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

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

The <device> group contains attributes that describe file
system partition's details:
(1) revision - show NILFS file system revision.
(2) blocksize - show volume block size in bytes.
(3) device_size - show volume size in bytes.
(4) free_blocks - show count of free blocks on volume.
(5) uuid - show volume's UUID.
(6) volume_name - show volume's name.

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, 20 insertions, 0 deletions

diff --git a/fs/nilfs2/sysfs.h b/fs/nilfs2/sysfs.h
index 0aed24661052..2353b28c2796 100644
--- a/fs/nilfs2/sysfs.h
+++ b/fs/nilfs2/sysfs.h
@@ -35,6 +35,17 @@ struct nilfs_##name##_attr { \
 
 NILFS_COMMON_ATTR_STRUCT(feature);
 
+#define NILFS_DEV_ATTR_STRUCT(name) \
+struct nilfs_##name##_attr { \
+        struct attribute attr; \
+        ssize_t (*show)(struct nilfs_##name##_attr *, struct the_nilfs *, \
+                        char *); \
+        ssize_t (*store)(struct nilfs_##name##_attr *, struct the_nilfs *, \
+                         const char *, size_t); \
+};
+
+NILFS_DEV_ATTR_STRUCT(dev);
+
 #define NILFS_ATTR(type, name, mode, show, store) \
         static struct nilfs_##type##_attr nilfs_##type##_attr_##name = \
                 __ATTR(name, mode, show, store)
@@ -55,7 +66,16 @@ NILFS_COMMON_ATTR_STRUCT(feature);
 #define NILFS_FEATURE_RW_ATTR(name) \
         NILFS_RW_ATTR(feature, name)
 
+#define NILFS_DEV_INFO_ATTR(name) \
+        NILFS_INFO_ATTR(dev, name)
+#define NILFS_DEV_RO_ATTR(name) \
+        NILFS_RO_ATTR(dev, name)
+#define NILFS_DEV_RW_ATTR(name) \
+        NILFS_RW_ATTR(dev, name)
+
 #define NILFS_FEATURE_ATTR_LIST(name) \
         (&nilfs_feature_attr_##name.attr)
+#define NILFS_DEV_ATTR_LIST(name) \
+        (&nilfs_dev_attr_##name.attr)
 
 #endif /* _NILFS_SYSFS_H */