[Concept] [PATCH 05/17] ext4l: bring in super.c

16 Dec 2025

From: Simon Glass <simon.glass@canonical.com>

Copy super.c from Linux v6.18 fs/ext4 directory. This file implements
superblock operations including mount, unmount, and filesystem options.

Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com>
---

 fs/ext4l/super.c | 7516 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 7516 insertions(+)
 create mode 100644 fs/ext4l/super.c

diff --git a/fs/ext4l/super.c b/fs/ext4l/super.c
new file mode 100644
index 00000000000..33e7c08c952
--- /dev/null
+++ b/fs/ext4l/super.c
@@ -0,0 +1,7516 @@
+// 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_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, bool simu_fail)
+{
+	if (simu_fail) {
+		clear_buffer_uptodate(bh);
+		unlock_buffer(bh);
+		return;
+	}
+
+	/*
+	 * 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, bool simu_fail)
+{
+	BUG_ON(!buffer_locked(bh));
+
+	if (ext4_buffer_uptodate(bh)) {
+		unlock_buffer(bh);
+		return;
+	}
+	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
+}
+
+int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
+		 bh_end_io_t *end_io, bool simu_fail)
+{
+	BUG_ON(!buffer_locked(bh));
+
+	if (ext4_buffer_uptodate(bh)) {
+		unlock_buffer(bh);
+		return 0;
+	}
+
+	__ext4_read_bh(bh, op_flags, end_io, simu_fail);
+
+	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, false);
+		return 0;
+	}
+	return ext4_read_bh(bh, op_flags, NULL, false);
+}
+
+/*
+ * 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);
+}
+
+struct buffer_head *ext4_sb_bread_nofail(struct super_block *sb,
+					 sector_t block)
+{
+	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_mapping,
+			~__GFP_FS) | __GFP_MOVABLE | __GFP_NOFAIL;
+
+	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);
+
+	if (likely(bh)) {
+		if (trylock_buffer(bh))
+			ext4_read_bh_nowait(bh, REQ_RAHEAD, NULL, false);
+		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 ext4_super_block *es)
+{
+	int offset = offsetof(struct ext4_super_block, s_checksum);
+	__u32 csum;
+
+	csum = ext4_chksum(~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_feature_metadata_csum(sb))
+		return 1;
+
+	return es->s_checksum == ext4_superblock_csum(es);
+}
+
+void ext4_superblock_csum_set(struct super_block *sb)
+{
+	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
+
+	if (!ext4_has_feature_metadata_csum(sb))
+		return;
+
+	es->s_checksum = ext4_superblock_csum(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(READ_ONCE(bg->bg_free_inodes_count_lo)) |
+		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
+		 (__u32)le16_to_cpu(READ_ONCE(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)
+{
+	WRITE_ONCE(bg->bg_free_inodes_count_lo, cpu_to_le16((__u16)count));
+	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
+		WRITE_ONCE(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)
+
+/*
+ * 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 sbi->s_sb_update_sec (def: 1 hour) has passed since the last
+ *    superblock update
+ * 2. More than sbi->s_sb_update_kb (def: 16MB) kbs 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 (ext4_emergency_state(sb) || 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 < sbi->s_sb_update_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 > sbi->s_sb_update_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;
+
+	BUG_ON(txn->t_state == T_FINISHED);
+
+	ext4_process_freed_data(sb, txn->t_tid);
+	ext4_maybe_update_superblock(sb);
+}
+
+static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode,
+		struct folio *folio)
+{
+	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 != jinode->i_transaction ||
+			    jh->b_next_transaction)))
+			return true;
+	} while ((bh = bh->b_this_page) != head);
+
+	return false;
+}
+
+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,
+        };
+	struct folio *folio = NULL;
+	int error;
+
+	/*
+	 * writeback_iter() already checks for dirty pages and calls
+	 * folio_clear_dirty_for_io(), which we want to write protect the
+	 * folios.
+	 *
+	 * However, we may have to redirty a folio sometimes.
+	 */
+	while ((folio = writeback_iter(mapping, &wbc, folio, &error))) {
+		if (ext4_journalled_writepage_needs_redirty(jinode, folio))
+			folio_redirty_for_writepage(&wbc, folio);
+		folio_unlock(folio);
+	}
+
+	return error;
+}
+
+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 && !ext4_emergency_ro(sb) && 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. We just need to be
+		 * careful when the journal is already shutting down. If we get
+		 * here in that case, just update the sb directly as the last
+		 * transaction won't commit anyway.
+		 */
+		if (continue_fs && journal &&
+		    !ext4_test_mount_flag(sb, EXT4_MF_JOURNAL_DESTROY))
+			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 (ext4_emergency_ro(sb) || continue_fs)
+		return;
+
+	ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
+	/*
+	 * We don't set SB_RDONLY because that requires sb->s_umount
+	 * semaphore and setting it without proper remount procedure is
+	 * confusing code such as freeze_super() leading to deadlocks
+	 * and other problems.
+	 */
+	set_bit(EXT4_FLAGS_EMERGENCY_RO, &EXT4_SB(sb)->s_ext4_flags);
+}
+
+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 (!ext4_emergency_state(sbi->s_sb) &&
+	    !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_emergency_state(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_emergency_state(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_emergency_state(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_emergency_state(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_emergency_state(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);
+
+	destroy_workqueue(sbi->rsv_conversion_wq);
+	ext4_release_orphan_info(sb);
+
+	if (sbi->s_journal) {
+		aborted = is_journal_aborted(sbi->s_journal);
+		err = ext4_journal_destroy(sbi, sbi->s_journal);
+		if ((err < 0) && !aborted) {
+			ext4_abort(sb, -err, "Couldn't clean up the journal");
+		}
+	} else
+		flush_work(&sbi->s_sb_upd_work);
+
+	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 (!ext4_emergency_state(sb) && !sb_rdonly(sb)) {
+		if (!aborted) {
+			ext4_clear_feature_journal_needs_recovery(sb);
+			ext4_clear_feature_orphan_present(sb);
+			es->s_state = cpu_to_le16(sbi->s_mount_state);
+		}
+		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);
+	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;
+	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
+	ext4_fc_init_inode(&ei->vfs_inode);
+	spin_lock_init(&ei->i_fc_lock);
+	return &ei->vfs_inode;
+}
+
+static int ext4_drop_inode(struct inode *inode)
+{
+	int drop = inode_generic_drop(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 (ext4_inode_orphan_tracked(inode)) {
+		ext4_msg(inode->i_sb, KERN_ERR,
+			 "Inode %lu (%p): inode tracked as orphan!",
+			 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);
+#ifdef CONFIG_FS_ENCRYPTION
+	ei->i_crypt_info = NULL;
+#endif
+#ifdef CONFIG_FS_VERITY
+	ei->i_verity_info = NULL;
+#endif
+}
+
+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 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;
+
+	/* i_version is always enabled now */
+	fc->sb_flags |= SB_I_VERSION;
+
+	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 __maybe_unused						\
+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 __maybe_unused						\
+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, ¶m);
+			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[65];
+	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;
+
+	strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts);
+
+	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
+	if (!fc)
+		return -ENOMEM;
+
+	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:
+	ext4_fc_free(fc);
+	kfree(fc);
+	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 (!sbi->s_journal &&
+		    ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT)) {
+			ext4_msg(NULL, KERN_WARNING,
+				 "Remounting fs w/o journal so ignoring data_err option");
+			ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_ERR_ABORT);
+		}
+
+		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)) ||
+	    ext4_get_resuid(es) != 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)) ||
+	    ext4_get_resgid(es) != 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 && sb->s_flags & SB_I_VERSION)
+		SEQ_OPTS_PUTS("i_version");
+	if (nodefs || sbi->s_stripe)
+		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
+	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
+			(sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
+		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
+			SEQ_OPTS_PUTS("data=journal");
+		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
+			SEQ_OPTS_PUTS("data=ordered");
+		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
+			SEQ_OPTS_PUTS("data=writeback");
+	}
+	if (nodefs ||
+	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
+		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
+			       sbi->s_inode_readahead_blks);
+
+	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
+		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
+		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
+	if (nodefs || sbi->s_max_dir_size_kb)
+		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
+	if (test_opt(sb, DATA_ERR_ABORT))
+		SEQ_OPTS_PUTS("data_err=abort");
+
+	fscrypt_show_test_dummy_encryption(seq, sep, sb);
+
+	if (sb->s_flags & SB_INLINECRYPT)
+		SEQ_OPTS_PUTS("inlinecrypt");
+
+	if (test_opt(sb, DAX_ALWAYS)) {
+		if (IS_EXT2_SB(sb))
+			SEQ_OPTS_PUTS("dax");
+		else
+			SEQ_OPTS_PUTS("dax=always");
+	} else if (test_opt2(sb, DAX_NEVER)) {
+		SEQ_OPTS_PUTS("dax=never");
+	} else if (test_opt2(sb, DAX_INODE)) {
+		SEQ_OPTS_PUTS("dax=inode");
+	}
+
+	if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
+			!test_opt2(sb, MB_OPTIMIZE_SCAN)) {
+		SEQ_OPTS_PUTS("mb_optimize_scan=0");
+	} else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
+			test_opt2(sb, MB_OPTIMIZE_SCAN)) {
+		SEQ_OPTS_PUTS("mb_optimize_scan=1");
+	}
+
+	if (nodefs && !test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS))
+		SEQ_OPTS_PUTS("prefetch_block_bitmaps");
+
+	if (ext4_emergency_ro(sb))
+		SEQ_OPTS_PUTS("emergency_ro");
+
+	if (ext4_forced_shutdown(sb))
+		SEQ_OPTS_PUTS("shutdown");
+
+	ext4_show_quota_options(seq, sb);
+	return 0;
+}
+
+static int ext4_show_options(struct seq_file *seq, struct dentry *root)
+{
+	return _ext4_show_options(seq, root->d_sb, 0);
+}
+
+int ext4_seq_options_show(struct seq_file *seq, void *offset)
+{
+	struct super_block *sb = seq->private;
+	int rc;
+
+	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
+	rc = _ext4_show_options(seq, sb, 1);
+	seq_putc(seq, '\n');
+	return rc;
+}
+
+static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
+			    int read_only)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	int err = 0;
+
+	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
+		ext4_msg(sb, KERN_ERR, "revision level too high, "
+			 "forcing read-only mode");
+		err = -EROFS;
+		goto done;
+	}
+	if (read_only)
+		goto done;
+	if (!(sbi->s_mount_state & EXT4_VALID_FS))
+		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
+			 "running e2fsck is recommended");
+	else if (sbi->s_mount_state & EXT4_ERROR_FS)
+		ext4_msg(sb, KERN_WARNING,
+			 "warning: mounting fs with errors, "
+			 "running e2fsck is recommended");
+	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
+		 le16_to_cpu(es->s_mnt_count) >=
+		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
+		ext4_msg(sb, KERN_WARNING,
+			 "warning: maximal mount count reached, "
+			 "running e2fsck is recommended");
+	else if (le32_to_cpu(es->s_checkinterval) &&
+		 (ext4_get_tstamp(es, s_lastcheck) +
+		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
+		ext4_msg(sb, KERN_WARNING,
+			 "warning: checktime reached, "
+			 "running e2fsck is recommended");
+	if (!sbi->s_journal)
+		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
+	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
+		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
+	le16_add_cpu(&es->s_mnt_count, 1);
+	ext4_update_tstamp(es, s_mtime);
+	if (sbi->s_journal) {
+		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
+	}
+
+	err = ext4_commit_super(sb);
+done:
+	if (test_opt(sb, DEBUG))
+		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
+				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
+			sb->s_blocksize,
+			sbi->s_groups_count,
+			EXT4_BLOCKS_PER_GROUP(sb),
+			EXT4_INODES_PER_GROUP(sb),
+			sbi->s_mount_opt, sbi->s_mount_opt2);
+	return err;
+}
+
+int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct flex_groups **old_groups, **new_groups;
+	int size, i, j;
+
+	if (!sbi->s_log_groups_per_flex)
+		return 0;
+
+	size = ext4_flex_group(sbi, ngroup - 1) + 1;
+	if (size <= sbi->s_flex_groups_allocated)
+		return 0;
+
+	new_groups = kvzalloc(roundup_pow_of_two(size *
+			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
+	if (!new_groups) {
+		ext4_msg(sb, KERN_ERR,
+			 "not enough memory for %d flex group pointers", size);
+		return -ENOMEM;
+	}
+	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
+		new_groups[i] = kvzalloc(roundup_pow_of_two(
+					 sizeof(struct flex_groups)),
+					 GFP_KERNEL);
+		if (!new_groups[i]) {
+			for (j = sbi->s_flex_groups_allocated; j < i; j++)
+				kvfree(new_groups[j]);
+			kvfree(new_groups);
+			ext4_msg(sb, KERN_ERR,
+				 "not enough memory for %d flex groups", size);
+			return -ENOMEM;
+		}
+	}
+	rcu_read_lock();
+	old_groups = rcu_dereference(sbi->s_flex_groups);
+	if (old_groups)
+		memcpy(new_groups, old_groups,
+		       (sbi->s_flex_groups_allocated *
+			sizeof(struct flex_groups *)));
+	rcu_read_unlock();
+	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
+	sbi->s_flex_groups_allocated = size;
+	if (old_groups)
+		ext4_kvfree_array_rcu(old_groups);
+	return 0;
+}
+
+static int ext4_fill_flex_info(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_group_desc *gdp = NULL;
+	struct flex_groups *fg;
+	ext4_group_t flex_group;
+	int i, err;
+
+	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
+	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
+		sbi->s_log_groups_per_flex = 0;
+		return 1;
+	}
+
+	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
+	if (err)
+		goto failed;
+
+	for (i = 0; i < sbi->s_groups_count; i++) {
+		gdp = ext4_get_group_desc(sb, i, NULL);
+
+		flex_group = ext4_flex_group(sbi, i);
+		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
+		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
+		atomic64_add(ext4_free_group_clusters(sb, gdp),
+			     &fg->free_clusters);
+		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
+	}
+
+	return 1;
+failed:
+	return 0;
+}
+
+static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
+				   struct ext4_group_desc *gdp)
+{
+	int offset = offsetof(struct ext4_group_desc, bg_checksum);
+	__u16 crc = 0;
+	__le32 le_group = cpu_to_le32(block_group);
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (ext4_has_feature_metadata_csum(sbi->s_sb)) {
+		/* Use new metadata_csum algorithm */
+		__u32 csum32;
+		__u16 dummy_csum = 0;
+
+		csum32 = ext4_chksum(sbi->s_csum_seed, (__u8 *)&le_group,
+				     sizeof(le_group));
+		csum32 = ext4_chksum(csum32, (__u8 *)gdp, offset);
+		csum32 = ext4_chksum(csum32, (__u8 *)&dummy_csum,
+				     sizeof(dummy_csum));
+		offset += sizeof(dummy_csum);
+		if (offset < sbi->s_desc_size)
+			csum32 = ext4_chksum(csum32, (__u8 *)gdp + offset,
+					     sbi->s_desc_size - offset);
+
+		crc = csum32 & 0xFFFF;
+		goto out;
+	}
+
+	/* old crc16 code */
+	if (!ext4_has_feature_gdt_csum(sb))
+		return 0;
+
+	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
+	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
+	crc = crc16(crc, (__u8 *)gdp, offset);
+	offset += sizeof(gdp->bg_checksum); /* skip checksum */
+	/* for checksum of struct ext4_group_desc do the rest...*/
+	if (ext4_has_feature_64bit(sb) && offset < sbi->s_desc_size)
+		crc = crc16(crc, (__u8 *)gdp + offset,
+			    sbi->s_desc_size - offset);
+
+out:
+	return cpu_to_le16(crc);
+}
+
+int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
+				struct ext4_group_desc *gdp)
+{
+	if (ext4_has_group_desc_csum(sb) &&
+	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
+		return 0;
+
+	return 1;
+}
+
+void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
+			      struct ext4_group_desc *gdp)
+{
+	if (!ext4_has_group_desc_csum(sb))
+		return;
+	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
+}
+
+/* Called at mount-time, super-block is locked */
+static int ext4_check_descriptors(struct super_block *sb,
+				  ext4_fsblk_t sb_block,
+				  ext4_group_t *first_not_zeroed)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
+	ext4_fsblk_t last_block;
+	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
+	ext4_fsblk_t block_bitmap;
+	ext4_fsblk_t inode_bitmap;
+	ext4_fsblk_t inode_table;
+	int flexbg_flag = 0;
+	ext4_group_t i, grp = sbi->s_groups_count;
+
+	if (ext4_has_feature_flex_bg(sb))
+		flexbg_flag = 1;
+
+	ext4_debug("Checking group descriptors");
+
+	for (i = 0; i < sbi->s_groups_count; i++) {
+		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
+
+		if (i == sbi->s_groups_count - 1 || flexbg_flag)
+			last_block = ext4_blocks_count(sbi->s_es) - 1;
+		else
+			last_block = first_block +
+				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
+
+		if ((grp == sbi->s_groups_count) &&
+		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
+			grp = i;
+
+		block_bitmap = ext4_block_bitmap(sb, gdp);
+		if (block_bitmap == sb_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Block bitmap for group %u overlaps "
+				 "superblock", i);
+			if (!sb_rdonly(sb))
+				return 0;
+		}
+		if (block_bitmap >= sb_block + 1 &&
+		    block_bitmap <= last_bg_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Block bitmap for group %u overlaps "
+				 "block group descriptors", i);
+			if (!sb_rdonly(sb))
+				return 0;
+		}
+		if (block_bitmap < first_block || block_bitmap > last_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+			       "Block bitmap for group %u not in group "
+			       "(block %llu)!", i, block_bitmap);
+			return 0;
+		}
+		inode_bitmap = ext4_inode_bitmap(sb, gdp);
+		if (inode_bitmap == sb_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Inode bitmap for group %u overlaps "
+				 "superblock", i);
+			if (!sb_rdonly(sb))
+				return 0;
+		}
+		if (inode_bitmap >= sb_block + 1 &&
+		    inode_bitmap <= last_bg_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Inode bitmap for group %u overlaps "
+				 "block group descriptors", i);
+			if (!sb_rdonly(sb))
+				return 0;
+		}
+		if (inode_bitmap < first_block || inode_bitmap > last_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+			       "Inode bitmap for group %u not in group "
+			       "(block %llu)!", i, inode_bitmap);
+			return 0;
+		}
+		inode_table = ext4_inode_table(sb, gdp);
+		if (inode_table == sb_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Inode table for group %u overlaps "
+				 "superblock", i);
+			if (!sb_rdonly(sb))
+				return 0;
+		}
+		if (inode_table >= sb_block + 1 &&
+		    inode_table <= last_bg_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Inode table for group %u overlaps "
+				 "block group descriptors", i);
+			if (!sb_rdonly(sb))
+				return 0;
+		}
+		if (inode_table < first_block ||
+		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+			       "Inode table for group %u not in group "
+			       "(block %llu)!", i, inode_table);
+			return 0;
+		}
+		ext4_lock_group(sb, i);
+		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
+			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
+				 "Checksum for group %u failed (%u!=%u)",
+				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
+				     gdp)), le16_to_cpu(gdp->bg_checksum));
+			if (!sb_rdonly(sb)) {
+				ext4_unlock_group(sb, i);
+				return 0;
+			}
+		}
+		ext4_unlock_group(sb, i);
+		if (!flexbg_flag)
+			first_block += EXT4_BLOCKS_PER_GROUP(sb);
+	}
+	if (NULL != first_not_zeroed)
+		*first_not_zeroed = grp;
+	return 1;
+}
+
+/*
+ * Maximal extent format file size.
+ * Resulting logical blkno at s_maxbytes must fit in our on-disk
+ * extent format containers, within a sector_t, and within i_blocks
+ * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
+ * so that won't be a limiting factor.
+ *
+ * However there is other limiting factor. We do store extents in the form
+ * of starting block and length, hence the resulting length of the extent
+ * covering maximum file size must fit into on-disk format containers as
+ * well. Given that length is always by 1 unit bigger than max unit (because
+ * we count 0 as well) we have to lower the s_maxbytes by one fs block.
+ *
+ * Note, this does *not* consider any metadata overhead for vfs i_blocks.
+ */
+static loff_t ext4_max_size(int blkbits, int has_huge_files)
+{
+	loff_t res;
+	loff_t upper_limit = MAX_LFS_FILESIZE;
+
+	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
+
+	if (!has_huge_files) {
+		upper_limit = (1LL << 32) - 1;
+
+		/* total blocks in file system block size */
+		upper_limit >>= (blkbits - 9);
+		upper_limit <<= blkbits;
+	}
+
+	/*
+	 * 32-bit extent-start container, ee_block. We lower the maxbytes
+	 * by one fs block, so ee_len can cover the extent of maximum file
+	 * size
+	 */
+	res = (1LL << 32) - 1;
+	res <<= blkbits;
+
+	/* Sanity check against vm- & vfs- imposed limits */
+	if (res > upper_limit)
+		res = upper_limit;
+
+	return res;
+}
+
+/*
+ * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
+ * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
+ * We need to be 1 filesystem block less than the 2^48 sector limit.
+ */
+static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
+{
+	loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
+	int meta_blocks;
+	unsigned int ppb = 1 << (bits - 2);
+
+	/*
+	 * This is calculated to be the largest file size for a dense, block
+	 * mapped file such that the file's total number of 512-byte sectors,
+	 * including data and all indirect blocks, does not exceed (2^48 - 1).
+	 *
+	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
+	 * number of 512-byte sectors of the file.
+	 */
+	if (!has_huge_files) {
+		/*
+		 * !has_huge_files or implies that the inode i_block field
+		 * represents total file blocks in 2^32 512-byte sectors ==
+		 * size of vfs inode i_blocks * 8
+		 */
+		upper_limit = (1LL << 32) - 1;
+
+		/* total blocks in file system block size */
+		upper_limit >>= (bits - 9);
+
+	} else {
+		/*
+		 * We use 48 bit ext4_inode i_blocks
+		 * With EXT4_HUGE_FILE_FL set the i_blocks
+		 * represent total number of blocks in
+		 * file system block size
+		 */
+		upper_limit = (1LL << 48) - 1;
+
+	}
+
+	/* Compute how many blocks we can address by block tree */
+	res += ppb;
+	res += ppb * ppb;
+	res += ((loff_t)ppb) * ppb * ppb;
+	/* Compute how many metadata blocks are needed */
+	meta_blocks = 1;
+	meta_blocks += 1 + ppb;
+	meta_blocks += 1 + ppb + ppb * ppb;
+	/* Does block tree limit file size? */
+	if (res + meta_blocks <= upper_limit)
+		goto check_lfs;
+
+	res = upper_limit;
+	/* How many metadata blocks are needed for addressing upper_limit? */
+	upper_limit -= EXT4_NDIR_BLOCKS;
+	/* indirect blocks */
+	meta_blocks = 1;
+	upper_limit -= ppb;
+	/* double indirect blocks */
+	if (upper_limit < ppb * ppb) {
+		meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
+		res -= meta_blocks;
+		goto check_lfs;
+	}
+	meta_blocks += 1 + ppb;
+	upper_limit -= ppb * ppb;
+	/* tripple indirect blocks for the rest */
+	meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
+		DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
+	res -= meta_blocks;
+check_lfs:
+	res <<= bits;
+	if (res > MAX_LFS_FILESIZE)
+		res = MAX_LFS_FILESIZE;
+
+	return res;
+}
+
+static ext4_fsblk_t descriptor_loc(struct super_block *sb,
+				   ext4_fsblk_t logical_sb_block, int nr)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	ext4_group_t bg, first_meta_bg;
+	int has_super = 0;
+
+	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
+
+	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
+		return logical_sb_block + nr + 1;
+	bg = sbi->s_desc_per_block * nr;
+	if (ext4_bg_has_super(sb, bg))
+		has_super = 1;
+
+	/*
+	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
+	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
+	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
+	 * compensate.
+	 */
+	if (sb->s_blocksize == 1024 && nr == 0 &&
+	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
+		has_super++;
+
+	return (has_super + ext4_group_first_block_no(sb, bg));
+}
+
+/**
+ * ext4_get_stripe_size: Get the stripe size.
+ * @sbi: In memory super block info
+ *
+ * If we have specified it via mount option, then
+ * use the mount option value. If the value specified at mount time is
+ * greater than the blocks per group use the super block value.
+ * If the super block value is greater than blocks per group return 0.
+ * Allocator needs it be less than blocks per group.
+ *
+ */
+static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
+{
+	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
+	unsigned long stripe_width =
+			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
+	int ret;
+
+	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
+		ret = sbi->s_stripe;
+	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
+		ret = stripe_width;
+	else if (stride && stride <= sbi->s_blocks_per_group)
+		ret = stride;
+	else
+		ret = 0;
+
+	/*
+	 * If the stripe width is 1, this makes no sense and
+	 * we set it to 0 to turn off stripe handling code.
+	 */
+	if (ret <= 1)
+		ret = 0;
+
+	return ret;
+}
+
+/*
+ * Check whether this filesystem can be mounted based on
+ * the features present and the RDONLY/RDWR mount requested.
+ * Returns 1 if this filesystem can be mounted as requested,
+ * 0 if it cannot be.
+ */
+int ext4_feature_set_ok(struct super_block *sb, int readonly)
+{
+	if (ext4_has_unknown_ext4_incompat_features(sb)) {
+		ext4_msg(sb, KERN_ERR,
+			"Couldn't mount because of "
+			"unsupported optional features (%x)",
+			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
+			~EXT4_FEATURE_INCOMPAT_SUPP));
+		return 0;
+	}
+
+	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Filesystem with casefold feature cannot be "
+			 "mounted without CONFIG_UNICODE");
+		return 0;
+	}
+
+	if (readonly)
+		return 1;
+
+	if (ext4_has_feature_readonly(sb)) {
+		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
+		sb->s_flags |= SB_RDONLY;
+		return 1;
+	}
+
+	/* Check that feature set is OK for a read-write mount */
+	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
+		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
+			 "unsupported optional features (%x)",
+			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
+				~EXT4_FEATURE_RO_COMPAT_SUPP));
+		return 0;
+	}
+	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Can't support bigalloc feature without "
+			 "extents feature\n");
+		return 0;
+	}
+
+#if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
+	if (!readonly && (ext4_has_feature_quota(sb) ||
+			  ext4_has_feature_project(sb))) {
+		ext4_msg(sb, KERN_ERR,
+			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
+		return 0;
+	}
+#endif  /* CONFIG_QUOTA */
+	return 1;
+}
+
+/*
+ * This function is called once a day if we have errors logged
+ * on the file system
+ */
+static void print_daily_error_info(struct timer_list *t)
+{
+	struct ext4_sb_info *sbi = timer_container_of(sbi, t, s_err_report);
+	struct super_block *sb = sbi->s_sb;
+	struct ext4_super_block *es = sbi->s_es;
+
+	if (es->s_error_count)
+		/* fsck newer than v1.41.13 is needed to clean this condition. */
+		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
+			 le32_to_cpu(es->s_error_count));
+	if (es->s_first_error_time) {
+		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
+		       sb->s_id,
+		       ext4_get_tstamp(es, s_first_error_time),
+		       (int) sizeof(es->s_first_error_func),
+		       es->s_first_error_func,
+		       le32_to_cpu(es->s_first_error_line));
+		if (es->s_first_error_ino)
+			printk(KERN_CONT ": inode %u",
+			       le32_to_cpu(es->s_first_error_ino));
+		if (es->s_first_error_block)
+			printk(KERN_CONT ": block %llu", (unsigned long long)
+			       le64_to_cpu(es->s_first_error_block));
+		printk(KERN_CONT "\n");
+	}
+	if (es->s_last_error_time) {
+		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
+		       sb->s_id,
+		       ext4_get_tstamp(es, s_last_error_time),
+		       (int) sizeof(es->s_last_error_func),
+		       es->s_last_error_func,
+		       le32_to_cpu(es->s_last_error_line));
+		if (es->s_last_error_ino)
+			printk(KERN_CONT ": inode %u",
+			       le32_to_cpu(es->s_last_error_ino));
+		if (es->s_last_error_block)
+			printk(KERN_CONT ": block %llu", (unsigned long long)
+			       le64_to_cpu(es->s_last_error_block));
+		printk(KERN_CONT "\n");
+	}
+	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
+}
+
+/* Find next suitable group and run ext4_init_inode_table */
+static int ext4_run_li_request(struct ext4_li_request *elr)
+{
+	struct ext4_group_desc *gdp = NULL;
+	struct super_block *sb = elr->lr_super;
+	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
+	ext4_group_t group = elr->lr_next_group;
+	unsigned int prefetch_ios = 0;
+	int ret = 0;
+	int nr = EXT4_SB(sb)->s_mb_prefetch;
+	u64 start_time;
+
+	if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
+		elr->lr_next_group = ext4_mb_prefetch(sb, group, nr, &prefetch_ios);
+		ext4_mb_prefetch_fini(sb, elr->lr_next_group, nr);
+		trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group, nr);
+		if (group >= elr->lr_next_group) {
+			ret = 1;
+			if (elr->lr_first_not_zeroed != ngroups &&
+			    !ext4_emergency_state(sb) && !sb_rdonly(sb) &&
+			    test_opt(sb, INIT_INODE_TABLE)) {
+				elr->lr_next_group = elr->lr_first_not_zeroed;
+				elr->lr_mode = EXT4_LI_MODE_ITABLE;
+				ret = 0;
+			}
+		}
+		return ret;
+	}
+
+	for (; group < ngroups; group++) {
+		gdp = ext4_get_group_desc(sb, group, NULL);
+		if (!gdp) {
+			ret = 1;
+			break;
+		}
+
+		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
+			break;
+	}
+
+	if (group >= ngroups)
+		ret = 1;
+
+	if (!ret) {
+		start_time = ktime_get_ns();
+		ret = ext4_init_inode_table(sb, group,
+					    elr->lr_timeout ? 0 : 1);
+		trace_ext4_lazy_itable_init(sb, group);
+		if (elr->lr_timeout == 0) {
+			elr->lr_timeout = nsecs_to_jiffies((ktime_get_ns() - start_time) *
+				EXT4_SB(elr->lr_super)->s_li_wait_mult);
+		}
+		elr->lr_next_sched = jiffies + elr->lr_timeout;
+		elr->lr_next_group = group + 1;
+	}
+	return ret;
+}
+
+/*
+ * Remove lr_request from the list_request and free the
+ * request structure. Should be called with li_list_mtx held
+ */
+static void ext4_remove_li_request(struct ext4_li_request *elr)
+{
+	if (!elr)
+		return;
+
+	list_del(&elr->lr_request);
+	EXT4_SB(elr->lr_super)->s_li_request = NULL;
+	kfree(elr);
+}
+
+static void ext4_unregister_li_request(struct super_block *sb)
+{
+	mutex_lock(&ext4_li_mtx);
+	if (!ext4_li_info) {
+		mutex_unlock(&ext4_li_mtx);
+		return;
+	}
+
+	mutex_lock(&ext4_li_info->li_list_mtx);
+	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
+	mutex_unlock(&ext4_li_info->li_list_mtx);
+	mutex_unlock(&ext4_li_mtx);
+}
+
+static struct task_struct *ext4_lazyinit_task;
+
+/*
+ * This is the function where ext4lazyinit thread lives. It walks
+ * through the request list searching for next scheduled filesystem.
+ * When such a fs is found, run the lazy initialization request
+ * (ext4_rn_li_request) and keep track of the time spend in this
+ * function. Based on that time we compute next schedule time of
+ * the request. When walking through the list is complete, compute
+ * next waking time and put itself into sleep.
+ */
+static int ext4_lazyinit_thread(void *arg)
+{
+	struct ext4_lazy_init *eli = arg;
+	struct list_head *pos, *n;
+	struct ext4_li_request *elr;
+	unsigned long next_wakeup, cur;
+
+	BUG_ON(NULL == eli);
+	set_freezable();
+
+cont_thread:
+	while (true) {
+		bool next_wakeup_initialized = false;
+
+		next_wakeup = 0;
+		mutex_lock(&eli->li_list_mtx);
+		if (list_empty(&eli->li_request_list)) {
+			mutex_unlock(&eli->li_list_mtx);
+			goto exit_thread;
+		}
+		list_for_each_safe(pos, n, &eli->li_request_list) {
+			int err = 0;
+			int progress = 0;
+			elr = list_entry(pos, struct ext4_li_request,
+					 lr_request);
+
+			if (time_before(jiffies, elr->lr_next_sched)) {
+				if (!next_wakeup_initialized ||
+				    time_before(elr->lr_next_sched, next_wakeup)) {
+					next_wakeup = elr->lr_next_sched;
+					next_wakeup_initialized = true;
+				}
+				continue;
+			}
+			if (down_read_trylock(&elr->lr_super->s_umount)) {
+				if (sb_start_write_trylock(elr->lr_super)) {
+					progress = 1;
+					/*
+					 * We hold sb->s_umount, sb can not
+					 * be removed from the list, it is
+					 * now safe to drop li_list_mtx
+					 */
+					mutex_unlock(&eli->li_list_mtx);
+					err = ext4_run_li_request(elr);
+					sb_end_write(elr->lr_super);
+					mutex_lock(&eli->li_list_mtx);
+					n = pos->next;
+				}
+				up_read((&elr->lr_super->s_umount));
+			}
+			/* error, remove the lazy_init job */
+			if (err) {
+				ext4_remove_li_request(elr);
+				continue;
+			}
+			if (!progress) {
+				elr->lr_next_sched = jiffies +
+					get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
+			}
+			if (!next_wakeup_initialized ||
+			    time_before(elr->lr_next_sched, next_wakeup)) {
+				next_wakeup = elr->lr_next_sched;
+				next_wakeup_initialized = true;
+			}
+		}
+		mutex_unlock(&eli->li_list_mtx);
+
+		try_to_freeze();
+
+		cur = jiffies;
+		if (!next_wakeup_initialized || time_after_eq(cur, next_wakeup)) {
+			cond_resched();
+			continue;
+		}
+
+		schedule_timeout_interruptible(next_wakeup - cur);
+
+		if (kthread_should_stop()) {
+			ext4_clear_request_list();
+			goto exit_thread;
+		}
+	}
+
+exit_thread:
+	/*
+	 * It looks like the request list is empty, but we need
+	 * to check it under the li_list_mtx lock, to prevent any
+	 * additions into it, and of course we should lock ext4_li_mtx
+	 * to atomically free the list and ext4_li_info, because at
+	 * this point another ext4 filesystem could be registering
+	 * new one.
+	 */
+	mutex_lock(&ext4_li_mtx);
+	mutex_lock(&eli->li_list_mtx);
+	if (!list_empty(&eli->li_request_list)) {
+		mutex_unlock(&eli->li_list_mtx);
+		mutex_unlock(&ext4_li_mtx);
+		goto cont_thread;
+	}
+	mutex_unlock(&eli->li_list_mtx);
+	kfree(ext4_li_info);
+	ext4_li_info = NULL;
+	mutex_unlock(&ext4_li_mtx);
+
+	return 0;
+}
+
+static void ext4_clear_request_list(void)
+{
+	struct list_head *pos, *n;
+	struct ext4_li_request *elr;
+
+	mutex_lock(&ext4_li_info->li_list_mtx);
+	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
+		elr = list_entry(pos, struct ext4_li_request,
+				 lr_request);
+		ext4_remove_li_request(elr);
+	}
+	mutex_unlock(&ext4_li_info->li_list_mtx);
+}
+
+static int ext4_run_lazyinit_thread(void)
+{
+	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
+					 ext4_li_info, "ext4lazyinit");
+	if (IS_ERR(ext4_lazyinit_task)) {
+		int err = PTR_ERR(ext4_lazyinit_task);
+		ext4_clear_request_list();
+		kfree(ext4_li_info);
+		ext4_li_info = NULL;
+		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
+				 "initialization thread\n",
+				 err);
+		return err;
+	}
+	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
+	return 0;
+}
+
+/*
+ * Check whether it make sense to run itable init. thread or not.
+ * If there is at least one uninitialized inode table, return
+ * corresponding group number, else the loop goes through all
+ * groups and return total number of groups.
+ */
+static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
+{
+	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
+	struct ext4_group_desc *gdp = NULL;
+
+	if (!ext4_has_group_desc_csum(sb))
+		return ngroups;
+
+	for (group = 0; group < ngroups; group++) {
+		gdp = ext4_get_group_desc(sb, group, NULL);
+		if (!gdp)
+			continue;
+
+		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
+			break;
+	}
+
+	return group;
+}
+
+static int ext4_li_info_new(void)
+{
+	struct ext4_lazy_init *eli = NULL;
+
+	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
+	if (!eli)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&eli->li_request_list);
+	mutex_init(&eli->li_list_mtx);
+
+	eli->li_state |= EXT4_LAZYINIT_QUIT;
+
+	ext4_li_info = eli;
+
+	return 0;
+}
+
+static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
+					    ext4_group_t start)
+{
+	struct ext4_li_request *elr;
+
+	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
+	if (!elr)
+		return NULL;
+
+	elr->lr_super = sb;
+	elr->lr_first_not_zeroed = start;
+	if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
+		elr->lr_mode = EXT4_LI_MODE_ITABLE;
+		elr->lr_next_group = start;
+	} else {
+		elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
+	}
+
+	/*
+	 * Randomize first schedule time of the request to
+	 * spread the inode table initialization requests
+	 * better.
+	 */
+	elr->lr_next_sched = jiffies + get_random_u32_below(EXT4_DEF_LI_MAX_START_DELAY * HZ);
+	return elr;
+}
+
+int ext4_register_li_request(struct super_block *sb,
+			     ext4_group_t first_not_zeroed)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_li_request *elr = NULL;
+	ext4_group_t ngroups = sbi->s_groups_count;
+	int ret = 0;
+
+	mutex_lock(&ext4_li_mtx);
+	if (sbi->s_li_request != NULL) {
+		/*
+		 * Reset timeout so it can be computed again, because
+		 * s_li_wait_mult might have changed.
+		 */
+		sbi->s_li_request->lr_timeout = 0;
+		goto out;
+	}
+
+	if (ext4_emergency_state(sb) || sb_rdonly(sb) ||
+	    (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
+	     (first_not_zeroed == ngroups || !test_opt(sb, INIT_INODE_TABLE))))
+		goto out;
+
+	elr = ext4_li_request_new(sb, first_not_zeroed);
+	if (!elr) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	if (NULL == ext4_li_info) {
+		ret = ext4_li_info_new();
+		if (ret)
+			goto out;
+	}
+
+	mutex_lock(&ext4_li_info->li_list_mtx);
+	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
+	mutex_unlock(&ext4_li_info->li_list_mtx);
+
+	sbi->s_li_request = elr;
+	/*
+	 * set elr to NULL here since it has been inserted to
+	 * the request_list and the removal and free of it is
+	 * handled by ext4_clear_request_list from now on.
+	 */
+	elr = NULL;
+
+	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
+		ret = ext4_run_lazyinit_thread();
+		if (ret)
+			goto out;
+	}
+out:
+	mutex_unlock(&ext4_li_mtx);
+	if (ret)
+		kfree(elr);
+	return ret;
+}
+
+/*
+ * We do not need to lock anything since this is called on
+ * module unload.
+ */
+static void ext4_destroy_lazyinit_thread(void)
+{
+	/*
+	 * If thread exited earlier
+	 * there's nothing to be done.
+	 */
+	if (!ext4_li_info || !ext4_lazyinit_task)
+		return;
+
+	kthread_stop(ext4_lazyinit_task);
+}
+
+static int set_journal_csum_feature_set(struct super_block *sb)
+{
+	int ret = 1;
+	int compat, incompat;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (ext4_has_feature_metadata_csum(sb)) {
+		/* journal checksum v3 */
+		compat = 0;
+		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
+	} else {
+		/* journal checksum v1 */
+		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
+		incompat = 0;
+	}
+
+	jbd2_journal_clear_features(sbi->s_journal,
+			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
+			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
+			JBD2_FEATURE_INCOMPAT_CSUM_V2);
+	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+		ret = jbd2_journal_set_features(sbi->s_journal,
+				compat, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
+				incompat);
+	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
+		ret = jbd2_journal_set_features(sbi->s_journal,
+				compat, 0,
+				incompat);
+		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+	} else {
+		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+	}
+
+	return ret;
+}
+
+/*
+ * Note: calculating the overhead so we can be compatible with
+ * historical BSD practice is quite difficult in the face of
+ * clusters/bigalloc.  This is because multiple metadata blocks from
+ * different block group can end up in the same allocation cluster.
+ * Calculating the exact overhead in the face of clustered allocation
+ * requires either O(all block bitmaps) in memory or O(number of block
+ * groups**2) in time.  We will still calculate the superblock for
+ * older file systems --- and if we come across with a bigalloc file
+ * system with zero in s_overhead_clusters the estimate will be close to
+ * correct especially for very large cluster sizes --- but for newer
+ * file systems, it's better to calculate this figure once at mkfs
+ * time, and store it in the superblock.  If the superblock value is
+ * present (even for non-bigalloc file systems), we will use it.
+ */
+static int count_overhead(struct super_block *sb, ext4_group_t grp,
+			  char *buf)
+{
+	struct ext4_sb_info	*sbi = EXT4_SB(sb);
+	struct ext4_group_desc	*gdp;
+	ext4_fsblk_t		first_block, last_block, b;
+	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
+	int			s, j, count = 0;
+	int			has_super = ext4_bg_has_super(sb, grp);
+
+	if (!ext4_has_feature_bigalloc(sb))
+		return (has_super + ext4_bg_num_gdb(sb, grp) +
+			(has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
+			sbi->s_itb_per_group + 2);
+
+	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
+		(grp * EXT4_BLOCKS_PER_GROUP(sb));
+	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
+	for (i = 0; i < ngroups; i++) {
+		gdp = ext4_get_group_desc(sb, i, NULL);
+		b = ext4_block_bitmap(sb, gdp);
+		if (b >= first_block && b <= last_block) {
+			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
+			count++;
+		}
+		b = ext4_inode_bitmap(sb, gdp);
+		if (b >= first_block && b <= last_block) {
+			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
+			count++;
+		}
+		b = ext4_inode_table(sb, gdp);
+		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
+			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
+				int c = EXT4_B2C(sbi, b - first_block);
+				ext4_set_bit(c, buf);
+				count++;
+			}
+		if (i != grp)
+			continue;
+		s = 0;
+		if (ext4_bg_has_super(sb, grp)) {
+			ext4_set_bit(s++, buf);
+			count++;
+		}
+		j = ext4_bg_num_gdb(sb, grp);
+		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
+			ext4_error(sb, "Invalid number of block group "
+				   "descriptor blocks: %d", j);
+			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
+		}
+		count += j;
+		for (; j > 0; j--)
+			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
+	}
+	if (!count)
+		return 0;
+	return EXT4_CLUSTERS_PER_GROUP(sb) -
+		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
+}
+
+/*
+ * Compute the overhead and stash it in sbi->s_overhead
+ */
+int ext4_calculate_overhead(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	struct inode *j_inode;
+	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
+	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
+	ext4_fsblk_t overhead = 0;
+	char *buf = (char *) get_zeroed_page(GFP_NOFS);
+
+	if (!buf)
+		return -ENOMEM;
+
+	/*
+	 * Compute the overhead (FS structures).  This is constant
+	 * for a given filesystem unless the number of block groups
+	 * changes so we cache the previous value until it does.
+	 */
+
+	/*
+	 * All of the blocks before first_data_block are overhead
+	 */
+	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
+
+	/*
+	 * Add the overhead found in each block group
+	 */
+	for (i = 0; i < ngroups; i++) {
+		int blks;
+
+		blks = count_overhead(sb, i, buf);
+		overhead += blks;
+		if (blks)
+			memset(buf, 0, PAGE_SIZE);
+		cond_resched();
+	}
+
+	/*
+	 * Add the internal journal blocks whether the journal has been
+	 * loaded or not
+	 */
+	if (sbi->s_journal && !sbi->s_journal_bdev_file)
+		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
+	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
+		/* j_inum for internal journal is non-zero */
+		j_inode = ext4_get_journal_inode(sb, j_inum);
+		if (!IS_ERR(j_inode)) {
+			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
+			overhead += EXT4_NUM_B2C(sbi, j_blocks);
+			iput(j_inode);
+		} else {
+			ext4_msg(sb, KERN_ERR, "can't get journal size");
+		}
+	}
+	sbi->s_overhead = overhead;
+	smp_wmb();
+	free_page((unsigned long) buf);
+	return 0;
+}
+
+static void ext4_set_resv_clusters(struct super_block *sb)
+{
+	ext4_fsblk_t resv_clusters;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	/*
+	 * There's no need to reserve anything when we aren't using extents.
+	 * The space estimates are exact, there are no unwritten extents,
+	 * hole punching doesn't need new metadata... This is needed especially
+	 * to keep ext2/3 backward compatibility.
+	 */
+	if (!ext4_has_feature_extents(sb))
+		return;
+	/*
+	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
+	 * This should cover the situations where we can not afford to run
+	 * out of space like for example punch hole, or converting
+	 * unwritten extents in delalloc path. In most cases such
+	 * allocation would require 1, or 2 blocks, higher numbers are
+	 * very rare.
+	 */
+	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
+			 sbi->s_cluster_bits);
+
+	do_div(resv_clusters, 50);
+	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
+
+	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
+}
+
+static const char *ext4_quota_mode(struct super_block *sb)
+{
+#ifdef CONFIG_QUOTA
+	if (!ext4_quota_capable(sb))
+		return "none";
+
+	if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
+		return "journalled";
+	else
+		return "writeback";
+#else
+	return "disabled";
+#endif
+}
+
+static void ext4_setup_csum_trigger(struct super_block *sb,
+				    enum ext4_journal_trigger_type type,
+				    void (*trigger)(
+					struct jbd2_buffer_trigger_type *type,
+					struct buffer_head *bh,
+					void *mapped_data,
+					size_t size))
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	sbi->s_journal_triggers[type].sb = sb;
+	sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
+}
+
+static void ext4_free_sbi(struct ext4_sb_info *sbi)
+{
+	if (!sbi)
+		return;
+
+	kfree(sbi->s_blockgroup_lock);
+	fs_put_dax(sbi->s_daxdev, NULL);
+	kfree(sbi);
+}
+
+static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi;
+
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi)
+		return NULL;
+
+	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
+					   NULL, NULL);
+
+	sbi->s_blockgroup_lock =
+		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
+
+	if (!sbi->s_blockgroup_lock)
+		goto err_out;
+
+	sb->s_fs_info = sbi;
+	sbi->s_sb = sb;
+	return sbi;
+err_out:
+	fs_put_dax(sbi->s_daxdev, NULL);
+	kfree(sbi);
+	return NULL;
+}
+
+static void ext4_set_def_opts(struct super_block *sb,
+			      struct ext4_super_block *es)
+{
+	unsigned long def_mount_opts;
+
+	/* Set defaults before we parse the mount options */
+	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+	set_opt(sb, INIT_INODE_TABLE);
+	if (def_mount_opts & EXT4_DEFM_DEBUG)
+		set_opt(sb, DEBUG);
+	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
+		set_opt(sb, GRPID);
+	if (def_mount_opts & EXT4_DEFM_UID16)
+		set_opt(sb, NO_UID32);
+	/* xattr user namespace & acls are now defaulted on */
+	set_opt(sb, XATTR_USER);
+#ifdef CONFIG_EXT4_FS_POSIX_ACL
+	set_opt(sb, POSIX_ACL);
+#endif
+	if (ext4_has_feature_fast_commit(sb))
+		set_opt2(sb, JOURNAL_FAST_COMMIT);
+	/* don't forget to enable journal_csum when metadata_csum is enabled. */
+	if (ext4_has_feature_metadata_csum(sb))
+		set_opt(sb, JOURNAL_CHECKSUM);
+
+	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
+		set_opt(sb, JOURNAL_DATA);
+	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
+		set_opt(sb, ORDERED_DATA);
+	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
+		set_opt(sb, WRITEBACK_DATA);
+
+	if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_PANIC)
+		set_opt(sb, ERRORS_PANIC);
+	else if (le16_to_cpu(es->s_errors) == EXT4_ERRORS_CONTINUE)
+		set_opt(sb, ERRORS_CONT);
+	else
+		set_opt(sb, ERRORS_RO);
+	/* block_validity enabled by default; disable with noblock_validity */
+	set_opt(sb, BLOCK_VALIDITY);
+	if (def_mount_opts & EXT4_DEFM_DISCARD)
+		set_opt(sb, DISCARD);
+
+	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
+		set_opt(sb, BARRIER);
+
+	/*
+	 * enable delayed allocation by default
+	 * Use -o nodelalloc to turn it off
+	 */
+	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
+	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
+		set_opt(sb, DELALLOC);
+
+	if (sb->s_blocksize <= PAGE_SIZE)
+		set_opt(sb, DIOREAD_NOLOCK);
+}
+
+static int ext4_handle_clustersize(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	int clustersize;
+
+	/* Handle clustersize */
+	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
+	if (ext4_has_feature_bigalloc(sb)) {
+		if (clustersize < sb->s_blocksize) {
+			ext4_msg(sb, KERN_ERR,
+				 "cluster size (%d) smaller than "
+				 "block size (%lu)", clustersize, sb->s_blocksize);
+			return -EINVAL;
+		}
+		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
+			le32_to_cpu(es->s_log_block_size);
+	} else {
+		if (clustersize != sb->s_blocksize) {
+			ext4_msg(sb, KERN_ERR,
+				 "fragment/cluster size (%d) != "
+				 "block size (%lu)", clustersize, sb->s_blocksize);
+			return -EINVAL;
+		}
+		if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {
+			ext4_msg(sb, KERN_ERR,
+				 "#blocks per group too big: %lu",
+				 sbi->s_blocks_per_group);
+			return -EINVAL;
+		}
+		sbi->s_cluster_bits = 0;
+	}
+	sbi->s_clusters_per_group = le32_to_cpu(es->s_clusters_per_group);
+	if (sbi->s_clusters_per_group > sb->s_blocksize * 8) {
+		ext4_msg(sb, KERN_ERR, "#clusters per group too big: %lu",
+			 sbi->s_clusters_per_group);
+		return -EINVAL;
+	}
+	if (sbi->s_blocks_per_group !=
+	    (sbi->s_clusters_per_group * (clustersize / sb->s_blocksize))) {
+		ext4_msg(sb, KERN_ERR,
+			 "blocks per group (%lu) and clusters per group (%lu) inconsistent",
+			 sbi->s_blocks_per_group, sbi->s_clusters_per_group);
+		return -EINVAL;
+	}
+	sbi->s_cluster_ratio = clustersize / sb->s_blocksize;
+
+	/* Do we have standard group size of clustersize * 8 blocks ? */
+	if (sbi->s_blocks_per_group == clustersize << 3)
+		set_opt2(sb, STD_GROUP_SIZE);
+
+	return 0;
+}
+
+/*
+ * ext4_atomic_write_init: Initializes filesystem min & max atomic write units.
+ * With non-bigalloc filesystem awu will be based upon filesystem blocksize
+ * & bdev awu units.
+ * With bigalloc it will be based upon bigalloc cluster size & bdev awu units.
+ * @sb: super block
+ */
+static void ext4_atomic_write_init(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct block_device *bdev = sb->s_bdev;
+	unsigned int clustersize = EXT4_CLUSTER_SIZE(sb);
+
+	if (!bdev_can_atomic_write(bdev))
+		return;
+
+	if (!ext4_has_feature_extents(sb))
+		return;
+
+	sbi->s_awu_min = max(sb->s_blocksize,
+			      bdev_atomic_write_unit_min_bytes(bdev));
+	sbi->s_awu_max = min(clustersize,
+			      bdev_atomic_write_unit_max_bytes(bdev));
+	if (sbi->s_awu_min && sbi->s_awu_max &&
+	    sbi->s_awu_min <= sbi->s_awu_max) {
+		ext4_msg(sb, KERN_NOTICE, "Supports (experimental) DIO atomic writes awu_min: %u, awu_max: %u",
+			 sbi->s_awu_min, sbi->s_awu_max);
+	} else {
+		sbi->s_awu_min = 0;
+		sbi->s_awu_max = 0;
+	}
+}
+
+static void ext4_fast_commit_init(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	/* Initialize fast commit stuff */
+	atomic_set(&sbi->s_fc_subtid, 0);
+	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
+	INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
+	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
+	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
+	sbi->s_fc_bytes = 0;
+	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
+	sbi->s_fc_ineligible_tid = 0;
+	mutex_init(&sbi->s_fc_lock);
+	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
+	sbi->s_fc_replay_state.fc_regions = NULL;
+	sbi->s_fc_replay_state.fc_regions_size = 0;
+	sbi->s_fc_replay_state.fc_regions_used = 0;
+	sbi->s_fc_replay_state.fc_regions_valid = 0;
+	sbi->s_fc_replay_state.fc_modified_inodes = NULL;
+	sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
+	sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
+}
+
+static int ext4_inode_info_init(struct super_block *sb,
+				struct ext4_super_block *es)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
+		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
+		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
+	} else {
+		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
+		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
+		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
+			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
+				 sbi->s_first_ino);
+			return -EINVAL;
+		}
+		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
+		    (!is_power_of_2(sbi->s_inode_size)) ||
+		    (sbi->s_inode_size > sb->s_blocksize)) {
+			ext4_msg(sb, KERN_ERR,
+			       "unsupported inode size: %d",
+			       sbi->s_inode_size);
+			ext4_msg(sb, KERN_ERR, "blocksize: %lu", sb->s_blocksize);
+			return -EINVAL;
+		}
+		/*
+		 * i_atime_extra is the last extra field available for
+		 * [acm]times in struct ext4_inode. Checking for that
+		 * field should suffice to ensure we have extra space
+		 * for all three.
+		 */
+		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
+			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
+			sb->s_time_gran = 1;
+			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
+		} else {
+			sb->s_time_gran = NSEC_PER_SEC;
+			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
+		}
+		sb->s_time_min = EXT4_TIMESTAMP_MIN;
+	}
+
+	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
+		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
+			EXT4_GOOD_OLD_INODE_SIZE;
+		if (ext4_has_feature_extra_isize(sb)) {
+			unsigned v, max = (sbi->s_inode_size -
+					   EXT4_GOOD_OLD_INODE_SIZE);
+
+			v = le16_to_cpu(es->s_want_extra_isize);
+			if (v > max) {
+				ext4_msg(sb, KERN_ERR,
+					 "bad s_want_extra_isize: %d", v);
+				return -EINVAL;
+			}
+			if (sbi->s_want_extra_isize < v)
+				sbi->s_want_extra_isize = v;
+
+			v = le16_to_cpu(es->s_min_extra_isize);
+			if (v > max) {
+				ext4_msg(sb, KERN_ERR,
+					 "bad s_min_extra_isize: %d", v);
+				return -EINVAL;
+			}
+			if (sbi->s_want_extra_isize < v)
+				sbi->s_want_extra_isize = v;
+		}
+	}
+
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_UNICODE)
+static int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
+{
+	const struct ext4_sb_encodings *encoding_info;
+	struct unicode_map *encoding;
+	__u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
+
+	if (!ext4_has_feature_casefold(sb) || sb->s_encoding)
+		return 0;
+
+	encoding_info = ext4_sb_read_encoding(es);
+	if (!encoding_info) {
+		ext4_msg(sb, KERN_ERR,
+			"Encoding requested by superblock is unknown");
+		return -EINVAL;
+	}
+
+	encoding = utf8_load(encoding_info->version);
+	if (IS_ERR(encoding)) {
+		ext4_msg(sb, KERN_ERR,
+			"can't mount with superblock charset: %s-%u.%u.%u "
+			"not supported by the kernel. flags: 0x%x.",
+			encoding_info->name,
+			unicode_major(encoding_info->version),
+			unicode_minor(encoding_info->version),
+			unicode_rev(encoding_info->version),
+			encoding_flags);
+		return -EINVAL;
+	}
+	ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
+		"%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
+		unicode_major(encoding_info->version),
+		unicode_minor(encoding_info->version),
+		unicode_rev(encoding_info->version),
+		encoding_flags);
+
+	sb->s_encoding = encoding;
+	sb->s_encoding_flags = encoding_flags;
+
+	return 0;
+}
+#else
+static inline int ext4_encoding_init(struct super_block *sb, struct ext4_super_block *es)
+{
+	return 0;
+}
+#endif
+
+static int ext4_init_metadata_csum(struct super_block *sb, struct ext4_super_block *es)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	/* Warn if metadata_csum and gdt_csum are both set. */
+	if (ext4_has_feature_metadata_csum(sb) &&
+	    ext4_has_feature_gdt_csum(sb))
+		ext4_warning(sb, "metadata_csum and uninit_bg are "
+			     "redundant flags; please run fsck.");
+
+	/* Check for a known checksum algorithm */
+	if (!ext4_verify_csum_type(sb, es)) {
+		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
+			 "unknown checksum algorithm.");
+		return -EINVAL;
+	}
+	ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
+				ext4_orphan_file_block_trigger);
+
+	/* Check superblock checksum */
+	if (!ext4_superblock_csum_verify(sb, es)) {
+		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
+			 "invalid superblock checksum.  Run e2fsck?");
+		return -EFSBADCRC;
+	}
+
+	/* Precompute checksum seed for all metadata */
+	if (ext4_has_feature_csum_seed(sb))
+		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
+	else if (ext4_has_feature_metadata_csum(sb) ||
+		 ext4_has_feature_ea_inode(sb))
+		sbi->s_csum_seed = ext4_chksum(~0, es->s_uuid,
+					       sizeof(es->s_uuid));
+	return 0;
+}
+
+static int ext4_check_feature_compatibility(struct super_block *sb,
+					    struct ext4_super_block *es,
+					    int silent)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
+	    (ext4_has_compat_features(sb) ||
+	     ext4_has_ro_compat_features(sb) ||
+	     ext4_has_incompat_features(sb)))
+		ext4_msg(sb, KERN_WARNING,
+		       "feature flags set on rev 0 fs, "
+		       "running e2fsck is recommended");
+
+	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
+		set_opt2(sb, HURD_COMPAT);
+		if (ext4_has_feature_64bit(sb)) {
+			ext4_msg(sb, KERN_ERR,
+				 "The Hurd can't support 64-bit file systems");
+			return -EINVAL;
+		}
+
+		/*
+		 * ea_inode feature uses l_i_version field which is not
+		 * available in HURD_COMPAT mode.
+		 */
+		if (ext4_has_feature_ea_inode(sb)) {
+			ext4_msg(sb, KERN_ERR,
+				 "ea_inode feature is not supported for Hurd");
+			return -EINVAL;
+		}
+	}
+
+	if (IS_EXT2_SB(sb)) {
+		if (ext2_feature_set_ok(sb))
+			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
+				 "using the ext4 subsystem");
+		else {
+			/*
+			 * If we're probing be silent, if this looks like
+			 * it's actually an ext[34] filesystem.
+			 */
+			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
+				return -EINVAL;
+			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
+				 "to feature incompatibilities");
+			return -EINVAL;
+		}
+	}
+
+	if (IS_EXT3_SB(sb)) {
+		if (ext3_feature_set_ok(sb))
+			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
+				 "using the ext4 subsystem");
+		else {
+			/*
+			 * If we're probing be silent, if this looks like
+			 * it's actually an ext4 filesystem.
+			 */
+			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
+				return -EINVAL;
+			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
+				 "to feature incompatibilities");
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * Check feature flags regardless of the revision level, since we
+	 * previously didn't change the revision level when setting the flags,
+	 * so there is a chance incompat flags are set on a rev 0 filesystem.
+	 */
+	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
+		return -EINVAL;
+
+	if (sbi->s_daxdev) {
+		if (sb->s_blocksize == PAGE_SIZE)
+			set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
+		else
+			ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
+	}
+
+	if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
+		if (ext4_has_feature_inline_data(sb)) {
+			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
+					" that may contain inline data");
+			return -EINVAL;
+		}
+		if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
+			ext4_msg(sb, KERN_ERR,
+				"DAX unsupported by block device.");
+			return -EINVAL;
+		}
+	}
+
+	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
+		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
+			 es->s_encryption_level);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ext4_check_geometry(struct super_block *sb,
+			       struct ext4_super_block *es)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	__u64 blocks_count;
+	int err;
+
+	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (sb->s_blocksize / 4)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Number of reserved GDT blocks insanely large: %d",
+			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
+		return -EINVAL;
+	}
+	/*
+	 * Test whether we have more sectors than will fit in sector_t,
+	 * and whether the max offset is addressable by the page cache.
+	 */
+	err = generic_check_addressable(sb->s_blocksize_bits,
+					ext4_blocks_count(es));
+	if (err) {
+		ext4_msg(sb, KERN_ERR, "filesystem"
+			 " too large to mount safely on this system");
+		return err;
+	}
+
+	/* check blocks count against device size */
+	blocks_count = sb_bdev_nr_blocks(sb);
+	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
+		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
+		       "exceeds size of device (%llu blocks)",
+		       ext4_blocks_count(es), blocks_count);
+		return -EINVAL;
+	}
+
+	/*
+	 * It makes no sense for the first data block to be beyond the end
+	 * of the filesystem.
+	 */
+	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
+		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
+			 "block %u is beyond end of filesystem (%llu)",
+			 le32_to_cpu(es->s_first_data_block),
+			 ext4_blocks_count(es));
+		return -EINVAL;
+	}
+	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
+	    (sbi->s_cluster_ratio == 1)) {
+		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
+			 "block is 0 with a 1k block and cluster size");
+		return -EINVAL;
+	}
+
+	blocks_count = (ext4_blocks_count(es) -
+			le32_to_cpu(es->s_first_data_block) +
+			EXT4_BLOCKS_PER_GROUP(sb) - 1);
+	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
+	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
+		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
+		       "(block count %llu, first data block %u, "
+		       "blocks per group %lu)", blocks_count,
+		       ext4_blocks_count(es),
+		       le32_to_cpu(es->s_first_data_block),
+		       EXT4_BLOCKS_PER_GROUP(sb));
+		return -EINVAL;
+	}
+	sbi->s_groups_count = blocks_count;
+	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
+			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
+	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
+	    le32_to_cpu(es->s_inodes_count)) {
+		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
+			 le32_to_cpu(es->s_inodes_count),
+			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ext4_group_desc_init(struct super_block *sb,
+				struct ext4_super_block *es,
+				ext4_fsblk_t logical_sb_block,
+				ext4_group_t *first_not_zeroed)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	unsigned int db_count;
+	ext4_fsblk_t block;
+	int i;
+
+	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
+		   EXT4_DESC_PER_BLOCK(sb);
+	if (ext4_has_feature_meta_bg(sb)) {
+		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
+			ext4_msg(sb, KERN_WARNING,
+				 "first meta block group too large: %u "
+				 "(group descriptor block count %u)",
+				 le32_to_cpu(es->s_first_meta_bg), db_count);
+			return -EINVAL;
+		}
+	}
+	rcu_assign_pointer(sbi->s_group_desc,
+			   kvmalloc_array(db_count,
+					  sizeof(struct buffer_head *),
+					  GFP_KERNEL));
+	if (sbi->s_group_desc == NULL) {
+		ext4_msg(sb, KERN_ERR, "not enough memory");
+		return -ENOMEM;
+	}
+
+	bgl_lock_init(sbi->s_blockgroup_lock);
+
+	/* Pre-read the descriptors into the buffer cache */
+	for (i = 0; i < db_count; i++) {
+		block = descriptor_loc(sb, logical_sb_block, i);
+		ext4_sb_breadahead_unmovable(sb, block);
+	}
+
+	for (i = 0; i < db_count; i++) {
+		struct buffer_head *bh;
+
+		block = descriptor_loc(sb, logical_sb_block, i);
+		bh = ext4_sb_bread_unmovable(sb, block);
+		if (IS_ERR(bh)) {
+			ext4_msg(sb, KERN_ERR,
+			       "can't read group descriptor %d", i);
+			sbi->s_gdb_count = i;
+			return PTR_ERR(bh);
+		}
+		rcu_read_lock();
+		rcu_dereference(sbi->s_group_desc)[i] = bh;
+		rcu_read_unlock();
+	}
+	sbi->s_gdb_count = db_count;
+	if (!ext4_check_descriptors(sb, logical_sb_block, first_not_zeroed)) {
+		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
+		return -EFSCORRUPTED;
+	}
+
+	return 0;
+}
+
+static int ext4_load_and_init_journal(struct super_block *sb,
+				      struct ext4_super_block *es,
+				      struct ext4_fs_context *ctx)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	int err;
+
+	err = ext4_load_journal(sb, es, ctx->journal_devnum);
+	if (err)
+		return err;
+
+	if (ext4_has_feature_64bit(sb) &&
+	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
+				       JBD2_FEATURE_INCOMPAT_64BIT)) {
+		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
+		goto out;
+	}
+
+	if (!set_journal_csum_feature_set(sb)) {
+		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
+			 "feature set");
+		goto out;
+	}
+
+	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
+		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
+					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
+		ext4_msg(sb, KERN_ERR,
+			"Failed to set fast commit journal feature");
+		goto out;
+	}
+
+	/* We have now updated the journal if required, so we can
+	 * validate the data journaling mode. */
+	switch (test_opt(sb, DATA_FLAGS)) {
+	case 0:
+		/* No mode set, assume a default based on the journal
+		 * capabilities: ORDERED_DATA if the journal can
+		 * cope, else JOURNAL_DATA
+		 */
+		if (jbd2_journal_check_available_features
+		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
+			set_opt(sb, ORDERED_DATA);
+			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
+		} else {
+			set_opt(sb, JOURNAL_DATA);
+			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
+		}
+		break;
+
+	case EXT4_MOUNT_ORDERED_DATA:
+	case EXT4_MOUNT_WRITEBACK_DATA:
+		if (!jbd2_journal_check_available_features
+		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
+			ext4_msg(sb, KERN_ERR, "Journal does not support "
+			       "requested data journaling mode");
+			goto out;
+		}
+		break;
+	default:
+		break;
+	}
+
+	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
+	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+		ext4_msg(sb, KERN_ERR, "can't mount with "
+			"journal_async_commit in data=ordered mode");
+		goto out;
+	}
+
+	set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
+
+	sbi->s_journal->j_submit_inode_data_buffers =
+		ext4_journal_submit_inode_data_buffers;
+	sbi->s_journal->j_finish_inode_data_buffers =
+		ext4_journal_finish_inode_data_buffers;
+
+	return 0;
+
+out:
+	ext4_journal_destroy(sbi, sbi->s_journal);
+	return -EINVAL;
+}
+
+static int ext4_check_journal_data_mode(struct super_block *sb)
+{
+	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
+		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with "
+			    "data=journal disables delayed allocation, "
+			    "dioread_nolock, O_DIRECT and fast_commit support!\n");
+		/* can't mount with both data=journal and dioread_nolock. */
+		clear_opt(sb, DIOREAD_NOLOCK);
+		clear_opt2(sb, JOURNAL_FAST_COMMIT);
+		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
+			ext4_msg(sb, KERN_ERR, "can't mount with "
+				 "both data=journal and delalloc");
+			return -EINVAL;
+		}
+		if (test_opt(sb, DAX_ALWAYS)) {
+			ext4_msg(sb, KERN_ERR, "can't mount with "
+				 "both data=journal and dax");
+			return -EINVAL;
+		}
+		if (ext4_has_feature_encrypt(sb)) {
+			ext4_msg(sb, KERN_WARNING,
+				 "encrypted files will use data=ordered "
+				 "instead of data journaling mode");
+		}
+		if (test_opt(sb, DELALLOC))
+			clear_opt(sb, DELALLOC);
+	} else {
+		sb->s_iflags |= SB_I_CGROUPWB;
+	}
+
+	return 0;
+}
+
+static const char *ext4_has_journal_option(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
+		return "journal_async_commit";
+	if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM))
+		return "journal_checksum";
+	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
+		return "commit=";
+	if (EXT4_MOUNT_DATA_FLAGS &
+	    (sbi->s_mount_opt ^ sbi->s_def_mount_opt))
+		return "data=";
+	if (test_opt(sb, DATA_ERR_ABORT))
+		return "data_err=abort";
+	return NULL;
+}
+
+static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
+			   int silent)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es;
+	ext4_fsblk_t logical_sb_block;
+	unsigned long offset = 0;
+	struct buffer_head *bh;
+	int ret = -EINVAL;
+	int blocksize;
+
+	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
+	if (!blocksize) {
+		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
+		return -EINVAL;
+	}
+
+	/*
+	 * The ext4 superblock will not be buffer aligned for other than 1kB
+	 * block sizes.  We need to calculate the offset from buffer start.
+	 */
+	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
+		logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
+		offset = do_div(logical_sb_block, blocksize);
+	} else {
+		logical_sb_block = sbi->s_sb_block;
+	}
+
+	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
+	if (IS_ERR(bh)) {
+		ext4_msg(sb, KERN_ERR, "unable to read superblock");
+		return PTR_ERR(bh);
+	}
+	/*
+	 * Note: s_es must be initialized as soon as possible because
+	 *       some ext4 macro-instructions depend on its value
+	 */
+	es = (struct ext4_super_block *) (bh->b_data + offset);
+	sbi->s_es = es;
+	sb->s_magic = le16_to_cpu(es->s_magic);
+	if (sb->s_magic != EXT4_SUPER_MAGIC) {
+		if (!silent)
+			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
+		goto out;
+	}
+
+	if (le32_to_cpu(es->s_log_block_size) >
+	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Invalid log block size: %u",
+			 le32_to_cpu(es->s_log_block_size));
+		goto out;
+	}
+	if (le32_to_cpu(es->s_log_cluster_size) >
+	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
+		ext4_msg(sb, KERN_ERR,
+			 "Invalid log cluster size: %u",
+			 le32_to_cpu(es->s_log_cluster_size));
+		goto out;
+	}
+
+	blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
+
+	/*
+	 * If the default block size is not the same as the real block size,
+	 * we need to reload it.
+	 */
+	if (sb->s_blocksize == blocksize) {
+		*lsb = logical_sb_block;
+		sbi->s_sbh = bh;
+		return 0;
+	}
+
+	/*
+	 * bh must be released before kill_bdev(), otherwise
+	 * it won't be freed and its page also. kill_bdev()
+	 * is called by sb_set_blocksize().
+	 */
+	brelse(bh);
+	/* Validate the filesystem blocksize */
+	if (!sb_set_blocksize(sb, blocksize)) {
+		ext4_msg(sb, KERN_ERR, "bad block size %d",
+				blocksize);
+		bh = NULL;
+		goto out;
+	}
+
+	logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
+	offset = do_div(logical_sb_block, blocksize);
+	bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
+	if (IS_ERR(bh)) {
+		ext4_msg(sb, KERN_ERR, "Can't read superblock on 2nd try");
+		ret = PTR_ERR(bh);
+		bh = NULL;
+		goto out;
+	}
+	es = (struct ext4_super_block *)(bh->b_data + offset);
+	sbi->s_es = es;
+	if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
+		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
+		goto out;
+	}
+	*lsb = logical_sb_block;
+	sbi->s_sbh = bh;
+	return 0;
+out:
+	brelse(bh);
+	return ret;
+}
+
+static int ext4_hash_info_init(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	unsigned int i;
+
+	sbi->s_def_hash_version = es->s_def_hash_version;
+
+	if (sbi->s_def_hash_version > DX_HASH_LAST) {
+		ext4_msg(sb, KERN_ERR,
+			 "Invalid default hash set in the superblock");
+		return -EINVAL;
+	} else if (sbi->s_def_hash_version == DX_HASH_SIPHASH) {
+		ext4_msg(sb, KERN_ERR,
+			 "SIPHASH is not a valid default hash value");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < 4; i++)
+		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
+
+	if (ext4_has_feature_dir_index(sb)) {
+		i = le32_to_cpu(es->s_flags);
+		if (i & EXT2_FLAGS_UNSIGNED_HASH)
+			sbi->s_hash_unsigned = 3;
+		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
+#ifdef __CHAR_UNSIGNED__
+			if (!sb_rdonly(sb))
+				es->s_flags |=
+					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
+			sbi->s_hash_unsigned = 3;
+#else
+			if (!sb_rdonly(sb))
+				es->s_flags |=
+					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
+#endif
+		}
+	}
+	return 0;
+}
+
+static int ext4_block_group_meta_init(struct super_block *sb, int silent)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	int has_huge_files;
+
+	has_huge_files = ext4_has_feature_huge_file(sb);
+	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
+						      has_huge_files);
+	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
+
+	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
+	if (ext4_has_feature_64bit(sb)) {
+		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
+		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
+		    !is_power_of_2(sbi->s_desc_size)) {
+			ext4_msg(sb, KERN_ERR,
+			       "unsupported descriptor size %lu",
+			       sbi->s_desc_size);
+			return -EINVAL;
+		}
+	} else
+		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
+
+	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
+	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
+
+	sbi->s_inodes_per_block = sb->s_blocksize / EXT4_INODE_SIZE(sb);
+	if (sbi->s_inodes_per_block == 0 || sbi->s_blocks_per_group == 0) {
+		if (!silent)
+			ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
+		return -EINVAL;
+	}
+	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
+	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {
+		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
+			 sbi->s_inodes_per_group);
+		return -EINVAL;
+	}
+	sbi->s_itb_per_group = sbi->s_inodes_per_group /
+					sbi->s_inodes_per_block;
+	sbi->s_desc_per_block = sb->s_blocksize / EXT4_DESC_SIZE(sb);
+	sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
+	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
+	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
+
+	return 0;
+}
+
+/*
+ * It's hard to get stripe aligned blocks if stripe is not aligned with
+ * cluster, just disable stripe and alert user to simplify code and avoid
+ * stripe aligned allocation which will rarely succeed.
+ */
+static bool ext4_is_stripe_incompatible(struct super_block *sb, unsigned long stripe)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	return (stripe > 0 && sbi->s_cluster_ratio > 1 &&
+		stripe % sbi->s_cluster_ratio != 0);
+}
+
+static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
+{
+	struct ext4_super_block *es = NULL;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	ext4_fsblk_t logical_sb_block;
+	struct inode *root;
+	int needs_recovery;
+	int err;
+	ext4_group_t first_not_zeroed;
+	struct ext4_fs_context *ctx = fc->fs_private;
+	int silent = fc->sb_flags & SB_SILENT;
+
+	/* Set defaults for the variables that will be set during parsing */
+	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
+		ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
+
+	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
+	sbi->s_sectors_written_start =
+		part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
+
+	err = ext4_load_super(sb, &logical_sb_block, silent);
+	if (err)
+		goto out_fail;
+
+	es = sbi->s_es;
+	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
+
+	err = ext4_init_metadata_csum(sb, es);
+	if (err)
+		goto failed_mount;
+
+	ext4_set_def_opts(sb, es);
+
+	sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
+	sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
+	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
+	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
+	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
+	sbi->s_sb_update_kb = EXT4_DEF_SB_UPDATE_INTERVAL_KB;
+	sbi->s_sb_update_sec = EXT4_DEF_SB_UPDATE_INTERVAL_SEC;
+
+	/*
+	 * set default s_li_wait_mult for lazyinit, for the case there is
+	 * no mount option specified.
+	 */
+	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
+
+	err = ext4_inode_info_init(sb, es);
+	if (err)
+		goto failed_mount;
+
+	err = parse_apply_sb_mount_options(sb, ctx);
+	if (err < 0)
+		goto failed_mount;
+
+	sbi->s_def_mount_opt = sbi->s_mount_opt;
+	sbi->s_def_mount_opt2 = sbi->s_mount_opt2;
+
+	err = ext4_check_opt_consistency(fc, sb);
+	if (err < 0)
+		goto failed_mount;
+
+	ext4_apply_options(fc, sb);
+
+	err = ext4_encoding_init(sb, es);
+	if (err)
+		goto failed_mount;
+
+	err = ext4_check_journal_data_mode(sb);
+	if (err)
+		goto failed_mount;
+
+	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
+		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
+
+	/* HSM events are allowed by default. */
+	sb->s_iflags |= SB_I_ALLOW_HSM;
+
+	err = ext4_check_feature_compatibility(sb, es, silent);
+	if (err)
+		goto failed_mount;
+
+	err = ext4_block_group_meta_init(sb, silent);
+	if (err)
+		goto failed_mount;
+
+	err = ext4_hash_info_init(sb);
+	if (err)
+		goto failed_mount;
+
+	err = ext4_handle_clustersize(sb);
+	if (err)
+		goto failed_mount;
+
+	err = ext4_check_geometry(sb, es);
+	if (err)
+		goto failed_mount;
+
+	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
+	spin_lock_init(&sbi->s_error_lock);
+	INIT_WORK(&sbi->s_sb_upd_work, update_super_work);
+
+	err = ext4_group_desc_init(sb, es, logical_sb_block, &first_not_zeroed);
+	if (err)
+		goto failed_mount3;
+
+	err = ext4_es_register_shrinker(sbi);
+	if (err)
+		goto failed_mount3;
+
+	sbi->s_stripe = ext4_get_stripe_size(sbi);
+	if (ext4_is_stripe_incompatible(sb, sbi->s_stripe)) {
+		ext4_msg(sb, KERN_WARNING,
+			 "stripe (%lu) is not aligned with cluster size (%u), "
+			 "stripe is disabled",
+			 sbi->s_stripe, sbi->s_cluster_ratio);
+		sbi->s_stripe = 0;
+	}
+	sbi->s_extent_max_zeroout_kb = 32;
+
+	/*
+	 * set up enough so that it can read an inode
+	 */
+	sb->s_op = &ext4_sops;
+	sb->s_export_op = &ext4_export_ops;
+	sb->s_xattr = ext4_xattr_handlers;
+#ifdef CONFIG_FS_ENCRYPTION
+	sb->s_cop = &ext4_cryptops;
+#endif
+#ifdef CONFIG_FS_VERITY
+	sb->s_vop = &ext4_verityops;
+#endif
+#ifdef CONFIG_QUOTA
+	sb->dq_op = &ext4_quota_operations;
+	if (ext4_has_feature_quota(sb))
+		sb->s_qcop = &dquot_quotactl_sysfile_ops;
+	else
+		sb->s_qcop = &ext4_qctl_operations;
+	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
+#endif
+	super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));
+	super_set_sysfs_name_bdev(sb);
+
+	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
+	mutex_init(&sbi->s_orphan_lock);
+
+	spin_lock_init(&sbi->s_bdev_wb_lock);
+
+	ext4_atomic_write_init(sb);
+	ext4_fast_commit_init(sb);
+
+	sb->s_root = NULL;
+
+	needs_recovery = (es->s_last_orphan != 0 ||
+			  ext4_has_feature_orphan_present(sb) ||
+			  ext4_has_feature_journal_needs_recovery(sb));
+
+	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb)) {
+		err = ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block));
+		if (err)
+			goto failed_mount3a;
+	}
+
+	err = -EINVAL;
+	/*
+	 * The first inode we look at is the journal inode.  Don't try
+	 * root first: it may be modified in the journal!
+	 */
+	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
+		err = ext4_load_and_init_journal(sb, es, ctx);
+		if (err)
+			goto failed_mount3a;
+		if (bdev_read_only(sb->s_bdev))
+		    needs_recovery = 0;
+	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
+		   ext4_has_feature_journal_needs_recovery(sb)) {
+		ext4_msg(sb, KERN_ERR, "required journal recovery "
+		       "suppressed and not mounted read-only");
+		goto failed_mount3a;
+	} else {
+		const char *journal_option;
+
+		/* Nojournal mode, all journal mount options are illegal */
+		journal_option = ext4_has_journal_option(sb);
+		if (journal_option != NULL) {
+			ext4_msg(sb, KERN_ERR,
+				 "can't mount with %s, fs mounted w/o journal",
+				 journal_option);
+			goto failed_mount3a;
+		}
+
+		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
+		clear_opt(sb, JOURNAL_CHECKSUM);
+		clear_opt(sb, DATA_FLAGS);
+		clear_opt2(sb, JOURNAL_FAST_COMMIT);
+		sbi->s_journal = NULL;
+		needs_recovery = 0;
+	}
+
+	if (!test_opt(sb, NO_MBCACHE)) {
+		sbi->s_ea_block_cache = ext4_xattr_create_cache();
+		if (!sbi->s_ea_block_cache) {
+			ext4_msg(sb, KERN_ERR,
+				 "Failed to create ea_block_cache");
+			err = -EINVAL;
+			goto failed_mount_wq;
+		}
+
+		if (ext4_has_feature_ea_inode(sb)) {
+			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
+			if (!sbi->s_ea_inode_cache) {
+				ext4_msg(sb, KERN_ERR,
+					 "Failed to create ea_inode_cache");
+				err = -EINVAL;
+				goto failed_mount_wq;
+			}
+		}
+	}
+
+	/*
+	 * Get the # of file system overhead blocks from the
+	 * superblock if present.
+	 */
+	sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
+	/* ignore the precalculated value if it is ridiculous */
+	if (sbi->s_overhead > ext4_blocks_count(es))
+		sbi->s_overhead = 0;
+	/*
+	 * If the bigalloc feature is not enabled recalculating the
+	 * overhead doesn't take long, so we might as well just redo
+	 * it to make sure we are using the correct value.
+	 */
+	if (!ext4_has_feature_bigalloc(sb))
+		sbi->s_overhead = 0;
+	if (sbi->s_overhead == 0) {
+		err = ext4_calculate_overhead(sb);
+		if (err)
+			goto failed_mount_wq;
+	}
+
+	/*
+	 * The maximum number of concurrent works can be high and
+	 * concurrency isn't really necessary.  Limit it to 1.
+	 */
+	EXT4_SB(sb)->rsv_conversion_wq =
+		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
+	if (!EXT4_SB(sb)->rsv_conversion_wq) {
+		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
+		err = -ENOMEM;
+		goto failed_mount4;
+	}
+
+	/*
+	 * The jbd2_journal_load will have done any necessary log recovery,
+	 * so we can safely mount the rest of the filesystem now.
+	 */
+
+	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
+	if (IS_ERR(root)) {
+		ext4_msg(sb, KERN_ERR, "get root inode failed");
+		err = PTR_ERR(root);
+		root = NULL;
+		goto failed_mount4;
+	}
+	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
+		iput(root);
+		err = -EFSCORRUPTED;
+		goto failed_mount4;
+	}
+
+	generic_set_sb_d_ops(sb);
+	sb->s_root = d_make_root(root);
+	if (!sb->s_root) {
+		ext4_msg(sb, KERN_ERR, "get root dentry failed");
+		err = -ENOMEM;
+		goto failed_mount4;
+	}
+
+	err = ext4_setup_super(sb, es, sb_rdonly(sb));
+	if (err == -EROFS) {
+		sb->s_flags |= SB_RDONLY;
+	} else if (err)
+		goto failed_mount4a;
+
+	ext4_set_resv_clusters(sb);
+
+	if (test_opt(sb, BLOCK_VALIDITY)) {
+		err = ext4_setup_system_zone(sb);
+		if (err) {
+			ext4_msg(sb, KERN_ERR, "failed to initialize system "
+				 "zone (%d)", err);
+			goto failed_mount4a;
+		}
+	}
+	ext4_fc_replay_cleanup(sb);
+
+	ext4_ext_init(sb);
+
+	/*
+	 * Enable optimize_scan if number of groups is > threshold. This can be
+	 * turned off by passing "mb_optimize_scan=0". This can also be
+	 * turned on forcefully by passing "mb_optimize_scan=1".
+	 */
+	if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
+		if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
+			set_opt2(sb, MB_OPTIMIZE_SCAN);
+		else
+			clear_opt2(sb, MB_OPTIMIZE_SCAN);
+	}
+
+	err = ext4_mb_init(sb);
+	if (err) {
+		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
+			 err);
+		goto failed_mount5;
+	}
+
+	/*
+	 * We can only set up the journal commit callback once
+	 * mballoc is initialized
+	 */
+	if (sbi->s_journal)
+		sbi->s_journal->j_commit_callback =
+			ext4_journal_commit_callback;
+
+	err = ext4_percpu_param_init(sbi);
+	if (err)
+		goto failed_mount6;
+
+	if (ext4_has_feature_flex_bg(sb))
+		if (!ext4_fill_flex_info(sb)) {
+			ext4_msg(sb, KERN_ERR,
+			       "unable to initialize "
+			       "flex_bg meta info!");
+			err = -ENOMEM;
+			goto failed_mount6;
+		}
+
+	err = ext4_register_li_request(sb, first_not_zeroed);
+	if (err)
+		goto failed_mount6;
+
+	err = ext4_init_orphan_info(sb);
+	if (err)
+		goto failed_mount7;
+#ifdef CONFIG_QUOTA
+	/* Enable quota usage during mount. */
+	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
+		err = ext4_enable_quotas(sb);
+		if (err)
+			goto failed_mount8;
+	}
+#endif  /* CONFIG_QUOTA */
+
+	/*
+	 * Save the original bdev mapping's wb_err value which could be
+	 * used to detect the metadata async write error.
+	 */
+	errseq_check_and_advance(&sb->s_bdev->bd_mapping->wb_err,
+				 &sbi->s_bdev_wb_err);
+	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
+	ext4_orphan_cleanup(sb, es);
+	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
+	/*
+	 * Update the checksum after updating free space/inode counters and
+	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
+	 * checksum in the buffer cache until it is written out and
+	 * e2fsprogs programs trying to open a file system immediately
+	 * after it is mounted can fail.
+	 */
+	ext4_superblock_csum_set(sb);
+	if (needs_recovery) {
+		ext4_msg(sb, KERN_INFO, "recovery complete");
+		err = ext4_mark_recovery_complete(sb, es);
+		if (err)
+			goto failed_mount9;
+	}
+
+	if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev)) {
+		ext4_msg(sb, KERN_WARNING,
+			 "mounting with \"discard\" option, but the device does not support discard");
+		clear_opt(sb, DISCARD);
+	}
+
+	if (es->s_error_count)
+		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
+
+	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
+	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
+	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
+	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
+	atomic_set(&sbi->s_warning_count, 0);
+	atomic_set(&sbi->s_msg_count, 0);
+
+	/* Register sysfs after all initializations are complete. */
+	err = ext4_register_sysfs(sb);
+	if (err)
+		goto failed_mount9;
+
+	return 0;
+
+failed_mount9:
+	ext4_quotas_off(sb, EXT4_MAXQUOTAS);
+failed_mount8: __maybe_unused
+	ext4_release_orphan_info(sb);
+failed_mount7:
+	ext4_unregister_li_request(sb);
+failed_mount6:
+	ext4_mb_release(sb);
+	ext4_flex_groups_free(sbi);
+	ext4_percpu_param_destroy(sbi);
+failed_mount5:
+	ext4_ext_release(sb);
+	ext4_release_system_zone(sb);
+failed_mount4a:
+	dput(sb->s_root);
+	sb->s_root = NULL;
+failed_mount4:
+	ext4_msg(sb, KERN_ERR, "mount failed");
+	if (EXT4_SB(sb)->rsv_conversion_wq)
+		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
+failed_mount_wq:
+	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;
+
+	if (sbi->s_journal) {
+		ext4_journal_destroy(sbi, sbi->s_journal);
+	}
+failed_mount3a:
+	ext4_es_unregister_shrinker(sbi);
+failed_mount3:
+	/* flush s_sb_upd_work before sbi destroy */
+	flush_work(&sbi->s_sb_upd_work);
+	ext4_stop_mmpd(sbi);
+	timer_delete_sync(&sbi->s_err_report);
+	ext4_group_desc_free(sbi);
+failed_mount:
+#if IS_ENABLED(CONFIG_UNICODE)
+	utf8_unload(sb->s_encoding);
+#endif
+
+#ifdef CONFIG_QUOTA
+	for (unsigned int i = 0; i < EXT4_MAXQUOTAS; i++)
+		kfree(get_qf_name(sb, sbi, i));
+#endif
+	fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
+	brelse(sbi->s_sbh);
+	if (sbi->s_journal_bdev_file) {
+		invalidate_bdev(file_bdev(sbi->s_journal_bdev_file));
+		bdev_fput(sbi->s_journal_bdev_file);
+	}
+out_fail:
+	invalidate_bdev(sb->s_bdev);
+	sb->s_fs_info = NULL;
+	return err;
+}
+
+static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct ext4_fs_context *ctx = fc->fs_private;
+	struct ext4_sb_info *sbi;
+	const char *descr;
+	int ret;
+
+	sbi = ext4_alloc_sbi(sb);
+	if (!sbi)
+		return -ENOMEM;
+
+	fc->s_fs_info = sbi;
+
+	/* Cleanup superblock name */
+	strreplace(sb->s_id, '/', '!');
+
+	sbi->s_sb_block = 1;	/* Default super block location */
+	if (ctx->spec & EXT4_SPEC_s_sb_block)
+		sbi->s_sb_block = ctx->s_sb_block;
+
+	ret = __ext4_fill_super(fc, sb);
+	if (ret < 0)
+		goto free_sbi;
+
+	if (sbi->s_journal) {
+		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
+			descr = " journalled data mode";
+		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
+			descr = " ordered data mode";
+		else
+			descr = " writeback data mode";
+	} else
+		descr = "out journal";
+
+	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
+		ext4_msg(sb, KERN_INFO, "mounted filesystem %pU %s with%s. "
+			 "Quota mode: %s.", &sb->s_uuid,
+			 sb_rdonly(sb) ? "ro" : "r/w", descr,
+			 ext4_quota_mode(sb));
+
+	/* Update the s_overhead_clusters if necessary */
+	ext4_update_overhead(sb, false);
+	return 0;
+
+free_sbi:
+	ext4_free_sbi(sbi);
+	fc->s_fs_info = NULL;
+	return ret;
+}
+
+static int ext4_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, ext4_fill_super);
+}
+
+/*
+ * Setup any per-fs journal parameters now.  We'll do this both on
+ * initial mount, once the journal has been initialised but before we've
+ * done any recovery; and again on any subsequent remount.
+ */
+static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	journal->j_commit_interval = sbi->s_commit_interval;
+	journal->j_min_batch_time = sbi->s_min_batch_time;
+	journal->j_max_batch_time = sbi->s_max_batch_time;
+	ext4_fc_init(sb, journal);
+
+	write_lock(&journal->j_state_lock);
+	if (test_opt(sb, BARRIER))
+		journal->j_flags |= JBD2_BARRIER;
+	else
+		journal->j_flags &= ~JBD2_BARRIER;
+	/*
+	 * Always enable journal cycle record option, letting the journal
+	 * records log transactions continuously between each mount.
+	 */
+	journal->j_flags |= JBD2_CYCLE_RECORD;
+	write_unlock(&journal->j_state_lock);
+}
+
+static struct inode *ext4_get_journal_inode(struct super_block *sb,
+					     unsigned int journal_inum)
+{
+	struct inode *journal_inode;
+
+	/*
+	 * Test for the existence of a valid inode on disk.  Bad things
+	 * happen if we iget() an unused inode, as the subsequent iput()
+	 * will try to delete it.
+	 */
+	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
+	if (IS_ERR(journal_inode)) {
+		ext4_msg(sb, KERN_ERR, "no journal found");
+		return ERR_CAST(journal_inode);
+	}
+	if (!journal_inode->i_nlink) {
+		make_bad_inode(journal_inode);
+		iput(journal_inode);
+		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
+		return ERR_PTR(-EFSCORRUPTED);
+	}
+	if (!S_ISREG(journal_inode->i_mode) || IS_ENCRYPTED(journal_inode)) {
+		ext4_msg(sb, KERN_ERR, "invalid journal inode");
+		iput(journal_inode);
+		return ERR_PTR(-EFSCORRUPTED);
+	}
+
+	ext4_debug("Journal inode found at %p: %lld bytes\n",
+		  journal_inode, journal_inode->i_size);
+	return journal_inode;
+}
+
+static int ext4_journal_bmap(journal_t *journal, sector_t *block)
+{
+	struct ext4_map_blocks map;
+	int ret;
+
+	if (journal->j_inode == NULL)
+		return 0;
+
+	map.m_lblk = *block;
+	map.m_len = 1;
+	ret = ext4_map_blocks(NULL, journal->j_inode, &map, 0);
+	if (ret <= 0) {
+		ext4_msg(journal->j_inode->i_sb, KERN_CRIT,
+			 "journal bmap failed: block %llu ret %d\n",
+			 *block, ret);
+		jbd2_journal_abort(journal, ret ? ret : -EIO);
+		return ret;
+	}
+	*block = map.m_pblk;
+	return 0;
+}
+
+static journal_t *ext4_open_inode_journal(struct super_block *sb,
+					  unsigned int journal_inum)
+{
+	struct inode *journal_inode;
+	journal_t *journal;
+
+	journal_inode = ext4_get_journal_inode(sb, journal_inum);
+	if (IS_ERR(journal_inode))
+		return ERR_CAST(journal_inode);
+
+	journal = jbd2_journal_init_inode(journal_inode);
+	if (IS_ERR(journal)) {
+		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
+		iput(journal_inode);
+		return ERR_CAST(journal);
+	}
+	journal->j_private = sb;
+	journal->j_bmap = ext4_journal_bmap;
+	ext4_init_journal_params(sb, journal);
+	return journal;
+}
+
+static struct file *ext4_get_journal_blkdev(struct super_block *sb,
+					dev_t j_dev, ext4_fsblk_t *j_start,
+					ext4_fsblk_t *j_len)
+{
+	struct buffer_head *bh;
+	struct block_device *bdev;
+	struct file *bdev_file;
+	int hblock, blocksize;
+	ext4_fsblk_t sb_block;
+	unsigned long offset;
+	struct ext4_super_block *es;
+	int errno;
+
+	bdev_file = bdev_file_open_by_dev(j_dev,
+		BLK_OPEN_READ | BLK_OPEN_WRITE | BLK_OPEN_RESTRICT_WRITES,
+		sb, &fs_holder_ops);
+	if (IS_ERR(bdev_file)) {
+		ext4_msg(sb, KERN_ERR,
+			 "failed to open journal device unknown-block(%u,%u) %ld",
+			 MAJOR(j_dev), MINOR(j_dev), PTR_ERR(bdev_file));
+		return bdev_file;
+	}
+
+	bdev = file_bdev(bdev_file);
+	blocksize = sb->s_blocksize;
+	hblock = bdev_logical_block_size(bdev);
+	if (blocksize < hblock) {
+		ext4_msg(sb, KERN_ERR,
+			"blocksize too small for journal device");
+		errno = -EINVAL;
+		goto out_bdev;
+	}
+
+	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
+	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
+	set_blocksize(bdev_file, blocksize);
+	bh = __bread(bdev, sb_block, blocksize);
+	if (!bh) {
+		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
+		       "external journal");
+		errno = -EINVAL;
+		goto out_bdev;
+	}
+
+	es = (struct ext4_super_block *) (bh->b_data + offset);
+	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
+	    !(le32_to_cpu(es->s_feature_incompat) &
+	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
+		ext4_msg(sb, KERN_ERR, "external journal has bad superblock");
+		errno = -EFSCORRUPTED;
+		goto out_bh;
+	}
+
+	if ((le32_to_cpu(es->s_feature_ro_compat) &
+	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
+	    es->s_checksum != ext4_superblock_csum(es)) {
+		ext4_msg(sb, KERN_ERR, "external journal has corrupt superblock");
+		errno = -EFSCORRUPTED;
+		goto out_bh;
+	}
+
+	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
+		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
+		errno = -EFSCORRUPTED;
+		goto out_bh;
+	}
+
+	*j_start = sb_block + 1;
+	*j_len = ext4_blocks_count(es);
+	brelse(bh);
+	return bdev_file;
+
+out_bh:
+	brelse(bh);
+out_bdev:
+	bdev_fput(bdev_file);
+	return ERR_PTR(errno);
+}
+
+static journal_t *ext4_open_dev_journal(struct super_block *sb,
+					dev_t j_dev)
+{
+	journal_t *journal;
+	ext4_fsblk_t j_start;
+	ext4_fsblk_t j_len;
+	struct file *bdev_file;
+	int errno = 0;
+
+	bdev_file = ext4_get_journal_blkdev(sb, j_dev, &j_start, &j_len);
+	if (IS_ERR(bdev_file))
+		return ERR_CAST(bdev_file);
+
+	journal = jbd2_journal_init_dev(file_bdev(bdev_file), sb->s_bdev, j_start,
+					j_len, sb->s_blocksize);
+	if (IS_ERR(journal)) {
+		ext4_msg(sb, KERN_ERR, "failed to create device journal");
+		errno = PTR_ERR(journal);
+		goto out_bdev;
+	}
+	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
+		ext4_msg(sb, KERN_ERR, "External journal has more than one "
+					"user (unsupported) - %d",
+			be32_to_cpu(journal->j_superblock->s_nr_users));
+		errno = -EINVAL;
+		goto out_journal;
+	}
+	journal->j_private = sb;
+	EXT4_SB(sb)->s_journal_bdev_file = bdev_file;
+	ext4_init_journal_params(sb, journal);
+	return journal;
+
+out_journal:
+	ext4_journal_destroy(EXT4_SB(sb), journal);
+out_bdev:
+	bdev_fput(bdev_file);
+	return ERR_PTR(errno);
+}
+
+static int ext4_load_journal(struct super_block *sb,
+			     struct ext4_super_block *es,
+			     unsigned long journal_devnum)
+{
+	journal_t *journal;
+	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
+	dev_t journal_dev;
+	int err = 0;
+	int really_read_only;
+	int journal_dev_ro;
+
+	if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
+		return -EFSCORRUPTED;
+
+	if (journal_devnum &&
+	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
+		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
+			"numbers have changed");
+		journal_dev = new_decode_dev(journal_devnum);
+	} else
+		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
+
+	if (journal_inum && journal_dev) {
+		ext4_msg(sb, KERN_ERR,
+			 "filesystem has both journal inode and journal device!");
+		return -EINVAL;
+	}
+
+	if (journal_inum) {
+		journal = ext4_open_inode_journal(sb, journal_inum);
+		if (IS_ERR(journal))
+			return PTR_ERR(journal);
+	} else {
+		journal = ext4_open_dev_journal(sb, journal_dev);
+		if (IS_ERR(journal))
+			return PTR_ERR(journal);
+	}
+
+	journal_dev_ro = bdev_read_only(journal->j_dev);
+	really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
+
+	if (journal_dev_ro && !sb_rdonly(sb)) {
+		ext4_msg(sb, KERN_ERR,
+			 "journal device read-only, try mounting with '-o ro'");
+		err = -EROFS;
+		goto err_out;
+	}
+
+	/*
+	 * Are we loading a blank journal or performing recovery after a
+	 * crash?  For recovery, we need to check in advance whether we
+	 * can get read-write access to the device.
+	 */
+	if (ext4_has_feature_journal_needs_recovery(sb)) {
+		if (sb_rdonly(sb)) {
+			ext4_msg(sb, KERN_INFO, "INFO: recovery "
+					"required on readonly filesystem");
+			if (really_read_only) {
+				ext4_msg(sb, KERN_ERR, "write access "
+					"unavailable, cannot proceed "
+					"(try mounting with noload)");
+				err = -EROFS;
+				goto err_out;
+			}
+			ext4_msg(sb, KERN_INFO, "write access will "
+			       "be enabled during recovery");
+		}
+	}
+
+	if (!(journal->j_flags & JBD2_BARRIER))
+		ext4_msg(sb, KERN_INFO, "barriers disabled");
+
+	if (!ext4_has_feature_journal_needs_recovery(sb))
+		err = jbd2_journal_wipe(journal, !really_read_only);
+	if (!err) {
+		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
+		__le16 orig_state;
+		bool changed = false;
+
+		if (save)
+			memcpy(save, ((char *) es) +
+			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
+		err = jbd2_journal_load(journal);
+		if (save && memcmp(((char *) es) + EXT4_S_ERR_START,
+				   save, EXT4_S_ERR_LEN)) {
+			memcpy(((char *) es) + EXT4_S_ERR_START,
+			       save, EXT4_S_ERR_LEN);
+			changed = true;
+		}
+		kfree(save);
+		orig_state = es->s_state;
+		es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state &
+					   EXT4_ERROR_FS);
+		if (orig_state != es->s_state)
+			changed = true;
+		/* Write out restored error information to the superblock */
+		if (changed && !really_read_only) {
+			int err2;
+			err2 = ext4_commit_super(sb);
+			err = err ? : err2;
+		}
+	}
+
+	if (err) {
+		ext4_msg(sb, KERN_ERR, "error loading journal");
+		goto err_out;
+	}
+
+	EXT4_SB(sb)->s_journal = journal;
+	err = ext4_clear_journal_err(sb, es);
+	if (err) {
+		ext4_journal_destroy(EXT4_SB(sb), journal);
+		return err;
+	}
+
+	if (!really_read_only && journal_devnum &&
+	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
+		es->s_journal_dev = cpu_to_le32(journal_devnum);
+		ext4_commit_super(sb);
+	}
+	if (!really_read_only && journal_inum &&
+	    journal_inum != le32_to_cpu(es->s_journal_inum)) {
+		es->s_journal_inum = cpu_to_le32(journal_inum);
+		ext4_commit_super(sb);
+	}
+
+	return 0;
+
+err_out:
+	ext4_journal_destroy(EXT4_SB(sb), journal);
+	return err;
+}
+
+/* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
+static void ext4_update_super(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	struct buffer_head *sbh = sbi->s_sbh;
+
+	lock_buffer(sbh);
+	/*
+	 * If the file system is mounted read-only, don't update the
+	 * superblock write time.  This avoids updating the superblock
+	 * write time when we are mounting the root file system
+	 * read/only but we need to replay the journal; at that point,
+	 * for people who are east of GMT and who make their clock
+	 * tick in localtime for Windows bug-for-bug compatibility,
+	 * the clock is set in the future, and this will cause e2fsck
+	 * to complain and force a full file system check.
+	 */
+	if (!sb_rdonly(sb))
+		ext4_update_tstamp(es, s_wtime);
+	es->s_kbytes_written =
+		cpu_to_le64(sbi->s_kbytes_written +
+		    ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
+		      sbi->s_sectors_written_start) >> 1));
+	if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
+		ext4_free_blocks_count_set(es,
+			EXT4_C2B(sbi, percpu_counter_sum_positive(
+				&sbi->s_freeclusters_counter)));
+	if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
+		es->s_free_inodes_count =
+			cpu_to_le32(percpu_counter_sum_positive(
+				&sbi->s_freeinodes_counter));
+	/* Copy error information to the on-disk superblock */
+	spin_lock(&sbi->s_error_lock);
+	if (sbi->s_add_error_count > 0) {
+		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
+		if (!es->s_first_error_time && !es->s_first_error_time_hi) {
+			__ext4_update_tstamp(&es->s_first_error_time,
+					     &es->s_first_error_time_hi,
+					     sbi->s_first_error_time);
+			strtomem_pad(es->s_first_error_func,
+				     sbi->s_first_error_func, 0);
+			es->s_first_error_line =
+				cpu_to_le32(sbi->s_first_error_line);
+			es->s_first_error_ino =
+				cpu_to_le32(sbi->s_first_error_ino);
+			es->s_first_error_block =
+				cpu_to_le64(sbi->s_first_error_block);
+			es->s_first_error_errcode =
+				ext4_errno_to_code(sbi->s_first_error_code);
+		}
+		__ext4_update_tstamp(&es->s_last_error_time,
+				     &es->s_last_error_time_hi,
+				     sbi->s_last_error_time);
+		strtomem_pad(es->s_last_error_func, sbi->s_last_error_func, 0);
+		es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
+		es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
+		es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
+		es->s_last_error_errcode =
+				ext4_errno_to_code(sbi->s_last_error_code);
+		/*
+		 * Start the daily error reporting function if it hasn't been
+		 * started already
+		 */
+		if (!es->s_error_count)
+			mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
+		le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
+		sbi->s_add_error_count = 0;
+	}
+	spin_unlock(&sbi->s_error_lock);
+
+	ext4_superblock_csum_set(sb);
+	unlock_buffer(sbh);
+}
+
+static int ext4_commit_super(struct super_block *sb)
+{
+	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
+
+	if (!sbh)
+		return -EINVAL;
+
+	ext4_update_super(sb);
+
+	lock_buffer(sbh);
+	/* Buffer got discarded which means block device got invalidated */
+	if (!buffer_mapped(sbh)) {
+		unlock_buffer(sbh);
+		return -EIO;
+	}
+
+	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
+		/*
+		 * Oh, dear.  A previous attempt to write the
+		 * superblock failed.  This could happen because the
+		 * USB device was yanked out.  Or it could happen to
+		 * be a transient write error and maybe the block will
+		 * be remapped.  Nothing we can do but to retry the
+		 * write and hope for the best.
+		 */
+		ext4_msg(sb, KERN_ERR, "previous I/O error to "
+		       "superblock detected");
+		clear_buffer_write_io_error(sbh);
+		set_buffer_uptodate(sbh);
+	}
+	get_bh(sbh);
+	/* Clear potential dirty bit if it was journalled update */
+	clear_buffer_dirty(sbh);
+	sbh->b_end_io = end_buffer_write_sync;
+	submit_bh(REQ_OP_WRITE | REQ_SYNC |
+		  (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
+	wait_on_buffer(sbh);
+	if (buffer_write_io_error(sbh)) {
+		ext4_msg(sb, KERN_ERR, "I/O error while writing "
+		       "superblock");
+		clear_buffer_write_io_error(sbh);
+		set_buffer_uptodate(sbh);
+		return -EIO;
+	}
+	return 0;
+}
+
+/*
+ * Have we just finished recovery?  If so, and if we are mounting (or
+ * remounting) the filesystem readonly, then we will end up with a
+ * consistent fs on disk.  Record that fact.
+ */
+static int ext4_mark_recovery_complete(struct super_block *sb,
+				       struct ext4_super_block *es)
+{
+	int err;
+	journal_t *journal = EXT4_SB(sb)->s_journal;
+
+	if (!ext4_has_feature_journal(sb)) {
+		if (journal != NULL) {
+			ext4_error(sb, "Journal got removed while the fs was "
+				   "mounted!");
+			return -EFSCORRUPTED;
+		}
+		return 0;
+	}
+	jbd2_journal_lock_updates(journal);
+	err = jbd2_journal_flush(journal, 0);
+	if (err < 0)
+		goto out;
+
+	if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
+	    ext4_has_feature_orphan_present(sb))) {
+		if (!ext4_orphan_file_empty(sb)) {
+			ext4_error(sb, "Orphan file not empty on read-only fs.");
+			err = -EFSCORRUPTED;
+			goto out;
+		}
+		ext4_clear_feature_journal_needs_recovery(sb);
+		ext4_clear_feature_orphan_present(sb);
+		ext4_commit_super(sb);
+	}
+out:
+	jbd2_journal_unlock_updates(journal);
+	return err;
+}
+
+/*
+ * If we are mounting (or read-write remounting) a filesystem whose journal
+ * has recorded an error from a previous lifetime, move that error to the
+ * main filesystem now.
+ */
+static int ext4_clear_journal_err(struct super_block *sb,
+				   struct ext4_super_block *es)
+{
+	journal_t *journal;
+	int j_errno;
+	const char *errstr;
+
+	if (!ext4_has_feature_journal(sb)) {
+		ext4_error(sb, "Journal got removed while the fs was mounted!");
+		return -EFSCORRUPTED;
+	}
+
+	journal = EXT4_SB(sb)->s_journal;
+
+	/*
+	 * Now check for any error status which may have been recorded in the
+	 * journal by a prior ext4_error() or ext4_abort()
+	 */
+
+	j_errno = jbd2_journal_errno(journal);
+	if (j_errno) {
+		char nbuf[16];
+
+		errstr = ext4_decode_error(sb, j_errno, nbuf);
+		ext4_warning(sb, "Filesystem error recorded "
+			     "from previous mount: %s", errstr);
+
+		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
+		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
+		j_errno = ext4_commit_super(sb);
+		if (j_errno)
+			return j_errno;
+		ext4_warning(sb, "Marked fs in need of filesystem check.");
+
+		jbd2_journal_clear_err(journal);
+		jbd2_journal_update_sb_errno(journal);
+	}
+	return 0;
+}
+
+/*
+ * Force the running and committing transactions to commit,
+ * and wait on the commit.
+ */
+int ext4_force_commit(struct super_block *sb)
+{
+	return ext4_journal_force_commit(EXT4_SB(sb)->s_journal);
+}
+
+static int ext4_sync_fs(struct super_block *sb, int wait)
+{
+	int ret = 0;
+	tid_t target;
+	bool needs_barrier = false;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	ret = ext4_emergency_state(sb);
+	if (unlikely(ret))
+		return ret;
+
+	trace_ext4_sync_fs(sb, wait);
+	flush_workqueue(sbi->rsv_conversion_wq);
+	/*
+	 * Writeback quota in non-journalled quota case - journalled quota has
+	 * no dirty dquots
+	 */
+	dquot_writeback_dquots(sb, -1);
+	/*
+	 * Data writeback is possible w/o journal transaction, so barrier must
+	 * being sent at the end of the function. But we can skip it if
+	 * transaction_commit will do it for us.
+	 */
+	if (sbi->s_journal) {
+		target = jbd2_get_latest_transaction(sbi->s_journal);
+		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
+		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
+			needs_barrier = true;
+
+		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
+			if (wait)
+				ret = jbd2_log_wait_commit(sbi->s_journal,
+							   target);
+		}
+	} else if (wait && test_opt(sb, BARRIER))
+		needs_barrier = true;
+	if (needs_barrier) {
+		int err;
+		err = blkdev_issue_flush(sb->s_bdev);
+		if (!ret)
+			ret = err;
+	}
+
+	return ret;
+}
+
+/*
+ * LVM calls this function before a (read-only) snapshot is created.  This
+ * gives us a chance to flush the journal completely and mark the fs clean.
+ *
+ * Note that only this function cannot bring a filesystem to be in a clean
+ * state independently. It relies on upper layer to stop all data & metadata
+ * modifications.
+ */
+static int ext4_freeze(struct super_block *sb)
+{
+	int error = 0;
+	journal_t *journal = EXT4_SB(sb)->s_journal;
+
+	if (journal) {
+		/* Now we set up the journal barrier. */
+		jbd2_journal_lock_updates(journal);
+
+		/*
+		 * Don't clear the needs_recovery flag if we failed to
+		 * flush the journal.
+		 */
+		error = jbd2_journal_flush(journal, 0);
+		if (error < 0)
+			goto out;
+
+		/* Journal blocked and flushed, clear needs_recovery flag. */
+		ext4_clear_feature_journal_needs_recovery(sb);
+		if (ext4_orphan_file_empty(sb))
+			ext4_clear_feature_orphan_present(sb);
+	}
+
+	error = ext4_commit_super(sb);
+out:
+	if (journal)
+		/* we rely on upper layer to stop further updates */
+		jbd2_journal_unlock_updates(journal);
+	return error;
+}
+
+/*
+ * Called by LVM after the snapshot is done.  We need to reset the RECOVER
+ * flag here, even though the filesystem is not technically dirty yet.
+ */
+static int ext4_unfreeze(struct super_block *sb)
+{
+	if (ext4_emergency_state(sb))
+		return 0;
+
+	if (EXT4_SB(sb)->s_journal) {
+		/* Reset the needs_recovery flag before the fs is unlocked. */
+		ext4_set_feature_journal_needs_recovery(sb);
+		if (ext4_has_feature_orphan_file(sb))
+			ext4_set_feature_orphan_present(sb);
+	}
+
+	ext4_commit_super(sb);
+	return 0;
+}
+
+/*
+ * Structure to save mount options for ext4_remount's benefit
+ */
+struct ext4_mount_options {
+	unsigned long s_mount_opt;
+	unsigned long s_mount_opt2;
+	kuid_t s_resuid;
+	kgid_t s_resgid;
+	unsigned long s_commit_interval;
+	u32 s_min_batch_time, s_max_batch_time;
+#ifdef CONFIG_QUOTA
+	int s_jquota_fmt;
+	char *s_qf_names[EXT4_MAXQUOTAS];
+#endif
+};
+
+static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
+{
+	struct ext4_fs_context *ctx = fc->fs_private;
+	struct ext4_super_block *es;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	unsigned long old_sb_flags;
+	struct ext4_mount_options old_opts;
+	ext4_group_t g;
+	int err = 0;
+	int alloc_ctx;
+#ifdef CONFIG_QUOTA
+	int enable_quota = 0;
+	int i, j;
+	char *to_free[EXT4_MAXQUOTAS];
+#endif
+
+
+	/* Store the original options */
+	old_sb_flags = sb->s_flags;
+	old_opts.s_mount_opt = sbi->s_mount_opt;
+	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
+	old_opts.s_resuid = sbi->s_resuid;
+	old_opts.s_resgid = sbi->s_resgid;
+	old_opts.s_commit_interval = sbi->s_commit_interval;
+	old_opts.s_min_batch_time = sbi->s_min_batch_time;
+	old_opts.s_max_batch_time = sbi->s_max_batch_time;
+#ifdef CONFIG_QUOTA
+	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
+	for (i = 0; i < EXT4_MAXQUOTAS; i++)
+		if (sbi->s_qf_names[i]) {
+			char *qf_name = get_qf_name(sb, sbi, i);
+
+			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
+			if (!old_opts.s_qf_names[i]) {
+				for (j = 0; j < i; j++)
+					kfree(old_opts.s_qf_names[j]);
+				return -ENOMEM;
+			}
+		} else
+			old_opts.s_qf_names[i] = NULL;
+#endif
+	if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
+		if (sbi->s_journal && sbi->s_journal->j_task->io_context)
+			ctx->journal_ioprio =
+				sbi->s_journal->j_task->io_context->ioprio;
+		else
+			ctx->journal_ioprio = EXT4_DEF_JOURNAL_IOPRIO;
+
+	}
+
+	if ((ctx->spec & EXT4_SPEC_s_stripe) &&
+	    ext4_is_stripe_incompatible(sb, ctx->s_stripe)) {
+		ext4_msg(sb, KERN_WARNING,
+			 "stripe (%lu) is not aligned with cluster size (%u), "
+			 "stripe is disabled",
+			 ctx->s_stripe, sbi->s_cluster_ratio);
+		ctx->s_stripe = 0;
+	}
+
+	/*
+	 * Changing the DIOREAD_NOLOCK or DELALLOC mount options may cause
+	 * two calls to ext4_should_dioread_nolock() to return inconsistent
+	 * values, triggering WARN_ON in ext4_add_complete_io(). we grab
+	 * here s_writepages_rwsem to avoid race between writepages ops and
+	 * remount.
+	 */
+	alloc_ctx = ext4_writepages_down_write(sb);
+	ext4_apply_options(fc, sb);
+	ext4_writepages_up_write(sb, alloc_ctx);
+
+	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
+	    test_opt(sb, JOURNAL_CHECKSUM)) {
+		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
+			 "during remount not supported; ignoring");
+		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
+	}
+
+	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
+		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
+			ext4_msg(sb, KERN_ERR, "can't mount with "
+				 "both data=journal and delalloc");
+			err = -EINVAL;
+			goto restore_opts;
+		}
+		if (test_opt(sb, DIOREAD_NOLOCK)) {
+			ext4_msg(sb, KERN_ERR, "can't mount with "
+				 "both data=journal and dioread_nolock");
+			err = -EINVAL;
+			goto restore_opts;
+		}
+	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
+		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+			ext4_msg(sb, KERN_ERR, "can't mount with "
+				"journal_async_commit in data=ordered mode");
+			err = -EINVAL;
+			goto restore_opts;
+		}
+	}
+
+	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
+		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
+		err = -EINVAL;
+		goto restore_opts;
+	}
+
+	if ((old_opts.s_mount_opt & EXT4_MOUNT_DELALLOC) &&
+	    !test_opt(sb, DELALLOC)) {
+		ext4_msg(sb, KERN_ERR, "can't disable delalloc during remount");
+		err = -EINVAL;
+		goto restore_opts;
+	}
+
+	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
+		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
+
+	es = sbi->s_es;
+
+	if (sbi->s_journal) {
+		ext4_init_journal_params(sb, sbi->s_journal);
+		set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
+	}
+
+	/* Flush outstanding errors before changing fs state */
+	flush_work(&sbi->s_sb_upd_work);
+
+	if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
+		if (ext4_emergency_state(sb)) {
+			err = -EROFS;
+			goto restore_opts;
+		}
+
+		if (fc->sb_flags & SB_RDONLY) {
+			err = sync_filesystem(sb);
+			if (err < 0)
+				goto restore_opts;
+			err = dquot_suspend(sb, -1);
+			if (err < 0)
+				goto restore_opts;
+
+			/*
+			 * First of all, the unconditional stuff we have to do
+			 * to disable replay of the journal when we next remount
+			 */
+			sb->s_flags |= SB_RDONLY;
+
+			/*
+			 * OK, test if we are remounting a valid rw partition
+			 * readonly, and if so set the rdonly flag and then
+			 * mark the partition as valid again.
+			 */
+			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
+			    (sbi->s_mount_state & EXT4_VALID_FS))
+				es->s_state = cpu_to_le16(sbi->s_mount_state);
+
+			if (sbi->s_journal) {
+				/*
+				 * We let remount-ro finish even if marking fs
+				 * as clean failed...
+				 */
+				ext4_mark_recovery_complete(sb, es);
+			}
+		} else {
+			/* Make sure we can mount this feature set readwrite */
+			if (ext4_has_feature_readonly(sb) ||
+			    !ext4_feature_set_ok(sb, 0)) {
+				err = -EROFS;
+				goto restore_opts;
+			}
+			/*
+			 * Make sure the group descriptor checksums
+			 * are sane.  If they aren't, refuse to remount r/w.
+			 */
+			for (g = 0; g < sbi->s_groups_count; g++) {
+				struct ext4_group_desc *gdp =
+					ext4_get_group_desc(sb, g, NULL);
+
+				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
+					ext4_msg(sb, KERN_ERR,
+	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
+		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
+					       le16_to_cpu(gdp->bg_checksum));
+					err = -EFSBADCRC;
+					goto restore_opts;
+				}
+			}
+
+			/*
+			 * If we have an unprocessed orphan list hanging
+			 * around from a previously readonly bdev mount,
+			 * require a full umount/remount for now.
+			 */
+			if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
+				ext4_msg(sb, KERN_WARNING, "Couldn't "
+				       "remount RDWR because of unprocessed "
+				       "orphan inode list.  Please "
+				       "umount/remount instead");
+				err = -EINVAL;
+				goto restore_opts;
+			}
+
+			/*
+			 * Mounting a RDONLY partition read-write, so reread
+			 * and store the current valid flag.  (It may have
+			 * been changed by e2fsck since we originally mounted
+			 * the partition.)
+			 */
+			if (sbi->s_journal) {
+				err = ext4_clear_journal_err(sb, es);
+				if (err)
+					goto restore_opts;
+			}
+			sbi->s_mount_state = (le16_to_cpu(es->s_state) &
+					      ~EXT4_FC_REPLAY);
+
+			err = ext4_setup_super(sb, es, 0);
+			if (err)
+				goto restore_opts;
+
+			sb->s_flags &= ~SB_RDONLY;
+			if (ext4_has_feature_mmp(sb)) {
+				err = ext4_multi_mount_protect(sb,
+						le64_to_cpu(es->s_mmp_block));
+				if (err)
+					goto restore_opts;
+			}
+#ifdef CONFIG_QUOTA
+			enable_quota = 1;
+#endif
+		}
+	}
+
+	/*
+	 * Handle creation of system zone data early because it can fail.
+	 * Releasing of existing data is done when we are sure remount will
+	 * succeed.
+	 */
+	if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
+		err = ext4_setup_system_zone(sb);
+		if (err)
+			goto restore_opts;
+	}
+
+	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
+		err = ext4_commit_super(sb);
+		if (err)
+			goto restore_opts;
+	}
+
+#ifdef CONFIG_QUOTA
+	if (enable_quota) {
+		if (sb_any_quota_suspended(sb))
+			dquot_resume(sb, -1);
+		else if (ext4_has_feature_quota(sb)) {
+			err = ext4_enable_quotas(sb);
+			if (err)
+				goto restore_opts;
+		}
+	}
+	/* Release old quota file names */
+	for (i = 0; i < EXT4_MAXQUOTAS; i++)
+		kfree(old_opts.s_qf_names[i]);
+#endif
+	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
+		ext4_release_system_zone(sb);
+
+	/*
+	 * Reinitialize lazy itable initialization thread based on
+	 * current settings
+	 */
+	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
+		ext4_unregister_li_request(sb);
+	else {
+		ext4_group_t first_not_zeroed;
+		first_not_zeroed = ext4_has_uninit_itable(sb);
+		ext4_register_li_request(sb, first_not_zeroed);
+	}
+
+	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
+		ext4_stop_mmpd(sbi);
+
+	/*
+	 * Handle aborting the filesystem as the last thing during remount to
+	 * avoid obsure errors during remount when some option changes fail to
+	 * apply due to shutdown filesystem.
+	 */
+	if (test_opt2(sb, ABORT))
+		ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
+
+	return 0;
+
+restore_opts:
+	/*
+	 * If there was a failing r/w to ro transition, we may need to
+	 * re-enable quota
+	 */
+	if (sb_rdonly(sb) && !(old_sb_flags & SB_RDONLY) &&
+	    sb_any_quota_suspended(sb))
+		dquot_resume(sb, -1);
+
+	alloc_ctx = ext4_writepages_down_write(sb);
+	sb->s_flags = old_sb_flags;
+	sbi->s_mount_opt = old_opts.s_mount_opt;
+	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
+	sbi->s_resuid = old_opts.s_resuid;
+	sbi->s_resgid = old_opts.s_resgid;
+	sbi->s_commit_interval = old_opts.s_commit_interval;
+	sbi->s_min_batch_time = old_opts.s_min_batch_time;
+	sbi->s_max_batch_time = old_opts.s_max_batch_time;
+	ext4_writepages_up_write(sb, alloc_ctx);
+
+	if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
+		ext4_release_system_zone(sb);
+#ifdef CONFIG_QUOTA
+	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
+	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
+		to_free[i] = get_qf_name(sb, sbi, i);
+		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
+	}
+	synchronize_rcu();
+	for (i = 0; i < EXT4_MAXQUOTAS; i++)
+		kfree(to_free[i]);
+#endif
+	if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
+		ext4_stop_mmpd(sbi);
+	return err;
+}
+
+static int ext4_reconfigure(struct fs_context *fc)
+{
+	struct super_block *sb = fc->root->d_sb;
+	int ret;
+	bool old_ro = sb_rdonly(sb);
+
+	fc->s_fs_info = EXT4_SB(sb);
+
+	ret = ext4_check_opt_consistency(fc, sb);
+	if (ret < 0)
+		return ret;
+
+	ret = __ext4_remount(fc, sb);
+	if (ret < 0)
+		return ret;
+
+	ext4_msg(sb, KERN_INFO, "re-mounted %pU%s.",
+		 &sb->s_uuid,
+		 (old_ro != sb_rdonly(sb)) ? (sb_rdonly(sb) ? " ro" : " r/w") : "");
+
+	return 0;
+}
+
+#ifdef CONFIG_QUOTA
+static int ext4_statfs_project(struct super_block *sb,
+			       kprojid_t projid, struct kstatfs *buf)
+{
+	struct kqid qid;
+	struct dquot *dquot;
+	u64 limit;
+	u64 curblock;
+
+	qid = make_kqid_projid(projid);
+	dquot = dqget(sb, qid);
+	if (IS_ERR(dquot))
+		return PTR_ERR(dquot);
+	spin_lock(&dquot->dq_dqb_lock);
+
+	limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
+			     dquot->dq_dqb.dqb_bhardlimit);
+	limit >>= sb->s_blocksize_bits;
+
+	if (limit) {
+		uint64_t	remaining = 0;
+
+		curblock = (dquot->dq_dqb.dqb_curspace +
+			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
+		if (limit > curblock)
+			remaining = limit - curblock;
+
+		buf->f_blocks = min(buf->f_blocks, limit);
+		buf->f_bfree = min(buf->f_bfree, remaining);
+		buf->f_bavail = min(buf->f_bavail, remaining);
+	}
+
+	limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
+			     dquot->dq_dqb.dqb_ihardlimit);
+	if (limit) {
+		uint64_t	remaining = 0;
+
+		if (limit > dquot->dq_dqb.dqb_curinodes)
+			remaining = limit - dquot->dq_dqb.dqb_curinodes;
+
+		buf->f_files = min(buf->f_files, limit);
+		buf->f_ffree = min(buf->f_ffree, remaining);
+	}
+
+	spin_unlock(&dquot->dq_dqb_lock);
+	dqput(dquot);
+	return 0;
+}
+#endif
+
+static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	ext4_fsblk_t overhead = 0, resv_blocks;
+	s64 bfree;
+	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
+
+	if (!test_opt(sb, MINIX_DF))
+		overhead = sbi->s_overhead;
+
+	buf->f_type = EXT4_SUPER_MAGIC;
+	buf->f_bsize = sb->s_blocksize;
+	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
+	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
+		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
+	/* prevent underflow in case that few free space is available */
+	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
+	buf->f_bavail = buf->f_bfree -
+			(ext4_r_blocks_count(es) + resv_blocks);
+	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
+		buf->f_bavail = 0;
+	buf->f_files = le32_to_cpu(es->s_inodes_count);
+	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
+	buf->f_namelen = EXT4_NAME_LEN;
+	buf->f_fsid = uuid_to_fsid(es->s_uuid);
+
+#ifdef CONFIG_QUOTA
+	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
+	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
+		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
+#endif
+	return 0;
+}
+
+
+#ifdef CONFIG_QUOTA
+
+/*
+ * Helper functions so that transaction is started before we acquire dqio_sem
+ * to keep correct lock ordering of transaction > dqio_sem
+ */
+static inline struct inode *dquot_to_inode(struct dquot *dquot)
+{
+	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
+}
+
+static int ext4_write_dquot(struct dquot *dquot)
+{
+	int ret, err;
+	handle_t *handle;
+	struct inode *inode;
+
+	inode = dquot_to_inode(dquot);
+	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
+				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+	ret = dquot_commit(dquot);
+	if (ret < 0)
+		ext4_error_err(dquot->dq_sb, -ret,
+			       "Failed to commit dquot type %d",
+			       dquot->dq_id.type);
+	err = ext4_journal_stop(handle);
+	if (!ret)
+		ret = err;
+	return ret;
+}
+
+static int ext4_acquire_dquot(struct dquot *dquot)
+{
+	int ret, err;
+	handle_t *handle;
+
+	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
+				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+	ret = dquot_acquire(dquot);
+	if (ret < 0)
+		ext4_error_err(dquot->dq_sb, -ret,
+			      "Failed to acquire dquot type %d",
+			      dquot->dq_id.type);
+	err = ext4_journal_stop(handle);
+	if (!ret)
+		ret = err;
+	return ret;
+}
+
+static int ext4_release_dquot(struct dquot *dquot)
+{
+	int ret, err;
+	handle_t *handle;
+	bool freeze_protected = false;
+
+	/*
+	 * Trying to sb_start_intwrite() in a running transaction
+	 * can result in a deadlock. Further, running transactions
+	 * are already protected from freezing.
+	 */
+	if (!ext4_journal_current_handle()) {
+		sb_start_intwrite(dquot->dq_sb);
+		freeze_protected = true;
+	}
+
+	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
+				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
+	if (IS_ERR(handle)) {
+		/* Release dquot anyway to avoid endless cycle in dqput() */
+		dquot_release(dquot);
+		if (freeze_protected)
+			sb_end_intwrite(dquot->dq_sb);
+		return PTR_ERR(handle);
+	}
+	ret = dquot_release(dquot);
+	if (ret < 0)
+		ext4_error_err(dquot->dq_sb, -ret,
+			       "Failed to release dquot type %d",
+			       dquot->dq_id.type);
+	err = ext4_journal_stop(handle);
+	if (!ret)
+		ret = err;
+
+	if (freeze_protected)
+		sb_end_intwrite(dquot->dq_sb);
+
+	return ret;
+}
+
+static int ext4_mark_dquot_dirty(struct dquot *dquot)
+{
+	struct super_block *sb = dquot->dq_sb;
+
+	if (ext4_is_quota_journalled(sb)) {
+		dquot_mark_dquot_dirty(dquot);
+		return ext4_write_dquot(dquot);
+	} else {
+		return dquot_mark_dquot_dirty(dquot);
+	}
+}
+
+static int ext4_write_info(struct super_block *sb, int type)
+{
+	int ret, err;
+	handle_t *handle;
+
+	/* Data block + inode block */
+	handle = ext4_journal_start_sb(sb, EXT4_HT_QUOTA, 2);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+	ret = dquot_commit_info(sb, type);
+	err = ext4_journal_stop(handle);
+	if (!ret)
+		ret = err;
+	return ret;
+}
+
+static void lockdep_set_quota_inode(struct inode *inode, int subclass)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+
+	/* The first argument of lockdep_set_subclass has to be
+	 * *exactly* the same as the argument to init_rwsem() --- in
+	 * this case, in init_once() --- or lockdep gets unhappy
+	 * because the name of the lock is set using the
+	 * stringification of the argument to init_rwsem().
+	 */
+	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
+	lockdep_set_subclass(&ei->i_data_sem, subclass);
+}
+
+/*
+ * Standard function to be called on quota_on
+ */
+static int ext4_quota_on(struct super_block *sb, int type, int format_id,
+			 const struct path *path)
+{
+	int err;
+
+	if (!test_opt(sb, QUOTA))
+		return -EINVAL;
+
+	/* Quotafile not on the same filesystem? */
+	if (path->dentry->d_sb != sb)
+		return -EXDEV;
+
+	/* Quota already enabled for this file? */
+	if (IS_NOQUOTA(d_inode(path->dentry)))
+		return -EBUSY;
+
+	/* Journaling quota? */
+	if (EXT4_SB(sb)->s_qf_names[type]) {
+		/* Quotafile not in fs root? */
+		if (path->dentry->d_parent != sb->s_root)
+			ext4_msg(sb, KERN_WARNING,
+				"Quota file not on filesystem root. "
+				"Journaled quota will not work");
+		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
+	} else {
+		/*
+		 * Clear the flag just in case mount options changed since
+		 * last time.
+		 */
+		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
+	}
+
+	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
+	err = dquot_quota_on(sb, type, format_id, path);
+	if (!err) {
+		struct inode *inode = d_inode(path->dentry);
+		handle_t *handle;
+
+		/*
+		 * Set inode flags to prevent userspace from messing with quota
+		 * files. If this fails, we return success anyway since quotas
+		 * are already enabled and this is not a hard failure.
+		 */
+		inode_lock(inode);
+		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
+		if (IS_ERR(handle))
+			goto unlock_inode;
+		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
+		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
+				S_NOATIME | S_IMMUTABLE);
+		err = ext4_mark_inode_dirty(handle, inode);
+		ext4_journal_stop(handle);
+	unlock_inode:
+		inode_unlock(inode);
+		if (err)
+			dquot_quota_off(sb, type);
+	}
+	if (err)
+		lockdep_set_quota_inode(path->dentry->d_inode,
+					     I_DATA_SEM_NORMAL);
+	return err;
+}
+
+static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum)
+{
+	switch (type) {
+	case USRQUOTA:
+		return qf_inum == EXT4_USR_QUOTA_INO;
+	case GRPQUOTA:
+		return qf_inum == EXT4_GRP_QUOTA_INO;
+	case PRJQUOTA:
+		return qf_inum >= EXT4_GOOD_OLD_FIRST_INO;
+	default:
+		BUG();
+	}
+}
+
+static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
+			     unsigned int flags)
+{
+	int err;
+	struct inode *qf_inode;
+	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
+	};
+
+	BUG_ON(!ext4_has_feature_quota(sb));
+
+	if (!qf_inums[type])
+		return -EPERM;
+
+	if (!ext4_check_quota_inum(type, qf_inums[type])) {
+		ext4_error(sb, "Bad quota inum: %lu, type: %d",
+				qf_inums[type], type);
+		return -EUCLEAN;
+	}
+
+	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
+	if (IS_ERR(qf_inode)) {
+		ext4_error(sb, "Bad quota inode: %lu, type: %d",
+				qf_inums[type], type);
+		return PTR_ERR(qf_inode);
+	}
+
+	/* Don't account quota for quota files to avoid recursion */
+	qf_inode->i_flags |= S_NOQUOTA;
+	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
+	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
+	if (err)
+		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
+	iput(qf_inode);
+
+	return err;
+}
+
+/* Enable usage tracking for all quota types. */
+int ext4_enable_quotas(struct super_block *sb)
+{
+	int type, err = 0;
+	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
+	};
+	bool quota_mopt[EXT4_MAXQUOTAS] = {
+		test_opt(sb, USRQUOTA),
+		test_opt(sb, GRPQUOTA),
+		test_opt(sb, PRJQUOTA),
+	};
+
+	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
+	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
+		if (qf_inums[type]) {
+			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
+				DQUOT_USAGE_ENABLED |
+				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
+			if (err) {
+				ext4_warning(sb,
+					"Failed to enable quota tracking "
+					"(type=%d, err=%d, ino=%lu). "
+					"Please run e2fsck to fix.", type,
+					err, qf_inums[type]);
+
+				ext4_quotas_off(sb, type);
+				return err;
+			}
+		}
+	}
+	return 0;
+}
+
+static int ext4_quota_off(struct super_block *sb, int type)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	handle_t *handle;
+	int err;
+
+	/* Force all delayed allocation blocks to be allocated.
+	 * Caller already holds s_umount sem */
+	if (test_opt(sb, DELALLOC))
+		sync_filesystem(sb);
+
+	if (!inode || !igrab(inode))
+		goto out;
+
+	err = dquot_quota_off(sb, type);
+	if (err || ext4_has_feature_quota(sb))
+		goto out_put;
+	/*
+	 * When the filesystem was remounted read-only first, we cannot cleanup
+	 * inode flags here. Bad luck but people should be using QUOTA feature
+	 * these days anyway.
+	 */
+	if (sb_rdonly(sb))
+		goto out_put;
+
+	inode_lock(inode);
+	/*
+	 * Update modification times of quota files when userspace can
+	 * start looking at them. If we fail, we return success anyway since
+	 * this is not a hard failure and quotas are already disabled.
+	 */
+	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
+	if (IS_ERR(handle)) {
+		err = PTR_ERR(handle);
+		goto out_unlock;
+	}
+	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
+	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
+	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+	err = ext4_mark_inode_dirty(handle, inode);
+	ext4_journal_stop(handle);
+out_unlock:
+	inode_unlock(inode);
+out_put:
+	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
+	iput(inode);
+	return err;
+out:
+	return dquot_quota_off(sb, type);
+}
+
+/* Read data from quotafile - avoid pagecache and such because we cannot afford
+ * acquiring the locks... As quota files are never truncated and quota code
+ * itself serializes the operations (and no one else should touch the files)
+ * we don't have to be afraid of races */
+static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
+			       size_t len, loff_t off)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
+	int offset = off & (sb->s_blocksize - 1);
+	int tocopy;
+	size_t toread;
+	struct buffer_head *bh;
+	loff_t i_size = i_size_read(inode);
+
+	if (off > i_size)
+		return 0;
+	if (off+len > i_size)
+		len = i_size-off;
+	toread = len;
+	while (toread > 0) {
+		tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
+		bh = ext4_bread(NULL, inode, blk, 0);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
+		if (!bh)	/* A hole? */
+			memset(data, 0, tocopy);
+		else
+			memcpy(data, bh->b_data+offset, tocopy);
+		brelse(bh);
+		offset = 0;
+		toread -= tocopy;
+		data += tocopy;
+		blk++;
+	}
+	return len;
+}
+
+/* Write to quotafile (we know the transaction is already started and has
+ * enough credits) */
+static ssize_t ext4_quota_write(struct super_block *sb, int type,
+				const char *data, size_t len, loff_t off)
+{
+	struct inode *inode = sb_dqopt(sb)->files[type];
+	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
+	int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
+	int retries = 0;
+	struct buffer_head *bh;
+	handle_t *handle = journal_current_handle();
+
+	if (!handle) {
+		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
+			" cancelled because transaction is not started",
+			(unsigned long long)off, (unsigned long long)len);
+		return -EIO;
+	}
+	/*
+	 * Since we account only one data block in transaction credits,
+	 * then it is impossible to cross a block boundary.
+	 */
+	if (sb->s_blocksize - offset < len) {
+		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
+			" cancelled because not block aligned",
+			(unsigned long long)off, (unsigned long long)len);
+		return -EIO;
+	}
+
+	do {
+		bh = ext4_bread(handle, inode, blk,
+				EXT4_GET_BLOCKS_CREATE |
+				EXT4_GET_BLOCKS_METADATA_NOFAIL);
+	} while (PTR_ERR(bh) == -ENOSPC &&
+		 ext4_should_retry_alloc(inode->i_sb, &retries));
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+	if (!bh)
+		goto out;
+	BUFFER_TRACE(bh, "get write access");
+	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
+	if (err) {
+		brelse(bh);
+		return err;
+	}
+	lock_buffer(bh);
+	memcpy(bh->b_data+offset, data, len);
+	flush_dcache_folio(bh->b_folio);
+	unlock_buffer(bh);
+	err = ext4_handle_dirty_metadata(handle, NULL, bh);
+	brelse(bh);
+out:
+	if (inode->i_size < off + len) {
+		i_size_write(inode, off + len);
+		EXT4_I(inode)->i_disksize = inode->i_size;
+		err2 = ext4_mark_inode_dirty(handle, inode);
+		if (unlikely(err2 && !err))
+			err = err2;
+	}
+	return err ? err : len;
+}
+#endif
+
+#if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
+static inline void register_as_ext2(void)
+{
+	int err = register_filesystem(&ext2_fs_type);
+	if (err)
+		printk(KERN_WARNING
+		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
+}
+
+static inline void unregister_as_ext2(void)
+{
+	unregister_filesystem(&ext2_fs_type);
+}
+
+static inline int ext2_feature_set_ok(struct super_block *sb)
+{
+	if (ext4_has_unknown_ext2_incompat_features(sb))
+		return 0;
+	if (sb_rdonly(sb))
+		return 1;
+	if (ext4_has_unknown_ext2_ro_compat_features(sb))
+		return 0;
+	return 1;
+}
+#else
+static inline void register_as_ext2(void) { }
+static inline void unregister_as_ext2(void) { }
+static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
+#endif
+
+static inline void register_as_ext3(void)
+{
+	int err = register_filesystem(&ext3_fs_type);
+	if (err)
+		printk(KERN_WARNING
+		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
+}
+
+static inline void unregister_as_ext3(void)
+{
+	unregister_filesystem(&ext3_fs_type);
+}
+
+static inline int ext3_feature_set_ok(struct super_block *sb)
+{
+	if (ext4_has_unknown_ext3_incompat_features(sb))
+		return 0;
+	if (!ext4_has_feature_journal(sb))
+		return 0;
+	if (sb_rdonly(sb))
+		return 1;
+	if (ext4_has_unknown_ext3_ro_compat_features(sb))
+		return 0;
+	return 1;
+}
+
+static void ext4_kill_sb(struct super_block *sb)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct file *bdev_file = sbi ? sbi->s_journal_bdev_file : NULL;
+
+	kill_block_super(sb);
+
+	if (bdev_file)
+		bdev_fput(bdev_file);
+}
+
+static struct file_system_type ext4_fs_type = {
+	.owner			= THIS_MODULE,
+	.name			= "ext4",
+	.init_fs_context	= ext4_init_fs_context,
+	.parameters		= ext4_param_specs,
+	.kill_sb		= ext4_kill_sb,
+	.fs_flags		= FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME,
+};
+MODULE_ALIAS_FS("ext4");
+
+static int __init ext4_init_fs(void)
+{
+	int err;
+
+	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
+	ext4_li_info = NULL;
+
+	/* Build-time check for flags consistency */
+	ext4_check_flag_values();
+
+	err = ext4_init_es();
+	if (err)
+		return err;
+
+	err = ext4_init_pending();
+	if (err)
+		goto out7;
+
+	err = ext4_init_post_read_processing();
+	if (err)
+		goto out6;
+
+	err = ext4_init_pageio();
+	if (err)
+		goto out5;
+
+	err = ext4_init_system_zone();
+	if (err)
+		goto out4;
+
+	err = ext4_init_sysfs();
+	if (err)
+		goto out3;
+
+	err = ext4_init_mballoc();
+	if (err)
+		goto out2;
+	err = init_inodecache();
+	if (err)
+		goto out1;
+
+	err = ext4_fc_init_dentry_cache();
+	if (err)
+		goto out05;
+
+	register_as_ext3();
+	register_as_ext2();
+	err = register_filesystem(&ext4_fs_type);
+	if (err)
+		goto out;
+
+	return 0;
+out:
+	unregister_as_ext2();
+	unregister_as_ext3();
+	ext4_fc_destroy_dentry_cache();
+out05:
+	destroy_inodecache();
+out1:
+	ext4_exit_mballoc();
+out2:
+	ext4_exit_sysfs();
+out3:
+	ext4_exit_system_zone();
+out4:
+	ext4_exit_pageio();
+out5:
+	ext4_exit_post_read_processing();
+out6:
+	ext4_exit_pending();
+out7:
+	ext4_exit_es();
+
+	return err;
+}
+
+static void __exit ext4_exit_fs(void)
+{
+	ext4_destroy_lazyinit_thread();
+	unregister_as_ext2();
+	unregister_as_ext3();
+	unregister_filesystem(&ext4_fs_type);
+	ext4_fc_destroy_dentry_cache();
+	destroy_inodecache();
+	ext4_exit_mballoc();
+	ext4_exit_sysfs();
+	ext4_exit_system_zone();
+	ext4_exit_pageio();
+	ext4_exit_post_read_processing();
+	ext4_exit_es();
+	ext4_exit_pending();
+}
+
+MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
+MODULE_DESCRIPTION("Fourth Extended Filesystem");
+MODULE_LICENSE("GPL");
+module_init(ext4_init_fs)
+module_exit(ext4_exit_fs)
-- 
2.43.0

    