ldiskfs/kernel_patches/patches/ubuntu18/ext4-data-in-dirent.patch

   1 this patch implements feature which allows ext4 fs users (e.g. Lustre)
   2 to store data in ext4 dirent.
   3 data is stored in ext4 dirent after file-name, this space is accounted
   4 in de->rec_len. flag EXT4_DIRENT_LUFID added to d_type if extra data
   5 is present.
   6
   7 make use of dentry->d_fsdata to pass fid to ext4. so no
   8 changes in ext4_add_entry() interface required.
   9
  10 Index: linux-4.15.0/fs/ext4/dir.c
  11 ===================================================================
  12 --- linux-4.15.0.orig/fs/ext4/dir.c
  13 +++ linux-4.15.0/fs/ext4/dir.c
  14 @@ -68,11 +68,11 @@ int __ext4_check_dir_entry(const char *f
  15         const int rlen = ext4_rec_len_from_disk(de->rec_len,
  16                                                 dir->i_sb->s_blocksize);
  17
  18 -       if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
  19 +       if (unlikely(rlen < __EXT4_DIR_REC_LEN(1)))
  20                 error_msg = "rec_len is smaller than minimal";
  21         else if (unlikely(rlen % 4 != 0))
  22                 error_msg = "rec_len % 4 != 0";
  23 -       else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
  24 +       else if (unlikely(rlen < EXT4_DIR_REC_LEN(de)))
  25                 error_msg = "rec_len is too small for name_len";
  26         else if (unlikely(((char *) de - buf) + rlen > size))
  27                 error_msg = "directory entry across range";
  28 @@ -219,7 +219,7 @@ static int ext4_readdir(struct file *fil
  29                                  * failure will be detected in the
  30                                  * dirent test below. */
  31                                 if (ext4_rec_len_from_disk(de->rec_len,
  32 -                                       sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
  33 +                                   sb->s_blocksize) < __EXT4_DIR_REC_LEN(1))
  34                                         break;
  35                                 i += ext4_rec_len_from_disk(de->rec_len,
  36                                                             sb->s_blocksize);
  37 @@ -442,12 +442,17 @@ int ext4_htree_store_dirent(struct file
  38         struct fname *fname, *new_fn;
  39         struct dir_private_info *info;
  40         int len;
  41 +       int extra_data = 0;
  42
  43         info = dir_file->private_data;
  44         p = &info->root.rb_node;
  45
  46         /* Create and allocate the fname structure */
  47 -       len = sizeof(struct fname) + ent_name->len + 1;
  48 +       if (dirent->file_type & EXT4_DIRENT_LUFID)
  49 +               extra_data = ext4_get_dirent_data_len(dirent);
  50 +
  51 +       len = sizeof(struct fname) + ent_name->len + extra_data + 1;
  52 +
  53         new_fn = kzalloc(len, GFP_KERNEL);
  54         if (!new_fn)
  55                 return -ENOMEM;
  56 @@ -456,7 +461,7 @@ int ext4_htree_store_dirent(struct file
  57         new_fn->inode = le32_to_cpu(dirent->inode);
  58         new_fn->name_len = ent_name->len;
  59         new_fn->file_type = dirent->file_type;
  60 -       memcpy(new_fn->name, ent_name->name, ent_name->len);
  61 +       memcpy(new_fn->name, ent_name->name, ent_name->len + extra_data);
  62         new_fn->name[ent_name->len] = 0;
  63
  64         while (*p) {
  65 Index: linux-4.15.0/fs/ext4/ext4.h
  66 ===================================================================
  67 --- linux-4.15.0.orig/fs/ext4/ext4.h
  68 +++ linux-4.15.0/fs/ext4/ext4.h
  69 @@ -1055,6 +1055,7 @@ struct ext4_inode_info {
  70         __u32 i_csum_seed;
  71
  72         kprojid_t i_projid;
  73 +       void *i_dirdata;
  74  };
  75
  76  /*
  77 @@ -1088,6 +1089,7 @@ struct ext4_inode_info {
  78   * Mount flags set via mount options or defaults
  79   */
  80  #define EXT4_MOUNT_NO_MBCACHE          0x00001 /* Do not use mbcache */
  81 +#define EXT4_MOUNT_DIRDATA             0x00002 /* Data in directory entries */
  82  #define EXT4_MOUNT_GRPID               0x00004 /* Create files with directory's group */
  83  #define EXT4_MOUNT_DEBUG               0x00008 /* Some debugging messages */
  84  #define EXT4_MOUNT_ERRORS_CONT         0x00010 /* Continue on errors */
  85 @@ -1768,6 +1770,7 @@ EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,              EN
  86                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
  87                                          EXT4_FEATURE_INCOMPAT_EA_INODE| \
  88                                          EXT4_FEATURE_INCOMPAT_MMP | \
  89 +                                        EXT4_FEATURE_INCOMPAT_DIRDATA| \
  90                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
  91                                          EXT4_FEATURE_INCOMPAT_ENCRYPT | \
  92                                          EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
  93 @@ -1943,6 +1946,43 @@ struct ext4_dir_entry_tail {
  94  #define EXT4_FT_SYMLINK                7
  95
  96  #define EXT4_FT_MAX            8
  97 +#define EXT4_FT_MASK           0xf
  98 +
  99 +#if EXT4_FT_MAX > EXT4_FT_MASK
 100 +#error "conflicting EXT4_FT_MAX and EXT4_FT_MASK"
 101 +#endif
 102 +
 103 +/*
 104 + * d_type has 4 unused bits, so it can hold four types data. these different
 105 + * type of data (e.g. lustre data, high 32 bits of 64-bit inode number) can be
 106 + * stored, in flag order, after file-name in ext4 dirent.
 107 +*/
 108 +/*
 109 + * this flag is added to d_type if ext4 dirent has extra data after
 110 + * filename. this data length is variable and length is stored in first byte
 111 + * of data. data start after filename NUL byte.
 112 + * This is used by Lustre FS.
 113 +  */
 114 +#define EXT4_DIRENT_LUFID              0x10
 115 +
 116 +#define EXT4_LUFID_MAGIC    0xAD200907UL
 117 +struct ext4_dentry_param {
 118 +       __u32  edp_magic;       /* EXT4_LUFID_MAGIC */
 119 +       char   edp_len;         /* size of edp_data in bytes */
 120 +       char   edp_data[0];     /* packed array of data */
 121 +} __packed;
 122 +
 123 +static inline unsigned char *ext4_dentry_get_data(struct super_block *sb,
 124 +                                                 struct ext4_dentry_param *p)
 125 +
 126 +{
 127 +       if (!ext4_has_feature_dirdata(sb))
 128 +               return NULL;
 129 +       if (p && p->edp_magic == EXT4_LUFID_MAGIC)
 130 +               return &p->edp_len;
 131 +       else
 132 +               return NULL;
 133 +}
 134
 135  #define EXT4_FT_DIR_CSUM       0xDE
 136
 137 @@ -1953,8 +1993,11 @@ struct ext4_dir_entry_tail {
 138   */
 139  #define EXT4_DIR_PAD                   4
 140  #define EXT4_DIR_ROUND                 (EXT4_DIR_PAD - 1)
 141 -#define EXT4_DIR_REC_LEN(name_len)     (((name_len) + 8 + EXT4_DIR_ROUND) & \
 142 +#define __EXT4_DIR_REC_LEN(name_len)   (((name_len) + 8 + EXT4_DIR_ROUND) & \
 143                                          ~EXT4_DIR_ROUND)
 144 +#define EXT4_DIR_REC_LEN(de)           (__EXT4_DIR_REC_LEN((de)->name_len +\
 145 +                                       ext4_get_dirent_data_len(de)))
 146 +
 147  #define EXT4_MAX_REC_LEN               ((1<<16)-1)
 148
 149  /*
 150 @@ -2357,11 +2400,11 @@ extern int ext4_find_dest_de(struct inod
 151                              struct buffer_head *bh,
 152                              void *buf, int buf_size,
 153                              struct ext4_filename *fname,
 154 -                            struct ext4_dir_entry_2 **dest_de);
 155 +                            struct ext4_dir_entry_2 **dest_de, int *dlen);
 156  void ext4_insert_dentry(struct inode *inode,
 157                         struct ext4_dir_entry_2 *de,
 158                         int buf_size,
 159 -                       struct ext4_filename *fname);
 160 +                       struct ext4_filename *fname, void *data);
 161  static inline void ext4_update_dx_flag(struct inode *inode)
 162  {
 163         if (!ext4_has_feature_dir_index(inode->i_sb))
 164 @@ -2373,10 +2416,17 @@ static const unsigned char ext4_filetype
 165
 166  static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
 167  {
 168 -       if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
 169 +       int fl_index = filetype & EXT4_FT_MASK;
 170 +
 171 +       if (!ext4_has_feature_filetype(sb) || fl_index >= EXT4_FT_MAX)
 172                 return DT_UNKNOWN;
 173
 174 -       return ext4_filetype_table[filetype];
 175 +       if (!test_opt(sb, DIRDATA))
 176 +               return ext4_filetype_table[fl_index];
 177 +
 178 +       return (ext4_filetype_table[fl_index]) |
 179 +               (filetype & EXT4_DIRENT_LUFID);
 180 +
 181  }
 182  extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
 183                              void *buf, int buf_size);
 184 @@ -2525,6 +2575,8 @@ extern struct inode *ext4_create_inode(h
 185  extern int ext4_delete_entry(handle_t *handle, struct inode * dir,
 186                              struct ext4_dir_entry_2 *de_del,
 187                              struct buffer_head *bh);
 188 +extern int ext4_add_dot_dotdot(handle_t *handle, struct inode *dir,
 189 +                              struct inode *inode, const void *, const void *);
 190  extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 191                                 __u32 start_minor_hash, __u32 *next_hash);
 192  extern int ext4_search_dir(struct buffer_head *bh,
 193 @@ -3265,6 +3317,36 @@ static inline void ext4_clear_io_unwritt
 194
 195  extern const struct iomap_ops ext4_iomap_ops;
 196
 197 +/*
 198 + * Compute the total directory entry data length.
 199 + * This includes the filename and an implicit NUL terminator (always present),
 200 + * and optional extensions.  Each extension has a bit set in the high 4 bits of
 201 + * de->file_type, and the extension length is the first byte in each entry.
 202 + */
 203 +static inline int ext4_get_dirent_data_len(struct ext4_dir_entry_2 *de)
 204 +{
 205 +       char *len = de->name + de->name_len + 1 /* NUL terminator */;
 206 +       int dlen = 0;
 207 +       __u8 extra_data_flags = (de->file_type & ~EXT4_FT_MASK) >> 4;
 208 +       struct ext4_dir_entry_tail *t = (struct ext4_dir_entry_tail *)de;
 209 +
 210 +       if (!t->det_reserved_zero1 &&
 211 +           le16_to_cpu(t->det_rec_len) ==
 212 +               sizeof(struct ext4_dir_entry_tail) &&
 213 +           !t->det_reserved_zero2 &&
 214 +           t->det_reserved_ft == EXT4_FT_DIR_CSUM)
 215 +               return 0;
 216 +
 217 +       while (extra_data_flags) {
 218 +               if (extra_data_flags & 1) {
 219 +                       dlen += *len + (dlen == 0);
 220 +                       len += *len;
 221 +               }
 222 +               extra_data_flags >>= 1;
 223 +       }
 224 +       return dlen;
 225 +}
 226 +
 227  #endif /* __KERNEL__ */
 228
 229  #define EFSBADCRC      EBADMSG         /* Bad CRC detected */
 230 Index: linux-4.15.0/fs/ext4/namei.c
 231 ===================================================================
 232 --- linux-4.15.0.orig/fs/ext4/namei.c
 233 +++ linux-4.15.0/fs/ext4/namei.c
 234 @@ -242,7 +242,8 @@ static unsigned dx_get_count(struct dx_e
 235  static unsigned dx_get_limit(struct dx_entry *entries);
 236  static void dx_set_count(struct dx_entry *entries, unsigned value);
 237  static void dx_set_limit(struct dx_entry *entries, unsigned value);
 238 -static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 239 +static inline unsigned dx_root_limit(struct inode *dir,
 240 +               struct ext4_dir_entry_2 *dot_de, unsigned infosize);
 241  static unsigned dx_node_limit(struct inode *dir);
 242  static struct dx_frame *dx_probe(struct ext4_filename *fname,
 243                                  struct inode *dir,
 244 @@ -385,22 +386,23 @@ static struct dx_countlimit *get_dx_coun
 245  {
 246         struct ext4_dir_entry *dp;
 247         struct dx_root_info *root;
 248 -       int count_offset;
 249 +       int count_offset, dot_rec_len, dotdot_rec_len;
 250
 251         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 252                 count_offset = 8;
 253 -       else if (le16_to_cpu(dirent->rec_len) == 12) {
 254 -               dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 255 +       else {
 256 +               dot_rec_len = le16_to_cpu(dirent->rec_len);
 257 +               dp = (struct ext4_dir_entry *)(((void *)dirent) + dot_rec_len);
 258                 if (le16_to_cpu(dp->rec_len) !=
 259 -                   EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 260 +                   EXT4_BLOCK_SIZE(inode->i_sb) - dot_rec_len)
 261                         return NULL;
 262 -               root = (struct dx_root_info *)(((void *)dp + 12));
 263 +               dotdot_rec_len = EXT4_DIR_REC_LEN((struct ext4_dir_entry_2 *)dp);
 264 +               root = (struct dx_root_info *)(((void *)dp + dotdot_rec_len));
 265                 if (root->reserved_zero ||
 266                     root->info_length != sizeof(struct dx_root_info))
 267                         return NULL;
 268 -               count_offset = 32;
 269 -       } else
 270 -               return NULL;
 271 +               count_offset = 8 + dot_rec_len + dotdot_rec_len;
 272 +       }
 273
 274         if (offset)
 275                 *offset = count_offset;
 276 @@ -505,11 +506,12 @@ ext4_next_entry(struct ext4_dir_entry_2
 277   */
 278  struct dx_root_info *dx_get_dx_info(struct ext4_dir_entry_2 *de)
 279  {
 280 +       BUG_ON(de->name_len != 1);
 281         /* get dotdot first */
 282 -       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
 283 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(de));
 284
 285         /* dx root info is after dotdot entry */
 286 -       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
 287 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(de));
 288
 289         return (struct dx_root_info *)de;
 290  }
 291 @@ -554,10 +556,16 @@ static inline void dx_set_limit(struct d
 292         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 293  }
 294
 295 -static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 296 +static inline unsigned dx_root_limit(struct inode *dir,
 297 +               struct ext4_dir_entry_2 *dot_de, unsigned infosize)
 298  {
 299 -       unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 300 -               EXT4_DIR_REC_LEN(2) - infosize;
 301 +       struct ext4_dir_entry_2 *dotdot_de;
 302 +       unsigned entry_space;
 303 +
 304 +       BUG_ON(dot_de->name_len != 1);
 305 +       dotdot_de = ext4_next_entry(dot_de, dir->i_sb->s_blocksize);
 306 +       entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(dot_de) -
 307 +                        EXT4_DIR_REC_LEN(dotdot_de) - infosize;
 308
 309         if (ext4_has_metadata_csum(dir->i_sb))
 310                 entry_space -= sizeof(struct dx_tail);
 311 @@ -566,7 +574,7 @@ static inline unsigned dx_root_limit(str
 312
 313  static inline unsigned dx_node_limit(struct inode *dir)
 314  {
 315 -       unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 316 +       unsigned entry_space = dir->i_sb->s_blocksize - __EXT4_DIR_REC_LEN(0);
 317
 318         if (ext4_has_metadata_csum(dir->i_sb))
 319                 entry_space -= sizeof(struct dx_tail);
 320 @@ -678,7 +686,7 @@ static struct stats dx_show_leaf(struct
 321                                        (unsigned) ((char *) de - base));
 322  #endif
 323                         }
 324 -                       space += EXT4_DIR_REC_LEN(de->name_len);
 325 +                       space += EXT4_DIR_REC_LEN(de);
 326                         names++;
 327                 }
 328                 de = ext4_next_entry(de, size);
 329 @@ -785,11 +793,14 @@ dx_probe(struct ext4_filename *fname, st
 330
 331         entries = (struct dx_entry *)(((char *)info) + info->info_length);
 332
 333 -       if (dx_get_limit(entries) != dx_root_limit(dir,
 334 -                                                  info->info_length)) {
 335 +       if (dx_get_limit(entries) !=
 336 +           dx_root_limit(dir, (struct ext4_dir_entry_2 *)frame->bh->b_data,
 337 +                         info->info_length)) {
 338                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 339                                    dx_get_limit(entries),
 340 -                                  dx_root_limit(dir, info->info_length));
 341 +                                  dx_root_limit(dir,
 342 +                                         (struct ext4_dir_entry_2 *)frame->bh->b_data,
 343 +                                         info->info_length));
 344                 goto fail;
 345         }
 346
 347 @@ -981,7 +992,7 @@ static int htree_dirblock_to_tree(struct
 348         de = (struct ext4_dir_entry_2 *) bh->b_data;
 349         top = (struct ext4_dir_entry_2 *) ((char *) de +
 350                                            dir->i_sb->s_blocksize -
 351 -                                          EXT4_DIR_REC_LEN(0));
 352 +                                          __EXT4_DIR_REC_LEN(0));
 353  #ifdef CONFIG_EXT4_FS_ENCRYPTION
 354         /* Check if the directory is encrypted */
 355         if (ext4_encrypted_inode(dir)) {
 356 @@ -1653,7 +1664,7 @@ dx_move_dirents(char *from, char *to, st
 357         while (count--) {
 358                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
 359                                                 (from + (map->offs<<2));
 360 -               rec_len = EXT4_DIR_REC_LEN(de->name_len);
 361 +               rec_len = EXT4_DIR_REC_LEN(de);
 362                 memcpy (to, de, rec_len);
 363                 ((struct ext4_dir_entry_2 *) to)->rec_len =
 364                                 ext4_rec_len_to_disk(rec_len, blocksize);
 365 @@ -1677,7 +1688,7 @@ static struct ext4_dir_entry_2* dx_pack_
 366         while ((char*)de < base + blocksize) {
 367                 next = ext4_next_entry(de, blocksize);
 368                 if (de->inode && de->name_len) {
 369 -                       rec_len = EXT4_DIR_REC_LEN(de->name_len);
 370 +                       rec_len = EXT4_DIR_REC_LEN(de);
 371                         if (de > to)
 372                                 memmove(to, de, rec_len);
 373                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
 374 @@ -1808,14 +1819,16 @@ int ext4_find_dest_de(struct inode *dir,
 375                       struct buffer_head *bh,
 376                       void *buf, int buf_size,
 377                       struct ext4_filename *fname,
 378 -                     struct ext4_dir_entry_2 **dest_de)
 379 +                     struct ext4_dir_entry_2 **dest_de, int *dlen)
 380  {
 381         struct ext4_dir_entry_2 *de;
 382 -       unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
 383 +       unsigned short reclen = __EXT4_DIR_REC_LEN(fname_len(fname)) +
 384 +                                                 (dlen ? *dlen : 0);
 385         int nlen, rlen;
 386         unsigned int offset = 0;
 387         char *top;
 388
 389 +       dlen ? *dlen = 0 : 0; /* default set to 0 */
 390         de = (struct ext4_dir_entry_2 *)buf;
 391         top = buf + buf_size - reclen;
 392         while ((char *) de <= top) {
 393 @@ -1824,10 +1837,26 @@ int ext4_find_dest_de(struct inode *dir,
 394                         return -EFSCORRUPTED;
 395                 if (ext4_match(fname, de))
 396                         return -EEXIST;
 397 -               nlen = EXT4_DIR_REC_LEN(de->name_len);
 398 +               nlen = EXT4_DIR_REC_LEN(de);
 399                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
 400                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
 401                         break;
 402 +               /* Then for dotdot entries, check for the smaller space
 403 +                * required for just the entry, no FID */
 404 +               if (fname_len(fname) == 2 && memcmp(fname_name(fname), "..", 2) == 0) {
 405 +                       if ((de->inode ? rlen - nlen : rlen) >=
 406 +                           __EXT4_DIR_REC_LEN(fname_len(fname))) {
 407 +                               /* set dlen=1 to indicate not
 408 +                                * enough space store fid */
 409 +                               dlen ? *dlen = 1 : 0;
 410 +                               break;
 411 +                       }
 412 +                       /* The new ".." entry must be written over the
 413 +                        * previous ".." entry, which is the first
 414 +                        * entry traversed by this scan. If it doesn't
 415 +                        * fit, something is badly wrong, so -EIO. */
 416 +                       return -EIO;
 417 +               }
 418                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
 419                 offset += rlen;
 420         }
 421 @@ -1841,12 +1870,12 @@ int ext4_find_dest_de(struct inode *dir,
 422  void ext4_insert_dentry(struct inode *inode,
 423                         struct ext4_dir_entry_2 *de,
 424                         int buf_size,
 425 -                       struct ext4_filename *fname)
 426 +                       struct ext4_filename *fname, void *data)
 427  {
 428
 429         int nlen, rlen;
 430
 431 -       nlen = EXT4_DIR_REC_LEN(de->name_len);
 432 +       nlen = EXT4_DIR_REC_LEN(de);
 433         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
 434         if (de->inode) {
 435                 struct ext4_dir_entry_2 *de1 =
 436 @@ -1860,6 +1889,11 @@ void ext4_insert_dentry(struct inode *in
 437         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
 438         de->name_len = fname_len(fname);
 439         memcpy(de->name, fname_name(fname), fname_len(fname));
 440 +       if (data) {
 441 +               de->name[fname_len(fname)] = 0;
 442 +               memcpy(&de->name[fname_len(fname) + 1], data, *(char *)data);
 443 +               de->file_type |= EXT4_DIRENT_LUFID;
 444 +       }
 445  }
 446
 447  /*
 448 @@ -1877,14 +1911,19 @@ static int add_dirent_to_buf(handle_t *h
 449  {
 450         unsigned int    blocksize = dir->i_sb->s_blocksize;
 451         int             csum_size = 0;
 452 -       int             err;
 453 +       int             err, dlen = 0;
 454 +       unsigned char   *data;
 455
 456 +       data = ext4_dentry_get_data(inode->i_sb, (struct ext4_dentry_param *)
 457 +                                               EXT4_I(inode)->i_dirdata);
 458         if (ext4_has_metadata_csum(inode->i_sb))
 459                 csum_size = sizeof(struct ext4_dir_entry_tail);
 460
 461         if (!de) {
 462 +               if (data)
 463 +                       dlen = (*data) + 1;
 464                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
 465 -                                       blocksize - csum_size, fname, &de);
 466 +                                       blocksize - csum_size, fname, &de, &dlen);
 467                 if (err)
 468                         return err;
 469         }
 470 @@ -1896,7 +1935,10 @@ static int add_dirent_to_buf(handle_t *h
 471         }
 472
 473         /* By now the buffer is marked for journaling */
 474 -       ext4_insert_dentry(inode, de, blocksize, fname);
 475 +       /* If writing the short form of "dotdot", don't add the data section */
 476 +       if (dlen == 1)
 477 +               data = NULL;
 478 +       ext4_insert_dentry(inode, de, blocksize, fname, data);
 479
 480         /*
 481          * XXX shouldn't update any times until successful
 482 @@ -2005,7 +2047,8 @@ static int make_indexed_dir(handle_t *ha
 483
 484         dx_set_block(entries, 1);
 485         dx_set_count(entries, 1);
 486 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
 487 +       dx_set_limit(entries, dx_root_limit(dir,
 488 +                                        dot_de, sizeof(*dx_info)));
 489
 490         /* Initialize as for dx_probe */
 491         fname->hinfo.hash_version = dx_info->hash_version;
 492 @@ -2055,6 +2098,8 @@ static int ext4_update_dotdot(handle_t *
 493         struct buffer_head *dir_block;
 494         struct ext4_dir_entry_2 *de;
 495         int len, journal = 0, err = 0;
 496 +       int dlen = 0;
 497 +       char *data;
 498
 499         if (IS_ERR(handle))
 500                 return PTR_ERR(handle);
 501 @@ -2072,19 +2117,24 @@ static int ext4_update_dotdot(handle_t *
 502         /* the first item must be "." */
 503         assert(de->name_len == 1 && de->name[0] == '.');
 504         len = le16_to_cpu(de->rec_len);
 505 -       assert(len >= EXT4_DIR_REC_LEN(1));
 506 -       if (len > EXT4_DIR_REC_LEN(1)) {
 507 +       assert(len >= __EXT4_DIR_REC_LEN(1));
 508 +       if (len > __EXT4_DIR_REC_LEN(1)) {
 509                 BUFFER_TRACE(dir_block, "get_write_access");
 510                 err = ext4_journal_get_write_access(handle, dir_block);
 511                 if (err)
 512                         goto out_journal;
 513
 514                 journal = 1;
 515 -               de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(1));
 516 +               de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(de));
 517         }
 518
 519 -       len -= EXT4_DIR_REC_LEN(1);
 520 -       assert(len == 0 || len >= EXT4_DIR_REC_LEN(2));
 521 +       len -= EXT4_DIR_REC_LEN(de);
 522 +       data = ext4_dentry_get_data(dir->i_sb,
 523 +                       (struct ext4_dentry_param *)dentry->d_fsdata);
 524 +       if (data)
 525 +               dlen = *data + 1;
 526 +       assert(len == 0 || len >= __EXT4_DIR_REC_LEN(2 + dlen));
 527 +
 528         de = (struct ext4_dir_entry_2 *)
 529                         ((char *) de + le16_to_cpu(de->rec_len));
 530         if (!journal) {
 531 @@ -2098,10 +2148,15 @@ static int ext4_update_dotdot(handle_t *
 532         if (len > 0)
 533                 de->rec_len = cpu_to_le16(len);
 534         else
 535 -               assert(le16_to_cpu(de->rec_len) >= EXT4_DIR_REC_LEN(2));
 536 +               assert(le16_to_cpu(de->rec_len) >= __EXT4_DIR_REC_LEN(2));
 537         de->name_len = 2;
 538         strcpy(de->name, "..");
 539 -       ext4_set_de_type(dir->i_sb, de, S_IFDIR);
 540 +       if (data != NULL && ext4_get_dirent_data_len(de) >= dlen) {
 541 +               de->name[2] = 0;
 542 +               memcpy(&de->name[2 + 1], data, *data);
 543 +               ext4_set_de_type(dir->i_sb, de, S_IFDIR);
 544 +               de->file_type |= EXT4_DIRENT_LUFID;
 545 +       }
 546
 547  out_journal:
 548         if (journal) {
 549 @@ -2140,6 +2195,7 @@ static int ext4_add_entry(handle_t *hand
 550         ext4_lblk_t block, blocks;
 551         int     csum_size = 0;
 552
 553 +       EXT4_I(inode)->i_dirdata = dentry->d_fsdata;
 554         if (ext4_has_metadata_csum(inode->i_sb))
 555                 csum_size = sizeof(struct ext4_dir_entry_tail);
 556
 557 @@ -2661,37 +2717,70 @@ err_unlock_inode:
 558         return err;
 559  }
 560
 561 +struct tp_block {
 562 +       struct inode *inode;
 563 +       void *data1;
 564 +       void *data2;
 565 +};
 566 +
 567  struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
 568                           struct ext4_dir_entry_2 *de,
 569                           int blocksize, int csum_size,
 570                           unsigned int parent_ino, int dotdot_real_len)
 571  {
 572 +       void *data1 = NULL, *data2 = NULL;
 573 +       int dot_reclen = 0;
 574 +
 575 +       if (dotdot_real_len == 10) {
 576 +               struct tp_block *tpb = (struct tp_block *)inode;
 577 +               data1 = tpb->data1;
 578 +               data2 = tpb->data2;
 579 +               inode = tpb->inode;
 580 +               dotdot_real_len = 0;
 581 +       }
 582         de->inode = cpu_to_le32(inode->i_ino);
 583         de->name_len = 1;
 584 -       de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
 585 -                                          blocksize);
 586         strcpy(de->name, ".");
 587         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
 588
 589 +       /* get packed fid data*/
 590 +       data1 = ext4_dentry_get_data(inode->i_sb,
 591 +                               (struct ext4_dentry_param *) data1);
 592 +       if (data1) {
 593 +               de->name[1] = 0;
 594 +               memcpy(&de->name[2], data1, *(char *) data1);
 595 +               de->file_type |= EXT4_DIRENT_LUFID;
 596 +       }
 597 +       de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(de));
 598 +       dot_reclen = cpu_to_le16(de->rec_len);
 599         de = ext4_next_entry(de, blocksize);
 600         de->inode = cpu_to_le32(parent_ino);
 601         de->name_len = 2;
 602 +       strcpy(de->name, "..");
 603 +       ext4_set_de_type(inode->i_sb, de, S_IFDIR);
 604 +       data2 = ext4_dentry_get_data(inode->i_sb,
 605 +                       (struct ext4_dentry_param *) data2);
 606 +       if (data2) {
 607 +               de->name[2] = 0;
 608 +               memcpy(&de->name[3], data2, *(char *) data2);
 609 +               de->file_type |= EXT4_DIRENT_LUFID;
 610 +       }
 611         if (!dotdot_real_len)
 612                 de->rec_len = ext4_rec_len_to_disk(blocksize -
 613 -                                       (csum_size + EXT4_DIR_REC_LEN(1)),
 614 +                                       (csum_size + dot_reclen),
 615                                         blocksize);
 616         else
 617                 de->rec_len = ext4_rec_len_to_disk(
 618 -                               EXT4_DIR_REC_LEN(de->name_len), blocksize);
 619 -       strcpy(de->name, "..");
 620 -       ext4_set_de_type(inode->i_sb, de, S_IFDIR);
 621 +                               EXT4_DIR_REC_LEN(de), blocksize);
 622
 623         return ext4_next_entry(de, blocksize);
 624  }
 625
 626  static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
 627 -                            struct inode *inode)
 628 +                            struct inode *inode,
 629 +                            const void *data1, const void *data2)
 630  {
 631 +       struct tp_block param;
 632         struct buffer_head *dir_block = NULL;
 633         struct ext4_dir_entry_2 *de;
 634         struct ext4_dir_entry_tail *t;
 635 @@ -2716,7 +2805,11 @@ static int ext4_init_new_dir(handle_t *h
 636         if (IS_ERR(dir_block))
 637                 return PTR_ERR(dir_block);
 638         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
 639 -       ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
 640 +       param.inode = inode;
 641 +       param.data1 = (void *)data1;
 642 +       param.data2 = (void *)data2;
 643 +       ext4_init_dot_dotdot((struct inode *)(&param), de, blocksize,
 644 +                            csum_size, dir->i_ino, 10);
 645         set_nlink(inode, 2);
 646         if (csum_size) {
 647                 t = EXT4_DIRENT_TAIL(dir_block->b_data, blocksize);
 648 @@ -2733,6 +2826,29 @@ out:
 649         return err;
 650  }
 651
 652 +/* Initialize @inode as a subdirectory of @dir, and add the
 653 + * "." and ".." entries into the first directory block. */
 654 +int ext4_add_dot_dotdot(handle_t *handle, struct inode *dir,
 655 +                       struct inode *inode,
 656 +                       const void *data1, const void *data2)
 657 +{
 658 +       int rc;
 659 +
 660 +       if (IS_ERR(handle))
 661 +               return PTR_ERR(handle);
 662 +
 663 +       if (IS_DIRSYNC(dir))
 664 +               ext4_handle_sync(handle);
 665 +
 666 +       inode->i_op = &ext4_dir_inode_operations;
 667 +       inode->i_fop = &ext4_dir_operations;
 668 +       rc = ext4_init_new_dir(handle, dir, inode, data1, data2);
 669 +       if (!rc)
 670 +               rc = ext4_mark_inode_dirty(handle, inode);
 671 +       return rc;
 672 +}
 673 +EXPORT_SYMBOL(ext4_add_dot_dotdot);
 674 +
 675  static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 676  {
 677         handle_t *handle;
 678 @@ -2759,7 +2875,7 @@ retry:
 679
 680         inode->i_op = &ext4_dir_inode_operations;
 681         inode->i_fop = &ext4_dir_operations;
 682 -       err = ext4_init_new_dir(handle, dir, inode);
 683 +       err = ext4_init_new_dir(handle, dir, inode, NULL, NULL);
 684         if (err)
 685                 goto out_clear_inode;
 686         err = ext4_mark_inode_dirty(handle, inode);
 687 @@ -2811,7 +2927,7 @@ bool ext4_empty_dir(struct inode *inode)
 688         }
 689
 690         sb = inode->i_sb;
 691 -       if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) {
 692 +       if (inode->i_size < __EXT4_DIR_REC_LEN(1) + __EXT4_DIR_REC_LEN(2)) {
 693                 EXT4_ERROR_INODE(inode, "invalid size");
 694                 return true;
 695         }
 696 Index: linux-4.15.0/fs/ext4/inline.c
 697 ===================================================================
 698 --- linux-4.15.0.orig/fs/ext4/inline.c
 699 +++ linux-4.15.0/fs/ext4/inline.c
 700 @@ -1017,7 +1017,7 @@ static int ext4_add_dirent_to_inline(han
 701         struct ext4_dir_entry_2 *de;
 702
 703         err = ext4_find_dest_de(dir, inode, iloc->bh, inline_start,
 704 -                               inline_size, fname, &de);
 705 +                               inline_size, fname, &de, NULL);
 706         if (err)
 707                 return err;
 708
 709 @@ -1025,7 +1025,7 @@ static int ext4_add_dirent_to_inline(han
 710         err = ext4_journal_get_write_access(handle, iloc->bh);
 711         if (err)
 712                 return err;
 713 -       ext4_insert_dentry(inode, de, inline_size, fname);
 714 +       ext4_insert_dentry(inode, de, inline_size, fname, NULL);
 715
 716         ext4_show_inline_dir(dir, iloc->bh, inline_start, inline_size);
 717
 718 @@ -1094,7 +1094,7 @@ static int ext4_update_inline_dir(handle
 719         int old_size = EXT4_I(dir)->i_inline_size - EXT4_MIN_INLINE_DATA_SIZE;
 720         int new_size = get_max_inline_xattr_value_size(dir, iloc);
 721
 722 -       if (new_size - old_size <= EXT4_DIR_REC_LEN(1))
 723 +       if (new_size - old_size <= __EXT4_DIR_REC_LEN(1))
 724                 return -ENOSPC;
 725
 726         ret = ext4_update_inline_data(handle, dir,
 727 @@ -1375,7 +1375,7 @@ int htree_inlinedir_to_tree(struct file
 728                         fake.name_len = 1;
 729                         strcpy(fake.name, ".");
 730                         fake.rec_len = ext4_rec_len_to_disk(
 731 -                                               EXT4_DIR_REC_LEN(fake.name_len),
 732 +                                               EXT4_DIR_REC_LEN(&fake),
 733                                                 inline_size);
 734                         ext4_set_de_type(inode->i_sb, &fake, S_IFDIR);
 735                         de = &fake;
 736 @@ -1385,7 +1385,7 @@ int htree_inlinedir_to_tree(struct file
 737                         fake.name_len = 2;
 738                         strcpy(fake.name, "..");
 739                         fake.rec_len = ext4_rec_len_to_disk(
 740 -                                               EXT4_DIR_REC_LEN(fake.name_len),
 741 +                                               EXT4_DIR_REC_LEN(&fake),
 742                                                 inline_size);
 743                         ext4_set_de_type(inode->i_sb, &fake, S_IFDIR);
 744                         de = &fake;
 745 @@ -1483,8 +1483,8 @@ int ext4_read_inline_dir(struct file *fi
 746          * So we will use extra_offset and extra_size to indicate them
 747          * during the inline dir iteration.
 748          */
 749 -       dotdot_offset = EXT4_DIR_REC_LEN(1);
 750 -       dotdot_size = dotdot_offset + EXT4_DIR_REC_LEN(2);
 751 +       dotdot_offset = __EXT4_DIR_REC_LEN(1);
 752 +       dotdot_size = dotdot_offset + __EXT4_DIR_REC_LEN(2);
 753         extra_offset = dotdot_size - EXT4_INLINE_DOTDOT_SIZE;
 754         extra_size = extra_offset + inline_size;
 755
 756 @@ -1519,7 +1519,7 @@ int ext4_read_inline_dir(struct file *fi
 757                          * failure will be detected in the
 758                          * dirent test below. */
 759                         if (ext4_rec_len_from_disk(de->rec_len, extra_size)
 760 -                               < EXT4_DIR_REC_LEN(1))
 761 +                               < __EXT4_DIR_REC_LEN(1))
 762                                 break;
 763                         i += ext4_rec_len_from_disk(de->rec_len,
 764                                                     extra_size);
 765 Index: linux-4.15.0/fs/ext4/super.c
 766 ===================================================================
 767 --- linux-4.15.0.orig/fs/ext4/super.c
 768 +++ linux-4.15.0/fs/ext4/super.c
 769 @@ -1347,7 +1347,7 @@ enum {
 770         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
 771         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 772         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
 773 -       Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
 774 +       Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err, Opt_dirdata,
 775         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
 776         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
 777         Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
 778 @@ -1420,6 +1420,7 @@ static const match_table_t tokens = {
 779         {Opt_nolazytime, "nolazytime"},
 780         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
 781         {Opt_nodelalloc, "nodelalloc"},
 782 +       {Opt_dirdata, "dirdata"},
 783         {Opt_removed, "mblk_io_submit"},
 784         {Opt_removed, "nomblk_io_submit"},
 785         {Opt_block_validity, "block_validity"},
 786 @@ -1641,6 +1642,7 @@ static const struct mount_opts {
 787         {Opt_usrjquota, 0, MOPT_Q},
 788         {Opt_grpjquota, 0, MOPT_Q},
 789         {Opt_offusrjquota, 0, MOPT_Q},
 790 +       {Opt_dirdata, EXT4_MOUNT_DIRDATA, MOPT_SET},
 791         {Opt_offgrpjquota, 0, MOPT_Q},
 792         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
 793         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},