[PATCH RESEND v2 4/5] f2fs: introduce a new per-sb directory in sysfs

From: Chao Yu
Date: Wed Dec 09 2020 - 03:44:47 EST


Add a new directory 'stat' in path of /sys/fs/f2fs/<devname>/, later
we can add new readonly stat sysfs file into this directory, it will
make <devname> directory less mess.

Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
fs/f2fs/f2fs.h | 5 +++-
fs/f2fs/sysfs.c | 69 +++++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 68 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index fbaef39e51df..cb94f650ec3d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1549,9 +1549,12 @@ struct f2fs_sb_info {
unsigned int node_io_flag;

/* For sysfs suppport */
- struct kobject s_kobj;
+ struct kobject s_kobj; /* /sys/fs/f2fs/<devname> */
struct completion s_kobj_unregister;

+ struct kobject s_stat_kobj; /* /sys/fs/f2fs/<devname>/stat */
+ struct completion s_stat_kobj_unregister;
+
/* For shrinker support */
struct list_head s_list;
int s_ndevs; /* number of devices */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 989a649cfa8b..ebca0b4961e8 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -711,6 +711,11 @@ static struct attribute *f2fs_feat_attrs[] = {
};
ATTRIBUTE_GROUPS(f2fs_feat);

+static struct attribute *f2fs_stat_attrs[] = {
+ NULL,
+};
+ATTRIBUTE_GROUPS(f2fs_stat);
+
static const struct sysfs_ops f2fs_attr_ops = {
.show = f2fs_attr_show,
.store = f2fs_attr_store,
@@ -739,6 +744,44 @@ static struct kobject f2fs_feat = {
.kset = &f2fs_kset,
};

+static ssize_t f2fs_stat_attr_show(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+ s_stat_kobj);
+ struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
+
+ return a->show ? a->show(a, sbi, buf) : 0;
+}
+
+static ssize_t f2fs_stat_attr_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+ s_stat_kobj);
+ struct f2fs_attr *a = container_of(attr, struct f2fs_attr, attr);
+
+ return a->store ? a->store(a, sbi, buf, len) : 0;
+}
+
+static void f2fs_stat_kobj_release(struct kobject *kobj)
+{
+ struct f2fs_sb_info *sbi = container_of(kobj, struct f2fs_sb_info,
+ s_stat_kobj);
+ complete(&sbi->s_stat_kobj_unregister);
+}
+
+static const struct sysfs_ops f2fs_stat_attr_ops = {
+ .show = f2fs_stat_attr_show,
+ .store = f2fs_stat_attr_store,
+};
+
+static struct kobj_type f2fs_stat_ktype = {
+ .default_groups = f2fs_stat_groups,
+ .sysfs_ops = &f2fs_stat_attr_ops,
+ .release = f2fs_stat_kobj_release,
+};
+
static int __maybe_unused segment_info_seq_show(struct seq_file *seq,
void *offset)
{
@@ -945,11 +988,15 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi)
init_completion(&sbi->s_kobj_unregister);
err = kobject_init_and_add(&sbi->s_kobj, &f2fs_sb_ktype, NULL,
"%s", sb->s_id);
- if (err) {
- kobject_put(&sbi->s_kobj);
- wait_for_completion(&sbi->s_kobj_unregister);
- return err;
- }
+ if (err)
+ goto put_sb_kobj;
+
+ sbi->s_stat_kobj.kset = &f2fs_kset;
+ init_completion(&sbi->s_stat_kobj_unregister);
+ err = kobject_init_and_add(&sbi->s_stat_kobj, &f2fs_stat_ktype,
+ &sbi->s_kobj, "stat");
+ if (err)
+ goto put_stat_kobj;

if (f2fs_proc_root)
sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
@@ -965,6 +1012,13 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi)
victim_bits_seq_show, sb);
}
return 0;
+put_stat_kobj:
+ kobject_put(&sbi->s_stat_kobj);
+ wait_for_completion(&sbi->s_stat_kobj_unregister);
+put_sb_kobj:
+ kobject_put(&sbi->s_kobj);
+ wait_for_completion(&sbi->s_kobj_unregister);
+ return err;
}

void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi)
@@ -976,6 +1030,11 @@ void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi)
remove_proc_entry("victim_bits", sbi->s_proc);
remove_proc_entry(sbi->sb->s_id, f2fs_proc_root);
}
+
+ kobject_del(&sbi->s_stat_kobj);
+ kobject_put(&sbi->s_stat_kobj);
+ wait_for_completion(&sbi->s_stat_kobj_unregister);
+
kobject_del(&sbi->s_kobj);
kobject_put(&sbi->s_kobj);
wait_for_completion(&sbi->s_kobj_unregister);
--
2.29.2