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>

1 files changed, 1 insertions, 23 deletions

diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c
index 3d3ea83..1e68821 100644
--- a/fs/nilfs2/segbuf.c
+++ b/fs/nilfs2/segbuf.c
@@ -64,27 +64,17 @@ struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)
 	INIT_LIST_HEAD(&segbuf->sb_list);
 	INIT_LIST_HEAD(&segbuf->sb_segsum_buffers);
 	INIT_LIST_HEAD(&segbuf->sb_payload_buffers);
-	segbuf->sb_segent = NULL;
 	return segbuf;
 }
 
 void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf)
 {
-	struct nilfs_segment_entry *ent = segbuf->sb_segent;
-
-	if (ent != NULL && list_empty(&ent->list)) {
-		/* free isolated segment list head */
-		nilfs_free_segment_entry(segbuf->sb_segent);
-		segbuf->sb_segent = NULL;
-	}
 	kmem_cache_free(nilfs_segbuf_cachep, segbuf);
 }
 
-int nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
+void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
 		     unsigned long offset, struct the_nilfs *nilfs)
 {
-	struct nilfs_segment_entry *ent;
-
 	segbuf->sb_segnum = segnum;
 	nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start,
 				&segbuf->sb_fseg_end);
@@ -92,18 +82,6 @@ int nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
 	segbuf->sb_pseg_start = segbuf->sb_fseg_start + offset;
 	segbuf->sb_rest_blocks =
 		segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
-
-	/* Attach a segment list head */
-	ent = segbuf->sb_segent;
-	if (ent == NULL) {
-		segbuf->sb_segent = nilfs_alloc_segment_entry(segnum);
-		if (unlikely(!segbuf->sb_segent))
-			return -ENOMEM;
-	} else {
-		BUG_ON(ent->bh_su || !list_empty(&ent->list));
-		ent->segnum = segnum;
-	}
-	return 0;
 }
 
 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf,