sys/gnu/fs/xfs/xfs_dir2_node.c

   1 /*
   2  * Copyright (c) 2000-2005 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_dir.h"
  26 #include "xfs_dir2.h"
  27 #include "xfs_dmapi.h"
  28 #include "xfs_mount.h"
  29 #include "xfs_da_btree.h"
  30 #include "xfs_bmap_btree.h"
  31 #include "xfs_dir_sf.h"
  32 #include "xfs_dir2_sf.h"
  33 #include "xfs_attr_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  * Function declarations.
  46  */
  47 static void xfs_dir2_free_log_header(xfs_trans_t *tp, xfs_dabuf_t *bp);
  48 static int xfs_dir2_leafn_add(xfs_dabuf_t *bp, xfs_da_args_t *args, int index);
  49 #ifdef DEBUG
  50 static void xfs_dir2_leafn_check(xfs_inode_t *dp, xfs_dabuf_t *bp);
  51 #else
  52 #define xfs_dir2_leafn_check(dp, bp)
  53 #endif
  54 static void xfs_dir2_leafn_moveents(xfs_da_args_t *args, xfs_dabuf_t *bp_s,
  55                                     int start_s, xfs_dabuf_t *bp_d, int start_d,
  56                                     int count);
  57 static void xfs_dir2_leafn_rebalance(xfs_da_state_t *state,
  58                                      xfs_da_state_blk_t *blk1,
  59                                      xfs_da_state_blk_t *blk2);
  60 static int xfs_dir2_leafn_remove(xfs_da_args_t *args, xfs_dabuf_t *bp,
  61                                  int index, xfs_da_state_blk_t *dblk,
  62                                  int *rval);
  63 static int xfs_dir2_node_addname_int(xfs_da_args_t *args,
  64                                      xfs_da_state_blk_t *fblk);
  65
  66 /*
  67  * Log entries from a freespace block.
  68  */
  69 void
  70 xfs_dir2_free_log_bests(
  71         xfs_trans_t             *tp,            /* transaction pointer */
  72         xfs_dabuf_t             *bp,            /* freespace buffer */
  73         int                     first,          /* first entry to log */
  74         int                     last)           /* last entry to log */
  75 {
  76         xfs_dir2_free_t         *free;          /* freespace structure */
  77
  78         free = bp->data;
  79         ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
  80         xfs_da_log_buf(tp, bp,
  81                 (uint)((char *)&free->bests[first] - (char *)free),
  82                 (uint)((char *)&free->bests[last] - (char *)free +
  83                        sizeof(free->bests[0]) - 1));
  84 }
  85
  86 /*
  87  * Log header from a freespace block.
  88  */
  89 static void
  90 xfs_dir2_free_log_header(
  91         xfs_trans_t             *tp,            /* transaction pointer */
  92         xfs_dabuf_t             *bp)            /* freespace buffer */
  93 {
  94         xfs_dir2_free_t         *free;          /* freespace structure */
  95
  96         free = bp->data;
  97         ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
  98         xfs_da_log_buf(tp, bp, (uint)((char *)&free->hdr - (char *)free),
  99                 (uint)(sizeof(xfs_dir2_free_hdr_t) - 1));
 100 }
 101
 102 /*
 103  * Convert a leaf-format directory to a node-format directory.
 104  * We need to change the magic number of the leaf block, and copy
 105  * the freespace table out of the leaf block into its own block.
 106  */
 107 int                                             /* error */
 108 xfs_dir2_leaf_to_node(
 109         xfs_da_args_t           *args,          /* operation arguments */
 110         xfs_dabuf_t             *lbp)           /* leaf buffer */
 111 {
 112         xfs_inode_t             *dp;            /* incore directory inode */
 113         int                     error;          /* error return value */
 114         xfs_dabuf_t             *fbp;           /* freespace buffer */
 115         xfs_dir2_db_t           fdb;            /* freespace block number */
 116         xfs_dir2_free_t         *free;          /* freespace structure */
 117         __be16                  *from;          /* pointer to freespace entry */
 118         int                     i;              /* leaf freespace index */
 119         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 120         xfs_dir2_leaf_tail_t    *ltp;           /* leaf tail structure */
 121         xfs_mount_t             *mp;            /* filesystem mount point */
 122         int                     n;              /* count of live freespc ents */
 123         xfs_dir2_data_off_t     off;            /* freespace entry value */
 124         __be16                  *to;            /* pointer to freespace entry */
 125         xfs_trans_t             *tp;            /* transaction pointer */
 126
 127         xfs_dir2_trace_args_b("leaf_to_node", args, lbp);
 128         dp = args->dp;
 129         mp = dp->i_mount;
 130         tp = args->trans;
 131         /*
 132          * Add a freespace block to the directory.
 133          */
 134         if ((error = xfs_dir2_grow_inode(args, XFS_DIR2_FREE_SPACE, &fdb))) {
 135                 return error;
 136         }
 137         ASSERT(fdb == XFS_DIR2_FREE_FIRSTDB(mp));
 138         /*
 139          * Get the buffer for the new freespace block.
 140          */
 141         if ((error = xfs_da_get_buf(tp, dp, XFS_DIR2_DB_TO_DA(mp, fdb), -1, &fbp,
 142                         XFS_DATA_FORK))) {
 143                 return error;
 144         }
 145         ASSERT(fbp != NULL);
 146         free = fbp->data;
 147         leaf = lbp->data;
 148         ltp = XFS_DIR2_LEAF_TAIL_P(mp, leaf);
 149         /*
 150          * Initialize the freespace block header.
 151          */
 152         free->hdr.magic = cpu_to_be32(XFS_DIR2_FREE_MAGIC);
 153         free->hdr.firstdb = 0;
 154         ASSERT(be32_to_cpu(ltp->bestcount) <= (uint)dp->i_d.di_size / mp->m_dirblksize);
 155         free->hdr.nvalid = ltp->bestcount;
 156         /*
 157          * Copy freespace entries from the leaf block to the new block.
 158          * Count active entries.
 159          */
 160         for (i = n = 0, from = XFS_DIR2_LEAF_BESTS_P(ltp), to = free->bests;
 161              i < be32_to_cpu(ltp->bestcount); i++, from++, to++) {
 162                 if ((off = be16_to_cpu(*from)) != NULLDATAOFF)
 163                         n++;
 164                 *to = cpu_to_be16(off);
 165         }
 166         free->hdr.nused = cpu_to_be32(n);
 167         leaf->hdr.info.magic = cpu_to_be16(XFS_DIR2_LEAFN_MAGIC);
 168         /*
 169          * Log everything.
 170          */
 171         xfs_dir2_leaf_log_header(tp, lbp);
 172         xfs_dir2_free_log_header(tp, fbp);
 173         xfs_dir2_free_log_bests(tp, fbp, 0, be32_to_cpu(free->hdr.nvalid) - 1);
 174         xfs_da_buf_done(fbp);
 175         xfs_dir2_leafn_check(dp, lbp);
 176         return 0;
 177 }
 178
 179 /*
 180  * Add a leaf entry to a leaf block in a node-form directory.
 181  * The other work necessary is done from the caller.
 182  */
 183 static int                                      /* error */
 184 xfs_dir2_leafn_add(
 185         xfs_dabuf_t             *bp,            /* leaf buffer */
 186         xfs_da_args_t           *args,          /* operation arguments */
 187         int                     index)          /* insertion pt for new entry */
 188 {
 189         int                     compact;        /* compacting stale leaves */
 190         xfs_inode_t             *dp;            /* incore directory inode */
 191         int                     highstale;      /* next stale entry */
 192         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 193         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
 194         int                     lfloghigh;      /* high leaf entry logging */
 195         int                     lfloglow;       /* low leaf entry logging */
 196         int                     lowstale;       /* previous stale entry */
 197         xfs_mount_t             *mp;            /* filesystem mount point */
 198         xfs_trans_t             *tp;            /* transaction pointer */
 199
 200         xfs_dir2_trace_args_sb("leafn_add", args, index, bp);
 201         dp = args->dp;
 202         mp = dp->i_mount;
 203         tp = args->trans;
 204         leaf = bp->data;
 205
 206         /*
 207          * Quick check just to make sure we are not going to index
 208          * into other peoples memory
 209          */
 210         if (index < 0)
 211                 return XFS_ERROR(EFSCORRUPTED);
 212
 213         /*
 214          * If there are already the maximum number of leaf entries in
 215          * the block, if there are no stale entries it won't fit.
 216          * Caller will do a split.  If there are stale entries we'll do
 217          * a compact.
 218          */
 219
 220         if (be16_to_cpu(leaf->hdr.count) == XFS_DIR2_MAX_LEAF_ENTS(mp)) {
 221                 if (!leaf->hdr.stale)
 222                         return XFS_ERROR(ENOSPC);
 223                 compact = be16_to_cpu(leaf->hdr.stale) > 1;
 224         } else
 225                 compact = 0;
 226         ASSERT(index == 0 || be32_to_cpu(leaf->ents[index - 1].hashval) <= args->hashval);
 227         ASSERT(index == be16_to_cpu(leaf->hdr.count) ||
 228                be32_to_cpu(leaf->ents[index].hashval) >= args->hashval);
 229
 230         if (args->justcheck)
 231                 return 0;
 232
 233         /*
 234          * Compact out all but one stale leaf entry.  Leaves behind
 235          * the entry closest to index.
 236          */
 237         if (compact) {
 238                 xfs_dir2_leaf_compact_x1(bp, &index, &lowstale, &highstale,
 239                         &lfloglow, &lfloghigh);
 240         }
 241         /*
 242          * Set impossible logging indices for this case.
 243          */
 244         else if (leaf->hdr.stale) {
 245                 lfloglow = be16_to_cpu(leaf->hdr.count);
 246                 lfloghigh = -1;
 247         }
 248         /*
 249          * No stale entries, just insert a space for the new entry.
 250          */
 251         if (!leaf->hdr.stale) {
 252                 lep = &leaf->ents[index];
 253                 if (index < be16_to_cpu(leaf->hdr.count))
 254                         memmove(lep + 1, lep,
 255                                 (be16_to_cpu(leaf->hdr.count) - index) * sizeof(*lep));
 256                 lfloglow = index;
 257                 lfloghigh = be16_to_cpu(leaf->hdr.count);
 258                 be16_add(&leaf->hdr.count, 1);
 259         }
 260         /*
 261          * There are stale entries.  We'll use one for the new entry.
 262          */
 263         else {
 264                 /*
 265                  * If we didn't do a compact then we need to figure out
 266                  * which stale entry will be used.
 267                  */
 268                 if (compact == 0) {
 269                         /*
 270                          * Find first stale entry before our insertion point.
 271                          */
 272                         for (lowstale = index - 1;
 273                              lowstale >= 0 &&
 274                                 be32_to_cpu(leaf->ents[lowstale].address) !=
 275                                 XFS_DIR2_NULL_DATAPTR;
 276                              lowstale--)
 277                                 continue;
 278                         /*
 279                          * Find next stale entry after insertion point.
 280                          * Stop looking if the answer would be worse than
 281                          * lowstale already found.
 282                          */
 283                         for (highstale = index;
 284                              highstale < be16_to_cpu(leaf->hdr.count) &&
 285                                 be32_to_cpu(leaf->ents[highstale].address) !=
 286                                 XFS_DIR2_NULL_DATAPTR &&
 287                                 (lowstale < 0 ||
 288                                  index - lowstale - 1 >= highstale - index);
 289                              highstale++)
 290                                 continue;
 291                 }
 292                 /*
 293                  * Using the low stale entry.
 294                  * Shift entries up toward the stale slot.
 295                  */
 296                 if (lowstale >= 0 &&
 297                     (highstale == be16_to_cpu(leaf->hdr.count) ||
 298                      index - lowstale - 1 < highstale - index)) {
 299                         ASSERT(be32_to_cpu(leaf->ents[lowstale].address) ==
 300                                XFS_DIR2_NULL_DATAPTR);
 301                         ASSERT(index - lowstale - 1 >= 0);
 302                         if (index - lowstale - 1 > 0)
 303                                 memmove(&leaf->ents[lowstale],
 304                                         &leaf->ents[lowstale + 1],
 305                                         (index - lowstale - 1) * sizeof(*lep));
 306                         lep = &leaf->ents[index - 1];
 307                         lfloglow = MIN(lowstale, lfloglow);
 308                         lfloghigh = MAX(index - 1, lfloghigh);
 309                 }
 310                 /*
 311                  * Using the high stale entry.
 312                  * Shift entries down toward the stale slot.
 313                  */
 314                 else {
 315                         ASSERT(be32_to_cpu(leaf->ents[highstale].address) ==
 316                                XFS_DIR2_NULL_DATAPTR);
 317                         ASSERT(highstale - index >= 0);
 318                         if (highstale - index > 0)
 319                                 memmove(&leaf->ents[index + 1],
 320                                         &leaf->ents[index],
 321                                         (highstale - index) * sizeof(*lep));
 322                         lep = &leaf->ents[index];
 323                         lfloglow = MIN(index, lfloglow);
 324                         lfloghigh = MAX(highstale, lfloghigh);
 325                 }
 326                 be16_add(&leaf->hdr.stale, -1);
 327         }
 328         /*
 329          * Insert the new entry, log everything.
 330          */
 331         lep->hashval = cpu_to_be32(args->hashval);
 332         lep->address = cpu_to_be32(XFS_DIR2_DB_OFF_TO_DATAPTR(mp,
 333                                 args->blkno, args->index));
 334         xfs_dir2_leaf_log_header(tp, bp);
 335         xfs_dir2_leaf_log_ents(tp, bp, lfloglow, lfloghigh);
 336         xfs_dir2_leafn_check(dp, bp);
 337         return 0;
 338 }
 339
 340 #ifdef DEBUG
 341 /*
 342  * Check internal consistency of a leafn block.
 343  */
 344 void
 345 xfs_dir2_leafn_check(
 346         xfs_inode_t     *dp,                    /* incore directory inode */
 347         xfs_dabuf_t     *bp)                    /* leaf buffer */
 348 {
 349         int             i;                      /* leaf index */
 350         xfs_dir2_leaf_t *leaf;                  /* leaf structure */
 351         xfs_mount_t     *mp;                    /* filesystem mount point */
 352         int             stale;                  /* count of stale leaves */
 353
 354         leaf = bp->data;
 355         mp = dp->i_mount;
 356         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 357         ASSERT(be16_to_cpu(leaf->hdr.count) <= XFS_DIR2_MAX_LEAF_ENTS(mp));
 358         for (i = stale = 0; i < be16_to_cpu(leaf->hdr.count); i++) {
 359                 if (i + 1 < be16_to_cpu(leaf->hdr.count)) {
 360                         ASSERT(be32_to_cpu(leaf->ents[i].hashval) <=
 361                                be32_to_cpu(leaf->ents[i + 1].hashval));
 362                 }
 363                 if (be32_to_cpu(leaf->ents[i].address) == XFS_DIR2_NULL_DATAPTR)
 364                         stale++;
 365         }
 366         ASSERT(be16_to_cpu(leaf->hdr.stale) == stale);
 367 }
 368 #endif  /* DEBUG */
 369
 370 /*
 371  * Return the last hash value in the leaf.
 372  * Stale entries are ok.
 373  */
 374 xfs_dahash_t                                    /* hash value */
 375 xfs_dir2_leafn_lasthash(
 376         xfs_dabuf_t     *bp,                    /* leaf buffer */
 377         int             *count)                 /* count of entries in leaf */
 378 {
 379         xfs_dir2_leaf_t *leaf;                  /* leaf structure */
 380
 381         leaf = bp->data;
 382         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 383         if (count)
 384                 *count = be16_to_cpu(leaf->hdr.count);
 385         if (!leaf->hdr.count)
 386                 return 0;
 387         return be32_to_cpu(leaf->ents[be16_to_cpu(leaf->hdr.count) - 1].hashval);
 388 }
 389
 390 /*
 391  * Look up a leaf entry in a node-format leaf block.
 392  * If this is an addname then the extrablk in state is a freespace block,
 393  * otherwise it's a data block.
 394  */
 395 int
 396 xfs_dir2_leafn_lookup_int(
 397         xfs_dabuf_t             *bp,            /* leaf buffer */
 398         xfs_da_args_t           *args,          /* operation arguments */
 399         int                     *indexp,        /* out: leaf entry index */
 400         xfs_da_state_t          *state)         /* state to fill in */
 401 {
 402         xfs_dabuf_t             *curbp;         /* current data/free buffer */
 403         xfs_dir2_db_t           curdb;          /* current data block number */
 404         xfs_dir2_db_t           curfdb;         /* current free block number */
 405         xfs_dir2_data_entry_t   *dep;           /* data block entry */
 406         xfs_inode_t             *dp;            /* incore directory inode */
 407         int                     error;          /* error return value */
 408         int                     fi;             /* free entry index */
 409         xfs_dir2_free_t         *free=NULL;     /* free block structure */
 410         int                     index;          /* leaf entry index */
 411         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 412         int                     length=0;       /* length of new data entry */
 413         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
 414         xfs_mount_t             *mp;            /* filesystem mount point */
 415         xfs_dir2_db_t           newdb;          /* new data block number */
 416         xfs_dir2_db_t           newfdb;         /* new free block number */
 417         xfs_trans_t             *tp;            /* transaction pointer */
 418
 419         dp = args->dp;
 420         tp = args->trans;
 421         mp = dp->i_mount;
 422         leaf = bp->data;
 423         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 424 #ifdef __KERNEL__
 425         ASSERT(be16_to_cpu(leaf->hdr.count) > 0);
 426 #endif
 427         xfs_dir2_leafn_check(dp, bp);
 428         /*
 429          * Look up the hash value in the leaf entries.
 430          */
 431         index = xfs_dir2_leaf_search_hash(args, bp);
 432         /*
 433          * Do we have a buffer coming in?
 434          */
 435         if (state->extravalid)
 436                 curbp = state->extrablk.bp;
 437         else
 438                 curbp = NULL;
 439         /*
 440          * For addname, it's a free block buffer, get the block number.
 441          */
 442         if (args->addname) {
 443                 curfdb = curbp ? state->extrablk.blkno : -1;
 444                 curdb = -1;
 445                 length = XFS_DIR2_DATA_ENTSIZE(args->namelen);
 446                 if ((free = (curbp ? curbp->data : NULL)))
 447                         ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
 448         }
 449         /*
 450          * For others, it's a data block buffer, get the block number.
 451          */
 452         else {
 453                 curfdb = -1;
 454                 curdb = curbp ? state->extrablk.blkno : -1;
 455         }
 456         /*
 457          * Loop over leaf entries with the right hash value.
 458          */
 459         for (lep = &leaf->ents[index];
 460              index < be16_to_cpu(leaf->hdr.count) && be32_to_cpu(lep->hashval) == args->hashval;
 461              lep++, index++) {
 462                 /*
 463                  * Skip stale leaf entries.
 464                  */
 465                 if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
 466                         continue;
 467                 /*
 468                  * Pull the data block number from the entry.
 469                  */
 470                 newdb = XFS_DIR2_DATAPTR_TO_DB(mp, be32_to_cpu(lep->address));
 471                 /*
 472                  * For addname, we're looking for a place to put the new entry.
 473                  * We want to use a data block with an entry of equal
 474                  * hash value to ours if there is one with room.
 475                  */
 476                 if (args->addname) {
 477                         /*
 478                          * If this block isn't the data block we already have
 479                          * in hand, take a look at it.
 480                          */
 481                         if (newdb != curdb) {
 482                                 curdb = newdb;
 483                                 /*
 484                                  * Convert the data block to the free block
 485                                  * holding its freespace information.
 486                                  */
 487                                 newfdb = XFS_DIR2_DB_TO_FDB(mp, newdb);
 488                                 /*
 489                                  * If it's not the one we have in hand,
 490                                  * read it in.
 491                                  */
 492                                 if (newfdb != curfdb) {
 493                                         /*
 494                                          * If we had one before, drop it.
 495                                          */
 496                                         if (curbp)
 497                                                 xfs_da_brelse(tp, curbp);
 498                                         /*
 499                                          * Read the free block.
 500                                          */
 501                                         if ((error = xfs_da_read_buf(tp, dp,
 502                                                         XFS_DIR2_DB_TO_DA(mp,
 503                                                                 newfdb),
 504                                                         -1, &curbp,
 505                                                         XFS_DATA_FORK))) {
 506                                                 return error;
 507                                         }
 508                                         curfdb = newfdb;
 509                                         free = curbp->data;
 510                                         ASSERT(be32_to_cpu(free->hdr.magic) ==
 511                                                XFS_DIR2_FREE_MAGIC);
 512                                         ASSERT((be32_to_cpu(free->hdr.firstdb) %
 513                                                 XFS_DIR2_MAX_FREE_BESTS(mp)) ==
 514                                                0);
 515                                         ASSERT(be32_to_cpu(free->hdr.firstdb) <= curdb);
 516                                         ASSERT(curdb <
 517                                                be32_to_cpu(free->hdr.firstdb) +
 518                                                be32_to_cpu(free->hdr.nvalid));
 519                                 }
 520                                 /*
 521                                  * Get the index for our entry.
 522                                  */
 523                                 fi = XFS_DIR2_DB_TO_FDINDEX(mp, curdb);
 524                                 /*
 525                                  * If it has room, return it.
 526                                  */
 527                                 if (unlikely(be16_to_cpu(free->bests[fi]) == NULLDATAOFF)) {
 528                                         XFS_ERROR_REPORT("xfs_dir2_leafn_lookup_int",
 529                                                          XFS_ERRLEVEL_LOW, mp);
 530                                         return XFS_ERROR(EFSCORRUPTED);
 531                                 }
 532                                 if (be16_to_cpu(free->bests[fi]) >= length) {
 533                                         *indexp = index;
 534                                         state->extravalid = 1;
 535                                         state->extrablk.bp = curbp;
 536                                         state->extrablk.blkno = curfdb;
 537                                         state->extrablk.index = fi;
 538                                         state->extrablk.magic =
 539                                                 XFS_DIR2_FREE_MAGIC;
 540                                         ASSERT(args->oknoent);
 541                                         return XFS_ERROR(ENOENT);
 542                                 }
 543                         }
 544                 }
 545                 /*
 546                  * Not adding a new entry, so we really want to find
 547                  * the name given to us.
 548                  */
 549                 else {
 550                         /*
 551                          * If it's a different data block, go get it.
 552                          */
 553                         if (newdb != curdb) {
 554                                 /*
 555                                  * If we had a block before, drop it.
 556                                  */
 557                                 if (curbp)
 558                                         xfs_da_brelse(tp, curbp);
 559                                 /*
 560                                  * Read the data block.
 561                                  */
 562                                 if ((error =
 563                                     xfs_da_read_buf(tp, dp,
 564                                             XFS_DIR2_DB_TO_DA(mp, newdb), -1,
 565                                             &curbp, XFS_DATA_FORK))) {
 566                                         return error;
 567                                 }
 568                                 xfs_dir2_data_check(dp, curbp);
 569                                 curdb = newdb;
 570                         }
 571                         /*
 572                          * Point to the data entry.
 573                          */
 574                         dep = (xfs_dir2_data_entry_t *)
 575                               ((char *)curbp->data +
 576                                XFS_DIR2_DATAPTR_TO_OFF(mp, be32_to_cpu(lep->address)));
 577                         /*
 578                          * Compare the entry, return it if it matches.
 579                          */
 580                         if (dep->namelen == args->namelen &&
 581                             dep->name[0] == args->name[0] &&
 582                             memcmp(dep->name, args->name, args->namelen) == 0) {
 583                                 args->inumber = INT_GET(dep->inumber, ARCH_CONVERT);
 584                                 *indexp = index;
 585                                 state->extravalid = 1;
 586                                 state->extrablk.bp = curbp;
 587                                 state->extrablk.blkno = curdb;
 588                                 state->extrablk.index =
 589                                         (int)((char *)dep -
 590                                               (char *)curbp->data);
 591                                 state->extrablk.magic = XFS_DIR2_DATA_MAGIC;
 592                                 return XFS_ERROR(EEXIST);
 593                         }
 594                 }
 595         }
 596         /*
 597          * Didn't find a match.
 598          * If we are holding a buffer, give it back in case our caller
 599          * finds it useful.
 600          */
 601         if ((state->extravalid = (curbp != NULL))) {
 602                 state->extrablk.bp = curbp;
 603                 state->extrablk.index = -1;
 604                 /*
 605                  * For addname, giving back a free block.
 606                  */
 607                 if (args->addname) {
 608                         state->extrablk.blkno = curfdb;
 609                         state->extrablk.magic = XFS_DIR2_FREE_MAGIC;
 610                 }
 611                 /*
 612                  * For other callers, giving back a data block.
 613                  */
 614                 else {
 615                         state->extrablk.blkno = curdb;
 616                         state->extrablk.magic = XFS_DIR2_DATA_MAGIC;
 617                 }
 618         }
 619         /*
 620          * Return the final index, that will be the insertion point.
 621          */
 622         *indexp = index;
 623         ASSERT(index == be16_to_cpu(leaf->hdr.count) || args->oknoent);
 624         return XFS_ERROR(ENOENT);
 625 }
 626
 627 /*
 628  * Move count leaf entries from source to destination leaf.
 629  * Log entries and headers.  Stale entries are preserved.
 630  */
 631 static void
 632 xfs_dir2_leafn_moveents(
 633         xfs_da_args_t   *args,                  /* operation arguments */
 634         xfs_dabuf_t     *bp_s,                  /* source leaf buffer */
 635         int             start_s,                /* source leaf index */
 636         xfs_dabuf_t     *bp_d,                  /* destination leaf buffer */
 637         int             start_d,                /* destination leaf index */
 638         int             count)                  /* count of leaves to copy */
 639 {
 640         xfs_dir2_leaf_t *leaf_d;                /* destination leaf structure */
 641         xfs_dir2_leaf_t *leaf_s;                /* source leaf structure */
 642         int             stale;                  /* count stale leaves copied */
 643         xfs_trans_t     *tp;                    /* transaction pointer */
 644
 645         xfs_dir2_trace_args_bibii("leafn_moveents", args, bp_s, start_s, bp_d,
 646                 start_d, count);
 647         /*
 648          * Silently return if nothing to do.
 649          */
 650         if (count == 0) {
 651                 return;
 652         }
 653         tp = args->trans;
 654         leaf_s = bp_s->data;
 655         leaf_d = bp_d->data;
 656         /*
 657          * If the destination index is not the end of the current
 658          * destination leaf entries, open up a hole in the destination
 659          * to hold the new entries.
 660          */
 661         if (start_d < be16_to_cpu(leaf_d->hdr.count)) {
 662                 memmove(&leaf_d->ents[start_d + count], &leaf_d->ents[start_d],
 663                         (be16_to_cpu(leaf_d->hdr.count) - start_d) *
 664                         sizeof(xfs_dir2_leaf_entry_t));
 665                 xfs_dir2_leaf_log_ents(tp, bp_d, start_d + count,
 666                         count + be16_to_cpu(leaf_d->hdr.count) - 1);
 667         }
 668         /*
 669          * If the source has stale leaves, count the ones in the copy range
 670          * so we can update the header correctly.
 671          */
 672         if (leaf_s->hdr.stale) {
 673                 int     i;                      /* temp leaf index */
 674
 675                 for (i = start_s, stale = 0; i < start_s + count; i++) {
 676                         if (be32_to_cpu(leaf_s->ents[i].address) == XFS_DIR2_NULL_DATAPTR)
 677                                 stale++;
 678                 }
 679         } else
 680                 stale = 0;
 681         /*
 682          * Copy the leaf entries from source to destination.
 683          */
 684         memcpy(&leaf_d->ents[start_d], &leaf_s->ents[start_s],
 685                 count * sizeof(xfs_dir2_leaf_entry_t));
 686         xfs_dir2_leaf_log_ents(tp, bp_d, start_d, start_d + count - 1);
 687         /*
 688          * If there are source entries after the ones we copied,
 689          * delete the ones we copied by sliding the next ones down.
 690          */
 691         if (start_s + count < be16_to_cpu(leaf_s->hdr.count)) {
 692                 memmove(&leaf_s->ents[start_s], &leaf_s->ents[start_s + count],
 693                         count * sizeof(xfs_dir2_leaf_entry_t));
 694                 xfs_dir2_leaf_log_ents(tp, bp_s, start_s, start_s + count - 1);
 695         }
 696         /*
 697          * Update the headers and log them.
 698          */
 699         be16_add(&leaf_s->hdr.count, -(count));
 700         be16_add(&leaf_s->hdr.stale, -(stale));
 701         be16_add(&leaf_d->hdr.count, count);
 702         be16_add(&leaf_d->hdr.stale, stale);
 703         xfs_dir2_leaf_log_header(tp, bp_s);
 704         xfs_dir2_leaf_log_header(tp, bp_d);
 705         xfs_dir2_leafn_check(args->dp, bp_s);
 706         xfs_dir2_leafn_check(args->dp, bp_d);
 707 }
 708
 709 /*
 710  * Determine the sort order of two leaf blocks.
 711  * Returns 1 if both are valid and leaf2 should be before leaf1, else 0.
 712  */
 713 int                                             /* sort order */
 714 xfs_dir2_leafn_order(
 715         xfs_dabuf_t     *leaf1_bp,              /* leaf1 buffer */
 716         xfs_dabuf_t     *leaf2_bp)              /* leaf2 buffer */
 717 {
 718         xfs_dir2_leaf_t *leaf1;                 /* leaf1 structure */
 719         xfs_dir2_leaf_t *leaf2;                 /* leaf2 structure */
 720
 721         leaf1 = leaf1_bp->data;
 722         leaf2 = leaf2_bp->data;
 723         ASSERT(be16_to_cpu(leaf1->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 724         ASSERT(be16_to_cpu(leaf2->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 725         if (be16_to_cpu(leaf1->hdr.count) > 0 &&
 726             be16_to_cpu(leaf2->hdr.count) > 0 &&
 727             (be32_to_cpu(leaf2->ents[0].hashval) < be32_to_cpu(leaf1->ents[0].hashval) ||
 728              be32_to_cpu(leaf2->ents[be16_to_cpu(leaf2->hdr.count) - 1].hashval) <
 729              be32_to_cpu(leaf1->ents[be16_to_cpu(leaf1->hdr.count) - 1].hashval)))
 730                 return 1;
 731         return 0;
 732 }
 733
 734 /*
 735  * Rebalance leaf entries between two leaf blocks.
 736  * This is actually only called when the second block is new,
 737  * though the code deals with the general case.
 738  * A new entry will be inserted in one of the blocks, and that
 739  * entry is taken into account when balancing.
 740  */
 741 static void
 742 xfs_dir2_leafn_rebalance(
 743         xfs_da_state_t          *state,         /* btree cursor */
 744         xfs_da_state_blk_t      *blk1,          /* first btree block */
 745         xfs_da_state_blk_t      *blk2)          /* second btree block */
 746 {
 747         xfs_da_args_t           *args;          /* operation arguments */
 748         int                     count;          /* count (& direction) leaves */
 749         int                     isleft;         /* new goes in left leaf */
 750         xfs_dir2_leaf_t         *leaf1;         /* first leaf structure */
 751         xfs_dir2_leaf_t         *leaf2;         /* second leaf structure */
 752         int                     mid;            /* midpoint leaf index */
 753 #ifdef DEBUG
 754         int                     oldstale;       /* old count of stale leaves */
 755 #endif
 756         int                     oldsum;         /* old total leaf count */
 757         int                     swap;           /* swapped leaf blocks */
 758
 759         args = state->args;
 760         /*
 761          * If the block order is wrong, swap the arguments.
 762          */
 763         if ((swap = xfs_dir2_leafn_order(blk1->bp, blk2->bp))) {
 764                 xfs_da_state_blk_t      *tmp;   /* temp for block swap */
 765
 766                 tmp = blk1;
 767                 blk1 = blk2;
 768                 blk2 = tmp;
 769         }
 770         leaf1 = blk1->bp->data;
 771         leaf2 = blk2->bp->data;
 772         oldsum = be16_to_cpu(leaf1->hdr.count) + be16_to_cpu(leaf2->hdr.count);
 773 #ifdef DEBUG
 774         oldstale = be16_to_cpu(leaf1->hdr.stale) + be16_to_cpu(leaf2->hdr.stale);
 775 #endif
 776         mid = oldsum >> 1;
 777         /*
 778          * If the old leaf count was odd then the new one will be even,
 779          * so we need to divide the new count evenly.
 780          */
 781         if (oldsum & 1) {
 782                 xfs_dahash_t    midhash;        /* middle entry hash value */
 783
 784                 if (mid >= be16_to_cpu(leaf1->hdr.count))
 785                         midhash = be32_to_cpu(leaf2->ents[mid - be16_to_cpu(leaf1->hdr.count)].hashval);
 786                 else
 787                         midhash = be32_to_cpu(leaf1->ents[mid].hashval);
 788                 isleft = args->hashval <= midhash;
 789         }
 790         /*
 791          * If the old count is even then the new count is odd, so there's
 792          * no preferred side for the new entry.
 793          * Pick the left one.
 794          */
 795         else
 796                 isleft = 1;
 797         /*
 798          * Calculate moved entry count.  Positive means left-to-right,
 799          * negative means right-to-left.  Then move the entries.
 800          */
 801         count = be16_to_cpu(leaf1->hdr.count) - mid + (isleft == 0);
 802         if (count > 0)
 803                 xfs_dir2_leafn_moveents(args, blk1->bp,
 804                         be16_to_cpu(leaf1->hdr.count) - count, blk2->bp, 0, count);
 805         else if (count < 0)
 806                 xfs_dir2_leafn_moveents(args, blk2->bp, 0, blk1->bp,
 807                         be16_to_cpu(leaf1->hdr.count), count);
 808         ASSERT(be16_to_cpu(leaf1->hdr.count) + be16_to_cpu(leaf2->hdr.count) == oldsum);
 809         ASSERT(be16_to_cpu(leaf1->hdr.stale) + be16_to_cpu(leaf2->hdr.stale) == oldstale);
 810         /*
 811          * Mark whether we're inserting into the old or new leaf.
 812          */
 813         if (be16_to_cpu(leaf1->hdr.count) < be16_to_cpu(leaf2->hdr.count))
 814                 state->inleaf = swap;
 815         else if (be16_to_cpu(leaf1->hdr.count) > be16_to_cpu(leaf2->hdr.count))
 816                 state->inleaf = !swap;
 817         else
 818                 state->inleaf =
 819                         swap ^ (blk1->index <= be16_to_cpu(leaf1->hdr.count));
 820         /*
 821          * Adjust the expected index for insertion.
 822          */
 823         if (!state->inleaf)
 824                 blk2->index = blk1->index - be16_to_cpu(leaf1->hdr.count);
 825
 826         /*
 827          * Finally sanity check just to make sure we are not returning a negative index
 828          */
 829         if(blk2->index < 0) {
 830                 state->inleaf = 1;
 831                 blk2->index = 0;
 832                 cmn_err(CE_ALERT,
 833                         "xfs_dir2_leafn_rebalance: picked the wrong leaf? reverting original leaf: "
 834                         "blk1->index %d\n",
 835                         blk1->index);
 836         }
 837 }
 838
 839 /*
 840  * Remove an entry from a node directory.
 841  * This removes the leaf entry and the data entry,
 842  * and updates the free block if necessary.
 843  */
 844 static int                                      /* error */
 845 xfs_dir2_leafn_remove(
 846         xfs_da_args_t           *args,          /* operation arguments */
 847         xfs_dabuf_t             *bp,            /* leaf buffer */
 848         int                     index,          /* leaf entry index */
 849         xfs_da_state_blk_t      *dblk,          /* data block */
 850         int                     *rval)          /* resulting block needs join */
 851 {
 852         xfs_dir2_data_t         *data;          /* data block structure */
 853         xfs_dir2_db_t           db;             /* data block number */
 854         xfs_dabuf_t             *dbp;           /* data block buffer */
 855         xfs_dir2_data_entry_t   *dep;           /* data block entry */
 856         xfs_inode_t             *dp;            /* incore directory inode */
 857         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
 858         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry */
 859         int                     longest;        /* longest data free entry */
 860         int                     off;            /* data block entry offset */
 861         xfs_mount_t             *mp;            /* filesystem mount point */
 862         int                     needlog;        /* need to log data header */
 863         int                     needscan;       /* need to rescan data frees */
 864         xfs_trans_t             *tp;            /* transaction pointer */
 865
 866         xfs_dir2_trace_args_sb("leafn_remove", args, index, bp);
 867         dp = args->dp;
 868         tp = args->trans;
 869         mp = dp->i_mount;
 870         leaf = bp->data;
 871         ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 872         /*
 873          * Point to the entry we're removing.
 874          */
 875         lep = &leaf->ents[index];
 876         /*
 877          * Extract the data block and offset from the entry.
 878          */
 879         db = XFS_DIR2_DATAPTR_TO_DB(mp, be32_to_cpu(lep->address));
 880         ASSERT(dblk->blkno == db);
 881         off = XFS_DIR2_DATAPTR_TO_OFF(mp, be32_to_cpu(lep->address));
 882         ASSERT(dblk->index == off);
 883         /*
 884          * Kill the leaf entry by marking it stale.
 885          * Log the leaf block changes.
 886          */
 887         be16_add(&leaf->hdr.stale, 1);
 888         xfs_dir2_leaf_log_header(tp, bp);
 889         lep->address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
 890         xfs_dir2_leaf_log_ents(tp, bp, index, index);
 891         /*
 892          * Make the data entry free.  Keep track of the longest freespace
 893          * in the data block in case it changes.
 894          */
 895         dbp = dblk->bp;
 896         data = dbp->data;
 897         dep = (xfs_dir2_data_entry_t *)((char *)data + off);
 898         longest = be16_to_cpu(data->hdr.bestfree[0].length);
 899         needlog = needscan = 0;
 900         xfs_dir2_data_make_free(tp, dbp, off,
 901                 XFS_DIR2_DATA_ENTSIZE(dep->namelen), &needlog, &needscan);
 902         /*
 903          * Rescan the data block freespaces for bestfree.
 904          * Log the data block header if needed.
 905          */
 906         if (needscan)
 907                 xfs_dir2_data_freescan(mp, data, &needlog, NULL);
 908         if (needlog)
 909                 xfs_dir2_data_log_header(tp, dbp);
 910         xfs_dir2_data_check(dp, dbp);
 911         /*
 912          * If the longest data block freespace changes, need to update
 913          * the corresponding freeblock entry.
 914          */
 915         if (longest < be16_to_cpu(data->hdr.bestfree[0].length)) {
 916                 int             error;          /* error return value */
 917                 xfs_dabuf_t     *fbp;           /* freeblock buffer */
 918                 xfs_dir2_db_t   fdb;            /* freeblock block number */
 919                 int             findex;         /* index in freeblock entries */
 920                 xfs_dir2_free_t *free;          /* freeblock structure */
 921                 int             logfree;        /* need to log free entry */
 922
 923                 /*
 924                  * Convert the data block number to a free block,
 925                  * read in the free block.
 926                  */
 927                 fdb = XFS_DIR2_DB_TO_FDB(mp, db);
 928                 if ((error = xfs_da_read_buf(tp, dp, XFS_DIR2_DB_TO_DA(mp, fdb),
 929                                 -1, &fbp, XFS_DATA_FORK))) {
 930                         return error;
 931                 }
 932                 free = fbp->data;
 933                 ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
 934                 ASSERT(be32_to_cpu(free->hdr.firstdb) ==
 935                        XFS_DIR2_MAX_FREE_BESTS(mp) *
 936                        (fdb - XFS_DIR2_FREE_FIRSTDB(mp)));
 937                 /*
 938                  * Calculate which entry we need to fix.
 939                  */
 940                 findex = XFS_DIR2_DB_TO_FDINDEX(mp, db);
 941                 longest = be16_to_cpu(data->hdr.bestfree[0].length);
 942                 /*
 943                  * If the data block is now empty we can get rid of it
 944                  * (usually).
 945                  */
 946                 if (longest == mp->m_dirblksize - (uint)sizeof(data->hdr)) {
 947                         /*
 948                          * Try to punch out the data block.
 949                          */
 950                         error = xfs_dir2_shrink_inode(args, db, dbp);
 951                         if (error == 0) {
 952                                 dblk->bp = NULL;
 953                                 data = NULL;
 954                         }
 955                         /*
 956                          * We can get ENOSPC if there's no space reservation.
 957                          * In this case just drop the buffer and some one else
 958                          * will eventually get rid of the empty block.
 959                          */
 960                         else if (error == ENOSPC && args->total == 0)
 961                                 xfs_da_buf_done(dbp);
 962                         else
 963                                 return error;
 964                 }
 965                 /*
 966                  * If we got rid of the data block, we can eliminate that entry
 967                  * in the free block.
 968                  */
 969                 if (data == NULL) {
 970                         /*
 971                          * One less used entry in the free table.
 972                          */
 973                         free->hdr.nused = cpu_to_be32(-1);
 974                         xfs_dir2_free_log_header(tp, fbp);
 975                         /*
 976                          * If this was the last entry in the table, we can
 977                          * trim the table size back.  There might be other
 978                          * entries at the end referring to non-existent
 979                          * data blocks, get those too.
 980                          */
 981                         if (findex == be32_to_cpu(free->hdr.nvalid) - 1) {
 982                                 int     i;              /* free entry index */
 983
 984                                 for (i = findex - 1;
 985                                      i >= 0 && be16_to_cpu(free->bests[i]) == NULLDATAOFF;
 986                                      i--)
 987                                         continue;
 988                                 free->hdr.nvalid = cpu_to_be32(i + 1);
 989                                 logfree = 0;
 990                         }
 991                         /*
 992                          * Not the last entry, just punch it out.
 993                          */
 994                         else {
 995                                 free->bests[findex] = cpu_to_be16(NULLDATAOFF);
 996                                 logfree = 1;
 997                         }
 998                         /*
 999                          * If there are no useful entries left in the block,
1000                          * get rid of the block if we can.
1001                          */
1002                         if (!free->hdr.nused) {
1003                                 error = xfs_dir2_shrink_inode(args, fdb, fbp);
1004                                 if (error == 0) {
1005                                         fbp = NULL;
1006                                         logfree = 0;
1007                                 } else if (error != ENOSPC || args->total != 0)
1008                                         return error;
1009                                 /*
1010                                  * It's possible to get ENOSPC if there is no
1011                                  * space reservation.  In this case some one
1012                                  * else will eventually get rid of this block.
1013                                  */
1014                         }
1015                 }
1016                 /*
1017                  * Data block is not empty, just set the free entry to
1018                  * the new value.
1019                  */
1020                 else {
1021                         free->bests[findex] = cpu_to_be16(longest);
1022                         logfree = 1;
1023                 }
1024                 /*
1025                  * Log the free entry that changed, unless we got rid of it.
1026                  */
1027                 if (logfree)
1028                         xfs_dir2_free_log_bests(tp, fbp, findex, findex);
1029                 /*
1030                  * Drop the buffer if we still have it.
1031                  */
1032                 if (fbp)
1033                         xfs_da_buf_done(fbp);
1034         }
1035         xfs_dir2_leafn_check(dp, bp);
1036         /*
1037          * Return indication of whether this leaf block is emtpy enough
1038          * to justify trying to join it with a neighbor.
1039          */
1040         *rval =
1041                 ((uint)sizeof(leaf->hdr) +
1042                  (uint)sizeof(leaf->ents[0]) *
1043                  (be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale))) <
1044                 mp->m_dir_magicpct;
1045         return 0;
1046 }
1047
1048 /*
1049  * Split the leaf entries in the old block into old and new blocks.
1050  */
1051 int                                             /* error */
1052 xfs_dir2_leafn_split(
1053         xfs_da_state_t          *state,         /* btree cursor */
1054         xfs_da_state_blk_t      *oldblk,        /* original block */
1055         xfs_da_state_blk_t      *newblk)        /* newly created block */
1056 {
1057         xfs_da_args_t           *args;          /* operation arguments */
1058         xfs_dablk_t             blkno;          /* new leaf block number */
1059         int                     error;          /* error return value */
1060         xfs_mount_t             *mp;            /* filesystem mount point */
1061
1062         /*
1063          * Allocate space for a new leaf node.
1064          */
1065         args = state->args;
1066         mp = args->dp->i_mount;
1067         ASSERT(args != NULL);
1068         ASSERT(oldblk->magic == XFS_DIR2_LEAFN_MAGIC);
1069         error = xfs_da_grow_inode(args, &blkno);
1070         if (error) {
1071                 return error;
1072         }
1073         /*
1074          * Initialize the new leaf block.
1075          */
1076         error = xfs_dir2_leaf_init(args, XFS_DIR2_DA_TO_DB(mp, blkno),
1077                 &newblk->bp, XFS_DIR2_LEAFN_MAGIC);
1078         if (error) {
1079                 return error;
1080         }
1081         newblk->blkno = blkno;
1082         newblk->magic = XFS_DIR2_LEAFN_MAGIC;
1083         /*
1084          * Rebalance the entries across the two leaves, link the new
1085          * block into the leaves.
1086          */
1087         xfs_dir2_leafn_rebalance(state, oldblk, newblk);
1088         error = xfs_da_blk_link(state, oldblk, newblk);
1089         if (error) {
1090                 return error;
1091         }
1092         /*
1093          * Insert the new entry in the correct block.
1094          */
1095         if (state->inleaf)
1096                 error = xfs_dir2_leafn_add(oldblk->bp, args, oldblk->index);
1097         else
1098                 error = xfs_dir2_leafn_add(newblk->bp, args, newblk->index);
1099         /*
1100          * Update last hashval in each block since we added the name.
1101          */
1102         oldblk->hashval = xfs_dir2_leafn_lasthash(oldblk->bp, NULL);
1103         newblk->hashval = xfs_dir2_leafn_lasthash(newblk->bp, NULL);
1104         xfs_dir2_leafn_check(args->dp, oldblk->bp);
1105         xfs_dir2_leafn_check(args->dp, newblk->bp);
1106         return error;
1107 }
1108
1109 /*
1110  * Check a leaf block and its neighbors to see if the block should be
1111  * collapsed into one or the other neighbor.  Always keep the block
1112  * with the smaller block number.
1113  * If the current block is over 50% full, don't try to join it, return 0.
1114  * If the block is empty, fill in the state structure and return 2.
1115  * If it can be collapsed, fill in the state structure and return 1.
1116  * If nothing can be done, return 0.
1117  */
1118 int                                             /* error */
1119 xfs_dir2_leafn_toosmall(
1120         xfs_da_state_t          *state,         /* btree cursor */
1121         int                     *action)        /* resulting action to take */
1122 {
1123         xfs_da_state_blk_t      *blk;           /* leaf block */
1124         xfs_dablk_t             blkno;          /* leaf block number */
1125         xfs_dabuf_t             *bp;            /* leaf buffer */
1126         int                     bytes;          /* bytes in use */
1127         int                     count;          /* leaf live entry count */
1128         int                     error;          /* error return value */
1129         int                     forward;        /* sibling block direction */
1130         int                     i;              /* sibling counter */
1131         xfs_da_blkinfo_t        *info;          /* leaf block header */
1132         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1133         int                     rval;           /* result from path_shift */
1134
1135         /*
1136          * Check for the degenerate case of the block being over 50% full.
1137          * If so, it's not worth even looking to see if we might be able
1138          * to coalesce with a sibling.
1139          */
1140         blk = &state->path.blk[state->path.active - 1];
1141         info = blk->bp->data;
1142         ASSERT(be16_to_cpu(info->magic) == XFS_DIR2_LEAFN_MAGIC);
1143         leaf = (xfs_dir2_leaf_t *)info;
1144         count = be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale);
1145         bytes = (uint)sizeof(leaf->hdr) + count * (uint)sizeof(leaf->ents[0]);
1146         if (bytes > (state->blocksize >> 1)) {
1147                 /*
1148                  * Blk over 50%, don't try to join.
1149                  */
1150                 *action = 0;
1151                 return 0;
1152         }
1153         /*
1154          * Check for the degenerate case of the block being empty.
1155          * If the block is empty, we'll simply delete it, no need to
1156          * coalesce it with a sibling block.  We choose (arbitrarily)
1157          * to merge with the forward block unless it is NULL.
1158          */
1159         if (count == 0) {
1160                 /*
1161                  * Make altpath point to the block we want to keep and
1162                  * path point to the block we want to drop (this one).
1163                  */
1164                 forward = (info->forw != 0);
1165                 memcpy(&state->altpath, &state->path, sizeof(state->path));
1166                 error = xfs_da_path_shift(state, &state->altpath, forward, 0,
1167                         &rval);
1168                 if (error)
1169                         return error;
1170                 *action = rval ? 2 : 0;
1171                 return 0;
1172         }
1173         /*
1174          * Examine each sibling block to see if we can coalesce with
1175          * at least 25% free space to spare.  We need to figure out
1176          * whether to merge with the forward or the backward block.
1177          * We prefer coalescing with the lower numbered sibling so as
1178          * to shrink a directory over time.
1179          */
1180         forward = be32_to_cpu(info->forw) < be32_to_cpu(info->back);
1181         for (i = 0, bp = NULL; i < 2; forward = !forward, i++) {
1182                 blkno = forward ? be32_to_cpu(info->forw) : be32_to_cpu(info->back);
1183                 if (blkno == 0)
1184                         continue;
1185                 /*
1186                  * Read the sibling leaf block.
1187                  */
1188                 if ((error =
1189                     xfs_da_read_buf(state->args->trans, state->args->dp, blkno,
1190                             -1, &bp, XFS_DATA_FORK))) {
1191                         return error;
1192                 }
1193                 ASSERT(bp != NULL);
1194                 /*
1195                  * Count bytes in the two blocks combined.
1196                  */
1197                 leaf = (xfs_dir2_leaf_t *)info;
1198                 count = be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale);
1199                 bytes = state->blocksize - (state->blocksize >> 2);
1200                 leaf = bp->data;
1201                 ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1202                 count += be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale);
1203                 bytes -= count * (uint)sizeof(leaf->ents[0]);
1204                 /*
1205                  * Fits with at least 25% to spare.
1206                  */
1207                 if (bytes >= 0)
1208                         break;
1209                 xfs_da_brelse(state->args->trans, bp);
1210         }
1211         /*
1212          * Didn't like either block, give up.
1213          */
1214         if (i >= 2) {
1215                 *action = 0;
1216                 return 0;
1217         }
1218         /*
1219          * Done with the sibling leaf block here, drop the dabuf
1220          * so path_shift can get it.
1221          */
1222         xfs_da_buf_done(bp);
1223         /*
1224          * Make altpath point to the block we want to keep (the lower
1225          * numbered block) and path point to the block we want to drop.
1226          */
1227         memcpy(&state->altpath, &state->path, sizeof(state->path));
1228         if (blkno < blk->blkno)
1229                 error = xfs_da_path_shift(state, &state->altpath, forward, 0,
1230                         &rval);
1231         else
1232                 error = xfs_da_path_shift(state, &state->path, forward, 0,
1233                         &rval);
1234         if (error) {
1235                 return error;
1236         }
1237         *action = rval ? 0 : 1;
1238         return 0;
1239 }
1240
1241 /*
1242  * Move all the leaf entries from drop_blk to save_blk.
1243  * This is done as part of a join operation.
1244  */
1245 void
1246 xfs_dir2_leafn_unbalance(
1247         xfs_da_state_t          *state,         /* cursor */
1248         xfs_da_state_blk_t      *drop_blk,      /* dead block */
1249         xfs_da_state_blk_t      *save_blk)      /* surviving block */
1250 {
1251         xfs_da_args_t           *args;          /* operation arguments */
1252         xfs_dir2_leaf_t         *drop_leaf;     /* dead leaf structure */
1253         xfs_dir2_leaf_t         *save_leaf;     /* surviving leaf structure */
1254
1255         args = state->args;
1256         ASSERT(drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
1257         ASSERT(save_blk->magic == XFS_DIR2_LEAFN_MAGIC);
1258         drop_leaf = drop_blk->bp->data;
1259         save_leaf = save_blk->bp->data;
1260         ASSERT(be16_to_cpu(drop_leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1261         ASSERT(be16_to_cpu(save_leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
1262         /*
1263          * If there are any stale leaf entries, take this opportunity
1264          * to purge them.
1265          */
1266         if (drop_leaf->hdr.stale)
1267                 xfs_dir2_leaf_compact(args, drop_blk->bp);
1268         if (save_leaf->hdr.stale)
1269                 xfs_dir2_leaf_compact(args, save_blk->bp);
1270         /*
1271          * Move the entries from drop to the appropriate end of save.
1272          */
1273         drop_blk->hashval = be32_to_cpu(drop_leaf->ents[be16_to_cpu(drop_leaf->hdr.count) - 1].hashval);
1274         if (xfs_dir2_leafn_order(save_blk->bp, drop_blk->bp))
1275                 xfs_dir2_leafn_moveents(args, drop_blk->bp, 0, save_blk->bp, 0,
1276                         be16_to_cpu(drop_leaf->hdr.count));
1277         else
1278                 xfs_dir2_leafn_moveents(args, drop_blk->bp, 0, save_blk->bp,
1279                         be16_to_cpu(save_leaf->hdr.count), be16_to_cpu(drop_leaf->hdr.count));
1280         save_blk->hashval = be32_to_cpu(save_leaf->ents[be16_to_cpu(save_leaf->hdr.count) - 1].hashval);
1281         xfs_dir2_leafn_check(args->dp, save_blk->bp);
1282 }
1283
1284 /*
1285  * Top-level node form directory addname routine.
1286  */
1287 int                                             /* error */
1288 xfs_dir2_node_addname(
1289         xfs_da_args_t           *args)          /* operation arguments */
1290 {
1291         xfs_da_state_blk_t      *blk;           /* leaf block for insert */
1292         int                     error;          /* error return value */
1293         int                     rval;           /* sub-return value */
1294         xfs_da_state_t          *state;         /* btree cursor */
1295
1296         xfs_dir2_trace_args("node_addname", args);
1297         /*
1298          * Allocate and initialize the state (btree cursor).
1299          */
1300         state = xfs_da_state_alloc();
1301         state->args = args;
1302         state->mp = args->dp->i_mount;
1303         state->blocksize = state->mp->m_dirblksize;
1304         state->node_ents = state->mp->m_dir_node_ents;
1305         /*
1306          * Look up the name.  We're not supposed to find it, but
1307          * this gives us the insertion point.
1308          */
1309         error = xfs_da_node_lookup_int(state, &rval);
1310         if (error)
1311                 rval = error;
1312         if (rval != ENOENT) {
1313                 goto done;
1314         }
1315         /*
1316          * Add the data entry to a data block.
1317          * Extravalid is set to a freeblock found by lookup.
1318          */
1319         rval = xfs_dir2_node_addname_int(args,
1320                 state->extravalid ? &state->extrablk : NULL);
1321         if (rval) {
1322                 goto done;
1323         }
1324         blk = &state->path.blk[state->path.active - 1];
1325         ASSERT(blk->magic == XFS_DIR2_LEAFN_MAGIC);
1326         /*
1327          * Add the new leaf entry.
1328          */
1329         rval = xfs_dir2_leafn_add(blk->bp, args, blk->index);
1330         if (rval == 0) {
1331                 /*
1332                  * It worked, fix the hash values up the btree.
1333                  */
1334                 if (!args->justcheck)
1335                         xfs_da_fixhashpath(state, &state->path);
1336         } else {
1337                 /*
1338                  * It didn't work, we need to split the leaf block.
1339                  */
1340                 if (args->total == 0) {
1341                         ASSERT(rval == ENOSPC);
1342                         goto done;
1343                 }
1344                 /*
1345                  * Split the leaf block and insert the new entry.
1346                  */
1347                 rval = xfs_da_split(state);
1348         }
1349 done:
1350         xfs_da_state_free(state);
1351         return rval;
1352 }
1353
1354 /*
1355  * Add the data entry for a node-format directory name addition.
1356  * The leaf entry is added in xfs_dir2_leafn_add.
1357  * We may enter with a freespace block that the lookup found.
1358  */
1359 static int                                      /* error */
1360 xfs_dir2_node_addname_int(
1361         xfs_da_args_t           *args,          /* operation arguments */
1362         xfs_da_state_blk_t      *fblk)          /* optional freespace block */
1363 {
1364         xfs_dir2_data_t         *data;          /* data block structure */
1365         xfs_dir2_db_t           dbno;           /* data block number */
1366         xfs_dabuf_t             *dbp;           /* data block buffer */
1367         xfs_dir2_data_entry_t   *dep;           /* data entry pointer */
1368         xfs_inode_t             *dp;            /* incore directory inode */
1369         xfs_dir2_data_unused_t  *dup;           /* data unused entry pointer */
1370         int                     error;          /* error return value */
1371         xfs_dir2_db_t           fbno;           /* freespace block number */
1372         xfs_dabuf_t             *fbp;           /* freespace buffer */
1373         int                     findex;         /* freespace entry index */
1374         xfs_dir2_free_t         *free=NULL;     /* freespace block structure */
1375         xfs_dir2_db_t           ifbno;          /* initial freespace block no */
1376         xfs_dir2_db_t           lastfbno=0;     /* highest freespace block no */
1377         int                     length;         /* length of the new entry */
1378         int                     logfree;        /* need to log free entry */
1379         xfs_mount_t             *mp;            /* filesystem mount point */
1380         int                     needlog;        /* need to log data header */
1381         int                     needscan;       /* need to rescan data frees */
1382         __be16                  *tagp;          /* data entry tag pointer */
1383         xfs_trans_t             *tp;            /* transaction pointer */
1384
1385         dp = args->dp;
1386         mp = dp->i_mount;
1387         tp = args->trans;
1388         length = XFS_DIR2_DATA_ENTSIZE(args->namelen);
1389         /*
1390          * If we came in with a freespace block that means that lookup
1391          * found an entry with our hash value.  This is the freespace
1392          * block for that data entry.
1393          */
1394         if (fblk) {
1395                 fbp = fblk->bp;
1396                 /*
1397                  * Remember initial freespace block number.
1398                  */
1399                 ifbno = fblk->blkno;
1400                 free = fbp->data;
1401                 ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
1402                 findex = fblk->index;
1403                 /*
1404                  * This means the free entry showed that the data block had
1405                  * space for our entry, so we remembered it.
1406                  * Use that data block.
1407                  */
1408                 if (findex >= 0) {
1409                         ASSERT(findex < be32_to_cpu(free->hdr.nvalid));
1410                         ASSERT(be16_to_cpu(free->bests[findex]) != NULLDATAOFF);
1411                         ASSERT(be16_to_cpu(free->bests[findex]) >= length);
1412                         dbno = be32_to_cpu(free->hdr.firstdb) + findex;
1413                 }
1414                 /*
1415                  * The data block looked at didn't have enough room.
1416                  * We'll start at the beginning of the freespace entries.
1417                  */
1418                 else {
1419                         dbno = -1;
1420                         findex = 0;
1421                 }
1422         }
1423         /*
1424          * Didn't come in with a freespace block, so don't have a data block.
1425          */
1426         else {
1427                 ifbno = dbno = -1;
1428                 fbp = NULL;
1429                 findex = 0;
1430         }
1431         /*
1432          * If we don't have a data block yet, we're going to scan the
1433          * freespace blocks looking for one.  Figure out what the
1434          * highest freespace block number is.
1435          */
1436         if (dbno == -1) {
1437                 xfs_fileoff_t   fo;             /* freespace block number */
1438
1439                 if ((error = xfs_bmap_last_offset(tp, dp, &fo, XFS_DATA_FORK)))
1440                         return error;
1441                 lastfbno = XFS_DIR2_DA_TO_DB(mp, (xfs_dablk_t)fo);
1442                 fbno = ifbno;
1443         }
1444         /*
1445          * While we haven't identified a data block, search the freeblock
1446          * data for a good data block.  If we find a null freeblock entry,
1447          * indicating a hole in the data blocks, remember that.
1448          */
1449         while (dbno == -1) {
1450                 /*
1451                  * If we don't have a freeblock in hand, get the next one.
1452                  */
1453                 if (fbp == NULL) {
1454                         /*
1455                          * Happens the first time through unless lookup gave
1456                          * us a freespace block to start with.
1457                          */
1458                         if (++fbno == 0)
1459                                 fbno = XFS_DIR2_FREE_FIRSTDB(mp);
1460                         /*
1461                          * If it's ifbno we already looked at it.
1462                          */
1463                         if (fbno == ifbno)
1464                                 fbno++;
1465                         /*
1466                          * If it's off the end we're done.
1467                          */
1468                         if (fbno >= lastfbno)
1469                                 break;
1470                         /*
1471                          * Read the block.  There can be holes in the
1472                          * freespace blocks, so this might not succeed.
1473                          * This should be really rare, so there's no reason
1474                          * to avoid it.
1475                          */
1476                         if ((error = xfs_da_read_buf(tp, dp,
1477                                         XFS_DIR2_DB_TO_DA(mp, fbno), -2, &fbp,
1478                                         XFS_DATA_FORK))) {
1479                                 return error;
1480                         }
1481                         if (unlikely(fbp == NULL)) {
1482                                 continue;
1483                         }
1484                         free = fbp->data;
1485                         ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
1486                         findex = 0;
1487                 }
1488                 /*
1489                  * Look at the current free entry.  Is it good enough?
1490                  */
1491                 if (be16_to_cpu(free->bests[findex]) != NULLDATAOFF &&
1492                     be16_to_cpu(free->bests[findex]) >= length)
1493                         dbno = be32_to_cpu(free->hdr.firstdb) + findex;
1494                 else {
1495                         /*
1496                          * Are we done with the freeblock?
1497                          */
1498                         if (++findex == be32_to_cpu(free->hdr.nvalid)) {
1499                                 /*
1500                                  * Drop the block.
1501                                  */
1502                                 xfs_da_brelse(tp, fbp);
1503                                 fbp = NULL;
1504                                 if (fblk && fblk->bp)
1505                                         fblk->bp = NULL;
1506                         }
1507                 }
1508         }
1509         /*
1510          * If we don't have a data block, we need to allocate one and make
1511          * the freespace entries refer to it.
1512          */
1513         if (unlikely(dbno == -1)) {
1514                 /*
1515                  * Not allowed to allocate, return failure.
1516                  */
1517                 if (args->justcheck || args->total == 0) {
1518                         /*
1519                          * Drop the freespace buffer unless it came from our
1520                          * caller.
1521                          */
1522                         if ((fblk == NULL || fblk->bp == NULL) && fbp != NULL)
1523                                 xfs_da_buf_done(fbp);
1524                         return XFS_ERROR(ENOSPC);
1525                 }
1526                 /*
1527                  * Allocate and initialize the new data block.
1528                  */
1529                 if (unlikely((error = xfs_dir2_grow_inode(args,
1530                                                          XFS_DIR2_DATA_SPACE,
1531                                                          &dbno)) ||
1532                     (error = xfs_dir2_data_init(args, dbno, &dbp)))) {
1533                         /*
1534                          * Drop the freespace buffer unless it came from our
1535                          * caller.
1536                          */
1537                         if ((fblk == NULL || fblk->bp == NULL) && fbp != NULL)
1538                                 xfs_da_buf_done(fbp);
1539                         return error;
1540                 }
1541                 /*
1542                  * If (somehow) we have a freespace block, get rid of it.
1543                  */
1544                 if (fbp)
1545                         xfs_da_brelse(tp, fbp);
1546                 if (fblk && fblk->bp)
1547                         fblk->bp = NULL;
1548
1549                 /*
1550                  * Get the freespace block corresponding to the data block
1551                  * that was just allocated.
1552                  */
1553                 fbno = XFS_DIR2_DB_TO_FDB(mp, dbno);
1554                 if (unlikely(error = xfs_da_read_buf(tp, dp,
1555                                 XFS_DIR2_DB_TO_DA(mp, fbno), -2, &fbp,
1556                                 XFS_DATA_FORK))) {
1557                         xfs_da_buf_done(dbp);
1558                         return error;
1559                 }
1560                 /*
1561                  * If there wasn't a freespace block, the read will
1562                  * return a NULL fbp.  Allocate and initialize a new one.
1563                  */
1564                 if( fbp == NULL ) {
1565                         if ((error = xfs_dir2_grow_inode(args, XFS_DIR2_FREE_SPACE,
1566                                                         &fbno))) {
1567                                 return error;
1568                         }
1569
1570                         if (unlikely(XFS_DIR2_DB_TO_FDB(mp, dbno) != fbno)) {
1571                                 cmn_err(CE_ALERT,
1572                                         "xfs_dir2_node_addname_int: dir ino "
1573                                         "%llu needed freesp block %lld for\n"
1574                                         "  data block %lld, got %lld\n"
1575                                         "  ifbno %llu lastfbno %d\n",
1576                                         (unsigned long long)dp->i_ino,
1577                                         (long long)XFS_DIR2_DB_TO_FDB(mp, dbno),
1578                                         (long long)dbno, (long long)fbno,
1579                                         (unsigned long long)ifbno, lastfbno);
1580                                 if (fblk) {
1581                                         cmn_err(CE_ALERT,
1582                                                 " fblk 0x%p blkno %llu "
1583                                                 "index %d magic 0x%x\n",
1584                                                 fblk,
1585                                                 (unsigned long long)fblk->blkno,
1586                                                 fblk->index,
1587                                                 fblk->magic);
1588                                 } else {
1589                                         cmn_err(CE_ALERT,
1590                                                 " ... fblk is NULL\n");
1591                                 }
1592                                 XFS_ERROR_REPORT("xfs_dir2_node_addname_int",
1593                                                  XFS_ERRLEVEL_LOW, mp);
1594                                 return XFS_ERROR(EFSCORRUPTED);
1595                         }
1596
1597                         /*
1598                          * Get a buffer for the new block.
1599                          */
1600                         if ((error = xfs_da_get_buf(tp, dp,
1601                                                    XFS_DIR2_DB_TO_DA(mp, fbno),
1602                                                    -1, &fbp, XFS_DATA_FORK))) {
1603                                 return error;
1604                         }
1605                         ASSERT(fbp != NULL);
1606
1607                         /*
1608                          * Initialize the new block to be empty, and remember
1609                          * its first slot as our empty slot.
1610                          */
1611                         free = fbp->data;
1612                         free->hdr.magic = cpu_to_be32(XFS_DIR2_FREE_MAGIC);
1613                         free->hdr.firstdb = cpu_to_be32(
1614                                 (fbno - XFS_DIR2_FREE_FIRSTDB(mp)) *
1615                                 XFS_DIR2_MAX_FREE_BESTS(mp));
1616                         free->hdr.nvalid = 0;
1617                         free->hdr.nused = 0;
1618                 } else {
1619                         free = fbp->data;
1620                         ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
1621                 }
1622
1623                 /*
1624                  * Set the freespace block index from the data block number.
1625                  */
1626                 findex = XFS_DIR2_DB_TO_FDINDEX(mp, dbno);
1627                 /*
1628                  * If it's after the end of the current entries in the
1629                  * freespace block, extend that table.
1630                  */
1631                 if (findex >= be32_to_cpu(free->hdr.nvalid)) {
1632                         ASSERT(findex < XFS_DIR2_MAX_FREE_BESTS(mp));
1633                         free->hdr.nvalid = cpu_to_be32(findex + 1);
1634                         /*
1635                          * Tag new entry so nused will go up.
1636                          */
1637                         free->bests[findex] = cpu_to_be16(NULLDATAOFF);
1638                 }
1639                 /*
1640                  * If this entry was for an empty data block
1641                  * (this should always be true) then update the header.
1642                  */
1643                 if (be16_to_cpu(free->bests[findex]) == NULLDATAOFF) {
1644                         be32_add(&free->hdr.nused, 1);
1645                         xfs_dir2_free_log_header(tp, fbp);
1646                 }
1647                 /*
1648                  * Update the real value in the table.
1649                  * We haven't allocated the data entry yet so this will
1650                  * change again.
1651                  */
1652                 data = dbp->data;
1653                 free->bests[findex] = data->hdr.bestfree[0].length;
1654                 logfree = 1;
1655         }
1656         /*
1657          * We had a data block so we don't have to make a new one.
1658          */
1659         else {
1660                 /*
1661                  * If just checking, we succeeded.
1662                  */
1663                 if (args->justcheck) {
1664                         if ((fblk == NULL || fblk->bp == NULL) && fbp != NULL)
1665                                 xfs_da_buf_done(fbp);
1666                         return 0;
1667                 }
1668                 /*
1669                  * Read the data block in.
1670                  */
1671                 if (unlikely(
1672                     error = xfs_da_read_buf(tp, dp, XFS_DIR2_DB_TO_DA(mp, dbno),
1673                                 -1, &dbp, XFS_DATA_FORK))) {
1674                         if ((fblk == NULL || fblk->bp == NULL) && fbp != NULL)
1675                                 xfs_da_buf_done(fbp);
1676                         return error;
1677                 }
1678                 data = dbp->data;
1679                 logfree = 0;
1680         }
1681         ASSERT(be16_to_cpu(data->hdr.bestfree[0].length) >= length);
1682         /*
1683          * Point to the existing unused space.
1684          */
1685         dup = (xfs_dir2_data_unused_t *)
1686               ((char *)data + be16_to_cpu(data->hdr.bestfree[0].offset));
1687         needscan = needlog = 0;
1688         /*
1689          * Mark the first part of the unused space, inuse for us.
1690          */
1691         xfs_dir2_data_use_free(tp, dbp, dup,
1692                 (xfs_dir2_data_aoff_t)((char *)dup - (char *)data), length,
1693                 &needlog, &needscan);
1694         /*
1695          * Fill in the new entry and log it.
1696          */
1697         dep = (xfs_dir2_data_entry_t *)dup;
1698         INT_SET(dep->inumber, ARCH_CONVERT, args->inumber);
1699         dep->namelen = args->namelen;
1700         memcpy(dep->name, args->name, dep->namelen);
1701         tagp = XFS_DIR2_DATA_ENTRY_TAG_P(dep);
1702         *tagp = cpu_to_be16((char *)dep - (char *)data);
1703         xfs_dir2_data_log_entry(tp, dbp, dep);
1704         /*
1705          * Rescan the block for bestfree if needed.
1706          */
1707         if (needscan)
1708                 xfs_dir2_data_freescan(mp, data, &needlog, NULL);
1709         /*
1710          * Log the data block header if needed.
1711          */
1712         if (needlog)
1713                 xfs_dir2_data_log_header(tp, dbp);
1714         /*
1715          * If the freespace entry is now wrong, update it.
1716          */
1717         if (be16_to_cpu(free->bests[findex]) != be16_to_cpu(data->hdr.bestfree[0].length)) {
1718                 free->bests[findex] = data->hdr.bestfree[0].length;
1719                 logfree = 1;
1720         }
1721         /*
1722          * Log the freespace entry if needed.
1723          */
1724         if (logfree)
1725                 xfs_dir2_free_log_bests(tp, fbp, findex, findex);
1726         /*
1727          * If the caller didn't hand us the freespace block, drop it.
1728          */
1729         if ((fblk == NULL || fblk->bp == NULL) && fbp != NULL)
1730                 xfs_da_buf_done(fbp);
1731         /*
1732          * Return the data block and offset in args, then drop the data block.
1733          */
1734         args->blkno = (xfs_dablk_t)dbno;
1735         args->index = be16_to_cpu(*tagp);
1736         xfs_da_buf_done(dbp);
1737         return 0;
1738 }
1739
1740 /*
1741  * Lookup an entry in a node-format directory.
1742  * All the real work happens in xfs_da_node_lookup_int.
1743  * The only real output is the inode number of the entry.
1744  */
1745 int                                             /* error */
1746 xfs_dir2_node_lookup(
1747         xfs_da_args_t   *args)                  /* operation arguments */
1748 {
1749         int             error;                  /* error return value */
1750         int             i;                      /* btree level */
1751         int             rval;                   /* operation return value */
1752         xfs_da_state_t  *state;                 /* btree cursor */
1753
1754         xfs_dir2_trace_args("node_lookup", args);
1755         /*
1756          * Allocate and initialize the btree cursor.
1757          */
1758         state = xfs_da_state_alloc();
1759         state->args = args;
1760         state->mp = args->dp->i_mount;
1761         state->blocksize = state->mp->m_dirblksize;
1762         state->node_ents = state->mp->m_dir_node_ents;
1763         /*
1764          * Fill in the path to the entry in the cursor.
1765          */
1766         error = xfs_da_node_lookup_int(state, &rval);
1767         if (error)
1768                 rval = error;
1769         /*
1770          * Release the btree blocks and leaf block.
1771          */
1772         for (i = 0; i < state->path.active; i++) {
1773                 xfs_da_brelse(args->trans, state->path.blk[i].bp);
1774                 state->path.blk[i].bp = NULL;
1775         }
1776         /*
1777          * Release the data block if we have it.
1778          */
1779         if (state->extravalid && state->extrablk.bp) {
1780                 xfs_da_brelse(args->trans, state->extrablk.bp);
1781                 state->extrablk.bp = NULL;
1782         }
1783         xfs_da_state_free(state);
1784         return rval;
1785 }
1786
1787 /*
1788  * Remove an entry from a node-format directory.
1789  */
1790 int                                             /* error */
1791 xfs_dir2_node_removename(
1792         xfs_da_args_t           *args)          /* operation arguments */
1793 {
1794         xfs_da_state_blk_t      *blk;           /* leaf block */
1795         int                     error;          /* error return value */
1796         int                     rval;           /* operation return value */
1797         xfs_da_state_t          *state;         /* btree cursor */
1798
1799         xfs_dir2_trace_args("node_removename", args);
1800         /*
1801          * Allocate and initialize the btree cursor.
1802          */
1803         state = xfs_da_state_alloc();
1804         state->args = args;
1805         state->mp = args->dp->i_mount;
1806         state->blocksize = state->mp->m_dirblksize;
1807         state->node_ents = state->mp->m_dir_node_ents;
1808         /*
1809          * Look up the entry we're deleting, set up the cursor.
1810          */
1811         error = xfs_da_node_lookup_int(state, &rval);
1812         if (error) {
1813                 rval = error;
1814         }
1815         /*
1816          * Didn't find it, upper layer screwed up.
1817          */
1818         if (rval != EEXIST) {
1819                 xfs_da_state_free(state);
1820                 return rval;
1821         }
1822         blk = &state->path.blk[state->path.active - 1];
1823         ASSERT(blk->magic == XFS_DIR2_LEAFN_MAGIC);
1824         ASSERT(state->extravalid);
1825         /*
1826          * Remove the leaf and data entries.
1827          * Extrablk refers to the data block.
1828          */
1829         error = xfs_dir2_leafn_remove(args, blk->bp, blk->index,
1830                 &state->extrablk, &rval);
1831         if (error) {
1832                 return error;
1833         }
1834         /*
1835          * Fix the hash values up the btree.
1836          */
1837         xfs_da_fixhashpath(state, &state->path);
1838         /*
1839          * If we need to join leaf blocks, do it.
1840          */
1841         if (rval && state->path.active > 1)
1842                 error = xfs_da_join(state);
1843         /*
1844          * If no errors so far, try conversion to leaf format.
1845          */
1846         if (!error)
1847                 error = xfs_dir2_node_to_leaf(state);
1848         xfs_da_state_free(state);
1849         return error;
1850 }
1851
1852 /*
1853  * Replace an entry's inode number in a node-format directory.
1854  */
1855 int                                             /* error */
1856 xfs_dir2_node_replace(
1857         xfs_da_args_t           *args)          /* operation arguments */
1858 {
1859         xfs_da_state_blk_t      *blk;           /* leaf block */
1860         xfs_dir2_data_t         *data;          /* data block structure */
1861         xfs_dir2_data_entry_t   *dep;           /* data entry changed */
1862         int                     error;          /* error return value */
1863         int                     i;              /* btree level */
1864         xfs_ino_t               inum;           /* new inode number */
1865         xfs_dir2_leaf_t         *leaf;          /* leaf structure */
1866         xfs_dir2_leaf_entry_t   *lep;           /* leaf entry being changed */
1867         int                     rval;           /* internal return value */
1868         xfs_da_state_t          *state;         /* btree cursor */
1869
1870         xfs_dir2_trace_args("node_replace", args);
1871         /*
1872          * Allocate and initialize the btree cursor.
1873          */
1874         state = xfs_da_state_alloc();
1875         state->args = args;
1876         state->mp = args->dp->i_mount;
1877         state->blocksize = state->mp->m_dirblksize;
1878         state->node_ents = state->mp->m_dir_node_ents;
1879         inum = args->inumber;
1880         /*
1881          * Lookup the entry to change in the btree.
1882          */
1883         error = xfs_da_node_lookup_int(state, &rval);
1884         if (error) {
1885                 rval = error;
1886         }
1887         /*
1888          * It should be found, since the vnodeops layer has looked it up
1889          * and locked it.  But paranoia is good.
1890          */
1891         if (rval == EEXIST) {
1892                 /*
1893                  * Find the leaf entry.
1894                  */
1895                 blk = &state->path.blk[state->path.active - 1];
1896                 ASSERT(blk->magic == XFS_DIR2_LEAFN_MAGIC);
1897                 leaf = blk->bp->data;
1898                 lep = &leaf->ents[blk->index];
1899                 ASSERT(state->extravalid);
1900                 /*
1901                  * Point to the data entry.
1902                  */
1903                 data = state->extrablk.bp->data;
1904                 ASSERT(be32_to_cpu(data->hdr.magic) == XFS_DIR2_DATA_MAGIC);
1905                 dep = (xfs_dir2_data_entry_t *)
1906                       ((char *)data +
1907                        XFS_DIR2_DATAPTR_TO_OFF(state->mp, be32_to_cpu(lep->address)));
1908                 ASSERT(inum != INT_GET(dep->inumber, ARCH_CONVERT));
1909                 /*
1910                  * Fill in the new inode number and log the entry.
1911                  */
1912                 INT_SET(dep->inumber, ARCH_CONVERT, inum);
1913                 xfs_dir2_data_log_entry(args->trans, state->extrablk.bp, dep);
1914                 rval = 0;
1915         }
1916         /*
1917          * Didn't find it, and we're holding a data block.  Drop it.
1918          */
1919         else if (state->extravalid) {
1920                 xfs_da_brelse(args->trans, state->extrablk.bp);
1921                 state->extrablk.bp = NULL;
1922         }
1923         /*
1924          * Release all the buffers in the cursor.
1925          */
1926         for (i = 0; i < state->path.active; i++) {
1927                 xfs_da_brelse(args->trans, state->path.blk[i].bp);
1928                 state->path.blk[i].bp = NULL;
1929         }
1930         xfs_da_state_free(state);
1931         return rval;
1932 }
1933
1934 /*
1935  * Trim off a trailing empty freespace block.
1936  * Return (in rvalp) 1 if we did it, 0 if not.
1937  */
1938 int                                             /* error */
1939 xfs_dir2_node_trim_free(
1940         xfs_da_args_t           *args,          /* operation arguments */
1941         xfs_fileoff_t           fo,             /* free block number */
1942         int                     *rvalp)         /* out: did something */
1943 {
1944         xfs_dabuf_t             *bp;            /* freespace buffer */
1945         xfs_inode_t             *dp;            /* incore directory inode */
1946         int                     error;          /* error return code */
1947         xfs_dir2_free_t         *free;          /* freespace structure */
1948         xfs_mount_t             *mp;            /* filesystem mount point */
1949         xfs_trans_t             *tp;            /* transaction pointer */
1950
1951         dp = args->dp;
1952         mp = dp->i_mount;
1953         tp = args->trans;
1954         /*
1955          * Read the freespace block.
1956          */
1957         if (unlikely(error = xfs_da_read_buf(tp, dp, (xfs_dablk_t)fo, -2, &bp,
1958                         XFS_DATA_FORK))) {
1959                 return error;
1960         }
1961
1962         /*
1963          * There can be holes in freespace.  If fo is a hole, there's
1964          * nothing to do.
1965          */
1966         if (bp == NULL) {
1967                 return 0;
1968         }
1969         free = bp->data;
1970         ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
1971         /*
1972          * If there are used entries, there's nothing to do.
1973          */
1974         if (be32_to_cpu(free->hdr.nused) > 0) {
1975                 xfs_da_brelse(tp, bp);
1976                 *rvalp = 0;
1977                 return 0;
1978         }
1979         /*
1980          * Blow the block away.
1981          */
1982         if ((error =
1983             xfs_dir2_shrink_inode(args, XFS_DIR2_DA_TO_DB(mp, (xfs_dablk_t)fo),
1984                     bp))) {
1985                 /*
1986                  * Can't fail with ENOSPC since that only happens with no
1987                  * space reservation, when breaking up an extent into two
1988                  * pieces.  This is the last block of an extent.
1989                  */
1990                 ASSERT(error != ENOSPC);
1991                 xfs_da_brelse(tp, bp);
1992                 return error;
1993         }
1994         /*
1995          * Return that we succeeded.
1996          */
1997         *rvalp = 1;
1998         return 0;
1999 }