ldiskfs/kernel_patches/patches/linux-5.4/ext4-data-in-dirent.patch

   1 commit 2db3b2b33ee796f4ea61316773452d936303ad27
   2 Author:     Pravin Shelar <Pravin.Shelar@sun.com>
   3 AuthorDate: Sun Oct 4 18:13:14 2009 +0000
   4 Subject: ext4: add ext4-data-in-dirent patch
   5
   6 Allows ext4 to store extra data records inside the ext4_dirent
   7 along with the regular directory entry (type, length, filename).
   8 Data is stored in ext4 dirent after filename, with a bit flag in
   9 de->file_type to indicate if any record after de->name is used.
  10 Each in-use record is variable length and must store a 1-byte
  11 length (including the length byte itself) at the start so that it
  12 can be skipped if the record type is unknown/uneeded.  The record
  13 starts after a NUL byte terminator for the filename.  This extra
  14 space is accounted in de->rec_len but not de->name_len.
  15
  16 Flag EXT4_DIRENT_LUFID is used for a 128-bit file identifier.
  17 Make use of dentry->d_fsdata to pass LUFID to ext4, so no changes
  18 in ext4_add_entry() interface are required.
  19
  20 Bugzilla-ID: b=17670
  21 Signed-off-by: Pravin Shelar <Pravin.Shelar@sun.com>
  22 Reviewed-by: Huang Hua <h.huang@sun.com>
  23 Signed-off-by: Andreas Dilger <andreas.dilger@sun.com>
  24
  25 diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
  26 index 9fdd2b2..2a73a69 100644
  27 --- a/fs/ext4/dir.c
  28 +++ b/fs/ext4/dir.c
  29 @@ -77,7 +77,7 @@ int __ext4_check_dir_entry(const char *function, unsigned int line,
  30                 error_msg = "rec_len is smaller than minimal";
  31         else if (unlikely(rlen % 4 != 0))
  32                 error_msg = "rec_len % 4 != 0";
  33 -       else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
  34 +       else if (unlikely(rlen < EXT4_DIR_ENTRY_LEN(de)))
  35                 error_msg = "rec_len is too small for name_len";
  36         else if (unlikely(((char *) de - buf) + rlen > size))
  37                 error_msg = "directory entry overrun";
  38 @@ -220,7 +220,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
  39                                  * failure will be detected in the
  40                                  * dirent test below. */
  41                                 if (ext4_rec_len_from_disk(de->rec_len,
  42 -                                       sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
  43 +                                   sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
  44                                         break;
  45                                 i += ext4_rec_len_from_disk(de->rec_len,
  46                                                             sb->s_blocksize);
  47 @@ -443,12 +443,17 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
  48         struct fname *fname, *new_fn;
  49         struct dir_private_info *info;
  50         int len;
  51 +       int extra_data = 0;
  52
  53         info = dir_file->private_data;
  54         p = &info->root.rb_node;
  55
  56         /* Create and allocate the fname structure */
  57 -       len = sizeof(struct fname) + ent_name->len + 1;
  58 +       if (dirent->file_type & EXT4_DIRENT_LUFID)
  59 +               extra_data = ext4_get_dirent_data_len(dirent);
  60 +
  61 +       len = sizeof(struct fname) + ent_name->len + extra_data + 1;
  62 +
  63         new_fn = kzalloc(len, GFP_KERNEL);
  64         if (!new_fn)
  65                 return -ENOMEM;
  66 @@ -457,7 +462,7 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
  67         new_fn->inode = le32_to_cpu(dirent->inode);
  68         new_fn->name_len = ent_name->len;
  69         new_fn->file_type = dirent->file_type;
  70 -       memcpy(new_fn->name, ent_name->name, ent_name->len);
  71 +       memcpy(new_fn->name, ent_name->name, ent_name->len + extra_data);
  72         new_fn->name[ent_name->len] = 0;
  73
  74         while (*p) {
  75 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  76 index cb649f0..fe35251 100644
  77 --- a/fs/ext4/ext4.h
  78 +++ b/fs/ext4/ext4.h
  79 @@ -1094,6 +1094,7 @@ struct ext4_inode_info {
  80         __u32 i_csum_seed;
  81
  82         kprojid_t i_projid;
  83 +       void *i_dirdata;
  84  };
  85
  86  /*
  87 @@ -1114,6 +1115,7 @@
  88   * Mount flags set via mount options or defaults
  89   */
  90  #define EXT4_MOUNT_NO_MBCACHE          0x00001 /* Do not use mbcache */
  91 +#define EXT4_MOUNT_DIRDATA             0x00002 /* Data in directory entries */
  92  #define EXT4_MOUNT_GRPID               0x00004 /* Create files with directory's group */
  93  #define EXT4_MOUNT_DEBUG               0x00008 /* Some debugging messages */
  94  #define EXT4_MOUNT_ERRORS_CONT         0x00010 /* Continue on errors */
  95 @@ -1843,6 +1845,7 @@
  96                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
  97                                          EXT4_FEATURE_INCOMPAT_EA_INODE| \
  98                                          EXT4_FEATURE_INCOMPAT_MMP | \
  99 +                                        EXT4_FEATURE_INCOMPAT_DIRDATA| \
 100                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
 101                                          EXT4_FEATURE_INCOMPAT_ENCRYPT | \
 102                                          EXT4_FEATURE_INCOMPAT_CASEFOLD | \
 103 @@ -2020,6 +2023,43 @@ struct ext4_dir_entry_tail {
 104  #define EXT4_FT_SYMLINK                7
 105
 106  #define EXT4_FT_MAX            8
 107 +#define EXT4_FT_MASK           0xf
 108 +
 109 +#if EXT4_FT_MAX > EXT4_FT_MASK
 110 +#error "conflicting EXT4_FT_MAX and EXT4_FT_MASK"
 111 +#endif
 112 +
 113 +/*
 114 + * d_type has 4 unused bits, so it can hold four types data. these different
 115 + * type of data (e.g. lustre data, high 32 bits of 64-bit inode number) can be
 116 + * stored, in flag order, after file-name in ext4 dirent.
 117 +*/
 118 +/*
 119 + * this flag is added to d_type if ext4 dirent has extra data after
 120 + * filename. this data length is variable and length is stored in first byte
 121 + * of data. data start after filename NUL byte.
 122 + * This is used by Lustre FS.
 123 +  */
 124 +#define EXT4_DIRENT_LUFID              0x10
 125 +
 126 +#define EXT4_LUFID_MAGIC    0xAD200907UL
 127 +struct ext4_dentry_param {
 128 +       __u32  edp_magic;       /* EXT4_LUFID_MAGIC */
 129 +       char   edp_len;         /* size of edp_data in bytes */
 130 +       char   edp_data[0];     /* packed array of data */
 131 +} __packed;
 132 +
 133 +static inline unsigned char *ext4_dentry_get_data(struct super_block *sb,
 134 +                                                 struct ext4_dentry_param *p)
 135 +
 136 +{
 137 +       if (!ext4_has_feature_dirdata(sb))
 138 +               return NULL;
 139 +       if (p && p->edp_magic == EXT4_LUFID_MAGIC)
 140 +               return &p->edp_len;
 141 +       else
 142 +               return NULL;
 143 +}
 144
 145  #define EXT4_FT_DIR_CSUM       0xDE
 146
 147 @@ -2030,8 +2070,16 @@ struct ext4_dir_entry_tail {
 148   */
 149  #define EXT4_DIR_PAD                   4
 150  #define EXT4_DIR_ROUND                 (EXT4_DIR_PAD - 1)
 151 -#define EXT4_DIR_REC_LEN(name_len)     (((name_len) + 8 + EXT4_DIR_ROUND) & \
 152 +#define EXT4_DIR_REC_LEN_(name_len)    (((name_len) + 8 + EXT4_DIR_ROUND) & \
 153                                          ~EXT4_DIR_ROUND)
 154 +#define EXT4_DIR_ENTRY_LEN_(de)                (EXT4_DIR_REC_LEN_((de)->name_len +\
 155 +                                       ext4_get_dirent_data_len(de)))
 156 +/* ldiskfs */
 157 +#define EXT4_DIR_REC_LEN(name_len)     EXT4_DIR_REC_LEN_((name_len))
 158 +#define EXT4_DIR_ENTRY_LEN(de)         EXT4_DIR_ENTRY_LEN_((de))
 159 +/* lustre osd_handler compat */
 160 +#define __EXT4_DIR_REC_LEN(name_len)   EXT4_DIR_REC_LEN_((name_len))
 161 +
 162  #define EXT4_MAX_REC_LEN               ((1<<16)-1)
 163
 164  /*
 165 @@ -2491,11 +2539,11 @@ extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
 166                              struct buffer_head *bh,
 167                              void *buf, int buf_size,
 168                              struct ext4_filename *fname,
 169 -                            struct ext4_dir_entry_2 **dest_de);
 170 +                            struct ext4_dir_entry_2 **dest_de, int *dlen);
 171  void ext4_insert_dentry(struct inode *inode,
 172                         struct ext4_dir_entry_2 *de,
 173                         int buf_size,
 174 -                       struct ext4_filename *fname);
 175 +                       struct ext4_filename *fname, void *data);
 176  static inline void ext4_update_dx_flag(struct inode *inode)
 177  {
 178         if (!ext4_has_feature_dir_index(inode->i_sb))
 179 @@ -2507,10 +2555,17 @@ static const unsigned char ext4_filetype_table[] = {
 180
 181  static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
 182  {
 183 -       if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
 184 +       int fl_index = filetype & EXT4_FT_MASK;
 185 +
 186 +       if (!ext4_has_feature_filetype(sb) || fl_index >= EXT4_FT_MAX)
 187                 return DT_UNKNOWN;
 188
 189 -       return ext4_filetype_table[filetype];
 190 +       if (!test_opt(sb, DIRDATA))
 191 +               return ext4_filetype_table[fl_index];
 192 +
 193 +       return (ext4_filetype_table[fl_index]) |
 194 +               (filetype & EXT4_DIRENT_LUFID);
 195 +
 196  }
 197  extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
 198                              void *buf, int buf_size);
 199 @@ -2673,6 +2728,8 @@ extern struct inode *ext4_create_inode(handle_t *handle,
 200  extern int ext4_delete_entry(handle_t *handle, struct inode * dir,
 201                              struct ext4_dir_entry_2 *de_del,
 202                              struct buffer_head *bh);
 203 +extern int ext4_add_dot_dotdot(handle_t *handle, struct inode *dir,
 204 +                              struct inode *inode, const void *, const void *);
 205  extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 206                                 __u32 start_minor_hash, __u32 *next_hash);
 207  extern int ext4_search_dir(struct buffer_head *bh,
 208 @@ -3428,6 +3485,36 @@ static inline int ext4_buffer_uptodate(struct buffer_head *bh)
 209         return buffer_uptodate(bh);
 210  }
 211
 212 +/*
 213 + * Compute the total directory entry data length.
 214 + * This includes the filename and an implicit NUL terminator (always present),
 215 + * and optional extensions.  Each extension has a bit set in the high 4 bits of
 216 + * de->file_type, and the extension length is the first byte in each entry.
 217 + */
 218 +static inline int ext4_get_dirent_data_len(struct ext4_dir_entry_2 *de)
 219 +{
 220 +       char *len = de->name + de->name_len + 1 /* NUL terminator */;
 221 +       int dlen = 0;
 222 +       __u8 extra_data_flags = (de->file_type & ~EXT4_FT_MASK) >> 4;
 223 +       struct ext4_dir_entry_tail *t = (struct ext4_dir_entry_tail *)de;
 224 +
 225 +       if (!t->det_reserved_zero1 &&
 226 +           le16_to_cpu(t->det_rec_len) ==
 227 +               sizeof(struct ext4_dir_entry_tail) &&
 228 +           !t->det_reserved_zero2 &&
 229 +           t->det_reserved_ft == EXT4_FT_DIR_CSUM)
 230 +               return 0;
 231 +
 232 +       while (extra_data_flags) {
 233 +               if (extra_data_flags & 1) {
 234 +                       dlen += *len + (dlen == 0);
 235 +                       len += *len;
 236 +               }
 237 +               extra_data_flags >>= 1;
 238 +       }
 239 +       return dlen;
 240 +}
 241 +
 242  #endif /* __KERNEL__ */
 243
 244  #define EFSBADCRC      EBADMSG         /* Bad CRC detected */
 245 diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
 246 index 2fec62d..3f35821 100644
 247 --- a/fs/ext4/inline.c
 248 +++ b/fs/ext4/inline.c
 249 @@ -1023,7 +1023,7 @@ static int ext4_add_dirent_to_inline(handle_t *handle,
 250         struct ext4_dir_entry_2 *de;
 251
 252         err = ext4_find_dest_de(dir, inode, iloc->bh, inline_start,
 253 -                               inline_size, fname, &de);
 254 +                               inline_size, fname, &de, NULL);
 255         if (err)
 256                 return err;
 257
 258 @@ -1031,7 +1031,7 @@ static int ext4_add_dirent_to_inline(handle_t *handle,
 259         err = ext4_journal_get_write_access(handle, iloc->bh);
 260         if (err)
 261                 return err;
 262 -       ext4_insert_dentry(inode, de, inline_size, fname);
 263 +       ext4_insert_dentry(inode, de, inline_size, fname, NULL);
 264
 265         ext4_show_inline_dir(dir, iloc->bh, inline_start, inline_size);
 266
 267 @@ -1378,7 +1378,7 @@ int ext4_inlinedir_to_tree(struct file *dir_file,
 268                         fake.name_len = 1;
 269                         strcpy(fake.name, ".");
 270                         fake.rec_len = ext4_rec_len_to_disk(
 271 -                                               EXT4_DIR_REC_LEN(fake.name_len),
 272 +                                               EXT4_DIR_ENTRY_LEN(&fake),
 273                                                 inline_size);
 274                         ext4_set_de_type(inode->i_sb, &fake, S_IFDIR);
 275                         de = &fake;
 276 @@ -1388,7 +1388,7 @@ int ext4_inlinedir_to_tree(struct file *dir_file,
 277                         fake.name_len = 2;
 278                         strcpy(fake.name, "..");
 279                         fake.rec_len = ext4_rec_len_to_disk(
 280 -                                               EXT4_DIR_REC_LEN(fake.name_len),
 281 +                                               EXT4_DIR_ENTRY_LEN(&fake),
 282                                                 inline_size);
 283                         ext4_set_de_type(inode->i_sb, &fake, S_IFDIR);
 284                         de = &fake;
 285 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
 286 index 8713671..23bd871 100644
 287 --- a/fs/ext4/namei.c
 288 +++ b/fs/ext4/namei.c
 289 @@ -258,7 +258,8 @@ static unsigned dx_get_count(struct dx_entry *entries);
 290  static unsigned dx_get_limit(struct dx_entry *entries);
 291  static void dx_set_count(struct dx_entry *entries, unsigned value);
 292  static void dx_set_limit(struct dx_entry *entries, unsigned value);
 293 -static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 294 +static inline unsigned dx_root_limit(struct inode *dir,
 295 +               struct ext4_dir_entry_2 *dot_de, unsigned infosize);
 296  static unsigned dx_node_limit(struct inode *dir);
 297  static struct dx_frame *dx_probe(struct ext4_filename *fname,
 298                                  struct inode *dir,
 299 @@ -402,22 +403,23 @@ static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 300  {
 301         struct ext4_dir_entry *dp;
 302         struct dx_root_info *root;
 303 -       int count_offset;
 304 +       int count_offset, dot_rec_len, dotdot_rec_len;
 305
 306         if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
 307                 count_offset = 8;
 308 -       else if (le16_to_cpu(dirent->rec_len) == 12) {
 309 -               dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
 310 +       else {
 311 +               dot_rec_len = le16_to_cpu(dirent->rec_len);
 312 +               dp = (struct ext4_dir_entry *)(((void *)dirent) + dot_rec_len);
 313                 if (le16_to_cpu(dp->rec_len) !=
 314 -                   EXT4_BLOCK_SIZE(inode->i_sb) - 12)
 315 +                   EXT4_BLOCK_SIZE(inode->i_sb) - dot_rec_len)
 316                         return NULL;
 317 -               root = (struct dx_root_info *)(((void *)dp + 12));
 318 +               dotdot_rec_len = EXT4_DIR_ENTRY_LEN((struct ext4_dir_entry_2 *)dp);
 319 +               root = (struct dx_root_info *)(((void *)dp + dotdot_rec_len));
 320                 if (root->reserved_zero ||
 321                     root->info_length != sizeof(struct dx_root_info))
 322                         return NULL;
 323 -               count_offset = 32;
 324 -       } else
 325 -               return NULL;
 326 +               count_offset = 8 + dot_rec_len + dotdot_rec_len;
 327 +       }
 328
 329         if (offset)
 330                 *offset = count_offset;
 331 @@ -522,11 +524,12 @@ ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 332   */
 333  struct dx_root_info *dx_get_dx_info(struct ext4_dir_entry_2 *de)
 334  {
 335 +       BUG_ON(de->name_len != 1);
 336         /* get dotdot first */
 337 -       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(1));
 338 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_ENTRY_LEN(de));
 339
 340         /* dx root info is after dotdot entry */
 341 -       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_REC_LEN(2));
 342 +       de = (struct ext4_dir_entry_2 *)((char *)de + EXT4_DIR_ENTRY_LEN(de));
 343
 344         return (struct dx_root_info *)de;
 345  }
 346 @@ -571,10 +574,16 @@ static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 347         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 348  }
 349
 350 -static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 351 +static inline unsigned dx_root_limit(struct inode *dir,
 352 +               struct ext4_dir_entry_2 *dot_de, unsigned infosize)
 353  {
 354 -       unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 355 -               EXT4_DIR_REC_LEN(2) - infosize;
 356 +       struct ext4_dir_entry_2 *dotdot_de;
 357 +       unsigned entry_space;
 358 +
 359 +       BUG_ON(dot_de->name_len != 1);
 360 +       dotdot_de = ext4_next_entry(dot_de, dir->i_sb->s_blocksize);
 361 +       entry_space = dir->i_sb->s_blocksize - EXT4_DIR_ENTRY_LEN(dot_de) -
 362 +                        EXT4_DIR_ENTRY_LEN(dotdot_de) - infosize;
 363
 364         if (ext4_has_metadata_csum(dir->i_sb))
 365                 entry_space -= sizeof(struct dx_tail);
 366 @@ -695,7 +704,7 @@ static struct stats dx_show_leaf(struct inode *dir,
 367                                        (unsigned) ((char *) de - base));
 368  #endif
 369                         }
 370 -                       space += EXT4_DIR_REC_LEN(de->name_len);
 371 +                       space += EXT4_DIR_ENTRY_LEN(de);
 372                         names++;
 373                 }
 374                 de = ext4_next_entry(de, size);
 375 @@ -802,11 +811,14 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
 376
 377         entries = (struct dx_entry *)(((char *)info) + info->info_length);
 378
 379 -       if (dx_get_limit(entries) != dx_root_limit(dir,
 380 -                                                  info->info_length)) {
 381 +       if (dx_get_limit(entries) !=
 382 +           dx_root_limit(dir, (struct ext4_dir_entry_2 *)frame->bh->b_data,
 383 +                         info->info_length)) {
 384                 ext4_warning_inode(dir, "dx entry: limit %u != root limit %u",
 385                                    dx_get_limit(entries),
 386 -                                  dx_root_limit(dir, info->info_length));
 387 +                                  dx_root_limit(dir,
 388 +                                         (struct ext4_dir_entry_2 *)frame->bh->b_data,
 389 +                                         info->info_length));
 390                 goto fail;
 391         }
 392
 393 @@ -1792,7 +1804,7 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
 394         while (count--) {
 395                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *)
 396                                                 (from + (map->offs<<2));
 397 -               rec_len = EXT4_DIR_REC_LEN(de->name_len);
 398 +               rec_len = EXT4_DIR_ENTRY_LEN(de);
 399                 memcpy (to, de, rec_len);
 400                 ((struct ext4_dir_entry_2 *) to)->rec_len =
 401                                 ext4_rec_len_to_disk(rec_len, blocksize);
 402 @@ -1816,7 +1828,7 @@ static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
 403         while ((char*)de < base + blocksize) {
 404                 next = ext4_next_entry(de, blocksize);
 405                 if (de->inode && de->name_len) {
 406 -                       rec_len = EXT4_DIR_REC_LEN(de->name_len);
 407 +                       rec_len = EXT4_DIR_ENTRY_LEN(de);
 408                         if (de > to)
 409                                 memmove(to, de, rec_len);
 410                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
 411 @@ -1943,14 +1955,16 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
 412                       struct buffer_head *bh,
 413                       void *buf, int buf_size,
 414                       struct ext4_filename *fname,
 415 -                     struct ext4_dir_entry_2 **dest_de)
 416 +                     struct ext4_dir_entry_2 **dest_de, int *dlen)
 417  {
 418         struct ext4_dir_entry_2 *de;
 419 -       unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname));
 420 +       unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname)) +
 421 +                                                 (dlen ? *dlen : 0);
 422         int nlen, rlen;
 423         unsigned int offset = 0;
 424         char *top;
 425
 426 +       dlen ? *dlen = 0 : 0; /* default set to 0 */
 427         de = (struct ext4_dir_entry_2 *)buf;
 428         top = buf + buf_size - reclen;
 429         while ((char *) de <= top) {
 430 @@ -1959,10 +1973,26 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
 431                         return -EFSCORRUPTED;
 432                 if (ext4_match(dir, fname, de))
 433                         return -EEXIST;
 434 -               nlen = EXT4_DIR_REC_LEN(de->name_len);
 435 +               nlen = EXT4_DIR_ENTRY_LEN(de);
 436                 rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
 437                 if ((de->inode ? rlen - nlen : rlen) >= reclen)
 438                         break;
 439 +               /* Then for dotdot entries, check for the smaller space
 440 +                * required for just the entry, no FID */
 441 +               if (fname_len(fname) == 2 && memcmp(fname_name(fname), "..", 2) == 0) {
 442 +                       if ((de->inode ? rlen - nlen : rlen) >=
 443 +                           EXT4_DIR_REC_LEN(fname_len(fname))) {
 444 +                               /* set dlen=1 to indicate not
 445 +                                * enough space store fid */
 446 +                               dlen ? *dlen = 1 : 0;
 447 +                               break;
 448 +                       }
 449 +                       /* The new ".." entry must be written over the
 450 +                        * previous ".." entry, which is the first
 451 +                        * entry traversed by this scan. If it doesn't
 452 +                        * fit, something is badly wrong, so -EIO. */
 453 +                       return -EIO;
 454 +               }
 455                 de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
 456                 offset += rlen;
 457         }
 458 @@ -1976,12 +2006,12 @@ int ext4_find_dest_de(struct inode *dir, struct inode *inode,
 459  void ext4_insert_dentry(struct inode *inode,
 460                         struct ext4_dir_entry_2 *de,
 461                         int buf_size,
 462 -                       struct ext4_filename *fname)
 463 +                       struct ext4_filename *fname, void *data)
 464  {
 465
 466         int nlen, rlen;
 467
 468 -       nlen = EXT4_DIR_REC_LEN(de->name_len);
 469 +       nlen = EXT4_DIR_ENTRY_LEN(de);
 470         rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
 471         if (de->inode) {
 472                 struct ext4_dir_entry_2 *de1 =
 473 @@ -1995,6 +2025,11 @@ void ext4_insert_dentry(struct inode *inode,
 474         ext4_set_de_type(inode->i_sb, de, inode->i_mode);
 475         de->name_len = fname_len(fname);
 476         memcpy(de->name, fname_name(fname), fname_len(fname));
 477 +       if (data) {
 478 +               de->name[fname_len(fname)] = 0;
 479 +               memcpy(&de->name[fname_len(fname) + 1], data, *(char *)data);
 480 +               de->file_type |= EXT4_DIRENT_LUFID;
 481 +       }
 482  }
 483
 484  /*
 485 @@ -2012,14 +2047,19 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
 486  {
 487         unsigned int    blocksize = dir->i_sb->s_blocksize;
 488         int             csum_size = 0;
 489 -       int             err;
 490 +       int             err, dlen = 0;
 491 +       unsigned char   *data;
 492
 493 +       data = ext4_dentry_get_data(inode->i_sb, (struct ext4_dentry_param *)
 494 +                                               EXT4_I(inode)->i_dirdata);
 495         if (ext4_has_metadata_csum(inode->i_sb))
 496                 csum_size = sizeof(struct ext4_dir_entry_tail);
 497
 498         if (!de) {
 499 +               if (data)
 500 +                       dlen = (*data) + 1;
 501                 err = ext4_find_dest_de(dir, inode, bh, bh->b_data,
 502 -                                       blocksize - csum_size, fname, &de);
 503 +                                       blocksize - csum_size, fname, &de, &dlen);
 504                 if (err)
 505                         return err;
 506         }
 507 @@ -2031,7 +2071,10 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
 508         }
 509
 510         /* By now the buffer is marked for journaling */
 511 -       ext4_insert_dentry(inode, de, blocksize, fname);
 512 +       /* If writing the short form of "dotdot", don't add the data section */
 513 +       if (dlen == 1)
 514 +               data = NULL;
 515 +       ext4_insert_dentry(inode, de, blocksize, fname, data);
 516
 517         /*
 518          * XXX shouldn't update any times until successful
 519 @@ -2136,7 +2179,8 @@ static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
 520
 521         dx_set_block(entries, 1);
 522         dx_set_count(entries, 1);
 523 -       dx_set_limit(entries, dx_root_limit(dir, sizeof(*dx_info)));
 524 +       dx_set_limit(entries, dx_root_limit(dir,
 525 +                                        dot_de, sizeof(*dx_info)));
 526
 527         /* Initialize as for dx_probe */
 528         fname->hinfo.hash_version = dx_info->hash_version;
 529 @@ -2186,6 +2230,8 @@ static int ext4_update_dotdot(handle_t *handle, struct dentry *dentry,
 530         struct buffer_head *dir_block;
 531         struct ext4_dir_entry_2 *de;
 532         int len, journal = 0, err = 0;
 533 +       int dlen = 0;
 534 +       char *data;
 535
 536         if (IS_ERR(handle))
 537                 return PTR_ERR(handle);
 538 @@ -2211,11 +2257,16 @@ static int ext4_update_dotdot(handle_t *handle, struct dentry *dentry,
 539                         goto out_journal;
 540
 541                 journal = 1;
 542 -               de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(1));
 543 +               de->rec_len = cpu_to_le16(EXT4_DIR_ENTRY_LEN(de));
 544         }
 545
 546 -       len -= EXT4_DIR_REC_LEN(1);
 547 -       assert(len == 0 || len >= EXT4_DIR_REC_LEN(2));
 548 +       len -= EXT4_DIR_ENTRY_LEN(de);
 549 +       data = ext4_dentry_get_data(dir->i_sb,
 550 +                       (struct ext4_dentry_param *)dentry->d_fsdata);
 551 +       if (data)
 552 +               dlen = *data + 1;
 553 +       assert(len == 0 || len >= EXT4_DIR_REC_LEN(2 + dlen));
 554 +
 555         de = (struct ext4_dir_entry_2 *)
 556                         ((char *) de + le16_to_cpu(de->rec_len));
 557         if (!journal) {
 558 @@ -2232,7 +2283,12 @@ static int ext4_update_dotdot(handle_t *handle, struct dentry *dentry,
 559                 assert(le16_to_cpu(de->rec_len) >= EXT4_DIR_REC_LEN(2));
 560         de->name_len = 2;
 561         strcpy(de->name, "..");
 562 -       ext4_set_de_type(dir->i_sb, de, S_IFDIR);
 563 +       if (data != NULL && ext4_get_dirent_data_len(de) >= dlen) {
 564 +               de->name[2] = 0;
 565 +               memcpy(&de->name[2 + 1], data, *data);
 566 +               ext4_set_de_type(dir->i_sb, de, S_IFDIR);
 567 +               de->file_type |= EXT4_DIRENT_LUFID;
 568 +       }
 569
 570  out_journal:
 571         if (journal) {
 572 @@ -2271,6 +2327,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 573         ext4_lblk_t block, blocks;
 574         int     csum_size = 0;
 575
 576 +       EXT4_I(inode)->i_dirdata = dentry->d_fsdata;
 577         if (ext4_has_metadata_csum(inode->i_sb))
 578                 csum_size = sizeof(struct ext4_dir_entry_tail);
 579
 580 @@ -2803,37 +2860,70 @@ err_unlock_inode:
 581         return err;
 582  }
 583
 584 +struct tp_block {
 585 +       struct inode *inode;
 586 +       void *data1;
 587 +       void *data2;
 588 +};
 589 +
 590  struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
 591                           struct ext4_dir_entry_2 *de,
 592                           int blocksize, int csum_size,
 593                           unsigned int parent_ino, int dotdot_real_len)
 594  {
 595 +       void *data1 = NULL, *data2 = NULL;
 596 +       int dot_reclen = 0;
 597 +
 598 +       if (dotdot_real_len == 10) {
 599 +               struct tp_block *tpb = (struct tp_block *)inode;
 600 +               data1 = tpb->data1;
 601 +               data2 = tpb->data2;
 602 +               inode = tpb->inode;
 603 +               dotdot_real_len = 0;
 604 +       }
 605         de->inode = cpu_to_le32(inode->i_ino);
 606         de->name_len = 1;
 607 -       de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
 608 -                                          blocksize);
 609         strcpy(de->name, ".");
 610         ext4_set_de_type(inode->i_sb, de, S_IFDIR);
 611
 612 +       /* get packed fid data*/
 613 +       data1 = ext4_dentry_get_data(inode->i_sb,
 614 +                               (struct ext4_dentry_param *) data1);
 615 +       if (data1) {
 616 +               de->name[1] = 0;
 617 +               memcpy(&de->name[2], data1, *(char *) data1);
 618 +               de->file_type |= EXT4_DIRENT_LUFID;
 619 +       }
 620 +       de->rec_len = cpu_to_le16(EXT4_DIR_ENTRY_LEN(de));
 621 +       dot_reclen = cpu_to_le16(de->rec_len);
 622         de = ext4_next_entry(de, blocksize);
 623         de->inode = cpu_to_le32(parent_ino);
 624         de->name_len = 2;
 625 +       strcpy(de->name, "..");
 626 +       ext4_set_de_type(inode->i_sb, de, S_IFDIR);
 627 +       data2 = ext4_dentry_get_data(inode->i_sb,
 628 +                       (struct ext4_dentry_param *) data2);
 629 +       if (data2) {
 630 +               de->name[2] = 0;
 631 +               memcpy(&de->name[3], data2, *(char *) data2);
 632 +               de->file_type |= EXT4_DIRENT_LUFID;
 633 +       }
 634         if (!dotdot_real_len)
 635                 de->rec_len = ext4_rec_len_to_disk(blocksize -
 636 -                                       (csum_size + EXT4_DIR_REC_LEN(1)),
 637 +                                       (csum_size + dot_reclen),
 638                                         blocksize);
 639         else
 640                 de->rec_len = ext4_rec_len_to_disk(
 641 -                               EXT4_DIR_REC_LEN(de->name_len), blocksize);
 642 -       strcpy(de->name, "..");
 643 -       ext4_set_de_type(inode->i_sb, de, S_IFDIR);
 644 +                               EXT4_DIR_ENTRY_LEN(de), blocksize);
 645
 646         return ext4_next_entry(de, blocksize);
 647  }
 648
 649  static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
 650 -                            struct inode *inode)
 651 +                            struct inode *inode,
 652 +                            const void *data1, const void *data2)
 653  {
 654 +       struct tp_block param;
 655         struct buffer_head *dir_block = NULL;
 656         struct ext4_dir_entry_2 *de;
 657         ext4_lblk_t block = 0;
 658 @@ -2857,7 +2947,11 @@ static int ext4_init_new_dir(handle_t *handle, struct inode *dir,
 659         if (IS_ERR(dir_block))
 660                 return PTR_ERR(dir_block);
 661         de = (struct ext4_dir_entry_2 *)dir_block->b_data;
 662 -       ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0);
 663 +       param.inode = inode;
 664 +       param.data1 = (void *)data1;
 665 +       param.data2 = (void *)data2;
 666 +       ext4_init_dot_dotdot((struct inode *)(&param), de, blocksize,
 667 +                            csum_size, dir->i_ino, 10);
 668         set_nlink(inode, 2);
 669         if (csum_size)
 670                 ext4_initialize_dirent_tail(dir_block, blocksize);
 671 @@ -2872,6 +2966,29 @@ out:
 672         return err;
 673  }
 674
 675 +/* Initialize @inode as a subdirectory of @dir, and add the
 676 + * "." and ".." entries into the first directory block. */
 677 +int ext4_add_dot_dotdot(handle_t *handle, struct inode *dir,
 678 +                       struct inode *inode,
 679 +                       const void *data1, const void *data2)
 680 +{
 681 +       int rc;
 682 +
 683 +       if (IS_ERR(handle))
 684 +               return PTR_ERR(handle);
 685 +
 686 +       if (IS_DIRSYNC(dir))
 687 +               ext4_handle_sync(handle);
 688 +
 689 +       inode->i_op = &ext4_dir_inode_operations;
 690 +       inode->i_fop = &ext4_dir_operations;
 691 +       rc = ext4_init_new_dir(handle, dir, inode, data1, data2);
 692 +       if (!rc)
 693 +               rc = ext4_mark_inode_dirty(handle, inode);
 694 +       return rc;
 695 +}
 696 +EXPORT_SYMBOL(ext4_add_dot_dotdot);
 697 +
 698  static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 699  {
 700         handle_t *handle;
 701 @@ -2898,7 +3015,7 @@ retry:
 702
 703         inode->i_op = &ext4_dir_inode_operations;
 704         inode->i_fop = &ext4_dir_operations;
 705 -       err = ext4_init_new_dir(handle, dir, inode);
 706 +       err = ext4_init_new_dir(handle, dir, inode, NULL, NULL);
 707         if (err)
 708                 goto out_clear_inode;
 709         err = ext4_mark_inode_dirty(handle, inode);
 710 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
 711 index d202d6d..0fcc33b 100644
 712 --- a/fs/ext4/super.c
 713 +++ b/fs/ext4/super.c
 714 @@ -1449,7 +1449,7 @@ enum {
 715         Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
 716         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 717         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
 718 -       Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
 719 +       Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err, Opt_dirdata,
 720         Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
 721         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
 722         Opt_nowarn_on_error, Opt_mblk_io_submit,
 723 @@ -1525,6 +1525,7 @@ static const match_table_t tokens = {
 724         {Opt_nolazytime, "nolazytime"},
 725         {Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
 726         {Opt_nodelalloc, "nodelalloc"},
 727 +       {Opt_dirdata, "dirdata"},
 728         {Opt_removed, "mblk_io_submit"},
 729         {Opt_removed, "nomblk_io_submit"},
 730         {Opt_block_validity, "block_validity"},
 731 @@ -1748,6 +1749,7 @@ static const struct mount_opts {
 732         {Opt_usrjquota, 0, MOPT_Q},
 733         {Opt_grpjquota, 0, MOPT_Q},
 734         {Opt_offusrjquota, 0, MOPT_Q},
 735 +       {Opt_dirdata, EXT4_MOUNT_DIRDATA, MOPT_SET},
 736         {Opt_offgrpjquota, 0, MOPT_Q},
 737         {Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
 738         {Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},