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, btreehashval;
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                 blk->magic = be16_to_cpu(curr->magic);
1083                 ASSERT(blk->magic == XFS_DA_NODE_MAGIC ||
1084                        blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1085                        blk->magic == XFS_ATTR_LEAF_MAGIC);
1086
1087                 /*
1088                  * Search an intermediate node for a match.
1089                  */
1090                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1091                         node = blk->bp->data;
1092                         max = be16_to_cpu(node->hdr.count);
1093                         blk->hashval = be32_to_cpu(node->btree[max-1].hashval);
1094
1095                         /*
1096                          * Binary search.  (note: small blocks will skip loop)
1097                          */
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                                 btreehashval = be32_to_cpu(btree->hashval);
1104                                 if (btreehashval < hashval)
1105                                         probe += span;
1106                                 else if (btreehashval > hashval)
1107                                         probe -= span;
1108                                 else
1109                                         break;
1110                         }
1111                         ASSERT((probe >= 0) && (probe < max));
1112                         ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval));
1113
1114                         /*
1115                          * Since we may have duplicate hashval's, find the first
1116                          * matching hashval in the node.
1117                          */
1118                         while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) {
1119                                 btree--;
1120                                 probe--;
1121                         }
1122                         while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) {
1123                                 btree++;
1124                                 probe++;
1125                         }
1126
1127                         /*
1128                          * Pick the right block to descend on.
1129                          */
1130                         if (probe == max) {
1131                                 blk->index = max-1;
1132                                 blkno = be32_to_cpu(node->btree[max-1].before);
1133                         } else {
1134                                 blk->index = probe;
1135                                 blkno = be32_to_cpu(btree->before);
1136                         }
1137                 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1138                         blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1139                         break;
1140                 } else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1141                         blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
1142                         break;
1143                 }
1144         }
1145
1146         /*
1147          * A leaf block that ends in the hashval that we are interested in
1148          * (final hashval == search hashval) means that the next block may
1149          * contain more entries with the same hashval, shift upward to the
1150          * next leaf and keep searching.
1151          */
1152         for (;;) {
1153                 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1154                         retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1155                                                         &blk->index, state);
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                 } else {
1161                         ASSERT(0);
1162                         return XFS_ERROR(EFSCORRUPTED);
1163                 }
1164                 if (((retval == ENOENT) || (retval == ENOATTR)) &&
1165                     (blk->hashval == args->hashval)) {
1166                         error = xfs_da_path_shift(state, &state->path, 1, 1,
1167                                                          &retval);
1168                         if (error)
1169                                 return(error);
1170                         if (retval == 0) {
1171                                 continue;
1172                         } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1173                                 /* path_shift() gives ENOENT */
1174                                 retval = XFS_ERROR(ENOATTR);
1175                         }
1176                 }
1177                 break;
1178         }
1179         *result = retval;
1180         return(0);
1181 }
1182
1183 /*========================================================================
1184  * Utility routines.
1185  *========================================================================*/
1186
1187 /*
1188  * Link a new block into a doubly linked list of blocks (of whatever type).
1189  */
1190 int                                                     /* error */
1191 xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
1192                                xfs_da_state_blk_t *new_blk)
1193 {
1194         xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
1195         xfs_da_args_t *args;
1196         int before=0, error;
1197         xfs_dabuf_t *bp;
1198
1199         /*
1200          * Set up environment.
1201          */
1202         args = state->args;
1203         ASSERT(args != NULL);
1204         old_info = old_blk->bp->data;
1205         new_info = new_blk->bp->data;
1206         ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1207                old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1208                old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1209         ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
1210         ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
1211         ASSERT(old_blk->magic == new_blk->magic);
1212
1213         switch (old_blk->magic) {
1214         case XFS_ATTR_LEAF_MAGIC:
1215                 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1216                 break;
1217         case XFS_DIR2_LEAFN_MAGIC:
1218                 before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
1219                 break;
1220         case XFS_DA_NODE_MAGIC:
1221                 before = xfs_da_node_order(old_blk->bp, new_blk->bp);
1222                 break;
1223         }
1224
1225         /*
1226          * Link blocks in appropriate order.
1227          */
1228         if (before) {
1229                 /*
1230                  * Link new block in before existing block.
1231                  */
1232                 new_info->forw = cpu_to_be32(old_blk->blkno);
1233                 new_info->back = old_info->back;
1234                 if (old_info->back) {
1235                         error = xfs_da_read_buf(args->trans, args->dp,
1236                                                 be32_to_cpu(old_info->back),
1237                                                 -1, &bp, args->whichfork);
1238                         if (error)
1239                                 return(error);
1240                         ASSERT(bp != NULL);
1241                         tmp_info = bp->data;
1242                         ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
1243                         ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1244                         tmp_info->forw = cpu_to_be32(new_blk->blkno);
1245                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1246                         xfs_da_buf_done(bp);
1247                 }
1248                 old_info->back = cpu_to_be32(new_blk->blkno);
1249         } else {
1250                 /*
1251                  * Link new block in after existing block.
1252                  */
1253                 new_info->forw = old_info->forw;
1254                 new_info->back = cpu_to_be32(old_blk->blkno);
1255                 if (old_info->forw) {
1256                         error = xfs_da_read_buf(args->trans, args->dp,
1257                                                 be32_to_cpu(old_info->forw),
1258                                                 -1, &bp, args->whichfork);
1259                         if (error)
1260                                 return(error);
1261                         ASSERT(bp != NULL);
1262                         tmp_info = bp->data;
1263                         ASSERT(tmp_info->magic == old_info->magic);
1264                         ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1265                         tmp_info->back = cpu_to_be32(new_blk->blkno);
1266                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1267                         xfs_da_buf_done(bp);
1268                 }
1269                 old_info->forw = cpu_to_be32(new_blk->blkno);
1270         }
1271
1272         xfs_da_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1273         xfs_da_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1274         return(0);
1275 }
1276
1277 /*
1278  * Compare two intermediate nodes for "order".
1279  */
1280 STATIC int
1281 xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp)
1282 {
1283         xfs_da_intnode_t *node1, *node2;
1284
1285         node1 = node1_bp->data;
1286         node2 = node2_bp->data;
1287         ASSERT((be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC) &&
1288                (be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC));
1289         if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
1290             ((be32_to_cpu(node2->btree[0].hashval) <
1291               be32_to_cpu(node1->btree[0].hashval)) ||
1292              (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
1293               be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
1294                 return(1);
1295         }
1296         return(0);
1297 }
1298
1299 /*
1300  * Pick up the last hashvalue from an intermediate node.
1301  */
1302 STATIC uint
1303 xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count)
1304 {
1305         xfs_da_intnode_t *node;
1306
1307         node = bp->data;
1308         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1309         if (count)
1310                 *count = be16_to_cpu(node->hdr.count);
1311         if (!node->hdr.count)
1312                 return(0);
1313         return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1314 }
1315
1316 /*
1317  * Unlink a block from a doubly linked list of blocks.
1318  */
1319 STATIC int                                              /* error */
1320 xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1321                                  xfs_da_state_blk_t *save_blk)
1322 {
1323         xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
1324         xfs_da_args_t *args;
1325         xfs_dabuf_t *bp;
1326         int error;
1327
1328         /*
1329          * Set up environment.
1330          */
1331         args = state->args;
1332         ASSERT(args != NULL);
1333         save_info = save_blk->bp->data;
1334         drop_info = drop_blk->bp->data;
1335         ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1336                save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1337                save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1338         ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
1339         ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
1340         ASSERT(save_blk->magic == drop_blk->magic);
1341         ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1342                (be32_to_cpu(save_info->back) == drop_blk->blkno));
1343         ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1344                (be32_to_cpu(drop_info->back) == save_blk->blkno));
1345
1346         /*
1347          * Unlink the leaf block from the doubly linked chain of leaves.
1348          */
1349         if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1350                 save_info->back = drop_info->back;
1351                 if (drop_info->back) {
1352                         error = xfs_da_read_buf(args->trans, args->dp,
1353                                                 be32_to_cpu(drop_info->back),
1354                                                 -1, &bp, args->whichfork);
1355                         if (error)
1356                                 return(error);
1357                         ASSERT(bp != NULL);
1358                         tmp_info = bp->data;
1359                         ASSERT(tmp_info->magic == save_info->magic);
1360                         ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1361                         tmp_info->forw = cpu_to_be32(save_blk->blkno);
1362                         xfs_da_log_buf(args->trans, bp, 0,
1363                                                     sizeof(*tmp_info) - 1);
1364                         xfs_da_buf_done(bp);
1365                 }
1366         } else {
1367                 save_info->forw = drop_info->forw;
1368                 if (drop_info->forw) {
1369                         error = xfs_da_read_buf(args->trans, args->dp,
1370                                                 be32_to_cpu(drop_info->forw),
1371                                                 -1, &bp, args->whichfork);
1372                         if (error)
1373                                 return(error);
1374                         ASSERT(bp != NULL);
1375                         tmp_info = bp->data;
1376                         ASSERT(tmp_info->magic == save_info->magic);
1377                         ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1378                         tmp_info->back = cpu_to_be32(save_blk->blkno);
1379                         xfs_da_log_buf(args->trans, bp, 0,
1380                                                     sizeof(*tmp_info) - 1);
1381                         xfs_da_buf_done(bp);
1382                 }
1383         }
1384
1385         xfs_da_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1386         return(0);
1387 }
1388
1389 /*
1390  * Move a path "forward" or "!forward" one block at the current level.
1391  *
1392  * This routine will adjust a "path" to point to the next block
1393  * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1394  * Btree, including updating pointers to the intermediate nodes between
1395  * the new bottom and the root.
1396  */
1397 int                                                     /* error */
1398 xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
1399                                  int forward, int release, int *result)
1400 {
1401         xfs_da_state_blk_t *blk;
1402         xfs_da_blkinfo_t *info;
1403         xfs_da_intnode_t *node;
1404         xfs_da_args_t *args;
1405         xfs_dablk_t blkno=0;
1406         int level, error;
1407
1408         /*
1409          * Roll up the Btree looking for the first block where our
1410          * current index is not at the edge of the block.  Note that
1411          * we skip the bottom layer because we want the sibling block.
1412          */
1413         args = state->args;
1414         ASSERT(args != NULL);
1415         ASSERT(path != NULL);
1416         ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1417         level = (path->active-1) - 1;   /* skip bottom layer in path */
1418         for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1419                 ASSERT(blk->bp != NULL);
1420                 node = blk->bp->data;
1421                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1422                 if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) {
1423                         blk->index++;
1424                         blkno = be32_to_cpu(node->btree[blk->index].before);
1425                         break;
1426                 } else if (!forward && (blk->index > 0)) {
1427                         blk->index--;
1428                         blkno = be32_to_cpu(node->btree[blk->index].before);
1429                         break;
1430                 }
1431         }
1432         if (level < 0) {
1433                 *result = XFS_ERROR(ENOENT);    /* we're out of our tree */
1434                 ASSERT(args->oknoent);
1435                 return(0);
1436         }
1437
1438         /*
1439          * Roll down the edge of the subtree until we reach the
1440          * same depth we were at originally.
1441          */
1442         for (blk++, level++; level < path->active; blk++, level++) {
1443                 /*
1444                  * Release the old block.
1445                  * (if it's dirty, trans won't actually let go)
1446                  */
1447                 if (release)
1448                         xfs_da_brelse(args->trans, blk->bp);
1449
1450                 /*
1451                  * Read the next child block.
1452                  */
1453                 blk->blkno = blkno;
1454                 error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
1455                                                      &blk->bp, args->whichfork);
1456                 if (error)
1457                         return(error);
1458                 ASSERT(blk->bp != NULL);
1459                 info = blk->bp->data;
1460                 ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC ||
1461                        be16_to_cpu(info->magic) == XFS_DIR2_LEAFN_MAGIC ||
1462                        be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC);
1463                 blk->magic = be16_to_cpu(info->magic);
1464                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1465                         node = (xfs_da_intnode_t *)info;
1466                         blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1467                         if (forward)
1468                                 blk->index = 0;
1469                         else
1470                                 blk->index = be16_to_cpu(node->hdr.count)-1;
1471                         blkno = be32_to_cpu(node->btree[blk->index].before);
1472                 } else {
1473                         ASSERT(level == path->active-1);
1474                         blk->index = 0;
1475                         switch(blk->magic) {
1476                         case XFS_ATTR_LEAF_MAGIC:
1477                                 blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
1478                                                                       NULL);
1479                                 break;
1480                         case XFS_DIR2_LEAFN_MAGIC:
1481                                 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
1482                                                                        NULL);
1483                                 break;
1484                         default:
1485                                 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
1486                                        blk->magic == XFS_DIR2_LEAFN_MAGIC);
1487                                 break;
1488                         }
1489                 }
1490         }
1491         *result = 0;
1492         return(0);
1493 }
1494
1495
1496 /*========================================================================
1497  * Utility routines.
1498  *========================================================================*/
1499
1500 /*
1501  * Implement a simple hash on a character string.
1502  * Rotate the hash value by 7 bits, then XOR each character in.
1503  * This is implemented with some source-level loop unrolling.
1504  */
1505 xfs_dahash_t
1506 xfs_da_hashname(const uchar_t *name, int namelen)
1507 {
1508         xfs_dahash_t hash;
1509
1510         /*
1511          * Do four characters at a time as long as we can.
1512          */
1513         for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1514                 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1515                        (name[3] << 0) ^ rol32(hash, 7 * 4);
1516
1517         /*
1518          * Now do the rest of the characters.
1519          */
1520         switch (namelen) {
1521         case 3:
1522                 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1523                        rol32(hash, 7 * 3);
1524         case 2:
1525                 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1526         case 1:
1527                 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1528         default: /* case 0: */
1529                 return hash;
1530         }
1531 }
1532
1533 /*
1534  * Add a block to the btree ahead of the file.
1535  * Return the new block number to the caller.
1536  */
1537 int
1538 xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
1539 {
1540         xfs_fileoff_t bno, b;
1541         xfs_bmbt_irec_t map;
1542         xfs_bmbt_irec_t *mapp;
1543         xfs_inode_t *dp;
1544         int nmap, error, w, count, c, got, i, mapi;
1545         xfs_trans_t *tp;
1546         xfs_mount_t *mp;
1547
1548         dp = args->dp;
1549         mp = dp->i_mount;
1550         w = args->whichfork;
1551         tp = args->trans;
1552         /*
1553          * For new directories adjust the file offset and block count.
1554          */
1555         if (w == XFS_DATA_FORK) {
1556                 bno = mp->m_dirleafblk;
1557                 count = mp->m_dirblkfsbs;
1558         } else {
1559                 bno = 0;
1560                 count = 1;
1561         }
1562         /*
1563          * Find a spot in the file space to put the new block.
1564          */
1565         if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, w)))
1566                 return error;
1567         if (w == XFS_DATA_FORK)
1568                 ASSERT(bno >= mp->m_dirleafblk && bno < mp->m_dirfreeblk);
1569         /*
1570          * Try mapping it in one filesystem block.
1571          */
1572         nmap = 1;
1573         ASSERT(args->firstblock != NULL);
1574         if ((error = xfs_bmapi(tp, dp, bno, count,
1575                         XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|
1576                         XFS_BMAPI_CONTIG,
1577                         args->firstblock, args->total, &map, &nmap,
1578                         args->flist, NULL))) {
1579                 return error;
1580         }
1581         ASSERT(nmap <= 1);
1582         if (nmap == 1) {
1583                 mapp = &map;
1584                 mapi = 1;
1585         }
1586         /*
1587          * If we didn't get it and the block might work if fragmented,
1588          * try without the CONTIG flag.  Loop until we get it all.
1589          */
1590         else if (nmap == 0 && count > 1) {
1591                 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1592                 for (b = bno, mapi = 0; b < bno + count; ) {
1593                         nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1594                         c = (int)(bno + count - b);
1595                         if ((error = xfs_bmapi(tp, dp, b, c,
1596                                         XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|
1597                                         XFS_BMAPI_METADATA,
1598                                         args->firstblock, args->total,
1599                                         &mapp[mapi], &nmap, args->flist,
1600                                         NULL))) {
1601                                 kmem_free(mapp, sizeof(*mapp) * count);
1602                                 return error;
1603                         }
1604                         if (nmap < 1)
1605                                 break;
1606                         mapi += nmap;
1607                         b = mapp[mapi - 1].br_startoff +
1608                             mapp[mapi - 1].br_blockcount;
1609                 }
1610         } else {
1611                 mapi = 0;
1612                 mapp = NULL;
1613         }
1614         /*
1615          * Count the blocks we got, make sure it matches the total.
1616          */
1617         for (i = 0, got = 0; i < mapi; i++)
1618                 got += mapp[i].br_blockcount;
1619         if (got != count || mapp[0].br_startoff != bno ||
1620             mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1621             bno + count) {
1622                 if (mapp != &map)
1623                         kmem_free(mapp, sizeof(*mapp) * count);
1624                 return XFS_ERROR(ENOSPC);
1625         }
1626         if (mapp != &map)
1627                 kmem_free(mapp, sizeof(*mapp) * count);
1628         *new_blkno = (xfs_dablk_t)bno;
1629         return 0;
1630 }
1631
1632 /*
1633  * Ick.  We need to always be able to remove a btree block, even
1634  * if there's no space reservation because the filesystem is full.
1635  * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1636  * It swaps the target block with the last block in the file.  The
1637  * last block in the file can always be removed since it can't cause
1638  * a bmap btree split to do that.
1639  */
1640 STATIC int
1641 xfs_da_swap_lastblock(xfs_da_args_t *args, xfs_dablk_t *dead_blknop,
1642                       xfs_dabuf_t **dead_bufp)
1643 {
1644         xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1645         xfs_dabuf_t *dead_buf, *last_buf, *sib_buf, *par_buf;
1646         xfs_fileoff_t lastoff;
1647         xfs_inode_t *ip;
1648         xfs_trans_t *tp;
1649         xfs_mount_t *mp;
1650         int error, w, entno, level, dead_level;
1651         xfs_da_blkinfo_t *dead_info, *sib_info;
1652         xfs_da_intnode_t *par_node, *dead_node;
1653         xfs_dir2_leaf_t *dead_leaf2;
1654         xfs_dahash_t dead_hash;
1655
1656         dead_buf = *dead_bufp;
1657         dead_blkno = *dead_blknop;
1658         tp = args->trans;
1659         ip = args->dp;
1660         w = args->whichfork;
1661         ASSERT(w == XFS_DATA_FORK);
1662         mp = ip->i_mount;
1663         lastoff = mp->m_dirfreeblk;
1664         error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1665         if (error)
1666                 return error;
1667         if (unlikely(lastoff == 0)) {
1668                 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1669                                  mp);
1670                 return XFS_ERROR(EFSCORRUPTED);
1671         }
1672         /*
1673          * Read the last block in the btree space.
1674          */
1675         last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1676         if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
1677                 return error;
1678         /*
1679          * Copy the last block into the dead buffer and log it.
1680          */
1681         memcpy(dead_buf->data, last_buf->data, mp->m_dirblksize);
1682         xfs_da_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1683         dead_info = dead_buf->data;
1684         /*
1685          * Get values from the moved block.
1686          */
1687         if (be16_to_cpu(dead_info->magic) == XFS_DIR2_LEAFN_MAGIC) {
1688                 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1689                 dead_level = 0;
1690                 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1691         } else {
1692                 ASSERT(be16_to_cpu(dead_info->magic) == XFS_DA_NODE_MAGIC);
1693                 dead_node = (xfs_da_intnode_t *)dead_info;
1694                 dead_level = be16_to_cpu(dead_node->hdr.level);
1695                 dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
1696         }
1697         sib_buf = par_buf = NULL;
1698         /*
1699          * If the moved block has a left sibling, fix up the pointers.
1700          */
1701         if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1702                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1703                         goto done;
1704                 sib_info = sib_buf->data;
1705                 if (unlikely(
1706                     be32_to_cpu(sib_info->forw) != last_blkno ||
1707                     sib_info->magic != dead_info->magic)) {
1708                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1709                                          XFS_ERRLEVEL_LOW, mp);
1710                         error = XFS_ERROR(EFSCORRUPTED);
1711                         goto done;
1712                 }
1713                 sib_info->forw = cpu_to_be32(dead_blkno);
1714                 xfs_da_log_buf(tp, sib_buf,
1715                         XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1716                                         sizeof(sib_info->forw)));
1717                 xfs_da_buf_done(sib_buf);
1718                 sib_buf = NULL;
1719         }
1720         /*
1721          * If the moved block has a right sibling, fix up the pointers.
1722          */
1723         if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1724                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1725                         goto done;
1726                 sib_info = sib_buf->data;
1727                 if (unlikely(
1728                        be32_to_cpu(sib_info->back) != last_blkno ||
1729                        sib_info->magic != dead_info->magic)) {
1730                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1731                                          XFS_ERRLEVEL_LOW, mp);
1732                         error = XFS_ERROR(EFSCORRUPTED);
1733                         goto done;
1734                 }
1735                 sib_info->back = cpu_to_be32(dead_blkno);
1736                 xfs_da_log_buf(tp, sib_buf,
1737                         XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1738                                         sizeof(sib_info->back)));
1739                 xfs_da_buf_done(sib_buf);
1740                 sib_buf = NULL;
1741         }
1742         par_blkno = mp->m_dirleafblk;
1743         level = -1;
1744         /*
1745          * Walk down the tree looking for the parent of the moved block.
1746          */
1747         for (;;) {
1748                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1749                         goto done;
1750                 par_node = par_buf->data;
1751                 if (unlikely(
1752                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC ||
1753                     (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
1754                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1755                                          XFS_ERRLEVEL_LOW, mp);
1756                         error = XFS_ERROR(EFSCORRUPTED);
1757                         goto done;
1758                 }
1759                 level = be16_to_cpu(par_node->hdr.level);
1760                 for (entno = 0;
1761                      entno < be16_to_cpu(par_node->hdr.count) &&
1762                      be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
1763                      entno++)
1764                         continue;
1765                 if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
1766                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1767                                          XFS_ERRLEVEL_LOW, mp);
1768                         error = XFS_ERROR(EFSCORRUPTED);
1769                         goto done;
1770                 }
1771                 par_blkno = be32_to_cpu(par_node->btree[entno].before);
1772                 if (level == dead_level + 1)
1773                         break;
1774                 xfs_da_brelse(tp, par_buf);
1775                 par_buf = NULL;
1776         }
1777         /*
1778          * We're in the right parent block.
1779          * Look for the right entry.
1780          */
1781         for (;;) {
1782                 for (;
1783                      entno < be16_to_cpu(par_node->hdr.count) &&
1784                      be32_to_cpu(par_node->btree[entno].before) != last_blkno;
1785                      entno++)
1786                         continue;
1787                 if (entno < be16_to_cpu(par_node->hdr.count))
1788                         break;
1789                 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1790                 xfs_da_brelse(tp, par_buf);
1791                 par_buf = NULL;
1792                 if (unlikely(par_blkno == 0)) {
1793                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1794                                          XFS_ERRLEVEL_LOW, mp);
1795                         error = XFS_ERROR(EFSCORRUPTED);
1796                         goto done;
1797                 }
1798                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1799                         goto done;
1800                 par_node = par_buf->data;
1801                 if (unlikely(
1802                     be16_to_cpu(par_node->hdr.level) != level ||
1803                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC)) {
1804                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1805                                          XFS_ERRLEVEL_LOW, mp);
1806                         error = XFS_ERROR(EFSCORRUPTED);
1807                         goto done;
1808                 }
1809                 entno = 0;
1810         }
1811         /*
1812          * Update the parent entry pointing to the moved block.
1813          */
1814         par_node->btree[entno].before = cpu_to_be32(dead_blkno);
1815         xfs_da_log_buf(tp, par_buf,
1816                 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1817                                 sizeof(par_node->btree[entno].before)));
1818         xfs_da_buf_done(par_buf);
1819         xfs_da_buf_done(dead_buf);
1820         *dead_blknop = last_blkno;
1821         *dead_bufp = last_buf;
1822         return 0;
1823 done:
1824         if (par_buf)
1825                 xfs_da_brelse(tp, par_buf);
1826         if (sib_buf)
1827                 xfs_da_brelse(tp, sib_buf);
1828         xfs_da_brelse(tp, last_buf);
1829         return error;
1830 }
1831
1832 /*
1833  * Remove a btree block from a directory or attribute.
1834  */
1835 int
1836 xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
1837                     xfs_dabuf_t *dead_buf)
1838 {
1839         xfs_inode_t *dp;
1840         int done, error, w, count;
1841         xfs_trans_t *tp;
1842         xfs_mount_t *mp;
1843
1844         dp = args->dp;
1845         w = args->whichfork;
1846         tp = args->trans;
1847         mp = dp->i_mount;
1848         if (w == XFS_DATA_FORK)
1849                 count = mp->m_dirblkfsbs;
1850         else
1851                 count = 1;
1852         for (;;) {
1853                 /*
1854                  * Remove extents.  If we get ENOSPC for a dir we have to move
1855                  * the last block to the place we want to kill.
1856                  */
1857                 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
1858                                 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_METADATA,
1859                                 0, args->firstblock, args->flist, NULL,
1860                                 &done)) == ENOSPC) {
1861                         if (w != XFS_DATA_FORK)
1862                                 break;
1863                         if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
1864                                         &dead_buf)))
1865                                 break;
1866                 } else {
1867                         break;
1868                 }
1869         }
1870         xfs_da_binval(tp, dead_buf);
1871         return error;
1872 }
1873
1874 /*
1875  * See if the mapping(s) for this btree block are valid, i.e.
1876  * don't contain holes, are logically contiguous, and cover the whole range.
1877  */
1878 STATIC int
1879 xfs_da_map_covers_blocks(
1880         int             nmap,
1881         xfs_bmbt_irec_t *mapp,
1882         xfs_dablk_t     bno,
1883         int             count)
1884 {
1885         int             i;
1886         xfs_fileoff_t   off;
1887
1888         for (i = 0, off = bno; i < nmap; i++) {
1889                 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
1890                     mapp[i].br_startblock == DELAYSTARTBLOCK) {
1891                         return 0;
1892                 }
1893                 if (off != mapp[i].br_startoff) {
1894                         return 0;
1895                 }
1896                 off += mapp[i].br_blockcount;
1897         }
1898         return off == bno + count;
1899 }
1900
1901 /*
1902  * Make a dabuf.
1903  * Used for get_buf, read_buf, read_bufr, and reada_buf.
1904  */
1905 STATIC int
1906 xfs_da_do_buf(
1907         xfs_trans_t     *trans,
1908         xfs_inode_t     *dp,
1909         xfs_dablk_t     bno,
1910         xfs_daddr_t     *mappedbnop,
1911         xfs_dabuf_t     **bpp,
1912         int             whichfork,
1913         int             caller,
1914         inst_t          *ra)
1915 {
1916         xfs_buf_t       *bp = NULL;
1917         xfs_buf_t       **bplist;
1918         int             error=0;
1919         int             i;
1920         xfs_bmbt_irec_t map;
1921         xfs_bmbt_irec_t *mapp;
1922         xfs_daddr_t     mappedbno;
1923         xfs_mount_t     *mp;
1924         int             nbplist=0;
1925         int             nfsb;
1926         int             nmap;
1927         xfs_dabuf_t     *rbp;
1928
1929         mp = dp->i_mount;
1930         nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
1931         mappedbno = *mappedbnop;
1932         /*
1933          * Caller doesn't have a mapping.  -2 means don't complain
1934          * if we land in a hole.
1935          */
1936         if (mappedbno == -1 || mappedbno == -2) {
1937                 /*
1938                  * Optimize the one-block case.
1939                  */
1940                 if (nfsb == 1) {
1941                         xfs_fsblock_t   fsb;
1942
1943                         if ((error =
1944                             xfs_bmapi_single(trans, dp, whichfork, &fsb,
1945                                     (xfs_fileoff_t)bno))) {
1946                                 return error;
1947                         }
1948                         mapp = &map;
1949                         if (fsb == NULLFSBLOCK) {
1950                                 nmap = 0;
1951                         } else {
1952                                 map.br_startblock = fsb;
1953                                 map.br_startoff = (xfs_fileoff_t)bno;
1954                                 map.br_blockcount = 1;
1955                                 nmap = 1;
1956                         }
1957                 } else {
1958                         mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
1959                         nmap = nfsb;
1960                         if ((error = xfs_bmapi(trans, dp, (xfs_fileoff_t)bno,
1961                                         nfsb,
1962                                         XFS_BMAPI_METADATA |
1963                                                 XFS_BMAPI_AFLAG(whichfork),
1964                                         NULL, 0, mapp, &nmap, NULL, NULL)))
1965                                 goto exit0;
1966                 }
1967         } else {
1968                 map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
1969                 map.br_startoff = (xfs_fileoff_t)bno;
1970                 map.br_blockcount = nfsb;
1971                 mapp = &map;
1972                 nmap = 1;
1973         }
1974         if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
1975                 error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
1976                 if (unlikely(error == EFSCORRUPTED)) {
1977                         if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
1978                                 int     i;
1979                                 cmn_err(CE_ALERT, "xfs_da_do_buf: bno %lld\n",
1980                                         (long long)bno);
1981                                 cmn_err(CE_ALERT, "dir: inode %lld\n",
1982                                         (long long)dp->i_ino);
1983                                 for (i = 0; i < nmap; i++) {
1984                                         cmn_err(CE_ALERT,
1985                                                 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d\n",
1986                                                 i,
1987                                                 (long long)mapp[i].br_startoff,
1988                                                 (long long)mapp[i].br_startblock,
1989                                                 (long long)mapp[i].br_blockcount,
1990                                                 mapp[i].br_state);
1991                                 }
1992                         }
1993                         XFS_ERROR_REPORT("xfs_da_do_buf(1)",
1994                                          XFS_ERRLEVEL_LOW, mp);
1995                 }
1996                 goto exit0;
1997         }
1998         if (caller != 3 && nmap > 1) {
1999                 bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
2000                 nbplist = 0;
2001         } else
2002                 bplist = NULL;
2003         /*
2004          * Turn the mapping(s) into buffer(s).
2005          */
2006         for (i = 0; i < nmap; i++) {
2007                 int     nmapped;
2008
2009                 mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
2010                 if (i == 0)
2011                         *mappedbnop = mappedbno;
2012                 nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
2013                 switch (caller) {
2014                 case 0:
2015                         bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
2016                                 mappedbno, nmapped, 0);
2017                         error = bp ? XFS_BUF_GETERROR(bp) : XFS_ERROR(EIO);
2018                         break;
2019                 case 1:
2020                 case 2:
2021                         bp = NULL;
2022                         error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
2023                                 mappedbno, nmapped, 0, &bp);
2024                         break;
2025                 case 3:
2026                         xfs_baread(mp->m_ddev_targp, mappedbno, nmapped);
2027                         error = 0;
2028                         bp = NULL;
2029                         break;
2030                 }
2031                 if (error) {
2032                         if (bp)
2033                                 xfs_trans_brelse(trans, bp);
2034                         goto exit1;
2035                 }
2036                 if (!bp)
2037                         continue;
2038                 if (caller == 1) {
2039                         if (whichfork == XFS_ATTR_FORK) {
2040                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_ATTR_BTREE,
2041                                                 XFS_ATTR_BTREE_REF);
2042                         } else {
2043                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_DIR_BTREE,
2044                                                 XFS_DIR_BTREE_REF);
2045                         }
2046                 }
2047                 if (bplist) {
2048                         bplist[nbplist++] = bp;
2049                 }
2050         }
2051         /*
2052          * Build a dabuf structure.
2053          */
2054         if (bplist) {
2055                 rbp = xfs_da_buf_make(nbplist, bplist, ra);
2056         } else if (bp)
2057                 rbp = xfs_da_buf_make(1, &bp, ra);
2058         else
2059                 rbp = NULL;
2060         /*
2061          * For read_buf, check the magic number.
2062          */
2063         if (caller == 1) {
2064                 xfs_dir2_data_t         *data;
2065                 xfs_dir2_free_t         *free;
2066                 xfs_da_blkinfo_t        *info;
2067                 uint                    magic, magic1;
2068
2069                 info = rbp->data;
2070                 data = rbp->data;
2071                 free = rbp->data;
2072                 magic = be16_to_cpu(info->magic);
2073                 magic1 = be32_to_cpu(data->hdr.magic);
2074                 if (unlikely(
2075                     XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2076                                    (magic != XFS_ATTR_LEAF_MAGIC) &&
2077                                    (magic != XFS_DIR2_LEAF1_MAGIC) &&
2078                                    (magic != XFS_DIR2_LEAFN_MAGIC) &&
2079                                    (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2080                                    (magic1 != XFS_DIR2_DATA_MAGIC) &&
2081                                    (be32_to_cpu(free->hdr.magic) != XFS_DIR2_FREE_MAGIC),
2082                                 mp, XFS_ERRTAG_DA_READ_BUF,
2083                                 XFS_RANDOM_DA_READ_BUF))) {
2084                         xfs_buftrace("DA READ ERROR", rbp->bps[0]);
2085                         XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2086                                              XFS_ERRLEVEL_LOW, mp, info);
2087                         error = XFS_ERROR(EFSCORRUPTED);
2088                         xfs_da_brelse(trans, rbp);
2089                         nbplist = 0;
2090                         goto exit1;
2091                 }
2092         }
2093         if (bplist) {
2094                 kmem_free(bplist, sizeof(*bplist) * nmap);
2095         }
2096         if (mapp != &map) {
2097                 kmem_free(mapp, sizeof(*mapp) * nfsb);
2098         }
2099         if (bpp)
2100                 *bpp = rbp;
2101         return 0;
2102 exit1:
2103         if (bplist) {
2104                 for (i = 0; i < nbplist; i++)
2105                         xfs_trans_brelse(trans, bplist[i]);
2106                 kmem_free(bplist, sizeof(*bplist) * nmap);
2107         }
2108 exit0:
2109         if (mapp != &map)
2110                 kmem_free(mapp, sizeof(*mapp) * nfsb);
2111         if (bpp)
2112                 *bpp = NULL;
2113         return error;
2114 }
2115
2116 /*
2117  * Get a buffer for the dir/attr block.
2118  */
2119 int
2120 xfs_da_get_buf(
2121         xfs_trans_t     *trans,
2122         xfs_inode_t     *dp,
2123         xfs_dablk_t     bno,
2124         xfs_daddr_t             mappedbno,
2125         xfs_dabuf_t     **bpp,
2126         int             whichfork)
2127 {
2128         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0,
2129                                                  (inst_t *)__return_address);
2130 }
2131
2132 /*
2133  * Get a buffer for the dir/attr block, fill in the contents.
2134  */
2135 int
2136 xfs_da_read_buf(
2137         xfs_trans_t     *trans,
2138         xfs_inode_t     *dp,
2139         xfs_dablk_t     bno,
2140         xfs_daddr_t             mappedbno,
2141         xfs_dabuf_t     **bpp,
2142         int             whichfork)
2143 {
2144         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1,
2145                 (inst_t *)__return_address);
2146 }
2147
2148 /*
2149  * Readahead the dir/attr block.
2150  */
2151 xfs_daddr_t
2152 xfs_da_reada_buf(
2153         xfs_trans_t     *trans,
2154         xfs_inode_t     *dp,
2155         xfs_dablk_t     bno,
2156         int             whichfork)
2157 {
2158         xfs_daddr_t             rval;
2159
2160         rval = -1;
2161         if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3,
2162                         (inst_t *)__return_address))
2163                 return -1;
2164         else
2165                 return rval;
2166 }
2167
2168 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2169 kmem_zone_t *xfs_dabuf_zone;            /* dabuf zone */
2170
2171 /*
2172  * Allocate a dir-state structure.
2173  * We don't put them on the stack since they're large.
2174  */
2175 xfs_da_state_t *
2176 xfs_da_state_alloc(void)
2177 {
2178         return kmem_zone_zalloc(xfs_da_state_zone, KM_SLEEP);
2179 }
2180
2181 /*
2182  * Kill the altpath contents of a da-state structure.
2183  */
2184 STATIC void
2185 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2186 {
2187         int     i;
2188
2189         for (i = 0; i < state->altpath.active; i++) {
2190                 if (state->altpath.blk[i].bp) {
2191                         if (state->altpath.blk[i].bp != state->path.blk[i].bp)
2192                                 xfs_da_buf_done(state->altpath.blk[i].bp);
2193                         state->altpath.blk[i].bp = NULL;
2194                 }
2195         }
2196         state->altpath.active = 0;
2197 }
2198
2199 /*
2200  * Free a da-state structure.
2201  */
2202 void
2203 xfs_da_state_free(xfs_da_state_t *state)
2204 {
2205         int     i;
2206
2207         xfs_da_state_kill_altpath(state);
2208         for (i = 0; i < state->path.active; i++) {
2209                 if (state->path.blk[i].bp)
2210                         xfs_da_buf_done(state->path.blk[i].bp);
2211         }
2212         if (state->extravalid && state->extrablk.bp)
2213                 xfs_da_buf_done(state->extrablk.bp);
2214 #ifdef DEBUG
2215         memset((char *)state, 0, sizeof(*state));
2216 #endif /* DEBUG */
2217         kmem_zone_free(xfs_da_state_zone, state);
2218 }
2219
2220 #ifdef XFS_DABUF_DEBUG
2221 xfs_dabuf_t     *xfs_dabuf_global_list;
2222 lock_t          xfs_dabuf_global_lock;
2223 #endif
2224
2225 /*
2226  * Create a dabuf.
2227  */
2228 /* ARGSUSED */
2229 STATIC xfs_dabuf_t *
2230 xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra)
2231 {
2232         xfs_buf_t       *bp;
2233         xfs_dabuf_t     *dabuf;
2234         int             i;
2235         int             off;
2236
2237         if (nbuf == 1)
2238                 dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_SLEEP);
2239         else
2240                 dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_SLEEP);
2241         dabuf->dirty = 0;
2242 #ifdef XFS_DABUF_DEBUG
2243         dabuf->ra = ra;
2244         dabuf->target = XFS_BUF_TARGET(bps[0]);
2245         dabuf->blkno = XFS_BUF_ADDR(bps[0]);
2246 #endif
2247         if (nbuf == 1) {
2248                 dabuf->nbuf = 1;
2249                 bp = bps[0];
2250                 dabuf->bbcount = (short)BTOBB(XFS_BUF_COUNT(bp));
2251                 dabuf->data = XFS_BUF_PTR(bp);
2252                 dabuf->bps[0] = bp;
2253         } else {
2254                 dabuf->nbuf = nbuf;
2255                 for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
2256                         dabuf->bps[i] = bp = bps[i];
2257                         dabuf->bbcount += BTOBB(XFS_BUF_COUNT(bp));
2258                 }
2259                 dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
2260                 for (i = off = 0; i < nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2261                         bp = bps[i];
2262                         memcpy((char *)dabuf->data + off, XFS_BUF_PTR(bp),
2263                                 XFS_BUF_COUNT(bp));
2264                 }
2265         }
2266 #ifdef XFS_DABUF_DEBUG
2267         {
2268                 SPLDECL(s);
2269                 xfs_dabuf_t     *p;
2270
2271                 s = mutex_spinlock(&xfs_dabuf_global_lock);
2272                 for (p = xfs_dabuf_global_list; p; p = p->next) {
2273                         ASSERT(p->blkno != dabuf->blkno ||
2274                                p->target != dabuf->target);
2275                 }
2276                 dabuf->prev = NULL;
2277                 if (xfs_dabuf_global_list)
2278                         xfs_dabuf_global_list->prev = dabuf;
2279                 dabuf->next = xfs_dabuf_global_list;
2280                 xfs_dabuf_global_list = dabuf;
2281                 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2282         }
2283 #endif
2284         return dabuf;
2285 }
2286
2287 /*
2288  * Un-dirty a dabuf.
2289  */
2290 STATIC void
2291 xfs_da_buf_clean(xfs_dabuf_t *dabuf)
2292 {
2293         xfs_buf_t       *bp;
2294         int             i;
2295         int             off;
2296
2297         if (dabuf->dirty) {
2298                 ASSERT(dabuf->nbuf > 1);
2299                 dabuf->dirty = 0;
2300                 for (i = off = 0; i < dabuf->nbuf;
2301                                 i++, off += XFS_BUF_COUNT(bp)) {
2302                         bp = dabuf->bps[i];
2303                         memcpy(XFS_BUF_PTR(bp), (char *)dabuf->data + off,
2304                                 XFS_BUF_COUNT(bp));
2305                 }
2306         }
2307 }
2308
2309 /*
2310  * Release a dabuf.
2311  */
2312 void
2313 xfs_da_buf_done(xfs_dabuf_t *dabuf)
2314 {
2315         ASSERT(dabuf);
2316         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2317         if (dabuf->dirty)
2318                 xfs_da_buf_clean(dabuf);
2319         if (dabuf->nbuf > 1)
2320                 kmem_free(dabuf->data, BBTOB(dabuf->bbcount));
2321 #ifdef XFS_DABUF_DEBUG
2322         {
2323                 SPLDECL(s);
2324
2325                 s = mutex_spinlock(&xfs_dabuf_global_lock);
2326                 if (dabuf->prev)
2327                         dabuf->prev->next = dabuf->next;
2328                 else
2329                         xfs_dabuf_global_list = dabuf->next;
2330                 if (dabuf->next)
2331                         dabuf->next->prev = dabuf->prev;
2332                 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2333         }
2334         memset(dabuf, 0, XFS_DA_BUF_SIZE(dabuf->nbuf));
2335 #endif
2336         if (dabuf->nbuf == 1)
2337                 kmem_zone_free(xfs_dabuf_zone, dabuf);
2338         else
2339                 kmem_free(dabuf, XFS_DA_BUF_SIZE(dabuf->nbuf));
2340 }
2341
2342 /*
2343  * Log transaction from a dabuf.
2344  */
2345 void
2346 xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
2347 {
2348         xfs_buf_t       *bp;
2349         uint            f;
2350         int             i;
2351         uint            l;
2352         int             off;
2353
2354         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2355         if (dabuf->nbuf == 1) {
2356                 ASSERT(dabuf->data == (void *)XFS_BUF_PTR(dabuf->bps[0]));
2357                 xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
2358                 return;
2359         }
2360         dabuf->dirty = 1;
2361         ASSERT(first <= last);
2362         for (i = off = 0; i < dabuf->nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2363                 bp = dabuf->bps[i];
2364                 f = off;
2365                 l = f + XFS_BUF_COUNT(bp) - 1;
2366                 if (f < first)
2367                         f = first;
2368                 if (l > last)
2369                         l = last;
2370                 if (f <= l)
2371                         xfs_trans_log_buf(tp, bp, f - off, l - off);
2372                 /*
2373                  * B_DONE is set by xfs_trans_log buf.
2374                  * If we don't set it on a new buffer (get not read)
2375                  * then if we don't put anything in the buffer it won't
2376                  * be set, and at commit it it released into the cache,
2377                  * and then a read will fail.
2378                  */
2379                 else if (!(XFS_BUF_ISDONE(bp)))
2380                   XFS_BUF_DONE(bp);
2381         }
2382         ASSERT(last < off);
2383 }
2384
2385 /*
2386  * Release dabuf from a transaction.
2387  * Have to free up the dabuf before the buffers are released,
2388  * since the synchronization on the dabuf is really the lock on the buffer.
2389  */
2390 void
2391 xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2392 {
2393         xfs_buf_t       *bp;
2394         xfs_buf_t       **bplist;
2395         int             i;
2396         int             nbuf;
2397
2398         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2399         if ((nbuf = dabuf->nbuf) == 1) {
2400                 bplist = &bp;
2401                 bp = dabuf->bps[0];
2402         } else {
2403                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2404                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2405         }
2406         xfs_da_buf_done(dabuf);
2407         for (i = 0; i < nbuf; i++)
2408                 xfs_trans_brelse(tp, bplist[i]);
2409         if (bplist != &bp)
2410                 kmem_free(bplist, nbuf * sizeof(*bplist));
2411 }
2412
2413 /*
2414  * Invalidate dabuf from a transaction.
2415  */
2416 void
2417 xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2418 {
2419         xfs_buf_t       *bp;
2420         xfs_buf_t       **bplist;
2421         int             i;
2422         int             nbuf;
2423
2424         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2425         if ((nbuf = dabuf->nbuf) == 1) {
2426                 bplist = &bp;
2427                 bp = dabuf->bps[0];
2428         } else {
2429                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2430                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2431         }
2432         xfs_da_buf_done(dabuf);
2433         for (i = 0; i < nbuf; i++)
2434                 xfs_trans_binval(tp, bplist[i]);
2435         if (bplist != &bp)
2436                 kmem_free(bplist, nbuf * sizeof(*bplist));
2437 }
2438
2439 /*
2440  * Get the first daddr from a dabuf.
2441  */
2442 xfs_daddr_t
2443 xfs_da_blkno(xfs_dabuf_t *dabuf)
2444 {
2445         ASSERT(dabuf->nbuf);
2446         ASSERT(dabuf->data);
2447         return XFS_BUF_ADDR(dabuf->bps[0]);
2448 }