--- /dev/null
+---
+ fs/ext4/ext4.h | 29 ++++++++++++++++++++++-
+ fs/ext4/ialloc.c | 3 ++-
+ fs/ext4/inode.c | 15 +++++++++++++++
+ fs/ext4/namei.c | 9 ++++++---
+ fs/ext4/super.c | 10 ++--------
+ 5 files changed, 47 insertions(+), 13 deletions(-)
+
+diff -ur a/fs/ext4/ext4.h b/fs/ext4/ext4.h
+--- a/fs/ext4/ext4.h 2021-12-09 07:30:00.134965109 -0700
++++ b/fs/ext4/ext4.h 2021-12-09 07:32:16.038650421 -0700
+@@ -1849,6 +1849,8 @@
+
+ #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
+
++#define JOURNAL_START_HAS_3ARGS 1
++
+ /*
+ * Codes for operating systems
+ */
+@@ -2089,7 +2091,21 @@
+
+ EXTN_FEATURE_FUNCS(2)
+ EXTN_FEATURE_FUNCS(3)
+-EXTN_FEATURE_FUNCS(4)
++static inline bool ext4_has_unknown_ext4_compat_features(struct super_block *sb)
++{
++ return ((EXT4_SB(sb)->s_es->s_feature_compat &
++ cpu_to_le32(~EXT4_FEATURE_COMPAT_SUPP)) != 0);
++}
++static inline bool ext4_has_unknown_ext4_ro_compat_features(struct super_block *sb)
++{
++ return ((EXT4_SB(sb)->s_es->s_feature_ro_compat &
++ cpu_to_le32(~EXT4_FEATURE_RO_COMPAT_SUPP)) != 0);
++}
++static inline bool ext4_has_unknown_ext4_incompat_features(struct super_block *sb)
++{
++ return ((EXT4_SB(sb)->s_es->s_feature_incompat &
++ cpu_to_le32(~EXT4_FEATURE_INCOMPAT_SUPP)) != 0);
++}
+
+ static inline bool ext4_has_compat_features(struct super_block *sb)
+ {
+@@ -3554,6 +3575,11 @@
+ #define EXT_MAX_BLOCKS 0xffffffff
+
+ extern void ext4_ext_tree_init(handle_t *handle, struct inode *inode);
++extern struct buffer_head *ext4_read_inode_bitmap(struct super_block *sb,
++ ext4_group_t block_group);
++extern struct buffer_head *ext4_append(handle_t *handle,
++ struct inode *inode,
++ ext4_lblk_t *block);
+ extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
+ extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
+ struct ext4_map_blocks *map, int flags);
+diff -ur a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
+--- a/fs/ext4/ialloc.c 2021-12-09 07:30:00.086965299 -0700
++++ b/fs/ext4/ialloc.c 2021-12-09 07:30:47.418778395 -0700
+@@ -120,7 +120,7 @@
+ *
+ * Return buffer_head of bitmap on success, or an ERR_PTR on error.
+ */
+-static struct buffer_head *
++struct buffer_head *
+ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
+ {
+ struct ext4_group_desc *desc;
+@@ -215,6 +215,7 @@
+ put_bh(bh);
+ return ERR_PTR(err);
+ }
++EXPORT_SYMBOL(ext4_read_inode_bitmap);
+
+ /*
+ * NOTE! When we get the inode, we're the only people
+diff -ur a/fs/ext4/inode.c b/fs/ext4/inode.c
+--- a/fs/ext4/inode.c 2021-12-09 07:30:00.126965141 -0700
++++ b/fs/ext4/inode.c 2021-12-09 07:30:47.422778379 -0700
+@@ -6197,3 +6197,19 @@
+
+ return ret;
+ }
++EXPORT_SYMBOL(ext4_map_blocks);
++EXPORT_SYMBOL(ext4_truncate);
++EXPORT_SYMBOL(ext4_iget);
++EXPORT_SYMBOL(ext4_bread);
++EXPORT_SYMBOL(ext4_itable_unused_count);
++EXPORT_SYMBOL(ext4_force_commit);
++EXPORT_SYMBOL(__ext4_mark_inode_dirty);
++EXPORT_SYMBOL(ext4_get_group_desc);
++EXPORT_SYMBOL(__ext4_journal_get_write_access);
++EXPORT_SYMBOL(__ext4_journal_start_sb);
++EXPORT_SYMBOL(__ext4_journal_stop);
++EXPORT_SYMBOL(__ext4_handle_dirty_metadata);
++EXPORT_SYMBOL(__ext4_std_error);
++EXPORT_SYMBOL(ext4fs_dirhash);
++EXPORT_SYMBOL(ext4_get_inode_loc);
++EXPORT_SYMBOL(__ext4_journal_ensure_credits);
+diff -ur a/fs/ext4/namei.c b/fs/ext4/namei.c
+--- a/fs/ext4/namei.c 2021-12-09 07:30:00.138965094 -0700
++++ b/fs/ext4/namei.c 2021-12-09 07:30:47.426778363 -0700
+@@ -50,7 +50,7 @@
+ #define NAMEI_RA_BLOCKS 4
+ #define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
+
+-static struct buffer_head *ext4_append(handle_t *handle,
++struct buffer_head *ext4_append(handle_t *handle,
+ struct inode *inode,
+ ext4_lblk_t *block)
+ {
+@@ -181,6 +181,7 @@
+ }
+ return bh;
+ }
++EXPORT_SYMBOL(ext4_append);
+
+ #ifndef assert
+ #define assert(test) J_ASSERT(test)
+@@ -2575,23 +2576,25 @@
+ * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set
+ * on regular files) and to avoid creating huge/slow non-HTREE directories.
+ */
+-static void ext4_inc_count(struct inode *inode)
++void ext4_inc_count(struct inode *inode)
+ {
+ inc_nlink(inode);
+ if (is_dx(inode) &&
+ (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
+ set_nlink(inode, 1);
+ }
++EXPORT_SYMBOL(ext4_inc_count);
+
+ /*
+ * If a directory had nlink == 1, then we should let it be 1. This indicates
+ * directory has >EXT4_LINK_MAX subdirs.
+ */
+-static void ext4_dec_count(struct inode *inode)
++void ext4_dec_count(struct inode *inode)
+ {
+ if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
+ drop_nlink(inode);
+ }
++EXPORT_SYMBOL(ext4_dec_count);
+
+
+ /*
+diff -ur a/fs/ext4/super.c b/fs/ext4/super.c
+--- a/fs/ext4/super.c 2021-12-09 07:30:00.050965441 -0700
++++ b/fs/ext4/super.c 2021-12-09 07:30:47.426778363 -0700
+@@ -435,7 +435,7 @@
+ return;
+ es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
+ ext4_update_tstamp(es, s_last_error_time);
+- strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
++ strlcpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
+ es->s_last_error_line = cpu_to_le32(line);
+ es->s_last_error_ino = cpu_to_le32(ino);
+ es->s_last_error_block = cpu_to_le64(block);
+@@ -496,7 +496,7 @@
+ if (!es->s_first_error_time) {
+ es->s_first_error_time = es->s_last_error_time;
+ es->s_first_error_time_hi = es->s_last_error_time_hi;
+- strncpy(es->s_first_error_func, func,
++ strlcpy(es->s_first_error_func, func,
+ sizeof(es->s_first_error_func));
+ es->s_first_error_line = cpu_to_le32(line);
+ es->s_first_error_ino = es->s_last_error_ino;
+@@ -6683,16 +6683,12 @@
+ 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();
+ out05:
+ destroy_inodecache();
+ out1:
+@@ -6716,8 +6712,6 @@
+ static void __exit ext4_exit_fs(void)
+ {
+ ext4_destroy_lazyinit_thread();
+- unregister_as_ext2();
+- unregister_as_ext3();
+ unregister_filesystem(&ext4_fs_type);
+ destroy_inodecache();
+ ext4_exit_mballoc();