fs/xfs/xfs_dir2_leaf.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_bit.h"
  22 #include "xfs_log.h"
  23 #include "xfs_inum.h"
  24 #include "xfs_trans.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_ag.h"
  27 #include "xfs_dir2.h"
  28 #include "xfs_dmapi.h"
  29 #include "xfs_mount.h"
  30 #include "xfs_da_btree.h"
  31 #include "xfs_bmap_btree.h"
  32 #include "xfs_attr_sf.h"
  33 #include "xfs_dir2_sf.h"
  34 #include "xfs_dinode.h"
  35 #include "xfs_inode.h"
  36 #include "xfs_bmap.h"
  37 #include "xfs_dir2_data.h"
  38 #include "xfs_dir2_leaf.h"
  39 #include "xfs_dir2_block.h"
  40 #include "xfs_dir2_node.h"
  41 #include "xfs_dir2_trace.h"
  42 #include "xfs_error.h"
  43
  44 /*
  45  * Local function declarations.
  46  */
  47 #ifdef DEBUG
  48 static void xfs_dir2_leaf_check(xfs_inode_t *dp, xfs_dabuf_t *bp);
  49 #else
  50 #define xfs_dir2_leaf_check(dp, bp)
  51 #endif
  52 static int xfs_dir2_leaf_lookup_int(xfs_da_args_t *args, xfs_dabuf_t **lbpp,
  53                                     int *indexp, xfs_dabuf_t **dbpp);
  54 static void xfs_dir2_leaf_log_bests(struct xfs_trans *tp, struct xfs_dabuf *bp,
  55                                     int first, int last);
  56 static void xfs_dir2_leaf_log_tail(struct xfs_trans *tp, struct xfs_dabuf *bp);
  57
  58
  59 /*
  60  * Convert a block form directory to a leaf form directory.
  61  */
  62 int                                             /* error */
  63 xfs_dir2_block_to_leaf(
  64         xfs_da_args_t           *args,          /* operation arguments */
  65         xfs_dabuf_t             *dbp)           /* input block's buffer */
  66 {
  67         __be16                  *bestsp;        /* leaf's bestsp entries */
  68         xfs_dablk_t             blkno;          /* leaf block's bno */
  69         xfs_dir2_block_t        *block;         /* block structure */
  70         xfs_dir2_leaf_entry_t   *blp;           /* block's leaf entries */
  71         xfs_dir2_block_tail_t   *btp;           /* block's tail */
  72         xfs_inode_t             *dp;            /* incore directory inode */
  73         int                     error;          /* error return code */
  74         xfs_dabuf_t             *lbp;           /* leaf block's buffer */
  75         xfs_dir2_db_t           ldb;            /* leaf block's bno */
  76         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
  77         xfs_dir2_leaf_tail_t    *ltp;           /* leaf's tail */
  78         xfs_mount_t             *mp;            /* filesystem mount point */
  79         int                     needlog;        /* need to log block header */
  80         int                     needscan;       /* need to rescan bestfree */
  81         xfs_trans_t             *tp;            /* transaction pointer */
  82
  83         xfs_dir2_trace_args_b("block_to_leaf", args, dbp);
  84         dp = args->dp;
  85         mp = dp->i_mount;
  86         tp = args->trans;
  87         /*
  88          * Add the leaf block to the inode.
  89          * This interface will only put blocks in the leaf/node range.
  90          * Since that's empty now, we'll get the root (block 0 in range).
  91          */
  92         if ((error = xfs_da_grow_inode(args, &blkno))) {
  93                 return error;
  94         }
  95         ldb = xfs_dir2_da_to_db(mp, blkno);
  96         ASSERT(ldb == XFS_DIR2_LEAF_FIRSTDB(mp));
  97         /*
  98          * Initialize the leaf block, get a buffer for it.
  99          */
 100         if ((error = xfs_dir2_leaf_init(args, ldb, &lbp, XFS_DIR2_LEAF1_MAGIC))) {
 101                 return error;
 102         }
 103         ASSERT(lbp != NULL);
 104         leaf = lbp->data;
 105         block = dbp->data;
 106         xfs_dir2_data_check(dp, dbp);
 107         btp = xfs_dir2_block_tail_p(mp, block);
 108         blp = xfs_dir2_block_leaf_p(btp);
 109         /*
 110          * Set the counts in the leaf header.
 111          */
 112         leaf->hdr.count = cpu_to_be16(be32_to_cpu(btp->count));
 113         leaf->hdr.stale = cpu_to_be16(be32_to_cpu(btp->stale));
 114         /*
 115          * Could compact these but I think we always do the conversion
 116          * after squeezing out stale entries.
 117          */
 118         memcpy(leaf->ents, blp, be32_to_cpu(btp->count) * sizeof(xfs_dir2_leaf_entry_t));
 119         xfs_dir2_leaf_log_ents(tp, lbp, 0, be16_to_cpu(leaf->hdr.count) - 1);
 120         needscan = 0;
 121         needlog = 1;
 122         /*
 123          * Make the space formerly occupied by the leaf entries and block
 124          * tail be free.
 125          */
 126         xfs_dir2_data_make_free(tp, dbp,
 127                 (xfs_dir2_data_aoff_t)((char *)blp - (char *)block),
 128                 (xfs_dir2_data_aoff_t)((char *)block + mp->m_dirblksize -
 129                                        (char *)blp),
 130                 &needlog, &needscan);
 131         /*
 132          * Fix up the block header, make it a data block.
 133          */
 134         block->hdr.magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 135         if (needscan)
 136                 xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
 137         /*
 138          * Set up leaf tail and bests table.
 139          */
 140         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
 141         ltp->bestcount = cpu_to_be32(1);
 142         bestsp = xfs_dir2_leaf_bests_p(ltp);
 143         bestsp[0] =  block->hdr.bestfree[0].length;
 144         /*
 145          * Log the data header and leaf bests table.
 146          */
 147         if (needlog)
 148                 xfs_dir2_data_log_header(tp, dbp);
 149         xfs_dir2_leaf_check(dp, lbp);
 150         xfs_dir2_data_check(dp, dbp);
 151         xfs_dir2_leaf_log_bests(tp, lbp, 0, 0);
 152         xfs_da_buf_done(lbp);
 153         return 0;
 154 }
 155
 156 /*
 157  * Add an entry to a leaf form directory.
 158  */
 159 int                                             /* error */
 160 xfs_dir2_leaf_addname(
 161         xfs_da_args_t           *args)          /* operation arguments */
 162 {
 163         __be16                  *bestsp;        /* freespace table in leaf */
 164         int                     compact;        /* need to compact leaves */
 165         xfs_dir2_data_t         *data;          /* data block structure */
 166         xfs_dabuf_t             *dbp;           /* data block buffer */
 167         xfs_dir2_data_entry_t   *dep;           /* data block entry */
 168         xfs_inode_t             *dp;            /* incore directory inode */
 169         xfs_dir2_data_unused_t  *dup;           /* data unused entry */
 170         int                     error;          /* error return value */
 171         int                     grown;          /* allocated new data block */
 172         int                     highstale;      /* index of next stale leaf */
 173         int                     i;              /* temporary, index */
 174         int                     index;          /* leaf table position */
 175         xfs_dabuf_t             *lbp;           /* leaf's buffer */
 176         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 177         int                     length;         /* length of new entry */
 178         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry table pointer */
 179         int                     lfloglow;       /* low leaf logging index */
 180         int                     lfloghigh;      /* high leaf logging index */
 181         int                     lowstale;       /* index of prev stale leaf */
 182         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail pointer */
 183         xfs_mount_t             *mp;            /* filesystem mount point */
 184         int                     needbytes;      /* leaf block bytes needed */
 185         int                     needlog;        /* need to log data header */
 186         int                     needscan;       /* need to rescan data free */
 187         __be16                  *tagp;          /* end of data entry */
 188         xfs_trans_t             *tp;            /* transaction pointer */
 189         xfs_dir2_db_t           use_block;      /* data block number */
 190
 191         xfs_dir2_trace_args("leaf_addname", args);
 192         dp = args->dp;
 193         tp = args->trans;
 194         mp = dp->i_mount;
 195         /*
 196          * Read the leaf block.
 197          */
 198         error = xfs_da_read_buf(tp, dp, mp->m_dirleafblk, -1, &lbp,
 199                 XFS_DATA_FORK);
 200         if (error) {
 201                 return error;
 202         }
 203         ASSERT(lbp != NULL);
 204         /*
 205          * Look up the entry by hash value and name.
 206          * We know it's not there, our caller has already done a lookup.
 207          * So the index is of the entry to insert in front of.
 208          * But if there are dup hash values the index is of the first of those.
 209          */
 210         index = xfs_dir2_leaf_search_hash(args, lbp);
 211         leaf = lbp->data;
 212         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
 213         bestsp = xfs_dir2_leaf_bests_p(ltp);
 214         length = xfs_dir2_data_entsize(args->namelen);
 215         /*
 216          * See if there are any entries with the same hash value
 217          * and space in their block for the new entry.
 218          * This is good because it puts multiple same-hash value entries
 219          * in a data block, improving the lookup of those entries.
 220          */
 221         for (use_block = -1, lep = &leaf->ents[index];
 222              index < be16_to_cpu(leaf->hdr.count) && be32_to_cpu(lep->hashval) == args->hashval;
 223              index++, lep++) {
 224                 if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
 225                         continue;
 226                 i = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
 227                 ASSERT(i < be32_to_cpu(ltp->bestcount));
 228                 ASSERT(be16_to_cpu(bestsp[i]) != NULLDATAOFF);
 229                 if (be16_to_cpu(bestsp[i]) >= length) {
 230                         use_block = i;
 231                         break;
 232                 }
 233         }
 234         /*
 235          * Didn't find a block yet, linear search all the data blocks.
 236          */
 237         if (use_block == -1) {
 238                 for (i = 0; i < be32_to_cpu(ltp->bestcount); i++) {
 239                         /*
 240                          * Remember a block we see that's missing.
 241                          */
 242                         if (be16_to_cpu(bestsp[i]) == NULLDATAOFF && use_block == -1)
 243                                 use_block = i;
 244                         else if (be16_to_cpu(bestsp[i]) >= length) {
 245                                 use_block = i;
 246                                 break;
 247                         }
 248                 }
 249         }
 250         /*
 251          * How many bytes do we need in the leaf block?
 252          */
 253         needbytes =
 254                 (leaf->hdr.stale ? 0 : (uint)sizeof(leaf->ents[0])) +
 255                 (use_block != -1 ? 0 : (uint)sizeof(leaf->bests[0]));
 256         /*
 257          * Now kill use_block if it refers to a missing block, so we
 258          * can use it as an indication of allocation needed.
 259          */
 260         if (use_block != -1 && be16_to_cpu(bestsp[use_block]) == NULLDATAOFF)
 261                 use_block = -1;
 262         /*
 263          * If we don't have enough free bytes but we can make enough
 264          * by compacting out stale entries, we'll do that.
 265          */
 266         if ((char *)bestsp - (char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] < needbytes &&
 267             be16_to_cpu(leaf->hdr.stale) > 1) {
 268                 compact = 1;
 269         }
 270         /*
 271          * Otherwise if we don't have enough free bytes we need to
 272          * convert to node form.
 273          */
 274         else if ((char *)bestsp - (char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] <
 275                  needbytes) {
 276                 /*
 277                  * Just checking or no space reservation, give up.
 278                  */
 279                 if (args->justcheck || args->total == 0) {
 280                         xfs_da_brelse(tp, lbp);
 281                         return XFS_ERROR(ENOSPC);
 282                 }
 283                 /*
 284                  * Convert to node form.
 285                  */
 286                 error = xfs_dir2_leaf_to_node(args, lbp);
 287                 xfs_da_buf_done(lbp);
 288                 if (error)
 289                         return error;
 290                 /*
 291                  * Then add the new entry.
 292                  */
 293                 return xfs_dir2_node_addname(args);
 294         }
 295         /*
 296          * Otherwise it will fit without compaction.
 297          */
 298         else
 299                 compact = 0;
 300         /*
 301          * If just checking, then it will fit unless we needed to allocate
 302          * a new data block.
 303          */
 304         if (args->justcheck) {
 305                 xfs_da_brelse(tp, lbp);
 306                 return use_block == -1 ? XFS_ERROR(ENOSPC) : 0;
 307         }
 308         /*
 309          * If no allocations are allowed, return now before we've
 310          * changed anything.
 311          */
 312         if (args->total == 0 && use_block == -1) {
 313                 xfs_da_brelse(tp, lbp);
 314                 return XFS_ERROR(ENOSPC);
 315         }
 316         /*
 317          * Need to compact the leaf entries, removing stale ones.
 318          * Leave one stale entry behind - the one closest to our
 319          * insertion index - and we'll shift that one to our insertion
 320          * point later.
 321          */
 322         if (compact) {
 323                 xfs_dir2_leaf_compact_x1(lbp, &index, &lowstale, &highstale,
 324                         &lfloglow, &lfloghigh);
 325         }
 326         /*
 327          * There are stale entries, so we'll need log-low and log-high
 328          * impossibly bad values later.
 329          */
 330         else if (be16_to_cpu(leaf->hdr.stale)) {
 331                 lfloglow = be16_to_cpu(leaf->hdr.count);
 332                 lfloghigh = -1;
 333         }
 334         /*
 335          * If there was no data block space found, we need to allocate
 336          * a new one.
 337          */
 338         if (use_block == -1) {
 339                 /*
 340                  * Add the new data block.
 341                  */
 342                 if ((error = xfs_dir2_grow_inode(args, XFS_DIR2_DATA_SPACE,
 343                                 &use_block))) {
 344                         xfs_da_brelse(tp, lbp);
 345                         return error;
 346                 }
 347                 /*
 348                  * Initialize the block.
 349                  */
 350                 if ((error = xfs_dir2_data_init(args, use_block, &dbp))) {
 351                         xfs_da_brelse(tp, lbp);
 352                         return error;
 353                 }
 354                 /*
 355                  * If we're adding a new data block on the end we need to
 356                  * extend the bests table.  Copy it up one entry.
 357                  */
 358                 if (use_block >= be32_to_cpu(ltp->bestcount)) {
 359                         bestsp--;
 360                         memmove(&bestsp[0], &bestsp[1],
 361                                 be32_to_cpu(ltp->bestcount) * sizeof(bestsp[0]));
 362                         be32_add(&ltp->bestcount, 1);
 363                         xfs_dir2_leaf_log_tail(tp, lbp);
 364                         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
 365                 }
 366                 /*
 367                  * If we're filling in a previously empty block just log it.
 368                  */
 369                 else
 370                         xfs_dir2_leaf_log_bests(tp, lbp, use_block, use_block);
 371                 data = dbp->data;
 372                 bestsp[use_block] = data->hdr.bestfree[0].length;
 373                 grown = 1;
 374         }
 375         /*
 376          * Already had space in some data block.
 377          * Just read that one in.
 378          */
 379         else {
 380                 if ((error =
 381                     xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp, use_block),
 382                             -1, &dbp, XFS_DATA_FORK))) {
 383                         xfs_da_brelse(tp, lbp);
 384                         return error;
 385                 }
 386                 data = dbp->data;
 387                 grown = 0;
 388         }
 389         xfs_dir2_data_check(dp, dbp);
 390         /*
 391          * Point to the biggest freespace in our data block.
 392          */
 393         dup = (xfs_dir2_data_unused_t *)
 394               ((char *)data + be16_to_cpu(data->hdr.bestfree[0].offset));
 395         ASSERT(be16_to_cpu(dup->length) >= length);
 396         needscan = needlog = 0;
 397         /*
 398          * Mark the initial part of our freespace in use for the new entry.
 399          */
 400         xfs_dir2_data_use_free(tp, dbp, dup,
 401                 (xfs_dir2_data_aoff_t)((char *)dup - (char *)data), length,
 402                 &needlog, &needscan);
 403         /*
 404          * Initialize our new entry (at last).
 405          */
 406         dep = (xfs_dir2_data_entry_t *)dup;
 407         dep->inumber = cpu_to_be64(args->inumber);
 408         dep->namelen = args->namelen;
 409         memcpy(dep->name, args->name, dep->namelen);
 410         tagp = xfs_dir2_data_entry_tag_p(dep);
 411         *tagp = cpu_to_be16((char *)dep - (char *)data);
 412         /*
 413          * Need to scan fix up the bestfree table.
 414          */
 415         if (needscan)
 416                 xfs_dir2_data_freescan(mp, data, &needlog);
 417         /*
 418          * Need to log the data block's header.
 419          */
 420         if (needlog)
 421                 xfs_dir2_data_log_header(tp, dbp);
 422         xfs_dir2_data_log_entry(tp, dbp, dep);
 423         /*
 424          * If the bests table needs to be changed, do it.
 425          * Log the change unless we've already done that.
 426          */
 427         if (be16_to_cpu(bestsp[use_block]) != be16_to_cpu(data->hdr.bestfree[0].length)) {
 428                 bestsp[use_block] = data->hdr.bestfree[0].length;
 429                 if (!grown)
 430                         xfs_dir2_leaf_log_bests(tp, lbp, use_block, use_block);
 431         }
 432         /*
 433          * Now we need to make room to insert the leaf entry.
 434          * If there are no stale entries, we just insert a hole at index.
 435          */
 436         if (!leaf->hdr.stale) {
 437                 /*
 438                  * lep is still good as the index leaf entry.
 439                  */
 440                 if (index < be16_to_cpu(leaf->hdr.count))
 441                         memmove(lep + 1, lep,
 442                                 (be16_to_cpu(leaf->hdr.count) - index) * sizeof(*lep));
 443                 /*
 444                  * Record low and high logging indices for the leaf.
 445                  */
 446                 lfloglow = index;
 447                 lfloghigh = be16_to_cpu(leaf->hdr.count);
 448                 be16_add(&leaf->hdr.count, 1);
 449         }
 450         /*
 451          * There are stale entries.
 452          * We will use one of them for the new entry.
 453          * It's probably not at the right location, so we'll have to
 454          * shift some up or down first.
 455          */
 456         else {
 457                 /*
 458                  * If we didn't compact before, we need to find the nearest
 459                  * stale entries before and after our insertion point.
 460                  */
 461                 if (compact == 0) {
 462                         /*
 463                          * Find the first stale entry before the insertion
 464                          * point, if any.
 465                          */
 466                         for (lowstale = index - 1;
 467                              lowstale >= 0 &&
 468                                 be32_to_cpu(leaf->ents[lowstale].address) !=
 469                                 XFS_DIR2_NULL_DATAPTR;
 470                              lowstale--)
 471                                 continue;
 472                         /*
 473                          * Find the next stale entry at or after the insertion
 474                          * point, if any.   Stop if we go so far that the
 475                          * lowstale entry would be better.
 476                          */
 477                         for (highstale = index;
 478                              highstale < be16_to_cpu(leaf->hdr.count) &&
 479                                 be32_to_cpu(leaf->ents[highstale].address) !=
 480                                 XFS_DIR2_NULL_DATAPTR &&
 481                                 (lowstale < 0 ||
 482                                  index - lowstale - 1 >= highstale - index);
 483                              highstale++)
 484                                 continue;
 485                 }
 486                 /*
 487                  * If the low one is better, use it.
 488                  */
 489                 if (lowstale >= 0 &&
 490                     (highstale == be16_to_cpu(leaf->hdr.count) ||
 491                      index - lowstale - 1 < highstale - index)) {
 492                         ASSERT(index - lowstale - 1 >= 0);
 493                         ASSERT(be32_to_cpu(leaf->ents[lowstale].address) ==
 494                                XFS_DIR2_NULL_DATAPTR);
 495                         /*
 496                          * Copy entries up to cover the stale entry
 497                          * and make room for the new entry.
 498                          */
 499                         if (index - lowstale - 1 > 0)
 500                                 memmove(&leaf->ents[lowstale],
 501                                         &leaf->ents[lowstale + 1],
 502                                         (index - lowstale - 1) * sizeof(*lep));
 503                         lep = &leaf->ents[index - 1];
 504                         lfloglow = MIN(lowstale, lfloglow);
 505                         lfloghigh = MAX(index - 1, lfloghigh);
 506                 }
 507                 /*
 508                  * The high one is better, so use that one.
 509                  */
 510                 else {
 511                         ASSERT(highstale - index >= 0);
 512                         ASSERT(be32_to_cpu(leaf->ents[highstale].address) ==
 513                                XFS_DIR2_NULL_DATAPTR);
 514                         /*
 515                          * Copy entries down to cover the stale entry
 516                          * and make room for the new entry.
 517                          */
 518                         if (highstale - index > 0)
 519                                 memmove(&leaf->ents[index + 1],
 520                                         &leaf->ents[index],
 521                                         (highstale - index) * sizeof(*lep));
 522                         lep = &leaf->ents[index];
 523                         lfloglow = MIN(index, lfloglow);
 524                         lfloghigh = MAX(highstale, lfloghigh);
 525                 }
 526                 be16_add(&leaf->hdr.stale, -1);
 527         }
 528         /*
 529          * Fill in the new leaf entry.
 530          */
 531         lep->hashval = cpu_to_be32(args->hashval);
 532         lep->address = cpu_to_be32(xfs_dir2_db_off_to_dataptr(mp, use_block,
 533                                 be16_to_cpu(*tagp)));
 534         /*
 535          * Log the leaf fields and give up the buffers.
 536          */
 537         xfs_dir2_leaf_log_header(tp, lbp);
 538         xfs_dir2_leaf_log_ents(tp, lbp, lfloglow, lfloghigh);
 539         xfs_dir2_leaf_check(dp, lbp);
 540         xfs_da_buf_done(lbp);
 541         xfs_dir2_data_check(dp, dbp);
 542         xfs_da_buf_done(dbp);
 543         return 0;
 544 }
 545
 546 #ifdef DEBUG
 547 /*
 548  * Check the internal consistency of a leaf1 block.
 549  * Pop an assert if something is wrong.
 550  */
 551 void
 552 xfs_dir2_leaf_check(
 553         xfs_inode_t             *dp,            /* incore directory inode */
 554         xfs_dabuf_t             *bp)            /* leaf's buffer */
 555 {
 556         int                     i;              /* leaf index */
 557         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 558         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail pointer */
 559         xfs_mount_t             *mp;            /* filesystem mount point */
 560         int                     stale;          /* count of stale leaves */
 561
 562         leaf = bp->data;
 563         mp = dp->i_mount;
 564         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
 565         /*
 566          * This value is not restrictive enough.
 567          * Should factor in the size of the bests table as well.
 568          * We can deduce a value for that from di_size.
 569          */
 570         ASSERT(be16_to_cpu(leaf->hdr.count) <= xfs_dir2_max_leaf_ents(mp));
 571         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
 572         /*
 573          * Leaves and bests don't overlap.
 574          */
 575         ASSERT((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] <=
 576                (char *)xfs_dir2_leaf_bests_p(ltp));
 577         /*
 578          * Check hash value order, count stale entries.
 579          */
 580         for (i = stale = 0; i < be16_to_cpu(leaf->hdr.count); i++) {
 581                 if (i + 1 < be16_to_cpu(leaf->hdr.count))
 582                         ASSERT(be32_to_cpu(leaf->ents[i].hashval) <=
 583                                be32_to_cpu(leaf->ents[i + 1].hashval));
 584                 if (be32_to_cpu(leaf->ents[i].address) == XFS_DIR2_NULL_DATAPTR)
 585                         stale++;
 586         }
 587         ASSERT(be16_to_cpu(leaf->hdr.stale) == stale);
 588 }
 589 #endif  /* DEBUG */
 590
 591 /*
 592  * Compact out any stale entries in the leaf.
 593  * Log the header and changed leaf entries, if any.
 594  */
 595 void
 596 xfs_dir2_leaf_compact(
 597         xfs_da_args_t   *args,          /* operation arguments */
 598         xfs_dabuf_t     *bp)            /* leaf buffer */
 599 {
 600         int             from;           /* source leaf index */
 601         xfs_dir2_leaf_t *leaf;          /* leaf structure */
 602         int             loglow;         /* first leaf entry to log */
 603         int             to;             /* target leaf index */
 604
 605         leaf = bp->data;
 606         if (!leaf->hdr.stale) {
 607                 return;
 608         }
 609         /*
 610          * Compress out the stale entries in place.
 611          */
 612         for (from = to = 0, loglow = -1; from < be16_to_cpu(leaf->hdr.count); from++) {
 613                 if (be32_to_cpu(leaf->ents[from].address) == XFS_DIR2_NULL_DATAPTR)
 614                         continue;
 615                 /*
 616                  * Only actually copy the entries that are different.
 617                  */
 618                 if (from > to) {
 619                         if (loglow == -1)
 620                                 loglow = to;
 621                         leaf->ents[to] = leaf->ents[from];
 622                 }
 623                 to++;
 624         }
 625         /*
 626          * Update and log the header, log the leaf entries.
 627          */
 628         ASSERT(be16_to_cpu(leaf->hdr.stale) == from - to);
 629         be16_add(&leaf->hdr.count, -(be16_to_cpu(leaf->hdr.stale)));
 630         leaf->hdr.stale = 0;
 631         xfs_dir2_leaf_log_header(args->trans, bp);
 632         if (loglow != -1)
 633                 xfs_dir2_leaf_log_ents(args->trans, bp, loglow, to - 1);
 634 }
 635
 636 /*
 637  * Compact the leaf entries, removing stale ones.
 638  * Leave one stale entry behind - the one closest to our
 639  * insertion index - and the caller will shift that one to our insertion
 640  * point later.
 641  * Return new insertion index, where the remaining stale entry is,
 642  * and leaf logging indices.
 643  */
 644 void
 645 xfs_dir2_leaf_compact_x1(
 646         xfs_dabuf_t     *bp,            /* leaf buffer */
 647         int             *indexp,        /* insertion index */
 648         int             *lowstalep,     /* out: stale entry before us */
 649         int             *highstalep,    /* out: stale entry after us */
 650         int             *lowlogp,       /* out: low log index */
 651         int             *highlogp)      /* out: high log index */
 652 {
 653         int             from;           /* source copy index */
 654         int             highstale;      /* stale entry at/after index */
 655         int             index;          /* insertion index */
 656         int             keepstale;      /* source index of kept stale */
 657         xfs_dir2_leaf_t *leaf;          /* leaf structure */
 658         int             lowstale;       /* stale entry before index */
 659         int             newindex=0;     /* new insertion index */
 660         int             to;             /* destination copy index */
 661
 662         leaf = bp->data;
 663         ASSERT(be16_to_cpu(leaf->hdr.stale) > 1);
 664         index = *indexp;
 665         /*
 666          * Find the first stale entry before our index, if any.
 667          */
 668         for (lowstale = index - 1;
 669              lowstale >= 0 &&
 670                 be32_to_cpu(leaf->ents[lowstale].address) != XFS_DIR2_NULL_DATAPTR;
 671              lowstale--)
 672                 continue;
 673         /*
 674          * Find the first stale entry at or after our index, if any.
 675          * Stop if the answer would be worse than lowstale.
 676          */
 677         for (highstale = index;
 678              highstale < be16_to_cpu(leaf->hdr.count) &&
 679                 be32_to_cpu(leaf->ents[highstale].address) != XFS_DIR2_NULL_DATAPTR &&
 680                 (lowstale < 0 || index - lowstale > highstale - index);
 681              highstale++)
 682                 continue;
 683         /*
 684          * Pick the better of lowstale and highstale.
 685          */
 686         if (lowstale >= 0 &&
 687             (highstale == be16_to_cpu(leaf->hdr.count) ||
 688              index - lowstale <= highstale - index))
 689                 keepstale = lowstale;
 690         else
 691                 keepstale = highstale;
 692         /*
 693          * Copy the entries in place, removing all the stale entries
 694          * except keepstale.
 695          */
 696         for (from = to = 0; from < be16_to_cpu(leaf->hdr.count); from++) {
 697                 /*
 698                  * Notice the new value of index.
 699                  */
 700                 if (index == from)
 701                         newindex = to;
 702                 if (from != keepstale &&
 703                     be32_to_cpu(leaf->ents[from].address) == XFS_DIR2_NULL_DATAPTR) {
 704                         if (from == to)
 705                                 *lowlogp = to;
 706                         continue;
 707                 }
 708                 /*
 709                  * Record the new keepstale value for the insertion.
 710                  */
 711                 if (from == keepstale)
 712                         lowstale = highstale = to;
 713                 /*
 714                  * Copy only the entries that have moved.
 715                  */
 716                 if (from > to)
 717                         leaf->ents[to] = leaf->ents[from];
 718                 to++;
 719         }
 720         ASSERT(from > to);
 721         /*
 722          * If the insertion point was past the last entry,
 723          * set the new insertion point accordingly.
 724          */
 725         if (index == from)
 726                 newindex = to;
 727         *indexp = newindex;
 728         /*
 729          * Adjust the leaf header values.
 730          */
 731         be16_add(&leaf->hdr.count, -(from - to));
 732         leaf->hdr.stale = cpu_to_be16(1);
 733         /*
 734          * Remember the low/high stale value only in the "right"
 735          * direction.
 736          */
 737         if (lowstale >= newindex)
 738                 lowstale = -1;
 739         else
 740                 highstale = be16_to_cpu(leaf->hdr.count);
 741         *highlogp = be16_to_cpu(leaf->hdr.count) - 1;
 742         *lowstalep = lowstale;
 743         *highstalep = highstale;
 744 }
 745
 746 /*
 747  * Getdents (readdir) for leaf and node directories.
 748  * This reads the data blocks only, so is the same for both forms.
 749  */
 750 int                                             /* error */
 751 xfs_dir2_leaf_getdents(
 752         xfs_trans_t             *tp,            /* transaction pointer */
 753         xfs_inode_t             *dp,            /* incore directory inode */
 754         uio_t                   *uio,           /* I/O control & vectors */
 755         int                     *eofp,          /* out: reached end of dir */
 756         xfs_dirent_t            *dbp,           /* caller's buffer */
 757         xfs_dir2_put_t          put)            /* ABI formatting routine */
 758 {
 759         xfs_dabuf_t             *bp;            /* data block buffer */
 760         int                     byteoff;        /* offset in current block */
 761         xfs_dir2_db_t           curdb;          /* db for current block */
 762         xfs_dir2_off_t          curoff;         /* current overall offset */
 763         xfs_dir2_data_t         *data;          /* data block structure */
 764         xfs_dir2_data_entry_t   *dep;           /* data entry */
 765         xfs_dir2_data_unused_t  *dup;           /* unused entry */
 766         int                     eof;            /* reached end of directory */
 767         int                     error = 0;      /* error return value */
 768         int                     i;              /* temporary loop index */
 769         int                     j;              /* temporary loop index */
 770         int                     length;         /* temporary length value */
 771         xfs_bmbt_irec_t         *map;           /* map vector for blocks */
 772         xfs_extlen_t            map_blocks;     /* number of fsbs in map */
 773         xfs_dablk_t             map_off;        /* last mapped file offset */
 774         int                     map_size;       /* total entries in *map */
 775         int                     map_valid;      /* valid entries in *map */
 776         xfs_mount_t             *mp;            /* filesystem mount point */
 777         xfs_dir2_off_t          newoff;         /* new curoff after new blk */
 778         int                     nmap;           /* mappings to ask xfs_bmapi */
 779         xfs_dir2_put_args_t     *p;             /* formatting arg bundle */
 780         char                    *ptr = NULL;    /* pointer to current data */
 781         int                     ra_current;     /* number of read-ahead blks */
 782         int                     ra_index;       /* *map index for read-ahead */
 783         int                     ra_offset;      /* map entry offset for ra */
 784         int                     ra_want;        /* readahead count wanted */
 785
 786         /*
 787          * If the offset is at or past the largest allowed value,
 788          * give up right away, return eof.
 789          */
 790         if (uio->uio_offset >= XFS_DIR2_MAX_DATAPTR) {
 791                 *eofp = 1;
 792                 return 0;
 793         }
 794         mp = dp->i_mount;
 795         /*
 796          * Setup formatting arguments.
 797          */
 798         p = kmem_alloc(sizeof(*p), KM_SLEEP);
 799         p->dbp = dbp;
 800         p->put = put;
 801         p->uio = uio;
 802         /*
 803          * Set up to bmap a number of blocks based on the caller's
 804          * buffer size, the directory block size, and the filesystem
 805          * block size.
 806          */
 807         map_size =
 808                 howmany(uio->uio_resid + mp->m_dirblksize,
 809                         mp->m_sb.sb_blocksize);
 810         map = kmem_alloc(map_size * sizeof(*map), KM_SLEEP);
 811         map_valid = ra_index = ra_offset = ra_current = map_blocks = 0;
 812         bp = NULL;
 813         eof = 1;
 814         /*
 815          * Inside the loop we keep the main offset value as a byte offset
 816          * in the directory file.
 817          */
 818         curoff = xfs_dir2_dataptr_to_byte(mp, uio->uio_offset);
 819         /*
 820          * Force this conversion through db so we truncate the offset
 821          * down to get the start of the data block.
 822          */
 823         map_off = xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, curoff));
 824         /*
 825          * Loop over directory entries until we reach the end offset.
 826          * Get more blocks and readahead as necessary.
 827          */
 828         while (curoff < XFS_DIR2_LEAF_OFFSET) {
 829                 /*
 830                  * If we have no buffer, or we're off the end of the
 831                  * current buffer, need to get another one.
 832                  */
 833                 if (!bp || ptr >= (char *)bp->data + mp->m_dirblksize) {
 834                         /*
 835                          * If we have a buffer, we need to release it and
 836                          * take it out of the mapping.
 837                          */
 838                         if (bp) {
 839                                 xfs_da_brelse(tp, bp);
 840                                 bp = NULL;
 841                                 map_blocks -= mp->m_dirblkfsbs;
 842                                 /*
 843                                  * Loop to get rid of the extents for the
 844                                  * directory block.
 845                                  */
 846                                 for (i = mp->m_dirblkfsbs; i > 0; ) {
 847                                         j = MIN((int)map->br_blockcount, i);
 848                                         map->br_blockcount -= j;
 849                                         map->br_startblock += j;
 850                                         map->br_startoff += j;
 851                                         /*
 852                                          * If mapping is done, pitch it from
 853                                          * the table.
 854                                          */
 855                                         if (!map->br_blockcount && --map_valid)
 856                                                 memmove(&map[0], &map[1],
 857                                                         sizeof(map[0]) *
 858                                                         map_valid);
 859                                         i -= j;
 860                                 }
 861                         }
 862                         /*
 863                          * Recalculate the readahead blocks wanted.
 864                          */
 865                         ra_want = howmany(uio->uio_resid + mp->m_dirblksize,
 866                                           mp->m_sb.sb_blocksize) - 1;
 867                         /*
 868                          * If we don't have as many as we want, and we haven't
 869                          * run out of data blocks, get some more mappings.
 870                          */
 871                         if (1 + ra_want > map_blocks &&
 872                             map_off <
 873                             xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) {
 874                                 /*
 875                                  * Get more bmaps, fill in after the ones
 876                                  * we already have in the table.
 877                                  */
 878                                 nmap = map_size - map_valid;
 879                                 error = xfs_bmapi(tp, dp,
 880                                         map_off,
 881                                         xfs_dir2_byte_to_da(mp,
 882                                                 XFS_DIR2_LEAF_OFFSET) - map_off,
 883                                         XFS_BMAPI_METADATA, NULL, 0,
 884                                         &map[map_valid], &nmap, NULL, NULL);
 885                                 /*
 886                                  * Don't know if we should ignore this or
 887                                  * try to return an error.
 888                                  * The trouble with returning errors
 889                                  * is that readdir will just stop without
 890                                  * actually passing the error through.
 891                                  */
 892                                 if (error)
 893                                         break;  /* XXX */
 894                                 /*
 895                                  * If we got all the mappings we asked for,
 896                                  * set the final map offset based on the
 897                                  * last bmap value received.
 898                                  * Otherwise, we've reached the end.
 899                                  */
 900                                 if (nmap == map_size - map_valid)
 901                                         map_off =
 902                                         map[map_valid + nmap - 1].br_startoff +
 903                                         map[map_valid + nmap - 1].br_blockcount;
 904                                 else
 905                                         map_off =
 906                                                 xfs_dir2_byte_to_da(mp,
 907                                                         XFS_DIR2_LEAF_OFFSET);
 908                                 /*
 909                                  * Look for holes in the mapping, and
 910                                  * eliminate them.  Count up the valid blocks.
 911                                  */
 912                                 for (i = map_valid; i < map_valid + nmap; ) {
 913                                         if (map[i].br_startblock ==
 914                                             HOLESTARTBLOCK) {
 915                                                 nmap--;
 916                                                 length = map_valid + nmap - i;
 917                                                 if (length)
 918                                                         memmove(&map[i],
 919                                                                 &map[i + 1],
 920                                                                 sizeof(map[i]) *
 921                                                                 length);
 922                                         } else {
 923                                                 map_blocks +=
 924                                                         map[i].br_blockcount;
 925                                                 i++;
 926                                         }
 927                                 }
 928                                 map_valid += nmap;
 929                         }
 930                         /*
 931                          * No valid mappings, so no more data blocks.
 932                          */
 933                         if (!map_valid) {
 934                                 curoff = xfs_dir2_da_to_byte(mp, map_off);
 935                                 break;
 936                         }
 937                         /*
 938                          * Read the directory block starting at the first
 939                          * mapping.
 940                          */
 941                         curdb = xfs_dir2_da_to_db(mp, map->br_startoff);
 942                         error = xfs_da_read_buf(tp, dp, map->br_startoff,
 943                                 map->br_blockcount >= mp->m_dirblkfsbs ?
 944                                     XFS_FSB_TO_DADDR(mp, map->br_startblock) :
 945                                     -1,
 946                                 &bp, XFS_DATA_FORK);
 947                         /*
 948                          * Should just skip over the data block instead
 949                          * of giving up.
 950                          */
 951                         if (error)
 952                                 break;  /* XXX */
 953                         /*
 954                          * Adjust the current amount of read-ahead: we just
 955                          * read a block that was previously ra.
 956                          */
 957                         if (ra_current)
 958                                 ra_current -= mp->m_dirblkfsbs;
 959                         /*
 960                          * Do we need more readahead?
 961                          */
 962                         for (ra_index = ra_offset = i = 0;
 963                              ra_want > ra_current && i < map_blocks;
 964                              i += mp->m_dirblkfsbs) {
 965                                 ASSERT(ra_index < map_valid);
 966                                 /*
 967                                  * Read-ahead a contiguous directory block.
 968                                  */
 969                                 if (i > ra_current &&
 970                                     map[ra_index].br_blockcount >=
 971                                     mp->m_dirblkfsbs) {
 972                                         xfs_baread(mp->m_ddev_targp,
 973                                                 XFS_FSB_TO_DADDR(mp,
 974                                                    map[ra_index].br_startblock +
 975                                                    ra_offset),
 976                                                 (int)BTOBB(mp->m_dirblksize));
 977                                         ra_current = i;
 978                                 }
 979                                 /*
 980                                  * Read-ahead a non-contiguous directory block.
 981                                  * This doesn't use our mapping, but this
 982                                  * is a very rare case.
 983                                  */
 984                                 else if (i > ra_current) {
 985                                         (void)xfs_da_reada_buf(tp, dp,
 986                                                 map[ra_index].br_startoff +
 987                                                 ra_offset, XFS_DATA_FORK);
 988                                         ra_current = i;
 989                                 }
 990                                 /*
 991                                  * Advance offset through the mapping table.
 992                                  */
 993                                 for (j = 0; j < mp->m_dirblkfsbs; j++) {
 994                                         /*
 995                                          * The rest of this extent but not
 996                                          * more than a dir block.
 997                                          */
 998                                         length = MIN(mp->m_dirblkfsbs,
 999                                                 (int)(map[ra_index].br_blockcount -
1000                                                 ra_offset));
1001                                         j += length;
1002                                         ra_offset += length;
1003                                         /*
1004                                          * Advance to the next mapping if
1005                                          * this one is used up.
1006                                          */
1007                                         if (ra_offset ==
1008                                             map[ra_index].br_blockcount) {
1009                                                 ra_offset = 0;
1010                                                 ra_index++;
1011                                         }
1012                                 }
1013                         }
1014                         /*
1015                          * Having done a read, we need to set a new offset.
1016                          */
1017                         newoff = xfs_dir2_db_off_to_byte(mp, curdb, 0);
1018                         /*
1019                          * Start of the current block.
1020                          */
1021                         if (curoff < newoff)
1022                                 curoff = newoff;
1023                         /*
1024                          * Make sure we're in the right block.
1025                          */
1026                         else if (curoff > newoff)
1027                                 ASSERT(xfs_dir2_byte_to_db(mp, curoff) ==
1028                                        curdb);
1029                         data = bp->data;
1030                         xfs_dir2_data_check(dp, bp);
1031                         /*
1032                          * Find our position in the block.
1033                          */
1034                         ptr = (char *)&data->u;
1035                         byteoff = xfs_dir2_byte_to_off(mp, curoff);
1036                         /*
1037                          * Skip past the header.
1038                          */
1039                         if (byteoff == 0)
1040                                 curoff += (uint)sizeof(data->hdr);
1041                         /*
1042                          * Skip past entries until we reach our offset.
1043                          */
1044                         else {
1045                                 while ((char *)ptr - (char *)data < byteoff) {
1046                                         dup = (xfs_dir2_data_unused_t *)ptr;
1047
1048                                         if (be16_to_cpu(dup->freetag)
1049                                                   == XFS_DIR2_DATA_FREE_TAG) {
1050
1051                                                 length = be16_to_cpu(dup->length);
1052                                                 ptr += length;
1053                                                 continue;
1054                                         }
1055                                         dep = (xfs_dir2_data_entry_t *)ptr;
1056                                         length =
1057                                            xfs_dir2_data_entsize(dep->namelen);
1058                                         ptr += length;
1059                                 }
1060                                 /*
1061                                  * Now set our real offset.
1062                                  */
1063                                 curoff =
1064                                         xfs_dir2_db_off_to_byte(mp,
1065                                             xfs_dir2_byte_to_db(mp, curoff),
1066                                             (char *)ptr - (char *)data);
1067                                 if (ptr >= (char *)data + mp->m_dirblksize) {
1068                                         continue;
1069                                 }
1070                         }
1071                 }
1072                 /*
1073                  * We have a pointer to an entry.
1074                  * Is it a live one?
1075                  */
1076                 dup = (xfs_dir2_data_unused_t *)ptr;
1077                 /*
1078                  * No, it's unused, skip over it.
1079                  */
1080                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
1081                         length = be16_to_cpu(dup->length);
1082                         ptr += length;
1083                         curoff += length;
1084                         continue;
1085                 }
1086
1087                 /*
1088                  * Copy the entry into the putargs, and try formatting it.
1089                  */
1090                 dep = (xfs_dir2_data_entry_t *)ptr;
1091
1092                 p->namelen = dep->namelen;
1093
1094                 length = xfs_dir2_data_entsize(p->namelen);
1095
1096                 p->cook = xfs_dir2_byte_to_dataptr(mp, curoff + length);
1097
1098                 p->ino = be64_to_cpu(dep->inumber);
1099 #if XFS_BIG_INUMS
1100                 p->ino += mp->m_inoadd;
1101 #endif
1102                 p->name = (char *)dep->name;
1103
1104                 error = p->put(p);
1105
1106                 /*
1107                  * Won't fit.  Return to caller.
1108                  */
1109                 if (!p->done) {
1110                         eof = 0;
1111                         break;
1112                 }
1113                 /*
1114                  * Advance to next entry in the block.
1115                  */
1116                 ptr += length;
1117                 curoff += length;
1118         }
1119
1120         /*
1121          * All done.  Set output offset value to current offset.
1122          */
1123         *eofp = eof;
1124         if (curoff > xfs_dir2_dataptr_to_byte(mp, XFS_DIR2_MAX_DATAPTR))
1125                 uio->uio_offset = XFS_DIR2_MAX_DATAPTR;
1126         else
1127                 uio->uio_offset = xfs_dir2_byte_to_dataptr(mp, curoff);
1128         kmem_free(map, map_size * sizeof(*map));
1129         kmem_free(p, sizeof(*p));
1130         if (bp)
1131                 xfs_da_brelse(tp, bp);
1132         return error;
1133 }
1134
1135 /*
1136  * Initialize a new leaf block, leaf1 or leafn magic accepted.
1137  */
1138 int
1139 xfs_dir2_leaf_init(
1140         xfs_da_args_t           *args,          /* operation arguments */
1141         xfs_dir2_db_t           bno,            /* directory block number */
1142         xfs_dabuf_t             **bpp,          /* out: leaf buffer */
1143         int                     magic)          /* magic number for block */
1144 {
1145         xfs_dabuf_t             *bp;            /* leaf buffer */
1146         xfs_inode_t             *dp;            /* incore directory inode */
1147         int                     error;          /* error return code */
1148         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1149         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1150         xfs_mount_t             *mp;            /* filesystem mount point */
1151         xfs_trans_t             *tp;            /* transaction pointer */
1152
1153         dp = args->dp;
1154         ASSERT(dp != NULL);
1155         tp = args->trans;
1156         mp = dp->i_mount;
1157         ASSERT(bno >= XFS_DIR2_LEAF_FIRSTDB(mp) &&
1158                bno < XFS_DIR2_FREE_FIRSTDB(mp));
1159         /*
1160          * Get the buffer for the block.
1161          */
1162         error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, bno), -1, &bp,
1163                 XFS_DATA_FORK);
1164         if (error) {
1165                 return error;
1166         }
1167         ASSERT(bp != NULL);
1168         leaf = bp->data;
1169         /*
1170          * Initialize the header.
1171          */
1172         leaf->hdr.info.magic = cpu_to_be16(magic);
1173         leaf->hdr.info.forw = 0;
1174         leaf->hdr.info.back = 0;
1175         leaf->hdr.count = 0;
1176         leaf->hdr.stale = 0;
1177         xfs_dir2_leaf_log_header(tp, bp);
1178         /*
1179          * If it's a leaf-format directory initialize the tail.
1180          * In this case our caller has the real bests table to copy into
1181          * the block.
1182          */
1183         if (magic == XFS_DIR2_LEAF1_MAGIC) {
1184                 ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1185                 ltp->bestcount = 0;
1186                 xfs_dir2_leaf_log_tail(tp, bp);
1187         }
1188         *bpp = bp;
1189         return 0;
1190 }
1191
1192 /*
1193  * Log the bests entries indicated from a leaf1 block.
1194  */
1195 static void
1196 xfs_dir2_leaf_log_bests(
1197         xfs_trans_t             *tp,            /* transaction pointer */
1198         xfs_dabuf_t             *bp,            /* leaf buffer */
1199         int                     first,          /* first entry to log */
1200         int                     last)           /* last entry to log */
1201 {
1202         __be16                  *firstb;        /* pointer to first entry */
1203         __be16                  *lastb;         /* pointer to last entry */
1204         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1205         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1206
1207         leaf = bp->data;
1208         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
1209         ltp = xfs_dir2_leaf_tail_p(tp->t_mountp, leaf);
1210         firstb = xfs_dir2_leaf_bests_p(ltp) + first;
1211         lastb = xfs_dir2_leaf_bests_p(ltp) + last;
1212         xfs_da_log_buf(tp, bp, (uint)((char *)firstb - (char *)leaf),
1213                 (uint)((char *)lastb - (char *)leaf + sizeof(*lastb) - 1));
1214 }
1215
1216 /*
1217  * Log the leaf entries indicated from a leaf1 or leafn block.
1218  */
1219 void
1220 xfs_dir2_leaf_log_ents(
1221         xfs_trans_t             *tp,            /* transaction pointer */
1222         xfs_dabuf_t             *bp,            /* leaf buffer */
1223         int                     first,          /* first entry to log */
1224         int                     last)           /* last entry to log */
1225 {
1226         xfs_dir2_leaf_entry_t   *firstlep;      /* pointer to first entry */
1227         xfs_dir2_leaf_entry_t   *lastlep;       /* pointer to last entry */
1228         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1229
1230         leaf = bp->data;
1231         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC ||
1232                be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1233         firstlep = &leaf->ents[first];
1234         lastlep = &leaf->ents[last];
1235         xfs_da_log_buf(tp, bp, (uint)((char *)firstlep - (char *)leaf),
1236                 (uint)((char *)lastlep - (char *)leaf + sizeof(*lastlep) - 1));
1237 }
1238
1239 /*
1240  * Log the header of the leaf1 or leafn block.
1241  */
1242 void
1243 xfs_dir2_leaf_log_header(
1244         xfs_trans_t             *tp,            /* transaction pointer */
1245         xfs_dabuf_t             *bp)            /* leaf buffer */
1246 {
1247         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1248
1249         leaf = bp->data;
1250         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC ||
1251                be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1252         xfs_da_log_buf(tp, bp, (uint)((char *)&leaf->hdr - (char *)leaf),
1253                 (uint)(sizeof(leaf->hdr) - 1));
1254 }
1255
1256 /*
1257  * Log the tail of the leaf1 block.
1258  */
1259 STATIC void
1260 xfs_dir2_leaf_log_tail(
1261         xfs_trans_t             *tp,            /* transaction pointer */
1262         xfs_dabuf_t             *bp)            /* leaf buffer */
1263 {
1264         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1265         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1266         xfs_mount_t             *mp;            /* filesystem mount point */
1267
1268         mp = tp->t_mountp;
1269         leaf = bp->data;
1270         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
1271         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1272         xfs_da_log_buf(tp, bp, (uint)((char *)ltp - (char *)leaf),
1273                 (uint)(mp->m_dirblksize - 1));
1274 }
1275
1276 /*
1277  * Look up the entry referred to by args in the leaf format directory.
1278  * Most of the work is done by the xfs_dir2_leaf_lookup_int routine which
1279  * is also used by the node-format code.
1280  */
1281 int
1282 xfs_dir2_leaf_lookup(
1283         xfs_da_args_t           *args)          /* operation arguments */
1284 {
1285         xfs_dabuf_t             *dbp;           /* data block buffer */
1286         xfs_dir2_data_entry_t   *dep;           /* data block entry */
1287         xfs_inode_t             *dp;            /* incore directory inode */
1288         int                     error;          /* error return code */
1289         int                     index;          /* found entry index */
1290         xfs_dabuf_t             *lbp;           /* leaf buffer */
1291         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1292         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1293         xfs_trans_t             *tp;            /* transaction pointer */
1294
1295         xfs_dir2_trace_args("leaf_lookup", args);
1296         /*
1297          * Look up name in the leaf block, returning both buffers and index.
1298          */
1299         if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1300                 return error;
1301         }
1302         tp = args->trans;
1303         dp = args->dp;
1304         xfs_dir2_leaf_check(dp, lbp);
1305         leaf = lbp->data;
1306         /*
1307          * Get to the leaf entry and contained data entry address.
1308          */
1309         lep = &leaf->ents[index];
1310         /*
1311          * Point to the data entry.
1312          */
1313         dep = (xfs_dir2_data_entry_t *)
1314               ((char *)dbp->data +
1315                xfs_dir2_dataptr_to_off(dp->i_mount, be32_to_cpu(lep->address)));
1316         /*
1317          * Return the found inode number.
1318          */
1319         args->inumber = be64_to_cpu(dep->inumber);
1320         xfs_da_brelse(tp, dbp);
1321         xfs_da_brelse(tp, lbp);
1322         return XFS_ERROR(EEXIST);
1323 }
1324
1325 /*
1326  * Look up name/hash in the leaf block.
1327  * Fill in indexp with the found index, and dbpp with the data buffer.
1328  * If not found dbpp will be NULL, and ENOENT comes back.
1329  * lbpp will always be filled in with the leaf buffer unless there's an error.
1330  */
1331 static int                                      /* error */
1332 xfs_dir2_leaf_lookup_int(
1333         xfs_da_args_t           *args,          /* operation arguments */
1334         xfs_dabuf_t             **lbpp,         /* out: leaf buffer */
1335         int                     *indexp,        /* out: index in leaf block */
1336         xfs_dabuf_t             **dbpp)         /* out: data buffer */
1337 {
1338         xfs_dir2_db_t           curdb;          /* current data block number */
1339         xfs_dabuf_t             *dbp;           /* data buffer */
1340         xfs_dir2_data_entry_t   *dep;           /* data entry */
1341         xfs_inode_t             *dp;            /* incore directory inode */
1342         int                     error;          /* error return code */
1343         int                     index;          /* index in leaf block */
1344         xfs_dabuf_t             *lbp;           /* leaf buffer */
1345         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1346         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1347         xfs_mount_t             *mp;            /* filesystem mount point */
1348         xfs_dir2_db_t           newdb;          /* new data block number */
1349         xfs_trans_t             *tp;            /* transaction pointer */
1350
1351         dp = args->dp;
1352         tp = args->trans;
1353         mp = dp->i_mount;
1354         /*
1355          * Read the leaf block into the buffer.
1356          */
1357         if ((error =
1358             xfs_da_read_buf(tp, dp, mp->m_dirleafblk, -1, &lbp,
1359                     XFS_DATA_FORK))) {
1360                 return error;
1361         }
1362         *lbpp = lbp;
1363         leaf = lbp->data;
1364         xfs_dir2_leaf_check(dp, lbp);
1365         /*
1366          * Look for the first leaf entry with our hash value.
1367          */
1368         index = xfs_dir2_leaf_search_hash(args, lbp);
1369         /*
1370          * Loop over all the entries with the right hash value
1371          * looking to match the name.
1372          */
1373         for (lep = &leaf->ents[index], dbp = NULL, curdb = -1;
1374              index < be16_to_cpu(leaf->hdr.count) && be32_to_cpu(lep->hashval) == args->hashval;
1375              lep++, index++) {
1376                 /*
1377                  * Skip over stale leaf entries.
1378                  */
1379                 if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
1380                         continue;
1381                 /*
1382                  * Get the new data block number.
1383                  */
1384                 newdb = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
1385                 /*
1386                  * If it's not the same as the old data block number,
1387                  * need to pitch the old one and read the new one.
1388                  */
1389                 if (newdb != curdb) {
1390                         if (dbp)
1391                                 xfs_da_brelse(tp, dbp);
1392                         if ((error =
1393                             xfs_da_read_buf(tp, dp,
1394                                     xfs_dir2_db_to_da(mp, newdb), -1, &dbp,
1395                                     XFS_DATA_FORK))) {
1396                                 xfs_da_brelse(tp, lbp);
1397                                 return error;
1398                         }
1399                         xfs_dir2_data_check(dp, dbp);
1400                         curdb = newdb;
1401                 }
1402                 /*
1403                  * Point to the data entry.
1404                  */
1405                 dep = (xfs_dir2_data_entry_t *)
1406                       ((char *)dbp->data +
1407                        xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
1408                 /*
1409                  * If it matches then return it.
1410                  */
1411                 if (dep->namelen == args->namelen &&
1412                     dep->name[0] == args->name[0] &&
1413                     memcmp(dep->name, args->name, args->namelen) == 0) {
1414                         *dbpp = dbp;
1415                         *indexp = index;
1416                         return 0;
1417                 }
1418         }
1419         /*
1420          * No match found, return ENOENT.
1421          */
1422         ASSERT(args->oknoent);
1423         if (dbp)
1424                 xfs_da_brelse(tp, dbp);
1425         xfs_da_brelse(tp, lbp);
1426         return XFS_ERROR(ENOENT);
1427 }
1428
1429 /*
1430  * Remove an entry from a leaf format directory.
1431  */
1432 int                                             /* error */
1433 xfs_dir2_leaf_removename(
1434         xfs_da_args_t           *args)          /* operation arguments */
1435 {
1436         __be16                  *bestsp;        /* leaf block best freespace */
1437         xfs_dir2_data_t         *data;          /* data block structure */
1438         xfs_dir2_db_t           db;             /* data block number */
1439         xfs_dabuf_t             *dbp;           /* data block buffer */
1440         xfs_dir2_data_entry_t   *dep;           /* data entry structure */
1441         xfs_inode_t             *dp;            /* incore directory inode */
1442         int                     error;          /* error return code */
1443         xfs_dir2_db_t           i;              /* temporary data block # */
1444         int                     index;          /* index into leaf entries */
1445         xfs_dabuf_t             *lbp;           /* leaf buffer */
1446         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1447         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1448         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1449         xfs_mount_t             *mp;            /* filesystem mount point */
1450         int                     needlog;        /* need to log data header */
1451         int                     needscan;       /* need to rescan data frees */
1452         xfs_dir2_data_off_t     oldbest;        /* old value of best free */
1453         xfs_trans_t             *tp;            /* transaction pointer */
1454
1455         xfs_dir2_trace_args("leaf_removename", args);
1456         /*
1457          * Lookup the leaf entry, get the leaf and data blocks read in.
1458          */
1459         if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1460                 return error;
1461         }
1462         dp = args->dp;
1463         tp = args->trans;
1464         mp = dp->i_mount;
1465         leaf = lbp->data;
1466         data = dbp->data;
1467         xfs_dir2_data_check(dp, dbp);
1468         /*
1469          * Point to the leaf entry, use that to point to the data entry.
1470          */
1471         lep = &leaf->ents[index];
1472         db = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
1473         dep = (xfs_dir2_data_entry_t *)
1474               ((char *)data + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
1475         needscan = needlog = 0;
1476         oldbest = be16_to_cpu(data->hdr.bestfree[0].length);
1477         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1478         bestsp = xfs_dir2_leaf_bests_p(ltp);
1479         ASSERT(be16_to_cpu(bestsp[db]) == oldbest);
1480         /*
1481          * Mark the former data entry unused.
1482          */
1483         xfs_dir2_data_make_free(tp, dbp,
1484                 (xfs_dir2_data_aoff_t)((char *)dep - (char *)data),
1485                 xfs_dir2_data_entsize(dep->namelen), &needlog, &needscan);
1486         /*
1487          * We just mark the leaf entry stale by putting a null in it.
1488          */
1489         be16_add(&leaf->hdr.stale, 1);
1490         xfs_dir2_leaf_log_header(tp, lbp);
1491         lep->address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
1492         xfs_dir2_leaf_log_ents(tp, lbp, index, index);
1493         /*
1494          * Scan the freespace in the data block again if necessary,
1495          * log the data block header if necessary.
1496          */
1497         if (needscan)
1498                 xfs_dir2_data_freescan(mp, data, &needlog);
1499         if (needlog)
1500                 xfs_dir2_data_log_header(tp, dbp);
1501         /*
1502          * If the longest freespace in the data block has changed,
1503          * put the new value in the bests table and log that.
1504          */
1505         if (be16_to_cpu(data->hdr.bestfree[0].length) != oldbest) {
1506                 bestsp[db] = data->hdr.bestfree[0].length;
1507                 xfs_dir2_leaf_log_bests(tp, lbp, db, db);
1508         }
1509         xfs_dir2_data_check(dp, dbp);
1510         /*
1511          * If the data block is now empty then get rid of the data block.
1512          */
1513         if (be16_to_cpu(data->hdr.bestfree[0].length) ==
1514             mp->m_dirblksize - (uint)sizeof(data->hdr)) {
1515                 ASSERT(db != mp->m_dirdatablk);
1516                 if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
1517                         /*
1518                          * Nope, can't get rid of it because it caused
1519                          * allocation of a bmap btree block to do so.
1520                          * Just go on, returning success, leaving the
1521                          * empty block in place.
1522                          */
1523                         if (error == ENOSPC && args->total == 0) {
1524                                 xfs_da_buf_done(dbp);
1525                                 error = 0;
1526                         }
1527                         xfs_dir2_leaf_check(dp, lbp);
1528                         xfs_da_buf_done(lbp);
1529                         return error;
1530                 }
1531                 dbp = NULL;
1532                 /*
1533                  * If this is the last data block then compact the
1534                  * bests table by getting rid of entries.
1535                  */
1536                 if (db == be32_to_cpu(ltp->bestcount) - 1) {
1537                         /*
1538                          * Look for the last active entry (i).
1539                          */
1540                         for (i = db - 1; i > 0; i--) {
1541                                 if (be16_to_cpu(bestsp[i]) != NULLDATAOFF)
1542                                         break;
1543                         }
1544                         /*
1545                          * Copy the table down so inactive entries at the
1546                          * end are removed.
1547                          */
1548                         memmove(&bestsp[db - i], bestsp,
1549                                 (be32_to_cpu(ltp->bestcount) - (db - i)) * sizeof(*bestsp));
1550                         be32_add(&ltp->bestcount, -(db - i));
1551                         xfs_dir2_leaf_log_tail(tp, lbp);
1552                         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1553                 } else
1554                         bestsp[db] = cpu_to_be16(NULLDATAOFF);
1555         }
1556         /*
1557          * If the data block was not the first one, drop it.
1558          */
1559         else if (db != mp->m_dirdatablk && dbp != NULL) {
1560                 xfs_da_buf_done(dbp);
1561                 dbp = NULL;
1562         }
1563         xfs_dir2_leaf_check(dp, lbp);
1564         /*
1565          * See if we can convert to block form.
1566          */
1567         return xfs_dir2_leaf_to_block(args, lbp, dbp);
1568 }
1569
1570 /*
1571  * Replace the inode number in a leaf format directory entry.
1572  */
1573 int                                             /* error */
1574 xfs_dir2_leaf_replace(
1575         xfs_da_args_t           *args)          /* operation arguments */
1576 {
1577         xfs_dabuf_t             *dbp;           /* data block buffer */
1578         xfs_dir2_data_entry_t   *dep;           /* data block entry */
1579         xfs_inode_t             *dp;            /* incore directory inode */
1580         int                     error;          /* error return code */
1581         int                     index;          /* index of leaf entry */
1582         xfs_dabuf_t             *lbp;           /* leaf buffer */
1583         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1584         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1585         xfs_trans_t             *tp;            /* transaction pointer */
1586
1587         xfs_dir2_trace_args("leaf_replace", args);
1588         /*
1589          * Look up the entry.
1590          */
1591         if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
1592                 return error;
1593         }
1594         dp = args->dp;
1595         leaf = lbp->data;
1596         /*
1597          * Point to the leaf entry, get data address from it.
1598          */
1599         lep = &leaf->ents[index];
1600         /*
1601          * Point to the data entry.
1602          */
1603         dep = (xfs_dir2_data_entry_t *)
1604               ((char *)dbp->data +
1605                xfs_dir2_dataptr_to_off(dp->i_mount, be32_to_cpu(lep->address)));
1606         ASSERT(args->inumber != be64_to_cpu(dep->inumber));
1607         /*
1608          * Put the new inode number in, log it.
1609          */
1610         dep->inumber = cpu_to_be64(args->inumber);
1611         tp = args->trans;
1612         xfs_dir2_data_log_entry(tp, dbp, dep);
1613         xfs_da_buf_done(dbp);
1614         xfs_dir2_leaf_check(dp, lbp);
1615         xfs_da_brelse(tp, lbp);
1616         return 0;
1617 }
1618
1619 /*
1620  * Return index in the leaf block (lbp) which is either the first
1621  * one with this hash value, or if there are none, the insert point
1622  * for that hash value.
1623  */
1624 int                                             /* index value */
1625 xfs_dir2_leaf_search_hash(
1626         xfs_da_args_t           *args,          /* operation arguments */
1627         xfs_dabuf_t             *lbp)           /* leaf buffer */
1628 {
1629         xfs_dahash_t            hash=0;         /* hash from this entry */
1630         xfs_dahash_t            hashwant;       /* hash value looking for */
1631         int                     high;           /* high leaf index */
1632         int                     low;            /* low leaf index */
1633         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1634         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
1635         int                     mid=0;          /* current leaf index */
1636
1637         leaf = lbp->data;
1638 #ifndef __KERNEL__
1639         if (!leaf->hdr.count)
1640                 return 0;
1641 #endif
1642         /*
1643          * Note, the table cannot be empty, so we have to go through the loop.
1644          * Binary search the leaf entries looking for our hash value.
1645          */
1646         for (lep = leaf->ents, low = 0, high = be16_to_cpu(leaf->hdr.count) - 1,
1647                 hashwant = args->hashval;
1648              low <= high; ) {
1649                 mid = (low + high) >> 1;
1650                 if ((hash = be32_to_cpu(lep[mid].hashval)) == hashwant)
1651                         break;
1652                 if (hash < hashwant)
1653                         low = mid + 1;
1654                 else
1655                         high = mid - 1;
1656         }
1657         /*
1658          * Found one, back up through all the equal hash values.
1659          */
1660         if (hash == hashwant) {
1661                 while (mid > 0 && be32_to_cpu(lep[mid - 1].hashval) == hashwant) {
1662                         mid--;
1663                 }
1664         }
1665         /*
1666          * Need to point to an entry higher than ours.
1667          */
1668         else if (hash < hashwant)
1669                 mid++;
1670         return mid;
1671 }
1672
1673 /*
1674  * Trim off a trailing data block.  We know it's empty since the leaf
1675  * freespace table says so.
1676  */
1677 int                                             /* error */
1678 xfs_dir2_leaf_trim_data(
1679         xfs_da_args_t           *args,          /* operation arguments */
1680         xfs_dabuf_t             *lbp,           /* leaf buffer */
1681         xfs_dir2_db_t           db)             /* data block number */
1682 {
1683         __be16                  *bestsp;        /* leaf bests table */
1684 #ifdef DEBUG
1685         xfs_dir2_data_t         *data;          /* data block structure */
1686 #endif
1687         xfs_dabuf_t             *dbp;           /* data block buffer */
1688         xfs_inode_t             *dp;            /* incore directory inode */
1689         int                     error;          /* error return value */
1690         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1691         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
1692         xfs_mount_t             *mp;            /* filesystem mount point */
1693         xfs_trans_t             *tp;            /* transaction pointer */
1694
1695         dp = args->dp;
1696         mp = dp->i_mount;
1697         tp = args->trans;
1698         /*
1699          * Read the offending data block.  We need its buffer.
1700          */
1701         if ((error = xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp, db), -1, &dbp,
1702                         XFS_DATA_FORK))) {
1703                 return error;
1704         }
1705 #ifdef DEBUG
1706         data = dbp->data;
1707         ASSERT(be32_to_cpu(data->hdr.magic) == XFS_DIR2_DATA_MAGIC);
1708 #endif
1709         /* this seems to be an error
1710          * data is only valid if DEBUG is defined?
1711          * RMC 09/08/1999
1712          */
1713
1714         leaf = lbp->data;
1715         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1716         ASSERT(be16_to_cpu(data->hdr.bestfree[0].length) ==
1717                mp->m_dirblksize - (uint)sizeof(data->hdr));
1718         ASSERT(db == be32_to_cpu(ltp->bestcount) - 1);
1719         /*
1720          * Get rid of the data block.
1721          */
1722         if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
1723                 ASSERT(error != ENOSPC);
1724                 xfs_da_brelse(tp, dbp);
1725                 return error;
1726         }
1727         /*
1728          * Eliminate the last bests entry from the table.
1729          */
1730         bestsp = xfs_dir2_leaf_bests_p(ltp);
1731         be32_add(&ltp->bestcount, -1);
1732         memmove(&bestsp[1], &bestsp[0], be32_to_cpu(ltp->bestcount) * sizeof(*bestsp));
1733         xfs_dir2_leaf_log_tail(tp, lbp);
1734         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1735         return 0;
1736 }
1737
1738 /*
1739  * Convert node form directory to leaf form directory.
1740  * The root of the node form dir needs to already be a LEAFN block.
1741  * Just return if we can't do anything.
1742  */
1743 int                                             /* error */
1744 xfs_dir2_node_to_leaf(
1745         xfs_da_state_t          *state)         /* directory operation state */
1746 {
1747         xfs_da_args_t           *args;          /* operation arguments */
1748         xfs_inode_t             *dp;            /* incore directory inode */
1749         int                     error;          /* error return code */
1750         xfs_dabuf_t             *fbp;           /* buffer for freespace block */
1751         xfs_fileoff_t           fo;             /* freespace file offset */
1752         xfs_dir2_free_t         *free;          /* freespace structure */
1753         xfs_dabuf_t             *lbp;           /* buffer for leaf block */
1754         xfs_dir2_leaf_tail_t    *ltp;           /* tail of leaf structure */
1755         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1756         xfs_mount_t             *mp;            /* filesystem mount point */
1757         int                     rval;           /* successful free trim? */
1758         xfs_trans_t             *tp;            /* transaction pointer */
1759
1760         /*
1761          * There's more than a leaf level in the btree, so there must
1762          * be multiple leafn blocks.  Give up.
1763          */
1764         if (state->path.active > 1)
1765                 return 0;
1766         args = state->args;
1767         xfs_dir2_trace_args("node_to_leaf", args);
1768         mp = state->mp;
1769         dp = args->dp;
1770         tp = args->trans;
1771         /*
1772          * Get the last offset in the file.
1773          */
1774         if ((error = xfs_bmap_last_offset(tp, dp, &fo, XFS_DATA_FORK))) {
1775                 return error;
1776         }
1777         fo -= mp->m_dirblkfsbs;
1778         /*
1779          * If there are freespace blocks other than the first one,
1780          * take this opportunity to remove trailing empty freespace blocks
1781          * that may have been left behind during no-space-reservation
1782          * operations.
1783          */
1784         while (fo > mp->m_dirfreeblk) {
1785                 if ((error = xfs_dir2_node_trim_free(args, fo, &rval))) {
1786                         return error;
1787                 }
1788                 if (rval)
1789                         fo -= mp->m_dirblkfsbs;
1790                 else
1791                         return 0;
1792         }
1793         /*
1794          * Now find the block just before the freespace block.
1795          */
1796         if ((error = xfs_bmap_last_before(tp, dp, &fo, XFS_DATA_FORK))) {
1797                 return error;
1798         }
1799         /*
1800          * If it's not the single leaf block, give up.
1801          */
1802         if (XFS_FSB_TO_B(mp, fo) > XFS_DIR2_LEAF_OFFSET + mp->m_dirblksize)
1803                 return 0;
1804         lbp = state->path.blk[0].bp;
1805         leaf = lbp->data;
1806         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1807         /*
1808          * Read the freespace block.
1809          */
1810         if ((error = xfs_da_read_buf(tp, dp, mp->m_dirfreeblk, -1, &fbp,
1811                         XFS_DATA_FORK))) {
1812                 return error;
1813         }
1814         free = fbp->data;
1815         ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
1816         ASSERT(!free->hdr.firstdb);
1817         /*
1818          * Now see if the leafn and free data will fit in a leaf1.
1819          * If not, release the buffer and give up.
1820          */
1821         if ((uint)sizeof(leaf->hdr) +
1822             (be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale)) * (uint)sizeof(leaf->ents[0]) +
1823             be32_to_cpu(free->hdr.nvalid) * (uint)sizeof(leaf->bests[0]) +
1824             (uint)sizeof(leaf->tail) >
1825             mp->m_dirblksize) {
1826                 xfs_da_brelse(tp, fbp);
1827                 return 0;
1828         }
1829         /*
1830          * If the leaf has any stale entries in it, compress them out.
1831          * The compact routine will log the header.
1832          */
1833         if (be16_to_cpu(leaf->hdr.stale))
1834                 xfs_dir2_leaf_compact(args, lbp);
1835         else
1836                 xfs_dir2_leaf_log_header(tp, lbp);
1837         leaf->hdr.info.magic = cpu_to_be16(XFS_DIR2_LEAF1_MAGIC);
1838         /*
1839          * Set up the leaf tail from the freespace block.
1840          */
1841         ltp = xfs_dir2_leaf_tail_p(mp, leaf);
1842         ltp->bestcount = free->hdr.nvalid;
1843         /*
1844          * Set up the leaf bests table.
1845          */
1846         memcpy(xfs_dir2_leaf_bests_p(ltp), free->bests,
1847                 be32_to_cpu(ltp->bestcount) * sizeof(leaf->bests[0]));
1848         xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
1849         xfs_dir2_leaf_log_tail(tp, lbp);
1850         xfs_dir2_leaf_check(dp, lbp);
1851         /*
1852          * Get rid of the freespace block.
1853          */
1854         error = xfs_dir2_shrink_inode(args, XFS_DIR2_FREE_FIRSTDB(mp), fbp);
1855         if (error) {
1856                 /*
1857                  * This can't fail here because it can only happen when
1858                  * punching out the middle of an extent, and this is an
1859                  * isolated block.
1860                  */
1861                 ASSERT(error != ENOSPC);
1862                 return error;
1863         }
1864         fbp = NULL;
1865         /*
1866          * Now see if we can convert the single-leaf directory
1867          * down to a block form directory.
1868          * This routine always kills the dabuf for the leaf, so
1869          * eliminate it from the path.
1870          */
1871         error = xfs_dir2_leaf_to_block(args, lbp, NULL);
1872         state->path.blk[0].bp = NULL;
1873         return error;
1874 }