1 files changed, 608 insertions, 0 deletions

diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
new file mode 100644
index 000000000..e2b8b3437
--- /dev/null
+++ b/fs/ext4/sysfs.c
@@ -0,0 +1,608 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/ext4/sysfs.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Theodore Ts'o (tytso@mit.edu)
+ *
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/part_stat.h>
+
+#include "ext4.h"
+#include "ext4_jbd2.h"
+
+typedef enum {
+	attr_noop,
+	attr_delayed_allocation_blocks,
+	attr_session_write_kbytes,
+	attr_lifetime_write_kbytes,
+	attr_reserved_clusters,
+	attr_sra_exceeded_retry_limit,
+	attr_inode_readahead,
+	attr_trigger_test_error,
+	attr_first_error_time,
+	attr_last_error_time,
+	attr_feature,
+	attr_pointer_ui,
+	attr_pointer_ul,
+	attr_pointer_u64,
+	attr_pointer_u8,
+	attr_pointer_string,
+	attr_pointer_atomic,
+	attr_journal_task,
+} attr_id_t;
+
+typedef enum {
+	ptr_explicit,
+	ptr_ext4_sb_info_offset,
+	ptr_ext4_super_block_offset,
+} attr_ptr_t;
+
+static const char proc_dirname[] = "fs/ext4";
+static struct proc_dir_entry *ext4_proc_root;
+
+struct ext4_attr {
+	struct attribute attr;
+	short attr_id;
+	short attr_ptr;
+	unsigned short attr_size;
+	union {
+		int offset;
+		void *explicit_ptr;
+	} u;
+};
+
+static ssize_t session_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
+{
+	struct super_block *sb = sbi->s_buddy_cache->i_sb;
+
+	return sysfs_emit(buf, "%lu\n",
+			(part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
+			 sbi->s_sectors_written_start) >> 1);
+}
+
+static ssize_t lifetime_write_kbytes_show(struct ext4_sb_info *sbi, char *buf)
+{
+	struct super_block *sb = sbi->s_buddy_cache->i_sb;
+
+	return sysfs_emit(buf, "%llu\n",
+			(unsigned long long)(sbi->s_kbytes_written +
+			((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
+			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
+}
+
+static ssize_t inode_readahead_blks_store(struct ext4_sb_info *sbi,
+					  const char *buf, size_t count)
+{
+	unsigned long t;
+	int ret;
+
+	ret = kstrtoul(skip_spaces(buf), 0, &t);
+	if (ret)
+		return ret;
+
+	if (t && (!is_power_of_2(t) || t > 0x40000000))
+		return -EINVAL;
+
+	sbi->s_inode_readahead_blks = t;
+	return count;
+}
+
+static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi,
+				   const char *buf, size_t count)
+{
+	unsigned long long val;
+	ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
+				 sbi->s_cluster_bits);
+	int ret;
+
+	ret = kstrtoull(skip_spaces(buf), 0, &val);
+	if (ret || val >= clusters)
+		return -EINVAL;
+
+	atomic64_set(&sbi->s_resv_clusters, val);
+	return count;
+}
+
+static ssize_t trigger_test_error(struct ext4_sb_info *sbi,
+				  const char *buf, size_t count)
+{
+	int len = count;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (len && buf[len-1] == '\n')
+		len--;
+
+	if (len)
+		ext4_error(sbi->s_sb, "%.*s", len, buf);
+	return count;
+}
+
+static ssize_t journal_task_show(struct ext4_sb_info *sbi, char *buf)
+{
+	if (!sbi->s_journal)
+		return sysfs_emit(buf, "<none>\n");
+	return sysfs_emit(buf, "%d\n",
+			task_pid_vnr(sbi->s_journal->j_task));
+}
+
+#define EXT4_ATTR(_name,_mode,_id)					\
+static struct ext4_attr ext4_attr_##_name = {				\
+	.attr = {.name = __stringify(_name), .mode = _mode },		\
+	.attr_id = attr_##_id,						\
+}
+
+#define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
+
+#define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
+
+#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)	\
+static struct ext4_attr ext4_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.attr_id = attr_##_id,					\
+	.attr_ptr = ptr_##_struct##_offset,			\
+	.u = {							\
+		.offset = offsetof(struct _struct, _elname),\
+	},							\
+}
+
+#define EXT4_ATTR_STRING(_name,_mode,_size,_struct,_elname)	\
+static struct ext4_attr ext4_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.attr_id = attr_pointer_string,				\
+	.attr_size = _size,					\
+	.attr_ptr = ptr_##_struct##_offset,			\
+	.u = {							\
+		.offset = offsetof(struct _struct, _elname),\
+	},							\
+}
+
+#define EXT4_RO_ATTR_ES_UI(_name,_elname)				\
+	EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
+
+#define EXT4_RO_ATTR_ES_U8(_name,_elname)				\
+	EXT4_ATTR_OFFSET(_name, 0444, pointer_u8, ext4_super_block, _elname)
+
+#define EXT4_RO_ATTR_ES_U64(_name,_elname)				\
+	EXT4_ATTR_OFFSET(_name, 0444, pointer_u64, ext4_super_block, _elname)
+
+#define EXT4_RO_ATTR_ES_STRING(_name,_elname,_size)			\
+	EXT4_ATTR_STRING(_name, 0444, _size, ext4_super_block, _elname)
+
+#define EXT4_RW_ATTR_SBI_UI(_name,_elname)	\
+	EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
+
+#define EXT4_RW_ATTR_SBI_UL(_name,_elname)	\
+	EXT4_ATTR_OFFSET(_name, 0644, pointer_ul, ext4_sb_info, _elname)
+
+#define EXT4_RO_ATTR_SBI_ATOMIC(_name,_elname)	\
+	EXT4_ATTR_OFFSET(_name, 0444, pointer_atomic, ext4_sb_info, _elname)
+
+#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
+static struct ext4_attr ext4_attr_##_name = {			\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.attr_id = attr_##_id,					\
+	.attr_ptr = ptr_explicit,				\
+	.u = {							\
+		.explicit_ptr = _ptr,				\
+	},							\
+}
+
+#define ATTR_LIST(name) &ext4_attr_##name.attr
+
+EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
+EXT4_ATTR_FUNC(session_write_kbytes, 0444);
+EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
+EXT4_ATTR_FUNC(reserved_clusters, 0644);
+EXT4_ATTR_FUNC(sra_exceeded_retry_limit, 0444);
+
+EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
+		 ext4_sb_info, s_inode_readahead_blks);
+EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
+EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
+EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
+EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
+EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
+EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
+EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
+EXT4_RW_ATTR_SBI_UI(mb_max_inode_prealloc, s_mb_max_inode_prealloc);
+EXT4_RW_ATTR_SBI_UI(mb_max_linear_groups, s_mb_max_linear_groups);
+EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
+EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
+EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
+EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
+EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
+EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst);
+EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval);
+EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst);
+#ifdef CONFIG_EXT4_DEBUG
+EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail);
+#endif
+EXT4_RO_ATTR_SBI_ATOMIC(warning_count, s_warning_count);
+EXT4_RO_ATTR_SBI_ATOMIC(msg_count, s_msg_count);
+EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
+EXT4_RO_ATTR_ES_U8(first_error_errcode, s_first_error_errcode);
+EXT4_RO_ATTR_ES_U8(last_error_errcode, s_last_error_errcode);
+EXT4_RO_ATTR_ES_UI(first_error_ino, s_first_error_ino);
+EXT4_RO_ATTR_ES_UI(last_error_ino, s_last_error_ino);
+EXT4_RO_ATTR_ES_U64(first_error_block, s_first_error_block);
+EXT4_RO_ATTR_ES_U64(last_error_block, s_last_error_block);
+EXT4_RO_ATTR_ES_UI(first_error_line, s_first_error_line);
+EXT4_RO_ATTR_ES_UI(last_error_line, s_last_error_line);
+EXT4_RO_ATTR_ES_STRING(first_error_func, s_first_error_func, 32);
+EXT4_RO_ATTR_ES_STRING(last_error_func, s_last_error_func, 32);
+EXT4_ATTR(first_error_time, 0444, first_error_time);
+EXT4_ATTR(last_error_time, 0444, last_error_time);
+EXT4_ATTR(journal_task, 0444, journal_task);
+EXT4_RW_ATTR_SBI_UI(mb_prefetch, s_mb_prefetch);
+EXT4_RW_ATTR_SBI_UI(mb_prefetch_limit, s_mb_prefetch_limit);
+EXT4_RW_ATTR_SBI_UL(last_trim_minblks, s_last_trim_minblks);
+
+static unsigned int old_bump_val = 128;
+EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
+
+static struct attribute *ext4_attrs[] = {
+	ATTR_LIST(delayed_allocation_blocks),
+	ATTR_LIST(session_write_kbytes),
+	ATTR_LIST(lifetime_write_kbytes),
+	ATTR_LIST(reserved_clusters),
+	ATTR_LIST(sra_exceeded_retry_limit),
+	ATTR_LIST(inode_readahead_blks),
+	ATTR_LIST(inode_goal),
+	ATTR_LIST(mb_stats),
+	ATTR_LIST(mb_max_to_scan),
+	ATTR_LIST(mb_min_to_scan),
+	ATTR_LIST(mb_order2_req),
+	ATTR_LIST(mb_stream_req),
+	ATTR_LIST(mb_group_prealloc),
+	ATTR_LIST(mb_max_inode_prealloc),
+	ATTR_LIST(mb_max_linear_groups),
+	ATTR_LIST(max_writeback_mb_bump),
+	ATTR_LIST(extent_max_zeroout_kb),
+	ATTR_LIST(trigger_fs_error),
+	ATTR_LIST(err_ratelimit_interval_ms),
+	ATTR_LIST(err_ratelimit_burst),
+	ATTR_LIST(warning_ratelimit_interval_ms),
+	ATTR_LIST(warning_ratelimit_burst),
+	ATTR_LIST(msg_ratelimit_interval_ms),
+	ATTR_LIST(msg_ratelimit_burst),
+	ATTR_LIST(errors_count),
+	ATTR_LIST(warning_count),
+	ATTR_LIST(msg_count),
+	ATTR_LIST(first_error_ino),
+	ATTR_LIST(last_error_ino),
+	ATTR_LIST(first_error_block),
+	ATTR_LIST(last_error_block),
+	ATTR_LIST(first_error_line),
+	ATTR_LIST(last_error_line),
+	ATTR_LIST(first_error_func),
+	ATTR_LIST(last_error_func),
+	ATTR_LIST(first_error_errcode),
+	ATTR_LIST(last_error_errcode),
+	ATTR_LIST(first_error_time),
+	ATTR_LIST(last_error_time),
+	ATTR_LIST(journal_task),
+#ifdef CONFIG_EXT4_DEBUG
+	ATTR_LIST(simulate_fail),
+#endif
+	ATTR_LIST(mb_prefetch),
+	ATTR_LIST(mb_prefetch_limit),
+	ATTR_LIST(last_trim_minblks),
+	NULL,
+};
+ATTRIBUTE_GROUPS(ext4);
+
+/* Features this copy of ext4 supports */
+EXT4_ATTR_FEATURE(lazy_itable_init);
+EXT4_ATTR_FEATURE(batched_discard);
+EXT4_ATTR_FEATURE(meta_bg_resize);
+#ifdef CONFIG_FS_ENCRYPTION
+EXT4_ATTR_FEATURE(encryption);
+EXT4_ATTR_FEATURE(test_dummy_encryption_v2);
+#endif
+#if IS_ENABLED(CONFIG_UNICODE)
+EXT4_ATTR_FEATURE(casefold);
+#endif
+#ifdef CONFIG_FS_VERITY
+EXT4_ATTR_FEATURE(verity);
+#endif
+EXT4_ATTR_FEATURE(metadata_csum_seed);
+EXT4_ATTR_FEATURE(fast_commit);
+#if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
+EXT4_ATTR_FEATURE(encrypted_casefold);
+#endif
+
+static struct attribute *ext4_feat_attrs[] = {
+	ATTR_LIST(lazy_itable_init),
+	ATTR_LIST(batched_discard),
+	ATTR_LIST(meta_bg_resize),
+#ifdef CONFIG_FS_ENCRYPTION
+	ATTR_LIST(encryption),
+	ATTR_LIST(test_dummy_encryption_v2),
+#endif
+#if IS_ENABLED(CONFIG_UNICODE)
+	ATTR_LIST(casefold),
+#endif
+#ifdef CONFIG_FS_VERITY
+	ATTR_LIST(verity),
+#endif
+	ATTR_LIST(metadata_csum_seed),
+	ATTR_LIST(fast_commit),
+#if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
+	ATTR_LIST(encrypted_casefold),
+#endif
+	NULL,
+};
+ATTRIBUTE_GROUPS(ext4_feat);
+
+static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
+{
+	switch (a->attr_ptr) {
+	case ptr_explicit:
+		return a->u.explicit_ptr;
+	case ptr_ext4_sb_info_offset:
+		return (void *) (((char *) sbi) + a->u.offset);
+	case ptr_ext4_super_block_offset:
+		return (void *) (((char *) sbi->s_es) + a->u.offset);
+	}
+	return NULL;
+}
+
+static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi)
+{
+	return sysfs_emit(buf, "%lld\n",
+			((time64_t)hi << 32) + le32_to_cpu(lo));
+}
+
+#define print_tstamp(buf, es, tstamp) \
+	__print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)
+
+static ssize_t ext4_attr_show(struct kobject *kobj,
+			      struct attribute *attr, char *buf)
+{
+	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
+						s_kobj);
+	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
+	void *ptr = calc_ptr(a, sbi);
+
+	switch (a->attr_id) {
+	case attr_delayed_allocation_blocks:
+		return sysfs_emit(buf, "%llu\n",
+				(s64) EXT4_C2B(sbi,
+		       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
+	case attr_session_write_kbytes:
+		return session_write_kbytes_show(sbi, buf);
+	case attr_lifetime_write_kbytes:
+		return lifetime_write_kbytes_show(sbi, buf);
+	case attr_reserved_clusters:
+		return sysfs_emit(buf, "%llu\n",
+				(unsigned long long)
+				atomic64_read(&sbi->s_resv_clusters));
+	case attr_sra_exceeded_retry_limit:
+		return sysfs_emit(buf, "%llu\n",
+				(unsigned long long)
+			percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));
+	case attr_inode_readahead:
+	case attr_pointer_ui:
+		if (!ptr)
+			return 0;
+		if (a->attr_ptr == ptr_ext4_super_block_offset)
+			return sysfs_emit(buf, "%u\n",
+					le32_to_cpup(ptr));
+		else
+			return sysfs_emit(buf, "%u\n",
+					*((unsigned int *) ptr));
+	case attr_pointer_ul:
+		if (!ptr)
+			return 0;
+		return sysfs_emit(buf, "%lu\n",
+				*((unsigned long *) ptr));
+	case attr_pointer_u8:
+		if (!ptr)
+			return 0;
+		return sysfs_emit(buf, "%u\n",
+				*((unsigned char *) ptr));
+	case attr_pointer_u64:
+		if (!ptr)
+			return 0;
+		if (a->attr_ptr == ptr_ext4_super_block_offset)
+			return sysfs_emit(buf, "%llu\n",
+					le64_to_cpup(ptr));
+		else
+			return sysfs_emit(buf, "%llu\n",
+					*((unsigned long long *) ptr));
+	case attr_pointer_string:
+		if (!ptr)
+			return 0;
+		return sysfs_emit(buf, "%.*s\n", a->attr_size,
+				(char *) ptr);
+	case attr_pointer_atomic:
+		if (!ptr)
+			return 0;
+		return sysfs_emit(buf, "%d\n",
+				atomic_read((atomic_t *) ptr));
+	case attr_feature:
+		return sysfs_emit(buf, "supported\n");
+	case attr_first_error_time:
+		return print_tstamp(buf, sbi->s_es, s_first_error_time);
+	case attr_last_error_time:
+		return print_tstamp(buf, sbi->s_es, s_last_error_time);
+	case attr_journal_task:
+		return journal_task_show(sbi, buf);
+	}
+
+	return 0;
+}
+
+static ssize_t ext4_attr_store(struct kobject *kobj,
+			       struct attribute *attr,
+			       const char *buf, size_t len)
+{
+	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
+						s_kobj);
+	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
+	void *ptr = calc_ptr(a, sbi);
+	unsigned long t;
+	int ret;
+
+	switch (a->attr_id) {
+	case attr_reserved_clusters:
+		return reserved_clusters_store(sbi, buf, len);
+	case attr_pointer_ui:
+		if (!ptr)
+			return 0;
+		ret = kstrtoul(skip_spaces(buf), 0, &t);
+		if (ret)
+			return ret;
+		if (a->attr_ptr == ptr_ext4_super_block_offset)
+			*((__le32 *) ptr) = cpu_to_le32(t);
+		else
+			*((unsigned int *) ptr) = t;
+		return len;
+	case attr_pointer_ul:
+		if (!ptr)
+			return 0;
+		ret = kstrtoul(skip_spaces(buf), 0, &t);
+		if (ret)
+			return ret;
+		*((unsigned long *) ptr) = t;
+		return len;
+	case attr_inode_readahead:
+		return inode_readahead_blks_store(sbi, buf, len);
+	case attr_trigger_test_error:
+		return trigger_test_error(sbi, buf, len);
+	}
+	return 0;
+}
+
+static void ext4_sb_release(struct kobject *kobj)
+{
+	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
+						s_kobj);
+	complete(&sbi->s_kobj_unregister);
+}
+
+static void ext4_feat_release(struct kobject *kobj)
+{
+	kfree(kobj);
+}
+
+static const struct sysfs_ops ext4_attr_ops = {
+	.show	= ext4_attr_show,
+	.store	= ext4_attr_store,
+};
+
+static struct kobj_type ext4_sb_ktype = {
+	.default_groups = ext4_groups,
+	.sysfs_ops	= &ext4_attr_ops,
+	.release	= ext4_sb_release,
+};
+
+static struct kobj_type ext4_feat_ktype = {
+	.default_groups = ext4_feat_groups,
+	.sysfs_ops	= &ext4_attr_ops,
+	.release	= ext4_feat_release,
+};
+
+void ext4_notify_error_sysfs(struct ext4_sb_info *sbi)
+{
+	sysfs_notify(&sbi->s_kobj, NULL, "errors_count");
+}
+
+static struct kobject *ext4_root;
+
+static struct kobject *ext4_feat;
+
+int ext4_register_sysfs(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	int err;
+
+	init_completion(&sbi->s_kobj_unregister);
+	err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, ext4_root,
+				   "%s", sb->s_id);
+	if (err) {
+		kobject_put(&sbi->s_kobj);
+		wait_for_completion(&sbi->s_kobj_unregister);
+		return err;
+	}
+
+	if (ext4_proc_root)
+		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
+	if (sbi->s_proc) {
+		proc_create_single_data("options", S_IRUGO, sbi->s_proc,
+				ext4_seq_options_show, sb);
+		proc_create_single_data("es_shrinker_info", S_IRUGO,
+				sbi->s_proc, ext4_seq_es_shrinker_info_show,
+				sb);
+		proc_create_single_data("fc_info", 0444, sbi->s_proc,
+					ext4_fc_info_show, sb);
+		proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc,
+				&ext4_mb_seq_groups_ops, sb);
+		proc_create_single_data("mb_stats", 0444, sbi->s_proc,
+				ext4_seq_mb_stats_show, sb);
+		proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
+				&ext4_mb_seq_structs_summary_ops, sb);
+	}
+	return 0;
+}
+
+void ext4_unregister_sysfs(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (sbi->s_proc)
+		remove_proc_subtree(sb->s_id, ext4_proc_root);
+	kobject_del(&sbi->s_kobj);
+}
+
+int __init ext4_init_sysfs(void)
+{
+	int ret;
+
+	ext4_root = kobject_create_and_add("ext4", fs_kobj);
+	if (!ext4_root)
+		return -ENOMEM;
+
+	ext4_feat = kzalloc(sizeof(*ext4_feat), GFP_KERNEL);
+	if (!ext4_feat) {
+		ret = -ENOMEM;
+		goto root_err;
+	}
+
+	ret = kobject_init_and_add(ext4_feat, &ext4_feat_ktype,
+				   ext4_root, "features");
+	if (ret)
+		goto feat_err;
+
+	ext4_proc_root = proc_mkdir(proc_dirname, NULL);
+	return ret;
+
+feat_err:
+	kobject_put(ext4_feat);
+	ext4_feat = NULL;
+root_err:
+	kobject_put(ext4_root);
+	ext4_root = NULL;
+	return ret;
+}
+
+void ext4_exit_sysfs(void)
+{
+	kobject_put(ext4_feat);
+	ext4_feat = NULL;
+	kobject_put(ext4_root);
+	ext4_root = NULL;
+	remove_proc_entry(proc_dirname, NULL);
+	ext4_proc_root = NULL;
+}
+