nilfs2: add /sys/fs/nilfs2/<device>/checkpoints group

This patch adds creation of /sys/fs/nilfs2/<device>/checkpoints
group.

The checkpoints group contains attributes that describe
details about volume's checkpoints:
(1) checkpoints_number - show number of checkpoints on volume.
(2) snapshots_number - show number of snapshots on volume.
(3) last_seg_checkpoint - show checkpoint number of the latest segment.
(4) next_checkpoint - show next checkpoint number.

Signed-off-by: Vyacheslav Dubeyko <Vyacheslav.Dubeyko@hgst.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/fs/nilfs2/sysfs.h b/fs/nilfs2/sysfs.h
index 228bdd14f945..62f0a0dc78ca 100644
--- a/fs/nilfs2/sysfs.h
+++ b/fs/nilfs2/sysfs.h
@@ -30,6 +30,8 @@
  * @sg_superblock_kobj_unregister: completion state
  * @sg_segctor_kobj: /sys/fs/<nilfs>/<device>/segctor
  * @sg_segctor_kobj_unregister: completion state
+ * @sg_checkpoints_kobj: /sys/fs/<nilfs>/<device>/checkpoints
+ * @sg_checkpoints_kobj_unregister: completion state
  * @sg_segments_kobj: /sys/fs/<nilfs>/<device>/segments
  * @sg_segments_kobj_unregister: completion state
  */
@@ -42,6 +44,10 @@ struct nilfs_sysfs_dev_subgroups {
         struct kobject sg_segctor_kobj;
         struct completion sg_segctor_kobj_unregister;
 
+        /* /sys/fs/<nilfs>/<device>/checkpoints */
+        struct kobject sg_checkpoints_kobj;
+        struct completion sg_checkpoints_kobj_unregister;
+
         /* /sys/fs/<nilfs>/<device>/segments */
         struct kobject sg_segments_kobj;
         struct completion sg_segments_kobj_unregister;
@@ -69,6 +75,7 @@ struct nilfs_##name##_attr { \
 
 NILFS_DEV_ATTR_STRUCT(dev);
 NILFS_DEV_ATTR_STRUCT(segments);
+NILFS_DEV_ATTR_STRUCT(checkpoints);
 NILFS_DEV_ATTR_STRUCT(superblock);
 NILFS_DEV_ATTR_STRUCT(segctor);
 
@@ -104,6 +111,11 @@ NILFS_DEV_ATTR_STRUCT(segctor);
 #define NILFS_SEGMENTS_RW_ATTR(name) \
         NILFS_RW_ATTR(segs_info, name)
 
+#define NILFS_CHECKPOINTS_RO_ATTR(name) \
+        NILFS_RO_ATTR(checkpoints, name)
+#define NILFS_CHECKPOINTS_RW_ATTR(name) \
+        NILFS_RW_ATTR(checkpoints, name)
+
 #define NILFS_SUPERBLOCK_RO_ATTR(name) \
         NILFS_RO_ATTR(superblock, name)
 #define NILFS_SUPERBLOCK_RW_ATTR(name) \
@@ -122,6 +134,8 @@ NILFS_DEV_ATTR_STRUCT(segctor);
         (&nilfs_dev_attr_##name.attr)
 #define NILFS_SEGMENTS_ATTR_LIST(name) \
         (&nilfs_segments_attr_##name.attr)
+#define NILFS_CHECKPOINTS_ATTR_LIST(name) \
+        (&nilfs_checkpoints_attr_##name.attr)
 #define NILFS_SUPERBLOCK_ATTR_LIST(name) \
         (&nilfs_superblock_attr_##name.attr)
 #define NILFS_SEGCTOR_ATTR_LIST(name) \