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>

1 files changed, 35 insertions, 1 deletions

diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index 5cc735fcc1d5..fc0c961d486a 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -112,6 +112,32 @@ void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \
 }
 
 /************************************************************************
+ *                    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);