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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // 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;
     BUFFER_TRACE(bh, "get_write_access");
     err = ext4_journal_get_write_access(handle, inode->i_sb, bh,
                         EXT4_JTR_NONE);
     if (err) {
         brelse(bh);
         ext4_std_error(inode->i_sb, err);
         return ERR_PTR(err);
     }
     return bh;
 }
 
 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) {
         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;
     }
     if (!bh && (type == INDEX || type == DIRENT_HTREE)) {
         ext4_error_inode(inode, func, line, block,
                  "Directory hole found for htree %s block",
                  (type == INDEX) ? "index" : "leaf");
         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_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 inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 static inline unsigned dx_get_hash(struct dx_entry *entry);
 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 static unsigned dx_get_count(struct dx_entry *entries);
 static unsigned dx_get_limit(struct dx_entry *entries);
 static void dx_set_count(struct dx_entry *entries, unsigned value);
 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 static unsigned dx_node_limit(struct inode *dir);
 static struct dx_frame *dx_probe(struct ext4_filename *fname,
                  struct inode *dir,
                  struct dx_hash_info *hinfo,
                  struct dx_frame *frame);
 static void dx_release(struct dx_frame *frames);
 static int dx_make_map(struct inode *dir, struct buffer_head *bh,
                struct dx_hash_info *hinfo,
                struct dx_map_entry *map_tail);
 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 static struct ext4_dir_entry_2 *dx_move_dirents(struct inode *dir, char *from,
                     char *to, struct dx_map_entry *offsets,
                     int count, unsigned int blocksize);
 static struct ext4_dir_entry_2 *dx_pack_dirents(struct inode *dir, char *base,
                         unsigned int blocksize);
 static void dx_insert_block(struct dx_frame *frame,
                     u32 hash, ext4_lblk_t block);
 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
                  struct dx_frame *frame,
                  struct dx_frame *frames,
                  __u32 *start_hash);
 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;
 
 #ifdef PARANOID
     struct ext4_dir_entry *d, *top;
 
     d = (struct ext4_dir_entry *)bh->b_data;
     top = (struct ext4_dir_entry *)(bh->b_data +
         (EXT4_BLOCK_SIZE(inode->i_sb) -
          sizeof(struct ext4_dir_entry_tail)));
     while (d < top && d->rec_len)
         d = (struct ext4_dir_entry *)(((void *)d) +
             le16_to_cpu(d->rec_len));
 
     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 ||
         le16_to_cpu(t->det_rec_len) != 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_sb_info *sbi = EXT4_SB(inode->i_sb);
     struct ext4_inode_info *ei = EXT4_I(inode);
     __u32 csum;
 
     csum = ext4_chksum(sbi, 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_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_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;
 
     if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
         count_offset = 8;
     else if (le16_to_cpu(dirent->rec_len) == 12) {
         dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
         if (le16_to_cpu(dp->rec_len) !=
             EXT4_BLOCK_SIZE(inode->i_sb) - 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_sb_info *sbi = EXT4_SB(inode->i_sb);
     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(sbi, ei->i_csum_seed, (__u8 *)dirent, size);
     csum = ext4_chksum(sbi, csum, (__u8 *)t, offset);
     csum = ext4_chksum(sbi, 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_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_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_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_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 */
                     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
                         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;
                 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)))
         ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
     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_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 {
             ext4fs_dirhash(dir, de->name, de->name_len, hinfo);
         }
         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;
 
     if (ext4_has_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
                 ext4fs_dirhash(dir, de->name, de->name_len, &h);
             map_tail--;
             map_tail->hash = h.hash;
             map_tail->offs = ((char *) de - base)>>2;
             map_tail->size = le16_to_cpu(de->rec_len);
             count++;
             cond_resched();
         }
         de = ext4_next_entry(de, dir->i_sb->s_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)
 /*
  * Test whether a case-insensitive directory entry matches the filename
  * being searched for.  If quick is set, assume the name being looked up
  * is already in the casefolded form.
  *
  * Returns: 0 if the directory entry matches, more than 0 if it
  * doesn't match or less than zero on error.
  */
 static int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
                u8 *de_name, size_t de_name_len, bool quick)
 {
     const struct super_block *sb = parent->i_sb;
     const struct unicode_map *um = sb->s_encoding;
     struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len);
     struct qstr entry = QSTR_INIT(de_name, de_name_len);
     int ret;
 
     if (IS_ENCRYPTED(parent)) {
         const struct fscrypt_str encrypted_name =
                 FSTR_INIT(de_name, de_name_len);
 
         decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL);
         if (!decrypted_name.name)
             return -ENOMEM;
         ret = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name,
                         &decrypted_name);
         if (ret < 0)
             goto out;
         entry.name = decrypted_name.name;
         entry.len = decrypted_name.len;
     }
 
     if (quick)
         ret = utf8_strncasecmp_folded(um, name, &entry);
     else
         ret = utf8_strncasecmp(um, name, &entry);
     if (ret < 0) {
         /* Handle invalid character sequence as either an error
          * or as an opaque byte sequence.
          */
         if (sb_has_strict_encoding(sb))
             ret = -EINVAL;
         else if (name->len != entry.len)
             ret = 1;
         else
             ret = !!memcmp(name->name, entry.name, entry.len);
     }
 out:
     kfree(decrypted_name.name);
     return ret;
 }
 
 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
                   struct ext4_filename *name)
 {
     struct fscrypt_str *cf_name = &name->cf_name;
     struct dx_hash_info *hinfo = &name->hinfo;
     int len;
 
     if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding ||
         (IS_ENCRYPTED(dir) && !fscrypt_has_encryption_key(dir))) {
         cf_name->name = NULL;
         return 0;
     }
 
     cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
     if (!cf_name->name)
         return -ENOMEM;
 
     len = utf8_casefold(dir->i_sb->s_encoding,
                 iname, cf_name->name,
                 EXT4_NAME_LEN);
     if (len <= 0) {
         kfree(cf_name->name);
         cf_name->name = NULL;
     }
     cf_name->len = (unsigned) len;
     if (!IS_ENCRYPTED(dir))
         return 0;
 
     hinfo->hash_version = DX_HASH_SIPHASH;
     hinfo->seed = NULL;
     if (cf_name->name)
         ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo);
     else
         ext4fs_dirhash(dir, iname->name, iname->len, hinfo);
     return 0;
 }
 #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 (parent->i_sb->s_encoding && IS_CASEFOLDED(parent) &&
         (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
         if (fname->cf_name.name) {
             struct qstr cf = {.name = fname->cf_name.name,
                       .len = fname->cf_name.len};
             if (IS_ENCRYPTED(parent)) {
                 if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
                     fname->hinfo.minor_hash !=
                         EXT4_DIRENT_MINOR_HASH(de)) {
 
                     return false;
                 }
             }
             return !ext4_ci_compare(parent, &cf, de->name,
                             de->name_len, true);
         }
         return !ext4_ci_compare(parent, fname->usr_fname, de->name,
                         de->name_len, false);
     }
 #endif
 
     return fscrypt_match_name(&f, de->name, de->name_len);
 }
 
 /*
  * Returns 0 if not found, -1 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 -1;
             *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 -1;
         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 (has_inline_data) {
             if (inlined)
                 *inlined = 1;
             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)
             goto cleanup_and_exit;
         dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
                    "falling back\n"));
         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)
                 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);
     generic_set_encrypted_ci_d_ops(dentry);
     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 (struct buffer_head *) 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 == -1) {
             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)
     if (!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;
     }
 #endif
     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_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 (struct ext4_dir_entry_2 *) 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;
 
     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:
     brelse(*bh);
     brelse(bh2);
     *bh = NULL;
     ext4_std_error(dir->i_sb, err);
     return ERR_PTR(err);
 }
 
 int ext4_find_dest_de(struct inode *dir, struct inode *inode,
               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_metadata_csum(inode->i_sb))
         csum_size = sizeof(struct ext4_dir_entry_tail);
 
     if (!de) {
         err = ext4_find_dest_de(dir, inode, 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.
      */
     dir->i_mtime = dir->i_ctime = current_time(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;
 }
 
 /*
  * 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_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;
 
     /* 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));
     if ((char *) de >= (((char *) root) + blocksize)) {
         EXT4_ERROR_INODE(dir, "invalid rec_len for '..'");
         brelse(bh);
         return -EFSCORRUPTED;
     }
     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)
         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))
         ext4fs_dirhash(dir, fname_name(fname),
                 fname_len(fname), &fname->hinfo);
 
     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_metadata_csum(inode->i_sb))
         csum_size = sizeof(struct ext4_dir_entry_tail);
 
     sb = dir->i_sb;
     blocksize = sb->s_blocksize;
     if (!dentry->d_name.len)
         return -EINVAL;
 
     if (fscrypt_is_nokey_name(dentry))
         return -ENOKEY;
 
 #if IS_ENABLED(CONFIG_UNICODE)
     if (sb_has_strict_encoding(sb) && IS_CASEFOLDED(dir) &&
         sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))
         return -EINVAL;
 #endif
 
     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_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)
             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)
                 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)
                 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)
                 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_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_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 user_namespace *mnt_userns, 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(mnt_userns, 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 user_namespace *mnt_userns, 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(mnt_userns, 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 user_namespace *mnt_userns, struct inode *dir,
             struct dentry *dentry, 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(mnt_userns, dir, mode,
                         NULL, 0, NULL,
                         EXT4_HT_DIR,
             EXT4_MAXQUOTAS_INIT_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(dentry, 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 err;
 err_unlock_inode:
     ext4_journal_stop(handle);
     unlock_new_inode(inode);
     return err;
 }
 
 struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
               struct ext4_dir_entry_2 *de,
               int blocksize, int csum_size,
               unsigned int parent_ino, int dotdot_real_len)
 {
     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);
     strcpy(de->name, ".");
     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;
     if (!dotdot_real_len)
         de->rec_len = ext4_rec_len_to_disk(blocksize -
                     (csum_size + ext4_dir_rec_len(1, NULL)),
                     blocksize);
     else
         de->rec_len = ext4_rec_len_to_disk(
                     ext4_dir_rec_len(de->name_len, NULL),
                     blocksize);
     strcpy(de->name, "..");
     ext4_set_de_type(inode->i_sb, de, S_IFDIR);
 
     return ext4_next_entry(de, blocksize);
 }
 
 int ext4_init_new_dir(handle_t *handle, struct inode *dir,
                  struct inode *inode)
 {
     struct buffer_head *dir_block = NULL;
     struct ext4_dir_entry_2 *de;
     ext4_lblk_t block = 0;
     unsigned int blocksize = dir->i_sb->s_blocksize;
     int csum_size = 0;
     int err;
 
     if (ext4_has_metadata_csum(dir->i_sb))
         csum_size = sizeof(struct ext4_dir_entry_tail);
 
     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;
     }
 
     inode->i_size = 0;
     dir_block = ext4_append(handle, inode, &block);
     if (IS_ERR(dir_block))
         return PTR_ERR(dir_block);
     de = (struct ext4_dir_entry_2 *)dir_block->b_data;
     ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
     set_nlink(inode, 2);
     if (csum_size)
         ext4_initialize_dirent_tail(dir_block, blocksize);
 
     BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
     err = ext4_handle_dirty_dirblock(handle, inode, dir_block);
     if (err)
         goto out;
     set_buffer_verified(dir_block);
 out:
     brelse(dir_block);
     return err;
 }
 
 static int ext4_mkdir(struct user_namespace *mnt_userns, 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 -EMLINK;
 
     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(mnt_userns, 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;
 }
 
 /*
  * 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;
     }
     /* The first directory block must not be a hole,
      * so treat it as DIRENT_HTREE
      */
     bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
     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 || strcmp(".", de->name)) {
         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 || strcmp("..", de->name)) {
         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;
 
     if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
         return -EIO;
 
     /* 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->i_ctime = dir->i_ctime = dir->i_mtime = current_time(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);
 
 #if IS_ENABLED(CONFIG_UNICODE)
     /* 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_CASEFOLDED(dir))
         d_invalidate(dentry);
 #endif
 
 end_rmdir:
     brelse(bh);
     if (handle)
         ext4_journal_stop(handle);
     return retval;
 }
 
 int __ext4_unlink(handle_t *handle, struct inode *dir, const struct qstr *d_name,
           struct inode *inode)
 {
     int retval = -ENOENT;
     struct buffer_head *bh;
     struct ext4_dir_entry_2 *de;
     int skip_remove_dentry = 0;
 
     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;
     }
 
     if (IS_DIRSYNC(dir))
         ext4_handle_sync(handle);
 
     if (!skip_remove_dentry) {
         retval = ext4_delete_entry(handle, dir, de, bh);
         if (retval)
             goto out;
         dir->i_ctime = dir->i_mtime = current_time(dir);
         ext4_update_dx_flag(dir);
         retval = ext4_mark_inode_dirty(handle, dir);
         if (retval)
             goto out;
     } 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->i_ctime = current_time(inode);
     retval = ext4_mark_inode_dirty(handle, inode);
 
 out:
     brelse(bh);
     return retval;
 }
 
 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
 {
     handle_t *handle;
     int retval;
 
     if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
         return -EIO;
 
     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;
 
     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_trace;
     }
 
     retval = __ext4_unlink(handle, dir, &dentry->d_name, d_inode(dentry));
     if (!retval)
         ext4_fc_track_unlink(handle, dentry);
 #if IS_ENABLED(CONFIG_UNICODE)
     /* 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_CASEFOLDED(dir))
         d_invalidate(dentry);
 #endif
     if (handle)
         ext4_journal_stop(handle);
 
 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 user_namespace *mnt_userns, 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;
 
     if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
         return -EIO;
 
     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(mnt_userns, 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;
             inode->i_link = (char *)&EXT4_I(inode)->i_data;
         }
     }
 
     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;
     }
     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_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->i_ctime = current_time(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;
 
         /* The first directory block must not be a hole, so
          * treat it as DIRENT_HTREE
          */
         bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE);
         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 ||
             strcmp(".", de->name)) {
             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 || strcmp("..", de->name)) {
             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)
 {
     int retval;
 
     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;
 
     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);
     ent->dir->i_ctime = ent->dir->i_mtime =
         current_time(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, NULL);
     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 user_namespace *mnt_userns,
                           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(mnt_userns, 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 user_namespace *mnt_userns, 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(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, NULL);
     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(mnt_userns, &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);
         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.
      */
     old.inode->i_ctime = current_time(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);
         new.inode->i_ctime = current_time(new.inode);
     }
     old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir);
     ext4_update_dx_flag(old.dir);
     if (old.dir_bh) {
         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 (S_ISDIR(old.inode->i_mode)) {
         /*
          * 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_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;
     struct timespec64 ctime;
 
     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)) {
         old.is_dir = true;
         retval = ext4_rename_dir_prepare(handle, &old);
         if (retval)
             goto end_rename;
     }
     if (S_ISDIR(new.inode->i_mode)) {
         new.is_dir = true;
         retval = ext4_rename_dir_prepare(handle, &new);
         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.
      */
     ctime = current_time(old.inode);
     old.inode->i_ctime = ctime;
     new.inode->i_ctime = ctime;
     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 user_namespace *mnt_userns,
             struct inode *old_dir, struct dentry *old_dentry,
             struct inode *new_dir, struct dentry *new_dentry,
             unsigned int flags)
 {
     int err;
 
     if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb))))
         return -EIO;
 
     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(mnt_userns, 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_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_acl    = ext4_get_acl,
     .set_acl    = ext4_set_acl,
 };