  * returns the tree buffer or NULL.
  */
-struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
-					struct btrfs_root *root, u32 blocksize,
+struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
+					struct btrfs_root *root,
 					u64 parent, u64 root_objectid,
 					struct btrfs_disk_key *key, int level,
 					u64 hint, u64 empty_size)
@@ -7311,18 +7334,18 @@ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
 	struct extent_buffer *buf;
 	u64 flags = 0;
 	int ret;
+	u32 blocksize = root->nodesize;
 	bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
 						 SKINNY_METADATA);
 
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-	if (unlikely(test_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state))) {
+	if (btrfs_test_is_dummy_root(root)) {
 		buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
 					    blocksize, level);
 		if (!IS_ERR(buf))
 			root->alloc_bytenr += blocksize;
 		return buf;
 	}
-#endif
+
 	block_rsv = use_block_rsv(trans, root, blocksize);
 	if (IS_ERR(block_rsv))
 		return ERR_CAST(block_rsv);
@@ -7417,7 +7440,7 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
 
 	eb = path->nodes[wc->level];
 	nritems = btrfs_header_nritems(eb);
-	blocksize = btrfs_level_size(root, wc->level - 1);
+	blocksize = root->nodesize;
 
 	for (slot = path->slots[wc->level]; slot < nritems; slot++) {
 		if (nread >= wc->reada_count)
@@ -7464,10 +7487,7 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
 				continue;
 		}
 reada:
-		ret = readahead_tree_block(root, bytenr, blocksize,
-					   generation);
-		if (ret)
-			break;
+		readahead_tree_block(root, bytenr, blocksize);
 		nread++;
 	}
 	wc->reada_slot = slot;
@@ -7626,7 +7646,6 @@ walk_down:
 	level = root_level;
 	while (level >= 0) {
 		if (path->nodes[level] == NULL) {
-			int child_bsize = root->nodesize;
 			int parent_slot;
 			u64 child_gen;
 			u64 child_bytenr;
@@ -7638,8 +7657,7 @@ walk_down:
 			child_bytenr = btrfs_node_blockptr(eb, parent_slot);
 			child_gen = btrfs_node_ptr_generation(eb, parent_slot);
 
-			eb = read_tree_block(root, child_bytenr, child_bsize,
-					     child_gen);
+			eb = read_tree_block(root, child_bytenr, child_gen);
 			if (!eb || !extent_buffer_uptodate(eb)) {
 				ret = -EIO;
 				goto out;
@@ -7655,7 +7673,7 @@ walk_down:
 			ret = btrfs_qgroup_record_ref(trans, root->fs_info,
 						root->objectid,
 						child_bytenr,
-						child_bsize,
+						root->nodesize,
 						BTRFS_QGROUP_OPER_SUB_SUBTREE,
 						0);
 			if (ret)
@@ -7806,9 +7824,9 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 	}
 
 	bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
-	blocksize = btrfs_level_size(root, level - 1);
+	blocksize = root->nodesize;
 
-	next = btrfs_find_tree_block(root, bytenr, blocksize);
+	next = btrfs_find_tree_block(root, bytenr);
 	if (!next) {
 		next = btrfs_find_create_tree_block(root, bytenr, blocksize);
 		if (!next)
@@ -7870,7 +7888,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 	if (!next) {
 		if (reada && level == 1)
 			reada_walk_down(trans, root, wc, path);
-		next = read_tree_block(root, bytenr, blocksize, generation);
+		next = read_tree_block(root, bytenr, generation);
 		if (!next || !extent_buffer_uptodate(next)) {
 			free_extent_buffer(next);
 			return -EIO;
@@ -8507,6 +8525,7 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
 	    min_allocable_bytes <= sinfo->total_bytes) {
 		sinfo->bytes_readonly += num_bytes;
 		cache->ro = 1;
+		list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
 		ret = 0;
 	}
 out:
@@ -8561,15 +8580,20 @@ int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
 
 /*
  * helper to account the unused space of all the readonly block group in the
- * list. takes mirrors into account.
+ * space_info. takes mirrors into account.
  */
-static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
+u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
 {
 	struct btrfs_block_group_cache *block_group;
 	u64 free_bytes = 0;
 	int factor;
 
-	list_for_each_entry(block_group, groups_list, list) {
+	/* It's df, we don't care if it's racey */
+	if (list_empty(&sinfo->ro_bgs))
+		return 0;
+
+	spin_lock(&sinfo->lock);
+	list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
 		spin_lock(&block_group->lock);
 
 		if (!block_group->ro) {
@@ -8590,26 +8614,6 @@ static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
 
 		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;
@@ -8629,6 +8633,7 @@ void btrfs_set_block_group_rw(struct btrfs_root *root,
 		    cache->bytes_super - btrfs_block_group_used(&cache->item);
 	sinfo->bytes_readonly -= num_bytes;
 	cache->ro = 0;
+	list_del_init(&cache->ro_list);
 	spin_unlock(&cache->lock);
 	spin_unlock(&sinfo->lock);
 }
@@ -8853,12 +8858,23 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
 	}
 	up_write(&info->commit_root_sem);
 
+	spin_lock(&info->unused_bgs_lock);
+	while (!list_empty(&info->unused_bgs)) {
+		block_group = list_first_entry(&info->unused_bgs,
+					       struct btrfs_block_group_cache,
+					       bg_list);
+		list_del_init(&block_group->bg_list);
+		btrfs_put_block_group(block_group);
+	}
+	spin_unlock(&info->unused_bgs_lock);
+
 	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);
+		RB_CLEAR_NODE(&block_group->cache_node);
 		spin_unlock(&info->block_group_cache_lock);
 
 		down_write(&block_group->space_info->groups_sem);
@@ -8987,8 +9003,10 @@ btrfs_create_block_group_cache(struct btrfs_root *root, u64 start, u64 size)
 	init_rwsem(&cache->data_rwsem);
 	INIT_LIST_HEAD(&cache->list);
 	INIT_LIST_HEAD(&cache->cluster_list);
-	INIT_LIST_HEAD(&cache->new_bg_list);
+	INIT_LIST_HEAD(&cache->bg_list);
+	INIT_LIST_HEAD(&cache->ro_list);
 	btrfs_init_free_space_ctl(cache);
+	atomic_set(&cache->trimming, 0);
 
 	return cache;
 }
@@ -9009,7 +9027,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 	root = info->extent_root;
 	key.objectid = 0;
 	key.offset = 0;
-	btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY);
+	key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
@@ -9115,6 +9133,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 			spin_lock(&info->block_group_cache_lock);
 			rb_erase(&cache->cache_node,
 				 &info->block_group_cache_tree);
+			RB_CLEAR_NODE(&cache->cache_node);
 			spin_unlock(&info->block_group_cache_lock);
 			btrfs_put_block_group(cache);
 			goto error;
@@ -9128,8 +9147,18 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 		__link_block_group(space_info, cache);
 
 		set_avail_alloc_bits(root->fs_info, cache->flags);
-		if (btrfs_chunk_readonly(root, cache->key.objectid))
+		if (btrfs_chunk_readonly(root, cache->key.objectid)) {
 			set_block_group_ro(cache, 1);
+		} else if (btrfs_block_group_used(&cache->item) == 0) {
+			spin_lock(&info->unused_bgs_lock);
+			/* Should always be true but just in case. */
+			if (list_empty(&cache->bg_list)) {
+				btrfs_get_block_group(cache);
+				list_add_tail(&cache->bg_list,
+					      &info->unused_bgs);
+			}
+			spin_unlock(&info->unused_bgs_lock);
+		}
 	}
 
 	list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
@@ -9170,12 +9199,9 @@ void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
 	struct btrfs_key key;
 	int ret = 0;
 
-	list_for_each_entry_safe(block_group, tmp, &trans->new_bgs,
-				 new_bg_list) {
-		list_del_init(&block_group->new_bg_list);
-
+	list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) {
 		if (ret)
-			continue;
+			goto next;
 
 		spin_lock(&block_group->lock);
 		memcpy(&item, &block_group->item, sizeof(item));
@@ -9190,6 +9216,8 @@ void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
 					       key.objectid, key.offset);
 		if (ret)
 			btrfs_abort_transaction(trans, extent_root, ret);
+next:
+		list_del_init(&block_group->bg_list);
 	}
 }
 
@@ -9247,6 +9275,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 		spin_lock(&root->fs_info->block_group_cache_lock);
 		rb_erase(&cache->cache_node,
 			 &root->fs_info->block_group_cache_tree);
+		RB_CLEAR_NODE(&cache->cache_node);
 		spin_unlock(&root->fs_info->block_group_cache_lock);
 		btrfs_put_block_group(cache);
 		return ret;
@@ -9259,7 +9288,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
 
 	__link_block_group(cache->space_info, cache);
 
-	list_add_tail(&cache->new_bg_list, &trans->new_bgs);
+	list_add_tail(&cache->bg_list, &trans->new_bgs);
 
 	set_avail_alloc_bits(extent_root->fs_info, type);
 
@@ -9282,7 +9311,8 @@ static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
 }
 
 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
-			     struct btrfs_root *root, u64 group_start)
+			     struct btrfs_root *root, u64 group_start,
+			     struct extent_map *em)
 {
 	struct btrfs_path *path;
 	struct btrfs_block_group_cache *block_group;
@@ -9294,6 +9324,8 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	int ret;
 	int index;
 	int factor;
+	struct btrfs_caching_control *caching_ctl = NULL;
+	bool remove_em;
 
 	root = root->fs_info->extent_root;
 
@@ -9378,6 +9410,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	spin_lock(&root->fs_info->block_group_cache_lock);
 	rb_erase(&block_group->cache_node,
 		 &root->fs_info->block_group_cache_tree);
+	RB_CLEAR_NODE(&block_group->cache_node);
 
 	if (root->fs_info->first_logical_byte == block_group->key.objectid)
 		root->fs_info->first_logical_byte = (u64)-1;
@@ -9400,12 +9433,37 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 		kobject_put(kobj);
 	}
 
+	if (block_group->has_caching_ctl)
+		caching_ctl = get_caching_control(block_group);
 	if (block_group->cached == BTRFS_CACHE_STARTED)
 		wait_block_group_cache_done(block_group);
+	if (block_group->has_caching_ctl) {
+		down_write(&root->fs_info->commit_root_sem);
+		if (!caching_ctl) {
+			struct btrfs_caching_control *ctl;
+
+			list_for_each_entry(ctl,
+				    &root->fs_info->caching_block_groups, list)
+				if (ctl->block_group == block_group) {
+					caching_ctl = ctl;
+					atomic_inc(&caching_ctl->count);
+					break;
+				}
+		}
+		if (caching_ctl)
+			list_del_init(&caching_ctl->list);
+		up_write(&root->fs_info->commit_root_sem);
+		if (caching_ctl) {
+			/* Once for the caching bgs list and once for us. */
+			put_caching_control(caching_ctl);
+			put_caching_control(caching_ctl);
+		}
+	}
 
 	btrfs_remove_free_space_cache(block_group);
 
 	spin_lock(&block_group->space_info->lock);
+	list_del_init(&block_group->ro_list);
 	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;
@@ -9413,7 +9471,70 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 
 	memcpy(&key, &block_group->key, sizeof(key));
 
-	btrfs_clear_space_info_full(root->fs_info);
+	lock_chunks(root);
+	if (!list_empty(&em->list)) {
+		/* We're in the transaction->pending_chunks list. */
+		free_extent_map(em);
+	}
+	spin_lock(&block_group->lock);
+	block_group->removed = 1;
+	/*
+	 * At this point trimming can't start on this block group, because we
+	 * removed the block group from the tree fs_info->block_group_cache_tree
+	 * so no one can't find it anymore and even if someone already got this
+	 * block group before we removed it from the rbtree, they have already
+	 * incremented block_group->trimming - if they didn't, they won't find
+	 * any free space entries because we already removed them all when we
+	 * called btrfs_remove_free_space_cache().
+	 *
+	 * And we must not remove the extent map from the fs_info->mapping_tree
+	 * to prevent the same logical address range and physical device space
+	 * ranges from being reused for a new block group. This is because our
+	 * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
+	 * completely transactionless, so while it is trimming a range the
+	 * currently running transaction might finish and a new one start,
+	 * allowing for new block groups to be created that can reuse the same
+	 * physical device locations unless we take this special care.
+	 */
+	remove_em = (atomic_read(&block_group->trimming) == 0);
+	/*
+	 * Make sure a trimmer task always sees the em in the pinned_chunks list
+	 * if it sees block_group->removed == 1 (needs to lock block_group->lock
+	 * before checking block_group->removed).
+	 */
+	if (!remove_em) {
+		/*
+		 * Our em might be in trans->transaction->pending_chunks which
+		 * is protected by fs_info->chunk_mutex ([lock|unlock]_chunks),
+		 * and so is the fs_info->pinned_chunks list.
+		 *
+		 * So at this point we must be holding the chunk_mutex to avoid
+		 * any races with chunk allocation (more specifically at
+		 * volumes.c:contains_pending_extent()), to ensure it always
+		 * sees the em, either in the pending_chunks list or in the
+		 * pinned_chunks list.
+		 */
+		list_move_tail(&em->list, &root->fs_info->pinned_chunks);
+	}
+	spin_unlock(&block_group->lock);
+
+	if (remove_em) {
+		struct extent_map_tree *em_tree;
+
+		em_tree = &root->fs_info->mapping_tree.map_tree;
+		write_lock(&em_tree->lock);
+		/*
+		 * The em might be in the pending_chunks list, so make sure the
+		 * chunk mutex is locked, since remove_extent_mapping() will
+		 * delete us from that list.
+		 */
+		remove_extent_mapping(em_tree, em);
+		write_unlock(&em_tree->lock);
+		/* once for the tree */
+		free_extent_map(em);
+	}
+
+	unlock_chunks(root);
 
 	btrfs_put_block_group(block_group);
 	btrfs_put_block_group(block_group);
@@ -9430,6 +9551,110 @@ out:
 	return ret;
 }
 
+/*
+ * Process the unused_bgs list and remove any that don't have any allocated
+ * space inside of them.
+ */
+void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_block_group_cache *block_group;
+	struct btrfs_space_info *space_info;
+	struct btrfs_root *root = fs_info->extent_root;
+	struct btrfs_trans_handle *trans;
+	int ret = 0;
+
+	if (!fs_info->open)
+		return;
+
+	spin_lock(&fs_info->unused_bgs_lock);
+	while (!list_empty(&fs_info->unused_bgs)) {
+		u64 start, end;
+
+		block_group = list_first_entry(&fs_info->unused_bgs,
+					       struct btrfs_block_group_cache,
+					       bg_list);
+		space_info = block_group->space_info;
+		list_del_init(&block_group->bg_list);
+		if (ret || btrfs_mixed_space_info(space_info)) {
+			btrfs_put_block_group(block_group);
+			continue;
+		}
+		spin_unlock(&fs_info->unused_bgs_lock);
+
+		/* Don't want to race with allocators so take the groups_sem */
+		down_write(&space_info->groups_sem);
+		spin_lock(&block_group->lock);
+		if (block_group->reserved ||
+		    btrfs_block_group_used(&block_group->item) ||
+		    block_group->ro) {
+			/*
+			 * We want to bail if we made new allocations or have
+			 * outstanding allocations in this block group.  We do
+			 * the ro check in case balance is currently acting on
+			 * this block group.
+			 */
+			spin_unlock(&block_group->lock);
+			up_write(&space_info->groups_sem);
+			goto next;
+		}
+		spin_unlock(&block_group->lock);
+
+		/* We don't want to force the issue, only flip if it's ok. */
+		ret = set_block_group_ro(block_group, 0);
+		up_write(&space_info->groups_sem);
+		if (ret < 0) {
+			ret = 0;
+			goto next;
+		}
+
+		/*
+		 * Want to do this before we do anything else so we can recover
+		 * properly if we fail to join the transaction.
+		 */
+		trans = btrfs_join_transaction(root);
+		if (IS_ERR(trans)) {
+			btrfs_set_block_group_rw(root, block_group);
+			ret = PTR_ERR(trans);
+			goto next;
+		}
+
+		/*
+		 * We could have pending pinned extents for this block group,
+		 * just delete them, we don't care about them anymore.
+		 */
+		start = block_group->key.objectid;
+		end = start + block_group->key.offset - 1;
+		ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
+				  EXTENT_DIRTY, GFP_NOFS);
+		if (ret) {
+			btrfs_set_block_group_rw(root, block_group);
+			goto end_trans;
+		}
+		ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
+				  EXTENT_DIRTY, GFP_NOFS);
+		if (ret) {
+			btrfs_set_block_group_rw(root, block_group);
+			goto end_trans;
+		}
+
+		/* Reset pinned so btrfs_put_block_group doesn't complain */
+		block_group->pinned = 0;
+
+		/*
+		 * Btrfs_remove_chunk will abort the transaction if things go
+		 * horribly wrong.
+		 */
+		ret = btrfs_remove_chunk(trans, root,
+					 block_group->key.objectid);
+end_trans:
+		btrfs_end_transaction(trans, root);
+next:
+		btrfs_put_block_group(block_group);
+		spin_lock(&fs_info->unused_bgs_lock);
+	}
+	spin_unlock(&fs_info->unused_bgs_lock);
+}
+
 int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_space_info *space_info;
@@ -9470,13 +9695,7 @@ out:
 
 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);
+	return unpin_extent_range(root, start, end, false);
 }
 
 int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
@@ -9542,12 +9761,14 @@ int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
 }
 
 /*
- * btrfs_{start,end}_write() is similar to mnt_{want, drop}_write(),
- * they are used to prevent the some tasks writing data into the page cache
- * by nocow before the subvolume is snapshoted, but flush the data into
- * the disk after the snapshot creation.
+ * btrfs_{start,end}_write_no_snapshoting() are similar to
+ * mnt_{want,drop}_write(), they are used to prevent some tasks from writing
+ * data into the page cache through nocow before the subvolume is snapshoted,
+ * but flush the data into disk after the snapshot creation, or to prevent
+ * operations while snapshoting is ongoing and that cause the snapshot to be
+ * inconsistent (writes followed by expanding truncates for example).
  */
-void btrfs_end_nocow_write(struct btrfs_root *root)
+void btrfs_end_write_no_snapshoting(struct btrfs_root *root)
 {
 	percpu_counter_dec(&root->subv_writers->counter);
 	/*
@@ -9559,9 +9780,9 @@ void btrfs_end_nocow_write(struct btrfs_root *root)
 		wake_up(&root->subv_writers->wait);
 }
 
-int btrfs_start_nocow_write(struct btrfs_root *root)
+int btrfs_start_write_no_snapshoting(struct btrfs_root *root)
 {
-	if (unlikely(atomic_read(&root->will_be_snapshoted)))
+	if (atomic_read(&root->will_be_snapshoted))
 		return 0;
 
 	percpu_counter_inc(&root->subv_writers->counter);
@@ -9569,8 +9790,8 @@ int btrfs_start_nocow_write(struct btrfs_root *root)
 	 * Make sure counter is updated before we check for snapshot creation.
 	 */
 	smp_mb();
-	if (unlikely(atomic_read(&root->will_be_snapshoted))) {
-		btrfs_end_nocow_write(root);
+	if (atomic_read(&root->will_be_snapshoted)) {
+		btrfs_end_write_no_snapshoting(root);
 		return 0;
 	}
 	return 1;