root/fs/nilfs2/sysfs.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Sysfs support implementation.
 *
 * Copyright (C) 2005-2014 Nippon Telegraph and Telephone Corporation.
 * Copyright (C) 2014 HGST, Inc., a Western Digital Company.
 *
 * Written by Vyacheslav Dubeyko <Vyacheslav.Dubeyko@hgst.com>
 */

#include <linux/kobject.h>

#include "nilfs.h"
#include "mdt.h"
#include "sufile.h"
#include "cpfile.h"
#include "sysfs.h"

/* /sys/fs/<nilfs>/ */
static struct kset *nilfs_kset;

#define NILFS_DEV_INT_GROUP_OPS(name, parent_name) \
static ssize_t nilfs_##name##_attr_show(struct kobject *kobj, \
                                        struct attribute *attr, char *buf) \
{ \
        struct the_nilfs *nilfs = container_of(kobj->parent, \
                                                struct the_nilfs, \
                                                ns_##parent_name##_kobj); \
        struct nilfs_##name##_attr *a = container_of(attr, \
                                                struct nilfs_##name##_attr, \
                                                attr); \
        return a->show ? a->show(a, nilfs, buf) : 0; \
} \
static ssize_t nilfs_##name##_attr_store(struct kobject *kobj, \
                                         struct attribute *attr, \
                                         const char *buf, size_t len) \
{ \
        struct the_nilfs *nilfs = container_of(kobj->parent, \
                                                struct the_nilfs, \
                                                ns_##parent_name##_kobj); \
        struct nilfs_##name##_attr *a = container_of(attr, \
                                                struct nilfs_##name##_attr, \
                                                attr); \
        return a->store ? a->store(a, nilfs, buf, len) : 0; \
} \
static const struct sysfs_ops nilfs_##name##_attr_ops = { \
        .show   = nilfs_##name##_attr_show, \
        .store  = nilfs_##name##_attr_store, \
}

#define NILFS_DEV_INT_GROUP_TYPE(name, parent_name) \
static void nilfs_##name##_attr_release(struct kobject *kobj) \
{ \
        struct nilfs_sysfs_##parent_name##_subgroups *subgroups = container_of(kobj, \
                                                struct nilfs_sysfs_##parent_name##_subgroups, \
                                                sg_##name##_kobj); \
        complete(&subgroups->sg_##name##_kobj_unregister); \
} \
static const struct kobj_type nilfs_##name##_ktype = { \
        .default_groups = nilfs_##name##_groups, \
        .sysfs_ops      = &nilfs_##name##_attr_ops, \
        .release        = nilfs_##name##_attr_release, \
}

#define NILFS_DEV_INT_GROUP_FNS(name, parent_name) \
static int nilfs_sysfs_create_##name##_group(struct the_nilfs *nilfs) \
{ \
        struct kobject *parent; \
        struct kobject *kobj; \
        struct completion *kobj_unregister; \
        struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \
        int err; \
        subgroups = nilfs->ns_##parent_name##_subgroups; \
        kobj = &subgroups->sg_##name##_kobj; \
        kobj_unregister = &subgroups->sg_##name##_kobj_unregister; \
        parent = &nilfs->ns_##parent_name##_kobj; \
        kobj->kset = nilfs_kset; \
        init_completion(kobj_unregister); \
        err = kobject_init_and_add(kobj, &nilfs_##name##_ktype, parent, \
                                    #name); \
        if (err) \
                kobject_put(kobj); \
        return err; \
} \
static void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \
{ \
        kobject_put(&nilfs->ns_##parent_name##_subgroups->sg_##name##_kobj); \
}

/************************************************************************
 *                        NILFS snapshot attrs                          *
 ************************************************************************/

static ssize_t
nilfs_snapshot_inodes_count_show(struct nilfs_snapshot_attr *attr,
                                 struct nilfs_root *root, char *buf)
{
        return sysfs_emit(buf, "%llu\n",
                        (unsigned long long)atomic64_read(&root->inodes_count));
}

static ssize_t
nilfs_snapshot_blocks_count_show(struct nilfs_snapshot_attr *attr,
                                 struct nilfs_root *root, char *buf)
{
        return sysfs_emit(buf, "%llu\n",
                        (unsigned long long)atomic64_read(&root->blocks_count));
}

static const char snapshot_readme_str[] =
        "The group contains details about mounted snapshot.\n\n"
        "(1) inodes_count\n\tshow number of inodes for snapshot.\n\n"
        "(2) blocks_count\n\tshow number of blocks for snapshot.\n\n";

static ssize_t
nilfs_snapshot_README_show(struct nilfs_snapshot_attr *attr,
                            struct nilfs_root *root, char *buf)
{
        return sysfs_emit(buf, snapshot_readme_str);
}

NILFS_SNAPSHOT_RO_ATTR(inodes_count);
NILFS_SNAPSHOT_RO_ATTR(blocks_count);
NILFS_SNAPSHOT_RO_ATTR(README);

static struct attribute *nilfs_snapshot_attrs[] = {
        NILFS_SNAPSHOT_ATTR_LIST(inodes_count),
        NILFS_SNAPSHOT_ATTR_LIST(blocks_count),
        NILFS_SNAPSHOT_ATTR_LIST(README),
        NULL,
};
ATTRIBUTE_GROUPS(nilfs_snapshot);

static ssize_t nilfs_snapshot_attr_show(struct kobject *kobj,
                                        struct attribute *attr, char *buf)
{
        struct nilfs_root *root =
                        container_of(kobj, struct nilfs_root, snapshot_kobj);
        struct nilfs_snapshot_attr *a =
                        container_of(attr, struct nilfs_snapshot_attr, attr);

        return a->show ? a->show(a, root, buf) : 0;
}

static ssize_t nilfs_snapshot_attr_store(struct kobject *kobj,
                                         struct attribute *attr,
                                         const char *buf, size_t len)
{
        struct nilfs_root *root =
                        container_of(kobj, struct nilfs_root, snapshot_kobj);
        struct nilfs_snapshot_attr *a =
                        container_of(attr, struct nilfs_snapshot_attr, attr);

        return a->store ? a->store(a, root, buf, len) : 0;
}

static void nilfs_snapshot_attr_release(struct kobject *kobj)
{
        struct nilfs_root *root = container_of(kobj, struct nilfs_root,
                                                snapshot_kobj);
        complete(&root->snapshot_kobj_unregister);
}

static const struct sysfs_ops nilfs_snapshot_attr_ops = {
        .show   = nilfs_snapshot_attr_show,
        .store  = nilfs_snapshot_attr_store,
};

static const struct kobj_type nilfs_snapshot_ktype = {
        .default_groups = nilfs_snapshot_groups,
        .sysfs_ops      = &nilfs_snapshot_attr_ops,
        .release        = nilfs_snapshot_attr_release,
};

int nilfs_sysfs_create_snapshot_group(struct nilfs_root *root)
{
        struct the_nilfs *nilfs;
        struct kobject *parent;
        int err;

        nilfs = root->nilfs;
        parent = &nilfs->ns_dev_subgroups->sg_mounted_snapshots_kobj;
        root->snapshot_kobj.kset = nilfs_kset;
        init_completion(&root->snapshot_kobj_unregister);

        if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
                err = kobject_init_and_add(&root->snapshot_kobj,
                                            &nilfs_snapshot_ktype,
                                            &nilfs->ns_dev_kobj,
                                            "current_checkpoint");
        } else {
                err = kobject_init_and_add(&root->snapshot_kobj,
                                            &nilfs_snapshot_ktype,
                                            parent,
                                            "%llu", root->cno);
        }

        if (err)
                kobject_put(&root->snapshot_kobj);

        return err;
}

void nilfs_sysfs_delete_snapshot_group(struct nilfs_root *root)
{
        kobject_put(&root->snapshot_kobj);
}

/************************************************************************
 *                    NILFS mounted snapshots attrs                     *
 ************************************************************************/

static const char mounted_snapshots_readme_str[] =
        "The mounted_snapshots group contains group for\n"
        "every mounted snapshot.\n";

static ssize_t
nilfs_mounted_snapshots_README_show(struct nilfs_mounted_snapshots_attr *attr,
                                    struct the_nilfs *nilfs, char *buf)
{
        return sysfs_emit(buf, mounted_snapshots_readme_str);
}

NILFS_MOUNTED_SNAPSHOTS_RO_ATTR(README);

static struct attribute *nilfs_mounted_snapshots_attrs[] = {
        NILFS_MOUNTED_SNAPSHOTS_ATTR_LIST(README),
        NULL,
};
ATTRIBUTE_GROUPS(nilfs_mounted_snapshots);

NILFS_DEV_INT_GROUP_OPS(mounted_snapshots, dev);
NILFS_DEV_INT_GROUP_TYPE(mounted_snapshots, dev);
NILFS_DEV_INT_GROUP_FNS(mounted_snapshots, dev);

/************************************************************************
 *                      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) {
                nilfs_err(nilfs->ns_sb, "unable to get checkpoint stat: err=%d",
                          err);
                return err;
        }

        ncheckpoints = cpstat.cs_ncps;

        return sysfs_emit(buf, "%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) {
                nilfs_err(nilfs->ns_sb, "unable to get checkpoint stat: err=%d",
                          err);
                return err;
        }

        nsnapshots = cpstat.cs_nsss;

        return sysfs_emit(buf, "%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 sysfs_emit(buf, "%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_segctor_sem);
        cno = nilfs->ns_cno;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%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 sysfs_emit(buf, 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,
};
ATTRIBUTE_GROUPS(nilfs_checkpoints);

NILFS_DEV_INT_GROUP_OPS(checkpoints, dev);
NILFS_DEV_INT_GROUP_TYPE(checkpoints, dev);
NILFS_DEV_INT_GROUP_FNS(checkpoints, dev);

/************************************************************************
 *                        NILFS segments attrs                          *
 ************************************************************************/

static ssize_t
nilfs_segments_segments_number_show(struct nilfs_segments_attr *attr,
                                     struct the_nilfs *nilfs,
                                     char *buf)
{
        return sysfs_emit(buf, "%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 sysfs_emit(buf, "%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 sysfs_emit(buf, "%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) {
                nilfs_err(nilfs->ns_sb, "unable to get segment stat: err=%d",
                          err);
                return err;
        }

        return sysfs_emit(buf, "%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 sysfs_emit(buf, 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,
};
ATTRIBUTE_GROUPS(nilfs_segments);

NILFS_DEV_INT_GROUP_OPS(segments, dev);
NILFS_DEV_INT_GROUP_TYPE(segments, dev);
NILFS_DEV_INT_GROUP_FNS(segments, dev);

/************************************************************************
 *                        NILFS segctor attrs                           *
 ************************************************************************/

static ssize_t
nilfs_segctor_last_pseg_block_show(struct nilfs_segctor_attr *attr,
                                    struct the_nilfs *nilfs,
                                    char *buf)
{
        sector_t last_pseg;

        spin_lock(&nilfs->ns_last_segment_lock);
        last_pseg = nilfs->ns_last_pseg;
        spin_unlock(&nilfs->ns_last_segment_lock);

        return sysfs_emit(buf, "%llu\n",
                        (unsigned long long)last_pseg);
}

static ssize_t
nilfs_segctor_last_seg_sequence_show(struct nilfs_segctor_attr *attr,
                                        struct the_nilfs *nilfs,
                                        char *buf)
{
        u64 last_seq;

        spin_lock(&nilfs->ns_last_segment_lock);
        last_seq = nilfs->ns_last_seq;
        spin_unlock(&nilfs->ns_last_segment_lock);

        return sysfs_emit(buf, "%llu\n", last_seq);
}

static ssize_t
nilfs_segctor_last_seg_checkpoint_show(struct nilfs_segctor_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 sysfs_emit(buf, "%llu\n", last_cno);
}

static ssize_t
nilfs_segctor_current_seg_sequence_show(struct nilfs_segctor_attr *attr,
                                        struct the_nilfs *nilfs,
                                        char *buf)
{
        u64 seg_seq;

        down_read(&nilfs->ns_segctor_sem);
        seg_seq = nilfs->ns_seg_seq;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%llu\n", seg_seq);
}

static ssize_t
nilfs_segctor_current_last_full_seg_show(struct nilfs_segctor_attr *attr,
                                         struct the_nilfs *nilfs,
                                         char *buf)
{
        __u64 segnum;

        down_read(&nilfs->ns_segctor_sem);
        segnum = nilfs->ns_segnum;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%llu\n", segnum);
}

static ssize_t
nilfs_segctor_next_full_seg_show(struct nilfs_segctor_attr *attr,
                                 struct the_nilfs *nilfs,
                                 char *buf)
{
        __u64 nextnum;

        down_read(&nilfs->ns_segctor_sem);
        nextnum = nilfs->ns_nextnum;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%llu\n", nextnum);
}

static ssize_t
nilfs_segctor_next_pseg_offset_show(struct nilfs_segctor_attr *attr,
                                        struct the_nilfs *nilfs,
                                        char *buf)
{
        unsigned long pseg_offset;

        down_read(&nilfs->ns_segctor_sem);
        pseg_offset = nilfs->ns_pseg_offset;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%lu\n", pseg_offset);
}

static ssize_t
nilfs_segctor_next_checkpoint_show(struct nilfs_segctor_attr *attr,
                                        struct the_nilfs *nilfs,
                                        char *buf)
{
        __u64 cno;

        down_read(&nilfs->ns_segctor_sem);
        cno = nilfs->ns_cno;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%llu\n", cno);
}

static ssize_t
nilfs_segctor_last_seg_write_time_show(struct nilfs_segctor_attr *attr,
                                        struct the_nilfs *nilfs,
                                        char *buf)
{
        time64_t ctime;

        down_read(&nilfs->ns_segctor_sem);
        ctime = nilfs->ns_ctime;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%ptTs\n", &ctime);
}

static ssize_t
nilfs_segctor_last_seg_write_time_secs_show(struct nilfs_segctor_attr *attr,
                                            struct the_nilfs *nilfs,
                                            char *buf)
{
        time64_t ctime;

        down_read(&nilfs->ns_segctor_sem);
        ctime = nilfs->ns_ctime;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%llu\n", ctime);
}

static ssize_t
nilfs_segctor_last_nongc_write_time_show(struct nilfs_segctor_attr *attr,
                                         struct the_nilfs *nilfs,
                                         char *buf)
{
        time64_t nongc_ctime;

        down_read(&nilfs->ns_segctor_sem);
        nongc_ctime = nilfs->ns_nongc_ctime;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%ptTs\n", &nongc_ctime);
}

static ssize_t
nilfs_segctor_last_nongc_write_time_secs_show(struct nilfs_segctor_attr *attr,
                                                struct the_nilfs *nilfs,
                                                char *buf)
{
        time64_t nongc_ctime;

        down_read(&nilfs->ns_segctor_sem);
        nongc_ctime = nilfs->ns_nongc_ctime;
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%llu\n", nongc_ctime);
}

static ssize_t
nilfs_segctor_dirty_data_blocks_count_show(struct nilfs_segctor_attr *attr,
                                            struct the_nilfs *nilfs,
                                            char *buf)
{
        u32 ndirtyblks;

        down_read(&nilfs->ns_segctor_sem);
        ndirtyblks = atomic_read(&nilfs->ns_ndirtyblks);
        up_read(&nilfs->ns_segctor_sem);

        return sysfs_emit(buf, "%u\n", ndirtyblks);
}

static const char segctor_readme_str[] =
        "The segctor group contains attributes that describe\n"
        "segctor thread activity details.\n\n"
        "(1) last_pseg_block\n"
        "\tshow start block number of the latest segment.\n\n"
        "(2) last_seg_sequence\n"
        "\tshow sequence value of the latest segment.\n\n"
        "(3) last_seg_checkpoint\n"
        "\tshow checkpoint number of the latest segment.\n\n"
        "(4) current_seg_sequence\n\tshow segment sequence counter.\n\n"
        "(5) current_last_full_seg\n"
        "\tshow index number of the latest full segment.\n\n"
        "(6) next_full_seg\n"
        "\tshow index number of the full segment index to be used next.\n\n"
        "(7) next_pseg_offset\n"
        "\tshow offset of next partial segment in the current full segment.\n\n"
        "(8) next_checkpoint\n\tshow next checkpoint number.\n\n"
        "(9) last_seg_write_time\n"
        "\tshow write time of the last segment in human-readable format.\n\n"
        "(10) last_seg_write_time_secs\n"
        "\tshow write time of the last segment in seconds.\n\n"
        "(11) last_nongc_write_time\n"
        "\tshow write time of the last segment not for cleaner operation "
        "in human-readable format.\n\n"
        "(12) last_nongc_write_time_secs\n"
        "\tshow write time of the last segment not for cleaner operation "
        "in seconds.\n\n"
        "(13) dirty_data_blocks_count\n"
        "\tshow number of dirty data blocks.\n\n";

static ssize_t
nilfs_segctor_README_show(struct nilfs_segctor_attr *attr,
                          struct the_nilfs *nilfs, char *buf)
{
        return sysfs_emit(buf, segctor_readme_str);
}

NILFS_SEGCTOR_RO_ATTR(last_pseg_block);
NILFS_SEGCTOR_RO_ATTR(last_seg_sequence);
NILFS_SEGCTOR_RO_ATTR(last_seg_checkpoint);
NILFS_SEGCTOR_RO_ATTR(current_seg_sequence);
NILFS_SEGCTOR_RO_ATTR(current_last_full_seg);
NILFS_SEGCTOR_RO_ATTR(next_full_seg);
NILFS_SEGCTOR_RO_ATTR(next_pseg_offset);
NILFS_SEGCTOR_RO_ATTR(next_checkpoint);
NILFS_SEGCTOR_RO_ATTR(last_seg_write_time);
NILFS_SEGCTOR_RO_ATTR(last_seg_write_time_secs);
NILFS_SEGCTOR_RO_ATTR(last_nongc_write_time);
NILFS_SEGCTOR_RO_ATTR(last_nongc_write_time_secs);
NILFS_SEGCTOR_RO_ATTR(dirty_data_blocks_count);
NILFS_SEGCTOR_RO_ATTR(README);

static struct attribute *nilfs_segctor_attrs[] = {
        NILFS_SEGCTOR_ATTR_LIST(last_pseg_block),
        NILFS_SEGCTOR_ATTR_LIST(last_seg_sequence),
        NILFS_SEGCTOR_ATTR_LIST(last_seg_checkpoint),
        NILFS_SEGCTOR_ATTR_LIST(current_seg_sequence),
        NILFS_SEGCTOR_ATTR_LIST(current_last_full_seg),
        NILFS_SEGCTOR_ATTR_LIST(next_full_seg),
        NILFS_SEGCTOR_ATTR_LIST(next_pseg_offset),
        NILFS_SEGCTOR_ATTR_LIST(next_checkpoint),
        NILFS_SEGCTOR_ATTR_LIST(last_seg_write_time),
        NILFS_SEGCTOR_ATTR_LIST(last_seg_write_time_secs),
        NILFS_SEGCTOR_ATTR_LIST(last_nongc_write_time),
        NILFS_SEGCTOR_ATTR_LIST(last_nongc_write_time_secs),
        NILFS_SEGCTOR_ATTR_LIST(dirty_data_blocks_count),
        NILFS_SEGCTOR_ATTR_LIST(README),
        NULL,
};
ATTRIBUTE_GROUPS(nilfs_segctor);

NILFS_DEV_INT_GROUP_OPS(segctor, dev);
NILFS_DEV_INT_GROUP_TYPE(segctor, dev);
NILFS_DEV_INT_GROUP_FNS(segctor, dev);

/************************************************************************
 *                        NILFS superblock attrs                        *
 ************************************************************************/

static ssize_t
nilfs_superblock_sb_write_time_show(struct nilfs_superblock_attr *attr,
                                     struct the_nilfs *nilfs,
                                     char *buf)
{
        time64_t sbwtime;

        down_read(&nilfs->ns_sem);
        sbwtime = nilfs->ns_sbwtime;
        up_read(&nilfs->ns_sem);

        return sysfs_emit(buf, "%ptTs\n", &sbwtime);
}

static ssize_t
nilfs_superblock_sb_write_time_secs_show(struct nilfs_superblock_attr *attr,
                                         struct the_nilfs *nilfs,
                                         char *buf)
{
        time64_t sbwtime;

        down_read(&nilfs->ns_sem);
        sbwtime = nilfs->ns_sbwtime;
        up_read(&nilfs->ns_sem);

        return sysfs_emit(buf, "%llu\n", sbwtime);
}

static ssize_t
nilfs_superblock_sb_write_count_show(struct nilfs_superblock_attr *attr,
                                      struct the_nilfs *nilfs,
                                      char *buf)
{
        unsigned int sbwcount;

        down_read(&nilfs->ns_sem);
        sbwcount = nilfs->ns_sbwcount;
        up_read(&nilfs->ns_sem);

        return sysfs_emit(buf, "%u\n", sbwcount);
}

static ssize_t
nilfs_superblock_sb_update_frequency_show(struct nilfs_superblock_attr *attr,
                                            struct the_nilfs *nilfs,
                                            char *buf)
{
        unsigned int sb_update_freq;

        down_read(&nilfs->ns_sem);
        sb_update_freq = nilfs->ns_sb_update_freq;
        up_read(&nilfs->ns_sem);

        return sysfs_emit(buf, "%u\n", sb_update_freq);
}

static ssize_t
nilfs_superblock_sb_update_frequency_store(struct nilfs_superblock_attr *attr,
                                            struct the_nilfs *nilfs,
                                            const char *buf, size_t count)
{
        unsigned int val;
        int err;

        err = kstrtouint(skip_spaces(buf), 0, &val);
        if (err) {
                nilfs_err(nilfs->ns_sb, "unable to convert string: err=%d",
                          err);
                return err;
        }

        if (val < NILFS_SB_FREQ) {
                val = NILFS_SB_FREQ;
                nilfs_warn(nilfs->ns_sb,
                           "superblock update frequency cannot be lesser than 10 seconds");
        }

        down_write(&nilfs->ns_sem);
        nilfs->ns_sb_update_freq = val;
        up_write(&nilfs->ns_sem);

        return count;
}

static const char sb_readme_str[] =
        "The superblock group contains attributes that describe\n"
        "superblock's details.\n\n"
        "(1) sb_write_time\n\tshow previous write time of super block "
        "in human-readable format.\n\n"
        "(2) sb_write_time_secs\n\tshow previous write time of super block "
        "in seconds.\n\n"
        "(3) sb_write_count\n\tshow write count of super block.\n\n"
        "(4) sb_update_frequency\n"
        "\tshow/set interval of periodical update of superblock (in seconds).\n\n"
        "\tYou can set preferable frequency of superblock update by command:\n\n"
        "\t'echo <val> > /sys/fs/<nilfs>/<dev>/superblock/sb_update_frequency'\n";

static ssize_t
nilfs_superblock_README_show(struct nilfs_superblock_attr *attr,
                                struct the_nilfs *nilfs, char *buf)
{
        return sysfs_emit(buf, sb_readme_str);
}

NILFS_SUPERBLOCK_RO_ATTR(sb_write_time);
NILFS_SUPERBLOCK_RO_ATTR(sb_write_time_secs);
NILFS_SUPERBLOCK_RO_ATTR(sb_write_count);
NILFS_SUPERBLOCK_RW_ATTR(sb_update_frequency);
NILFS_SUPERBLOCK_RO_ATTR(README);

static struct attribute *nilfs_superblock_attrs[] = {
        NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time),
        NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time_secs),
        NILFS_SUPERBLOCK_ATTR_LIST(sb_write_count),
        NILFS_SUPERBLOCK_ATTR_LIST(sb_update_frequency),
        NILFS_SUPERBLOCK_ATTR_LIST(README),
        NULL,
};
ATTRIBUTE_GROUPS(nilfs_superblock);

NILFS_DEV_INT_GROUP_OPS(superblock, dev);
NILFS_DEV_INT_GROUP_TYPE(superblock, dev);
NILFS_DEV_INT_GROUP_FNS(superblock, dev);

/************************************************************************
 *                        NILFS device attrs                            *
 ************************************************************************/

static
ssize_t nilfs_dev_revision_show(struct nilfs_dev_attr *attr,
                                struct the_nilfs *nilfs,
                                char *buf)
{
        struct nilfs_super_block *raw_sb;
        u32 major;
        u16 minor;

        down_read(&nilfs->ns_sem);
        raw_sb = nilfs->ns_sbp[0];
        major = le32_to_cpu(raw_sb->s_rev_level);
        minor = le16_to_cpu(raw_sb->s_minor_rev_level);
        up_read(&nilfs->ns_sem);

        return sysfs_emit(buf, "%d.%d\n", major, minor);
}

static
ssize_t nilfs_dev_blocksize_show(struct nilfs_dev_attr *attr,
                                 struct the_nilfs *nilfs,
                                 char *buf)
{
        return sysfs_emit(buf, "%u\n", nilfs->ns_blocksize);
}

static
ssize_t nilfs_dev_device_size_show(struct nilfs_dev_attr *attr,
                                    struct the_nilfs *nilfs,
                                    char *buf)
{
        struct nilfs_super_block *raw_sb;
        u64 dev_size;

        down_read(&nilfs->ns_sem);
        raw_sb = nilfs->ns_sbp[0];
        dev_size = le64_to_cpu(raw_sb->s_dev_size);
        up_read(&nilfs->ns_sem);

        return sysfs_emit(buf, "%llu\n", dev_size);
}

static
ssize_t nilfs_dev_free_blocks_show(struct nilfs_dev_attr *attr,
                                   struct the_nilfs *nilfs,
                                   char *buf)
{
        sector_t free_blocks = 0;

        nilfs_count_free_blocks(nilfs, &free_blocks);
        return sysfs_emit(buf, "%llu\n",
                        (unsigned long long)free_blocks);
}

static
ssize_t nilfs_dev_uuid_show(struct nilfs_dev_attr *attr,
                            struct the_nilfs *nilfs,
                            char *buf)
{
        struct nilfs_super_block *raw_sb;
        ssize_t len;

        down_read(&nilfs->ns_sem);
        raw_sb = nilfs->ns_sbp[0];
        len = sysfs_emit(buf, "%pUb\n", raw_sb->s_uuid);
        up_read(&nilfs->ns_sem);

        return len;
}

static
ssize_t nilfs_dev_volume_name_show(struct nilfs_dev_attr *attr,
                                    struct the_nilfs *nilfs,
                                    char *buf)
{
        struct nilfs_super_block *raw_sb;
        ssize_t len;

        down_read(&nilfs->ns_sem);
        raw_sb = nilfs->ns_sbp[0];
        len = scnprintf(buf, sizeof(raw_sb->s_volume_name), "%s\n",
                        raw_sb->s_volume_name);
        up_read(&nilfs->ns_sem);

        return len;
}

static const char dev_readme_str[] =
        "The <device> group contains attributes that describe file system\n"
        "partition's details.\n\n"
        "(1) revision\n\tshow NILFS file system revision.\n\n"
        "(2) blocksize\n\tshow volume block size in bytes.\n\n"
        "(3) device_size\n\tshow volume size in bytes.\n\n"
        "(4) free_blocks\n\tshow count of free blocks on volume.\n\n"
        "(5) uuid\n\tshow volume's UUID.\n\n"
        "(6) volume_name\n\tshow volume's name.\n\n";

static ssize_t nilfs_dev_README_show(struct nilfs_dev_attr *attr,
                                     struct the_nilfs *nilfs,
                                     char *buf)
{
        return sysfs_emit(buf, dev_readme_str);
}

NILFS_DEV_RO_ATTR(revision);
NILFS_DEV_RO_ATTR(blocksize);
NILFS_DEV_RO_ATTR(device_size);
NILFS_DEV_RO_ATTR(free_blocks);
NILFS_DEV_RO_ATTR(uuid);
NILFS_DEV_RO_ATTR(volume_name);
NILFS_DEV_RO_ATTR(README);

static struct attribute *nilfs_dev_attrs[] = {
        NILFS_DEV_ATTR_LIST(revision),
        NILFS_DEV_ATTR_LIST(blocksize),
        NILFS_DEV_ATTR_LIST(device_size),
        NILFS_DEV_ATTR_LIST(free_blocks),
        NILFS_DEV_ATTR_LIST(uuid),
        NILFS_DEV_ATTR_LIST(volume_name),
        NILFS_DEV_ATTR_LIST(README),
        NULL,
};
ATTRIBUTE_GROUPS(nilfs_dev);

static ssize_t nilfs_dev_attr_show(struct kobject *kobj,
                                    struct attribute *attr, char *buf)
{
        struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
                                                ns_dev_kobj);
        struct nilfs_dev_attr *a = container_of(attr, struct nilfs_dev_attr,
                                                attr);

        return a->show ? a->show(a, nilfs, buf) : 0;
}

static ssize_t nilfs_dev_attr_store(struct kobject *kobj,
                                    struct attribute *attr,
                                    const char *buf, size_t len)
{
        struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
                                                ns_dev_kobj);
        struct nilfs_dev_attr *a = container_of(attr, struct nilfs_dev_attr,
                                                attr);

        return a->store ? a->store(a, nilfs, buf, len) : 0;
}

static void nilfs_dev_attr_release(struct kobject *kobj)
{
        struct the_nilfs *nilfs = container_of(kobj, struct the_nilfs,
                                                ns_dev_kobj);
        complete(&nilfs->ns_dev_kobj_unregister);
}

static const struct sysfs_ops nilfs_dev_attr_ops = {
        .show   = nilfs_dev_attr_show,
        .store  = nilfs_dev_attr_store,
};

static const struct kobj_type nilfs_dev_ktype = {
        .default_groups = nilfs_dev_groups,
        .sysfs_ops      = &nilfs_dev_attr_ops,
        .release        = nilfs_dev_attr_release,
};

int nilfs_sysfs_create_device_group(struct super_block *sb)
{
        struct the_nilfs *nilfs = sb->s_fs_info;
        size_t devgrp_size = sizeof(struct nilfs_sysfs_dev_subgroups);
        int err;

        nilfs->ns_dev_subgroups = kzalloc(devgrp_size, GFP_KERNEL);
        if (unlikely(!nilfs->ns_dev_subgroups)) {
                err = -ENOMEM;
                nilfs_err(sb, "unable to allocate memory for device group");
                goto failed_create_device_group;
        }

        nilfs->ns_dev_kobj.kset = nilfs_kset;
        init_completion(&nilfs->ns_dev_kobj_unregister);
        err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL,
                                    "%s", sb->s_id);
        if (err)
                goto cleanup_dev_kobject;

        err = nilfs_sysfs_create_mounted_snapshots_group(nilfs);
        if (err)
                goto cleanup_dev_kobject;

        err = nilfs_sysfs_create_checkpoints_group(nilfs);
        if (err)
                goto delete_mounted_snapshots_group;

        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;

        err = nilfs_sysfs_create_segctor_group(nilfs);
        if (err)
                goto delete_superblock_group;

        return 0;

delete_superblock_group:
        nilfs_sysfs_delete_superblock_group(nilfs);

delete_segments_group:
        nilfs_sysfs_delete_segments_group(nilfs);

delete_checkpoints_group:
        nilfs_sysfs_delete_checkpoints_group(nilfs);

delete_mounted_snapshots_group:
        nilfs_sysfs_delete_mounted_snapshots_group(nilfs);

cleanup_dev_kobject:
        kobject_put(&nilfs->ns_dev_kobj);
        kfree(nilfs->ns_dev_subgroups);

failed_create_device_group:
        return err;
}

void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)
{
        nilfs_sysfs_delete_mounted_snapshots_group(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);
        kobject_del(&nilfs->ns_dev_kobj);
        kobject_put(&nilfs->ns_dev_kobj);
        kfree(nilfs->ns_dev_subgroups);
}

/************************************************************************
 *                        NILFS feature attrs                           *
 ************************************************************************/

static ssize_t nilfs_feature_revision_show(struct kobject *kobj,
                                            struct kobj_attribute *attr, char *buf)
{
        return sysfs_emit(buf, "%d.%d\n",
                        NILFS_CURRENT_REV, NILFS_MINOR_REV);
}

static const char features_readme_str[] =
        "The features group contains attributes that describe NILFS file\n"
        "system driver features.\n\n"
        "(1) revision\n\tshow current revision of NILFS file system driver.\n";

static ssize_t nilfs_feature_README_show(struct kobject *kobj,
                                         struct kobj_attribute *attr,
                                         char *buf)
{
        return sysfs_emit(buf, features_readme_str);
}

NILFS_FEATURE_RO_ATTR(revision);
NILFS_FEATURE_RO_ATTR(README);

static struct attribute *nilfs_feature_attrs[] = {
        NILFS_FEATURE_ATTR_LIST(revision),
        NILFS_FEATURE_ATTR_LIST(README),
        NULL,
};

static const struct attribute_group nilfs_feature_attr_group = {
        .name = "features",
        .attrs = nilfs_feature_attrs,
};

int __init nilfs_sysfs_init(void)
{
        int err;

        nilfs_kset = kset_create_and_add(NILFS_ROOT_GROUP_NAME, NULL, fs_kobj);
        if (!nilfs_kset) {
                err = -ENOMEM;
                nilfs_err(NULL, "unable to create sysfs entry: err=%d", err);
                goto failed_sysfs_init;
        }

        err = sysfs_create_group(&nilfs_kset->kobj, &nilfs_feature_attr_group);
        if (unlikely(err)) {
                nilfs_err(NULL, "unable to create feature group: err=%d", err);
                goto cleanup_sysfs_init;
        }

        return 0;

cleanup_sysfs_init:
        kset_unregister(nilfs_kset);

failed_sysfs_init:
        return err;
}

void nilfs_sysfs_exit(void)
{
        sysfs_remove_group(&nilfs_kset->kobj, &nilfs_feature_attr_group);
        kset_unregister(nilfs_kset);
}