[PATCH v3 7/9] nilfs2: add /sys/fs/nilfs2/<device>/mounted_snapshots group

[Vyacheslav Dubeyko]

From: Vyacheslav Dubeyko <Vyacheslav.Dubeyko-***@public.gmane.org>
Subject: [PATCH v3 7/9] 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-***@public.gmane.org>
CC: Vyacheslav Dubeyko <slava-***@public.gmane.org>
CC: Ryusuke Konishi <konishi.ryusuke-***@public.gmane.org>
CC: Michael L. Semon <mlsemon35-***@public.gmane.org>
---
Documentation/ABI/testing/sysfs-fs-nilfs2 | 8 +++++++
fs/nilfs2/sysfs.c | 36 ++++++++++++++++++++++++++++-
fs/nilfs2/sysfs.h | 12 ++++++++++
3 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-nilfs2 b/Documentation/ABI/testing/sysfs-fs-nilfs2
index c3d2c0f..db3cf80 100644
--- a/Documentation/ABI/testing/sysfs-fs-nilfs2
+++ b/Documentation/ABI/testing/sysfs-fs-nilfs2
@@ -279,3 +279,11 @@ Contact: "Vyacheslav Dubeyko" <slava-***@public.gmane.org>
Description:
Describe attributes of /sys/fs/nilfs2/<device>/checkpoints
group.
+
+What: /sys/fs/nilfs2/<device>/mounted_snapshots/README
+Date: April 2014
+KernelVersion: 3.15
+Contact: "Vyacheslav Dubeyko" <slava-***@public.gmane.org>
+Description:
+ Describe content of /sys/fs/nilfs2/<device>/mounted_snapshots
+ group.
diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index 46e7bd9..3de3b30 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);
diff --git a/fs/nilfs2/sysfs.h b/fs/nilfs2/sysfs.h
index b4e2db3..b10830d 100644
--- a/fs/nilfs2/sysfs.h
+++ b/fs/nilfs2/sysfs.h
@@ -28,6 +28,8 @@
* @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
@@ -42,6 +44,10 @@ 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;
@@ -73,6 +79,7 @@ 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);
@@ -109,6 +116,9 @@ 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) \
@@ -132,6 +142,8 @@ 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) \