[Concept] [PATCH 04/17] ext4l: bring in namei.c

16 Dec 2025

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

Copy namei.c from Linux v6.18 fs/ext4 directory. This file implements
directory operations including lookup, create, link, unlink, and rename.

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

 fs/ext4l/namei.c | 4241 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 4241 insertions(+)
 create mode 100644 fs/ext4l/namei.c

diff --git a/fs/ext4l/namei.c b/fs/ext4l/namei.c
new file mode 100644
index 00000000000..2cd36f59c9e
--- /dev/null
+++ b/fs/ext4l/namei.c
@@ -0,0 +1,4241 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/ext4/namei.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/namei.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *  Directory entry file type support and forward compatibility hooks
+ *	for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
+ *  Hash Tree Directory indexing (c)
+ *	Daniel Phillips, 2001
+ *  Hash Tree Directory indexing porting
+ *	Christopher Li, 2002
+ *  Hash Tree Directory indexing cleanup
+ *	Theodore Ts'o, 2002
+ */
+
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/time.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/bio.h>
+#include <linux/iversion.h>
+#include <linux/unicode.h>
+#include "ext4.h"
+#include "ext4_jbd2.h"
+
+#include "xattr.h"
+#include "acl.h"
+
+#include <trace/events/ext4.h>
+/*
+ * define how far ahead to read directories while searching them.
+ */
+#define NAMEI_RA_CHUNKS  2
+#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 inode *inode,
+					ext4_lblk_t *block)
+{
+	struct ext4_map_blocks map;
+	struct buffer_head *bh;
+	int err;
+
+	if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb &&
+		     ((inode->i_size >> 10) >=
+		      EXT4_SB(inode->i_sb)->s_max_dir_size_kb)))
+		return ERR_PTR(-ENOSPC);
+
+	*block = inode->i_size >> inode->i_sb->s_blocksize_bits;
+	map.m_lblk = *block;
+	map.m_len = 1;
+
+	/*
+	 * We're appending new directory block. Make sure the block is not
+	 * allocated yet, otherwise we will end up corrupting the
+	 * directory.
+	 */
+	err = ext4_map_blocks(NULL, inode, &map, 0);
+	if (err < 0)
+		return ERR_PTR(err);
+	if (err) {
+		EXT4_ERROR_INODE(inode, "Logical block already allocated");
+		return ERR_PTR(-EFSCORRUPTED);
+	}
+
+	bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE);
+	if (IS_ERR(bh))
+		return bh;
+	inode->i_size += inode->i_sb->s_blocksize;
+	EXT4_I(inode)->i_disksize = inode->i_size;
+	err = ext4_mark_inode_dirty(handle, inode);
+	if (err)
+		goto out;
+	BUFFER_TRACE(bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+					    EXT4_JTR_NONE);
+	if (err)
+		goto out;
+	return bh;
+
+out:
+	brelse(bh);
+	ext4_std_error(inode->i_sb, err);
+	return ERR_PTR(err);
+}
+
+static int ext4_dx_csum_verify(struct inode *inode,
+			       struct ext4_dir_entry *dirent);
+
+/*
+ * Hints to ext4_read_dirblock regarding whether we expect a directory
+ * block being read to be an index block, or a block containing
+ * directory entries (and if the latter, whether it was found via a
+ * logical block in an htree index block).  This is used to control
+ * what sort of sanity checkinig ext4_read_dirblock() will do on the
+ * directory block read from the storage device.  EITHER will means
+ * the caller doesn't know what kind of directory block will be read,
+ * so no specific verification will be done.
+ */
+typedef enum {
+	EITHER, INDEX, DIRENT, DIRENT_HTREE
+} dirblock_type_t;
+
+#define ext4_read_dirblock(inode, block, type) \
+	__ext4_read_dirblock((inode), (block), (type), __func__, __LINE__)
+
+static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
+						ext4_lblk_t block,
+						dirblock_type_t type,
+						const char *func,
+						unsigned int line)
+{
+	struct buffer_head *bh;
+	struct ext4_dir_entry *dirent;
+	int is_dx_block = 0;
+
+	if (block >= inode->i_size >> inode->i_blkbits) {
+		ext4_error_inode(inode, func, line, block,
+		       "Attempting to read directory block (%u) that is past i_size (%llu)",
+		       block, inode->i_size);
+		return ERR_PTR(-EFSCORRUPTED);
+	}
+
+	if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO))
+		bh = ERR_PTR(-EIO);
+	else
+		bh = ext4_bread(NULL, inode, block, 0);
+	if (IS_ERR(bh)) {
+		__ext4_warning(inode->i_sb, func, line,
+			       "inode #%lu: lblock %lu: comm %s: "
+			       "error %ld reading directory block",
+			       inode->i_ino, (unsigned long)block,
+			       current->comm, PTR_ERR(bh));
+
+		return bh;
+	}
+	/* The first directory block must not be a hole. */
+	if (!bh && (type == INDEX || type == DIRENT_HTREE || block == 0)) {
+		ext4_error_inode(inode, func, line, block,
+				 "Directory hole found for htree %s block %u",
+				 (type == INDEX) ? "index" : "leaf", block);
+		return ERR_PTR(-EFSCORRUPTED);
+	}
+	if (!bh)
+		return NULL;
+	dirent = (struct ext4_dir_entry *) bh->b_data;
+	/* Determine whether or not we have an index block */
+	if (is_dx(inode)) {
+		if (block == 0)
+			is_dx_block = 1;
+		else if (ext4_rec_len_from_disk(dirent->rec_len,
+						inode->i_sb->s_blocksize) ==
+			 inode->i_sb->s_blocksize)
+			is_dx_block = 1;
+	}
+	if (!is_dx_block && type == INDEX) {
+		ext4_error_inode(inode, func, line, block,
+		       "directory leaf block found instead of index block");
+		brelse(bh);
+		return ERR_PTR(-EFSCORRUPTED);
+	}
+	if (!ext4_has_feature_metadata_csum(inode->i_sb) ||
+	    buffer_verified(bh))
+		return bh;
+
+	/*
+	 * An empty leaf block can get mistaken for a index block; for
+	 * this reason, we can only check the index checksum when the
+	 * caller is sure it should be an index block.
+	 */
+	if (is_dx_block && type == INDEX) {
+		if (ext4_dx_csum_verify(inode, dirent) &&
+		    !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
+			set_buffer_verified(bh);
+		else {
+			ext4_error_inode_err(inode, func, line, block,
+					     EFSBADCRC,
+					     "Directory index failed checksum");
+			brelse(bh);
+			return ERR_PTR(-EFSBADCRC);
+		}
+	}
+	if (!is_dx_block) {
+		if (ext4_dirblock_csum_verify(inode, bh) &&
+		    !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC))
+			set_buffer_verified(bh);
+		else {
+			ext4_error_inode_err(inode, func, line, block,
+					     EFSBADCRC,
+					     "Directory block failed checksum");
+			brelse(bh);
+			return ERR_PTR(-EFSBADCRC);
+		}
+	}
+	return bh;
+}
+
+#ifdef DX_DEBUG
+#define dxtrace(command) command
+#else
+#define dxtrace(command)
+#endif
+
+struct fake_dirent
+{
+	__le32 inode;
+	__le16 rec_len;
+	u8 name_len;
+	u8 file_type;
+};
+
+struct dx_countlimit
+{
+	__le16 limit;
+	__le16 count;
+};
+
+struct dx_entry
+{
+	__le32 hash;
+	__le32 block;
+};
+
+/*
+ * dx_root_info is laid out so that if it should somehow get overlaid by a
+ * dirent the two low bits of the hash version will be zero.  Therefore, the
+ * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
+ */
+
+struct dx_root
+{
+	struct fake_dirent dot;
+	char dot_name[4];
+	struct fake_dirent dotdot;
+	char dotdot_name[4];
+	struct dx_root_info
+	{
+		__le32 reserved_zero;
+		u8 hash_version;
+		u8 info_length; /* 8 */
+		u8 indirect_levels;
+		u8 unused_flags;
+	}
+	info;
+	struct dx_entry	entries[];
+};
+
+struct dx_node
+{
+	struct fake_dirent fake;
+	struct dx_entry	entries[];
+};
+
+
+struct dx_frame
+{
+	struct buffer_head *bh;
+	struct dx_entry *entries;
+	struct dx_entry *at;
+};
+
+struct dx_map_entry
+{
+	u32 hash;
+	u16 offs;
+	u16 size;
+};
+
+/*
+ * This goes at the end of each htree block.
+ */
+struct dx_tail {
+	u32 dt_reserved;
+	__le32 dt_checksum;	/* crc32c(uuid+inum+dirblock) */
+};
+
+static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
+		struct ext4_filename *fname,
+		struct ext4_dir_entry_2 **res_dir);
+static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
+			     struct inode *dir, struct inode *inode);
+
+/* checksumming functions */
+void ext4_initialize_dirent_tail(struct buffer_head *bh,
+				 unsigned int blocksize)
+{
+	struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize);
+
+	memset(t, 0, sizeof(struct ext4_dir_entry_tail));
+	t->det_rec_len = ext4_rec_len_to_disk(
+			sizeof(struct ext4_dir_entry_tail), blocksize);
+	t->det_reserved_ft = EXT4_FT_DIR_CSUM;
+}
+
+/* Walk through a dirent block to find a checksum "dirent" at the tail */
+static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
+						   struct buffer_head *bh)
+{
+	struct ext4_dir_entry_tail *t;
+	int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
+
+#ifdef PARANOID
+	struct ext4_dir_entry *d, *top;
+
+	d = (struct ext4_dir_entry *)bh->b_data;
+	top = (struct ext4_dir_entry *)(bh->b_data +
+		(blocksize - sizeof(struct ext4_dir_entry_tail)));
+	while (d < top && ext4_rec_len_from_disk(d->rec_len, blocksize))
+		d = (struct ext4_dir_entry *)(((void *)d) +
+		    ext4_rec_len_from_disk(d->rec_len, blocksize));
+
+	if (d != top)
+		return NULL;
+
+	t = (struct ext4_dir_entry_tail *)d;
+#else
+	t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb));
+#endif
+
+	if (t->det_reserved_zero1 ||
+	    (ext4_rec_len_from_disk(t->det_rec_len, blocksize) !=
+	     sizeof(struct ext4_dir_entry_tail)) ||
+	    t->det_reserved_zero2 ||
+	    t->det_reserved_ft != EXT4_FT_DIR_CSUM)
+		return NULL;
+
+	return t;
+}
+
+static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	__u32 csum;
+
+	csum = ext4_chksum(ei->i_csum_seed, (__u8 *)dirent, size);
+	return cpu_to_le32(csum);
+}
+
+#define warn_no_space_for_csum(inode)					\
+	__warn_no_space_for_csum((inode), __func__, __LINE__)
+
+static void __warn_no_space_for_csum(struct inode *inode, const char *func,
+				     unsigned int line)
+{
+	__ext4_warning_inode(inode, func, line,
+		"No space for directory leaf checksum. Please run e2fsck -D.");
+}
+
+int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh)
+{
+	struct ext4_dir_entry_tail *t;
+
+	if (!ext4_has_feature_metadata_csum(inode->i_sb))
+		return 1;
+
+	t = get_dirent_tail(inode, bh);
+	if (!t) {
+		warn_no_space_for_csum(inode);
+		return 0;
+	}
+
+	if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data,
+						  (char *)t - bh->b_data))
+		return 0;
+
+	return 1;
+}
+
+static void ext4_dirblock_csum_set(struct inode *inode,
+				 struct buffer_head *bh)
+{
+	struct ext4_dir_entry_tail *t;
+
+	if (!ext4_has_feature_metadata_csum(inode->i_sb))
+		return;
+
+	t = get_dirent_tail(inode, bh);
+	if (!t) {
+		warn_no_space_for_csum(inode);
+		return;
+	}
+
+	t->det_checksum = ext4_dirblock_csum(inode, bh->b_data,
+					     (char *)t - bh->b_data);
+}
+
+int ext4_handle_dirty_dirblock(handle_t *handle,
+			       struct inode *inode,
+			       struct buffer_head *bh)
+{
+	ext4_dirblock_csum_set(inode, bh);
+	return ext4_handle_dirty_metadata(handle, inode, bh);
+}
+
+static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
+					       struct ext4_dir_entry *dirent,
+					       int *offset)
+{
+	struct ext4_dir_entry *dp;
+	struct dx_root_info *root;
+	int count_offset;
+	int blocksize = EXT4_BLOCK_SIZE(inode->i_sb);
+	unsigned int rlen = ext4_rec_len_from_disk(dirent->rec_len, blocksize);
+
+	if (rlen == blocksize)
+		count_offset = 8;
+	else if (rlen == 12) {
+		dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
+		if (ext4_rec_len_from_disk(dp->rec_len, blocksize) != blocksize - 12)
+			return NULL;
+		root = (struct dx_root_info *)(((void *)dp + 12));
+		if (root->reserved_zero ||
+		    root->info_length != sizeof(struct dx_root_info))
+			return NULL;
+		count_offset = 32;
+	} else
+		return NULL;
+
+	if (offset)
+		*offset = count_offset;
+	return (struct dx_countlimit *)(((void *)dirent) + count_offset);
+}
+
+static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
+			   int count_offset, int count, struct dx_tail *t)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	__u32 csum;
+	int size;
+	__u32 dummy_csum = 0;
+	int offset = offsetof(struct dx_tail, dt_checksum);
+
+	size = count_offset + (count * sizeof(struct dx_entry));
+	csum = ext4_chksum(ei->i_csum_seed, (__u8 *)dirent, size);
+	csum = ext4_chksum(csum, (__u8 *)t, offset);
+	csum = ext4_chksum(csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
+
+	return cpu_to_le32(csum);
+}
+
+static int ext4_dx_csum_verify(struct inode *inode,
+			       struct ext4_dir_entry *dirent)
+{
+	struct dx_countlimit *c;
+	struct dx_tail *t;
+	int count_offset, limit, count;
+
+	if (!ext4_has_feature_metadata_csum(inode->i_sb))
+		return 1;
+
+	c = get_dx_countlimit(inode, dirent, &count_offset);
+	if (!c) {
+		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
+		return 0;
+	}
+	limit = le16_to_cpu(c->limit);
+	count = le16_to_cpu(c->count);
+	if (count_offset + (limit * sizeof(struct dx_entry)) >
+	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
+		warn_no_space_for_csum(inode);
+		return 0;
+	}
+	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
+
+	if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset,
+					    count, t))
+		return 0;
+	return 1;
+}
+
+static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
+{
+	struct dx_countlimit *c;
+	struct dx_tail *t;
+	int count_offset, limit, count;
+
+	if (!ext4_has_feature_metadata_csum(inode->i_sb))
+		return;
+
+	c = get_dx_countlimit(inode, dirent, &count_offset);
+	if (!c) {
+		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
+		return;
+	}
+	limit = le16_to_cpu(c->limit);
+	count = le16_to_cpu(c->count);
+	if (count_offset + (limit * sizeof(struct dx_entry)) >
+	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
+		warn_no_space_for_csum(inode);
+		return;
+	}
+	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
+
+	t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t);
+}
+
+static inline int ext4_handle_dirty_dx_node(handle_t *handle,
+					    struct inode *inode,
+					    struct buffer_head *bh)
+{
+	ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
+	return ext4_handle_dirty_metadata(handle, inode, bh);
+}
+
+/*
+ * p is at least 6 bytes before the end of page
+ */
+static inline struct ext4_dir_entry_2 *
+ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
+{
+	return (struct ext4_dir_entry_2 *)((char *)p +
+		ext4_rec_len_from_disk(p->rec_len, blocksize));
+}
+
+/*
+ * Future: use high four bits of block for coalesce-on-delete flags
+ * Mask them off for now.
+ */
+
+static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
+{
+	return le32_to_cpu(entry->block) & 0x0fffffff;
+}
+
+static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
+{
+	entry->block = cpu_to_le32(value);
+}
+
+static inline unsigned dx_get_hash(struct dx_entry *entry)
+{
+	return le32_to_cpu(entry->hash);
+}
+
+static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
+{
+	entry->hash = cpu_to_le32(value);
+}
+
+static inline unsigned dx_get_count(struct dx_entry *entries)
+{
+	return le16_to_cpu(((struct dx_countlimit *) entries)->count);
+}
+
+static inline unsigned dx_get_limit(struct dx_entry *entries)
+{
+	return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
+}
+
+static inline void dx_set_count(struct dx_entry *entries, unsigned value)
+{
+	((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
+}
+
+static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
+{
+	((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
+}
+
+static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
+{
+	unsigned int entry_space = dir->i_sb->s_blocksize -
+			ext4_dir_rec_len(1, NULL) -
+			ext4_dir_rec_len(2, NULL) - infosize;
+
+	if (ext4_has_feature_metadata_csum(dir->i_sb))
+		entry_space -= sizeof(struct dx_tail);
+	return entry_space / sizeof(struct dx_entry);
+}
+
+static inline unsigned dx_node_limit(struct inode *dir)
+{
+	unsigned int entry_space = dir->i_sb->s_blocksize -
+			ext4_dir_rec_len(0, dir);
+
+	if (ext4_has_feature_metadata_csum(dir->i_sb))
+		entry_space -= sizeof(struct dx_tail);
+	return entry_space / sizeof(struct dx_entry);
+}
+
+/*
+ * Debug
+ */
+#ifdef DX_DEBUG
+static void dx_show_index(char * label, struct dx_entry *entries)
+{
+	int i, n = dx_get_count (entries);
+	printk(KERN_DEBUG "%s index", label);
+	for (i = 0; i < n; i++) {
+		printk(KERN_CONT " %x->%lu",
+		       i ? dx_get_hash(entries + i) : 0,
+		       (unsigned long)dx_get_block(entries + i));
+	}
+	printk(KERN_CONT "\n");
+}
+
+struct stats
+{
+	unsigned names;
+	unsigned space;
+	unsigned bcount;
+};
+
+static struct stats dx_show_leaf(struct inode *dir,
+				struct dx_hash_info *hinfo,
+				struct ext4_dir_entry_2 *de,
+				int size, int show_names)
+{
+	unsigned names = 0, space = 0;
+	char *base = (char *) de;
+	struct dx_hash_info h = *hinfo;
+
+	printk("names: ");
+	while ((char *) de < base + size)
+	{
+		if (de->inode)
+		{
+			if (show_names)
+			{
+#ifdef CONFIG_FS_ENCRYPTION
+				int len;
+				char *name;
+				struct fscrypt_str fname_crypto_str =
+					FSTR_INIT(NULL, 0);
+				int res = 0;
+
+				name  = de->name;
+				len = de->name_len;
+				if (!IS_ENCRYPTED(dir)) {
+					/* Directory is not encrypted */
+					(void) ext4fs_dirhash(dir, de->name,
+						de->name_len, &h);
+					printk("%*.s:(U)%x.%u ", len,
+					       name, h.hash,
+					       (unsigned) ((char *) de
+							   - base));
+				} else {
+					struct fscrypt_str de_name =
+						FSTR_INIT(name, len);
+
+					/* Directory is encrypted */
+					res = fscrypt_fname_alloc_buffer(
+						len, &fname_crypto_str);
+					if (res)
+						printk(KERN_WARNING "Error "
+							"allocating crypto "
+							"buffer--skipping "
+							"crypto\n");
+					res = fscrypt_fname_disk_to_usr(dir,
+						0, 0, &de_name,
+						&fname_crypto_str);
+					if (res) {
+						printk(KERN_WARNING "Error "
+							"converting filename "
+							"from disk to usr"
+							"\n");
+						name = "??";
+						len = 2;
+					} else {
+						name = fname_crypto_str.name;
+						len = fname_crypto_str.len;
+					}
+					if (IS_CASEFOLDED(dir))
+						h.hash = EXT4_DIRENT_HASH(de);
+					else
+						(void) ext4fs_dirhash(dir,
+							de->name,
+							de->name_len, &h);
+					printk("%*.s:(E)%x.%u ", len, name,
+					       h.hash, (unsigned) ((char *) de
+								   - base));
+					fscrypt_fname_free_buffer(
+							&fname_crypto_str);
+				}
+#else
+				int len = de->name_len;
+				char *name = de->name;
+				(void) ext4fs_dirhash(dir, de->name,
+						      de->name_len, &h);
+				printk("%*.s:%x.%u ", len, name, h.hash,
+				       (unsigned) ((char *) de - base));
+#endif
+			}
+			space += ext4_dir_rec_len(de->name_len, dir);
+			names++;
+		}
+		de = ext4_next_entry(de, size);
+	}
+	printk(KERN_CONT "(%i)\n", names);
+	return (struct stats) { names, space, 1 };
+}
+
+struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
+			     struct dx_entry *entries, int levels)
+{
+	unsigned blocksize = dir->i_sb->s_blocksize;
+	unsigned count = dx_get_count(entries), names = 0, space = 0, i;
+	unsigned bcount = 0;
+	struct buffer_head *bh;
+	printk("%i indexed blocks...\n", count);
+	for (i = 0; i < count; i++, entries++)
+	{
+		ext4_lblk_t block = dx_get_block(entries);
+		ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
+		u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
+		struct stats stats;
+		printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
+		bh = ext4_bread(NULL,dir, block, 0);
+		if (!bh || IS_ERR(bh))
+			continue;
+		stats = levels?
+		   dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
+		   dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
+			bh->b_data, blocksize, 0);
+		names += stats.names;
+		space += stats.space;
+		bcount += stats.bcount;
+		brelse(bh);
+	}
+	if (bcount)
+		printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
+		       levels ? "" : "   ", names, space/bcount,
+		       (space/bcount)*100/blocksize);
+	return (struct stats) { names, space, bcount};
+}
+
+/*
+ * Linear search cross check
+ */
+static inline void htree_rep_invariant_check(struct dx_entry *at,
+					     struct dx_entry *target,
+					     u32 hash, unsigned int n)
+{
+	while (n--) {
+		dxtrace(printk(KERN_CONT ","));
+		if (dx_get_hash(++at) > hash) {
+			at--;
+			break;
+		}
+	}
+	ASSERT(at == target - 1);
+}
+#else /* DX_DEBUG */
+static inline void htree_rep_invariant_check(struct dx_entry *at,
+					     struct dx_entry *target,
+					     u32 hash, unsigned int n)
+{
+}
+#endif /* DX_DEBUG */
+
+/*
+ * Probe for a directory leaf block to search.
+ *
+ * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
+ * error in the directory index, and the caller should fall back to
+ * searching the directory normally.  The callers of dx_probe **MUST**
+ * check for this error code, and make sure it never gets reflected
+ * back to userspace.
+ */
+static struct dx_frame *
+dx_probe(struct ext4_filename *fname, struct inode *dir,
+	 struct dx_hash_info *hinfo, struct dx_frame *frame_in)
+{
+	unsigned count, indirect, level, i;
+	struct dx_entry *at, *entries, *p, *q, *m;
+	struct dx_root *root;
+	struct dx_frame *frame = frame_in;
+	struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR);
+	u32 hash;
+	ext4_lblk_t block;
+	ext4_lblk_t blocks[EXT4_HTREE_LEVEL];
+
+	memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0]));
+	frame->bh = ext4_read_dirblock(dir, 0, INDEX);
+	if (IS_ERR(frame->bh))
+		return (struct dx_frame *) frame->bh;
+
+	root = (struct dx_root *) frame->bh->b_data;
+	if (root->info.hash_version != DX_HASH_TEA &&
+	    root->info.hash_version != DX_HASH_HALF_MD4 &&
+	    root->info.hash_version != DX_HASH_LEGACY &&
+	    root->info.hash_version != DX_HASH_SIPHASH) {
+		ext4_warning_inode(dir, "Unrecognised inode hash code %u",
+				   root->info.hash_version);
+		goto fail;
+	}
+	if (ext4_hash_in_dirent(dir)) {
+		if (root->info.hash_version != DX_HASH_SIPHASH) {
+			ext4_warning_inode(dir,
+				"Hash in dirent, but hash is not SIPHASH");
+			goto fail;
+		}
+	} else {
+		if (root->info.hash_version == DX_HASH_SIPHASH) {
+			ext4_warning_inode(dir,
+				"Hash code is SIPHASH, but hash not in dirent");
+			goto fail;
+		}
+	}
+	if (fname)
+		hinfo = &fname->hinfo;
+	hinfo->hash_version = root->info.hash_version;
+	if (hinfo->hash_version <= DX_HASH_TEA)
+		hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
+	hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
+	/* hash is already computed for encrypted casefolded directory */
+	if (fname && fname_name(fname) &&
+	    !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir))) {
+		int ret = ext4fs_dirhash(dir, fname_name(fname),
+					 fname_len(fname), hinfo);
+		if (ret < 0) {
+			ret_err = ERR_PTR(ret);
+			goto fail;
+		}
+	}
+	hash = hinfo->hash;
+
+	if (root->info.unused_flags & 1) {
+		ext4_warning_inode(dir, "Unimplemented hash flags: %#06x",
+				   root->info.unused_flags);
+		goto fail;
+	}
+
+	indirect = root->info.indirect_levels;
+	if (indirect >= ext4_dir_htree_level(dir->i_sb)) {
+		ext4_warning(dir->i_sb,
+			     "Directory (ino: %lu) htree depth %#06x exceed"
+			     "supported value", dir->i_ino,
+			     ext4_dir_htree_level(dir->i_sb));
+		if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) {
+			ext4_warning(dir->i_sb, "Enable large directory "
+						"feature to access it");
+		}
+		goto fail;
+	}
+
+	entries = (struct dx_entry *)(((char *)&root->info) +
+				      root->info.info_length);
+
+	if (dx_get_limit(entries) != dx_root_limit(dir,
+						   root->info.info_length)) {
+		ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
+				   dx_get_limit(entries),
+				   dx_root_limit(dir, root->info.info_length));
+		goto fail;
+	}
+
+	dxtrace(printk("Look up %x", hash));
+	level = 0;
+	blocks[0] = 0;
+	while (1) {
+		count = dx_get_count(entries);
+		if (!count || count > dx_get_limit(entries)) {
+			ext4_warning_inode(dir,
+					   "dx entry: count %u beyond limit %u",
+					   count, dx_get_limit(entries));
+			goto fail;
+		}
+
+		p = entries + 1;
+		q = entries + count - 1;
+		while (p <= q) {
+			m = p + (q - p) / 2;
+			dxtrace(printk(KERN_CONT "."));
+			if (dx_get_hash(m) > hash)
+				q = m - 1;
+			else
+				p = m + 1;
+		}
+
+		htree_rep_invariant_check(entries, p, hash, count - 1);
+
+		at = p - 1;
+		dxtrace(printk(KERN_CONT " %x->%u\n",
+			       at == entries ? 0 : dx_get_hash(at),
+			       dx_get_block(at)));
+		frame->entries = entries;
+		frame->at = at;
+
+		block = dx_get_block(at);
+		for (i = 0; i <= level; i++) {
+			if (blocks[i] == block) {
+				ext4_warning_inode(dir,
+					"dx entry: tree cycle block %u points back to block %u",
+					blocks[level], block);
+				goto fail;
+			}
+		}
+		if (++level > indirect)
+			return frame;
+		blocks[level] = block;
+		frame++;
+		frame->bh = ext4_read_dirblock(dir, block, INDEX);
+		if (IS_ERR(frame->bh)) {
+			ret_err = (struct dx_frame *) frame->bh;
+			frame->bh = NULL;
+			goto fail;
+		}
+
+		entries = ((struct dx_node *) frame->bh->b_data)->entries;
+
+		if (dx_get_limit(entries) != dx_node_limit(dir)) {
+			ext4_warning_inode(dir,
+				"dx entry: limit %u != node limit %u",
+				dx_get_limit(entries), dx_node_limit(dir));
+			goto fail;
+		}
+	}
+fail:
+	while (frame >= frame_in) {
+		brelse(frame->bh);
+		frame--;
+	}
+
+	if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
+		ext4_warning_inode(dir,
+			"Corrupt directory, running e2fsck is recommended");
+	return ret_err;
+}
+
+static void dx_release(struct dx_frame *frames)
+{
+	struct dx_root_info *info;
+	int i;
+	unsigned int indirect_levels;
+
+	if (frames[0].bh == NULL)
+		return;
+
+	info = &((struct dx_root *)frames[0].bh->b_data)->info;
+	/* save local copy, "info" may be freed after brelse() */
+	indirect_levels = info->indirect_levels;
+	for (i = 0; i <= indirect_levels; i++) {
+		if (frames[i].bh == NULL)
+			break;
+		brelse(frames[i].bh);
+		frames[i].bh = NULL;
+	}
+}
+
+/*
+ * This function increments the frame pointer to search the next leaf
+ * block, and reads in the necessary intervening nodes if the search
+ * should be necessary.  Whether or not the search is necessary is
+ * controlled by the hash parameter.  If the hash value is even, then
+ * the search is only continued if the next block starts with that
+ * hash value.  This is used if we are searching for a specific file.
+ *
+ * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
+ *
+ * This function returns 1 if the caller should continue to search,
+ * or 0 if it should not.  If there is an error reading one of the
+ * index blocks, it will a negative error code.
+ *
+ * If start_hash is non-null, it will be filled in with the starting
+ * hash of the next page.
+ */
+static int ext4_htree_next_block(struct inode *dir, __u32 hash,
+				 struct dx_frame *frame,
+				 struct dx_frame *frames,
+				 __u32 *start_hash)
+{
+	struct dx_frame *p;
+	struct buffer_head *bh;
+	int num_frames = 0;
+	__u32 bhash;
+
+	p = frame;
+	/*
+	 * Find the next leaf page by incrementing the frame pointer.
+	 * If we run out of entries in the interior node, loop around and
+	 * increment pointer in the parent node.  When we break out of
+	 * this loop, num_frames indicates the number of interior
+	 * nodes need to be read.
+	 */
+	while (1) {
+		if (++(p->at) < p->entries + dx_get_count(p->entries))
+			break;
+		if (p == frames)
+			return 0;
+		num_frames++;
+		p--;
+	}
+
+	/*
+	 * If the hash is 1, then continue only if the next page has a
+	 * continuation hash of any value.  This is used for readdir
+	 * handling.  Otherwise, check to see if the hash matches the
+	 * desired continuation hash.  If it doesn't, return since
+	 * there's no point to read in the successive index pages.
+	 */
+	bhash = dx_get_hash(p->at);
+	if (start_hash)
+		*start_hash = bhash;
+	if ((hash & 1) == 0) {
+		if ((bhash & ~1) != hash)
+			return 0;
+	}
+	/*
+	 * If the hash is HASH_NB_ALWAYS, we always go to the next
+	 * block so no check is necessary
+	 */
+	while (num_frames--) {
+		bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
+		p++;
+		brelse(p->bh);
+		p->bh = bh;
+		p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
+	}
+	return 1;
+}
+
+
+/*
+ * This function fills a red-black tree with information from a
+ * directory block.  It returns the number directory entries loaded
+ * into the tree.  If there is an error it is returned in err.
+ */
+static int htree_dirblock_to_tree(struct file *dir_file,
+				  struct inode *dir, ext4_lblk_t block,
+				  struct dx_hash_info *hinfo,
+				  __u32 start_hash, __u32 start_minor_hash)
+{
+	struct buffer_head *bh;
+	struct ext4_dir_entry_2 *de, *top;
+	int err = 0, count = 0;
+	struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str;
+	int csum = ext4_has_feature_metadata_csum(dir->i_sb);
+
+	dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
+							(unsigned long)block));
+	bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+
+	de = (struct ext4_dir_entry_2 *) bh->b_data;
+	/* csum entries are not larger in the casefolded encrypted case */
+	top = (struct ext4_dir_entry_2 *) ((char *) de +
+					   dir->i_sb->s_blocksize -
+					   ext4_dir_rec_len(0,
+							   csum ? NULL : dir));
+	/* Check if the directory is encrypted */
+	if (IS_ENCRYPTED(dir)) {
+		err = fscrypt_prepare_readdir(dir);
+		if (err < 0) {
+			brelse(bh);
+			return err;
+		}
+		err = fscrypt_fname_alloc_buffer(EXT4_NAME_LEN,
+						 &fname_crypto_str);
+		if (err < 0) {
+			brelse(bh);
+			return err;
+		}
+	}
+
+	for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
+		if (ext4_check_dir_entry(dir, NULL, de, bh,
+				bh->b_data, bh->b_size,
+				(block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
+					 + ((char *)de - bh->b_data))) {
+			/* silently ignore the rest of the block */
+			break;
+		}
+		if (ext4_hash_in_dirent(dir)) {
+			if (de->name_len && de->inode) {
+				hinfo->hash = EXT4_DIRENT_HASH(de);
+				hinfo->minor_hash = EXT4_DIRENT_MINOR_HASH(de);
+			} else {
+				hinfo->hash = 0;
+				hinfo->minor_hash = 0;
+			}
+		} else {
+			err = ext4fs_dirhash(dir, de->name,
+					     de->name_len, hinfo);
+			if (err < 0) {
+				count = err;
+				goto errout;
+			}
+		}
+		if ((hinfo->hash < start_hash) ||
+		    ((hinfo->hash == start_hash) &&
+		     (hinfo->minor_hash < start_minor_hash)))
+			continue;
+		if (de->inode == 0)
+			continue;
+		if (!IS_ENCRYPTED(dir)) {
+			tmp_str.name = de->name;
+			tmp_str.len = de->name_len;
+			err = ext4_htree_store_dirent(dir_file,
+				   hinfo->hash, hinfo->minor_hash, de,
+				   &tmp_str);
+		} else {
+			int save_len = fname_crypto_str.len;
+			struct fscrypt_str de_name = FSTR_INIT(de->name,
+								de->name_len);
+
+			/* Directory is encrypted */
+			err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
+					hinfo->minor_hash, &de_name,
+					&fname_crypto_str);
+			if (err) {
+				count = err;
+				goto errout;
+			}
+			err = ext4_htree_store_dirent(dir_file,
+				   hinfo->hash, hinfo->minor_hash, de,
+					&fname_crypto_str);
+			fname_crypto_str.len = save_len;
+		}
+		if (err != 0) {
+			count = err;
+			goto errout;
+		}
+		count++;
+	}
+errout:
+	brelse(bh);
+	fscrypt_fname_free_buffer(&fname_crypto_str);
+	return count;
+}
+
+
+/*
+ * This function fills a red-black tree with information from a
+ * directory.  We start scanning the directory in hash order, starting
+ * at start_hash and start_minor_hash.
+ *
+ * This function returns the number of entries inserted into the tree,
+ * or a negative error code.
+ */
+int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
+			 __u32 start_minor_hash, __u32 *next_hash)
+{
+	struct dx_hash_info hinfo;
+	struct ext4_dir_entry_2 *de;
+	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
+	struct inode *dir;
+	ext4_lblk_t block;
+	int count = 0;
+	int ret, err;
+	__u32 hashval;
+	struct fscrypt_str tmp_str;
+
+	dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
+		       start_hash, start_minor_hash));
+	dir = file_inode(dir_file);
+	if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
+		if (ext4_hash_in_dirent(dir))
+			hinfo.hash_version = DX_HASH_SIPHASH;
+		else
+			hinfo.hash_version =
+					EXT4_SB(dir->i_sb)->s_def_hash_version;
+		if (hinfo.hash_version <= DX_HASH_TEA)
+			hinfo.hash_version +=
+				EXT4_SB(dir->i_sb)->s_hash_unsigned;
+		hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
+		if (ext4_has_inline_data(dir)) {
+			int has_inline_data = 1;
+			count = ext4_inlinedir_to_tree(dir_file, dir, 0,
+						       &hinfo, start_hash,
+						       start_minor_hash,
+						       &has_inline_data);
+			if (has_inline_data) {
+				*next_hash = ~0;
+				return count;
+			}
+		}
+		count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
+					       start_hash, start_minor_hash);
+		*next_hash = ~0;
+		return count;
+	}
+	hinfo.hash = start_hash;
+	hinfo.minor_hash = 0;
+	frame = dx_probe(NULL, dir, &hinfo, frames);
+	if (IS_ERR(frame))
+		return PTR_ERR(frame);
+
+	/* Add '.' and '..' from the htree header */
+	if (!start_hash && !start_minor_hash) {
+		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
+		tmp_str.name = de->name;
+		tmp_str.len = de->name_len;
+		err = ext4_htree_store_dirent(dir_file, 0, 0,
+					      de, &tmp_str);
+		if (err != 0)
+			goto errout;
+		count++;
+	}
+	if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
+		de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
+		de = ext4_next_entry(de, dir->i_sb->s_blocksize);
+		tmp_str.name = de->name;
+		tmp_str.len = de->name_len;
+		err = ext4_htree_store_dirent(dir_file, 2, 0,
+					      de, &tmp_str);
+		if (err != 0)
+			goto errout;
+		count++;
+	}
+
+	while (1) {
+		if (fatal_signal_pending(current)) {
+			err = -ERESTARTSYS;
+			goto errout;
+		}
+		cond_resched();
+		block = dx_get_block(frame->at);
+		ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
+					     start_hash, start_minor_hash);
+		if (ret < 0) {
+			err = ret;
+			goto errout;
+		}
+		count += ret;
+		hashval = ~0;
+		ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
+					    frame, frames, &hashval);
+		*next_hash = hashval;
+		if (ret < 0) {
+			err = ret;
+			goto errout;
+		}
+		/*
+		 * Stop if:  (a) there are no more entries, or
+		 * (b) we have inserted at least one entry and the
+		 * next hash value is not a continuation
+		 */
+		if ((ret == 0) ||
+		    (count && ((hashval & 1) == 0)))
+			break;
+	}
+	dx_release(frames);
+	dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
+		       "next hash: %x\n", count, *next_hash));
+	return count;
+errout:
+	dx_release(frames);
+	return (err);
+}
+
+static inline int search_dirblock(struct buffer_head *bh,
+				  struct inode *dir,
+				  struct ext4_filename *fname,
+				  unsigned int offset,
+				  struct ext4_dir_entry_2 **res_dir)
+{
+	return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir,
+			       fname, offset, res_dir);
+}
+
+/*
+ * Directory block splitting, compacting
+ */
+
+/*
+ * Create map of hash values, offsets, and sizes, stored at end of block.
+ * Returns number of entries mapped.
+ */
+static int dx_make_map(struct inode *dir, struct buffer_head *bh,
+		       struct dx_hash_info *hinfo,
+		       struct dx_map_entry *map_tail)
+{
+	int count = 0;
+	struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)bh->b_data;
+	unsigned int buflen = bh->b_size;
+	char *base = bh->b_data;
+	struct dx_hash_info h = *hinfo;
+	int blocksize = EXT4_BLOCK_SIZE(dir->i_sb);
+
+	if (ext4_has_feature_metadata_csum(dir->i_sb))
+		buflen -= sizeof(struct ext4_dir_entry_tail);
+
+	while ((char *) de < base + buflen) {
+		if (ext4_check_dir_entry(dir, NULL, de, bh, base, buflen,
+					 ((char *)de) - base))
+			return -EFSCORRUPTED;
+		if (de->name_len && de->inode) {
+			if (ext4_hash_in_dirent(dir))
+				h.hash = EXT4_DIRENT_HASH(de);
+			else {
+				int err = ext4fs_dirhash(dir, de->name,
+						     de->name_len, &h);
+				if (err < 0)
+					return err;
+			}
+			map_tail--;
+			map_tail->hash = h.hash;
+			map_tail->offs = ((char *) de - base)>>2;
+			map_tail->size = ext4_rec_len_from_disk(de->rec_len,
+								blocksize);
+			count++;
+			cond_resched();
+		}
+		de = ext4_next_entry(de, blocksize);
+	}
+	return count;
+}
+
+/* Sort map by hash value */
+static void dx_sort_map (struct dx_map_entry *map, unsigned count)
+{
+	struct dx_map_entry *p, *q, *top = map + count - 1;
+	int more;
+	/* Combsort until bubble sort doesn't suck */
+	while (count > 2) {
+		count = count*10/13;
+		if (count - 9 < 2) /* 9, 10 -> 11 */
+			count = 11;
+		for (p = top, q = p - count; q >= map; p--, q--)
+			if (p->hash < q->hash)
+				swap(*p, *q);
+	}
+	/* Garden variety bubble sort */
+	do {
+		more = 0;
+		q = top;
+		while (q-- > map) {
+			if (q[1].hash >= q[0].hash)
+				continue;
+			swap(*(q+1), *q);
+			more = 1;
+		}
+	} while(more);
+}
+
+static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
+{
+	struct dx_entry *entries = frame->entries;
+	struct dx_entry *old = frame->at, *new = old + 1;
+	int count = dx_get_count(entries);
+
+	ASSERT(count < dx_get_limit(entries));
+	ASSERT(old < entries + count);
+	memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
+	dx_set_hash(new, hash);
+	dx_set_block(new, block);
+	dx_set_count(entries, count + 1);
+}
+
+#if IS_ENABLED(CONFIG_UNICODE)
+int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
+				  struct ext4_filename *name)
+{
+	struct qstr *cf_name = &name->cf_name;
+	unsigned char *buf;
+	struct dx_hash_info *hinfo = &name->hinfo;
+	int len;
+
+	if (!IS_CASEFOLDED(dir) ||
+	    (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) {
+		cf_name->name = NULL;
+		return 0;
+	}
+
+	buf = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
+	if (!buf)
+		return -ENOMEM;
+
+	len = utf8_casefold(dir->i_sb->s_encoding, iname, buf, EXT4_NAME_LEN);
+	if (len <= 0) {
+		kfree(buf);
+		buf = NULL;
+	}
+	cf_name->name = buf;
+	cf_name->len = (unsigned) len;
+
+	if (!IS_ENCRYPTED(dir))
+		return 0;
+
+	hinfo->hash_version = DX_HASH_SIPHASH;
+	hinfo->seed = NULL;
+	if (cf_name->name)
+		return ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo);
+	else
+		return ext4fs_dirhash(dir, iname->name, iname->len, hinfo);
+}
+#endif
+
+/*
+ * Test whether a directory entry matches the filename being searched for.
+ *
+ * Return: %true if the directory entry matches, otherwise %false.
+ */
+static bool ext4_match(struct inode *parent,
+			      const struct ext4_filename *fname,
+			      struct ext4_dir_entry_2 *de)
+{
+	struct fscrypt_name f;
+
+	if (!de->inode)
+		return false;
+
+	f.usr_fname = fname->usr_fname;
+	f.disk_name = fname->disk_name;
+#ifdef CONFIG_FS_ENCRYPTION
+	f.crypto_buf = fname->crypto_buf;
+#endif
+
+#if IS_ENABLED(CONFIG_UNICODE)
+	if (IS_CASEFOLDED(parent) &&
+	    (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
+		/*
+		 * Just checking IS_ENCRYPTED(parent) below is not
+		 * sufficient to decide whether one can use the hash for
+		 * skipping the string comparison, because the key might
+		 * have been added right after
+		 * ext4_fname_setup_ci_filename().  In this case, a hash
+		 * mismatch will be a false negative.  Therefore, make
+		 * sure cf_name was properly initialized before
+		 * considering the calculated hash.
+		 */
+		if (sb_no_casefold_compat_fallback(parent->i_sb) &&
+		    IS_ENCRYPTED(parent) && fname->cf_name.name &&
+		    (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
+		     fname->hinfo.minor_hash != EXT4_DIRENT_MINOR_HASH(de)))
+			return false;
+		/*
+		 * Treat comparison errors as not a match.  The
+		 * only case where it happens is on a disk
+		 * corruption or ENOMEM.
+		 */
+
+		return generic_ci_match(parent, fname->usr_fname,
+					&fname->cf_name, de->name,
+					de->name_len) > 0;
+	}
+#endif
+
+	return fscrypt_match_name(&f, de->name, de->name_len);
+}
+
+/*
+ * Returns 0 if not found, -EFSCORRUPTED on failure, and 1 on success
+ */
+int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
+		    struct inode *dir, struct ext4_filename *fname,
+		    unsigned int offset, struct ext4_dir_entry_2 **res_dir)
+{
+	struct ext4_dir_entry_2 * de;
+	char * dlimit;
+	int de_len;
+
+	de = (struct ext4_dir_entry_2 *)search_buf;
+	dlimit = search_buf + buf_size;
+	while ((char *) de < dlimit - EXT4_BASE_DIR_LEN) {
+		/* this code is executed quadratically often */
+		/* do minimal checking `by hand' */
+		if (de->name + de->name_len <= dlimit &&
+		    ext4_match(dir, fname, de)) {
+			/* found a match - just to be sure, do
+			 * a full check */
+			if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
+						 buf_size, offset))
+				return -EFSCORRUPTED;
+			*res_dir = de;
+			return 1;
+		}
+		/* prevent looping on a bad block */
+		de_len = ext4_rec_len_from_disk(de->rec_len,
+						dir->i_sb->s_blocksize);
+		if (de_len <= 0)
+			return -EFSCORRUPTED;
+		offset += de_len;
+		de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
+	}
+	return 0;
+}
+
+static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block,
+			       struct ext4_dir_entry *de)
+{
+	struct super_block *sb = dir->i_sb;
+
+	if (!is_dx(dir))
+		return 0;
+	if (block == 0)
+		return 1;
+	if (de->inode == 0 &&
+	    ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) ==
+			sb->s_blocksize)
+		return 1;
+	return 0;
+}
+
+/*
+ *	__ext4_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the cache buffer in which the entry was found, and the entry
+ * itself (as a parameter - res_dir). It does NOT read the inode of the
+ * entry - you'll have to do that yourself if you want to.
+ *
+ * The returned buffer_head has ->b_count elevated.  The caller is expected
+ * to brelse() it when appropriate.
+ */
+static struct buffer_head *__ext4_find_entry(struct inode *dir,
+					     struct ext4_filename *fname,
+					     struct ext4_dir_entry_2 **res_dir,
+					     int *inlined)
+{
+	struct super_block *sb;
+	struct buffer_head *bh_use[NAMEI_RA_SIZE];
+	struct buffer_head *bh, *ret = NULL;
+	ext4_lblk_t start, block;
+	const u8 *name = fname->usr_fname->name;
+	size_t ra_max = 0;	/* Number of bh's in the readahead
+				   buffer, bh_use[] */
+	size_t ra_ptr = 0;	/* Current index into readahead
+				   buffer */
+	ext4_lblk_t  nblocks;
+	int i, namelen, retval;
+
+	*res_dir = NULL;
+	sb = dir->i_sb;
+	namelen = fname->usr_fname->len;
+	if (namelen > EXT4_NAME_LEN)
+		return NULL;
+
+	if (ext4_has_inline_data(dir)) {
+		int has_inline_data = 1;
+		ret = ext4_find_inline_entry(dir, fname, res_dir,
+					     &has_inline_data);
+		if (inlined)
+			*inlined = has_inline_data;
+		if (has_inline_data || IS_ERR(ret))
+			goto cleanup_and_exit;
+	}
+
+	if ((namelen <= 2) && (name[0] == '.') &&
+	    (name[1] == '.' || name[1] == '\0')) {
+		/*
+		 * "." or ".." will only be in the first block
+		 * NFS may look up ".."; "." should be handled by the VFS
+		 */
+		block = start = 0;
+		nblocks = 1;
+		goto restart;
+	}
+	if (is_dx(dir)) {
+		ret = ext4_dx_find_entry(dir, fname, res_dir);
+		/*
+		 * On success, or if the error was file not found,
+		 * return.  Otherwise, fall back to doing a search the
+		 * old fashioned way.
+		 */
+		if (IS_ERR(ret) && PTR_ERR(ret) == ERR_BAD_DX_DIR)
+			dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
+				       "falling back\n"));
+		else if (!sb_no_casefold_compat_fallback(dir->i_sb) &&
+			 *res_dir == NULL && IS_CASEFOLDED(dir))
+			dxtrace(printk(KERN_DEBUG "ext4_find_entry: casefold "
+				       "failed, falling back\n"));
+		else
+			goto cleanup_and_exit;
+		ret = NULL;
+	}
+	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
+	if (!nblocks) {
+		ret = NULL;
+		goto cleanup_and_exit;
+	}
+	start = EXT4_I(dir)->i_dir_start_lookup;
+	if (start >= nblocks)
+		start = 0;
+	block = start;
+restart:
+	do {
+		/*
+		 * We deal with the read-ahead logic here.
+		 */
+		cond_resched();
+		if (ra_ptr >= ra_max) {
+			/* Refill the readahead buffer */
+			ra_ptr = 0;
+			if (block < start)
+				ra_max = start - block;
+			else
+				ra_max = nblocks - block;
+			ra_max = min(ra_max, ARRAY_SIZE(bh_use));
+			retval = ext4_bread_batch(dir, block, ra_max,
+						  false /* wait */, bh_use);
+			if (retval) {
+				ret = ERR_PTR(retval);
+				ra_max = 0;
+				goto cleanup_and_exit;
+			}
+		}
+		if ((bh = bh_use[ra_ptr++]) == NULL)
+			goto next;
+		wait_on_buffer(bh);
+		if (!buffer_uptodate(bh)) {
+			EXT4_ERROR_INODE_ERR(dir, EIO,
+					     "reading directory lblock %lu",
+					     (unsigned long) block);
+			brelse(bh);
+			ret = ERR_PTR(-EIO);
+			goto cleanup_and_exit;
+		}
+		if (!buffer_verified(bh) &&
+		    !is_dx_internal_node(dir, block,
+					 (struct ext4_dir_entry *)bh->b_data) &&
+		    !ext4_dirblock_csum_verify(dir, bh)) {
+			EXT4_ERROR_INODE_ERR(dir, EFSBADCRC,
+					     "checksumming directory "
+					     "block %lu", (unsigned long)block);
+			brelse(bh);
+			ret = ERR_PTR(-EFSBADCRC);
+			goto cleanup_and_exit;
+		}
+		set_buffer_verified(bh);
+		i = search_dirblock(bh, dir, fname,
+			    block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
+		if (i == 1) {
+			EXT4_I(dir)->i_dir_start_lookup = block;
+			ret = bh;
+			goto cleanup_and_exit;
+		} else {
+			brelse(bh);
+			if (i < 0) {
+				ret = ERR_PTR(i);
+				goto cleanup_and_exit;
+			}
+		}
+	next:
+		if (++block >= nblocks)
+			block = 0;
+	} while (block != start);
+
+	/*
+	 * If the directory has grown while we were searching, then
+	 * search the last part of the directory before giving up.
+	 */
+	block = nblocks;
+	nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
+	if (block < nblocks) {
+		start = 0;
+		goto restart;
+	}
+
+cleanup_and_exit:
+	/* Clean up the read-ahead blocks */
+	for (; ra_ptr < ra_max; ra_ptr++)
+		brelse(bh_use[ra_ptr]);
+	return ret;
+}
+
+static struct buffer_head *ext4_find_entry(struct inode *dir,
+					   const struct qstr *d_name,
+					   struct ext4_dir_entry_2 **res_dir,
+					   int *inlined)
+{
+	int err;
+	struct ext4_filename fname;
+	struct buffer_head *bh;
+
+	err = ext4_fname_setup_filename(dir, d_name, 1, &fname);
+	if (err == -ENOENT)
+		return NULL;
+	if (err)
+		return ERR_PTR(err);
+
+	bh = __ext4_find_entry(dir, &fname, res_dir, inlined);
+
+	ext4_fname_free_filename(&fname);
+	return bh;
+}
+
+static struct buffer_head *ext4_lookup_entry(struct inode *dir,
+					     struct dentry *dentry,
+					     struct ext4_dir_entry_2 **res_dir)
+{
+	int err;
+	struct ext4_filename fname;
+	struct buffer_head *bh;
+
+	err = ext4_fname_prepare_lookup(dir, dentry, &fname);
+	if (err == -ENOENT)
+		return NULL;
+	if (err)
+		return ERR_PTR(err);
+
+	bh = __ext4_find_entry(dir, &fname, res_dir, NULL);
+
+	ext4_fname_free_filename(&fname);
+	return bh;
+}
+
+static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
+			struct ext4_filename *fname,
+			struct ext4_dir_entry_2 **res_dir)
+{
+	struct super_block * sb = dir->i_sb;
+	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
+	struct buffer_head *bh;
+	ext4_lblk_t block;
+	int retval;
+
+#ifdef CONFIG_FS_ENCRYPTION
+	*res_dir = NULL;
+#endif
+	frame = dx_probe(fname, dir, NULL, frames);
+	if (IS_ERR(frame))
+		return ERR_CAST(frame);
+	do {
+		block = dx_get_block(frame->at);
+		bh = ext4_read_dirblock(dir, block, DIRENT_HTREE);
+		if (IS_ERR(bh))
+			goto errout;
+
+		retval = search_dirblock(bh, dir, fname,
+					 block << EXT4_BLOCK_SIZE_BITS(sb),
+					 res_dir);
+		if (retval == 1)
+			goto success;
+		brelse(bh);
+		if (retval < 0) {
+			bh = ERR_PTR(ERR_BAD_DX_DIR);
+			goto errout;
+		}
+
+		/* Check to see if we should continue to search */
+		retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame,
+					       frames, NULL);
+		if (retval < 0) {
+			ext4_warning_inode(dir,
+				"error %d reading directory index block",
+				retval);
+			bh = ERR_PTR(retval);
+			goto errout;
+		}
+	} while (retval == 1);
+
+	bh = NULL;
+errout:
+	dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name));
+success:
+	dx_release(frames);
+	return bh;
+}
+
+static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+	struct inode *inode;
+	struct ext4_dir_entry_2 *de;
+	struct buffer_head *bh;
+
+	if (dentry->d_name.len > EXT4_NAME_LEN)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	bh = ext4_lookup_entry(dir, dentry, &de);
+	if (IS_ERR(bh))
+		return ERR_CAST(bh);
+	inode = NULL;
+	if (bh) {
+		__u32 ino = le32_to_cpu(de->inode);
+		brelse(bh);
+		if (!ext4_valid_inum(dir->i_sb, ino)) {
+			EXT4_ERROR_INODE(dir, "bad inode number: %u", ino);
+			return ERR_PTR(-EFSCORRUPTED);
+		}
+		if (unlikely(ino == dir->i_ino)) {
+			EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir",
+					 dentry);
+			return ERR_PTR(-EFSCORRUPTED);
+		}
+		inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);
+		if (inode == ERR_PTR(-ESTALE)) {
+			EXT4_ERROR_INODE(dir,
+					 "deleted inode referenced: %u",
+					 ino);
+			return ERR_PTR(-EFSCORRUPTED);
+		}
+		if (!IS_ERR(inode) && IS_ENCRYPTED(dir) &&
+		    (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
+		    !fscrypt_has_permitted_context(dir, inode)) {
+			ext4_warning(inode->i_sb,
+				     "Inconsistent encryption contexts: %lu/%lu",
+				     dir->i_ino, inode->i_ino);
+			iput(inode);
+			return ERR_PTR(-EPERM);
+		}
+	}
+
+	if (IS_ENABLED(CONFIG_UNICODE) && !inode && IS_CASEFOLDED(dir)) {
+		/* Eventually we want to call d_add_ci(dentry, NULL)
+		 * for negative dentries in the encoding case as
+		 * well.  For now, prevent the negative dentry
+		 * from being cached.
+		 */
+		return NULL;
+	}
+
+	return d_splice_alias(inode, dentry);
+}
+
+
+struct dentry *ext4_get_parent(struct dentry *child)
+{
+	__u32 ino;
+	struct ext4_dir_entry_2 * de;
+	struct buffer_head *bh;
+
+	bh = ext4_find_entry(d_inode(child), &dotdot_name, &de, NULL);
+	if (IS_ERR(bh))
+		return ERR_CAST(bh);
+	if (!bh)
+		return ERR_PTR(-ENOENT);
+	ino = le32_to_cpu(de->inode);
+	brelse(bh);
+
+	if (!ext4_valid_inum(child->d_sb, ino)) {
+		EXT4_ERROR_INODE(d_inode(child),
+				 "bad parent inode number: %u", ino);
+		return ERR_PTR(-EFSCORRUPTED);
+	}
+
+	return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));
+}
+
+/*
+ * Move count entries from end of map between two memory locations.
+ * Returns pointer to last entry moved.
+ */
+static struct ext4_dir_entry_2 *
+dx_move_dirents(struct inode *dir, char *from, char *to,
+		struct dx_map_entry *map, int count,
+		unsigned blocksize)
+{
+	unsigned rec_len = 0;
+
+	while (count--) {
+		struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
+						(from + (map->offs<<2));
+		rec_len = ext4_dir_rec_len(de->name_len, dir);
+
+		memcpy (to, de, rec_len);
+		((struct ext4_dir_entry_2 *) to)->rec_len =
+				ext4_rec_len_to_disk(rec_len, blocksize);
+
+		/* wipe dir_entry excluding the rec_len field */
+		de->inode = 0;
+		memset(&de->name_len, 0, ext4_rec_len_from_disk(de->rec_len,
+								blocksize) -
+					 offsetof(struct ext4_dir_entry_2,
+								name_len));
+
+		map++;
+		to += rec_len;
+	}
+	return (struct ext4_dir_entry_2 *) (to - rec_len);
+}
+
+/*
+ * Compact each dir entry in the range to the minimal rec_len.
+ * Returns pointer to last entry in range.
+ */
+static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
+							unsigned int blocksize)
+{
+	struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
+	unsigned rec_len = 0;
+
+	prev = to = de;
+	while ((char*)de < base + blocksize) {
+		next = ext4_next_entry(de, blocksize);
+		if (de->inode && de->name_len) {
+			rec_len = ext4_dir_rec_len(de->name_len, dir);
+			if (de > to)
+				memmove(to, de, rec_len);
+			to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
+			prev = to;
+			to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
+		}
+		de = next;
+	}
+	return prev;
+}
+
+/*
+ * Split a full leaf block to make room for a new dir entry.
+ * Allocate a new block, and move entries so that they are approx. equally full.
+ * Returns pointer to de in block into which the new entry will be inserted.
+ */
+static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
+			struct buffer_head **bh,struct dx_frame *frame,
+			struct dx_hash_info *hinfo)
+{
+	unsigned blocksize = dir->i_sb->s_blocksize;
+	unsigned continued;
+	int count;
+	struct buffer_head *bh2;
+	ext4_lblk_t newblock;
+	u32 hash2;
+	struct dx_map_entry *map;
+	char *data1 = (*bh)->b_data, *data2;
+	unsigned split, move, size;
+	struct ext4_dir_entry_2 *de = NULL, *de2;
+	int	csum_size = 0;
+	int	err = 0, i;
+
+	if (ext4_has_feature_metadata_csum(dir->i_sb))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
+	bh2 = ext4_append(handle, dir, &newblock);
+	if (IS_ERR(bh2)) {
+		brelse(*bh);
+		*bh = NULL;
+		return ERR_CAST(bh2);
+	}
+
+	BUFFER_TRACE(*bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, dir->i_sb, *bh,
+					    EXT4_JTR_NONE);
+	if (err)
+		goto journal_error;
+
+	BUFFER_TRACE(frame->bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, dir->i_sb, frame->bh,
+					    EXT4_JTR_NONE);
+	if (err)
+		goto journal_error;
+
+	data2 = bh2->b_data;
+
+	/* create map in the end of data2 block */
+	map = (struct dx_map_entry *) (data2 + blocksize);
+	count = dx_make_map(dir, *bh, hinfo, map);
+	if (count < 0) {
+		err = count;
+		goto journal_error;
+	}
+	map -= count;
+	dx_sort_map(map, count);
+	/* Ensure that neither split block is over half full */
+	size = 0;
+	move = 0;
+	for (i = count-1; i >= 0; i--) {
+		/* is more than half of this entry in 2nd half of the block? */
+		if (size + map[i].size/2 > blocksize/2)
+			break;
+		size += map[i].size;
+		move++;
+	}
+	/*
+	 * map index at which we will split
+	 *
+	 * If the sum of active entries didn't exceed half the block size, just
+	 * split it in half by count; each resulting block will have at least
+	 * half the space free.
+	 */
+	if (i >= 0)
+		split = count - move;
+	else
+		split = count/2;
+
+	if (WARN_ON_ONCE(split == 0)) {
+		/* Should never happen, but avoid out-of-bounds access below */
+		ext4_error_inode_block(dir, (*bh)->b_blocknr, 0,
+			"bad indexed directory? hash=%08x:%08x count=%d move=%u",
+			hinfo->hash, hinfo->minor_hash, count, move);
+		err = -EFSCORRUPTED;
+		goto out;
+	}
+
+	hash2 = map[split].hash;
+	continued = hash2 == map[split - 1].hash;
+	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
+			(unsigned long)dx_get_block(frame->at),
+					hash2, split, count-split));
+
+	/* Fancy dance to stay within two buffers */
+	de2 = dx_move_dirents(dir, data1, data2, map + split, count - split,
+			      blocksize);
+	de = dx_pack_dirents(dir, data1, blocksize);
+	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
+					   (char *) de,
+					   blocksize);
+	de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
+					    (char *) de2,
+					    blocksize);
+	if (csum_size) {
+		ext4_initialize_dirent_tail(*bh, blocksize);
+		ext4_initialize_dirent_tail(bh2, blocksize);
+	}
+
+	dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
+			blocksize, 1));
+	dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
+			blocksize, 1));
+
+	/* Which block gets the new entry? */
+	if (hinfo->hash >= hash2) {
+		swap(*bh, bh2);
+		de = de2;
+	}
+	dx_insert_block(frame, hash2 + continued, newblock);
+	err = ext4_handle_dirty_dirblock(handle, dir, bh2);
+	if (err)
+		goto journal_error;
+	err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
+	if (err)
+		goto journal_error;
+	brelse(bh2);
+	dxtrace(dx_show_index("frame", frame->entries));
+	return de;
+
+journal_error:
+	ext4_std_error(dir->i_sb, err);
+out:
+	brelse(*bh);
+	brelse(bh2);
+	*bh = NULL;
+	return ERR_PTR(err);
+}
+
+int ext4_find_dest_de(struct inode *dir, struct buffer_head *bh,
+		      void *buf, int buf_size,
+		      struct ext4_filename *fname,
+		      struct ext4_dir_entry_2 **dest_de)
+{
+	struct ext4_dir_entry_2 *de;
+	unsigned short reclen = ext4_dir_rec_len(fname_len(fname), dir);
+	int nlen, rlen;
+	unsigned int offset = 0;
+	char *top;
+
+	de = buf;
+	top = buf + buf_size - reclen;
+	while ((char *) de <= top) {
+		if (ext4_check_dir_entry(dir, NULL, de, bh,
+					 buf, buf_size, offset))
+			return -EFSCORRUPTED;
+		if (ext4_match(dir, fname, de))
+			return -EEXIST;
+		nlen = ext4_dir_rec_len(de->name_len, dir);
+		rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+		if ((de->inode ? rlen - nlen : rlen) >= reclen)
+			break;
+		de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
+		offset += rlen;
+	}
+	if ((char *) de > top)
+		return -ENOSPC;
+
+	*dest_de = de;
+	return 0;
+}
+
+void ext4_insert_dentry(struct inode *dir,
+			struct inode *inode,
+			struct ext4_dir_entry_2 *de,
+			int buf_size,
+			struct ext4_filename *fname)
+{
+
+	int nlen, rlen;
+
+	nlen = ext4_dir_rec_len(de->name_len, dir);
+	rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
+	if (de->inode) {
+		struct ext4_dir_entry_2 *de1 =
+			(struct ext4_dir_entry_2 *)((char *)de + nlen);
+		de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, buf_size);
+		de->rec_len = ext4_rec_len_to_disk(nlen, buf_size);
+		de = de1;
+	}
+	de->file_type = EXT4_FT_UNKNOWN;
+	de->inode = cpu_to_le32(inode->i_ino);
+	ext4_set_de_type(inode->i_sb, de, inode->i_mode);
+	de->name_len = fname_len(fname);
+	memcpy(de->name, fname_name(fname), fname_len(fname));
+	if (ext4_hash_in_dirent(dir)) {
+		struct dx_hash_info *hinfo = &fname->hinfo;
+
+		EXT4_DIRENT_HASHES(de)->hash = cpu_to_le32(hinfo->hash);
+		EXT4_DIRENT_HASHES(de)->minor_hash =
+						cpu_to_le32(hinfo->minor_hash);
+	}
+}
+
+/*
+ * Add a new entry into a directory (leaf) block.  If de is non-NULL,
+ * it points to a directory entry which is guaranteed to be large
+ * enough for new directory entry.  If de is NULL, then
+ * add_dirent_to_buf will attempt search the directory block for
+ * space.  It will return -ENOSPC if no space is available, and -EIO
+ * and -EEXIST if directory entry already exists.
+ */
+static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
+			     struct inode *dir,
+			     struct inode *inode, struct ext4_dir_entry_2 *de,
+			     struct buffer_head *bh)
+{
+	unsigned int	blocksize = dir->i_sb->s_blocksize;
+	int		csum_size = 0;
+	int		err, err2;
+
+	if (ext4_has_feature_metadata_csum(inode->i_sb))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
+	if (!de) {
+		err = ext4_find_dest_de(dir, bh, bh->b_data,
+					blocksize - csum_size, fname, &de);
+		if (err)
+			return err;
+	}
+	BUFFER_TRACE(bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
+					    EXT4_JTR_NONE);
+	if (err) {
+		ext4_std_error(dir->i_sb, err);
+		return err;
+	}
+
+	/* By now the buffer is marked for journaling */
+	ext4_insert_dentry(dir, inode, de, blocksize, fname);
+
+	/*
+	 * XXX shouldn't update any times until successful
+	 * completion of syscall, but too many callers depend
+	 * on this.
+	 *
+	 * XXX similarly, too many callers depend on
+	 * ext4_new_inode() setting the times, but error
+	 * recovery deletes the inode, so the worst that can
+	 * happen is that the times are slightly out of date
+	 * and/or different from the directory change time.
+	 */
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	ext4_update_dx_flag(dir);
+	inode_inc_iversion(dir);
+	err2 = ext4_mark_inode_dirty(handle, dir);
+	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+	err = ext4_handle_dirty_dirblock(handle, dir, bh);
+	if (err)
+		ext4_std_error(dir->i_sb, err);
+	return err ? err : err2;
+}
+
+static bool ext4_check_dx_root(struct inode *dir, struct dx_root *root)
+{
+	struct fake_dirent *fde;
+	const char *error_msg;
+	unsigned int rlen;
+	unsigned int blocksize = dir->i_sb->s_blocksize;
+	char *blockend = (char *)root + dir->i_sb->s_blocksize;
+
+	fde = &root->dot;
+	if (unlikely(fde->name_len != 1)) {
+		error_msg = "invalid name_len for '.'";
+		goto corrupted;
+	}
+	if (unlikely(strncmp(root->dot_name, ".", fde->name_len))) {
+		error_msg = "invalid name for '.'";
+		goto corrupted;
+	}
+	rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
+	if (unlikely((char *)fde + rlen >= blockend)) {
+		error_msg = "invalid rec_len for '.'";
+		goto corrupted;
+	}
+
+	fde = &root->dotdot;
+	if (unlikely(fde->name_len != 2)) {
+		error_msg = "invalid name_len for '..'";
+		goto corrupted;
+	}
+	if (unlikely(strncmp(root->dotdot_name, "..", fde->name_len))) {
+		error_msg = "invalid name for '..'";
+		goto corrupted;
+	}
+	rlen = ext4_rec_len_from_disk(fde->rec_len, blocksize);
+	if (unlikely((char *)fde + rlen >= blockend)) {
+		error_msg = "invalid rec_len for '..'";
+		goto corrupted;
+	}
+
+	return true;
+
+corrupted:
+	EXT4_ERROR_INODE(dir, "Corrupt dir, %s, running e2fsck is recommended",
+			 error_msg);
+	return false;
+}
+
+/*
+ * This converts a one block unindexed directory to a 3 block indexed
+ * directory, and adds the dentry to the indexed directory.
+ */
+static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
+			    struct inode *dir,
+			    struct inode *inode, struct buffer_head *bh)
+{
+	struct buffer_head *bh2;
+	struct dx_root	*root;
+	struct dx_frame	frames[EXT4_HTREE_LEVEL], *frame;
+	struct dx_entry *entries;
+	struct ext4_dir_entry_2	*de, *de2;
+	char		*data2, *top;
+	unsigned	len;
+	int		retval;
+	unsigned	blocksize;
+	ext4_lblk_t  block;
+	struct fake_dirent *fde;
+	int csum_size = 0;
+
+	if (ext4_has_feature_metadata_csum(inode->i_sb))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
+	blocksize =  dir->i_sb->s_blocksize;
+	dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
+	BUFFER_TRACE(bh, "get_write_access");
+	retval = ext4_journal_get_write_access(handle, dir->i_sb, bh,
+					       EXT4_JTR_NONE);
+	if (retval) {
+		ext4_std_error(dir->i_sb, retval);
+		brelse(bh);
+		return retval;
+	}
+
+	root = (struct dx_root *) bh->b_data;
+	if (!ext4_check_dx_root(dir, root)) {
+		brelse(bh);
+		return -EFSCORRUPTED;
+	}
+
+	/* The 0th block becomes the root, move the dirents out */
+	fde = &root->dotdot;
+	de = (struct ext4_dir_entry_2 *)((char *)fde +
+		ext4_rec_len_from_disk(fde->rec_len, blocksize));
+	len = ((char *) root) + (blocksize - csum_size) - (char *) de;
+
+	/* Allocate new block for the 0th block's dirents */
+	bh2 = ext4_append(handle, dir, &block);
+	if (IS_ERR(bh2)) {
+		brelse(bh);
+		return PTR_ERR(bh2);
+	}
+	ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
+	data2 = bh2->b_data;
+
+	memcpy(data2, de, len);
+	memset(de, 0, len); /* wipe old data */
+	de = (struct ext4_dir_entry_2 *) data2;
+	top = data2 + len;
+	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) {
+		if (ext4_check_dir_entry(dir, NULL, de, bh2, data2, len,
+					(char *)de - data2)) {
+			brelse(bh2);
+			brelse(bh);
+			return -EFSCORRUPTED;
+		}
+		de = de2;
+	}
+	de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
+					   (char *) de, blocksize);
+
+	if (csum_size)
+		ext4_initialize_dirent_tail(bh2, blocksize);
+
+	/* Initialize the root; the dot dirents already exist */
+	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
+	de->rec_len = ext4_rec_len_to_disk(
+			blocksize - ext4_dir_rec_len(2, NULL), blocksize);
+	memset (&root->info, 0, sizeof(root->info));
+	root->info.info_length = sizeof(root->info);
+	if (ext4_hash_in_dirent(dir))
+		root->info.hash_version = DX_HASH_SIPHASH;
+	else
+		root->info.hash_version =
+				EXT4_SB(dir->i_sb)->s_def_hash_version;
+
+	entries = root->entries;
+	dx_set_block(entries, 1);
+	dx_set_count(entries, 1);
+	dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
+
+	/* Initialize as for dx_probe */
+	fname->hinfo.hash_version = root->info.hash_version;
+	if (fname->hinfo.hash_version <= DX_HASH_TEA)
+		fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
+	fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
+
+	/* casefolded encrypted hashes are computed on fname setup */
+	if (!ext4_hash_in_dirent(dir)) {
+		int err = ext4fs_dirhash(dir, fname_name(fname),
+					 fname_len(fname), &fname->hinfo);
+		if (err < 0) {
+			brelse(bh2);
+			brelse(bh);
+			return err;
+		}
+	}
+	memset(frames, 0, sizeof(frames));
+	frame = frames;
+	frame->entries = entries;
+	frame->at = entries;
+	frame->bh = bh;
+
+	retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
+	if (retval)
+		goto out_frames;
+	retval = ext4_handle_dirty_dirblock(handle, dir, bh2);
+	if (retval)
+		goto out_frames;
+
+	de = do_split(handle,dir, &bh2, frame, &fname->hinfo);
+	if (IS_ERR(de)) {
+		retval = PTR_ERR(de);
+		goto out_frames;
+	}
+
+	retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2);
+out_frames:
+	/*
+	 * Even if the block split failed, we have to properly write
+	 * out all the changes we did so far. Otherwise we can end up
+	 * with corrupted filesystem.
+	 */
+	if (retval)
+		ext4_mark_inode_dirty(handle, dir);
+	dx_release(frames);
+	brelse(bh2);
+	return retval;
+}
+
+/*
+ *	ext4_add_entry()
+ *
+ * adds a file entry to the specified directory, using the same
+ * semantics as ext4_find_entry(). It returns NULL if it failed.
+ *
+ * NOTE!! The inode part of 'de' is left at 0 - which means you
+ * may not sleep between calling this and putting something into
+ * the entry, as someone else might have used it while you slept.
+ */
+static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
+			  struct inode *inode)
+{
+	struct inode *dir = d_inode(dentry->d_parent);
+	struct buffer_head *bh = NULL;
+	struct ext4_dir_entry_2 *de;
+	struct super_block *sb;
+	struct ext4_filename fname;
+	int	retval;
+	int	dx_fallback=0;
+	unsigned blocksize;
+	ext4_lblk_t block, blocks;
+	int	csum_size = 0;
+
+	if (ext4_has_feature_metadata_csum(inode->i_sb))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
+	sb = dir->i_sb;
+	blocksize = sb->s_blocksize;
+
+	if (fscrypt_is_nokey_name(dentry))
+		return -ENOKEY;
+
+	if (!generic_ci_validate_strict_name(dir, &dentry->d_name))
+		return -EINVAL;
+
+	retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname);
+	if (retval)
+		return retval;
+
+	if (ext4_has_inline_data(dir)) {
+		retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
+		if (retval < 0)
+			goto out;
+		if (retval == 1) {
+			retval = 0;
+			goto out;
+		}
+	}
+
+	if (is_dx(dir)) {
+		retval = ext4_dx_add_entry(handle, &fname, dir, inode);
+		if (!retval || (retval != ERR_BAD_DX_DIR))
+			goto out;
+		/* Can we just ignore htree data? */
+		if (ext4_has_feature_metadata_csum(sb)) {
+			EXT4_ERROR_INODE(dir,
+				"Directory has corrupted htree index.");
+			retval = -EFSCORRUPTED;
+			goto out;
+		}
+		ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
+		dx_fallback++;
+		retval = ext4_mark_inode_dirty(handle, dir);
+		if (unlikely(retval))
+			goto out;
+	}
+	blocks = dir->i_size >> sb->s_blocksize_bits;
+	for (block = 0; block < blocks; block++) {
+		bh = ext4_read_dirblock(dir, block, DIRENT);
+		if (bh == NULL) {
+			bh = ext4_bread(handle, dir, block,
+					EXT4_GET_BLOCKS_CREATE);
+			goto add_to_new_block;
+		}
+		if (IS_ERR(bh)) {
+			retval = PTR_ERR(bh);
+			bh = NULL;
+			goto out;
+		}
+		retval = add_dirent_to_buf(handle, &fname, dir, inode,
+					   NULL, bh);
+		if (retval != -ENOSPC)
+			goto out;
+
+		if (blocks == 1 && !dx_fallback &&
+		    ext4_has_feature_dir_index(sb)) {
+			retval = make_indexed_dir(handle, &fname, dir,
+						  inode, bh);
+			bh = NULL; /* make_indexed_dir releases bh */
+			goto out;
+		}
+		brelse(bh);
+	}
+	bh = ext4_append(handle, dir, &block);
+add_to_new_block:
+	if (IS_ERR(bh)) {
+		retval = PTR_ERR(bh);
+		bh = NULL;
+		goto out;
+	}
+	de = (struct ext4_dir_entry_2 *) bh->b_data;
+	de->inode = 0;
+	de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
+
+	if (csum_size)
+		ext4_initialize_dirent_tail(bh, blocksize);
+
+	retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh);
+out:
+	ext4_fname_free_filename(&fname);
+	brelse(bh);
+	if (retval == 0)
+		ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);
+	return retval;
+}
+
+/*
+ * Returns 0 for success, or a negative error value
+ */
+static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
+			     struct inode *dir, struct inode *inode)
+{
+	struct dx_frame frames[EXT4_HTREE_LEVEL], *frame;
+	struct dx_entry *entries, *at;
+	struct buffer_head *bh;
+	struct super_block *sb = dir->i_sb;
+	struct ext4_dir_entry_2 *de;
+	int restart;
+	int err;
+
+again:
+	restart = 0;
+	frame = dx_probe(fname, dir, NULL, frames);
+	if (IS_ERR(frame))
+		return PTR_ERR(frame);
+	entries = frame->entries;
+	at = frame->at;
+	bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE);
+	if (IS_ERR(bh)) {
+		err = PTR_ERR(bh);
+		bh = NULL;
+		goto cleanup;
+	}
+
+	BUFFER_TRACE(bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
+	if (err)
+		goto journal_error;
+
+	err = add_dirent_to_buf(handle, fname, dir, inode, NULL, bh);
+	if (err != -ENOSPC)
+		goto cleanup;
+
+	err = 0;
+	/* Block full, should compress but for now just split */
+	dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
+		       dx_get_count(entries), dx_get_limit(entries)));
+	/* Need to split index? */
+	if (dx_get_count(entries) == dx_get_limit(entries)) {
+		ext4_lblk_t newblock;
+		int levels = frame - frames + 1;
+		unsigned int icount;
+		int add_level = 1;
+		struct dx_entry *entries2;
+		struct dx_node *node2;
+		struct buffer_head *bh2;
+
+		while (frame > frames) {
+			if (dx_get_count((frame - 1)->entries) <
+			    dx_get_limit((frame - 1)->entries)) {
+				add_level = 0;
+				break;
+			}
+			frame--; /* split higher index block */
+			at = frame->at;
+			entries = frame->entries;
+			restart = 1;
+		}
+		if (add_level && levels == ext4_dir_htree_level(sb)) {
+			ext4_warning(sb, "Directory (ino: %lu) index full, "
+					 "reach max htree level :%d",
+					 dir->i_ino, levels);
+			if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) {
+				ext4_warning(sb, "Large directory feature is "
+						 "not enabled on this "
+						 "filesystem");
+			}
+			err = -ENOSPC;
+			goto cleanup;
+		}
+		icount = dx_get_count(entries);
+		bh2 = ext4_append(handle, dir, &newblock);
+		if (IS_ERR(bh2)) {
+			err = PTR_ERR(bh2);
+			goto cleanup;
+		}
+		node2 = (struct dx_node *)(bh2->b_data);
+		entries2 = node2->entries;
+		memset(&node2->fake, 0, sizeof(struct fake_dirent));
+		node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
+							   sb->s_blocksize);
+		BUFFER_TRACE(frame->bh, "get_write_access");
+		err = ext4_journal_get_write_access(handle, sb, frame->bh,
+						    EXT4_JTR_NONE);
+		if (err) {
+			brelse(bh2);
+			goto journal_error;
+		}
+		if (!add_level) {
+			unsigned icount1 = icount/2, icount2 = icount - icount1;
+			unsigned hash2 = dx_get_hash(entries + icount1);
+			dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
+				       icount1, icount2));
+
+			BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
+			err = ext4_journal_get_write_access(handle, sb,
+							    (frame - 1)->bh,
+							    EXT4_JTR_NONE);
+			if (err) {
+				brelse(bh2);
+				goto journal_error;
+			}
+
+			memcpy((char *) entries2, (char *) (entries + icount1),
+			       icount2 * sizeof(struct dx_entry));
+			dx_set_count(entries, icount1);
+			dx_set_count(entries2, icount2);
+			dx_set_limit(entries2, dx_node_limit(dir));
+
+			/* Which index block gets the new entry? */
+			if (at - entries >= icount1) {
+				frame->at = at - entries - icount1 + entries2;
+				frame->entries = entries = entries2;
+				swap(frame->bh, bh2);
+			}
+			dx_insert_block((frame - 1), hash2, newblock);
+			dxtrace(dx_show_index("node", frame->entries));
+			dxtrace(dx_show_index("node",
+			       ((struct dx_node *) bh2->b_data)->entries));
+			err = ext4_handle_dirty_dx_node(handle, dir, bh2);
+			if (err) {
+				brelse(bh2);
+				goto journal_error;
+			}
+			brelse (bh2);
+			err = ext4_handle_dirty_dx_node(handle, dir,
+						   (frame - 1)->bh);
+			if (err)
+				goto journal_error;
+			err = ext4_handle_dirty_dx_node(handle, dir,
+							frame->bh);
+			if (restart || err)
+				goto journal_error;
+		} else {
+			struct dx_root *dxroot;
+			memcpy((char *) entries2, (char *) entries,
+			       icount * sizeof(struct dx_entry));
+			dx_set_limit(entries2, dx_node_limit(dir));
+
+			/* Set up root */
+			dx_set_count(entries, 1);
+			dx_set_block(entries + 0, newblock);
+			dxroot = (struct dx_root *)frames[0].bh->b_data;
+			dxroot->info.indirect_levels += 1;
+			dxtrace(printk(KERN_DEBUG
+				       "Creating %d level index...\n",
+				       dxroot->info.indirect_levels));
+			err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
+			if (err) {
+				brelse(bh2);
+				goto journal_error;
+			}
+			err = ext4_handle_dirty_dx_node(handle, dir, bh2);
+			brelse(bh2);
+			restart = 1;
+			goto journal_error;
+		}
+	}
+	de = do_split(handle, dir, &bh, frame, &fname->hinfo);
+	if (IS_ERR(de)) {
+		err = PTR_ERR(de);
+		goto cleanup;
+	}
+	err = add_dirent_to_buf(handle, fname, dir, inode, de, bh);
+	goto cleanup;
+
+journal_error:
+	ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */
+cleanup:
+	brelse(bh);
+	dx_release(frames);
+	/* @restart is true means htree-path has been changed, we need to
+	 * repeat dx_probe() to find out valid htree-path
+	 */
+	if (restart && err == 0)
+		goto again;
+	return err;
+}
+
+/*
+ * ext4_generic_delete_entry deletes a directory entry by merging it
+ * with the previous entry
+ */
+int ext4_generic_delete_entry(struct inode *dir,
+			      struct ext4_dir_entry_2 *de_del,
+			      struct buffer_head *bh,
+			      void *entry_buf,
+			      int buf_size,
+			      int csum_size)
+{
+	struct ext4_dir_entry_2 *de, *pde;
+	unsigned int blocksize = dir->i_sb->s_blocksize;
+	int i;
+
+	i = 0;
+	pde = NULL;
+	de = entry_buf;
+	while (i < buf_size - csum_size) {
+		if (ext4_check_dir_entry(dir, NULL, de, bh,
+					 entry_buf, buf_size, i))
+			return -EFSCORRUPTED;
+		if (de == de_del)  {
+			if (pde) {
+				pde->rec_len = ext4_rec_len_to_disk(
+					ext4_rec_len_from_disk(pde->rec_len,
+							       blocksize) +
+					ext4_rec_len_from_disk(de->rec_len,
+							       blocksize),
+					blocksize);
+
+				/* wipe entire dir_entry */
+				memset(de, 0, ext4_rec_len_from_disk(de->rec_len,
+								blocksize));
+			} else {
+				/* wipe dir_entry excluding the rec_len field */
+				de->inode = 0;
+				memset(&de->name_len, 0,
+					ext4_rec_len_from_disk(de->rec_len,
+								blocksize) -
+					offsetof(struct ext4_dir_entry_2,
+								name_len));
+			}
+
+			inode_inc_iversion(dir);
+			return 0;
+		}
+		i += ext4_rec_len_from_disk(de->rec_len, blocksize);
+		pde = de;
+		de = ext4_next_entry(de, blocksize);
+	}
+	return -ENOENT;
+}
+
+static int ext4_delete_entry(handle_t *handle,
+			     struct inode *dir,
+			     struct ext4_dir_entry_2 *de_del,
+			     struct buffer_head *bh)
+{
+	int err, csum_size = 0;
+
+	if (ext4_has_inline_data(dir)) {
+		int has_inline_data = 1;
+		err = ext4_delete_inline_entry(handle, dir, de_del, bh,
+					       &has_inline_data);
+		if (has_inline_data)
+			return err;
+	}
+
+	if (ext4_has_feature_metadata_csum(dir->i_sb))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
+	BUFFER_TRACE(bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, dir->i_sb, bh,
+					    EXT4_JTR_NONE);
+	if (unlikely(err))
+		goto out;
+
+	err = ext4_generic_delete_entry(dir, de_del, bh, bh->b_data,
+					dir->i_sb->s_blocksize, csum_size);
+	if (err)
+		goto out;
+
+	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+	err = ext4_handle_dirty_dirblock(handle, dir, bh);
+	if (unlikely(err))
+		goto out;
+
+	return 0;
+out:
+	if (err != -ENOENT)
+		ext4_std_error(dir->i_sb, err);
+	return err;
+}
+
+/*
+ * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2
+ * since this indicates that nlinks count was previously 1 to avoid overflowing
+ * the 16-bit i_links_count field on disk.  Directories with i_nlink == 1 mean
+ * that subdirectory link counts are not being maintained accurately.
+ *
+ * The caller has already checked for i_nlink overflow in case the DIR_LINK
+ * feature is not enabled and returned -EMLINK.  The is_dx() check is a proxy
+ * 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)
+{
+	inc_nlink(inode);
+	if (is_dx(inode) &&
+	    (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2))
+		set_nlink(inode, 1);
+}
+
+/*
+ * 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)
+{
+	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
+		drop_nlink(inode);
+}
+
+
+/*
+ * Add non-directory inode to a directory. On success, the inode reference is
+ * consumed by dentry is instantiation. This is also indicated by clearing of
+ * *inodep pointer. On failure, the caller is responsible for dropping the
+ * inode reference in the safe context.
+ */
+static int ext4_add_nondir(handle_t *handle,
+		struct dentry *dentry, struct inode **inodep)
+{
+	struct inode *dir = d_inode(dentry->d_parent);
+	struct inode *inode = *inodep;
+	int err = ext4_add_entry(handle, dentry, inode);
+	if (!err) {
+		err = ext4_mark_inode_dirty(handle, inode);
+		if (IS_DIRSYNC(dir))
+			ext4_handle_sync(handle);
+		d_instantiate_new(dentry, inode);
+		*inodep = NULL;
+		return err;
+	}
+	drop_nlink(inode);
+	ext4_mark_inode_dirty(handle, inode);
+	ext4_orphan_add(handle, inode);
+	unlock_new_inode(inode);
+	return err;
+}
+
+/*
+ * By the time this is called, we already have created
+ * the directory cache entry for the new file, but it
+ * is so far negative - it has no inode.
+ *
+ * If the create succeeds, we fill in the inode information
+ * with d_instantiate().
+ */
+static int ext4_create(struct mnt_idmap *idmap, struct inode *dir,
+		       struct dentry *dentry, umode_t mode, bool excl)
+{
+	handle_t *handle;
+	struct inode *inode;
+	int err, credits, retries = 0;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
+retry:
+	inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
+					    0, NULL, EXT4_HT_DIR, credits);
+	handle = ext4_journal_current_handle();
+	err = PTR_ERR(inode);
+	if (!IS_ERR(inode)) {
+		inode->i_op = &ext4_file_inode_operations;
+		inode->i_fop = &ext4_file_operations;
+		ext4_set_aops(inode);
+		err = ext4_add_nondir(handle, dentry, &inode);
+		if (!err)
+			ext4_fc_track_create(handle, dentry);
+	}
+	if (handle)
+		ext4_journal_stop(handle);
+	if (!IS_ERR_OR_NULL(inode))
+		iput(inode);
+	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+		goto retry;
+	return err;
+}
+
+static int ext4_mknod(struct mnt_idmap *idmap, struct inode *dir,
+		      struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+	handle_t *handle;
+	struct inode *inode;
+	int err, credits, retries = 0;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
+retry:
+	inode = ext4_new_inode_start_handle(idmap, dir, mode, &dentry->d_name,
+					    0, NULL, EXT4_HT_DIR, credits);
+	handle = ext4_journal_current_handle();
+	err = PTR_ERR(inode);
+	if (!IS_ERR(inode)) {
+		init_special_inode(inode, inode->i_mode, rdev);
+		inode->i_op = &ext4_special_inode_operations;
+		err = ext4_add_nondir(handle, dentry, &inode);
+		if (!err)
+			ext4_fc_track_create(handle, dentry);
+	}
+	if (handle)
+		ext4_journal_stop(handle);
+	if (!IS_ERR_OR_NULL(inode))
+		iput(inode);
+	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+		goto retry;
+	return err;
+}
+
+static int ext4_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
+			struct file *file, umode_t mode)
+{
+	handle_t *handle;
+	struct inode *inode;
+	int err, retries = 0;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+retry:
+	inode = ext4_new_inode_start_handle(idmap, dir, mode,
+					    NULL, 0, NULL,
+					    EXT4_HT_DIR,
+			EXT4_MAXQUOTAS_TRANS_BLOCKS(dir->i_sb) +
+			  4 + EXT4_XATTR_TRANS_BLOCKS);
+	handle = ext4_journal_current_handle();
+	err = PTR_ERR(inode);
+	if (!IS_ERR(inode)) {
+		inode->i_op = &ext4_file_inode_operations;
+		inode->i_fop = &ext4_file_operations;
+		ext4_set_aops(inode);
+		d_tmpfile(file, inode);
+		err = ext4_orphan_add(handle, inode);
+		if (err)
+			goto err_unlock_inode;
+		mark_inode_dirty(inode);
+		unlock_new_inode(inode);
+	}
+	if (handle)
+		ext4_journal_stop(handle);
+	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+		goto retry;
+	return finish_open_simple(file, err);
+err_unlock_inode:
+	ext4_journal_stop(handle);
+	unlock_new_inode(inode);
+	return err;
+}
+
+int ext4_init_dirblock(handle_t *handle, struct inode *inode,
+		       struct buffer_head *bh, unsigned int parent_ino,
+		       void *inline_buf, int inline_size)
+{
+	struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) bh->b_data;
+	size_t			blocksize = bh->b_size;
+	int			csum_size = 0, header_size;
+
+	if (ext4_has_feature_metadata_csum(inode->i_sb))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
+	de->inode = cpu_to_le32(inode->i_ino);
+	de->name_len = 1;
+	de->rec_len = ext4_rec_len_to_disk(ext4_dir_rec_len(de->name_len, NULL),
+					   blocksize);
+	memcpy(de->name, ".", 2);
+	ext4_set_de_type(inode->i_sb, de, S_IFDIR);
+
+	de = ext4_next_entry(de, blocksize);
+	de->inode = cpu_to_le32(parent_ino);
+	de->name_len = 2;
+	memcpy(de->name, "..", 3);
+	ext4_set_de_type(inode->i_sb, de, S_IFDIR);
+	if (inline_buf) {
+		de->rec_len = ext4_rec_len_to_disk(
+					ext4_dir_rec_len(de->name_len, NULL),
+					blocksize);
+		de = ext4_next_entry(de, blocksize);
+		header_size = (char *)de - bh->b_data;
+		memcpy((void *)de, inline_buf, inline_size);
+		ext4_update_final_de(bh->b_data, inline_size + header_size,
+			blocksize - csum_size);
+	} else {
+		de->rec_len = ext4_rec_len_to_disk(blocksize -
+					(csum_size + ext4_dir_rec_len(1, NULL)),
+					blocksize);
+	}
+
+	if (csum_size)
+		ext4_initialize_dirent_tail(bh, blocksize);
+	BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
+	set_buffer_uptodate(bh);
+	set_buffer_verified(bh);
+	return ext4_handle_dirty_dirblock(handle, inode, bh);
+}
+
+int ext4_init_new_dir(handle_t *handle, struct inode *dir,
+			     struct inode *inode)
+{
+	struct buffer_head *dir_block = NULL;
+	ext4_lblk_t block = 0;
+	int err;
+
+	if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
+		err = ext4_try_create_inline_dir(handle, dir, inode);
+		if (err < 0 && err != -ENOSPC)
+			goto out;
+		if (!err)
+			goto out;
+	}
+
+	set_nlink(inode, 2);
+	inode->i_size = 0;
+	dir_block = ext4_append(handle, inode, &block);
+	if (IS_ERR(dir_block))
+		return PTR_ERR(dir_block);
+	err = ext4_init_dirblock(handle, inode, dir_block, dir->i_ino, NULL, 0);
+out:
+	brelse(dir_block);
+	return err;
+}
+
+static struct dentry *ext4_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+				 struct dentry *dentry, umode_t mode)
+{
+	handle_t *handle;
+	struct inode *inode;
+	int err, err2 = 0, credits, retries = 0;
+
+	if (EXT4_DIR_LINK_MAX(dir))
+		return ERR_PTR(-EMLINK);
+
+	err = dquot_initialize(dir);
+	if (err)
+		return ERR_PTR(err);
+
+	credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3);
+retry:
+	inode = ext4_new_inode_start_handle(idmap, dir, S_IFDIR | mode,
+					    &dentry->d_name,
+					    0, NULL, EXT4_HT_DIR, credits);
+	handle = ext4_journal_current_handle();
+	err = PTR_ERR(inode);
+	if (IS_ERR(inode))
+		goto out_stop;
+
+	inode->i_op = &ext4_dir_inode_operations;
+	inode->i_fop = &ext4_dir_operations;
+	err = ext4_init_new_dir(handle, dir, inode);
+	if (err)
+		goto out_clear_inode;
+	err = ext4_mark_inode_dirty(handle, inode);
+	if (!err)
+		err = ext4_add_entry(handle, dentry, inode);
+	if (err) {
+out_clear_inode:
+		clear_nlink(inode);
+		ext4_orphan_add(handle, inode);
+		unlock_new_inode(inode);
+		err2 = ext4_mark_inode_dirty(handle, inode);
+		if (unlikely(err2))
+			err = err2;
+		ext4_journal_stop(handle);
+		iput(inode);
+		goto out_retry;
+	}
+	ext4_inc_count(dir);
+
+	ext4_update_dx_flag(dir);
+	err = ext4_mark_inode_dirty(handle, dir);
+	if (err)
+		goto out_clear_inode;
+	d_instantiate_new(dentry, inode);
+	ext4_fc_track_create(handle, dentry);
+	if (IS_DIRSYNC(dir))
+		ext4_handle_sync(handle);
+
+out_stop:
+	if (handle)
+		ext4_journal_stop(handle);
+out_retry:
+	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+		goto retry;
+	return ERR_PTR(err);
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+bool ext4_empty_dir(struct inode *inode)
+{
+	unsigned int offset;
+	struct buffer_head *bh;
+	struct ext4_dir_entry_2 *de;
+	struct super_block *sb;
+
+	if (ext4_has_inline_data(inode)) {
+		int has_inline_data = 1;
+		int ret;
+
+		ret = empty_inline_dir(inode, &has_inline_data);
+		if (has_inline_data)
+			return ret;
+	}
+
+	sb = inode->i_sb;
+	if (inode->i_size < ext4_dir_rec_len(1, NULL) +
+					ext4_dir_rec_len(2, NULL)) {
+		EXT4_ERROR_INODE(inode, "invalid size");
+		return false;
+	}
+	bh = ext4_read_dirblock(inode, 0, EITHER);
+	if (IS_ERR(bh))
+		return false;
+
+	de = (struct ext4_dir_entry_2 *) bh->b_data;
+	if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
+				 0) ||
+	    le32_to_cpu(de->inode) != inode->i_ino || de->name_len != 1 ||
+	    de->name[0] != '.') {
+		ext4_warning_inode(inode, "directory missing '.'");
+		brelse(bh);
+		return false;
+	}
+	offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
+	de = ext4_next_entry(de, sb->s_blocksize);
+	if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size,
+				 offset) ||
+	    le32_to_cpu(de->inode) == 0 || de->name_len != 2 ||
+	    de->name[0] != '.' || de->name[1] != '.') {
+		ext4_warning_inode(inode, "directory missing '..'");
+		brelse(bh);
+		return false;
+	}
+	offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
+	while (offset < inode->i_size) {
+		if (!(offset & (sb->s_blocksize - 1))) {
+			unsigned int lblock;
+			brelse(bh);
+			lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb);
+			bh = ext4_read_dirblock(inode, lblock, EITHER);
+			if (bh == NULL) {
+				offset += sb->s_blocksize;
+				continue;
+			}
+			if (IS_ERR(bh))
+				return false;
+		}
+		de = (struct ext4_dir_entry_2 *) (bh->b_data +
+					(offset & (sb->s_blocksize - 1)));
+		if (ext4_check_dir_entry(inode, NULL, de, bh,
+					 bh->b_data, bh->b_size, offset) ||
+		    le32_to_cpu(de->inode)) {
+			brelse(bh);
+			return false;
+		}
+		offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
+	}
+	brelse(bh);
+	return true;
+}
+
+static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	int retval;
+	struct inode *inode;
+	struct buffer_head *bh;
+	struct ext4_dir_entry_2 *de;
+	handle_t *handle = NULL;
+
+	retval = ext4_emergency_state(dir->i_sb);
+	if (unlikely(retval))
+		return retval;
+
+	/* Initialize quotas before so that eventual writes go in
+	 * separate transaction */
+	retval = dquot_initialize(dir);
+	if (retval)
+		return retval;
+	retval = dquot_initialize(d_inode(dentry));
+	if (retval)
+		return retval;
+
+	retval = -ENOENT;
+	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+	if (!bh)
+		goto end_rmdir;
+
+	inode = d_inode(dentry);
+
+	retval = -EFSCORRUPTED;
+	if (le32_to_cpu(de->inode) != inode->i_ino)
+		goto end_rmdir;
+
+	retval = -ENOTEMPTY;
+	if (!ext4_empty_dir(inode))
+		goto end_rmdir;
+
+	handle = ext4_journal_start(dir, EXT4_HT_DIR,
+				    EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
+	if (IS_ERR(handle)) {
+		retval = PTR_ERR(handle);
+		handle = NULL;
+		goto end_rmdir;
+	}
+
+	if (IS_DIRSYNC(dir))
+		ext4_handle_sync(handle);
+
+	retval = ext4_delete_entry(handle, dir, de, bh);
+	if (retval)
+		goto end_rmdir;
+	if (!EXT4_DIR_LINK_EMPTY(inode))
+		ext4_warning_inode(inode,
+			     "empty directory '%.*s' has too many links (%u)",
+			     dentry->d_name.len, dentry->d_name.name,
+			     inode->i_nlink);
+	inode_inc_iversion(inode);
+	clear_nlink(inode);
+	/* There's no need to set i_disksize: the fact that i_nlink is
+	 * zero will ensure that the right thing happens during any
+	 * recovery. */
+	inode->i_size = 0;
+	ext4_orphan_add(handle, inode);
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	inode_set_ctime_current(inode);
+	retval = ext4_mark_inode_dirty(handle, inode);
+	if (retval)
+		goto end_rmdir;
+	ext4_dec_count(dir);
+	ext4_update_dx_flag(dir);
+	ext4_fc_track_unlink(handle, dentry);
+	retval = ext4_mark_inode_dirty(handle, dir);
+
+	/* VFS negative dentries are incompatible with Encoding and
+	 * Case-insensitiveness. Eventually we'll want avoid
+	 * invalidating the dentries here, alongside with returning the
+	 * negative dentries at ext4_lookup(), when it is better
+	 * supported by the VFS for the CI case.
+	 */
+	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
+		d_invalidate(dentry);
+
+end_rmdir:
+	brelse(bh);
+	if (handle)
+		ext4_journal_stop(handle);
+	return retval;
+}
+
+int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
+		  struct inode *inode,
+		  struct dentry *dentry /* NULL during fast_commit recovery */)
+{
+	int retval = -ENOENT;
+	struct buffer_head *bh;
+	struct ext4_dir_entry_2 *de;
+	handle_t *handle;
+	int skip_remove_dentry = 0;
+
+	/*
+	 * Keep this outside the transaction; it may have to set up the
+	 * directory's encryption key, which isn't GFP_NOFS-safe.
+	 */
+	bh = ext4_find_entry(dir, d_name, &de, NULL);
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+
+	if (!bh)
+		return -ENOENT;
+
+	if (le32_to_cpu(de->inode) != inode->i_ino) {
+		/*
+		 * It's okay if we find dont find dentry which matches
+		 * the inode. That's because it might have gotten
+		 * renamed to a different inode number
+		 */
+		if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
+			skip_remove_dentry = 1;
+		else
+			goto out_bh;
+	}
+
+	handle = ext4_journal_start(dir, EXT4_HT_DIR,
+				    EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
+	if (IS_ERR(handle)) {
+		retval = PTR_ERR(handle);
+		goto out_bh;
+	}
+
+	if (IS_DIRSYNC(dir))
+		ext4_handle_sync(handle);
+
+	if (!skip_remove_dentry) {
+		retval = ext4_delete_entry(handle, dir, de, bh);
+		if (retval)
+			goto out_handle;
+		inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+		ext4_update_dx_flag(dir);
+		retval = ext4_mark_inode_dirty(handle, dir);
+		if (retval)
+			goto out_handle;
+	} else {
+		retval = 0;
+	}
+	if (inode->i_nlink == 0)
+		ext4_warning_inode(inode, "Deleting file '%.*s' with no links",
+				   d_name->len, d_name->name);
+	else
+		drop_nlink(inode);
+	if (!inode->i_nlink)
+		ext4_orphan_add(handle, inode);
+	inode_set_ctime_current(inode);
+	retval = ext4_mark_inode_dirty(handle, inode);
+	if (dentry && !retval)
+		ext4_fc_track_unlink(handle, dentry);
+out_handle:
+	ext4_journal_stop(handle);
+out_bh:
+	brelse(bh);
+	return retval;
+}
+
+static int ext4_unlink(struct inode *dir, struct dentry *dentry)
+{
+	int retval;
+
+	retval = ext4_emergency_state(dir->i_sb);
+	if (unlikely(retval))
+		return retval;
+
+	trace_ext4_unlink_enter(dir, dentry);
+	/*
+	 * Initialize quotas before so that eventual writes go
+	 * in separate transaction
+	 */
+	retval = dquot_initialize(dir);
+	if (retval)
+		goto out_trace;
+	retval = dquot_initialize(d_inode(dentry));
+	if (retval)
+		goto out_trace;
+
+	retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry);
+
+	/* VFS negative dentries are incompatible with Encoding and
+	 * Case-insensitiveness. Eventually we'll want avoid
+	 * invalidating the dentries here, alongside with returning the
+	 * negative dentries at ext4_lookup(), when it is  better
+	 * supported by the VFS for the CI case.
+	 */
+	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
+		d_invalidate(dentry);
+
+out_trace:
+	trace_ext4_unlink_exit(dentry, retval);
+	return retval;
+}
+
+static int ext4_init_symlink_block(handle_t *handle, struct inode *inode,
+				   struct fscrypt_str *disk_link)
+{
+	struct buffer_head *bh;
+	char *kaddr;
+	int err = 0;
+
+	bh = ext4_bread(handle, inode, 0, EXT4_GET_BLOCKS_CREATE);
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+
+	BUFFER_TRACE(bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE);
+	if (err)
+		goto out;
+
+	kaddr = (char *)bh->b_data;
+	memcpy(kaddr, disk_link->name, disk_link->len);
+	inode->i_size = disk_link->len - 1;
+	EXT4_I(inode)->i_disksize = inode->i_size;
+	err = ext4_handle_dirty_metadata(handle, inode, bh);
+out:
+	brelse(bh);
+	return err;
+}
+
+static int ext4_symlink(struct mnt_idmap *idmap, struct inode *dir,
+			struct dentry *dentry, const char *symname)
+{
+	handle_t *handle;
+	struct inode *inode;
+	int err, len = strlen(symname);
+	int credits;
+	struct fscrypt_str disk_link;
+	int retries = 0;
+
+	err = ext4_emergency_state(dir->i_sb);
+	if (unlikely(err))
+		return err;
+
+	err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize,
+				      &disk_link);
+	if (err)
+		return err;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+
+	/*
+	 * EXT4_INDEX_EXTRA_TRANS_BLOCKS for addition of entry into the
+	 * directory. +3 for inode, inode bitmap, group descriptor allocation.
+	 * EXT4_DATA_TRANS_BLOCKS for the data block allocation and
+	 * modification.
+	 */
+	credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+		  EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3;
+retry:
+	inode = ext4_new_inode_start_handle(idmap, dir, S_IFLNK|S_IRWXUGO,
+					    &dentry->d_name, 0, NULL,
+					    EXT4_HT_DIR, credits);
+	handle = ext4_journal_current_handle();
+	if (IS_ERR(inode)) {
+		if (handle)
+			ext4_journal_stop(handle);
+		err = PTR_ERR(inode);
+		goto out_retry;
+	}
+
+	if (IS_ENCRYPTED(inode)) {
+		err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
+		if (err)
+			goto err_drop_inode;
+		inode->i_op = &ext4_encrypted_symlink_inode_operations;
+	} else {
+		if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
+			inode->i_op = &ext4_symlink_inode_operations;
+		} else {
+			inode->i_op = &ext4_fast_symlink_inode_operations;
+		}
+	}
+
+	if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
+		/* alloc symlink block and fill it */
+		err = ext4_init_symlink_block(handle, inode, &disk_link);
+		if (err)
+			goto err_drop_inode;
+	} else {
+		/* clear the extent format for fast symlink */
+		ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
+		memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
+		       disk_link.len);
+		inode->i_size = disk_link.len - 1;
+		EXT4_I(inode)->i_disksize = inode->i_size;
+		if (!IS_ENCRYPTED(inode))
+			inode_set_cached_link(inode, (char *)&EXT4_I(inode)->i_data,
+					      inode->i_size);
+	}
+	err = ext4_add_nondir(handle, dentry, &inode);
+	if (handle)
+		ext4_journal_stop(handle);
+	iput(inode);
+	goto out_retry;
+
+err_drop_inode:
+	clear_nlink(inode);
+	ext4_mark_inode_dirty(handle, inode);
+	ext4_orphan_add(handle, inode);
+	unlock_new_inode(inode);
+	if (handle)
+		ext4_journal_stop(handle);
+	iput(inode);
+out_retry:
+	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+		goto retry;
+	if (disk_link.name != (unsigned char *)symname)
+		kfree(disk_link.name);
+	return err;
+}
+
+int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
+{
+	handle_t *handle;
+	int err, retries = 0;
+retry:
+	handle = ext4_journal_start(dir, EXT4_HT_DIR,
+		(EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
+		 EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_DIRSYNC(dir))
+		ext4_handle_sync(handle);
+
+	inode_set_ctime_current(inode);
+	ext4_inc_count(inode);
+	ihold(inode);
+
+	err = ext4_add_entry(handle, dentry, inode);
+	if (!err) {
+		err = ext4_mark_inode_dirty(handle, inode);
+		/* this can happen only for tmpfile being
+		 * linked the first time
+		 */
+		if (inode->i_nlink == 1)
+			ext4_orphan_del(handle, inode);
+		d_instantiate(dentry, inode);
+		ext4_fc_track_link(handle, dentry);
+	} else {
+		drop_nlink(inode);
+		iput(inode);
+	}
+	ext4_journal_stop(handle);
+	if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
+		goto retry;
+	return err;
+}
+
+static int ext4_link(struct dentry *old_dentry,
+		     struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = d_inode(old_dentry);
+	int err;
+
+	if (inode->i_nlink >= EXT4_LINK_MAX)
+		return -EMLINK;
+
+	err = fscrypt_prepare_link(old_dentry, dir, dentry);
+	if (err)
+		return err;
+
+	if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
+	    (!projid_eq(EXT4_I(dir)->i_projid,
+			EXT4_I(old_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
+	err = dquot_initialize(dir);
+	if (err)
+		return err;
+	return __ext4_link(dir, inode, dentry);
+}
+
+/*
+ * Try to find buffer head where contains the parent block.
+ * It should be the inode block if it is inlined or the 1st block
+ * if it is a normal dir.
+ */
+static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
+					struct inode *inode,
+					int *retval,
+					struct ext4_dir_entry_2 **parent_de,
+					int *inlined)
+{
+	struct buffer_head *bh;
+
+	if (!ext4_has_inline_data(inode)) {
+		struct ext4_dir_entry_2 *de;
+		unsigned int offset;
+
+		bh = ext4_read_dirblock(inode, 0, EITHER);
+		if (IS_ERR(bh)) {
+			*retval = PTR_ERR(bh);
+			return NULL;
+		}
+
+		de = (struct ext4_dir_entry_2 *) bh->b_data;
+		if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
+					 bh->b_size, 0) ||
+		    le32_to_cpu(de->inode) != inode->i_ino ||
+		    de->name_len != 1 || de->name[0] != '.') {
+			EXT4_ERROR_INODE(inode, "directory missing '.'");
+			brelse(bh);
+			*retval = -EFSCORRUPTED;
+			return NULL;
+		}
+		offset = ext4_rec_len_from_disk(de->rec_len,
+						inode->i_sb->s_blocksize);
+		de = ext4_next_entry(de, inode->i_sb->s_blocksize);
+		if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data,
+					 bh->b_size, offset) ||
+		    le32_to_cpu(de->inode) == 0 || de->name_len != 2 ||
+		    de->name[0] != '.' || de->name[1] != '.') {
+			EXT4_ERROR_INODE(inode, "directory missing '..'");
+			brelse(bh);
+			*retval = -EFSCORRUPTED;
+			return NULL;
+		}
+		*parent_de = de;
+
+		return bh;
+	}
+
+	*inlined = 1;
+	return ext4_get_first_inline_block(inode, parent_de, retval);
+}
+
+struct ext4_renament {
+	struct inode *dir;
+	struct dentry *dentry;
+	struct inode *inode;
+	bool is_dir;
+	int dir_nlink_delta;
+
+	/* entry for "dentry" */
+	struct buffer_head *bh;
+	struct ext4_dir_entry_2 *de;
+	int inlined;
+
+	/* entry for ".." in inode if it's a directory */
+	struct buffer_head *dir_bh;
+	struct ext4_dir_entry_2 *parent_de;
+	int dir_inlined;
+};
+
+static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent, bool is_cross)
+{
+	int retval;
+
+	ent->is_dir = true;
+	if (!is_cross)
+		return 0;
+
+	ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode,
+					      &retval, &ent->parent_de,
+					      &ent->dir_inlined);
+	if (!ent->dir_bh)
+		return retval;
+	if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino)
+		return -EFSCORRUPTED;
+	BUFFER_TRACE(ent->dir_bh, "get_write_access");
+	return ext4_journal_get_write_access(handle, ent->dir->i_sb,
+					     ent->dir_bh, EXT4_JTR_NONE);
+}
+
+static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent,
+				  unsigned dir_ino)
+{
+	int retval;
+
+	if (!ent->dir_bh)
+		return 0;
+
+	ent->parent_de->inode = cpu_to_le32(dir_ino);
+	BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata");
+	if (!ent->dir_inlined) {
+		if (is_dx(ent->inode)) {
+			retval = ext4_handle_dirty_dx_node(handle,
+							   ent->inode,
+							   ent->dir_bh);
+		} else {
+			retval = ext4_handle_dirty_dirblock(handle, ent->inode,
+							    ent->dir_bh);
+		}
+	} else {
+		retval = ext4_mark_inode_dirty(handle, ent->inode);
+	}
+	if (retval) {
+		ext4_std_error(ent->dir->i_sb, retval);
+		return retval;
+	}
+	return 0;
+}
+
+static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
+		       unsigned ino, unsigned file_type)
+{
+	int retval, retval2;
+
+	BUFFER_TRACE(ent->bh, "get write access");
+	retval = ext4_journal_get_write_access(handle, ent->dir->i_sb, ent->bh,
+					       EXT4_JTR_NONE);
+	if (retval)
+		return retval;
+	ent->de->inode = cpu_to_le32(ino);
+	if (ext4_has_feature_filetype(ent->dir->i_sb))
+		ent->de->file_type = file_type;
+	inode_inc_iversion(ent->dir);
+	inode_set_mtime_to_ts(ent->dir, inode_set_ctime_current(ent->dir));
+	retval = ext4_mark_inode_dirty(handle, ent->dir);
+	BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata");
+	if (!ent->inlined) {
+		retval2 = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh);
+		if (unlikely(retval2)) {
+			ext4_std_error(ent->dir->i_sb, retval2);
+			return retval2;
+		}
+	}
+	return retval;
+}
+
+static void ext4_resetent(handle_t *handle, struct ext4_renament *ent,
+			  unsigned ino, unsigned file_type)
+{
+	struct ext4_renament old = *ent;
+	int retval = 0;
+
+	/*
+	 * old->de could have moved from under us during make indexed dir,
+	 * so the old->de may no longer valid and need to find it again
+	 * before reset old inode info.
+	 */
+	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
+				 &old.inlined);
+	if (IS_ERR(old.bh))
+		retval = PTR_ERR(old.bh);
+	if (!old.bh)
+		retval = -ENOENT;
+	if (retval) {
+		ext4_std_error(old.dir->i_sb, retval);
+		return;
+	}
+
+	ext4_setent(handle, &old, ino, file_type);
+	brelse(old.bh);
+}
+
+static int ext4_find_delete_entry(handle_t *handle, struct inode *dir,
+				  const struct qstr *d_name)
+{
+	int retval = -ENOENT;
+	struct buffer_head *bh;
+	struct ext4_dir_entry_2 *de;
+
+	bh = ext4_find_entry(dir, d_name, &de, NULL);
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+	if (bh) {
+		retval = ext4_delete_entry(handle, dir, de, bh);
+		brelse(bh);
+	}
+	return retval;
+}
+
+static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
+			       int force_reread)
+{
+	int retval;
+	/*
+	 * ent->de could have moved from under us during htree split, so make
+	 * sure that we are deleting the right entry.  We might also be pointing
+	 * to a stale entry in the unused part of ent->bh so just checking inum
+	 * and the name isn't enough.
+	 */
+	if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino ||
+	    ent->de->name_len != ent->dentry->d_name.len ||
+	    strncmp(ent->de->name, ent->dentry->d_name.name,
+		    ent->de->name_len) ||
+	    force_reread) {
+		retval = ext4_find_delete_entry(handle, ent->dir,
+						&ent->dentry->d_name);
+	} else {
+		retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
+		if (retval == -ENOENT) {
+			retval = ext4_find_delete_entry(handle, ent->dir,
+							&ent->dentry->d_name);
+		}
+	}
+
+	if (retval) {
+		ext4_warning_inode(ent->dir,
+				   "Deleting old file: nlink %d, error=%d",
+				   ent->dir->i_nlink, retval);
+	}
+}
+
+static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent)
+{
+	if (ent->dir_nlink_delta) {
+		if (ent->dir_nlink_delta == -1)
+			ext4_dec_count(ent->dir);
+		else
+			ext4_inc_count(ent->dir);
+		ext4_mark_inode_dirty(handle, ent->dir);
+	}
+}
+
+static struct inode *ext4_whiteout_for_rename(struct mnt_idmap *idmap,
+					      struct ext4_renament *ent,
+					      int credits, handle_t **h)
+{
+	struct inode *wh;
+	handle_t *handle;
+	int retries = 0;
+
+	/*
+	 * for inode block, sb block, group summaries,
+	 * and inode bitmap
+	 */
+	credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) +
+		    EXT4_XATTR_TRANS_BLOCKS + 4);
+retry:
+	wh = ext4_new_inode_start_handle(idmap, ent->dir,
+					 S_IFCHR | WHITEOUT_MODE,
+					 &ent->dentry->d_name, 0, NULL,
+					 EXT4_HT_DIR, credits);
+
+	handle = ext4_journal_current_handle();
+	if (IS_ERR(wh)) {
+		if (handle)
+			ext4_journal_stop(handle);
+		if (PTR_ERR(wh) == -ENOSPC &&
+		    ext4_should_retry_alloc(ent->dir->i_sb, &retries))
+			goto retry;
+	} else {
+		*h = handle;
+		init_special_inode(wh, wh->i_mode, WHITEOUT_DEV);
+		wh->i_op = &ext4_special_inode_operations;
+	}
+	return wh;
+}
+
+/*
+ * Anybody can rename anything with this: the permission checks are left to the
+ * higher-level routines.
+ *
+ * n.b.  old_{dentry,inode) refers to the source dentry/inode
+ * while new_{dentry,inode) refers to the destination dentry/inode
+ * This comes from rename(const char *oldpath, const char *newpath)
+ */
+static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir,
+		       struct dentry *old_dentry, struct inode *new_dir,
+		       struct dentry *new_dentry, unsigned int flags)
+{
+	handle_t *handle = NULL;
+	struct ext4_renament old = {
+		.dir = old_dir,
+		.dentry = old_dentry,
+		.inode = d_inode(old_dentry),
+	};
+	struct ext4_renament new = {
+		.dir = new_dir,
+		.dentry = new_dentry,
+		.inode = d_inode(new_dentry),
+	};
+	int force_reread;
+	int retval;
+	struct inode *whiteout = NULL;
+	int credits;
+	u8 old_file_type;
+
+	if (new.inode && new.inode->i_nlink == 0) {
+		EXT4_ERROR_INODE(new.inode,
+				 "target of rename is already freed");
+		return -EFSCORRUPTED;
+	}
+
+	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
+	    (!projid_eq(EXT4_I(new_dir)->i_projid,
+			EXT4_I(old_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
+	retval = dquot_initialize(old.dir);
+	if (retval)
+		return retval;
+	retval = dquot_initialize(old.inode);
+	if (retval)
+		return retval;
+	retval = dquot_initialize(new.dir);
+	if (retval)
+		return retval;
+
+	/* Initialize quotas before so that eventual writes go
+	 * in separate transaction */
+	if (new.inode) {
+		retval = dquot_initialize(new.inode);
+		if (retval)
+			return retval;
+	}
+
+	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de,
+				 &old.inlined);
+	if (IS_ERR(old.bh))
+		return PTR_ERR(old.bh);
+
+	/*
+	 *  Check for inode number is _not_ due to possible IO errors.
+	 *  We might rmdir the source, keep it as pwd of some process
+	 *  and merrily kill the link to whatever was created under the
+	 *  same name. Goodbye sticky bit ;-<
+	 */
+	retval = -ENOENT;
+	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
+		goto release_bh;
+
+	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
+				 &new.de, &new.inlined);
+	if (IS_ERR(new.bh)) {
+		retval = PTR_ERR(new.bh);
+		new.bh = NULL;
+		goto release_bh;
+	}
+	if (new.bh) {
+		if (!new.inode) {
+			brelse(new.bh);
+			new.bh = NULL;
+		}
+	}
+	if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
+		ext4_alloc_da_blocks(old.inode);
+
+	credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
+		   EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
+	if (!(flags & RENAME_WHITEOUT)) {
+		handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
+		if (IS_ERR(handle)) {
+			retval = PTR_ERR(handle);
+			goto release_bh;
+		}
+	} else {
+		whiteout = ext4_whiteout_for_rename(idmap, &old, credits, &handle);
+		if (IS_ERR(whiteout)) {
+			retval = PTR_ERR(whiteout);
+			goto release_bh;
+		}
+	}
+
+	old_file_type = old.de->file_type;
+	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
+		ext4_handle_sync(handle);
+
+	if (S_ISDIR(old.inode->i_mode)) {
+		if (new.inode) {
+			retval = -ENOTEMPTY;
+			if (!ext4_empty_dir(new.inode))
+				goto end_rename;
+		} else {
+			retval = -EMLINK;
+			if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir))
+				goto end_rename;
+		}
+		retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
+		if (retval)
+			goto end_rename;
+	}
+	/*
+	 * If we're renaming a file within an inline_data dir and adding or
+	 * setting the new dirent causes a conversion from inline_data to
+	 * extents/blockmap, we need to force the dirent delete code to
+	 * re-read the directory, or else we end up trying to delete a dirent
+	 * from what is now the extent tree root (or a block map).
+	 */
+	force_reread = (new.dir->i_ino == old.dir->i_ino &&
+			ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
+
+	if (whiteout) {
+		/*
+		 * Do this before adding a new entry, so the old entry is sure
+		 * to be still pointing to the valid old entry.
+		 */
+		retval = ext4_setent(handle, &old, whiteout->i_ino,
+				     EXT4_FT_CHRDEV);
+		if (retval)
+			goto end_rename;
+		retval = ext4_mark_inode_dirty(handle, whiteout);
+		if (unlikely(retval))
+			goto end_rename;
+
+	}
+	if (!new.bh) {
+		retval = ext4_add_entry(handle, new.dentry, old.inode);
+		if (retval)
+			goto end_rename;
+	} else {
+		retval = ext4_setent(handle, &new,
+				     old.inode->i_ino, old_file_type);
+		if (retval)
+			goto end_rename;
+	}
+	if (force_reread)
+		force_reread = !ext4_test_inode_flag(new.dir,
+						     EXT4_INODE_INLINE_DATA);
+
+	/*
+	 * Like most other Unix systems, set the ctime for inodes on a
+	 * rename.
+	 */
+	inode_set_ctime_current(old.inode);
+	retval = ext4_mark_inode_dirty(handle, old.inode);
+	if (unlikely(retval))
+		goto end_rename;
+
+	if (!whiteout) {
+		/*
+		 * ok, that's it
+		 */
+		ext4_rename_delete(handle, &old, force_reread);
+	}
+
+	if (new.inode) {
+		ext4_dec_count(new.inode);
+		inode_set_ctime_current(new.inode);
+	}
+	inode_set_mtime_to_ts(old.dir, inode_set_ctime_current(old.dir));
+	ext4_update_dx_flag(old.dir);
+	if (old.is_dir) {
+		retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
+		if (retval)
+			goto end_rename;
+
+		ext4_dec_count(old.dir);
+		if (new.inode) {
+			/* checked ext4_empty_dir above, can't have another
+			 * parent, ext4_dec_count() won't work for many-linked
+			 * dirs */
+			clear_nlink(new.inode);
+		} else {
+			ext4_inc_count(new.dir);
+			ext4_update_dx_flag(new.dir);
+			retval = ext4_mark_inode_dirty(handle, new.dir);
+			if (unlikely(retval))
+				goto end_rename;
+		}
+	}
+	retval = ext4_mark_inode_dirty(handle, old.dir);
+	if (unlikely(retval))
+		goto end_rename;
+
+	if (old.is_dir) {
+		/*
+		 * We disable fast commits here that's because the
+		 * replay code is not yet capable of changing dot dot
+		 * dirents in directories.
+		 */
+		ext4_fc_mark_ineligible(old.inode->i_sb,
+			EXT4_FC_REASON_RENAME_DIR, handle);
+	} else {
+		struct super_block *sb = old.inode->i_sb;
+
+		if (new.inode)
+			ext4_fc_track_unlink(handle, new.dentry);
+		if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
+		    !(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) &&
+		    !(ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE))) {
+			__ext4_fc_track_link(handle, old.inode, new.dentry);
+			__ext4_fc_track_unlink(handle, old.inode, old.dentry);
+			if (whiteout)
+				__ext4_fc_track_create(handle, whiteout,
+						       old.dentry);
+		}
+	}
+
+	if (new.inode) {
+		retval = ext4_mark_inode_dirty(handle, new.inode);
+		if (unlikely(retval))
+			goto end_rename;
+		if (!new.inode->i_nlink)
+			ext4_orphan_add(handle, new.inode);
+	}
+	retval = 0;
+
+end_rename:
+	if (whiteout) {
+		if (retval) {
+			ext4_resetent(handle, &old,
+				      old.inode->i_ino, old_file_type);
+			drop_nlink(whiteout);
+			ext4_mark_inode_dirty(handle, whiteout);
+			ext4_orphan_add(handle, whiteout);
+		}
+		unlock_new_inode(whiteout);
+		ext4_journal_stop(handle);
+		iput(whiteout);
+	} else {
+		ext4_journal_stop(handle);
+	}
+release_bh:
+	brelse(old.dir_bh);
+	brelse(old.bh);
+	brelse(new.bh);
+
+	return retval;
+}
+
+static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
+			     struct inode *new_dir, struct dentry *new_dentry)
+{
+	handle_t *handle = NULL;
+	struct ext4_renament old = {
+		.dir = old_dir,
+		.dentry = old_dentry,
+		.inode = d_inode(old_dentry),
+	};
+	struct ext4_renament new = {
+		.dir = new_dir,
+		.dentry = new_dentry,
+		.inode = d_inode(new_dentry),
+	};
+	u8 new_file_type;
+	int retval;
+
+	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
+	     !projid_eq(EXT4_I(new_dir)->i_projid,
+			EXT4_I(old_dentry->d_inode)->i_projid)) ||
+	    (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
+	     !projid_eq(EXT4_I(old_dir)->i_projid,
+			EXT4_I(new_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
+	retval = dquot_initialize(old.dir);
+	if (retval)
+		return retval;
+	retval = dquot_initialize(new.dir);
+	if (retval)
+		return retval;
+
+	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
+				 &old.de, &old.inlined);
+	if (IS_ERR(old.bh))
+		return PTR_ERR(old.bh);
+	/*
+	 *  Check for inode number is _not_ due to possible IO errors.
+	 *  We might rmdir the source, keep it as pwd of some process
+	 *  and merrily kill the link to whatever was created under the
+	 *  same name. Goodbye sticky bit ;-<
+	 */
+	retval = -ENOENT;
+	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
+		goto end_rename;
+
+	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
+				 &new.de, &new.inlined);
+	if (IS_ERR(new.bh)) {
+		retval = PTR_ERR(new.bh);
+		new.bh = NULL;
+		goto end_rename;
+	}
+
+	/* RENAME_EXCHANGE case: old *and* new must both exist */
+	if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino)
+		goto end_rename;
+
+	handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
+		(2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
+		 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
+	if (IS_ERR(handle)) {
+		retval = PTR_ERR(handle);
+		handle = NULL;
+		goto end_rename;
+	}
+
+	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
+		ext4_handle_sync(handle);
+
+	if (S_ISDIR(old.inode->i_mode)) {
+		retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir);
+		if (retval)
+			goto end_rename;
+	}
+	if (S_ISDIR(new.inode->i_mode)) {
+		retval = ext4_rename_dir_prepare(handle, &new, new.dir != old.dir);
+		if (retval)
+			goto end_rename;
+	}
+
+	/*
+	 * Other than the special case of overwriting a directory, parents'
+	 * nlink only needs to be modified if this is a cross directory rename.
+	 */
+	if (old.dir != new.dir && old.is_dir != new.is_dir) {
+		old.dir_nlink_delta = old.is_dir ? -1 : 1;
+		new.dir_nlink_delta = -old.dir_nlink_delta;
+		retval = -EMLINK;
+		if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) ||
+		    (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir)))
+			goto end_rename;
+	}
+
+	new_file_type = new.de->file_type;
+	retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type);
+	if (retval)
+		goto end_rename;
+
+	retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type);
+	if (retval)
+		goto end_rename;
+
+	/*
+	 * Like most other Unix systems, set the ctime for inodes on a
+	 * rename.
+	 */
+	inode_set_ctime_current(old.inode);
+	inode_set_ctime_current(new.inode);
+	retval = ext4_mark_inode_dirty(handle, old.inode);
+	if (unlikely(retval))
+		goto end_rename;
+	retval = ext4_mark_inode_dirty(handle, new.inode);
+	if (unlikely(retval))
+		goto end_rename;
+	ext4_fc_mark_ineligible(new.inode->i_sb,
+				EXT4_FC_REASON_CROSS_RENAME, handle);
+	if (old.dir_bh) {
+		retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino);
+		if (retval)
+			goto end_rename;
+	}
+	if (new.dir_bh) {
+		retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino);
+		if (retval)
+			goto end_rename;
+	}
+	ext4_update_dir_count(handle, &old);
+	ext4_update_dir_count(handle, &new);
+	retval = 0;
+
+end_rename:
+	brelse(old.dir_bh);
+	brelse(new.dir_bh);
+	brelse(old.bh);
+	brelse(new.bh);
+	if (handle)
+		ext4_journal_stop(handle);
+	return retval;
+}
+
+static int ext4_rename2(struct mnt_idmap *idmap,
+			struct inode *old_dir, struct dentry *old_dentry,
+			struct inode *new_dir, struct dentry *new_dentry,
+			unsigned int flags)
+{
+	int err;
+
+	err = ext4_emergency_state(old_dir->i_sb);
+	if (unlikely(err))
+		return err;
+
+	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
+		return -EINVAL;
+
+	err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
+				     flags);
+	if (err)
+		return err;
+
+	if (flags & RENAME_EXCHANGE) {
+		return ext4_cross_rename(old_dir, old_dentry,
+					 new_dir, new_dentry);
+	}
+
+	return ext4_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags);
+}
+
+/*
+ * directories can handle most operations...
+ */
+const struct inode_operations ext4_dir_inode_operations = {
+	.create		= ext4_create,
+	.lookup		= ext4_lookup,
+	.link		= ext4_link,
+	.unlink		= ext4_unlink,
+	.symlink	= ext4_symlink,
+	.mkdir		= ext4_mkdir,
+	.rmdir		= ext4_rmdir,
+	.mknod		= ext4_mknod,
+	.tmpfile	= ext4_tmpfile,
+	.rename		= ext4_rename2,
+	.setattr	= ext4_setattr,
+	.getattr	= ext4_getattr,
+	.listxattr	= ext4_listxattr,
+	.get_inode_acl	= ext4_get_acl,
+	.set_acl	= ext4_set_acl,
+	.fiemap         = ext4_fiemap,
+	.fileattr_get	= ext4_fileattr_get,
+	.fileattr_set	= ext4_fileattr_set,
+};
+
+const struct inode_operations ext4_special_inode_operations = {
+	.setattr	= ext4_setattr,
+	.getattr	= ext4_getattr,
+	.listxattr	= ext4_listxattr,
+	.get_inode_acl	= ext4_get_acl,
+	.set_acl	= ext4_set_acl,
+};
-- 
2.43.0

    