diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 2aa3d882aede..591151266372 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -912,6 +912,7 @@ struct btrfs_fs_info {
 
 	/* Extent buffer radix tree */
 	spinlock_t buffer_lock;
+	/* Entries are eb->start / sectorsize */
 	struct radix_tree_root buffer_radix;
 
 	/* next backup root to be overwritten */
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 092ccb811eac..1dfbe859c650 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -5107,7 +5107,7 @@ struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
 
 	rcu_read_lock();
 	eb = radix_tree_lookup(&fs_info->buffer_radix,
-			       start >> PAGE_SHIFT);
+			       start >> fs_info->sectorsize_bits);
 	if (eb && atomic_inc_not_zero(&eb->refs)) {
 		rcu_read_unlock();
 		/*
@@ -5159,7 +5159,7 @@ again:
 	}
 	spin_lock(&fs_info->buffer_lock);
 	ret = radix_tree_insert(&fs_info->buffer_radix,
-				start >> PAGE_SHIFT, eb);
+				start >> fs_info->sectorsize_bits, eb);
 	spin_unlock(&fs_info->buffer_lock);
 	radix_tree_preload_end();
 	if (ret == -EEXIST) {
@@ -5267,7 +5267,7 @@ again:
 
 	spin_lock(&fs_info->buffer_lock);
 	ret = radix_tree_insert(&fs_info->buffer_radix,
-				start >> PAGE_SHIFT, eb);
+				start >> fs_info->sectorsize_bits, eb);
 	spin_unlock(&fs_info->buffer_lock);
 	radix_tree_preload_end();
 	if (ret == -EEXIST) {
@@ -5323,7 +5323,7 @@ static int release_extent_buffer(struct extent_buffer *eb)
 
 			spin_lock(&fs_info->buffer_lock);
 			radix_tree_delete(&fs_info->buffer_radix,
-					  eb->start >> PAGE_SHIFT);
+					  eb->start >> fs_info->sectorsize_bits);
 			spin_unlock(&fs_info->buffer_lock);
 		} else {
 			spin_unlock(&eb->refs_lock);