diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index a910b27..94e9442 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -55,8 +55,8 @@
 int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
 
 int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
-				struct btrfs_fs_info *fs_info, u64 bytenr,
-				u64 time_seq, struct ulist **roots);
+			 struct btrfs_fs_info *fs_info, u64 bytenr,
+			 u64 time_seq, struct ulist **roots);
 char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 			u32 name_len, unsigned long name_off,
 			struct extent_buffer *eb_in, u64 parent,
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 2f10e12..bbbe4f1 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -356,44 +356,14 @@
 }
 
 /*
- * Increment the upper half of tree_mod_seq, set lower half zero.
- *
- * Must be called with fs_info->tree_mod_seq_lock held.
+ * Pull a new tree mod seq number for our operation.
  */
-static inline u64 btrfs_inc_tree_mod_seq_major(struct btrfs_fs_info *fs_info)
-{
-	u64 seq = atomic64_read(&fs_info->tree_mod_seq);
-	seq &= 0xffffffff00000000ull;
-	seq += 1ull << 32;
-	atomic64_set(&fs_info->tree_mod_seq, seq);
-	return seq;
-}
-
-/*
- * Increment the lower half of tree_mod_seq.
- *
- * Must be called with fs_info->tree_mod_seq_lock held. The way major numbers
- * are generated should not technically require a spin lock here. (Rationale:
- * incrementing the minor while incrementing the major seq number is between its
- * atomic64_read and atomic64_set calls doesn't duplicate sequence numbers, it
- * just returns a unique sequence number as usual.) We have decided to leave
- * that requirement in here and rethink it once we notice it really imposes a
- * problem on some workload.
- */
-static inline u64 btrfs_inc_tree_mod_seq_minor(struct btrfs_fs_info *fs_info)
+static inline u64 btrfs_inc_tree_mod_seq(struct btrfs_fs_info *fs_info)
 {
 	return atomic64_inc_return(&fs_info->tree_mod_seq);
 }
 
 /*
- * return the last minor in the previous major tree_mod_seq number
- */
-u64 btrfs_tree_mod_seq_prev(u64 seq)
-{
-	return (seq & 0xffffffff00000000ull) - 1ull;
-}
-
-/*
  * This adds a new blocker to the tree mod log's blocker list if the @elem
  * passed does not already have a sequence number set. So when a caller expects
  * to record tree modifications, it should ensure to set elem->seq to zero
@@ -404,19 +374,16 @@
 u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info,
 			   struct seq_list *elem)
 {
-	u64 seq;
-
 	tree_mod_log_write_lock(fs_info);
 	spin_lock(&fs_info->tree_mod_seq_lock);
 	if (!elem->seq) {
-		elem->seq = btrfs_inc_tree_mod_seq_major(fs_info);
+		elem->seq = btrfs_inc_tree_mod_seq(fs_info);
 		list_add_tail(&elem->list, &fs_info->tree_mod_seq_list);
 	}
-	seq = btrfs_inc_tree_mod_seq_minor(fs_info);
 	spin_unlock(&fs_info->tree_mod_seq_lock);
 	tree_mod_log_write_unlock(fs_info);
 
-	return seq;
+	return elem->seq;
 }
 
 void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info,
@@ -489,9 +456,7 @@
 
 	BUG_ON(!tm);
 
-	spin_lock(&fs_info->tree_mod_seq_lock);
-	tm->seq = btrfs_inc_tree_mod_seq_minor(fs_info);
-	spin_unlock(&fs_info->tree_mod_seq_lock);
+	tm->seq = btrfs_inc_tree_mod_seq(fs_info);
 
 	tm_root = &fs_info->tree_mod_log;
 	new = &tm_root->rb_node;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index efd3bf6..06cc384 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1648,7 +1648,10 @@
 
 	/* holds configuration and tracking. Protected by qgroup_lock */
 	struct rb_root qgroup_tree;
+	struct rb_root qgroup_op_tree;
 	spinlock_t qgroup_lock;
+	spinlock_t qgroup_op_lock;
+	atomic_t qgroup_op_seq;
 
 	/*
 	 * used to avoid frequently calling ulist_alloc()/ulist_free()
@@ -3300,9 +3303,9 @@
 			 u64 min_alloc_size, u64 empty_size, u64 hint_byte,
 			 struct btrfs_key *ins, int is_data);
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		  struct extent_buffer *buf, int full_backref, int for_cow);
+		  struct extent_buffer *buf, int full_backref, int no_quota);
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		  struct extent_buffer *buf, int full_backref, int for_cow);
+		  struct extent_buffer *buf, int full_backref, int no_quota);
 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
 				struct btrfs_root *root,
 				u64 bytenr, u64 num_bytes, u64 flags,
@@ -3310,7 +3313,7 @@
 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);
+		      u64 owner, u64 offset, int no_quota);
 
 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len);
 int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
@@ -3322,7 +3325,7 @@
 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);
+			 u64 root_objectid, u64 owner, u64 offset, int no_quota);
 
 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
 				    struct btrfs_root *root);
@@ -3410,7 +3413,6 @@
 int btrfs_delayed_refs_qgroup_accounting(struct btrfs_trans_handle *trans,
 					 struct btrfs_fs_info *fs_info);
 int __get_raid_index(u64 flags);
-
 int btrfs_start_nocow_write(struct btrfs_root *root);
 void btrfs_end_nocow_write(struct btrfs_root *root);
 /* ctree.c */
@@ -3586,7 +3588,6 @@
 			   struct seq_list *elem);
 void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info,
 			    struct seq_list *elem);
-u64 btrfs_tree_mod_seq_prev(u64 seq);
 int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq);
 
 /* root-item.c */
@@ -4094,52 +4095,6 @@
 int btree_readahead_hook(struct btrfs_root *root, struct extent_buffer *eb,
 			 u64 start, int err);
 
-/* qgroup.c */
-struct qgroup_update {
-	struct list_head list;
-	struct btrfs_delayed_ref_node *node;
-	struct btrfs_delayed_extent_op *extent_op;
-};
-
-int btrfs_quota_enable(struct btrfs_trans_handle *trans,
-		       struct btrfs_fs_info *fs_info);
-int btrfs_quota_disable(struct btrfs_trans_handle *trans,
-			struct btrfs_fs_info *fs_info);
-int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
-void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
-int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info);
-int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
-			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
-int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
-			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
-int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
-			struct btrfs_fs_info *fs_info, u64 qgroupid,
-			char *name);
-int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
-			      struct btrfs_fs_info *fs_info, u64 qgroupid);
-int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
-		       struct btrfs_fs_info *fs_info, u64 qgroupid,
-		       struct btrfs_qgroup_limit *limit);
-int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info);
-void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info);
-struct btrfs_delayed_extent_op;
-int btrfs_qgroup_record_ref(struct btrfs_trans_handle *trans,
-			    struct btrfs_delayed_ref_node *node,
-			    struct btrfs_delayed_extent_op *extent_op);
-int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans,
-			     struct btrfs_fs_info *fs_info,
-			     struct btrfs_delayed_ref_node *node,
-			     struct btrfs_delayed_extent_op *extent_op);
-int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
-		      struct btrfs_fs_info *fs_info);
-int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
-			 struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
-			 struct btrfs_qgroup_inherit *inherit);
-int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes);
-void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes);
-
-void assert_qgroups_uptodate(struct btrfs_trans_handle *trans);
-
 static inline int is_fstree(u64 rootid)
 {
 	if (rootid == BTRFS_FS_TREE_OBJECTID ||
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 3129964..6d16bea 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -106,6 +106,10 @@
 		return -1;
 	if (ref1->type > ref2->type)
 		return 1;
+	if (ref1->no_quota > ref2->no_quota)
+		return 1;
+	if (ref1->no_quota < ref2->no_quota)
+		return -1;
 	/* merging of sequenced refs is not allowed */
 	if (compare_seq) {
 		if (ref1->seq < ref2->seq)
@@ -635,7 +639,7 @@
 		     struct btrfs_delayed_ref_head *head_ref,
 		     struct btrfs_delayed_ref_node *ref, u64 bytenr,
 		     u64 num_bytes, u64 parent, u64 ref_root, int level,
-		     int action, int for_cow)
+		     int action, int no_quota)
 {
 	struct btrfs_delayed_ref_node *existing;
 	struct btrfs_delayed_tree_ref *full_ref;
@@ -645,6 +649,8 @@
 	if (action == BTRFS_ADD_DELAYED_EXTENT)
 		action = BTRFS_ADD_DELAYED_REF;
 
+	if (is_fstree(ref_root))
+		seq = atomic64_read(&fs_info->tree_mod_seq);
 	delayed_refs = &trans->transaction->delayed_refs;
 
 	/* first set the basic ref node struct up */
@@ -655,9 +661,7 @@
 	ref->action = action;
 	ref->is_head = 0;
 	ref->in_tree = 1;
-
-	if (need_ref_seq(for_cow, ref_root))
-		seq = btrfs_get_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
+	ref->no_quota = no_quota;
 	ref->seq = seq;
 
 	full_ref = btrfs_delayed_node_to_tree_ref(ref);
@@ -697,7 +701,7 @@
 		     struct btrfs_delayed_ref_head *head_ref,
 		     struct btrfs_delayed_ref_node *ref, u64 bytenr,
 		     u64 num_bytes, u64 parent, u64 ref_root, u64 owner,
-		     u64 offset, int action, int for_cow)
+		     u64 offset, int action, int no_quota)
 {
 	struct btrfs_delayed_ref_node *existing;
 	struct btrfs_delayed_data_ref *full_ref;
@@ -709,6 +713,9 @@
 
 	delayed_refs = &trans->transaction->delayed_refs;
 
+	if (is_fstree(ref_root))
+		seq = atomic64_read(&fs_info->tree_mod_seq);
+
 	/* first set the basic ref node struct up */
 	atomic_set(&ref->refs, 1);
 	ref->bytenr = bytenr;
@@ -717,9 +724,7 @@
 	ref->action = action;
 	ref->is_head = 0;
 	ref->in_tree = 1;
-
-	if (need_ref_seq(for_cow, ref_root))
-		seq = btrfs_get_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
+	ref->no_quota = no_quota;
 	ref->seq = seq;
 
 	full_ref = btrfs_delayed_node_to_data_ref(ref);
@@ -762,12 +767,15 @@
 			       u64 bytenr, u64 num_bytes, u64 parent,
 			       u64 ref_root,  int level, int action,
 			       struct btrfs_delayed_extent_op *extent_op,
-			       int for_cow)
+			       int no_quota)
 {
 	struct btrfs_delayed_tree_ref *ref;
 	struct btrfs_delayed_ref_head *head_ref;
 	struct btrfs_delayed_ref_root *delayed_refs;
 
+	if (!is_fstree(ref_root) || !fs_info->quota_enabled)
+		no_quota = 0;
+
 	BUG_ON(extent_op && extent_op->is_data);
 	ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
 	if (!ref)
@@ -793,10 +801,8 @@
 
 	add_delayed_tree_ref(fs_info, trans, head_ref, &ref->node, bytenr,
 				   num_bytes, parent, ref_root, level, action,
-				   for_cow);
+				   no_quota);
 	spin_unlock(&delayed_refs->lock);
-	if (need_ref_seq(for_cow, ref_root))
-		btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
 
 	return 0;
 }
@@ -810,12 +816,15 @@
 			       u64 parent, u64 ref_root,
 			       u64 owner, u64 offset, int action,
 			       struct btrfs_delayed_extent_op *extent_op,
-			       int for_cow)
+			       int no_quota)
 {
 	struct btrfs_delayed_data_ref *ref;
 	struct btrfs_delayed_ref_head *head_ref;
 	struct btrfs_delayed_ref_root *delayed_refs;
 
+	if (!is_fstree(ref_root) || !fs_info->quota_enabled)
+		no_quota = 0;
+
 	BUG_ON(extent_op && !extent_op->is_data);
 	ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
 	if (!ref)
@@ -841,10 +850,8 @@
 
 	add_delayed_data_ref(fs_info, trans, head_ref, &ref->node, bytenr,
 				   num_bytes, parent, ref_root, owner, offset,
-				   action, for_cow);
+				   action, no_quota);
 	spin_unlock(&delayed_refs->lock);
-	if (need_ref_seq(for_cow, ref_root))
-		btrfs_qgroup_record_ref(trans, &ref->node, extent_op);
 
 	return 0;
 }
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index 4ba9b93..a764e23 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/fs/btrfs/delayed-ref.h
@@ -52,6 +52,7 @@
 
 	unsigned int action:8;
 	unsigned int type:8;
+	unsigned int no_quota:1;
 	/* is this node still in the rbtree? */
 	unsigned int is_head:1;
 	unsigned int in_tree:1;
@@ -196,14 +197,14 @@
 			       u64 bytenr, u64 num_bytes, u64 parent,
 			       u64 ref_root, int level, int action,
 			       struct btrfs_delayed_extent_op *extent_op,
-			       int for_cow);
+			       int no_quota);
 int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
 			       struct btrfs_trans_handle *trans,
 			       u64 bytenr, u64 num_bytes,
 			       u64 parent, u64 ref_root,
 			       u64 owner, u64 offset, int action,
 			       struct btrfs_delayed_extent_op *extent_op,
-			       int for_cow);
+			       int no_quota);
 int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
 				struct btrfs_trans_handle *trans,
 				u64 bytenr, u64 num_bytes,
@@ -231,25 +232,6 @@
 			    u64 seq);
 
 /*
- * delayed refs with a ref_seq > 0 must be held back during backref walking.
- * this only applies to items in one of the fs-trees. for_cow items never need
- * to be held back, so they won't get a ref_seq number.
- */
-static inline int need_ref_seq(int for_cow, u64 rootid)
-{
-	if (for_cow)
-		return 0;
-
-	if (rootid == BTRFS_FS_TREE_OBJECTID)
-		return 1;
-
-	if ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID)
-		return 1;
-
-	return 0;
-}
-
-/*
  * a node might live in a head or a regular ref, this lets you
  * test for the proper type to use.
  */
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e54f0cd..77f92a3 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -49,6 +49,7 @@
 #include "dev-replace.h"
 #include "raid56.h"
 #include "sysfs.h"
+#include "qgroup.h"
 
 #ifdef CONFIG_X86
 #include <asm/cpufeature.h>
@@ -2219,6 +2220,7 @@
 	spin_lock_init(&fs_info->free_chunk_lock);
 	spin_lock_init(&fs_info->tree_mod_seq_lock);
 	spin_lock_init(&fs_info->super_lock);
+	spin_lock_init(&fs_info->qgroup_op_lock);
 	spin_lock_init(&fs_info->buffer_lock);
 	rwlock_init(&fs_info->tree_mod_log_lock);
 	mutex_init(&fs_info->reloc_mutex);
@@ -2244,6 +2246,7 @@
 	atomic_set(&fs_info->async_submit_draining, 0);
 	atomic_set(&fs_info->nr_async_bios, 0);
 	atomic_set(&fs_info->defrag_running, 0);
+	atomic_set(&fs_info->qgroup_op_seq, 0);
 	atomic64_set(&fs_info->tree_mod_seq, 0);
 	fs_info->sb = sb;
 	fs_info->max_inline = 8192 * 1024;
@@ -2353,6 +2356,7 @@
 	spin_lock_init(&fs_info->qgroup_lock);
 	mutex_init(&fs_info->qgroup_ioctl_lock);
 	fs_info->qgroup_tree = RB_ROOT;
+	fs_info->qgroup_op_tree = RB_ROOT;
 	INIT_LIST_HEAD(&fs_info->dirty_qgroups);
 	fs_info->qgroup_seq = 1;
 	fs_info->quota_enabled = 0;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index aff579d..343eb10 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -35,6 +35,7 @@
 #include "free-space-cache.h"
 #include "math.h"
 #include "sysfs.h"
+#include "qgroup.h"
 
 #undef SCRAMBLE_DELAYED_REFS
 
@@ -80,7 +81,8 @@
 				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);
+				struct btrfs_delayed_extent_op *extra_op,
+				int no_quota);
 static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
 				    struct extent_buffer *leaf,
 				    struct btrfs_extent_item *ei);
@@ -93,7 +95,8 @@
 				     struct btrfs_root *root,
 				     u64 parent, u64 root_objectid,
 				     u64 flags, struct btrfs_disk_key *key,
-				     int level, struct btrfs_key *ins);
+				     int level, struct btrfs_key *ins,
+				     int no_quota);
 static int do_chunk_alloc(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *extent_root, u64 flags,
 			  int force);
@@ -1270,7 +1273,7 @@
 static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
 					   struct btrfs_root *root,
 					   struct btrfs_path *path,
-					   int refs_to_drop)
+					   int refs_to_drop, int *last_ref)
 {
 	struct btrfs_key key;
 	struct btrfs_extent_data_ref *ref1 = NULL;
@@ -1306,6 +1309,7 @@
 
 	if (num_refs == 0) {
 		ret = btrfs_del_item(trans, root, path);
+		*last_ref = 1;
 	} else {
 		if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
 			btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
@@ -1763,7 +1767,8 @@
 				  struct btrfs_path *path,
 				  struct btrfs_extent_inline_ref *iref,
 				  int refs_to_mod,
-				  struct btrfs_delayed_extent_op *extent_op)
+				  struct btrfs_delayed_extent_op *extent_op,
+				  int *last_ref)
 {
 	struct extent_buffer *leaf;
 	struct btrfs_extent_item *ei;
@@ -1807,6 +1812,7 @@
 		else
 			btrfs_set_shared_data_ref_count(leaf, sref, refs);
 	} else {
+		*last_ref = 1;
 		size =  btrfs_extent_inline_ref_size(type);
 		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 		ptr = (unsigned long)iref;
@@ -1838,7 +1844,7 @@
 	if (ret == 0) {
 		BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
 		update_inline_extent_backref(root, path, iref,
-					     refs_to_add, extent_op);
+					     refs_to_add, extent_op, NULL);
 	} else if (ret == -ENOENT) {
 		setup_inline_extent_backref(root, path, iref, parent,
 					    root_objectid, owner, offset,
@@ -1871,17 +1877,19 @@
 				 struct btrfs_root *root,
 				 struct btrfs_path *path,
 				 struct btrfs_extent_inline_ref *iref,
-				 int refs_to_drop, int is_data)
+				 int refs_to_drop, int is_data, int *last_ref)
 {
 	int ret = 0;
 
 	BUG_ON(!is_data && refs_to_drop != 1);
 	if (iref) {
 		update_inline_extent_backref(root, path, iref,
-					     -refs_to_drop, NULL);
+					     -refs_to_drop, NULL, last_ref);
 	} else if (is_data) {
-		ret = remove_extent_data_ref(trans, root, path, refs_to_drop);
+		ret = remove_extent_data_ref(trans, root, path, refs_to_drop,
+					     last_ref);
 	} else {
+		*last_ref = 1;
 		ret = btrfs_del_item(trans, root, path);
 	}
 	return ret;
@@ -1945,7 +1953,8 @@
 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)
+			 u64 root_objectid, u64 owner, u64 offset,
+			 int no_quota)
 {
 	int ret;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -1957,12 +1966,12 @@
 		ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
 					num_bytes,
 					parent, root_objectid, (int)owner,
-					BTRFS_ADD_DELAYED_REF, NULL, for_cow);
+					BTRFS_ADD_DELAYED_REF, NULL, no_quota);
 	} 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);
+					BTRFS_ADD_DELAYED_REF, NULL, no_quota);
 	}
 	return ret;
 }
@@ -1972,31 +1981,64 @@
 				  u64 bytenr, u64 num_bytes,
 				  u64 parent, u64 root_objectid,
 				  u64 owner, u64 offset, int refs_to_add,
+				  int no_quota,
 				  struct btrfs_delayed_extent_op *extent_op)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_path *path;
 	struct extent_buffer *leaf;
 	struct btrfs_extent_item *item;
+	struct btrfs_key key;
 	u64 refs;
 	int ret;
+	enum btrfs_qgroup_operation_type type = BTRFS_QGROUP_OPER_ADD_EXCL;
 
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
 
+	if (!is_fstree(root_objectid) || !root->fs_info->quota_enabled)
+		no_quota = 1;
+
 	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,
+	ret = insert_inline_extent_backref(trans, fs_info->extent_root, path,
+					   bytenr, num_bytes, parent,
 					   root_objectid, owner, offset,
 					   refs_to_add, extent_op);
-	if (ret != -EAGAIN)
+	if ((ret < 0 && ret != -EAGAIN) || (!ret && no_quota))
 		goto out;
+	/*
+	 * Ok we were able to insert an inline extent and it appears to be a new
+	 * reference, deal with the qgroup accounting.
+	 */
+	if (!ret && !no_quota) {
+		ASSERT(root->fs_info->quota_enabled);
+		leaf = path->nodes[0];
+		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+		item = btrfs_item_ptr(leaf, path->slots[0],
+				      struct btrfs_extent_item);
+		if (btrfs_extent_refs(leaf, item) > (u64)refs_to_add)
+			type = BTRFS_QGROUP_OPER_ADD_SHARED;
+		btrfs_release_path(path);
 
+		ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
+					      bytenr, num_bytes, type, 0);
+		goto out;
+	}
+
+	/*
+	 * Ok we had -EAGAIN which means we didn't have space to insert and
+	 * inline extent ref, so just update the reference count and add a
+	 * normal backref.
+	 */
 	leaf = path->nodes[0];
+	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
 	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
 	refs = btrfs_extent_refs(leaf, item);
+	if (refs)
+		type = BTRFS_QGROUP_OPER_ADD_SHARED;
 	btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
 	if (extent_op)
 		__run_delayed_extent_op(extent_op, leaf, item);
@@ -2004,9 +2046,15 @@
 	btrfs_mark_buffer_dirty(leaf);
 	btrfs_release_path(path);
 
+	if (!no_quota) {
+		ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
+					      bytenr, num_bytes, type, 0);
+		if (ret)
+			goto out;
+	}
+
 	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,
@@ -2040,8 +2088,7 @@
 
 	if (node->type == BTRFS_SHARED_DATA_REF_KEY)
 		parent = ref->parent;
-	else
-		ref_root = ref->root;
+	ref_root = ref->root;
 
 	if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
 		if (extent_op)
@@ -2055,13 +2102,13 @@
 					     node->num_bytes, parent,
 					     ref_root, ref->objectid,
 					     ref->offset, node->ref_mod,
-					     extent_op);
+					     node->no_quota, 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);
+					  extent_op, node->no_quota);
 	} else {
 		BUG();
 	}
@@ -2198,8 +2245,7 @@
 
 	if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
 		parent = ref->parent;
-	else
-		ref_root = ref->root;
+	ref_root = ref->root;
 
 	ins.objectid = node->bytenr;
 	if (skinny_metadata) {
@@ -2217,15 +2263,18 @@
 						parent, ref_root,
 						extent_op->flags_to_set,
 						&extent_op->key,
-						ref->level, &ins);
+						ref->level, &ins,
+						node->no_quota);
 	} 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);
+					     ref->level, 0, 1, node->no_quota,
+					     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);
+					  ref->level, 0, 1, extent_op,
+					  node->no_quota);
 	} else {
 		BUG();
 	}
@@ -2573,42 +2622,6 @@
 }
 #endif
 
-int btrfs_delayed_refs_qgroup_accounting(struct btrfs_trans_handle *trans,
-					 struct btrfs_fs_info *fs_info)
-{
-	struct qgroup_update *qgroup_update;
-	int ret = 0;
-
-	if (list_empty(&trans->qgroup_ref_list) !=
-	    !trans->delayed_ref_elem.seq) {
-		/* list without seq or seq without list */
-		btrfs_err(fs_info,
-			"qgroup accounting update error, list is%s empty, seq is %#x.%x",
-			list_empty(&trans->qgroup_ref_list) ? "" : " not",
-			(u32)(trans->delayed_ref_elem.seq >> 32),
-			(u32)trans->delayed_ref_elem.seq);
-		BUG();
-	}
-
-	if (!trans->delayed_ref_elem.seq)
-		return 0;
-
-	while (!list_empty(&trans->qgroup_ref_list)) {
-		qgroup_update = list_first_entry(&trans->qgroup_ref_list,
-						 struct qgroup_update, list);
-		list_del(&qgroup_update->list);
-		if (!ret)
-			ret = btrfs_qgroup_account_ref(
-					trans, fs_info, qgroup_update->node,
-					qgroup_update->extent_op);
-		kfree(qgroup_update);
-	}
-
-	btrfs_put_tree_mod_seq(fs_info, &trans->delayed_ref_elem);
-
-	return ret;
-}
-
 static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads)
 {
 	u64 num_bytes;
@@ -2697,8 +2710,6 @@
 	if (root == root->fs_info->extent_root)
 		root = root->fs_info->tree_root;
 
-	btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
-
 	delayed_refs = &trans->transaction->delayed_refs;
 	if (count == 0) {
 		count = atomic_read(&delayed_refs->num_entries) * 2;
@@ -2757,6 +2768,9 @@
 		goto again;
 	}
 out:
+	ret = btrfs_delayed_qgroup_accounting(trans, root->fs_info);
+	if (ret)
+		return ret;
 	assert_qgroups_uptodate(trans);
 	return 0;
 }
@@ -2963,7 +2977,7 @@
 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)
+			   int full_backref, int inc, int no_quota)
 {
 	u64 bytenr;
 	u64 num_bytes;
@@ -3013,7 +3027,7 @@
 			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);
+					   key.offset, no_quota);
 			if (ret)
 				goto fail;
 		} else {
@@ -3021,7 +3035,7 @@
 			num_bytes = btrfs_level_size(root, level - 1);
 			ret = process_func(trans, root, bytenr, num_bytes,
 					   parent, ref_root, level - 1, 0,
-					   for_cow);
+					   no_quota);
 			if (ret)
 				goto fail;
 		}
@@ -3032,15 +3046,15 @@
 }
 
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		  struct extent_buffer *buf, int full_backref, int for_cow)
+		  struct extent_buffer *buf, int full_backref, int no_quota)
 {
-	return __btrfs_mod_ref(trans, root, buf, full_backref, 1, for_cow);
+	return __btrfs_mod_ref(trans, root, buf, full_backref, 1, no_quota);
 }
 
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
-		  struct extent_buffer *buf, int full_backref, int for_cow)
+		  struct extent_buffer *buf, int full_backref, int no_quota)
 {
-	return __btrfs_mod_ref(trans, root, buf, full_backref, 0, for_cow);
+	return __btrfs_mod_ref(trans, root, buf, full_backref, 0, no_quota);
 }
 
 static int write_one_cache_group(struct btrfs_trans_handle *trans,
@@ -5723,7 +5737,8 @@
 				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_delayed_extent_op *extent_op,
+				int no_quota)
 {
 	struct btrfs_key key;
 	struct btrfs_path *path;
@@ -5739,9 +5754,14 @@
 	int num_to_del = 1;
 	u32 item_size;
 	u64 refs;
+	int last_ref = 0;
+	enum btrfs_qgroup_operation_type type = BTRFS_QGROUP_OPER_SUB_EXCL;
 	bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
 						 SKINNY_METADATA);
 
+	if (!info->quota_enabled || !is_fstree(root_objectid))
+		no_quota = 1;
+
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
@@ -5789,7 +5809,7 @@
 			BUG_ON(iref);
 			ret = remove_extent_backref(trans, extent_root, path,
 						    NULL, refs_to_drop,
-						    is_data);
+						    is_data, &last_ref);
 			if (ret) {
 				btrfs_abort_transaction(trans, extent_root, ret);
 				goto out;
@@ -5916,6 +5936,7 @@
 	refs -= refs_to_drop;
 
 	if (refs > 0) {
+		type = BTRFS_QGROUP_OPER_SUB_SHARED;
 		if (extent_op)
 			__run_delayed_extent_op(extent_op, leaf, ei);
 		/*
@@ -5931,7 +5952,7 @@
 		if (found_extent) {
 			ret = remove_extent_backref(trans, extent_root, path,
 						    iref, refs_to_drop,
-						    is_data);
+						    is_data, &last_ref);
 			if (ret) {
 				btrfs_abort_transaction(trans, extent_root, ret);
 				goto out;
@@ -5952,6 +5973,7 @@
 			}
 		}
 
+		last_ref = 1;
 		ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
 				      num_to_del);
 		if (ret) {
@@ -5974,6 +5996,20 @@
 			goto out;
 		}
 	}
+	btrfs_release_path(path);
+
+	/* Deal with the quota accounting */
+	if (!ret && last_ref && !no_quota) {
+		int mod_seq = 0;
+
+		if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID &&
+		    type == BTRFS_QGROUP_OPER_SUB_SHARED)
+			mod_seq = 1;
+
+		ret = btrfs_qgroup_record_ref(trans, info, root_objectid,
+					      bytenr, num_bytes, type,
+					      mod_seq);
+	}
 out:
 	btrfs_free_path(path);
 	return ret;
@@ -6110,7 +6146,7 @@
 /* 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)
+		      u64 owner, u64 offset, int no_quota)
 {
 	int ret;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -6130,13 +6166,13 @@
 		ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
 					num_bytes,
 					parent, root_objectid, (int)owner,
-					BTRFS_DROP_DELAYED_REF, NULL, for_cow);
+					BTRFS_DROP_DELAYED_REF, NULL, no_quota);
 	} 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);
+						NULL, no_quota);
 	}
 	return ret;
 }
@@ -6842,6 +6878,13 @@
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 	btrfs_free_path(path);
 
+	/* Always set parent to 0 here since its exclusive anyway. */
+	ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
+				      ins->objectid, ins->offset,
+				      BTRFS_QGROUP_OPER_ADD_EXCL, 0);
+	if (ret)
+		return ret;
+
 	ret = update_block_group(root, ins->objectid, ins->offset, 1);
 	if (ret) { /* -ENOENT, logic error */
 		btrfs_err(fs_info, "update block group failed for %llu %llu",
@@ -6856,7 +6899,8 @@
 				     struct btrfs_root *root,
 				     u64 parent, u64 root_objectid,
 				     u64 flags, struct btrfs_disk_key *key,
-				     int level, struct btrfs_key *ins)
+				     int level, struct btrfs_key *ins,
+				     int no_quota)
 {
 	int ret;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -6866,6 +6910,7 @@
 	struct btrfs_path *path;
 	struct extent_buffer *leaf;
 	u32 size = sizeof(*extent_item) + sizeof(*iref);
+	u64 num_bytes = ins->offset;
 	bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
 						 SKINNY_METADATA);
 
@@ -6899,6 +6944,7 @@
 
 	if (skinny_metadata) {
 		iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
+		num_bytes = root->leafsize;
 	} else {
 		block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
 		btrfs_set_tree_block_key(leaf, block_info, key);
@@ -6920,6 +6966,14 @@
 	btrfs_mark_buffer_dirty(leaf);
 	btrfs_free_path(path);
 
+	if (!no_quota) {
+		ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid,
+					      ins->objectid, num_bytes,
+					      BTRFS_QGROUP_OPER_ADD_EXCL, 0);
+		if (ret)
+			return ret;
+	}
+
 	ret = update_block_group(root, ins->objectid, root->leafsize, 1);
 	if (ret) { /* -ENOENT, logic error */
 		btrfs_err(fs_info, "update block group failed for %llu %llu",
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 5c6947d..8accf94 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -40,6 +40,7 @@
 #include "tree-log.h"
 #include "locking.h"
 #include "volumes.h"
+#include "qgroup.h"
 
 static struct kmem_cache *btrfs_inode_defrag_cachep;
 /*
@@ -849,7 +850,7 @@
 						disk_bytenr, num_bytes, 0,
 						root->root_key.objectid,
 						new_key.objectid,
-						start - extent_offset, 0);
+						start - extent_offset, 1);
 				BUG_ON(ret); /* -ENOMEM */
 			}
 			key.offset = start;
@@ -1206,7 +1207,7 @@
 
 		ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
 					   root->root_key.objectid,
-					   ino, orig_offset, 0);
+					   ino, orig_offset, 1);
 		BUG_ON(ret); /* -ENOMEM */
 
 		if (split == start) {
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 242a37c..a21a4ac 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -58,6 +58,7 @@
 #include "dev-replace.h"
 #include "props.h"
 #include "sysfs.h"
+#include "qgroup.h"
 
 #ifdef CONFIG_64BIT
 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
@@ -2941,6 +2942,41 @@
 	return ret;
 }
 
+/* Helper to check and see if this root currently has a ref on the given disk
+ * bytenr.  If it does then we need to update the quota for this root.  This
+ * doesn't do anything if quotas aren't enabled.
+ */
+static int check_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		     u64 disko)
+{
+	struct seq_list tree_mod_seq_elem = {};
+	struct ulist *roots;
+	struct ulist_iterator uiter;
+	struct ulist_node *root_node = NULL;
+	int ret;
+
+	if (!root->fs_info->quota_enabled)
+		return 1;
+
+	btrfs_get_tree_mod_seq(root->fs_info, &tree_mod_seq_elem);
+	ret = btrfs_find_all_roots(trans, root->fs_info, disko,
+				   tree_mod_seq_elem.seq, &roots);
+	if (ret < 0)
+		goto out;
+	ret = 0;
+	ULIST_ITER_INIT(&uiter);
+	while ((root_node = ulist_next(roots, &uiter))) {
+		if (root_node->val == root->objectid) {
+			ret = 1;
+			break;
+		}
+	}
+	ulist_free(roots);
+out:
+	btrfs_put_tree_mod_seq(root->fs_info, &tree_mod_seq_elem);
+	return ret;
+}
+
 /**
  * btrfs_clone() - clone a range from inode file to another
  *
@@ -2964,7 +3000,9 @@
 	u32 nritems;
 	int slot;
 	int ret;
+	int no_quota;
 	u64 len = olen_aligned;
+	u64 last_disko = 0;
 
 	ret = -ENOMEM;
 	buf = vmalloc(btrfs_level_size(root, 0));
@@ -2996,6 +3034,7 @@
 
 		nritems = btrfs_header_nritems(path->nodes[0]);
 process_slot:
+		no_quota = 1;
 		if (path->slots[0] >= nritems) {
 			ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
 			if (ret < 0)
@@ -3128,6 +3167,28 @@
 							     datao);
 				btrfs_set_file_extent_num_bytes(leaf, extent,
 								datal);
+
+				/*
+				 * We need to look up the roots that point at
+				 * this bytenr and see if the new root does.  If
+				 * it does not we need to make sure we update
+				 * quotas appropriately.
+				 */
+				if (disko && root != BTRFS_I(src)->root &&
+				    disko != last_disko) {
+					no_quota = check_ref(trans, root,
+							     disko);
+					if (no_quota < 0) {
+						btrfs_abort_transaction(trans,
+									root,
+									ret);
+						btrfs_end_transaction(trans,
+								      root);
+						ret = no_quota;
+						goto out;
+					}
+				}
+
 				if (disko) {
 					inode_add_bytes(inode, datal);
 					ret = btrfs_inc_extent_ref(trans, root,
@@ -3135,7 +3196,7 @@
 							root->root_key.objectid,
 							btrfs_ino(inode),
 							new_key.offset - datao,
-							0);
+							no_quota);
 					if (ret) {
 						btrfs_abort_transaction(trans,
 									root,
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 2cf9058..09b8cc8 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -32,6 +32,7 @@
 #include "ulist.h"
 #include "backref.h"
 #include "extent_io.h"
+#include "qgroup.h"
 
 /* TODO XXX FIXME
  *  - subvol delete -> delete when ref goes to 0? delete limits also?
@@ -84,8 +85,8 @@
 	/*
 	 * temp variables for accounting operations
 	 */
-	u64 tag;
-	u64 refcnt;
+	u64 old_refcnt;
+	u64 new_refcnt;
 };
 
 /*
@@ -98,6 +99,9 @@
 	struct btrfs_qgroup *member;
 };
 
+#define ptr_to_u64(x) ((u64)(uintptr_t)x)
+#define u64_to_ptr(x) ((struct btrfs_qgroup *)(uintptr_t)x)
+
 static int
 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 		   int init_flags);
@@ -1174,33 +1178,198 @@
 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
 	return ret;
 }
+static int comp_oper(struct btrfs_qgroup_operation *oper1,
+		     struct btrfs_qgroup_operation *oper2)
+{
+	if (oper1->bytenr < oper2->bytenr)
+		return -1;
+	if (oper1->bytenr > oper2->bytenr)
+		return 1;
+	if (oper1->seq < oper2->seq)
+		return -1;
+	if (oper1->seq > oper2->seq)
+		return -1;
+	if (oper1->ref_root < oper2->ref_root)
+		return -1;
+	if (oper1->ref_root > oper2->ref_root)
+		return 1;
+	if (oper1->type < oper2->type)
+		return -1;
+	if (oper1->type > oper2->type)
+		return 1;
+	return 0;
+}
+
+static int insert_qgroup_oper(struct btrfs_fs_info *fs_info,
+			      struct btrfs_qgroup_operation *oper)
+{
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct btrfs_qgroup_operation *cur;
+	int cmp;
+
+	spin_lock(&fs_info->qgroup_op_lock);
+	p = &fs_info->qgroup_op_tree.rb_node;
+	while (*p) {
+		parent = *p;
+		cur = rb_entry(parent, struct btrfs_qgroup_operation, n);
+		cmp = comp_oper(cur, oper);
+		if (cmp < 0) {
+			p = &(*p)->rb_right;
+		} else if (cmp) {
+			p = &(*p)->rb_left;
+		} else {
+			spin_unlock(&fs_info->qgroup_op_lock);
+			return -EEXIST;
+		}
+	}
+	rb_link_node(&oper->n, parent, p);
+	rb_insert_color(&oper->n, &fs_info->qgroup_op_tree);
+	spin_unlock(&fs_info->qgroup_op_lock);
+	return 0;
+}
 
 /*
- * btrfs_qgroup_record_ref is called when the ref is added or deleted. it puts
- * the modification into a list that's later used by btrfs_end_transaction to
- * pass the recorded modifications on to btrfs_qgroup_account_ref.
+ * Record a quota operation for processing later on.
+ * @trans: the transaction we are adding the delayed op to.
+ * @fs_info: the fs_info for this fs.
+ * @ref_root: the root of the reference we are acting on,
+ * @bytenr: the bytenr we are acting on.
+ * @num_bytes: the number of bytes in the reference.
+ * @type: the type of operation this is.
+ * @mod_seq: do we need to get a sequence number for looking up roots.
+ *
+ * We just add it to our trans qgroup_ref_list and carry on and process these
+ * operations in order at some later point.  If the reference root isn't a fs
+ * root then we don't bother with doing anything.
+ *
+ * MUST BE HOLDING THE REF LOCK.
  */
 int btrfs_qgroup_record_ref(struct btrfs_trans_handle *trans,
-			    struct btrfs_delayed_ref_node *node,
-			    struct btrfs_delayed_extent_op *extent_op)
+			    struct btrfs_fs_info *fs_info, u64 ref_root,
+			    u64 bytenr, u64 num_bytes,
+			    enum btrfs_qgroup_operation_type type, int mod_seq)
 {
-	struct qgroup_update *u;
+	struct btrfs_qgroup_operation *oper;
+	int ret;
 
-	BUG_ON(!trans->delayed_ref_elem.seq);
-	u = kmalloc(sizeof(*u), GFP_NOFS);
-	if (!u)
+	if (!is_fstree(ref_root) || !fs_info->quota_enabled)
+		return 0;
+
+	oper = kmalloc(sizeof(*oper), GFP_NOFS);
+	if (!oper)
 		return -ENOMEM;
 
-	u->node = node;
-	u->extent_op = extent_op;
-	list_add_tail(&u->list, &trans->qgroup_ref_list);
+	oper->ref_root = ref_root;
+	oper->bytenr = bytenr;
+	oper->num_bytes = num_bytes;
+	oper->type = type;
+	oper->seq = atomic_inc_return(&fs_info->qgroup_op_seq);
+	INIT_LIST_HEAD(&oper->elem.list);
+	oper->elem.seq = 0;
+	ret = insert_qgroup_oper(fs_info, oper);
+	if (ret) {
+		/* Shouldn't happen so have an assert for developers */
+		ASSERT(0);
+		kfree(oper);
+		return ret;
+	}
+	list_add_tail(&oper->list, &trans->qgroup_ref_list);
+
+	if (mod_seq)
+		btrfs_get_tree_mod_seq(fs_info, &oper->elem);
 
 	return 0;
 }
 
-static int qgroup_account_ref_step1(struct btrfs_fs_info *fs_info,
-				    struct ulist *roots, struct ulist *tmp,
-				    u64 seq)
+/*
+ * The easy accounting, if we are adding/removing the only ref for an extent
+ * then this qgroup and all of the parent qgroups get their refrence and
+ * exclusive counts adjusted.
+ */
+static int qgroup_excl_accounting(struct btrfs_fs_info *fs_info,
+				  struct btrfs_qgroup_operation *oper)
+{
+	struct btrfs_qgroup *qgroup;
+	struct ulist *tmp;
+	struct btrfs_qgroup_list *glist;
+	struct ulist_node *unode;
+	struct ulist_iterator uiter;
+	int sign = 0;
+	int ret = 0;
+
+	tmp = ulist_alloc(GFP_NOFS);
+	if (!tmp)
+		return -ENOMEM;
+
+	spin_lock(&fs_info->qgroup_lock);
+	if (!fs_info->quota_root)
+		goto out;
+	qgroup = find_qgroup_rb(fs_info, oper->ref_root);
+	if (!qgroup)
+		goto out;
+	switch (oper->type) {
+	case BTRFS_QGROUP_OPER_ADD_EXCL:
+		sign = 1;
+		break;
+	case BTRFS_QGROUP_OPER_SUB_EXCL:
+		sign = -1;
+		break;
+	default:
+		ASSERT(0);
+	}
+	qgroup->rfer += sign * oper->num_bytes;
+	qgroup->rfer_cmpr += sign * oper->num_bytes;
+
+	WARN_ON(sign < 0 && qgroup->excl < oper->num_bytes);
+	qgroup->excl += sign * oper->num_bytes;
+	qgroup->excl_cmpr += sign * oper->num_bytes;
+
+	qgroup_dirty(fs_info, qgroup);
+
+	/* Get all of the parent groups that contain this qgroup */
+	list_for_each_entry(glist, &qgroup->groups, next_group) {
+		ret = ulist_add(tmp, glist->group->qgroupid,
+				ptr_to_u64(glist->group), GFP_ATOMIC);
+		if (ret < 0)
+			goto out;
+	}
+
+	/* Iterate all of the parents and adjust their reference counts */
+	ULIST_ITER_INIT(&uiter);
+	while ((unode = ulist_next(tmp, &uiter))) {
+		qgroup = u64_to_ptr(unode->aux);
+		qgroup->rfer += sign * oper->num_bytes;
+		qgroup->rfer_cmpr += sign * oper->num_bytes;
+		qgroup->excl += sign * oper->num_bytes;
+		if (sign < 0)
+			WARN_ON(qgroup->excl < oper->num_bytes);
+		qgroup->excl_cmpr += sign * oper->num_bytes;
+		qgroup_dirty(fs_info, qgroup);
+
+		/* Add any parents of the parents */
+		list_for_each_entry(glist, &qgroup->groups, next_group) {
+			ret = ulist_add(tmp, glist->group->qgroupid,
+					ptr_to_u64(glist->group), GFP_ATOMIC);
+			if (ret < 0)
+				goto out;
+		}
+	}
+	ret = 0;
+out:
+	spin_unlock(&fs_info->qgroup_lock);
+	ulist_free(tmp);
+	return ret;
+}
+
+/*
+ * Walk all of the roots that pointed to our bytenr and adjust their refcnts as
+ * properly.
+ */
+static int qgroup_calc_old_refcnt(struct btrfs_fs_info *fs_info,
+				  u64 root_to_skip, struct ulist *tmp,
+				  struct ulist *roots, struct ulist *qgroups,
+				  u64 seq, int *old_roots, int rescan)
 {
 	struct ulist_node *unode;
 	struct ulist_iterator uiter;
@@ -1211,129 +1380,482 @@
 
 	ULIST_ITER_INIT(&uiter);
 	while ((unode = ulist_next(roots, &uiter))) {
+		/* We don't count our current root here */
+		if (unode->val == root_to_skip)
+			continue;
 		qg = find_qgroup_rb(fs_info, unode->val);
 		if (!qg)
 			continue;
+		/*
+		 * We could have a pending removal of this same ref so we may
+		 * not have actually found our ref root when doing
+		 * btrfs_find_all_roots, so we need to keep track of how many
+		 * old roots we find in case we removed ours and added a
+		 * different one at the same time.  I don't think this could
+		 * happen in practice but that sort of thinking leads to pain
+		 * and suffering and to the dark side.
+		 */
+		(*old_roots)++;
 
 		ulist_reinit(tmp);
-						/* XXX id not needed */
-		ret = ulist_add(tmp, qg->qgroupid,
-				(u64)(uintptr_t)qg, GFP_ATOMIC);
+		ret = ulist_add(qgroups, qg->qgroupid, ptr_to_u64(qg),
+				GFP_ATOMIC);
+		if (ret < 0)
+			return ret;
+		ret = ulist_add(tmp, qg->qgroupid, ptr_to_u64(qg), GFP_ATOMIC);
 		if (ret < 0)
 			return ret;
 		ULIST_ITER_INIT(&tmp_uiter);
 		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
 			struct btrfs_qgroup_list *glist;
 
-			qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
-			if (qg->refcnt < seq)
-				qg->refcnt = seq + 1;
+			qg = u64_to_ptr(tmp_unode->aux);
+			/*
+			 * We use this sequence number to keep from having to
+			 * run the whole list and 0 out the refcnt every time.
+			 * We basically use sequnce as the known 0 count and
+			 * then add 1 everytime we see a qgroup.  This is how we
+			 * get how many of the roots actually point up to the
+			 * upper level qgroups in order to determine exclusive
+			 * counts.
+			 *
+			 * For rescan we want to set old_refcnt to seq so our
+			 * exclusive calculations end up correct.
+			 */
+			if (rescan)
+				qg->old_refcnt = seq;
+			else if (qg->old_refcnt < seq)
+				qg->old_refcnt = seq + 1;
 			else
-				++qg->refcnt;
+				qg->old_refcnt++;
 
+			if (qg->new_refcnt < seq)
+				qg->new_refcnt = seq + 1;
+			else
+				qg->new_refcnt++;
 			list_for_each_entry(glist, &qg->groups, next_group) {
+				ret = ulist_add(qgroups, glist->group->qgroupid,
+						ptr_to_u64(glist->group),
+						GFP_ATOMIC);
+				if (ret < 0)
+					return ret;
 				ret = ulist_add(tmp, glist->group->qgroupid,
-						(u64)(uintptr_t)glist->group,
+						ptr_to_u64(glist->group),
 						GFP_ATOMIC);
 				if (ret < 0)
 					return ret;
 			}
 		}
 	}
-
 	return 0;
 }
 
-static int qgroup_account_ref_step2(struct btrfs_fs_info *fs_info,
-				    struct ulist *roots, struct ulist *tmp,
-				    u64 seq, int sgn, u64 num_bytes,
-				    struct btrfs_qgroup *qgroup)
+/*
+ * We need to walk forward in our operation tree and account for any roots that
+ * were deleted after we made this operation.
+ */
+static int qgroup_account_deleted_refs(struct btrfs_fs_info *fs_info,
+				       struct btrfs_qgroup_operation *oper,
+				       struct ulist *tmp,
+				       struct ulist *qgroups, u64 seq,
+				       int *old_roots)
 {
 	struct ulist_node *unode;
 	struct ulist_iterator uiter;
 	struct btrfs_qgroup *qg;
-	struct btrfs_qgroup_list *glist;
+	struct btrfs_qgroup_operation *tmp_oper;
+	struct rb_node *n;
 	int ret;
 
 	ulist_reinit(tmp);
-	ret = ulist_add(tmp, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
-	if (ret < 0)
-		return ret;
 
+	/*
+	 * We only walk forward in the tree since we're only interested in
+	 * removals that happened _after_  our operation.
+	 */
+	spin_lock(&fs_info->qgroup_op_lock);
+	n = rb_next(&oper->n);
+	spin_unlock(&fs_info->qgroup_op_lock);
+	if (!n)
+		return 0;
+	tmp_oper = rb_entry(n, struct btrfs_qgroup_operation, n);
+	while (tmp_oper->bytenr == oper->bytenr) {
+		/*
+		 * If it's not a removal we don't care, additions work out
+		 * properly with our refcnt tracking.
+		 */
+		if (tmp_oper->type != BTRFS_QGROUP_OPER_SUB_SHARED &&
+		    tmp_oper->type != BTRFS_QGROUP_OPER_SUB_EXCL)
+			goto next;
+		qg = find_qgroup_rb(fs_info, tmp_oper->ref_root);
+		if (!qg)
+			goto next;
+		ret = ulist_add(qgroups, qg->qgroupid, ptr_to_u64(qg),
+				GFP_ATOMIC);
+		if (ret) {
+			if (ret < 0)
+				return ret;
+			/*
+			 * We only want to increase old_roots if this qgroup is
+			 * not already in the list of qgroups.  If it is already
+			 * there then that means it must have been re-added or
+			 * the delete will be discarded because we had an
+			 * existing ref that we haven't looked up yet.  In this
+			 * case we don't want to increase old_roots.  So if ret
+			 * == 1 then we know that this is the first time we've
+			 * seen this qgroup and we can bump the old_roots.
+			 */
+			(*old_roots)++;
+			ret = ulist_add(tmp, qg->qgroupid, ptr_to_u64(qg),
+					GFP_ATOMIC);
+			if (ret < 0)
+				return ret;
+		}
+next:
+		spin_lock(&fs_info->qgroup_op_lock);
+		n = rb_next(&tmp_oper->n);
+		spin_unlock(&fs_info->qgroup_op_lock);
+		if (!n)
+			break;
+		tmp_oper = rb_entry(n, struct btrfs_qgroup_operation, n);
+	}
+
+	/* Ok now process the qgroups we found */
 	ULIST_ITER_INIT(&uiter);
 	while ((unode = ulist_next(tmp, &uiter))) {
-		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
-		if (qg->refcnt < seq) {
-			/* not visited by step 1 */
-			qg->rfer += sgn * num_bytes;
-			qg->rfer_cmpr += sgn * num_bytes;
-			if (roots->nnodes == 0) {
-				qg->excl += sgn * num_bytes;
-				qg->excl_cmpr += sgn * num_bytes;
-			}
-			qgroup_dirty(fs_info, qg);
-		}
-		WARN_ON(qg->tag >= seq);
-		qg->tag = seq;
+		struct btrfs_qgroup_list *glist;
 
+		qg = u64_to_ptr(unode->aux);
+		if (qg->old_refcnt < seq)
+			qg->old_refcnt = seq + 1;
+		else
+			qg->old_refcnt++;
+		if (qg->new_refcnt < seq)
+			qg->new_refcnt = seq + 1;
+		else
+			qg->new_refcnt++;
 		list_for_each_entry(glist, &qg->groups, next_group) {
+			ret = ulist_add(qgroups, glist->group->qgroupid,
+					ptr_to_u64(glist->group), GFP_ATOMIC);
+			if (ret < 0)
+				return ret;
 			ret = ulist_add(tmp, glist->group->qgroupid,
-					(uintptr_t)glist->group, GFP_ATOMIC);
+					ptr_to_u64(glist->group), GFP_ATOMIC);
 			if (ret < 0)
 				return ret;
 		}
 	}
-
 	return 0;
 }
 
-static int qgroup_account_ref_step3(struct btrfs_fs_info *fs_info,
-				    struct ulist *roots, struct ulist *tmp,
-				    u64 seq, int sgn, u64 num_bytes)
+/* Add refcnt for the newly added reference. */
+static int qgroup_calc_new_refcnt(struct btrfs_fs_info *fs_info,
+				  struct btrfs_qgroup_operation *oper,
+				  struct btrfs_qgroup *qgroup,
+				  struct ulist *tmp, struct ulist *qgroups,
+				  u64 seq)
 {
 	struct ulist_node *unode;
 	struct ulist_iterator uiter;
 	struct btrfs_qgroup *qg;
-	struct ulist_node *tmp_unode;
-	struct ulist_iterator tmp_uiter;
 	int ret;
 
+	ulist_reinit(tmp);
+	ret = ulist_add(qgroups, qgroup->qgroupid, ptr_to_u64(qgroup),
+			GFP_ATOMIC);
+	if (ret < 0)
+		return ret;
+	ret = ulist_add(tmp, qgroup->qgroupid, ptr_to_u64(qgroup),
+			GFP_ATOMIC);
+	if (ret < 0)
+		return ret;
+	ULIST_ITER_INIT(&uiter);
+	while ((unode = ulist_next(tmp, &uiter))) {
+		struct btrfs_qgroup_list *glist;
+
+		qg = u64_to_ptr(unode->aux);
+		if (oper->type == BTRFS_QGROUP_OPER_ADD_SHARED) {
+			if (qg->new_refcnt < seq)
+				qg->new_refcnt = seq + 1;
+			else
+				qg->new_refcnt++;
+		} else {
+			if (qg->old_refcnt < seq)
+				qg->old_refcnt = seq + 1;
+			else
+				qg->old_refcnt++;
+		}
+		list_for_each_entry(glist, &qg->groups, next_group) {
+			ret = ulist_add(tmp, glist->group->qgroupid,
+					ptr_to_u64(glist->group), GFP_ATOMIC);
+			if (ret < 0)
+				return ret;
+			ret = ulist_add(qgroups, glist->group->qgroupid,
+					ptr_to_u64(glist->group), GFP_ATOMIC);
+			if (ret < 0)
+				return ret;
+		}
+	}
+	return 0;
+}
+
+/*
+ * This adjusts the counters for all referenced qgroups if need be.
+ */
+static int qgroup_adjust_counters(struct btrfs_fs_info *fs_info,
+				  u64 root_to_skip, u64 num_bytes,
+				  struct ulist *qgroups, u64 seq,
+				  int old_roots, int new_roots, int rescan)
+{
+	struct ulist_node *unode;
+	struct ulist_iterator uiter;
+	struct btrfs_qgroup *qg;
+	u64 cur_new_count, cur_old_count;
+
+	ULIST_ITER_INIT(&uiter);
+	while ((unode = ulist_next(qgroups, &uiter))) {
+		bool dirty = false;
+
+		qg = u64_to_ptr(unode->aux);
+		/*
+		 * Wasn't referenced before but is now, add to the reference
+		 * counters.
+		 */
+		if (qg->old_refcnt <= seq && qg->new_refcnt > seq) {
+			qg->rfer += num_bytes;
+			qg->rfer_cmpr += num_bytes;
+			dirty = true;
+		}
+
+		/*
+		 * Was referenced before but isn't now, subtract from the
+		 * reference counters.
+		 */
+		if (qg->old_refcnt > seq && qg->new_refcnt <= seq) {
+			qg->rfer -= num_bytes;
+			qg->rfer_cmpr -= num_bytes;
+			dirty = true;
+		}
+
+		if (qg->old_refcnt < seq)
+			cur_old_count = 0;
+		else
+			cur_old_count = qg->old_refcnt - seq;
+		if (qg->new_refcnt < seq)
+			cur_new_count = 0;
+		else
+			cur_new_count = qg->new_refcnt - seq;
+
+		/*
+		 * If our refcount was the same as the roots previously but our
+		 * new count isn't the same as the number of roots now then we
+		 * went from having a exclusive reference on this range to not.
+		 */
+		if (old_roots && cur_old_count == old_roots &&
+		    (cur_new_count != new_roots || new_roots == 0)) {
+			WARN_ON(cur_new_count != new_roots && new_roots == 0);
+			qg->excl -= num_bytes;
+			qg->excl_cmpr -= num_bytes;
+			dirty = true;
+		}
+
+		/*
+		 * If we didn't reference all the roots before but now we do we
+		 * have an exclusive reference to this range.
+		 */
+		if ((!old_roots || (old_roots && cur_old_count != old_roots))
+		    && cur_new_count == new_roots) {
+			qg->excl += num_bytes;
+			qg->excl_cmpr += num_bytes;
+			dirty = true;
+		}
+
+		if (dirty)
+			qgroup_dirty(fs_info, qg);
+	}
+	return 0;
+}
+
+/*
+ * If we removed a data extent and there were other references for that bytenr
+ * then we need to lookup all referenced roots to make sure we still don't
+ * reference this bytenr.  If we do then we can just discard this operation.
+ */
+static int check_existing_refs(struct btrfs_trans_handle *trans,
+			       struct btrfs_fs_info *fs_info,
+			       struct btrfs_qgroup_operation *oper)
+{
+	struct ulist *roots = NULL;
+	struct ulist_node *unode;
+	struct ulist_iterator uiter;
+	int ret = 0;
+
+	ret = btrfs_find_all_roots(trans, fs_info, oper->bytenr,
+				   oper->elem.seq, &roots);
+	if (ret < 0)
+		return ret;
+	ret = 0;
+
 	ULIST_ITER_INIT(&uiter);
 	while ((unode = ulist_next(roots, &uiter))) {
-		qg = find_qgroup_rb(fs_info, unode->val);
-		if (!qg)
-			continue;
-
-		ulist_reinit(tmp);
-		ret = ulist_add(tmp, qg->qgroupid, (uintptr_t)qg, GFP_ATOMIC);
-		if (ret < 0)
-			return ret;
-
-		ULIST_ITER_INIT(&tmp_uiter);
-		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
-			struct btrfs_qgroup_list *glist;
-
-			qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
-			if (qg->tag == seq)
-				continue;
-
-			if (qg->refcnt - seq == roots->nnodes) {
-				qg->excl -= sgn * num_bytes;
-				qg->excl_cmpr -= sgn * num_bytes;
-				qgroup_dirty(fs_info, qg);
-			}
-
-			list_for_each_entry(glist, &qg->groups, next_group) {
-				ret = ulist_add(tmp, glist->group->qgroupid,
-						(uintptr_t)glist->group,
-						GFP_ATOMIC);
-				if (ret < 0)
-					return ret;
-			}
+		if (unode->val == oper->ref_root) {
+			ret = 1;
+			break;
 		}
 	}
+	ulist_free(roots);
+	btrfs_put_tree_mod_seq(fs_info, &oper->elem);
 
-	return 0;
+	return ret;
+}
+
+/*
+ * If we share a reference across multiple roots then we may need to adjust
+ * various qgroups referenced and exclusive counters.  The basic premise is this
+ *
+ * 1) We have seq to represent a 0 count.  Instead of looping through all of the
+ * qgroups and resetting their refcount to 0 we just constantly bump this
+ * sequence number to act as the base reference count.  This means that if
+ * anybody is equal to or below this sequence they were never referenced.  We
+ * jack this sequence up by the number of roots we found each time in order to
+ * make sure we don't have any overlap.
+ *
+ * 2) We first search all the roots that reference the area _except_ the root
+ * we're acting on currently.  This makes up the old_refcnt of all the qgroups
+ * before.
+ *
+ * 3) We walk all of the qgroups referenced by the root we are currently acting
+ * on, and will either adjust old_refcnt in the case of a removal or the
+ * new_refcnt in the case of an addition.
+ *
+ * 4) Finally we walk all the qgroups that are referenced by this range
+ * including the root we are acting on currently.  We will adjust the counters
+ * based on the number of roots we had and will have after this operation.
+ *
+ * Take this example as an illustration
+ *
+ *			[qgroup 1/0]
+ *		     /         |          \
+ *		[qg 0/0]   [qg 0/1]	[qg 0/2]
+ *		   \          |            /
+ *		  [	   extent	    ]
+ *
+ * Say we are adding a reference that is covered by qg 0/0.  The first step
+ * would give a refcnt of 1 to qg 0/1 and 0/2 and a refcnt of 2 to qg 1/0 with
+ * old_roots being 2.  Because it is adding new_roots will be 1.  We then go
+ * through qg 0/0 which will get the new_refcnt set to 1 and add 1 to qg 1/0's
+ * new_refcnt, bringing it to 3.  We then walk through all of the qgroups, we
+ * notice that the old refcnt for qg 0/0 < the new refcnt, so we added a
+ * reference and thus must add the size to the referenced bytes.  Everything
+ * else is the same so nothing else changes.
+ */
+static int qgroup_shared_accounting(struct btrfs_trans_handle *trans,
+				    struct btrfs_fs_info *fs_info,
+				    struct btrfs_qgroup_operation *oper)
+{
+	struct ulist *roots = NULL;
+	struct ulist *qgroups, *tmp;
+	struct btrfs_qgroup *qgroup;
+	struct seq_list elem = {};
+	u64 seq;
+	int old_roots = 0;
+	int new_roots = 0;
+	int ret = 0;
+
+	if (oper->elem.seq) {
+		ret = check_existing_refs(trans, fs_info, oper);
+		if (ret < 0)
+			return ret;
+		if (ret)
+			return 0;
+	}
+
+	qgroups = ulist_alloc(GFP_NOFS);
+	if (!qgroups)
+		return -ENOMEM;
+
+	tmp = ulist_alloc(GFP_NOFS);
+	if (!tmp)
+		return -ENOMEM;
+
+	btrfs_get_tree_mod_seq(fs_info, &elem);
+	ret = btrfs_find_all_roots(trans, fs_info, oper->bytenr, elem.seq,
+				   &roots);
+	btrfs_put_tree_mod_seq(fs_info, &elem);
+	if (ret < 0) {
+		ulist_free(qgroups);
+		ulist_free(tmp);
+		return ret;
+	}
+	spin_lock(&fs_info->qgroup_lock);
+	qgroup = find_qgroup_rb(fs_info, oper->ref_root);
+	if (!qgroup)
+		goto out;
+	seq = fs_info->qgroup_seq;
+
+	/*
+	 * So roots is the list of all the roots currently pointing at the
+	 * bytenr, including the ref we are adding if we are adding, or not if
+	 * we are removing a ref.  So we pass in the ref_root to skip that root
+	 * in our calculations.  We set old_refnct and new_refcnt cause who the
+	 * hell knows what everything looked like before, and it doesn't matter
+	 * except...
+	 */
+	ret = qgroup_calc_old_refcnt(fs_info, oper->ref_root, tmp, roots, qgroups,
+				     seq, &old_roots, 0);
+	if (ret < 0)
+		goto out;
+
+	/*
+	 * Now adjust the refcounts of the qgroups that care about this
+	 * reference, either the old_count in the case of removal or new_count
+	 * in the case of an addition.
+	 */
+	ret = qgroup_calc_new_refcnt(fs_info, oper, qgroup, tmp, qgroups,
+				     seq);
+	if (ret < 0)
+		goto out;
+
+	/*
+	 * ...in the case of removals.  If we had a removal before we got around
+	 * to processing this operation then we need to find that guy and count
+	 * his references as if they really existed so we don't end up screwing
+	 * up the exclusive counts.  Then whenever we go to process the delete
+	 * everything will be grand and we can account for whatever exclusive
+	 * changes need to be made there.  We also have to pass in old_roots so
+	 * we have an accurate count of the roots as it pertains to this
+	 * operations view of the world.
+	 */
+	ret = qgroup_account_deleted_refs(fs_info, oper, tmp, qgroups, seq,
+					  &old_roots);
+	if (ret < 0)
+		goto out;
+
+	/*
+	 * We are adding our root, need to adjust up the number of roots,
+	 * otherwise old_roots is the number of roots we want.
+	 */
+	if (oper->type == BTRFS_QGROUP_OPER_ADD_SHARED) {
+		new_roots = old_roots + 1;
+	} else {
+		new_roots = old_roots;
+		old_roots++;
+	}
+	fs_info->qgroup_seq += old_roots + 1;
+
+
+	/*
+	 * And now the magic happens, bless Arne for having a pretty elegant
+	 * solution for this.
+	 */
+	qgroup_adjust_counters(fs_info, oper->ref_root, oper->num_bytes,
+			       qgroups, seq, old_roots, new_roots, 0);
+out:
+	spin_unlock(&fs_info->qgroup_lock);
+	ulist_free(qgroups);
+	ulist_free(roots);
+	ulist_free(tmp);
+	return ret;
 }
 
 /*
@@ -1342,125 +1864,65 @@
  * then the space is accounted accordingly to the different roots. The
  * accounting algorithm works in 3 steps documented inline.
  */
-int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans,
-			     struct btrfs_fs_info *fs_info,
-			     struct btrfs_delayed_ref_node *node,
-			     struct btrfs_delayed_extent_op *extent_op)
+static int btrfs_qgroup_account(struct btrfs_trans_handle *trans,
+				struct btrfs_fs_info *fs_info,
+				struct btrfs_qgroup_operation *oper)
 {
-	struct btrfs_root *quota_root;
-	u64 ref_root;
-	struct btrfs_qgroup *qgroup;
-	struct ulist *roots = NULL;
-	u64 seq;
 	int ret = 0;
-	int sgn;
 
 	if (!fs_info->quota_enabled)
 		return 0;
 
 	BUG_ON(!fs_info->quota_root);
 
-	if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
-	    node->type == BTRFS_SHARED_BLOCK_REF_KEY) {
-		struct btrfs_delayed_tree_ref *ref;
-		ref = btrfs_delayed_node_to_tree_ref(node);
-		ref_root = ref->root;
-	} else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
-		   node->type == BTRFS_SHARED_DATA_REF_KEY) {
-		struct btrfs_delayed_data_ref *ref;
-		ref = btrfs_delayed_node_to_data_ref(node);
-		ref_root = ref->root;
-	} else {
-		BUG();
-	}
-
-	if (!is_fstree(ref_root)) {
-		/*
-		 * non-fs-trees are not being accounted
-		 */
-		return 0;
-	}
-
-	switch (node->action) {
-	case BTRFS_ADD_DELAYED_REF:
-	case BTRFS_ADD_DELAYED_EXTENT:
-		sgn = 1;
-		seq = btrfs_tree_mod_seq_prev(node->seq);
-		break;
-	case BTRFS_DROP_DELAYED_REF:
-		sgn = -1;
-		seq = node->seq;
-		break;
-	case BTRFS_UPDATE_DELAYED_HEAD:
-		return 0;
-	default:
-		BUG();
-	}
-
 	mutex_lock(&fs_info->qgroup_rescan_lock);
 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
-		if (fs_info->qgroup_rescan_progress.objectid <= node->bytenr) {
+		if (fs_info->qgroup_rescan_progress.objectid <= oper->bytenr) {
 			mutex_unlock(&fs_info->qgroup_rescan_lock);
 			return 0;
 		}
 	}
 	mutex_unlock(&fs_info->qgroup_rescan_lock);
 
-	/*
-	 * the delayed ref sequence number we pass depends on the direction of
-	 * the operation. for add operations, we pass
-	 * tree_mod_log_prev_seq(node->seq) to skip
-	 * the delayed ref's current sequence number, because we need the state
-	 * of the tree before the add operation. for delete operations, we pass
-	 * (node->seq) to include the delayed ref's current sequence number,
-	 * because we need the state of the tree after the delete operation.
-	 */
-	ret = btrfs_find_all_roots(trans, fs_info, node->bytenr, seq, &roots);
-	if (ret < 0)
-		return ret;
+	ASSERT(is_fstree(oper->ref_root));
 
-	spin_lock(&fs_info->qgroup_lock);
+	switch (oper->type) {
+	case BTRFS_QGROUP_OPER_ADD_EXCL:
+	case BTRFS_QGROUP_OPER_SUB_EXCL:
+		ret = qgroup_excl_accounting(fs_info, oper);
+		break;
+	case BTRFS_QGROUP_OPER_ADD_SHARED:
+	case BTRFS_QGROUP_OPER_SUB_SHARED:
+		ret = qgroup_shared_accounting(trans, fs_info, oper);
+		break;
+	default:
+		ASSERT(0);
+	}
+	return ret;
+}
 
-	quota_root = fs_info->quota_root;
-	if (!quota_root)
-		goto unlock;
+/*
+ * Needs to be called everytime we run delayed refs, even if there is an error
+ * in order to cleanup outstanding operations.
+ */
+int btrfs_delayed_qgroup_accounting(struct btrfs_trans_handle *trans,
+				    struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_qgroup_operation *oper;
+	int ret = 0;
 
-	qgroup = find_qgroup_rb(fs_info, ref_root);
-	if (!qgroup)
-		goto unlock;
-
-	/*
-	 * step 1: for each old ref, visit all nodes once and inc refcnt
-	 */
-	ulist_reinit(fs_info->qgroup_ulist);
-	seq = fs_info->qgroup_seq;
-	fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */
-
-	ret = qgroup_account_ref_step1(fs_info, roots, fs_info->qgroup_ulist,
-				       seq);
-	if (ret)
-		goto unlock;
-
-	/*
-	 * step 2: walk from the new root
-	 */
-	ret = qgroup_account_ref_step2(fs_info, roots, fs_info->qgroup_ulist,
-				       seq, sgn, node->num_bytes, qgroup);
-	if (ret)
-		goto unlock;
-
-	/*
-	 * step 3: walk again from old refs
-	 */
-	ret = qgroup_account_ref_step3(fs_info, roots, fs_info->qgroup_ulist,
-				       seq, sgn, node->num_bytes);
-	if (ret)
-		goto unlock;
-
-unlock:
-	spin_unlock(&fs_info->qgroup_lock);
-	ulist_free(roots);
-
+	while (!list_empty(&trans->qgroup_ref_list)) {
+		oper = list_first_entry(&trans->qgroup_ref_list,
+					struct btrfs_qgroup_operation, list);
+		list_del_init(&oper->list);
+		if (!ret || !trans->aborted)
+			ret = btrfs_qgroup_account(trans, fs_info, oper);
+		spin_lock(&fs_info->qgroup_op_lock);
+		rb_erase(&oper->n, &fs_info->qgroup_op_tree);
+		spin_unlock(&fs_info->qgroup_op_lock);
+		btrfs_put_tree_mod_seq(fs_info, &oper->elem);
+		kfree(oper);
+	}
 	return ret;
 }
 
@@ -1629,8 +2091,16 @@
 		srcgroup = find_qgroup_rb(fs_info, srcid);
 		if (!srcgroup)
 			goto unlock;
-		dstgroup->rfer = srcgroup->rfer - level_size;
-		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr - level_size;
+
+		/*
+		 * We call inherit after we clone the root in order to make sure
+		 * our counts don't go crazy, so at this point the only
+		 * difference between the two roots should be the root node.
+		 */
+		dstgroup->rfer = srcgroup->rfer;
+		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr;
+		dstgroup->excl = level_size;
+		dstgroup->excl_cmpr = level_size;
 		srcgroup->excl = level_size;
 		srcgroup->excl_cmpr = level_size;
 		qgroup_dirty(fs_info, dstgroup);
@@ -1734,7 +2204,7 @@
 		struct btrfs_qgroup *qg;
 		struct btrfs_qgroup_list *glist;
 
-		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
+		qg = u64_to_ptr(unode->aux);
 
 		if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) &&
 		    qg->reserved + (s64)qg->rfer + num_bytes >
@@ -1766,7 +2236,7 @@
 	while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) {
 		struct btrfs_qgroup *qg;
 
-		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
+		qg = u64_to_ptr(unode->aux);
 
 		qg->reserved += num_bytes;
 	}
@@ -1812,7 +2282,7 @@
 		struct btrfs_qgroup *qg;
 		struct btrfs_qgroup_list *glist;
 
-		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
+		qg = u64_to_ptr(unode->aux);
 
 		qg->reserved -= num_bytes;
 
@@ -1848,15 +2318,15 @@
  */
 static int
 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
-		   struct btrfs_trans_handle *trans, struct ulist *tmp,
-		   struct extent_buffer *scratch_leaf)
+		   struct btrfs_trans_handle *trans, struct ulist *qgroups,
+		   struct ulist *tmp, struct extent_buffer *scratch_leaf)
 {
 	struct btrfs_key found;
 	struct ulist *roots = NULL;
-	struct ulist_node *unode;
-	struct ulist_iterator uiter;
 	struct seq_list tree_mod_seq_elem = {};
+	u64 num_bytes;
 	u64 seq;
+	int new_roots;
 	int slot;
 	int ret;
 
@@ -1897,8 +2367,6 @@
 	mutex_unlock(&fs_info->qgroup_rescan_lock);
 
 	for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) {
-		u64 num_bytes;
-
 		btrfs_item_key_to_cpu(scratch_leaf, &found, slot);
 		if (found.type != BTRFS_EXTENT_ITEM_KEY &&
 		    found.type != BTRFS_METADATA_ITEM_KEY)
@@ -1908,76 +2376,34 @@
 		else
 			num_bytes = found.offset;
 
-		ret = btrfs_find_all_roots(trans, fs_info, found.objectid,
-					   tree_mod_seq_elem.seq, &roots);
+		ulist_reinit(qgroups);
+		ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
+					   &roots);
 		if (ret < 0)
 			goto out;
 		spin_lock(&fs_info->qgroup_lock);
 		seq = fs_info->qgroup_seq;
 		fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */
 
-		ret = qgroup_account_ref_step1(fs_info, roots, tmp, seq);
-		if (ret) {
+		new_roots = 0;
+		ret = qgroup_calc_old_refcnt(fs_info, 0, tmp, roots, qgroups,
+					     seq, &new_roots, 1);
+		if (ret < 0) {
 			spin_unlock(&fs_info->qgroup_lock);
 			ulist_free(roots);
 			goto out;
 		}
 
-		/*
-		 * step2 of btrfs_qgroup_account_ref works from a single root,
-		 * we're doing all at once here.
-		 */
-		ulist_reinit(tmp);
-		ULIST_ITER_INIT(&uiter);
-		while ((unode = ulist_next(roots, &uiter))) {
-			struct btrfs_qgroup *qg;
-
-			qg = find_qgroup_rb(fs_info, unode->val);
-			if (!qg)
-				continue;
-
-			ret = ulist_add(tmp, qg->qgroupid, (uintptr_t)qg,
-					GFP_ATOMIC);
-			if (ret < 0) {
-				spin_unlock(&fs_info->qgroup_lock);
-				ulist_free(roots);
-				goto out;
-			}
+		ret = qgroup_adjust_counters(fs_info, 0, num_bytes, qgroups,
+					     seq, 0, new_roots, 1);
+		if (ret < 0) {
+			spin_unlock(&fs_info->qgroup_lock);
+			ulist_free(roots);
+			goto out;
 		}
-
-		/* this loop is similar to step 2 of btrfs_qgroup_account_ref */
-		ULIST_ITER_INIT(&uiter);
-		while ((unode = ulist_next(tmp, &uiter))) {
-			struct btrfs_qgroup *qg;
-			struct btrfs_qgroup_list *glist;
-
-			qg = (struct btrfs_qgroup *)(uintptr_t) unode->aux;
-			qg->rfer += num_bytes;
-			qg->rfer_cmpr += num_bytes;
-			WARN_ON(qg->tag >= seq);
-			if (qg->refcnt - seq == roots->nnodes) {
-				qg->excl += num_bytes;
-				qg->excl_cmpr += num_bytes;
-			}
-			qgroup_dirty(fs_info, qg);
-
-			list_for_each_entry(glist, &qg->groups, next_group) {
-				ret = ulist_add(tmp, glist->group->qgroupid,
-						(uintptr_t)glist->group,
-						GFP_ATOMIC);
-				if (ret < 0) {
-					spin_unlock(&fs_info->qgroup_lock);
-					ulist_free(roots);
-					goto out;
-				}
-			}
-		}
-
 		spin_unlock(&fs_info->qgroup_lock);
 		ulist_free(roots);
-		ret = 0;
 	}
-
 out:
 	btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
 
@@ -1990,13 +2416,16 @@
 						     qgroup_rescan_work);
 	struct btrfs_path *path;
 	struct btrfs_trans_handle *trans = NULL;
-	struct ulist *tmp = NULL;
+	struct ulist *tmp = NULL, *qgroups = NULL;
 	struct extent_buffer *scratch_leaf = NULL;
 	int err = -ENOMEM;
 
 	path = btrfs_alloc_path();
 	if (!path)
 		goto out;
+	qgroups = ulist_alloc(GFP_NOFS);
+	if (!qgroups)
+		goto out;
 	tmp = ulist_alloc(GFP_NOFS);
 	if (!tmp)
 		goto out;
@@ -2015,7 +2444,7 @@
 			err = -EINTR;
 		} else {
 			err = qgroup_rescan_leaf(fs_info, path, trans,
-						 tmp, scratch_leaf);
+						 qgroups, tmp, scratch_leaf);
 		}
 		if (err > 0)
 			btrfs_commit_transaction(trans, fs_info->fs_root);
@@ -2025,7 +2454,7 @@
 
 out:
 	kfree(scratch_leaf);
-	ulist_free(tmp);
+	ulist_free(qgroups);
 	btrfs_free_path(path);
 
 	mutex_lock(&fs_info->qgroup_rescan_lock);
diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
new file mode 100644
index 0000000..5952ff1
--- /dev/null
+++ b/fs/btrfs/qgroup.h
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2014 Facebook.  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.
+ */
+
+#ifndef __BTRFS_QGROUP__
+#define __BTRFS_QGROUP__
+
+/*
+ * A description of the operations, all of these operations only happen when we
+ * are adding the 1st reference for that subvolume in the case of adding space
+ * or on the last reference delete in the case of subtraction.  The only
+ * exception is the last one, which is added for confusion.
+ *
+ * BTRFS_QGROUP_OPER_ADD_EXCL: adding bytes where this subvolume is the only
+ * one pointing at the bytes we are adding.  This is called on the first
+ * allocation.
+ *
+ * BTRFS_QGROUP_OPER_ADD_SHARED: adding bytes where this bytenr is going to be
+ * shared between subvols.  This is called on the creation of a ref that already
+ * has refs from a different subvolume, so basically reflink.
+ *
+ * BTRFS_QGROUP_OPER_SUB_EXCL: removing bytes where this subvolume is the only
+ * one referencing the range.
+ *
+ * BTRFS_QGROUP_OPER_SUB_SHARED: removing bytes where this subvolume shares with
+ * refs with other subvolumes.
+ */
+enum btrfs_qgroup_operation_type {
+	BTRFS_QGROUP_OPER_ADD_EXCL,
+	BTRFS_QGROUP_OPER_ADD_SHARED,
+	BTRFS_QGROUP_OPER_SUB_EXCL,
+	BTRFS_QGROUP_OPER_SUB_SHARED,
+};
+
+struct btrfs_qgroup_operation {
+	u64 ref_root;
+	u64 bytenr;
+	u64 num_bytes;
+	u64 seq;
+	enum btrfs_qgroup_operation_type type;
+	struct seq_list elem;
+	struct rb_node n;
+	struct list_head list;
+};
+
+int btrfs_quota_enable(struct btrfs_trans_handle *trans,
+		       struct btrfs_fs_info *fs_info);
+int btrfs_quota_disable(struct btrfs_trans_handle *trans,
+			struct btrfs_fs_info *fs_info);
+int btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info);
+void btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info);
+int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info);
+int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans,
+			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
+int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans,
+			      struct btrfs_fs_info *fs_info, u64 src, u64 dst);
+int btrfs_create_qgroup(struct btrfs_trans_handle *trans,
+			struct btrfs_fs_info *fs_info, u64 qgroupid,
+			char *name);
+int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
+			      struct btrfs_fs_info *fs_info, u64 qgroupid);
+int btrfs_limit_qgroup(struct btrfs_trans_handle *trans,
+		       struct btrfs_fs_info *fs_info, u64 qgroupid,
+		       struct btrfs_qgroup_limit *limit);
+int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info);
+void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info);
+struct btrfs_delayed_extent_op;
+int btrfs_qgroup_record_ref(struct btrfs_trans_handle *trans,
+			    struct btrfs_fs_info *fs_info, u64 ref_root,
+			    u64 bytenr, u64 num_bytes,
+			    enum btrfs_qgroup_operation_type type,
+			    int mod_seq);
+int btrfs_delayed_qgroup_accounting(struct btrfs_trans_handle *trans,
+				    struct btrfs_fs_info *fs_info);
+void btrfs_remove_qgroup_operation(struct btrfs_trans_handle *trans,
+				   struct btrfs_fs_info *fs_info,
+				   struct btrfs_qgroup_operation *oper);
+int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
+		      struct btrfs_fs_info *fs_info);
+int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
+			 struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
+			 struct btrfs_qgroup_inherit *inherit);
+int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes);
+void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes);
+
+void assert_qgroups_uptodate(struct btrfs_trans_handle *trans);
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
+			       u64 rfer, u64 excl);
+#endif
+
+#endif /* __BTRFS_QGROUP__ */
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 7c4c049..3aafbde 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -31,6 +31,7 @@
 #include "inode-map.h"
 #include "volumes.h"
 #include "dev-replace.h"
+#include "qgroup.h"
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
@@ -703,23 +704,9 @@
 		return 0;
 	}
 
-	/*
-	 * do the qgroup accounting as early as possible
-	 */
-	err = btrfs_delayed_refs_qgroup_accounting(trans, info);
-
 	btrfs_trans_release_metadata(trans, root);
 	trans->block_rsv = NULL;
 
-	if (trans->qgroup_reserved) {
-		/*
-		 * the same root has to be passed here between start_transaction
-		 * and end_transaction. Subvolume quota depends on this.
-		 */
-		btrfs_qgroup_free(trans->root, trans->qgroup_reserved);
-		trans->qgroup_reserved = 0;
-	}
-
 	if (!list_empty(&trans->new_bgs))
 		btrfs_create_pending_block_groups(trans, root);
 
@@ -730,6 +717,15 @@
 		btrfs_run_delayed_refs(trans, root, cur);
 	}
 
+	if (trans->qgroup_reserved) {
+		/*
+		 * the same root has to be passed here between start_transaction
+		 * and end_transaction. Subvolume quota depends on this.
+		 */
+		btrfs_qgroup_free(trans->root, trans->qgroup_reserved);
+		trans->qgroup_reserved = 0;
+	}
+
 	btrfs_trans_release_metadata(trans, root);
 	trans->block_rsv = NULL;
 
@@ -1169,12 +1165,6 @@
 			goto no_free_objectid;
 	}
 
-	pending->error = btrfs_qgroup_inherit(trans, fs_info,
-					      root->root_key.objectid,
-					      objectid, pending->inherit);
-	if (pending->error)
-		goto no_free_objectid;
-
 	key.objectid = objectid;
 	key.offset = (u64)-1;
 	key.type = BTRFS_ROOT_ITEM_KEY;
@@ -1271,6 +1261,22 @@
 		goto fail;
 	}
 
+	/*
+	 * We need to flush delayed refs in order to make sure all of our quota
+	 * operations have been done before we call btrfs_qgroup_inherit.
+	 */
+	ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
+	if (ret) {
+		btrfs_abort_transaction(trans, root, ret);
+		goto fail;
+	}
+
+	pending->error = btrfs_qgroup_inherit(trans, fs_info,
+					      root->root_key.objectid,
+					      objectid, pending->inherit);
+	if (pending->error)
+		goto no_free_objectid;
+
 	/* see comments in should_cow_block() */
 	set_bit(BTRFS_ROOT_FORCE_COW, &root->state);
 	smp_wmb();
@@ -1599,12 +1605,6 @@
 	 * them now so that they hinder processing of more delayed refs
 	 * as little as possible.
 	 */
-	if (ret) {
-		btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
-		return ret;
-	}
-
-	ret = btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
 	if (ret)
 		return ret;