fs/xfs/xfs_da_btree.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_bit.h"
  22 #include "xfs_log.h"
  23 #include "xfs_inum.h"
  24 #include "xfs_trans.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_ag.h"
  27 #include "xfs_dir2.h"
  28 #include "xfs_dmapi.h"
  29 #include "xfs_mount.h"
  30 #include "xfs_da_btree.h"
  31 #include "xfs_bmap_btree.h"
  32 #include "xfs_alloc_btree.h"
  33 #include "xfs_ialloc_btree.h"
  34 #include "xfs_dir2_sf.h"
  35 #include "xfs_attr_sf.h"
  36 #include "xfs_dinode.h"
  37 #include "xfs_inode.h"
  38 #include "xfs_inode_item.h"
  39 #include "xfs_alloc.h"
  40 #include "xfs_btree.h"
  41 #include "xfs_bmap.h"
  42 #include "xfs_attr.h"
  43 #include "xfs_attr_leaf.h"
  44 #include "xfs_dir2_data.h"
  45 #include "xfs_dir2_leaf.h"
  46 #include "xfs_dir2_block.h"
  47 #include "xfs_dir2_node.h"
  48 #include "xfs_error.h"
  49
  50 /*
  51  * xfs_da_btree.c
  52  *
  53  * Routines to implement directories as Btrees of hashed names.
  54  */
  55
  56 /*========================================================================
  57  * Function prototypes for the kernel.
  58  *========================================================================*/
  59
  60 /*
  61  * Routines used for growing the Btree.
  62  */
  63 STATIC int xfs_da_root_split(xfs_da_state_t *state,
  64                                             xfs_da_state_blk_t *existing_root,
  65                                             xfs_da_state_blk_t *new_child);
  66 STATIC int xfs_da_node_split(xfs_da_state_t *state,
  67                                             xfs_da_state_blk_t *existing_blk,
  68                                             xfs_da_state_blk_t *split_blk,
  69                                             xfs_da_state_blk_t *blk_to_add,
  70                                             int treelevel,
  71                                             int *result);
  72 STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
  73                                          xfs_da_state_blk_t *node_blk_1,
  74                                          xfs_da_state_blk_t *node_blk_2);
  75 STATIC void xfs_da_node_add(xfs_da_state_t *state,
  76                                    xfs_da_state_blk_t *old_node_blk,
  77                                    xfs_da_state_blk_t *new_node_blk);
  78
  79 /*
  80  * Routines used for shrinking the Btree.
  81  */
  82 STATIC int xfs_da_root_join(xfs_da_state_t *state,
  83                                            xfs_da_state_blk_t *root_blk);
  84 STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
  85 STATIC void xfs_da_node_remove(xfs_da_state_t *state,
  86                                               xfs_da_state_blk_t *drop_blk);
  87 STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
  88                                          xfs_da_state_blk_t *src_node_blk,
  89                                          xfs_da_state_blk_t *dst_node_blk);
  90
  91 /*
  92  * Utility routines.
  93  */
  94 STATIC uint     xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count);
  95 STATIC int      xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp);
  96 STATIC xfs_dabuf_t *xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra);
  97 STATIC int      xfs_da_blk_unlink(xfs_da_state_t *state,
  98                                   xfs_da_state_blk_t *drop_blk,
  99                                   xfs_da_state_blk_t *save_blk);
 100 STATIC void     xfs_da_state_kill_altpath(xfs_da_state_t *state);
 101
 102 /*========================================================================
 103  * Routines used for growing the Btree.
 104  *========================================================================*/
 105
 106 /*
 107  * Create the initial contents of an intermediate node.
 108  */
 109 int
 110 xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
 111                                  xfs_dabuf_t **bpp, int whichfork)
 112 {
 113         xfs_da_intnode_t *node;
 114         xfs_dabuf_t *bp;
 115         int error;
 116         xfs_trans_t *tp;
 117
 118         tp = args->trans;
 119         error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
 120         if (error)
 121                 return(error);
 122         ASSERT(bp != NULL);
 123         node = bp->data;
 124         node->hdr.info.forw = 0;
 125         node->hdr.info.back = 0;
 126         node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC);
 127         node->hdr.info.pad = 0;
 128         node->hdr.count = 0;
 129         node->hdr.level = cpu_to_be16(level);
 130
 131         xfs_da_log_buf(tp, bp,
 132                 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 133
 134         *bpp = bp;
 135         return(0);
 136 }
 137
 138 /*
 139  * Split a leaf node, rebalance, then possibly split
 140  * intermediate nodes, rebalance, etc.
 141  */
 142 int                                                     /* error */
 143 xfs_da_split(xfs_da_state_t *state)
 144 {
 145         xfs_da_state_blk_t *oldblk, *newblk, *addblk;
 146         xfs_da_intnode_t *node;
 147         xfs_dabuf_t *bp;
 148         int max, action, error, i;
 149
 150         /*
 151          * Walk back up the tree splitting/inserting/adjusting as necessary.
 152          * If we need to insert and there isn't room, split the node, then
 153          * decide which fragment to insert the new block from below into.
 154          * Note that we may split the root this way, but we need more fixup.
 155          */
 156         max = state->path.active - 1;
 157         ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
 158         ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
 159                state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
 160
 161         addblk = &state->path.blk[max];         /* initial dummy value */
 162         for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
 163                 oldblk = &state->path.blk[i];
 164                 newblk = &state->altpath.blk[i];
 165
 166                 /*
 167                  * If a leaf node then
 168                  *     Allocate a new leaf node, then rebalance across them.
 169                  * else if an intermediate node then
 170                  *     We split on the last layer, must we split the node?
 171                  */
 172                 switch (oldblk->magic) {
 173                 case XFS_ATTR_LEAF_MAGIC:
 174                         error = xfs_attr_leaf_split(state, oldblk, newblk);
 175                         if ((error != 0) && (error != ENOSPC)) {
 176                                 return(error);  /* GROT: attr is inconsistent */
 177                         }
 178                         if (!error) {
 179                                 addblk = newblk;
 180                                 break;
 181                         }
 182                         /*
 183                          * Entry wouldn't fit, split the leaf again.
 184                          */
 185                         state->extravalid = 1;
 186                         if (state->inleaf) {
 187                                 state->extraafter = 0;  /* before newblk */
 188                                 error = xfs_attr_leaf_split(state, oldblk,
 189                                                             &state->extrablk);
 190                         } else {
 191                                 state->extraafter = 1;  /* after newblk */
 192                                 error = xfs_attr_leaf_split(state, newblk,
 193                                                             &state->extrablk);
 194                         }
 195                         if (error)
 196                                 return(error);  /* GROT: attr inconsistent */
 197                         addblk = newblk;
 198                         break;
 199                 case XFS_DIR2_LEAFN_MAGIC:
 200                         error = xfs_dir2_leafn_split(state, oldblk, newblk);
 201                         if (error)
 202                                 return error;
 203                         addblk = newblk;
 204                         break;
 205                 case XFS_DA_NODE_MAGIC:
 206                         error = xfs_da_node_split(state, oldblk, newblk, addblk,
 207                                                          max - i, &action);
 208                         xfs_da_buf_done(addblk->bp);
 209                         addblk->bp = NULL;
 210                         if (error)
 211                                 return(error);  /* GROT: dir is inconsistent */
 212                         /*
 213                          * Record the newly split block for the next time thru?
 214                          */
 215                         if (action)
 216                                 addblk = newblk;
 217                         else
 218                                 addblk = NULL;
 219                         break;
 220                 }
 221
 222                 /*
 223                  * Update the btree to show the new hashval for this child.
 224                  */
 225                 xfs_da_fixhashpath(state, &state->path);
 226                 /*
 227                  * If we won't need this block again, it's getting dropped
 228                  * from the active path by the loop control, so we need
 229                  * to mark it done now.
 230                  */
 231                 if (i > 0 || !addblk)
 232                         xfs_da_buf_done(oldblk->bp);
 233         }
 234         if (!addblk)
 235                 return(0);
 236
 237         /*
 238          * Split the root node.
 239          */
 240         ASSERT(state->path.active == 0);
 241         oldblk = &state->path.blk[0];
 242         error = xfs_da_root_split(state, oldblk, addblk);
 243         if (error) {
 244                 xfs_da_buf_done(oldblk->bp);
 245                 xfs_da_buf_done(addblk->bp);
 246                 addblk->bp = NULL;
 247                 return(error);  /* GROT: dir is inconsistent */
 248         }
 249
 250         /*
 251          * Update pointers to the node which used to be block 0 and
 252          * just got bumped because of the addition of a new root node.
 253          * There might be three blocks involved if a double split occurred,
 254          * and the original block 0 could be at any position in the list.
 255          */
 256
 257         node = oldblk->bp->data;
 258         if (node->hdr.info.forw) {
 259                 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
 260                         bp = addblk->bp;
 261                 } else {
 262                         ASSERT(state->extravalid);
 263                         bp = state->extrablk.bp;
 264                 }
 265                 node = bp->data;
 266                 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
 267                 xfs_da_log_buf(state->args->trans, bp,
 268                     XFS_DA_LOGRANGE(node, &node->hdr.info,
 269                     sizeof(node->hdr.info)));
 270         }
 271         node = oldblk->bp->data;
 272         if (node->hdr.info.back) {
 273                 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
 274                         bp = addblk->bp;
 275                 } else {
 276                         ASSERT(state->extravalid);
 277                         bp = state->extrablk.bp;
 278                 }
 279                 node = bp->data;
 280                 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
 281                 xfs_da_log_buf(state->args->trans, bp,
 282                     XFS_DA_LOGRANGE(node, &node->hdr.info,
 283                     sizeof(node->hdr.info)));
 284         }
 285         xfs_da_buf_done(oldblk->bp);
 286         xfs_da_buf_done(addblk->bp);
 287         addblk->bp = NULL;
 288         return(0);
 289 }
 290
 291 /*
 292  * Split the root.  We have to create a new root and point to the two
 293  * parts (the split old root) that we just created.  Copy block zero to
 294  * the EOF, extending the inode in process.
 295  */
 296 STATIC int                                              /* error */
 297 xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
 298                                  xfs_da_state_blk_t *blk2)
 299 {
 300         xfs_da_intnode_t *node, *oldroot;
 301         xfs_da_args_t *args;
 302         xfs_dablk_t blkno;
 303         xfs_dabuf_t *bp;
 304         int error, size;
 305         xfs_inode_t *dp;
 306         xfs_trans_t *tp;
 307         xfs_mount_t *mp;
 308         xfs_dir2_leaf_t *leaf;
 309
 310         /*
 311          * Copy the existing (incorrect) block from the root node position
 312          * to a free space somewhere.
 313          */
 314         args = state->args;
 315         ASSERT(args != NULL);
 316         error = xfs_da_grow_inode(args, &blkno);
 317         if (error)
 318                 return(error);
 319         dp = args->dp;
 320         tp = args->trans;
 321         mp = state->mp;
 322         error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
 323         if (error)
 324                 return(error);
 325         ASSERT(bp != NULL);
 326         node = bp->data;
 327         oldroot = blk1->bp->data;
 328         if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC) {
 329                 size = (int)((char *)&oldroot->btree[be16_to_cpu(oldroot->hdr.count)] -
 330                              (char *)oldroot);
 331         } else {
 332                 ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 333                 leaf = (xfs_dir2_leaf_t *)oldroot;
 334                 size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] -
 335                              (char *)leaf);
 336         }
 337         memcpy(node, oldroot, size);
 338         xfs_da_log_buf(tp, bp, 0, size - 1);
 339         xfs_da_buf_done(blk1->bp);
 340         blk1->bp = bp;
 341         blk1->blkno = blkno;
 342
 343         /*
 344          * Set up the new root node.
 345          */
 346         error = xfs_da_node_create(args,
 347                 (args->whichfork == XFS_DATA_FORK) ? mp->m_dirleafblk : 0,
 348                 be16_to_cpu(node->hdr.level) + 1, &bp, args->whichfork);
 349         if (error)
 350                 return(error);
 351         node = bp->data;
 352         node->btree[0].hashval = cpu_to_be32(blk1->hashval);
 353         node->btree[0].before = cpu_to_be32(blk1->blkno);
 354         node->btree[1].hashval = cpu_to_be32(blk2->hashval);
 355         node->btree[1].before = cpu_to_be32(blk2->blkno);
 356         node->hdr.count = cpu_to_be16(2);
 357
 358 #ifdef DEBUG
 359         if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC) {
 360                 ASSERT(blk1->blkno >= mp->m_dirleafblk &&
 361                        blk1->blkno < mp->m_dirfreeblk);
 362                 ASSERT(blk2->blkno >= mp->m_dirleafblk &&
 363                        blk2->blkno < mp->m_dirfreeblk);
 364         }
 365 #endif
 366
 367         /* Header is already logged by xfs_da_node_create */
 368         xfs_da_log_buf(tp, bp,
 369                 XFS_DA_LOGRANGE(node, node->btree,
 370                         sizeof(xfs_da_node_entry_t) * 2));
 371         xfs_da_buf_done(bp);
 372
 373         return(0);
 374 }
 375
 376 /*
 377  * Split the node, rebalance, then add the new entry.
 378  */
 379 STATIC int                                              /* error */
 380 xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
 381                                  xfs_da_state_blk_t *newblk,
 382                                  xfs_da_state_blk_t *addblk,
 383                                  int treelevel, int *result)
 384 {
 385         xfs_da_intnode_t *node;
 386         xfs_dablk_t blkno;
 387         int newcount, error;
 388         int useextra;
 389
 390         node = oldblk->bp->data;
 391         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 392
 393         /*
 394          * With V2 dirs the extra block is data or freespace.
 395          */
 396         useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
 397         newcount = 1 + useextra;
 398         /*
 399          * Do we have to split the node?
 400          */
 401         if ((be16_to_cpu(node->hdr.count) + newcount) > state->node_ents) {
 402                 /*
 403                  * Allocate a new node, add to the doubly linked chain of
 404                  * nodes, then move some of our excess entries into it.
 405                  */
 406                 error = xfs_da_grow_inode(state->args, &blkno);
 407                 if (error)
 408                         return(error);  /* GROT: dir is inconsistent */
 409
 410                 error = xfs_da_node_create(state->args, blkno, treelevel,
 411                                            &newblk->bp, state->args->whichfork);
 412                 if (error)
 413                         return(error);  /* GROT: dir is inconsistent */
 414                 newblk->blkno = blkno;
 415                 newblk->magic = XFS_DA_NODE_MAGIC;
 416                 xfs_da_node_rebalance(state, oldblk, newblk);
 417                 error = xfs_da_blk_link(state, oldblk, newblk);
 418                 if (error)
 419                         return(error);
 420                 *result = 1;
 421         } else {
 422                 *result = 0;
 423         }
 424
 425         /*
 426          * Insert the new entry(s) into the correct block
 427          * (updating last hashval in the process).
 428          *
 429          * xfs_da_node_add() inserts BEFORE the given index,
 430          * and as a result of using node_lookup_int() we always
 431          * point to a valid entry (not after one), but a split
 432          * operation always results in a new block whose hashvals
 433          * FOLLOW the current block.
 434          *
 435          * If we had double-split op below us, then add the extra block too.
 436          */
 437         node = oldblk->bp->data;
 438         if (oldblk->index <= be16_to_cpu(node->hdr.count)) {
 439                 oldblk->index++;
 440                 xfs_da_node_add(state, oldblk, addblk);
 441                 if (useextra) {
 442                         if (state->extraafter)
 443                                 oldblk->index++;
 444                         xfs_da_node_add(state, oldblk, &state->extrablk);
 445                         state->extravalid = 0;
 446                 }
 447         } else {
 448                 newblk->index++;
 449                 xfs_da_node_add(state, newblk, addblk);
 450                 if (useextra) {
 451                         if (state->extraafter)
 452                                 newblk->index++;
 453                         xfs_da_node_add(state, newblk, &state->extrablk);
 454                         state->extravalid = 0;
 455                 }
 456         }
 457
 458         return(0);
 459 }
 460
 461 /*
 462  * Balance the btree elements between two intermediate nodes,
 463  * usually one full and one empty.
 464  *
 465  * NOTE: if blk2 is empty, then it will get the upper half of blk1.
 466  */
 467 STATIC void
 468 xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
 469                                      xfs_da_state_blk_t *blk2)
 470 {
 471         xfs_da_intnode_t *node1, *node2, *tmpnode;
 472         xfs_da_node_entry_t *btree_s, *btree_d;
 473         int count, tmp;
 474         xfs_trans_t *tp;
 475
 476         node1 = blk1->bp->data;
 477         node2 = blk2->bp->data;
 478         /*
 479          * Figure out how many entries need to move, and in which direction.
 480          * Swap the nodes around if that makes it simpler.
 481          */
 482         if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
 483             ((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) ||
 484              (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
 485               be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
 486                 tmpnode = node1;
 487                 node1 = node2;
 488                 node2 = tmpnode;
 489         }
 490         ASSERT(be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 491         ASSERT(be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 492         count = (be16_to_cpu(node1->hdr.count) - be16_to_cpu(node2->hdr.count)) / 2;
 493         if (count == 0)
 494                 return;
 495         tp = state->args->trans;
 496         /*
 497          * Two cases: high-to-low and low-to-high.
 498          */
 499         if (count > 0) {
 500                 /*
 501                  * Move elements in node2 up to make a hole.
 502                  */
 503                 if ((tmp = be16_to_cpu(node2->hdr.count)) > 0) {
 504                         tmp *= (uint)sizeof(xfs_da_node_entry_t);
 505                         btree_s = &node2->btree[0];
 506                         btree_d = &node2->btree[count];
 507                         memmove(btree_d, btree_s, tmp);
 508                 }
 509
 510                 /*
 511                  * Move the req'd B-tree elements from high in node1 to
 512                  * low in node2.
 513                  */
 514                 be16_add(&node2->hdr.count, count);
 515                 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
 516                 btree_s = &node1->btree[be16_to_cpu(node1->hdr.count) - count];
 517                 btree_d = &node2->btree[0];
 518                 memcpy(btree_d, btree_s, tmp);
 519                 be16_add(&node1->hdr.count, -count);
 520         } else {
 521                 /*
 522                  * Move the req'd B-tree elements from low in node2 to
 523                  * high in node1.
 524                  */
 525                 count = -count;
 526                 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
 527                 btree_s = &node2->btree[0];
 528                 btree_d = &node1->btree[be16_to_cpu(node1->hdr.count)];
 529                 memcpy(btree_d, btree_s, tmp);
 530                 be16_add(&node1->hdr.count, count);
 531                 xfs_da_log_buf(tp, blk1->bp,
 532                         XFS_DA_LOGRANGE(node1, btree_d, tmp));
 533
 534                 /*
 535                  * Move elements in node2 down to fill the hole.
 536                  */
 537                 tmp  = be16_to_cpu(node2->hdr.count) - count;
 538                 tmp *= (uint)sizeof(xfs_da_node_entry_t);
 539                 btree_s = &node2->btree[count];
 540                 btree_d = &node2->btree[0];
 541                 memmove(btree_d, btree_s, tmp);
 542                 be16_add(&node2->hdr.count, -count);
 543         }
 544
 545         /*
 546          * Log header of node 1 and all current bits of node 2.
 547          */
 548         xfs_da_log_buf(tp, blk1->bp,
 549                 XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
 550         xfs_da_log_buf(tp, blk2->bp,
 551                 XFS_DA_LOGRANGE(node2, &node2->hdr,
 552                         sizeof(node2->hdr) +
 553                         sizeof(node2->btree[0]) * be16_to_cpu(node2->hdr.count)));
 554
 555         /*
 556          * Record the last hashval from each block for upward propagation.
 557          * (note: don't use the swapped node pointers)
 558          */
 559         node1 = blk1->bp->data;
 560         node2 = blk2->bp->data;
 561         blk1->hashval = be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval);
 562         blk2->hashval = be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval);
 563
 564         /*
 565          * Adjust the expected index for insertion.
 566          */
 567         if (blk1->index >= be16_to_cpu(node1->hdr.count)) {
 568                 blk2->index = blk1->index - be16_to_cpu(node1->hdr.count);
 569                 blk1->index = be16_to_cpu(node1->hdr.count) + 1;        /* make it invalid */
 570         }
 571 }
 572
 573 /*
 574  * Add a new entry to an intermediate node.
 575  */
 576 STATIC void
 577 xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
 578                                xfs_da_state_blk_t *newblk)
 579 {
 580         xfs_da_intnode_t *node;
 581         xfs_da_node_entry_t *btree;
 582         int tmp;
 583         xfs_mount_t *mp;
 584
 585         node = oldblk->bp->data;
 586         mp = state->mp;
 587         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 588         ASSERT((oldblk->index >= 0) && (oldblk->index <= be16_to_cpu(node->hdr.count)));
 589         ASSERT(newblk->blkno != 0);
 590         if (state->args->whichfork == XFS_DATA_FORK)
 591                 ASSERT(newblk->blkno >= mp->m_dirleafblk &&
 592                        newblk->blkno < mp->m_dirfreeblk);
 593
 594         /*
 595          * We may need to make some room before we insert the new node.
 596          */
 597         tmp = 0;
 598         btree = &node->btree[ oldblk->index ];
 599         if (oldblk->index < be16_to_cpu(node->hdr.count)) {
 600                 tmp = (be16_to_cpu(node->hdr.count) - oldblk->index) * (uint)sizeof(*btree);
 601                 memmove(btree + 1, btree, tmp);
 602         }
 603         btree->hashval = cpu_to_be32(newblk->hashval);
 604         btree->before = cpu_to_be32(newblk->blkno);
 605         xfs_da_log_buf(state->args->trans, oldblk->bp,
 606                 XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
 607         be16_add(&node->hdr.count, 1);
 608         xfs_da_log_buf(state->args->trans, oldblk->bp,
 609                 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 610
 611         /*
 612          * Copy the last hash value from the oldblk to propagate upwards.
 613          */
 614         oldblk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1 ].hashval);
 615 }
 616
 617 /*========================================================================
 618  * Routines used for shrinking the Btree.
 619  *========================================================================*/
 620
 621 /*
 622  * Deallocate an empty leaf node, remove it from its parent,
 623  * possibly deallocating that block, etc...
 624  */
 625 int
 626 xfs_da_join(xfs_da_state_t *state)
 627 {
 628         xfs_da_state_blk_t *drop_blk, *save_blk;
 629         int action, error;
 630
 631         action = 0;
 632         drop_blk = &state->path.blk[ state->path.active-1 ];
 633         save_blk = &state->altpath.blk[ state->path.active-1 ];
 634         ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
 635         ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
 636                drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
 637
 638         /*
 639          * Walk back up the tree joining/deallocating as necessary.
 640          * When we stop dropping blocks, break out.
 641          */
 642         for (  ; state->path.active >= 2; drop_blk--, save_blk--,
 643                  state->path.active--) {
 644                 /*
 645                  * See if we can combine the block with a neighbor.
 646                  *   (action == 0) => no options, just leave
 647                  *   (action == 1) => coalesce, then unlink
 648                  *   (action == 2) => block empty, unlink it
 649                  */
 650                 switch (drop_blk->magic) {
 651                 case XFS_ATTR_LEAF_MAGIC:
 652                         error = xfs_attr_leaf_toosmall(state, &action);
 653                         if (error)
 654                                 return(error);
 655                         if (action == 0)
 656                                 return(0);
 657                         xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
 658                         break;
 659                 case XFS_DIR2_LEAFN_MAGIC:
 660                         error = xfs_dir2_leafn_toosmall(state, &action);
 661                         if (error)
 662                                 return error;
 663                         if (action == 0)
 664                                 return 0;
 665                         xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
 666                         break;
 667                 case XFS_DA_NODE_MAGIC:
 668                         /*
 669                          * Remove the offending node, fixup hashvals,
 670                          * check for a toosmall neighbor.
 671                          */
 672                         xfs_da_node_remove(state, drop_blk);
 673                         xfs_da_fixhashpath(state, &state->path);
 674                         error = xfs_da_node_toosmall(state, &action);
 675                         if (error)
 676                                 return(error);
 677                         if (action == 0)
 678                                 return 0;
 679                         xfs_da_node_unbalance(state, drop_blk, save_blk);
 680                         break;
 681                 }
 682                 xfs_da_fixhashpath(state, &state->altpath);
 683                 error = xfs_da_blk_unlink(state, drop_blk, save_blk);
 684                 xfs_da_state_kill_altpath(state);
 685                 if (error)
 686                         return(error);
 687                 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
 688                                                          drop_blk->bp);
 689                 drop_blk->bp = NULL;
 690                 if (error)
 691                         return(error);
 692         }
 693         /*
 694          * We joined all the way to the top.  If it turns out that
 695          * we only have one entry in the root, make the child block
 696          * the new root.
 697          */
 698         xfs_da_node_remove(state, drop_blk);
 699         xfs_da_fixhashpath(state, &state->path);
 700         error = xfs_da_root_join(state, &state->path.blk[0]);
 701         return(error);
 702 }
 703
 704 /*
 705  * We have only one entry in the root.  Copy the only remaining child of
 706  * the old root to block 0 as the new root node.
 707  */
 708 STATIC int
 709 xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
 710 {
 711         xfs_da_intnode_t *oldroot;
 712         /* REFERENCED */
 713         xfs_da_blkinfo_t *blkinfo;
 714         xfs_da_args_t *args;
 715         xfs_dablk_t child;
 716         xfs_dabuf_t *bp;
 717         int error;
 718
 719         args = state->args;
 720         ASSERT(args != NULL);
 721         ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
 722         oldroot = root_blk->bp->data;
 723         ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 724         ASSERT(!oldroot->hdr.info.forw);
 725         ASSERT(!oldroot->hdr.info.back);
 726
 727         /*
 728          * If the root has more than one child, then don't do anything.
 729          */
 730         if (be16_to_cpu(oldroot->hdr.count) > 1)
 731                 return(0);
 732
 733         /*
 734          * Read in the (only) child block, then copy those bytes into
 735          * the root block's buffer and free the original child block.
 736          */
 737         child = be32_to_cpu(oldroot->btree[0].before);
 738         ASSERT(child != 0);
 739         error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp,
 740                                              args->whichfork);
 741         if (error)
 742                 return(error);
 743         ASSERT(bp != NULL);
 744         blkinfo = bp->data;
 745         if (be16_to_cpu(oldroot->hdr.level) == 1) {
 746                 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DIR2_LEAFN_MAGIC ||
 747                        be16_to_cpu(blkinfo->magic) == XFS_ATTR_LEAF_MAGIC);
 748         } else {
 749                 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DA_NODE_MAGIC);
 750         }
 751         ASSERT(!blkinfo->forw);
 752         ASSERT(!blkinfo->back);
 753         memcpy(root_blk->bp->data, bp->data, state->blocksize);
 754         xfs_da_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
 755         error = xfs_da_shrink_inode(args, child, bp);
 756         return(error);
 757 }
 758
 759 /*
 760  * Check a node block and its neighbors to see if the block should be
 761  * collapsed into one or the other neighbor.  Always keep the block
 762  * with the smaller block number.
 763  * If the current block is over 50% full, don't try to join it, return 0.
 764  * If the block is empty, fill in the state structure and return 2.
 765  * If it can be collapsed, fill in the state structure and return 1.
 766  * If nothing can be done, return 0.
 767  */
 768 STATIC int
 769 xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
 770 {
 771         xfs_da_intnode_t *node;
 772         xfs_da_state_blk_t *blk;
 773         xfs_da_blkinfo_t *info;
 774         int count, forward, error, retval, i;
 775         xfs_dablk_t blkno;
 776         xfs_dabuf_t *bp;
 777
 778         /*
 779          * Check for the degenerate case of the block being over 50% full.
 780          * If so, it's not worth even looking to see if we might be able
 781          * to coalesce with a sibling.
 782          */
 783         blk = &state->path.blk[ state->path.active-1 ];
 784         info = blk->bp->data;
 785         ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC);
 786         node = (xfs_da_intnode_t *)info;
 787         count = be16_to_cpu(node->hdr.count);
 788         if (count > (state->node_ents >> 1)) {
 789                 *action = 0;    /* blk over 50%, don't try to join */
 790                 return(0);      /* blk over 50%, don't try to join */
 791         }
 792
 793         /*
 794          * Check for the degenerate case of the block being empty.
 795          * If the block is empty, we'll simply delete it, no need to
 796          * coalesce it with a sibling block.  We choose (arbitrarily)
 797          * to merge with the forward block unless it is NULL.
 798          */
 799         if (count == 0) {
 800                 /*
 801                  * Make altpath point to the block we want to keep and
 802                  * path point to the block we want to drop (this one).
 803                  */
 804                 forward = (info->forw != 0);
 805                 memcpy(&state->altpath, &state->path, sizeof(state->path));
 806                 error = xfs_da_path_shift(state, &state->altpath, forward,
 807                                                  0, &retval);
 808                 if (error)
 809                         return(error);
 810                 if (retval) {
 811                         *action = 0;
 812                 } else {
 813                         *action = 2;
 814                 }
 815                 return(0);
 816         }
 817
 818         /*
 819          * Examine each sibling block to see if we can coalesce with
 820          * at least 25% free space to spare.  We need to figure out
 821          * whether to merge with the forward or the backward block.
 822          * We prefer coalescing with the lower numbered sibling so as
 823          * to shrink a directory over time.
 824          */
 825         /* start with smaller blk num */
 826         forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
 827         for (i = 0; i < 2; forward = !forward, i++) {
 828                 if (forward)
 829                         blkno = be32_to_cpu(info->forw);
 830                 else
 831                         blkno = be32_to_cpu(info->back);
 832                 if (blkno == 0)
 833                         continue;
 834                 error = xfs_da_read_buf(state->args->trans, state->args->dp,
 835                                         blkno, -1, &bp, state->args->whichfork);
 836                 if (error)
 837                         return(error);
 838                 ASSERT(bp != NULL);
 839
 840                 node = (xfs_da_intnode_t *)info;
 841                 count  = state->node_ents;
 842                 count -= state->node_ents >> 2;
 843                 count -= be16_to_cpu(node->hdr.count);
 844                 node = bp->data;
 845                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 846                 count -= be16_to_cpu(node->hdr.count);
 847                 xfs_da_brelse(state->args->trans, bp);
 848                 if (count >= 0)
 849                         break;  /* fits with at least 25% to spare */
 850         }
 851         if (i >= 2) {
 852                 *action = 0;
 853                 return(0);
 854         }
 855
 856         /*
 857          * Make altpath point to the block we want to keep (the lower
 858          * numbered block) and path point to the block we want to drop.
 859          */
 860         memcpy(&state->altpath, &state->path, sizeof(state->path));
 861         if (blkno < blk->blkno) {
 862                 error = xfs_da_path_shift(state, &state->altpath, forward,
 863                                                  0, &retval);
 864                 if (error) {
 865                         return(error);
 866                 }
 867                 if (retval) {
 868                         *action = 0;
 869                         return(0);
 870                 }
 871         } else {
 872                 error = xfs_da_path_shift(state, &state->path, forward,
 873                                                  0, &retval);
 874                 if (error) {
 875                         return(error);
 876                 }
 877                 if (retval) {
 878                         *action = 0;
 879                         return(0);
 880                 }
 881         }
 882         *action = 1;
 883         return(0);
 884 }
 885
 886 /*
 887  * Walk back up the tree adjusting hash values as necessary,
 888  * when we stop making changes, return.
 889  */
 890 void
 891 xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
 892 {
 893         xfs_da_state_blk_t *blk;
 894         xfs_da_intnode_t *node;
 895         xfs_da_node_entry_t *btree;
 896         xfs_dahash_t lasthash=0;
 897         int level, count;
 898
 899         level = path->active-1;
 900         blk = &path->blk[ level ];
 901         switch (blk->magic) {
 902         case XFS_ATTR_LEAF_MAGIC:
 903                 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
 904                 if (count == 0)
 905                         return;
 906                 break;
 907         case XFS_DIR2_LEAFN_MAGIC:
 908                 lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
 909                 if (count == 0)
 910                         return;
 911                 break;
 912         case XFS_DA_NODE_MAGIC:
 913                 lasthash = xfs_da_node_lasthash(blk->bp, &count);
 914                 if (count == 0)
 915                         return;
 916                 break;
 917         }
 918         for (blk--, level--; level >= 0; blk--, level--) {
 919                 node = blk->bp->data;
 920                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 921                 btree = &node->btree[ blk->index ];
 922                 if (be32_to_cpu(btree->hashval) == lasthash)
 923                         break;
 924                 blk->hashval = lasthash;
 925                 btree->hashval = cpu_to_be32(lasthash);
 926                 xfs_da_log_buf(state->args->trans, blk->bp,
 927                                   XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
 928
 929                 lasthash = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
 930         }
 931 }
 932
 933 /*
 934  * Remove an entry from an intermediate node.
 935  */
 936 STATIC void
 937 xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
 938 {
 939         xfs_da_intnode_t *node;
 940         xfs_da_node_entry_t *btree;
 941         int tmp;
 942
 943         node = drop_blk->bp->data;
 944         ASSERT(drop_blk->index < be16_to_cpu(node->hdr.count));
 945         ASSERT(drop_blk->index >= 0);
 946
 947         /*
 948          * Copy over the offending entry, or just zero it out.
 949          */
 950         btree = &node->btree[drop_blk->index];
 951         if (drop_blk->index < (be16_to_cpu(node->hdr.count)-1)) {
 952                 tmp  = be16_to_cpu(node->hdr.count) - drop_blk->index - 1;
 953                 tmp *= (uint)sizeof(xfs_da_node_entry_t);
 954                 memmove(btree, btree + 1, tmp);
 955                 xfs_da_log_buf(state->args->trans, drop_blk->bp,
 956                     XFS_DA_LOGRANGE(node, btree, tmp));
 957                 btree = &node->btree[be16_to_cpu(node->hdr.count)-1];
 958         }
 959         memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
 960         xfs_da_log_buf(state->args->trans, drop_blk->bp,
 961             XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
 962         be16_add(&node->hdr.count, -1);
 963         xfs_da_log_buf(state->args->trans, drop_blk->bp,
 964             XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 965
 966         /*
 967          * Copy the last hash value from the block to propagate upwards.
 968          */
 969         btree--;
 970         drop_blk->hashval = be32_to_cpu(btree->hashval);
 971 }
 972
 973 /*
 974  * Unbalance the btree elements between two intermediate nodes,
 975  * move all Btree elements from one node into another.
 976  */
 977 STATIC void
 978 xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
 979                                      xfs_da_state_blk_t *save_blk)
 980 {
 981         xfs_da_intnode_t *drop_node, *save_node;
 982         xfs_da_node_entry_t *btree;
 983         int tmp;
 984         xfs_trans_t *tp;
 985
 986         drop_node = drop_blk->bp->data;
 987         save_node = save_blk->bp->data;
 988         ASSERT(be16_to_cpu(drop_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 989         ASSERT(be16_to_cpu(save_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 990         tp = state->args->trans;
 991
 992         /*
 993          * If the dying block has lower hashvals, then move all the
 994          * elements in the remaining block up to make a hole.
 995          */
 996         if ((be32_to_cpu(drop_node->btree[0].hashval) < be32_to_cpu(save_node->btree[ 0 ].hashval)) ||
 997             (be32_to_cpu(drop_node->btree[be16_to_cpu(drop_node->hdr.count)-1].hashval) <
 998              be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval)))
 999         {
1000                 btree = &save_node->btree[be16_to_cpu(drop_node->hdr.count)];
1001                 tmp = be16_to_cpu(save_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1002                 memmove(btree, &save_node->btree[0], tmp);
1003                 btree = &save_node->btree[0];
1004                 xfs_da_log_buf(tp, save_blk->bp,
1005                         XFS_DA_LOGRANGE(save_node, btree,
1006                                 (be16_to_cpu(save_node->hdr.count) + be16_to_cpu(drop_node->hdr.count)) *
1007                                 sizeof(xfs_da_node_entry_t)));
1008         } else {
1009                 btree = &save_node->btree[be16_to_cpu(save_node->hdr.count)];
1010                 xfs_da_log_buf(tp, save_blk->bp,
1011                         XFS_DA_LOGRANGE(save_node, btree,
1012                                 be16_to_cpu(drop_node->hdr.count) *
1013                                 sizeof(xfs_da_node_entry_t)));
1014         }
1015
1016         /*
1017          * Move all the B-tree elements from drop_blk to save_blk.
1018          */
1019         tmp = be16_to_cpu(drop_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1020         memcpy(btree, &drop_node->btree[0], tmp);
1021         be16_add(&save_node->hdr.count, be16_to_cpu(drop_node->hdr.count));
1022
1023         xfs_da_log_buf(tp, save_blk->bp,
1024                 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1025                         sizeof(save_node->hdr)));
1026
1027         /*
1028          * Save the last hashval in the remaining block for upward propagation.
1029          */
1030         save_blk->hashval = be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval);
1031 }
1032
1033 /*========================================================================
1034  * Routines used for finding things in the Btree.
1035  *========================================================================*/
1036
1037 /*
1038  * Walk down the Btree looking for a particular filename, filling
1039  * in the state structure as we go.
1040  *
1041  * We will set the state structure to point to each of the elements
1042  * in each of the nodes where either the hashval is or should be.
1043  *
1044  * We support duplicate hashval's so for each entry in the current
1045  * node that could contain the desired hashval, descend.  This is a
1046  * pruned depth-first tree search.
1047  */
1048 int                                                     /* error */
1049 xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
1050 {
1051         xfs_da_state_blk_t *blk;
1052         xfs_da_blkinfo_t *curr;
1053         xfs_da_intnode_t *node;
1054         xfs_da_node_entry_t *btree;
1055         xfs_dablk_t blkno;
1056         int probe, span, max, error, retval;
1057         xfs_dahash_t hashval;
1058         xfs_da_args_t *args;
1059
1060         args = state->args;
1061
1062         /*
1063          * Descend thru the B-tree searching each level for the right
1064          * node to use, until the right hashval is found.
1065          */
1066         blkno = (args->whichfork == XFS_DATA_FORK)? state->mp->m_dirleafblk : 0;
1067         for (blk = &state->path.blk[0], state->path.active = 1;
1068                          state->path.active <= XFS_DA_NODE_MAXDEPTH;
1069                          blk++, state->path.active++) {
1070                 /*
1071                  * Read the next node down in the tree.
1072                  */
1073                 blk->blkno = blkno;
1074                 error = xfs_da_read_buf(args->trans, args->dp, blkno,
1075                                         -1, &blk->bp, args->whichfork);
1076                 if (error) {
1077                         blk->blkno = 0;
1078                         state->path.active--;
1079                         return(error);
1080                 }
1081                 curr = blk->bp->data;
1082                 ASSERT(be16_to_cpu(curr->magic) == XFS_DA_NODE_MAGIC ||
1083                        be16_to_cpu(curr->magic) == XFS_DIR2_LEAFN_MAGIC ||
1084                        be16_to_cpu(curr->magic) == XFS_ATTR_LEAF_MAGIC);
1085
1086                 /*
1087                  * Search an intermediate node for a match.
1088                  */
1089                 blk->magic = be16_to_cpu(curr->magic);
1090                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1091                         node = blk->bp->data;
1092                         blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1093
1094                         /*
1095                          * Binary search.  (note: small blocks will skip loop)
1096                          */
1097                         max = be16_to_cpu(node->hdr.count);
1098                         probe = span = max / 2;
1099                         hashval = args->hashval;
1100                         for (btree = &node->btree[probe]; span > 4;
1101                                    btree = &node->btree[probe]) {
1102                                 span /= 2;
1103                                 if (be32_to_cpu(btree->hashval) < hashval)
1104                                         probe += span;
1105                                 else if (be32_to_cpu(btree->hashval) > hashval)
1106                                         probe -= span;
1107                                 else
1108                                         break;
1109                         }
1110                         ASSERT((probe >= 0) && (probe < max));
1111                         ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval));
1112
1113                         /*
1114                          * Since we may have duplicate hashval's, find the first
1115                          * matching hashval in the node.
1116                          */
1117                         while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) {
1118                                 btree--;
1119                                 probe--;
1120                         }
1121                         while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) {
1122                                 btree++;
1123                                 probe++;
1124                         }
1125
1126                         /*
1127                          * Pick the right block to descend on.
1128                          */
1129                         if (probe == max) {
1130                                 blk->index = max-1;
1131                                 blkno = be32_to_cpu(node->btree[max-1].before);
1132                         } else {
1133                                 blk->index = probe;
1134                                 blkno = be32_to_cpu(btree->before);
1135                         }
1136                 } else if (be16_to_cpu(curr->magic) == XFS_ATTR_LEAF_MAGIC) {
1137                         blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1138                         break;
1139                 } else if (be16_to_cpu(curr->magic) == XFS_DIR2_LEAFN_MAGIC) {
1140                         blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
1141                         break;
1142                 }
1143         }
1144
1145         /*
1146          * A leaf block that ends in the hashval that we are interested in
1147          * (final hashval == search hashval) means that the next block may
1148          * contain more entries with the same hashval, shift upward to the
1149          * next leaf and keep searching.
1150          */
1151         for (;;) {
1152                 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1153                         retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1154                                                         &blk->index, state);
1155                 }
1156                 else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1157                         retval = xfs_attr_leaf_lookup_int(blk->bp, args);
1158                         blk->index = args->index;
1159                         args->blkno = blk->blkno;
1160                 }
1161                 if (((retval == ENOENT) || (retval == ENOATTR)) &&
1162                     (blk->hashval == args->hashval)) {
1163                         error = xfs_da_path_shift(state, &state->path, 1, 1,
1164                                                          &retval);
1165                         if (error)
1166                                 return(error);
1167                         if (retval == 0) {
1168                                 continue;
1169                         }
1170                         else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1171                                 /* path_shift() gives ENOENT */
1172                                 retval = XFS_ERROR(ENOATTR);
1173                         }
1174                 }
1175                 break;
1176         }
1177         *result = retval;
1178         return(0);
1179 }
1180
1181 /*========================================================================
1182  * Utility routines.
1183  *========================================================================*/
1184
1185 /*
1186  * Link a new block into a doubly linked list of blocks (of whatever type).
1187  */
1188 int                                                     /* error */
1189 xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
1190                                xfs_da_state_blk_t *new_blk)
1191 {
1192         xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
1193         xfs_da_args_t *args;
1194         int before=0, error;
1195         xfs_dabuf_t *bp;
1196
1197         /*
1198          * Set up environment.
1199          */
1200         args = state->args;
1201         ASSERT(args != NULL);
1202         old_info = old_blk->bp->data;
1203         new_info = new_blk->bp->data;
1204         ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1205                old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1206                old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1207         ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
1208         ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
1209         ASSERT(old_blk->magic == new_blk->magic);
1210
1211         switch (old_blk->magic) {
1212         case XFS_ATTR_LEAF_MAGIC:
1213                 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1214                 break;
1215         case XFS_DIR2_LEAFN_MAGIC:
1216                 before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
1217                 break;
1218         case XFS_DA_NODE_MAGIC:
1219                 before = xfs_da_node_order(old_blk->bp, new_blk->bp);
1220                 break;
1221         }
1222
1223         /*
1224          * Link blocks in appropriate order.
1225          */
1226         if (before) {
1227                 /*
1228                  * Link new block in before existing block.
1229                  */
1230                 new_info->forw = cpu_to_be32(old_blk->blkno);
1231                 new_info->back = old_info->back;
1232                 if (old_info->back) {
1233                         error = xfs_da_read_buf(args->trans, args->dp,
1234                                                 be32_to_cpu(old_info->back),
1235                                                 -1, &bp, args->whichfork);
1236                         if (error)
1237                                 return(error);
1238                         ASSERT(bp != NULL);
1239                         tmp_info = bp->data;
1240                         ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
1241                         ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1242                         tmp_info->forw = cpu_to_be32(new_blk->blkno);
1243                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1244                         xfs_da_buf_done(bp);
1245                 }
1246                 old_info->back = cpu_to_be32(new_blk->blkno);
1247         } else {
1248                 /*
1249                  * Link new block in after existing block.
1250                  */
1251                 new_info->forw = old_info->forw;
1252                 new_info->back = cpu_to_be32(old_blk->blkno);
1253                 if (old_info->forw) {
1254                         error = xfs_da_read_buf(args->trans, args->dp,
1255                                                 be32_to_cpu(old_info->forw),
1256                                                 -1, &bp, args->whichfork);
1257                         if (error)
1258                                 return(error);
1259                         ASSERT(bp != NULL);
1260                         tmp_info = bp->data;
1261                         ASSERT(tmp_info->magic == old_info->magic);
1262                         ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1263                         tmp_info->back = cpu_to_be32(new_blk->blkno);
1264                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1265                         xfs_da_buf_done(bp);
1266                 }
1267                 old_info->forw = cpu_to_be32(new_blk->blkno);
1268         }
1269
1270         xfs_da_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1271         xfs_da_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1272         return(0);
1273 }
1274
1275 /*
1276  * Compare two intermediate nodes for "order".
1277  */
1278 STATIC int
1279 xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp)
1280 {
1281         xfs_da_intnode_t *node1, *node2;
1282
1283         node1 = node1_bp->data;
1284         node2 = node2_bp->data;
1285         ASSERT((be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC) &&
1286                (be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC));
1287         if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
1288             ((be32_to_cpu(node2->btree[0].hashval) <
1289               be32_to_cpu(node1->btree[0].hashval)) ||
1290              (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
1291               be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
1292                 return(1);
1293         }
1294         return(0);
1295 }
1296
1297 /*
1298  * Pick up the last hashvalue from an intermediate node.
1299  */
1300 STATIC uint
1301 xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count)
1302 {
1303         xfs_da_intnode_t *node;
1304
1305         node = bp->data;
1306         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1307         if (count)
1308                 *count = be16_to_cpu(node->hdr.count);
1309         if (!node->hdr.count)
1310                 return(0);
1311         return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1312 }
1313
1314 /*
1315  * Unlink a block from a doubly linked list of blocks.
1316  */
1317 STATIC int                                              /* error */
1318 xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1319                                  xfs_da_state_blk_t *save_blk)
1320 {
1321         xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
1322         xfs_da_args_t *args;
1323         xfs_dabuf_t *bp;
1324         int error;
1325
1326         /*
1327          * Set up environment.
1328          */
1329         args = state->args;
1330         ASSERT(args != NULL);
1331         save_info = save_blk->bp->data;
1332         drop_info = drop_blk->bp->data;
1333         ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1334                save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1335                save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1336         ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
1337         ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
1338         ASSERT(save_blk->magic == drop_blk->magic);
1339         ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1340                (be32_to_cpu(save_info->back) == drop_blk->blkno));
1341         ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1342                (be32_to_cpu(drop_info->back) == save_blk->blkno));
1343
1344         /*
1345          * Unlink the leaf block from the doubly linked chain of leaves.
1346          */
1347         if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1348                 save_info->back = drop_info->back;
1349                 if (drop_info->back) {
1350                         error = xfs_da_read_buf(args->trans, args->dp,
1351                                                 be32_to_cpu(drop_info->back),
1352                                                 -1, &bp, args->whichfork);
1353                         if (error)
1354                                 return(error);
1355                         ASSERT(bp != NULL);
1356                         tmp_info = bp->data;
1357                         ASSERT(tmp_info->magic == save_info->magic);
1358                         ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1359                         tmp_info->forw = cpu_to_be32(save_blk->blkno);
1360                         xfs_da_log_buf(args->trans, bp, 0,
1361                                                     sizeof(*tmp_info) - 1);
1362                         xfs_da_buf_done(bp);
1363                 }
1364         } else {
1365                 save_info->forw = drop_info->forw;
1366                 if (drop_info->forw) {
1367                         error = xfs_da_read_buf(args->trans, args->dp,
1368                                                 be32_to_cpu(drop_info->forw),
1369                                                 -1, &bp, args->whichfork);
1370                         if (error)
1371                                 return(error);
1372                         ASSERT(bp != NULL);
1373                         tmp_info = bp->data;
1374                         ASSERT(tmp_info->magic == save_info->magic);
1375                         ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1376                         tmp_info->back = cpu_to_be32(save_blk->blkno);
1377                         xfs_da_log_buf(args->trans, bp, 0,
1378                                                     sizeof(*tmp_info) - 1);
1379                         xfs_da_buf_done(bp);
1380                 }
1381         }
1382
1383         xfs_da_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1384         return(0);
1385 }
1386
1387 /*
1388  * Move a path "forward" or "!forward" one block at the current level.
1389  *
1390  * This routine will adjust a "path" to point to the next block
1391  * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1392  * Btree, including updating pointers to the intermediate nodes between
1393  * the new bottom and the root.
1394  */
1395 int                                                     /* error */
1396 xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
1397                                  int forward, int release, int *result)
1398 {
1399         xfs_da_state_blk_t *blk;
1400         xfs_da_blkinfo_t *info;
1401         xfs_da_intnode_t *node;
1402         xfs_da_args_t *args;
1403         xfs_dablk_t blkno=0;
1404         int level, error;
1405
1406         /*
1407          * Roll up the Btree looking for the first block where our
1408          * current index is not at the edge of the block.  Note that
1409          * we skip the bottom layer because we want the sibling block.
1410          */
1411         args = state->args;
1412         ASSERT(args != NULL);
1413         ASSERT(path != NULL);
1414         ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1415         level = (path->active-1) - 1;   /* skip bottom layer in path */
1416         for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1417                 ASSERT(blk->bp != NULL);
1418                 node = blk->bp->data;
1419                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1420                 if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) {
1421                         blk->index++;
1422                         blkno = be32_to_cpu(node->btree[blk->index].before);
1423                         break;
1424                 } else if (!forward && (blk->index > 0)) {
1425                         blk->index--;
1426                         blkno = be32_to_cpu(node->btree[blk->index].before);
1427                         break;
1428                 }
1429         }
1430         if (level < 0) {
1431                 *result = XFS_ERROR(ENOENT);    /* we're out of our tree */
1432                 ASSERT(args->oknoent);
1433                 return(0);
1434         }
1435
1436         /*
1437          * Roll down the edge of the subtree until we reach the
1438          * same depth we were at originally.
1439          */
1440         for (blk++, level++; level < path->active; blk++, level++) {
1441                 /*
1442                  * Release the old block.
1443                  * (if it's dirty, trans won't actually let go)
1444                  */
1445                 if (release)
1446                         xfs_da_brelse(args->trans, blk->bp);
1447
1448                 /*
1449                  * Read the next child block.
1450                  */
1451                 blk->blkno = blkno;
1452                 error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
1453                                                      &blk->bp, args->whichfork);
1454                 if (error)
1455                         return(error);
1456                 ASSERT(blk->bp != NULL);
1457                 info = blk->bp->data;
1458                 ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC ||
1459                        be16_to_cpu(info->magic) == XFS_DIR2_LEAFN_MAGIC ||
1460                        be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC);
1461                 blk->magic = be16_to_cpu(info->magic);
1462                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1463                         node = (xfs_da_intnode_t *)info;
1464                         blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1465                         if (forward)
1466                                 blk->index = 0;
1467                         else
1468                                 blk->index = be16_to_cpu(node->hdr.count)-1;
1469                         blkno = be32_to_cpu(node->btree[blk->index].before);
1470                 } else {
1471                         ASSERT(level == path->active-1);
1472                         blk->index = 0;
1473                         switch(blk->magic) {
1474                         case XFS_ATTR_LEAF_MAGIC:
1475                                 blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
1476                                                                       NULL);
1477                                 break;
1478                         case XFS_DIR2_LEAFN_MAGIC:
1479                                 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
1480                                                                        NULL);
1481                                 break;
1482                         default:
1483                                 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
1484                                        blk->magic == XFS_DIR2_LEAFN_MAGIC);
1485                                 break;
1486                         }
1487                 }
1488         }
1489         *result = 0;
1490         return(0);
1491 }
1492
1493
1494 /*========================================================================
1495  * Utility routines.
1496  *========================================================================*/
1497
1498 /*
1499  * Implement a simple hash on a character string.
1500  * Rotate the hash value by 7 bits, then XOR each character in.
1501  * This is implemented with some source-level loop unrolling.
1502  */
1503 xfs_dahash_t
1504 xfs_da_hashname(const uchar_t *name, int namelen)
1505 {
1506         xfs_dahash_t hash;
1507
1508         /*
1509          * Do four characters at a time as long as we can.
1510          */
1511         for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1512                 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1513                        (name[3] << 0) ^ rol32(hash, 7 * 4);
1514
1515         /*
1516          * Now do the rest of the characters.
1517          */
1518         switch (namelen) {
1519         case 3:
1520                 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1521                        rol32(hash, 7 * 3);
1522         case 2:
1523                 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1524         case 1:
1525                 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1526         default: /* case 0: */
1527                 return hash;
1528         }
1529 }
1530
1531 /*
1532  * Add a block to the btree ahead of the file.
1533  * Return the new block number to the caller.
1534  */
1535 int
1536 xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
1537 {
1538         xfs_fileoff_t bno, b;
1539         xfs_bmbt_irec_t map;
1540         xfs_bmbt_irec_t *mapp;
1541         xfs_inode_t *dp;
1542         int nmap, error, w, count, c, got, i, mapi;
1543         xfs_trans_t *tp;
1544         xfs_mount_t *mp;
1545
1546         dp = args->dp;
1547         mp = dp->i_mount;
1548         w = args->whichfork;
1549         tp = args->trans;
1550         /*
1551          * For new directories adjust the file offset and block count.
1552          */
1553         if (w == XFS_DATA_FORK) {
1554                 bno = mp->m_dirleafblk;
1555                 count = mp->m_dirblkfsbs;
1556         } else {
1557                 bno = 0;
1558                 count = 1;
1559         }
1560         /*
1561          * Find a spot in the file space to put the new block.
1562          */
1563         if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, w)))
1564                 return error;
1565         if (w == XFS_DATA_FORK)
1566                 ASSERT(bno >= mp->m_dirleafblk && bno < mp->m_dirfreeblk);
1567         /*
1568          * Try mapping it in one filesystem block.
1569          */
1570         nmap = 1;
1571         ASSERT(args->firstblock != NULL);
1572         if ((error = xfs_bmapi(tp, dp, bno, count,
1573                         XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|
1574                         XFS_BMAPI_CONTIG,
1575                         args->firstblock, args->total, &map, &nmap,
1576                         args->flist, NULL))) {
1577                 return error;
1578         }
1579         ASSERT(nmap <= 1);
1580         if (nmap == 1) {
1581                 mapp = &map;
1582                 mapi = 1;
1583         }
1584         /*
1585          * If we didn't get it and the block might work if fragmented,
1586          * try without the CONTIG flag.  Loop until we get it all.
1587          */
1588         else if (nmap == 0 && count > 1) {
1589                 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1590                 for (b = bno, mapi = 0; b < bno + count; ) {
1591                         nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1592                         c = (int)(bno + count - b);
1593                         if ((error = xfs_bmapi(tp, dp, b, c,
1594                                         XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|
1595                                         XFS_BMAPI_METADATA,
1596                                         args->firstblock, args->total,
1597                                         &mapp[mapi], &nmap, args->flist,
1598                                         NULL))) {
1599                                 kmem_free(mapp, sizeof(*mapp) * count);
1600                                 return error;
1601                         }
1602                         if (nmap < 1)
1603                                 break;
1604                         mapi += nmap;
1605                         b = mapp[mapi - 1].br_startoff +
1606                             mapp[mapi - 1].br_blockcount;
1607                 }
1608         } else {
1609                 mapi = 0;
1610                 mapp = NULL;
1611         }
1612         /*
1613          * Count the blocks we got, make sure it matches the total.
1614          */
1615         for (i = 0, got = 0; i < mapi; i++)
1616                 got += mapp[i].br_blockcount;
1617         if (got != count || mapp[0].br_startoff != bno ||
1618             mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1619             bno + count) {
1620                 if (mapp != &map)
1621                         kmem_free(mapp, sizeof(*mapp) * count);
1622                 return XFS_ERROR(ENOSPC);
1623         }
1624         if (mapp != &map)
1625                 kmem_free(mapp, sizeof(*mapp) * count);
1626         *new_blkno = (xfs_dablk_t)bno;
1627         return 0;
1628 }
1629
1630 /*
1631  * Ick.  We need to always be able to remove a btree block, even
1632  * if there's no space reservation because the filesystem is full.
1633  * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1634  * It swaps the target block with the last block in the file.  The
1635  * last block in the file can always be removed since it can't cause
1636  * a bmap btree split to do that.
1637  */
1638 STATIC int
1639 xfs_da_swap_lastblock(xfs_da_args_t *args, xfs_dablk_t *dead_blknop,
1640                       xfs_dabuf_t **dead_bufp)
1641 {
1642         xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1643         xfs_dabuf_t *dead_buf, *last_buf, *sib_buf, *par_buf;
1644         xfs_fileoff_t lastoff;
1645         xfs_inode_t *ip;
1646         xfs_trans_t *tp;
1647         xfs_mount_t *mp;
1648         int error, w, entno, level, dead_level;
1649         xfs_da_blkinfo_t *dead_info, *sib_info;
1650         xfs_da_intnode_t *par_node, *dead_node;
1651         xfs_dir2_leaf_t *dead_leaf2;
1652         xfs_dahash_t dead_hash;
1653
1654         dead_buf = *dead_bufp;
1655         dead_blkno = *dead_blknop;
1656         tp = args->trans;
1657         ip = args->dp;
1658         w = args->whichfork;
1659         ASSERT(w == XFS_DATA_FORK);
1660         mp = ip->i_mount;
1661         lastoff = mp->m_dirfreeblk;
1662         error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1663         if (error)
1664                 return error;
1665         if (unlikely(lastoff == 0)) {
1666                 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1667                                  mp);
1668                 return XFS_ERROR(EFSCORRUPTED);
1669         }
1670         /*
1671          * Read the last block in the btree space.
1672          */
1673         last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1674         if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
1675                 return error;
1676         /*
1677          * Copy the last block into the dead buffer and log it.
1678          */
1679         memcpy(dead_buf->data, last_buf->data, mp->m_dirblksize);
1680         xfs_da_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1681         dead_info = dead_buf->data;
1682         /*
1683          * Get values from the moved block.
1684          */
1685         if (be16_to_cpu(dead_info->magic) == XFS_DIR2_LEAFN_MAGIC) {
1686                 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1687                 dead_level = 0;
1688                 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1689         } else {
1690                 ASSERT(be16_to_cpu(dead_info->magic) == XFS_DA_NODE_MAGIC);
1691                 dead_node = (xfs_da_intnode_t *)dead_info;
1692                 dead_level = be16_to_cpu(dead_node->hdr.level);
1693                 dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
1694         }
1695         sib_buf = par_buf = NULL;
1696         /*
1697          * If the moved block has a left sibling, fix up the pointers.
1698          */
1699         if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1700                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1701                         goto done;
1702                 sib_info = sib_buf->data;
1703                 if (unlikely(
1704                     be32_to_cpu(sib_info->forw) != last_blkno ||
1705                     sib_info->magic != dead_info->magic)) {
1706                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1707                                          XFS_ERRLEVEL_LOW, mp);
1708                         error = XFS_ERROR(EFSCORRUPTED);
1709                         goto done;
1710                 }
1711                 sib_info->forw = cpu_to_be32(dead_blkno);
1712                 xfs_da_log_buf(tp, sib_buf,
1713                         XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1714                                         sizeof(sib_info->forw)));
1715                 xfs_da_buf_done(sib_buf);
1716                 sib_buf = NULL;
1717         }
1718         /*
1719          * If the moved block has a right sibling, fix up the pointers.
1720          */
1721         if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1722                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1723                         goto done;
1724                 sib_info = sib_buf->data;
1725                 if (unlikely(
1726                        be32_to_cpu(sib_info->back) != last_blkno ||
1727                        sib_info->magic != dead_info->magic)) {
1728                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1729                                          XFS_ERRLEVEL_LOW, mp);
1730                         error = XFS_ERROR(EFSCORRUPTED);
1731                         goto done;
1732                 }
1733                 sib_info->back = cpu_to_be32(dead_blkno);
1734                 xfs_da_log_buf(tp, sib_buf,
1735                         XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1736                                         sizeof(sib_info->back)));
1737                 xfs_da_buf_done(sib_buf);
1738                 sib_buf = NULL;
1739         }
1740         par_blkno = mp->m_dirleafblk;
1741         level = -1;
1742         /*
1743          * Walk down the tree looking for the parent of the moved block.
1744          */
1745         for (;;) {
1746                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1747                         goto done;
1748                 par_node = par_buf->data;
1749                 if (unlikely(
1750                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC ||
1751                     (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
1752                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1753                                          XFS_ERRLEVEL_LOW, mp);
1754                         error = XFS_ERROR(EFSCORRUPTED);
1755                         goto done;
1756                 }
1757                 level = be16_to_cpu(par_node->hdr.level);
1758                 for (entno = 0;
1759                      entno < be16_to_cpu(par_node->hdr.count) &&
1760                      be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
1761                      entno++)
1762                         continue;
1763                 if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
1764                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1765                                          XFS_ERRLEVEL_LOW, mp);
1766                         error = XFS_ERROR(EFSCORRUPTED);
1767                         goto done;
1768                 }
1769                 par_blkno = be32_to_cpu(par_node->btree[entno].before);
1770                 if (level == dead_level + 1)
1771                         break;
1772                 xfs_da_brelse(tp, par_buf);
1773                 par_buf = NULL;
1774         }
1775         /*
1776          * We're in the right parent block.
1777          * Look for the right entry.
1778          */
1779         for (;;) {
1780                 for (;
1781                      entno < be16_to_cpu(par_node->hdr.count) &&
1782                      be32_to_cpu(par_node->btree[entno].before) != last_blkno;
1783                      entno++)
1784                         continue;
1785                 if (entno < be16_to_cpu(par_node->hdr.count))
1786                         break;
1787                 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1788                 xfs_da_brelse(tp, par_buf);
1789                 par_buf = NULL;
1790                 if (unlikely(par_blkno == 0)) {
1791                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1792                                          XFS_ERRLEVEL_LOW, mp);
1793                         error = XFS_ERROR(EFSCORRUPTED);
1794                         goto done;
1795                 }
1796                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1797                         goto done;
1798                 par_node = par_buf->data;
1799                 if (unlikely(
1800                     be16_to_cpu(par_node->hdr.level) != level ||
1801                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC)) {
1802                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1803                                          XFS_ERRLEVEL_LOW, mp);
1804                         error = XFS_ERROR(EFSCORRUPTED);
1805                         goto done;
1806                 }
1807                 entno = 0;
1808         }
1809         /*
1810          * Update the parent entry pointing to the moved block.
1811          */
1812         par_node->btree[entno].before = cpu_to_be32(dead_blkno);
1813         xfs_da_log_buf(tp, par_buf,
1814                 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1815                                 sizeof(par_node->btree[entno].before)));
1816         xfs_da_buf_done(par_buf);
1817         xfs_da_buf_done(dead_buf);
1818         *dead_blknop = last_blkno;
1819         *dead_bufp = last_buf;
1820         return 0;
1821 done:
1822         if (par_buf)
1823                 xfs_da_brelse(tp, par_buf);
1824         if (sib_buf)
1825                 xfs_da_brelse(tp, sib_buf);
1826         xfs_da_brelse(tp, last_buf);
1827         return error;
1828 }
1829
1830 /*
1831  * Remove a btree block from a directory or attribute.
1832  */
1833 int
1834 xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
1835                     xfs_dabuf_t *dead_buf)
1836 {
1837         xfs_inode_t *dp;
1838         int done, error, w, count;
1839         xfs_trans_t *tp;
1840         xfs_mount_t *mp;
1841
1842         dp = args->dp;
1843         w = args->whichfork;
1844         tp = args->trans;
1845         mp = dp->i_mount;
1846         if (w == XFS_DATA_FORK)
1847                 count = mp->m_dirblkfsbs;
1848         else
1849                 count = 1;
1850         for (;;) {
1851                 /*
1852                  * Remove extents.  If we get ENOSPC for a dir we have to move
1853                  * the last block to the place we want to kill.
1854                  */
1855                 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
1856                                 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_METADATA,
1857                                 0, args->firstblock, args->flist, NULL,
1858                                 &done)) == ENOSPC) {
1859                         if (w != XFS_DATA_FORK)
1860                                 break;
1861                         if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
1862                                         &dead_buf)))
1863                                 break;
1864                 } else {
1865                         break;
1866                 }
1867         }
1868         xfs_da_binval(tp, dead_buf);
1869         return error;
1870 }
1871
1872 /*
1873  * See if the mapping(s) for this btree block are valid, i.e.
1874  * don't contain holes, are logically contiguous, and cover the whole range.
1875  */
1876 STATIC int
1877 xfs_da_map_covers_blocks(
1878         int             nmap,
1879         xfs_bmbt_irec_t *mapp,
1880         xfs_dablk_t     bno,
1881         int             count)
1882 {
1883         int             i;
1884         xfs_fileoff_t   off;
1885
1886         for (i = 0, off = bno; i < nmap; i++) {
1887                 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
1888                     mapp[i].br_startblock == DELAYSTARTBLOCK) {
1889                         return 0;
1890                 }
1891                 if (off != mapp[i].br_startoff) {
1892                         return 0;
1893                 }
1894                 off += mapp[i].br_blockcount;
1895         }
1896         return off == bno + count;
1897 }
1898
1899 /*
1900  * Make a dabuf.
1901  * Used for get_buf, read_buf, read_bufr, and reada_buf.
1902  */
1903 STATIC int
1904 xfs_da_do_buf(
1905         xfs_trans_t     *trans,
1906         xfs_inode_t     *dp,
1907         xfs_dablk_t     bno,
1908         xfs_daddr_t     *mappedbnop,
1909         xfs_dabuf_t     **bpp,
1910         int             whichfork,
1911         int             caller,
1912         inst_t          *ra)
1913 {
1914         xfs_buf_t       *bp = NULL;
1915         xfs_buf_t       **bplist;
1916         int             error=0;
1917         int             i;
1918         xfs_bmbt_irec_t map;
1919         xfs_bmbt_irec_t *mapp;
1920         xfs_daddr_t     mappedbno;
1921         xfs_mount_t     *mp;
1922         int             nbplist=0;
1923         int             nfsb;
1924         int             nmap;
1925         xfs_dabuf_t     *rbp;
1926
1927         mp = dp->i_mount;
1928         nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
1929         mappedbno = *mappedbnop;
1930         /*
1931          * Caller doesn't have a mapping.  -2 means don't complain
1932          * if we land in a hole.
1933          */
1934         if (mappedbno == -1 || mappedbno == -2) {
1935                 /*
1936                  * Optimize the one-block case.
1937                  */
1938                 if (nfsb == 1) {
1939                         xfs_fsblock_t   fsb;
1940
1941                         if ((error =
1942                             xfs_bmapi_single(trans, dp, whichfork, &fsb,
1943                                     (xfs_fileoff_t)bno))) {
1944                                 return error;
1945                         }
1946                         mapp = &map;
1947                         if (fsb == NULLFSBLOCK) {
1948                                 nmap = 0;
1949                         } else {
1950                                 map.br_startblock = fsb;
1951                                 map.br_startoff = (xfs_fileoff_t)bno;
1952                                 map.br_blockcount = 1;
1953                                 nmap = 1;
1954                         }
1955                 } else {
1956                         mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
1957                         nmap = nfsb;
1958                         if ((error = xfs_bmapi(trans, dp, (xfs_fileoff_t)bno,
1959                                         nfsb,
1960                                         XFS_BMAPI_METADATA |
1961                                                 XFS_BMAPI_AFLAG(whichfork),
1962                                         NULL, 0, mapp, &nmap, NULL, NULL)))
1963                                 goto exit0;
1964                 }
1965         } else {
1966                 map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
1967                 map.br_startoff = (xfs_fileoff_t)bno;
1968                 map.br_blockcount = nfsb;
1969                 mapp = &map;
1970                 nmap = 1;
1971         }
1972         if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
1973                 error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
1974                 if (unlikely(error == EFSCORRUPTED)) {
1975                         if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
1976                                 int     i;
1977                                 cmn_err(CE_ALERT, "xfs_da_do_buf: bno %lld\n",
1978                                         (long long)bno);
1979                                 cmn_err(CE_ALERT, "dir: inode %lld\n",
1980                                         (long long)dp->i_ino);
1981                                 for (i = 0; i < nmap; i++) {
1982                                         cmn_err(CE_ALERT,
1983                                                 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d\n",
1984                                                 i,
1985                                                 (long long)mapp[i].br_startoff,
1986                                                 (long long)mapp[i].br_startblock,
1987                                                 (long long)mapp[i].br_blockcount,
1988                                                 mapp[i].br_state);
1989                                 }
1990                         }
1991                         XFS_ERROR_REPORT("xfs_da_do_buf(1)",
1992                                          XFS_ERRLEVEL_LOW, mp);
1993                 }
1994                 goto exit0;
1995         }
1996         if (caller != 3 && nmap > 1) {
1997                 bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
1998                 nbplist = 0;
1999         } else
2000                 bplist = NULL;
2001         /*
2002          * Turn the mapping(s) into buffer(s).
2003          */
2004         for (i = 0; i < nmap; i++) {
2005                 int     nmapped;
2006
2007                 mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
2008                 if (i == 0)
2009                         *mappedbnop = mappedbno;
2010                 nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
2011                 switch (caller) {
2012                 case 0:
2013                         bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
2014                                 mappedbno, nmapped, 0);
2015                         error = bp ? XFS_BUF_GETERROR(bp) : XFS_ERROR(EIO);
2016                         break;
2017                 case 1:
2018                 case 2:
2019                         bp = NULL;
2020                         error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
2021                                 mappedbno, nmapped, 0, &bp);
2022                         break;
2023                 case 3:
2024                         xfs_baread(mp->m_ddev_targp, mappedbno, nmapped);
2025                         error = 0;
2026                         bp = NULL;
2027                         break;
2028                 }
2029                 if (error) {
2030                         if (bp)
2031                                 xfs_trans_brelse(trans, bp);
2032                         goto exit1;
2033                 }
2034                 if (!bp)
2035                         continue;
2036                 if (caller == 1) {
2037                         if (whichfork == XFS_ATTR_FORK) {
2038                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_ATTR_BTREE,
2039                                                 XFS_ATTR_BTREE_REF);
2040                         } else {
2041                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_DIR_BTREE,
2042                                                 XFS_DIR_BTREE_REF);
2043                         }
2044                 }
2045                 if (bplist) {
2046                         bplist[nbplist++] = bp;
2047                 }
2048         }
2049         /*
2050          * Build a dabuf structure.
2051          */
2052         if (bplist) {
2053                 rbp = xfs_da_buf_make(nbplist, bplist, ra);
2054         } else if (bp)
2055                 rbp = xfs_da_buf_make(1, &bp, ra);
2056         else
2057                 rbp = NULL;
2058         /*
2059          * For read_buf, check the magic number.
2060          */
2061         if (caller == 1) {
2062                 xfs_dir2_data_t         *data;
2063                 xfs_dir2_free_t         *free;
2064                 xfs_da_blkinfo_t        *info;
2065                 uint                    magic, magic1;
2066
2067                 info = rbp->data;
2068                 data = rbp->data;
2069                 free = rbp->data;
2070                 magic = be16_to_cpu(info->magic);
2071                 magic1 = be32_to_cpu(data->hdr.magic);
2072                 if (unlikely(
2073                     XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2074                                    (magic != XFS_ATTR_LEAF_MAGIC) &&
2075                                    (magic != XFS_DIR2_LEAF1_MAGIC) &&
2076                                    (magic != XFS_DIR2_LEAFN_MAGIC) &&
2077                                    (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2078                                    (magic1 != XFS_DIR2_DATA_MAGIC) &&
2079                                    (be32_to_cpu(free->hdr.magic) != XFS_DIR2_FREE_MAGIC),
2080                                 mp, XFS_ERRTAG_DA_READ_BUF,
2081                                 XFS_RANDOM_DA_READ_BUF))) {
2082                         xfs_buftrace("DA READ ERROR", rbp->bps[0]);
2083                         XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2084                                              XFS_ERRLEVEL_LOW, mp, info);
2085                         error = XFS_ERROR(EFSCORRUPTED);
2086                         xfs_da_brelse(trans, rbp);
2087                         nbplist = 0;
2088                         goto exit1;
2089                 }
2090         }
2091         if (bplist) {
2092                 kmem_free(bplist, sizeof(*bplist) * nmap);
2093         }
2094         if (mapp != &map) {
2095                 kmem_free(mapp, sizeof(*mapp) * nfsb);
2096         }
2097         if (bpp)
2098                 *bpp = rbp;
2099         return 0;
2100 exit1:
2101         if (bplist) {
2102                 for (i = 0; i < nbplist; i++)
2103                         xfs_trans_brelse(trans, bplist[i]);
2104                 kmem_free(bplist, sizeof(*bplist) * nmap);
2105         }
2106 exit0:
2107         if (mapp != &map)
2108                 kmem_free(mapp, sizeof(*mapp) * nfsb);
2109         if (bpp)
2110                 *bpp = NULL;
2111         return error;
2112 }
2113
2114 /*
2115  * Get a buffer for the dir/attr block.
2116  */
2117 int
2118 xfs_da_get_buf(
2119         xfs_trans_t     *trans,
2120         xfs_inode_t     *dp,
2121         xfs_dablk_t     bno,
2122         xfs_daddr_t             mappedbno,
2123         xfs_dabuf_t     **bpp,
2124         int             whichfork)
2125 {
2126         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0,
2127                                                  (inst_t *)__return_address);
2128 }
2129
2130 /*
2131  * Get a buffer for the dir/attr block, fill in the contents.
2132  */
2133 int
2134 xfs_da_read_buf(
2135         xfs_trans_t     *trans,
2136         xfs_inode_t     *dp,
2137         xfs_dablk_t     bno,
2138         xfs_daddr_t             mappedbno,
2139         xfs_dabuf_t     **bpp,
2140         int             whichfork)
2141 {
2142         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1,
2143                 (inst_t *)__return_address);
2144 }
2145
2146 /*
2147  * Readahead the dir/attr block.
2148  */
2149 xfs_daddr_t
2150 xfs_da_reada_buf(
2151         xfs_trans_t     *trans,
2152         xfs_inode_t     *dp,
2153         xfs_dablk_t     bno,
2154         int             whichfork)
2155 {
2156         xfs_daddr_t             rval;
2157
2158         rval = -1;
2159         if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3,
2160                         (inst_t *)__return_address))
2161                 return -1;
2162         else
2163                 return rval;
2164 }
2165
2166 /*
2167  * Calculate the number of bits needed to hold i different values.
2168  */
2169 uint
2170 xfs_da_log2_roundup(uint i)
2171 {
2172         uint rval;
2173
2174         for (rval = 0; rval < NBBY * sizeof(i); rval++) {
2175                 if ((1 << rval) >= i)
2176                         break;
2177         }
2178         return(rval);
2179 }
2180
2181 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2182 kmem_zone_t *xfs_dabuf_zone;            /* dabuf zone */
2183
2184 /*
2185  * Allocate a dir-state structure.
2186  * We don't put them on the stack since they're large.
2187  */
2188 xfs_da_state_t *
2189 xfs_da_state_alloc(void)
2190 {
2191         return kmem_zone_zalloc(xfs_da_state_zone, KM_SLEEP);
2192 }
2193
2194 /*
2195  * Kill the altpath contents of a da-state structure.
2196  */
2197 STATIC void
2198 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2199 {
2200         int     i;
2201
2202         for (i = 0; i < state->altpath.active; i++) {
2203                 if (state->altpath.blk[i].bp) {
2204                         if (state->altpath.blk[i].bp != state->path.blk[i].bp)
2205                                 xfs_da_buf_done(state->altpath.blk[i].bp);
2206                         state->altpath.blk[i].bp = NULL;
2207                 }
2208         }
2209         state->altpath.active = 0;
2210 }
2211
2212 /*
2213  * Free a da-state structure.
2214  */
2215 void
2216 xfs_da_state_free(xfs_da_state_t *state)
2217 {
2218         int     i;
2219
2220         xfs_da_state_kill_altpath(state);
2221         for (i = 0; i < state->path.active; i++) {
2222                 if (state->path.blk[i].bp)
2223                         xfs_da_buf_done(state->path.blk[i].bp);
2224         }
2225         if (state->extravalid && state->extrablk.bp)
2226                 xfs_da_buf_done(state->extrablk.bp);
2227 #ifdef DEBUG
2228         memset((char *)state, 0, sizeof(*state));
2229 #endif /* DEBUG */
2230         kmem_zone_free(xfs_da_state_zone, state);
2231 }
2232
2233 #ifdef XFS_DABUF_DEBUG
2234 xfs_dabuf_t     *xfs_dabuf_global_list;
2235 lock_t          xfs_dabuf_global_lock;
2236 #endif
2237
2238 /*
2239  * Create a dabuf.
2240  */
2241 /* ARGSUSED */
2242 STATIC xfs_dabuf_t *
2243 xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra)
2244 {
2245         xfs_buf_t       *bp;
2246         xfs_dabuf_t     *dabuf;
2247         int             i;
2248         int             off;
2249
2250         if (nbuf == 1)
2251                 dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_SLEEP);
2252         else
2253                 dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_SLEEP);
2254         dabuf->dirty = 0;
2255 #ifdef XFS_DABUF_DEBUG
2256         dabuf->ra = ra;
2257         dabuf->target = XFS_BUF_TARGET(bps[0]);
2258         dabuf->blkno = XFS_BUF_ADDR(bps[0]);
2259 #endif
2260         if (nbuf == 1) {
2261                 dabuf->nbuf = 1;
2262                 bp = bps[0];
2263                 dabuf->bbcount = (short)BTOBB(XFS_BUF_COUNT(bp));
2264                 dabuf->data = XFS_BUF_PTR(bp);
2265                 dabuf->bps[0] = bp;
2266         } else {
2267                 dabuf->nbuf = nbuf;
2268                 for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
2269                         dabuf->bps[i] = bp = bps[i];
2270                         dabuf->bbcount += BTOBB(XFS_BUF_COUNT(bp));
2271                 }
2272                 dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
2273                 for (i = off = 0; i < nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2274                         bp = bps[i];
2275                         memcpy((char *)dabuf->data + off, XFS_BUF_PTR(bp),
2276                                 XFS_BUF_COUNT(bp));
2277                 }
2278         }
2279 #ifdef XFS_DABUF_DEBUG
2280         {
2281                 SPLDECL(s);
2282                 xfs_dabuf_t     *p;
2283
2284                 s = mutex_spinlock(&xfs_dabuf_global_lock);
2285                 for (p = xfs_dabuf_global_list; p; p = p->next) {
2286                         ASSERT(p->blkno != dabuf->blkno ||
2287                                p->target != dabuf->target);
2288                 }
2289                 dabuf->prev = NULL;
2290                 if (xfs_dabuf_global_list)
2291                         xfs_dabuf_global_list->prev = dabuf;
2292                 dabuf->next = xfs_dabuf_global_list;
2293                 xfs_dabuf_global_list = dabuf;
2294                 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2295         }
2296 #endif
2297         return dabuf;
2298 }
2299
2300 /*
2301  * Un-dirty a dabuf.
2302  */
2303 STATIC void
2304 xfs_da_buf_clean(xfs_dabuf_t *dabuf)
2305 {
2306         xfs_buf_t       *bp;
2307         int             i;
2308         int             off;
2309
2310         if (dabuf->dirty) {
2311                 ASSERT(dabuf->nbuf > 1);
2312                 dabuf->dirty = 0;
2313                 for (i = off = 0; i < dabuf->nbuf;
2314                                 i++, off += XFS_BUF_COUNT(bp)) {
2315                         bp = dabuf->bps[i];
2316                         memcpy(XFS_BUF_PTR(bp), (char *)dabuf->data + off,
2317                                 XFS_BUF_COUNT(bp));
2318                 }
2319         }
2320 }
2321
2322 /*
2323  * Release a dabuf.
2324  */
2325 void
2326 xfs_da_buf_done(xfs_dabuf_t *dabuf)
2327 {
2328         ASSERT(dabuf);
2329         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2330         if (dabuf->dirty)
2331                 xfs_da_buf_clean(dabuf);
2332         if (dabuf->nbuf > 1)
2333                 kmem_free(dabuf->data, BBTOB(dabuf->bbcount));
2334 #ifdef XFS_DABUF_DEBUG
2335         {
2336                 SPLDECL(s);
2337
2338                 s = mutex_spinlock(&xfs_dabuf_global_lock);
2339                 if (dabuf->prev)
2340                         dabuf->prev->next = dabuf->next;
2341                 else
2342                         xfs_dabuf_global_list = dabuf->next;
2343                 if (dabuf->next)
2344                         dabuf->next->prev = dabuf->prev;
2345                 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2346         }
2347         memset(dabuf, 0, XFS_DA_BUF_SIZE(dabuf->nbuf));
2348 #endif
2349         if (dabuf->nbuf == 1)
2350                 kmem_zone_free(xfs_dabuf_zone, dabuf);
2351         else
2352                 kmem_free(dabuf, XFS_DA_BUF_SIZE(dabuf->nbuf));
2353 }
2354
2355 /*
2356  * Log transaction from a dabuf.
2357  */
2358 void
2359 xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
2360 {
2361         xfs_buf_t       *bp;
2362         uint            f;
2363         int             i;
2364         uint            l;
2365         int             off;
2366
2367         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2368         if (dabuf->nbuf == 1) {
2369                 ASSERT(dabuf->data == (void *)XFS_BUF_PTR(dabuf->bps[0]));
2370                 xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
2371                 return;
2372         }
2373         dabuf->dirty = 1;
2374         ASSERT(first <= last);
2375         for (i = off = 0; i < dabuf->nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2376                 bp = dabuf->bps[i];
2377                 f = off;
2378                 l = f + XFS_BUF_COUNT(bp) - 1;
2379                 if (f < first)
2380                         f = first;
2381                 if (l > last)
2382                         l = last;
2383                 if (f <= l)
2384                         xfs_trans_log_buf(tp, bp, f - off, l - off);
2385                 /*
2386                  * B_DONE is set by xfs_trans_log buf.
2387                  * If we don't set it on a new buffer (get not read)
2388                  * then if we don't put anything in the buffer it won't
2389                  * be set, and at commit it it released into the cache,
2390                  * and then a read will fail.
2391                  */
2392                 else if (!(XFS_BUF_ISDONE(bp)))
2393                   XFS_BUF_DONE(bp);
2394         }
2395         ASSERT(last < off);
2396 }
2397
2398 /*
2399  * Release dabuf from a transaction.
2400  * Have to free up the dabuf before the buffers are released,
2401  * since the synchronization on the dabuf is really the lock on the buffer.
2402  */
2403 void
2404 xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2405 {
2406         xfs_buf_t       *bp;
2407         xfs_buf_t       **bplist;
2408         int             i;
2409         int             nbuf;
2410
2411         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2412         if ((nbuf = dabuf->nbuf) == 1) {
2413                 bplist = &bp;
2414                 bp = dabuf->bps[0];
2415         } else {
2416                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2417                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2418         }
2419         xfs_da_buf_done(dabuf);
2420         for (i = 0; i < nbuf; i++)
2421                 xfs_trans_brelse(tp, bplist[i]);
2422         if (bplist != &bp)
2423                 kmem_free(bplist, nbuf * sizeof(*bplist));
2424 }
2425
2426 /*
2427  * Invalidate dabuf from a transaction.
2428  */
2429 void
2430 xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2431 {
2432         xfs_buf_t       *bp;
2433         xfs_buf_t       **bplist;
2434         int             i;
2435         int             nbuf;
2436
2437         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2438         if ((nbuf = dabuf->nbuf) == 1) {
2439                 bplist = &bp;
2440                 bp = dabuf->bps[0];
2441         } else {
2442                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2443                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2444         }
2445         xfs_da_buf_done(dabuf);
2446         for (i = 0; i < nbuf; i++)
2447                 xfs_trans_binval(tp, bplist[i]);
2448         if (bplist != &bp)
2449                 kmem_free(bplist, nbuf * sizeof(*bplist));
2450 }
2451
2452 /*
2453  * Get the first daddr from a dabuf.
2454  */
2455 xfs_daddr_t
2456 xfs_da_blkno(xfs_dabuf_t *dabuf)
2457 {
2458         ASSERT(dabuf->nbuf);
2459         ASSERT(dabuf->data);
2460         return XFS_BUF_ADDR(dabuf->bps[0]);
2461 }