nilfs2: add /sys/fs/nilfs2/<device>/checkpoints group
This patch adds creation of /sys/fs/nilfs2/<device>/checkpoints
group.
The checkpoints group contains attributes that describe
details about volume's checkpoints:
(1) checkpoints_number - show number of checkpoints on volume.
(2) snapshots_number - show number of snapshots on volume.
(3) last_seg_checkpoint - show checkpoint number of the latest segment.
(4) next_checkpoint - show next checkpoint number.
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/sysfs.c b/fs/nilfs2/sysfs.c
index fe8e141..5cc735f 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -112,6 +112,119 @@
}
/************************************************************************
+ * NILFS checkpoints attrs *
+ ************************************************************************/
+
+static ssize_t
+nilfs_checkpoints_checkpoints_number_show(struct nilfs_checkpoints_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ __u64 ncheckpoints;
+ struct nilfs_cpstat cpstat;
+ int err;
+
+ down_read(&nilfs->ns_segctor_sem);
+ err = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
+ up_read(&nilfs->ns_segctor_sem);
+ if (err < 0) {
+ printk(KERN_ERR "NILFS: unable to get checkpoint stat: err=%d\n",
+ err);
+ return err;
+ }
+
+ ncheckpoints = cpstat.cs_ncps;
+
+ return snprintf(buf, PAGE_SIZE, "%llu\n", ncheckpoints);
+}
+
+static ssize_t
+nilfs_checkpoints_snapshots_number_show(struct nilfs_checkpoints_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ __u64 nsnapshots;
+ struct nilfs_cpstat cpstat;
+ int err;
+
+ down_read(&nilfs->ns_segctor_sem);
+ err = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
+ up_read(&nilfs->ns_segctor_sem);
+ if (err < 0) {
+ printk(KERN_ERR "NILFS: unable to get checkpoint stat: err=%d\n",
+ err);
+ return err;
+ }
+
+ nsnapshots = cpstat.cs_nsss;
+
+ return snprintf(buf, PAGE_SIZE, "%llu\n", nsnapshots);
+}
+
+static ssize_t
+nilfs_checkpoints_last_seg_checkpoint_show(struct nilfs_checkpoints_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ __u64 last_cno;
+
+ spin_lock(&nilfs->ns_last_segment_lock);
+ last_cno = nilfs->ns_last_cno;
+ spin_unlock(&nilfs->ns_last_segment_lock);
+
+ return snprintf(buf, PAGE_SIZE, "%llu\n", last_cno);
+}
+
+static ssize_t
+nilfs_checkpoints_next_checkpoint_show(struct nilfs_checkpoints_attr *attr,
+ struct the_nilfs *nilfs,
+ char *buf)
+{
+ __u64 cno;
+
+ down_read(&nilfs->ns_sem);
+ cno = nilfs->ns_cno;
+ up_read(&nilfs->ns_sem);
+
+ return snprintf(buf, PAGE_SIZE, "%llu\n", cno);
+}
+
+static const char checkpoints_readme_str[] =
+ "The checkpoints group contains attributes that describe\n"
+ "details about volume's checkpoints.\n\n"
+ "(1) checkpoints_number\n\tshow number of checkpoints on volume.\n\n"
+ "(2) snapshots_number\n\tshow number of snapshots on volume.\n\n"
+ "(3) last_seg_checkpoint\n"
+ "\tshow checkpoint number of the latest segment.\n\n"
+ "(4) next_checkpoint\n\tshow next checkpoint number.\n\n";
+
+static ssize_t
+nilfs_checkpoints_README_show(struct nilfs_checkpoints_attr *attr,
+ struct the_nilfs *nilfs, char *buf)
+{
+ return snprintf(buf, PAGE_SIZE, checkpoints_readme_str);
+}
+
+NILFS_CHECKPOINTS_RO_ATTR(checkpoints_number);
+NILFS_CHECKPOINTS_RO_ATTR(snapshots_number);
+NILFS_CHECKPOINTS_RO_ATTR(last_seg_checkpoint);
+NILFS_CHECKPOINTS_RO_ATTR(next_checkpoint);
+NILFS_CHECKPOINTS_RO_ATTR(README);
+
+static struct attribute *nilfs_checkpoints_attrs[] = {
+ NILFS_CHECKPOINTS_ATTR_LIST(checkpoints_number),
+ NILFS_CHECKPOINTS_ATTR_LIST(snapshots_number),
+ NILFS_CHECKPOINTS_ATTR_LIST(last_seg_checkpoint),
+ NILFS_CHECKPOINTS_ATTR_LIST(next_checkpoint),
+ NILFS_CHECKPOINTS_ATTR_LIST(README),
+ NULL,
+};
+
+NILFS_DEV_INT_GROUP_OPS(checkpoints, dev);
+NILFS_DEV_INT_GROUP_TYPE(checkpoints, dev);
+NILFS_DEV_INT_GROUP_FNS(checkpoints, dev);
+
+/************************************************************************
* NILFS segments attrs *
************************************************************************/
@@ -753,10 +866,14 @@
if (err)
goto free_dev_subgroups;
- err = nilfs_sysfs_create_segments_group(nilfs);
+ err = nilfs_sysfs_create_checkpoints_group(nilfs);
if (err)
goto cleanup_dev_kobject;
+ err = nilfs_sysfs_create_segments_group(nilfs);
+ if (err)
+ goto delete_checkpoints_group;
+
err = nilfs_sysfs_create_superblock_group(nilfs);
if (err)
goto delete_segments_group;
@@ -773,6 +890,9 @@
delete_segments_group:
nilfs_sysfs_delete_segments_group(nilfs);
+delete_checkpoints_group:
+ nilfs_sysfs_delete_checkpoints_group(nilfs);
+
cleanup_dev_kobject:
kobject_del(&nilfs->ns_dev_kobj);
@@ -785,6 +905,7 @@
void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
{
+ nilfs_sysfs_delete_checkpoints_group(nilfs);
nilfs_sysfs_delete_segments_group(nilfs);
nilfs_sysfs_delete_superblock_group(nilfs);
nilfs_sysfs_delete_segctor_group(nilfs);