fs/xfs/xfs_dir2_block.c

   1 /*
   2  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_types.h"
  21 #include "xfs_log.h"
  22 #include "xfs_inum.h"
  23 #include "xfs_trans.h"
  24 #include "xfs_sb.h"
  25 #include "xfs_ag.h"
  26 #include "xfs_dir2.h"
  27 #include "xfs_mount.h"
  28 #include "xfs_da_btree.h"
  29 #include "xfs_bmap_btree.h"
  30 #include "xfs_dir2_sf.h"
  31 #include "xfs_dinode.h"
  32 #include "xfs_inode.h"
  33 #include "xfs_inode_item.h"
  34 #include "xfs_dir2_data.h"
  35 #include "xfs_dir2_leaf.h"
  36 #include "xfs_dir2_block.h"
  37 #include "xfs_error.h"
  38 #include "xfs_trace.h"
  39
  40 /*
  41  * Local function prototypes.
  42  */
  43 static void xfs_dir2_block_log_leaf(xfs_trans_t *tp, xfs_dabuf_t *bp, int first,
  44                                     int last);
  45 static void xfs_dir2_block_log_tail(xfs_trans_t *tp, xfs_dabuf_t *bp);
  46 static int xfs_dir2_block_lookup_int(xfs_da_args_t *args, xfs_dabuf_t **bpp,
  47                                      int *entno);
  48 static int xfs_dir2_block_sort(const void *a, const void *b);
  49
  50 static xfs_dahash_t xfs_dir_hash_dot, xfs_dir_hash_dotdot;
  51
  52 /*
  53  * One-time startup routine called from xfs_init().
  54  */
  55 void
  56 xfs_dir_startup(void)
  57 {
  58         xfs_dir_hash_dot = xfs_da_hashname((unsigned char *)".", 1);
  59         xfs_dir_hash_dotdot = xfs_da_hashname((unsigned char *)"..", 2);
  60 }
  61
  62 /*
  63  * Add an entry to a block directory.
  64  */
  65 int                                             /* error */
  66 xfs_dir2_block_addname(
  67         xfs_da_args_t           *args)          /* directory op arguments */
  68 {
  69         xfs_dir2_data_free_t    *bf;            /* bestfree table in block */
  70         xfs_dir2_block_t        *block;         /* directory block structure */
  71         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
  72         xfs_dabuf_t             *bp;            /* buffer for block */
  73         xfs_dir2_block_tail_t   *btp;           /* block tail */
  74         int                     compact;        /* need to compact leaf ents */
  75         xfs_dir2_data_entry_t   *dep;           /* block data entry */
  76         xfs_inode_t             *dp;            /* directory inode */
  77         xfs_dir2_data_unused_t  *dup;           /* block unused entry */
  78         int                     error;          /* error return value */
  79         xfs_dir2_data_unused_t  *enddup=NULL;   /* unused at end of data */
  80         xfs_dahash_t            hash;           /* hash value of found entry */
  81         int                     high;           /* high index for binary srch */
  82         int                     highstale;      /* high stale index */
  83         int                     lfloghigh=0;    /* last final leaf to log */
  84         int                     lfloglow=0;     /* first final leaf to log */
  85         int                     len;            /* length of the new entry */
  86         int                     low;            /* low index for binary srch */
  87         int                     lowstale;       /* low stale index */
  88         int                     mid=0;          /* midpoint for binary srch */
  89         xfs_mount_t             *mp;            /* filesystem mount point */
  90         int                     needlog;        /* need to log header */
  91         int                     needscan;       /* need to rescan freespace */
  92         __be16                  *tagp;          /* pointer to tag value */
  93         xfs_trans_t             *tp;            /* transaction structure */
  94
  95         trace_xfs_dir2_block_addname(args);
  96
  97         dp = args->dp;
  98         tp = args->trans;
  99         mp = dp->i_mount;
 100         /*
 101          * Read the (one and only) directory block into dabuf bp.
 102          */
 103         if ((error =
 104             xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, XFS_DATA_FORK))) {
 105                 return error;
 106         }
 107         ASSERT(bp != NULL);
 108         block = bp->data;
 109         /*
 110          * Check the magic number, corrupted if wrong.
 111          */
 112         if (unlikely(be32_to_cpu(block->hdr.magic) != XFS_DIR2_BLOCK_MAGIC)) {
 113                 XFS_CORRUPTION_ERROR("xfs_dir2_block_addname",
 114                                      XFS_ERRLEVEL_LOW, mp, block);
 115                 xfs_da_brelse(tp, bp);
 116                 return XFS_ERROR(EFSCORRUPTED);
 117         }
 118         len = xfs_dir2_data_entsize(args->namelen);
 119         /*
 120          * Set up pointers to parts of the block.
 121          */
 122         bf = block->hdr.bestfree;
 123         btp = xfs_dir2_block_tail_p(mp, block);
 124         blp = xfs_dir2_block_leaf_p(btp);
 125         /*
 126          * No stale entries?  Need space for entry and new leaf.
 127          */
 128         if (!btp->stale) {
 129                 /*
 130                  * Tag just before the first leaf entry.
 131                  */
 132                 tagp = (__be16 *)blp - 1;
 133                 /*
 134                  * Data object just before the first leaf entry.
 135                  */
 136                 enddup = (xfs_dir2_data_unused_t *)((char *)block + be16_to_cpu(*tagp));
 137                 /*
 138                  * If it's not free then can't do this add without cleaning up:
 139                  * the space before the first leaf entry needs to be free so it
 140                  * can be expanded to hold the pointer to the new entry.
 141                  */
 142                 if (be16_to_cpu(enddup->freetag) != XFS_DIR2_DATA_FREE_TAG)
 143                         dup = enddup = NULL;
 144                 /*
 145                  * Check out the biggest freespace and see if it's the same one.
 146                  */
 147                 else {
 148                         dup = (xfs_dir2_data_unused_t *)
 149                               ((char *)block + be16_to_cpu(bf[0].offset));
 150                         if (dup == enddup) {
 151                                 /*
 152                                  * It is the biggest freespace, is it too small
 153                                  * to hold the new leaf too?
 154                                  */
 155                                 if (be16_to_cpu(dup->length) < len + (uint)sizeof(*blp)) {
 156                                         /*
 157                                          * Yes, we use the second-largest
 158                                          * entry instead if it works.
 159                                          */
 160                                         if (be16_to_cpu(bf[1].length) >= len)
 161                                                 dup = (xfs_dir2_data_unused_t *)
 162                                                       ((char *)block +
 163                                                        be16_to_cpu(bf[1].offset));
 164                                         else
 165                                                 dup = NULL;
 166                                 }
 167                         } else {
 168                                 /*
 169                                  * Not the same free entry,
 170                                  * just check its length.
 171                                  */
 172                                 if (be16_to_cpu(dup->length) < len) {
 173                                         dup = NULL;
 174                                 }
 175                         }
 176                 }
 177                 compact = 0;
 178         }
 179         /*
 180          * If there are stale entries we'll use one for the leaf.
 181          * Is the biggest entry enough to avoid compaction?
 182          */
 183         else if (be16_to_cpu(bf[0].length) >= len) {
 184                 dup = (xfs_dir2_data_unused_t *)
 185                       ((char *)block + be16_to_cpu(bf[0].offset));
 186                 compact = 0;
 187         }
 188         /*
 189          * Will need to compact to make this work.
 190          */
 191         else {
 192                 /*
 193                  * Tag just before the first leaf entry.
 194                  */
 195                 tagp = (__be16 *)blp - 1;
 196                 /*
 197                  * Data object just before the first leaf entry.
 198                  */
 199                 dup = (xfs_dir2_data_unused_t *)((char *)block + be16_to_cpu(*tagp));
 200                 /*
 201                  * If it's not free then the data will go where the
 202                  * leaf data starts now, if it works at all.
 203                  */
 204                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 205                         if (be16_to_cpu(dup->length) + (be32_to_cpu(btp->stale) - 1) *
 206                             (uint)sizeof(*blp) < len)
 207                                 dup = NULL;
 208                 } else if ((be32_to_cpu(btp->stale) - 1) * (uint)sizeof(*blp) < len)
 209                         dup = NULL;
 210                 else
 211                         dup = (xfs_dir2_data_unused_t *)blp;
 212                 compact = 1;
 213         }
 214         /*
 215          * If this isn't a real add, we're done with the buffer.
 216          */
 217         if (args->op_flags & XFS_DA_OP_JUSTCHECK)
 218                 xfs_da_brelse(tp, bp);
 219         /*
 220          * If we don't have space for the new entry & leaf ...
 221          */
 222         if (!dup) {
 223                 /*
 224                  * Not trying to actually do anything, or don't have
 225                  * a space reservation: return no-space.
 226                  */
 227                 if ((args->op_flags & XFS_DA_OP_JUSTCHECK) || args->total == 0)
 228                         return XFS_ERROR(ENOSPC);
 229                 /*
 230                  * Convert to the next larger format.
 231                  * Then add the new entry in that format.
 232                  */
 233                 error = xfs_dir2_block_to_leaf(args, bp);
 234                 xfs_da_buf_done(bp);
 235                 if (error)
 236                         return error;
 237                 return xfs_dir2_leaf_addname(args);
 238         }
 239         /*
 240          * Just checking, and it would work, so say so.
 241          */
 242         if (args->op_flags & XFS_DA_OP_JUSTCHECK)
 243                 return 0;
 244         needlog = needscan = 0;
 245         /*
 246          * If need to compact the leaf entries, do it now.
 247          * Leave the highest-numbered stale entry stale.
 248          * XXX should be the one closest to mid but mid is not yet computed.
 249          */
 250         if (compact) {
 251                 int     fromidx;                /* source leaf index */
 252                 int     toidx;                  /* target leaf index */
 253
 254                 for (fromidx = toidx = be32_to_cpu(btp->count) - 1,
 255                         highstale = lfloghigh = -1;
 256                      fromidx >= 0;
 257                      fromidx--) {
 258                         if (be32_to_cpu(blp[fromidx].address) == XFS_DIR2_NULL_DATAPTR) {
 259                                 if (highstale == -1)
 260                                         highstale = toidx;
 261                                 else {
 262                                         if (lfloghigh == -1)
 263                                                 lfloghigh = toidx;
 264                                         continue;
 265                                 }
 266                         }
 267                         if (fromidx < toidx)
 268                                 blp[toidx] = blp[fromidx];
 269                         toidx--;
 270                 }
 271                 lfloglow = toidx + 1 - (be32_to_cpu(btp->stale) - 1);
 272                 lfloghigh -= be32_to_cpu(btp->stale) - 1;
 273                 be32_add_cpu(&btp->count, -(be32_to_cpu(btp->stale) - 1));
 274                 xfs_dir2_data_make_free(tp, bp,
 275                         (xfs_dir2_data_aoff_t)((char *)blp - (char *)block),
 276                         (xfs_dir2_data_aoff_t)((be32_to_cpu(btp->stale) - 1) * sizeof(*blp)),
 277                         &needlog, &needscan);
 278                 blp += be32_to_cpu(btp->stale) - 1;
 279                 btp->stale = cpu_to_be32(1);
 280                 /*
 281                  * If we now need to rebuild the bestfree map, do so.
 282                  * This needs to happen before the next call to use_free.
 283                  */
 284                 if (needscan) {
 285                         xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
 286                         needscan = 0;
 287                 }
 288         }
 289         /*
 290          * Set leaf logging boundaries to impossible state.
 291          * For the no-stale case they're set explicitly.
 292          */
 293         else if (btp->stale) {
 294                 lfloglow = be32_to_cpu(btp->count);
 295                 lfloghigh = -1;
 296         }
 297         /*
 298          * Find the slot that's first lower than our hash value, -1 if none.
 299          */
 300         for (low = 0, high = be32_to_cpu(btp->count) - 1; low <= high; ) {
 301                 mid = (low + high) >> 1;
 302                 if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
 303                         break;
 304                 if (hash < args->hashval)
 305                         low = mid + 1;
 306                 else
 307                         high = mid - 1;
 308         }
 309         while (mid >= 0 && be32_to_cpu(blp[mid].hashval) >= args->hashval) {
 310                 mid--;
 311         }
 312         /*
 313          * No stale entries, will use enddup space to hold new leaf.
 314          */
 315         if (!btp->stale) {
 316                 /*
 317                  * Mark the space needed for the new leaf entry, now in use.
 318                  */
 319                 xfs_dir2_data_use_free(tp, bp, enddup,
 320                         (xfs_dir2_data_aoff_t)
 321                         ((char *)enddup - (char *)block + be16_to_cpu(enddup->length) -
 322                          sizeof(*blp)),
 323                         (xfs_dir2_data_aoff_t)sizeof(*blp),
 324                         &needlog, &needscan);
 325                 /*
 326                  * Update the tail (entry count).
 327                  */
 328                 be32_add_cpu(&btp->count, 1);
 329                 /*
 330                  * If we now need to rebuild the bestfree map, do so.
 331                  * This needs to happen before the next call to use_free.
 332                  */
 333                 if (needscan) {
 334                         xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block,
 335                                 &needlog);
 336                         needscan = 0;
 337                 }
 338                 /*
 339                  * Adjust pointer to the first leaf entry, we're about to move
 340                  * the table up one to open up space for the new leaf entry.
 341                  * Then adjust our index to match.
 342                  */
 343                 blp--;
 344                 mid++;
 345                 if (mid)
 346                         memmove(blp, &blp[1], mid * sizeof(*blp));
 347                 lfloglow = 0;
 348                 lfloghigh = mid;
 349         }
 350         /*
 351          * Use a stale leaf for our new entry.
 352          */
 353         else {
 354                 for (lowstale = mid;
 355                      lowstale >= 0 &&
 356                         be32_to_cpu(blp[lowstale].address) != XFS_DIR2_NULL_DATAPTR;
 357                      lowstale--)
 358                         continue;
 359                 for (highstale = mid + 1;
 360                      highstale < be32_to_cpu(btp->count) &&
 361                         be32_to_cpu(blp[highstale].address) != XFS_DIR2_NULL_DATAPTR &&
 362                         (lowstale < 0 || mid - lowstale > highstale - mid);
 363                      highstale++)
 364                         continue;
 365                 /*
 366                  * Move entries toward the low-numbered stale entry.
 367                  */
 368                 if (lowstale >= 0 &&
 369                     (highstale == be32_to_cpu(btp->count) ||
 370                      mid - lowstale <= highstale - mid)) {
 371                         if (mid - lowstale)
 372                                 memmove(&blp[lowstale], &blp[lowstale + 1],
 373                                         (mid - lowstale) * sizeof(*blp));
 374                         lfloglow = MIN(lowstale, lfloglow);
 375                         lfloghigh = MAX(mid, lfloghigh);
 376                 }
 377                 /*
 378                  * Move entries toward the high-numbered stale entry.
 379                  */
 380                 else {
 381                         ASSERT(highstale < be32_to_cpu(btp->count));
 382                         mid++;
 383                         if (highstale - mid)
 384                                 memmove(&blp[mid + 1], &blp[mid],
 385                                         (highstale - mid) * sizeof(*blp));
 386                         lfloglow = MIN(mid, lfloglow);
 387                         lfloghigh = MAX(highstale, lfloghigh);
 388                 }
 389                 be32_add_cpu(&btp->stale, -1);
 390         }
 391         /*
 392          * Point to the new data entry.
 393          */
 394         dep = (xfs_dir2_data_entry_t *)dup;
 395         /*
 396          * Fill in the leaf entry.
 397          */
 398         blp[mid].hashval = cpu_to_be32(args->hashval);
 399         blp[mid].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
 400                                 (char *)dep - (char *)block));
 401         xfs_dir2_block_log_leaf(tp, bp, lfloglow, lfloghigh);
 402         /*
 403          * Mark space for the data entry used.
 404          */
 405         xfs_dir2_data_use_free(tp, bp, dup,
 406                 (xfs_dir2_data_aoff_t)((char *)dup - (char *)block),
 407                 (xfs_dir2_data_aoff_t)len, &needlog, &needscan);
 408         /*
 409          * Create the new data entry.
 410          */
 411         dep->inumber = cpu_to_be64(args->inumber);
 412         dep->namelen = args->namelen;
 413         memcpy(dep->name, args->name, args->namelen);
 414         tagp = xfs_dir2_data_entry_tag_p(dep);
 415         *tagp = cpu_to_be16((char *)dep - (char *)block);
 416         /*
 417          * Clean up the bestfree array and log the header, tail, and entry.
 418          */
 419         if (needscan)
 420                 xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
 421         if (needlog)
 422                 xfs_dir2_data_log_header(tp, bp);
 423         xfs_dir2_block_log_tail(tp, bp);
 424         xfs_dir2_data_log_entry(tp, bp, dep);
 425         xfs_dir2_data_check(dp, bp);
 426         xfs_da_buf_done(bp);
 427         return 0;
 428 }
 429
 430 /*
 431  * Readdir for block directories.
 432  */
 433 int                                             /* error */
 434 xfs_dir2_block_getdents(
 435         xfs_inode_t             *dp,            /* incore inode */
 436         void                    *dirent,
 437         xfs_off_t               *offset,
 438         filldir_t               filldir)
 439 {
 440         xfs_dir2_block_t        *block;         /* directory block structure */
 441         xfs_dabuf_t             *bp;            /* buffer for block */
 442         xfs_dir2_block_tail_t   *btp;           /* block tail */
 443         xfs_dir2_data_entry_t   *dep;           /* block data entry */
 444         xfs_dir2_data_unused_t  *dup;           /* block unused entry */
 445         char                    *endptr;        /* end of the data entries */
 446         int                     error;          /* error return value */
 447         xfs_mount_t             *mp;            /* filesystem mount point */
 448         char                    *ptr;           /* current data entry */
 449         int                     wantoff;        /* starting block offset */
 450         xfs_off_t               cook;
 451
 452         mp = dp->i_mount;
 453         /*
 454          * If the block number in the offset is out of range, we're done.
 455          */
 456         if (xfs_dir2_dataptr_to_db(mp, *offset) > mp->m_dirdatablk) {
 457                 return 0;
 458         }
 459         /*
 460          * Can't read the block, give up, else get dabuf in bp.
 461          */
 462         error = xfs_da_read_buf(NULL, dp, mp->m_dirdatablk, -1,
 463                                 &bp, XFS_DATA_FORK);
 464         if (error)
 465                 return error;
 466
 467         ASSERT(bp != NULL);
 468         /*
 469          * Extract the byte offset we start at from the seek pointer.
 470          * We'll skip entries before this.
 471          */
 472         wantoff = xfs_dir2_dataptr_to_off(mp, *offset);
 473         block = bp->data;
 474         xfs_dir2_data_check(dp, bp);
 475         /*
 476          * Set up values for the loop.
 477          */
 478         btp = xfs_dir2_block_tail_p(mp, block);
 479         ptr = (char *)block->u;
 480         endptr = (char *)xfs_dir2_block_leaf_p(btp);
 481
 482         /*
 483          * Loop over the data portion of the block.
 484          * Each object is a real entry (dep) or an unused one (dup).
 485          */
 486         while (ptr < endptr) {
 487                 dup = (xfs_dir2_data_unused_t *)ptr;
 488                 /*
 489                  * Unused, skip it.
 490                  */
 491                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 492                         ptr += be16_to_cpu(dup->length);
 493                         continue;
 494                 }
 495
 496                 dep = (xfs_dir2_data_entry_t *)ptr;
 497
 498                 /*
 499                  * Bump pointer for the next iteration.
 500                  */
 501                 ptr += xfs_dir2_data_entsize(dep->namelen);
 502                 /*
 503                  * The entry is before the desired starting point, skip it.
 504                  */
 505                 if ((char *)dep - (char *)block < wantoff)
 506                         continue;
 507
 508                 cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
 509                                             (char *)dep - (char *)block);
 510
 511                 /*
 512                  * If it didn't fit, set the final offset to here & return.
 513                  */
 514                 if (filldir(dirent, (char *)dep->name, dep->namelen,
 515                             cook & 0x7fffffff, be64_to_cpu(dep->inumber),
 516                             DT_UNKNOWN)) {
 517                         *offset = cook & 0x7fffffff;
 518                         xfs_da_brelse(NULL, bp);
 519                         return 0;
 520                 }
 521         }
 522
 523         /*
 524          * Reached the end of the block.
 525          * Set the offset to a non-existent block 1 and return.
 526          */
 527         *offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) &
 528                         0x7fffffff;
 529         xfs_da_brelse(NULL, bp);
 530         return 0;
 531 }
 532
 533 /*
 534  * Log leaf entries from the block.
 535  */
 536 static void
 537 xfs_dir2_block_log_leaf(
 538         xfs_trans_t             *tp,            /* transaction structure */
 539         xfs_dabuf_t             *bp,            /* block buffer */
 540         int                     first,          /* index of first logged leaf */
 541         int                     last)           /* index of last logged leaf */
 542 {
 543         xfs_dir2_block_t        *block;         /* directory block structure */
 544         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
 545         xfs_dir2_block_tail_t   *btp;           /* block tail */
 546         xfs_mount_t             *mp;            /* filesystem mount point */
 547
 548         mp = tp->t_mountp;
 549         block = bp->data;
 550         btp = xfs_dir2_block_tail_p(mp, block);
 551         blp = xfs_dir2_block_leaf_p(btp);
 552         xfs_da_log_buf(tp, bp, (uint)((char *)&blp[first] - (char *)block),
 553                 (uint)((char *)&blp[last + 1] - (char *)block - 1));
 554 }
 555
 556 /*
 557  * Log the block tail.
 558  */
 559 static void
 560 xfs_dir2_block_log_tail(
 561         xfs_trans_t             *tp,            /* transaction structure */
 562         xfs_dabuf_t             *bp)            /* block buffer */
 563 {
 564         xfs_dir2_block_t        *block;         /* directory block structure */
 565         xfs_dir2_block_tail_t   *btp;           /* block tail */
 566         xfs_mount_t             *mp;            /* filesystem mount point */
 567
 568         mp = tp->t_mountp;
 569         block = bp->data;
 570         btp = xfs_dir2_block_tail_p(mp, block);
 571         xfs_da_log_buf(tp, bp, (uint)((char *)btp - (char *)block),
 572                 (uint)((char *)(btp + 1) - (char *)block - 1));
 573 }
 574
 575 /*
 576  * Look up an entry in the block.  This is the external routine,
 577  * xfs_dir2_block_lookup_int does the real work.
 578  */
 579 int                                             /* error */
 580 xfs_dir2_block_lookup(
 581         xfs_da_args_t           *args)          /* dir lookup arguments */
 582 {
 583         xfs_dir2_block_t        *block;         /* block structure */
 584         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
 585         xfs_dabuf_t             *bp;            /* block buffer */
 586         xfs_dir2_block_tail_t   *btp;           /* block tail */
 587         xfs_dir2_data_entry_t   *dep;           /* block data entry */
 588         xfs_inode_t             *dp;            /* incore inode */
 589         int                     ent;            /* entry index */
 590         int                     error;          /* error return value */
 591         xfs_mount_t             *mp;            /* filesystem mount point */
 592
 593         trace_xfs_dir2_block_lookup(args);
 594
 595         /*
 596          * Get the buffer, look up the entry.
 597          * If not found (ENOENT) then return, have no buffer.
 598          */
 599         if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent)))
 600                 return error;
 601         dp = args->dp;
 602         mp = dp->i_mount;
 603         block = bp->data;
 604         xfs_dir2_data_check(dp, bp);
 605         btp = xfs_dir2_block_tail_p(mp, block);
 606         blp = xfs_dir2_block_leaf_p(btp);
 607         /*
 608          * Get the offset from the leaf entry, to point to the data.
 609          */
 610         dep = (xfs_dir2_data_entry_t *)((char *)block +
 611                 xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
 612         /*
 613          * Fill in inode number, CI name if appropriate, release the block.
 614          */
 615         args->inumber = be64_to_cpu(dep->inumber);
 616         error = xfs_dir_cilookup_result(args, dep->name, dep->namelen);
 617         xfs_da_brelse(args->trans, bp);
 618         return XFS_ERROR(error);
 619 }
 620
 621 /*
 622  * Internal block lookup routine.
 623  */
 624 static int                                      /* error */
 625 xfs_dir2_block_lookup_int(
 626         xfs_da_args_t           *args,          /* dir lookup arguments */
 627         xfs_dabuf_t             **bpp,          /* returned block buffer */
 628         int                     *entno)         /* returned entry number */
 629 {
 630         xfs_dir2_dataptr_t      addr;           /* data entry address */
 631         xfs_dir2_block_t        *block;         /* block structure */
 632         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
 633         xfs_dabuf_t             *bp;            /* block buffer */
 634         xfs_dir2_block_tail_t   *btp;           /* block tail */
 635         xfs_dir2_data_entry_t   *dep;           /* block data entry */
 636         xfs_inode_t             *dp;            /* incore inode */
 637         int                     error;          /* error return value */
 638         xfs_dahash_t            hash;           /* found hash value */
 639         int                     high;           /* binary search high index */
 640         int                     low;            /* binary search low index */
 641         int                     mid;            /* binary search current idx */
 642         xfs_mount_t             *mp;            /* filesystem mount point */
 643         xfs_trans_t             *tp;            /* transaction pointer */
 644         enum xfs_dacmp          cmp;            /* comparison result */
 645
 646         dp = args->dp;
 647         tp = args->trans;
 648         mp = dp->i_mount;
 649         /*
 650          * Read the buffer, return error if we can't get it.
 651          */
 652         if ((error =
 653             xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, XFS_DATA_FORK))) {
 654                 return error;
 655         }
 656         ASSERT(bp != NULL);
 657         block = bp->data;
 658         xfs_dir2_data_check(dp, bp);
 659         btp = xfs_dir2_block_tail_p(mp, block);
 660         blp = xfs_dir2_block_leaf_p(btp);
 661         /*
 662          * Loop doing a binary search for our hash value.
 663          * Find our entry, ENOENT if it's not there.
 664          */
 665         for (low = 0, high = be32_to_cpu(btp->count) - 1; ; ) {
 666                 ASSERT(low <= high);
 667                 mid = (low + high) >> 1;
 668                 if ((hash = be32_to_cpu(blp[mid].hashval)) == args->hashval)
 669                         break;
 670                 if (hash < args->hashval)
 671                         low = mid + 1;
 672                 else
 673                         high = mid - 1;
 674                 if (low > high) {
 675                         ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
 676                         xfs_da_brelse(tp, bp);
 677                         return XFS_ERROR(ENOENT);
 678                 }
 679         }
 680         /*
 681          * Back up to the first one with the right hash value.
 682          */
 683         while (mid > 0 && be32_to_cpu(blp[mid - 1].hashval) == args->hashval) {
 684                 mid--;
 685         }
 686         /*
 687          * Now loop forward through all the entries with the
 688          * right hash value looking for our name.
 689          */
 690         do {
 691                 if ((addr = be32_to_cpu(blp[mid].address)) == XFS_DIR2_NULL_DATAPTR)
 692                         continue;
 693                 /*
 694                  * Get pointer to the entry from the leaf.
 695                  */
 696                 dep = (xfs_dir2_data_entry_t *)
 697                         ((char *)block + xfs_dir2_dataptr_to_off(mp, addr));
 698                 /*
 699                  * Compare name and if it's an exact match, return the index
 700                  * and buffer. If it's the first case-insensitive match, store
 701                  * the index and buffer and continue looking for an exact match.
 702                  */
 703                 cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
 704                 if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
 705                         args->cmpresult = cmp;
 706                         *bpp = bp;
 707                         *entno = mid;
 708                         if (cmp == XFS_CMP_EXACT)
 709                                 return 0;
 710                 }
 711         } while (++mid < be32_to_cpu(btp->count) &&
 712                         be32_to_cpu(blp[mid].hashval) == hash);
 713
 714         ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
 715         /*
 716          * Here, we can only be doing a lookup (not a rename or replace).
 717          * If a case-insensitive match was found earlier, return success.
 718          */
 719         if (args->cmpresult == XFS_CMP_CASE)
 720                 return 0;
 721         /*
 722          * No match, release the buffer and return ENOENT.
 723          */
 724         xfs_da_brelse(tp, bp);
 725         return XFS_ERROR(ENOENT);
 726 }
 727
 728 /*
 729  * Remove an entry from a block format directory.
 730  * If that makes the block small enough to fit in shortform, transform it.
 731  */
 732 int                                             /* error */
 733 xfs_dir2_block_removename(
 734         xfs_da_args_t           *args)          /* directory operation args */
 735 {
 736         xfs_dir2_block_t        *block;         /* block structure */
 737         xfs_dir2_leaf_entry_t   *blp;           /* block leaf pointer */
 738         xfs_dabuf_t             *bp;            /* block buffer */
 739         xfs_dir2_block_tail_t   *btp;           /* block tail */
 740         xfs_dir2_data_entry_t   *dep;           /* block data entry */
 741         xfs_inode_t             *dp;            /* incore inode */
 742         int                     ent;            /* block leaf entry index */
 743         int                     error;          /* error return value */
 744         xfs_mount_t             *mp;            /* filesystem mount point */
 745         int                     needlog;        /* need to log block header */
 746         int                     needscan;       /* need to fixup bestfree */
 747         xfs_dir2_sf_hdr_t       sfh;            /* shortform header */
 748         int                     size;           /* shortform size */
 749         xfs_trans_t             *tp;            /* transaction pointer */
 750
 751         trace_xfs_dir2_block_removename(args);
 752
 753         /*
 754          * Look up the entry in the block.  Gets the buffer and entry index.
 755          * It will always be there, the vnodeops level does a lookup first.
 756          */
 757         if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent))) {
 758                 return error;
 759         }
 760         dp = args->dp;
 761         tp = args->trans;
 762         mp = dp->i_mount;
 763         block = bp->data;
 764         btp = xfs_dir2_block_tail_p(mp, block);
 765         blp = xfs_dir2_block_leaf_p(btp);
 766         /*
 767          * Point to the data entry using the leaf entry.
 768          */
 769         dep = (xfs_dir2_data_entry_t *)
 770               ((char *)block + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
 771         /*
 772          * Mark the data entry's space free.
 773          */
 774         needlog = needscan = 0;
 775         xfs_dir2_data_make_free(tp, bp,
 776                 (xfs_dir2_data_aoff_t)((char *)dep - (char *)block),
 777                 xfs_dir2_data_entsize(dep->namelen), &needlog, &needscan);
 778         /*
 779          * Fix up the block tail.
 780          */
 781         be32_add_cpu(&btp->stale, 1);
 782         xfs_dir2_block_log_tail(tp, bp);
 783         /*
 784          * Remove the leaf entry by marking it stale.
 785          */
 786         blp[ent].address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
 787         xfs_dir2_block_log_leaf(tp, bp, ent, ent);
 788         /*
 789          * Fix up bestfree, log the header if necessary.
 790          */
 791         if (needscan)
 792                 xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
 793         if (needlog)
 794                 xfs_dir2_data_log_header(tp, bp);
 795         xfs_dir2_data_check(dp, bp);
 796         /*
 797          * See if the size as a shortform is good enough.
 798          */
 799         if ((size = xfs_dir2_block_sfsize(dp, block, &sfh)) >
 800             XFS_IFORK_DSIZE(dp)) {
 801                 xfs_da_buf_done(bp);
 802                 return 0;
 803         }
 804         /*
 805          * If it works, do the conversion.
 806          */
 807         return xfs_dir2_block_to_sf(args, bp, size, &sfh);
 808 }
 809
 810 /*
 811  * Replace an entry in a V2 block directory.
 812  * Change the inode number to the new value.
 813  */
 814 int                                             /* error */
 815 xfs_dir2_block_replace(
 816         xfs_da_args_t           *args)          /* directory operation args */
 817 {
 818         xfs_dir2_block_t        *block;         /* block structure */
 819         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
 820         xfs_dabuf_t             *bp;            /* block buffer */
 821         xfs_dir2_block_tail_t   *btp;           /* block tail */
 822         xfs_dir2_data_entry_t   *dep;           /* block data entry */
 823         xfs_inode_t             *dp;            /* incore inode */
 824         int                     ent;            /* leaf entry index */
 825         int                     error;          /* error return value */
 826         xfs_mount_t             *mp;            /* filesystem mount point */
 827
 828         trace_xfs_dir2_block_replace(args);
 829
 830         /*
 831          * Lookup the entry in the directory.  Get buffer and entry index.
 832          * This will always succeed since the caller has already done a lookup.
 833          */
 834         if ((error = xfs_dir2_block_lookup_int(args, &bp, &ent))) {
 835                 return error;
 836         }
 837         dp = args->dp;
 838         mp = dp->i_mount;
 839         block = bp->data;
 840         btp = xfs_dir2_block_tail_p(mp, block);
 841         blp = xfs_dir2_block_leaf_p(btp);
 842         /*
 843          * Point to the data entry we need to change.
 844          */
 845         dep = (xfs_dir2_data_entry_t *)
 846               ((char *)block + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(blp[ent].address)));
 847         ASSERT(be64_to_cpu(dep->inumber) != args->inumber);
 848         /*
 849          * Change the inode number to the new value.
 850          */
 851         dep->inumber = cpu_to_be64(args->inumber);
 852         xfs_dir2_data_log_entry(args->trans, bp, dep);
 853         xfs_dir2_data_check(dp, bp);
 854         xfs_da_buf_done(bp);
 855         return 0;
 856 }
 857
 858 /*
 859  * Qsort comparison routine for the block leaf entries.
 860  */
 861 static int                                      /* sort order */
 862 xfs_dir2_block_sort(
 863         const void                      *a,     /* first leaf entry */
 864         const void                      *b)     /* second leaf entry */
 865 {
 866         const xfs_dir2_leaf_entry_t     *la;    /* first leaf entry */
 867         const xfs_dir2_leaf_entry_t     *lb;    /* second leaf entry */
 868
 869         la = a;
 870         lb = b;
 871         return be32_to_cpu(la->hashval) < be32_to_cpu(lb->hashval) ? -1 :
 872                 (be32_to_cpu(la->hashval) > be32_to_cpu(lb->hashval) ? 1 : 0);
 873 }
 874
 875 /*
 876  * Convert a V2 leaf directory to a V2 block directory if possible.
 877  */
 878 int                                             /* error */
 879 xfs_dir2_leaf_to_block(
 880         xfs_da_args_t           *args,          /* operation arguments */
 881         xfs_dabuf_t             *lbp,           /* leaf buffer */
 882         xfs_dabuf_t             *dbp)           /* data buffer */
 883 {
 884         __be16                  *bestsp;        /* leaf bests table */
 885         xfs_dir2_block_t        *block;         /* block structure */
 886         xfs_dir2_block_tail_t   *btp;           /* block tail */
 887         xfs_inode_t             *dp;            /* incore directory inode */
 888         xfs_dir2_data_unused_t  *dup;           /* unused data entry */
 889         int                     error;          /* error return value */
 890         int                     from;           /* leaf from index */
 891         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 892         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
 893         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
 894         xfs_mount_t             *mp;            /* file system mount point */
 895         int                     needlog;        /* need to log data header */
 896         int                     needscan;       /* need to scan for bestfree */
 897         xfs_dir2_sf_hdr_t       sfh;            /* shortform header */
 898         int                     size;           /* bytes used */
 899         __be16                  *tagp;          /* end of entry (tag) */
 900         int                     to;             /* block/leaf to index */
 901         xfs_trans_t             *tp;            /* transaction pointer */
 902
 903         trace_xfs_dir2_leaf_to_block(args);
 904
 905         dp = args->dp;
 906         tp = args->trans;
 907         mp = dp->i_mount;
 908         leaf = lbp->data;
 909         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
 910         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
 911         /*
 912          * If there are data blocks other than the first one, take this
 913          * opportunity to remove trailing empty data blocks that may have
 914          * been left behind during no-space-reservation operations.
 915          * These will show up in the leaf bests table.
 916          */
 917         while (dp->i_d.di_size > mp->m_dirblksize) {
 918                 bestsp = xfs_dir2_leaf_bests_p(ltp);
 919                 if (be16_to_cpu(bestsp[be32_to_cpu(ltp->bestcount) - 1]) ==
 920                     mp->m_dirblksize - (uint)sizeof(block->hdr)) {
 921                         if ((error =
 922                             xfs_dir2_leaf_trim_data(args, lbp,
 923                                     (xfs_dir2_db_t)(be32_to_cpu(ltp->bestcount) - 1))))
 924                                 goto out;
 925                 } else {
 926                         error = 0;
 927                         goto out;
 928                 }
 929         }
 930         /*
 931          * Read the data block if we don't already have it, give up if it fails.
 932          */
 933         if (dbp == NULL &&
 934             (error = xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &dbp,
 935                     XFS_DATA_FORK))) {
 936                 goto out;
 937         }
 938         block = dbp->data;
 939         ASSERT(be32_to_cpu(block->hdr.magic) == XFS_DIR2_DATA_MAGIC);
 940         /*
 941          * Size of the "leaf" area in the block.
 942          */
 943         size = (uint)sizeof(block->tail) +
 944                (uint)sizeof(*lep) * (be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale));
 945         /*
 946          * Look at the last data entry.
 947          */
 948         tagp = (__be16 *)((char *)block + mp->m_dirblksize) - 1;
 949         dup = (xfs_dir2_data_unused_t *)((char *)block + be16_to_cpu(*tagp));
 950         /*
 951          * If it's not free or is too short we can't do it.
 952          */
 953         if (be16_to_cpu(dup->freetag) != XFS_DIR2_DATA_FREE_TAG ||
 954             be16_to_cpu(dup->length) < size) {
 955                 error = 0;
 956                 goto out;
 957         }
 958         /*
 959          * Start converting it to block form.
 960          */
 961         block->hdr.magic = cpu_to_be32(XFS_DIR2_BLOCK_MAGIC);
 962         needlog = 1;
 963         needscan = 0;
 964         /*
 965          * Use up the space at the end of the block (blp/btp).
 966          */
 967         xfs_dir2_data_use_free(tp, dbp, dup, mp->m_dirblksize - size, size,
 968                 &needlog, &needscan);
 969         /*
 970          * Initialize the block tail.
 971          */
 972         btp = xfs_dir2_block_tail_p(mp, block);
 973         btp->count = cpu_to_be32(be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale));
 974         btp->stale = 0;
 975         xfs_dir2_block_log_tail(tp, dbp);
 976         /*
 977          * Initialize the block leaf area.  We compact out stale entries.
 978          */
 979         lep = xfs_dir2_block_leaf_p(btp);
 980         for (from = to = 0; from < be16_to_cpu(leaf->hdr.count); from++) {
 981                 if (be32_to_cpu(leaf->ents[from].address) == XFS_DIR2_NULL_DATAPTR)
 982                         continue;
 983                 lep[to++] = leaf->ents[from];
 984         }
 985         ASSERT(to == be32_to_cpu(btp->count));
 986         xfs_dir2_block_log_leaf(tp, dbp, 0, be32_to_cpu(btp->count) - 1);
 987         /*
 988          * Scan the bestfree if we need it and log the data block header.
 989          */
 990         if (needscan)
 991                 xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
 992         if (needlog)
 993                 xfs_dir2_data_log_header(tp, dbp);
 994         /*
 995          * Pitch the old leaf block.
 996          */
 997         error = xfs_da_shrink_inode(args, mp->m_dirleafblk, lbp);
 998         lbp = NULL;
 999         if (error) {
1000                 goto out;
1001         }
1002         /*
1003          * Now see if the resulting block can be shrunken to shortform.
1004          */
1005         if ((size = xfs_dir2_block_sfsize(dp, block, &sfh)) >
1006             XFS_IFORK_DSIZE(dp)) {
1007                 error = 0;
1008                 goto out;
1009         }
1010         return xfs_dir2_block_to_sf(args, dbp, size, &sfh);
1011 out:
1012         if (lbp)
1013                 xfs_da_buf_done(lbp);
1014         if (dbp)
1015                 xfs_da_buf_done(dbp);
1016         return error;
1017 }
1018
1019 /*
1020  * Convert the shortform directory to block form.
1021  */
1022 int                                             /* error */
1023 xfs_dir2_sf_to_block(
1024         xfs_da_args_t           *args)          /* operation arguments */
1025 {
1026         xfs_dir2_db_t           blkno;          /* dir-relative block # (0) */
1027         xfs_dir2_block_t        *block;         /* block structure */
1028         xfs_dir2_leaf_entry_t   *blp;           /* block leaf entries */
1029         xfs_dabuf_t             *bp;            /* block buffer */
1030         xfs_dir2_block_tail_t   *btp;           /* block tail pointer */
1031         char                    *buf;           /* sf buffer */
1032         int                     buf_len;
1033         xfs_dir2_data_entry_t   *dep;           /* data entry pointer */
1034         xfs_inode_t             *dp;            /* incore directory inode */
1035         int                     dummy;          /* trash */
1036         xfs_dir2_data_unused_t  *dup;           /* unused entry pointer */
1037         int                     endoffset;      /* end of data objects */
1038         int                     error;          /* error return value */
1039         int                     i;              /* index */
1040         xfs_mount_t             *mp;            /* filesystem mount point */
1041         int                     needlog;        /* need to log block header */
1042         int                     needscan;       /* need to scan block freespc */
1043         int                     newoffset;      /* offset from current entry */
1044         int                     offset;         /* target block offset */
1045         xfs_dir2_sf_entry_t     *sfep;          /* sf entry pointer */
1046         xfs_dir2_sf_t           *sfp;           /* shortform structure */
1047         __be16                  *tagp;          /* end of data entry */
1048         xfs_trans_t             *tp;            /* transaction pointer */
1049         struct xfs_name         name;
1050
1051         trace_xfs_dir2_sf_to_block(args);
1052
1053         dp = args->dp;
1054         tp = args->trans;
1055         mp = dp->i_mount;
1056         ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
1057         /*
1058          * Bomb out if the shortform directory is way too short.
1059          */
1060         if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) {
1061                 ASSERT(XFS_FORCED_SHUTDOWN(mp));
1062                 return XFS_ERROR(EIO);
1063         }
1064         ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
1065         ASSERT(dp->i_df.if_u1.if_data != NULL);
1066         sfp = (xfs_dir2_sf_t *)dp->i_df.if_u1.if_data;
1067         ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->hdr.i8count));
1068         /*
1069          * Copy the directory into the stack buffer.
1070          * Then pitch the incore inode data so we can make extents.
1071          */
1072
1073         buf_len = dp->i_df.if_bytes;
1074         buf = kmem_alloc(buf_len, KM_SLEEP);
1075
1076         memcpy(buf, sfp, buf_len);
1077         xfs_idata_realloc(dp, -buf_len, XFS_DATA_FORK);
1078         dp->i_d.di_size = 0;
1079         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1080         /*
1081          * Reset pointer - old sfp is gone.
1082          */
1083         sfp = (xfs_dir2_sf_t *)buf;
1084         /*
1085          * Add block 0 to the inode.
1086          */
1087         error = xfs_dir2_grow_inode(args, XFS_DIR2_DATA_SPACE, &blkno);
1088         if (error) {
1089                 kmem_free(buf);
1090                 return error;
1091         }
1092         /*
1093          * Initialize the data block.
1094          */
1095         error = xfs_dir2_data_init(args, blkno, &bp);
1096         if (error) {
1097                 kmem_free(buf);
1098                 return error;
1099         }
1100         block = bp->data;
1101         block->hdr.magic = cpu_to_be32(XFS_DIR2_BLOCK_MAGIC);
1102         /*
1103          * Compute size of block "tail" area.
1104          */
1105         i = (uint)sizeof(*btp) +
1106             (sfp->hdr.count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t);
1107         /*
1108          * The whole thing is initialized to free by the init routine.
1109          * Say we're using the leaf and tail area.
1110          */
1111         dup = (xfs_dir2_data_unused_t *)block->u;
1112         needlog = needscan = 0;
1113         xfs_dir2_data_use_free(tp, bp, dup, mp->m_dirblksize - i, i, &needlog,
1114                 &needscan);
1115         ASSERT(needscan == 0);
1116         /*
1117          * Fill in the tail.
1118          */
1119         btp = xfs_dir2_block_tail_p(mp, block);
1120         btp->count = cpu_to_be32(sfp->hdr.count + 2);   /* ., .. */
1121         btp->stale = 0;
1122         blp = xfs_dir2_block_leaf_p(btp);
1123         endoffset = (uint)((char *)blp - (char *)block);
1124         /*
1125          * Remove the freespace, we'll manage it.
1126          */
1127         xfs_dir2_data_use_free(tp, bp, dup,
1128                 (xfs_dir2_data_aoff_t)((char *)dup - (char *)block),
1129                 be16_to_cpu(dup->length), &needlog, &needscan);
1130         /*
1131          * Create entry for .
1132          */
1133         dep = (xfs_dir2_data_entry_t *)
1134               ((char *)block + XFS_DIR2_DATA_DOT_OFFSET);
1135         dep->inumber = cpu_to_be64(dp->i_ino);
1136         dep->namelen = 1;
1137         dep->name[0] = '.';
1138         tagp = xfs_dir2_data_entry_tag_p(dep);
1139         *tagp = cpu_to_be16((char *)dep - (char *)block);
1140         xfs_dir2_data_log_entry(tp, bp, dep);
1141         blp[0].hashval = cpu_to_be32(xfs_dir_hash_dot);
1142         blp[0].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
1143                                 (char *)dep - (char *)block));
1144         /*
1145          * Create entry for ..
1146          */
1147         dep = (xfs_dir2_data_entry_t *)
1148                 ((char *)block + XFS_DIR2_DATA_DOTDOT_OFFSET);
1149         dep->inumber = cpu_to_be64(xfs_dir2_sf_get_inumber(sfp, &sfp->hdr.parent));
1150         dep->namelen = 2;
1151         dep->name[0] = dep->name[1] = '.';
1152         tagp = xfs_dir2_data_entry_tag_p(dep);
1153         *tagp = cpu_to_be16((char *)dep - (char *)block);
1154         xfs_dir2_data_log_entry(tp, bp, dep);
1155         blp[1].hashval = cpu_to_be32(xfs_dir_hash_dotdot);
1156         blp[1].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
1157                                 (char *)dep - (char *)block));
1158         offset = XFS_DIR2_DATA_FIRST_OFFSET;
1159         /*
1160          * Loop over existing entries, stuff them in.
1161          */
1162         if ((i = 0) == sfp->hdr.count)
1163                 sfep = NULL;
1164         else
1165                 sfep = xfs_dir2_sf_firstentry(sfp);
1166         /*
1167          * Need to preserve the existing offset values in the sf directory.
1168          * Insert holes (unused entries) where necessary.
1169          */
1170         while (offset < endoffset) {
1171                 /*
1172                  * sfep is null when we reach the end of the list.
1173                  */
1174                 if (sfep == NULL)
1175                         newoffset = endoffset;
1176                 else
1177                         newoffset = xfs_dir2_sf_get_offset(sfep);
1178                 /*
1179                  * There should be a hole here, make one.
1180                  */
1181                 if (offset < newoffset) {
1182                         dup = (xfs_dir2_data_unused_t *)
1183                               ((char *)block + offset);
1184                         dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
1185                         dup->length = cpu_to_be16(newoffset - offset);
1186                         *xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16(
1187                                 ((char *)dup - (char *)block));
1188                         xfs_dir2_data_log_unused(tp, bp, dup);
1189                         (void)xfs_dir2_data_freeinsert((xfs_dir2_data_t *)block,
1190                                 dup, &dummy);
1191                         offset += be16_to_cpu(dup->length);
1192                         continue;
1193                 }
1194                 /*
1195                  * Copy a real entry.
1196                  */
1197                 dep = (xfs_dir2_data_entry_t *)((char *)block + newoffset);
1198                 dep->inumber = cpu_to_be64(xfs_dir2_sf_get_inumber(sfp,
1199                                 xfs_dir2_sf_inumberp(sfep)));
1200                 dep->namelen = sfep->namelen;
1201                 memcpy(dep->name, sfep->name, dep->namelen);
1202                 tagp = xfs_dir2_data_entry_tag_p(dep);
1203                 *tagp = cpu_to_be16((char *)dep - (char *)block);
1204                 xfs_dir2_data_log_entry(tp, bp, dep);
1205                 name.name = sfep->name;
1206                 name.len = sfep->namelen;
1207                 blp[2 + i].hashval = cpu_to_be32(mp->m_dirnameops->
1208                                                         hashname(&name));
1209                 blp[2 + i].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
1210                                                  (char *)dep - (char *)block));
1211                 offset = (int)((char *)(tagp + 1) - (char *)block);
1212                 if (++i == sfp->hdr.count)
1213                         sfep = NULL;
1214                 else
1215                         sfep = xfs_dir2_sf_nextentry(sfp, sfep);
1216         }
1217         /* Done with the temporary buffer */
1218         kmem_free(buf);
1219         /*
1220          * Sort the leaf entries by hash value.
1221          */
1222         xfs_sort(blp, be32_to_cpu(btp->count), sizeof(*blp), xfs_dir2_block_sort);
1223         /*
1224          * Log the leaf entry area and tail.
1225          * Already logged the header in data_init, ignore needlog.
1226          */
1227         ASSERT(needscan == 0);
1228         xfs_dir2_block_log_leaf(tp, bp, 0, be32_to_cpu(btp->count) - 1);
1229         xfs_dir2_block_log_tail(tp, bp);
1230         xfs_dir2_data_check(dp, bp);
1231         xfs_da_buf_done(bp);
1232         return 0;
1233 }