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 #include "xfs_trace.h"
  50
  51 /*
  52  * xfs_da_btree.c
  53  *
  54  * Routines to implement directories as Btrees of hashed names.
  55  */
  56
  57 /*========================================================================
  58  * Function prototypes for the kernel.
  59  *========================================================================*/
  60
  61 /*
  62  * Routines used for growing the Btree.
  63  */
  64 STATIC int xfs_da_root_split(xfs_da_state_t *state,
  65                                             xfs_da_state_blk_t *existing_root,
  66                                             xfs_da_state_blk_t *new_child);
  67 STATIC int xfs_da_node_split(xfs_da_state_t *state,
  68                                             xfs_da_state_blk_t *existing_blk,
  69                                             xfs_da_state_blk_t *split_blk,
  70                                             xfs_da_state_blk_t *blk_to_add,
  71                                             int treelevel,
  72                                             int *result);
  73 STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
  74                                          xfs_da_state_blk_t *node_blk_1,
  75                                          xfs_da_state_blk_t *node_blk_2);
  76 STATIC void xfs_da_node_add(xfs_da_state_t *state,
  77                                    xfs_da_state_blk_t *old_node_blk,
  78                                    xfs_da_state_blk_t *new_node_blk);
  79
  80 /*
  81  * Routines used for shrinking the Btree.
  82  */
  83 STATIC int xfs_da_root_join(xfs_da_state_t *state,
  84                                            xfs_da_state_blk_t *root_blk);
  85 STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
  86 STATIC void xfs_da_node_remove(xfs_da_state_t *state,
  87                                               xfs_da_state_blk_t *drop_blk);
  88 STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
  89                                          xfs_da_state_blk_t *src_node_blk,
  90                                          xfs_da_state_blk_t *dst_node_blk);
  91
  92 /*
  93  * Utility routines.
  94  */
  95 STATIC uint     xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count);
  96 STATIC int      xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp);
  97 STATIC xfs_dabuf_t *xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra);
  98 STATIC int      xfs_da_blk_unlink(xfs_da_state_t *state,
  99                                   xfs_da_state_blk_t *drop_blk,
 100                                   xfs_da_state_blk_t *save_blk);
 101 STATIC void     xfs_da_state_kill_altpath(xfs_da_state_t *state);
 102
 103 /*========================================================================
 104  * Routines used for growing the Btree.
 105  *========================================================================*/
 106
 107 /*
 108  * Create the initial contents of an intermediate node.
 109  */
 110 int
 111 xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
 112                                  xfs_dabuf_t **bpp, int whichfork)
 113 {
 114         xfs_da_intnode_t *node;
 115         xfs_dabuf_t *bp;
 116         int error;
 117         xfs_trans_t *tp;
 118
 119         tp = args->trans;
 120         error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
 121         if (error)
 122                 return(error);
 123         ASSERT(bp != NULL);
 124         node = bp->data;
 125         node->hdr.info.forw = 0;
 126         node->hdr.info.back = 0;
 127         node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC);
 128         node->hdr.info.pad = 0;
 129         node->hdr.count = 0;
 130         node->hdr.level = cpu_to_be16(level);
 131
 132         xfs_da_log_buf(tp, bp,
 133                 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 134
 135         *bpp = bp;
 136         return(0);
 137 }
 138
 139 /*
 140  * Split a leaf node, rebalance, then possibly split
 141  * intermediate nodes, rebalance, etc.
 142  */
 143 int                                                     /* error */
 144 xfs_da_split(xfs_da_state_t *state)
 145 {
 146         xfs_da_state_blk_t *oldblk, *newblk, *addblk;
 147         xfs_da_intnode_t *node;
 148         xfs_dabuf_t *bp;
 149         int max, action, error, i;
 150
 151         /*
 152          * Walk back up the tree splitting/inserting/adjusting as necessary.
 153          * If we need to insert and there isn't room, split the node, then
 154          * decide which fragment to insert the new block from below into.
 155          * Note that we may split the root this way, but we need more fixup.
 156          */
 157         max = state->path.active - 1;
 158         ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
 159         ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
 160                state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
 161
 162         addblk = &state->path.blk[max];         /* initial dummy value */
 163         for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
 164                 oldblk = &state->path.blk[i];
 165                 newblk = &state->altpath.blk[i];
 166
 167                 /*
 168                  * If a leaf node then
 169                  *     Allocate a new leaf node, then rebalance across them.
 170                  * else if an intermediate node then
 171                  *     We split on the last layer, must we split the node?
 172                  */
 173                 switch (oldblk->magic) {
 174                 case XFS_ATTR_LEAF_MAGIC:
 175                         error = xfs_attr_leaf_split(state, oldblk, newblk);
 176                         if ((error != 0) && (error != ENOSPC)) {
 177                                 return(error);  /* GROT: attr is inconsistent */
 178                         }
 179                         if (!error) {
 180                                 addblk = newblk;
 181                                 break;
 182                         }
 183                         /*
 184                          * Entry wouldn't fit, split the leaf again.
 185                          */
 186                         state->extravalid = 1;
 187                         if (state->inleaf) {
 188                                 state->extraafter = 0;  /* before newblk */
 189                                 error = xfs_attr_leaf_split(state, oldblk,
 190                                                             &state->extrablk);
 191                         } else {
 192                                 state->extraafter = 1;  /* after newblk */
 193                                 error = xfs_attr_leaf_split(state, newblk,
 194                                                             &state->extrablk);
 195                         }
 196                         if (error)
 197                                 return(error);  /* GROT: attr inconsistent */
 198                         addblk = newblk;
 199                         break;
 200                 case XFS_DIR2_LEAFN_MAGIC:
 201                         error = xfs_dir2_leafn_split(state, oldblk, newblk);
 202                         if (error)
 203                                 return error;
 204                         addblk = newblk;
 205                         break;
 206                 case XFS_DA_NODE_MAGIC:
 207                         error = xfs_da_node_split(state, oldblk, newblk, addblk,
 208                                                          max - i, &action);
 209                         xfs_da_buf_done(addblk->bp);
 210                         addblk->bp = NULL;
 211                         if (error)
 212                                 return(error);  /* GROT: dir is inconsistent */
 213                         /*
 214                          * Record the newly split block for the next time thru?
 215                          */
 216                         if (action)
 217                                 addblk = newblk;
 218                         else
 219                                 addblk = NULL;
 220                         break;
 221                 }
 222
 223                 /*
 224                  * Update the btree to show the new hashval for this child.
 225                  */
 226                 xfs_da_fixhashpath(state, &state->path);
 227                 /*
 228                  * If we won't need this block again, it's getting dropped
 229                  * from the active path by the loop control, so we need
 230                  * to mark it done now.
 231                  */
 232                 if (i > 0 || !addblk)
 233                         xfs_da_buf_done(oldblk->bp);
 234         }
 235         if (!addblk)
 236                 return(0);
 237
 238         /*
 239          * Split the root node.
 240          */
 241         ASSERT(state->path.active == 0);
 242         oldblk = &state->path.blk[0];
 243         error = xfs_da_root_split(state, oldblk, addblk);
 244         if (error) {
 245                 xfs_da_buf_done(oldblk->bp);
 246                 xfs_da_buf_done(addblk->bp);
 247                 addblk->bp = NULL;
 248                 return(error);  /* GROT: dir is inconsistent */
 249         }
 250
 251         /*
 252          * Update pointers to the node which used to be block 0 and
 253          * just got bumped because of the addition of a new root node.
 254          * There might be three blocks involved if a double split occurred,
 255          * and the original block 0 could be at any position in the list.
 256          */
 257
 258         node = oldblk->bp->data;
 259         if (node->hdr.info.forw) {
 260                 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
 261                         bp = addblk->bp;
 262                 } else {
 263                         ASSERT(state->extravalid);
 264                         bp = state->extrablk.bp;
 265                 }
 266                 node = bp->data;
 267                 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
 268                 xfs_da_log_buf(state->args->trans, bp,
 269                     XFS_DA_LOGRANGE(node, &node->hdr.info,
 270                     sizeof(node->hdr.info)));
 271         }
 272         node = oldblk->bp->data;
 273         if (node->hdr.info.back) {
 274                 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
 275                         bp = addblk->bp;
 276                 } else {
 277                         ASSERT(state->extravalid);
 278                         bp = state->extrablk.bp;
 279                 }
 280                 node = bp->data;
 281                 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
 282                 xfs_da_log_buf(state->args->trans, bp,
 283                     XFS_DA_LOGRANGE(node, &node->hdr.info,
 284                     sizeof(node->hdr.info)));
 285         }
 286         xfs_da_buf_done(oldblk->bp);
 287         xfs_da_buf_done(addblk->bp);
 288         addblk->bp = NULL;
 289         return(0);
 290 }
 291
 292 /*
 293  * Split the root.  We have to create a new root and point to the two
 294  * parts (the split old root) that we just created.  Copy block zero to
 295  * the EOF, extending the inode in process.
 296  */
 297 STATIC int                                              /* error */
 298 xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
 299                                  xfs_da_state_blk_t *blk2)
 300 {
 301         xfs_da_intnode_t *node, *oldroot;
 302         xfs_da_args_t *args;
 303         xfs_dablk_t blkno;
 304         xfs_dabuf_t *bp;
 305         int error, size;
 306         xfs_inode_t *dp;
 307         xfs_trans_t *tp;
 308         xfs_mount_t *mp;
 309         xfs_dir2_leaf_t *leaf;
 310
 311         /*
 312          * Copy the existing (incorrect) block from the root node position
 313          * to a free space somewhere.
 314          */
 315         args = state->args;
 316         ASSERT(args != NULL);
 317         error = xfs_da_grow_inode(args, &blkno);
 318         if (error)
 319                 return(error);
 320         dp = args->dp;
 321         tp = args->trans;
 322         mp = state->mp;
 323         error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
 324         if (error)
 325                 return(error);
 326         ASSERT(bp != NULL);
 327         node = bp->data;
 328         oldroot = blk1->bp->data;
 329         if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC) {
 330                 size = (int)((char *)&oldroot->btree[be16_to_cpu(oldroot->hdr.count)] -
 331                              (char *)oldroot);
 332         } else {
 333                 ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 334                 leaf = (xfs_dir2_leaf_t *)oldroot;
 335                 size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] -
 336                              (char *)leaf);
 337         }
 338         memcpy(node, oldroot, size);
 339         xfs_da_log_buf(tp, bp, 0, size - 1);
 340         xfs_da_buf_done(blk1->bp);
 341         blk1->bp = bp;
 342         blk1->blkno = blkno;
 343
 344         /*
 345          * Set up the new root node.
 346          */
 347         error = xfs_da_node_create(args,
 348                 (args->whichfork == XFS_DATA_FORK) ? mp->m_dirleafblk : 0,
 349                 be16_to_cpu(node->hdr.level) + 1, &bp, args->whichfork);
 350         if (error)
 351                 return(error);
 352         node = bp->data;
 353         node->btree[0].hashval = cpu_to_be32(blk1->hashval);
 354         node->btree[0].before = cpu_to_be32(blk1->blkno);
 355         node->btree[1].hashval = cpu_to_be32(blk2->hashval);
 356         node->btree[1].before = cpu_to_be32(blk2->blkno);
 357         node->hdr.count = cpu_to_be16(2);
 358
 359 #ifdef DEBUG
 360         if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC) {
 361                 ASSERT(blk1->blkno >= mp->m_dirleafblk &&
 362                        blk1->blkno < mp->m_dirfreeblk);
 363                 ASSERT(blk2->blkno >= mp->m_dirleafblk &&
 364                        blk2->blkno < mp->m_dirfreeblk);
 365         }
 366 #endif
 367
 368         /* Header is already logged by xfs_da_node_create */
 369         xfs_da_log_buf(tp, bp,
 370                 XFS_DA_LOGRANGE(node, node->btree,
 371                         sizeof(xfs_da_node_entry_t) * 2));
 372         xfs_da_buf_done(bp);
 373
 374         return(0);
 375 }
 376
 377 /*
 378  * Split the node, rebalance, then add the new entry.
 379  */
 380 STATIC int                                              /* error */
 381 xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
 382                                  xfs_da_state_blk_t *newblk,
 383                                  xfs_da_state_blk_t *addblk,
 384                                  int treelevel, int *result)
 385 {
 386         xfs_da_intnode_t *node;
 387         xfs_dablk_t blkno;
 388         int newcount, error;
 389         int useextra;
 390
 391         node = oldblk->bp->data;
 392         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 393
 394         /*
 395          * With V2 dirs the extra block is data or freespace.
 396          */
 397         useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
 398         newcount = 1 + useextra;
 399         /*
 400          * Do we have to split the node?
 401          */
 402         if ((be16_to_cpu(node->hdr.count) + newcount) > state->node_ents) {
 403                 /*
 404                  * Allocate a new node, add to the doubly linked chain of
 405                  * nodes, then move some of our excess entries into it.
 406                  */
 407                 error = xfs_da_grow_inode(state->args, &blkno);
 408                 if (error)
 409                         return(error);  /* GROT: dir is inconsistent */
 410
 411                 error = xfs_da_node_create(state->args, blkno, treelevel,
 412                                            &newblk->bp, state->args->whichfork);
 413                 if (error)
 414                         return(error);  /* GROT: dir is inconsistent */
 415                 newblk->blkno = blkno;
 416                 newblk->magic = XFS_DA_NODE_MAGIC;
 417                 xfs_da_node_rebalance(state, oldblk, newblk);
 418                 error = xfs_da_blk_link(state, oldblk, newblk);
 419                 if (error)
 420                         return(error);
 421                 *result = 1;
 422         } else {
 423                 *result = 0;
 424         }
 425
 426         /*
 427          * Insert the new entry(s) into the correct block
 428          * (updating last hashval in the process).
 429          *
 430          * xfs_da_node_add() inserts BEFORE the given index,
 431          * and as a result of using node_lookup_int() we always
 432          * point to a valid entry (not after one), but a split
 433          * operation always results in a new block whose hashvals
 434          * FOLLOW the current block.
 435          *
 436          * If we had double-split op below us, then add the extra block too.
 437          */
 438         node = oldblk->bp->data;
 439         if (oldblk->index <= be16_to_cpu(node->hdr.count)) {
 440                 oldblk->index++;
 441                 xfs_da_node_add(state, oldblk, addblk);
 442                 if (useextra) {
 443                         if (state->extraafter)
 444                                 oldblk->index++;
 445                         xfs_da_node_add(state, oldblk, &state->extrablk);
 446                         state->extravalid = 0;
 447                 }
 448         } else {
 449                 newblk->index++;
 450                 xfs_da_node_add(state, newblk, addblk);
 451                 if (useextra) {
 452                         if (state->extraafter)
 453                                 newblk->index++;
 454                         xfs_da_node_add(state, newblk, &state->extrablk);
 455                         state->extravalid = 0;
 456                 }
 457         }
 458
 459         return(0);
 460 }
 461
 462 /*
 463  * Balance the btree elements between two intermediate nodes,
 464  * usually one full and one empty.
 465  *
 466  * NOTE: if blk2 is empty, then it will get the upper half of blk1.
 467  */
 468 STATIC void
 469 xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
 470                                      xfs_da_state_blk_t *blk2)
 471 {
 472         xfs_da_intnode_t *node1, *node2, *tmpnode;
 473         xfs_da_node_entry_t *btree_s, *btree_d;
 474         int count, tmp;
 475         xfs_trans_t *tp;
 476
 477         node1 = blk1->bp->data;
 478         node2 = blk2->bp->data;
 479         /*
 480          * Figure out how many entries need to move, and in which direction.
 481          * Swap the nodes around if that makes it simpler.
 482          */
 483         if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
 484             ((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) ||
 485              (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
 486               be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
 487                 tmpnode = node1;
 488                 node1 = node2;
 489                 node2 = tmpnode;
 490         }
 491         ASSERT(be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 492         ASSERT(be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 493         count = (be16_to_cpu(node1->hdr.count) - be16_to_cpu(node2->hdr.count)) / 2;
 494         if (count == 0)
 495                 return;
 496         tp = state->args->trans;
 497         /*
 498          * Two cases: high-to-low and low-to-high.
 499          */
 500         if (count > 0) {
 501                 /*
 502                  * Move elements in node2 up to make a hole.
 503                  */
 504                 if ((tmp = be16_to_cpu(node2->hdr.count)) > 0) {
 505                         tmp *= (uint)sizeof(xfs_da_node_entry_t);
 506                         btree_s = &node2->btree[0];
 507                         btree_d = &node2->btree[count];
 508                         memmove(btree_d, btree_s, tmp);
 509                 }
 510
 511                 /*
 512                  * Move the req'd B-tree elements from high in node1 to
 513                  * low in node2.
 514                  */
 515                 be16_add_cpu(&node2->hdr.count, count);
 516                 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
 517                 btree_s = &node1->btree[be16_to_cpu(node1->hdr.count) - count];
 518                 btree_d = &node2->btree[0];
 519                 memcpy(btree_d, btree_s, tmp);
 520                 be16_add_cpu(&node1->hdr.count, -count);
 521         } else {
 522                 /*
 523                  * Move the req'd B-tree elements from low in node2 to
 524                  * high in node1.
 525                  */
 526                 count = -count;
 527                 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
 528                 btree_s = &node2->btree[0];
 529                 btree_d = &node1->btree[be16_to_cpu(node1->hdr.count)];
 530                 memcpy(btree_d, btree_s, tmp);
 531                 be16_add_cpu(&node1->hdr.count, count);
 532                 xfs_da_log_buf(tp, blk1->bp,
 533                         XFS_DA_LOGRANGE(node1, btree_d, tmp));
 534
 535                 /*
 536                  * Move elements in node2 down to fill the hole.
 537                  */
 538                 tmp  = be16_to_cpu(node2->hdr.count) - count;
 539                 tmp *= (uint)sizeof(xfs_da_node_entry_t);
 540                 btree_s = &node2->btree[count];
 541                 btree_d = &node2->btree[0];
 542                 memmove(btree_d, btree_s, tmp);
 543                 be16_add_cpu(&node2->hdr.count, -count);
 544         }
 545
 546         /*
 547          * Log header of node 1 and all current bits of node 2.
 548          */
 549         xfs_da_log_buf(tp, blk1->bp,
 550                 XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
 551         xfs_da_log_buf(tp, blk2->bp,
 552                 XFS_DA_LOGRANGE(node2, &node2->hdr,
 553                         sizeof(node2->hdr) +
 554                         sizeof(node2->btree[0]) * be16_to_cpu(node2->hdr.count)));
 555
 556         /*
 557          * Record the last hashval from each block for upward propagation.
 558          * (note: don't use the swapped node pointers)
 559          */
 560         node1 = blk1->bp->data;
 561         node2 = blk2->bp->data;
 562         blk1->hashval = be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval);
 563         blk2->hashval = be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval);
 564
 565         /*
 566          * Adjust the expected index for insertion.
 567          */
 568         if (blk1->index >= be16_to_cpu(node1->hdr.count)) {
 569                 blk2->index = blk1->index - be16_to_cpu(node1->hdr.count);
 570                 blk1->index = be16_to_cpu(node1->hdr.count) + 1;        /* make it invalid */
 571         }
 572 }
 573
 574 /*
 575  * Add a new entry to an intermediate node.
 576  */
 577 STATIC void
 578 xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
 579                                xfs_da_state_blk_t *newblk)
 580 {
 581         xfs_da_intnode_t *node;
 582         xfs_da_node_entry_t *btree;
 583         int tmp;
 584         xfs_mount_t *mp;
 585
 586         node = oldblk->bp->data;
 587         mp = state->mp;
 588         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 589         ASSERT((oldblk->index >= 0) && (oldblk->index <= be16_to_cpu(node->hdr.count)));
 590         ASSERT(newblk->blkno != 0);
 591         if (state->args->whichfork == XFS_DATA_FORK)
 592                 ASSERT(newblk->blkno >= mp->m_dirleafblk &&
 593                        newblk->blkno < mp->m_dirfreeblk);
 594
 595         /*
 596          * We may need to make some room before we insert the new node.
 597          */
 598         tmp = 0;
 599         btree = &node->btree[ oldblk->index ];
 600         if (oldblk->index < be16_to_cpu(node->hdr.count)) {
 601                 tmp = (be16_to_cpu(node->hdr.count) - oldblk->index) * (uint)sizeof(*btree);
 602                 memmove(btree + 1, btree, tmp);
 603         }
 604         btree->hashval = cpu_to_be32(newblk->hashval);
 605         btree->before = cpu_to_be32(newblk->blkno);
 606         xfs_da_log_buf(state->args->trans, oldblk->bp,
 607                 XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
 608         be16_add_cpu(&node->hdr.count, 1);
 609         xfs_da_log_buf(state->args->trans, oldblk->bp,
 610                 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 611
 612         /*
 613          * Copy the last hash value from the oldblk to propagate upwards.
 614          */
 615         oldblk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1 ].hashval);
 616 }
 617
 618 /*========================================================================
 619  * Routines used for shrinking the Btree.
 620  *========================================================================*/
 621
 622 /*
 623  * Deallocate an empty leaf node, remove it from its parent,
 624  * possibly deallocating that block, etc...
 625  */
 626 int
 627 xfs_da_join(xfs_da_state_t *state)
 628 {
 629         xfs_da_state_blk_t *drop_blk, *save_blk;
 630         int action, error;
 631
 632         action = 0;
 633         drop_blk = &state->path.blk[ state->path.active-1 ];
 634         save_blk = &state->altpath.blk[ state->path.active-1 ];
 635         ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
 636         ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
 637                drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
 638
 639         /*
 640          * Walk back up the tree joining/deallocating as necessary.
 641          * When we stop dropping blocks, break out.
 642          */
 643         for (  ; state->path.active >= 2; drop_blk--, save_blk--,
 644                  state->path.active--) {
 645                 /*
 646                  * See if we can combine the block with a neighbor.
 647                  *   (action == 0) => no options, just leave
 648                  *   (action == 1) => coalesce, then unlink
 649                  *   (action == 2) => block empty, unlink it
 650                  */
 651                 switch (drop_blk->magic) {
 652                 case XFS_ATTR_LEAF_MAGIC:
 653                         error = xfs_attr_leaf_toosmall(state, &action);
 654                         if (error)
 655                                 return(error);
 656                         if (action == 0)
 657                                 return(0);
 658                         xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
 659                         break;
 660                 case XFS_DIR2_LEAFN_MAGIC:
 661                         error = xfs_dir2_leafn_toosmall(state, &action);
 662                         if (error)
 663                                 return error;
 664                         if (action == 0)
 665                                 return 0;
 666                         xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
 667                         break;
 668                 case XFS_DA_NODE_MAGIC:
 669                         /*
 670                          * Remove the offending node, fixup hashvals,
 671                          * check for a toosmall neighbor.
 672                          */
 673                         xfs_da_node_remove(state, drop_blk);
 674                         xfs_da_fixhashpath(state, &state->path);
 675                         error = xfs_da_node_toosmall(state, &action);
 676                         if (error)
 677                                 return(error);
 678                         if (action == 0)
 679                                 return 0;
 680                         xfs_da_node_unbalance(state, drop_blk, save_blk);
 681                         break;
 682                 }
 683                 xfs_da_fixhashpath(state, &state->altpath);
 684                 error = xfs_da_blk_unlink(state, drop_blk, save_blk);
 685                 xfs_da_state_kill_altpath(state);
 686                 if (error)
 687                         return(error);
 688                 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
 689                                                          drop_blk->bp);
 690                 drop_blk->bp = NULL;
 691                 if (error)
 692                         return(error);
 693         }
 694         /*
 695          * We joined all the way to the top.  If it turns out that
 696          * we only have one entry in the root, make the child block
 697          * the new root.
 698          */
 699         xfs_da_node_remove(state, drop_blk);
 700         xfs_da_fixhashpath(state, &state->path);
 701         error = xfs_da_root_join(state, &state->path.blk[0]);
 702         return(error);
 703 }
 704
 705 /*
 706  * We have only one entry in the root.  Copy the only remaining child of
 707  * the old root to block 0 as the new root node.
 708  */
 709 STATIC int
 710 xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
 711 {
 712         xfs_da_intnode_t *oldroot;
 713         /* REFERENCED */
 714         xfs_da_blkinfo_t *blkinfo;
 715         xfs_da_args_t *args;
 716         xfs_dablk_t child;
 717         xfs_dabuf_t *bp;
 718         int error;
 719
 720         args = state->args;
 721         ASSERT(args != NULL);
 722         ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
 723         oldroot = root_blk->bp->data;
 724         ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 725         ASSERT(!oldroot->hdr.info.forw);
 726         ASSERT(!oldroot->hdr.info.back);
 727
 728         /*
 729          * If the root has more than one child, then don't do anything.
 730          */
 731         if (be16_to_cpu(oldroot->hdr.count) > 1)
 732                 return(0);
 733
 734         /*
 735          * Read in the (only) child block, then copy those bytes into
 736          * the root block's buffer and free the original child block.
 737          */
 738         child = be32_to_cpu(oldroot->btree[0].before);
 739         ASSERT(child != 0);
 740         error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp,
 741                                              args->whichfork);
 742         if (error)
 743                 return(error);
 744         ASSERT(bp != NULL);
 745         blkinfo = bp->data;
 746         if (be16_to_cpu(oldroot->hdr.level) == 1) {
 747                 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DIR2_LEAFN_MAGIC ||
 748                        be16_to_cpu(blkinfo->magic) == XFS_ATTR_LEAF_MAGIC);
 749         } else {
 750                 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DA_NODE_MAGIC);
 751         }
 752         ASSERT(!blkinfo->forw);
 753         ASSERT(!blkinfo->back);
 754         memcpy(root_blk->bp->data, bp->data, state->blocksize);
 755         xfs_da_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
 756         error = xfs_da_shrink_inode(args, child, bp);
 757         return(error);
 758 }
 759
 760 /*
 761  * Check a node block and its neighbors to see if the block should be
 762  * collapsed into one or the other neighbor.  Always keep the block
 763  * with the smaller block number.
 764  * If the current block is over 50% full, don't try to join it, return 0.
 765  * If the block is empty, fill in the state structure and return 2.
 766  * If it can be collapsed, fill in the state structure and return 1.
 767  * If nothing can be done, return 0.
 768  */
 769 STATIC int
 770 xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
 771 {
 772         xfs_da_intnode_t *node;
 773         xfs_da_state_blk_t *blk;
 774         xfs_da_blkinfo_t *info;
 775         int count, forward, error, retval, i;
 776         xfs_dablk_t blkno;
 777         xfs_dabuf_t *bp;
 778
 779         /*
 780          * Check for the degenerate case of the block being over 50% full.
 781          * If so, it's not worth even looking to see if we might be able
 782          * to coalesce with a sibling.
 783          */
 784         blk = &state->path.blk[ state->path.active-1 ];
 785         info = blk->bp->data;
 786         ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC);
 787         node = (xfs_da_intnode_t *)info;
 788         count = be16_to_cpu(node->hdr.count);
 789         if (count > (state->node_ents >> 1)) {
 790                 *action = 0;    /* blk over 50%, don't try to join */
 791                 return(0);      /* blk over 50%, don't try to join */
 792         }
 793
 794         /*
 795          * Check for the degenerate case of the block being empty.
 796          * If the block is empty, we'll simply delete it, no need to
 797          * coalesce it with a sibling block.  We choose (arbitrarily)
 798          * to merge with the forward block unless it is NULL.
 799          */
 800         if (count == 0) {
 801                 /*
 802                  * Make altpath point to the block we want to keep and
 803                  * path point to the block we want to drop (this one).
 804                  */
 805                 forward = (info->forw != 0);
 806                 memcpy(&state->altpath, &state->path, sizeof(state->path));
 807                 error = xfs_da_path_shift(state, &state->altpath, forward,
 808                                                  0, &retval);
 809                 if (error)
 810                         return(error);
 811                 if (retval) {
 812                         *action = 0;
 813                 } else {
 814                         *action = 2;
 815                 }
 816                 return(0);
 817         }
 818
 819         /*
 820          * Examine each sibling block to see if we can coalesce with
 821          * at least 25% free space to spare.  We need to figure out
 822          * whether to merge with the forward or the backward block.
 823          * We prefer coalescing with the lower numbered sibling so as
 824          * to shrink a directory over time.
 825          */
 826         /* start with smaller blk num */
 827         forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
 828         for (i = 0; i < 2; forward = !forward, i++) {
 829                 if (forward)
 830                         blkno = be32_to_cpu(info->forw);
 831                 else
 832                         blkno = be32_to_cpu(info->back);
 833                 if (blkno == 0)
 834                         continue;
 835                 error = xfs_da_read_buf(state->args->trans, state->args->dp,
 836                                         blkno, -1, &bp, state->args->whichfork);
 837                 if (error)
 838                         return(error);
 839                 ASSERT(bp != NULL);
 840
 841                 node = (xfs_da_intnode_t *)info;
 842                 count  = state->node_ents;
 843                 count -= state->node_ents >> 2;
 844                 count -= be16_to_cpu(node->hdr.count);
 845                 node = bp->data;
 846                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 847                 count -= be16_to_cpu(node->hdr.count);
 848                 xfs_da_brelse(state->args->trans, bp);
 849                 if (count >= 0)
 850                         break;  /* fits with at least 25% to spare */
 851         }
 852         if (i >= 2) {
 853                 *action = 0;
 854                 return(0);
 855         }
 856
 857         /*
 858          * Make altpath point to the block we want to keep (the lower
 859          * numbered block) and path point to the block we want to drop.
 860          */
 861         memcpy(&state->altpath, &state->path, sizeof(state->path));
 862         if (blkno < blk->blkno) {
 863                 error = xfs_da_path_shift(state, &state->altpath, forward,
 864                                                  0, &retval);
 865                 if (error) {
 866                         return(error);
 867                 }
 868                 if (retval) {
 869                         *action = 0;
 870                         return(0);
 871                 }
 872         } else {
 873                 error = xfs_da_path_shift(state, &state->path, forward,
 874                                                  0, &retval);
 875                 if (error) {
 876                         return(error);
 877                 }
 878                 if (retval) {
 879                         *action = 0;
 880                         return(0);
 881                 }
 882         }
 883         *action = 1;
 884         return(0);
 885 }
 886
 887 /*
 888  * Walk back up the tree adjusting hash values as necessary,
 889  * when we stop making changes, return.
 890  */
 891 void
 892 xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
 893 {
 894         xfs_da_state_blk_t *blk;
 895         xfs_da_intnode_t *node;
 896         xfs_da_node_entry_t *btree;
 897         xfs_dahash_t lasthash=0;
 898         int level, count;
 899
 900         level = path->active-1;
 901         blk = &path->blk[ level ];
 902         switch (blk->magic) {
 903         case XFS_ATTR_LEAF_MAGIC:
 904                 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
 905                 if (count == 0)
 906                         return;
 907                 break;
 908         case XFS_DIR2_LEAFN_MAGIC:
 909                 lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
 910                 if (count == 0)
 911                         return;
 912                 break;
 913         case XFS_DA_NODE_MAGIC:
 914                 lasthash = xfs_da_node_lasthash(blk->bp, &count);
 915                 if (count == 0)
 916                         return;
 917                 break;
 918         }
 919         for (blk--, level--; level >= 0; blk--, level--) {
 920                 node = blk->bp->data;
 921                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 922                 btree = &node->btree[ blk->index ];
 923                 if (be32_to_cpu(btree->hashval) == lasthash)
 924                         break;
 925                 blk->hashval = lasthash;
 926                 btree->hashval = cpu_to_be32(lasthash);
 927                 xfs_da_log_buf(state->args->trans, blk->bp,
 928                                   XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
 929
 930                 lasthash = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
 931         }
 932 }
 933
 934 /*
 935  * Remove an entry from an intermediate node.
 936  */
 937 STATIC void
 938 xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
 939 {
 940         xfs_da_intnode_t *node;
 941         xfs_da_node_entry_t *btree;
 942         int tmp;
 943
 944         node = drop_blk->bp->data;
 945         ASSERT(drop_blk->index < be16_to_cpu(node->hdr.count));
 946         ASSERT(drop_blk->index >= 0);
 947
 948         /*
 949          * Copy over the offending entry, or just zero it out.
 950          */
 951         btree = &node->btree[drop_blk->index];
 952         if (drop_blk->index < (be16_to_cpu(node->hdr.count)-1)) {
 953                 tmp  = be16_to_cpu(node->hdr.count) - drop_blk->index - 1;
 954                 tmp *= (uint)sizeof(xfs_da_node_entry_t);
 955                 memmove(btree, btree + 1, tmp);
 956                 xfs_da_log_buf(state->args->trans, drop_blk->bp,
 957                     XFS_DA_LOGRANGE(node, btree, tmp));
 958                 btree = &node->btree[be16_to_cpu(node->hdr.count)-1];
 959         }
 960         memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
 961         xfs_da_log_buf(state->args->trans, drop_blk->bp,
 962             XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
 963         be16_add_cpu(&node->hdr.count, -1);
 964         xfs_da_log_buf(state->args->trans, drop_blk->bp,
 965             XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 966
 967         /*
 968          * Copy the last hash value from the block to propagate upwards.
 969          */
 970         btree--;
 971         drop_blk->hashval = be32_to_cpu(btree->hashval);
 972 }
 973
 974 /*
 975  * Unbalance the btree elements between two intermediate nodes,
 976  * move all Btree elements from one node into another.
 977  */
 978 STATIC void
 979 xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
 980                                      xfs_da_state_blk_t *save_blk)
 981 {
 982         xfs_da_intnode_t *drop_node, *save_node;
 983         xfs_da_node_entry_t *btree;
 984         int tmp;
 985         xfs_trans_t *tp;
 986
 987         drop_node = drop_blk->bp->data;
 988         save_node = save_blk->bp->data;
 989         ASSERT(be16_to_cpu(drop_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 990         ASSERT(be16_to_cpu(save_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 991         tp = state->args->trans;
 992
 993         /*
 994          * If the dying block has lower hashvals, then move all the
 995          * elements in the remaining block up to make a hole.
 996          */
 997         if ((be32_to_cpu(drop_node->btree[0].hashval) < be32_to_cpu(save_node->btree[ 0 ].hashval)) ||
 998             (be32_to_cpu(drop_node->btree[be16_to_cpu(drop_node->hdr.count)-1].hashval) <
 999              be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval)))
1000         {
1001                 btree = &save_node->btree[be16_to_cpu(drop_node->hdr.count)];
1002                 tmp = be16_to_cpu(save_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1003                 memmove(btree, &save_node->btree[0], tmp);
1004                 btree = &save_node->btree[0];
1005                 xfs_da_log_buf(tp, save_blk->bp,
1006                         XFS_DA_LOGRANGE(save_node, btree,
1007                                 (be16_to_cpu(save_node->hdr.count) + be16_to_cpu(drop_node->hdr.count)) *
1008                                 sizeof(xfs_da_node_entry_t)));
1009         } else {
1010                 btree = &save_node->btree[be16_to_cpu(save_node->hdr.count)];
1011                 xfs_da_log_buf(tp, save_blk->bp,
1012                         XFS_DA_LOGRANGE(save_node, btree,
1013                                 be16_to_cpu(drop_node->hdr.count) *
1014                                 sizeof(xfs_da_node_entry_t)));
1015         }
1016
1017         /*
1018          * Move all the B-tree elements from drop_blk to save_blk.
1019          */
1020         tmp = be16_to_cpu(drop_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1021         memcpy(btree, &drop_node->btree[0], tmp);
1022         be16_add_cpu(&save_node->hdr.count, be16_to_cpu(drop_node->hdr.count));
1023
1024         xfs_da_log_buf(tp, save_blk->bp,
1025                 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1026                         sizeof(save_node->hdr)));
1027
1028         /*
1029          * Save the last hashval in the remaining block for upward propagation.
1030          */
1031         save_blk->hashval = be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval);
1032 }
1033
1034 /*========================================================================
1035  * Routines used for finding things in the Btree.
1036  *========================================================================*/
1037
1038 /*
1039  * Walk down the Btree looking for a particular filename, filling
1040  * in the state structure as we go.
1041  *
1042  * We will set the state structure to point to each of the elements
1043  * in each of the nodes where either the hashval is or should be.
1044  *
1045  * We support duplicate hashval's so for each entry in the current
1046  * node that could contain the desired hashval, descend.  This is a
1047  * pruned depth-first tree search.
1048  */
1049 int                                                     /* error */
1050 xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
1051 {
1052         xfs_da_state_blk_t *blk;
1053         xfs_da_blkinfo_t *curr;
1054         xfs_da_intnode_t *node;
1055         xfs_da_node_entry_t *btree;
1056         xfs_dablk_t blkno;
1057         int probe, span, max, error, retval;
1058         xfs_dahash_t hashval, btreehashval;
1059         xfs_da_args_t *args;
1060
1061         args = state->args;
1062
1063         /*
1064          * Descend thru the B-tree searching each level for the right
1065          * node to use, until the right hashval is found.
1066          */
1067         blkno = (args->whichfork == XFS_DATA_FORK)? state->mp->m_dirleafblk : 0;
1068         for (blk = &state->path.blk[0], state->path.active = 1;
1069                          state->path.active <= XFS_DA_NODE_MAXDEPTH;
1070                          blk++, state->path.active++) {
1071                 /*
1072                  * Read the next node down in the tree.
1073                  */
1074                 blk->blkno = blkno;
1075                 error = xfs_da_read_buf(args->trans, args->dp, blkno,
1076                                         -1, &blk->bp, args->whichfork);
1077                 if (error) {
1078                         blk->blkno = 0;
1079                         state->path.active--;
1080                         return(error);
1081                 }
1082                 curr = blk->bp->data;
1083                 blk->magic = be16_to_cpu(curr->magic);
1084                 ASSERT(blk->magic == XFS_DA_NODE_MAGIC ||
1085                        blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1086                        blk->magic == XFS_ATTR_LEAF_MAGIC);
1087
1088                 /*
1089                  * Search an intermediate node for a match.
1090                  */
1091                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1092                         node = blk->bp->data;
1093                         max = be16_to_cpu(node->hdr.count);
1094                         blk->hashval = be32_to_cpu(node->btree[max-1].hashval);
1095
1096                         /*
1097                          * Binary search.  (note: small blocks will skip loop)
1098                          */
1099                         probe = span = max / 2;
1100                         hashval = args->hashval;
1101                         for (btree = &node->btree[probe]; span > 4;
1102                                    btree = &node->btree[probe]) {
1103                                 span /= 2;
1104                                 btreehashval = be32_to_cpu(btree->hashval);
1105                                 if (btreehashval < hashval)
1106                                         probe += span;
1107                                 else if (btreehashval > hashval)
1108                                         probe -= span;
1109                                 else
1110                                         break;
1111                         }
1112                         ASSERT((probe >= 0) && (probe < max));
1113                         ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval));
1114
1115                         /*
1116                          * Since we may have duplicate hashval's, find the first
1117                          * matching hashval in the node.
1118                          */
1119                         while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) {
1120                                 btree--;
1121                                 probe--;
1122                         }
1123                         while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) {
1124                                 btree++;
1125                                 probe++;
1126                         }
1127
1128                         /*
1129                          * Pick the right block to descend on.
1130                          */
1131                         if (probe == max) {
1132                                 blk->index = max-1;
1133                                 blkno = be32_to_cpu(node->btree[max-1].before);
1134                         } else {
1135                                 blk->index = probe;
1136                                 blkno = be32_to_cpu(btree->before);
1137                         }
1138                 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1139                         blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1140                         break;
1141                 } else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1142                         blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
1143                         break;
1144                 }
1145         }
1146
1147         /*
1148          * A leaf block that ends in the hashval that we are interested in
1149          * (final hashval == search hashval) means that the next block may
1150          * contain more entries with the same hashval, shift upward to the
1151          * next leaf and keep searching.
1152          */
1153         for (;;) {
1154                 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1155                         retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1156                                                         &blk->index, state);
1157                 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1158                         retval = xfs_attr_leaf_lookup_int(blk->bp, args);
1159                         blk->index = args->index;
1160                         args->blkno = blk->blkno;
1161                 } else {
1162                         ASSERT(0);
1163                         return XFS_ERROR(EFSCORRUPTED);
1164                 }
1165                 if (((retval == ENOENT) || (retval == ENOATTR)) &&
1166                     (blk->hashval == args->hashval)) {
1167                         error = xfs_da_path_shift(state, &state->path, 1, 1,
1168                                                          &retval);
1169                         if (error)
1170                                 return(error);
1171                         if (retval == 0) {
1172                                 continue;
1173                         } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1174                                 /* path_shift() gives ENOENT */
1175                                 retval = XFS_ERROR(ENOATTR);
1176                         }
1177                 }
1178                 break;
1179         }
1180         *result = retval;
1181         return(0);
1182 }
1183
1184 /*========================================================================
1185  * Utility routines.
1186  *========================================================================*/
1187
1188 /*
1189  * Link a new block into a doubly linked list of blocks (of whatever type).
1190  */
1191 int                                                     /* error */
1192 xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
1193                                xfs_da_state_blk_t *new_blk)
1194 {
1195         xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
1196         xfs_da_args_t *args;
1197         int before=0, error;
1198         xfs_dabuf_t *bp;
1199
1200         /*
1201          * Set up environment.
1202          */
1203         args = state->args;
1204         ASSERT(args != NULL);
1205         old_info = old_blk->bp->data;
1206         new_info = new_blk->bp->data;
1207         ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1208                old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1209                old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1210         ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
1211         ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
1212         ASSERT(old_blk->magic == new_blk->magic);
1213
1214         switch (old_blk->magic) {
1215         case XFS_ATTR_LEAF_MAGIC:
1216                 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1217                 break;
1218         case XFS_DIR2_LEAFN_MAGIC:
1219                 before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
1220                 break;
1221         case XFS_DA_NODE_MAGIC:
1222                 before = xfs_da_node_order(old_blk->bp, new_blk->bp);
1223                 break;
1224         }
1225
1226         /*
1227          * Link blocks in appropriate order.
1228          */
1229         if (before) {
1230                 /*
1231                  * Link new block in before existing block.
1232                  */
1233                 new_info->forw = cpu_to_be32(old_blk->blkno);
1234                 new_info->back = old_info->back;
1235                 if (old_info->back) {
1236                         error = xfs_da_read_buf(args->trans, args->dp,
1237                                                 be32_to_cpu(old_info->back),
1238                                                 -1, &bp, args->whichfork);
1239                         if (error)
1240                                 return(error);
1241                         ASSERT(bp != NULL);
1242                         tmp_info = bp->data;
1243                         ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
1244                         ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1245                         tmp_info->forw = cpu_to_be32(new_blk->blkno);
1246                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1247                         xfs_da_buf_done(bp);
1248                 }
1249                 old_info->back = cpu_to_be32(new_blk->blkno);
1250         } else {
1251                 /*
1252                  * Link new block in after existing block.
1253                  */
1254                 new_info->forw = old_info->forw;
1255                 new_info->back = cpu_to_be32(old_blk->blkno);
1256                 if (old_info->forw) {
1257                         error = xfs_da_read_buf(args->trans, args->dp,
1258                                                 be32_to_cpu(old_info->forw),
1259                                                 -1, &bp, args->whichfork);
1260                         if (error)
1261                                 return(error);
1262                         ASSERT(bp != NULL);
1263                         tmp_info = bp->data;
1264                         ASSERT(tmp_info->magic == old_info->magic);
1265                         ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1266                         tmp_info->back = cpu_to_be32(new_blk->blkno);
1267                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1268                         xfs_da_buf_done(bp);
1269                 }
1270                 old_info->forw = cpu_to_be32(new_blk->blkno);
1271         }
1272
1273         xfs_da_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1274         xfs_da_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1275         return(0);
1276 }
1277
1278 /*
1279  * Compare two intermediate nodes for "order".
1280  */
1281 STATIC int
1282 xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp)
1283 {
1284         xfs_da_intnode_t *node1, *node2;
1285
1286         node1 = node1_bp->data;
1287         node2 = node2_bp->data;
1288         ASSERT((be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC) &&
1289                (be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC));
1290         if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
1291             ((be32_to_cpu(node2->btree[0].hashval) <
1292               be32_to_cpu(node1->btree[0].hashval)) ||
1293              (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
1294               be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
1295                 return(1);
1296         }
1297         return(0);
1298 }
1299
1300 /*
1301  * Pick up the last hashvalue from an intermediate node.
1302  */
1303 STATIC uint
1304 xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count)
1305 {
1306         xfs_da_intnode_t *node;
1307
1308         node = bp->data;
1309         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1310         if (count)
1311                 *count = be16_to_cpu(node->hdr.count);
1312         if (!node->hdr.count)
1313                 return(0);
1314         return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1315 }
1316
1317 /*
1318  * Unlink a block from a doubly linked list of blocks.
1319  */
1320 STATIC int                                              /* error */
1321 xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1322                                  xfs_da_state_blk_t *save_blk)
1323 {
1324         xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
1325         xfs_da_args_t *args;
1326         xfs_dabuf_t *bp;
1327         int error;
1328
1329         /*
1330          * Set up environment.
1331          */
1332         args = state->args;
1333         ASSERT(args != NULL);
1334         save_info = save_blk->bp->data;
1335         drop_info = drop_blk->bp->data;
1336         ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1337                save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1338                save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1339         ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
1340         ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
1341         ASSERT(save_blk->magic == drop_blk->magic);
1342         ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1343                (be32_to_cpu(save_info->back) == drop_blk->blkno));
1344         ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1345                (be32_to_cpu(drop_info->back) == save_blk->blkno));
1346
1347         /*
1348          * Unlink the leaf block from the doubly linked chain of leaves.
1349          */
1350         if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1351                 save_info->back = drop_info->back;
1352                 if (drop_info->back) {
1353                         error = xfs_da_read_buf(args->trans, args->dp,
1354                                                 be32_to_cpu(drop_info->back),
1355                                                 -1, &bp, args->whichfork);
1356                         if (error)
1357                                 return(error);
1358                         ASSERT(bp != NULL);
1359                         tmp_info = bp->data;
1360                         ASSERT(tmp_info->magic == save_info->magic);
1361                         ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1362                         tmp_info->forw = cpu_to_be32(save_blk->blkno);
1363                         xfs_da_log_buf(args->trans, bp, 0,
1364                                                     sizeof(*tmp_info) - 1);
1365                         xfs_da_buf_done(bp);
1366                 }
1367         } else {
1368                 save_info->forw = drop_info->forw;
1369                 if (drop_info->forw) {
1370                         error = xfs_da_read_buf(args->trans, args->dp,
1371                                                 be32_to_cpu(drop_info->forw),
1372                                                 -1, &bp, args->whichfork);
1373                         if (error)
1374                                 return(error);
1375                         ASSERT(bp != NULL);
1376                         tmp_info = bp->data;
1377                         ASSERT(tmp_info->magic == save_info->magic);
1378                         ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1379                         tmp_info->back = cpu_to_be32(save_blk->blkno);
1380                         xfs_da_log_buf(args->trans, bp, 0,
1381                                                     sizeof(*tmp_info) - 1);
1382                         xfs_da_buf_done(bp);
1383                 }
1384         }
1385
1386         xfs_da_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1387         return(0);
1388 }
1389
1390 /*
1391  * Move a path "forward" or "!forward" one block at the current level.
1392  *
1393  * This routine will adjust a "path" to point to the next block
1394  * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1395  * Btree, including updating pointers to the intermediate nodes between
1396  * the new bottom and the root.
1397  */
1398 int                                                     /* error */
1399 xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
1400                                  int forward, int release, int *result)
1401 {
1402         xfs_da_state_blk_t *blk;
1403         xfs_da_blkinfo_t *info;
1404         xfs_da_intnode_t *node;
1405         xfs_da_args_t *args;
1406         xfs_dablk_t blkno=0;
1407         int level, error;
1408
1409         /*
1410          * Roll up the Btree looking for the first block where our
1411          * current index is not at the edge of the block.  Note that
1412          * we skip the bottom layer because we want the sibling block.
1413          */
1414         args = state->args;
1415         ASSERT(args != NULL);
1416         ASSERT(path != NULL);
1417         ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1418         level = (path->active-1) - 1;   /* skip bottom layer in path */
1419         for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1420                 ASSERT(blk->bp != NULL);
1421                 node = blk->bp->data;
1422                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1423                 if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) {
1424                         blk->index++;
1425                         blkno = be32_to_cpu(node->btree[blk->index].before);
1426                         break;
1427                 } else if (!forward && (blk->index > 0)) {
1428                         blk->index--;
1429                         blkno = be32_to_cpu(node->btree[blk->index].before);
1430                         break;
1431                 }
1432         }
1433         if (level < 0) {
1434                 *result = XFS_ERROR(ENOENT);    /* we're out of our tree */
1435                 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1436                 return(0);
1437         }
1438
1439         /*
1440          * Roll down the edge of the subtree until we reach the
1441          * same depth we were at originally.
1442          */
1443         for (blk++, level++; level < path->active; blk++, level++) {
1444                 /*
1445                  * Release the old block.
1446                  * (if it's dirty, trans won't actually let go)
1447                  */
1448                 if (release)
1449                         xfs_da_brelse(args->trans, blk->bp);
1450
1451                 /*
1452                  * Read the next child block.
1453                  */
1454                 blk->blkno = blkno;
1455                 error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
1456                                                      &blk->bp, args->whichfork);
1457                 if (error)
1458                         return(error);
1459                 ASSERT(blk->bp != NULL);
1460                 info = blk->bp->data;
1461                 ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC ||
1462                        be16_to_cpu(info->magic) == XFS_DIR2_LEAFN_MAGIC ||
1463                        be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC);
1464                 blk->magic = be16_to_cpu(info->magic);
1465                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1466                         node = (xfs_da_intnode_t *)info;
1467                         blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1468                         if (forward)
1469                                 blk->index = 0;
1470                         else
1471                                 blk->index = be16_to_cpu(node->hdr.count)-1;
1472                         blkno = be32_to_cpu(node->btree[blk->index].before);
1473                 } else {
1474                         ASSERT(level == path->active-1);
1475                         blk->index = 0;
1476                         switch(blk->magic) {
1477                         case XFS_ATTR_LEAF_MAGIC:
1478                                 blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
1479                                                                       NULL);
1480                                 break;
1481                         case XFS_DIR2_LEAFN_MAGIC:
1482                                 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
1483                                                                        NULL);
1484                                 break;
1485                         default:
1486                                 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
1487                                        blk->magic == XFS_DIR2_LEAFN_MAGIC);
1488                                 break;
1489                         }
1490                 }
1491         }
1492         *result = 0;
1493         return(0);
1494 }
1495
1496
1497 /*========================================================================
1498  * Utility routines.
1499  *========================================================================*/
1500
1501 /*
1502  * Implement a simple hash on a character string.
1503  * Rotate the hash value by 7 bits, then XOR each character in.
1504  * This is implemented with some source-level loop unrolling.
1505  */
1506 xfs_dahash_t
1507 xfs_da_hashname(const __uint8_t *name, int namelen)
1508 {
1509         xfs_dahash_t hash;
1510
1511         /*
1512          * Do four characters at a time as long as we can.
1513          */
1514         for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1515                 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1516                        (name[3] << 0) ^ rol32(hash, 7 * 4);
1517
1518         /*
1519          * Now do the rest of the characters.
1520          */
1521         switch (namelen) {
1522         case 3:
1523                 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1524                        rol32(hash, 7 * 3);
1525         case 2:
1526                 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1527         case 1:
1528                 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1529         default: /* case 0: */
1530                 return hash;
1531         }
1532 }
1533
1534 enum xfs_dacmp
1535 xfs_da_compname(
1536         struct xfs_da_args *args,
1537         const unsigned char *name,
1538         int             len)
1539 {
1540         return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
1541                                         XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
1542 }
1543
1544 static xfs_dahash_t
1545 xfs_default_hashname(
1546         struct xfs_name *name)
1547 {
1548         return xfs_da_hashname(name->name, name->len);
1549 }
1550
1551 const struct xfs_nameops xfs_default_nameops = {
1552         .hashname       = xfs_default_hashname,
1553         .compname       = xfs_da_compname
1554 };
1555
1556 /*
1557  * Add a block to the btree ahead of the file.
1558  * Return the new block number to the caller.
1559  */
1560 int
1561 xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
1562 {
1563         xfs_fileoff_t bno, b;
1564         xfs_bmbt_irec_t map;
1565         xfs_bmbt_irec_t *mapp;
1566         xfs_inode_t *dp;
1567         int nmap, error, w, count, c, got, i, mapi;
1568         xfs_trans_t *tp;
1569         xfs_mount_t *mp;
1570         xfs_drfsbno_t   nblks;
1571
1572         dp = args->dp;
1573         mp = dp->i_mount;
1574         w = args->whichfork;
1575         tp = args->trans;
1576         nblks = dp->i_d.di_nblocks;
1577
1578         /*
1579          * For new directories adjust the file offset and block count.
1580          */
1581         if (w == XFS_DATA_FORK) {
1582                 bno = mp->m_dirleafblk;
1583                 count = mp->m_dirblkfsbs;
1584         } else {
1585                 bno = 0;
1586                 count = 1;
1587         }
1588         /*
1589          * Find a spot in the file space to put the new block.
1590          */
1591         if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, w)))
1592                 return error;
1593         if (w == XFS_DATA_FORK)
1594                 ASSERT(bno >= mp->m_dirleafblk && bno < mp->m_dirfreeblk);
1595         /*
1596          * Try mapping it in one filesystem block.
1597          */
1598         nmap = 1;
1599         ASSERT(args->firstblock != NULL);
1600         if ((error = xfs_bmapi(tp, dp, bno, count,
1601                         xfs_bmapi_aflag(w)|XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|
1602                         XFS_BMAPI_CONTIG,
1603                         args->firstblock, args->total, &map, &nmap,
1604                         args->flist, NULL))) {
1605                 return error;
1606         }
1607         ASSERT(nmap <= 1);
1608         if (nmap == 1) {
1609                 mapp = &map;
1610                 mapi = 1;
1611         }
1612         /*
1613          * If we didn't get it and the block might work if fragmented,
1614          * try without the CONTIG flag.  Loop until we get it all.
1615          */
1616         else if (nmap == 0 && count > 1) {
1617                 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1618                 for (b = bno, mapi = 0; b < bno + count; ) {
1619                         nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1620                         c = (int)(bno + count - b);
1621                         if ((error = xfs_bmapi(tp, dp, b, c,
1622                                         xfs_bmapi_aflag(w)|XFS_BMAPI_WRITE|
1623                                         XFS_BMAPI_METADATA,
1624                                         args->firstblock, args->total,
1625                                         &mapp[mapi], &nmap, args->flist,
1626                                         NULL))) {
1627                                 kmem_free(mapp);
1628                                 return error;
1629                         }
1630                         if (nmap < 1)
1631                                 break;
1632                         mapi += nmap;
1633                         b = mapp[mapi - 1].br_startoff +
1634                             mapp[mapi - 1].br_blockcount;
1635                 }
1636         } else {
1637                 mapi = 0;
1638                 mapp = NULL;
1639         }
1640         /*
1641          * Count the blocks we got, make sure it matches the total.
1642          */
1643         for (i = 0, got = 0; i < mapi; i++)
1644                 got += mapp[i].br_blockcount;
1645         if (got != count || mapp[0].br_startoff != bno ||
1646             mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1647             bno + count) {
1648                 if (mapp != &map)
1649                         kmem_free(mapp);
1650                 return XFS_ERROR(ENOSPC);
1651         }
1652         if (mapp != &map)
1653                 kmem_free(mapp);
1654         /* account for newly allocated blocks in reserved blocks total */
1655         args->total -= dp->i_d.di_nblocks - nblks;
1656         *new_blkno = (xfs_dablk_t)bno;
1657         return 0;
1658 }
1659
1660 /*
1661  * Ick.  We need to always be able to remove a btree block, even
1662  * if there's no space reservation because the filesystem is full.
1663  * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1664  * It swaps the target block with the last block in the file.  The
1665  * last block in the file can always be removed since it can't cause
1666  * a bmap btree split to do that.
1667  */
1668 STATIC int
1669 xfs_da_swap_lastblock(xfs_da_args_t *args, xfs_dablk_t *dead_blknop,
1670                       xfs_dabuf_t **dead_bufp)
1671 {
1672         xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1673         xfs_dabuf_t *dead_buf, *last_buf, *sib_buf, *par_buf;
1674         xfs_fileoff_t lastoff;
1675         xfs_inode_t *ip;
1676         xfs_trans_t *tp;
1677         xfs_mount_t *mp;
1678         int error, w, entno, level, dead_level;
1679         xfs_da_blkinfo_t *dead_info, *sib_info;
1680         xfs_da_intnode_t *par_node, *dead_node;
1681         xfs_dir2_leaf_t *dead_leaf2;
1682         xfs_dahash_t dead_hash;
1683
1684         dead_buf = *dead_bufp;
1685         dead_blkno = *dead_blknop;
1686         tp = args->trans;
1687         ip = args->dp;
1688         w = args->whichfork;
1689         ASSERT(w == XFS_DATA_FORK);
1690         mp = ip->i_mount;
1691         lastoff = mp->m_dirfreeblk;
1692         error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1693         if (error)
1694                 return error;
1695         if (unlikely(lastoff == 0)) {
1696                 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1697                                  mp);
1698                 return XFS_ERROR(EFSCORRUPTED);
1699         }
1700         /*
1701          * Read the last block in the btree space.
1702          */
1703         last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1704         if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
1705                 return error;
1706         /*
1707          * Copy the last block into the dead buffer and log it.
1708          */
1709         memcpy(dead_buf->data, last_buf->data, mp->m_dirblksize);
1710         xfs_da_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1711         dead_info = dead_buf->data;
1712         /*
1713          * Get values from the moved block.
1714          */
1715         if (be16_to_cpu(dead_info->magic) == XFS_DIR2_LEAFN_MAGIC) {
1716                 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1717                 dead_level = 0;
1718                 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1719         } else {
1720                 ASSERT(be16_to_cpu(dead_info->magic) == XFS_DA_NODE_MAGIC);
1721                 dead_node = (xfs_da_intnode_t *)dead_info;
1722                 dead_level = be16_to_cpu(dead_node->hdr.level);
1723                 dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
1724         }
1725         sib_buf = par_buf = NULL;
1726         /*
1727          * If the moved block has a left sibling, fix up the pointers.
1728          */
1729         if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1730                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1731                         goto done;
1732                 sib_info = sib_buf->data;
1733                 if (unlikely(
1734                     be32_to_cpu(sib_info->forw) != last_blkno ||
1735                     sib_info->magic != dead_info->magic)) {
1736                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1737                                          XFS_ERRLEVEL_LOW, mp);
1738                         error = XFS_ERROR(EFSCORRUPTED);
1739                         goto done;
1740                 }
1741                 sib_info->forw = cpu_to_be32(dead_blkno);
1742                 xfs_da_log_buf(tp, sib_buf,
1743                         XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1744                                         sizeof(sib_info->forw)));
1745                 xfs_da_buf_done(sib_buf);
1746                 sib_buf = NULL;
1747         }
1748         /*
1749          * If the moved block has a right sibling, fix up the pointers.
1750          */
1751         if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1752                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1753                         goto done;
1754                 sib_info = sib_buf->data;
1755                 if (unlikely(
1756                        be32_to_cpu(sib_info->back) != last_blkno ||
1757                        sib_info->magic != dead_info->magic)) {
1758                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1759                                          XFS_ERRLEVEL_LOW, mp);
1760                         error = XFS_ERROR(EFSCORRUPTED);
1761                         goto done;
1762                 }
1763                 sib_info->back = cpu_to_be32(dead_blkno);
1764                 xfs_da_log_buf(tp, sib_buf,
1765                         XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1766                                         sizeof(sib_info->back)));
1767                 xfs_da_buf_done(sib_buf);
1768                 sib_buf = NULL;
1769         }
1770         par_blkno = mp->m_dirleafblk;
1771         level = -1;
1772         /*
1773          * Walk down the tree looking for the parent of the moved block.
1774          */
1775         for (;;) {
1776                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1777                         goto done;
1778                 par_node = par_buf->data;
1779                 if (unlikely(
1780                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC ||
1781                     (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
1782                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1783                                          XFS_ERRLEVEL_LOW, mp);
1784                         error = XFS_ERROR(EFSCORRUPTED);
1785                         goto done;
1786                 }
1787                 level = be16_to_cpu(par_node->hdr.level);
1788                 for (entno = 0;
1789                      entno < be16_to_cpu(par_node->hdr.count) &&
1790                      be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
1791                      entno++)
1792                         continue;
1793                 if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
1794                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1795                                          XFS_ERRLEVEL_LOW, mp);
1796                         error = XFS_ERROR(EFSCORRUPTED);
1797                         goto done;
1798                 }
1799                 par_blkno = be32_to_cpu(par_node->btree[entno].before);
1800                 if (level == dead_level + 1)
1801                         break;
1802                 xfs_da_brelse(tp, par_buf);
1803                 par_buf = NULL;
1804         }
1805         /*
1806          * We're in the right parent block.
1807          * Look for the right entry.
1808          */
1809         for (;;) {
1810                 for (;
1811                      entno < be16_to_cpu(par_node->hdr.count) &&
1812                      be32_to_cpu(par_node->btree[entno].before) != last_blkno;
1813                      entno++)
1814                         continue;
1815                 if (entno < be16_to_cpu(par_node->hdr.count))
1816                         break;
1817                 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1818                 xfs_da_brelse(tp, par_buf);
1819                 par_buf = NULL;
1820                 if (unlikely(par_blkno == 0)) {
1821                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1822                                          XFS_ERRLEVEL_LOW, mp);
1823                         error = XFS_ERROR(EFSCORRUPTED);
1824                         goto done;
1825                 }
1826                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1827                         goto done;
1828                 par_node = par_buf->data;
1829                 if (unlikely(
1830                     be16_to_cpu(par_node->hdr.level) != level ||
1831                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC)) {
1832                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1833                                          XFS_ERRLEVEL_LOW, mp);
1834                         error = XFS_ERROR(EFSCORRUPTED);
1835                         goto done;
1836                 }
1837                 entno = 0;
1838         }
1839         /*
1840          * Update the parent entry pointing to the moved block.
1841          */
1842         par_node->btree[entno].before = cpu_to_be32(dead_blkno);
1843         xfs_da_log_buf(tp, par_buf,
1844                 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1845                                 sizeof(par_node->btree[entno].before)));
1846         xfs_da_buf_done(par_buf);
1847         xfs_da_buf_done(dead_buf);
1848         *dead_blknop = last_blkno;
1849         *dead_bufp = last_buf;
1850         return 0;
1851 done:
1852         if (par_buf)
1853                 xfs_da_brelse(tp, par_buf);
1854         if (sib_buf)
1855                 xfs_da_brelse(tp, sib_buf);
1856         xfs_da_brelse(tp, last_buf);
1857         return error;
1858 }
1859
1860 /*
1861  * Remove a btree block from a directory or attribute.
1862  */
1863 int
1864 xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
1865                     xfs_dabuf_t *dead_buf)
1866 {
1867         xfs_inode_t *dp;
1868         int done, error, w, count;
1869         xfs_trans_t *tp;
1870         xfs_mount_t *mp;
1871
1872         dp = args->dp;
1873         w = args->whichfork;
1874         tp = args->trans;
1875         mp = dp->i_mount;
1876         if (w == XFS_DATA_FORK)
1877                 count = mp->m_dirblkfsbs;
1878         else
1879                 count = 1;
1880         for (;;) {
1881                 /*
1882                  * Remove extents.  If we get ENOSPC for a dir we have to move
1883                  * the last block to the place we want to kill.
1884                  */
1885                 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
1886                                 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
1887                                 0, args->firstblock, args->flist, NULL,
1888                                 &done)) == ENOSPC) {
1889                         if (w != XFS_DATA_FORK)
1890                                 break;
1891                         if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
1892                                         &dead_buf)))
1893                                 break;
1894                 } else {
1895                         break;
1896                 }
1897         }
1898         xfs_da_binval(tp, dead_buf);
1899         return error;
1900 }
1901
1902 /*
1903  * See if the mapping(s) for this btree block are valid, i.e.
1904  * don't contain holes, are logically contiguous, and cover the whole range.
1905  */
1906 STATIC int
1907 xfs_da_map_covers_blocks(
1908         int             nmap,
1909         xfs_bmbt_irec_t *mapp,
1910         xfs_dablk_t     bno,
1911         int             count)
1912 {
1913         int             i;
1914         xfs_fileoff_t   off;
1915
1916         for (i = 0, off = bno; i < nmap; i++) {
1917                 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
1918                     mapp[i].br_startblock == DELAYSTARTBLOCK) {
1919                         return 0;
1920                 }
1921                 if (off != mapp[i].br_startoff) {
1922                         return 0;
1923                 }
1924                 off += mapp[i].br_blockcount;
1925         }
1926         return off == bno + count;
1927 }
1928
1929 /*
1930  * Make a dabuf.
1931  * Used for get_buf, read_buf, read_bufr, and reada_buf.
1932  */
1933 STATIC int
1934 xfs_da_do_buf(
1935         xfs_trans_t     *trans,
1936         xfs_inode_t     *dp,
1937         xfs_dablk_t     bno,
1938         xfs_daddr_t     *mappedbnop,
1939         xfs_dabuf_t     **bpp,
1940         int             whichfork,
1941         int             caller,
1942         inst_t          *ra)
1943 {
1944         xfs_buf_t       *bp = NULL;
1945         xfs_buf_t       **bplist;
1946         int             error=0;
1947         int             i;
1948         xfs_bmbt_irec_t map;
1949         xfs_bmbt_irec_t *mapp;
1950         xfs_daddr_t     mappedbno;
1951         xfs_mount_t     *mp;
1952         int             nbplist=0;
1953         int             nfsb;
1954         int             nmap;
1955         xfs_dabuf_t     *rbp;
1956
1957         mp = dp->i_mount;
1958         nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
1959         mappedbno = *mappedbnop;
1960         /*
1961          * Caller doesn't have a mapping.  -2 means don't complain
1962          * if we land in a hole.
1963          */
1964         if (mappedbno == -1 || mappedbno == -2) {
1965                 /*
1966                  * Optimize the one-block case.
1967                  */
1968                 if (nfsb == 1) {
1969                         xfs_fsblock_t   fsb;
1970
1971                         if ((error =
1972                             xfs_bmapi_single(trans, dp, whichfork, &fsb,
1973                                     (xfs_fileoff_t)bno))) {
1974                                 return error;
1975                         }
1976                         mapp = &map;
1977                         if (fsb == NULLFSBLOCK) {
1978                                 nmap = 0;
1979                         } else {
1980                                 map.br_startblock = fsb;
1981                                 map.br_startoff = (xfs_fileoff_t)bno;
1982                                 map.br_blockcount = 1;
1983                                 nmap = 1;
1984                         }
1985                 } else {
1986                         mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
1987                         nmap = nfsb;
1988                         if ((error = xfs_bmapi(trans, dp, (xfs_fileoff_t)bno,
1989                                         nfsb,
1990                                         XFS_BMAPI_METADATA |
1991                                                 xfs_bmapi_aflag(whichfork),
1992                                         NULL, 0, mapp, &nmap, NULL, NULL)))
1993                                 goto exit0;
1994                 }
1995         } else {
1996                 map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
1997                 map.br_startoff = (xfs_fileoff_t)bno;
1998                 map.br_blockcount = nfsb;
1999                 mapp = &map;
2000                 nmap = 1;
2001         }
2002         if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
2003                 error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
2004                 if (unlikely(error == EFSCORRUPTED)) {
2005                         if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2006                                 cmn_err(CE_ALERT, "xfs_da_do_buf: bno %lld\n",
2007                                         (long long)bno);
2008                                 cmn_err(CE_ALERT, "dir: inode %lld\n",
2009                                         (long long)dp->i_ino);
2010                                 for (i = 0; i < nmap; i++) {
2011                                         cmn_err(CE_ALERT,
2012                                                 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d\n",
2013                                                 i,
2014                                                 (long long)mapp[i].br_startoff,
2015                                                 (long long)mapp[i].br_startblock,
2016                                                 (long long)mapp[i].br_blockcount,
2017                                                 mapp[i].br_state);
2018                                 }
2019                         }
2020                         XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2021                                          XFS_ERRLEVEL_LOW, mp);
2022                 }
2023                 goto exit0;
2024         }
2025         if (caller != 3 && nmap > 1) {
2026                 bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
2027                 nbplist = 0;
2028         } else
2029                 bplist = NULL;
2030         /*
2031          * Turn the mapping(s) into buffer(s).
2032          */
2033         for (i = 0; i < nmap; i++) {
2034                 int     nmapped;
2035
2036                 mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
2037                 if (i == 0)
2038                         *mappedbnop = mappedbno;
2039                 nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
2040                 switch (caller) {
2041                 case 0:
2042                         bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
2043                                 mappedbno, nmapped, 0);
2044                         error = bp ? XFS_BUF_GETERROR(bp) : XFS_ERROR(EIO);
2045                         break;
2046                 case 1:
2047                 case 2:
2048                         bp = NULL;
2049                         error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
2050                                 mappedbno, nmapped, 0, &bp);
2051                         break;
2052                 case 3:
2053                         xfs_baread(mp->m_ddev_targp, mappedbno, nmapped);
2054                         error = 0;
2055                         bp = NULL;
2056                         break;
2057                 }
2058                 if (error) {
2059                         if (bp)
2060                                 xfs_trans_brelse(trans, bp);
2061                         goto exit1;
2062                 }
2063                 if (!bp)
2064                         continue;
2065                 if (caller == 1) {
2066                         if (whichfork == XFS_ATTR_FORK) {
2067                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_ATTR_BTREE,
2068                                                 XFS_ATTR_BTREE_REF);
2069                         } else {
2070                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_DIR_BTREE,
2071                                                 XFS_DIR_BTREE_REF);
2072                         }
2073                 }
2074                 if (bplist) {
2075                         bplist[nbplist++] = bp;
2076                 }
2077         }
2078         /*
2079          * Build a dabuf structure.
2080          */
2081         if (bplist) {
2082                 rbp = xfs_da_buf_make(nbplist, bplist, ra);
2083         } else if (bp)
2084                 rbp = xfs_da_buf_make(1, &bp, ra);
2085         else
2086                 rbp = NULL;
2087         /*
2088          * For read_buf, check the magic number.
2089          */
2090         if (caller == 1) {
2091                 xfs_dir2_data_t         *data;
2092                 xfs_dir2_free_t         *free;
2093                 xfs_da_blkinfo_t        *info;
2094                 uint                    magic, magic1;
2095
2096                 info = rbp->data;
2097                 data = rbp->data;
2098                 free = rbp->data;
2099                 magic = be16_to_cpu(info->magic);
2100                 magic1 = be32_to_cpu(data->hdr.magic);
2101                 if (unlikely(
2102                     XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2103                                    (magic != XFS_ATTR_LEAF_MAGIC) &&
2104                                    (magic != XFS_DIR2_LEAF1_MAGIC) &&
2105                                    (magic != XFS_DIR2_LEAFN_MAGIC) &&
2106                                    (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2107                                    (magic1 != XFS_DIR2_DATA_MAGIC) &&
2108                                    (be32_to_cpu(free->hdr.magic) != XFS_DIR2_FREE_MAGIC),
2109                                 mp, XFS_ERRTAG_DA_READ_BUF,
2110                                 XFS_RANDOM_DA_READ_BUF))) {
2111                         trace_xfs_da_btree_corrupt(rbp->bps[0], _RET_IP_);
2112                         XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2113                                              XFS_ERRLEVEL_LOW, mp, info);
2114                         error = XFS_ERROR(EFSCORRUPTED);
2115                         xfs_da_brelse(trans, rbp);
2116                         nbplist = 0;
2117                         goto exit1;
2118                 }
2119         }
2120         if (bplist) {
2121                 kmem_free(bplist);
2122         }
2123         if (mapp != &map) {
2124                 kmem_free(mapp);
2125         }
2126         if (bpp)
2127                 *bpp = rbp;
2128         return 0;
2129 exit1:
2130         if (bplist) {
2131                 for (i = 0; i < nbplist; i++)
2132                         xfs_trans_brelse(trans, bplist[i]);
2133                 kmem_free(bplist);
2134         }
2135 exit0:
2136         if (mapp != &map)
2137                 kmem_free(mapp);
2138         if (bpp)
2139                 *bpp = NULL;
2140         return error;
2141 }
2142
2143 /*
2144  * Get a buffer for the dir/attr block.
2145  */
2146 int
2147 xfs_da_get_buf(
2148         xfs_trans_t     *trans,
2149         xfs_inode_t     *dp,
2150         xfs_dablk_t     bno,
2151         xfs_daddr_t             mappedbno,
2152         xfs_dabuf_t     **bpp,
2153         int             whichfork)
2154 {
2155         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0,
2156                                                  (inst_t *)__return_address);
2157 }
2158
2159 /*
2160  * Get a buffer for the dir/attr block, fill in the contents.
2161  */
2162 int
2163 xfs_da_read_buf(
2164         xfs_trans_t     *trans,
2165         xfs_inode_t     *dp,
2166         xfs_dablk_t     bno,
2167         xfs_daddr_t             mappedbno,
2168         xfs_dabuf_t     **bpp,
2169         int             whichfork)
2170 {
2171         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1,
2172                 (inst_t *)__return_address);
2173 }
2174
2175 /*
2176  * Readahead the dir/attr block.
2177  */
2178 xfs_daddr_t
2179 xfs_da_reada_buf(
2180         xfs_trans_t     *trans,
2181         xfs_inode_t     *dp,
2182         xfs_dablk_t     bno,
2183         int             whichfork)
2184 {
2185         xfs_daddr_t             rval;
2186
2187         rval = -1;
2188         if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3,
2189                         (inst_t *)__return_address))
2190                 return -1;
2191         else
2192                 return rval;
2193 }
2194
2195 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2196 kmem_zone_t *xfs_dabuf_zone;            /* dabuf zone */
2197
2198 /*
2199  * Allocate a dir-state structure.
2200  * We don't put them on the stack since they're large.
2201  */
2202 xfs_da_state_t *
2203 xfs_da_state_alloc(void)
2204 {
2205         return kmem_zone_zalloc(xfs_da_state_zone, KM_NOFS);
2206 }
2207
2208 /*
2209  * Kill the altpath contents of a da-state structure.
2210  */
2211 STATIC void
2212 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2213 {
2214         int     i;
2215
2216         for (i = 0; i < state->altpath.active; i++) {
2217                 if (state->altpath.blk[i].bp) {
2218                         if (state->altpath.blk[i].bp != state->path.blk[i].bp)
2219                                 xfs_da_buf_done(state->altpath.blk[i].bp);
2220                         state->altpath.blk[i].bp = NULL;
2221                 }
2222         }
2223         state->altpath.active = 0;
2224 }
2225
2226 /*
2227  * Free a da-state structure.
2228  */
2229 void
2230 xfs_da_state_free(xfs_da_state_t *state)
2231 {
2232         int     i;
2233
2234         xfs_da_state_kill_altpath(state);
2235         for (i = 0; i < state->path.active; i++) {
2236                 if (state->path.blk[i].bp)
2237                         xfs_da_buf_done(state->path.blk[i].bp);
2238         }
2239         if (state->extravalid && state->extrablk.bp)
2240                 xfs_da_buf_done(state->extrablk.bp);
2241 #ifdef DEBUG
2242         memset((char *)state, 0, sizeof(*state));
2243 #endif /* DEBUG */
2244         kmem_zone_free(xfs_da_state_zone, state);
2245 }
2246
2247 #ifdef XFS_DABUF_DEBUG
2248 xfs_dabuf_t     *xfs_dabuf_global_list;
2249 static DEFINE_SPINLOCK(xfs_dabuf_global_lock);
2250 #endif
2251
2252 /*
2253  * Create a dabuf.
2254  */
2255 /* ARGSUSED */
2256 STATIC xfs_dabuf_t *
2257 xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra)
2258 {
2259         xfs_buf_t       *bp;
2260         xfs_dabuf_t     *dabuf;
2261         int             i;
2262         int             off;
2263
2264         if (nbuf == 1)
2265                 dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_NOFS);
2266         else
2267                 dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_NOFS);
2268         dabuf->dirty = 0;
2269 #ifdef XFS_DABUF_DEBUG
2270         dabuf->ra = ra;
2271         dabuf->target = XFS_BUF_TARGET(bps[0]);
2272         dabuf->blkno = XFS_BUF_ADDR(bps[0]);
2273 #endif
2274         if (nbuf == 1) {
2275                 dabuf->nbuf = 1;
2276                 bp = bps[0];
2277                 dabuf->bbcount = (short)BTOBB(XFS_BUF_COUNT(bp));
2278                 dabuf->data = XFS_BUF_PTR(bp);
2279                 dabuf->bps[0] = bp;
2280         } else {
2281                 dabuf->nbuf = nbuf;
2282                 for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
2283                         dabuf->bps[i] = bp = bps[i];
2284                         dabuf->bbcount += BTOBB(XFS_BUF_COUNT(bp));
2285                 }
2286                 dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
2287                 for (i = off = 0; i < nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2288                         bp = bps[i];
2289                         memcpy((char *)dabuf->data + off, XFS_BUF_PTR(bp),
2290                                 XFS_BUF_COUNT(bp));
2291                 }
2292         }
2293 #ifdef XFS_DABUF_DEBUG
2294         {
2295                 xfs_dabuf_t     *p;
2296
2297                 spin_lock(&xfs_dabuf_global_lock);
2298                 for (p = xfs_dabuf_global_list; p; p = p->next) {
2299                         ASSERT(p->blkno != dabuf->blkno ||
2300                                p->target != dabuf->target);
2301                 }
2302                 dabuf->prev = NULL;
2303                 if (xfs_dabuf_global_list)
2304                         xfs_dabuf_global_list->prev = dabuf;
2305                 dabuf->next = xfs_dabuf_global_list;
2306                 xfs_dabuf_global_list = dabuf;
2307                 spin_unlock(&xfs_dabuf_global_lock);
2308         }
2309 #endif
2310         return dabuf;
2311 }
2312
2313 /*
2314  * Un-dirty a dabuf.
2315  */
2316 STATIC void
2317 xfs_da_buf_clean(xfs_dabuf_t *dabuf)
2318 {
2319         xfs_buf_t       *bp;
2320         int             i;
2321         int             off;
2322
2323         if (dabuf->dirty) {
2324                 ASSERT(dabuf->nbuf > 1);
2325                 dabuf->dirty = 0;
2326                 for (i = off = 0; i < dabuf->nbuf;
2327                                 i++, off += XFS_BUF_COUNT(bp)) {
2328                         bp = dabuf->bps[i];
2329                         memcpy(XFS_BUF_PTR(bp), (char *)dabuf->data + off,
2330                                 XFS_BUF_COUNT(bp));
2331                 }
2332         }
2333 }
2334
2335 /*
2336  * Release a dabuf.
2337  */
2338 void
2339 xfs_da_buf_done(xfs_dabuf_t *dabuf)
2340 {
2341         ASSERT(dabuf);
2342         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2343         if (dabuf->dirty)
2344                 xfs_da_buf_clean(dabuf);
2345         if (dabuf->nbuf > 1)
2346                 kmem_free(dabuf->data);
2347 #ifdef XFS_DABUF_DEBUG
2348         {
2349                 spin_lock(&xfs_dabuf_global_lock);
2350                 if (dabuf->prev)
2351                         dabuf->prev->next = dabuf->next;
2352                 else
2353                         xfs_dabuf_global_list = dabuf->next;
2354                 if (dabuf->next)
2355                         dabuf->next->prev = dabuf->prev;
2356                 spin_unlock(&xfs_dabuf_global_lock);
2357         }
2358         memset(dabuf, 0, XFS_DA_BUF_SIZE(dabuf->nbuf));
2359 #endif
2360         if (dabuf->nbuf == 1)
2361                 kmem_zone_free(xfs_dabuf_zone, dabuf);
2362         else
2363                 kmem_free(dabuf);
2364 }
2365
2366 /*
2367  * Log transaction from a dabuf.
2368  */
2369 void
2370 xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
2371 {
2372         xfs_buf_t       *bp;
2373         uint            f;
2374         int             i;
2375         uint            l;
2376         int             off;
2377
2378         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2379         if (dabuf->nbuf == 1) {
2380                 ASSERT(dabuf->data == (void *)XFS_BUF_PTR(dabuf->bps[0]));
2381                 xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
2382                 return;
2383         }
2384         dabuf->dirty = 1;
2385         ASSERT(first <= last);
2386         for (i = off = 0; i < dabuf->nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2387                 bp = dabuf->bps[i];
2388                 f = off;
2389                 l = f + XFS_BUF_COUNT(bp) - 1;
2390                 if (f < first)
2391                         f = first;
2392                 if (l > last)
2393                         l = last;
2394                 if (f <= l)
2395                         xfs_trans_log_buf(tp, bp, f - off, l - off);
2396                 /*
2397                  * B_DONE is set by xfs_trans_log buf.
2398                  * If we don't set it on a new buffer (get not read)
2399                  * then if we don't put anything in the buffer it won't
2400                  * be set, and at commit it it released into the cache,
2401                  * and then a read will fail.
2402                  */
2403                 else if (!(XFS_BUF_ISDONE(bp)))
2404                   XFS_BUF_DONE(bp);
2405         }
2406         ASSERT(last < off);
2407 }
2408
2409 /*
2410  * Release dabuf from a transaction.
2411  * Have to free up the dabuf before the buffers are released,
2412  * since the synchronization on the dabuf is really the lock on the buffer.
2413  */
2414 void
2415 xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2416 {
2417         xfs_buf_t       *bp;
2418         xfs_buf_t       **bplist;
2419         int             i;
2420         int             nbuf;
2421
2422         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2423         if ((nbuf = dabuf->nbuf) == 1) {
2424                 bplist = &bp;
2425                 bp = dabuf->bps[0];
2426         } else {
2427                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2428                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2429         }
2430         xfs_da_buf_done(dabuf);
2431         for (i = 0; i < nbuf; i++)
2432                 xfs_trans_brelse(tp, bplist[i]);
2433         if (bplist != &bp)
2434                 kmem_free(bplist);
2435 }
2436
2437 /*
2438  * Invalidate dabuf from a transaction.
2439  */
2440 void
2441 xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2442 {
2443         xfs_buf_t       *bp;
2444         xfs_buf_t       **bplist;
2445         int             i;
2446         int             nbuf;
2447
2448         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2449         if ((nbuf = dabuf->nbuf) == 1) {
2450                 bplist = &bp;
2451                 bp = dabuf->bps[0];
2452         } else {
2453                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2454                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2455         }
2456         xfs_da_buf_done(dabuf);
2457         for (i = 0; i < nbuf; i++)
2458                 xfs_trans_binval(tp, bplist[i]);
2459         if (bplist != &bp)
2460                 kmem_free(bplist);
2461 }
2462
2463 /*
2464  * Get the first daddr from a dabuf.
2465  */
2466 xfs_daddr_t
2467 xfs_da_blkno(xfs_dabuf_t *dabuf)
2468 {
2469         ASSERT(dabuf->nbuf);
2470         ASSERT(dabuf->data);
2471         return XFS_BUF_ADDR(dabuf->bps[0]);
2472 }