root/fs/gfs2/sys.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/uaccess.h>
#include <linux/gfs2_ondisk.h>
#include <linux/blkdev.h>

#include "gfs2.h"
#include "incore.h"
#include "sys.h"
#include "super.h"
#include "glock.h"
#include "quota.h"
#include "util.h"
#include "glops.h"
#include "recovery.h"

struct gfs2_attr {
        struct attribute attr;
        ssize_t (*show)(struct gfs2_sbd *, char *);
        ssize_t (*store)(struct gfs2_sbd *, const char *, size_t);
};

static ssize_t gfs2_attr_show(struct kobject *kobj, struct attribute *attr,
                              char *buf)
{
        struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
        struct gfs2_attr *a = container_of(attr, struct gfs2_attr, attr);
        return a->show ? a->show(sdp, buf) : 0;
}

static ssize_t gfs2_attr_store(struct kobject *kobj, struct attribute *attr,
                               const char *buf, size_t len)
{
        struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
        struct gfs2_attr *a = container_of(attr, struct gfs2_attr, attr);
        return a->store ? a->store(sdp, buf, len) : len;
}

static const struct sysfs_ops gfs2_attr_ops = {
        .show  = gfs2_attr_show,
        .store = gfs2_attr_store,
};


static struct kset *gfs2_kset;

static ssize_t id_show(struct gfs2_sbd *sdp, char *buf)
{
        return sysfs_emit(buf, "%u:%u\n",
                        MAJOR(sdp->sd_vfs->s_dev), MINOR(sdp->sd_vfs->s_dev));
}

static ssize_t status_show(struct gfs2_sbd *sdp, char *buf)
{
        unsigned long f = sdp->sd_flags;
        ssize_t s;

        s = sysfs_emit(buf,
                     "Journal Checked:          %d\n"
                     "Journal Live:             %d\n"
                     "Journal ID:               %d\n"
                     "Spectator:                %d\n"
                     "Withdrawn:                %d\n"
                     "No barriers:              %d\n"
                     "No recovery:              %d\n"
                     "Demote:                   %d\n"
                     "No Journal ID:            %d\n"
                     "Mounted RO:               %d\n"
                     "RO Recovery:              %d\n"
                     "Skip DLM Unlock:          %d\n"
                     "Force AIL Flush:          %d\n"
                     "FS Freeze Initiator:      %d\n"
                     "FS Frozen:                %d\n"
                     "Killing:                  %d\n"
                     "sd_log_error:             %d\n"
                     "sd_log_flush_lock:        %d\n"
                     "sd_log_num_revoke:        %u\n"
                     "sd_log_in_flight:         %d\n"
                     "sd_log_blks_needed:       %d\n"
                     "sd_log_blks_free:         %d\n"
                     "sd_log_flush_head:        %d\n"
                     "sd_log_flush_tail:        %d\n"
                     "sd_log_blks_reserved:     %d\n"
                     "sd_log_revokes_available: %d\n"
                     "sd_log_pinned:            %d\n"
                     "sd_log_thresh1:           %d\n"
                     "sd_log_thresh2:           %d\n",
                     test_bit(SDF_JOURNAL_CHECKED, &f),
                     test_bit(SDF_JOURNAL_LIVE, &f),
                     (sdp->sd_jdesc ? sdp->sd_jdesc->jd_jid : 0),
                     (sdp->sd_args.ar_spectator ? 1 : 0),
                     test_bit(SDF_WITHDRAWN, &f),
                     test_bit(SDF_NOBARRIERS, &f),
                     test_bit(SDF_NORECOVERY, &f),
                     test_bit(SDF_DEMOTE, &f),
                     test_bit(SDF_NOJOURNALID, &f),
                     (sb_rdonly(sdp->sd_vfs) ? 1 : 0),
                     test_bit(SDF_RORECOVERY, &f),
                     test_bit(SDF_SKIP_DLM_UNLOCK, &f),
                     test_bit(SDF_FORCE_AIL_FLUSH, &f),
                     test_bit(SDF_FREEZE_INITIATOR, &f),
                     test_bit(SDF_FROZEN, &f),
                     test_bit(SDF_KILL, &f),
                     sdp->sd_log_error,
                     rwsem_is_locked(&sdp->sd_log_flush_lock),
                     sdp->sd_log_num_revoke,
                     atomic_read(&sdp->sd_log_in_flight),
                     atomic_read(&sdp->sd_log_blks_needed),
                     atomic_read(&sdp->sd_log_blks_free),
                     sdp->sd_log_flush_head,
                     sdp->sd_log_flush_tail,
                     sdp->sd_log_blks_reserved,
                     atomic_read(&sdp->sd_log_revokes_available),
                     atomic_read(&sdp->sd_log_pinned),
                     atomic_read(&sdp->sd_log_thresh1),
                     atomic_read(&sdp->sd_log_thresh2));
        return s;
}

static ssize_t fsname_show(struct gfs2_sbd *sdp, char *buf)
{
        return sysfs_emit(buf, "%s\n", sdp->sd_fsname);
}

static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
{
        struct super_block *s = sdp->sd_vfs;

        buf[0] = '\0';
        if (uuid_is_null(&s->s_uuid))
                return 0;
        return sysfs_emit(buf, "%pUB\n", &s->s_uuid);
}

static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
{
        struct super_block *sb = sdp->sd_vfs;
        int frozen = (sb->s_writers.frozen == SB_UNFROZEN) ? 0 : 1;

        return sysfs_emit(buf, "%d\n", frozen);
}

static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
        int error, n;

        error = kstrtoint(buf, 0, &n);
        if (error)
                return error;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        switch (n) {
        case 0:
                error = thaw_super(sdp->sd_vfs, FREEZE_HOLDER_USERSPACE, NULL);
                break;
        case 1:
                error = freeze_super(sdp->sd_vfs, FREEZE_HOLDER_USERSPACE, NULL);
                break;
        default:
                return -EINVAL;
        }

        if (error) {
                fs_warn(sdp, "freeze %d error %d\n", n, error);
                return error;
        }

        return len;
}

static ssize_t withdraw_show(struct gfs2_sbd *sdp, char *buf)
{
        unsigned int b = gfs2_withdrawn(sdp);
        return sysfs_emit(buf, "%u\n", b);
}

static ssize_t withdraw_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
        int error, val;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        error = kstrtoint(buf, 0, &val);
        if (error)
                return error;

        if (val != 1)
                return -EINVAL;

        gfs2_lm(sdp, "withdrawing from cluster at user's request\n");
        gfs2_withdraw(sdp);

        return len;
}

static ssize_t statfs_sync_store(struct gfs2_sbd *sdp, const char *buf,
                                 size_t len)
{
        int error, val;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        error = kstrtoint(buf, 0, &val);
        if (error)
                return error;

        if (val != 1)
                return -EINVAL;

        gfs2_statfs_sync(sdp->sd_vfs, 0);
        return len;
}

static ssize_t quota_sync_store(struct gfs2_sbd *sdp, const char *buf,
                                size_t len)
{
        int error, val;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        error = kstrtoint(buf, 0, &val);
        if (error)
                return error;

        if (val != 1)
                return -EINVAL;

        gfs2_quota_sync(sdp->sd_vfs, 0);
        return len;
}

static ssize_t quota_refresh_user_store(struct gfs2_sbd *sdp, const char *buf,
                                        size_t len)
{
        struct kqid qid;
        int error;
        u32 id;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        error = kstrtou32(buf, 0, &id);
        if (error)
                return error;

        qid = make_kqid(current_user_ns(), USRQUOTA, id);
        if (!qid_valid(qid))
                return -EINVAL;

        error = gfs2_quota_refresh(sdp, qid);
        return error ? error : len;
}

static ssize_t quota_refresh_group_store(struct gfs2_sbd *sdp, const char *buf,
                                         size_t len)
{
        struct kqid qid;
        int error;
        u32 id;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        error = kstrtou32(buf, 0, &id);
        if (error)
                return error;

        qid = make_kqid(current_user_ns(), GRPQUOTA, id);
        if (!qid_valid(qid))
                return -EINVAL;

        error = gfs2_quota_refresh(sdp, qid);
        return error ? error : len;
}

static ssize_t demote_rq_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
        struct gfs2_glock *gl;
        const struct gfs2_glock_operations *glops;
        unsigned int glmode;
        unsigned int gltype;
        unsigned long long glnum;
        char mode[16];
        int rv;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        rv = sscanf(buf, "%u:%llu %15s", &gltype, &glnum,
                    mode);
        if (rv != 3)
                return -EINVAL;

        if (strcmp(mode, "EX") == 0)
                glmode = LM_ST_UNLOCKED;
        else if ((strcmp(mode, "CW") == 0) || (strcmp(mode, "DF") == 0))
                glmode = LM_ST_DEFERRED;
        else if ((strcmp(mode, "PR") == 0) || (strcmp(mode, "SH") == 0))
                glmode = LM_ST_SHARED;
        else
                return -EINVAL;

        if (gltype > LM_TYPE_JOURNAL)
                return -EINVAL;
        if (gltype == LM_TYPE_NONDISK && glnum == GFS2_FREEZE_LOCK)
                glops = &gfs2_freeze_glops;
        else
                glops = gfs2_glops_list[gltype];
        if (glops == NULL)
                return -EINVAL;
        if (!test_and_set_bit(SDF_DEMOTE, &sdp->sd_flags))
                fs_info(sdp, "demote interface used\n");
        rv = gfs2_glock_get(sdp, glnum, glops, NO_CREATE, &gl);
        if (rv)
                return rv;
        gfs2_glock_cb(gl, glmode);
        gfs2_glock_put(gl);
        return len;
}


#define GFS2_ATTR(name, mode, show, store) \
static struct gfs2_attr gfs2_attr_##name = __ATTR(name, mode, show, store)

GFS2_ATTR(id,                  0444, id_show,       NULL);
GFS2_ATTR(fsname,              0444, fsname_show,   NULL);
GFS2_ATTR(uuid,                0444, uuid_show,     NULL);
GFS2_ATTR(freeze,              0644, freeze_show,   freeze_store);
GFS2_ATTR(withdraw,            0644, withdraw_show, withdraw_store);
GFS2_ATTR(statfs_sync,         0200, NULL,          statfs_sync_store);
GFS2_ATTR(quota_sync,          0200, NULL,          quota_sync_store);
GFS2_ATTR(quota_refresh_user,  0200, NULL,          quota_refresh_user_store);
GFS2_ATTR(quota_refresh_group, 0200, NULL,          quota_refresh_group_store);
GFS2_ATTR(demote_rq,           0200, NULL,          demote_rq_store);
GFS2_ATTR(status,              0400, status_show,   NULL);

static struct attribute *gfs2_attrs[] = {
        &gfs2_attr_id.attr,
        &gfs2_attr_fsname.attr,
        &gfs2_attr_uuid.attr,
        &gfs2_attr_freeze.attr,
        &gfs2_attr_withdraw.attr,
        &gfs2_attr_statfs_sync.attr,
        &gfs2_attr_quota_sync.attr,
        &gfs2_attr_quota_refresh_user.attr,
        &gfs2_attr_quota_refresh_group.attr,
        &gfs2_attr_demote_rq.attr,
        &gfs2_attr_status.attr,
        NULL,
};
ATTRIBUTE_GROUPS(gfs2);

static void gfs2_sbd_release(struct kobject *kobj)
{
        struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);

        complete(&sdp->sd_kobj_unregister);
}

static struct kobj_type gfs2_ktype = {
        .release = gfs2_sbd_release,
        .default_groups = gfs2_groups,
        .sysfs_ops     = &gfs2_attr_ops,
};


/*
 * lock_module. Originally from lock_dlm
 */

static ssize_t proto_name_show(struct gfs2_sbd *sdp, char *buf)
{
        const struct lm_lockops *ops = sdp->sd_lockstruct.ls_ops;
        return sysfs_emit(buf, "%s\n", ops->lm_proto_name);
}

static ssize_t block_show(struct gfs2_sbd *sdp, char *buf)
{
        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
        ssize_t ret;
        int val = 0;

        if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))
                val = 1;
        ret = sysfs_emit(buf, "%d\n", val);
        return ret;
}

static ssize_t block_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
        int ret, val;

        ret = kstrtoint(buf, 0, &val);
        if (ret)
                return ret;

        if (val == 1)
                set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
        else if (val == 0) {
                clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
                smp_mb__after_atomic();
                gfs2_glock_thaw(sdp);
        } else {
                return -EINVAL;
        }
        return len;
}

static ssize_t withdraw_helper_status_store(struct gfs2_sbd *sdp,
                                            const char *buf,
                                            size_t len)
{
        int ret, val;

        ret = kstrtoint(buf, 0, &val);
        if (ret)
                return ret;
        if (val < 0 || val > 1)
                return -EINVAL;

        sdp->sd_withdraw_helper_status = val;
        complete(&sdp->sd_withdraw_helper);
        return len;
}

static ssize_t lkfirst_show(struct gfs2_sbd *sdp, char *buf)
{
        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
        return sysfs_emit(buf, "%d\n", ls->ls_first);
}

static ssize_t lkfirst_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
        unsigned first;
        int rv;

        rv = sscanf(buf, "%u", &first);
        if (rv != 1 || first > 1)
                return -EINVAL;
        rv = wait_for_completion_killable(&sdp->sd_locking_init);
        if (rv)
                return rv;
        spin_lock(&sdp->sd_jindex_spin);
        rv = -EBUSY;
        if (test_bit(SDF_NOJOURNALID, &sdp->sd_flags) == 0)
                goto out;
        rv = -EINVAL;
        if (sdp->sd_args.ar_spectator)
                goto out;
        if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
                goto out;
        sdp->sd_lockstruct.ls_first = first;
        rv = 0;
out:
        spin_unlock(&sdp->sd_jindex_spin);
        return rv ? rv : len;
}

static ssize_t first_done_show(struct gfs2_sbd *sdp, char *buf)
{
        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
        return sysfs_emit(buf, "%d\n", !!test_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags));
}

int gfs2_recover_set(struct gfs2_sbd *sdp, unsigned jid)
{
        struct gfs2_jdesc *jd;
        int rv;

        /* Wait for our primary journal to be initialized */
        wait_for_completion(&sdp->sd_journal_ready);

        spin_lock(&sdp->sd_jindex_spin);
        rv = -EBUSY;
        /**
         * If we're a spectator, we use journal0, but it's not really ours.
         * So we need to wait for its recovery too. If we skip it we'd never
         * queue work to the recovery workqueue, and so its completion would
         * never clear the DFL_BLOCK_LOCKS flag, so all our locks would
         * permanently stop working.
         */
        if (!sdp->sd_jdesc)
                goto out;
        if (sdp->sd_jdesc->jd_jid == jid && !sdp->sd_args.ar_spectator)
                goto out;
        rv = -ENOENT;
        list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
                if (jd->jd_jid != jid && !sdp->sd_args.ar_spectator)
                        continue;
                rv = gfs2_recover_journal(jd, false);
                break;
        }
out:
        spin_unlock(&sdp->sd_jindex_spin);
        return rv;
}

static ssize_t recover_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
        unsigned jid;
        int rv;

        rv = sscanf(buf, "%u", &jid);
        if (rv != 1)
                return -EINVAL;

        if (test_bit(SDF_NORECOVERY, &sdp->sd_flags)) {
                rv = -ESHUTDOWN;
                goto out;
        }

        rv = gfs2_recover_set(sdp, jid);
out:
        return rv ? rv : len;
}

static ssize_t recover_done_show(struct gfs2_sbd *sdp, char *buf)
{
        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
        return sysfs_emit(buf, "%d\n", ls->ls_recover_jid_done);
}

static ssize_t recover_status_show(struct gfs2_sbd *sdp, char *buf)
{
        struct lm_lockstruct *ls = &sdp->sd_lockstruct;
        return sysfs_emit(buf, "%d\n", ls->ls_recover_jid_status);
}

static ssize_t jid_show(struct gfs2_sbd *sdp, char *buf)
{
        return sysfs_emit(buf, "%d\n", sdp->sd_lockstruct.ls_jid);
}

static ssize_t jid_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
{
        int jid;
        int rv;

        rv = sscanf(buf, "%d", &jid);
        if (rv != 1)
                return -EINVAL;
        rv = wait_for_completion_killable(&sdp->sd_locking_init);
        if (rv)
                return rv;
        spin_lock(&sdp->sd_jindex_spin);
        rv = -EINVAL;
        if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
                goto out;
        rv = -EBUSY;
        if (test_bit(SDF_NOJOURNALID, &sdp->sd_flags) == 0)
                goto out;
        rv = 0;
        if (sdp->sd_args.ar_spectator && jid > 0)
                rv = jid = -EINVAL;
        sdp->sd_lockstruct.ls_jid = jid;
        clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
        smp_mb__after_atomic();
        wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
out:
        spin_unlock(&sdp->sd_jindex_spin);
        return rv ? rv : len;
}

#define GDLM_ATTR(_name,_mode,_show,_store) \
static struct gfs2_attr gdlm_attr_##_name = __ATTR(_name,_mode,_show,_store)

GDLM_ATTR(proto_name,           0444, proto_name_show,          NULL);
GDLM_ATTR(block,                0644, block_show,               block_store);
GDLM_ATTR(withdraw,             0200, NULL,                     withdraw_helper_status_store);
GDLM_ATTR(jid,                  0644, jid_show,                 jid_store);
GDLM_ATTR(first,                0644, lkfirst_show,             lkfirst_store);
GDLM_ATTR(first_done,           0444, first_done_show,          NULL);
GDLM_ATTR(recover,              0600, NULL,                     recover_store);
GDLM_ATTR(recover_done,         0444, recover_done_show,        NULL);
GDLM_ATTR(recover_status,       0444, recover_status_show,      NULL);

static struct attribute *lock_module_attrs[] = {
        &gdlm_attr_proto_name.attr,
        &gdlm_attr_block.attr,
        &gdlm_attr_withdraw.attr,
        &gdlm_attr_jid.attr,
        &gdlm_attr_first.attr,
        &gdlm_attr_first_done.attr,
        &gdlm_attr_recover.attr,
        &gdlm_attr_recover_done.attr,
        &gdlm_attr_recover_status.attr,
        NULL,
};

/*
 * get and set struct gfs2_tune fields
 */

static ssize_t quota_scale_show(struct gfs2_sbd *sdp, char *buf)
{
        return sysfs_emit(buf, "%u %u\n",
                        sdp->sd_tune.gt_quota_scale_num,
                        sdp->sd_tune.gt_quota_scale_den);
}

static ssize_t quota_scale_store(struct gfs2_sbd *sdp, const char *buf,
                                 size_t len)
{
        struct gfs2_tune *gt = &sdp->sd_tune;
        unsigned int x, y;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (sscanf(buf, "%u %u", &x, &y) != 2 || !y)
                return -EINVAL;

        spin_lock(&gt->gt_spin);
        gt->gt_quota_scale_num = x;
        gt->gt_quota_scale_den = y;
        spin_unlock(&gt->gt_spin);
        return len;
}

static ssize_t tune_set(struct gfs2_sbd *sdp, unsigned int *field,
                        int check_zero, const char *buf, size_t len)
{
        struct gfs2_tune *gt = &sdp->sd_tune;
        unsigned int x;
        int error;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        error = kstrtouint(buf, 0, &x);
        if (error)
                return error;

        if (check_zero && !x)
                return -EINVAL;

        spin_lock(&gt->gt_spin);
        *field = x;
        spin_unlock(&gt->gt_spin);
        return len;
}

#define TUNE_ATTR_3(name, show, store)                                        \
static struct gfs2_attr tune_attr_##name = __ATTR(name, 0644, show, store)

#define TUNE_ATTR_2(name, store)                                              \
static ssize_t name##_show(struct gfs2_sbd *sdp, char *buf)                   \
{                                                                             \
        return sysfs_emit(buf, "%u\n", sdp->sd_tune.gt_##name);               \
}                                                                             \
TUNE_ATTR_3(name, name##_show, store)

#define TUNE_ATTR(name, check_zero)                                           \
static ssize_t name##_store(struct gfs2_sbd *sdp, const char *buf, size_t len)\
{                                                                             \
        return tune_set(sdp, &sdp->sd_tune.gt_##name, check_zero, buf, len);  \
}                                                                             \
TUNE_ATTR_2(name, name##_store)

TUNE_ATTR(quota_warn_period, 0);
TUNE_ATTR(quota_quantum, 0);
TUNE_ATTR(max_readahead, 0);
TUNE_ATTR(complain_secs, 0);
TUNE_ATTR(statfs_slow, 0);
TUNE_ATTR(new_files_jdata, 0);
TUNE_ATTR(statfs_quantum, 1);
TUNE_ATTR_3(quota_scale, quota_scale_show, quota_scale_store);
TUNE_ATTR(withdraw_helper_timeout, 1);

static struct attribute *tune_attrs[] = {
        &tune_attr_quota_warn_period.attr,
        &tune_attr_quota_quantum.attr,
        &tune_attr_max_readahead.attr,
        &tune_attr_complain_secs.attr,
        &tune_attr_statfs_slow.attr,
        &tune_attr_statfs_quantum.attr,
        &tune_attr_quota_scale.attr,
        &tune_attr_new_files_jdata.attr,
        &tune_attr_withdraw_helper_timeout.attr,
        NULL,
};

static const struct attribute_group tune_group = {
        .name = "tune",
        .attrs = tune_attrs,
};

static const struct attribute_group lock_module_group = {
        .name = "lock_module",
        .attrs = lock_module_attrs,
};

int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
{
        struct super_block *sb = sdp->sd_vfs;
        int error;
        char ro[20];
        char spectator[20];
        char *envp[] = { ro, spectator, NULL };

        sprintf(ro, "RDONLY=%d", sb_rdonly(sb));
        sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);

        init_completion(&sdp->sd_kobj_unregister);
        sdp->sd_kobj.kset = gfs2_kset;
        error = kobject_init_and_add(&sdp->sd_kobj, &gfs2_ktype, NULL,
                                     "%s", sdp->sd_table_name);
        if (error)
                goto fail_reg;

        error = sysfs_create_group(&sdp->sd_kobj, &tune_group);
        if (error)
                goto fail_reg;

        error = sysfs_create_group(&sdp->sd_kobj, &lock_module_group);
        if (error)
                goto fail_tune;

        error = sysfs_create_link(&sdp->sd_kobj,
                                  &disk_to_dev(sb->s_bdev->bd_disk)->kobj,
                                  "device");
        if (error)
                goto fail_lock_module;

        kobject_uevent_env(&sdp->sd_kobj, KOBJ_ADD, envp);
        return 0;

fail_lock_module:
        sysfs_remove_group(&sdp->sd_kobj, &lock_module_group);
fail_tune:
        sysfs_remove_group(&sdp->sd_kobj, &tune_group);
fail_reg:
        fs_err(sdp, "error %d adding sysfs files\n", error);
        kobject_put(&sdp->sd_kobj);
        wait_for_completion(&sdp->sd_kobj_unregister);
        return error;
}

void gfs2_sys_fs_del(struct gfs2_sbd *sdp)
{
        sysfs_remove_link(&sdp->sd_kobj, "device");
        sysfs_remove_group(&sdp->sd_kobj, &tune_group);
        sysfs_remove_group(&sdp->sd_kobj, &lock_module_group);
        kobject_put(&sdp->sd_kobj);
        wait_for_completion(&sdp->sd_kobj_unregister);
}

static int gfs2_uevent(const struct kobject *kobj, struct kobj_uevent_env *env)
{
        const struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
        const struct super_block *s = sdp->sd_vfs;

        add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name);
        add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name);
        if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags))
                add_uevent_var(env, "JOURNALID=%d", sdp->sd_lockstruct.ls_jid);
        if (!uuid_is_null(&s->s_uuid))
                add_uevent_var(env, "UUID=%pUB", &s->s_uuid);
        return 0;
}

static const struct kset_uevent_ops gfs2_uevent_ops = {
        .uevent = gfs2_uevent,
};

int gfs2_sys_init(void)
{
        gfs2_kset = kset_create_and_add("gfs2", &gfs2_uevent_ops, fs_kobj);
        if (!gfs2_kset)
                return -ENOMEM;
        return 0;
}

void gfs2_sys_uninit(void)
{
        kset_unregister(gfs2_kset);
}