diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 19833b4af630..93270e20a8e7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1149,12 +1149,6 @@ struct btrfs_fs_info {
 	struct mutex unused_bg_unpin_mutex;
 	struct mutex delete_unused_bgs_mutex;
 
-	/*
-	 * Chunks that can't be freed yet (under a trim/discard operation)
-	 * and will be latter freed. Protected by fs_info->chunk_mutex.
-	 */
-	struct list_head pinned_chunks;
-
 	/* Cached block sizes */
 	u32 nodesize;
 	u32 sectorsize;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8c10702a3f83..0b2b75a7efbd 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2774,8 +2774,6 @@ int open_ctree(struct super_block *sb,
 	init_waitqueue_head(&fs_info->async_submit_wait);
 	init_waitqueue_head(&fs_info->delayed_iputs_wait);
 
-	INIT_LIST_HEAD(&fs_info->pinned_chunks);
-
 	/* Usable values until the real ones are cached from the superblock */
 	fs_info->nodesize = 4096;
 	fs_info->sectorsize = 4096;
@@ -4050,15 +4048,6 @@ void close_ctree(struct btrfs_fs_info *fs_info)
 
 	btrfs_free_stripe_hash_table(fs_info);
 	btrfs_free_ref_cache(fs_info);
-
-	while (!list_empty(&fs_info->pinned_chunks)) {
-		struct extent_map *em;
-
-		em = list_first_entry(&fs_info->pinned_chunks,
-				      struct extent_map, list);
-		list_del_init(&em->list);
-		free_extent_map(em);
-	}
 }
 
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index c5f9e8359c6f..a9f504e7be33 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -10946,10 +10946,6 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	memcpy(&key, &block_group->key, sizeof(key));
 
 	mutex_lock(&fs_info->chunk_mutex);
-	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;
 	/*
@@ -10976,25 +10972,6 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	 * the transaction commit has completed.
 	 */
 	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, &fs_info->pinned_chunks);
-	}
 	spin_unlock(&block_group->lock);
 
 	if (remove_em) {
@@ -11002,11 +10979,6 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 
 		em_tree = &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 */
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 928f729c55ba..5a79a656dfa6 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -4,6 +4,7 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include "ctree.h"
+#include "volumes.h"
 #include "extent_map.h"
 #include "compression.h"
 
@@ -337,6 +338,37 @@ static inline void setup_extent_mapping(struct extent_map_tree *tree,
 		try_merge_map(tree, em);
 }
 
+static void extent_map_device_set_bits(struct extent_map *em, unsigned bits)
+{
+	struct map_lookup *map = em->map_lookup;
+	u64 stripe_size = em->orig_block_len;
+	int i;
+
+	for (i = 0; i < map->num_stripes; i++) {
+		struct btrfs_bio_stripe *stripe = &map->stripes[i];
+		struct btrfs_device *device = stripe->dev;
+
+		set_extent_bits_nowait(&device->alloc_state, stripe->physical,
+				 stripe->physical + stripe_size - 1, bits);
+	}
+}
+
+static void extent_map_device_clear_bits(struct extent_map *em, unsigned bits)
+{
+	struct map_lookup *map = em->map_lookup;
+	u64 stripe_size = em->orig_block_len;
+	int i;
+
+	for (i = 0; i < map->num_stripes; i++) {
+		struct btrfs_bio_stripe *stripe = &map->stripes[i];
+		struct btrfs_device *device = stripe->dev;
+
+		__clear_extent_bit(&device->alloc_state, stripe->physical,
+				   stripe->physical + stripe_size - 1, bits,
+				   0, 0, NULL, GFP_NOWAIT, NULL);
+	}
+}
+
 /**
  * add_extent_mapping - add new extent map to the extent tree
  * @tree:	tree to insert new map in
@@ -357,6 +389,8 @@ int add_extent_mapping(struct extent_map_tree *tree,
 		goto out;
 
 	setup_extent_mapping(tree, em, modified);
+	if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags))
+		extent_map_device_set_bits(em, CHUNK_ALLOCATED);
 out:
 	return ret;
 }
@@ -438,6 +472,8 @@ void remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
 	rb_erase_cached(&em->rb_node, &tree->map);
 	if (!test_bit(EXTENT_FLAG_LOGGING, &em->flags))
 		list_del_init(&em->list);
+	if (test_bit(EXTENT_FLAG_FS_MAPPING, &em->flags))
+		extent_map_device_clear_bits(em, CHUNK_ALLOCATED);
 	RB_CLEAR_NODE(&em->rb_node);
 }
 
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 74aa552f4793..207fb50dcc7a 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -3366,10 +3366,6 @@ void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
 		em = lookup_extent_mapping(em_tree, block_group->key.objectid,
 					   1);
 		BUG_ON(!em); /* logic error, can't happen */
-		/*
-		 * remove_extent_mapping() will delete us from the pinned_chunks
-		 * list, which is protected by the chunk mutex.
-		 */
 		remove_extent_mapping(em_tree, em);
 		write_unlock(&em_tree->lock);
 		mutex_unlock(&fs_info->chunk_mutex);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index b32769998bbb..e5404326fc55 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -50,14 +50,6 @@ void btrfs_put_transaction(struct btrfs_transaction *transaction)
 			btrfs_err(transaction->fs_info,
 				  "pending csums is %llu",
 				  transaction->delayed_refs.pending_csums);
-		while (!list_empty(&transaction->pending_chunks)) {
-			struct extent_map *em;
-
-			em = list_first_entry(&transaction->pending_chunks,
-					      struct extent_map, list);
-			list_del_init(&em->list);
-			free_extent_map(em);
-		}
 		/*
 		 * If any block groups are found in ->deleted_bgs then it's
 		 * because the transaction was aborted and a commit did not
@@ -235,7 +227,6 @@ static noinline int join_transaction(struct btrfs_fs_info *fs_info,
 	spin_lock_init(&cur_trans->delayed_refs.lock);
 
 	INIT_LIST_HEAD(&cur_trans->pending_snapshots);
-	INIT_LIST_HEAD(&cur_trans->pending_chunks);
 	INIT_LIST_HEAD(&cur_trans->dev_update_list);
 	INIT_LIST_HEAD(&cur_trans->switch_commits);
 	INIT_LIST_HEAD(&cur_trans->dirty_bgs);
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 2bd76f681520..4419a4a0294b 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -51,7 +51,6 @@ struct btrfs_transaction {
 	wait_queue_head_t writer_wait;
 	wait_queue_head_t commit_wait;
 	struct list_head pending_snapshots;
-	struct list_head pending_chunks;
 	struct list_head dev_update_list;
 	struct list_head switch_commits;
 	struct list_head dirty_bgs;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2bde9e9c188e..2e5e48d8dd2f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -336,6 +336,7 @@ void btrfs_free_device(struct btrfs_device *device)
 {
 	WARN_ON(!list_empty(&device->post_commit_list));
 	rcu_string_free(device->name);
+	extent_io_tree_release(&device->alloc_state);
 	bio_put(device->flush_bio);
 	kfree(device);
 }
@@ -412,6 +413,7 @@ static struct btrfs_device *__alloc_device(void)
 	btrfs_device_data_ordered_init(dev);
 	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
 	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
+	extent_io_tree_init(NULL, &dev->alloc_state, 0, NULL);
 
 	return dev;
 }
@@ -1499,58 +1501,30 @@ struct btrfs_device *btrfs_scan_one_device(const char *path, fmode_t flags,
 	return device;
 }
 
-static int contains_pending_extent(struct btrfs_transaction *transaction,
-				   struct btrfs_device *device,
-				   u64 *start, u64 len)
+/*
+ * Try to find a chunk that intersects [start, start + len] range and when one
+ * such is found, record the end of it in *start
+ */
+#define in_range(b, first, len)        ((b) >= (first) && (b) < (first) + (len))
+static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
+				    u64 len)
 {
-	struct btrfs_fs_info *fs_info = device->fs_info;
-	struct extent_map *em;
-	struct list_head *search_list = &fs_info->pinned_chunks;
-	int ret = 0;
-	u64 physical_start = *start;
+	u64 physical_start, physical_end;
 
-	if (transaction)
-		search_list = &transaction->pending_chunks;
-again:
-	list_for_each_entry(em, search_list, list) {
-		struct map_lookup *map;
-		int i;
+	lockdep_assert_held(&device->fs_info->chunk_mutex);
 
-		map = em->map_lookup;
-		for (i = 0; i < map->num_stripes; i++) {
-			u64 end;
+	if (!find_first_extent_bit(&device->alloc_state, *start,
+				   &physical_start, &physical_end,
+				   CHUNK_ALLOCATED, NULL)) {
 
-			if (map->stripes[i].dev != device)
-				continue;
-			if (map->stripes[i].physical >= physical_start + len ||
-			    map->stripes[i].physical + em->orig_block_len <=
-			    physical_start)
-				continue;
-			/*
-			 * Make sure that while processing the pinned list we do
-			 * not override our *start with a lower value, because
-			 * we can have pinned chunks that fall within this
-			 * device hole and that have lower physical addresses
-			 * than the pending chunks we processed before. If we
-			 * do not take this special care we can end up getting
-			 * 2 pending chunks that start at the same physical
-			 * device offsets because the end offset of a pinned
-			 * chunk can be equal to the start offset of some
-			 * pending chunk.
-			 */
-			end = map->stripes[i].physical + em->orig_block_len;
-			if (end > *start) {
-				*start = end;
-				ret = 1;
-			}
+		if (in_range(physical_start, *start, len) ||
+		    in_range(*start, physical_start,
+			     physical_end - physical_start)) {
+			*start = physical_end + 1;
+			return true;
 		}
 	}
-	if (search_list != &fs_info->pinned_chunks) {
-		search_list = &fs_info->pinned_chunks;
-		goto again;
-	}
-
-	return ret;
+	return false;
 }
 
 
@@ -1661,15 +1635,12 @@ int find_free_dev_extent_start(struct btrfs_transaction *transaction,
 			 * Have to check before we set max_hole_start, otherwise
 			 * we could end up sending back this offset anyway.
 			 */
-			if (contains_pending_extent(transaction, device,
-						    &search_start,
+			if (contains_pending_extent(device, &search_start,
 						    hole_size)) {
-				if (key.offset >= search_start) {
+				if (key.offset >= search_start)
 					hole_size = key.offset - search_start;
-				} else {
-					WARN_ON_ONCE(1);
+				else
 					hole_size = 0;
-				}
 			}
 
 			if (hole_size > max_hole_size) {
@@ -1710,8 +1681,7 @@ int find_free_dev_extent_start(struct btrfs_transaction *transaction,
 	if (search_end > search_start) {
 		hole_size = search_end - search_start;
 
-		if (contains_pending_extent(transaction, device, &search_start,
-					    hole_size)) {
+		if (contains_pending_extent(device, &search_start, hole_size)) {
 			btrfs_release_path(path);
 			goto again;
 		}
@@ -4756,7 +4726,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 	 * in-memory chunks are synced to disk so that the loop below sees them
 	 * and relocates them accordingly.
 	 */
-	if (contains_pending_extent(trans->transaction, device, &start, diff)) {
+	if (contains_pending_extent(device, &start, diff)) {
 		mutex_unlock(&fs_info->chunk_mutex);
 		ret = btrfs_commit_transaction(trans);
 		if (ret)
@@ -5189,9 +5159,6 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 		free_extent_map(em);
 		goto error;
 	}
-
-	list_add_tail(&em->list, &trans->transaction->pending_chunks);
-	refcount_inc(&em->refs);
 	write_unlock(&em_tree->lock);
 
 	ret = btrfs_make_block_group(trans, 0, type, start, chunk_size);
@@ -5224,8 +5191,6 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	free_extent_map(em);
 	/* One for the tree reference */
 	free_extent_map(em);
-	/* One for the pending_chunks list reference */
-	free_extent_map(em);
 error:
 	kfree(devices_info);
 	return ret;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index d3658a4e65db..6c466ac27c2e 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -133,6 +133,8 @@ struct btrfs_device {
 	/* Counter to record the change of device stats */
 	atomic_t dev_stats_ccnt;
 	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
+
+	struct extent_io_tree alloc_state;
 };
 
 /*