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xfs: convert buffer verifiers to an ops structure.
[deliverable/linux.git] / 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_trans.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_btree.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_dir2.h"
30 #include "xfs_dir2_format.h"
31 #include "xfs_dir2_priv.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_inode_item.h"
35 #include "xfs_alloc.h"
36 #include "xfs_bmap.h"
37 #include "xfs_attr.h"
38 #include "xfs_attr_leaf.h"
39 #include "xfs_error.h"
40 #include "xfs_trace.h"
41
42 /*
43 * xfs_da_btree.c
44 *
45 * Routines to implement directories as Btrees of hashed names.
46 */
47
48 /*========================================================================
49 * Function prototypes for the kernel.
50 *========================================================================*/
51
52 /*
53 * Routines used for growing the Btree.
54 */
55 STATIC int xfs_da_root_split(xfs_da_state_t *state,
56 xfs_da_state_blk_t *existing_root,
57 xfs_da_state_blk_t *new_child);
58 STATIC int xfs_da_node_split(xfs_da_state_t *state,
59 xfs_da_state_blk_t *existing_blk,
60 xfs_da_state_blk_t *split_blk,
61 xfs_da_state_blk_t *blk_to_add,
62 int treelevel,
63 int *result);
64 STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
65 xfs_da_state_blk_t *node_blk_1,
66 xfs_da_state_blk_t *node_blk_2);
67 STATIC void xfs_da_node_add(xfs_da_state_t *state,
68 xfs_da_state_blk_t *old_node_blk,
69 xfs_da_state_blk_t *new_node_blk);
70
71 /*
72 * Routines used for shrinking the Btree.
73 */
74 STATIC int xfs_da_root_join(xfs_da_state_t *state,
75 xfs_da_state_blk_t *root_blk);
76 STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
77 STATIC void xfs_da_node_remove(xfs_da_state_t *state,
78 xfs_da_state_blk_t *drop_blk);
79 STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
80 xfs_da_state_blk_t *src_node_blk,
81 xfs_da_state_blk_t *dst_node_blk);
82
83 /*
84 * Utility routines.
85 */
86 STATIC uint xfs_da_node_lasthash(struct xfs_buf *bp, int *count);
87 STATIC int xfs_da_node_order(struct xfs_buf *node1_bp,
88 struct xfs_buf *node2_bp);
89 STATIC int xfs_da_blk_unlink(xfs_da_state_t *state,
90 xfs_da_state_blk_t *drop_blk,
91 xfs_da_state_blk_t *save_blk);
92 STATIC void xfs_da_state_kill_altpath(xfs_da_state_t *state);
93
94 static void
95 xfs_da_node_verify(
96 struct xfs_buf *bp)
97 {
98 struct xfs_mount *mp = bp->b_target->bt_mount;
99 struct xfs_da_node_hdr *hdr = bp->b_addr;
100 int block_ok = 0;
101
102 block_ok = hdr->info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC);
103 block_ok = block_ok &&
104 be16_to_cpu(hdr->level) > 0 &&
105 be16_to_cpu(hdr->count) > 0 ;
106 if (!block_ok) {
107 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, hdr);
108 xfs_buf_ioerror(bp, EFSCORRUPTED);
109 }
110
111 }
112
113 static void
114 xfs_da_node_write_verify(
115 struct xfs_buf *bp)
116 {
117 xfs_da_node_verify(bp);
118 }
119
120 /*
121 * leaf/node format detection on trees is sketchy, so a node read can be done on
122 * leaf level blocks when detection identifies the tree as a node format tree
123 * incorrectly. In this case, we need to swap the verifier to match the correct
124 * format of the block being read.
125 */
126 static void
127 xfs_da_node_read_verify(
128 struct xfs_buf *bp)
129 {
130 struct xfs_mount *mp = bp->b_target->bt_mount;
131 struct xfs_da_blkinfo *info = bp->b_addr;
132
133 switch (be16_to_cpu(info->magic)) {
134 case XFS_DA_NODE_MAGIC:
135 xfs_da_node_verify(bp);
136 break;
137 case XFS_ATTR_LEAF_MAGIC:
138 bp->b_ops = &xfs_attr_leaf_buf_ops;
139 bp->b_ops->verify_read(bp);
140 return;
141 case XFS_DIR2_LEAFN_MAGIC:
142 bp->b_ops = &xfs_dir2_leafn_buf_ops;
143 bp->b_ops->verify_read(bp);
144 return;
145 default:
146 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW,
147 mp, info);
148 xfs_buf_ioerror(bp, EFSCORRUPTED);
149 break;
150 }
151 }
152
153 const struct xfs_buf_ops xfs_da_node_buf_ops = {
154 .verify_read = xfs_da_node_read_verify,
155 .verify_write = xfs_da_node_write_verify,
156 };
157
158
159 int
160 xfs_da_node_read(
161 struct xfs_trans *tp,
162 struct xfs_inode *dp,
163 xfs_dablk_t bno,
164 xfs_daddr_t mappedbno,
165 struct xfs_buf **bpp,
166 int which_fork)
167 {
168 return xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
169 which_fork, &xfs_da_node_buf_ops);
170 }
171
172 /*========================================================================
173 * Routines used for growing the Btree.
174 *========================================================================*/
175
176 /*
177 * Create the initial contents of an intermediate node.
178 */
179 int
180 xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
181 struct xfs_buf **bpp, int whichfork)
182 {
183 xfs_da_intnode_t *node;
184 struct xfs_buf *bp;
185 int error;
186 xfs_trans_t *tp;
187
188 trace_xfs_da_node_create(args);
189
190 tp = args->trans;
191 error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
192 if (error)
193 return(error);
194 ASSERT(bp != NULL);
195 node = bp->b_addr;
196 node->hdr.info.forw = 0;
197 node->hdr.info.back = 0;
198 node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC);
199 node->hdr.info.pad = 0;
200 node->hdr.count = 0;
201 node->hdr.level = cpu_to_be16(level);
202
203 xfs_trans_log_buf(tp, bp,
204 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
205
206 bp->b_ops = &xfs_da_node_buf_ops;
207 *bpp = bp;
208 return(0);
209 }
210
211 /*
212 * Split a leaf node, rebalance, then possibly split
213 * intermediate nodes, rebalance, etc.
214 */
215 int /* error */
216 xfs_da_split(xfs_da_state_t *state)
217 {
218 xfs_da_state_blk_t *oldblk, *newblk, *addblk;
219 xfs_da_intnode_t *node;
220 struct xfs_buf *bp;
221 int max, action, error, i;
222
223 trace_xfs_da_split(state->args);
224
225 /*
226 * Walk back up the tree splitting/inserting/adjusting as necessary.
227 * If we need to insert and there isn't room, split the node, then
228 * decide which fragment to insert the new block from below into.
229 * Note that we may split the root this way, but we need more fixup.
230 */
231 max = state->path.active - 1;
232 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
233 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
234 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
235
236 addblk = &state->path.blk[max]; /* initial dummy value */
237 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
238 oldblk = &state->path.blk[i];
239 newblk = &state->altpath.blk[i];
240
241 /*
242 * If a leaf node then
243 * Allocate a new leaf node, then rebalance across them.
244 * else if an intermediate node then
245 * We split on the last layer, must we split the node?
246 */
247 switch (oldblk->magic) {
248 case XFS_ATTR_LEAF_MAGIC:
249 error = xfs_attr_leaf_split(state, oldblk, newblk);
250 if ((error != 0) && (error != ENOSPC)) {
251 return(error); /* GROT: attr is inconsistent */
252 }
253 if (!error) {
254 addblk = newblk;
255 break;
256 }
257 /*
258 * Entry wouldn't fit, split the leaf again.
259 */
260 state->extravalid = 1;
261 if (state->inleaf) {
262 state->extraafter = 0; /* before newblk */
263 trace_xfs_attr_leaf_split_before(state->args);
264 error = xfs_attr_leaf_split(state, oldblk,
265 &state->extrablk);
266 } else {
267 state->extraafter = 1; /* after newblk */
268 trace_xfs_attr_leaf_split_after(state->args);
269 error = xfs_attr_leaf_split(state, newblk,
270 &state->extrablk);
271 }
272 if (error)
273 return(error); /* GROT: attr inconsistent */
274 addblk = newblk;
275 break;
276 case XFS_DIR2_LEAFN_MAGIC:
277 error = xfs_dir2_leafn_split(state, oldblk, newblk);
278 if (error)
279 return error;
280 addblk = newblk;
281 break;
282 case XFS_DA_NODE_MAGIC:
283 error = xfs_da_node_split(state, oldblk, newblk, addblk,
284 max - i, &action);
285 addblk->bp = NULL;
286 if (error)
287 return(error); /* GROT: dir is inconsistent */
288 /*
289 * Record the newly split block for the next time thru?
290 */
291 if (action)
292 addblk = newblk;
293 else
294 addblk = NULL;
295 break;
296 }
297
298 /*
299 * Update the btree to show the new hashval for this child.
300 */
301 xfs_da_fixhashpath(state, &state->path);
302 }
303 if (!addblk)
304 return(0);
305
306 /*
307 * Split the root node.
308 */
309 ASSERT(state->path.active == 0);
310 oldblk = &state->path.blk[0];
311 error = xfs_da_root_split(state, oldblk, addblk);
312 if (error) {
313 addblk->bp = NULL;
314 return(error); /* GROT: dir is inconsistent */
315 }
316
317 /*
318 * Update pointers to the node which used to be block 0 and
319 * just got bumped because of the addition of a new root node.
320 * There might be three blocks involved if a double split occurred,
321 * and the original block 0 could be at any position in the list.
322 */
323
324 node = oldblk->bp->b_addr;
325 if (node->hdr.info.forw) {
326 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
327 bp = addblk->bp;
328 } else {
329 ASSERT(state->extravalid);
330 bp = state->extrablk.bp;
331 }
332 node = bp->b_addr;
333 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
334 xfs_trans_log_buf(state->args->trans, bp,
335 XFS_DA_LOGRANGE(node, &node->hdr.info,
336 sizeof(node->hdr.info)));
337 }
338 node = oldblk->bp->b_addr;
339 if (node->hdr.info.back) {
340 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
341 bp = addblk->bp;
342 } else {
343 ASSERT(state->extravalid);
344 bp = state->extrablk.bp;
345 }
346 node = bp->b_addr;
347 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
348 xfs_trans_log_buf(state->args->trans, bp,
349 XFS_DA_LOGRANGE(node, &node->hdr.info,
350 sizeof(node->hdr.info)));
351 }
352 addblk->bp = NULL;
353 return(0);
354 }
355
356 /*
357 * Split the root. We have to create a new root and point to the two
358 * parts (the split old root) that we just created. Copy block zero to
359 * the EOF, extending the inode in process.
360 */
361 STATIC int /* error */
362 xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
363 xfs_da_state_blk_t *blk2)
364 {
365 xfs_da_intnode_t *node, *oldroot;
366 xfs_da_args_t *args;
367 xfs_dablk_t blkno;
368 struct xfs_buf *bp;
369 int error, size;
370 xfs_inode_t *dp;
371 xfs_trans_t *tp;
372 xfs_mount_t *mp;
373 xfs_dir2_leaf_t *leaf;
374
375 trace_xfs_da_root_split(state->args);
376
377 /*
378 * Copy the existing (incorrect) block from the root node position
379 * to a free space somewhere.
380 */
381 args = state->args;
382 ASSERT(args != NULL);
383 error = xfs_da_grow_inode(args, &blkno);
384 if (error)
385 return(error);
386 dp = args->dp;
387 tp = args->trans;
388 mp = state->mp;
389 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
390 if (error)
391 return(error);
392 ASSERT(bp != NULL);
393 node = bp->b_addr;
394 oldroot = blk1->bp->b_addr;
395 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)) {
396 size = (int)((char *)&oldroot->btree[be16_to_cpu(oldroot->hdr.count)] -
397 (char *)oldroot);
398 } else {
399 ASSERT(oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC));
400 leaf = (xfs_dir2_leaf_t *)oldroot;
401 size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] -
402 (char *)leaf);
403 }
404 memcpy(node, oldroot, size);
405 xfs_trans_log_buf(tp, bp, 0, size - 1);
406
407 bp->b_ops = blk1->bp->b_ops;
408 blk1->bp = bp;
409 blk1->blkno = blkno;
410
411 /*
412 * Set up the new root node.
413 */
414 error = xfs_da_node_create(args,
415 (args->whichfork == XFS_DATA_FORK) ? mp->m_dirleafblk : 0,
416 be16_to_cpu(node->hdr.level) + 1, &bp, args->whichfork);
417 if (error)
418 return(error);
419 node = bp->b_addr;
420 node->btree[0].hashval = cpu_to_be32(blk1->hashval);
421 node->btree[0].before = cpu_to_be32(blk1->blkno);
422 node->btree[1].hashval = cpu_to_be32(blk2->hashval);
423 node->btree[1].before = cpu_to_be32(blk2->blkno);
424 node->hdr.count = cpu_to_be16(2);
425
426 #ifdef DEBUG
427 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)) {
428 ASSERT(blk1->blkno >= mp->m_dirleafblk &&
429 blk1->blkno < mp->m_dirfreeblk);
430 ASSERT(blk2->blkno >= mp->m_dirleafblk &&
431 blk2->blkno < mp->m_dirfreeblk);
432 }
433 #endif
434
435 /* Header is already logged by xfs_da_node_create */
436 xfs_trans_log_buf(tp, bp,
437 XFS_DA_LOGRANGE(node, node->btree,
438 sizeof(xfs_da_node_entry_t) * 2));
439
440 return(0);
441 }
442
443 /*
444 * Split the node, rebalance, then add the new entry.
445 */
446 STATIC int /* error */
447 xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
448 xfs_da_state_blk_t *newblk,
449 xfs_da_state_blk_t *addblk,
450 int treelevel, int *result)
451 {
452 xfs_da_intnode_t *node;
453 xfs_dablk_t blkno;
454 int newcount, error;
455 int useextra;
456
457 trace_xfs_da_node_split(state->args);
458
459 node = oldblk->bp->b_addr;
460 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
461
462 /*
463 * With V2 dirs the extra block is data or freespace.
464 */
465 useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
466 newcount = 1 + useextra;
467 /*
468 * Do we have to split the node?
469 */
470 if ((be16_to_cpu(node->hdr.count) + newcount) > state->node_ents) {
471 /*
472 * Allocate a new node, add to the doubly linked chain of
473 * nodes, then move some of our excess entries into it.
474 */
475 error = xfs_da_grow_inode(state->args, &blkno);
476 if (error)
477 return(error); /* GROT: dir is inconsistent */
478
479 error = xfs_da_node_create(state->args, blkno, treelevel,
480 &newblk->bp, state->args->whichfork);
481 if (error)
482 return(error); /* GROT: dir is inconsistent */
483 newblk->blkno = blkno;
484 newblk->magic = XFS_DA_NODE_MAGIC;
485 xfs_da_node_rebalance(state, oldblk, newblk);
486 error = xfs_da_blk_link(state, oldblk, newblk);
487 if (error)
488 return(error);
489 *result = 1;
490 } else {
491 *result = 0;
492 }
493
494 /*
495 * Insert the new entry(s) into the correct block
496 * (updating last hashval in the process).
497 *
498 * xfs_da_node_add() inserts BEFORE the given index,
499 * and as a result of using node_lookup_int() we always
500 * point to a valid entry (not after one), but a split
501 * operation always results in a new block whose hashvals
502 * FOLLOW the current block.
503 *
504 * If we had double-split op below us, then add the extra block too.
505 */
506 node = oldblk->bp->b_addr;
507 if (oldblk->index <= be16_to_cpu(node->hdr.count)) {
508 oldblk->index++;
509 xfs_da_node_add(state, oldblk, addblk);
510 if (useextra) {
511 if (state->extraafter)
512 oldblk->index++;
513 xfs_da_node_add(state, oldblk, &state->extrablk);
514 state->extravalid = 0;
515 }
516 } else {
517 newblk->index++;
518 xfs_da_node_add(state, newblk, addblk);
519 if (useextra) {
520 if (state->extraafter)
521 newblk->index++;
522 xfs_da_node_add(state, newblk, &state->extrablk);
523 state->extravalid = 0;
524 }
525 }
526
527 return(0);
528 }
529
530 /*
531 * Balance the btree elements between two intermediate nodes,
532 * usually one full and one empty.
533 *
534 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
535 */
536 STATIC void
537 xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
538 xfs_da_state_blk_t *blk2)
539 {
540 xfs_da_intnode_t *node1, *node2, *tmpnode;
541 xfs_da_node_entry_t *btree_s, *btree_d;
542 int count, tmp;
543 xfs_trans_t *tp;
544
545 trace_xfs_da_node_rebalance(state->args);
546
547 node1 = blk1->bp->b_addr;
548 node2 = blk2->bp->b_addr;
549 /*
550 * Figure out how many entries need to move, and in which direction.
551 * Swap the nodes around if that makes it simpler.
552 */
553 if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
554 ((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) ||
555 (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
556 be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
557 tmpnode = node1;
558 node1 = node2;
559 node2 = tmpnode;
560 }
561 ASSERT(node1->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
562 ASSERT(node2->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
563 count = (be16_to_cpu(node1->hdr.count) - be16_to_cpu(node2->hdr.count)) / 2;
564 if (count == 0)
565 return;
566 tp = state->args->trans;
567 /*
568 * Two cases: high-to-low and low-to-high.
569 */
570 if (count > 0) {
571 /*
572 * Move elements in node2 up to make a hole.
573 */
574 if ((tmp = be16_to_cpu(node2->hdr.count)) > 0) {
575 tmp *= (uint)sizeof(xfs_da_node_entry_t);
576 btree_s = &node2->btree[0];
577 btree_d = &node2->btree[count];
578 memmove(btree_d, btree_s, tmp);
579 }
580
581 /*
582 * Move the req'd B-tree elements from high in node1 to
583 * low in node2.
584 */
585 be16_add_cpu(&node2->hdr.count, count);
586 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
587 btree_s = &node1->btree[be16_to_cpu(node1->hdr.count) - count];
588 btree_d = &node2->btree[0];
589 memcpy(btree_d, btree_s, tmp);
590 be16_add_cpu(&node1->hdr.count, -count);
591 } else {
592 /*
593 * Move the req'd B-tree elements from low in node2 to
594 * high in node1.
595 */
596 count = -count;
597 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
598 btree_s = &node2->btree[0];
599 btree_d = &node1->btree[be16_to_cpu(node1->hdr.count)];
600 memcpy(btree_d, btree_s, tmp);
601 be16_add_cpu(&node1->hdr.count, count);
602 xfs_trans_log_buf(tp, blk1->bp,
603 XFS_DA_LOGRANGE(node1, btree_d, tmp));
604
605 /*
606 * Move elements in node2 down to fill the hole.
607 */
608 tmp = be16_to_cpu(node2->hdr.count) - count;
609 tmp *= (uint)sizeof(xfs_da_node_entry_t);
610 btree_s = &node2->btree[count];
611 btree_d = &node2->btree[0];
612 memmove(btree_d, btree_s, tmp);
613 be16_add_cpu(&node2->hdr.count, -count);
614 }
615
616 /*
617 * Log header of node 1 and all current bits of node 2.
618 */
619 xfs_trans_log_buf(tp, blk1->bp,
620 XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
621 xfs_trans_log_buf(tp, blk2->bp,
622 XFS_DA_LOGRANGE(node2, &node2->hdr,
623 sizeof(node2->hdr) +
624 sizeof(node2->btree[0]) * be16_to_cpu(node2->hdr.count)));
625
626 /*
627 * Record the last hashval from each block for upward propagation.
628 * (note: don't use the swapped node pointers)
629 */
630 node1 = blk1->bp->b_addr;
631 node2 = blk2->bp->b_addr;
632 blk1->hashval = be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval);
633 blk2->hashval = be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval);
634
635 /*
636 * Adjust the expected index for insertion.
637 */
638 if (blk1->index >= be16_to_cpu(node1->hdr.count)) {
639 blk2->index = blk1->index - be16_to_cpu(node1->hdr.count);
640 blk1->index = be16_to_cpu(node1->hdr.count) + 1; /* make it invalid */
641 }
642 }
643
644 /*
645 * Add a new entry to an intermediate node.
646 */
647 STATIC void
648 xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
649 xfs_da_state_blk_t *newblk)
650 {
651 xfs_da_intnode_t *node;
652 xfs_da_node_entry_t *btree;
653 int tmp;
654
655 trace_xfs_da_node_add(state->args);
656
657 node = oldblk->bp->b_addr;
658 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
659 ASSERT((oldblk->index >= 0) && (oldblk->index <= be16_to_cpu(node->hdr.count)));
660 ASSERT(newblk->blkno != 0);
661 if (state->args->whichfork == XFS_DATA_FORK)
662 ASSERT(newblk->blkno >= state->mp->m_dirleafblk &&
663 newblk->blkno < state->mp->m_dirfreeblk);
664
665 /*
666 * We may need to make some room before we insert the new node.
667 */
668 tmp = 0;
669 btree = &node->btree[ oldblk->index ];
670 if (oldblk->index < be16_to_cpu(node->hdr.count)) {
671 tmp = (be16_to_cpu(node->hdr.count) - oldblk->index) * (uint)sizeof(*btree);
672 memmove(btree + 1, btree, tmp);
673 }
674 btree->hashval = cpu_to_be32(newblk->hashval);
675 btree->before = cpu_to_be32(newblk->blkno);
676 xfs_trans_log_buf(state->args->trans, oldblk->bp,
677 XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
678 be16_add_cpu(&node->hdr.count, 1);
679 xfs_trans_log_buf(state->args->trans, oldblk->bp,
680 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
681
682 /*
683 * Copy the last hash value from the oldblk to propagate upwards.
684 */
685 oldblk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1 ].hashval);
686 }
687
688 /*========================================================================
689 * Routines used for shrinking the Btree.
690 *========================================================================*/
691
692 /*
693 * Deallocate an empty leaf node, remove it from its parent,
694 * possibly deallocating that block, etc...
695 */
696 int
697 xfs_da_join(xfs_da_state_t *state)
698 {
699 xfs_da_state_blk_t *drop_blk, *save_blk;
700 int action, error;
701
702 trace_xfs_da_join(state->args);
703
704 action = 0;
705 drop_blk = &state->path.blk[ state->path.active-1 ];
706 save_blk = &state->altpath.blk[ state->path.active-1 ];
707 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
708 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
709 drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
710
711 /*
712 * Walk back up the tree joining/deallocating as necessary.
713 * When we stop dropping blocks, break out.
714 */
715 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
716 state->path.active--) {
717 /*
718 * See if we can combine the block with a neighbor.
719 * (action == 0) => no options, just leave
720 * (action == 1) => coalesce, then unlink
721 * (action == 2) => block empty, unlink it
722 */
723 switch (drop_blk->magic) {
724 case XFS_ATTR_LEAF_MAGIC:
725 error = xfs_attr_leaf_toosmall(state, &action);
726 if (error)
727 return(error);
728 if (action == 0)
729 return(0);
730 xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
731 break;
732 case XFS_DIR2_LEAFN_MAGIC:
733 error = xfs_dir2_leafn_toosmall(state, &action);
734 if (error)
735 return error;
736 if (action == 0)
737 return 0;
738 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
739 break;
740 case XFS_DA_NODE_MAGIC:
741 /*
742 * Remove the offending node, fixup hashvals,
743 * check for a toosmall neighbor.
744 */
745 xfs_da_node_remove(state, drop_blk);
746 xfs_da_fixhashpath(state, &state->path);
747 error = xfs_da_node_toosmall(state, &action);
748 if (error)
749 return(error);
750 if (action == 0)
751 return 0;
752 xfs_da_node_unbalance(state, drop_blk, save_blk);
753 break;
754 }
755 xfs_da_fixhashpath(state, &state->altpath);
756 error = xfs_da_blk_unlink(state, drop_blk, save_blk);
757 xfs_da_state_kill_altpath(state);
758 if (error)
759 return(error);
760 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
761 drop_blk->bp);
762 drop_blk->bp = NULL;
763 if (error)
764 return(error);
765 }
766 /*
767 * We joined all the way to the top. If it turns out that
768 * we only have one entry in the root, make the child block
769 * the new root.
770 */
771 xfs_da_node_remove(state, drop_blk);
772 xfs_da_fixhashpath(state, &state->path);
773 error = xfs_da_root_join(state, &state->path.blk[0]);
774 return(error);
775 }
776
777 #ifdef DEBUG
778 static void
779 xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
780 {
781 __be16 magic = blkinfo->magic;
782
783 if (level == 1) {
784 ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
785 magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC));
786 } else
787 ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
788 ASSERT(!blkinfo->forw);
789 ASSERT(!blkinfo->back);
790 }
791 #else /* !DEBUG */
792 #define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
793 #endif /* !DEBUG */
794
795 /*
796 * We have only one entry in the root. Copy the only remaining child of
797 * the old root to block 0 as the new root node.
798 */
799 STATIC int
800 xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
801 {
802 xfs_da_intnode_t *oldroot;
803 xfs_da_args_t *args;
804 xfs_dablk_t child;
805 struct xfs_buf *bp;
806 int error;
807
808 trace_xfs_da_root_join(state->args);
809
810 args = state->args;
811 ASSERT(args != NULL);
812 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
813 oldroot = root_blk->bp->b_addr;
814 ASSERT(oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
815 ASSERT(!oldroot->hdr.info.forw);
816 ASSERT(!oldroot->hdr.info.back);
817
818 /*
819 * If the root has more than one child, then don't do anything.
820 */
821 if (be16_to_cpu(oldroot->hdr.count) > 1)
822 return(0);
823
824 /*
825 * Read in the (only) child block, then copy those bytes into
826 * the root block's buffer and free the original child block.
827 */
828 child = be32_to_cpu(oldroot->btree[0].before);
829 ASSERT(child != 0);
830 error = xfs_da_node_read(args->trans, args->dp, child, -1, &bp,
831 args->whichfork);
832 if (error)
833 return(error);
834 ASSERT(bp != NULL);
835 xfs_da_blkinfo_onlychild_validate(bp->b_addr,
836 be16_to_cpu(oldroot->hdr.level));
837
838 /*
839 * This could be copying a leaf back into the root block in the case of
840 * there only being a single leaf block left in the tree. Hence we have
841 * to update the b_ops pointer as well to match the buffer type change
842 * that could occur.
843 */
844 memcpy(root_blk->bp->b_addr, bp->b_addr, state->blocksize);
845 root_blk->bp->b_ops = bp->b_ops;
846 xfs_trans_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
847 error = xfs_da_shrink_inode(args, child, bp);
848 return(error);
849 }
850
851 /*
852 * Check a node block and its neighbors to see if the block should be
853 * collapsed into one or the other neighbor. Always keep the block
854 * with the smaller block number.
855 * If the current block is over 50% full, don't try to join it, return 0.
856 * If the block is empty, fill in the state structure and return 2.
857 * If it can be collapsed, fill in the state structure and return 1.
858 * If nothing can be done, return 0.
859 */
860 STATIC int
861 xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
862 {
863 xfs_da_intnode_t *node;
864 xfs_da_state_blk_t *blk;
865 xfs_da_blkinfo_t *info;
866 int count, forward, error, retval, i;
867 xfs_dablk_t blkno;
868 struct xfs_buf *bp;
869
870 trace_xfs_da_node_toosmall(state->args);
871
872 /*
873 * Check for the degenerate case of the block being over 50% full.
874 * If so, it's not worth even looking to see if we might be able
875 * to coalesce with a sibling.
876 */
877 blk = &state->path.blk[ state->path.active-1 ];
878 info = blk->bp->b_addr;
879 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
880 node = (xfs_da_intnode_t *)info;
881 count = be16_to_cpu(node->hdr.count);
882 if (count > (state->node_ents >> 1)) {
883 *action = 0; /* blk over 50%, don't try to join */
884 return(0); /* blk over 50%, don't try to join */
885 }
886
887 /*
888 * Check for the degenerate case of the block being empty.
889 * If the block is empty, we'll simply delete it, no need to
890 * coalesce it with a sibling block. We choose (arbitrarily)
891 * to merge with the forward block unless it is NULL.
892 */
893 if (count == 0) {
894 /*
895 * Make altpath point to the block we want to keep and
896 * path point to the block we want to drop (this one).
897 */
898 forward = (info->forw != 0);
899 memcpy(&state->altpath, &state->path, sizeof(state->path));
900 error = xfs_da_path_shift(state, &state->altpath, forward,
901 0, &retval);
902 if (error)
903 return(error);
904 if (retval) {
905 *action = 0;
906 } else {
907 *action = 2;
908 }
909 return(0);
910 }
911
912 /*
913 * Examine each sibling block to see if we can coalesce with
914 * at least 25% free space to spare. We need to figure out
915 * whether to merge with the forward or the backward block.
916 * We prefer coalescing with the lower numbered sibling so as
917 * to shrink a directory over time.
918 */
919 /* start with smaller blk num */
920 forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
921 for (i = 0; i < 2; forward = !forward, i++) {
922 if (forward)
923 blkno = be32_to_cpu(info->forw);
924 else
925 blkno = be32_to_cpu(info->back);
926 if (blkno == 0)
927 continue;
928 error = xfs_da_node_read(state->args->trans, state->args->dp,
929 blkno, -1, &bp, state->args->whichfork);
930 if (error)
931 return(error);
932 ASSERT(bp != NULL);
933
934 node = (xfs_da_intnode_t *)info;
935 count = state->node_ents;
936 count -= state->node_ents >> 2;
937 count -= be16_to_cpu(node->hdr.count);
938 node = bp->b_addr;
939 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
940 count -= be16_to_cpu(node->hdr.count);
941 xfs_trans_brelse(state->args->trans, bp);
942 if (count >= 0)
943 break; /* fits with at least 25% to spare */
944 }
945 if (i >= 2) {
946 *action = 0;
947 return(0);
948 }
949
950 /*
951 * Make altpath point to the block we want to keep (the lower
952 * numbered block) and path point to the block we want to drop.
953 */
954 memcpy(&state->altpath, &state->path, sizeof(state->path));
955 if (blkno < blk->blkno) {
956 error = xfs_da_path_shift(state, &state->altpath, forward,
957 0, &retval);
958 if (error) {
959 return(error);
960 }
961 if (retval) {
962 *action = 0;
963 return(0);
964 }
965 } else {
966 error = xfs_da_path_shift(state, &state->path, forward,
967 0, &retval);
968 if (error) {
969 return(error);
970 }
971 if (retval) {
972 *action = 0;
973 return(0);
974 }
975 }
976 *action = 1;
977 return(0);
978 }
979
980 /*
981 * Walk back up the tree adjusting hash values as necessary,
982 * when we stop making changes, return.
983 */
984 void
985 xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
986 {
987 xfs_da_state_blk_t *blk;
988 xfs_da_intnode_t *node;
989 xfs_da_node_entry_t *btree;
990 xfs_dahash_t lasthash=0;
991 int level, count;
992
993 trace_xfs_da_fixhashpath(state->args);
994
995 level = path->active-1;
996 blk = &path->blk[ level ];
997 switch (blk->magic) {
998 case XFS_ATTR_LEAF_MAGIC:
999 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
1000 if (count == 0)
1001 return;
1002 break;
1003 case XFS_DIR2_LEAFN_MAGIC:
1004 lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
1005 if (count == 0)
1006 return;
1007 break;
1008 case XFS_DA_NODE_MAGIC:
1009 lasthash = xfs_da_node_lasthash(blk->bp, &count);
1010 if (count == 0)
1011 return;
1012 break;
1013 }
1014 for (blk--, level--; level >= 0; blk--, level--) {
1015 node = blk->bp->b_addr;
1016 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1017 btree = &node->btree[ blk->index ];
1018 if (be32_to_cpu(btree->hashval) == lasthash)
1019 break;
1020 blk->hashval = lasthash;
1021 btree->hashval = cpu_to_be32(lasthash);
1022 xfs_trans_log_buf(state->args->trans, blk->bp,
1023 XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
1024
1025 lasthash = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1026 }
1027 }
1028
1029 /*
1030 * Remove an entry from an intermediate node.
1031 */
1032 STATIC void
1033 xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
1034 {
1035 xfs_da_intnode_t *node;
1036 xfs_da_node_entry_t *btree;
1037 int tmp;
1038
1039 trace_xfs_da_node_remove(state->args);
1040
1041 node = drop_blk->bp->b_addr;
1042 ASSERT(drop_blk->index < be16_to_cpu(node->hdr.count));
1043 ASSERT(drop_blk->index >= 0);
1044
1045 /*
1046 * Copy over the offending entry, or just zero it out.
1047 */
1048 btree = &node->btree[drop_blk->index];
1049 if (drop_blk->index < (be16_to_cpu(node->hdr.count)-1)) {
1050 tmp = be16_to_cpu(node->hdr.count) - drop_blk->index - 1;
1051 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1052 memmove(btree, btree + 1, tmp);
1053 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1054 XFS_DA_LOGRANGE(node, btree, tmp));
1055 btree = &node->btree[be16_to_cpu(node->hdr.count)-1];
1056 }
1057 memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
1058 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1059 XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
1060 be16_add_cpu(&node->hdr.count, -1);
1061 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1062 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
1063
1064 /*
1065 * Copy the last hash value from the block to propagate upwards.
1066 */
1067 btree--;
1068 drop_blk->hashval = be32_to_cpu(btree->hashval);
1069 }
1070
1071 /*
1072 * Unbalance the btree elements between two intermediate nodes,
1073 * move all Btree elements from one node into another.
1074 */
1075 STATIC void
1076 xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1077 xfs_da_state_blk_t *save_blk)
1078 {
1079 xfs_da_intnode_t *drop_node, *save_node;
1080 xfs_da_node_entry_t *btree;
1081 int tmp;
1082 xfs_trans_t *tp;
1083
1084 trace_xfs_da_node_unbalance(state->args);
1085
1086 drop_node = drop_blk->bp->b_addr;
1087 save_node = save_blk->bp->b_addr;
1088 ASSERT(drop_node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1089 ASSERT(save_node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1090 tp = state->args->trans;
1091
1092 /*
1093 * If the dying block has lower hashvals, then move all the
1094 * elements in the remaining block up to make a hole.
1095 */
1096 if ((be32_to_cpu(drop_node->btree[0].hashval) < be32_to_cpu(save_node->btree[ 0 ].hashval)) ||
1097 (be32_to_cpu(drop_node->btree[be16_to_cpu(drop_node->hdr.count)-1].hashval) <
1098 be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval)))
1099 {
1100 btree = &save_node->btree[be16_to_cpu(drop_node->hdr.count)];
1101 tmp = be16_to_cpu(save_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1102 memmove(btree, &save_node->btree[0], tmp);
1103 btree = &save_node->btree[0];
1104 xfs_trans_log_buf(tp, save_blk->bp,
1105 XFS_DA_LOGRANGE(save_node, btree,
1106 (be16_to_cpu(save_node->hdr.count) + be16_to_cpu(drop_node->hdr.count)) *
1107 sizeof(xfs_da_node_entry_t)));
1108 } else {
1109 btree = &save_node->btree[be16_to_cpu(save_node->hdr.count)];
1110 xfs_trans_log_buf(tp, save_blk->bp,
1111 XFS_DA_LOGRANGE(save_node, btree,
1112 be16_to_cpu(drop_node->hdr.count) *
1113 sizeof(xfs_da_node_entry_t)));
1114 }
1115
1116 /*
1117 * Move all the B-tree elements from drop_blk to save_blk.
1118 */
1119 tmp = be16_to_cpu(drop_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1120 memcpy(btree, &drop_node->btree[0], tmp);
1121 be16_add_cpu(&save_node->hdr.count, be16_to_cpu(drop_node->hdr.count));
1122
1123 xfs_trans_log_buf(tp, save_blk->bp,
1124 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1125 sizeof(save_node->hdr)));
1126
1127 /*
1128 * Save the last hashval in the remaining block for upward propagation.
1129 */
1130 save_blk->hashval = be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval);
1131 }
1132
1133 /*========================================================================
1134 * Routines used for finding things in the Btree.
1135 *========================================================================*/
1136
1137 /*
1138 * Walk down the Btree looking for a particular filename, filling
1139 * in the state structure as we go.
1140 *
1141 * We will set the state structure to point to each of the elements
1142 * in each of the nodes where either the hashval is or should be.
1143 *
1144 * We support duplicate hashval's so for each entry in the current
1145 * node that could contain the desired hashval, descend. This is a
1146 * pruned depth-first tree search.
1147 */
1148 int /* error */
1149 xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
1150 {
1151 xfs_da_state_blk_t *blk;
1152 xfs_da_blkinfo_t *curr;
1153 xfs_da_intnode_t *node;
1154 xfs_da_node_entry_t *btree;
1155 xfs_dablk_t blkno;
1156 int probe, span, max, error, retval;
1157 xfs_dahash_t hashval, btreehashval;
1158 xfs_da_args_t *args;
1159
1160 args = state->args;
1161
1162 /*
1163 * Descend thru the B-tree searching each level for the right
1164 * node to use, until the right hashval is found.
1165 */
1166 blkno = (args->whichfork == XFS_DATA_FORK)? state->mp->m_dirleafblk : 0;
1167 for (blk = &state->path.blk[0], state->path.active = 1;
1168 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1169 blk++, state->path.active++) {
1170 /*
1171 * Read the next node down in the tree.
1172 */
1173 blk->blkno = blkno;
1174 error = xfs_da_node_read(args->trans, args->dp, blkno,
1175 -1, &blk->bp, args->whichfork);
1176 if (error) {
1177 blk->blkno = 0;
1178 state->path.active--;
1179 return(error);
1180 }
1181 curr = blk->bp->b_addr;
1182 blk->magic = be16_to_cpu(curr->magic);
1183 ASSERT(blk->magic == XFS_DA_NODE_MAGIC ||
1184 blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1185 blk->magic == XFS_ATTR_LEAF_MAGIC);
1186
1187 /*
1188 * Search an intermediate node for a match.
1189 */
1190 if (blk->magic == XFS_DA_NODE_MAGIC) {
1191 node = blk->bp->b_addr;
1192 max = be16_to_cpu(node->hdr.count);
1193 blk->hashval = be32_to_cpu(node->btree[max-1].hashval);
1194
1195 /*
1196 * Binary search. (note: small blocks will skip loop)
1197 */
1198 probe = span = max / 2;
1199 hashval = args->hashval;
1200 for (btree = &node->btree[probe]; span > 4;
1201 btree = &node->btree[probe]) {
1202 span /= 2;
1203 btreehashval = be32_to_cpu(btree->hashval);
1204 if (btreehashval < hashval)
1205 probe += span;
1206 else if (btreehashval > hashval)
1207 probe -= span;
1208 else
1209 break;
1210 }
1211 ASSERT((probe >= 0) && (probe < max));
1212 ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval));
1213
1214 /*
1215 * Since we may have duplicate hashval's, find the first
1216 * matching hashval in the node.
1217 */
1218 while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) {
1219 btree--;
1220 probe--;
1221 }
1222 while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) {
1223 btree++;
1224 probe++;
1225 }
1226
1227 /*
1228 * Pick the right block to descend on.
1229 */
1230 if (probe == max) {
1231 blk->index = max-1;
1232 blkno = be32_to_cpu(node->btree[max-1].before);
1233 } else {
1234 blk->index = probe;
1235 blkno = be32_to_cpu(btree->before);
1236 }
1237 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1238 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1239 break;
1240 } else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1241 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
1242 break;
1243 }
1244 }
1245
1246 /*
1247 * A leaf block that ends in the hashval that we are interested in
1248 * (final hashval == search hashval) means that the next block may
1249 * contain more entries with the same hashval, shift upward to the
1250 * next leaf and keep searching.
1251 */
1252 for (;;) {
1253 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1254 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1255 &blk->index, state);
1256 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1257 retval = xfs_attr_leaf_lookup_int(blk->bp, args);
1258 blk->index = args->index;
1259 args->blkno = blk->blkno;
1260 } else {
1261 ASSERT(0);
1262 return XFS_ERROR(EFSCORRUPTED);
1263 }
1264 if (((retval == ENOENT) || (retval == ENOATTR)) &&
1265 (blk->hashval == args->hashval)) {
1266 error = xfs_da_path_shift(state, &state->path, 1, 1,
1267 &retval);
1268 if (error)
1269 return(error);
1270 if (retval == 0) {
1271 continue;
1272 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1273 /* path_shift() gives ENOENT */
1274 retval = XFS_ERROR(ENOATTR);
1275 }
1276 }
1277 break;
1278 }
1279 *result = retval;
1280 return(0);
1281 }
1282
1283 /*========================================================================
1284 * Utility routines.
1285 *========================================================================*/
1286
1287 /*
1288 * Link a new block into a doubly linked list of blocks (of whatever type).
1289 */
1290 int /* error */
1291 xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
1292 xfs_da_state_blk_t *new_blk)
1293 {
1294 xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
1295 xfs_da_args_t *args;
1296 int before=0, error;
1297 struct xfs_buf *bp;
1298
1299 /*
1300 * Set up environment.
1301 */
1302 args = state->args;
1303 ASSERT(args != NULL);
1304 old_info = old_blk->bp->b_addr;
1305 new_info = new_blk->bp->b_addr;
1306 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1307 old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1308 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1309 ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
1310 ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
1311 ASSERT(old_blk->magic == new_blk->magic);
1312
1313 switch (old_blk->magic) {
1314 case XFS_ATTR_LEAF_MAGIC:
1315 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1316 break;
1317 case XFS_DIR2_LEAFN_MAGIC:
1318 before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
1319 break;
1320 case XFS_DA_NODE_MAGIC:
1321 before = xfs_da_node_order(old_blk->bp, new_blk->bp);
1322 break;
1323 }
1324
1325 /*
1326 * Link blocks in appropriate order.
1327 */
1328 if (before) {
1329 /*
1330 * Link new block in before existing block.
1331 */
1332 trace_xfs_da_link_before(args);
1333 new_info->forw = cpu_to_be32(old_blk->blkno);
1334 new_info->back = old_info->back;
1335 if (old_info->back) {
1336 error = xfs_da_node_read(args->trans, args->dp,
1337 be32_to_cpu(old_info->back),
1338 -1, &bp, args->whichfork);
1339 if (error)
1340 return(error);
1341 ASSERT(bp != NULL);
1342 tmp_info = bp->b_addr;
1343 ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
1344 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1345 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1346 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1347 }
1348 old_info->back = cpu_to_be32(new_blk->blkno);
1349 } else {
1350 /*
1351 * Link new block in after existing block.
1352 */
1353 trace_xfs_da_link_after(args);
1354 new_info->forw = old_info->forw;
1355 new_info->back = cpu_to_be32(old_blk->blkno);
1356 if (old_info->forw) {
1357 error = xfs_da_node_read(args->trans, args->dp,
1358 be32_to_cpu(old_info->forw),
1359 -1, &bp, args->whichfork);
1360 if (error)
1361 return(error);
1362 ASSERT(bp != NULL);
1363 tmp_info = bp->b_addr;
1364 ASSERT(tmp_info->magic == old_info->magic);
1365 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1366 tmp_info->back = cpu_to_be32(new_blk->blkno);
1367 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1368 }
1369 old_info->forw = cpu_to_be32(new_blk->blkno);
1370 }
1371
1372 xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1373 xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1374 return(0);
1375 }
1376
1377 /*
1378 * Compare two intermediate nodes for "order".
1379 */
1380 STATIC int
1381 xfs_da_node_order(
1382 struct xfs_buf *node1_bp,
1383 struct xfs_buf *node2_bp)
1384 {
1385 xfs_da_intnode_t *node1, *node2;
1386
1387 node1 = node1_bp->b_addr;
1388 node2 = node2_bp->b_addr;
1389 ASSERT(node1->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) &&
1390 node2->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1391 if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
1392 ((be32_to_cpu(node2->btree[0].hashval) <
1393 be32_to_cpu(node1->btree[0].hashval)) ||
1394 (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
1395 be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
1396 return(1);
1397 }
1398 return(0);
1399 }
1400
1401 /*
1402 * Pick up the last hashvalue from an intermediate node.
1403 */
1404 STATIC uint
1405 xfs_da_node_lasthash(
1406 struct xfs_buf *bp,
1407 int *count)
1408 {
1409 xfs_da_intnode_t *node;
1410
1411 node = bp->b_addr;
1412 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1413 if (count)
1414 *count = be16_to_cpu(node->hdr.count);
1415 if (!node->hdr.count)
1416 return(0);
1417 return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1418 }
1419
1420 /*
1421 * Unlink a block from a doubly linked list of blocks.
1422 */
1423 STATIC int /* error */
1424 xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1425 xfs_da_state_blk_t *save_blk)
1426 {
1427 xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
1428 xfs_da_args_t *args;
1429 struct xfs_buf *bp;
1430 int error;
1431
1432 /*
1433 * Set up environment.
1434 */
1435 args = state->args;
1436 ASSERT(args != NULL);
1437 save_info = save_blk->bp->b_addr;
1438 drop_info = drop_blk->bp->b_addr;
1439 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1440 save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1441 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1442 ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
1443 ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
1444 ASSERT(save_blk->magic == drop_blk->magic);
1445 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1446 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1447 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1448 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1449
1450 /*
1451 * Unlink the leaf block from the doubly linked chain of leaves.
1452 */
1453 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1454 trace_xfs_da_unlink_back(args);
1455 save_info->back = drop_info->back;
1456 if (drop_info->back) {
1457 error = xfs_da_node_read(args->trans, args->dp,
1458 be32_to_cpu(drop_info->back),
1459 -1, &bp, args->whichfork);
1460 if (error)
1461 return(error);
1462 ASSERT(bp != NULL);
1463 tmp_info = bp->b_addr;
1464 ASSERT(tmp_info->magic == save_info->magic);
1465 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1466 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1467 xfs_trans_log_buf(args->trans, bp, 0,
1468 sizeof(*tmp_info) - 1);
1469 }
1470 } else {
1471 trace_xfs_da_unlink_forward(args);
1472 save_info->forw = drop_info->forw;
1473 if (drop_info->forw) {
1474 error = xfs_da_node_read(args->trans, args->dp,
1475 be32_to_cpu(drop_info->forw),
1476 -1, &bp, args->whichfork);
1477 if (error)
1478 return(error);
1479 ASSERT(bp != NULL);
1480 tmp_info = bp->b_addr;
1481 ASSERT(tmp_info->magic == save_info->magic);
1482 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1483 tmp_info->back = cpu_to_be32(save_blk->blkno);
1484 xfs_trans_log_buf(args->trans, bp, 0,
1485 sizeof(*tmp_info) - 1);
1486 }
1487 }
1488
1489 xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1490 return(0);
1491 }
1492
1493 /*
1494 * Move a path "forward" or "!forward" one block at the current level.
1495 *
1496 * This routine will adjust a "path" to point to the next block
1497 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1498 * Btree, including updating pointers to the intermediate nodes between
1499 * the new bottom and the root.
1500 */
1501 int /* error */
1502 xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
1503 int forward, int release, int *result)
1504 {
1505 xfs_da_state_blk_t *blk;
1506 xfs_da_blkinfo_t *info;
1507 xfs_da_intnode_t *node;
1508 xfs_da_args_t *args;
1509 xfs_dablk_t blkno=0;
1510 int level, error;
1511
1512 trace_xfs_da_path_shift(state->args);
1513
1514 /*
1515 * Roll up the Btree looking for the first block where our
1516 * current index is not at the edge of the block. Note that
1517 * we skip the bottom layer because we want the sibling block.
1518 */
1519 args = state->args;
1520 ASSERT(args != NULL);
1521 ASSERT(path != NULL);
1522 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1523 level = (path->active-1) - 1; /* skip bottom layer in path */
1524 for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1525 ASSERT(blk->bp != NULL);
1526 node = blk->bp->b_addr;
1527 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1528 if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) {
1529 blk->index++;
1530 blkno = be32_to_cpu(node->btree[blk->index].before);
1531 break;
1532 } else if (!forward && (blk->index > 0)) {
1533 blk->index--;
1534 blkno = be32_to_cpu(node->btree[blk->index].before);
1535 break;
1536 }
1537 }
1538 if (level < 0) {
1539 *result = XFS_ERROR(ENOENT); /* we're out of our tree */
1540 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1541 return(0);
1542 }
1543
1544 /*
1545 * Roll down the edge of the subtree until we reach the
1546 * same depth we were at originally.
1547 */
1548 for (blk++, level++; level < path->active; blk++, level++) {
1549 /*
1550 * Release the old block.
1551 * (if it's dirty, trans won't actually let go)
1552 */
1553 if (release)
1554 xfs_trans_brelse(args->trans, blk->bp);
1555
1556 /*
1557 * Read the next child block.
1558 */
1559 blk->blkno = blkno;
1560 error = xfs_da_node_read(args->trans, args->dp, blkno, -1,
1561 &blk->bp, args->whichfork);
1562 if (error)
1563 return(error);
1564 ASSERT(blk->bp != NULL);
1565 info = blk->bp->b_addr;
1566 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1567 info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1568 info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC));
1569 blk->magic = be16_to_cpu(info->magic);
1570 if (blk->magic == XFS_DA_NODE_MAGIC) {
1571 node = (xfs_da_intnode_t *)info;
1572 blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1573 if (forward)
1574 blk->index = 0;
1575 else
1576 blk->index = be16_to_cpu(node->hdr.count)-1;
1577 blkno = be32_to_cpu(node->btree[blk->index].before);
1578 } else {
1579 ASSERT(level == path->active-1);
1580 blk->index = 0;
1581 switch(blk->magic) {
1582 case XFS_ATTR_LEAF_MAGIC:
1583 blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
1584 NULL);
1585 break;
1586 case XFS_DIR2_LEAFN_MAGIC:
1587 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
1588 NULL);
1589 break;
1590 default:
1591 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
1592 blk->magic == XFS_DIR2_LEAFN_MAGIC);
1593 break;
1594 }
1595 }
1596 }
1597 *result = 0;
1598 return(0);
1599 }
1600
1601
1602 /*========================================================================
1603 * Utility routines.
1604 *========================================================================*/
1605
1606 /*
1607 * Implement a simple hash on a character string.
1608 * Rotate the hash value by 7 bits, then XOR each character in.
1609 * This is implemented with some source-level loop unrolling.
1610 */
1611 xfs_dahash_t
1612 xfs_da_hashname(const __uint8_t *name, int namelen)
1613 {
1614 xfs_dahash_t hash;
1615
1616 /*
1617 * Do four characters at a time as long as we can.
1618 */
1619 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1620 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1621 (name[3] << 0) ^ rol32(hash, 7 * 4);
1622
1623 /*
1624 * Now do the rest of the characters.
1625 */
1626 switch (namelen) {
1627 case 3:
1628 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1629 rol32(hash, 7 * 3);
1630 case 2:
1631 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1632 case 1:
1633 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1634 default: /* case 0: */
1635 return hash;
1636 }
1637 }
1638
1639 enum xfs_dacmp
1640 xfs_da_compname(
1641 struct xfs_da_args *args,
1642 const unsigned char *name,
1643 int len)
1644 {
1645 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
1646 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
1647 }
1648
1649 static xfs_dahash_t
1650 xfs_default_hashname(
1651 struct xfs_name *name)
1652 {
1653 return xfs_da_hashname(name->name, name->len);
1654 }
1655
1656 const struct xfs_nameops xfs_default_nameops = {
1657 .hashname = xfs_default_hashname,
1658 .compname = xfs_da_compname
1659 };
1660
1661 int
1662 xfs_da_grow_inode_int(
1663 struct xfs_da_args *args,
1664 xfs_fileoff_t *bno,
1665 int count)
1666 {
1667 struct xfs_trans *tp = args->trans;
1668 struct xfs_inode *dp = args->dp;
1669 int w = args->whichfork;
1670 xfs_drfsbno_t nblks = dp->i_d.di_nblocks;
1671 struct xfs_bmbt_irec map, *mapp;
1672 int nmap, error, got, i, mapi;
1673
1674 /*
1675 * Find a spot in the file space to put the new block.
1676 */
1677 error = xfs_bmap_first_unused(tp, dp, count, bno, w);
1678 if (error)
1679 return error;
1680
1681 /*
1682 * Try mapping it in one filesystem block.
1683 */
1684 nmap = 1;
1685 ASSERT(args->firstblock != NULL);
1686 error = xfs_bmapi_write(tp, dp, *bno, count,
1687 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
1688 args->firstblock, args->total, &map, &nmap,
1689 args->flist);
1690 if (error)
1691 return error;
1692
1693 ASSERT(nmap <= 1);
1694 if (nmap == 1) {
1695 mapp = &map;
1696 mapi = 1;
1697 } else if (nmap == 0 && count > 1) {
1698 xfs_fileoff_t b;
1699 int c;
1700
1701 /*
1702 * If we didn't get it and the block might work if fragmented,
1703 * try without the CONTIG flag. Loop until we get it all.
1704 */
1705 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1706 for (b = *bno, mapi = 0; b < *bno + count; ) {
1707 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1708 c = (int)(*bno + count - b);
1709 error = xfs_bmapi_write(tp, dp, b, c,
1710 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
1711 args->firstblock, args->total,
1712 &mapp[mapi], &nmap, args->flist);
1713 if (error)
1714 goto out_free_map;
1715 if (nmap < 1)
1716 break;
1717 mapi += nmap;
1718 b = mapp[mapi - 1].br_startoff +
1719 mapp[mapi - 1].br_blockcount;
1720 }
1721 } else {
1722 mapi = 0;
1723 mapp = NULL;
1724 }
1725
1726 /*
1727 * Count the blocks we got, make sure it matches the total.
1728 */
1729 for (i = 0, got = 0; i < mapi; i++)
1730 got += mapp[i].br_blockcount;
1731 if (got != count || mapp[0].br_startoff != *bno ||
1732 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1733 *bno + count) {
1734 error = XFS_ERROR(ENOSPC);
1735 goto out_free_map;
1736 }
1737
1738 /* account for newly allocated blocks in reserved blocks total */
1739 args->total -= dp->i_d.di_nblocks - nblks;
1740
1741 out_free_map:
1742 if (mapp != &map)
1743 kmem_free(mapp);
1744 return error;
1745 }
1746
1747 /*
1748 * Add a block to the btree ahead of the file.
1749 * Return the new block number to the caller.
1750 */
1751 int
1752 xfs_da_grow_inode(
1753 struct xfs_da_args *args,
1754 xfs_dablk_t *new_blkno)
1755 {
1756 xfs_fileoff_t bno;
1757 int count;
1758 int error;
1759
1760 trace_xfs_da_grow_inode(args);
1761
1762 if (args->whichfork == XFS_DATA_FORK) {
1763 bno = args->dp->i_mount->m_dirleafblk;
1764 count = args->dp->i_mount->m_dirblkfsbs;
1765 } else {
1766 bno = 0;
1767 count = 1;
1768 }
1769
1770 error = xfs_da_grow_inode_int(args, &bno, count);
1771 if (!error)
1772 *new_blkno = (xfs_dablk_t)bno;
1773 return error;
1774 }
1775
1776 /*
1777 * Ick. We need to always be able to remove a btree block, even
1778 * if there's no space reservation because the filesystem is full.
1779 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1780 * It swaps the target block with the last block in the file. The
1781 * last block in the file can always be removed since it can't cause
1782 * a bmap btree split to do that.
1783 */
1784 STATIC int
1785 xfs_da_swap_lastblock(
1786 xfs_da_args_t *args,
1787 xfs_dablk_t *dead_blknop,
1788 struct xfs_buf **dead_bufp)
1789 {
1790 xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1791 struct xfs_buf *dead_buf, *last_buf, *sib_buf, *par_buf;
1792 xfs_fileoff_t lastoff;
1793 xfs_inode_t *ip;
1794 xfs_trans_t *tp;
1795 xfs_mount_t *mp;
1796 int error, w, entno, level, dead_level;
1797 xfs_da_blkinfo_t *dead_info, *sib_info;
1798 xfs_da_intnode_t *par_node, *dead_node;
1799 xfs_dir2_leaf_t *dead_leaf2;
1800 xfs_dahash_t dead_hash;
1801
1802 trace_xfs_da_swap_lastblock(args);
1803
1804 dead_buf = *dead_bufp;
1805 dead_blkno = *dead_blknop;
1806 tp = args->trans;
1807 ip = args->dp;
1808 w = args->whichfork;
1809 ASSERT(w == XFS_DATA_FORK);
1810 mp = ip->i_mount;
1811 lastoff = mp->m_dirfreeblk;
1812 error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1813 if (error)
1814 return error;
1815 if (unlikely(lastoff == 0)) {
1816 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1817 mp);
1818 return XFS_ERROR(EFSCORRUPTED);
1819 }
1820 /*
1821 * Read the last block in the btree space.
1822 */
1823 last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1824 error = xfs_da_node_read(tp, ip, last_blkno, -1, &last_buf, w);
1825 if (error)
1826 return error;
1827 /*
1828 * Copy the last block into the dead buffer and log it.
1829 */
1830 memcpy(dead_buf->b_addr, last_buf->b_addr, mp->m_dirblksize);
1831 xfs_trans_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1832 dead_info = dead_buf->b_addr;
1833 /*
1834 * Get values from the moved block.
1835 */
1836 if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)) {
1837 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1838 dead_level = 0;
1839 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1840 } else {
1841 ASSERT(dead_info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1842 dead_node = (xfs_da_intnode_t *)dead_info;
1843 dead_level = be16_to_cpu(dead_node->hdr.level);
1844 dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
1845 }
1846 sib_buf = par_buf = NULL;
1847 /*
1848 * If the moved block has a left sibling, fix up the pointers.
1849 */
1850 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1851 error = xfs_da_node_read(tp, ip, sib_blkno, -1, &sib_buf, w);
1852 if (error)
1853 goto done;
1854 sib_info = sib_buf->b_addr;
1855 if (unlikely(
1856 be32_to_cpu(sib_info->forw) != last_blkno ||
1857 sib_info->magic != dead_info->magic)) {
1858 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1859 XFS_ERRLEVEL_LOW, mp);
1860 error = XFS_ERROR(EFSCORRUPTED);
1861 goto done;
1862 }
1863 sib_info->forw = cpu_to_be32(dead_blkno);
1864 xfs_trans_log_buf(tp, sib_buf,
1865 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1866 sizeof(sib_info->forw)));
1867 sib_buf = NULL;
1868 }
1869 /*
1870 * If the moved block has a right sibling, fix up the pointers.
1871 */
1872 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1873 error = xfs_da_node_read(tp, ip, sib_blkno, -1, &sib_buf, w);
1874 if (error)
1875 goto done;
1876 sib_info = sib_buf->b_addr;
1877 if (unlikely(
1878 be32_to_cpu(sib_info->back) != last_blkno ||
1879 sib_info->magic != dead_info->magic)) {
1880 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1881 XFS_ERRLEVEL_LOW, mp);
1882 error = XFS_ERROR(EFSCORRUPTED);
1883 goto done;
1884 }
1885 sib_info->back = cpu_to_be32(dead_blkno);
1886 xfs_trans_log_buf(tp, sib_buf,
1887 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1888 sizeof(sib_info->back)));
1889 sib_buf = NULL;
1890 }
1891 par_blkno = mp->m_dirleafblk;
1892 level = -1;
1893 /*
1894 * Walk down the tree looking for the parent of the moved block.
1895 */
1896 for (;;) {
1897 error = xfs_da_node_read(tp, ip, par_blkno, -1, &par_buf, w);
1898 if (error)
1899 goto done;
1900 par_node = par_buf->b_addr;
1901 if (unlikely(par_node->hdr.info.magic !=
1902 cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1903 (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
1904 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1905 XFS_ERRLEVEL_LOW, mp);
1906 error = XFS_ERROR(EFSCORRUPTED);
1907 goto done;
1908 }
1909 level = be16_to_cpu(par_node->hdr.level);
1910 for (entno = 0;
1911 entno < be16_to_cpu(par_node->hdr.count) &&
1912 be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
1913 entno++)
1914 continue;
1915 if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
1916 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1917 XFS_ERRLEVEL_LOW, mp);
1918 error = XFS_ERROR(EFSCORRUPTED);
1919 goto done;
1920 }
1921 par_blkno = be32_to_cpu(par_node->btree[entno].before);
1922 if (level == dead_level + 1)
1923 break;
1924 xfs_trans_brelse(tp, par_buf);
1925 par_buf = NULL;
1926 }
1927 /*
1928 * We're in the right parent block.
1929 * Look for the right entry.
1930 */
1931 for (;;) {
1932 for (;
1933 entno < be16_to_cpu(par_node->hdr.count) &&
1934 be32_to_cpu(par_node->btree[entno].before) != last_blkno;
1935 entno++)
1936 continue;
1937 if (entno < be16_to_cpu(par_node->hdr.count))
1938 break;
1939 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1940 xfs_trans_brelse(tp, par_buf);
1941 par_buf = NULL;
1942 if (unlikely(par_blkno == 0)) {
1943 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1944 XFS_ERRLEVEL_LOW, mp);
1945 error = XFS_ERROR(EFSCORRUPTED);
1946 goto done;
1947 }
1948 error = xfs_da_node_read(tp, ip, par_blkno, -1, &par_buf, w);
1949 if (error)
1950 goto done;
1951 par_node = par_buf->b_addr;
1952 if (unlikely(
1953 be16_to_cpu(par_node->hdr.level) != level ||
1954 par_node->hdr.info.magic != cpu_to_be16(XFS_DA_NODE_MAGIC))) {
1955 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1956 XFS_ERRLEVEL_LOW, mp);
1957 error = XFS_ERROR(EFSCORRUPTED);
1958 goto done;
1959 }
1960 entno = 0;
1961 }
1962 /*
1963 * Update the parent entry pointing to the moved block.
1964 */
1965 par_node->btree[entno].before = cpu_to_be32(dead_blkno);
1966 xfs_trans_log_buf(tp, par_buf,
1967 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1968 sizeof(par_node->btree[entno].before)));
1969 *dead_blknop = last_blkno;
1970 *dead_bufp = last_buf;
1971 return 0;
1972 done:
1973 if (par_buf)
1974 xfs_trans_brelse(tp, par_buf);
1975 if (sib_buf)
1976 xfs_trans_brelse(tp, sib_buf);
1977 xfs_trans_brelse(tp, last_buf);
1978 return error;
1979 }
1980
1981 /*
1982 * Remove a btree block from a directory or attribute.
1983 */
1984 int
1985 xfs_da_shrink_inode(
1986 xfs_da_args_t *args,
1987 xfs_dablk_t dead_blkno,
1988 struct xfs_buf *dead_buf)
1989 {
1990 xfs_inode_t *dp;
1991 int done, error, w, count;
1992 xfs_trans_t *tp;
1993 xfs_mount_t *mp;
1994
1995 trace_xfs_da_shrink_inode(args);
1996
1997 dp = args->dp;
1998 w = args->whichfork;
1999 tp = args->trans;
2000 mp = dp->i_mount;
2001 if (w == XFS_DATA_FORK)
2002 count = mp->m_dirblkfsbs;
2003 else
2004 count = 1;
2005 for (;;) {
2006 /*
2007 * Remove extents. If we get ENOSPC for a dir we have to move
2008 * the last block to the place we want to kill.
2009 */
2010 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
2011 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2012 0, args->firstblock, args->flist,
2013 &done)) == ENOSPC) {
2014 if (w != XFS_DATA_FORK)
2015 break;
2016 if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
2017 &dead_buf)))
2018 break;
2019 } else {
2020 break;
2021 }
2022 }
2023 xfs_trans_binval(tp, dead_buf);
2024 return error;
2025 }
2026
2027 /*
2028 * See if the mapping(s) for this btree block are valid, i.e.
2029 * don't contain holes, are logically contiguous, and cover the whole range.
2030 */
2031 STATIC int
2032 xfs_da_map_covers_blocks(
2033 int nmap,
2034 xfs_bmbt_irec_t *mapp,
2035 xfs_dablk_t bno,
2036 int count)
2037 {
2038 int i;
2039 xfs_fileoff_t off;
2040
2041 for (i = 0, off = bno; i < nmap; i++) {
2042 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
2043 mapp[i].br_startblock == DELAYSTARTBLOCK) {
2044 return 0;
2045 }
2046 if (off != mapp[i].br_startoff) {
2047 return 0;
2048 }
2049 off += mapp[i].br_blockcount;
2050 }
2051 return off == bno + count;
2052 }
2053
2054 /*
2055 * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
2056 *
2057 * For the single map case, it is assumed that the caller has provided a pointer
2058 * to a valid xfs_buf_map. For the multiple map case, this function will
2059 * allocate the xfs_buf_map to hold all the maps and replace the caller's single
2060 * map pointer with the allocated map.
2061 */
2062 static int
2063 xfs_buf_map_from_irec(
2064 struct xfs_mount *mp,
2065 struct xfs_buf_map **mapp,
2066 unsigned int *nmaps,
2067 struct xfs_bmbt_irec *irecs,
2068 unsigned int nirecs)
2069 {
2070 struct xfs_buf_map *map;
2071 int i;
2072
2073 ASSERT(*nmaps == 1);
2074 ASSERT(nirecs >= 1);
2075
2076 if (nirecs > 1) {
2077 map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_SLEEP);
2078 if (!map)
2079 return ENOMEM;
2080 *mapp = map;
2081 }
2082
2083 *nmaps = nirecs;
2084 map = *mapp;
2085 for (i = 0; i < *nmaps; i++) {
2086 ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
2087 irecs[i].br_startblock != HOLESTARTBLOCK);
2088 map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
2089 map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
2090 }
2091 return 0;
2092 }
2093
2094 /*
2095 * Map the block we are given ready for reading. There are three possible return
2096 * values:
2097 * -1 - will be returned if we land in a hole and mappedbno == -2 so the
2098 * caller knows not to execute a subsequent read.
2099 * 0 - if we mapped the block successfully
2100 * >0 - positive error number if there was an error.
2101 */
2102 static int
2103 xfs_dabuf_map(
2104 struct xfs_trans *trans,
2105 struct xfs_inode *dp,
2106 xfs_dablk_t bno,
2107 xfs_daddr_t mappedbno,
2108 int whichfork,
2109 struct xfs_buf_map **map,
2110 int *nmaps)
2111 {
2112 struct xfs_mount *mp = dp->i_mount;
2113 int nfsb;
2114 int error = 0;
2115 struct xfs_bmbt_irec irec;
2116 struct xfs_bmbt_irec *irecs = &irec;
2117 int nirecs;
2118
2119 ASSERT(map && *map);
2120 ASSERT(*nmaps == 1);
2121
2122 nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
2123
2124 /*
2125 * Caller doesn't have a mapping. -2 means don't complain
2126 * if we land in a hole.
2127 */
2128 if (mappedbno == -1 || mappedbno == -2) {
2129 /*
2130 * Optimize the one-block case.
2131 */
2132 if (nfsb != 1)
2133 irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_SLEEP);
2134
2135 nirecs = nfsb;
2136 error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
2137 &nirecs, xfs_bmapi_aflag(whichfork));
2138 if (error)
2139 goto out;
2140 } else {
2141 irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2142 irecs->br_startoff = (xfs_fileoff_t)bno;
2143 irecs->br_blockcount = nfsb;
2144 irecs->br_state = 0;
2145 nirecs = 1;
2146 }
2147
2148 if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
2149 error = mappedbno == -2 ? -1 : XFS_ERROR(EFSCORRUPTED);
2150 if (unlikely(error == EFSCORRUPTED)) {
2151 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2152 int i;
2153 xfs_alert(mp, "%s: bno %lld dir: inode %lld",
2154 __func__, (long long)bno,
2155 (long long)dp->i_ino);
2156 for (i = 0; i < *nmaps; i++) {
2157 xfs_alert(mp,
2158 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2159 i,
2160 (long long)irecs[i].br_startoff,
2161 (long long)irecs[i].br_startblock,
2162 (long long)irecs[i].br_blockcount,
2163 irecs[i].br_state);
2164 }
2165 }
2166 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2167 XFS_ERRLEVEL_LOW, mp);
2168 }
2169 goto out;
2170 }
2171 error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
2172 out:
2173 if (irecs != &irec)
2174 kmem_free(irecs);
2175 return error;
2176 }
2177
2178 /*
2179 * Get a buffer for the dir/attr block.
2180 */
2181 int
2182 xfs_da_get_buf(
2183 struct xfs_trans *trans,
2184 struct xfs_inode *dp,
2185 xfs_dablk_t bno,
2186 xfs_daddr_t mappedbno,
2187 struct xfs_buf **bpp,
2188 int whichfork)
2189 {
2190 struct xfs_buf *bp;
2191 struct xfs_buf_map map;
2192 struct xfs_buf_map *mapp;
2193 int nmap;
2194 int error;
2195
2196 *bpp = NULL;
2197 mapp = &map;
2198 nmap = 1;
2199 error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
2200 &mapp, &nmap);
2201 if (error) {
2202 /* mapping a hole is not an error, but we don't continue */
2203 if (error == -1)
2204 error = 0;
2205 goto out_free;
2206 }
2207
2208 bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
2209 mapp, nmap, 0);
2210 error = bp ? bp->b_error : XFS_ERROR(EIO);
2211 if (error) {
2212 xfs_trans_brelse(trans, bp);
2213 goto out_free;
2214 }
2215
2216 *bpp = bp;
2217
2218 out_free:
2219 if (mapp != &map)
2220 kmem_free(mapp);
2221
2222 return error;
2223 }
2224
2225 /*
2226 * Get a buffer for the dir/attr block, fill in the contents.
2227 */
2228 int
2229 xfs_da_read_buf(
2230 struct xfs_trans *trans,
2231 struct xfs_inode *dp,
2232 xfs_dablk_t bno,
2233 xfs_daddr_t mappedbno,
2234 struct xfs_buf **bpp,
2235 int whichfork,
2236 const struct xfs_buf_ops *ops)
2237 {
2238 struct xfs_buf *bp;
2239 struct xfs_buf_map map;
2240 struct xfs_buf_map *mapp;
2241 int nmap;
2242 int error;
2243
2244 *bpp = NULL;
2245 mapp = &map;
2246 nmap = 1;
2247 error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
2248 &mapp, &nmap);
2249 if (error) {
2250 /* mapping a hole is not an error, but we don't continue */
2251 if (error == -1)
2252 error = 0;
2253 goto out_free;
2254 }
2255
2256 error = xfs_trans_read_buf_map(dp->i_mount, trans,
2257 dp->i_mount->m_ddev_targp,
2258 mapp, nmap, 0, &bp, ops);
2259 if (error)
2260 goto out_free;
2261
2262 if (whichfork == XFS_ATTR_FORK)
2263 xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2264 else
2265 xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2266
2267 /*
2268 * This verification code will be moved to a CRC verification callback
2269 * function so just leave it here unchanged until then.
2270 */
2271 {
2272 xfs_dir2_data_hdr_t *hdr = bp->b_addr;
2273 xfs_dir2_free_t *free = bp->b_addr;
2274 xfs_da_blkinfo_t *info = bp->b_addr;
2275 uint magic, magic1;
2276 struct xfs_mount *mp = dp->i_mount;
2277
2278 magic = be16_to_cpu(info->magic);
2279 magic1 = be32_to_cpu(hdr->magic);
2280 if (unlikely(
2281 XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2282 (magic != XFS_ATTR_LEAF_MAGIC) &&
2283 (magic != XFS_DIR2_LEAF1_MAGIC) &&
2284 (magic != XFS_DIR2_LEAFN_MAGIC) &&
2285 (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2286 (magic1 != XFS_DIR2_DATA_MAGIC) &&
2287 (free->hdr.magic != cpu_to_be32(XFS_DIR2_FREE_MAGIC)),
2288 mp, XFS_ERRTAG_DA_READ_BUF,
2289 XFS_RANDOM_DA_READ_BUF))) {
2290 trace_xfs_da_btree_corrupt(bp, _RET_IP_);
2291 XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2292 XFS_ERRLEVEL_LOW, mp, info);
2293 error = XFS_ERROR(EFSCORRUPTED);
2294 xfs_trans_brelse(trans, bp);
2295 goto out_free;
2296 }
2297 }
2298 *bpp = bp;
2299 out_free:
2300 if (mapp != &map)
2301 kmem_free(mapp);
2302
2303 return error;
2304 }
2305
2306 /*
2307 * Readahead the dir/attr block.
2308 */
2309 xfs_daddr_t
2310 xfs_da_reada_buf(
2311 struct xfs_trans *trans,
2312 struct xfs_inode *dp,
2313 xfs_dablk_t bno,
2314 xfs_daddr_t mappedbno,
2315 int whichfork,
2316 const struct xfs_buf_ops *ops)
2317 {
2318 struct xfs_buf_map map;
2319 struct xfs_buf_map *mapp;
2320 int nmap;
2321 int error;
2322
2323 mapp = &map;
2324 nmap = 1;
2325 error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
2326 &mapp, &nmap);
2327 if (error) {
2328 /* mapping a hole is not an error, but we don't continue */
2329 if (error == -1)
2330 error = 0;
2331 goto out_free;
2332 }
2333
2334 mappedbno = mapp[0].bm_bn;
2335 xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
2336
2337 out_free:
2338 if (mapp != &map)
2339 kmem_free(mapp);
2340
2341 if (error)
2342 return -1;
2343 return mappedbno;
2344 }
2345
2346 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2347
2348 /*
2349 * Allocate a dir-state structure.
2350 * We don't put them on the stack since they're large.
2351 */
2352 xfs_da_state_t *
2353 xfs_da_state_alloc(void)
2354 {
2355 return kmem_zone_zalloc(xfs_da_state_zone, KM_NOFS);
2356 }
2357
2358 /*
2359 * Kill the altpath contents of a da-state structure.
2360 */
2361 STATIC void
2362 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2363 {
2364 int i;
2365
2366 for (i = 0; i < state->altpath.active; i++)
2367 state->altpath.blk[i].bp = NULL;
2368 state->altpath.active = 0;
2369 }
2370
2371 /*
2372 * Free a da-state structure.
2373 */
2374 void
2375 xfs_da_state_free(xfs_da_state_t *state)
2376 {
2377 xfs_da_state_kill_altpath(state);
2378 #ifdef DEBUG
2379 memset((char *)state, 0, sizeof(*state));
2380 #endif /* DEBUG */
2381 kmem_zone_free(xfs_da_state_zone, state);
2382 }
Linux kernel - Deliverables
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