[XFS] Remove useless memory barrier
[linux-2.6] / fs / xfs / xfs_da_btree.c
1 /*
2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_dir2.h"
28 #include "xfs_dmapi.h"
29 #include "xfs_mount.h"
30 #include "xfs_da_btree.h"
31 #include "xfs_bmap_btree.h"
32 #include "xfs_alloc_btree.h"
33 #include "xfs_ialloc_btree.h"
34 #include "xfs_dir2_sf.h"
35 #include "xfs_attr_sf.h"
36 #include "xfs_dinode.h"
37 #include "xfs_inode.h"
38 #include "xfs_inode_item.h"
39 #include "xfs_alloc.h"
40 #include "xfs_btree.h"
41 #include "xfs_bmap.h"
42 #include "xfs_attr.h"
43 #include "xfs_attr_leaf.h"
44 #include "xfs_dir2_data.h"
45 #include "xfs_dir2_leaf.h"
46 #include "xfs_dir2_block.h"
47 #include "xfs_dir2_node.h"
48 #include "xfs_error.h"
49
50 /*
51  * xfs_da_btree.c
52  *
53  * Routines to implement directories as Btrees of hashed names.
54  */
55
56 /*========================================================================
57  * Function prototypes for the kernel.
58  *========================================================================*/
59
60 /*
61  * Routines used for growing the Btree.
62  */
63 STATIC int xfs_da_root_split(xfs_da_state_t *state,
64                                             xfs_da_state_blk_t *existing_root,
65                                             xfs_da_state_blk_t *new_child);
66 STATIC int xfs_da_node_split(xfs_da_state_t *state,
67                                             xfs_da_state_blk_t *existing_blk,
68                                             xfs_da_state_blk_t *split_blk,
69                                             xfs_da_state_blk_t *blk_to_add,
70                                             int treelevel,
71                                             int *result);
72 STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
73                                          xfs_da_state_blk_t *node_blk_1,
74                                          xfs_da_state_blk_t *node_blk_2);
75 STATIC void xfs_da_node_add(xfs_da_state_t *state,
76                                    xfs_da_state_blk_t *old_node_blk,
77                                    xfs_da_state_blk_t *new_node_blk);
78
79 /*
80  * Routines used for shrinking the Btree.
81  */
82 STATIC int xfs_da_root_join(xfs_da_state_t *state,
83                                            xfs_da_state_blk_t *root_blk);
84 STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
85 STATIC void xfs_da_node_remove(xfs_da_state_t *state,
86                                               xfs_da_state_blk_t *drop_blk);
87 STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
88                                          xfs_da_state_blk_t *src_node_blk,
89                                          xfs_da_state_blk_t *dst_node_blk);
90
91 /*
92  * Utility routines.
93  */
94 STATIC uint     xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count);
95 STATIC int      xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp);
96 STATIC xfs_dabuf_t *xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra);
97 STATIC int      xfs_da_blk_unlink(xfs_da_state_t *state,
98                                   xfs_da_state_blk_t *drop_blk,
99                                   xfs_da_state_blk_t *save_blk);
100 STATIC void     xfs_da_state_kill_altpath(xfs_da_state_t *state);
101
102 /*========================================================================
103  * Routines used for growing the Btree.
104  *========================================================================*/
105
106 /*
107  * Create the initial contents of an intermediate node.
108  */
109 int
110 xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
111                                  xfs_dabuf_t **bpp, int whichfork)
112 {
113         xfs_da_intnode_t *node;
114         xfs_dabuf_t *bp;
115         int error;
116         xfs_trans_t *tp;
117
118         tp = args->trans;
119         error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
120         if (error)
121                 return(error);
122         ASSERT(bp != NULL);
123         node = bp->data;
124         node->hdr.info.forw = 0;
125         node->hdr.info.back = 0;
126         node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC);
127         node->hdr.info.pad = 0;
128         node->hdr.count = 0;
129         node->hdr.level = cpu_to_be16(level);
130
131         xfs_da_log_buf(tp, bp,
132                 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
133
134         *bpp = bp;
135         return(0);
136 }
137
138 /*
139  * Split a leaf node, rebalance, then possibly split
140  * intermediate nodes, rebalance, etc.
141  */
142 int                                                     /* error */
143 xfs_da_split(xfs_da_state_t *state)
144 {
145         xfs_da_state_blk_t *oldblk, *newblk, *addblk;
146         xfs_da_intnode_t *node;
147         xfs_dabuf_t *bp;
148         int max, action, error, i;
149
150         /*
151          * Walk back up the tree splitting/inserting/adjusting as necessary.
152          * If we need to insert and there isn't room, split the node, then
153          * decide which fragment to insert the new block from below into.
154          * Note that we may split the root this way, but we need more fixup.
155          */
156         max = state->path.active - 1;
157         ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
158         ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
159                state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
160
161         addblk = &state->path.blk[max];         /* initial dummy value */
162         for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
163                 oldblk = &state->path.blk[i];
164                 newblk = &state->altpath.blk[i];
165
166                 /*
167                  * If a leaf node then
168                  *     Allocate a new leaf node, then rebalance across them.
169                  * else if an intermediate node then
170                  *     We split on the last layer, must we split the node?
171                  */
172                 switch (oldblk->magic) {
173                 case XFS_ATTR_LEAF_MAGIC:
174                         error = xfs_attr_leaf_split(state, oldblk, newblk);
175                         if ((error != 0) && (error != ENOSPC)) {
176                                 return(error);  /* GROT: attr is inconsistent */
177                         }
178                         if (!error) {
179                                 addblk = newblk;
180                                 break;
181                         }
182                         /*
183                          * Entry wouldn't fit, split the leaf again.
184                          */
185                         state->extravalid = 1;
186                         if (state->inleaf) {
187                                 state->extraafter = 0;  /* before newblk */
188                                 error = xfs_attr_leaf_split(state, oldblk,
189                                                             &state->extrablk);
190                         } else {
191                                 state->extraafter = 1;  /* after newblk */
192                                 error = xfs_attr_leaf_split(state, newblk,
193                                                             &state->extrablk);
194                         }
195                         if (error)
196                                 return(error);  /* GROT: attr inconsistent */
197                         addblk = newblk;
198                         break;
199                 case XFS_DIR2_LEAFN_MAGIC:
200                         error = xfs_dir2_leafn_split(state, oldblk, newblk);
201                         if (error)
202                                 return error;
203                         addblk = newblk;
204                         break;
205                 case XFS_DA_NODE_MAGIC:
206                         error = xfs_da_node_split(state, oldblk, newblk, addblk,
207                                                          max - i, &action);
208                         xfs_da_buf_done(addblk->bp);
209                         addblk->bp = NULL;
210                         if (error)
211                                 return(error);  /* GROT: dir is inconsistent */
212                         /*
213                          * Record the newly split block for the next time thru?
214                          */
215                         if (action)
216                                 addblk = newblk;
217                         else
218                                 addblk = NULL;
219                         break;
220                 }
221
222                 /*
223                  * Update the btree to show the new hashval for this child.
224                  */
225                 xfs_da_fixhashpath(state, &state->path);
226                 /*
227                  * If we won't need this block again, it's getting dropped
228                  * from the active path by the loop control, so we need
229                  * to mark it done now.
230                  */
231                 if (i > 0 || !addblk)
232                         xfs_da_buf_done(oldblk->bp);
233         }
234         if (!addblk)
235                 return(0);
236
237         /*
238          * Split the root node.
239          */
240         ASSERT(state->path.active == 0);
241         oldblk = &state->path.blk[0];
242         error = xfs_da_root_split(state, oldblk, addblk);
243         if (error) {
244                 xfs_da_buf_done(oldblk->bp);
245                 xfs_da_buf_done(addblk->bp);
246                 addblk->bp = NULL;
247                 return(error);  /* GROT: dir is inconsistent */
248         }
249
250         /*
251          * Update pointers to the node which used to be block 0 and
252          * just got bumped because of the addition of a new root node.
253          * There might be three blocks involved if a double split occurred,
254          * and the original block 0 could be at any position in the list.
255          */
256
257         node = oldblk->bp->data;
258         if (node->hdr.info.forw) {
259                 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
260                         bp = addblk->bp;
261                 } else {
262                         ASSERT(state->extravalid);
263                         bp = state->extrablk.bp;
264                 }
265                 node = bp->data;
266                 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
267                 xfs_da_log_buf(state->args->trans, bp,
268                     XFS_DA_LOGRANGE(node, &node->hdr.info,
269                     sizeof(node->hdr.info)));
270         }
271         node = oldblk->bp->data;
272         if (node->hdr.info.back) {
273                 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
274                         bp = addblk->bp;
275                 } else {
276                         ASSERT(state->extravalid);
277                         bp = state->extrablk.bp;
278                 }
279                 node = bp->data;
280                 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
281                 xfs_da_log_buf(state->args->trans, bp,
282                     XFS_DA_LOGRANGE(node, &node->hdr.info,
283                     sizeof(node->hdr.info)));
284         }
285         xfs_da_buf_done(oldblk->bp);
286         xfs_da_buf_done(addblk->bp);
287         addblk->bp = NULL;
288         return(0);
289 }
290
291 /*
292  * Split the root.  We have to create a new root and point to the two
293  * parts (the split old root) that we just created.  Copy block zero to
294  * the EOF, extending the inode in process.
295  */
296 STATIC int                                              /* error */
297 xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
298                                  xfs_da_state_blk_t *blk2)
299 {
300         xfs_da_intnode_t *node, *oldroot;
301         xfs_da_args_t *args;
302         xfs_dablk_t blkno;
303         xfs_dabuf_t *bp;
304         int error, size;
305         xfs_inode_t *dp;
306         xfs_trans_t *tp;
307         xfs_mount_t *mp;
308         xfs_dir2_leaf_t *leaf;
309
310         /*
311          * Copy the existing (incorrect) block from the root node position
312          * to a free space somewhere.
313          */
314         args = state->args;
315         ASSERT(args != NULL);
316         error = xfs_da_grow_inode(args, &blkno);
317         if (error)
318                 return(error);
319         dp = args->dp;
320         tp = args->trans;
321         mp = state->mp;
322         error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
323         if (error)
324                 return(error);
325         ASSERT(bp != NULL);
326         node = bp->data;
327         oldroot = blk1->bp->data;
328         if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC) {
329                 size = (int)((char *)&oldroot->btree[be16_to_cpu(oldroot->hdr.count)] -
330                              (char *)oldroot);
331         } else {
332                 ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
333                 leaf = (xfs_dir2_leaf_t *)oldroot;
334                 size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] -
335                              (char *)leaf);
336         }
337         memcpy(node, oldroot, size);
338         xfs_da_log_buf(tp, bp, 0, size - 1);
339         xfs_da_buf_done(blk1->bp);
340         blk1->bp = bp;
341         blk1->blkno = blkno;
342
343         /*
344          * Set up the new root node.
345          */
346         error = xfs_da_node_create(args,
347                 (args->whichfork == XFS_DATA_FORK) ? mp->m_dirleafblk : 0,
348                 be16_to_cpu(node->hdr.level) + 1, &bp, args->whichfork);
349         if (error)
350                 return(error);
351         node = bp->data;
352         node->btree[0].hashval = cpu_to_be32(blk1->hashval);
353         node->btree[0].before = cpu_to_be32(blk1->blkno);
354         node->btree[1].hashval = cpu_to_be32(blk2->hashval);
355         node->btree[1].before = cpu_to_be32(blk2->blkno);
356         node->hdr.count = cpu_to_be16(2);
357
358 #ifdef DEBUG
359         if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC) {
360                 ASSERT(blk1->blkno >= mp->m_dirleafblk &&
361                        blk1->blkno < mp->m_dirfreeblk);
362                 ASSERT(blk2->blkno >= mp->m_dirleafblk &&
363                        blk2->blkno < mp->m_dirfreeblk);
364         }
365 #endif
366
367         /* Header is already logged by xfs_da_node_create */
368         xfs_da_log_buf(tp, bp,
369                 XFS_DA_LOGRANGE(node, node->btree,
370                         sizeof(xfs_da_node_entry_t) * 2));
371         xfs_da_buf_done(bp);
372
373         return(0);
374 }
375
376 /*
377  * Split the node, rebalance, then add the new entry.
378  */
379 STATIC int                                              /* error */
380 xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
381                                  xfs_da_state_blk_t *newblk,
382                                  xfs_da_state_blk_t *addblk,
383                                  int treelevel, int *result)
384 {
385         xfs_da_intnode_t *node;
386         xfs_dablk_t blkno;
387         int newcount, error;
388         int useextra;
389
390         node = oldblk->bp->data;
391         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
392
393         /*
394          * With V2 dirs the extra block is data or freespace.
395          */
396         useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
397         newcount = 1 + useextra;
398         /*
399          * Do we have to split the node?
400          */
401         if ((be16_to_cpu(node->hdr.count) + newcount) > state->node_ents) {
402                 /*
403                  * Allocate a new node, add to the doubly linked chain of
404                  * nodes, then move some of our excess entries into it.
405                  */
406                 error = xfs_da_grow_inode(state->args, &blkno);
407                 if (error)
408                         return(error);  /* GROT: dir is inconsistent */
409
410                 error = xfs_da_node_create(state->args, blkno, treelevel,
411                                            &newblk->bp, state->args->whichfork);
412                 if (error)
413                         return(error);  /* GROT: dir is inconsistent */
414                 newblk->blkno = blkno;
415                 newblk->magic = XFS_DA_NODE_MAGIC;
416                 xfs_da_node_rebalance(state, oldblk, newblk);
417                 error = xfs_da_blk_link(state, oldblk, newblk);
418                 if (error)
419                         return(error);
420                 *result = 1;
421         } else {
422                 *result = 0;
423         }
424
425         /*
426          * Insert the new entry(s) into the correct block
427          * (updating last hashval in the process).
428          *
429          * xfs_da_node_add() inserts BEFORE the given index,
430          * and as a result of using node_lookup_int() we always
431          * point to a valid entry (not after one), but a split
432          * operation always results in a new block whose hashvals
433          * FOLLOW the current block.
434          *
435          * If we had double-split op below us, then add the extra block too.
436          */
437         node = oldblk->bp->data;
438         if (oldblk->index <= be16_to_cpu(node->hdr.count)) {
439                 oldblk->index++;
440                 xfs_da_node_add(state, oldblk, addblk);
441                 if (useextra) {
442                         if (state->extraafter)
443                                 oldblk->index++;
444                         xfs_da_node_add(state, oldblk, &state->extrablk);
445                         state->extravalid = 0;
446                 }
447         } else {
448                 newblk->index++;
449                 xfs_da_node_add(state, newblk, addblk);
450                 if (useextra) {
451                         if (state->extraafter)
452                                 newblk->index++;
453                         xfs_da_node_add(state, newblk, &state->extrablk);
454                         state->extravalid = 0;
455                 }
456         }
457
458         return(0);
459 }
460
461 /*
462  * Balance the btree elements between two intermediate nodes,
463  * usually one full and one empty.
464  *
465  * NOTE: if blk2 is empty, then it will get the upper half of blk1.
466  */
467 STATIC void
468 xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
469                                      xfs_da_state_blk_t *blk2)
470 {
471         xfs_da_intnode_t *node1, *node2, *tmpnode;
472         xfs_da_node_entry_t *btree_s, *btree_d;
473         int count, tmp;
474         xfs_trans_t *tp;
475
476         node1 = blk1->bp->data;
477         node2 = blk2->bp->data;
478         /*
479          * Figure out how many entries need to move, and in which direction.
480          * Swap the nodes around if that makes it simpler.
481          */
482         if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
483             ((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) ||
484              (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
485               be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
486                 tmpnode = node1;
487                 node1 = node2;
488                 node2 = tmpnode;
489         }
490         ASSERT(be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC);
491         ASSERT(be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC);
492         count = (be16_to_cpu(node1->hdr.count) - be16_to_cpu(node2->hdr.count)) / 2;
493         if (count == 0)
494                 return;
495         tp = state->args->trans;
496         /*
497          * Two cases: high-to-low and low-to-high.
498          */
499         if (count > 0) {
500                 /*
501                  * Move elements in node2 up to make a hole.
502                  */
503                 if ((tmp = be16_to_cpu(node2->hdr.count)) > 0) {
504                         tmp *= (uint)sizeof(xfs_da_node_entry_t);
505                         btree_s = &node2->btree[0];
506                         btree_d = &node2->btree[count];
507                         memmove(btree_d, btree_s, tmp);
508                 }
509
510                 /*
511                  * Move the req'd B-tree elements from high in node1 to
512                  * low in node2.
513                  */
514                 be16_add(&node2->hdr.count, count);
515                 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
516                 btree_s = &node1->btree[be16_to_cpu(node1->hdr.count) - count];
517                 btree_d = &node2->btree[0];
518                 memcpy(btree_d, btree_s, tmp);
519                 be16_add(&node1->hdr.count, -count);
520         } else {
521                 /*
522                  * Move the req'd B-tree elements from low in node2 to
523                  * high in node1.
524                  */
525                 count = -count;
526                 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
527                 btree_s = &node2->btree[0];
528                 btree_d = &node1->btree[be16_to_cpu(node1->hdr.count)];
529                 memcpy(btree_d, btree_s, tmp);
530                 be16_add(&node1->hdr.count, count);
531                 xfs_da_log_buf(tp, blk1->bp,
532                         XFS_DA_LOGRANGE(node1, btree_d, tmp));
533
534                 /*
535                  * Move elements in node2 down to fill the hole.
536                  */
537                 tmp  = be16_to_cpu(node2->hdr.count) - count;
538                 tmp *= (uint)sizeof(xfs_da_node_entry_t);
539                 btree_s = &node2->btree[count];
540                 btree_d = &node2->btree[0];
541                 memmove(btree_d, btree_s, tmp);
542                 be16_add(&node2->hdr.count, -count);
543         }
544
545         /*
546          * Log header of node 1 and all current bits of node 2.
547          */
548         xfs_da_log_buf(tp, blk1->bp,
549                 XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
550         xfs_da_log_buf(tp, blk2->bp,
551                 XFS_DA_LOGRANGE(node2, &node2->hdr,
552                         sizeof(node2->hdr) +
553                         sizeof(node2->btree[0]) * be16_to_cpu(node2->hdr.count)));
554
555         /*
556          * Record the last hashval from each block for upward propagation.
557          * (note: don't use the swapped node pointers)
558          */
559         node1 = blk1->bp->data;
560         node2 = blk2->bp->data;
561         blk1->hashval = be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval);
562         blk2->hashval = be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval);
563
564         /*
565          * Adjust the expected index for insertion.
566          */
567         if (blk1->index >= be16_to_cpu(node1->hdr.count)) {
568                 blk2->index = blk1->index - be16_to_cpu(node1->hdr.count);
569                 blk1->index = be16_to_cpu(node1->hdr.count) + 1;        /* make it invalid */
570         }
571 }
572
573 /*
574  * Add a new entry to an intermediate node.
575  */
576 STATIC void
577 xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
578                                xfs_da_state_blk_t *newblk)
579 {
580         xfs_da_intnode_t *node;
581         xfs_da_node_entry_t *btree;
582         int tmp;
583         xfs_mount_t *mp;
584
585         node = oldblk->bp->data;
586         mp = state->mp;
587         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
588         ASSERT((oldblk->index >= 0) && (oldblk->index <= be16_to_cpu(node->hdr.count)));
589         ASSERT(newblk->blkno != 0);
590         if (state->args->whichfork == XFS_DATA_FORK)
591                 ASSERT(newblk->blkno >= mp->m_dirleafblk &&
592                        newblk->blkno < mp->m_dirfreeblk);
593
594         /*
595          * We may need to make some room before we insert the new node.
596          */
597         tmp = 0;
598         btree = &node->btree[ oldblk->index ];
599         if (oldblk->index < be16_to_cpu(node->hdr.count)) {
600                 tmp = (be16_to_cpu(node->hdr.count) - oldblk->index) * (uint)sizeof(*btree);
601                 memmove(btree + 1, btree, tmp);
602         }
603         btree->hashval = cpu_to_be32(newblk->hashval);
604         btree->before = cpu_to_be32(newblk->blkno);
605         xfs_da_log_buf(state->args->trans, oldblk->bp,
606                 XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
607         be16_add(&node->hdr.count, 1);
608         xfs_da_log_buf(state->args->trans, oldblk->bp,
609                 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
610
611         /*
612          * Copy the last hash value from the oldblk to propagate upwards.
613          */
614         oldblk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1 ].hashval);
615 }
616
617 /*========================================================================
618  * Routines used for shrinking the Btree.
619  *========================================================================*/
620
621 /*
622  * Deallocate an empty leaf node, remove it from its parent,
623  * possibly deallocating that block, etc...
624  */
625 int
626 xfs_da_join(xfs_da_state_t *state)
627 {
628         xfs_da_state_blk_t *drop_blk, *save_blk;
629         int action, error;
630
631         action = 0;
632         drop_blk = &state->path.blk[ state->path.active-1 ];
633         save_blk = &state->altpath.blk[ state->path.active-1 ];
634         ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
635         ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
636                drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
637
638         /*
639          * Walk back up the tree joining/deallocating as necessary.
640          * When we stop dropping blocks, break out.
641          */
642         for (  ; state->path.active >= 2; drop_blk--, save_blk--,
643                  state->path.active--) {
644                 /*
645                  * See if we can combine the block with a neighbor.
646                  *   (action == 0) => no options, just leave
647                  *   (action == 1) => coalesce, then unlink
648                  *   (action == 2) => block empty, unlink it
649                  */
650                 switch (drop_blk->magic) {
651                 case XFS_ATTR_LEAF_MAGIC:
652                         error = xfs_attr_leaf_toosmall(state, &action);
653                         if (error)
654                                 return(error);
655                         if (action == 0)
656                                 return(0);
657                         xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
658                         break;
659                 case XFS_DIR2_LEAFN_MAGIC:
660                         error = xfs_dir2_leafn_toosmall(state, &action);
661                         if (error)
662                                 return error;
663                         if (action == 0)
664                                 return 0;
665                         xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
666                         break;
667                 case XFS_DA_NODE_MAGIC:
668                         /*
669                          * Remove the offending node, fixup hashvals,
670                          * check for a toosmall neighbor.
671                          */
672                         xfs_da_node_remove(state, drop_blk);
673                         xfs_da_fixhashpath(state, &state->path);
674                         error = xfs_da_node_toosmall(state, &action);
675                         if (error)
676                                 return(error);
677                         if (action == 0)
678                                 return 0;
679                         xfs_da_node_unbalance(state, drop_blk, save_blk);
680                         break;
681                 }
682                 xfs_da_fixhashpath(state, &state->altpath);
683                 error = xfs_da_blk_unlink(state, drop_blk, save_blk);
684                 xfs_da_state_kill_altpath(state);
685                 if (error)
686                         return(error);
687                 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
688                                                          drop_blk->bp);
689                 drop_blk->bp = NULL;
690                 if (error)
691                         return(error);
692         }
693         /*
694          * We joined all the way to the top.  If it turns out that
695          * we only have one entry in the root, make the child block
696          * the new root.
697          */
698         xfs_da_node_remove(state, drop_blk);
699         xfs_da_fixhashpath(state, &state->path);
700         error = xfs_da_root_join(state, &state->path.blk[0]);
701         return(error);
702 }
703
704 /*
705  * We have only one entry in the root.  Copy the only remaining child of
706  * the old root to block 0 as the new root node.
707  */
708 STATIC int
709 xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
710 {
711         xfs_da_intnode_t *oldroot;
712         /* REFERENCED */
713         xfs_da_blkinfo_t *blkinfo;
714         xfs_da_args_t *args;
715         xfs_dablk_t child;
716         xfs_dabuf_t *bp;
717         int error;
718
719         args = state->args;
720         ASSERT(args != NULL);
721         ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
722         oldroot = root_blk->bp->data;
723         ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC);
724         ASSERT(!oldroot->hdr.info.forw);
725         ASSERT(!oldroot->hdr.info.back);
726
727         /*
728          * If the root has more than one child, then don't do anything.
729          */
730         if (be16_to_cpu(oldroot->hdr.count) > 1)
731                 return(0);
732
733         /*
734          * Read in the (only) child block, then copy those bytes into
735          * the root block's buffer and free the original child block.
736          */
737         child = be32_to_cpu(oldroot->btree[0].before);
738         ASSERT(child != 0);
739         error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp,
740                                              args->whichfork);
741         if (error)
742                 return(error);
743         ASSERT(bp != NULL);
744         blkinfo = bp->data;
745         if (be16_to_cpu(oldroot->hdr.level) == 1) {
746                 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DIR2_LEAFN_MAGIC ||
747                        be16_to_cpu(blkinfo->magic) == XFS_ATTR_LEAF_MAGIC);
748         } else {
749                 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DA_NODE_MAGIC);
750         }
751         ASSERT(!blkinfo->forw);
752         ASSERT(!blkinfo->back);
753         memcpy(root_blk->bp->data, bp->data, state->blocksize);
754         xfs_da_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
755         error = xfs_da_shrink_inode(args, child, bp);
756         return(error);
757 }
758
759 /*
760  * Check a node block and its neighbors to see if the block should be
761  * collapsed into one or the other neighbor.  Always keep the block
762  * with the smaller block number.
763  * If the current block is over 50% full, don't try to join it, return 0.
764  * If the block is empty, fill in the state structure and return 2.
765  * If it can be collapsed, fill in the state structure and return 1.
766  * If nothing can be done, return 0.
767  */
768 STATIC int
769 xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
770 {
771         xfs_da_intnode_t *node;
772         xfs_da_state_blk_t *blk;
773         xfs_da_blkinfo_t *info;
774         int count, forward, error, retval, i;
775         xfs_dablk_t blkno;
776         xfs_dabuf_t *bp;
777
778         /*
779          * Check for the degenerate case of the block being over 50% full.
780          * If so, it's not worth even looking to see if we might be able
781          * to coalesce with a sibling.
782          */
783         blk = &state->path.blk[ state->path.active-1 ];
784         info = blk->bp->data;
785         ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC);
786         node = (xfs_da_intnode_t *)info;
787         count = be16_to_cpu(node->hdr.count);
788         if (count > (state->node_ents >> 1)) {
789                 *action = 0;    /* blk over 50%, don't try to join */
790                 return(0);      /* blk over 50%, don't try to join */
791         }
792
793         /*
794          * Check for the degenerate case of the block being empty.
795          * If the block is empty, we'll simply delete it, no need to
796          * coalesce it with a sibling block.  We choose (arbitrarily)
797          * to merge with the forward block unless it is NULL.
798          */
799         if (count == 0) {
800                 /*
801                  * Make altpath point to the block we want to keep and
802                  * path point to the block we want to drop (this one).
803                  */
804                 forward = (info->forw != 0);
805                 memcpy(&state->altpath, &state->path, sizeof(state->path));
806                 error = xfs_da_path_shift(state, &state->altpath, forward,
807                                                  0, &retval);
808                 if (error)
809                         return(error);
810                 if (retval) {
811                         *action = 0;
812                 } else {
813                         *action = 2;
814                 }
815                 return(0);
816         }
817
818         /*
819          * Examine each sibling block to see if we can coalesce with
820          * at least 25% free space to spare.  We need to figure out
821          * whether to merge with the forward or the backward block.
822          * We prefer coalescing with the lower numbered sibling so as
823          * to shrink a directory over time.
824          */
825         /* start with smaller blk num */
826         forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
827         for (i = 0; i < 2; forward = !forward, i++) {
828                 if (forward)
829                         blkno = be32_to_cpu(info->forw);
830                 else
831                         blkno = be32_to_cpu(info->back);
832                 if (blkno == 0)
833                         continue;
834                 error = xfs_da_read_buf(state->args->trans, state->args->dp,
835                                         blkno, -1, &bp, state->args->whichfork);
836                 if (error)
837                         return(error);
838                 ASSERT(bp != NULL);
839
840                 node = (xfs_da_intnode_t *)info;
841                 count  = state->node_ents;
842                 count -= state->node_ents >> 2;
843                 count -= be16_to_cpu(node->hdr.count);
844                 node = bp->data;
845                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
846                 count -= be16_to_cpu(node->hdr.count);
847                 xfs_da_brelse(state->args->trans, bp);
848                 if (count >= 0)
849                         break;  /* fits with at least 25% to spare */
850         }
851         if (i >= 2) {
852                 *action = 0;
853                 return(0);
854         }
855
856         /*
857          * Make altpath point to the block we want to keep (the lower
858          * numbered block) and path point to the block we want to drop.
859          */
860         memcpy(&state->altpath, &state->path, sizeof(state->path));
861         if (blkno < blk->blkno) {
862                 error = xfs_da_path_shift(state, &state->altpath, forward,
863                                                  0, &retval);
864                 if (error) {
865                         return(error);
866                 }
867                 if (retval) {
868                         *action = 0;
869                         return(0);
870                 }
871         } else {
872                 error = xfs_da_path_shift(state, &state->path, forward,
873                                                  0, &retval);
874                 if (error) {
875                         return(error);
876                 }
877                 if (retval) {
878                         *action = 0;
879                         return(0);
880                 }
881         }
882         *action = 1;
883         return(0);
884 }
885
886 /*
887  * Walk back up the tree adjusting hash values as necessary,
888  * when we stop making changes, return.
889  */
890 void
891 xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
892 {
893         xfs_da_state_blk_t *blk;
894         xfs_da_intnode_t *node;
895         xfs_da_node_entry_t *btree;
896         xfs_dahash_t lasthash=0;
897         int level, count;
898
899         level = path->active-1;
900         blk = &path->blk[ level ];
901         switch (blk->magic) {
902         case XFS_ATTR_LEAF_MAGIC:
903                 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
904                 if (count == 0)
905                         return;
906                 break;
907         case XFS_DIR2_LEAFN_MAGIC:
908                 lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
909                 if (count == 0)
910                         return;
911                 break;
912         case XFS_DA_NODE_MAGIC:
913                 lasthash = xfs_da_node_lasthash(blk->bp, &count);
914                 if (count == 0)
915                         return;
916                 break;
917         }
918         for (blk--, level--; level >= 0; blk--, level--) {
919                 node = blk->bp->data;
920                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
921                 btree = &node->btree[ blk->index ];
922                 if (be32_to_cpu(btree->hashval) == lasthash)
923                         break;
924                 blk->hashval = lasthash;
925                 btree->hashval = cpu_to_be32(lasthash);
926                 xfs_da_log_buf(state->args->trans, blk->bp,
927                                   XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
928
929                 lasthash = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
930         }
931 }
932
933 /*
934  * Remove an entry from an intermediate node.
935  */
936 STATIC void
937 xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
938 {
939         xfs_da_intnode_t *node;
940         xfs_da_node_entry_t *btree;
941         int tmp;
942
943         node = drop_blk->bp->data;
944         ASSERT(drop_blk->index < be16_to_cpu(node->hdr.count));
945         ASSERT(drop_blk->index >= 0);
946
947         /*
948          * Copy over the offending entry, or just zero it out.
949          */
950         btree = &node->btree[drop_blk->index];
951         if (drop_blk->index < (be16_to_cpu(node->hdr.count)-1)) {
952                 tmp  = be16_to_cpu(node->hdr.count) - drop_blk->index - 1;
953                 tmp *= (uint)sizeof(xfs_da_node_entry_t);
954                 memmove(btree, btree + 1, tmp);
955                 xfs_da_log_buf(state->args->trans, drop_blk->bp,
956                     XFS_DA_LOGRANGE(node, btree, tmp));
957                 btree = &node->btree[be16_to_cpu(node->hdr.count)-1];
958         }
959         memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
960         xfs_da_log_buf(state->args->trans, drop_blk->bp,
961             XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
962         be16_add(&node->hdr.count, -1);
963         xfs_da_log_buf(state->args->trans, drop_blk->bp,
964             XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
965
966         /*
967          * Copy the last hash value from the block to propagate upwards.
968          */
969         btree--;
970         drop_blk->hashval = be32_to_cpu(btree->hashval);
971 }
972
973 /*
974  * Unbalance the btree elements between two intermediate nodes,
975  * move all Btree elements from one node into another.
976  */
977 STATIC void
978 xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
979                                      xfs_da_state_blk_t *save_blk)
980 {
981         xfs_da_intnode_t *drop_node, *save_node;
982         xfs_da_node_entry_t *btree;
983         int tmp;
984         xfs_trans_t *tp;
985
986         drop_node = drop_blk->bp->data;
987         save_node = save_blk->bp->data;
988         ASSERT(be16_to_cpu(drop_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
989         ASSERT(be16_to_cpu(save_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
990         tp = state->args->trans;
991
992         /*
993          * If the dying block has lower hashvals, then move all the
994          * elements in the remaining block up to make a hole.
995          */
996         if ((be32_to_cpu(drop_node->btree[0].hashval) < be32_to_cpu(save_node->btree[ 0 ].hashval)) ||
997             (be32_to_cpu(drop_node->btree[be16_to_cpu(drop_node->hdr.count)-1].hashval) <
998              be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval)))
999         {
1000                 btree = &save_node->btree[be16_to_cpu(drop_node->hdr.count)];
1001                 tmp = be16_to_cpu(save_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1002                 memmove(btree, &save_node->btree[0], tmp);
1003                 btree = &save_node->btree[0];
1004                 xfs_da_log_buf(tp, save_blk->bp,
1005                         XFS_DA_LOGRANGE(save_node, btree,
1006                                 (be16_to_cpu(save_node->hdr.count) + be16_to_cpu(drop_node->hdr.count)) *
1007                                 sizeof(xfs_da_node_entry_t)));
1008         } else {
1009                 btree = &save_node->btree[be16_to_cpu(save_node->hdr.count)];
1010                 xfs_da_log_buf(tp, save_blk->bp,
1011                         XFS_DA_LOGRANGE(save_node, btree,
1012                                 be16_to_cpu(drop_node->hdr.count) *
1013                                 sizeof(xfs_da_node_entry_t)));
1014         }
1015
1016         /*
1017          * Move all the B-tree elements from drop_blk to save_blk.
1018          */
1019         tmp = be16_to_cpu(drop_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1020         memcpy(btree, &drop_node->btree[0], tmp);
1021         be16_add(&save_node->hdr.count, be16_to_cpu(drop_node->hdr.count));
1022
1023         xfs_da_log_buf(tp, save_blk->bp,
1024                 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1025                         sizeof(save_node->hdr)));
1026
1027         /*
1028          * Save the last hashval in the remaining block for upward propagation.
1029          */
1030         save_blk->hashval = be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval);
1031 }
1032
1033 /*========================================================================
1034  * Routines used for finding things in the Btree.
1035  *========================================================================*/
1036
1037 /*
1038  * Walk down the Btree looking for a particular filename, filling
1039  * in the state structure as we go.
1040  *
1041  * We will set the state structure to point to each of the elements
1042  * in each of the nodes where either the hashval is or should be.
1043  *
1044  * We support duplicate hashval's so for each entry in the current
1045  * node that could contain the desired hashval, descend.  This is a
1046  * pruned depth-first tree search.
1047  */
1048 int                                                     /* error */
1049 xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
1050 {
1051         xfs_da_state_blk_t *blk;
1052         xfs_da_blkinfo_t *curr;
1053         xfs_da_intnode_t *node;
1054         xfs_da_node_entry_t *btree;
1055         xfs_dablk_t blkno;
1056         int probe, span, max, error, retval;
1057         xfs_dahash_t hashval, btreehashval;
1058         xfs_da_args_t *args;
1059
1060         args = state->args;
1061
1062         /*
1063          * Descend thru the B-tree searching each level for the right
1064          * node to use, until the right hashval is found.
1065          */
1066         blkno = (args->whichfork == XFS_DATA_FORK)? state->mp->m_dirleafblk : 0;
1067         for (blk = &state->path.blk[0], state->path.active = 1;
1068                          state->path.active <= XFS_DA_NODE_MAXDEPTH;
1069                          blk++, state->path.active++) {
1070                 /*
1071                  * Read the next node down in the tree.
1072                  */
1073                 blk->blkno = blkno;
1074                 error = xfs_da_read_buf(args->trans, args->dp, blkno,
1075                                         -1, &blk->bp, args->whichfork);
1076                 if (error) {
1077                         blk->blkno = 0;
1078                         state->path.active--;
1079                         return(error);
1080                 }
1081                 curr = blk->bp->data;
1082                 blk->magic = be16_to_cpu(curr->magic);
1083                 ASSERT(blk->magic == XFS_DA_NODE_MAGIC ||
1084                        blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1085                        blk->magic == XFS_ATTR_LEAF_MAGIC);
1086
1087                 /*
1088                  * Search an intermediate node for a match.
1089                  */
1090                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1091                         node = blk->bp->data;
1092                         max = be16_to_cpu(node->hdr.count);
1093                         blk->hashval = be32_to_cpu(node->btree[max-1].hashval);
1094
1095                         /*
1096                          * Binary search.  (note: small blocks will skip loop)
1097                          */
1098                         probe = span = max / 2;
1099                         hashval = args->hashval;
1100                         for (btree = &node->btree[probe]; span > 4;
1101                                    btree = &node->btree[probe]) {
1102                                 span /= 2;
1103                                 btreehashval = be32_to_cpu(btree->hashval);
1104                                 if (btreehashval < hashval)
1105                                         probe += span;
1106                                 else if (btreehashval > hashval)
1107                                         probe -= span;
1108                                 else
1109                                         break;
1110                         }
1111                         ASSERT((probe >= 0) && (probe < max));
1112                         ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval));
1113
1114                         /*
1115                          * Since we may have duplicate hashval's, find the first
1116                          * matching hashval in the node.
1117                          */
1118                         while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) {
1119                                 btree--;
1120                                 probe--;
1121                         }
1122                         while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) {
1123                                 btree++;
1124                                 probe++;
1125                         }
1126
1127                         /*
1128                          * Pick the right block to descend on.
1129                          */
1130                         if (probe == max) {
1131                                 blk->index = max-1;
1132                                 blkno = be32_to_cpu(node->btree[max-1].before);
1133                         } else {
1134                                 blk->index = probe;
1135                                 blkno = be32_to_cpu(btree->before);
1136                         }
1137                 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1138                         blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1139                         break;
1140                 } else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1141                         blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
1142                         break;
1143                 }
1144         }
1145
1146         /*
1147          * A leaf block that ends in the hashval that we are interested in
1148          * (final hashval == search hashval) means that the next block may
1149          * contain more entries with the same hashval, shift upward to the
1150          * next leaf and keep searching.
1151          */
1152         for (;;) {
1153                 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1154                         retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1155                                                         &blk->index, state);
1156                 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1157                         retval = xfs_attr_leaf_lookup_int(blk->bp, args);
1158                         blk->index = args->index;
1159                         args->blkno = blk->blkno;
1160                 } else {
1161                         ASSERT(0);
1162                         return XFS_ERROR(EFSCORRUPTED);
1163                 }
1164                 if (((retval == ENOENT) || (retval == ENOATTR)) &&
1165                     (blk->hashval == args->hashval)) {
1166                         error = xfs_da_path_shift(state, &state->path, 1, 1,
1167                                                          &retval);
1168                         if (error)
1169                                 return(error);
1170                         if (retval == 0) {
1171                                 continue;
1172                         } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1173                                 /* path_shift() gives ENOENT */
1174                                 retval = XFS_ERROR(ENOATTR);
1175                         }
1176                 }
1177                 break;
1178         }
1179         *result = retval;
1180         return(0);
1181 }
1182
1183 /*========================================================================
1184  * Utility routines.
1185  *========================================================================*/
1186
1187 /*
1188  * Link a new block into a doubly linked list of blocks (of whatever type).
1189  */
1190 int                                                     /* error */
1191 xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
1192                                xfs_da_state_blk_t *new_blk)
1193 {
1194         xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
1195         xfs_da_args_t *args;
1196         int before=0, error;
1197         xfs_dabuf_t *bp;
1198
1199         /*
1200          * Set up environment.
1201          */
1202         args = state->args;
1203         ASSERT(args != NULL);
1204         old_info = old_blk->bp->data;
1205         new_info = new_blk->bp->data;
1206         ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1207                old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1208                old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1209         ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
1210         ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
1211         ASSERT(old_blk->magic == new_blk->magic);
1212
1213         switch (old_blk->magic) {
1214         case XFS_ATTR_LEAF_MAGIC:
1215                 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1216                 break;
1217         case XFS_DIR2_LEAFN_MAGIC:
1218                 before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
1219                 break;
1220         case XFS_DA_NODE_MAGIC:
1221                 before = xfs_da_node_order(old_blk->bp, new_blk->bp);
1222                 break;
1223         }
1224
1225         /*
1226          * Link blocks in appropriate order.
1227          */
1228         if (before) {
1229                 /*
1230                  * Link new block in before existing block.
1231                  */
1232                 new_info->forw = cpu_to_be32(old_blk->blkno);
1233                 new_info->back = old_info->back;
1234                 if (old_info->back) {
1235                         error = xfs_da_read_buf(args->trans, args->dp,
1236                                                 be32_to_cpu(old_info->back),
1237                                                 -1, &bp, args->whichfork);
1238                         if (error)
1239                                 return(error);
1240                         ASSERT(bp != NULL);
1241                         tmp_info = bp->data;
1242                         ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
1243                         ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1244                         tmp_info->forw = cpu_to_be32(new_blk->blkno);
1245                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1246                         xfs_da_buf_done(bp);
1247                 }
1248                 old_info->back = cpu_to_be32(new_blk->blkno);
1249         } else {
1250                 /*
1251                  * Link new block in after existing block.
1252                  */
1253                 new_info->forw = old_info->forw;
1254                 new_info->back = cpu_to_be32(old_blk->blkno);
1255                 if (old_info->forw) {
1256                         error = xfs_da_read_buf(args->trans, args->dp,
1257                                                 be32_to_cpu(old_info->forw),
1258                                                 -1, &bp, args->whichfork);
1259                         if (error)
1260                                 return(error);
1261                         ASSERT(bp != NULL);
1262                         tmp_info = bp->data;
1263                         ASSERT(tmp_info->magic == old_info->magic);
1264                         ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1265                         tmp_info->back = cpu_to_be32(new_blk->blkno);
1266                         xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1267                         xfs_da_buf_done(bp);
1268                 }
1269                 old_info->forw = cpu_to_be32(new_blk->blkno);
1270         }
1271
1272         xfs_da_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1273         xfs_da_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1274         return(0);
1275 }
1276
1277 /*
1278  * Compare two intermediate nodes for "order".
1279  */
1280 STATIC int
1281 xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp)
1282 {
1283         xfs_da_intnode_t *node1, *node2;
1284
1285         node1 = node1_bp->data;
1286         node2 = node2_bp->data;
1287         ASSERT((be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC) &&
1288                (be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC));
1289         if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
1290             ((be32_to_cpu(node2->btree[0].hashval) <
1291               be32_to_cpu(node1->btree[0].hashval)) ||
1292              (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
1293               be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
1294                 return(1);
1295         }
1296         return(0);
1297 }
1298
1299 /*
1300  * Pick up the last hashvalue from an intermediate node.
1301  */
1302 STATIC uint
1303 xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count)
1304 {
1305         xfs_da_intnode_t *node;
1306
1307         node = bp->data;
1308         ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1309         if (count)
1310                 *count = be16_to_cpu(node->hdr.count);
1311         if (!node->hdr.count)
1312                 return(0);
1313         return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1314 }
1315
1316 /*
1317  * Unlink a block from a doubly linked list of blocks.
1318  */
1319 STATIC int                                              /* error */
1320 xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1321                                  xfs_da_state_blk_t *save_blk)
1322 {
1323         xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
1324         xfs_da_args_t *args;
1325         xfs_dabuf_t *bp;
1326         int error;
1327
1328         /*
1329          * Set up environment.
1330          */
1331         args = state->args;
1332         ASSERT(args != NULL);
1333         save_info = save_blk->bp->data;
1334         drop_info = drop_blk->bp->data;
1335         ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1336                save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1337                save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1338         ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
1339         ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
1340         ASSERT(save_blk->magic == drop_blk->magic);
1341         ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1342                (be32_to_cpu(save_info->back) == drop_blk->blkno));
1343         ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1344                (be32_to_cpu(drop_info->back) == save_blk->blkno));
1345
1346         /*
1347          * Unlink the leaf block from the doubly linked chain of leaves.
1348          */
1349         if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1350                 save_info->back = drop_info->back;
1351                 if (drop_info->back) {
1352                         error = xfs_da_read_buf(args->trans, args->dp,
1353                                                 be32_to_cpu(drop_info->back),
1354                                                 -1, &bp, args->whichfork);
1355                         if (error)
1356                                 return(error);
1357                         ASSERT(bp != NULL);
1358                         tmp_info = bp->data;
1359                         ASSERT(tmp_info->magic == save_info->magic);
1360                         ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1361                         tmp_info->forw = cpu_to_be32(save_blk->blkno);
1362                         xfs_da_log_buf(args->trans, bp, 0,
1363                                                     sizeof(*tmp_info) - 1);
1364                         xfs_da_buf_done(bp);
1365                 }
1366         } else {
1367                 save_info->forw = drop_info->forw;
1368                 if (drop_info->forw) {
1369                         error = xfs_da_read_buf(args->trans, args->dp,
1370                                                 be32_to_cpu(drop_info->forw),
1371                                                 -1, &bp, args->whichfork);
1372                         if (error)
1373                                 return(error);
1374                         ASSERT(bp != NULL);
1375                         tmp_info = bp->data;
1376                         ASSERT(tmp_info->magic == save_info->magic);
1377                         ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1378                         tmp_info->back = cpu_to_be32(save_blk->blkno);
1379                         xfs_da_log_buf(args->trans, bp, 0,
1380                                                     sizeof(*tmp_info) - 1);
1381                         xfs_da_buf_done(bp);
1382                 }
1383         }
1384
1385         xfs_da_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1386         return(0);
1387 }
1388
1389 /*
1390  * Move a path "forward" or "!forward" one block at the current level.
1391  *
1392  * This routine will adjust a "path" to point to the next block
1393  * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1394  * Btree, including updating pointers to the intermediate nodes between
1395  * the new bottom and the root.
1396  */
1397 int                                                     /* error */
1398 xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
1399                                  int forward, int release, int *result)
1400 {
1401         xfs_da_state_blk_t *blk;
1402         xfs_da_blkinfo_t *info;
1403         xfs_da_intnode_t *node;
1404         xfs_da_args_t *args;
1405         xfs_dablk_t blkno=0;
1406         int level, error;
1407
1408         /*
1409          * Roll up the Btree looking for the first block where our
1410          * current index is not at the edge of the block.  Note that
1411          * we skip the bottom layer because we want the sibling block.
1412          */
1413         args = state->args;
1414         ASSERT(args != NULL);
1415         ASSERT(path != NULL);
1416         ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1417         level = (path->active-1) - 1;   /* skip bottom layer in path */
1418         for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1419                 ASSERT(blk->bp != NULL);
1420                 node = blk->bp->data;
1421                 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1422                 if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) {
1423                         blk->index++;
1424                         blkno = be32_to_cpu(node->btree[blk->index].before);
1425                         break;
1426                 } else if (!forward && (blk->index > 0)) {
1427                         blk->index--;
1428                         blkno = be32_to_cpu(node->btree[blk->index].before);
1429                         break;
1430                 }
1431         }
1432         if (level < 0) {
1433                 *result = XFS_ERROR(ENOENT);    /* we're out of our tree */
1434                 ASSERT(args->oknoent);
1435                 return(0);
1436         }
1437
1438         /*
1439          * Roll down the edge of the subtree until we reach the
1440          * same depth we were at originally.
1441          */
1442         for (blk++, level++; level < path->active; blk++, level++) {
1443                 /*
1444                  * Release the old block.
1445                  * (if it's dirty, trans won't actually let go)
1446                  */
1447                 if (release)
1448                         xfs_da_brelse(args->trans, blk->bp);
1449
1450                 /*
1451                  * Read the next child block.
1452                  */
1453                 blk->blkno = blkno;
1454                 error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
1455                                                      &blk->bp, args->whichfork);
1456                 if (error)
1457                         return(error);
1458                 ASSERT(blk->bp != NULL);
1459                 info = blk->bp->data;
1460                 ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC ||
1461                        be16_to_cpu(info->magic) == XFS_DIR2_LEAFN_MAGIC ||
1462                        be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC);
1463                 blk->magic = be16_to_cpu(info->magic);
1464                 if (blk->magic == XFS_DA_NODE_MAGIC) {
1465                         node = (xfs_da_intnode_t *)info;
1466                         blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1467                         if (forward)
1468                                 blk->index = 0;
1469                         else
1470                                 blk->index = be16_to_cpu(node->hdr.count)-1;
1471                         blkno = be32_to_cpu(node->btree[blk->index].before);
1472                 } else {
1473                         ASSERT(level == path->active-1);
1474                         blk->index = 0;
1475                         switch(blk->magic) {
1476                         case XFS_ATTR_LEAF_MAGIC:
1477                                 blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
1478                                                                       NULL);
1479                                 break;
1480                         case XFS_DIR2_LEAFN_MAGIC:
1481                                 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
1482                                                                        NULL);
1483                                 break;
1484                         default:
1485                                 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
1486                                        blk->magic == XFS_DIR2_LEAFN_MAGIC);
1487                                 break;
1488                         }
1489                 }
1490         }
1491         *result = 0;
1492         return(0);
1493 }
1494
1495
1496 /*========================================================================
1497  * Utility routines.
1498  *========================================================================*/
1499
1500 /*
1501  * Implement a simple hash on a character string.
1502  * Rotate the hash value by 7 bits, then XOR each character in.
1503  * This is implemented with some source-level loop unrolling.
1504  */
1505 xfs_dahash_t
1506 xfs_da_hashname(const uchar_t *name, int namelen)
1507 {
1508         xfs_dahash_t hash;
1509
1510         /*
1511          * Do four characters at a time as long as we can.
1512          */
1513         for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1514                 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1515                        (name[3] << 0) ^ rol32(hash, 7 * 4);
1516
1517         /*
1518          * Now do the rest of the characters.
1519          */
1520         switch (namelen) {
1521         case 3:
1522                 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1523                        rol32(hash, 7 * 3);
1524         case 2:
1525                 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1526         case 1:
1527                 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1528         default: /* case 0: */
1529                 return hash;
1530         }
1531 }
1532
1533 /*
1534  * Add a block to the btree ahead of the file.
1535  * Return the new block number to the caller.
1536  */
1537 int
1538 xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
1539 {
1540         xfs_fileoff_t bno, b;
1541         xfs_bmbt_irec_t map;
1542         xfs_bmbt_irec_t *mapp;
1543         xfs_inode_t *dp;
1544         int nmap, error, w, count, c, got, i, mapi;
1545         xfs_trans_t *tp;
1546         xfs_mount_t *mp;
1547
1548         dp = args->dp;
1549         mp = dp->i_mount;
1550         w = args->whichfork;
1551         tp = args->trans;
1552         /*
1553          * For new directories adjust the file offset and block count.
1554          */
1555         if (w == XFS_DATA_FORK) {
1556                 bno = mp->m_dirleafblk;
1557                 count = mp->m_dirblkfsbs;
1558         } else {
1559                 bno = 0;
1560                 count = 1;
1561         }
1562         /*
1563          * Find a spot in the file space to put the new block.
1564          */
1565         if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, w)))
1566                 return error;
1567         if (w == XFS_DATA_FORK)
1568                 ASSERT(bno >= mp->m_dirleafblk && bno < mp->m_dirfreeblk);
1569         /*
1570          * Try mapping it in one filesystem block.
1571          */
1572         nmap = 1;
1573         ASSERT(args->firstblock != NULL);
1574         if ((error = xfs_bmapi(tp, dp, bno, count,
1575                         XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|
1576                         XFS_BMAPI_CONTIG,
1577                         args->firstblock, args->total, &map, &nmap,
1578                         args->flist, NULL))) {
1579                 return error;
1580         }
1581         ASSERT(nmap <= 1);
1582         if (nmap == 1) {
1583                 mapp = &map;
1584                 mapi = 1;
1585         }
1586         /*
1587          * If we didn't get it and the block might work if fragmented,
1588          * try without the CONTIG flag.  Loop until we get it all.
1589          */
1590         else if (nmap == 0 && count > 1) {
1591                 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1592                 for (b = bno, mapi = 0; b < bno + count; ) {
1593                         nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1594                         c = (int)(bno + count - b);
1595                         if ((error = xfs_bmapi(tp, dp, b, c,
1596                                         XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|
1597                                         XFS_BMAPI_METADATA,
1598                                         args->firstblock, args->total,
1599                                         &mapp[mapi], &nmap, args->flist,
1600                                         NULL))) {
1601                                 kmem_free(mapp, sizeof(*mapp) * count);
1602                                 return error;
1603                         }
1604                         if (nmap < 1)
1605                                 break;
1606                         mapi += nmap;
1607                         b = mapp[mapi - 1].br_startoff +
1608                             mapp[mapi - 1].br_blockcount;
1609                 }
1610         } else {
1611                 mapi = 0;
1612                 mapp = NULL;
1613         }
1614         /*
1615          * Count the blocks we got, make sure it matches the total.
1616          */
1617         for (i = 0, got = 0; i < mapi; i++)
1618                 got += mapp[i].br_blockcount;
1619         if (got != count || mapp[0].br_startoff != bno ||
1620             mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1621             bno + count) {
1622                 if (mapp != &map)
1623                         kmem_free(mapp, sizeof(*mapp) * count);
1624                 return XFS_ERROR(ENOSPC);
1625         }
1626         if (mapp != &map)
1627                 kmem_free(mapp, sizeof(*mapp) * count);
1628         *new_blkno = (xfs_dablk_t)bno;
1629         return 0;
1630 }
1631
1632 /*
1633  * Ick.  We need to always be able to remove a btree block, even
1634  * if there's no space reservation because the filesystem is full.
1635  * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1636  * It swaps the target block with the last block in the file.  The
1637  * last block in the file can always be removed since it can't cause
1638  * a bmap btree split to do that.
1639  */
1640 STATIC int
1641 xfs_da_swap_lastblock(xfs_da_args_t *args, xfs_dablk_t *dead_blknop,
1642                       xfs_dabuf_t **dead_bufp)
1643 {
1644         xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1645         xfs_dabuf_t *dead_buf, *last_buf, *sib_buf, *par_buf;
1646         xfs_fileoff_t lastoff;
1647         xfs_inode_t *ip;
1648         xfs_trans_t *tp;
1649         xfs_mount_t *mp;
1650         int error, w, entno, level, dead_level;
1651         xfs_da_blkinfo_t *dead_info, *sib_info;
1652         xfs_da_intnode_t *par_node, *dead_node;
1653         xfs_dir2_leaf_t *dead_leaf2;
1654         xfs_dahash_t dead_hash;
1655
1656         dead_buf = *dead_bufp;
1657         dead_blkno = *dead_blknop;
1658         tp = args->trans;
1659         ip = args->dp;
1660         w = args->whichfork;
1661         ASSERT(w == XFS_DATA_FORK);
1662         mp = ip->i_mount;
1663         lastoff = mp->m_dirfreeblk;
1664         error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1665         if (error)
1666                 return error;
1667         if (unlikely(lastoff == 0)) {
1668                 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1669                                  mp);
1670                 return XFS_ERROR(EFSCORRUPTED);
1671         }
1672         /*
1673          * Read the last block in the btree space.
1674          */
1675         last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1676         if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
1677                 return error;
1678         /*
1679          * Copy the last block into the dead buffer and log it.
1680          */
1681         memcpy(dead_buf->data, last_buf->data, mp->m_dirblksize);
1682         xfs_da_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1683         dead_info = dead_buf->data;
1684         /*
1685          * Get values from the moved block.
1686          */
1687         if (be16_to_cpu(dead_info->magic) == XFS_DIR2_LEAFN_MAGIC) {
1688                 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1689                 dead_level = 0;
1690                 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1691         } else {
1692                 ASSERT(be16_to_cpu(dead_info->magic) == XFS_DA_NODE_MAGIC);
1693                 dead_node = (xfs_da_intnode_t *)dead_info;
1694                 dead_level = be16_to_cpu(dead_node->hdr.level);
1695                 dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
1696         }
1697         sib_buf = par_buf = NULL;
1698         /*
1699          * If the moved block has a left sibling, fix up the pointers.
1700          */
1701         if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1702                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1703                         goto done;
1704                 sib_info = sib_buf->data;
1705                 if (unlikely(
1706                     be32_to_cpu(sib_info->forw) != last_blkno ||
1707                     sib_info->magic != dead_info->magic)) {
1708                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1709                                          XFS_ERRLEVEL_LOW, mp);
1710                         error = XFS_ERROR(EFSCORRUPTED);
1711                         goto done;
1712                 }
1713                 sib_info->forw = cpu_to_be32(dead_blkno);
1714                 xfs_da_log_buf(tp, sib_buf,
1715                         XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1716                                         sizeof(sib_info->forw)));
1717                 xfs_da_buf_done(sib_buf);
1718                 sib_buf = NULL;
1719         }
1720         /*
1721          * If the moved block has a right sibling, fix up the pointers.
1722          */
1723         if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1724                 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1725                         goto done;
1726                 sib_info = sib_buf->data;
1727                 if (unlikely(
1728                        be32_to_cpu(sib_info->back) != last_blkno ||
1729                        sib_info->magic != dead_info->magic)) {
1730                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1731                                          XFS_ERRLEVEL_LOW, mp);
1732                         error = XFS_ERROR(EFSCORRUPTED);
1733                         goto done;
1734                 }
1735                 sib_info->back = cpu_to_be32(dead_blkno);
1736                 xfs_da_log_buf(tp, sib_buf,
1737                         XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1738                                         sizeof(sib_info->back)));
1739                 xfs_da_buf_done(sib_buf);
1740                 sib_buf = NULL;
1741         }
1742         par_blkno = mp->m_dirleafblk;
1743         level = -1;
1744         /*
1745          * Walk down the tree looking for the parent of the moved block.
1746          */
1747         for (;;) {
1748                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1749                         goto done;
1750                 par_node = par_buf->data;
1751                 if (unlikely(
1752                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC ||
1753                     (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
1754                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1755                                          XFS_ERRLEVEL_LOW, mp);
1756                         error = XFS_ERROR(EFSCORRUPTED);
1757                         goto done;
1758                 }
1759                 level = be16_to_cpu(par_node->hdr.level);
1760                 for (entno = 0;
1761                      entno < be16_to_cpu(par_node->hdr.count) &&
1762                      be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
1763                      entno++)
1764                         continue;
1765                 if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
1766                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1767                                          XFS_ERRLEVEL_LOW, mp);
1768                         error = XFS_ERROR(EFSCORRUPTED);
1769                         goto done;
1770                 }
1771                 par_blkno = be32_to_cpu(par_node->btree[entno].before);
1772                 if (level == dead_level + 1)
1773                         break;
1774                 xfs_da_brelse(tp, par_buf);
1775                 par_buf = NULL;
1776         }
1777         /*
1778          * We're in the right parent block.
1779          * Look for the right entry.
1780          */
1781         for (;;) {
1782                 for (;
1783                      entno < be16_to_cpu(par_node->hdr.count) &&
1784                      be32_to_cpu(par_node->btree[entno].before) != last_blkno;
1785                      entno++)
1786                         continue;
1787                 if (entno < be16_to_cpu(par_node->hdr.count))
1788                         break;
1789                 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1790                 xfs_da_brelse(tp, par_buf);
1791                 par_buf = NULL;
1792                 if (unlikely(par_blkno == 0)) {
1793                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1794                                          XFS_ERRLEVEL_LOW, mp);
1795                         error = XFS_ERROR(EFSCORRUPTED);
1796                         goto done;
1797                 }
1798                 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1799                         goto done;
1800                 par_node = par_buf->data;
1801                 if (unlikely(
1802                     be16_to_cpu(par_node->hdr.level) != level ||
1803                     be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC)) {
1804                         XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1805                                          XFS_ERRLEVEL_LOW, mp);
1806                         error = XFS_ERROR(EFSCORRUPTED);
1807                         goto done;
1808                 }
1809                 entno = 0;
1810         }
1811         /*
1812          * Update the parent entry pointing to the moved block.
1813          */
1814         par_node->btree[entno].before = cpu_to_be32(dead_blkno);
1815         xfs_da_log_buf(tp, par_buf,
1816                 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1817                                 sizeof(par_node->btree[entno].before)));
1818         xfs_da_buf_done(par_buf);
1819         xfs_da_buf_done(dead_buf);
1820         *dead_blknop = last_blkno;
1821         *dead_bufp = last_buf;
1822         return 0;
1823 done:
1824         if (par_buf)
1825                 xfs_da_brelse(tp, par_buf);
1826         if (sib_buf)
1827                 xfs_da_brelse(tp, sib_buf);
1828         xfs_da_brelse(tp, last_buf);
1829         return error;
1830 }
1831
1832 /*
1833  * Remove a btree block from a directory or attribute.
1834  */
1835 int
1836 xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
1837                     xfs_dabuf_t *dead_buf)
1838 {
1839         xfs_inode_t *dp;
1840         int done, error, w, count;
1841         xfs_trans_t *tp;
1842         xfs_mount_t *mp;
1843
1844         dp = args->dp;
1845         w = args->whichfork;
1846         tp = args->trans;
1847         mp = dp->i_mount;
1848         if (w == XFS_DATA_FORK)
1849                 count = mp->m_dirblkfsbs;
1850         else
1851                 count = 1;
1852         for (;;) {
1853                 /*
1854                  * Remove extents.  If we get ENOSPC for a dir we have to move
1855                  * the last block to the place we want to kill.
1856                  */
1857                 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
1858                                 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_METADATA,
1859                                 0, args->firstblock, args->flist, NULL,
1860                                 &done)) == ENOSPC) {
1861                         if (w != XFS_DATA_FORK)
1862                                 break;
1863                         if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
1864                                         &dead_buf)))
1865                                 break;
1866                 } else {
1867                         break;
1868                 }
1869         }
1870         xfs_da_binval(tp, dead_buf);
1871         return error;
1872 }
1873
1874 /*
1875  * See if the mapping(s) for this btree block are valid, i.e.
1876  * don't contain holes, are logically contiguous, and cover the whole range.
1877  */
1878 STATIC int
1879 xfs_da_map_covers_blocks(
1880         int             nmap,
1881         xfs_bmbt_irec_t *mapp,
1882         xfs_dablk_t     bno,
1883         int             count)
1884 {
1885         int             i;
1886         xfs_fileoff_t   off;
1887
1888         for (i = 0, off = bno; i < nmap; i++) {
1889                 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
1890                     mapp[i].br_startblock == DELAYSTARTBLOCK) {
1891                         return 0;
1892                 }
1893                 if (off != mapp[i].br_startoff) {
1894                         return 0;
1895                 }
1896                 off += mapp[i].br_blockcount;
1897         }
1898         return off == bno + count;
1899 }
1900
1901 /*
1902  * Make a dabuf.
1903  * Used for get_buf, read_buf, read_bufr, and reada_buf.
1904  */
1905 STATIC int
1906 xfs_da_do_buf(
1907         xfs_trans_t     *trans,
1908         xfs_inode_t     *dp,
1909         xfs_dablk_t     bno,
1910         xfs_daddr_t     *mappedbnop,
1911         xfs_dabuf_t     **bpp,
1912         int             whichfork,
1913         int             caller,
1914         inst_t          *ra)
1915 {
1916         xfs_buf_t       *bp = NULL;
1917         xfs_buf_t       **bplist;
1918         int             error=0;
1919         int             i;
1920         xfs_bmbt_irec_t map;
1921         xfs_bmbt_irec_t *mapp;
1922         xfs_daddr_t     mappedbno;
1923         xfs_mount_t     *mp;
1924         int             nbplist=0;
1925         int             nfsb;
1926         int             nmap;
1927         xfs_dabuf_t     *rbp;
1928
1929         mp = dp->i_mount;
1930         nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
1931         mappedbno = *mappedbnop;
1932         /*
1933          * Caller doesn't have a mapping.  -2 means don't complain
1934          * if we land in a hole.
1935          */
1936         if (mappedbno == -1 || mappedbno == -2) {
1937                 /*
1938                  * Optimize the one-block case.
1939                  */
1940                 if (nfsb == 1) {
1941                         xfs_fsblock_t   fsb;
1942
1943                         if ((error =
1944                             xfs_bmapi_single(trans, dp, whichfork, &fsb,
1945                                     (xfs_fileoff_t)bno))) {
1946                                 return error;
1947                         }
1948                         mapp = &map;
1949                         if (fsb == NULLFSBLOCK) {
1950                                 nmap = 0;
1951                         } else {
1952                                 map.br_startblock = fsb;
1953                                 map.br_startoff = (xfs_fileoff_t)bno;
1954                                 map.br_blockcount = 1;
1955                                 nmap = 1;
1956                         }
1957                 } else {
1958                         mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
1959                         nmap = nfsb;
1960                         if ((error = xfs_bmapi(trans, dp, (xfs_fileoff_t)bno,
1961                                         nfsb,
1962                                         XFS_BMAPI_METADATA |
1963                                                 XFS_BMAPI_AFLAG(whichfork),
1964                                         NULL, 0, mapp, &nmap, NULL, NULL)))
1965                                 goto exit0;
1966                 }
1967         } else {
1968                 map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
1969                 map.br_startoff = (xfs_fileoff_t)bno;
1970                 map.br_blockcount = nfsb;
1971                 mapp = &map;
1972                 nmap = 1;
1973         }
1974         if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
1975                 error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
1976                 if (unlikely(error == EFSCORRUPTED)) {
1977                         if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
1978                                 int     i;
1979                                 cmn_err(CE_ALERT, "xfs_da_do_buf: bno %lld\n",
1980                                         (long long)bno);
1981                                 cmn_err(CE_ALERT, "dir: inode %lld\n",
1982                                         (long long)dp->i_ino);
1983                                 for (i = 0; i < nmap; i++) {
1984                                         cmn_err(CE_ALERT,
1985                                                 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d\n",
1986                                                 i,
1987                                                 (long long)mapp[i].br_startoff,
1988                                                 (long long)mapp[i].br_startblock,
1989                                                 (long long)mapp[i].br_blockcount,
1990                                                 mapp[i].br_state);
1991                                 }
1992                         }
1993                         XFS_ERROR_REPORT("xfs_da_do_buf(1)",
1994                                          XFS_ERRLEVEL_LOW, mp);
1995                 }
1996                 goto exit0;
1997         }
1998         if (caller != 3 && nmap > 1) {
1999                 bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
2000                 nbplist = 0;
2001         } else
2002                 bplist = NULL;
2003         /*
2004          * Turn the mapping(s) into buffer(s).
2005          */
2006         for (i = 0; i < nmap; i++) {
2007                 int     nmapped;
2008
2009                 mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
2010                 if (i == 0)
2011                         *mappedbnop = mappedbno;
2012                 nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
2013                 switch (caller) {
2014                 case 0:
2015                         bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
2016                                 mappedbno, nmapped, 0);
2017                         error = bp ? XFS_BUF_GETERROR(bp) : XFS_ERROR(EIO);
2018                         break;
2019                 case 1:
2020                 case 2:
2021                         bp = NULL;
2022                         error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
2023                                 mappedbno, nmapped, 0, &bp);
2024                         break;
2025                 case 3:
2026                         xfs_baread(mp->m_ddev_targp, mappedbno, nmapped);
2027                         error = 0;
2028                         bp = NULL;
2029                         break;
2030                 }
2031                 if (error) {
2032                         if (bp)
2033                                 xfs_trans_brelse(trans, bp);
2034                         goto exit1;
2035                 }
2036                 if (!bp)
2037                         continue;
2038                 if (caller == 1) {
2039                         if (whichfork == XFS_ATTR_FORK) {
2040                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_ATTR_BTREE,
2041                                                 XFS_ATTR_BTREE_REF);
2042                         } else {
2043                                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_DIR_BTREE,
2044                                                 XFS_DIR_BTREE_REF);
2045                         }
2046                 }
2047                 if (bplist) {
2048                         bplist[nbplist++] = bp;
2049                 }
2050         }
2051         /*
2052          * Build a dabuf structure.
2053          */
2054         if (bplist) {
2055                 rbp = xfs_da_buf_make(nbplist, bplist, ra);
2056         } else if (bp)
2057                 rbp = xfs_da_buf_make(1, &bp, ra);
2058         else
2059                 rbp = NULL;
2060         /*
2061          * For read_buf, check the magic number.
2062          */
2063         if (caller == 1) {
2064                 xfs_dir2_data_t         *data;
2065                 xfs_dir2_free_t         *free;
2066                 xfs_da_blkinfo_t        *info;
2067                 uint                    magic, magic1;
2068
2069                 info = rbp->data;
2070                 data = rbp->data;
2071                 free = rbp->data;
2072                 magic = be16_to_cpu(info->magic);
2073                 magic1 = be32_to_cpu(data->hdr.magic);
2074                 if (unlikely(
2075                     XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2076                                    (magic != XFS_ATTR_LEAF_MAGIC) &&
2077                                    (magic != XFS_DIR2_LEAF1_MAGIC) &&
2078                                    (magic != XFS_DIR2_LEAFN_MAGIC) &&
2079                                    (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2080                                    (magic1 != XFS_DIR2_DATA_MAGIC) &&
2081                                    (be32_to_cpu(free->hdr.magic) != XFS_DIR2_FREE_MAGIC),
2082                                 mp, XFS_ERRTAG_DA_READ_BUF,
2083                                 XFS_RANDOM_DA_READ_BUF))) {
2084                         xfs_buftrace("DA READ ERROR", rbp->bps[0]);
2085                         XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2086                                              XFS_ERRLEVEL_LOW, mp, info);
2087                         error = XFS_ERROR(EFSCORRUPTED);
2088                         xfs_da_brelse(trans, rbp);
2089                         nbplist = 0;
2090                         goto exit1;
2091                 }
2092         }
2093         if (bplist) {
2094                 kmem_free(bplist, sizeof(*bplist) * nmap);
2095         }
2096         if (mapp != &map) {
2097                 kmem_free(mapp, sizeof(*mapp) * nfsb);
2098         }
2099         if (bpp)
2100                 *bpp = rbp;
2101         return 0;
2102 exit1:
2103         if (bplist) {
2104                 for (i = 0; i < nbplist; i++)
2105                         xfs_trans_brelse(trans, bplist[i]);
2106                 kmem_free(bplist, sizeof(*bplist) * nmap);
2107         }
2108 exit0:
2109         if (mapp != &map)
2110                 kmem_free(mapp, sizeof(*mapp) * nfsb);
2111         if (bpp)
2112                 *bpp = NULL;
2113         return error;
2114 }
2115
2116 /*
2117  * Get a buffer for the dir/attr block.
2118  */
2119 int
2120 xfs_da_get_buf(
2121         xfs_trans_t     *trans,
2122         xfs_inode_t     *dp,
2123         xfs_dablk_t     bno,
2124         xfs_daddr_t             mappedbno,
2125         xfs_dabuf_t     **bpp,
2126         int             whichfork)
2127 {
2128         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0,
2129                                                  (inst_t *)__return_address);
2130 }
2131
2132 /*
2133  * Get a buffer for the dir/attr block, fill in the contents.
2134  */
2135 int
2136 xfs_da_read_buf(
2137         xfs_trans_t     *trans,
2138         xfs_inode_t     *dp,
2139         xfs_dablk_t     bno,
2140         xfs_daddr_t             mappedbno,
2141         xfs_dabuf_t     **bpp,
2142         int             whichfork)
2143 {
2144         return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1,
2145                 (inst_t *)__return_address);
2146 }
2147
2148 /*
2149  * Readahead the dir/attr block.
2150  */
2151 xfs_daddr_t
2152 xfs_da_reada_buf(
2153         xfs_trans_t     *trans,
2154         xfs_inode_t     *dp,
2155         xfs_dablk_t     bno,
2156         int             whichfork)
2157 {
2158         xfs_daddr_t             rval;
2159
2160         rval = -1;
2161         if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3,
2162                         (inst_t *)__return_address))
2163                 return -1;
2164         else
2165                 return rval;
2166 }
2167
2168 /*
2169  * Calculate the number of bits needed to hold i different values.
2170  */
2171 uint
2172 xfs_da_log2_roundup(uint i)
2173 {
2174         uint rval;
2175
2176         for (rval = 0; rval < NBBY * sizeof(i); rval++) {
2177                 if ((1 << rval) >= i)
2178                         break;
2179         }
2180         return(rval);
2181 }
2182
2183 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2184 kmem_zone_t *xfs_dabuf_zone;            /* dabuf zone */
2185
2186 /*
2187  * Allocate a dir-state structure.
2188  * We don't put them on the stack since they're large.
2189  */
2190 xfs_da_state_t *
2191 xfs_da_state_alloc(void)
2192 {
2193         return kmem_zone_zalloc(xfs_da_state_zone, KM_SLEEP);
2194 }
2195
2196 /*
2197  * Kill the altpath contents of a da-state structure.
2198  */
2199 STATIC void
2200 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2201 {
2202         int     i;
2203
2204         for (i = 0; i < state->altpath.active; i++) {
2205                 if (state->altpath.blk[i].bp) {
2206                         if (state->altpath.blk[i].bp != state->path.blk[i].bp)
2207                                 xfs_da_buf_done(state->altpath.blk[i].bp);
2208                         state->altpath.blk[i].bp = NULL;
2209                 }
2210         }
2211         state->altpath.active = 0;
2212 }
2213
2214 /*
2215  * Free a da-state structure.
2216  */
2217 void
2218 xfs_da_state_free(xfs_da_state_t *state)
2219 {
2220         int     i;
2221
2222         xfs_da_state_kill_altpath(state);
2223         for (i = 0; i < state->path.active; i++) {
2224                 if (state->path.blk[i].bp)
2225                         xfs_da_buf_done(state->path.blk[i].bp);
2226         }
2227         if (state->extravalid && state->extrablk.bp)
2228                 xfs_da_buf_done(state->extrablk.bp);
2229 #ifdef DEBUG
2230         memset((char *)state, 0, sizeof(*state));
2231 #endif /* DEBUG */
2232         kmem_zone_free(xfs_da_state_zone, state);
2233 }
2234
2235 #ifdef XFS_DABUF_DEBUG
2236 xfs_dabuf_t     *xfs_dabuf_global_list;
2237 lock_t          xfs_dabuf_global_lock;
2238 #endif
2239
2240 /*
2241  * Create a dabuf.
2242  */
2243 /* ARGSUSED */
2244 STATIC xfs_dabuf_t *
2245 xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra)
2246 {
2247         xfs_buf_t       *bp;
2248         xfs_dabuf_t     *dabuf;
2249         int             i;
2250         int             off;
2251
2252         if (nbuf == 1)
2253                 dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_SLEEP);
2254         else
2255                 dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_SLEEP);
2256         dabuf->dirty = 0;
2257 #ifdef XFS_DABUF_DEBUG
2258         dabuf->ra = ra;
2259         dabuf->target = XFS_BUF_TARGET(bps[0]);
2260         dabuf->blkno = XFS_BUF_ADDR(bps[0]);
2261 #endif
2262         if (nbuf == 1) {
2263                 dabuf->nbuf = 1;
2264                 bp = bps[0];
2265                 dabuf->bbcount = (short)BTOBB(XFS_BUF_COUNT(bp));
2266                 dabuf->data = XFS_BUF_PTR(bp);
2267                 dabuf->bps[0] = bp;
2268         } else {
2269                 dabuf->nbuf = nbuf;
2270                 for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
2271                         dabuf->bps[i] = bp = bps[i];
2272                         dabuf->bbcount += BTOBB(XFS_BUF_COUNT(bp));
2273                 }
2274                 dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
2275                 for (i = off = 0; i < nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2276                         bp = bps[i];
2277                         memcpy((char *)dabuf->data + off, XFS_BUF_PTR(bp),
2278                                 XFS_BUF_COUNT(bp));
2279                 }
2280         }
2281 #ifdef XFS_DABUF_DEBUG
2282         {
2283                 SPLDECL(s);
2284                 xfs_dabuf_t     *p;
2285
2286                 s = mutex_spinlock(&xfs_dabuf_global_lock);
2287                 for (p = xfs_dabuf_global_list; p; p = p->next) {
2288                         ASSERT(p->blkno != dabuf->blkno ||
2289                                p->target != dabuf->target);
2290                 }
2291                 dabuf->prev = NULL;
2292                 if (xfs_dabuf_global_list)
2293                         xfs_dabuf_global_list->prev = dabuf;
2294                 dabuf->next = xfs_dabuf_global_list;
2295                 xfs_dabuf_global_list = dabuf;
2296                 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2297         }
2298 #endif
2299         return dabuf;
2300 }
2301
2302 /*
2303  * Un-dirty a dabuf.
2304  */
2305 STATIC void
2306 xfs_da_buf_clean(xfs_dabuf_t *dabuf)
2307 {
2308         xfs_buf_t       *bp;
2309         int             i;
2310         int             off;
2311
2312         if (dabuf->dirty) {
2313                 ASSERT(dabuf->nbuf > 1);
2314                 dabuf->dirty = 0;
2315                 for (i = off = 0; i < dabuf->nbuf;
2316                                 i++, off += XFS_BUF_COUNT(bp)) {
2317                         bp = dabuf->bps[i];
2318                         memcpy(XFS_BUF_PTR(bp), (char *)dabuf->data + off,
2319                                 XFS_BUF_COUNT(bp));
2320                 }
2321         }
2322 }
2323
2324 /*
2325  * Release a dabuf.
2326  */
2327 void
2328 xfs_da_buf_done(xfs_dabuf_t *dabuf)
2329 {
2330         ASSERT(dabuf);
2331         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2332         if (dabuf->dirty)
2333                 xfs_da_buf_clean(dabuf);
2334         if (dabuf->nbuf > 1)
2335                 kmem_free(dabuf->data, BBTOB(dabuf->bbcount));
2336 #ifdef XFS_DABUF_DEBUG
2337         {
2338                 SPLDECL(s);
2339
2340                 s = mutex_spinlock(&xfs_dabuf_global_lock);
2341                 if (dabuf->prev)
2342                         dabuf->prev->next = dabuf->next;
2343                 else
2344                         xfs_dabuf_global_list = dabuf->next;
2345                 if (dabuf->next)
2346                         dabuf->next->prev = dabuf->prev;
2347                 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2348         }
2349         memset(dabuf, 0, XFS_DA_BUF_SIZE(dabuf->nbuf));
2350 #endif
2351         if (dabuf->nbuf == 1)
2352                 kmem_zone_free(xfs_dabuf_zone, dabuf);
2353         else
2354                 kmem_free(dabuf, XFS_DA_BUF_SIZE(dabuf->nbuf));
2355 }
2356
2357 /*
2358  * Log transaction from a dabuf.
2359  */
2360 void
2361 xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
2362 {
2363         xfs_buf_t       *bp;
2364         uint            f;
2365         int             i;
2366         uint            l;
2367         int             off;
2368
2369         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2370         if (dabuf->nbuf == 1) {
2371                 ASSERT(dabuf->data == (void *)XFS_BUF_PTR(dabuf->bps[0]));
2372                 xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
2373                 return;
2374         }
2375         dabuf->dirty = 1;
2376         ASSERT(first <= last);
2377         for (i = off = 0; i < dabuf->nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2378                 bp = dabuf->bps[i];
2379                 f = off;
2380                 l = f + XFS_BUF_COUNT(bp) - 1;
2381                 if (f < first)
2382                         f = first;
2383                 if (l > last)
2384                         l = last;
2385                 if (f <= l)
2386                         xfs_trans_log_buf(tp, bp, f - off, l - off);
2387                 /*
2388                  * B_DONE is set by xfs_trans_log buf.
2389                  * If we don't set it on a new buffer (get not read)
2390                  * then if we don't put anything in the buffer it won't
2391                  * be set, and at commit it it released into the cache,
2392                  * and then a read will fail.
2393                  */
2394                 else if (!(XFS_BUF_ISDONE(bp)))
2395                   XFS_BUF_DONE(bp);
2396         }
2397         ASSERT(last < off);
2398 }
2399
2400 /*
2401  * Release dabuf from a transaction.
2402  * Have to free up the dabuf before the buffers are released,
2403  * since the synchronization on the dabuf is really the lock on the buffer.
2404  */
2405 void
2406 xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2407 {
2408         xfs_buf_t       *bp;
2409         xfs_buf_t       **bplist;
2410         int             i;
2411         int             nbuf;
2412
2413         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2414         if ((nbuf = dabuf->nbuf) == 1) {
2415                 bplist = &bp;
2416                 bp = dabuf->bps[0];
2417         } else {
2418                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2419                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2420         }
2421         xfs_da_buf_done(dabuf);
2422         for (i = 0; i < nbuf; i++)
2423                 xfs_trans_brelse(tp, bplist[i]);
2424         if (bplist != &bp)
2425                 kmem_free(bplist, nbuf * sizeof(*bplist));
2426 }
2427
2428 /*
2429  * Invalidate dabuf from a transaction.
2430  */
2431 void
2432 xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2433 {
2434         xfs_buf_t       *bp;
2435         xfs_buf_t       **bplist;
2436         int             i;
2437         int             nbuf;
2438
2439         ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2440         if ((nbuf = dabuf->nbuf) == 1) {
2441                 bplist = &bp;
2442                 bp = dabuf->bps[0];
2443         } else {
2444                 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2445                 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2446         }
2447         xfs_da_buf_done(dabuf);
2448         for (i = 0; i < nbuf; i++)
2449                 xfs_trans_binval(tp, bplist[i]);
2450         if (bplist != &bp)
2451                 kmem_free(bplist, nbuf * sizeof(*bplist));
2452 }
2453
2454 /*
2455  * Get the first daddr from a dabuf.
2456  */
2457 xfs_daddr_t
2458 xfs_da_blkno(xfs_dabuf_t *dabuf)
2459 {
2460         ASSERT(dabuf->nbuf);
2461         ASSERT(dabuf->data);
2462         return XFS_BUF_ADDR(dabuf->bps[0]);
2463 }