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

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

The mounted_snapshots group contains group for every
mounted snapshot.

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>

diff --git a/Documentation/ABI/testing/sysfs-fs-nilfs2 b/Documentation/ABI/testing/sysfs-fs-nilfs2
index 7b820d6..29dbc8f 100644 (file)
--- a/Documentation/ABI/testing/sysfs-fs-nilfs2
+++ b/Documentation/ABI/testing/sysfs-fs-nilfs2
@@ -241,3 +241,10 @@ Contact:   "Vyacheslav Dubeyko" <slava@dubeyko.com>
 Description:
                Describe attributes of /sys/fs/nilfs2/<device>/checkpoints
                group.
+
+What:          /sys/fs/nilfs2/<device>/mounted_snapshots/README
+Date:          April 2014
+Contact:       "Vyacheslav Dubeyko" <slava@dubeyko.com>
+Description:
+               Describe content of /sys/fs/nilfs2/<device>/mounted_snapshots
+               group.

diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index 5cc735f..fc0c961 100644 (file)
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -111,6 +111,32 @@ void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \
        kobject_del(&nilfs->ns_##parent_name##_subgroups->sg_##name##_kobj); \
 }
 
+/************************************************************************
+ *                    NILFS mounted snapshots attrs                     *
+ ************************************************************************/
+
+static const char mounted_snapshots_readme_str[] =
+       "The mounted_snapshots group contains group for\n"
+       "every mounted snapshot.\n";
+
+static ssize_t
+nilfs_mounted_snapshots_README_show(struct nilfs_mounted_snapshots_attr *attr,
+                                   struct the_nilfs *nilfs, char *buf)
+{
+       return snprintf(buf, PAGE_SIZE, mounted_snapshots_readme_str);
+}
+
+NILFS_MOUNTED_SNAPSHOTS_RO_ATTR(README);
+
+static struct attribute *nilfs_mounted_snapshots_attrs[] = {
+       NILFS_MOUNTED_SNAPSHOTS_ATTR_LIST(README),
+       NULL,
+};
+
+NILFS_DEV_INT_GROUP_OPS(mounted_snapshots, dev);
+NILFS_DEV_INT_GROUP_TYPE(mounted_snapshots, dev);
+NILFS_DEV_INT_GROUP_FNS(mounted_snapshots, dev);
+
 /************************************************************************
  *                      NILFS checkpoints attrs                         *
  ************************************************************************/
@@ -866,10 +892,14 @@ int nilfs_sysfs_create_device_group(struct super_block *sb)
        if (err)
                goto free_dev_subgroups;
 
-       err = nilfs_sysfs_create_checkpoints_group(nilfs);
+       err = nilfs_sysfs_create_mounted_snapshots_group(nilfs);
        if (err)
                goto cleanup_dev_kobject;
 
+       err = nilfs_sysfs_create_checkpoints_group(nilfs);
+       if (err)
+               goto delete_mounted_snapshots_group;
+
        err = nilfs_sysfs_create_segments_group(nilfs);
        if (err)
                goto delete_checkpoints_group;
@@ -893,6 +923,9 @@ delete_segments_group:
 delete_checkpoints_group:
        nilfs_sysfs_delete_checkpoints_group(nilfs);
 
+delete_mounted_snapshots_group:
+       nilfs_sysfs_delete_mounted_snapshots_group(nilfs);
+
 cleanup_dev_kobject:
        kobject_del(&nilfs->ns_dev_kobj);
 
@@ -905,6 +938,7 @@ failed_create_device_group:
 
 void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
 {
+       nilfs_sysfs_delete_mounted_snapshots_group(nilfs);
        nilfs_sysfs_delete_checkpoints_group(nilfs);
        nilfs_sysfs_delete_segments_group(nilfs);
        nilfs_sysfs_delete_superblock_group(nilfs);

diff --git a/fs/nilfs2/sysfs.h b/fs/nilfs2/sysfs.h
index 62f0a0d..4e84e23 100644 (file)
--- 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_mounted_snapshots_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots
+ * @sg_mounted_snapshots_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
@@ -44,6 +46,10 @@ struct nilfs_sysfs_dev_subgroups {
        struct kobject sg_segctor_kobj;
        struct completion sg_segctor_kobj_unregister;
 
+       /* /sys/fs/<nilfs>/<device>/mounted_snapshots */
+       struct kobject sg_mounted_snapshots_kobj;
+       struct completion sg_mounted_snapshots_kobj_unregister;
+
        /* /sys/fs/<nilfs>/<device>/checkpoints */
        struct kobject sg_checkpoints_kobj;
        struct completion sg_checkpoints_kobj_unregister;
@@ -75,6 +81,7 @@ struct nilfs_##name##_attr { \
 
 NILFS_DEV_ATTR_STRUCT(dev);
 NILFS_DEV_ATTR_STRUCT(segments);
+NILFS_DEV_ATTR_STRUCT(mounted_snapshots);
 NILFS_DEV_ATTR_STRUCT(checkpoints);
 NILFS_DEV_ATTR_STRUCT(superblock);
 NILFS_DEV_ATTR_STRUCT(segctor);
@@ -111,6 +118,9 @@ NILFS_DEV_ATTR_STRUCT(segctor);
 #define NILFS_SEGMENTS_RW_ATTR(name) \
        NILFS_RW_ATTR(segs_info, name)
 
+#define NILFS_MOUNTED_SNAPSHOTS_RO_ATTR(name) \
+       NILFS_RO_ATTR(mounted_snapshots, name)
+
 #define NILFS_CHECKPOINTS_RO_ATTR(name) \
        NILFS_RO_ATTR(checkpoints, name)
 #define NILFS_CHECKPOINTS_RW_ATTR(name) \
@@ -134,6 +144,8 @@ NILFS_DEV_ATTR_STRUCT(segctor);
        (&nilfs_dev_attr_##name.attr)
 #define NILFS_SEGMENTS_ATTR_LIST(name) \
        (&nilfs_segments_attr_##name.attr)
+#define NILFS_MOUNTED_SNAPSHOTS_ATTR_LIST(name) \
+       (&nilfs_mounted_snapshots_attr_##name.attr)
 #define NILFS_CHECKPOINTS_ATTR_LIST(name) \
        (&nilfs_checkpoints_attr_##name.attr)
 #define NILFS_SUPERBLOCK_ATTR_LIST(name) \