[PATCH v4 5/9] nilfs2: add /sys/fs/nilfs2/<device>/segments group

[Vyacheslav Dubeyko]

From: Vyacheslav Dubeyko <Vyacheslav.Dubeyko-***@public.gmane.org>
Subject: [PATCH v4 5/9] nilfs2: add /sys/fs/nilfs2/<device>/segments group

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

The segments group contains attributes that describe
details about volume's segments:
(1) segments_number - show number of segments on volume.
(2) blocks_per_segment - show number of blocks in segment.
(3) clean_segments - show count of clean segments.
(4) dirty_segments - show count of dirty segments.

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 | 31 +++++++++
fs/nilfs2/sysfs.c | 99 ++++++++++++++++++++++++++++-
fs/nilfs2/sysfs.h | 14 ++++
3 files changed, 143 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-nilfs2 b/Documentation/ABI/testing/sysfs-fs-nilfs2
index c9952f4..d39e076 100644
--- a/Documentation/ABI/testing/sysfs-fs-nilfs2
+++ b/Documentation/ABI/testing/sysfs-fs-nilfs2
@@ -179,3 +179,34 @@ Contact: "Vyacheslav Dubeyko" <slava-***@public.gmane.org>
Description:
Describe attributes of /sys/fs/nilfs2/<device>/segctor
group.
+
+What: /sys/fs/nilfs2/<device>/segments/segments_number
+Date: April 2014
+Contact: "Vyacheslav Dubeyko" <slava-***@public.gmane.org>
+Description:
+ Show number of segments on a volume.
+
+What: /sys/fs/nilfs2/<device>/segments/blocks_per_segment
+Date: April 2014
+Contact: "Vyacheslav Dubeyko" <slava-***@public.gmane.org>
+Description:
+ Show number of blocks in segment.
+
+What: /sys/fs/nilfs2/<device>/segments/clean_segments
+Date: April 2014
+Contact: "Vyacheslav Dubeyko" <slava-***@public.gmane.org>
+Description:
+ Show count of clean segments.
+
+What: /sys/fs/nilfs2/<device>/segments/dirty_segments
+Date: April 2014
+Contact: "Vyacheslav Dubeyko" <slava-***@public.gmane.org>
+Description:
+ Show count of dirty segments.
+
+What: /sys/fs/nilfs2/<device>/segments/README
+Date: April 2014
+Contact: "Vyacheslav Dubeyko" <slava-***@public.gmane.org>
+Description:
+ Describe attributes of /sys/fs/nilfs2/<device>/segments
+ group.
diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index 61454a8..fe8e141 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -112,6 +112,95 @@ void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \
}

/************************************************************************
+ * NILFS segments attrs *
+ ************************************************************************/
+
+static ssize_t
+nilfs_segments_segments_number_show(struct nilfs_segments_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%lu\n", nilfs->ns_nsegments);
+}
+
+static ssize_t
+nilfs_segments_blocks_per_segment_show(struct nilfs_segments_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, "%lu\n", nilfs->ns_blocks_per_segment);
+}
+
+static ssize_t
+nilfs_segments_clean_segments_show(struct nilfs_segments_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ unsigned long ncleansegs;
+
+ down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
+ ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
+ up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
+
+ return snprintf(buf, PAGE_SIZE, "%lu\n", ncleansegs);
+}
+
+static ssize_t
+nilfs_segments_dirty_segments_show(struct nilfs_segments_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ struct nilfs_sustat sustat;
+ int err;
+
+ down_read(&nilfs->ns_segctor_sem);
+ err = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
+ up_read(&nilfs->ns_segctor_sem);
+ if (err < 0) {
+ printk(KERN_ERR "NILFS: unable to get segment stat: err=%d\n",
+ err);
+ return err;
+ }
+
+ return snprintf(buf, PAGE_SIZE, "%llu\n", sustat.ss_ndirtysegs);
+}
+
+static const char segments_readme_str[] =
+ "The segments group contains attributes that describe\n"
+ "details about volume's segments.\n\n"
+ "(1) segments_number\n\tshow number of segments on volume.\n\n"
+ "(2) blocks_per_segment\n\tshow number of blocks in segment.\n\n"
+ "(3) clean_segments\n\tshow count of clean segments.\n\n"
+ "(4) dirty_segments\n\tshow count of dirty segments.\n\n";
+
+static ssize_t
+nilfs_segments_README_show(struct nilfs_segments_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, segments_readme_str);
+}
+
+NILFS_SEGMENTS_RO_ATTR(segments_number);
+NILFS_SEGMENTS_RO_ATTR(blocks_per_segment);
+NILFS_SEGMENTS_RO_ATTR(clean_segments);
+NILFS_SEGMENTS_RO_ATTR(dirty_segments);
+NILFS_SEGMENTS_RO_ATTR(README);
+
+static struct attribute *nilfs_segments_attrs[] = {
+ NILFS_SEGMENTS_ATTR_LIST(segments_number),
+ NILFS_SEGMENTS_ATTR_LIST(blocks_per_segment),
+ NILFS_SEGMENTS_ATTR_LIST(clean_segments),
+ NILFS_SEGMENTS_ATTR_LIST(dirty_segments),
+ NILFS_SEGMENTS_ATTR_LIST(README),
+ NULL,
+};
+
+NILFS_DEV_INT_GROUP_OPS(segments, dev);
+NILFS_DEV_INT_GROUP_TYPE(segments, dev);
+NILFS_DEV_INT_GROUP_FNS(segments, dev);
+
+/************************************************************************
* NILFS segctor attrs *
************************************************************************/

@@ -664,10 +753,14 @@ int nilfs_sysfs_create_device_group(struct super_block *sb)
if (err)
goto free_dev_subgroups;

- err = nilfs_sysfs_create_superblock_group(nilfs);
+ err = nilfs_sysfs_create_segments_group(nilfs);
if (err)
goto cleanup_dev_kobject;

+ err = nilfs_sysfs_create_superblock_group(nilfs);
+ if (err)
+ goto delete_segments_group;
+
err = nilfs_sysfs_create_segctor_group(nilfs);
if (err)
goto delete_superblock_group;
@@ -677,6 +770,9 @@ int nilfs_sysfs_create_device_group(struct super_block *sb)
delete_superblock_group:
nilfs_sysfs_delete_superblock_group(nilfs);

+delete_segments_group:
+ nilfs_sysfs_delete_segments_group(nilfs);
+
cleanup_dev_kobject:
kobject_del(&nilfs->ns_dev_kobj);

@@ -689,6 +785,7 @@ failed_create_device_group:

void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
{
+ nilfs_sysfs_delete_segments_group(nilfs);
nilfs_sysfs_delete_superblock_group(nilfs);
nilfs_sysfs_delete_segctor_group(nilfs);
kobject_del(&nilfs->ns_dev_kobj);
diff --git a/fs/nilfs2/sysfs.h b/fs/nilfs2/sysfs.h
index ad4d5bc..228bdd1 100644
--- 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_segments_kobj: /sys/fs/<nilfs>/<device>/segments
+ * @sg_segments_kobj_unregister: completion state
*/
struct nilfs_sysfs_dev_subgroups {
/* /sys/fs/<nilfs>/<device>/superblock */
@@ -39,6 +41,10 @@ struct nilfs_sysfs_dev_subgroups {
/* /sys/fs/<nilfs>/<device>/segctor */
struct kobject sg_segctor_kobj;
struct completion sg_segctor_kobj_unregister;
+
+ /* /sys/fs/<nilfs>/<device>/segments */
+ struct kobject sg_segments_kobj;
+ struct completion sg_segments_kobj_unregister;
};

#define NILFS_COMMON_ATTR_STRUCT(name) \
@@ -62,6 +68,7 @@ struct nilfs_##name##_attr { \
};

NILFS_DEV_ATTR_STRUCT(dev);
+NILFS_DEV_ATTR_STRUCT(segments);
NILFS_DEV_ATTR_STRUCT(superblock);
NILFS_DEV_ATTR_STRUCT(segctor);

@@ -92,6 +99,11 @@ NILFS_DEV_ATTR_STRUCT(segctor);
#define NILFS_DEV_RW_ATTR(name) \
NILFS_RW_ATTR(dev, name)

+#define NILFS_SEGMENTS_RO_ATTR(name) \
+ NILFS_RO_ATTR(segments, name)
+#define NILFS_SEGMENTS_RW_ATTR(name) \
+ NILFS_RW_ATTR(segs_info, name)
+
#define NILFS_SUPERBLOCK_RO_ATTR(name) \
NILFS_RO_ATTR(superblock, name)
#define NILFS_SUPERBLOCK_RW_ATTR(name) \
@@ -108,6 +120,8 @@ NILFS_DEV_ATTR_STRUCT(segctor);
(&nilfs_feature_attr_##name.attr)
#define NILFS_DEV_ATTR_LIST(name) \
(&nilfs_dev_attr_##name.attr)
+#define NILFS_SEGMENTS_ATTR_LIST(name) \
+ (&nilfs_segments_attr_##name.attr)
#define NILFS_SUPERBLOCK_ATTR_LIST(name) \
(&nilfs_superblock_attr_##name.attr)
#define NILFS_SEGCTOR_ATTR_LIST(name) \