nilfs2: simplify handling of active state of segments

will reduce some lines of segment constructor.  Previously, the state was
complexly controlled through a list of segments in order to keep
consistency in meta data of usage state of segments.  Instead, this
presents ``calculated'' active flags to userland cleaner program and stop
maintaining its real flag on disk.

Only by this fake flag, the cleaner cannot exactly know if each segment is
reclaimable or not.  However, the recent extension of nilfs_sustat ioctl
struct (nilfs2-extend-nilfs_sustat-ioctl-struct.patch) can prevent the
cleaner from reclaiming in-use segment wrongly.

So, now I can apply this for simplification.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nilfs2/segment.h b/fs/nilfs2/segment.h
index bb7d417..4a64eb8 100644
--- a/fs/nilfs2/segment.h
+++ b/fs/nilfs2/segment.h
@@ -90,7 +90,6 @@
  * @sc_nblk_inc: Block count of current generation
  * @sc_dirty_files: List of files to be written
  * @sc_gc_inodes: List of GC inodes having blocks to be written
- * @sc_active_segments: List of active segments that were already written out
  * @sc_cleaning_segments: List of segments to be freed through construction
  * @sc_copied_buffers: List of copied buffers (buffer heads) to freeze data
  * @sc_dsync_inode: inode whose data pages are written for a sync operation
@@ -132,7 +131,6 @@
 
 	struct list_head	sc_dirty_files;
 	struct list_head	sc_gc_inodes;
-	struct list_head	sc_active_segments;
 	struct list_head	sc_cleaning_segments;
 	struct list_head	sc_copied_buffers;
 
@@ -232,8 +230,7 @@
 						  __u64 *, size_t);
 extern void nilfs_segctor_clear_segments_to_be_freed(struct nilfs_sc_info *);
 
-extern int nilfs_attach_segment_constructor(struct nilfs_sb_info *,
-					    struct nilfs_recovery_info *);
+extern int nilfs_attach_segment_constructor(struct nilfs_sb_info *);
 extern void nilfs_detach_segment_constructor(struct nilfs_sb_info *);
 
 /* recovery.c */