sys.c

linux 内核源代码

ARGS_ATTR(posix_acl,       "%d\n");
ARGS_ATTR(quota,           "%u\n");
ARGS_ATTR(suiddir,         "%d\n");
ARGS_ATTR(data,            "%d\n");

/* one oddball doesn't fit the macro mold */
static ssize_t noatime_show(struct gfs2_sbd *sdp, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%d\n",
			!!test_bit(SDF_NOATIME, &sdp->sd_flags));
}
static struct args_attr args_attr_noatime = __ATTR_RO(noatime);

static struct attribute *args_attrs[] = {
	&args_attr_lockproto.attr,
	&args_attr_locktable.attr,
	&args_attr_hostdata.attr,
	&args_attr_spectator.attr,
	&args_attr_ignore_local_fs.attr,
	&args_attr_localcaching.attr,
	&args_attr_localflocks.attr,
	&args_attr_debug.attr,
	&args_attr_upgrade.attr,
	&args_attr_num_glockd.attr,
	&args_attr_posix_acl.attr,
	&args_attr_quota.attr,
	&args_attr_suiddir.attr,
	&args_attr_data.attr,
	&args_attr_noatime.attr,
	NULL,
};

/*
 * display counters from superblock
 */

struct counters_attr {
	struct attribute attr;
	ssize_t (*show)(struct gfs2_sbd *, char *);
};

#define COUNTERS_ATTR(name, fmt)                                            \
static ssize_t name##_show(struct gfs2_sbd *sdp, char *buf)                 \
{                                                                           \
	return snprintf(buf, PAGE_SIZE, fmt,                                \
			(unsigned int)atomic_read(&sdp->sd_##name));        \
}                                                                           \
static struct counters_attr counters_attr_##name = __ATTR_RO(name)

COUNTERS_ATTR(glock_count,      "%u\n");
COUNTERS_ATTR(glock_held_count, "%u\n");
COUNTERS_ATTR(inode_count,      "%u\n");
COUNTERS_ATTR(reclaimed,        "%u\n");

static struct attribute *counters_attrs[] = {
	&counters_attr_glock_count.attr,
	&counters_attr_glock_held_count.attr,
	&counters_attr_inode_count.attr,
	&counters_attr_reclaimed.attr,
	NULL,
};

/*
 * get and set struct gfs2_tune fields
 */

static ssize_t quota_scale_show(struct gfs2_sbd *sdp, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%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 -EACCES;

	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;

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

	x = simple_strtoul(buf, NULL, 0);

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

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

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

#define TUNE_ATTR_3(name, show, store)                                        \
static struct tune_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 snprintf(buf, PAGE_SIZE, "%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)

#define TUNE_ATTR_DAEMON(name, process)                                       \
static ssize_t name##_store(struct gfs2_sbd *sdp, const char *buf, size_t len)\
{                                                                             \
	ssize_t r = tune_set(sdp, &sdp->sd_tune.gt_##name, 1, buf, len);      \
	wake_up_process(sdp->sd_##process);                                   \
	return r;                                                             \
}                                                                             \
TUNE_ATTR_2(name, name##_store)

TUNE_ATTR(demote_secs, 0);
TUNE_ATTR(incore_log_blocks, 0);
TUNE_ATTR(log_flush_secs, 0);
TUNE_ATTR(jindex_refresh_secs, 0);
TUNE_ATTR(quota_warn_period, 0);
TUNE_ATTR(quota_quantum, 0);
TUNE_ATTR(atime_quantum, 0);
TUNE_ATTR(max_readahead, 0);
TUNE_ATTR(complain_secs, 0);
TUNE_ATTR(reclaim_limit, 0);
TUNE_ATTR(statfs_slow, 0);
TUNE_ATTR(new_files_jdata, 0);
TUNE_ATTR(new_files_directio, 0);
TUNE_ATTR(quota_simul_sync, 1);
TUNE_ATTR(quota_cache_secs, 1);
TUNE_ATTR(stall_secs, 1);
TUNE_ATTR(statfs_quantum, 1);
TUNE_ATTR_DAEMON(recoverd_secs, recoverd_process);
TUNE_ATTR_DAEMON(logd_secs, logd_process);
TUNE_ATTR_DAEMON(quotad_secs, quotad_process);
TUNE_ATTR_3(quota_scale, quota_scale_show, quota_scale_store);

static struct attribute *tune_attrs[] = {
	&tune_attr_demote_secs.attr,
	&tune_attr_incore_log_blocks.attr,
	&tune_attr_log_flush_secs.attr,
	&tune_attr_jindex_refresh_secs.attr,
	&tune_attr_quota_warn_period.attr,
	&tune_attr_quota_quantum.attr,
	&tune_attr_atime_quantum.attr,
	&tune_attr_max_readahead.attr,
	&tune_attr_complain_secs.attr,
	&tune_attr_reclaim_limit.attr,
	&tune_attr_statfs_slow.attr,
	&tune_attr_quota_simul_sync.attr,
	&tune_attr_quota_cache_secs.attr,
	&tune_attr_stall_secs.attr,
	&tune_attr_statfs_quantum.attr,
	&tune_attr_recoverd_secs.attr,
	&tune_attr_logd_secs.attr,
	&tune_attr_quotad_secs.attr,
	&tune_attr_quota_scale.attr,
	&tune_attr_new_files_jdata.attr,
	&tune_attr_new_files_directio.attr,
	NULL,
};

static struct attribute_group lockstruct_group = {
	.name = "lockstruct",
	.attrs = lockstruct_attrs,
};

static struct attribute_group counters_group = {
	.name = "counters",
	.attrs = counters_attrs,
};

static struct attribute_group args_group = {
	.name = "args",
	.attrs = args_attrs,
};

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

int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
{
	int error;

	sdp->sd_kobj.kset = &gfs2_kset;
	sdp->sd_kobj.ktype = &gfs2_ktype;

	error = kobject_set_name(&sdp->sd_kobj, "%s", sdp->sd_table_name);
	if (error)
		goto fail;

	error = kobject_register(&sdp->sd_kobj);
	if (error)
		goto fail;

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

	error = sysfs_create_group(&sdp->sd_kobj, &counters_group);
	if (error)
		goto fail_lockstruct;

	error = sysfs_create_group(&sdp->sd_kobj, &args_group);
	if (error)
		goto fail_counters;

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

	return 0;

fail_args:
	sysfs_remove_group(&sdp->sd_kobj, &args_group);
fail_counters:
	sysfs_remove_group(&sdp->sd_kobj, &counters_group);
fail_lockstruct:
	sysfs_remove_group(&sdp->sd_kobj, &lockstruct_group);
fail_reg:
	kobject_unregister(&sdp->sd_kobj);
fail:
	fs_err(sdp, "error %d adding sysfs files", error);
	return error;
}

void gfs2_sys_fs_del(struct gfs2_sbd *sdp)
{
	sysfs_remove_group(&sdp->sd_kobj, &tune_group);
	sysfs_remove_group(&sdp->sd_kobj, &args_group);
	sysfs_remove_group(&sdp->sd_kobj, &counters_group);
	sysfs_remove_group(&sdp->sd_kobj, &lockstruct_group);
	kobject_unregister(&sdp->sd_kobj);
}

int gfs2_sys_init(void)
{
	gfs2_sys_margs = NULL;
	spin_lock_init(&gfs2_sys_margs_lock);
	kobject_set_name(&gfs2_kset.kobj, "gfs2");
	kobj_set_kset_s(&gfs2_kset, fs_subsys);
	return kset_register(&gfs2_kset);
}

void gfs2_sys_uninit(void)
{
	kfree(gfs2_sys_margs);
	kset_unregister(&gfs2_kset);
}