nilfs2: add /sys/fs/nilfs2/<device>/superblock group
This patch adds creation of /sys/fs/nilfs2/<device>/superblock
group.
The superblock group contains attributes that describe
superblock's details:
(1) sb_write_time - show previous write time of super block in
human-readable format.
(2) sb_write_time_secs - show previous write time of super block
in seconds.
(3) sb_write_count - show write count of super block.
(4) sb_update_frequency - show/set interval of periodical update
of superblock (in seconds). You can set preferable frequency of
superblock update by command:
echo <value> > /sys/fs/nilfs2/<device>/superblock/sb_update_frequency
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/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index 34bc7bd..7fe8223 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -33,6 +33,7 @@
#include <linux/slab.h>
struct nilfs_sc_info;
+struct nilfs_sysfs_dev_subgroups;
/* the_nilfs struct */
enum {
@@ -54,6 +55,7 @@
* @ns_sbwcount: write count of super block
* @ns_sbsize: size of valid data in super block
* @ns_mount_state: file system state
+ * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds)
* @ns_seg_seq: segment sequence counter
* @ns_segnum: index number of the latest full segment.
* @ns_nextnum: index number of the full segment index to be used next
@@ -97,6 +99,7 @@
* @ns_crc_seed: seed value of CRC32 calculation
* @ns_dev_kobj: /sys/fs/<nilfs>/<device>
* @ns_dev_kobj_unregister: completion state
+ * @ns_dev_subgroups: <device> subgroups pointer
*/
struct the_nilfs {
unsigned long ns_flags;
@@ -116,6 +119,7 @@
unsigned ns_sbwcount;
unsigned ns_sbsize;
unsigned ns_mount_state;
+ unsigned ns_sb_update_freq;
/*
* Following fields are dedicated to a writable FS-instance.
@@ -194,6 +198,7 @@
/* /sys/fs/<nilfs>/<device> */
struct kobject ns_dev_kobj;
struct completion ns_dev_kobj_unregister;
+ struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups;
};
#define THE_NILFS_FNS(bit, name) \
@@ -260,7 +265,8 @@
static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)
{
u64 t = get_seconds();
- return t < nilfs->ns_sbwtime || t > nilfs->ns_sbwtime + NILFS_SB_FREQ;
+ return t < nilfs->ns_sbwtime ||
+ t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq;
}
static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs)