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WAN: Simplify sca_init_port() in HD64572 driver.
[linux-2.6/cjktty.git] / fs / xfs / xfs_da_btree.c
bloba11a8390bf6caa7d12270e182efabee7f5fcffac
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_cpu(&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_cpu(&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_cpu(&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_cpu(&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_cpu(&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_cpu(&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_cpu(&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->op_flags & XFS_DA_OP_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 enum xfs_dacmp
1534 xfs_da_compname(
1535 struct xfs_da_args *args,
1536 const char *name,
1537 int len)
1538 {
1539 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
1540 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
1541 }
1542
1543 static xfs_dahash_t
1544 xfs_default_hashname(
1545 struct xfs_name *name)
1546 {
1547 return xfs_da_hashname(name->name, name->len);
1548 }
1549
1550 const struct xfs_nameops xfs_default_nameops = {
1551 .hashname = xfs_default_hashname,
1552 .compname = xfs_da_compname
1553 };
1554
1555 /*
1556 * Add a block to the btree ahead of the file.
1557 * Return the new block number to the caller.
1558 */
1559 int
1560 xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
1561 {
1562 xfs_fileoff_t bno, b;
1563 xfs_bmbt_irec_t map;
1564 xfs_bmbt_irec_t *mapp;
1565 xfs_inode_t *dp;
1566 int nmap, error, w, count, c, got, i, mapi;
1567 xfs_trans_t *tp;
1568 xfs_mount_t *mp;
1569 xfs_drfsbno_t nblks;
1570
1571 dp = args->dp;
1572 mp = dp->i_mount;
1573 w = args->whichfork;
1574 tp = args->trans;
1575 nblks = dp->i_d.di_nblocks;
1576
1577 /*
1578 * For new directories adjust the file offset and block count.
1579 */
1580 if (w == XFS_DATA_FORK) {
1581 bno = mp->m_dirleafblk;
1582 count = mp->m_dirblkfsbs;
1583 } else {
1584 bno = 0;
1585 count = 1;
1586 }
1587 /*
1588 * Find a spot in the file space to put the new block.
1589 */
1590 if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, w)))
1591 return error;
1592 if (w == XFS_DATA_FORK)
1593 ASSERT(bno >= mp->m_dirleafblk && bno < mp->m_dirfreeblk);
1594 /*
1595 * Try mapping it in one filesystem block.
1596 */
1597 nmap = 1;
1598 ASSERT(args->firstblock != NULL);
1599 if ((error = xfs_bmapi(tp, dp, bno, count,
1600 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|
1601 XFS_BMAPI_CONTIG,
1602 args->firstblock, args->total, &map, &nmap,
1603 args->flist, NULL))) {
1604 return error;
1605 }
1606 ASSERT(nmap <= 1);
1607 if (nmap == 1) {
1608 mapp = &map;
1609 mapi = 1;
1610 }
1611 /*
1612 * If we didn't get it and the block might work if fragmented,
1613 * try without the CONTIG flag. Loop until we get it all.
1614 */
1615 else if (nmap == 0 && count > 1) {
1616 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1617 for (b = bno, mapi = 0; b < bno + count; ) {
1618 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1619 c = (int)(bno + count - b);
1620 if ((error = xfs_bmapi(tp, dp, b, c,
1621 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|
1622 XFS_BMAPI_METADATA,
1623 args->firstblock, args->total,
1624 &mapp[mapi], &nmap, args->flist,
1625 NULL))) {
1626 kmem_free(mapp);
1627 return error;
1628 }
1629 if (nmap < 1)
1630 break;
1631 mapi += nmap;
1632 b = mapp[mapi - 1].br_startoff +
1633 mapp[mapi - 1].br_blockcount;
1634 }
1635 } else {
1636 mapi = 0;
1637 mapp = NULL;
1638 }
1639 /*
1640 * Count the blocks we got, make sure it matches the total.
1641 */
1642 for (i = 0, got = 0; i < mapi; i++)
1643 got += mapp[i].br_blockcount;
1644 if (got != count || mapp[0].br_startoff != bno ||
1645 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1646 bno + count) {
1647 if (mapp != &map)
1648 kmem_free(mapp);
1649 return XFS_ERROR(ENOSPC);
1650 }
1651 if (mapp != &map)
1652 kmem_free(mapp);
1653 /* account for newly allocated blocks in reserved blocks total */
1654 args->total -= dp->i_d.di_nblocks - nblks;
1655 *new_blkno = (xfs_dablk_t)bno;
1656 return 0;
1657 }
1658
1659 /*
1660 * Ick. We need to always be able to remove a btree block, even
1661 * if there's no space reservation because the filesystem is full.
1662 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1663 * It swaps the target block with the last block in the file. The
1664 * last block in the file can always be removed since it can't cause
1665 * a bmap btree split to do that.
1666 */
1667 STATIC int
1668 xfs_da_swap_lastblock(xfs_da_args_t *args, xfs_dablk_t *dead_blknop,
1669 xfs_dabuf_t **dead_bufp)
1670 {
1671 xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1672 xfs_dabuf_t *dead_buf, *last_buf, *sib_buf, *par_buf;
1673 xfs_fileoff_t lastoff;
1674 xfs_inode_t *ip;
1675 xfs_trans_t *tp;
1676 xfs_mount_t *mp;
1677 int error, w, entno, level, dead_level;
1678 xfs_da_blkinfo_t *dead_info, *sib_info;
1679 xfs_da_intnode_t *par_node, *dead_node;
1680 xfs_dir2_leaf_t *dead_leaf2;
1681 xfs_dahash_t dead_hash;
1682
1683 dead_buf = *dead_bufp;
1684 dead_blkno = *dead_blknop;
1685 tp = args->trans;
1686 ip = args->dp;
1687 w = args->whichfork;
1688 ASSERT(w == XFS_DATA_FORK);
1689 mp = ip->i_mount;
1690 lastoff = mp->m_dirfreeblk;
1691 error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1692 if (error)
1693 return error;
1694 if (unlikely(lastoff == 0)) {
1695 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1696 mp);
1697 return XFS_ERROR(EFSCORRUPTED);
1698 }
1699 /*
1700 * Read the last block in the btree space.
1701 */
1702 last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1703 if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
1704 return error;
1705 /*
1706 * Copy the last block into the dead buffer and log it.
1707 */
1708 memcpy(dead_buf->data, last_buf->data, mp->m_dirblksize);
1709 xfs_da_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1710 dead_info = dead_buf->data;
1711 /*
1712 * Get values from the moved block.
1713 */
1714 if (be16_to_cpu(dead_info->magic) == XFS_DIR2_LEAFN_MAGIC) {
1715 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1716 dead_level = 0;
1717 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1718 } else {
1719 ASSERT(be16_to_cpu(dead_info->magic) == XFS_DA_NODE_MAGIC);
1720 dead_node = (xfs_da_intnode_t *)dead_info;
1721 dead_level = be16_to_cpu(dead_node->hdr.level);
1722 dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
1723 }
1724 sib_buf = par_buf = NULL;
1725 /*
1726 * If the moved block has a left sibling, fix up the pointers.
1727 */
1728 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1729 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1730 goto done;
1731 sib_info = sib_buf->data;
1732 if (unlikely(
1733 be32_to_cpu(sib_info->forw) != last_blkno ||
1734 sib_info->magic != dead_info->magic)) {
1735 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1736 XFS_ERRLEVEL_LOW, mp);
1737 error = XFS_ERROR(EFSCORRUPTED);
1738 goto done;
1739 }
1740 sib_info->forw = cpu_to_be32(dead_blkno);
1741 xfs_da_log_buf(tp, sib_buf,
1742 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1743 sizeof(sib_info->forw)));
1744 xfs_da_buf_done(sib_buf);
1745 sib_buf = NULL;
1746 }
1747 /*
1748 * If the moved block has a right sibling, fix up the pointers.
1749 */
1750 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1751 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1752 goto done;
1753 sib_info = sib_buf->data;
1754 if (unlikely(
1755 be32_to_cpu(sib_info->back) != last_blkno ||
1756 sib_info->magic != dead_info->magic)) {
1757 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1758 XFS_ERRLEVEL_LOW, mp);
1759 error = XFS_ERROR(EFSCORRUPTED);
1760 goto done;
1761 }
1762 sib_info->back = cpu_to_be32(dead_blkno);
1763 xfs_da_log_buf(tp, sib_buf,
1764 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1765 sizeof(sib_info->back)));
1766 xfs_da_buf_done(sib_buf);
1767 sib_buf = NULL;
1768 }
1769 par_blkno = mp->m_dirleafblk;
1770 level = -1;
1771 /*
1772 * Walk down the tree looking for the parent of the moved block.
1773 */
1774 for (;;) {
1775 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1776 goto done;
1777 par_node = par_buf->data;
1778 if (unlikely(
1779 be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC ||
1780 (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
1781 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1782 XFS_ERRLEVEL_LOW, mp);
1783 error = XFS_ERROR(EFSCORRUPTED);
1784 goto done;
1785 }
1786 level = be16_to_cpu(par_node->hdr.level);
1787 for (entno = 0;
1788 entno < be16_to_cpu(par_node->hdr.count) &&
1789 be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
1790 entno++)
1791 continue;
1792 if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
1793 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1794 XFS_ERRLEVEL_LOW, mp);
1795 error = XFS_ERROR(EFSCORRUPTED);
1796 goto done;
1797 }
1798 par_blkno = be32_to_cpu(par_node->btree[entno].before);
1799 if (level == dead_level + 1)
1800 break;
1801 xfs_da_brelse(tp, par_buf);
1802 par_buf = NULL;
1803 }
1804 /*
1805 * We're in the right parent block.
1806 * Look for the right entry.
1807 */
1808 for (;;) {
1809 for (;
1810 entno < be16_to_cpu(par_node->hdr.count) &&
1811 be32_to_cpu(par_node->btree[entno].before) != last_blkno;
1812 entno++)
1813 continue;
1814 if (entno < be16_to_cpu(par_node->hdr.count))
1815 break;
1816 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1817 xfs_da_brelse(tp, par_buf);
1818 par_buf = NULL;
1819 if (unlikely(par_blkno == 0)) {
1820 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1821 XFS_ERRLEVEL_LOW, mp);
1822 error = XFS_ERROR(EFSCORRUPTED);
1823 goto done;
1824 }
1825 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1826 goto done;
1827 par_node = par_buf->data;
1828 if (unlikely(
1829 be16_to_cpu(par_node->hdr.level) != level ||
1830 be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC)) {
1831 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1832 XFS_ERRLEVEL_LOW, mp);
1833 error = XFS_ERROR(EFSCORRUPTED);
1834 goto done;
1835 }
1836 entno = 0;
1837 }
1838 /*
1839 * Update the parent entry pointing to the moved block.
1840 */
1841 par_node->btree[entno].before = cpu_to_be32(dead_blkno);
1842 xfs_da_log_buf(tp, par_buf,
1843 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1844 sizeof(par_node->btree[entno].before)));
1845 xfs_da_buf_done(par_buf);
1846 xfs_da_buf_done(dead_buf);
1847 *dead_blknop = last_blkno;
1848 *dead_bufp = last_buf;
1849 return 0;
1850 done:
1851 if (par_buf)
1852 xfs_da_brelse(tp, par_buf);
1853 if (sib_buf)
1854 xfs_da_brelse(tp, sib_buf);
1855 xfs_da_brelse(tp, last_buf);
1856 return error;
1857 }
1858
1859 /*
1860 * Remove a btree block from a directory or attribute.
1861 */
1862 int
1863 xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
1864 xfs_dabuf_t *dead_buf)
1865 {
1866 xfs_inode_t *dp;
1867 int done, error, w, count;
1868 xfs_trans_t *tp;
1869 xfs_mount_t *mp;
1870
1871 dp = args->dp;
1872 w = args->whichfork;
1873 tp = args->trans;
1874 mp = dp->i_mount;
1875 if (w == XFS_DATA_FORK)
1876 count = mp->m_dirblkfsbs;
1877 else
1878 count = 1;
1879 for (;;) {
1880 /*
1881 * Remove extents. If we get ENOSPC for a dir we have to move
1882 * the last block to the place we want to kill.
1883 */
1884 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
1885 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_METADATA,
1886 0, args->firstblock, args->flist, NULL,
1887 &done)) == ENOSPC) {
1888 if (w != XFS_DATA_FORK)
1889 break;
1890 if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
1891 &dead_buf)))
1892 break;
1893 } else {
1894 break;
1895 }
1896 }
1897 xfs_da_binval(tp, dead_buf);
1898 return error;
1899 }
1900
1901 /*
1902 * See if the mapping(s) for this btree block are valid, i.e.
1903 * don't contain holes, are logically contiguous, and cover the whole range.
1904 */
1905 STATIC int
1906 xfs_da_map_covers_blocks(
1907 int nmap,
1908 xfs_bmbt_irec_t *mapp,
1909 xfs_dablk_t bno,
1910 int count)
1911 {
1912 int i;
1913 xfs_fileoff_t off;
1914
1915 for (i = 0, off = bno; i < nmap; i++) {
1916 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
1917 mapp[i].br_startblock == DELAYSTARTBLOCK) {
1918 return 0;
1919 }
1920 if (off != mapp[i].br_startoff) {
1921 return 0;
1922 }
1923 off += mapp[i].br_blockcount;
1924 }
1925 return off == bno + count;
1926 }
1927
1928 /*
1929 * Make a dabuf.
1930 * Used for get_buf, read_buf, read_bufr, and reada_buf.
1931 */
1932 STATIC int
1933 xfs_da_do_buf(
1934 xfs_trans_t *trans,
1935 xfs_inode_t *dp,
1936 xfs_dablk_t bno,
1937 xfs_daddr_t *mappedbnop,
1938 xfs_dabuf_t **bpp,
1939 int whichfork,
1940 int caller,
1941 inst_t *ra)
1942 {
1943 xfs_buf_t *bp = NULL;
1944 xfs_buf_t **bplist;
1945 int error=0;
1946 int i;
1947 xfs_bmbt_irec_t map;
1948 xfs_bmbt_irec_t *mapp;
1949 xfs_daddr_t mappedbno;
1950 xfs_mount_t *mp;
1951 int nbplist=0;
1952 int nfsb;
1953 int nmap;
1954 xfs_dabuf_t *rbp;
1955
1956 mp = dp->i_mount;
1957 nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
1958 mappedbno = *mappedbnop;
1959 /*
1960 * Caller doesn't have a mapping. -2 means don't complain
1961 * if we land in a hole.
1962 */
1963 if (mappedbno == -1 || mappedbno == -2) {
1964 /*
1965 * Optimize the one-block case.
1966 */
1967 if (nfsb == 1) {
1968 xfs_fsblock_t fsb;
1969
1970 if ((error =
1971 xfs_bmapi_single(trans, dp, whichfork, &fsb,
1972 (xfs_fileoff_t)bno))) {
1973 return error;
1974 }
1975 mapp = &map;
1976 if (fsb == NULLFSBLOCK) {
1977 nmap = 0;
1978 } else {
1979 map.br_startblock = fsb;
1980 map.br_startoff = (xfs_fileoff_t)bno;
1981 map.br_blockcount = 1;
1982 nmap = 1;
1983 }
1984 } else {
1985 mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
1986 nmap = nfsb;
1987 if ((error = xfs_bmapi(trans, dp, (xfs_fileoff_t)bno,
1988 nfsb,
1989 XFS_BMAPI_METADATA |
1990 XFS_BMAPI_AFLAG(whichfork),
1991 NULL, 0, mapp, &nmap, NULL, NULL)))
1992 goto exit0;
1993 }
1994 } else {
1995 map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
1996 map.br_startoff = (xfs_fileoff_t)bno;
1997 map.br_blockcount = nfsb;
1998 mapp = &map;
1999 nmap = 1;
2000 }
2001 if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
2002 error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
2003 if (unlikely(error == EFSCORRUPTED)) {
2004 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2005 cmn_err(CE_ALERT, "xfs_da_do_buf: bno %lld\n",
2006 (long long)bno);
2007 cmn_err(CE_ALERT, "dir: inode %lld\n",
2008 (long long)dp->i_ino);
2009 for (i = 0; i < nmap; i++) {
2010 cmn_err(CE_ALERT,
2011 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d\n",
2012 i,
2013 (long long)mapp[i].br_startoff,
2014 (long long)mapp[i].br_startblock,
2015 (long long)mapp[i].br_blockcount,
2016 mapp[i].br_state);
2017 }
2018 }
2019 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2020 XFS_ERRLEVEL_LOW, mp);
2021 }
2022 goto exit0;
2023 }
2024 if (caller != 3 && nmap > 1) {
2025 bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
2026 nbplist = 0;
2027 } else
2028 bplist = NULL;
2029 /*
2030 * Turn the mapping(s) into buffer(s).
2031 */
2032 for (i = 0; i < nmap; i++) {
2033 int nmapped;
2034
2035 mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
2036 if (i == 0)
2037 *mappedbnop = mappedbno;
2038 nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
2039 switch (caller) {
2040 case 0:
2041 bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
2042 mappedbno, nmapped, 0);
2043 error = bp ? XFS_BUF_GETERROR(bp) : XFS_ERROR(EIO);
2044 break;
2045 case 1:
2046 case 2:
2047 bp = NULL;
2048 error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
2049 mappedbno, nmapped, 0, &bp);
2050 break;
2051 case 3:
2052 xfs_baread(mp->m_ddev_targp, mappedbno, nmapped);
2053 error = 0;
2054 bp = NULL;
2055 break;
2056 }
2057 if (error) {
2058 if (bp)
2059 xfs_trans_brelse(trans, bp);
2060 goto exit1;
2061 }
2062 if (!bp)
2063 continue;
2064 if (caller == 1) {
2065 if (whichfork == XFS_ATTR_FORK) {
2066 XFS_BUF_SET_VTYPE_REF(bp, B_FS_ATTR_BTREE,
2067 XFS_ATTR_BTREE_REF);
2068 } else {
2069 XFS_BUF_SET_VTYPE_REF(bp, B_FS_DIR_BTREE,
2070 XFS_DIR_BTREE_REF);
2071 }
2072 }
2073 if (bplist) {
2074 bplist[nbplist++] = bp;
2075 }
2076 }
2077 /*
2078 * Build a dabuf structure.
2079 */
2080 if (bplist) {
2081 rbp = xfs_da_buf_make(nbplist, bplist, ra);
2082 } else if (bp)
2083 rbp = xfs_da_buf_make(1, &bp, ra);
2084 else
2085 rbp = NULL;
2086 /*
2087 * For read_buf, check the magic number.
2088 */
2089 if (caller == 1) {
2090 xfs_dir2_data_t *data;
2091 xfs_dir2_free_t *free;
2092 xfs_da_blkinfo_t *info;
2093 uint magic, magic1;
2094
2095 info = rbp->data;
2096 data = rbp->data;
2097 free = rbp->data;
2098 magic = be16_to_cpu(info->magic);
2099 magic1 = be32_to_cpu(data->hdr.magic);
2100 if (unlikely(
2101 XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2102 (magic != XFS_ATTR_LEAF_MAGIC) &&
2103 (magic != XFS_DIR2_LEAF1_MAGIC) &&
2104 (magic != XFS_DIR2_LEAFN_MAGIC) &&
2105 (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2106 (magic1 != XFS_DIR2_DATA_MAGIC) &&
2107 (be32_to_cpu(free->hdr.magic) != XFS_DIR2_FREE_MAGIC),
2108 mp, XFS_ERRTAG_DA_READ_BUF,
2109 XFS_RANDOM_DA_READ_BUF))) {
2110 xfs_buftrace("DA READ ERROR", rbp->bps[0]);
2111 XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2112 XFS_ERRLEVEL_LOW, mp, info);
2113 error = XFS_ERROR(EFSCORRUPTED);
2114 xfs_da_brelse(trans, rbp);
2115 nbplist = 0;
2116 goto exit1;
2117 }
2118 }
2119 if (bplist) {
2120 kmem_free(bplist);
2121 }
2122 if (mapp != &map) {
2123 kmem_free(mapp);
2124 }
2125 if (bpp)
2126 *bpp = rbp;
2127 return 0;
2128 exit1:
2129 if (bplist) {
2130 for (i = 0; i < nbplist; i++)
2131 xfs_trans_brelse(trans, bplist[i]);
2132 kmem_free(bplist);
2133 }
2134 exit0:
2135 if (mapp != &map)
2136 kmem_free(mapp);
2137 if (bpp)
2138 *bpp = NULL;
2139 return error;
2140 }
2141
2142 /*
2143 * Get a buffer for the dir/attr block.
2144 */
2145 int
2146 xfs_da_get_buf(
2147 xfs_trans_t *trans,
2148 xfs_inode_t *dp,
2149 xfs_dablk_t bno,
2150 xfs_daddr_t mappedbno,
2151 xfs_dabuf_t **bpp,
2152 int whichfork)
2153 {
2154 return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0,
2155 (inst_t *)__return_address);
2156 }
2157
2158 /*
2159 * Get a buffer for the dir/attr block, fill in the contents.
2160 */
2161 int
2162 xfs_da_read_buf(
2163 xfs_trans_t *trans,
2164 xfs_inode_t *dp,
2165 xfs_dablk_t bno,
2166 xfs_daddr_t mappedbno,
2167 xfs_dabuf_t **bpp,
2168 int whichfork)
2169 {
2170 return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1,
2171 (inst_t *)__return_address);
2172 }
2173
2174 /*
2175 * Readahead the dir/attr block.
2176 */
2177 xfs_daddr_t
2178 xfs_da_reada_buf(
2179 xfs_trans_t *trans,
2180 xfs_inode_t *dp,
2181 xfs_dablk_t bno,
2182 int whichfork)
2183 {
2184 xfs_daddr_t rval;
2185
2186 rval = -1;
2187 if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3,
2188 (inst_t *)__return_address))
2189 return -1;
2190 else
2191 return rval;
2192 }
2193
2194 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2195 kmem_zone_t *xfs_dabuf_zone; /* dabuf zone */
2196
2197 /*
2198 * Allocate a dir-state structure.
2199 * We don't put them on the stack since they're large.
2200 */
2201 xfs_da_state_t *
2202 xfs_da_state_alloc(void)
2203 {
2204 return kmem_zone_zalloc(xfs_da_state_zone, KM_SLEEP);
2205 }
2206
2207 /*
2208 * Kill the altpath contents of a da-state structure.
2209 */
2210 STATIC void
2211 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2212 {
2213 int i;
2214
2215 for (i = 0; i < state->altpath.active; i++) {
2216 if (state->altpath.blk[i].bp) {
2217 if (state->altpath.blk[i].bp != state->path.blk[i].bp)
2218 xfs_da_buf_done(state->altpath.blk[i].bp);
2219 state->altpath.blk[i].bp = NULL;
2220 }
2221 }
2222 state->altpath.active = 0;
2223 }
2224
2225 /*
2226 * Free a da-state structure.
2227 */
2228 void
2229 xfs_da_state_free(xfs_da_state_t *state)
2230 {
2231 int i;
2232
2233 xfs_da_state_kill_altpath(state);
2234 for (i = 0; i < state->path.active; i++) {
2235 if (state->path.blk[i].bp)
2236 xfs_da_buf_done(state->path.blk[i].bp);
2237 }
2238 if (state->extravalid && state->extrablk.bp)
2239 xfs_da_buf_done(state->extrablk.bp);
2240 #ifdef DEBUG
2241 memset((char *)state, 0, sizeof(*state));
2242 #endif /* DEBUG */
2243 kmem_zone_free(xfs_da_state_zone, state);
2244 }
2245
2246 #ifdef XFS_DABUF_DEBUG
2247 xfs_dabuf_t *xfs_dabuf_global_list;
2248 static DEFINE_SPINLOCK(xfs_dabuf_global_lock);
2249 #endif
2250
2251 /*
2252 * Create a dabuf.
2253 */
2254 /* ARGSUSED */
2255 STATIC xfs_dabuf_t *
2256 xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra)
2257 {
2258 xfs_buf_t *bp;
2259 xfs_dabuf_t *dabuf;
2260 int i;
2261 int off;
2262
2263 if (nbuf == 1)
2264 dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_SLEEP);
2265 else
2266 dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_SLEEP);
2267 dabuf->dirty = 0;
2268 #ifdef XFS_DABUF_DEBUG
2269 dabuf->ra = ra;
2270 dabuf->target = XFS_BUF_TARGET(bps[0]);
2271 dabuf->blkno = XFS_BUF_ADDR(bps[0]);
2272 #endif
2273 if (nbuf == 1) {
2274 dabuf->nbuf = 1;
2275 bp = bps[0];
2276 dabuf->bbcount = (short)BTOBB(XFS_BUF_COUNT(bp));
2277 dabuf->data = XFS_BUF_PTR(bp);
2278 dabuf->bps[0] = bp;
2279 } else {
2280 dabuf->nbuf = nbuf;
2281 for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
2282 dabuf->bps[i] = bp = bps[i];
2283 dabuf->bbcount += BTOBB(XFS_BUF_COUNT(bp));
2284 }
2285 dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
2286 for (i = off = 0; i < nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2287 bp = bps[i];
2288 memcpy((char *)dabuf->data + off, XFS_BUF_PTR(bp),
2289 XFS_BUF_COUNT(bp));
2290 }
2291 }
2292 #ifdef XFS_DABUF_DEBUG
2293 {
2294 xfs_dabuf_t *p;
2295
2296 spin_lock(&xfs_dabuf_global_lock);
2297 for (p = xfs_dabuf_global_list; p; p = p->next) {
2298 ASSERT(p->blkno != dabuf->blkno ||
2299 p->target != dabuf->target);
2300 }
2301 dabuf->prev = NULL;
2302 if (xfs_dabuf_global_list)
2303 xfs_dabuf_global_list->prev = dabuf;
2304 dabuf->next = xfs_dabuf_global_list;
2305 xfs_dabuf_global_list = dabuf;
2306 spin_unlock(&xfs_dabuf_global_lock);
2307 }
2308 #endif
2309 return dabuf;
2310 }
2311
2312 /*
2313 * Un-dirty a dabuf.
2314 */
2315 STATIC void
2316 xfs_da_buf_clean(xfs_dabuf_t *dabuf)
2317 {
2318 xfs_buf_t *bp;
2319 int i;
2320 int off;
2321
2322 if (dabuf->dirty) {
2323 ASSERT(dabuf->nbuf > 1);
2324 dabuf->dirty = 0;
2325 for (i = off = 0; i < dabuf->nbuf;
2326 i++, off += XFS_BUF_COUNT(bp)) {
2327 bp = dabuf->bps[i];
2328 memcpy(XFS_BUF_PTR(bp), (char *)dabuf->data + off,
2329 XFS_BUF_COUNT(bp));
2330 }
2331 }
2332 }
2333
2334 /*
2335 * Release a dabuf.
2336 */
2337 void
2338 xfs_da_buf_done(xfs_dabuf_t *dabuf)
2339 {
2340 ASSERT(dabuf);
2341 ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2342 if (dabuf->dirty)
2343 xfs_da_buf_clean(dabuf);
2344 if (dabuf->nbuf > 1)
2345 kmem_free(dabuf->data);
2346 #ifdef XFS_DABUF_DEBUG
2347 {
2348 spin_lock(&xfs_dabuf_global_lock);
2349 if (dabuf->prev)
2350 dabuf->prev->next = dabuf->next;
2351 else
2352 xfs_dabuf_global_list = dabuf->next;
2353 if (dabuf->next)
2354 dabuf->next->prev = dabuf->prev;
2355 spin_unlock(&xfs_dabuf_global_lock);
2356 }
2357 memset(dabuf, 0, XFS_DA_BUF_SIZE(dabuf->nbuf));
2358 #endif
2359 if (dabuf->nbuf == 1)
2360 kmem_zone_free(xfs_dabuf_zone, dabuf);
2361 else
2362 kmem_free(dabuf);
2363 }
2364
2365 /*
2366 * Log transaction from a dabuf.
2367 */
2368 void
2369 xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
2370 {
2371 xfs_buf_t *bp;
2372 uint f;
2373 int i;
2374 uint l;
2375 int off;
2376
2377 ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2378 if (dabuf->nbuf == 1) {
2379 ASSERT(dabuf->data == (void *)XFS_BUF_PTR(dabuf->bps[0]));
2380 xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
2381 return;
2382 }
2383 dabuf->dirty = 1;
2384 ASSERT(first <= last);
2385 for (i = off = 0; i < dabuf->nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2386 bp = dabuf->bps[i];
2387 f = off;
2388 l = f + XFS_BUF_COUNT(bp) - 1;
2389 if (f < first)
2390 f = first;
2391 if (l > last)
2392 l = last;
2393 if (f <= l)
2394 xfs_trans_log_buf(tp, bp, f - off, l - off);
2395 /*
2396 * B_DONE is set by xfs_trans_log buf.
2397 * If we don't set it on a new buffer (get not read)
2398 * then if we don't put anything in the buffer it won't
2399 * be set, and at commit it it released into the cache,
2400 * and then a read will fail.
2401 */
2402 else if (!(XFS_BUF_ISDONE(bp)))
2403 XFS_BUF_DONE(bp);
2404 }
2405 ASSERT(last < off);
2406 }
2407
2408 /*
2409 * Release dabuf from a transaction.
2410 * Have to free up the dabuf before the buffers are released,
2411 * since the synchronization on the dabuf is really the lock on the buffer.
2412 */
2413 void
2414 xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2415 {
2416 xfs_buf_t *bp;
2417 xfs_buf_t **bplist;
2418 int i;
2419 int nbuf;
2420
2421 ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2422 if ((nbuf = dabuf->nbuf) == 1) {
2423 bplist = &bp;
2424 bp = dabuf->bps[0];
2425 } else {
2426 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2427 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2428 }
2429 xfs_da_buf_done(dabuf);
2430 for (i = 0; i < nbuf; i++)
2431 xfs_trans_brelse(tp, bplist[i]);
2432 if (bplist != &bp)
2433 kmem_free(bplist);
2434 }
2435
2436 /*
2437 * Invalidate dabuf from a transaction.
2438 */
2439 void
2440 xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2441 {
2442 xfs_buf_t *bp;
2443 xfs_buf_t **bplist;
2444 int i;
2445 int nbuf;
2446
2447 ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2448 if ((nbuf = dabuf->nbuf) == 1) {
2449 bplist = &bp;
2450 bp = dabuf->bps[0];
2451 } else {
2452 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2453 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2454 }
2455 xfs_da_buf_done(dabuf);
2456 for (i = 0; i < nbuf; i++)
2457 xfs_trans_binval(tp, bplist[i]);
2458 if (bplist != &bp)
2459 kmem_free(bplist);
2460 }
2461
2462 /*
2463 * Get the first daddr from a dabuf.
2464 */
2465 xfs_daddr_t
2466 xfs_da_blkno(xfs_dabuf_t *dabuf)
2467 {
2468 ASSERT(dabuf->nbuf);
2469 ASSERT(dabuf->data);
2470 return XFS_BUF_ADDR(dabuf->bps[0]);
2471 }
CJK support for tty framebuffer vt