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_dir.h"
  28 #include "xfs_dir2.h"
  29 #include "xfs_dmapi.h"
  30 #include "xfs_mount.h"
  31 #include "xfs_da_btree.h"
  32 #include "xfs_bmap_btree.h"
  33 #include "xfs_alloc_btree.h"
  34 #include "xfs_ialloc_btree.h"
  35 #include "xfs_dir_sf.h"
  36 #include "xfs_dir2_sf.h"
  37 #include "xfs_attr_sf.h"
  38 #include "xfs_dinode.h"
  39 #include "xfs_inode.h"
  40 #include "xfs_inode_item.h"
  41 #include "xfs_alloc.h"
  42 #include "xfs_btree.h"
  43 #include "xfs_bmap.h"
  44 #include "xfs_attr.h"
  45 #include "xfs_attr_leaf.h"
  46 #include "xfs_dir_leaf.h"
  47 #include "xfs_dir2_data.h"
  48 #include "xfs_dir2_leaf.h"
  49 #include "xfs_dir2_block.h"
  50 #include "xfs_dir2_node.h"
  51 #include "xfs_error.h"
  52
  53 /*
  54  * xfs_da_btree.c
  55  *
  56  * Routines to implement directories as Btrees of hashed names.
  57  */
  58
  59 /*========================================================================
  60  * Function prototypes for the kernel.
  61  *========================================================================*/
  62
  63 /*
  64  * Routines used for growing the Btree.
  65  */
  66 STATIC int xfs_da_root_split(xfs_da_state_t *state,
  67                                             xfs_da_state_blk_t *existing_root,
  68                                             xfs_da_state_blk_t *new_child);
  69 STATIC int xfs_da_node_split(xfs_da_state_t *state,
  70                                             xfs_da_state_blk_t *existing_blk,
  71                                             xfs_da_state_blk_t *split_blk,
  72                                             xfs_da_state_blk_t *blk_to_add,
  73                                             int treelevel,
  74                                             int *result);
  75 STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
  76                                          xfs_da_state_blk_t *node_blk_1,
  77                                          xfs_da_state_blk_t *node_blk_2);
  78 STATIC void xfs_da_node_add(xfs_da_state_t *state,
  79                                    xfs_da_state_blk_t *old_node_blk,
  80                                    xfs_da_state_blk_t *new_node_blk);
  81
  82 /*
  83  * Routines used for shrinking the Btree.
  84  */
  85 STATIC int xfs_da_root_join(xfs_da_state_t *state,
  86                                            xfs_da_state_blk_t *root_blk);
  87 STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
  88 STATIC void xfs_da_node_remove(xfs_da_state_t *state,
  89                                               xfs_da_state_blk_t *drop_blk);
  90 STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
  91                                          xfs_da_state_blk_t *src_node_blk,
  92                                          xfs_da_state_blk_t *dst_node_blk);
  93
  94 /*
  95  * Utility routines.
  96  */
  97 STATIC uint     xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count);
  98 STATIC int      xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp);
  99 STATIC xfs_dabuf_t *xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra);
 100 STATIC int      xfs_da_blk_unlink(xfs_da_state_t *state,
 101                                   xfs_da_state_blk_t *drop_blk,
 102                                   xfs_da_state_blk_t *save_blk);
 103 STATIC void     xfs_da_state_kill_altpath(xfs_da_state_t *state);
 104
 105 /*========================================================================
 106  * Routines used for growing the Btree.
 107  *========================================================================*/
 108
 109 /*
 110  * Create the initial contents of an intermediate node.
 111  */
 112 int
 113 xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
 114                                  xfs_dabuf_t **bpp, int whichfork)
 115 {
 116         xfs_da_intnode_t *node;
 117         xfs_dabuf_t *bp;
 118         int error;
 119         xfs_trans_t *tp;
 120
 121         tp = args->trans;
 122         error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
 123         if (error)
 124                 return(error);
 125         ASSERT(bp != NULL);
 126         node = bp->data;
 127         node->hdr.info.forw = 0;
 128         node->hdr.info.back = 0;
 129         node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC);
 130         node->hdr.info.pad = 0;
 131         node->hdr.count = 0;
 132         INT_SET(node->hdr.level, ARCH_CONVERT, level);
 133
 134         xfs_da_log_buf(tp, bp,
 135                 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 136
 137         *bpp = bp;
 138         return(0);
 139 }
 140
 141 /*
 142  * Split a leaf node, rebalance, then possibly split
 143  * intermediate nodes, rebalance, etc.
 144  */
 145 int                                                     /* error */
 146 xfs_da_split(xfs_da_state_t *state)
 147 {
 148         xfs_da_state_blk_t *oldblk, *newblk, *addblk;
 149         xfs_da_intnode_t *node;
 150         xfs_dabuf_t *bp;
 151         int max, action, error, i;
 152
 153         /*
 154          * Walk back up the tree splitting/inserting/adjusting as necessary.
 155          * If we need to insert and there isn't room, split the node, then
 156          * decide which fragment to insert the new block from below into.
 157          * Note that we may split the root this way, but we need more fixup.
 158          */
 159         max = state->path.active - 1;
 160         ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
 161         ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
 162                state->path.blk[max].magic == XFS_DIRX_LEAF_MAGIC(state->mp));
 163
 164         addblk = &state->path.blk[max];         /* initial dummy value */
 165         for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
 166                 oldblk = &state->path.blk[i];
 167                 newblk = &state->altpath.blk[i];
 168
 169                 /*
 170                  * If a leaf node then
 171                  *     Allocate a new leaf node, then rebalance across them.
 172                  * else if an intermediate node then
 173                  *     We split on the last layer, must we split the node?
 174                  */
 175                 switch (oldblk->magic) {
 176                 case XFS_ATTR_LEAF_MAGIC:
 177                         error = xfs_attr_leaf_split(state, oldblk, newblk);
 178                         if ((error != 0) && (error != ENOSPC)) {
 179                                 return(error);  /* GROT: attr is inconsistent */
 180                         }
 181                         if (!error) {
 182                                 addblk = newblk;
 183                                 break;
 184                         }
 185                         /*
 186                          * Entry wouldn't fit, split the leaf again.
 187                          */
 188                         state->extravalid = 1;
 189                         if (state->inleaf) {
 190                                 state->extraafter = 0;  /* before newblk */
 191                                 error = xfs_attr_leaf_split(state, oldblk,
 192                                                             &state->extrablk);
 193                         } else {
 194                                 state->extraafter = 1;  /* after newblk */
 195                                 error = xfs_attr_leaf_split(state, newblk,
 196                                                             &state->extrablk);
 197                         }
 198                         if (error)
 199                                 return(error);  /* GROT: attr inconsistent */
 200                         addblk = newblk;
 201                         break;
 202                 case XFS_DIR_LEAF_MAGIC:
 203                         ASSERT(XFS_DIR_IS_V1(state->mp));
 204                         error = xfs_dir_leaf_split(state, oldblk, newblk);
 205                         if ((error != 0) && (error != ENOSPC)) {
 206                                 return(error);  /* GROT: dir is inconsistent */
 207                         }
 208                         if (!error) {
 209                                 addblk = newblk;
 210                                 break;
 211                         }
 212                         /*
 213                          * Entry wouldn't fit, split the leaf again.
 214                          */
 215                         state->extravalid = 1;
 216                         if (state->inleaf) {
 217                                 state->extraafter = 0;  /* before newblk */
 218                                 error = xfs_dir_leaf_split(state, oldblk,
 219                                                            &state->extrablk);
 220                                 if (error)
 221                                         return(error);  /* GROT: dir incon. */
 222                                 addblk = newblk;
 223                         } else {
 224                                 state->extraafter = 1;  /* after newblk */
 225                                 error = xfs_dir_leaf_split(state, newblk,
 226                                                            &state->extrablk);
 227                                 if (error)
 228                                         return(error);  /* GROT: dir incon. */
 229                                 addblk = newblk;
 230                         }
 231                         break;
 232                 case XFS_DIR2_LEAFN_MAGIC:
 233                         ASSERT(XFS_DIR_IS_V2(state->mp));
 234                         error = xfs_dir2_leafn_split(state, oldblk, newblk);
 235                         if (error)
 236                                 return error;
 237                         addblk = newblk;
 238                         break;
 239                 case XFS_DA_NODE_MAGIC:
 240                         error = xfs_da_node_split(state, oldblk, newblk, addblk,
 241                                                          max - i, &action);
 242                         xfs_da_buf_done(addblk->bp);
 243                         addblk->bp = NULL;
 244                         if (error)
 245                                 return(error);  /* GROT: dir is inconsistent */
 246                         /*
 247                          * Record the newly split block for the next time thru?
 248                          */
 249                         if (action)
 250                                 addblk = newblk;
 251                         else
 252                                 addblk = NULL;
 253                         break;
 254                 }
 255
 256                 /*
 257                  * Update the btree to show the new hashval for this child.
 258                  */
 259                 xfs_da_fixhashpath(state, &state->path);
 260                 /*
 261                  * If we won't need this block again, it's getting dropped
 262                  * from the active path by the loop control, so we need
 263                  * to mark it done now.
 264                  */
 265                 if (i > 0 || !addblk)
 266                         xfs_da_buf_done(oldblk->bp);
 267         }
 268         if (!addblk)
 269                 return(0);
 270
 271         /*
 272          * Split the root node.
 273          */
 274         ASSERT(state->path.active == 0);
 275         oldblk = &state->path.blk[0];
 276         error = xfs_da_root_split(state, oldblk, addblk);
 277         if (error) {
 278                 xfs_da_buf_done(oldblk->bp);
 279                 xfs_da_buf_done(addblk->bp);
 280                 addblk->bp = NULL;
 281                 return(error);  /* GROT: dir is inconsistent */
 282         }
 283
 284         /*
 285          * Update pointers to the node which used to be block 0 and
 286          * just got bumped because of the addition of a new root node.
 287          * There might be three blocks involved if a double split occurred,
 288          * and the original block 0 could be at any position in the list.
 289          */
 290
 291         node = oldblk->bp->data;
 292         if (node->hdr.info.forw) {
 293                 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
 294                         bp = addblk->bp;
 295                 } else {
 296                         ASSERT(state->extravalid);
 297                         bp = state->extrablk.bp;
 298                 }
 299                 node = bp->data;
 300                 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
 301                 xfs_da_log_buf(state->args->trans, bp,
 302                     XFS_DA_LOGRANGE(node, &node->hdr.info,
 303                     sizeof(node->hdr.info)));
 304         }
 305         node = oldblk->bp->data;
 306         if (node->hdr.info.back) {
 307                 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
 308                         bp = addblk->bp;
 309                 } else {
 310                         ASSERT(state->extravalid);
 311                         bp = state->extrablk.bp;
 312                 }
 313                 node = bp->data;
 314                 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
 315                 xfs_da_log_buf(state->args->trans, bp,
 316                     XFS_DA_LOGRANGE(node, &node->hdr.info,
 317                     sizeof(node->hdr.info)));
 318         }
 319         xfs_da_buf_done(oldblk->bp);
 320         xfs_da_buf_done(addblk->bp);
 321         addblk->bp = NULL;
 322         return(0);
 323 }
 324
 325 /*
 326  * Split the root.  We have to create a new root and point to the two
 327  * parts (the split old root) that we just created.  Copy block zero to
 328  * the EOF, extending the inode in process.
 329  */
 330 STATIC int                                              /* error */
 331 xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
 332                                  xfs_da_state_blk_t *blk2)
 333 {
 334         xfs_da_intnode_t *node, *oldroot;
 335         xfs_da_args_t *args;
 336         xfs_dablk_t blkno;
 337         xfs_dabuf_t *bp;
 338         int error, size;
 339         xfs_inode_t *dp;
 340         xfs_trans_t *tp;
 341         xfs_mount_t *mp;
 342         xfs_dir2_leaf_t *leaf;
 343
 344         /*
 345          * Copy the existing (incorrect) block from the root node position
 346          * to a free space somewhere.
 347          */
 348         args = state->args;
 349         ASSERT(args != NULL);
 350         error = xfs_da_grow_inode(args, &blkno);
 351         if (error)
 352                 return(error);
 353         dp = args->dp;
 354         tp = args->trans;
 355         mp = state->mp;
 356         error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
 357         if (error)
 358                 return(error);
 359         ASSERT(bp != NULL);
 360         node = bp->data;
 361         oldroot = blk1->bp->data;
 362         if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC) {
 363                 size = (int)((char *)&oldroot->btree[INT_GET(oldroot->hdr.count, ARCH_CONVERT)] -
 364                              (char *)oldroot);
 365         } else {
 366                 ASSERT(XFS_DIR_IS_V2(mp));
 367                 ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
 368                 leaf = (xfs_dir2_leaf_t *)oldroot;
 369                 size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] -
 370                              (char *)leaf);
 371         }
 372         memcpy(node, oldroot, size);
 373         xfs_da_log_buf(tp, bp, 0, size - 1);
 374         xfs_da_buf_done(blk1->bp);
 375         blk1->bp = bp;
 376         blk1->blkno = blkno;
 377
 378         /*
 379          * Set up the new root node.
 380          */
 381         error = xfs_da_node_create(args,
 382                 args->whichfork == XFS_DATA_FORK &&
 383                 XFS_DIR_IS_V2(mp) ? mp->m_dirleafblk : 0,
 384                 INT_GET(node->hdr.level, ARCH_CONVERT) + 1, &bp, args->whichfork);
 385         if (error)
 386                 return(error);
 387         node = bp->data;
 388         INT_SET(node->btree[0].hashval, ARCH_CONVERT, blk1->hashval);
 389         INT_SET(node->btree[0].before, ARCH_CONVERT, blk1->blkno);
 390         INT_SET(node->btree[1].hashval, ARCH_CONVERT, blk2->hashval);
 391         INT_SET(node->btree[1].before, ARCH_CONVERT, blk2->blkno);
 392         INT_SET(node->hdr.count, ARCH_CONVERT, 2);
 393
 394 #ifdef DEBUG
 395         if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC) {
 396                 ASSERT(blk1->blkno >= mp->m_dirleafblk &&
 397                        blk1->blkno < mp->m_dirfreeblk);
 398                 ASSERT(blk2->blkno >= mp->m_dirleafblk &&
 399                        blk2->blkno < mp->m_dirfreeblk);
 400         }
 401 #endif
 402
 403         /* Header is already logged by xfs_da_node_create */
 404         xfs_da_log_buf(tp, bp,
 405                 XFS_DA_LOGRANGE(node, node->btree,
 406                         sizeof(xfs_da_node_entry_t) * 2));
 407         xfs_da_buf_done(bp);
 408
 409         return(0);
 410 }
 411
 412 /*
 413  * Split the node, rebalance, then add the new entry.
 414  */
 415 STATIC int                                              /* error */
 416 xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
 417                                  xfs_da_state_blk_t *newblk,
 418                                  xfs_da_state_blk_t *addblk,
 419                                  int treelevel, int *result)
 420 {
 421         xfs_da_intnode_t *node;
 422         xfs_dablk_t blkno;
 423         int newcount, error;
 424         int useextra;
 425
 426         node = oldblk->bp->data;
 427         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 428
 429         /*
 430          * With V2 the extra block is data or freespace.
 431          */
 432         useextra = state->extravalid && (XFS_DIR_IS_V1(state->mp) ||
 433                         state->args->whichfork == XFS_ATTR_FORK);
 434         newcount = 1 + useextra;
 435         /*
 436          * Do we have to split the node?
 437          */
 438         if ((INT_GET(node->hdr.count, ARCH_CONVERT) + newcount) > state->node_ents) {
 439                 /*
 440                  * Allocate a new node, add to the doubly linked chain of
 441                  * nodes, then move some of our excess entries into it.
 442                  */
 443                 error = xfs_da_grow_inode(state->args, &blkno);
 444                 if (error)
 445                         return(error);  /* GROT: dir is inconsistent */
 446
 447                 error = xfs_da_node_create(state->args, blkno, treelevel,
 448                                            &newblk->bp, state->args->whichfork);
 449                 if (error)
 450                         return(error);  /* GROT: dir is inconsistent */
 451                 newblk->blkno = blkno;
 452                 newblk->magic = XFS_DA_NODE_MAGIC;
 453                 xfs_da_node_rebalance(state, oldblk, newblk);
 454                 error = xfs_da_blk_link(state, oldblk, newblk);
 455                 if (error)
 456                         return(error);
 457                 *result = 1;
 458         } else {
 459                 *result = 0;
 460         }
 461
 462         /*
 463          * Insert the new entry(s) into the correct block
 464          * (updating last hashval in the process).
 465          *
 466          * xfs_da_node_add() inserts BEFORE the given index,
 467          * and as a result of using node_lookup_int() we always
 468          * point to a valid entry (not after one), but a split
 469          * operation always results in a new block whose hashvals
 470          * FOLLOW the current block.
 471          *
 472          * If we had double-split op below us, then add the extra block too.
 473          */
 474         node = oldblk->bp->data;
 475         if (oldblk->index <= INT_GET(node->hdr.count, ARCH_CONVERT)) {
 476                 oldblk->index++;
 477                 xfs_da_node_add(state, oldblk, addblk);
 478                 if (useextra) {
 479                         if (state->extraafter)
 480                                 oldblk->index++;
 481                         xfs_da_node_add(state, oldblk, &state->extrablk);
 482                         state->extravalid = 0;
 483                 }
 484         } else {
 485                 newblk->index++;
 486                 xfs_da_node_add(state, newblk, addblk);
 487                 if (useextra) {
 488                         if (state->extraafter)
 489                                 newblk->index++;
 490                         xfs_da_node_add(state, newblk, &state->extrablk);
 491                         state->extravalid = 0;
 492                 }
 493         }
 494
 495         return(0);
 496 }
 497
 498 /*
 499  * Balance the btree elements between two intermediate nodes,
 500  * usually one full and one empty.
 501  *
 502  * NOTE: if blk2 is empty, then it will get the upper half of blk1.
 503  */
 504 STATIC void
 505 xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
 506                                      xfs_da_state_blk_t *blk2)
 507 {
 508         xfs_da_intnode_t *node1, *node2, *tmpnode;
 509         xfs_da_node_entry_t *btree_s, *btree_d;
 510         int count, tmp;
 511         xfs_trans_t *tp;
 512
 513         node1 = blk1->bp->data;
 514         node2 = blk2->bp->data;
 515         /*
 516          * Figure out how many entries need to move, and in which direction.
 517          * Swap the nodes around if that makes it simpler.
 518          */
 519         if ((INT_GET(node1->hdr.count, ARCH_CONVERT) > 0) && (INT_GET(node2->hdr.count, ARCH_CONVERT) > 0) &&
 520             ((INT_GET(node2->btree[ 0 ].hashval, ARCH_CONVERT) < INT_GET(node1->btree[ 0 ].hashval, ARCH_CONVERT)) ||
 521              (INT_GET(node2->btree[ INT_GET(node2->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT) <
 522               INT_GET(node1->btree[ INT_GET(node1->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT)))) {
 523                 tmpnode = node1;
 524                 node1 = node2;
 525                 node2 = tmpnode;
 526         }
 527         ASSERT(be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 528         ASSERT(be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 529         count = (INT_GET(node1->hdr.count, ARCH_CONVERT) - INT_GET(node2->hdr.count, ARCH_CONVERT)) / 2;
 530         if (count == 0)
 531                 return;
 532         tp = state->args->trans;
 533         /*
 534          * Two cases: high-to-low and low-to-high.
 535          */
 536         if (count > 0) {
 537                 /*
 538                  * Move elements in node2 up to make a hole.
 539                  */
 540                 if ((tmp = INT_GET(node2->hdr.count, ARCH_CONVERT)) > 0) {
 541                         tmp *= (uint)sizeof(xfs_da_node_entry_t);
 542                         btree_s = &node2->btree[0];
 543                         btree_d = &node2->btree[count];
 544                         memmove(btree_d, btree_s, tmp);
 545                 }
 546
 547                 /*
 548                  * Move the req'd B-tree elements from high in node1 to
 549                  * low in node2.
 550                  */
 551                 INT_MOD(node2->hdr.count, ARCH_CONVERT, count);
 552                 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
 553                 btree_s = &node1->btree[INT_GET(node1->hdr.count, ARCH_CONVERT) - count];
 554                 btree_d = &node2->btree[0];
 555                 memcpy(btree_d, btree_s, tmp);
 556                 INT_MOD(node1->hdr.count, ARCH_CONVERT, -(count));
 557
 558         } else {
 559                 /*
 560                  * Move the req'd B-tree elements from low in node2 to
 561                  * high in node1.
 562                  */
 563                 count = -count;
 564                 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
 565                 btree_s = &node2->btree[0];
 566                 btree_d = &node1->btree[INT_GET(node1->hdr.count, ARCH_CONVERT)];
 567                 memcpy(btree_d, btree_s, tmp);
 568                 INT_MOD(node1->hdr.count, ARCH_CONVERT, count);
 569                 xfs_da_log_buf(tp, blk1->bp,
 570                         XFS_DA_LOGRANGE(node1, btree_d, tmp));
 571
 572                 /*
 573                  * Move elements in node2 down to fill the hole.
 574                  */
 575                 tmp  = INT_GET(node2->hdr.count, ARCH_CONVERT) - count;
 576                 tmp *= (uint)sizeof(xfs_da_node_entry_t);
 577                 btree_s = &node2->btree[count];
 578                 btree_d = &node2->btree[0];
 579                 memmove(btree_d, btree_s, tmp);
 580                 INT_MOD(node2->hdr.count, ARCH_CONVERT, -(count));
 581         }
 582
 583         /*
 584          * Log header of node 1 and all current bits of node 2.
 585          */
 586         xfs_da_log_buf(tp, blk1->bp,
 587                 XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
 588         xfs_da_log_buf(tp, blk2->bp,
 589                 XFS_DA_LOGRANGE(node2, &node2->hdr,
 590                         sizeof(node2->hdr) +
 591                         sizeof(node2->btree[0]) * INT_GET(node2->hdr.count, ARCH_CONVERT)));
 592
 593         /*
 594          * Record the last hashval from each block for upward propagation.
 595          * (note: don't use the swapped node pointers)
 596          */
 597         node1 = blk1->bp->data;
 598         node2 = blk2->bp->data;
 599         blk1->hashval = INT_GET(node1->btree[ INT_GET(node1->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
 600         blk2->hashval = INT_GET(node2->btree[ INT_GET(node2->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
 601
 602         /*
 603          * Adjust the expected index for insertion.
 604          */
 605         if (blk1->index >= INT_GET(node1->hdr.count, ARCH_CONVERT)) {
 606                 blk2->index = blk1->index - INT_GET(node1->hdr.count, ARCH_CONVERT);
 607                 blk1->index = INT_GET(node1->hdr.count, ARCH_CONVERT) + 1;      /* make it invalid */
 608         }
 609 }
 610
 611 /*
 612  * Add a new entry to an intermediate node.
 613  */
 614 STATIC void
 615 xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
 616                                xfs_da_state_blk_t *newblk)
 617 {
 618         xfs_da_intnode_t *node;
 619         xfs_da_node_entry_t *btree;
 620         int tmp;
 621         xfs_mount_t *mp;
 622
 623         node = oldblk->bp->data;
 624         mp = state->mp;
 625         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 626         ASSERT((oldblk->index >= 0) && (oldblk->index <= INT_GET(node->hdr.count, ARCH_CONVERT)));
 627         ASSERT(newblk->blkno != 0);
 628         if (state->args->whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
 629                 ASSERT(newblk->blkno >= mp->m_dirleafblk &&
 630                        newblk->blkno < mp->m_dirfreeblk);
 631
 632         /*
 633          * We may need to make some room before we insert the new node.
 634          */
 635         tmp = 0;
 636         btree = &node->btree[ oldblk->index ];
 637         if (oldblk->index < INT_GET(node->hdr.count, ARCH_CONVERT)) {
 638                 tmp = (INT_GET(node->hdr.count, ARCH_CONVERT) - oldblk->index) * (uint)sizeof(*btree);
 639                 memmove(btree + 1, btree, tmp);
 640         }
 641         INT_SET(btree->hashval, ARCH_CONVERT, newblk->hashval);
 642         INT_SET(btree->before, ARCH_CONVERT, newblk->blkno);
 643         xfs_da_log_buf(state->args->trans, oldblk->bp,
 644                 XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
 645         INT_MOD(node->hdr.count, ARCH_CONVERT, +1);
 646         xfs_da_log_buf(state->args->trans, oldblk->bp,
 647                 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 648
 649         /*
 650          * Copy the last hash value from the oldblk to propagate upwards.
 651          */
 652         oldblk->hashval = INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
 653 }
 654
 655 /*========================================================================
 656  * Routines used for shrinking the Btree.
 657  *========================================================================*/
 658
 659 /*
 660  * Deallocate an empty leaf node, remove it from its parent,
 661  * possibly deallocating that block, etc...
 662  */
 663 int
 664 xfs_da_join(xfs_da_state_t *state)
 665 {
 666         xfs_da_state_blk_t *drop_blk, *save_blk;
 667         int action, error;
 668
 669         action = 0;
 670         drop_blk = &state->path.blk[ state->path.active-1 ];
 671         save_blk = &state->altpath.blk[ state->path.active-1 ];
 672         ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
 673         ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
 674                drop_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp));
 675
 676         /*
 677          * Walk back up the tree joining/deallocating as necessary.
 678          * When we stop dropping blocks, break out.
 679          */
 680         for (  ; state->path.active >= 2; drop_blk--, save_blk--,
 681                  state->path.active--) {
 682                 /*
 683                  * See if we can combine the block with a neighbor.
 684                  *   (action == 0) => no options, just leave
 685                  *   (action == 1) => coalesce, then unlink
 686                  *   (action == 2) => block empty, unlink it
 687                  */
 688                 switch (drop_blk->magic) {
 689                 case XFS_ATTR_LEAF_MAGIC:
 690                         error = xfs_attr_leaf_toosmall(state, &action);
 691                         if (error)
 692                                 return(error);
 693                         if (action == 0)
 694                                 return(0);
 695                         xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
 696                         break;
 697                 case XFS_DIR_LEAF_MAGIC:
 698                         ASSERT(XFS_DIR_IS_V1(state->mp));
 699                         error = xfs_dir_leaf_toosmall(state, &action);
 700                         if (error)
 701                                 return(error);
 702                         if (action == 0)
 703                                 return(0);
 704                         xfs_dir_leaf_unbalance(state, drop_blk, save_blk);
 705                         break;
 706                 case XFS_DIR2_LEAFN_MAGIC:
 707                         ASSERT(XFS_DIR_IS_V2(state->mp));
 708                         error = xfs_dir2_leafn_toosmall(state, &action);
 709                         if (error)
 710                                 return error;
 711                         if (action == 0)
 712                                 return 0;
 713                         xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
 714                         break;
 715                 case XFS_DA_NODE_MAGIC:
 716                         /*
 717                          * Remove the offending node, fixup hashvals,
 718                          * check for a toosmall neighbor.
 719                          */
 720                         xfs_da_node_remove(state, drop_blk);
 721                         xfs_da_fixhashpath(state, &state->path);
 722                         error = xfs_da_node_toosmall(state, &action);
 723                         if (error)
 724                                 return(error);
 725                         if (action == 0)
 726                                 return 0;
 727                         xfs_da_node_unbalance(state, drop_blk, save_blk);
 728                         break;
 729                 }
 730                 xfs_da_fixhashpath(state, &state->altpath);
 731                 error = xfs_da_blk_unlink(state, drop_blk, save_blk);
 732                 xfs_da_state_kill_altpath(state);
 733                 if (error)
 734                         return(error);
 735                 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
 736                                                          drop_blk->bp);
 737                 drop_blk->bp = NULL;
 738                 if (error)
 739                         return(error);
 740         }
 741         /*
 742          * We joined all the way to the top.  If it turns out that
 743          * we only have one entry in the root, make the child block
 744          * the new root.
 745          */
 746         xfs_da_node_remove(state, drop_blk);
 747         xfs_da_fixhashpath(state, &state->path);
 748         error = xfs_da_root_join(state, &state->path.blk[0]);
 749         return(error);
 750 }
 751
 752 /*
 753  * We have only one entry in the root.  Copy the only remaining child of
 754  * the old root to block 0 as the new root node.
 755  */
 756 STATIC int
 757 xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
 758 {
 759         xfs_da_intnode_t *oldroot;
 760         /* REFERENCED */
 761         xfs_da_blkinfo_t *blkinfo;
 762         xfs_da_args_t *args;
 763         xfs_dablk_t child;
 764         xfs_dabuf_t *bp;
 765         int error;
 766
 767         args = state->args;
 768         ASSERT(args != NULL);
 769         ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
 770         oldroot = root_blk->bp->data;
 771         ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 772         ASSERT(!oldroot->hdr.info.forw);
 773         ASSERT(!oldroot->hdr.info.back);
 774
 775         /*
 776          * If the root has more than one child, then don't do anything.
 777          */
 778         if (INT_GET(oldroot->hdr.count, ARCH_CONVERT) > 1)
 779                 return(0);
 780
 781         /*
 782          * Read in the (only) child block, then copy those bytes into
 783          * the root block's buffer and free the original child block.
 784          */
 785         child = INT_GET(oldroot->btree[ 0 ].before, ARCH_CONVERT);
 786         ASSERT(child != 0);
 787         error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp,
 788                                              args->whichfork);
 789         if (error)
 790                 return(error);
 791         ASSERT(bp != NULL);
 792         blkinfo = bp->data;
 793         if (INT_GET(oldroot->hdr.level, ARCH_CONVERT) == 1) {
 794                 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
 795                        be16_to_cpu(blkinfo->magic) == XFS_ATTR_LEAF_MAGIC);
 796         } else {
 797                 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DA_NODE_MAGIC);
 798         }
 799         ASSERT(!blkinfo->forw);
 800         ASSERT(!blkinfo->back);
 801         memcpy(root_blk->bp->data, bp->data, state->blocksize);
 802         xfs_da_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
 803         error = xfs_da_shrink_inode(args, child, bp);
 804         return(error);
 805 }
 806
 807 /*
 808  * Check a node block and its neighbors to see if the block should be
 809  * collapsed into one or the other neighbor.  Always keep the block
 810  * with the smaller block number.
 811  * If the current block is over 50% full, don't try to join it, return 0.
 812  * If the block is empty, fill in the state structure and return 2.
 813  * If it can be collapsed, fill in the state structure and return 1.
 814  * If nothing can be done, return 0.
 815  */
 816 STATIC int
 817 xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
 818 {
 819         xfs_da_intnode_t *node;
 820         xfs_da_state_blk_t *blk;
 821         xfs_da_blkinfo_t *info;
 822         int count, forward, error, retval, i;
 823         xfs_dablk_t blkno;
 824         xfs_dabuf_t *bp;
 825
 826         /*
 827          * Check for the degenerate case of the block being over 50% full.
 828          * If so, it's not worth even looking to see if we might be able
 829          * to coalesce with a sibling.
 830          */
 831         blk = &state->path.blk[ state->path.active-1 ];
 832         info = blk->bp->data;
 833         ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC);
 834         node = (xfs_da_intnode_t *)info;
 835         count = INT_GET(node->hdr.count, ARCH_CONVERT);
 836         if (count > (state->node_ents >> 1)) {
 837                 *action = 0;    /* blk over 50%, don't try to join */
 838                 return(0);      /* blk over 50%, don't try to join */
 839         }
 840
 841         /*
 842          * Check for the degenerate case of the block being empty.
 843          * If the block is empty, we'll simply delete it, no need to
 844          * coalesce it with a sibling block.  We choose (aribtrarily)
 845          * to merge with the forward block unless it is NULL.
 846          */
 847         if (count == 0) {
 848                 /*
 849                  * Make altpath point to the block we want to keep and
 850                  * path point to the block we want to drop (this one).
 851                  */
 852                 forward = (info->forw != 0);
 853                 memcpy(&state->altpath, &state->path, sizeof(state->path));
 854                 error = xfs_da_path_shift(state, &state->altpath, forward,
 855                                                  0, &retval);
 856                 if (error)
 857                         return(error);
 858                 if (retval) {
 859                         *action = 0;
 860                 } else {
 861                         *action = 2;
 862                 }
 863                 return(0);
 864         }
 865
 866         /*
 867          * Examine each sibling block to see if we can coalesce with
 868          * at least 25% free space to spare.  We need to figure out
 869          * whether to merge with the forward or the backward block.
 870          * We prefer coalescing with the lower numbered sibling so as
 871          * to shrink a directory over time.
 872          */
 873         /* start with smaller blk num */
 874         forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
 875         for (i = 0; i < 2; forward = !forward, i++) {
 876                 if (forward)
 877                         blkno = be32_to_cpu(info->forw);
 878                 else
 879                         blkno = be32_to_cpu(info->back);
 880                 if (blkno == 0)
 881                         continue;
 882                 error = xfs_da_read_buf(state->args->trans, state->args->dp,
 883                                         blkno, -1, &bp, state->args->whichfork);
 884                 if (error)
 885                         return(error);
 886                 ASSERT(bp != NULL);
 887
 888                 node = (xfs_da_intnode_t *)info;
 889                 count  = state->node_ents;
 890                 count -= state->node_ents >> 2;
 891                 count -= INT_GET(node->hdr.count, ARCH_CONVERT);
 892                 node = bp->data;
 893                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 894                 count -= INT_GET(node->hdr.count, ARCH_CONVERT);
 895                 xfs_da_brelse(state->args->trans, bp);
 896                 if (count >= 0)
 897                         break;  /* fits with at least 25% to spare */
 898         }
 899         if (i >= 2) {
 900                 *action = 0;
 901                 return(0);
 902         }
 903
 904         /*
 905          * Make altpath point to the block we want to keep (the lower
 906          * numbered block) and path point to the block we want to drop.
 907          */
 908         memcpy(&state->altpath, &state->path, sizeof(state->path));
 909         if (blkno < blk->blkno) {
 910                 error = xfs_da_path_shift(state, &state->altpath, forward,
 911                                                  0, &retval);
 912                 if (error) {
 913                         return(error);
 914                 }
 915                 if (retval) {
 916                         *action = 0;
 917                         return(0);
 918                 }
 919         } else {
 920                 error = xfs_da_path_shift(state, &state->path, forward,
 921                                                  0, &retval);
 922                 if (error) {
 923                         return(error);
 924                 }
 925                 if (retval) {
 926                         *action = 0;
 927                         return(0);
 928                 }
 929         }
 930         *action = 1;
 931         return(0);
 932 }
 933
 934 /*
 935  * Walk back up the tree adjusting hash values as necessary,
 936  * when we stop making changes, return.
 937  */
 938 void
 939 xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
 940 {
 941         xfs_da_state_blk_t *blk;
 942         xfs_da_intnode_t *node;
 943         xfs_da_node_entry_t *btree;
 944         xfs_dahash_t lasthash=0;
 945         int level, count;
 946
 947         level = path->active-1;
 948         blk = &path->blk[ level ];
 949         switch (blk->magic) {
 950         case XFS_ATTR_LEAF_MAGIC:
 951                 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
 952                 if (count == 0)
 953                         return;
 954                 break;
 955         case XFS_DIR_LEAF_MAGIC:
 956                 ASSERT(XFS_DIR_IS_V1(state->mp));
 957                 lasthash = xfs_dir_leaf_lasthash(blk->bp, &count);
 958                 if (count == 0)
 959                         return;
 960                 break;
 961         case XFS_DIR2_LEAFN_MAGIC:
 962                 ASSERT(XFS_DIR_IS_V2(state->mp));
 963                 lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
 964                 if (count == 0)
 965                         return;
 966                 break;
 967         case XFS_DA_NODE_MAGIC:
 968                 lasthash = xfs_da_node_lasthash(blk->bp, &count);
 969                 if (count == 0)
 970                         return;
 971                 break;
 972         }
 973         for (blk--, level--; level >= 0; blk--, level--) {
 974                 node = blk->bp->data;
 975                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
 976                 btree = &node->btree[ blk->index ];
 977                 if (INT_GET(btree->hashval, ARCH_CONVERT) == lasthash)
 978                         break;
 979                 blk->hashval = lasthash;
 980                 INT_SET(btree->hashval, ARCH_CONVERT, lasthash);
 981                 xfs_da_log_buf(state->args->trans, blk->bp,
 982                                   XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
 983
 984                 lasthash = INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
 985         }
 986 }
 987
 988 /*
 989  * Remove an entry from an intermediate node.
 990  */
 991 STATIC void
 992 xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
 993 {
 994         xfs_da_intnode_t *node;
 995         xfs_da_node_entry_t *btree;
 996         int tmp;
 997
 998         node = drop_blk->bp->data;
 999         ASSERT(drop_blk->index < INT_GET(node->hdr.count, ARCH_CONVERT));
1000         ASSERT(drop_blk->index >= 0);
1001
1002         /*
1003          * Copy over the offending entry, or just zero it out.
1004          */
1005         btree = &node->btree[drop_blk->index];
1006         if (drop_blk->index < (INT_GET(node->hdr.count, ARCH_CONVERT)-1)) {
1007                 tmp  = INT_GET(node->hdr.count, ARCH_CONVERT) - drop_blk->index - 1;
1008                 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1009                 memmove(btree, btree + 1, tmp);
1010                 xfs_da_log_buf(state->args->trans, drop_blk->bp,
1011                     XFS_DA_LOGRANGE(node, btree, tmp));
1012                 btree = &node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ];
1013         }
1014         memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
1015         xfs_da_log_buf(state->args->trans, drop_blk->bp,
1016             XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
1017         INT_MOD(node->hdr.count, ARCH_CONVERT, -1);
1018         xfs_da_log_buf(state->args->trans, drop_blk->bp,
1019             XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
1020
1021         /*
1022          * Copy the last hash value from the block to propagate upwards.
1023          */
1024         btree--;
1025         drop_blk->hashval = INT_GET(btree->hashval, ARCH_CONVERT);
1026 }
1027
1028 /*
1029  * Unbalance the btree elements between two intermediate nodes,
1030  * move all Btree elements from one node into another.
1031  */
1032 STATIC void
1033 xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1034                                      xfs_da_state_blk_t *save_blk)
1035 {
1036         xfs_da_intnode_t *drop_node, *save_node;
1037         xfs_da_node_entry_t *btree;
1038         int tmp;
1039         xfs_trans_t *tp;
1040
1041         drop_node = drop_blk->bp->data;
1042         save_node = save_blk->bp->data;
1043         ASSERT(be16_to_cpu(drop_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1044         ASSERT(be16_to_cpu(save_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1045         tp = state->args->trans;
1046
1047         /*
1048          * If the dying block has lower hashvals, then move all the
1049          * elements in the remaining block up to make a hole.
1050          */
1051         if ((INT_GET(drop_node->btree[ 0 ].hashval, ARCH_CONVERT) < INT_GET(save_node->btree[ 0 ].hashval, ARCH_CONVERT)) ||
1052             (INT_GET(drop_node->btree[ INT_GET(drop_node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT) <
1053              INT_GET(save_node->btree[ INT_GET(save_node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT)))
1054         {
1055                 btree = &save_node->btree[ INT_GET(drop_node->hdr.count, ARCH_CONVERT) ];
1056                 tmp = INT_GET(save_node->hdr.count, ARCH_CONVERT) * (uint)sizeof(xfs_da_node_entry_t);
1057                 memmove(btree, &save_node->btree[0], tmp);
1058                 btree = &save_node->btree[0];
1059                 xfs_da_log_buf(tp, save_blk->bp,
1060                         XFS_DA_LOGRANGE(save_node, btree,
1061                                 (INT_GET(save_node->hdr.count, ARCH_CONVERT) + INT_GET(drop_node->hdr.count, ARCH_CONVERT)) *
1062                                 sizeof(xfs_da_node_entry_t)));
1063         } else {
1064                 btree = &save_node->btree[ INT_GET(save_node->hdr.count, ARCH_CONVERT) ];
1065                 xfs_da_log_buf(tp, save_blk->bp,
1066                         XFS_DA_LOGRANGE(save_node, btree,
1067                                 INT_GET(drop_node->hdr.count, ARCH_CONVERT) *
1068                                 sizeof(xfs_da_node_entry_t)));
1069         }
1070
1071         /*
1072          * Move all the B-tree elements from drop_blk to save_blk.
1073          */
1074         tmp = INT_GET(drop_node->hdr.count, ARCH_CONVERT) * (uint)sizeof(xfs_da_node_entry_t);
1075         memcpy(btree, &drop_node->btree[0], tmp);
1076         INT_MOD(save_node->hdr.count, ARCH_CONVERT, INT_GET(drop_node->hdr.count, ARCH_CONVERT));
1077
1078         xfs_da_log_buf(tp, save_blk->bp,
1079                 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1080                         sizeof(save_node->hdr)));
1081
1082         /*
1083          * Save the last hashval in the remaining block for upward propagation.
1084          */
1085         save_blk->hashval = INT_GET(save_node->btree[ INT_GET(save_node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
1086 }
1087
1088 /*========================================================================
1089  * Routines used for finding things in the Btree.
1090  *========================================================================*/
1091
1092 /*
1093  * Walk down the Btree looking for a particular filename, filling
1094  * in the state structure as we go.
1095  *
1096  * We will set the state structure to point to each of the elements
1097  * in each of the nodes where either the hashval is or should be.
1098  *
1099  * We support duplicate hashval's so for each entry in the current
1100  * node that could contain the desired hashval, descend.  This is a
1101  * pruned depth-first tree search.
1102  */
1103 int                                                     /* error */
1104 xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
1105 {
1106         xfs_da_state_blk_t *blk;
1107         xfs_da_blkinfo_t *curr;
1108         xfs_da_intnode_t *node;
1109         xfs_da_node_entry_t *btree;
1110         xfs_dablk_t blkno;
1111         int probe, span, max, error, retval;
1112         xfs_dahash_t hashval;
1113         xfs_da_args_t *args;
1114
1115         args = state->args;
1116
1117         /*
1118          * Descend thru the B-tree searching each level for the right
1119          * node to use, until the right hashval is found.
1120          */
1121         if (args->whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(state->mp))
1122                 blkno = state->mp->m_dirleafblk;
1123         else
1124                 blkno = 0;
1125         for (blk = &state->path.blk[0], state->path.active = 1;
1126                          state->path.active <= XFS_DA_NODE_MAXDEPTH;
1127                          blk++, state->path.active++) {
1128                 /*
1129                  * Read the next node down in the tree.
1130                  */
1131                 blk->blkno = blkno;
1132                 error = xfs_da_read_buf(args->trans, args->dp, blkno,
1133                                         -1, &blk->bp, args->whichfork);
1134                 if (error) {
1135                         blk->blkno = 0;
1136                         state->path.active--;
1137                         return(error);
1138                 }
1139                 curr = blk->bp->data;
1140                 ASSERT(be16_to_cpu(curr->magic) == XFS_DA_NODE_MAGIC ||
1141                        be16_to_cpu(curr->magic) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
1142                        be16_to_cpu(curr->magic) == XFS_ATTR_LEAF_MAGIC);
1143
1144                 /*
1145                  * Search an intermediate node for a match.
1146                  */
1147                 blk->magic = be16_to_cpu(curr->magic);
1148                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1149                         node = blk->bp->data;
1150                         blk->hashval = INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
1151
1152                         /*
1153                          * Binary search.  (note: small blocks will skip loop)
1154                          */
1155                         max = INT_GET(node->hdr.count, ARCH_CONVERT);
1156                         probe = span = max / 2;
1157                         hashval = args->hashval;
1158                         for (btree = &node->btree[probe]; span > 4;
1159                                    btree = &node->btree[probe]) {
1160                                 span /= 2;
1161                                 if (INT_GET(btree->hashval, ARCH_CONVERT) < hashval)
1162                                         probe += span;
1163                                 else if (INT_GET(btree->hashval, ARCH_CONVERT) > hashval)
1164                                         probe -= span;
1165                                 else
1166                                         break;
1167                         }
1168                         ASSERT((probe >= 0) && (probe < max));
1169                         ASSERT((span <= 4) || (INT_GET(btree->hashval, ARCH_CONVERT) == hashval));
1170
1171                         /*
1172                          * Since we may have duplicate hashval's, find the first
1173                          * matching hashval in the node.
1174                          */
1175                         while ((probe > 0) && (INT_GET(btree->hashval, ARCH_CONVERT) >= hashval)) {
1176                                 btree--;
1177                                 probe--;
1178                         }
1179                         while ((probe < max) && (INT_GET(btree->hashval, ARCH_CONVERT) < hashval)) {
1180                                 btree++;
1181                                 probe++;
1182                         }
1183
1184                         /*
1185                          * Pick the right block to descend on.
1186                          */
1187                         if (probe == max) {
1188                                 blk->index = max-1;
1189                                 blkno = INT_GET(node->btree[ max-1 ].before, ARCH_CONVERT);
1190                         } else {
1191                                 blk->index = probe;
1192                                 blkno = INT_GET(btree->before, ARCH_CONVERT);
1193                         }
1194                 }
1195                 else if (be16_to_cpu(curr->magic) == XFS_ATTR_LEAF_MAGIC) {
1196                         blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1197                         break;
1198                 }
1199                 else if (be16_to_cpu(curr->magic) == XFS_DIR_LEAF_MAGIC) {
1200                         blk->hashval = xfs_dir_leaf_lasthash(blk->bp, NULL);
1201                         break;
1202                 }
1203                 else if (be16_to_cpu(curr->magic) == XFS_DIR2_LEAFN_MAGIC) {
1204                         blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
1205                         break;
1206                 }
1207         }
1208
1209         /*
1210          * A leaf block that ends in the hashval that we are interested in
1211          * (final hashval == search hashval) means that the next block may
1212          * contain more entries with the same hashval, shift upward to the
1213          * next leaf and keep searching.
1214          */
1215         for (;;) {
1216                 if (blk->magic == XFS_DIR_LEAF_MAGIC) {
1217                         ASSERT(XFS_DIR_IS_V1(state->mp));
1218                         retval = xfs_dir_leaf_lookup_int(blk->bp, args,
1219                                                                   &blk->index);
1220                 } else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1221                         ASSERT(XFS_DIR_IS_V2(state->mp));
1222                         retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1223                                                         &blk->index, state);
1224                 }
1225                 else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1226                         retval = xfs_attr_leaf_lookup_int(blk->bp, args);
1227                         blk->index = args->index;
1228                         args->blkno = blk->blkno;
1229                 }
1230                 if (((retval == ENOENT) || (retval == ENOATTR)) &&
1231                     (blk->hashval == args->hashval)) {
1232                         error = xfs_da_path_shift(state, &state->path, 1, 1,
1233                                                          &retval);
1234                         if (error)
1235                                 return(error);
1236                         if (retval == 0) {
1237                                 continue;
1238                         }
1239                         else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1240                                 /* path_shift() gives ENOENT */
1241                                 retval = XFS_ERROR(ENOATTR);
1242                         }
1243                 }
1244                 break;
1245         }
1246         *result = retval;
1247         return(0);
1248 }
1249
1250 /*========================================================================
1251  * Utility routines.
1252  *========================================================================*/
1253
1254 /*
1255  * Link a new block into a doubly linked list of blocks (of whatever type).
1256  */
1257 int                                                     /* error */
1258 xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
1259                                xfs_da_state_blk_t *new_blk)
1260 {
1261         xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
1262         xfs_da_args_t *args;
1263         int before=0, error;
1264         xfs_dabuf_t *bp;
1265
1266         /*
1267          * Set up environment.
1268          */
1269         args = state->args;
1270         ASSERT(args != NULL);
1271         old_info = old_blk->bp->data;
1272         new_info = new_blk->bp->data;
1273         ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1274                old_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp) ||
1275                old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1276         ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
1277         ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
1278         ASSERT(old_blk->magic == new_blk->magic);
1279
1280         switch (old_blk->magic) {
1281         case XFS_ATTR_LEAF_MAGIC:
1282                 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1283                 break;
1284         case XFS_DIR_LEAF_MAGIC:
1285                 ASSERT(XFS_DIR_IS_V1(state->mp));
1286                 before = xfs_dir_leaf_order(old_blk->bp, new_blk->bp);
1287                 break;
1288         case XFS_DIR2_LEAFN_MAGIC:
1289                 ASSERT(XFS_DIR_IS_V2(state->mp));
1290                 before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
1291                 break;
1292         case XFS_DA_NODE_MAGIC:
1293                 before = xfs_da_node_order(old_blk->bp, new_blk->bp);
1294                 break;
1295         }
1296
1297         /*
1298          * Link blocks in appropriate order.
1299          */
1300         if (before) {
1301                 /*
1302                  * Link new block in before existing block.
1303                  */
1304                 new_info->forw = cpu_to_be32(old_blk->blkno);
1305                 new_info->back = old_info->back;
1306                 if (old_info->back) {
1307                         error = xfs_da_read_buf(args->trans, args->dp,
1308                                                 be32_to_cpu(old_info->back),
1309                                                 -1, &bp, args->whichfork);
1310                         if (error)
1311                                 return(error);
1312                         ASSERT(bp != NULL);
1313                         tmp_info = bp->data;
1314                         ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
1315                         ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1316                         tmp_info->forw = cpu_to_be32(new_blk->blkno);
1317                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1318                         xfs_da_buf_done(bp);
1319                 }
1320                 old_info->back = cpu_to_be32(new_blk->blkno);
1321         } else {
1322                 /*
1323                  * Link new block in after existing block.
1324                  */
1325                 new_info->forw = old_info->forw;
1326                 new_info->back = cpu_to_be32(old_blk->blkno);
1327                 if (old_info->forw) {
1328                         error = xfs_da_read_buf(args->trans, args->dp,
1329                                                 be32_to_cpu(old_info->forw),
1330                                                 -1, &bp, args->whichfork);
1331                         if (error)
1332                                 return(error);
1333                         ASSERT(bp != NULL);
1334                         tmp_info = bp->data;
1335                         ASSERT(tmp_info->magic == old_info->magic);
1336                         ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1337                         tmp_info->back = cpu_to_be32(new_blk->blkno);
1338                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1339                         xfs_da_buf_done(bp);
1340                 }
1341                 old_info->forw = cpu_to_be32(new_blk->blkno);
1342         }
1343
1344         xfs_da_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1345         xfs_da_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1346         return(0);
1347 }
1348
1349 /*
1350  * Compare two intermediate nodes for "order".
1351  */
1352 STATIC int
1353 xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp)
1354 {
1355         xfs_da_intnode_t *node1, *node2;
1356
1357         node1 = node1_bp->data;
1358         node2 = node2_bp->data;
1359         ASSERT((be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC) &&
1360                (be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC));
1361         if ((INT_GET(node1->hdr.count, ARCH_CONVERT) > 0) && (INT_GET(node2->hdr.count, ARCH_CONVERT) > 0) &&
1362             ((INT_GET(node2->btree[ 0 ].hashval, ARCH_CONVERT) <
1363               INT_GET(node1->btree[ 0 ].hashval, ARCH_CONVERT)) ||
1364              (INT_GET(node2->btree[ INT_GET(node2->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT) <
1365               INT_GET(node1->btree[ INT_GET(node1->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT)))) {
1366                 return(1);
1367         }
1368         return(0);
1369 }
1370
1371 /*
1372  * Pick up the last hashvalue from an intermediate node.
1373  */
1374 STATIC uint
1375 xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count)
1376 {
1377         xfs_da_intnode_t *node;
1378
1379         node = bp->data;
1380         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1381         if (count)
1382                 *count = INT_GET(node->hdr.count, ARCH_CONVERT);
1383         if (!node->hdr.count)
1384                 return(0);
1385         return(INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT));
1386 }
1387
1388 /*
1389  * Unlink a block from a doubly linked list of blocks.
1390  */
1391 STATIC int                                              /* error */
1392 xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1393                                  xfs_da_state_blk_t *save_blk)
1394 {
1395         xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
1396         xfs_da_args_t *args;
1397         xfs_dabuf_t *bp;
1398         int error;
1399
1400         /*
1401          * Set up environment.
1402          */
1403         args = state->args;
1404         ASSERT(args != NULL);
1405         save_info = save_blk->bp->data;
1406         drop_info = drop_blk->bp->data;
1407         ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1408                save_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp) ||
1409                save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1410         ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
1411         ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
1412         ASSERT(save_blk->magic == drop_blk->magic);
1413         ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1414                (be32_to_cpu(save_info->back) == drop_blk->blkno));
1415         ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1416                (be32_to_cpu(drop_info->back) == save_blk->blkno));
1417
1418         /*
1419          * Unlink the leaf block from the doubly linked chain of leaves.
1420          */
1421         if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1422                 save_info->back = drop_info->back;
1423                 if (drop_info->back) {
1424                         error = xfs_da_read_buf(args->trans, args->dp,
1425                                                 be32_to_cpu(drop_info->back),
1426                                                 -1, &bp, args->whichfork);
1427                         if (error)
1428                                 return(error);
1429                         ASSERT(bp != NULL);
1430                         tmp_info = bp->data;
1431                         ASSERT(tmp_info->magic == save_info->magic);
1432                         ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1433                         tmp_info->forw = cpu_to_be32(save_blk->blkno);
1434                         xfs_da_log_buf(args->trans, bp, 0,
1435                                                     sizeof(*tmp_info) - 1);
1436                         xfs_da_buf_done(bp);
1437                 }
1438         } else {
1439                 save_info->forw = drop_info->forw;
1440                 if (drop_info->forw) {
1441                         error = xfs_da_read_buf(args->trans, args->dp,
1442                                                 be32_to_cpu(drop_info->forw),
1443                                                 -1, &bp, args->whichfork);
1444                         if (error)
1445                                 return(error);
1446                         ASSERT(bp != NULL);
1447                         tmp_info = bp->data;
1448                         ASSERT(tmp_info->magic == save_info->magic);
1449                         ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1450                         tmp_info->back = cpu_to_be32(save_blk->blkno);
1451                         xfs_da_log_buf(args->trans, bp, 0,
1452                                                     sizeof(*tmp_info) - 1);
1453                         xfs_da_buf_done(bp);
1454                 }
1455         }
1456
1457         xfs_da_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1458         return(0);
1459 }
1460
1461 /*
1462  * Move a path "forward" or "!forward" one block at the current level.
1463  *
1464  * This routine will adjust a "path" to point to the next block
1465  * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1466  * Btree, including updating pointers to the intermediate nodes between
1467  * the new bottom and the root.
1468  */
1469 int                                                     /* error */
1470 xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
1471                                  int forward, int release, int *result)
1472 {
1473         xfs_da_state_blk_t *blk;
1474         xfs_da_blkinfo_t *info;
1475         xfs_da_intnode_t *node;
1476         xfs_da_args_t *args;
1477         xfs_dablk_t blkno=0;
1478         int level, error;
1479
1480         /*
1481          * Roll up the Btree looking for the first block where our
1482          * current index is not at the edge of the block.  Note that
1483          * we skip the bottom layer because we want the sibling block.
1484          */
1485         args = state->args;
1486         ASSERT(args != NULL);
1487         ASSERT(path != NULL);
1488         ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1489         level = (path->active-1) - 1;   /* skip bottom layer in path */
1490         for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1491                 ASSERT(blk->bp != NULL);
1492                 node = blk->bp->data;
1493                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1494                 if (forward && (blk->index < INT_GET(node->hdr.count, ARCH_CONVERT)-1)) {
1495                         blk->index++;
1496                         blkno = INT_GET(node->btree[ blk->index ].before, ARCH_CONVERT);
1497                         break;
1498                 } else if (!forward && (blk->index > 0)) {
1499                         blk->index--;
1500                         blkno = INT_GET(node->btree[ blk->index ].before, ARCH_CONVERT);
1501                         break;
1502                 }
1503         }
1504         if (level < 0) {
1505                 *result = XFS_ERROR(ENOENT);    /* we're out of our tree */
1506                 ASSERT(args->oknoent);
1507                 return(0);
1508         }
1509
1510         /*
1511          * Roll down the edge of the subtree until we reach the
1512          * same depth we were at originally.
1513          */
1514         for (blk++, level++; level < path->active; blk++, level++) {
1515                 /*
1516                  * Release the old block.
1517                  * (if it's dirty, trans won't actually let go)
1518                  */
1519                 if (release)
1520                         xfs_da_brelse(args->trans, blk->bp);
1521
1522                 /*
1523                  * Read the next child block.
1524                  */
1525                 blk->blkno = blkno;
1526                 error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
1527                                                      &blk->bp, args->whichfork);
1528                 if (error)
1529                         return(error);
1530                 ASSERT(blk->bp != NULL);
1531                 info = blk->bp->data;
1532                 ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC ||
1533                        be16_to_cpu(info->magic) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
1534                        be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC);
1535                 blk->magic = be16_to_cpu(info->magic);
1536                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1537                         node = (xfs_da_intnode_t *)info;
1538                         blk->hashval = INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
1539                         if (forward)
1540                                 blk->index = 0;
1541                         else
1542                                 blk->index = INT_GET(node->hdr.count, ARCH_CONVERT)-1;
1543                         blkno = INT_GET(node->btree[ blk->index ].before, ARCH_CONVERT);
1544                 } else {
1545                         ASSERT(level == path->active-1);
1546                         blk->index = 0;
1547                         switch(blk->magic) {
1548                         case XFS_ATTR_LEAF_MAGIC:
1549                                 blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
1550                                                                       NULL);
1551                                 break;
1552                         case XFS_DIR_LEAF_MAGIC:
1553                                 ASSERT(XFS_DIR_IS_V1(state->mp));
1554                                 blk->hashval = xfs_dir_leaf_lasthash(blk->bp,
1555                                                                      NULL);
1556                                 break;
1557                         case XFS_DIR2_LEAFN_MAGIC:
1558                                 ASSERT(XFS_DIR_IS_V2(state->mp));
1559                                 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
1560                                                                        NULL);
1561                                 break;
1562                         default:
1563                                 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
1564                                        blk->magic ==
1565                                        XFS_DIRX_LEAF_MAGIC(state->mp));
1566                                 break;
1567                         }
1568                 }
1569         }
1570         *result = 0;
1571         return(0);
1572 }
1573
1574
1575 /*========================================================================
1576  * Utility routines.
1577  *========================================================================*/
1578
1579 /*
1580  * Implement a simple hash on a character string.
1581  * Rotate the hash value by 7 bits, then XOR each character in.
1582  * This is implemented with some source-level loop unrolling.
1583  */
1584 xfs_dahash_t
1585 xfs_da_hashname(const uchar_t *name, int namelen)
1586 {
1587         xfs_dahash_t hash;
1588
1589         /*
1590          * Do four characters at a time as long as we can.
1591          */
1592         for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1593                 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1594                        (name[3] << 0) ^ rol32(hash, 7 * 4);
1595
1596         /*
1597          * Now do the rest of the characters.
1598          */
1599         switch (namelen) {
1600         case 3:
1601                 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1602                        rol32(hash, 7 * 3);
1603         case 2:
1604                 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1605         case 1:
1606                 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1607         default: /* case 0: */
1608                 return hash;
1609         }
1610 }
1611
1612 /*
1613  * Add a block to the btree ahead of the file.
1614  * Return the new block number to the caller.
1615  */
1616 int
1617 xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
1618 {
1619         xfs_fileoff_t bno, b;
1620         xfs_bmbt_irec_t map;
1621         xfs_bmbt_irec_t *mapp;
1622         xfs_inode_t *dp;
1623         int nmap, error, w, count, c, got, i, mapi;
1624         xfs_fsize_t size;
1625         xfs_trans_t *tp;
1626         xfs_mount_t *mp;
1627
1628         dp = args->dp;
1629         mp = dp->i_mount;
1630         w = args->whichfork;
1631         tp = args->trans;
1632         /*
1633          * For new directories adjust the file offset and block count.
1634          */
1635         if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp)) {
1636                 bno = mp->m_dirleafblk;
1637                 count = mp->m_dirblkfsbs;
1638         } else {
1639                 bno = 0;
1640                 count = 1;
1641         }
1642         /*
1643          * Find a spot in the file space to put the new block.
1644          */
1645         if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, w))) {
1646                 return error;
1647         }
1648         if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
1649                 ASSERT(bno >= mp->m_dirleafblk && bno < mp->m_dirfreeblk);
1650         /*
1651          * Try mapping it in one filesystem block.
1652          */
1653         nmap = 1;
1654         ASSERT(args->firstblock != NULL);
1655         if ((error = xfs_bmapi(tp, dp, bno, count,
1656                         XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|
1657                         XFS_BMAPI_CONTIG,
1658                         args->firstblock, args->total, &map, &nmap,
1659                         args->flist))) {
1660                 return error;
1661         }
1662         ASSERT(nmap <= 1);
1663         if (nmap == 1) {
1664                 mapp = &map;
1665                 mapi = 1;
1666         }
1667         /*
1668          * If we didn't get it and the block might work if fragmented,
1669          * try without the CONTIG flag.  Loop until we get it all.
1670          */
1671         else if (nmap == 0 && count > 1) {
1672                 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1673                 for (b = bno, mapi = 0; b < bno + count; ) {
1674                         nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1675                         c = (int)(bno + count - b);
1676                         if ((error = xfs_bmapi(tp, dp, b, c,
1677                                         XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|
1678                                         XFS_BMAPI_METADATA,
1679                                         args->firstblock, args->total,
1680                                         &mapp[mapi], &nmap, args->flist))) {
1681                                 kmem_free(mapp, sizeof(*mapp) * count);
1682                                 return error;
1683                         }
1684                         if (nmap < 1)
1685                                 break;
1686                         mapi += nmap;
1687                         b = mapp[mapi - 1].br_startoff +
1688                             mapp[mapi - 1].br_blockcount;
1689                 }
1690         } else {
1691                 mapi = 0;
1692                 mapp = NULL;
1693         }
1694         /*
1695          * Count the blocks we got, make sure it matches the total.
1696          */
1697         for (i = 0, got = 0; i < mapi; i++)
1698                 got += mapp[i].br_blockcount;
1699         if (got != count || mapp[0].br_startoff != bno ||
1700             mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1701             bno + count) {
1702                 if (mapp != &map)
1703                         kmem_free(mapp, sizeof(*mapp) * count);
1704                 return XFS_ERROR(ENOSPC);
1705         }
1706         if (mapp != &map)
1707                 kmem_free(mapp, sizeof(*mapp) * count);
1708         *new_blkno = (xfs_dablk_t)bno;
1709         /*
1710          * For version 1 directories, adjust the file size if it changed.
1711          */
1712         if (w == XFS_DATA_FORK && XFS_DIR_IS_V1(mp)) {
1713                 ASSERT(mapi == 1);
1714                 if ((error = xfs_bmap_last_offset(tp, dp, &bno, w)))
1715                         return error;
1716                 size = XFS_FSB_TO_B(mp, bno);
1717                 if (size != dp->i_d.di_size) {
1718                         dp->i_d.di_size = size;
1719                         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1720                 }
1721         }
1722         return 0;
1723 }
1724
1725 /*
1726  * Ick.  We need to always be able to remove a btree block, even
1727  * if there's no space reservation because the filesystem is full.
1728  * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1729  * It swaps the target block with the last block in the file.  The
1730  * last block in the file can always be removed since it can't cause
1731  * a bmap btree split to do that.
1732  */
1733 STATIC int
1734 xfs_da_swap_lastblock(xfs_da_args_t *args, xfs_dablk_t *dead_blknop,
1735                       xfs_dabuf_t **dead_bufp)
1736 {
1737         xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1738         xfs_dabuf_t *dead_buf, *last_buf, *sib_buf, *par_buf;
1739         xfs_fileoff_t lastoff;
1740         xfs_inode_t *ip;
1741         xfs_trans_t *tp;
1742         xfs_mount_t *mp;
1743         int error, w, entno, level, dead_level;
1744         xfs_da_blkinfo_t *dead_info, *sib_info;
1745         xfs_da_intnode_t *par_node, *dead_node;
1746         xfs_dir_leafblock_t *dead_leaf;
1747         xfs_dir2_leaf_t *dead_leaf2;
1748         xfs_dahash_t dead_hash;
1749
1750         dead_buf = *dead_bufp;
1751         dead_blkno = *dead_blknop;
1752         tp = args->trans;
1753         ip = args->dp;
1754         w = args->whichfork;
1755         ASSERT(w == XFS_DATA_FORK);
1756         mp = ip->i_mount;
1757         if (XFS_DIR_IS_V2(mp)) {
1758                 lastoff = mp->m_dirfreeblk;
1759                 error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1760         } else
1761                 error = xfs_bmap_last_offset(tp, ip, &lastoff, w);
1762         if (error)
1763                 return error;
1764         if (unlikely(lastoff == 0)) {
1765                 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1766                                  mp);
1767                 return XFS_ERROR(EFSCORRUPTED);
1768         }
1769         /*
1770          * Read the last block in the btree space.
1771          */
1772         last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1773         if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
1774                 return error;
1775         /*
1776          * Copy the last block into the dead buffer and log it.
1777          */
1778         memcpy(dead_buf->data, last_buf->data, mp->m_dirblksize);
1779         xfs_da_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1780         dead_info = dead_buf->data;
1781         /*
1782          * Get values from the moved block.
1783          */
1784         if (be16_to_cpu(dead_info->magic) == XFS_DIR_LEAF_MAGIC) {
1785                 ASSERT(XFS_DIR_IS_V1(mp));
1786                 dead_leaf = (xfs_dir_leafblock_t *)dead_info;
1787                 dead_level = 0;
1788                 dead_hash =
1789                         INT_GET(dead_leaf->entries[INT_GET(dead_leaf->hdr.count, ARCH_CONVERT) - 1].hashval, ARCH_CONVERT);
1790         } else if (be16_to_cpu(dead_info->magic) == XFS_DIR2_LEAFN_MAGIC) {
1791                 ASSERT(XFS_DIR_IS_V2(mp));
1792                 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1793                 dead_level = 0;
1794                 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1795         } else {
1796                 ASSERT(be16_to_cpu(dead_info->magic) == XFS_DA_NODE_MAGIC);
1797                 dead_node = (xfs_da_intnode_t *)dead_info;
1798                 dead_level = INT_GET(dead_node->hdr.level, ARCH_CONVERT);
1799                 dead_hash = INT_GET(dead_node->btree[INT_GET(dead_node->hdr.count, ARCH_CONVERT) - 1].hashval, ARCH_CONVERT);
1800         }
1801         sib_buf = par_buf = NULL;
1802         /*
1803          * If the moved block has a left sibling, fix up the pointers.
1804          */
1805         if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1806                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1807                         goto done;
1808                 sib_info = sib_buf->data;
1809                 if (unlikely(
1810                     be32_to_cpu(sib_info->forw) != last_blkno ||
1811                     sib_info->magic != dead_info->magic)) {
1812                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1813                                          XFS_ERRLEVEL_LOW, mp);
1814                         error = XFS_ERROR(EFSCORRUPTED);
1815                         goto done;
1816                 }
1817                 sib_info->forw = cpu_to_be32(dead_blkno);
1818                 xfs_da_log_buf(tp, sib_buf,
1819                         XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1820                                         sizeof(sib_info->forw)));
1821                 xfs_da_buf_done(sib_buf);
1822                 sib_buf = NULL;
1823         }
1824         /*
1825          * If the moved block has a right sibling, fix up the pointers.
1826          */
1827         if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1828                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1829                         goto done;
1830                 sib_info = sib_buf->data;
1831                 if (unlikely(
1832                        be32_to_cpu(sib_info->back) != last_blkno ||
1833                        sib_info->magic != dead_info->magic)) {
1834                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1835                                          XFS_ERRLEVEL_LOW, mp);
1836                         error = XFS_ERROR(EFSCORRUPTED);
1837                         goto done;
1838                 }
1839                 sib_info->back = cpu_to_be32(dead_blkno);
1840                 xfs_da_log_buf(tp, sib_buf,
1841                         XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1842                                         sizeof(sib_info->back)));
1843                 xfs_da_buf_done(sib_buf);
1844                 sib_buf = NULL;
1845         }
1846         par_blkno = XFS_DIR_IS_V1(mp) ? 0 : mp->m_dirleafblk;
1847         level = -1;
1848         /*
1849          * Walk down the tree looking for the parent of the moved block.
1850          */
1851         for (;;) {
1852                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1853                         goto done;
1854                 par_node = par_buf->data;
1855                 if (unlikely(
1856                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC ||
1857                     (level >= 0 && level != INT_GET(par_node->hdr.level, ARCH_CONVERT) + 1))) {
1858                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1859                                          XFS_ERRLEVEL_LOW, mp);
1860                         error = XFS_ERROR(EFSCORRUPTED);
1861                         goto done;
1862                 }
1863                 level = INT_GET(par_node->hdr.level, ARCH_CONVERT);
1864                 for (entno = 0;
1865                      entno < INT_GET(par_node->hdr.count, ARCH_CONVERT) &&
1866                      INT_GET(par_node->btree[entno].hashval, ARCH_CONVERT) < dead_hash;
1867                      entno++)
1868                         continue;
1869                 if (unlikely(entno == INT_GET(par_node->hdr.count, ARCH_CONVERT))) {
1870                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1871                                          XFS_ERRLEVEL_LOW, mp);
1872                         error = XFS_ERROR(EFSCORRUPTED);
1873                         goto done;
1874                 }
1875                 par_blkno = INT_GET(par_node->btree[entno].before, ARCH_CONVERT);
1876                 if (level == dead_level + 1)
1877                         break;
1878                 xfs_da_brelse(tp, par_buf);
1879                 par_buf = NULL;
1880         }
1881         /*
1882          * We're in the right parent block.
1883          * Look for the right entry.
1884          */
1885         for (;;) {
1886                 for (;
1887                      entno < INT_GET(par_node->hdr.count, ARCH_CONVERT) &&
1888                      INT_GET(par_node->btree[entno].before, ARCH_CONVERT) != last_blkno;
1889                      entno++)
1890                         continue;
1891                 if (entno < INT_GET(par_node->hdr.count, ARCH_CONVERT))
1892                         break;
1893                 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1894                 xfs_da_brelse(tp, par_buf);
1895                 par_buf = NULL;
1896                 if (unlikely(par_blkno == 0)) {
1897                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1898                                          XFS_ERRLEVEL_LOW, mp);
1899                         error = XFS_ERROR(EFSCORRUPTED);
1900                         goto done;
1901                 }
1902                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1903                         goto done;
1904                 par_node = par_buf->data;
1905                 if (unlikely(
1906                     INT_GET(par_node->hdr.level, ARCH_CONVERT) != level ||
1907                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC)) {
1908                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1909                                          XFS_ERRLEVEL_LOW, mp);
1910                         error = XFS_ERROR(EFSCORRUPTED);
1911                         goto done;
1912                 }
1913                 entno = 0;
1914         }
1915         /*
1916          * Update the parent entry pointing to the moved block.
1917          */
1918         INT_SET(par_node->btree[entno].before, ARCH_CONVERT, dead_blkno);
1919         xfs_da_log_buf(tp, par_buf,
1920                 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1921                                 sizeof(par_node->btree[entno].before)));
1922         xfs_da_buf_done(par_buf);
1923         xfs_da_buf_done(dead_buf);
1924         *dead_blknop = last_blkno;
1925         *dead_bufp = last_buf;
1926         return 0;
1927 done:
1928         if (par_buf)
1929                 xfs_da_brelse(tp, par_buf);
1930         if (sib_buf)
1931                 xfs_da_brelse(tp, sib_buf);
1932         xfs_da_brelse(tp, last_buf);
1933         return error;
1934 }
1935
1936 /*
1937  * Remove a btree block from a directory or attribute.
1938  */
1939 int
1940 xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
1941                     xfs_dabuf_t *dead_buf)
1942 {
1943         xfs_inode_t *dp;
1944         int done, error, w, count;
1945         xfs_fileoff_t bno;
1946         xfs_fsize_t size;
1947         xfs_trans_t *tp;
1948         xfs_mount_t *mp;
1949
1950         dp = args->dp;
1951         w = args->whichfork;
1952         tp = args->trans;
1953         mp = dp->i_mount;
1954         if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
1955                 count = mp->m_dirblkfsbs;
1956         else
1957                 count = 1;
1958         for (;;) {
1959                 /*
1960                  * Remove extents.  If we get ENOSPC for a dir we have to move
1961                  * the last block to the place we want to kill.
1962                  */
1963                 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
1964                                 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_METADATA,
1965                                 0, args->firstblock, args->flist,
1966                                 &done)) == ENOSPC) {
1967                         if (w != XFS_DATA_FORK)
1968                                 goto done;
1969                         if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
1970                                         &dead_buf)))
1971                                 goto done;
1972                 } else if (error)
1973                         goto done;
1974                 else
1975                         break;
1976         }
1977         ASSERT(done);
1978         xfs_da_binval(tp, dead_buf);
1979         /*
1980          * Adjust the directory size for version 1.
1981          */
1982         if (w == XFS_DATA_FORK && XFS_DIR_IS_V1(mp)) {
1983                 if ((error = xfs_bmap_last_offset(tp, dp, &bno, w)))
1984                         return error;
1985                 size = XFS_FSB_TO_B(dp->i_mount, bno);
1986                 if (size != dp->i_d.di_size) {
1987                         dp->i_d.di_size = size;
1988                         xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1989                 }
1990         }
1991         return 0;
1992 done:
1993         xfs_da_binval(tp, dead_buf);
1994         return error;
1995 }
1996
1997 /*
1998  * See if the mapping(s) for this btree block are valid, i.e.
1999  * don't contain holes, are logically contiguous, and cover the whole range.
2000  */
2001 STATIC int
2002 xfs_da_map_covers_blocks(
2003         int             nmap,
2004         xfs_bmbt_irec_t *mapp,
2005         xfs_dablk_t     bno,
2006         int             count)
2007 {
2008         int             i;
2009         xfs_fileoff_t   off;
2010
2011         for (i = 0, off = bno; i < nmap; i++) {
2012                 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
2013                     mapp[i].br_startblock == DELAYSTARTBLOCK) {
2014                         return 0;
2015                 }
2016                 if (off != mapp[i].br_startoff) {
2017                         return 0;
2018                 }
2019                 off += mapp[i].br_blockcount;
2020         }
2021         return off == bno + count;
2022 }
2023
2024 /*
2025  * Make a dabuf.
2026  * Used for get_buf, read_buf, read_bufr, and reada_buf.
2027  */
2028 STATIC int
2029 xfs_da_do_buf(
2030         xfs_trans_t     *trans,
2031         xfs_inode_t     *dp,
2032         xfs_dablk_t     bno,
2033         xfs_daddr_t     *mappedbnop,
2034         xfs_dabuf_t     **bpp,
2035         int             whichfork,
2036         int             caller,
2037         inst_t          *ra)
2038 {
2039         xfs_buf_t       *bp = NULL;
2040         xfs_buf_t       **bplist;
2041         int             error=0;
2042         int             i;
2043         xfs_bmbt_irec_t map;
2044         xfs_bmbt_irec_t *mapp;
2045         xfs_daddr_t     mappedbno;
2046         xfs_mount_t     *mp;
2047         int             nbplist=0;
2048         int             nfsb;
2049         int             nmap;
2050         xfs_dabuf_t     *rbp;
2051
2052         mp = dp->i_mount;
2053         if (whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
2054                 nfsb = mp->m_dirblkfsbs;
2055         else
2056                 nfsb = 1;
2057         mappedbno = *mappedbnop;
2058         /*
2059          * Caller doesn't have a mapping.  -2 means don't complain
2060          * if we land in a hole.
2061          */
2062         if (mappedbno == -1 || mappedbno == -2) {
2063                 /*
2064                  * Optimize the one-block case.
2065                  */
2066                 if (nfsb == 1) {
2067                         xfs_fsblock_t   fsb;
2068
2069                         if ((error =
2070                             xfs_bmapi_single(trans, dp, whichfork, &fsb,
2071                                     (xfs_fileoff_t)bno))) {
2072                                 return error;
2073                         }
2074                         mapp = &map;
2075                         if (fsb == NULLFSBLOCK) {
2076                                 nmap = 0;
2077                         } else {
2078                                 map.br_startblock = fsb;
2079                                 map.br_startoff = (xfs_fileoff_t)bno;
2080                                 map.br_blockcount = 1;
2081                                 nmap = 1;
2082                         }
2083                 } else {
2084                         mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
2085                         nmap = nfsb;
2086                         if ((error = xfs_bmapi(trans, dp, (xfs_fileoff_t)bno,
2087                                         nfsb,
2088                                         XFS_BMAPI_METADATA |
2089                                                 XFS_BMAPI_AFLAG(whichfork),
2090                                         NULL, 0, mapp, &nmap, NULL)))
2091                                 goto exit0;
2092                 }
2093         } else {
2094                 map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2095                 map.br_startoff = (xfs_fileoff_t)bno;
2096                 map.br_blockcount = nfsb;
2097                 mapp = &map;
2098                 nmap = 1;
2099         }
2100         if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
2101                 error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
2102                 if (unlikely(error == EFSCORRUPTED)) {
2103                         if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2104                                 int     i;
2105                                 cmn_err(CE_ALERT, "xfs_da_do_buf: bno %lld\n",
2106                                         (long long)bno);
2107                                 cmn_err(CE_ALERT, "dir: inode %lld\n",
2108                                         (long long)dp->i_ino);
2109                                 for (i = 0; i < nmap; i++) {
2110                                         cmn_err(CE_ALERT,
2111                                                 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d\n",
2112                                                 i,
2113                                                 (long long)mapp[i].br_startoff,
2114                                                 (long long)mapp[i].br_startblock,
2115                                                 (long long)mapp[i].br_blockcount,
2116                                                 mapp[i].br_state);
2117                                 }
2118                         }
2119                         XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2120                                          XFS_ERRLEVEL_LOW, mp);
2121                 }
2122                 goto exit0;
2123         }
2124         if (caller != 3 && nmap > 1) {
2125                 bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
2126                 nbplist = 0;
2127         } else
2128                 bplist = NULL;
2129         /*
2130          * Turn the mapping(s) into buffer(s).
2131          */
2132         for (i = 0; i < nmap; i++) {
2133                 int     nmapped;
2134
2135                 mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
2136                 if (i == 0)
2137                         *mappedbnop = mappedbno;
2138                 nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
2139                 switch (caller) {
2140                 case 0:
2141                         bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
2142                                 mappedbno, nmapped, 0);
2143                         error = bp ? XFS_BUF_GETERROR(bp) : XFS_ERROR(EIO);
2144                         break;
2145                 case 1:
2146                 case 2:
2147                         bp = NULL;
2148                         error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
2149                                 mappedbno, nmapped, 0, &bp);
2150                         break;
2151                 case 3:
2152                         xfs_baread(mp->m_ddev_targp, mappedbno, nmapped);
2153                         error = 0;
2154                         bp = NULL;
2155                         break;
2156                 }
2157                 if (error) {
2158                         if (bp)
2159                                 xfs_trans_brelse(trans, bp);
2160                         goto exit1;
2161                 }
2162                 if (!bp)
2163                         continue;
2164                 if (caller == 1) {
2165                         if (whichfork == XFS_ATTR_FORK) {
2166                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_ATTR_BTREE,
2167                                                 XFS_ATTR_BTREE_REF);
2168                         } else {
2169                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_DIR_BTREE,
2170                                                 XFS_DIR_BTREE_REF);
2171                         }
2172                 }
2173                 if (bplist) {
2174                         bplist[nbplist++] = bp;
2175                 }
2176         }
2177         /*
2178          * Build a dabuf structure.
2179          */
2180         if (bplist) {
2181                 rbp = xfs_da_buf_make(nbplist, bplist, ra);
2182         } else if (bp)
2183                 rbp = xfs_da_buf_make(1, &bp, ra);
2184         else
2185                 rbp = NULL;
2186         /*
2187          * For read_buf, check the magic number.
2188          */
2189         if (caller == 1) {
2190                 xfs_dir2_data_t         *data;
2191                 xfs_dir2_free_t         *free;
2192                 xfs_da_blkinfo_t        *info;
2193                 uint                    magic, magic1;
2194
2195                 info = rbp->data;
2196                 data = rbp->data;
2197                 free = rbp->data;
2198                 magic = be16_to_cpu(info->magic);
2199                 magic1 = be32_to_cpu(data->hdr.magic);
2200                 if (unlikely(
2201                     XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2202                                    (magic != XFS_DIR_LEAF_MAGIC) &&
2203                                    (magic != XFS_ATTR_LEAF_MAGIC) &&
2204                                    (magic != XFS_DIR2_LEAF1_MAGIC) &&
2205                                    (magic != XFS_DIR2_LEAFN_MAGIC) &&
2206                                    (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2207                                    (magic1 != XFS_DIR2_DATA_MAGIC) &&
2208                                    (be32_to_cpu(free->hdr.magic) != XFS_DIR2_FREE_MAGIC),
2209                                 mp, XFS_ERRTAG_DA_READ_BUF,
2210                                 XFS_RANDOM_DA_READ_BUF))) {
2211                         xfs_buftrace("DA READ ERROR", rbp->bps[0]);
2212                         XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2213                                              XFS_ERRLEVEL_LOW, mp, info);
2214                         error = XFS_ERROR(EFSCORRUPTED);
2215                         xfs_da_brelse(trans, rbp);
2216                         nbplist = 0;
2217                         goto exit1;
2218                 }
2219         }
2220         if (bplist) {
2221                 kmem_free(bplist, sizeof(*bplist) * nmap);
2222         }
2223         if (mapp != &map) {
2224                 kmem_free(mapp, sizeof(*mapp) * nfsb);
2225         }
2226         if (bpp)
2227                 *bpp = rbp;
2228         return 0;
2229 exit1:
2230         if (bplist) {
2231                 for (i = 0; i < nbplist; i++)
2232                         xfs_trans_brelse(trans, bplist[i]);
2233                 kmem_free(bplist, sizeof(*bplist) * nmap);
2234         }
2235 exit0:
2236         if (mapp != &map)
2237                 kmem_free(mapp, sizeof(*mapp) * nfsb);
2238         if (bpp)
2239                 *bpp = NULL;
2240         return error;
2241 }
2242
2243 /*
2244  * Get a buffer for the dir/attr block.
2245  */
2246 int
2247 xfs_da_get_buf(
2248         xfs_trans_t     *trans,
2249         xfs_inode_t     *dp,
2250         xfs_dablk_t     bno,
2251         xfs_daddr_t             mappedbno,
2252         xfs_dabuf_t     **bpp,
2253         int             whichfork)
2254 {
2255         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0,
2256                                                  (inst_t *)__return_address);
2257 }
2258
2259 /*
2260  * Get a buffer for the dir/attr block, fill in the contents.
2261  */
2262 int
2263 xfs_da_read_buf(
2264         xfs_trans_t     *trans,
2265         xfs_inode_t     *dp,
2266         xfs_dablk_t     bno,
2267         xfs_daddr_t             mappedbno,
2268         xfs_dabuf_t     **bpp,
2269         int             whichfork)
2270 {
2271         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1,
2272                 (inst_t *)__return_address);
2273 }
2274
2275 /*
2276  * Readahead the dir/attr block.
2277  */
2278 xfs_daddr_t
2279 xfs_da_reada_buf(
2280         xfs_trans_t     *trans,
2281         xfs_inode_t     *dp,
2282         xfs_dablk_t     bno,
2283         int             whichfork)
2284 {
2285         xfs_daddr_t             rval;
2286
2287         rval = -1;
2288         if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3,
2289                         (inst_t *)__return_address))
2290                 return -1;
2291         else
2292                 return rval;
2293 }
2294
2295 /*
2296  * Calculate the number of bits needed to hold i different values.
2297  */
2298 uint
2299 xfs_da_log2_roundup(uint i)
2300 {
2301         uint rval;
2302
2303         for (rval = 0; rval < NBBY * sizeof(i); rval++) {
2304                 if ((1 << rval) >= i)
2305                         break;
2306         }
2307         return(rval);
2308 }
2309
2310 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2311 kmem_zone_t *xfs_dabuf_zone;            /* dabuf zone */
2312
2313 /*
2314  * Allocate a dir-state structure.
2315  * We don't put them on the stack since they're large.
2316  */
2317 xfs_da_state_t *
2318 xfs_da_state_alloc(void)
2319 {
2320         return kmem_zone_zalloc(xfs_da_state_zone, KM_SLEEP);
2321 }
2322
2323 /*
2324  * Kill the altpath contents of a da-state structure.
2325  */
2326 STATIC void
2327 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2328 {
2329         int     i;
2330
2331         for (i = 0; i < state->altpath.active; i++) {
2332                 if (state->altpath.blk[i].bp) {
2333                         if (state->altpath.blk[i].bp != state->path.blk[i].bp)
2334                                 xfs_da_buf_done(state->altpath.blk[i].bp);
2335                         state->altpath.blk[i].bp = NULL;
2336                 }
2337         }
2338         state->altpath.active = 0;
2339 }
2340
2341 /*
2342  * Free a da-state structure.
2343  */
2344 void
2345 xfs_da_state_free(xfs_da_state_t *state)
2346 {
2347         int     i;
2348
2349         xfs_da_state_kill_altpath(state);
2350         for (i = 0; i < state->path.active; i++) {
2351                 if (state->path.blk[i].bp)
2352                         xfs_da_buf_done(state->path.blk[i].bp);
2353         }
2354         if (state->extravalid && state->extrablk.bp)
2355                 xfs_da_buf_done(state->extrablk.bp);
2356 #ifdef DEBUG
2357         memset((char *)state, 0, sizeof(*state));
2358 #endif /* DEBUG */
2359         kmem_zone_free(xfs_da_state_zone, state);
2360 }
2361
2362 #ifdef XFS_DABUF_DEBUG
2363 xfs_dabuf_t     *xfs_dabuf_global_list;
2364 lock_t          xfs_dabuf_global_lock;
2365 #endif
2366
2367 /*
2368  * Create a dabuf.
2369  */
2370 /* ARGSUSED */
2371 STATIC xfs_dabuf_t *
2372 xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra)
2373 {
2374         xfs_buf_t       *bp;
2375         xfs_dabuf_t     *dabuf;
2376         int             i;
2377         int             off;
2378
2379         if (nbuf == 1)
2380                 dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_SLEEP);
2381         else
2382                 dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_SLEEP);
2383         dabuf->dirty = 0;
2384 #ifdef XFS_DABUF_DEBUG
2385         dabuf->ra = ra;
2386         dabuf->target = XFS_BUF_TARGET(bps[0]);
2387         dabuf->blkno = XFS_BUF_ADDR(bps[0]);
2388 #endif
2389         if (nbuf == 1) {
2390                 dabuf->nbuf = 1;
2391                 bp = bps[0];
2392                 dabuf->bbcount = (short)BTOBB(XFS_BUF_COUNT(bp));
2393                 dabuf->data = XFS_BUF_PTR(bp);
2394                 dabuf->bps[0] = bp;
2395         } else {
2396                 dabuf->nbuf = nbuf;
2397                 for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
2398                         dabuf->bps[i] = bp = bps[i];
2399                         dabuf->bbcount += BTOBB(XFS_BUF_COUNT(bp));
2400                 }
2401                 dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
2402                 for (i = off = 0; i < nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2403                         bp = bps[i];
2404                         memcpy((char *)dabuf->data + off, XFS_BUF_PTR(bp),
2405                                 XFS_BUF_COUNT(bp));
2406                 }
2407         }
2408 #ifdef XFS_DABUF_DEBUG
2409         {
2410                 SPLDECL(s);
2411                 xfs_dabuf_t     *p;
2412
2413                 s = mutex_spinlock(&xfs_dabuf_global_lock);
2414                 for (p = xfs_dabuf_global_list; p; p = p->next) {
2415                         ASSERT(p->blkno != dabuf->blkno ||
2416                                p->target != dabuf->target);
2417                 }
2418                 dabuf->prev = NULL;
2419                 if (xfs_dabuf_global_list)
2420                         xfs_dabuf_global_list->prev = dabuf;
2421                 dabuf->next = xfs_dabuf_global_list;
2422                 xfs_dabuf_global_list = dabuf;
2423                 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2424         }
2425 #endif
2426         return dabuf;
2427 }
2428
2429 /*
2430  * Un-dirty a dabuf.
2431  */
2432 STATIC void
2433 xfs_da_buf_clean(xfs_dabuf_t *dabuf)
2434 {
2435         xfs_buf_t       *bp;
2436         int             i;
2437         int             off;
2438
2439         if (dabuf->dirty) {
2440                 ASSERT(dabuf->nbuf > 1);
2441                 dabuf->dirty = 0;
2442                 for (i = off = 0; i < dabuf->nbuf;
2443                                 i++, off += XFS_BUF_COUNT(bp)) {
2444                         bp = dabuf->bps[i];
2445                         memcpy(XFS_BUF_PTR(bp), (char *)dabuf->data + off,
2446                                 XFS_BUF_COUNT(bp));
2447                 }
2448         }
2449 }
2450
2451 /*
2452  * Release a dabuf.
2453  */
2454 void
2455 xfs_da_buf_done(xfs_dabuf_t *dabuf)
2456 {
2457         ASSERT(dabuf);
2458         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2459         if (dabuf->dirty)
2460                 xfs_da_buf_clean(dabuf);
2461         if (dabuf->nbuf > 1)
2462                 kmem_free(dabuf->data, BBTOB(dabuf->bbcount));
2463 #ifdef XFS_DABUF_DEBUG
2464         {
2465                 SPLDECL(s);
2466
2467                 s = mutex_spinlock(&xfs_dabuf_global_lock);
2468                 if (dabuf->prev)
2469                         dabuf->prev->next = dabuf->next;
2470                 else
2471                         xfs_dabuf_global_list = dabuf->next;
2472                 if (dabuf->next)
2473                         dabuf->next->prev = dabuf->prev;
2474                 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2475         }
2476         memset(dabuf, 0, XFS_DA_BUF_SIZE(dabuf->nbuf));
2477 #endif
2478         if (dabuf->nbuf == 1)
2479                 kmem_zone_free(xfs_dabuf_zone, dabuf);
2480         else
2481                 kmem_free(dabuf, XFS_DA_BUF_SIZE(dabuf->nbuf));
2482 }
2483
2484 /*
2485  * Log transaction from a dabuf.
2486  */
2487 void
2488 xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
2489 {
2490         xfs_buf_t       *bp;
2491         uint            f;
2492         int             i;
2493         uint            l;
2494         int             off;
2495
2496         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2497         if (dabuf->nbuf == 1) {
2498                 ASSERT(dabuf->data == (void *)XFS_BUF_PTR(dabuf->bps[0]));
2499                 xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
2500                 return;
2501         }
2502         dabuf->dirty = 1;
2503         ASSERT(first <= last);
2504         for (i = off = 0; i < dabuf->nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2505                 bp = dabuf->bps[i];
2506                 f = off;
2507                 l = f + XFS_BUF_COUNT(bp) - 1;
2508                 if (f < first)
2509                         f = first;
2510                 if (l > last)
2511                         l = last;
2512                 if (f <= l)
2513                         xfs_trans_log_buf(tp, bp, f - off, l - off);
2514                 /*
2515                  * B_DONE is set by xfs_trans_log buf.
2516                  * If we don't set it on a new buffer (get not read)
2517                  * then if we don't put anything in the buffer it won't
2518                  * be set, and at commit it it released into the cache,
2519                  * and then a read will fail.
2520                  */
2521                 else if (!(XFS_BUF_ISDONE(bp)))
2522                   XFS_BUF_DONE(bp);
2523         }
2524         ASSERT(last < off);
2525 }
2526
2527 /*
2528  * Release dabuf from a transaction.
2529  * Have to free up the dabuf before the buffers are released,
2530  * since the synchronization on the dabuf is really the lock on the buffer.
2531  */
2532 void
2533 xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2534 {
2535         xfs_buf_t       *bp;
2536         xfs_buf_t       **bplist;
2537         int             i;
2538         int             nbuf;
2539
2540         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2541         if ((nbuf = dabuf->nbuf) == 1) {
2542                 bplist = &bp;
2543                 bp = dabuf->bps[0];
2544         } else {
2545                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2546                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2547         }
2548         xfs_da_buf_done(dabuf);
2549         for (i = 0; i < nbuf; i++)
2550                 xfs_trans_brelse(tp, bplist[i]);
2551         if (bplist != &bp)
2552                 kmem_free(bplist, nbuf * sizeof(*bplist));
2553 }
2554
2555 /*
2556  * Invalidate dabuf from a transaction.
2557  */
2558 void
2559 xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2560 {
2561         xfs_buf_t       *bp;
2562         xfs_buf_t       **bplist;
2563         int             i;
2564         int             nbuf;
2565
2566         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2567         if ((nbuf = dabuf->nbuf) == 1) {
2568                 bplist = &bp;
2569                 bp = dabuf->bps[0];
2570         } else {
2571                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2572                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2573         }
2574         xfs_da_buf_done(dabuf);
2575         for (i = 0; i < nbuf; i++)
2576                 xfs_trans_binval(tp, bplist[i]);
2577         if (bplist != &bp)
2578                 kmem_free(bplist, nbuf * sizeof(*bplist));
2579 }
2580
2581 /*
2582  * Get the first daddr from a dabuf.
2583  */
2584 xfs_daddr_t
2585 xfs_da_blkno(xfs_dabuf_t *dabuf)
2586 {
2587         ASSERT(dabuf->nbuf);
2588         ASSERT(dabuf->data);
2589         return XFS_BUF_ADDR(dabuf->bps[0]);
2590 }