fs/ext4/super.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/ext4/super.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/fs/minix/inode.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

#include <linux/module.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/parser.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/vfs.h>
#include <linux/random.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#include <linux/ctype.h>
#include <linux/log2.h>
#include <linux/crc16.h>
#include <linux/dax.h>
#include <linux/uaccess.h>
#include <linux/iversion.h>
#include <linux/unicode.h>
#include <linux/part_stat.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/fsnotify.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>

#include "ext4.h"
#include "ext4_extents.h"	/* Needed for trace points definition */
#include "ext4_jbd2.h"
#include "xattr.h"
#include "acl.h"
#include "mballoc.h"
#include "fsmap.h"

#define CREATE_TRACE_POINTS
#include <trace/events/ext4.h>

static struct ext4_lazy_init *ext4_li_info;
static DEFINE_MUTEX(ext4_li_mtx);
static struct ratelimit_state ext4_mount_msg_ratelimit;

static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
			     unsigned long journal_devnum);
static int ext4_show_options(struct seq_file *seq, struct dentry *root);
static void ext4_update_super(struct super_block *sb);
static int ext4_commit_super(struct super_block *sb);
static int ext4_mark_recovery_complete(struct super_block *sb,
					struct ext4_super_block *es);
static int ext4_clear_journal_err(struct super_block *sb,
				  struct ext4_super_block *es);
static int ext4_sync_fs(struct super_block *sb, int wait);
static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
static int ext4_unfreeze(struct super_block *sb);
static int ext4_freeze(struct super_block *sb);
static inline int ext2_feature_set_ok(struct super_block *sb);
static inline int ext3_feature_set_ok(struct super_block *sb);
static void ext4_destroy_lazyinit_thread(void);
static void ext4_unregister_li_request(struct super_block *sb);
static void ext4_clear_request_list(void);
static struct inode *ext4_get_journal_inode(struct super_block *sb,
					    unsigned int journal_inum);
static int ext4_validate_options(struct fs_context *fc);
static int ext4_check_opt_consistency(struct fs_context *fc,
				      struct super_block *sb);
static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
static int ext4_get_tree(struct fs_context *fc);
static int ext4_reconfigure(struct fs_context *fc);
static void ext4_fc_free(struct fs_context *fc);
static int ext4_init_fs_context(struct fs_context *fc);
static void ext4_kill_sb(struct super_block *sb);
static const struct fs_parameter_spec ext4_param_specs[];

/*
 * Lock ordering
 *
 * page fault path:
 * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
 *   -> page lock -> i_data_sem (rw)
 *
 * buffered write path:
 * sb_start_write -> i_mutex -> mmap_lock
 * sb_start_write -> i_mutex -> transaction start -> page lock ->
 *   i_data_sem (rw)
 *
 * truncate:
 * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
 *   page lock
 * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
 *   i_data_sem (rw)
 *
 * direct IO:
 * sb_start_write -> i_mutex -> mmap_lock
 * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
 *
 * writepages:
 * transaction start -> page lock(s) -> i_data_sem (rw)
 */

static const struct fs_context_operations ext4_context_ops = {
	.parse_param	= ext4_parse_param,
	.get_tree	= ext4_get_tree,
	.reconfigure	= ext4_reconfigure,
	.free		= ext4_fc_free,
};


#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
static struct file_system_type ext2_fs_type = {
	.owner			= THIS_MODULE,
	.name			= "ext2",
	.init_fs_context	= ext4_init_fs_context,
	.parameters		= ext4_param_specs,
	.kill_sb		= ext4_kill_sb,
	.fs_flags		= FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("ext2");
MODULE_ALIAS("ext2");
#define IS_EXT2_SB(sb) ((sb)->s_type == &ext2_fs_type)
#else
#define IS_EXT2_SB(sb) (0)
#endif


static struct file_system_type ext3_fs_type = {
	.owner			= THIS_MODULE,
	.name			= "ext3",
	.init_fs_context	= ext4_init_fs_context,
	.parameters		= ext4_param_specs,
	.kill_sb		= ext4_kill_sb,
	.fs_flags		= FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("ext3");
MODULE_ALIAS("ext3");
#define IS_EXT3_SB(sb) ((sb)->s_type == &ext3_fs_type)


static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
				  bh_end_io_t *end_io)
{
	/*
	 * buffer's verified bit is no longer valid after reading from
	 * disk again due to write out error, clear it to make sure we
	 * recheck the buffer contents.
	 */
	clear_buffer_verified(bh);

	bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
	get_bh(bh);
	submit_bh(REQ_OP_READ | op_flags, bh);
}

void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
			 bh_end_io_t *end_io)
{
	BUG_ON(!buffer_locked(bh));

	if (ext4_buffer_uptodate(bh)) {
		unlock_buffer(bh);
		return;
	}
	__ext4_read_bh(bh, op_flags, end_io);
}

int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
{
	BUG_ON(!buffer_locked(bh));

	if (ext4_buffer_uptodate(bh)) {
		unlock_buffer(bh);
		return 0;
	}

	__ext4_read_bh(bh, op_flags, end_io);

	wait_on_buffer(bh);
	if (buffer_uptodate(bh))
		return 0;
	return -EIO;
}

int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
{
	lock_buffer(bh);
	if (!wait) {
		ext4_read_bh_nowait(bh, op_flags, NULL);
		return 0;
	}
	return ext4_read_bh(bh, op_flags, NULL);
}

/*
 * This works like __bread_gfp() except it uses ERR_PTR for error
 * returns.  Currently with sb_bread it's impossible to distinguish
 * between ENOMEM and EIO situations (since both result in a NULL
 * return.
 */
static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
					       sector_t block,
					       blk_opf_t op_flags, gfp_t gfp)
{
	struct buffer_head *bh;
	int ret;

	bh = sb_getblk_gfp(sb, block, gfp);
	if (bh == NULL)
		return ERR_PTR(-ENOMEM);
	if (ext4_buffer_uptodate(bh))
		return bh;

	ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
	if (ret) {
		put_bh(bh);
		return ERR_PTR(ret);
	}
	return bh;
}

struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
				   blk_opf_t op_flags)
{
	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
			~__GFP_FS) | __GFP_MOVABLE;

	return __ext4_sb_bread_gfp(sb, block, op_flags, gfp);
}

struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
					    sector_t block)
{
	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
			~__GFP_FS);

	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
}

void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
{
	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
			sb->s_blocksize, GFP_NOWAIT | __GFP_NOWARN);

	if (likely(bh)) {
		if (trylock_buffer(bh))
			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL);
		brelse(bh);
	}
}

static int ext4_verify_csum_type(struct super_block *sb,
				 struct ext4_super_block *es)
{
	if (!ext4_has_feature_metadata_csum(sb))
		return 1;

	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
}

__le32 ext4_superblock_csum(struct super_block *sb,
			    struct ext4_super_block *es)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	int offset = offsetof(struct ext4_super_block, s_checksum);
	__u32 csum;

	csum = ext4_chksum(sbi, ~0, (char *)es, offset);

	return cpu_to_le32(csum);
}

static int ext4_superblock_csum_verify(struct super_block *sb,
				       struct ext4_super_block *es)
{
	if (!ext4_has_metadata_csum(sb))
		return 1;

	return es->s_checksum == ext4_superblock_csum(sb, es);
}

void ext4_superblock_csum_set(struct super_block *sb)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;

	if (!ext4_has_metadata_csum(sb))
		return;

	es->s_checksum = ext4_superblock_csum(sb, es);
}

ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
			       struct ext4_group_desc *bg)
{
	return le32_to_cpu(bg->bg_block_bitmap_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
}

ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
			       struct ext4_group_desc *bg)
{
	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
}

ext4_fsblk_t ext4_inode_table(struct super_block *sb,
			      struct ext4_group_desc *bg)
{
	return le32_to_cpu(bg->bg_inode_table_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
}

__u32 ext4_free_group_clusters(struct super_block *sb,
			       struct ext4_group_desc *bg)
{
	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
}

__u32 ext4_free_inodes_count(struct super_block *sb,
			      struct ext4_group_desc *bg)
{
	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
}

__u32 ext4_used_dirs_count(struct super_block *sb,
			      struct ext4_group_desc *bg)
{
	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
}

__u32 ext4_itable_unused_count(struct super_block *sb,
			      struct ext4_group_desc *bg)
{
	return le16_to_cpu(bg->bg_itable_unused_lo) |
		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
}

void ext4_block_bitmap_set(struct super_block *sb,
			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
{
	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
}

void ext4_inode_bitmap_set(struct super_block *sb,
			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
{
	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
}

void ext4_inode_table_set(struct super_block *sb,
			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
{
	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
}

void ext4_free_group_clusters_set(struct super_block *sb,
				  struct ext4_group_desc *bg, __u32 count)
{
	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
}

void ext4_free_inodes_set(struct super_block *sb,
			  struct ext4_group_desc *bg, __u32 count)
{
	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
}

void ext4_used_dirs_set(struct super_block *sb,
			  struct ext4_group_desc *bg, __u32 count)
{
	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
}

void ext4_itable_unused_set(struct super_block *sb,
			  struct ext4_group_desc *bg, __u32 count)
{
	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
}

static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
{
	now = clamp_val(now, 0, (1ull << 40) - 1);

	*lo = cpu_to_le32(lower_32_bits(now));
	*hi = upper_32_bits(now);
}

static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
{
	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
}
#define ext4_update_tstamp(es, tstamp) \
	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
			     ktime_get_real_seconds())
#define ext4_get_tstamp(es, tstamp) \
	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)

#define EXT4_SB_REFRESH_INTERVAL_SEC (3600) /* seconds (1 hour) */
#define EXT4_SB_REFRESH_INTERVAL_KB (16384) /* kilobytes (16MB) */

/*
 * The ext4_maybe_update_superblock() function checks and updates the
 * superblock if needed.
 *
 * This function is designed to update the on-disk superblock only under
 * certain conditions to prevent excessive disk writes and unnecessary
 * waking of the disk from sleep. The superblock will be updated if:
 * 1. More than an hour has passed since the last superblock update, and
 * 2. More than 16MB have been written since the last superblock update.
 *
 * @sb: The superblock
 */
static void ext4_maybe_update_superblock(struct super_block *sb)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	journal_t *journal = sbi->s_journal;
	time64_t now;
	__u64 last_update;
	__u64 lifetime_write_kbytes;
	__u64 diff_size;

	if (sb_rdonly(sb) || !(sb->s_flags & SB_ACTIVE) ||
	    !journal || (journal->j_flags & JBD2_UNMOUNT))
		return;

	now = ktime_get_real_seconds();
	last_update = ext4_get_tstamp(es, s_wtime);

	if (likely(now - last_update < EXT4_SB_REFRESH_INTERVAL_SEC))
		return;

	lifetime_write_kbytes = sbi->s_kbytes_written +
		((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
		  sbi->s_sectors_written_start) >> 1);

	/* Get the number of kilobytes not written to disk to account
	 * for statistics and compare with a multiple of 16 MB. This
	 * is used to determine when the next superblock commit should
	 * occur (i.e. not more often than once per 16MB if there was
	 * less written in an hour).
	 */
	diff_size = lifetime_write_kbytes - le64_to_cpu(es->s_kbytes_written);

	if (diff_size > EXT4_SB_REFRESH_INTERVAL_KB)
		schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
}

static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
{
	struct super_block		*sb = journal->j_private;
	struct ext4_sb_info		*sbi = EXT4_SB(sb);
	int				error = is_journal_aborted(journal);
	struct ext4_journal_cb_entry	*jce;

	BUG_ON(txn->t_state == T_FINISHED);

	ext4_process_freed_data(sb, txn->t_tid);
	ext4_maybe_update_superblock(sb);

	spin_lock(&sbi->s_md_lock);
	while (!list_empty(&txn->t_private_list)) {
		jce = list_entry(txn->t_private_list.next,
				 struct ext4_journal_cb_entry, jce_list);
		list_del_init(&jce->jce_list);
		spin_unlock(&sbi->s_md_lock);
		jce->jce_func(sb, jce, error);
		spin_lock(&sbi->s_md_lock);
	}
	spin_unlock(&sbi->s_md_lock);
}

/*
 * This writepage callback for write_cache_pages()
 * takes care of a few cases after page cleaning.
 *
 * write_cache_pages() already checks for dirty pages
 * and calls clear_page_dirty_for_io(), which we want,
 * to write protect the pages.
 *
 * However, we may have to redirty a page (see below.)
 */
static int ext4_journalled_writepage_callback(struct folio *folio,
					      struct writeback_control *wbc,
					      void *data)
{
	transaction_t *transaction = (transaction_t *) data;
	struct buffer_head *bh, *head;
	struct journal_head *jh;

	bh = head = folio_buffers(folio);
	do {
		/*
		 * We have to redirty a page in these cases:
		 * 1) If buffer is dirty, it means the page was dirty because it
		 * contains a buffer that needs checkpointing. So the dirty bit
		 * needs to be preserved so that checkpointing writes the buffer
		 * properly.
		 * 2) If buffer is not part of the committing transaction
		 * (we may have just accidentally come across this buffer because
		 * inode range tracking is not exact) or if the currently running
		 * transaction already contains this buffer as well, dirty bit
		 * needs to be preserved so that the buffer gets writeprotected
		 * properly on running transaction's commit.
		 */
		jh = bh2jh(bh);
		if (buffer_dirty(bh) ||
		    (jh && (jh->b_transaction != transaction ||
			    jh->b_next_transaction))) {
			folio_redirty_for_writepage(wbc, folio);
			goto out;
		}
	} while ((bh = bh->b_this_page) != head);

out:
	return AOP_WRITEPAGE_ACTIVATE;
}

static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
{
	struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
	struct writeback_control wbc = {
		.sync_mode =  WB_SYNC_ALL,
		.nr_to_write = LONG_MAX,
		.range_start = jinode->i_dirty_start,
		.range_end = jinode->i_dirty_end,
        };

	return write_cache_pages(mapping, &wbc,
				 ext4_journalled_writepage_callback,
				 jinode->i_transaction);
}

static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
{
	int ret;

	if (ext4_should_journal_data(jinode->i_vfs_inode))
		ret = ext4_journalled_submit_inode_data_buffers(jinode);
	else
		ret = ext4_normal_submit_inode_data_buffers(jinode);
	return ret;
}

static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
{
	int ret = 0;

	if (!ext4_should_journal_data(jinode->i_vfs_inode))
		ret = jbd2_journal_finish_inode_data_buffers(jinode);

	return ret;
}

static bool system_going_down(void)
{
	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
		|| system_state == SYSTEM_RESTART;
}

struct ext4_err_translation {
	int code;
	int errno;
};

#define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }

static struct ext4_err_translation err_translation[] = {
	EXT4_ERR_TRANSLATE(EIO),
	EXT4_ERR_TRANSLATE(ENOMEM),
	EXT4_ERR_TRANSLATE(EFSBADCRC),
	EXT4_ERR_TRANSLATE(EFSCORRUPTED),
	EXT4_ERR_TRANSLATE(ENOSPC),
	EXT4_ERR_TRANSLATE(ENOKEY),
	EXT4_ERR_TRANSLATE(EROFS),
	EXT4_ERR_TRANSLATE(EFBIG),
	EXT4_ERR_TRANSLATE(EEXIST),
	EXT4_ERR_TRANSLATE(ERANGE),
	EXT4_ERR_TRANSLATE(EOVERFLOW),
	EXT4_ERR_TRANSLATE(EBUSY),
	EXT4_ERR_TRANSLATE(ENOTDIR),
	EXT4_ERR_TRANSLATE(ENOTEMPTY),
	EXT4_ERR_TRANSLATE(ESHUTDOWN),
	EXT4_ERR_TRANSLATE(EFAULT),
};

static int ext4_errno_to_code(int errno)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(err_translation); i++)
		if (err_translation[i].errno == errno)
			return err_translation[i].code;
	return EXT4_ERR_UNKNOWN;
}

static void save_error_info(struct super_block *sb, int error,
			    __u32 ino, __u64 block,
			    const char *func, unsigned int line)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	/* We default to EFSCORRUPTED error... */
	if (error == 0)
		error = EFSCORRUPTED;

	spin_lock(&sbi->s_error_lock);
	sbi->s_add_error_count++;
	sbi->s_last_error_code = error;
	sbi->s_last_error_line = line;
	sbi->s_last_error_ino = ino;
	sbi->s_last_error_block = block;
	sbi->s_last_error_func = func;
	sbi->s_last_error_time = ktime_get_real_seconds();
	if (!sbi->s_first_error_time) {
		sbi->s_first_error_code = error;
		sbi->s_first_error_line = line;
		sbi->s_first_error_ino = ino;
		sbi->s_first_error_block = block;
		sbi->s_first_error_func = func;
		sbi->s_first_error_time = sbi->s_last_error_time;
	}
	spin_unlock(&sbi->s_error_lock);
}

/* Deal with the reporting of failure conditions on a filesystem such as
 * inconsistencies detected or read IO failures.
 *
 * On ext2, we can store the error state of the filesystem in the
 * superblock.  That is not possible on ext4, because we may have other
 * write ordering constraints on the superblock which prevent us from
 * writing it out straight away; and given that the journal is about to
 * be aborted, we can't rely on the current, or future, transactions to
 * write out the superblock safely.
 *
 * We'll just use the jbd2_journal_abort() error code to record an error in
 * the journal instead.  On recovery, the journal will complain about
 * that error until we've noted it down and cleared it.
 *
 * If force_ro is set, we unconditionally force the filesystem into an
 * ABORT|READONLY state, unless the error response on the fs has been set to
 * panic in which case we take the easy way out and panic immediately. This is
 * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
 * at a critical moment in log management.
 */
static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
			      __u32 ino, __u64 block,
			      const char *func, unsigned int line)
{
	journal_t *journal = EXT4_SB(sb)->s_journal;
	bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);

	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
	if (test_opt(sb, WARN_ON_ERROR))
		WARN_ON_ONCE(1);

	if (!continue_fs && !sb_rdonly(sb)) {
		set_bit(EXT4_FLAGS_SHUTDOWN, &EXT4_SB(sb)->s_ext4_flags);
		if (journal)
			jbd2_journal_abort(journal, -EIO);
	}

	if (!bdev_read_only(sb->s_bdev)) {
		save_error_info(sb, error, ino, block, func, line);
		/*
		 * In case the fs should keep running, we need to writeout
		 * superblock through the journal. Due to lock ordering
		 * constraints, it may not be safe to do it right here so we
		 * defer superblock flushing to a workqueue.
		 */
		if (continue_fs && journal)
			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
		else
			ext4_commit_super(sb);
	}

	/*
	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
	 * could panic during 'reboot -f' as the underlying device got already
	 * disabled.
	 */
	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
		panic("EXT4-fs (device %s): panic forced after error\n",
			sb->s_id);
	}

	if (sb_rdonly(sb) || continue_fs)
		return;

	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
	/*
	 * Make sure updated value of ->s_mount_flags will be visible before
	 * ->s_flags update
	 */
	smp_wmb();
	sb->s_flags |= SB_RDONLY;
}

static void update_super_work(struct work_struct *work)
{
	struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
						s_sb_upd_work);
	journal_t *journal = sbi->s_journal;
	handle_t *handle;

	/*
	 * If the journal is still running, we have to write out superblock
	 * through the journal to avoid collisions of other journalled sb
	 * updates.
	 *
	 * We use directly jbd2 functions here to avoid recursing back into
	 * ext4 error handling code during handling of previous errors.
	 */
	if (!sb_rdonly(sbi->s_sb) && journal) {
		struct buffer_head *sbh = sbi->s_sbh;
		bool call_notify_err = false;

		handle = jbd2_journal_start(journal, 1);
		if (IS_ERR(handle))
			goto write_directly;
		if (jbd2_journal_get_write_access(handle, sbh)) {
			jbd2_journal_stop(handle);
			goto write_directly;
		}

		if (sbi->s_add_error_count > 0)
			call_notify_err = true;

		ext4_update_super(sbi->s_sb);
		if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
			ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
				 "superblock detected");
			clear_buffer_write_io_error(sbh);
			set_buffer_uptodate(sbh);
		}

		if (jbd2_journal_dirty_metadata(handle, sbh)) {
			jbd2_journal_stop(handle);
			goto write_directly;
		}
		jbd2_journal_stop(handle);

		if (call_notify_err)
			ext4_notify_error_sysfs(sbi);

		return;
	}
write_directly:
	/*
	 * Write through journal failed. Write sb directly to get error info
	 * out and hope for the best.
	 */
	ext4_commit_super(sbi->s_sb);
	ext4_notify_error_sysfs(sbi);
}

#define ext4_error_ratelimit(sb)					\
		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
			     "EXT4-fs error")

void __ext4_error(struct super_block *sb, const char *function,
		  unsigned int line, bool force_ro, int error, __u64 block,
		  const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	if (unlikely(ext4_forced_shutdown(sb)))
		return;

	trace_ext4_error(sb, function, line);
	if (ext4_error_ratelimit(sb)) {
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		printk(KERN_CRIT
		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
		       sb->s_id, function, line, current->comm, &vaf);
		va_end(args);
	}
	fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);

	ext4_handle_error(sb, force_ro, error, 0, block, function, line);
}

void __ext4_error_inode(struct inode *inode, const char *function,
			unsigned int line, ext4_fsblk_t block, int error,
			const char *fmt, ...)
{
	va_list args;
	struct va_format vaf;

	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
		return;

	trace_ext4_error(inode->i_sb, function, line);
	if (ext4_error_ratelimit(inode->i_sb)) {
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		if (block)
			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
			       "inode #%lu: block %llu: comm %s: %pV\n",
			       inode->i_sb->s_id, function, line, inode->i_ino,
			       block, current->comm, &vaf);
		else
			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
			       "inode #%lu: comm %s: %pV\n",
			       inode->i_sb->s_id, function, line, inode->i_ino,
			       current->comm, &vaf);
		va_end(args);
	}
	fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);

	ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
			  function, line);
}

void __ext4_error_file(struct file *file, const char *function,
		       unsigned int line, ext4_fsblk_t block,
		       const char *fmt, ...)
{
	va_list args;
	struct va_format vaf;
	struct inode *inode = file_inode(file);
	char pathname[80], *path;

	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
		return;

	trace_ext4_error(inode->i_sb, function, line);
	if (ext4_error_ratelimit(inode->i_sb)) {
		path = file_path(file, pathname, sizeof(pathname));
		if (IS_ERR(path))
			path = "(unknown)";
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		if (block)
			printk(KERN_CRIT
			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
			       "block %llu: comm %s: path %s: %pV\n",
			       inode->i_sb->s_id, function, line, inode->i_ino,
			       block, current->comm, path, &vaf);
		else
			printk(KERN_CRIT
			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
			       "comm %s: path %s: %pV\n",
			       inode->i_sb->s_id, function, line, inode->i_ino,
			       current->comm, path, &vaf);
		va_end(args);
	}
	fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);

	ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
			  function, line);
}

const char *ext4_decode_error(struct super_block *sb, int errno,
			      char nbuf[16])
{
	char *errstr = NULL;

	switch (errno) {
	case -EFSCORRUPTED:
		errstr = "Corrupt filesystem";
		break;
	case -EFSBADCRC:
		errstr = "Filesystem failed CRC";
		break;
	case -EIO:
		errstr = "IO failure";
		break;
	case -ENOMEM:
		errstr = "Out of memory";
		break;
	case -EROFS:
		if (!sb || (EXT4_SB(sb)->s_journal &&
			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
			errstr = "Journal has aborted";
		else
			errstr = "Readonly filesystem";
		break;
	default:
		/* If the caller passed in an extra buffer for unknown
		 * errors, textualise them now.  Else we just return
		 * NULL. */
		if (nbuf) {
			/* Check for truncated error codes... */
			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
				errstr = nbuf;
		}
		break;
	}

	return errstr;
}

/* __ext4_std_error decodes expected errors from journaling functions
 * automatically and invokes the appropriate error response.  */

void __ext4_std_error(struct super_block *sb, const char *function,
		      unsigned int line, int errno)
{
	char nbuf[16];
	const char *errstr;

	if (unlikely(ext4_forced_shutdown(sb)))
		return;

	/* Special case: if the error is EROFS, and we're not already
	 * inside a transaction, then there's really no point in logging
	 * an error. */
	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
		return;

	if (ext4_error_ratelimit(sb)) {
		errstr = ext4_decode_error(sb, errno, nbuf);
		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
		       sb->s_id, function, line, errstr);
	}
	fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);

	ext4_handle_error(sb, false, -errno, 0, 0, function, line);
}

void __ext4_msg(struct super_block *sb,
		const char *prefix, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	if (sb) {
		atomic_inc(&EXT4_SB(sb)->s_msg_count);
		if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
				  "EXT4-fs"))
			return;
	}

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	if (sb)
		printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
	else
		printk("%sEXT4-fs: %pV\n", prefix, &vaf);
	va_end(args);
}

static int ext4_warning_ratelimit(struct super_block *sb)
{
	atomic_inc(&EXT4_SB(sb)->s_warning_count);
	return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
			    "EXT4-fs warning");
}

void __ext4_warning(struct super_block *sb, const char *function,
		    unsigned int line, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	if (!ext4_warning_ratelimit(sb))
		return;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
	       sb->s_id, function, line, &vaf);
	va_end(args);
}

void __ext4_warning_inode(const struct inode *inode, const char *function,
			  unsigned int line, const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	if (!ext4_warning_ratelimit(inode->i_sb))
		return;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
	       function, line, inode->i_ino, current->comm, &vaf);
	va_end(args);
}

void __ext4_grp_locked_error(const char *function, unsigned int line,
			     struct super_block *sb, ext4_group_t grp,
			     unsigned long ino, ext4_fsblk_t block,
			     const char *fmt, ...)
__releases(bitlock)
__acquires(bitlock)
{
	struct va_format vaf;
	va_list args;

	if (unlikely(ext4_forced_shutdown(sb)))
		return;

	trace_ext4_error(sb, function, line);
	if (ext4_error_ratelimit(sb)) {
		va_start(args, fmt);
		vaf.fmt = fmt;
		vaf.va = &args;
		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
		       sb->s_id, function, line, grp);
		if (ino)
			printk(KERN_CONT "inode %lu: ", ino);
		if (block)
			printk(KERN_CONT "block %llu:",
			       (unsigned long long) block);
		printk(KERN_CONT "%pV\n", &vaf);
		va_end(args);
	}

	if (test_opt(sb, ERRORS_CONT)) {
		if (test_opt(sb, WARN_ON_ERROR))
			WARN_ON_ONCE(1);
		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
		if (!bdev_read_only(sb->s_bdev)) {
			save_error_info(sb, EFSCORRUPTED, ino, block, function,
					line);
			schedule_work(&EXT4_SB(sb)->s_sb_upd_work);
		}
		return;
	}
	ext4_unlock_group(sb, grp);
	ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
	/*
	 * We only get here in the ERRORS_RO case; relocking the group
	 * may be dangerous, but nothing bad will happen since the
	 * filesystem will have already been marked read/only and the
	 * journal has been aborted.  We return 1 as a hint to callers
	 * who might what to use the return value from
	 * ext4_grp_locked_error() to distinguish between the
	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
	 * aggressively from the ext4 function in question, with a
	 * more appropriate error code.
	 */
	ext4_lock_group(sb, grp);
	return;
}

void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
				     ext4_group_t group,
				     unsigned int flags)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
	int ret;

	if (!grp || !gdp)
		return;
	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
					    &grp->bb_state);
		if (!ret)
			percpu_counter_sub(&sbi->s_freeclusters_counter,
					   grp->bb_free);
	}

	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
					    &grp->bb_state);
		if (!ret && gdp) {
			int count;

			count = ext4_free_inodes_count(sb, gdp);
			percpu_counter_sub(&sbi->s_freeinodes_counter,
					   count);
		}
	}
}

void ext4_update_dynamic_rev(struct super_block *sb)
{
	struct ext4_super_block *es = EXT4_SB(sb)->s_es;

	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
		return;

	ext4_warning(sb,
		     "updating to rev %d because of new feature flag, "
		     "running e2fsck is recommended",
		     EXT4_DYNAMIC_REV);

	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
	/* leave es->s_feature_*compat flags alone */
	/* es->s_uuid will be set by e2fsck if empty */

	/*
	 * The rest of the superblock fields should be zero, and if not it
	 * means they are likely already in use, so leave them alone.  We
	 * can leave it up to e2fsck to clean up any inconsistencies there.
	 */
}

static inline struct inode *orphan_list_entry(struct list_head *l)
{
	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
}

static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
{
	struct list_head *l;

	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
		 le32_to_cpu(sbi->s_es->s_last_orphan));

	printk(KERN_ERR "sb_info orphan list:\n");
	list_for_each(l, &sbi->s_orphan) {
		struct inode *inode = orphan_list_entry(l);
		printk(KERN_ERR "  "
		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
		       inode->i_sb->s_id, inode->i_ino, inode,
		       inode->i_mode, inode->i_nlink,
		       NEXT_ORPHAN(inode));
	}
}

#ifdef CONFIG_QUOTA
static int ext4_quota_off(struct super_block *sb, int type);

static inline void ext4_quotas_off(struct super_block *sb, int type)
{
	BUG_ON(type > EXT4_MAXQUOTAS);

	/* Use our quota_off function to clear inode flags etc. */
	for (type--; type >= 0; type--)
		ext4_quota_off(sb, type);
}

/*
 * This is a helper function which is used in the mount/remount
 * codepaths (which holds s_umount) to fetch the quota file name.
 */
static inline char *get_qf_name(struct super_block *sb,
				struct ext4_sb_info *sbi,
				int type)
{
	return rcu_dereference_protected(sbi->s_qf_names[type],
					 lockdep_is_held(&sb->s_umount));
}
#else
static inline void ext4_quotas_off(struct super_block *sb, int type)
{
}
#endif

static int ext4_percpu_param_init(struct ext4_sb_info *sbi)
{
	ext4_fsblk_t block;
	int err;

	block = ext4_count_free_clusters(sbi->s_sb);
	ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block));
	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
				  GFP_KERNEL);
	if (!err) {
		unsigned long freei = ext4_count_free_inodes(sbi->s_sb);
		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
					  GFP_KERNEL);
	}
	if (!err)
		err = percpu_counter_init(&sbi->s_dirs_counter,
					  ext4_count_dirs(sbi->s_sb), GFP_KERNEL);
	if (!err)
		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
					  GFP_KERNEL);
	if (!err)
		err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
					  GFP_KERNEL);
	if (!err)
		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);

	if (err)
		ext4_msg(sbi->s_sb, KERN_ERR, "insufficient memory");

	return err;
}

static void ext4_percpu_param_destroy(struct ext4_sb_info *sbi)
{
	percpu_counter_destroy(&sbi->s_freeclusters_counter);
	percpu_counter_destroy(&sbi->s_freeinodes_counter);
	percpu_counter_destroy(&sbi->s_dirs_counter);
	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
	percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
	percpu_free_rwsem(&sbi->s_writepages_rwsem);
}

static void ext4_group_desc_free(struct ext4_sb_info *sbi)
{
	struct buffer_head **group_desc;
	int i;

	rcu_read_lock();
	group_desc = rcu_dereference(sbi->s_group_desc);
	for (i = 0; i < sbi->s_gdb_count; i++)
		brelse(group_desc[i]);
	kvfree(group_desc);
	rcu_read_unlock();
}

static void ext4_flex_groups_free(struct ext4_sb_info *sbi)
{
	struct flex_groups **flex_groups;
	int i;

	rcu_read_lock();
	flex_groups = rcu_dereference(sbi->s_flex_groups);
	if (flex_groups) {
		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
			kvfree(flex_groups[i]);
		kvfree(flex_groups);
	}
	rcu_read_unlock();
}

static void ext4_put_super(struct super_block *sb)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	int aborted = 0;
	int err;

	/*
	 * Unregister sysfs before destroying jbd2 journal.
	 * Since we could still access attr_journal_task attribute via sysfs
	 * path which could have sbi->s_journal->j_task as NULL
	 * Unregister sysfs before flush sbi->s_sb_upd_work.
	 * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
	 * read metadata verify failed then will queue error work.
	 * update_super_work will call start_this_handle may trigger
	 * BUG_ON.
	 */
	ext4_unregister_sysfs(sb);

	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
		ext4_msg(sb, KERN_INFO, "unmounting filesystem %pU.",
			 &sb->s_uuid);

	ext4_unregister_li_request(sb);
	ext4_quotas_off(sb, EXT4_MAXQUOTAS);

	flush_work(&sbi->s_sb_upd_work);
	destroy_workqueue(sbi->rsv_conversion_wq);
	ext4_release_orphan_info(sb);

	if (sbi->s_journal) {
		aborted = is_journal_aborted(sbi->s_journal);
		err = jbd2_journal_destroy(sbi->s_journal);
		sbi->s_journal = NULL;
		if ((err < 0) && !aborted) {
			ext4_abort(sb, -err, "Couldn't clean up the journal");
		}
	}

	ext4_es_unregister_shrinker(sbi);
	timer_shutdown_sync(&sbi->s_err_report);
	ext4_release_system_zone(sb);
	ext4_mb_release(sb);
	ext4_ext_release(sb);

	if (!sb_rdonly(sb) && !aborted) {
		ext4_clear_feature_journal_needs_recovery(sb);
		ext4_clear_feature_orphan_present(sb);
		es->s_state = cpu_to_le16(sbi->s_mount_state);
	}
	if (!sb_rdonly(sb))
		ext4_commit_super(sb);

	ext4_group_desc_free(sbi);
	ext4_flex_groups_free(sbi);

	WARN_ON_ONCE(!(sbi->s_mount_state & EXT4_ERROR_FS) &&
		     percpu_counter_sum(&sbi->s_dirtyclusters_counter));
	ext4_percpu_param_destroy(sbi);
#ifdef CONFIG_QUOTA
	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
		kfree(get_qf_name(sb, sbi, i));
#endif

	/* Debugging code just in case the in-memory inode orphan list
	 * isn't empty.  The on-disk one can be non-empty if we've
	 * detected an error and taken the fs readonly, but the
	 * in-memory list had better be clean by this point. */
	if (!list_empty(&sbi->s_orphan))
		dump_orphan_list(sb, sbi);
	ASSERT(list_empty(&sbi->s_orphan));

	sync_blockdev(sb->s_bdev);
	invalidate_bdev(sb->s_bdev);
	if (sbi->s_journal_bdev_file) {
		/*
		 * Invalidate the journal device's buffers.  We don't want them
		 * floating about in memory - the physical journal device may
		 * hotswapped, and it breaks the `ro-after' testing code.
		 */
		sync_blockdev(file_bdev(sbi->s_journal_bdev_file));
		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
	}

	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
	sbi->s_ea_inode_cache = NULL;

	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
	sbi->s_ea_block_cache = NULL;

	ext4_stop_mmpd(sbi);

	brelse(sbi->s_sbh);
	sb->s_fs_info = NULL;
	/*
	 * Now that we are completely done shutting down the
	 * superblock, we need to actually destroy the kobject.
	 */
	kobject_put(&sbi->s_kobj);
	wait_for_completion(&sbi->s_kobj_unregister);
	if (sbi->s_chksum_driver)
		crypto_free_shash(sbi->s_chksum_driver);
	kfree(sbi->s_blockgroup_lock);
	fs_put_dax(sbi->s_daxdev, NULL);
	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
#if IS_ENABLED(CONFIG_UNICODE)
	utf8_unload(sb->s_encoding);
#endif
	kfree(sbi);
}

static struct kmem_cache *ext4_inode_cachep;

/*
 * Called inside transaction, so use GFP_NOFS
 */
static struct inode *ext4_alloc_inode(struct super_block *sb)
{
	struct ext4_inode_info *ei;

	ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
	if (!ei)
		return NULL;

	inode_set_iversion(&ei->vfs_inode, 1);
	ei->i_flags = 0;
	spin_lock_init(&ei->i_raw_lock);
	ei->i_prealloc_node = RB_ROOT;
	atomic_set(&ei->i_prealloc_active, 0);
	rwlock_init(&ei->i_prealloc_lock);
	ext4_es_init_tree(&ei->i_es_tree);
	rwlock_init(&ei->i_es_lock);
	INIT_LIST_HEAD(&ei->i_es_list);
	ei->i_es_all_nr = 0;
	ei->i_es_shk_nr = 0;
	ei->i_es_shrink_lblk = 0;
	ei->i_reserved_data_blocks = 0;
	spin_lock_init(&(ei->i_block_reservation_lock));
	ext4_init_pending_tree(&ei->i_pending_tree);
#ifdef CONFIG_QUOTA
	ei->i_reserved_quota = 0;
	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
#endif
	ei->jinode = NULL;
	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
	spin_lock_init(&ei->i_completed_io_lock);
	ei->i_sync_tid = 0;
	ei->i_datasync_tid = 0;
	atomic_set(&ei->i_unwritten, 0);
	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
	ext4_fc_init_inode(&ei->vfs_inode);
	mutex_init(&ei->i_fc_lock);
	return &ei->vfs_inode;
}

static int ext4_drop_inode(struct inode *inode)
{
	int drop = generic_drop_inode(inode);

	if (!drop)
		drop = fscrypt_drop_inode(inode);

	trace_ext4_drop_inode(inode, drop);
	return drop;
}

static void ext4_free_in_core_inode(struct inode *inode)
{
	fscrypt_free_inode(inode);
	if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
		pr_warn("%s: inode %ld still in fc list",
			__func__, inode->i_ino);
	}
	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
}

static void ext4_destroy_inode(struct inode *inode)
{
	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
		ext4_msg(inode->i_sb, KERN_ERR,
			 "Inode %lu (%p): orphan list check failed!",
			 inode->i_ino, EXT4_I(inode));
		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
				EXT4_I(inode), sizeof(struct ext4_inode_info),
				true);
		dump_stack();
	}

	if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
	    WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
		ext4_msg(inode->i_sb, KERN_ERR,
			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
			 inode->i_ino, EXT4_I(inode),
			 EXT4_I(inode)->i_reserved_data_blocks);
}

static void ext4_shutdown(struct super_block *sb)
{
       ext4_force_shutdown(sb, EXT4_GOING_FLAGS_NOLOGFLUSH);
}

static void init_once(void *foo)
{
	struct ext4_inode_info *ei = foo;

	INIT_LIST_HEAD(&ei->i_orphan);
	init_rwsem(&ei->xattr_sem);
	init_rwsem(&ei->i_data_sem);
	inode_init_once(&ei->vfs_inode);
	ext4_fc_init_inode(&ei->vfs_inode);
}

static int __init init_inodecache(void)
{
	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
				sizeof(struct ext4_inode_info), 0,
				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
				offsetof(struct ext4_inode_info, i_data),
				sizeof_field(struct ext4_inode_info, i_data),
				init_once);
	if (ext4_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	kmem_cache_destroy(ext4_inode_cachep);
}

void ext4_clear_inode(struct inode *inode)
{
	ext4_fc_del(inode);
	invalidate_inode_buffers(inode);
	clear_inode(inode);
	ext4_discard_preallocations(inode);
	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
	dquot_drop(inode);
	if (EXT4_I(inode)->jinode) {
		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
					       EXT4_I(inode)->jinode);
		jbd2_free_inode(EXT4_I(inode)->jinode);
		EXT4_I(inode)->jinode = NULL;
	}
	fscrypt_put_encryption_info(inode);
	fsverity_cleanup_inode(inode);
}

static struct inode *ext4_nfs_get_inode(struct super_block *sb,
					u64 ino, u32 generation)
{
	struct inode *inode;

	/*
	 * Currently we don't know the generation for parent directory, so
	 * a generation of 0 means "accept any"
	 */
	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
	if (IS_ERR(inode))
		return ERR_CAST(inode);
	if (generation && inode->i_generation != generation) {
		iput(inode);
		return ERR_PTR(-ESTALE);
	}

	return inode;
}

static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
					int fh_len, int fh_type)
{
	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
				    ext4_nfs_get_inode);
}

static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
					int fh_len, int fh_type)
{
	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
				    ext4_nfs_get_inode);
}

static int ext4_nfs_commit_metadata(struct inode *inode)
{
	struct writeback_control wbc = {
		.sync_mode = WB_SYNC_ALL
	};

	trace_ext4_nfs_commit_metadata(inode);
	return ext4_write_inode(inode, &wbc);
}

#ifdef CONFIG_QUOTA
static const char * const quotatypes[] = INITQFNAMES;
#define QTYPE2NAME(t) (quotatypes[t])

static int ext4_write_dquot(struct dquot *dquot);
static int ext4_acquire_dquot(struct dquot *dquot);
static int ext4_release_dquot(struct dquot *dquot);
static int ext4_mark_dquot_dirty(struct dquot *dquot);
static int ext4_write_info(struct super_block *sb, int type);
static int ext4_quota_on(struct super_block *sb, int type, int format_id,
			 const struct path *path);
static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
			       size_t len, loff_t off);
static ssize_t ext4_quota_write(struct super_block *sb, int type,
				const char *data, size_t len, loff_t off);
static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
			     unsigned int flags);

static struct dquot __rcu **ext4_get_dquots(struct inode *inode)
{
	return EXT4_I(inode)->i_dquot;
}

static const struct dquot_operations ext4_quota_operations = {
	.get_reserved_space	= ext4_get_reserved_space,
	.write_dquot		= ext4_write_dquot,
	.acquire_dquot		= ext4_acquire_dquot,
	.release_dquot		= ext4_release_dquot,
	.mark_dirty		= ext4_mark_dquot_dirty,
	.write_info		= ext4_write_info,
	.alloc_dquot		= dquot_alloc,
	.destroy_dquot		= dquot_destroy,
	.get_projid		= ext4_get_projid,
	.get_inode_usage	= ext4_get_inode_usage,
	.get_next_id		= dquot_get_next_id,
};

static const struct quotactl_ops ext4_qctl_operations = {
	.quota_on	= ext4_quota_on,
	.quota_off	= ext4_quota_off,
	.quota_sync	= dquot_quota_sync,
	.get_state	= dquot_get_state,
	.set_info	= dquot_set_dqinfo,
	.get_dqblk	= dquot_get_dqblk,
	.set_dqblk	= dquot_set_dqblk,
	.get_nextdqblk	= dquot_get_next_dqblk,
};
#endif

static const struct super_operations ext4_sops = {
	.alloc_inode	= ext4_alloc_inode,
	.free_inode	= ext4_free_in_core_inode,
	.destroy_inode	= ext4_destroy_inode,
	.write_inode	= ext4_write_inode,
	.dirty_inode	= ext4_dirty_inode,
	.drop_inode	= ext4_drop_inode,
	.evict_inode	= ext4_evict_inode,
	.put_super	= ext4_put_super,
	.sync_fs	= ext4_sync_fs,
	.freeze_fs	= ext4_freeze,
	.unfreeze_fs	= ext4_unfreeze,
	.statfs		= ext4_statfs,
	.show_options	= ext4_show_options,
	.shutdown	= ext4_shutdown,
#ifdef CONFIG_QUOTA
	.quota_read	= ext4_quota_read,
	.quota_write	= ext4_quota_write,
	.get_dquots	= ext4_get_dquots,
#endif
};

static const struct export_operations ext4_export_ops = {
	.encode_fh = generic_encode_ino32_fh,
	.fh_to_dentry = ext4_fh_to_dentry,
	.fh_to_parent = ext4_fh_to_parent,
	.get_parent = ext4_get_parent,
	.commit_metadata = ext4_nfs_commit_metadata,
};

enum {
	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
	Opt_resgid, Opt_resuid, Opt_sb,
	Opt_nouid32, Opt_debug, Opt_removed,
	Opt_user_xattr, Opt_acl,
	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
	Opt_inlinecrypt,
	Opt_usrjquota, Opt_grpjquota, Opt_quota,
	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
	Opt_usrquota, Opt_grpquota, Opt_prjquota,
	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
	Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
	Opt_inode_readahead_blks, Opt_journal_ioprio,
	Opt_dioread_nolock, Opt_dioread_lock,
	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
	Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
	Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
#ifdef CONFIG_EXT4_DEBUG
	Opt_fc_debug_max_replay, Opt_fc_debug_force
#endif
};

static const struct constant_table ext4_param_errors[] = {
	{"continue",	EXT4_MOUNT_ERRORS_CONT},
	{"panic",	EXT4_MOUNT_ERRORS_PANIC},
	{"remount-ro",	EXT4_MOUNT_ERRORS_RO},
	{}
};

static const struct constant_table ext4_param_data[] = {
	{"journal",	EXT4_MOUNT_JOURNAL_DATA},
	{"ordered",	EXT4_MOUNT_ORDERED_DATA},
	{"writeback",	EXT4_MOUNT_WRITEBACK_DATA},
	{}
};

static const struct constant_table ext4_param_data_err[] = {
	{"abort",	Opt_data_err_abort},
	{"ignore",	Opt_data_err_ignore},
	{}
};

static const struct constant_table ext4_param_jqfmt[] = {
	{"vfsold",	QFMT_VFS_OLD},
	{"vfsv0",	QFMT_VFS_V0},
	{"vfsv1",	QFMT_VFS_V1},
	{}
};

static const struct constant_table ext4_param_dax[] = {
	{"always",	Opt_dax_always},
	{"inode",	Opt_dax_inode},
	{"never",	Opt_dax_never},
	{}
};

/*
 * Mount option specification
 * We don't use fsparam_flag_no because of the way we set the
 * options and the way we show them in _ext4_show_options(). To
 * keep the changes to a minimum, let's keep the negative options
 * separate for now.
 */
static const struct fs_parameter_spec ext4_param_specs[] = {
	fsparam_flag	("bsddf",		Opt_bsd_df),
	fsparam_flag	("minixdf",		Opt_minix_df),
	fsparam_flag	("grpid",		Opt_grpid),
	fsparam_flag	("bsdgroups",		Opt_grpid),
	fsparam_flag	("nogrpid",		Opt_nogrpid),
	fsparam_flag	("sysvgroups",		Opt_nogrpid),
	fsparam_gid	("resgid",		Opt_resgid),
	fsparam_uid	("resuid",		Opt_resuid),
	fsparam_u32	("sb",			Opt_sb),
	fsparam_enum	("errors",		Opt_errors, ext4_param_errors),
	fsparam_flag	("nouid32",		Opt_nouid32),
	fsparam_flag	("debug",		Opt_debug),
	fsparam_flag	("oldalloc",		Opt_removed),
	fsparam_flag	("orlov",		Opt_removed),
	fsparam_flag	("user_xattr",		Opt_user_xattr),
	fsparam_flag	("acl",			Opt_acl),
	fsparam_flag	("norecovery",		Opt_noload),
	fsparam_flag	("noload",		Opt_noload),
	fsparam_flag	("bh",			Opt_removed),
	fsparam_flag	("nobh",		Opt_removed),
	fsparam_u32	("commit",		Opt_commit),
	fsparam_u32	("min_batch_time",	Opt_min_batch_time),
	fsparam_u32	("max_batch_time",	Opt_max_batch_time),
	fsparam_u32	("journal_dev",		Opt_journal_dev),
	fsparam_bdev	("journal_path",	Opt_journal_path),
	fsparam_flag	("journal_checksum",	Opt_journal_checksum),
	fsparam_flag	("nojournal_checksum",	Opt_nojournal_checksum),
	fsparam_flag	("journal_async_commit",Opt_journal_async_commit),
	fsparam_flag	("abort",		Opt_abort),
	fsparam_enum	("data",		Opt_data, ext4_param_data),
	fsparam_enum	("data_err",		Opt_data_err,
						ext4_param_data_err),
	fsparam_string_empty
			("usrjquota",		Opt_usrjquota),
	fsparam_string_empty
			("grpjquota",		Opt_grpjquota),
	fsparam_enum	("jqfmt",		Opt_jqfmt, ext4_param_jqfmt),
	fsparam_flag	("grpquota",		Opt_grpquota),
	fsparam_flag	("quota",		Opt_quota),
	fsparam_flag	("noquota",		Opt_noquota),
	fsparam_flag	("usrquota",		Opt_usrquota),
	fsparam_flag	("prjquota",		Opt_prjquota),
	fsparam_flag	("barrier",		Opt_barrier),
	fsparam_u32	("barrier",		Opt_barrier),
	fsparam_flag	("nobarrier",		Opt_nobarrier),
	fsparam_flag	("i_version",		Opt_removed),
	fsparam_flag	("dax",			Opt_dax),
	fsparam_enum	("dax",			Opt_dax_type, ext4_param_dax),
	fsparam_u32	("stripe",		Opt_stripe),
	fsparam_flag	("delalloc",		Opt_delalloc),
	fsparam_flag	("nodelalloc",		Opt_nodelalloc),
	fsparam_flag	("warn_on_error",	Opt_warn_on_error),
	fsparam_flag	("nowarn_on_error",	Opt_nowarn_on_error),
	fsparam_u32	("debug_want_extra_isize",
						Opt_debug_want_extra_isize),
	fsparam_flag	("mblk_io_submit",	Opt_removed),
	fsparam_flag	("nomblk_io_submit",	Opt_removed),
	fsparam_flag	("block_validity",	Opt_block_validity),
	fsparam_flag	("noblock_validity",	Opt_noblock_validity),
	fsparam_u32	("inode_readahead_blks",
						Opt_inode_readahead_blks),
	fsparam_u32	("journal_ioprio",	Opt_journal_ioprio),
	fsparam_u32	("auto_da_alloc",	Opt_auto_da_alloc),
	fsparam_flag	("auto_da_alloc",	Opt_auto_da_alloc),
	fsparam_flag	("noauto_da_alloc",	Opt_noauto_da_alloc),
	fsparam_flag	("dioread_nolock",	Opt_dioread_nolock),
	fsparam_flag	("nodioread_nolock",	Opt_dioread_lock),
	fsparam_flag	("dioread_lock",	Opt_dioread_lock),
	fsparam_flag	("discard",		Opt_discard),
	fsparam_flag	("nodiscard",		Opt_nodiscard),
	fsparam_u32	("init_itable",		Opt_init_itable),
	fsparam_flag	("init_itable",		Opt_init_itable),
	fsparam_flag	("noinit_itable",	Opt_noinit_itable),
#ifdef CONFIG_EXT4_DEBUG
	fsparam_flag	("fc_debug_force",	Opt_fc_debug_force),
	fsparam_u32	("fc_debug_max_replay",	Opt_fc_debug_max_replay),
#endif
	fsparam_u32	("max_dir_size_kb",	Opt_max_dir_size_kb),
	fsparam_flag	("test_dummy_encryption",
						Opt_test_dummy_encryption),
	fsparam_string	("test_dummy_encryption",
						Opt_test_dummy_encryption),
	fsparam_flag	("inlinecrypt",		Opt_inlinecrypt),
	fsparam_flag	("nombcache",		Opt_nombcache),
	fsparam_flag	("no_mbcache",		Opt_nombcache),	/* for backward compatibility */
	fsparam_flag	("prefetch_block_bitmaps",
						Opt_removed),
	fsparam_flag	("no_prefetch_block_bitmaps",
						Opt_no_prefetch_block_bitmaps),
	fsparam_s32	("mb_optimize_scan",	Opt_mb_optimize_scan),
	fsparam_string	("check",		Opt_removed),	/* mount option from ext2/3 */
	fsparam_flag	("nocheck",		Opt_removed),	/* mount option from ext2/3 */
	fsparam_flag	("reservation",		Opt_removed),	/* mount option from ext2/3 */
	fsparam_flag	("noreservation",	Opt_removed),	/* mount option from ext2/3 */
	fsparam_u32	("journal",		Opt_removed),	/* mount option from ext2/3 */
	{}
};

#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))

#define MOPT_SET	0x0001
#define MOPT_CLEAR	0x0002
#define MOPT_NOSUPPORT	0x0004
#define MOPT_EXPLICIT	0x0008
#ifdef CONFIG_QUOTA
#define MOPT_Q		0
#define MOPT_QFMT	0x0010
#else
#define MOPT_Q		MOPT_NOSUPPORT
#define MOPT_QFMT	MOPT_NOSUPPORT
#endif
#define MOPT_NO_EXT2	0x0020
#define MOPT_NO_EXT3	0x0040
#define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
#define MOPT_SKIP	0x0080
#define	MOPT_2		0x0100

static const struct mount_opts {
	int	token;
	int	mount_opt;
	int	flags;
} ext4_mount_opts[] = {
	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
	 MOPT_EXT4_ONLY | MOPT_SET},
	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
	 MOPT_EXT4_ONLY | MOPT_CLEAR},
	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
	 MOPT_EXT4_ONLY | MOPT_CLEAR},
	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
	{Opt_commit, 0, MOPT_NO_EXT2},
	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
	 MOPT_EXT4_ONLY | MOPT_CLEAR},
	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
				    EXT4_MOUNT_JOURNAL_CHECKSUM),
	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
	{Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
	{Opt_dax_type, 0, MOPT_EXT4_ONLY},
	{Opt_journal_dev, 0, MOPT_NO_EXT2},
	{Opt_journal_path, 0, MOPT_NO_EXT2},
	{Opt_journal_ioprio, 0, MOPT_NO_EXT2},
	{Opt_data, 0, MOPT_NO_EXT2},
	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
#ifdef CONFIG_EXT4_FS_POSIX_ACL
	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
#else
	{Opt_acl, 0, MOPT_NOSUPPORT},
#endif
	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
							MOPT_SET | MOPT_Q},
	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
							MOPT_SET | MOPT_Q},
	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
							MOPT_SET | MOPT_Q},
	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
							MOPT_CLEAR | MOPT_Q},
	{Opt_usrjquota, 0, MOPT_Q},
	{Opt_grpjquota, 0, MOPT_Q},
	{Opt_jqfmt, 0, MOPT_QFMT},
	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
	{Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
	 MOPT_SET},
#ifdef CONFIG_EXT4_DEBUG
	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
#endif
	{Opt_abort, EXT4_MOUNT2_ABORT, MOPT_SET | MOPT_2},
	{Opt_err, 0, 0}
};

#if IS_ENABLED(CONFIG_UNICODE)
static const struct ext4_sb_encodings {
	__u16 magic;
	char *name;
	unsigned int version;
} ext4_sb_encoding_map[] = {
	{EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
};

static const struct ext4_sb_encodings *
ext4_sb_read_encoding(const struct ext4_super_block *es)
{
	__u16 magic = le16_to_cpu(es->s_encoding);
	int i;

	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
		if (magic == ext4_sb_encoding_map[i].magic)
			return &ext4_sb_encoding_map[i];

	return NULL;
}
#endif

#define EXT4_SPEC_JQUOTA			(1 <<  0)
#define EXT4_SPEC_JQFMT				(1 <<  1)
#define EXT4_SPEC_DATAJ				(1 <<  2)
#define EXT4_SPEC_SB_BLOCK			(1 <<  3)
#define EXT4_SPEC_JOURNAL_DEV			(1 <<  4)
#define EXT4_SPEC_JOURNAL_IOPRIO		(1 <<  5)
#define EXT4_SPEC_s_want_extra_isize		(1 <<  7)
#define EXT4_SPEC_s_max_batch_time		(1 <<  8)
#define EXT4_SPEC_s_min_batch_time		(1 <<  9)
#define EXT4_SPEC_s_inode_readahead_blks	(1 << 10)
#define EXT4_SPEC_s_li_wait_mult		(1 << 11)
#define EXT4_SPEC_s_max_dir_size_kb		(1 << 12)
#define EXT4_SPEC_s_stripe			(1 << 13)
#define EXT4_SPEC_s_resuid			(1 << 14)
#define EXT4_SPEC_s_resgid			(1 << 15)
#define EXT4_SPEC_s_commit_interval		(1 << 16)
#define EXT4_SPEC_s_fc_debug_max_replay		(1 << 17)
#define EXT4_SPEC_s_sb_block			(1 << 18)
#define EXT4_SPEC_mb_optimize_scan		(1 << 19)

struct ext4_fs_context {
	char		*s_qf_names[EXT4_MAXQUOTAS];
	struct fscrypt_dummy_policy dummy_enc_policy;
	int		s_jquota_fmt;	/* Format of quota to use */
#ifdef CONFIG_EXT4_DEBUG
	int s_fc_debug_max_replay;
#endif
	unsigned short	qname_spec;
	unsigned long	vals_s_flags;	/* Bits to set in s_flags */
	unsigned long	mask_s_flags;	/* Bits changed in s_flags */
	unsigned long	journal_devnum;
	unsigned long	s_commit_interval;
	unsigned long	s_stripe;
	unsigned int	s_inode_readahead_blks;
	unsigned int	s_want_extra_isize;
	unsigned int	s_li_wait_mult;
	unsigned int	s_max_dir_size_kb;
	unsigned int	journal_ioprio;
	unsigned int	vals_s_mount_opt;
	unsigned int	mask_s_mount_opt;
	unsigned int	vals_s_mount_opt2;
	unsigned int	mask_s_mount_opt2;
	unsigned int	opt_flags;	/* MOPT flags */
	unsigned int	spec;
	u32		s_max_batch_time;
	u32		s_min_batch_time;
	kuid_t		s_resuid;
	kgid_t		s_resgid;
	ext4_fsblk_t	s_sb_block;
};

static void ext4_fc_free(struct fs_context *fc)
{
	struct ext4_fs_context *ctx = fc->fs_private;
	int i;

	if (!ctx)
		return;

	for (i = 0; i < EXT4_MAXQUOTAS; i++)
		kfree(ctx->s_qf_names[i]);

	fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
	kfree(ctx);
}

int ext4_init_fs_context(struct fs_context *fc)
{
	struct ext4_fs_context *ctx;

	ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	fc->fs_private = ctx;
	fc->ops = &ext4_context_ops;

	return 0;
}

#ifdef CONFIG_QUOTA
/*
 * Note the name of the specified quota file.
 */
static int note_qf_name(struct fs_context *fc, int qtype,
		       struct fs_parameter *param)
{
	struct ext4_fs_context *ctx = fc->fs_private;
	char *qname;

	if (param->size < 1) {
		ext4_msg(NULL, KERN_ERR, "Missing quota name");
		return -EINVAL;
	}
	if (strchr(param->string, '/')) {
		ext4_msg(NULL, KERN_ERR,
			 "quotafile must be on filesystem root");
		return -EINVAL;
	}
	if (ctx->s_qf_names[qtype]) {
		if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
			ext4_msg(NULL, KERN_ERR,
				 "%s quota file already specified",
				 QTYPE2NAME(qtype));
			return -EINVAL;
		}
		return 0;
	}

	qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
	if (!qname) {
		ext4_msg(NULL, KERN_ERR,
			 "Not enough memory for storing quotafile name");
		return -ENOMEM;
	}
	ctx->s_qf_names[qtype] = qname;
	ctx->qname_spec |= 1 << qtype;
	ctx->spec |= EXT4_SPEC_JQUOTA;
	return 0;
}

/*
 * Clear the name of the specified quota file.
 */
static int unnote_qf_name(struct fs_context *fc, int qtype)
{
	struct ext4_fs_context *ctx = fc->fs_private;

	kfree(ctx->s_qf_names[qtype]);

	ctx->s_qf_names[qtype] = NULL;
	ctx->qname_spec |= 1 << qtype;
	ctx->spec |= EXT4_SPEC_JQUOTA;
	return 0;
}
#endif

static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
					    struct ext4_fs_context *ctx)
{
	int err;

	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
		ext4_msg(NULL, KERN_WARNING,
			 "test_dummy_encryption option not supported");
		return -EINVAL;
	}
	err = fscrypt_parse_test_dummy_encryption(param,
						  &ctx->dummy_enc_policy);
	if (err == -EINVAL) {
		ext4_msg(NULL, KERN_WARNING,
			 "Value of option \"%s\" is unrecognized", param->key);
	} else if (err == -EEXIST) {
		ext4_msg(NULL, KERN_WARNING,
			 "Conflicting test_dummy_encryption options");
		return -EINVAL;
	}
	return err;
}

#define EXT4_SET_CTX(name)						\
static inline void ctx_set_##name(struct ext4_fs_context *ctx,		\
				  unsigned long flag)			\
{									\
	ctx->mask_s_##name |= flag;					\
	ctx->vals_s_##name |= flag;					\
}

#define EXT4_CLEAR_CTX(name)						\
static inline void ctx_clear_##name(struct ext4_fs_context *ctx,	\
				    unsigned long flag)			\
{									\
	ctx->mask_s_##name |= flag;					\
	ctx->vals_s_##name &= ~flag;					\
}

#define EXT4_TEST_CTX(name)						\
static inline unsigned long						\
ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
{									\
	return (ctx->vals_s_##name & flag);				\
}

EXT4_SET_CTX(flags); /* set only */
EXT4_SET_CTX(mount_opt);
EXT4_CLEAR_CTX(mount_opt);
EXT4_TEST_CTX(mount_opt);
EXT4_SET_CTX(mount_opt2);
EXT4_CLEAR_CTX(mount_opt2);
EXT4_TEST_CTX(mount_opt2);

static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
	struct ext4_fs_context *ctx = fc->fs_private;
	struct fs_parse_result result;
	const struct mount_opts *m;
	int is_remount;
	int token;

	token = fs_parse(fc, ext4_param_specs, param, &result);
	if (token < 0)
		return token;
	is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;

	for (m = ext4_mount_opts; m->token != Opt_err; m++)
		if (token == m->token)
			break;

	ctx->opt_flags |= m->flags;

	if (m->flags & MOPT_EXPLICIT) {
		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
			ctx_set_mount_opt2(ctx,
				       EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
		} else
			return -EINVAL;
	}

	if (m->flags & MOPT_NOSUPPORT) {
		ext4_msg(NULL, KERN_ERR, "%s option not supported",
			 param->key);
		return 0;
	}

	switch (token) {
#ifdef CONFIG_QUOTA
	case Opt_usrjquota:
		if (!*param->string)
			return unnote_qf_name(fc, USRQUOTA);
		else
			return note_qf_name(fc, USRQUOTA, param);
	case Opt_grpjquota:
		if (!*param->string)
			return unnote_qf_name(fc, GRPQUOTA);
		else
			return note_qf_name(fc, GRPQUOTA, param);
#endif
	case Opt_sb:
		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
			ext4_msg(NULL, KERN_WARNING,
				 "Ignoring %s option on remount", param->key);
		} else {
			ctx->s_sb_block = result.uint_32;
			ctx->spec |= EXT4_SPEC_s_sb_block;
		}
		return 0;
	case Opt_removed:
		ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
			 param->key);
		return 0;
	case Opt_inlinecrypt:
#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
		ctx_set_flags(ctx, SB_INLINECRYPT);
#else
		ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
#endif
		return 0;
	case Opt_errors:
		ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
		ctx_set_mount_opt(ctx, result.uint_32);
		return 0;
#ifdef CONFIG_QUOTA
	case Opt_jqfmt:
		ctx->s_jquota_fmt = result.uint_32;
		ctx->spec |= EXT4_SPEC_JQFMT;
		return 0;
#endif
	case Opt_data:
		ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
		ctx_set_mount_opt(ctx, result.uint_32);
		ctx->spec |= EXT4_SPEC_DATAJ;
		return 0;
	case Opt_commit:
		if (result.uint_32 == 0)
			result.uint_32 = JBD2_DEFAULT_MAX_COMMIT_AGE;
		else if (result.uint_32 > INT_MAX / HZ) {
			ext4_msg(NULL, KERN_ERR,
				 "Invalid commit interval %d, "
				 "must be smaller than %d",
				 result.uint_32, INT_MAX / HZ);
			return -EINVAL;
		}
		ctx->s_commit_interval = HZ * result.uint_32;
		ctx->spec |= EXT4_SPEC_s_commit_interval;
		return 0;
	case Opt_debug_want_extra_isize:
		if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
			ext4_msg(NULL, KERN_ERR,
				 "Invalid want_extra_isize %d", result.uint_32);
			return -EINVAL;
		}
		ctx->s_want_extra_isize = result.uint_32;
		ctx->spec |= EXT4_SPEC_s_want_extra_isize;
		return 0;
	case Opt_max_batch_time:
		ctx->s_max_batch_time = result.uint_32;
		ctx->spec |= EXT4_SPEC_s_max_batch_time;
		return 0;
	case Opt_min_batch_time:
		ctx->s_min_batch_time = result.uint_32;
		ctx->spec |= EXT4_SPEC_s_min_batch_time;
		return 0;
	case Opt_inode_readahead_blks:
		if (result.uint_32 &&
		    (result.uint_32 > (1 << 30) ||
		     !is_power_of_2(result.uint_32))) {
			ext4_msg(NULL, KERN_ERR,
				 "EXT4-fs: inode_readahead_blks must be "
				 "0 or a power of 2 smaller than 2^31");
			return -EINVAL;
		}
		ctx->s_inode_readahead_blks = result.uint_32;
		ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
		return 0;
	case Opt_init_itable:
		ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
		ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
		if (param->type == fs_value_is_string)
			ctx->s_li_wait_mult = result.uint_32;
		ctx->spec |= EXT4_SPEC_s_li_wait_mult;
		return 0;
	case Opt_max_dir_size_kb:
		ctx->s_max_dir_size_kb = result.uint_32;
		ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
		return 0;
#ifdef CONFIG_EXT4_DEBUG
	case Opt_fc_debug_max_replay:
		ctx->s_fc_debug_max_replay = result.uint_32;
		ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
		return 0;
#endif
	case Opt_stripe:
		ctx->s_stripe = result.uint_32;
		ctx->spec |= EXT4_SPEC_s_stripe;
		return 0;
	case Opt_resuid:
		ctx->s_resuid = result.uid;
		ctx->spec |= EXT4_SPEC_s_resuid;
		return 0;
	case Opt_resgid:
		ctx->s_resgid = result.gid;
		ctx->spec |= EXT4_SPEC_s_resgid;
		return 0;
	case Opt_journal_dev:
		if (is_remount) {
			ext4_msg(NULL, KERN_ERR,
				 "Cannot specify journal on remount");
			return -EINVAL;
		}
		ctx->journal_devnum = result.uint_32;
		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
		return 0;
	case Opt_journal_path:
	{
		struct inode *journal_inode;
		struct path path;
		int error;

		if (is_remount) {
			ext4_msg(NULL, KERN_ERR,
				 "Cannot specify journal on remount");
			return -EINVAL;
		}

		error = fs_lookup_param(fc, param, 1, LOOKUP_FOLLOW, &path);
		if (error) {
			ext4_msg(NULL, KERN_ERR, "error: could not find "
				 "journal device path");
			return -EINVAL;
		}

		journal_inode = d_inode(path.dentry);
		ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
		ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
		path_put(&path);
		return 0;
	}
	case Opt_journal_ioprio:
		if (result.uint_32 > 7) {
			ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
				 " (must be 0-7)");
			return -EINVAL;
		}
		ctx->journal_ioprio =
			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
		ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
		return 0;
	case Opt_test_dummy_encryption:
		return ext4_parse_test_dummy_encryption(param, ctx);
	case Opt_dax:
	case Opt_dax_type:
#ifdef CONFIG_FS_DAX
	{
		int type = (token == Opt_dax) ?
			   Opt_dax : result.uint_32;

		switch (type) {
		case Opt_dax:
		case Opt_dax_always:
			ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
			break;
		case Opt_dax_never:
			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
			break;
		case Opt_dax_inode:
			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
			/* Strictly for printing options */
			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
			break;
		}
		return 0;
	}
#else
		ext4_msg(NULL, KERN_INFO, "dax option not supported");
		return -EINVAL;
#endif
	case Opt_data_err:
		if (result.uint_32 == Opt_data_err_abort)
			ctx_set_mount_opt(ctx, m->mount_opt);
		else if (result.uint_32 == Opt_data_err_ignore)
			ctx_clear_mount_opt(ctx, m->mount_opt);
		return 0;
	case Opt_mb_optimize_scan:
		if (result.int_32 == 1) {
			ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
		} else if (result.int_32 == 0) {
			ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
			ctx->spec |= EXT4_SPEC_mb_optimize_scan;
		} else {
			ext4_msg(NULL, KERN_WARNING,
				 "mb_optimize_scan should be set to 0 or 1.");
			return -EINVAL;
		}
		return 0;
	}

	/*
	 * At this point we should only be getting options requiring MOPT_SET,
	 * or MOPT_CLEAR. Anything else is a bug
	 */
	if (m->token == Opt_err) {
		ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
			 param->key);
		WARN_ON(1);
		return -EINVAL;
	}

	else {
		unsigned int set = 0;

		if ((param->type == fs_value_is_flag) ||
		    result.uint_32 > 0)
			set = 1;

		if (m->flags & MOPT_CLEAR)
			set = !set;
		else if (unlikely(!(m->flags & MOPT_SET))) {
			ext4_msg(NULL, KERN_WARNING,
				 "buggy handling of option %s",
				 param->key);
			WARN_ON(1);
			return -EINVAL;
		}
		if (m->flags & MOPT_2) {
			if (set != 0)
				ctx_set_mount_opt2(ctx, m->mount_opt);
			else
				ctx_clear_mount_opt2(ctx, m->mount_opt);
		} else {
			if (set != 0)
				ctx_set_mount_opt(ctx, m->mount_opt);
			else
				ctx_clear_mount_opt(ctx, m->mount_opt);
		}
	}

	return 0;
}

static int parse_options(struct fs_context *fc, char *options)
{
	struct fs_parameter param;
	int ret;
	char *key;

	if (!options)
		return 0;

	while ((key = strsep(&options, ",")) != NULL) {
		if (*key) {
			size_t v_len = 0;
			char *value = strchr(key, '=');

			param.type = fs_value_is_flag;
			param.string = NULL;

			if (value) {
				if (value == key)
					continue;

				*value++ = 0;
				v_len = strlen(value);
				param.string = kmemdup_nul(value, v_len,
							   GFP_KERNEL);
				if (!param.string)
					return -ENOMEM;
				param.type = fs_value_is_string;
			}

			param.key = key;
			param.size = v_len;

			ret = ext4_parse_param(fc, &param);
			kfree(param.string);
			if (ret < 0)
				return ret;
		}
	}

	ret = ext4_validate_options(fc);
	if (ret < 0)
		return ret;

	return 0;
}

static int parse_apply_sb_mount_options(struct super_block *sb,
					struct ext4_fs_context *m_ctx)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	char *s_mount_opts = NULL;
	struct ext4_fs_context *s_ctx = NULL;
	struct fs_context *fc = NULL;
	int ret = -ENOMEM;

	if (!sbi->s_es->s_mount_opts[0])
		return 0;

	s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
				sizeof(sbi->s_es->s_mount_opts),
				GFP_KERNEL);
	if (!s_mount_opts)
		return ret;

	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
	if (!fc)
		goto out_free;

	s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
	if (!s_ctx)
		goto out_free;

	fc->fs_private = s_ctx;
	fc->s_fs_info = sbi;

	ret = parse_options(fc, s_mount_opts);
	if (ret < 0)
		goto parse_failed;

	ret = ext4_check_opt_consistency(fc, sb);
	if (ret < 0) {
parse_failed:
		ext4_msg(sb, KERN_WARNING,
			 "failed to parse options in superblock: %s",
			 s_mount_opts);
		ret = 0;
		goto out_free;
	}

	if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
		m_ctx->journal_devnum = s_ctx->journal_devnum;
	if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
		m_ctx->journal_ioprio = s_ctx->journal_ioprio;

	ext4_apply_options(fc, sb);
	ret = 0;

out_free:
	if (fc) {
		ext4_fc_free(fc);
		kfree(fc);
	}
	kfree(s_mount_opts);
	return ret;
}

static void ext4_apply_quota_options(struct fs_context *fc,
				     struct super_block *sb)
{
#ifdef CONFIG_QUOTA
	bool quota_feature = ext4_has_feature_quota(sb);
	struct ext4_fs_context *ctx = fc->fs_private;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	char *qname;
	int i;

	if (quota_feature)
		return;

	if (ctx->spec & EXT4_SPEC_JQUOTA) {
		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
			if (!(ctx->qname_spec & (1 << i)))
				continue;

			qname = ctx->s_qf_names[i]; /* May be NULL */
			if (qname)
				set_opt(sb, QUOTA);
			ctx->s_qf_names[i] = NULL;
			qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
						lockdep_is_held(&sb->s_umount));
			if (qname)
				kfree_rcu_mightsleep(qname);
		}
	}

	if (ctx->spec & EXT4_SPEC_JQFMT)
		sbi->s_jquota_fmt = ctx->s_jquota_fmt;
#endif
}

/*
 * Check quota settings consistency.
 */
static int ext4_check_quota_consistency(struct fs_context *fc,
					struct super_block *sb)
{
#ifdef CONFIG_QUOTA
	struct ext4_fs_context *ctx = fc->fs_private;
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	bool quota_feature = ext4_has_feature_quota(sb);
	bool quota_loaded = sb_any_quota_loaded(sb);
	bool usr_qf_name, grp_qf_name, usrquota, grpquota;
	int quota_flags, i;

	/*
	 * We do the test below only for project quotas. 'usrquota' and
	 * 'grpquota' mount options are allowed even without quota feature
	 * to support legacy quotas in quota files.
	 */
	if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
	    !ext4_has_feature_project(sb)) {
		ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
			 "Cannot enable project quota enforcement.");
		return -EINVAL;
	}

	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
	if (quota_loaded &&
	    ctx->mask_s_mount_opt & quota_flags &&
	    !ctx_test_mount_opt(ctx, quota_flags))
		goto err_quota_change;

	if (ctx->spec & EXT4_SPEC_JQUOTA) {

		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
			if (!(ctx->qname_spec & (1 << i)))
				continue;

			if (quota_loaded &&
			    !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
				goto err_jquota_change;

			if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
			    strcmp(get_qf_name(sb, sbi, i),
				   ctx->s_qf_names[i]) != 0)
				goto err_jquota_specified;
		}

		if (quota_feature) {
			ext4_msg(NULL, KERN_INFO,
				 "Journaled quota options ignored when "
				 "QUOTA feature is enabled");
			return 0;
		}
	}

	if (ctx->spec & EXT4_SPEC_JQFMT) {
		if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
			goto err_jquota_change;
		if (quota_feature) {
			ext4_msg(NULL, KERN_INFO, "Quota format mount options "
				 "ignored when QUOTA feature is enabled");
			return 0;
		}
	}

	/* Make sure we don't mix old and new quota format */
	usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
		       ctx->s_qf_names[USRQUOTA]);
	grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
		       ctx->s_qf_names[GRPQUOTA]);

	usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
		    test_opt(sb, USRQUOTA));

	grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
		    test_opt(sb, GRPQUOTA));

	if (usr_qf_name) {
		ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
		usrquota = false;
	}
	if (grp_qf_name) {
		ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
		grpquota = false;
	}

	if (usr_qf_name || grp_qf_name) {
		if (usrquota || grpquota) {
			ext4_msg(NULL, KERN_ERR, "old and new quota "
				 "format mixing");
			return -EINVAL;
		}

		if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
			ext4_msg(NULL, KERN_ERR, "journaled quota format "
				 "not specified");
			return -EINVAL;
		}
	}

	return 0;

err_quota_change:
	ext4_msg(NULL, KERN_ERR,
		 "Cannot change quota options when quota turned on");
	return -EINVAL;
err_jquota_change:
	ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
		 "options when quota turned on");
	return -EINVAL;
err_jquota_specified:
	ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
		 QTYPE2NAME(i));
	return -EINVAL;
#else
	return 0;
#endif
}

static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
					    struct super_block *sb)
{
	const struct ext4_fs_context *ctx = fc->fs_private;
	const struct ext4_sb_info *sbi = EXT4_SB(sb);

	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
		return 0;

	if (!ext4_has_feature_encrypt(sb)) {
		ext4_msg(NULL, KERN_WARNING,
			 "test_dummy_encryption requires encrypt feature");
		return -EINVAL;
	}
	/*
	 * This mount option is just for testing, and it's not worthwhile to
	 * implement the extra complexity (e.g. RCU protection) that would be
	 * needed to allow it to be set or changed during remount.  We do allow
	 * it to be specified during remount, but only if there is no change.
	 */
	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
						 &ctx->dummy_enc_policy))
			return 0;
		ext4_msg(NULL, KERN_WARNING,
			 "Can't set or change test_dummy_encryption on remount");
		return -EINVAL;
	}
	/* Also make sure s_mount_opts didn't contain a conflicting value. */
	if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
		if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
						 &ctx->dummy_enc_policy))
			return 0;
		ext4_msg(NULL, KERN_WARNING,
			 "Conflicting test_dummy_encryption options");
		return -EINVAL;
	}
	return 0;
}

static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
					     struct super_block *sb)
{
	if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
	    /* if already set, it was already verified to be the same */
	    fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
		return;
	EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
	memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
	ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
}

static int ext4_check_opt_consistency(struct fs_context *fc,
				      struct super_block *sb)
{
	struct ext4_fs_context *ctx = fc->fs_private;
	struct ext4_sb_info *sbi = fc->s_fs_info;
	int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
	int err;

	if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
		ext4_msg(NULL, KERN_ERR,
			 "Mount option(s) incompatible with ext2");
		return -EINVAL;
	}
	if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
		ext4_msg(NULL, KERN_ERR,
			 "Mount option(s) incompatible with ext3");
		return -EINVAL;
	}

	if (ctx->s_want_extra_isize >
	    (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
		ext4_msg(NULL, KERN_ERR,
			 "Invalid want_extra_isize %d",
			 ctx->s_want_extra_isize);
		return -EINVAL;
	}

	err = ext4_check_test_dummy_encryption(fc, sb);
	if (err)
		return err;

	if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
		if (!sbi->s_journal) {
			ext4_msg(NULL, KERN_WARNING,
				 "Remounting file system with no journal "
				 "so ignoring journalled data option");
			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
		} else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
			   test_opt(sb, DATA_FLAGS)) {
			ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
				 "on remount");
			return -EINVAL;
		}
	}

	if (is_remount) {
		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
		    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
			ext4_msg(NULL, KERN_ERR, "can't mount with "
				 "both data=journal and dax");
			return -EINVAL;
		}

		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
		    (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
		     (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
fail_dax_change_remount:
			ext4_msg(NULL, KERN_ERR, "can't change "
				 "dax mount option while remounting");
			return -EINVAL;
		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
			 (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
			  (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
			goto fail_dax_change_remount;
		} else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
			   ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
			    (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
			    !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
			goto fail_dax_change_remount;
		}
	}

	return ext4_check_quota_consistency(fc, sb);
}

static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
{
	struct ext4_fs_context *ctx = fc->fs_private;
	struct ext4_sb_info *sbi = fc->s_fs_info;

	sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
	sbi->s_mount_opt |= ctx->vals_s_mount_opt;
	sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
	sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
	sb->s_flags &= ~ctx->mask_s_flags;
	sb->s_flags |= ctx->vals_s_flags;

#define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
	APPLY(s_commit_interval);
	APPLY(s_stripe);
	APPLY(s_max_batch_time);
	APPLY(s_min_batch_time);
	APPLY(s_want_extra_isize);
	APPLY(s_inode_readahead_blks);
	APPLY(s_max_dir_size_kb);
	APPLY(s_li_wait_mult);
	APPLY(s_resgid);
	APPLY(s_resuid);

#ifdef CONFIG_EXT4_DEBUG
	APPLY(s_fc_debug_max_replay);
#endif

	ext4_apply_quota_options(fc, sb);
	ext4_apply_test_dummy_encryption(ctx, sb);
}


static int ext4_validate_options(struct fs_context *fc)
{
#ifdef CONFIG_QUOTA
	struct ext4_fs_context *ctx = fc->fs_private;
	char *usr_qf_name, *grp_qf_name;

	usr_qf_name = ctx->s_qf_names[USRQUOTA];
	grp_qf_name = ctx->s_qf_names[GRPQUOTA];

	if (usr_qf_name || grp_qf_name) {
		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
			ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);

		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
			ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);

		if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
		    ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
			ext4_msg(NULL, KERN_ERR, "old and new quota "
				 "format mixing");
			return -EINVAL;
		}
	}
#endif
	return 1;
}

static inline void ext4_show_quota_options(struct seq_file *seq,
					   struct super_block *sb)
{
#if defined(CONFIG_QUOTA)
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	char *usr_qf_name, *grp_qf_name;

	if (sbi->s_jquota_fmt) {
		char *fmtname = "";

		switch (sbi->s_jquota_fmt) {
		case QFMT_VFS_OLD:
			fmtname = "vfsold";
			break;
		case QFMT_VFS_V0:
			fmtname = "vfsv0";
			break;
		case QFMT_VFS_V1:
			fmtname = "vfsv1";
			break;
		}
		seq_printf(seq, ",jqfmt=%s", fmtname);
	}

	rcu_read_lock();
	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
	if (usr_qf_name)
		seq_show_option(seq, "usrjquota", usr_qf_name);
	if (grp_qf_name)
		seq_show_option(seq, "grpjquota", grp_qf_name);
	rcu_read_unlock();
#endif
}

static const char *token2str(int token)
{
	const struct fs_parameter_spec *spec;

	for (spec = ext4_param_specs; spec->name != NULL; spec++)
		if (spec->opt == token && !spec->type)
			break;
	return spec->name;
}

/*
 * Show an option if
 *  - it's set to a non-default value OR
 *  - if the per-sb default is different from the global default
 */
static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
			      int nodefs)
{
	struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;
	int def_errors;
	const struct mount_opts *m;
	char sep = nodefs ? '\n' : ',';

#define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)

	if (sbi->s_sb_block != 1)
		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);

	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
		int want_set = m->flags & MOPT_SET;
		int opt_2 = m->flags & MOPT_2;
		unsigned int mount_opt, def_mount_opt;

		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
		    m->flags & MOPT_SKIP)
			continue;

		if (opt_2) {
			mount_opt = sbi->s_mount_opt2;
			def_mount_opt = sbi->s_def_mount_opt2;
		} else {
			mount_opt = sbi->s_mount_opt;
			def_mount_opt = sbi->s_def_mount_opt;
		}
		/* skip if same as the default */
		if (!nodefs && !(m->mount_opt & (mount_opt ^ def_mount_opt)))
			continue;
		/* select Opt_noFoo vs Opt_Foo */
		if ((want_set &&
		     (mount_opt & m->mount_opt) != m->mount_opt) ||
		    (!want_set && (mount_opt & m->mount_opt)))
			continue;
		SEQ_OPTS_PRINT("%s", token2str(m->token));
	}

	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
		SEQ_OPTS_PRINT("resuid=%u",
				from_kuid_munged(&init_user_ns, sbi->s_resuid));
	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
		SEQ_OPTS_PRINT("resgid=%u",
				from_kgid_munged(&init_user_ns, sbi->s_resgid));
	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
		SEQ_OPTS_PUTS("errors=remount-ro");
	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
		SEQ_OPTS_PUTS("errors=continue");
	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
		SEQ_OPTS_PUTS("errors=panic");
	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
	if (nodefs || sbi->s_stripe)
		SEQ_OPTS_PRINT("stripe=%lu", sbi