btrfs: Remove EXTENT_FIRST_DELALLOC bit

With the refactoring introduced in 8b62f87b ("Btrfs: reworki
outstanding_extents") this flag became unused. Remove it and renumber
the following flags accordingly. No functional changes.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent_io.c

@@ -585,7 +585,6 @@ int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 
 	if (delete)
 		bits |= ~EXTENT_CTLBITS;
-	bits |= EXTENT_FIRST_DELALLOC;
 
 	if (bits & (EXTENT_IOBITS | EXTENT_BOUNDARY))
 		clear = 1;
@@ -850,7 +849,6 @@ __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 
 	btrfs_debug_check_extent_io_range(tree, start, end);
 
-	bits |= EXTENT_FIRST_DELALLOC;
 again:
 	if (!prealloc && gfpflags_allow_blocking(mask)) {
 		/*

fs/btrfs/extent_io.h

@@ -18,17 +18,16 @@
 #define EXTENT_BOUNDARY		(1U << 9)
 #define EXTENT_NODATASUM	(1U << 10)
 #define EXTENT_CLEAR_META_RESV	(1U << 11)
-#define EXTENT_FIRST_DELALLOC	(1U << 12)
-#define EXTENT_NEED_WAIT	(1U << 13)
-#define EXTENT_DAMAGED		(1U << 14)
-#define EXTENT_NORESERVE	(1U << 15)
-#define EXTENT_QGROUP_RESERVED	(1U << 16)
-#define EXTENT_CLEAR_DATA_RESV	(1U << 17)
-#define EXTENT_DELALLOC_NEW	(1U << 18)
+#define EXTENT_NEED_WAIT	(1U << 12)
+#define EXTENT_DAMAGED		(1U << 13)
+#define EXTENT_NORESERVE	(1U << 14)
+#define EXTENT_QGROUP_RESERVED	(1U << 15)
+#define EXTENT_CLEAR_DATA_RESV	(1U << 16)
+#define EXTENT_DELALLOC_NEW	(1U << 17)
 #define EXTENT_IOBITS		(EXTENT_LOCKED | EXTENT_WRITEBACK)
 #define EXTENT_DO_ACCOUNTING    (EXTENT_CLEAR_META_RESV | \
 				 EXTENT_CLEAR_DATA_RESV)
-#define EXTENT_CTLBITS		(EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)
+#define EXTENT_CTLBITS		(EXTENT_DO_ACCOUNTING)
 
 /*
  * flags for bio submission. The high bits indicate the compression