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1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * Copyright (c) 2013 Red Hat, Inc.
4 * All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19#include "xfs.h"
20#include "xfs_fs.h"
21#include "xfs_shared.h"
22#include "xfs_format.h"
23#include "xfs_log_format.h"
24#include "xfs_trans_resv.h"
25#include "xfs_bit.h"
26#include "xfs_mount.h"
27#include "xfs_da_format.h"
28#include "xfs_da_btree.h"
29#include "xfs_dir2.h"
30#include "xfs_dir2_priv.h"
31#include "xfs_inode.h"
32#include "xfs_trans.h"
33#include "xfs_inode_item.h"
34#include "xfs_alloc.h"
35#include "xfs_bmap.h"
36#include "xfs_attr.h"
37#include "xfs_attr_leaf.h"
38#include "xfs_error.h"
39#include "xfs_trace.h"
40#include "xfs_cksum.h"
41#include "xfs_buf_item.h"
42#include "xfs_log.h"
43
44/*
45 * xfs_da_btree.c
46 *
47 * Routines to implement directories as Btrees of hashed names.
48 */
49
50/*========================================================================
51 * Function prototypes for the kernel.
52 *========================================================================*/
53
54/*
55 * Routines used for growing the Btree.
56 */
57STATIC int xfs_da3_root_split(xfs_da_state_t *state,
58 xfs_da_state_blk_t *existing_root,
59 xfs_da_state_blk_t *new_child);
60STATIC int xfs_da3_node_split(xfs_da_state_t *state,
61 xfs_da_state_blk_t *existing_blk,
62 xfs_da_state_blk_t *split_blk,
63 xfs_da_state_blk_t *blk_to_add,
64 int treelevel,
65 int *result);
66STATIC void xfs_da3_node_rebalance(xfs_da_state_t *state,
67 xfs_da_state_blk_t *node_blk_1,
68 xfs_da_state_blk_t *node_blk_2);
69STATIC void xfs_da3_node_add(xfs_da_state_t *state,
70 xfs_da_state_blk_t *old_node_blk,
71 xfs_da_state_blk_t *new_node_blk);
72
73/*
74 * Routines used for shrinking the Btree.
75 */
76STATIC int xfs_da3_root_join(xfs_da_state_t *state,
77 xfs_da_state_blk_t *root_blk);
78STATIC int xfs_da3_node_toosmall(xfs_da_state_t *state, int *retval);
79STATIC void xfs_da3_node_remove(xfs_da_state_t *state,
80 xfs_da_state_blk_t *drop_blk);
81STATIC void xfs_da3_node_unbalance(xfs_da_state_t *state,
82 xfs_da_state_blk_t *src_node_blk,
83 xfs_da_state_blk_t *dst_node_blk);
84
85/*
86 * Utility routines.
87 */
88STATIC int xfs_da3_blk_unlink(xfs_da_state_t *state,
89 xfs_da_state_blk_t *drop_blk,
90 xfs_da_state_blk_t *save_blk);
91
92
93kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
94
95/*
96 * Allocate a dir-state structure.
97 * We don't put them on the stack since they're large.
98 */
99xfs_da_state_t *
100xfs_da_state_alloc(void)
101{
102 return kmem_zone_zalloc(xfs_da_state_zone, KM_NOFS);
103}
104
105/*
106 * Kill the altpath contents of a da-state structure.
107 */
108STATIC void
109xfs_da_state_kill_altpath(xfs_da_state_t *state)
110{
111 int i;
112
113 for (i = 0; i < state->altpath.active; i++)
114 state->altpath.blk[i].bp = NULL;
115 state->altpath.active = 0;
116}
117
118/*
119 * Free a da-state structure.
120 */
121void
122xfs_da_state_free(xfs_da_state_t *state)
123{
124 xfs_da_state_kill_altpath(state);
125#ifdef DEBUG
126 memset((char *)state, 0, sizeof(*state));
127#endif /* DEBUG */
128 kmem_zone_free(xfs_da_state_zone, state);
129}
130
131static xfs_failaddr_t
132xfs_da3_node_verify(
133 struct xfs_buf *bp)
134{
135 struct xfs_mount *mp = bp->b_target->bt_mount;
136 struct xfs_da_intnode *hdr = bp->b_addr;
137 struct xfs_da3_icnode_hdr ichdr;
138 const struct xfs_dir_ops *ops;
139
140 ops = xfs_dir_get_ops(mp, NULL);
141
142 ops->node_hdr_from_disk(&ichdr, hdr);
143
144 if (xfs_sb_version_hascrc(&mp->m_sb)) {
145 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
146
147 if (ichdr.magic != XFS_DA3_NODE_MAGIC)
148 return __this_address;
149
150 if (!uuid_equal(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid))
151 return __this_address;
152 if (be64_to_cpu(hdr3->info.blkno) != bp->b_bn)
153 return __this_address;
154 if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->info.lsn)))
155 return __this_address;
156 } else {
157 if (ichdr.magic != XFS_DA_NODE_MAGIC)
158 return __this_address;
159 }
160 if (ichdr.level == 0)
161 return __this_address;
162 if (ichdr.level > XFS_DA_NODE_MAXDEPTH)
163 return __this_address;
164 if (ichdr.count == 0)
165 return __this_address;
166
167 /*
168 * we don't know if the node is for and attribute or directory tree,
169 * so only fail if the count is outside both bounds
170 */
171 if (ichdr.count > mp->m_dir_geo->node_ents &&
172 ichdr.count > mp->m_attr_geo->node_ents)
173 return __this_address;
174
175 /* XXX: hash order check? */
176
177 return NULL;
178}
179
180static void
181xfs_da3_node_write_verify(
182 struct xfs_buf *bp)
183{
184 struct xfs_mount *mp = bp->b_target->bt_mount;
185 struct xfs_buf_log_item *bip = bp->b_log_item;
186 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
187 xfs_failaddr_t fa;
188
189 fa = xfs_da3_node_verify(bp);
190 if (fa) {
191 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
192 return;
193 }
194
195 if (!xfs_sb_version_hascrc(&mp->m_sb))
196 return;
197
198 if (bip)
199 hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
200
201 xfs_buf_update_cksum(bp, XFS_DA3_NODE_CRC_OFF);
202}
203
204/*
205 * leaf/node format detection on trees is sketchy, so a node read can be done on
206 * leaf level blocks when detection identifies the tree as a node format tree
207 * incorrectly. In this case, we need to swap the verifier to match the correct
208 * format of the block being read.
209 */
210static void
211xfs_da3_node_read_verify(
212 struct xfs_buf *bp)
213{
214 struct xfs_da_blkinfo *info = bp->b_addr;
215 xfs_failaddr_t fa;
216
217 switch (be16_to_cpu(info->magic)) {
218 case XFS_DA3_NODE_MAGIC:
219 if (!xfs_buf_verify_cksum(bp, XFS_DA3_NODE_CRC_OFF)) {
220 xfs_verifier_error(bp, -EFSBADCRC,
221 __this_address);
222 break;
223 }
224 /* fall through */
225 case XFS_DA_NODE_MAGIC:
226 fa = xfs_da3_node_verify(bp);
227 if (fa)
228 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
229 return;
230 case XFS_ATTR_LEAF_MAGIC:
231 case XFS_ATTR3_LEAF_MAGIC:
232 bp->b_ops = &xfs_attr3_leaf_buf_ops;
233 bp->b_ops->verify_read(bp);
234 return;
235 case XFS_DIR2_LEAFN_MAGIC:
236 case XFS_DIR3_LEAFN_MAGIC:
237 bp->b_ops = &xfs_dir3_leafn_buf_ops;
238 bp->b_ops->verify_read(bp);
239 return;
240 default:
241 xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
242 break;
243 }
244}
245
246/* Verify the structure of a da3 block. */
247static xfs_failaddr_t
248xfs_da3_node_verify_struct(
249 struct xfs_buf *bp)
250{
251 struct xfs_da_blkinfo *info = bp->b_addr;
252
253 switch (be16_to_cpu(info->magic)) {
254 case XFS_DA3_NODE_MAGIC:
255 case XFS_DA_NODE_MAGIC:
256 return xfs_da3_node_verify(bp);
257 case XFS_ATTR_LEAF_MAGIC:
258 case XFS_ATTR3_LEAF_MAGIC:
259 bp->b_ops = &xfs_attr3_leaf_buf_ops;
260 return bp->b_ops->verify_struct(bp);
261 case XFS_DIR2_LEAFN_MAGIC:
262 case XFS_DIR3_LEAFN_MAGIC:
263 bp->b_ops = &xfs_dir3_leafn_buf_ops;
264 return bp->b_ops->verify_struct(bp);
265 default:
266 return __this_address;
267 }
268}
269
270const struct xfs_buf_ops xfs_da3_node_buf_ops = {
271 .name = "xfs_da3_node",
272 .verify_read = xfs_da3_node_read_verify,
273 .verify_write = xfs_da3_node_write_verify,
274 .verify_struct = xfs_da3_node_verify_struct,
275};
276
277int
278xfs_da3_node_read(
279 struct xfs_trans *tp,
280 struct xfs_inode *dp,
281 xfs_dablk_t bno,
282 xfs_daddr_t mappedbno,
283 struct xfs_buf **bpp,
284 int which_fork)
285{
286 int err;
287
288 err = xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
289 which_fork, &xfs_da3_node_buf_ops);
290 if (!err && tp && *bpp) {
291 struct xfs_da_blkinfo *info = (*bpp)->b_addr;
292 int type;
293
294 switch (be16_to_cpu(info->magic)) {
295 case XFS_DA_NODE_MAGIC:
296 case XFS_DA3_NODE_MAGIC:
297 type = XFS_BLFT_DA_NODE_BUF;
298 break;
299 case XFS_ATTR_LEAF_MAGIC:
300 case XFS_ATTR3_LEAF_MAGIC:
301 type = XFS_BLFT_ATTR_LEAF_BUF;
302 break;
303 case XFS_DIR2_LEAFN_MAGIC:
304 case XFS_DIR3_LEAFN_MAGIC:
305 type = XFS_BLFT_DIR_LEAFN_BUF;
306 break;
307 default:
308 type = 0;
309 ASSERT(0);
310 break;
311 }
312 xfs_trans_buf_set_type(tp, *bpp, type);
313 }
314 return err;
315}
316
317/*========================================================================
318 * Routines used for growing the Btree.
319 *========================================================================*/
320
321/*
322 * Create the initial contents of an intermediate node.
323 */
324int
325xfs_da3_node_create(
326 struct xfs_da_args *args,
327 xfs_dablk_t blkno,
328 int level,
329 struct xfs_buf **bpp,
330 int whichfork)
331{
332 struct xfs_da_intnode *node;
333 struct xfs_trans *tp = args->trans;
334 struct xfs_mount *mp = tp->t_mountp;
335 struct xfs_da3_icnode_hdr ichdr = {0};
336 struct xfs_buf *bp;
337 int error;
338 struct xfs_inode *dp = args->dp;
339
340 trace_xfs_da_node_create(args);
341 ASSERT(level <= XFS_DA_NODE_MAXDEPTH);
342
343 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, whichfork);
344 if (error)
345 return error;
346 bp->b_ops = &xfs_da3_node_buf_ops;
347 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
348 node = bp->b_addr;
349
350 if (xfs_sb_version_hascrc(&mp->m_sb)) {
351 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
352
353 memset(hdr3, 0, sizeof(struct xfs_da3_node_hdr));
354 ichdr.magic = XFS_DA3_NODE_MAGIC;
355 hdr3->info.blkno = cpu_to_be64(bp->b_bn);
356 hdr3->info.owner = cpu_to_be64(args->dp->i_ino);
357 uuid_copy(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid);
358 } else {
359 ichdr.magic = XFS_DA_NODE_MAGIC;
360 }
361 ichdr.level = level;
362
363 dp->d_ops->node_hdr_to_disk(node, &ichdr);
364 xfs_trans_log_buf(tp, bp,
365 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
366
367 *bpp = bp;
368 return 0;
369}
370
371/*
372 * Split a leaf node, rebalance, then possibly split
373 * intermediate nodes, rebalance, etc.
374 */
375int /* error */
376xfs_da3_split(
377 struct xfs_da_state *state)
378{
379 struct xfs_da_state_blk *oldblk;
380 struct xfs_da_state_blk *newblk;
381 struct xfs_da_state_blk *addblk;
382 struct xfs_da_intnode *node;
383 int max;
384 int action = 0;
385 int error;
386 int i;
387
388 trace_xfs_da_split(state->args);
389
390 /*
391 * Walk back up the tree splitting/inserting/adjusting as necessary.
392 * If we need to insert and there isn't room, split the node, then
393 * decide which fragment to insert the new block from below into.
394 * Note that we may split the root this way, but we need more fixup.
395 */
396 max = state->path.active - 1;
397 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
398 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
399 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
400
401 addblk = &state->path.blk[max]; /* initial dummy value */
402 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
403 oldblk = &state->path.blk[i];
404 newblk = &state->altpath.blk[i];
405
406 /*
407 * If a leaf node then
408 * Allocate a new leaf node, then rebalance across them.
409 * else if an intermediate node then
410 * We split on the last layer, must we split the node?
411 */
412 switch (oldblk->magic) {
413 case XFS_ATTR_LEAF_MAGIC:
414 error = xfs_attr3_leaf_split(state, oldblk, newblk);
415 if ((error != 0) && (error != -ENOSPC)) {
416 return error; /* GROT: attr is inconsistent */
417 }
418 if (!error) {
419 addblk = newblk;
420 break;
421 }
422 /*
423 * Entry wouldn't fit, split the leaf again. The new
424 * extrablk will be consumed by xfs_da3_node_split if
425 * the node is split.
426 */
427 state->extravalid = 1;
428 if (state->inleaf) {
429 state->extraafter = 0; /* before newblk */
430 trace_xfs_attr_leaf_split_before(state->args);
431 error = xfs_attr3_leaf_split(state, oldblk,
432 &state->extrablk);
433 } else {
434 state->extraafter = 1; /* after newblk */
435 trace_xfs_attr_leaf_split_after(state->args);
436 error = xfs_attr3_leaf_split(state, newblk,
437 &state->extrablk);
438 }
439 if (error)
440 return error; /* GROT: attr inconsistent */
441 addblk = newblk;
442 break;
443 case XFS_DIR2_LEAFN_MAGIC:
444 error = xfs_dir2_leafn_split(state, oldblk, newblk);
445 if (error)
446 return error;
447 addblk = newblk;
448 break;
449 case XFS_DA_NODE_MAGIC:
450 error = xfs_da3_node_split(state, oldblk, newblk, addblk,
451 max - i, &action);
452 addblk->bp = NULL;
453 if (error)
454 return error; /* GROT: dir is inconsistent */
455 /*
456 * Record the newly split block for the next time thru?
457 */
458 if (action)
459 addblk = newblk;
460 else
461 addblk = NULL;
462 break;
463 }
464
465 /*
466 * Update the btree to show the new hashval for this child.
467 */
468 xfs_da3_fixhashpath(state, &state->path);
469 }
470 if (!addblk)
471 return 0;
472
473 /*
474 * xfs_da3_node_split() should have consumed any extra blocks we added
475 * during a double leaf split in the attr fork. This is guaranteed as
476 * we can't be here if the attr fork only has a single leaf block.
477 */
478 ASSERT(state->extravalid == 0 ||
479 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
480
481 /*
482 * Split the root node.
483 */
484 ASSERT(state->path.active == 0);
485 oldblk = &state->path.blk[0];
486 error = xfs_da3_root_split(state, oldblk, addblk);
487 if (error) {
488 addblk->bp = NULL;
489 return error; /* GROT: dir is inconsistent */
490 }
491
492 /*
493 * Update pointers to the node which used to be block 0 and just got
494 * bumped because of the addition of a new root node. Note that the
495 * original block 0 could be at any position in the list of blocks in
496 * the tree.
497 *
498 * Note: the magic numbers and sibling pointers are in the same physical
499 * place for both v2 and v3 headers (by design). Hence it doesn't matter
500 * which version of the xfs_da_intnode structure we use here as the
501 * result will be the same using either structure.
502 */
503 node = oldblk->bp->b_addr;
504 if (node->hdr.info.forw) {
505 ASSERT(be32_to_cpu(node->hdr.info.forw) == addblk->blkno);
506 node = addblk->bp->b_addr;
507 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
508 xfs_trans_log_buf(state->args->trans, addblk->bp,
509 XFS_DA_LOGRANGE(node, &node->hdr.info,
510 sizeof(node->hdr.info)));
511 }
512 node = oldblk->bp->b_addr;
513 if (node->hdr.info.back) {
514 ASSERT(be32_to_cpu(node->hdr.info.back) == addblk->blkno);
515 node = addblk->bp->b_addr;
516 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
517 xfs_trans_log_buf(state->args->trans, addblk->bp,
518 XFS_DA_LOGRANGE(node, &node->hdr.info,
519 sizeof(node->hdr.info)));
520 }
521 addblk->bp = NULL;
522 return 0;
523}
524
525/*
526 * Split the root. We have to create a new root and point to the two
527 * parts (the split old root) that we just created. Copy block zero to
528 * the EOF, extending the inode in process.
529 */
530STATIC int /* error */
531xfs_da3_root_split(
532 struct xfs_da_state *state,
533 struct xfs_da_state_blk *blk1,
534 struct xfs_da_state_blk *blk2)
535{
536 struct xfs_da_intnode *node;
537 struct xfs_da_intnode *oldroot;
538 struct xfs_da_node_entry *btree;
539 struct xfs_da3_icnode_hdr nodehdr;
540 struct xfs_da_args *args;
541 struct xfs_buf *bp;
542 struct xfs_inode *dp;
543 struct xfs_trans *tp;
544 struct xfs_dir2_leaf *leaf;
545 xfs_dablk_t blkno;
546 int level;
547 int error;
548 int size;
549
550 trace_xfs_da_root_split(state->args);
551
552 /*
553 * Copy the existing (incorrect) block from the root node position
554 * to a free space somewhere.
555 */
556 args = state->args;
557 error = xfs_da_grow_inode(args, &blkno);
558 if (error)
559 return error;
560
561 dp = args->dp;
562 tp = args->trans;
563 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
564 if (error)
565 return error;
566 node = bp->b_addr;
567 oldroot = blk1->bp->b_addr;
568 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
569 oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
570 struct xfs_da3_icnode_hdr icnodehdr;
571
572 dp->d_ops->node_hdr_from_disk(&icnodehdr, oldroot);
573 btree = dp->d_ops->node_tree_p(oldroot);
574 size = (int)((char *)&btree[icnodehdr.count] - (char *)oldroot);
575 level = icnodehdr.level;
576
577 /*
578 * we are about to copy oldroot to bp, so set up the type
579 * of bp while we know exactly what it will be.
580 */
581 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
582 } else {
583 struct xfs_dir3_icleaf_hdr leafhdr;
584 struct xfs_dir2_leaf_entry *ents;
585
586 leaf = (xfs_dir2_leaf_t *)oldroot;
587 dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
588 ents = dp->d_ops->leaf_ents_p(leaf);
589
590 ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
591 leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
592 size = (int)((char *)&ents[leafhdr.count] - (char *)leaf);
593 level = 0;
594
595 /*
596 * we are about to copy oldroot to bp, so set up the type
597 * of bp while we know exactly what it will be.
598 */
599 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
600 }
601
602 /*
603 * we can copy most of the information in the node from one block to
604 * another, but for CRC enabled headers we have to make sure that the
605 * block specific identifiers are kept intact. We update the buffer
606 * directly for this.
607 */
608 memcpy(node, oldroot, size);
609 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
610 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
611 struct xfs_da3_intnode *node3 = (struct xfs_da3_intnode *)node;
612
613 node3->hdr.info.blkno = cpu_to_be64(bp->b_bn);
614 }
615 xfs_trans_log_buf(tp, bp, 0, size - 1);
616
617 bp->b_ops = blk1->bp->b_ops;
618 xfs_trans_buf_copy_type(bp, blk1->bp);
619 blk1->bp = bp;
620 blk1->blkno = blkno;
621
622 /*
623 * Set up the new root node.
624 */
625 error = xfs_da3_node_create(args,
626 (args->whichfork == XFS_DATA_FORK) ? args->geo->leafblk : 0,
627 level + 1, &bp, args->whichfork);
628 if (error)
629 return error;
630
631 node = bp->b_addr;
632 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
633 btree = dp->d_ops->node_tree_p(node);
634 btree[0].hashval = cpu_to_be32(blk1->hashval);
635 btree[0].before = cpu_to_be32(blk1->blkno);
636 btree[1].hashval = cpu_to_be32(blk2->hashval);
637 btree[1].before = cpu_to_be32(blk2->blkno);
638 nodehdr.count = 2;
639 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
640
641#ifdef DEBUG
642 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
643 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
644 ASSERT(blk1->blkno >= args->geo->leafblk &&
645 blk1->blkno < args->geo->freeblk);
646 ASSERT(blk2->blkno >= args->geo->leafblk &&
647 blk2->blkno < args->geo->freeblk);
648 }
649#endif
650
651 /* Header is already logged by xfs_da_node_create */
652 xfs_trans_log_buf(tp, bp,
653 XFS_DA_LOGRANGE(node, btree, sizeof(xfs_da_node_entry_t) * 2));
654
655 return 0;
656}
657
658/*
659 * Split the node, rebalance, then add the new entry.
660 */
661STATIC int /* error */
662xfs_da3_node_split(
663 struct xfs_da_state *state,
664 struct xfs_da_state_blk *oldblk,
665 struct xfs_da_state_blk *newblk,
666 struct xfs_da_state_blk *addblk,
667 int treelevel,
668 int *result)
669{
670 struct xfs_da_intnode *node;
671 struct xfs_da3_icnode_hdr nodehdr;
672 xfs_dablk_t blkno;
673 int newcount;
674 int error;
675 int useextra;
676 struct xfs_inode *dp = state->args->dp;
677
678 trace_xfs_da_node_split(state->args);
679
680 node = oldblk->bp->b_addr;
681 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
682
683 /*
684 * With V2 dirs the extra block is data or freespace.
685 */
686 useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
687 newcount = 1 + useextra;
688 /*
689 * Do we have to split the node?
690 */
691 if (nodehdr.count + newcount > state->args->geo->node_ents) {
692 /*
693 * Allocate a new node, add to the doubly linked chain of
694 * nodes, then move some of our excess entries into it.
695 */
696 error = xfs_da_grow_inode(state->args, &blkno);
697 if (error)
698 return error; /* GROT: dir is inconsistent */
699
700 error = xfs_da3_node_create(state->args, blkno, treelevel,
701 &newblk->bp, state->args->whichfork);
702 if (error)
703 return error; /* GROT: dir is inconsistent */
704 newblk->blkno = blkno;
705 newblk->magic = XFS_DA_NODE_MAGIC;
706 xfs_da3_node_rebalance(state, oldblk, newblk);
707 error = xfs_da3_blk_link(state, oldblk, newblk);
708 if (error)
709 return error;
710 *result = 1;
711 } else {
712 *result = 0;
713 }
714
715 /*
716 * Insert the new entry(s) into the correct block
717 * (updating last hashval in the process).
718 *
719 * xfs_da3_node_add() inserts BEFORE the given index,
720 * and as a result of using node_lookup_int() we always
721 * point to a valid entry (not after one), but a split
722 * operation always results in a new block whose hashvals
723 * FOLLOW the current block.
724 *
725 * If we had double-split op below us, then add the extra block too.
726 */
727 node = oldblk->bp->b_addr;
728 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
729 if (oldblk->index <= nodehdr.count) {
730 oldblk->index++;
731 xfs_da3_node_add(state, oldblk, addblk);
732 if (useextra) {
733 if (state->extraafter)
734 oldblk->index++;
735 xfs_da3_node_add(state, oldblk, &state->extrablk);
736 state->extravalid = 0;
737 }
738 } else {
739 newblk->index++;
740 xfs_da3_node_add(state, newblk, addblk);
741 if (useextra) {
742 if (state->extraafter)
743 newblk->index++;
744 xfs_da3_node_add(state, newblk, &state->extrablk);
745 state->extravalid = 0;
746 }
747 }
748
749 return 0;
750}
751
752/*
753 * Balance the btree elements between two intermediate nodes,
754 * usually one full and one empty.
755 *
756 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
757 */
758STATIC void
759xfs_da3_node_rebalance(
760 struct xfs_da_state *state,
761 struct xfs_da_state_blk *blk1,
762 struct xfs_da_state_blk *blk2)
763{
764 struct xfs_da_intnode *node1;
765 struct xfs_da_intnode *node2;
766 struct xfs_da_intnode *tmpnode;
767 struct xfs_da_node_entry *btree1;
768 struct xfs_da_node_entry *btree2;
769 struct xfs_da_node_entry *btree_s;
770 struct xfs_da_node_entry *btree_d;
771 struct xfs_da3_icnode_hdr nodehdr1;
772 struct xfs_da3_icnode_hdr nodehdr2;
773 struct xfs_trans *tp;
774 int count;
775 int tmp;
776 int swap = 0;
777 struct xfs_inode *dp = state->args->dp;
778
779 trace_xfs_da_node_rebalance(state->args);
780
781 node1 = blk1->bp->b_addr;
782 node2 = blk2->bp->b_addr;
783 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
784 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
785 btree1 = dp->d_ops->node_tree_p(node1);
786 btree2 = dp->d_ops->node_tree_p(node2);
787
788 /*
789 * Figure out how many entries need to move, and in which direction.
790 * Swap the nodes around if that makes it simpler.
791 */
792 if (nodehdr1.count > 0 && nodehdr2.count > 0 &&
793 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
794 (be32_to_cpu(btree2[nodehdr2.count - 1].hashval) <
795 be32_to_cpu(btree1[nodehdr1.count - 1].hashval)))) {
796 tmpnode = node1;
797 node1 = node2;
798 node2 = tmpnode;
799 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
800 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
801 btree1 = dp->d_ops->node_tree_p(node1);
802 btree2 = dp->d_ops->node_tree_p(node2);
803 swap = 1;
804 }
805
806 count = (nodehdr1.count - nodehdr2.count) / 2;
807 if (count == 0)
808 return;
809 tp = state->args->trans;
810 /*
811 * Two cases: high-to-low and low-to-high.
812 */
813 if (count > 0) {
814 /*
815 * Move elements in node2 up to make a hole.
816 */
817 tmp = nodehdr2.count;
818 if (tmp > 0) {
819 tmp *= (uint)sizeof(xfs_da_node_entry_t);
820 btree_s = &btree2[0];
821 btree_d = &btree2[count];
822 memmove(btree_d, btree_s, tmp);
823 }
824
825 /*
826 * Move the req'd B-tree elements from high in node1 to
827 * low in node2.
828 */
829 nodehdr2.count += count;
830 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
831 btree_s = &btree1[nodehdr1.count - count];
832 btree_d = &btree2[0];
833 memcpy(btree_d, btree_s, tmp);
834 nodehdr1.count -= count;
835 } else {
836 /*
837 * Move the req'd B-tree elements from low in node2 to
838 * high in node1.
839 */
840 count = -count;
841 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
842 btree_s = &btree2[0];
843 btree_d = &btree1[nodehdr1.count];
844 memcpy(btree_d, btree_s, tmp);
845 nodehdr1.count += count;
846
847 xfs_trans_log_buf(tp, blk1->bp,
848 XFS_DA_LOGRANGE(node1, btree_d, tmp));
849
850 /*
851 * Move elements in node2 down to fill the hole.
852 */
853 tmp = nodehdr2.count - count;
854 tmp *= (uint)sizeof(xfs_da_node_entry_t);
855 btree_s = &btree2[count];
856 btree_d = &btree2[0];
857 memmove(btree_d, btree_s, tmp);
858 nodehdr2.count -= count;
859 }
860
861 /*
862 * Log header of node 1 and all current bits of node 2.
863 */
864 dp->d_ops->node_hdr_to_disk(node1, &nodehdr1);
865 xfs_trans_log_buf(tp, blk1->bp,
866 XFS_DA_LOGRANGE(node1, &node1->hdr, dp->d_ops->node_hdr_size));
867
868 dp->d_ops->node_hdr_to_disk(node2, &nodehdr2);
869 xfs_trans_log_buf(tp, blk2->bp,
870 XFS_DA_LOGRANGE(node2, &node2->hdr,
871 dp->d_ops->node_hdr_size +
872 (sizeof(btree2[0]) * nodehdr2.count)));
873
874 /*
875 * Record the last hashval from each block for upward propagation.
876 * (note: don't use the swapped node pointers)
877 */
878 if (swap) {
879 node1 = blk1->bp->b_addr;
880 node2 = blk2->bp->b_addr;
881 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
882 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
883 btree1 = dp->d_ops->node_tree_p(node1);
884 btree2 = dp->d_ops->node_tree_p(node2);
885 }
886 blk1->hashval = be32_to_cpu(btree1[nodehdr1.count - 1].hashval);
887 blk2->hashval = be32_to_cpu(btree2[nodehdr2.count - 1].hashval);
888
889 /*
890 * Adjust the expected index for insertion.
891 */
892 if (blk1->index >= nodehdr1.count) {
893 blk2->index = blk1->index - nodehdr1.count;
894 blk1->index = nodehdr1.count + 1; /* make it invalid */
895 }
896}
897
898/*
899 * Add a new entry to an intermediate node.
900 */
901STATIC void
902xfs_da3_node_add(
903 struct xfs_da_state *state,
904 struct xfs_da_state_blk *oldblk,
905 struct xfs_da_state_blk *newblk)
906{
907 struct xfs_da_intnode *node;
908 struct xfs_da3_icnode_hdr nodehdr;
909 struct xfs_da_node_entry *btree;
910 int tmp;
911 struct xfs_inode *dp = state->args->dp;
912
913 trace_xfs_da_node_add(state->args);
914
915 node = oldblk->bp->b_addr;
916 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
917 btree = dp->d_ops->node_tree_p(node);
918
919 ASSERT(oldblk->index >= 0 && oldblk->index <= nodehdr.count);
920 ASSERT(newblk->blkno != 0);
921 if (state->args->whichfork == XFS_DATA_FORK)
922 ASSERT(newblk->blkno >= state->args->geo->leafblk &&
923 newblk->blkno < state->args->geo->freeblk);
924
925 /*
926 * We may need to make some room before we insert the new node.
927 */
928 tmp = 0;
929 if (oldblk->index < nodehdr.count) {
930 tmp = (nodehdr.count - oldblk->index) * (uint)sizeof(*btree);
931 memmove(&btree[oldblk->index + 1], &btree[oldblk->index], tmp);
932 }
933 btree[oldblk->index].hashval = cpu_to_be32(newblk->hashval);
934 btree[oldblk->index].before = cpu_to_be32(newblk->blkno);
935 xfs_trans_log_buf(state->args->trans, oldblk->bp,
936 XFS_DA_LOGRANGE(node, &btree[oldblk->index],
937 tmp + sizeof(*btree)));
938
939 nodehdr.count += 1;
940 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
941 xfs_trans_log_buf(state->args->trans, oldblk->bp,
942 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
943
944 /*
945 * Copy the last hash value from the oldblk to propagate upwards.
946 */
947 oldblk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
948}
949
950/*========================================================================
951 * Routines used for shrinking the Btree.
952 *========================================================================*/
953
954/*
955 * Deallocate an empty leaf node, remove it from its parent,
956 * possibly deallocating that block, etc...
957 */
958int
959xfs_da3_join(
960 struct xfs_da_state *state)
961{
962 struct xfs_da_state_blk *drop_blk;
963 struct xfs_da_state_blk *save_blk;
964 int action = 0;
965 int error;
966
967 trace_xfs_da_join(state->args);
968
969 drop_blk = &state->path.blk[ state->path.active-1 ];
970 save_blk = &state->altpath.blk[ state->path.active-1 ];
971 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
972 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
973 drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
974
975 /*
976 * Walk back up the tree joining/deallocating as necessary.
977 * When we stop dropping blocks, break out.
978 */
979 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
980 state->path.active--) {
981 /*
982 * See if we can combine the block with a neighbor.
983 * (action == 0) => no options, just leave
984 * (action == 1) => coalesce, then unlink
985 * (action == 2) => block empty, unlink it
986 */
987 switch (drop_blk->magic) {
988 case XFS_ATTR_LEAF_MAGIC:
989 error = xfs_attr3_leaf_toosmall(state, &action);
990 if (error)
991 return error;
992 if (action == 0)
993 return 0;
994 xfs_attr3_leaf_unbalance(state, drop_blk, save_blk);
995 break;
996 case XFS_DIR2_LEAFN_MAGIC:
997 error = xfs_dir2_leafn_toosmall(state, &action);
998 if (error)
999 return error;
1000 if (action == 0)
1001 return 0;
1002 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
1003 break;
1004 case XFS_DA_NODE_MAGIC:
1005 /*
1006 * Remove the offending node, fixup hashvals,
1007 * check for a toosmall neighbor.
1008 */
1009 xfs_da3_node_remove(state, drop_blk);
1010 xfs_da3_fixhashpath(state, &state->path);
1011 error = xfs_da3_node_toosmall(state, &action);
1012 if (error)
1013 return error;
1014 if (action == 0)
1015 return 0;
1016 xfs_da3_node_unbalance(state, drop_blk, save_blk);
1017 break;
1018 }
1019 xfs_da3_fixhashpath(state, &state->altpath);
1020 error = xfs_da3_blk_unlink(state, drop_blk, save_blk);
1021 xfs_da_state_kill_altpath(state);
1022 if (error)
1023 return error;
1024 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
1025 drop_blk->bp);
1026 drop_blk->bp = NULL;
1027 if (error)
1028 return error;
1029 }
1030 /*
1031 * We joined all the way to the top. If it turns out that
1032 * we only have one entry in the root, make the child block
1033 * the new root.
1034 */
1035 xfs_da3_node_remove(state, drop_blk);
1036 xfs_da3_fixhashpath(state, &state->path);
1037 error = xfs_da3_root_join(state, &state->path.blk[0]);
1038 return error;
1039}
1040
1041#ifdef DEBUG
1042static void
1043xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
1044{
1045 __be16 magic = blkinfo->magic;
1046
1047 if (level == 1) {
1048 ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1049 magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1050 magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1051 magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1052 } else {
1053 ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1054 magic == cpu_to_be16(XFS_DA3_NODE_MAGIC));
1055 }
1056 ASSERT(!blkinfo->forw);
1057 ASSERT(!blkinfo->back);
1058}
1059#else /* !DEBUG */
1060#define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
1061#endif /* !DEBUG */
1062
1063/*
1064 * We have only one entry in the root. Copy the only remaining child of
1065 * the old root to block 0 as the new root node.
1066 */
1067STATIC int
1068xfs_da3_root_join(
1069 struct xfs_da_state *state,
1070 struct xfs_da_state_blk *root_blk)
1071{
1072 struct xfs_da_intnode *oldroot;
1073 struct xfs_da_args *args;
1074 xfs_dablk_t child;
1075 struct xfs_buf *bp;
1076 struct xfs_da3_icnode_hdr oldroothdr;
1077 struct xfs_da_node_entry *btree;
1078 int error;
1079 struct xfs_inode *dp = state->args->dp;
1080
1081 trace_xfs_da_root_join(state->args);
1082
1083 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
1084
1085 args = state->args;
1086 oldroot = root_blk->bp->b_addr;
1087 dp->d_ops->node_hdr_from_disk(&oldroothdr, oldroot);
1088 ASSERT(oldroothdr.forw == 0);
1089 ASSERT(oldroothdr.back == 0);
1090
1091 /*
1092 * If the root has more than one child, then don't do anything.
1093 */
1094 if (oldroothdr.count > 1)
1095 return 0;
1096
1097 /*
1098 * Read in the (only) child block, then copy those bytes into
1099 * the root block's buffer and free the original child block.
1100 */
1101 btree = dp->d_ops->node_tree_p(oldroot);
1102 child = be32_to_cpu(btree[0].before);
1103 ASSERT(child != 0);
1104 error = xfs_da3_node_read(args->trans, dp, child, -1, &bp,
1105 args->whichfork);
1106 if (error)
1107 return error;
1108 xfs_da_blkinfo_onlychild_validate(bp->b_addr, oldroothdr.level);
1109
1110 /*
1111 * This could be copying a leaf back into the root block in the case of
1112 * there only being a single leaf block left in the tree. Hence we have
1113 * to update the b_ops pointer as well to match the buffer type change
1114 * that could occur. For dir3 blocks we also need to update the block
1115 * number in the buffer header.
1116 */
1117 memcpy(root_blk->bp->b_addr, bp->b_addr, args->geo->blksize);
1118 root_blk->bp->b_ops = bp->b_ops;
1119 xfs_trans_buf_copy_type(root_blk->bp, bp);
1120 if (oldroothdr.magic == XFS_DA3_NODE_MAGIC) {
1121 struct xfs_da3_blkinfo *da3 = root_blk->bp->b_addr;
1122 da3->blkno = cpu_to_be64(root_blk->bp->b_bn);
1123 }
1124 xfs_trans_log_buf(args->trans, root_blk->bp, 0,
1125 args->geo->blksize - 1);
1126 error = xfs_da_shrink_inode(args, child, bp);
1127 return error;
1128}
1129
1130/*
1131 * Check a node block and its neighbors to see if the block should be
1132 * collapsed into one or the other neighbor. Always keep the block
1133 * with the smaller block number.
1134 * If the current block is over 50% full, don't try to join it, return 0.
1135 * If the block is empty, fill in the state structure and return 2.
1136 * If it can be collapsed, fill in the state structure and return 1.
1137 * If nothing can be done, return 0.
1138 */
1139STATIC int
1140xfs_da3_node_toosmall(
1141 struct xfs_da_state *state,
1142 int *action)
1143{
1144 struct xfs_da_intnode *node;
1145 struct xfs_da_state_blk *blk;
1146 struct xfs_da_blkinfo *info;
1147 xfs_dablk_t blkno;
1148 struct xfs_buf *bp;
1149 struct xfs_da3_icnode_hdr nodehdr;
1150 int count;
1151 int forward;
1152 int error;
1153 int retval;
1154 int i;
1155 struct xfs_inode *dp = state->args->dp;
1156
1157 trace_xfs_da_node_toosmall(state->args);
1158
1159 /*
1160 * Check for the degenerate case of the block being over 50% full.
1161 * If so, it's not worth even looking to see if we might be able
1162 * to coalesce with a sibling.
1163 */
1164 blk = &state->path.blk[ state->path.active-1 ];
1165 info = blk->bp->b_addr;
1166 node = (xfs_da_intnode_t *)info;
1167 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1168 if (nodehdr.count > (state->args->geo->node_ents >> 1)) {
1169 *action = 0; /* blk over 50%, don't try to join */
1170 return 0; /* blk over 50%, don't try to join */
1171 }
1172
1173 /*
1174 * Check for the degenerate case of the block being empty.
1175 * If the block is empty, we'll simply delete it, no need to
1176 * coalesce it with a sibling block. We choose (arbitrarily)
1177 * to merge with the forward block unless it is NULL.
1178 */
1179 if (nodehdr.count == 0) {
1180 /*
1181 * Make altpath point to the block we want to keep and
1182 * path point to the block we want to drop (this one).
1183 */
1184 forward = (info->forw != 0);
1185 memcpy(&state->altpath, &state->path, sizeof(state->path));
1186 error = xfs_da3_path_shift(state, &state->altpath, forward,
1187 0, &retval);
1188 if (error)
1189 return error;
1190 if (retval) {
1191 *action = 0;
1192 } else {
1193 *action = 2;
1194 }
1195 return 0;
1196 }
1197
1198 /*
1199 * Examine each sibling block to see if we can coalesce with
1200 * at least 25% free space to spare. We need to figure out
1201 * whether to merge with the forward or the backward block.
1202 * We prefer coalescing with the lower numbered sibling so as
1203 * to shrink a directory over time.
1204 */
1205 count = state->args->geo->node_ents;
1206 count -= state->args->geo->node_ents >> 2;
1207 count -= nodehdr.count;
1208
1209 /* start with smaller blk num */
1210 forward = nodehdr.forw < nodehdr.back;
1211 for (i = 0; i < 2; forward = !forward, i++) {
1212 struct xfs_da3_icnode_hdr thdr;
1213 if (forward)
1214 blkno = nodehdr.forw;
1215 else
1216 blkno = nodehdr.back;
1217 if (blkno == 0)
1218 continue;
1219 error = xfs_da3_node_read(state->args->trans, dp,
1220 blkno, -1, &bp, state->args->whichfork);
1221 if (error)
1222 return error;
1223
1224 node = bp->b_addr;
1225 dp->d_ops->node_hdr_from_disk(&thdr, node);
1226 xfs_trans_brelse(state->args->trans, bp);
1227
1228 if (count - thdr.count >= 0)
1229 break; /* fits with at least 25% to spare */
1230 }
1231 if (i >= 2) {
1232 *action = 0;
1233 return 0;
1234 }
1235
1236 /*
1237 * Make altpath point to the block we want to keep (the lower
1238 * numbered block) and path point to the block we want to drop.
1239 */
1240 memcpy(&state->altpath, &state->path, sizeof(state->path));
1241 if (blkno < blk->blkno) {
1242 error = xfs_da3_path_shift(state, &state->altpath, forward,
1243 0, &retval);
1244 } else {
1245 error = xfs_da3_path_shift(state, &state->path, forward,
1246 0, &retval);
1247 }
1248 if (error)
1249 return error;
1250 if (retval) {
1251 *action = 0;
1252 return 0;
1253 }
1254 *action = 1;
1255 return 0;
1256}
1257
1258/*
1259 * Pick up the last hashvalue from an intermediate node.
1260 */
1261STATIC uint
1262xfs_da3_node_lasthash(
1263 struct xfs_inode *dp,
1264 struct xfs_buf *bp,
1265 int *count)
1266{
1267 struct xfs_da_intnode *node;
1268 struct xfs_da_node_entry *btree;
1269 struct xfs_da3_icnode_hdr nodehdr;
1270
1271 node = bp->b_addr;
1272 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1273 if (count)
1274 *count = nodehdr.count;
1275 if (!nodehdr.count)
1276 return 0;
1277 btree = dp->d_ops->node_tree_p(node);
1278 return be32_to_cpu(btree[nodehdr.count - 1].hashval);
1279}
1280
1281/*
1282 * Walk back up the tree adjusting hash values as necessary,
1283 * when we stop making changes, return.
1284 */
1285void
1286xfs_da3_fixhashpath(
1287 struct xfs_da_state *state,
1288 struct xfs_da_state_path *path)
1289{
1290 struct xfs_da_state_blk *blk;
1291 struct xfs_da_intnode *node;
1292 struct xfs_da_node_entry *btree;
1293 xfs_dahash_t lasthash=0;
1294 int level;
1295 int count;
1296 struct xfs_inode *dp = state->args->dp;
1297
1298 trace_xfs_da_fixhashpath(state->args);
1299
1300 level = path->active-1;
1301 blk = &path->blk[ level ];
1302 switch (blk->magic) {
1303 case XFS_ATTR_LEAF_MAGIC:
1304 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
1305 if (count == 0)
1306 return;
1307 break;
1308 case XFS_DIR2_LEAFN_MAGIC:
1309 lasthash = xfs_dir2_leaf_lasthash(dp, blk->bp, &count);
1310 if (count == 0)
1311 return;
1312 break;
1313 case XFS_DA_NODE_MAGIC:
1314 lasthash = xfs_da3_node_lasthash(dp, blk->bp, &count);
1315 if (count == 0)
1316 return;
1317 break;
1318 }
1319 for (blk--, level--; level >= 0; blk--, level--) {
1320 struct xfs_da3_icnode_hdr nodehdr;
1321
1322 node = blk->bp->b_addr;
1323 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1324 btree = dp->d_ops->node_tree_p(node);
1325 if (be32_to_cpu(btree[blk->index].hashval) == lasthash)
1326 break;
1327 blk->hashval = lasthash;
1328 btree[blk->index].hashval = cpu_to_be32(lasthash);
1329 xfs_trans_log_buf(state->args->trans, blk->bp,
1330 XFS_DA_LOGRANGE(node, &btree[blk->index],
1331 sizeof(*btree)));
1332
1333 lasthash = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1334 }
1335}
1336
1337/*
1338 * Remove an entry from an intermediate node.
1339 */
1340STATIC void
1341xfs_da3_node_remove(
1342 struct xfs_da_state *state,
1343 struct xfs_da_state_blk *drop_blk)
1344{
1345 struct xfs_da_intnode *node;
1346 struct xfs_da3_icnode_hdr nodehdr;
1347 struct xfs_da_node_entry *btree;
1348 int index;
1349 int tmp;
1350 struct xfs_inode *dp = state->args->dp;
1351
1352 trace_xfs_da_node_remove(state->args);
1353
1354 node = drop_blk->bp->b_addr;
1355 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1356 ASSERT(drop_blk->index < nodehdr.count);
1357 ASSERT(drop_blk->index >= 0);
1358
1359 /*
1360 * Copy over the offending entry, or just zero it out.
1361 */
1362 index = drop_blk->index;
1363 btree = dp->d_ops->node_tree_p(node);
1364 if (index < nodehdr.count - 1) {
1365 tmp = nodehdr.count - index - 1;
1366 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1367 memmove(&btree[index], &btree[index + 1], tmp);
1368 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1369 XFS_DA_LOGRANGE(node, &btree[index], tmp));
1370 index = nodehdr.count - 1;
1371 }
1372 memset(&btree[index], 0, sizeof(xfs_da_node_entry_t));
1373 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1374 XFS_DA_LOGRANGE(node, &btree[index], sizeof(btree[index])));
1375 nodehdr.count -= 1;
1376 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
1377 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1378 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
1379
1380 /*
1381 * Copy the last hash value from the block to propagate upwards.
1382 */
1383 drop_blk->hashval = be32_to_cpu(btree[index - 1].hashval);
1384}
1385
1386/*
1387 * Unbalance the elements between two intermediate nodes,
1388 * move all Btree elements from one node into another.
1389 */
1390STATIC void
1391xfs_da3_node_unbalance(
1392 struct xfs_da_state *state,
1393 struct xfs_da_state_blk *drop_blk,
1394 struct xfs_da_state_blk *save_blk)
1395{
1396 struct xfs_da_intnode *drop_node;
1397 struct xfs_da_intnode *save_node;
1398 struct xfs_da_node_entry *drop_btree;
1399 struct xfs_da_node_entry *save_btree;
1400 struct xfs_da3_icnode_hdr drop_hdr;
1401 struct xfs_da3_icnode_hdr save_hdr;
1402 struct xfs_trans *tp;
1403 int sindex;
1404 int tmp;
1405 struct xfs_inode *dp = state->args->dp;
1406
1407 trace_xfs_da_node_unbalance(state->args);
1408
1409 drop_node = drop_blk->bp->b_addr;
1410 save_node = save_blk->bp->b_addr;
1411 dp->d_ops->node_hdr_from_disk(&drop_hdr, drop_node);
1412 dp->d_ops->node_hdr_from_disk(&save_hdr, save_node);
1413 drop_btree = dp->d_ops->node_tree_p(drop_node);
1414 save_btree = dp->d_ops->node_tree_p(save_node);
1415 tp = state->args->trans;
1416
1417 /*
1418 * If the dying block has lower hashvals, then move all the
1419 * elements in the remaining block up to make a hole.
1420 */
1421 if ((be32_to_cpu(drop_btree[0].hashval) <
1422 be32_to_cpu(save_btree[0].hashval)) ||
1423 (be32_to_cpu(drop_btree[drop_hdr.count - 1].hashval) <
1424 be32_to_cpu(save_btree[save_hdr.count - 1].hashval))) {
1425 /* XXX: check this - is memmove dst correct? */
1426 tmp = save_hdr.count * sizeof(xfs_da_node_entry_t);
1427 memmove(&save_btree[drop_hdr.count], &save_btree[0], tmp);
1428
1429 sindex = 0;
1430 xfs_trans_log_buf(tp, save_blk->bp,
1431 XFS_DA_LOGRANGE(save_node, &save_btree[0],
1432 (save_hdr.count + drop_hdr.count) *
1433 sizeof(xfs_da_node_entry_t)));
1434 } else {
1435 sindex = save_hdr.count;
1436 xfs_trans_log_buf(tp, save_blk->bp,
1437 XFS_DA_LOGRANGE(save_node, &save_btree[sindex],
1438 drop_hdr.count * sizeof(xfs_da_node_entry_t)));
1439 }
1440
1441 /*
1442 * Move all the B-tree elements from drop_blk to save_blk.
1443 */
1444 tmp = drop_hdr.count * (uint)sizeof(xfs_da_node_entry_t);
1445 memcpy(&save_btree[sindex], &drop_btree[0], tmp);
1446 save_hdr.count += drop_hdr.count;
1447
1448 dp->d_ops->node_hdr_to_disk(save_node, &save_hdr);
1449 xfs_trans_log_buf(tp, save_blk->bp,
1450 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1451 dp->d_ops->node_hdr_size));
1452
1453 /*
1454 * Save the last hashval in the remaining block for upward propagation.
1455 */
1456 save_blk->hashval = be32_to_cpu(save_btree[save_hdr.count - 1].hashval);
1457}
1458
1459/*========================================================================
1460 * Routines used for finding things in the Btree.
1461 *========================================================================*/
1462
1463/*
1464 * Walk down the Btree looking for a particular filename, filling
1465 * in the state structure as we go.
1466 *
1467 * We will set the state structure to point to each of the elements
1468 * in each of the nodes where either the hashval is or should be.
1469 *
1470 * We support duplicate hashval's so for each entry in the current
1471 * node that could contain the desired hashval, descend. This is a
1472 * pruned depth-first tree search.
1473 */
1474int /* error */
1475xfs_da3_node_lookup_int(
1476 struct xfs_da_state *state,
1477 int *result)
1478{
1479 struct xfs_da_state_blk *blk;
1480 struct xfs_da_blkinfo *curr;
1481 struct xfs_da_intnode *node;
1482 struct xfs_da_node_entry *btree;
1483 struct xfs_da3_icnode_hdr nodehdr;
1484 struct xfs_da_args *args;
1485 xfs_dablk_t blkno;
1486 xfs_dahash_t hashval;
1487 xfs_dahash_t btreehashval;
1488 int probe;
1489 int span;
1490 int max;
1491 int error;
1492 int retval;
1493 unsigned int expected_level = 0;
1494 struct xfs_inode *dp = state->args->dp;
1495
1496 args = state->args;
1497
1498 /*
1499 * Descend thru the B-tree searching each level for the right
1500 * node to use, until the right hashval is found.
1501 */
1502 blkno = args->geo->leafblk;
1503 for (blk = &state->path.blk[0], state->path.active = 1;
1504 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1505 blk++, state->path.active++) {
1506 /*
1507 * Read the next node down in the tree.
1508 */
1509 blk->blkno = blkno;
1510 error = xfs_da3_node_read(args->trans, args->dp, blkno,
1511 -1, &blk->bp, args->whichfork);
1512 if (error) {
1513 blk->blkno = 0;
1514 state->path.active--;
1515 return error;
1516 }
1517 curr = blk->bp->b_addr;
1518 blk->magic = be16_to_cpu(curr->magic);
1519
1520 if (blk->magic == XFS_ATTR_LEAF_MAGIC ||
1521 blk->magic == XFS_ATTR3_LEAF_MAGIC) {
1522 blk->magic = XFS_ATTR_LEAF_MAGIC;
1523 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1524 break;
1525 }
1526
1527 if (blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1528 blk->magic == XFS_DIR3_LEAFN_MAGIC) {
1529 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1530 blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
1531 blk->bp, NULL);
1532 break;
1533 }
1534
1535 blk->magic = XFS_DA_NODE_MAGIC;
1536
1537
1538 /*
1539 * Search an intermediate node for a match.
1540 */
1541 node = blk->bp->b_addr;
1542 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1543 btree = dp->d_ops->node_tree_p(node);
1544
1545 /* Tree taller than we can handle; bail out! */
1546 if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
1547 return -EFSCORRUPTED;
1548
1549 /* Check the level from the root. */
1550 if (blkno == args->geo->leafblk)
1551 expected_level = nodehdr.level - 1;
1552 else if (expected_level != nodehdr.level)
1553 return -EFSCORRUPTED;
1554 else
1555 expected_level--;
1556
1557 max = nodehdr.count;
1558 blk->hashval = be32_to_cpu(btree[max - 1].hashval);
1559
1560 /*
1561 * Binary search. (note: small blocks will skip loop)
1562 */
1563 probe = span = max / 2;
1564 hashval = args->hashval;
1565 while (span > 4) {
1566 span /= 2;
1567 btreehashval = be32_to_cpu(btree[probe].hashval);
1568 if (btreehashval < hashval)
1569 probe += span;
1570 else if (btreehashval > hashval)
1571 probe -= span;
1572 else
1573 break;
1574 }
1575 ASSERT((probe >= 0) && (probe < max));
1576 ASSERT((span <= 4) ||
1577 (be32_to_cpu(btree[probe].hashval) == hashval));
1578
1579 /*
1580 * Since we may have duplicate hashval's, find the first
1581 * matching hashval in the node.
1582 */
1583 while (probe > 0 &&
1584 be32_to_cpu(btree[probe].hashval) >= hashval) {
1585 probe--;
1586 }
1587 while (probe < max &&
1588 be32_to_cpu(btree[probe].hashval) < hashval) {
1589 probe++;
1590 }
1591
1592 /*
1593 * Pick the right block to descend on.
1594 */
1595 if (probe == max) {
1596 blk->index = max - 1;
1597 blkno = be32_to_cpu(btree[max - 1].before);
1598 } else {
1599 blk->index = probe;
1600 blkno = be32_to_cpu(btree[probe].before);
1601 }
1602
1603 /* We can't point back to the root. */
1604 if (blkno == args->geo->leafblk)
1605 return -EFSCORRUPTED;
1606 }
1607
1608 if (expected_level != 0)
1609 return -EFSCORRUPTED;
1610
1611 /*
1612 * A leaf block that ends in the hashval that we are interested in
1613 * (final hashval == search hashval) means that the next block may
1614 * contain more entries with the same hashval, shift upward to the
1615 * next leaf and keep searching.
1616 */
1617 for (;;) {
1618 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1619 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1620 &blk->index, state);
1621 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1622 retval = xfs_attr3_leaf_lookup_int(blk->bp, args);
1623 blk->index = args->index;
1624 args->blkno = blk->blkno;
1625 } else {
1626 ASSERT(0);
1627 return -EFSCORRUPTED;
1628 }
1629 if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
1630 (blk->hashval == args->hashval)) {
1631 error = xfs_da3_path_shift(state, &state->path, 1, 1,
1632 &retval);
1633 if (error)
1634 return error;
1635 if (retval == 0) {
1636 continue;
1637 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1638 /* path_shift() gives ENOENT */
1639 retval = -ENOATTR;
1640 }
1641 }
1642 break;
1643 }
1644 *result = retval;
1645 return 0;
1646}
1647
1648/*========================================================================
1649 * Utility routines.
1650 *========================================================================*/
1651
1652/*
1653 * Compare two intermediate nodes for "order".
1654 */
1655STATIC int
1656xfs_da3_node_order(
1657 struct xfs_inode *dp,
1658 struct xfs_buf *node1_bp,
1659 struct xfs_buf *node2_bp)
1660{
1661 struct xfs_da_intnode *node1;
1662 struct xfs_da_intnode *node2;
1663 struct xfs_da_node_entry *btree1;
1664 struct xfs_da_node_entry *btree2;
1665 struct xfs_da3_icnode_hdr node1hdr;
1666 struct xfs_da3_icnode_hdr node2hdr;
1667
1668 node1 = node1_bp->b_addr;
1669 node2 = node2_bp->b_addr;
1670 dp->d_ops->node_hdr_from_disk(&node1hdr, node1);
1671 dp->d_ops->node_hdr_from_disk(&node2hdr, node2);
1672 btree1 = dp->d_ops->node_tree_p(node1);
1673 btree2 = dp->d_ops->node_tree_p(node2);
1674
1675 if (node1hdr.count > 0 && node2hdr.count > 0 &&
1676 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
1677 (be32_to_cpu(btree2[node2hdr.count - 1].hashval) <
1678 be32_to_cpu(btree1[node1hdr.count - 1].hashval)))) {
1679 return 1;
1680 }
1681 return 0;
1682}
1683
1684/*
1685 * Link a new block into a doubly linked list of blocks (of whatever type).
1686 */
1687int /* error */
1688xfs_da3_blk_link(
1689 struct xfs_da_state *state,
1690 struct xfs_da_state_blk *old_blk,
1691 struct xfs_da_state_blk *new_blk)
1692{
1693 struct xfs_da_blkinfo *old_info;
1694 struct xfs_da_blkinfo *new_info;
1695 struct xfs_da_blkinfo *tmp_info;
1696 struct xfs_da_args *args;
1697 struct xfs_buf *bp;
1698 int before = 0;
1699 int error;
1700 struct xfs_inode *dp = state->args->dp;
1701
1702 /*
1703 * Set up environment.
1704 */
1705 args = state->args;
1706 ASSERT(args != NULL);
1707 old_info = old_blk->bp->b_addr;
1708 new_info = new_blk->bp->b_addr;
1709 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1710 old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1711 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1712
1713 switch (old_blk->magic) {
1714 case XFS_ATTR_LEAF_MAGIC:
1715 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1716 break;
1717 case XFS_DIR2_LEAFN_MAGIC:
1718 before = xfs_dir2_leafn_order(dp, old_blk->bp, new_blk->bp);
1719 break;
1720 case XFS_DA_NODE_MAGIC:
1721 before = xfs_da3_node_order(dp, old_blk->bp, new_blk->bp);
1722 break;
1723 }
1724
1725 /*
1726 * Link blocks in appropriate order.
1727 */
1728 if (before) {
1729 /*
1730 * Link new block in before existing block.
1731 */
1732 trace_xfs_da_link_before(args);
1733 new_info->forw = cpu_to_be32(old_blk->blkno);
1734 new_info->back = old_info->back;
1735 if (old_info->back) {
1736 error = xfs_da3_node_read(args->trans, dp,
1737 be32_to_cpu(old_info->back),
1738 -1, &bp, args->whichfork);
1739 if (error)
1740 return error;
1741 ASSERT(bp != NULL);
1742 tmp_info = bp->b_addr;
1743 ASSERT(tmp_info->magic == old_info->magic);
1744 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1745 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1746 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1747 }
1748 old_info->back = cpu_to_be32(new_blk->blkno);
1749 } else {
1750 /*
1751 * Link new block in after existing block.
1752 */
1753 trace_xfs_da_link_after(args);
1754 new_info->forw = old_info->forw;
1755 new_info->back = cpu_to_be32(old_blk->blkno);
1756 if (old_info->forw) {
1757 error = xfs_da3_node_read(args->trans, dp,
1758 be32_to_cpu(old_info->forw),
1759 -1, &bp, args->whichfork);
1760 if (error)
1761 return error;
1762 ASSERT(bp != NULL);
1763 tmp_info = bp->b_addr;
1764 ASSERT(tmp_info->magic == old_info->magic);
1765 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1766 tmp_info->back = cpu_to_be32(new_blk->blkno);
1767 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1768 }
1769 old_info->forw = cpu_to_be32(new_blk->blkno);
1770 }
1771
1772 xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1773 xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1774 return 0;
1775}
1776
1777/*
1778 * Unlink a block from a doubly linked list of blocks.
1779 */
1780STATIC int /* error */
1781xfs_da3_blk_unlink(
1782 struct xfs_da_state *state,
1783 struct xfs_da_state_blk *drop_blk,
1784 struct xfs_da_state_blk *save_blk)
1785{
1786 struct xfs_da_blkinfo *drop_info;
1787 struct xfs_da_blkinfo *save_info;
1788 struct xfs_da_blkinfo *tmp_info;
1789 struct xfs_da_args *args;
1790 struct xfs_buf *bp;
1791 int error;
1792
1793 /*
1794 * Set up environment.
1795 */
1796 args = state->args;
1797 ASSERT(args != NULL);
1798 save_info = save_blk->bp->b_addr;
1799 drop_info = drop_blk->bp->b_addr;
1800 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1801 save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1802 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1803 ASSERT(save_blk->magic == drop_blk->magic);
1804 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1805 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1806 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1807 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1808
1809 /*
1810 * Unlink the leaf block from the doubly linked chain of leaves.
1811 */
1812 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1813 trace_xfs_da_unlink_back(args);
1814 save_info->back = drop_info->back;
1815 if (drop_info->back) {
1816 error = xfs_da3_node_read(args->trans, args->dp,
1817 be32_to_cpu(drop_info->back),
1818 -1, &bp, args->whichfork);
1819 if (error)
1820 return error;
1821 ASSERT(bp != NULL);
1822 tmp_info = bp->b_addr;
1823 ASSERT(tmp_info->magic == save_info->magic);
1824 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1825 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1826 xfs_trans_log_buf(args->trans, bp, 0,
1827 sizeof(*tmp_info) - 1);
1828 }
1829 } else {
1830 trace_xfs_da_unlink_forward(args);
1831 save_info->forw = drop_info->forw;
1832 if (drop_info->forw) {
1833 error = xfs_da3_node_read(args->trans, args->dp,
1834 be32_to_cpu(drop_info->forw),
1835 -1, &bp, args->whichfork);
1836 if (error)
1837 return error;
1838 ASSERT(bp != NULL);
1839 tmp_info = bp->b_addr;
1840 ASSERT(tmp_info->magic == save_info->magic);
1841 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1842 tmp_info->back = cpu_to_be32(save_blk->blkno);
1843 xfs_trans_log_buf(args->trans, bp, 0,
1844 sizeof(*tmp_info) - 1);
1845 }
1846 }
1847
1848 xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1849 return 0;
1850}
1851
1852/*
1853 * Move a path "forward" or "!forward" one block at the current level.
1854 *
1855 * This routine will adjust a "path" to point to the next block
1856 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1857 * Btree, including updating pointers to the intermediate nodes between
1858 * the new bottom and the root.
1859 */
1860int /* error */
1861xfs_da3_path_shift(
1862 struct xfs_da_state *state,
1863 struct xfs_da_state_path *path,
1864 int forward,
1865 int release,
1866 int *result)
1867{
1868 struct xfs_da_state_blk *blk;
1869 struct xfs_da_blkinfo *info;
1870 struct xfs_da_intnode *node;
1871 struct xfs_da_args *args;
1872 struct xfs_da_node_entry *btree;
1873 struct xfs_da3_icnode_hdr nodehdr;
1874 struct xfs_buf *bp;
1875 xfs_dablk_t blkno = 0;
1876 int level;
1877 int error;
1878 struct xfs_inode *dp = state->args->dp;
1879
1880 trace_xfs_da_path_shift(state->args);
1881
1882 /*
1883 * Roll up the Btree looking for the first block where our
1884 * current index is not at the edge of the block. Note that
1885 * we skip the bottom layer because we want the sibling block.
1886 */
1887 args = state->args;
1888 ASSERT(args != NULL);
1889 ASSERT(path != NULL);
1890 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1891 level = (path->active-1) - 1; /* skip bottom layer in path */
1892 for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1893 node = blk->bp->b_addr;
1894 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1895 btree = dp->d_ops->node_tree_p(node);
1896
1897 if (forward && (blk->index < nodehdr.count - 1)) {
1898 blk->index++;
1899 blkno = be32_to_cpu(btree[blk->index].before);
1900 break;
1901 } else if (!forward && (blk->index > 0)) {
1902 blk->index--;
1903 blkno = be32_to_cpu(btree[blk->index].before);
1904 break;
1905 }
1906 }
1907 if (level < 0) {
1908 *result = -ENOENT; /* we're out of our tree */
1909 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1910 return 0;
1911 }
1912
1913 /*
1914 * Roll down the edge of the subtree until we reach the
1915 * same depth we were at originally.
1916 */
1917 for (blk++, level++; level < path->active; blk++, level++) {
1918 /*
1919 * Read the next child block into a local buffer.
1920 */
1921 error = xfs_da3_node_read(args->trans, dp, blkno, -1, &bp,
1922 args->whichfork);
1923 if (error)
1924 return error;
1925
1926 /*
1927 * Release the old block (if it's dirty, the trans doesn't
1928 * actually let go) and swap the local buffer into the path
1929 * structure. This ensures failure of the above read doesn't set
1930 * a NULL buffer in an active slot in the path.
1931 */
1932 if (release)
1933 xfs_trans_brelse(args->trans, blk->bp);
1934 blk->blkno = blkno;
1935 blk->bp = bp;
1936
1937 info = blk->bp->b_addr;
1938 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1939 info->magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
1940 info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1941 info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1942 info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1943 info->magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1944
1945
1946 /*
1947 * Note: we flatten the magic number to a single type so we
1948 * don't have to compare against crc/non-crc types elsewhere.
1949 */
1950 switch (be16_to_cpu(info->magic)) {
1951 case XFS_DA_NODE_MAGIC:
1952 case XFS_DA3_NODE_MAGIC:
1953 blk->magic = XFS_DA_NODE_MAGIC;
1954 node = (xfs_da_intnode_t *)info;
1955 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1956 btree = dp->d_ops->node_tree_p(node);
1957 blk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1958 if (forward)
1959 blk->index = 0;
1960 else
1961 blk->index = nodehdr.count - 1;
1962 blkno = be32_to_cpu(btree[blk->index].before);
1963 break;
1964 case XFS_ATTR_LEAF_MAGIC:
1965 case XFS_ATTR3_LEAF_MAGIC:
1966 blk->magic = XFS_ATTR_LEAF_MAGIC;
1967 ASSERT(level == path->active-1);
1968 blk->index = 0;
1969 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1970 break;
1971 case XFS_DIR2_LEAFN_MAGIC:
1972 case XFS_DIR3_LEAFN_MAGIC:
1973 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1974 ASSERT(level == path->active-1);
1975 blk->index = 0;
1976 blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
1977 blk->bp, NULL);
1978 break;
1979 default:
1980 ASSERT(0);
1981 break;
1982 }
1983 }
1984 *result = 0;
1985 return 0;
1986}
1987
1988
1989/*========================================================================
1990 * Utility routines.
1991 *========================================================================*/
1992
1993/*
1994 * Implement a simple hash on a character string.
1995 * Rotate the hash value by 7 bits, then XOR each character in.
1996 * This is implemented with some source-level loop unrolling.
1997 */
1998xfs_dahash_t
1999xfs_da_hashname(const uint8_t *name, int namelen)
2000{
2001 xfs_dahash_t hash;
2002
2003 /*
2004 * Do four characters at a time as long as we can.
2005 */
2006 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
2007 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
2008 (name[3] << 0) ^ rol32(hash, 7 * 4);
2009
2010 /*
2011 * Now do the rest of the characters.
2012 */
2013 switch (namelen) {
2014 case 3:
2015 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
2016 rol32(hash, 7 * 3);
2017 case 2:
2018 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
2019 case 1:
2020 return (name[0] << 0) ^ rol32(hash, 7 * 1);
2021 default: /* case 0: */
2022 return hash;
2023 }
2024}
2025
2026enum xfs_dacmp
2027xfs_da_compname(
2028 struct xfs_da_args *args,
2029 const unsigned char *name,
2030 int len)
2031{
2032 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
2033 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
2034}
2035
2036static xfs_dahash_t
2037xfs_default_hashname(
2038 struct xfs_name *name)
2039{
2040 return xfs_da_hashname(name->name, name->len);
2041}
2042
2043const struct xfs_nameops xfs_default_nameops = {
2044 .hashname = xfs_default_hashname,
2045 .compname = xfs_da_compname
2046};
2047
2048int
2049xfs_da_grow_inode_int(
2050 struct xfs_da_args *args,
2051 xfs_fileoff_t *bno,
2052 int count)
2053{
2054 struct xfs_trans *tp = args->trans;
2055 struct xfs_inode *dp = args->dp;
2056 int w = args->whichfork;
2057 xfs_rfsblock_t nblks = dp->i_d.di_nblocks;
2058 struct xfs_bmbt_irec map, *mapp;
2059 int nmap, error, got, i, mapi;
2060
2061 /*
2062 * Find a spot in the file space to put the new block.
2063 */
2064 error = xfs_bmap_first_unused(tp, dp, count, bno, w);
2065 if (error)
2066 return error;
2067
2068 /*
2069 * Try mapping it in one filesystem block.
2070 */
2071 nmap = 1;
2072 ASSERT(args->firstblock != NULL);
2073 error = xfs_bmapi_write(tp, dp, *bno, count,
2074 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
2075 args->firstblock, args->total, &map, &nmap,
2076 args->dfops);
2077 if (error)
2078 return error;
2079
2080 ASSERT(nmap <= 1);
2081 if (nmap == 1) {
2082 mapp = ↦
2083 mapi = 1;
2084 } else if (nmap == 0 && count > 1) {
2085 xfs_fileoff_t b;
2086 int c;
2087
2088 /*
2089 * If we didn't get it and the block might work if fragmented,
2090 * try without the CONTIG flag. Loop until we get it all.
2091 */
2092 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
2093 for (b = *bno, mapi = 0; b < *bno + count; ) {
2094 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
2095 c = (int)(*bno + count - b);
2096 error = xfs_bmapi_write(tp, dp, b, c,
2097 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2098 args->firstblock, args->total,
2099 &mapp[mapi], &nmap, args->dfops);
2100 if (error)
2101 goto out_free_map;
2102 if (nmap < 1)
2103 break;
2104 mapi += nmap;
2105 b = mapp[mapi - 1].br_startoff +
2106 mapp[mapi - 1].br_blockcount;
2107 }
2108 } else {
2109 mapi = 0;
2110 mapp = NULL;
2111 }
2112
2113 /*
2114 * Count the blocks we got, make sure it matches the total.
2115 */
2116 for (i = 0, got = 0; i < mapi; i++)
2117 got += mapp[i].br_blockcount;
2118 if (got != count || mapp[0].br_startoff != *bno ||
2119 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
2120 *bno + count) {
2121 error = -ENOSPC;
2122 goto out_free_map;
2123 }
2124
2125 /* account for newly allocated blocks in reserved blocks total */
2126 args->total -= dp->i_d.di_nblocks - nblks;
2127
2128out_free_map:
2129 if (mapp != &map)
2130 kmem_free(mapp);
2131 return error;
2132}
2133
2134/*
2135 * Add a block to the btree ahead of the file.
2136 * Return the new block number to the caller.
2137 */
2138int
2139xfs_da_grow_inode(
2140 struct xfs_da_args *args,
2141 xfs_dablk_t *new_blkno)
2142{
2143 xfs_fileoff_t bno;
2144 int error;
2145
2146 trace_xfs_da_grow_inode(args);
2147
2148 bno = args->geo->leafblk;
2149 error = xfs_da_grow_inode_int(args, &bno, args->geo->fsbcount);
2150 if (!error)
2151 *new_blkno = (xfs_dablk_t)bno;
2152 return error;
2153}
2154
2155/*
2156 * Ick. We need to always be able to remove a btree block, even
2157 * if there's no space reservation because the filesystem is full.
2158 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
2159 * It swaps the target block with the last block in the file. The
2160 * last block in the file can always be removed since it can't cause
2161 * a bmap btree split to do that.
2162 */
2163STATIC int
2164xfs_da3_swap_lastblock(
2165 struct xfs_da_args *args,
2166 xfs_dablk_t *dead_blknop,
2167 struct xfs_buf **dead_bufp)
2168{
2169 struct xfs_da_blkinfo *dead_info;
2170 struct xfs_da_blkinfo *sib_info;
2171 struct xfs_da_intnode *par_node;
2172 struct xfs_da_intnode *dead_node;
2173 struct xfs_dir2_leaf *dead_leaf2;
2174 struct xfs_da_node_entry *btree;
2175 struct xfs_da3_icnode_hdr par_hdr;
2176 struct xfs_inode *dp;
2177 struct xfs_trans *tp;
2178 struct xfs_mount *mp;
2179 struct xfs_buf *dead_buf;
2180 struct xfs_buf *last_buf;
2181 struct xfs_buf *sib_buf;
2182 struct xfs_buf *par_buf;
2183 xfs_dahash_t dead_hash;
2184 xfs_fileoff_t lastoff;
2185 xfs_dablk_t dead_blkno;
2186 xfs_dablk_t last_blkno;
2187 xfs_dablk_t sib_blkno;
2188 xfs_dablk_t par_blkno;
2189 int error;
2190 int w;
2191 int entno;
2192 int level;
2193 int dead_level;
2194
2195 trace_xfs_da_swap_lastblock(args);
2196
2197 dead_buf = *dead_bufp;
2198 dead_blkno = *dead_blknop;
2199 tp = args->trans;
2200 dp = args->dp;
2201 w = args->whichfork;
2202 ASSERT(w == XFS_DATA_FORK);
2203 mp = dp->i_mount;
2204 lastoff = args->geo->freeblk;
2205 error = xfs_bmap_last_before(tp, dp, &lastoff, w);
2206 if (error)
2207 return error;
2208 if (unlikely(lastoff == 0)) {
2209 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
2210 mp);
2211 return -EFSCORRUPTED;
2212 }
2213 /*
2214 * Read the last block in the btree space.
2215 */
2216 last_blkno = (xfs_dablk_t)lastoff - args->geo->fsbcount;
2217 error = xfs_da3_node_read(tp, dp, last_blkno, -1, &last_buf, w);
2218 if (error)
2219 return error;
2220 /*
2221 * Copy the last block into the dead buffer and log it.
2222 */
2223 memcpy(dead_buf->b_addr, last_buf->b_addr, args->geo->blksize);
2224 xfs_trans_log_buf(tp, dead_buf, 0, args->geo->blksize - 1);
2225 dead_info = dead_buf->b_addr;
2226 /*
2227 * Get values from the moved block.
2228 */
2229 if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2230 dead_info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
2231 struct xfs_dir3_icleaf_hdr leafhdr;
2232 struct xfs_dir2_leaf_entry *ents;
2233
2234 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
2235 dp->d_ops->leaf_hdr_from_disk(&leafhdr, dead_leaf2);
2236 ents = dp->d_ops->leaf_ents_p(dead_leaf2);
2237 dead_level = 0;
2238 dead_hash = be32_to_cpu(ents[leafhdr.count - 1].hashval);
2239 } else {
2240 struct xfs_da3_icnode_hdr deadhdr;
2241
2242 dead_node = (xfs_da_intnode_t *)dead_info;
2243 dp->d_ops->node_hdr_from_disk(&deadhdr, dead_node);
2244 btree = dp->d_ops->node_tree_p(dead_node);
2245 dead_level = deadhdr.level;
2246 dead_hash = be32_to_cpu(btree[deadhdr.count - 1].hashval);
2247 }
2248 sib_buf = par_buf = NULL;
2249 /*
2250 * If the moved block has a left sibling, fix up the pointers.
2251 */
2252 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
2253 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2254 if (error)
2255 goto done;
2256 sib_info = sib_buf->b_addr;
2257 if (unlikely(
2258 be32_to_cpu(sib_info->forw) != last_blkno ||
2259 sib_info->magic != dead_info->magic)) {
2260 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
2261 XFS_ERRLEVEL_LOW, mp);
2262 error = -EFSCORRUPTED;
2263 goto done;
2264 }
2265 sib_info->forw = cpu_to_be32(dead_blkno);
2266 xfs_trans_log_buf(tp, sib_buf,
2267 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
2268 sizeof(sib_info->forw)));
2269 sib_buf = NULL;
2270 }
2271 /*
2272 * If the moved block has a right sibling, fix up the pointers.
2273 */
2274 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
2275 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2276 if (error)
2277 goto done;
2278 sib_info = sib_buf->b_addr;
2279 if (unlikely(
2280 be32_to_cpu(sib_info->back) != last_blkno ||
2281 sib_info->magic != dead_info->magic)) {
2282 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
2283 XFS_ERRLEVEL_LOW, mp);
2284 error = -EFSCORRUPTED;
2285 goto done;
2286 }
2287 sib_info->back = cpu_to_be32(dead_blkno);
2288 xfs_trans_log_buf(tp, sib_buf,
2289 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
2290 sizeof(sib_info->back)));
2291 sib_buf = NULL;
2292 }
2293 par_blkno = args->geo->leafblk;
2294 level = -1;
2295 /*
2296 * Walk down the tree looking for the parent of the moved block.
2297 */
2298 for (;;) {
2299 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2300 if (error)
2301 goto done;
2302 par_node = par_buf->b_addr;
2303 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2304 if (level >= 0 && level != par_hdr.level + 1) {
2305 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
2306 XFS_ERRLEVEL_LOW, mp);
2307 error = -EFSCORRUPTED;
2308 goto done;
2309 }
2310 level = par_hdr.level;
2311 btree = dp->d_ops->node_tree_p(par_node);
2312 for (entno = 0;
2313 entno < par_hdr.count &&
2314 be32_to_cpu(btree[entno].hashval) < dead_hash;
2315 entno++)
2316 continue;
2317 if (entno == par_hdr.count) {
2318 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
2319 XFS_ERRLEVEL_LOW, mp);
2320 error = -EFSCORRUPTED;
2321 goto done;
2322 }
2323 par_blkno = be32_to_cpu(btree[entno].before);
2324 if (level == dead_level + 1)
2325 break;
2326 xfs_trans_brelse(tp, par_buf);
2327 par_buf = NULL;
2328 }
2329 /*
2330 * We're in the right parent block.
2331 * Look for the right entry.
2332 */
2333 for (;;) {
2334 for (;
2335 entno < par_hdr.count &&
2336 be32_to_cpu(btree[entno].before) != last_blkno;
2337 entno++)
2338 continue;
2339 if (entno < par_hdr.count)
2340 break;
2341 par_blkno = par_hdr.forw;
2342 xfs_trans_brelse(tp, par_buf);
2343 par_buf = NULL;
2344 if (unlikely(par_blkno == 0)) {
2345 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
2346 XFS_ERRLEVEL_LOW, mp);
2347 error = -EFSCORRUPTED;
2348 goto done;
2349 }
2350 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2351 if (error)
2352 goto done;
2353 par_node = par_buf->b_addr;
2354 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2355 if (par_hdr.level != level) {
2356 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
2357 XFS_ERRLEVEL_LOW, mp);
2358 error = -EFSCORRUPTED;
2359 goto done;
2360 }
2361 btree = dp->d_ops->node_tree_p(par_node);
2362 entno = 0;
2363 }
2364 /*
2365 * Update the parent entry pointing to the moved block.
2366 */
2367 btree[entno].before = cpu_to_be32(dead_blkno);
2368 xfs_trans_log_buf(tp, par_buf,
2369 XFS_DA_LOGRANGE(par_node, &btree[entno].before,
2370 sizeof(btree[entno].before)));
2371 *dead_blknop = last_blkno;
2372 *dead_bufp = last_buf;
2373 return 0;
2374done:
2375 if (par_buf)
2376 xfs_trans_brelse(tp, par_buf);
2377 if (sib_buf)
2378 xfs_trans_brelse(tp, sib_buf);
2379 xfs_trans_brelse(tp, last_buf);
2380 return error;
2381}
2382
2383/*
2384 * Remove a btree block from a directory or attribute.
2385 */
2386int
2387xfs_da_shrink_inode(
2388 xfs_da_args_t *args,
2389 xfs_dablk_t dead_blkno,
2390 struct xfs_buf *dead_buf)
2391{
2392 xfs_inode_t *dp;
2393 int done, error, w, count;
2394 xfs_trans_t *tp;
2395
2396 trace_xfs_da_shrink_inode(args);
2397
2398 dp = args->dp;
2399 w = args->whichfork;
2400 tp = args->trans;
2401 count = args->geo->fsbcount;
2402 for (;;) {
2403 /*
2404 * Remove extents. If we get ENOSPC for a dir we have to move
2405 * the last block to the place we want to kill.
2406 */
2407 error = xfs_bunmapi(tp, dp, dead_blkno, count,
2408 xfs_bmapi_aflag(w), 0, args->firstblock,
2409 args->dfops, &done);
2410 if (error == -ENOSPC) {
2411 if (w != XFS_DATA_FORK)
2412 break;
2413 error = xfs_da3_swap_lastblock(args, &dead_blkno,
2414 &dead_buf);
2415 if (error)
2416 break;
2417 } else {
2418 break;
2419 }
2420 }
2421 xfs_trans_binval(tp, dead_buf);
2422 return error;
2423}
2424
2425/*
2426 * See if the mapping(s) for this btree block are valid, i.e.
2427 * don't contain holes, are logically contiguous, and cover the whole range.
2428 */
2429STATIC int
2430xfs_da_map_covers_blocks(
2431 int nmap,
2432 xfs_bmbt_irec_t *mapp,
2433 xfs_dablk_t bno,
2434 int count)
2435{
2436 int i;
2437 xfs_fileoff_t off;
2438
2439 for (i = 0, off = bno; i < nmap; i++) {
2440 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
2441 mapp[i].br_startblock == DELAYSTARTBLOCK) {
2442 return 0;
2443 }
2444 if (off != mapp[i].br_startoff) {
2445 return 0;
2446 }
2447 off += mapp[i].br_blockcount;
2448 }
2449 return off == bno + count;
2450}
2451
2452/*
2453 * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
2454 *
2455 * For the single map case, it is assumed that the caller has provided a pointer
2456 * to a valid xfs_buf_map. For the multiple map case, this function will
2457 * allocate the xfs_buf_map to hold all the maps and replace the caller's single
2458 * map pointer with the allocated map.
2459 */
2460static int
2461xfs_buf_map_from_irec(
2462 struct xfs_mount *mp,
2463 struct xfs_buf_map **mapp,
2464 int *nmaps,
2465 struct xfs_bmbt_irec *irecs,
2466 int nirecs)
2467{
2468 struct xfs_buf_map *map;
2469 int i;
2470
2471 ASSERT(*nmaps == 1);
2472 ASSERT(nirecs >= 1);
2473
2474 if (nirecs > 1) {
2475 map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map),
2476 KM_SLEEP | KM_NOFS);
2477 if (!map)
2478 return -ENOMEM;
2479 *mapp = map;
2480 }
2481
2482 *nmaps = nirecs;
2483 map = *mapp;
2484 for (i = 0; i < *nmaps; i++) {
2485 ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
2486 irecs[i].br_startblock != HOLESTARTBLOCK);
2487 map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
2488 map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
2489 }
2490 return 0;
2491}
2492
2493/*
2494 * Map the block we are given ready for reading. There are three possible return
2495 * values:
2496 * -1 - will be returned if we land in a hole and mappedbno == -2 so the
2497 * caller knows not to execute a subsequent read.
2498 * 0 - if we mapped the block successfully
2499 * >0 - positive error number if there was an error.
2500 */
2501static int
2502xfs_dabuf_map(
2503 struct xfs_inode *dp,
2504 xfs_dablk_t bno,
2505 xfs_daddr_t mappedbno,
2506 int whichfork,
2507 struct xfs_buf_map **map,
2508 int *nmaps)
2509{
2510 struct xfs_mount *mp = dp->i_mount;
2511 int nfsb;
2512 int error = 0;
2513 struct xfs_bmbt_irec irec;
2514 struct xfs_bmbt_irec *irecs = &irec;
2515 int nirecs;
2516
2517 ASSERT(map && *map);
2518 ASSERT(*nmaps == 1);
2519
2520 if (whichfork == XFS_DATA_FORK)
2521 nfsb = mp->m_dir_geo->fsbcount;
2522 else
2523 nfsb = mp->m_attr_geo->fsbcount;
2524
2525 /*
2526 * Caller doesn't have a mapping. -2 means don't complain
2527 * if we land in a hole.
2528 */
2529 if (mappedbno == -1 || mappedbno == -2) {
2530 /*
2531 * Optimize the one-block case.
2532 */
2533 if (nfsb != 1)
2534 irecs = kmem_zalloc(sizeof(irec) * nfsb,
2535 KM_SLEEP | KM_NOFS);
2536
2537 nirecs = nfsb;
2538 error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
2539 &nirecs, xfs_bmapi_aflag(whichfork));
2540 if (error)
2541 goto out;
2542 } else {
2543 irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2544 irecs->br_startoff = (xfs_fileoff_t)bno;
2545 irecs->br_blockcount = nfsb;
2546 irecs->br_state = 0;
2547 nirecs = 1;
2548 }
2549
2550 if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
2551 error = mappedbno == -2 ? -1 : -EFSCORRUPTED;
2552 if (unlikely(error == -EFSCORRUPTED)) {
2553 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2554 int i;
2555 xfs_alert(mp, "%s: bno %lld dir: inode %lld",
2556 __func__, (long long)bno,
2557 (long long)dp->i_ino);
2558 for (i = 0; i < *nmaps; i++) {
2559 xfs_alert(mp,
2560"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2561 i,
2562 (long long)irecs[i].br_startoff,
2563 (long long)irecs[i].br_startblock,
2564 (long long)irecs[i].br_blockcount,
2565 irecs[i].br_state);
2566 }
2567 }
2568 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2569 XFS_ERRLEVEL_LOW, mp);
2570 }
2571 goto out;
2572 }
2573 error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
2574out:
2575 if (irecs != &irec)
2576 kmem_free(irecs);
2577 return error;
2578}
2579
2580/*
2581 * Get a buffer for the dir/attr block.
2582 */
2583int
2584xfs_da_get_buf(
2585 struct xfs_trans *trans,
2586 struct xfs_inode *dp,
2587 xfs_dablk_t bno,
2588 xfs_daddr_t mappedbno,
2589 struct xfs_buf **bpp,
2590 int whichfork)
2591{
2592 struct xfs_buf *bp;
2593 struct xfs_buf_map map;
2594 struct xfs_buf_map *mapp;
2595 int nmap;
2596 int error;
2597
2598 *bpp = NULL;
2599 mapp = ↦
2600 nmap = 1;
2601 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2602 &mapp, &nmap);
2603 if (error) {
2604 /* mapping a hole is not an error, but we don't continue */
2605 if (error == -1)
2606 error = 0;
2607 goto out_free;
2608 }
2609
2610 bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
2611 mapp, nmap, 0);
2612 error = bp ? bp->b_error : -EIO;
2613 if (error) {
2614 if (bp)
2615 xfs_trans_brelse(trans, bp);
2616 goto out_free;
2617 }
2618
2619 *bpp = bp;
2620
2621out_free:
2622 if (mapp != &map)
2623 kmem_free(mapp);
2624
2625 return error;
2626}
2627
2628/*
2629 * Get a buffer for the dir/attr block, fill in the contents.
2630 */
2631int
2632xfs_da_read_buf(
2633 struct xfs_trans *trans,
2634 struct xfs_inode *dp,
2635 xfs_dablk_t bno,
2636 xfs_daddr_t mappedbno,
2637 struct xfs_buf **bpp,
2638 int whichfork,
2639 const struct xfs_buf_ops *ops)
2640{
2641 struct xfs_buf *bp;
2642 struct xfs_buf_map map;
2643 struct xfs_buf_map *mapp;
2644 int nmap;
2645 int error;
2646
2647 *bpp = NULL;
2648 mapp = ↦
2649 nmap = 1;
2650 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2651 &mapp, &nmap);
2652 if (error) {
2653 /* mapping a hole is not an error, but we don't continue */
2654 if (error == -1)
2655 error = 0;
2656 goto out_free;
2657 }
2658
2659 error = xfs_trans_read_buf_map(dp->i_mount, trans,
2660 dp->i_mount->m_ddev_targp,
2661 mapp, nmap, 0, &bp, ops);
2662 if (error)
2663 goto out_free;
2664
2665 if (whichfork == XFS_ATTR_FORK)
2666 xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2667 else
2668 xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2669 *bpp = bp;
2670out_free:
2671 if (mapp != &map)
2672 kmem_free(mapp);
2673
2674 return error;
2675}
2676
2677/*
2678 * Readahead the dir/attr block.
2679 */
2680int
2681xfs_da_reada_buf(
2682 struct xfs_inode *dp,
2683 xfs_dablk_t bno,
2684 xfs_daddr_t mappedbno,
2685 int whichfork,
2686 const struct xfs_buf_ops *ops)
2687{
2688 struct xfs_buf_map map;
2689 struct xfs_buf_map *mapp;
2690 int nmap;
2691 int error;
2692
2693 mapp = ↦
2694 nmap = 1;
2695 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2696 &mapp, &nmap);
2697 if (error) {
2698 /* mapping a hole is not an error, but we don't continue */
2699 if (error == -1)
2700 error = 0;
2701 goto out_free;
2702 }
2703
2704 mappedbno = mapp[0].bm_bn;
2705 xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
2706
2707out_free:
2708 if (mapp != &map)
2709 kmem_free(mapp);
2710
2711 return error;
2712}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * Copyright (c) 2013 Red Hat, Inc.
5 * All Rights Reserved.
6 */
7#include "xfs.h"
8#include "xfs_fs.h"
9#include "xfs_shared.h"
10#include "xfs_format.h"
11#include "xfs_log_format.h"
12#include "xfs_trans_resv.h"
13#include "xfs_bit.h"
14#include "xfs_mount.h"
15#include "xfs_inode.h"
16#include "xfs_dir2.h"
17#include "xfs_dir2_priv.h"
18#include "xfs_trans.h"
19#include "xfs_bmap.h"
20#include "xfs_attr_leaf.h"
21#include "xfs_error.h"
22#include "xfs_trace.h"
23#include "xfs_buf_item.h"
24#include "xfs_log.h"
25
26/*
27 * xfs_da_btree.c
28 *
29 * Routines to implement directories as Btrees of hashed names.
30 */
31
32/*========================================================================
33 * Function prototypes for the kernel.
34 *========================================================================*/
35
36/*
37 * Routines used for growing the Btree.
38 */
39STATIC int xfs_da3_root_split(xfs_da_state_t *state,
40 xfs_da_state_blk_t *existing_root,
41 xfs_da_state_blk_t *new_child);
42STATIC int xfs_da3_node_split(xfs_da_state_t *state,
43 xfs_da_state_blk_t *existing_blk,
44 xfs_da_state_blk_t *split_blk,
45 xfs_da_state_blk_t *blk_to_add,
46 int treelevel,
47 int *result);
48STATIC void xfs_da3_node_rebalance(xfs_da_state_t *state,
49 xfs_da_state_blk_t *node_blk_1,
50 xfs_da_state_blk_t *node_blk_2);
51STATIC void xfs_da3_node_add(xfs_da_state_t *state,
52 xfs_da_state_blk_t *old_node_blk,
53 xfs_da_state_blk_t *new_node_blk);
54
55/*
56 * Routines used for shrinking the Btree.
57 */
58STATIC int xfs_da3_root_join(xfs_da_state_t *state,
59 xfs_da_state_blk_t *root_blk);
60STATIC int xfs_da3_node_toosmall(xfs_da_state_t *state, int *retval);
61STATIC void xfs_da3_node_remove(xfs_da_state_t *state,
62 xfs_da_state_blk_t *drop_blk);
63STATIC void xfs_da3_node_unbalance(xfs_da_state_t *state,
64 xfs_da_state_blk_t *src_node_blk,
65 xfs_da_state_blk_t *dst_node_blk);
66
67/*
68 * Utility routines.
69 */
70STATIC int xfs_da3_blk_unlink(xfs_da_state_t *state,
71 xfs_da_state_blk_t *drop_blk,
72 xfs_da_state_blk_t *save_blk);
73
74
75kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
76
77/*
78 * Allocate a dir-state structure.
79 * We don't put them on the stack since they're large.
80 */
81struct xfs_da_state *
82xfs_da_state_alloc(
83 struct xfs_da_args *args)
84{
85 struct xfs_da_state *state;
86
87 state = kmem_cache_zalloc(xfs_da_state_zone, GFP_NOFS | __GFP_NOFAIL);
88 state->args = args;
89 state->mp = args->dp->i_mount;
90 return state;
91}
92
93/*
94 * Kill the altpath contents of a da-state structure.
95 */
96STATIC void
97xfs_da_state_kill_altpath(xfs_da_state_t *state)
98{
99 int i;
100
101 for (i = 0; i < state->altpath.active; i++)
102 state->altpath.blk[i].bp = NULL;
103 state->altpath.active = 0;
104}
105
106/*
107 * Free a da-state structure.
108 */
109void
110xfs_da_state_free(xfs_da_state_t *state)
111{
112 xfs_da_state_kill_altpath(state);
113#ifdef DEBUG
114 memset((char *)state, 0, sizeof(*state));
115#endif /* DEBUG */
116 kmem_cache_free(xfs_da_state_zone, state);
117}
118
119static inline int xfs_dabuf_nfsb(struct xfs_mount *mp, int whichfork)
120{
121 if (whichfork == XFS_DATA_FORK)
122 return mp->m_dir_geo->fsbcount;
123 return mp->m_attr_geo->fsbcount;
124}
125
126void
127xfs_da3_node_hdr_from_disk(
128 struct xfs_mount *mp,
129 struct xfs_da3_icnode_hdr *to,
130 struct xfs_da_intnode *from)
131{
132 if (xfs_sb_version_hascrc(&mp->m_sb)) {
133 struct xfs_da3_intnode *from3 = (struct xfs_da3_intnode *)from;
134
135 to->forw = be32_to_cpu(from3->hdr.info.hdr.forw);
136 to->back = be32_to_cpu(from3->hdr.info.hdr.back);
137 to->magic = be16_to_cpu(from3->hdr.info.hdr.magic);
138 to->count = be16_to_cpu(from3->hdr.__count);
139 to->level = be16_to_cpu(from3->hdr.__level);
140 to->btree = from3->__btree;
141 ASSERT(to->magic == XFS_DA3_NODE_MAGIC);
142 } else {
143 to->forw = be32_to_cpu(from->hdr.info.forw);
144 to->back = be32_to_cpu(from->hdr.info.back);
145 to->magic = be16_to_cpu(from->hdr.info.magic);
146 to->count = be16_to_cpu(from->hdr.__count);
147 to->level = be16_to_cpu(from->hdr.__level);
148 to->btree = from->__btree;
149 ASSERT(to->magic == XFS_DA_NODE_MAGIC);
150 }
151}
152
153void
154xfs_da3_node_hdr_to_disk(
155 struct xfs_mount *mp,
156 struct xfs_da_intnode *to,
157 struct xfs_da3_icnode_hdr *from)
158{
159 if (xfs_sb_version_hascrc(&mp->m_sb)) {
160 struct xfs_da3_intnode *to3 = (struct xfs_da3_intnode *)to;
161
162 ASSERT(from->magic == XFS_DA3_NODE_MAGIC);
163 to3->hdr.info.hdr.forw = cpu_to_be32(from->forw);
164 to3->hdr.info.hdr.back = cpu_to_be32(from->back);
165 to3->hdr.info.hdr.magic = cpu_to_be16(from->magic);
166 to3->hdr.__count = cpu_to_be16(from->count);
167 to3->hdr.__level = cpu_to_be16(from->level);
168 } else {
169 ASSERT(from->magic == XFS_DA_NODE_MAGIC);
170 to->hdr.info.forw = cpu_to_be32(from->forw);
171 to->hdr.info.back = cpu_to_be32(from->back);
172 to->hdr.info.magic = cpu_to_be16(from->magic);
173 to->hdr.__count = cpu_to_be16(from->count);
174 to->hdr.__level = cpu_to_be16(from->level);
175 }
176}
177
178/*
179 * Verify an xfs_da3_blkinfo structure. Note that the da3 fields are only
180 * accessible on v5 filesystems. This header format is common across da node,
181 * attr leaf and dir leaf blocks.
182 */
183xfs_failaddr_t
184xfs_da3_blkinfo_verify(
185 struct xfs_buf *bp,
186 struct xfs_da3_blkinfo *hdr3)
187{
188 struct xfs_mount *mp = bp->b_mount;
189 struct xfs_da_blkinfo *hdr = &hdr3->hdr;
190
191 if (!xfs_verify_magic16(bp, hdr->magic))
192 return __this_address;
193
194 if (xfs_sb_version_hascrc(&mp->m_sb)) {
195 if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_meta_uuid))
196 return __this_address;
197 if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
198 return __this_address;
199 if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->lsn)))
200 return __this_address;
201 }
202
203 return NULL;
204}
205
206static xfs_failaddr_t
207xfs_da3_node_verify(
208 struct xfs_buf *bp)
209{
210 struct xfs_mount *mp = bp->b_mount;
211 struct xfs_da_intnode *hdr = bp->b_addr;
212 struct xfs_da3_icnode_hdr ichdr;
213 xfs_failaddr_t fa;
214
215 xfs_da3_node_hdr_from_disk(mp, &ichdr, hdr);
216
217 fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
218 if (fa)
219 return fa;
220
221 if (ichdr.level == 0)
222 return __this_address;
223 if (ichdr.level > XFS_DA_NODE_MAXDEPTH)
224 return __this_address;
225 if (ichdr.count == 0)
226 return __this_address;
227
228 /*
229 * we don't know if the node is for and attribute or directory tree,
230 * so only fail if the count is outside both bounds
231 */
232 if (ichdr.count > mp->m_dir_geo->node_ents &&
233 ichdr.count > mp->m_attr_geo->node_ents)
234 return __this_address;
235
236 /* XXX: hash order check? */
237
238 return NULL;
239}
240
241static void
242xfs_da3_node_write_verify(
243 struct xfs_buf *bp)
244{
245 struct xfs_mount *mp = bp->b_mount;
246 struct xfs_buf_log_item *bip = bp->b_log_item;
247 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
248 xfs_failaddr_t fa;
249
250 fa = xfs_da3_node_verify(bp);
251 if (fa) {
252 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
253 return;
254 }
255
256 if (!xfs_sb_version_hascrc(&mp->m_sb))
257 return;
258
259 if (bip)
260 hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
261
262 xfs_buf_update_cksum(bp, XFS_DA3_NODE_CRC_OFF);
263}
264
265/*
266 * leaf/node format detection on trees is sketchy, so a node read can be done on
267 * leaf level blocks when detection identifies the tree as a node format tree
268 * incorrectly. In this case, we need to swap the verifier to match the correct
269 * format of the block being read.
270 */
271static void
272xfs_da3_node_read_verify(
273 struct xfs_buf *bp)
274{
275 struct xfs_da_blkinfo *info = bp->b_addr;
276 xfs_failaddr_t fa;
277
278 switch (be16_to_cpu(info->magic)) {
279 case XFS_DA3_NODE_MAGIC:
280 if (!xfs_buf_verify_cksum(bp, XFS_DA3_NODE_CRC_OFF)) {
281 xfs_verifier_error(bp, -EFSBADCRC,
282 __this_address);
283 break;
284 }
285 fallthrough;
286 case XFS_DA_NODE_MAGIC:
287 fa = xfs_da3_node_verify(bp);
288 if (fa)
289 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
290 return;
291 case XFS_ATTR_LEAF_MAGIC:
292 case XFS_ATTR3_LEAF_MAGIC:
293 bp->b_ops = &xfs_attr3_leaf_buf_ops;
294 bp->b_ops->verify_read(bp);
295 return;
296 case XFS_DIR2_LEAFN_MAGIC:
297 case XFS_DIR3_LEAFN_MAGIC:
298 bp->b_ops = &xfs_dir3_leafn_buf_ops;
299 bp->b_ops->verify_read(bp);
300 return;
301 default:
302 xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
303 break;
304 }
305}
306
307/* Verify the structure of a da3 block. */
308static xfs_failaddr_t
309xfs_da3_node_verify_struct(
310 struct xfs_buf *bp)
311{
312 struct xfs_da_blkinfo *info = bp->b_addr;
313
314 switch (be16_to_cpu(info->magic)) {
315 case XFS_DA3_NODE_MAGIC:
316 case XFS_DA_NODE_MAGIC:
317 return xfs_da3_node_verify(bp);
318 case XFS_ATTR_LEAF_MAGIC:
319 case XFS_ATTR3_LEAF_MAGIC:
320 bp->b_ops = &xfs_attr3_leaf_buf_ops;
321 return bp->b_ops->verify_struct(bp);
322 case XFS_DIR2_LEAFN_MAGIC:
323 case XFS_DIR3_LEAFN_MAGIC:
324 bp->b_ops = &xfs_dir3_leafn_buf_ops;
325 return bp->b_ops->verify_struct(bp);
326 default:
327 return __this_address;
328 }
329}
330
331const struct xfs_buf_ops xfs_da3_node_buf_ops = {
332 .name = "xfs_da3_node",
333 .magic16 = { cpu_to_be16(XFS_DA_NODE_MAGIC),
334 cpu_to_be16(XFS_DA3_NODE_MAGIC) },
335 .verify_read = xfs_da3_node_read_verify,
336 .verify_write = xfs_da3_node_write_verify,
337 .verify_struct = xfs_da3_node_verify_struct,
338};
339
340static int
341xfs_da3_node_set_type(
342 struct xfs_trans *tp,
343 struct xfs_buf *bp)
344{
345 struct xfs_da_blkinfo *info = bp->b_addr;
346
347 switch (be16_to_cpu(info->magic)) {
348 case XFS_DA_NODE_MAGIC:
349 case XFS_DA3_NODE_MAGIC:
350 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
351 return 0;
352 case XFS_ATTR_LEAF_MAGIC:
353 case XFS_ATTR3_LEAF_MAGIC:
354 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_ATTR_LEAF_BUF);
355 return 0;
356 case XFS_DIR2_LEAFN_MAGIC:
357 case XFS_DIR3_LEAFN_MAGIC:
358 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
359 return 0;
360 default:
361 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, tp->t_mountp,
362 info, sizeof(*info));
363 xfs_trans_brelse(tp, bp);
364 return -EFSCORRUPTED;
365 }
366}
367
368int
369xfs_da3_node_read(
370 struct xfs_trans *tp,
371 struct xfs_inode *dp,
372 xfs_dablk_t bno,
373 struct xfs_buf **bpp,
374 int whichfork)
375{
376 int error;
377
378 error = xfs_da_read_buf(tp, dp, bno, 0, bpp, whichfork,
379 &xfs_da3_node_buf_ops);
380 if (error || !*bpp || !tp)
381 return error;
382 return xfs_da3_node_set_type(tp, *bpp);
383}
384
385int
386xfs_da3_node_read_mapped(
387 struct xfs_trans *tp,
388 struct xfs_inode *dp,
389 xfs_daddr_t mappedbno,
390 struct xfs_buf **bpp,
391 int whichfork)
392{
393 struct xfs_mount *mp = dp->i_mount;
394 int error;
395
396 error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, mappedbno,
397 XFS_FSB_TO_BB(mp, xfs_dabuf_nfsb(mp, whichfork)), 0,
398 bpp, &xfs_da3_node_buf_ops);
399 if (error || !*bpp)
400 return error;
401
402 if (whichfork == XFS_ATTR_FORK)
403 xfs_buf_set_ref(*bpp, XFS_ATTR_BTREE_REF);
404 else
405 xfs_buf_set_ref(*bpp, XFS_DIR_BTREE_REF);
406
407 if (!tp)
408 return 0;
409 return xfs_da3_node_set_type(tp, *bpp);
410}
411
412/*========================================================================
413 * Routines used for growing the Btree.
414 *========================================================================*/
415
416/*
417 * Create the initial contents of an intermediate node.
418 */
419int
420xfs_da3_node_create(
421 struct xfs_da_args *args,
422 xfs_dablk_t blkno,
423 int level,
424 struct xfs_buf **bpp,
425 int whichfork)
426{
427 struct xfs_da_intnode *node;
428 struct xfs_trans *tp = args->trans;
429 struct xfs_mount *mp = tp->t_mountp;
430 struct xfs_da3_icnode_hdr ichdr = {0};
431 struct xfs_buf *bp;
432 int error;
433 struct xfs_inode *dp = args->dp;
434
435 trace_xfs_da_node_create(args);
436 ASSERT(level <= XFS_DA_NODE_MAXDEPTH);
437
438 error = xfs_da_get_buf(tp, dp, blkno, &bp, whichfork);
439 if (error)
440 return error;
441 bp->b_ops = &xfs_da3_node_buf_ops;
442 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
443 node = bp->b_addr;
444
445 if (xfs_sb_version_hascrc(&mp->m_sb)) {
446 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
447
448 memset(hdr3, 0, sizeof(struct xfs_da3_node_hdr));
449 ichdr.magic = XFS_DA3_NODE_MAGIC;
450 hdr3->info.blkno = cpu_to_be64(bp->b_bn);
451 hdr3->info.owner = cpu_to_be64(args->dp->i_ino);
452 uuid_copy(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid);
453 } else {
454 ichdr.magic = XFS_DA_NODE_MAGIC;
455 }
456 ichdr.level = level;
457
458 xfs_da3_node_hdr_to_disk(dp->i_mount, node, &ichdr);
459 xfs_trans_log_buf(tp, bp,
460 XFS_DA_LOGRANGE(node, &node->hdr, args->geo->node_hdr_size));
461
462 *bpp = bp;
463 return 0;
464}
465
466/*
467 * Split a leaf node, rebalance, then possibly split
468 * intermediate nodes, rebalance, etc.
469 */
470int /* error */
471xfs_da3_split(
472 struct xfs_da_state *state)
473{
474 struct xfs_da_state_blk *oldblk;
475 struct xfs_da_state_blk *newblk;
476 struct xfs_da_state_blk *addblk;
477 struct xfs_da_intnode *node;
478 int max;
479 int action = 0;
480 int error;
481 int i;
482
483 trace_xfs_da_split(state->args);
484
485 /*
486 * Walk back up the tree splitting/inserting/adjusting as necessary.
487 * If we need to insert and there isn't room, split the node, then
488 * decide which fragment to insert the new block from below into.
489 * Note that we may split the root this way, but we need more fixup.
490 */
491 max = state->path.active - 1;
492 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
493 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
494 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
495
496 addblk = &state->path.blk[max]; /* initial dummy value */
497 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
498 oldblk = &state->path.blk[i];
499 newblk = &state->altpath.blk[i];
500
501 /*
502 * If a leaf node then
503 * Allocate a new leaf node, then rebalance across them.
504 * else if an intermediate node then
505 * We split on the last layer, must we split the node?
506 */
507 switch (oldblk->magic) {
508 case XFS_ATTR_LEAF_MAGIC:
509 error = xfs_attr3_leaf_split(state, oldblk, newblk);
510 if ((error != 0) && (error != -ENOSPC)) {
511 return error; /* GROT: attr is inconsistent */
512 }
513 if (!error) {
514 addblk = newblk;
515 break;
516 }
517 /*
518 * Entry wouldn't fit, split the leaf again. The new
519 * extrablk will be consumed by xfs_da3_node_split if
520 * the node is split.
521 */
522 state->extravalid = 1;
523 if (state->inleaf) {
524 state->extraafter = 0; /* before newblk */
525 trace_xfs_attr_leaf_split_before(state->args);
526 error = xfs_attr3_leaf_split(state, oldblk,
527 &state->extrablk);
528 } else {
529 state->extraafter = 1; /* after newblk */
530 trace_xfs_attr_leaf_split_after(state->args);
531 error = xfs_attr3_leaf_split(state, newblk,
532 &state->extrablk);
533 }
534 if (error)
535 return error; /* GROT: attr inconsistent */
536 addblk = newblk;
537 break;
538 case XFS_DIR2_LEAFN_MAGIC:
539 error = xfs_dir2_leafn_split(state, oldblk, newblk);
540 if (error)
541 return error;
542 addblk = newblk;
543 break;
544 case XFS_DA_NODE_MAGIC:
545 error = xfs_da3_node_split(state, oldblk, newblk, addblk,
546 max - i, &action);
547 addblk->bp = NULL;
548 if (error)
549 return error; /* GROT: dir is inconsistent */
550 /*
551 * Record the newly split block for the next time thru?
552 */
553 if (action)
554 addblk = newblk;
555 else
556 addblk = NULL;
557 break;
558 }
559
560 /*
561 * Update the btree to show the new hashval for this child.
562 */
563 xfs_da3_fixhashpath(state, &state->path);
564 }
565 if (!addblk)
566 return 0;
567
568 /*
569 * xfs_da3_node_split() should have consumed any extra blocks we added
570 * during a double leaf split in the attr fork. This is guaranteed as
571 * we can't be here if the attr fork only has a single leaf block.
572 */
573 ASSERT(state->extravalid == 0 ||
574 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
575
576 /*
577 * Split the root node.
578 */
579 ASSERT(state->path.active == 0);
580 oldblk = &state->path.blk[0];
581 error = xfs_da3_root_split(state, oldblk, addblk);
582 if (error)
583 goto out;
584
585 /*
586 * Update pointers to the node which used to be block 0 and just got
587 * bumped because of the addition of a new root node. Note that the
588 * original block 0 could be at any position in the list of blocks in
589 * the tree.
590 *
591 * Note: the magic numbers and sibling pointers are in the same physical
592 * place for both v2 and v3 headers (by design). Hence it doesn't matter
593 * which version of the xfs_da_intnode structure we use here as the
594 * result will be the same using either structure.
595 */
596 node = oldblk->bp->b_addr;
597 if (node->hdr.info.forw) {
598 if (be32_to_cpu(node->hdr.info.forw) != addblk->blkno) {
599 xfs_buf_mark_corrupt(oldblk->bp);
600 error = -EFSCORRUPTED;
601 goto out;
602 }
603 node = addblk->bp->b_addr;
604 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
605 xfs_trans_log_buf(state->args->trans, addblk->bp,
606 XFS_DA_LOGRANGE(node, &node->hdr.info,
607 sizeof(node->hdr.info)));
608 }
609 node = oldblk->bp->b_addr;
610 if (node->hdr.info.back) {
611 if (be32_to_cpu(node->hdr.info.back) != addblk->blkno) {
612 xfs_buf_mark_corrupt(oldblk->bp);
613 error = -EFSCORRUPTED;
614 goto out;
615 }
616 node = addblk->bp->b_addr;
617 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
618 xfs_trans_log_buf(state->args->trans, addblk->bp,
619 XFS_DA_LOGRANGE(node, &node->hdr.info,
620 sizeof(node->hdr.info)));
621 }
622out:
623 addblk->bp = NULL;
624 return error;
625}
626
627/*
628 * Split the root. We have to create a new root and point to the two
629 * parts (the split old root) that we just created. Copy block zero to
630 * the EOF, extending the inode in process.
631 */
632STATIC int /* error */
633xfs_da3_root_split(
634 struct xfs_da_state *state,
635 struct xfs_da_state_blk *blk1,
636 struct xfs_da_state_blk *blk2)
637{
638 struct xfs_da_intnode *node;
639 struct xfs_da_intnode *oldroot;
640 struct xfs_da_node_entry *btree;
641 struct xfs_da3_icnode_hdr nodehdr;
642 struct xfs_da_args *args;
643 struct xfs_buf *bp;
644 struct xfs_inode *dp;
645 struct xfs_trans *tp;
646 struct xfs_dir2_leaf *leaf;
647 xfs_dablk_t blkno;
648 int level;
649 int error;
650 int size;
651
652 trace_xfs_da_root_split(state->args);
653
654 /*
655 * Copy the existing (incorrect) block from the root node position
656 * to a free space somewhere.
657 */
658 args = state->args;
659 error = xfs_da_grow_inode(args, &blkno);
660 if (error)
661 return error;
662
663 dp = args->dp;
664 tp = args->trans;
665 error = xfs_da_get_buf(tp, dp, blkno, &bp, args->whichfork);
666 if (error)
667 return error;
668 node = bp->b_addr;
669 oldroot = blk1->bp->b_addr;
670 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
671 oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
672 struct xfs_da3_icnode_hdr icnodehdr;
673
674 xfs_da3_node_hdr_from_disk(dp->i_mount, &icnodehdr, oldroot);
675 btree = icnodehdr.btree;
676 size = (int)((char *)&btree[icnodehdr.count] - (char *)oldroot);
677 level = icnodehdr.level;
678
679 /*
680 * we are about to copy oldroot to bp, so set up the type
681 * of bp while we know exactly what it will be.
682 */
683 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
684 } else {
685 struct xfs_dir3_icleaf_hdr leafhdr;
686
687 leaf = (xfs_dir2_leaf_t *)oldroot;
688 xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr, leaf);
689
690 ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
691 leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
692 size = (int)((char *)&leafhdr.ents[leafhdr.count] -
693 (char *)leaf);
694 level = 0;
695
696 /*
697 * we are about to copy oldroot to bp, so set up the type
698 * of bp while we know exactly what it will be.
699 */
700 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
701 }
702
703 /*
704 * we can copy most of the information in the node from one block to
705 * another, but for CRC enabled headers we have to make sure that the
706 * block specific identifiers are kept intact. We update the buffer
707 * directly for this.
708 */
709 memcpy(node, oldroot, size);
710 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
711 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
712 struct xfs_da3_intnode *node3 = (struct xfs_da3_intnode *)node;
713
714 node3->hdr.info.blkno = cpu_to_be64(bp->b_bn);
715 }
716 xfs_trans_log_buf(tp, bp, 0, size - 1);
717
718 bp->b_ops = blk1->bp->b_ops;
719 xfs_trans_buf_copy_type(bp, blk1->bp);
720 blk1->bp = bp;
721 blk1->blkno = blkno;
722
723 /*
724 * Set up the new root node.
725 */
726 error = xfs_da3_node_create(args,
727 (args->whichfork == XFS_DATA_FORK) ? args->geo->leafblk : 0,
728 level + 1, &bp, args->whichfork);
729 if (error)
730 return error;
731
732 node = bp->b_addr;
733 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
734 btree = nodehdr.btree;
735 btree[0].hashval = cpu_to_be32(blk1->hashval);
736 btree[0].before = cpu_to_be32(blk1->blkno);
737 btree[1].hashval = cpu_to_be32(blk2->hashval);
738 btree[1].before = cpu_to_be32(blk2->blkno);
739 nodehdr.count = 2;
740 xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
741
742#ifdef DEBUG
743 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
744 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
745 ASSERT(blk1->blkno >= args->geo->leafblk &&
746 blk1->blkno < args->geo->freeblk);
747 ASSERT(blk2->blkno >= args->geo->leafblk &&
748 blk2->blkno < args->geo->freeblk);
749 }
750#endif
751
752 /* Header is already logged by xfs_da_node_create */
753 xfs_trans_log_buf(tp, bp,
754 XFS_DA_LOGRANGE(node, btree, sizeof(xfs_da_node_entry_t) * 2));
755
756 return 0;
757}
758
759/*
760 * Split the node, rebalance, then add the new entry.
761 */
762STATIC int /* error */
763xfs_da3_node_split(
764 struct xfs_da_state *state,
765 struct xfs_da_state_blk *oldblk,
766 struct xfs_da_state_blk *newblk,
767 struct xfs_da_state_blk *addblk,
768 int treelevel,
769 int *result)
770{
771 struct xfs_da_intnode *node;
772 struct xfs_da3_icnode_hdr nodehdr;
773 xfs_dablk_t blkno;
774 int newcount;
775 int error;
776 int useextra;
777 struct xfs_inode *dp = state->args->dp;
778
779 trace_xfs_da_node_split(state->args);
780
781 node = oldblk->bp->b_addr;
782 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
783
784 /*
785 * With V2 dirs the extra block is data or freespace.
786 */
787 useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
788 newcount = 1 + useextra;
789 /*
790 * Do we have to split the node?
791 */
792 if (nodehdr.count + newcount > state->args->geo->node_ents) {
793 /*
794 * Allocate a new node, add to the doubly linked chain of
795 * nodes, then move some of our excess entries into it.
796 */
797 error = xfs_da_grow_inode(state->args, &blkno);
798 if (error)
799 return error; /* GROT: dir is inconsistent */
800
801 error = xfs_da3_node_create(state->args, blkno, treelevel,
802 &newblk->bp, state->args->whichfork);
803 if (error)
804 return error; /* GROT: dir is inconsistent */
805 newblk->blkno = blkno;
806 newblk->magic = XFS_DA_NODE_MAGIC;
807 xfs_da3_node_rebalance(state, oldblk, newblk);
808 error = xfs_da3_blk_link(state, oldblk, newblk);
809 if (error)
810 return error;
811 *result = 1;
812 } else {
813 *result = 0;
814 }
815
816 /*
817 * Insert the new entry(s) into the correct block
818 * (updating last hashval in the process).
819 *
820 * xfs_da3_node_add() inserts BEFORE the given index,
821 * and as a result of using node_lookup_int() we always
822 * point to a valid entry (not after one), but a split
823 * operation always results in a new block whose hashvals
824 * FOLLOW the current block.
825 *
826 * If we had double-split op below us, then add the extra block too.
827 */
828 node = oldblk->bp->b_addr;
829 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
830 if (oldblk->index <= nodehdr.count) {
831 oldblk->index++;
832 xfs_da3_node_add(state, oldblk, addblk);
833 if (useextra) {
834 if (state->extraafter)
835 oldblk->index++;
836 xfs_da3_node_add(state, oldblk, &state->extrablk);
837 state->extravalid = 0;
838 }
839 } else {
840 newblk->index++;
841 xfs_da3_node_add(state, newblk, addblk);
842 if (useextra) {
843 if (state->extraafter)
844 newblk->index++;
845 xfs_da3_node_add(state, newblk, &state->extrablk);
846 state->extravalid = 0;
847 }
848 }
849
850 return 0;
851}
852
853/*
854 * Balance the btree elements between two intermediate nodes,
855 * usually one full and one empty.
856 *
857 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
858 */
859STATIC void
860xfs_da3_node_rebalance(
861 struct xfs_da_state *state,
862 struct xfs_da_state_blk *blk1,
863 struct xfs_da_state_blk *blk2)
864{
865 struct xfs_da_intnode *node1;
866 struct xfs_da_intnode *node2;
867 struct xfs_da_intnode *tmpnode;
868 struct xfs_da_node_entry *btree1;
869 struct xfs_da_node_entry *btree2;
870 struct xfs_da_node_entry *btree_s;
871 struct xfs_da_node_entry *btree_d;
872 struct xfs_da3_icnode_hdr nodehdr1;
873 struct xfs_da3_icnode_hdr nodehdr2;
874 struct xfs_trans *tp;
875 int count;
876 int tmp;
877 int swap = 0;
878 struct xfs_inode *dp = state->args->dp;
879
880 trace_xfs_da_node_rebalance(state->args);
881
882 node1 = blk1->bp->b_addr;
883 node2 = blk2->bp->b_addr;
884 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
885 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
886 btree1 = nodehdr1.btree;
887 btree2 = nodehdr2.btree;
888
889 /*
890 * Figure out how many entries need to move, and in which direction.
891 * Swap the nodes around if that makes it simpler.
892 */
893 if (nodehdr1.count > 0 && nodehdr2.count > 0 &&
894 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
895 (be32_to_cpu(btree2[nodehdr2.count - 1].hashval) <
896 be32_to_cpu(btree1[nodehdr1.count - 1].hashval)))) {
897 tmpnode = node1;
898 node1 = node2;
899 node2 = tmpnode;
900 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
901 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
902 btree1 = nodehdr1.btree;
903 btree2 = nodehdr2.btree;
904 swap = 1;
905 }
906
907 count = (nodehdr1.count - nodehdr2.count) / 2;
908 if (count == 0)
909 return;
910 tp = state->args->trans;
911 /*
912 * Two cases: high-to-low and low-to-high.
913 */
914 if (count > 0) {
915 /*
916 * Move elements in node2 up to make a hole.
917 */
918 tmp = nodehdr2.count;
919 if (tmp > 0) {
920 tmp *= (uint)sizeof(xfs_da_node_entry_t);
921 btree_s = &btree2[0];
922 btree_d = &btree2[count];
923 memmove(btree_d, btree_s, tmp);
924 }
925
926 /*
927 * Move the req'd B-tree elements from high in node1 to
928 * low in node2.
929 */
930 nodehdr2.count += count;
931 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
932 btree_s = &btree1[nodehdr1.count - count];
933 btree_d = &btree2[0];
934 memcpy(btree_d, btree_s, tmp);
935 nodehdr1.count -= count;
936 } else {
937 /*
938 * Move the req'd B-tree elements from low in node2 to
939 * high in node1.
940 */
941 count = -count;
942 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
943 btree_s = &btree2[0];
944 btree_d = &btree1[nodehdr1.count];
945 memcpy(btree_d, btree_s, tmp);
946 nodehdr1.count += count;
947
948 xfs_trans_log_buf(tp, blk1->bp,
949 XFS_DA_LOGRANGE(node1, btree_d, tmp));
950
951 /*
952 * Move elements in node2 down to fill the hole.
953 */
954 tmp = nodehdr2.count - count;
955 tmp *= (uint)sizeof(xfs_da_node_entry_t);
956 btree_s = &btree2[count];
957 btree_d = &btree2[0];
958 memmove(btree_d, btree_s, tmp);
959 nodehdr2.count -= count;
960 }
961
962 /*
963 * Log header of node 1 and all current bits of node 2.
964 */
965 xfs_da3_node_hdr_to_disk(dp->i_mount, node1, &nodehdr1);
966 xfs_trans_log_buf(tp, blk1->bp,
967 XFS_DA_LOGRANGE(node1, &node1->hdr,
968 state->args->geo->node_hdr_size));
969
970 xfs_da3_node_hdr_to_disk(dp->i_mount, node2, &nodehdr2);
971 xfs_trans_log_buf(tp, blk2->bp,
972 XFS_DA_LOGRANGE(node2, &node2->hdr,
973 state->args->geo->node_hdr_size +
974 (sizeof(btree2[0]) * nodehdr2.count)));
975
976 /*
977 * Record the last hashval from each block for upward propagation.
978 * (note: don't use the swapped node pointers)
979 */
980 if (swap) {
981 node1 = blk1->bp->b_addr;
982 node2 = blk2->bp->b_addr;
983 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr1, node1);
984 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr2, node2);
985 btree1 = nodehdr1.btree;
986 btree2 = nodehdr2.btree;
987 }
988 blk1->hashval = be32_to_cpu(btree1[nodehdr1.count - 1].hashval);
989 blk2->hashval = be32_to_cpu(btree2[nodehdr2.count - 1].hashval);
990
991 /*
992 * Adjust the expected index for insertion.
993 */
994 if (blk1->index >= nodehdr1.count) {
995 blk2->index = blk1->index - nodehdr1.count;
996 blk1->index = nodehdr1.count + 1; /* make it invalid */
997 }
998}
999
1000/*
1001 * Add a new entry to an intermediate node.
1002 */
1003STATIC void
1004xfs_da3_node_add(
1005 struct xfs_da_state *state,
1006 struct xfs_da_state_blk *oldblk,
1007 struct xfs_da_state_blk *newblk)
1008{
1009 struct xfs_da_intnode *node;
1010 struct xfs_da3_icnode_hdr nodehdr;
1011 struct xfs_da_node_entry *btree;
1012 int tmp;
1013 struct xfs_inode *dp = state->args->dp;
1014
1015 trace_xfs_da_node_add(state->args);
1016
1017 node = oldblk->bp->b_addr;
1018 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1019 btree = nodehdr.btree;
1020
1021 ASSERT(oldblk->index >= 0 && oldblk->index <= nodehdr.count);
1022 ASSERT(newblk->blkno != 0);
1023 if (state->args->whichfork == XFS_DATA_FORK)
1024 ASSERT(newblk->blkno >= state->args->geo->leafblk &&
1025 newblk->blkno < state->args->geo->freeblk);
1026
1027 /*
1028 * We may need to make some room before we insert the new node.
1029 */
1030 tmp = 0;
1031 if (oldblk->index < nodehdr.count) {
1032 tmp = (nodehdr.count - oldblk->index) * (uint)sizeof(*btree);
1033 memmove(&btree[oldblk->index + 1], &btree[oldblk->index], tmp);
1034 }
1035 btree[oldblk->index].hashval = cpu_to_be32(newblk->hashval);
1036 btree[oldblk->index].before = cpu_to_be32(newblk->blkno);
1037 xfs_trans_log_buf(state->args->trans, oldblk->bp,
1038 XFS_DA_LOGRANGE(node, &btree[oldblk->index],
1039 tmp + sizeof(*btree)));
1040
1041 nodehdr.count += 1;
1042 xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
1043 xfs_trans_log_buf(state->args->trans, oldblk->bp,
1044 XFS_DA_LOGRANGE(node, &node->hdr,
1045 state->args->geo->node_hdr_size));
1046
1047 /*
1048 * Copy the last hash value from the oldblk to propagate upwards.
1049 */
1050 oldblk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1051}
1052
1053/*========================================================================
1054 * Routines used for shrinking the Btree.
1055 *========================================================================*/
1056
1057/*
1058 * Deallocate an empty leaf node, remove it from its parent,
1059 * possibly deallocating that block, etc...
1060 */
1061int
1062xfs_da3_join(
1063 struct xfs_da_state *state)
1064{
1065 struct xfs_da_state_blk *drop_blk;
1066 struct xfs_da_state_blk *save_blk;
1067 int action = 0;
1068 int error;
1069
1070 trace_xfs_da_join(state->args);
1071
1072 drop_blk = &state->path.blk[ state->path.active-1 ];
1073 save_blk = &state->altpath.blk[ state->path.active-1 ];
1074 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
1075 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
1076 drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
1077
1078 /*
1079 * Walk back up the tree joining/deallocating as necessary.
1080 * When we stop dropping blocks, break out.
1081 */
1082 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
1083 state->path.active--) {
1084 /*
1085 * See if we can combine the block with a neighbor.
1086 * (action == 0) => no options, just leave
1087 * (action == 1) => coalesce, then unlink
1088 * (action == 2) => block empty, unlink it
1089 */
1090 switch (drop_blk->magic) {
1091 case XFS_ATTR_LEAF_MAGIC:
1092 error = xfs_attr3_leaf_toosmall(state, &action);
1093 if (error)
1094 return error;
1095 if (action == 0)
1096 return 0;
1097 xfs_attr3_leaf_unbalance(state, drop_blk, save_blk);
1098 break;
1099 case XFS_DIR2_LEAFN_MAGIC:
1100 error = xfs_dir2_leafn_toosmall(state, &action);
1101 if (error)
1102 return error;
1103 if (action == 0)
1104 return 0;
1105 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
1106 break;
1107 case XFS_DA_NODE_MAGIC:
1108 /*
1109 * Remove the offending node, fixup hashvals,
1110 * check for a toosmall neighbor.
1111 */
1112 xfs_da3_node_remove(state, drop_blk);
1113 xfs_da3_fixhashpath(state, &state->path);
1114 error = xfs_da3_node_toosmall(state, &action);
1115 if (error)
1116 return error;
1117 if (action == 0)
1118 return 0;
1119 xfs_da3_node_unbalance(state, drop_blk, save_blk);
1120 break;
1121 }
1122 xfs_da3_fixhashpath(state, &state->altpath);
1123 error = xfs_da3_blk_unlink(state, drop_blk, save_blk);
1124 xfs_da_state_kill_altpath(state);
1125 if (error)
1126 return error;
1127 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
1128 drop_blk->bp);
1129 drop_blk->bp = NULL;
1130 if (error)
1131 return error;
1132 }
1133 /*
1134 * We joined all the way to the top. If it turns out that
1135 * we only have one entry in the root, make the child block
1136 * the new root.
1137 */
1138 xfs_da3_node_remove(state, drop_blk);
1139 xfs_da3_fixhashpath(state, &state->path);
1140 error = xfs_da3_root_join(state, &state->path.blk[0]);
1141 return error;
1142}
1143
1144#ifdef DEBUG
1145static void
1146xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
1147{
1148 __be16 magic = blkinfo->magic;
1149
1150 if (level == 1) {
1151 ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1152 magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1153 magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1154 magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1155 } else {
1156 ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1157 magic == cpu_to_be16(XFS_DA3_NODE_MAGIC));
1158 }
1159 ASSERT(!blkinfo->forw);
1160 ASSERT(!blkinfo->back);
1161}
1162#else /* !DEBUG */
1163#define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
1164#endif /* !DEBUG */
1165
1166/*
1167 * We have only one entry in the root. Copy the only remaining child of
1168 * the old root to block 0 as the new root node.
1169 */
1170STATIC int
1171xfs_da3_root_join(
1172 struct xfs_da_state *state,
1173 struct xfs_da_state_blk *root_blk)
1174{
1175 struct xfs_da_intnode *oldroot;
1176 struct xfs_da_args *args;
1177 xfs_dablk_t child;
1178 struct xfs_buf *bp;
1179 struct xfs_da3_icnode_hdr oldroothdr;
1180 int error;
1181 struct xfs_inode *dp = state->args->dp;
1182
1183 trace_xfs_da_root_join(state->args);
1184
1185 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
1186
1187 args = state->args;
1188 oldroot = root_blk->bp->b_addr;
1189 xfs_da3_node_hdr_from_disk(dp->i_mount, &oldroothdr, oldroot);
1190 ASSERT(oldroothdr.forw == 0);
1191 ASSERT(oldroothdr.back == 0);
1192
1193 /*
1194 * If the root has more than one child, then don't do anything.
1195 */
1196 if (oldroothdr.count > 1)
1197 return 0;
1198
1199 /*
1200 * Read in the (only) child block, then copy those bytes into
1201 * the root block's buffer and free the original child block.
1202 */
1203 child = be32_to_cpu(oldroothdr.btree[0].before);
1204 ASSERT(child != 0);
1205 error = xfs_da3_node_read(args->trans, dp, child, &bp, args->whichfork);
1206 if (error)
1207 return error;
1208 xfs_da_blkinfo_onlychild_validate(bp->b_addr, oldroothdr.level);
1209
1210 /*
1211 * This could be copying a leaf back into the root block in the case of
1212 * there only being a single leaf block left in the tree. Hence we have
1213 * to update the b_ops pointer as well to match the buffer type change
1214 * that could occur. For dir3 blocks we also need to update the block
1215 * number in the buffer header.
1216 */
1217 memcpy(root_blk->bp->b_addr, bp->b_addr, args->geo->blksize);
1218 root_blk->bp->b_ops = bp->b_ops;
1219 xfs_trans_buf_copy_type(root_blk->bp, bp);
1220 if (oldroothdr.magic == XFS_DA3_NODE_MAGIC) {
1221 struct xfs_da3_blkinfo *da3 = root_blk->bp->b_addr;
1222 da3->blkno = cpu_to_be64(root_blk->bp->b_bn);
1223 }
1224 xfs_trans_log_buf(args->trans, root_blk->bp, 0,
1225 args->geo->blksize - 1);
1226 error = xfs_da_shrink_inode(args, child, bp);
1227 return error;
1228}
1229
1230/*
1231 * Check a node block and its neighbors to see if the block should be
1232 * collapsed into one or the other neighbor. Always keep the block
1233 * with the smaller block number.
1234 * If the current block is over 50% full, don't try to join it, return 0.
1235 * If the block is empty, fill in the state structure and return 2.
1236 * If it can be collapsed, fill in the state structure and return 1.
1237 * If nothing can be done, return 0.
1238 */
1239STATIC int
1240xfs_da3_node_toosmall(
1241 struct xfs_da_state *state,
1242 int *action)
1243{
1244 struct xfs_da_intnode *node;
1245 struct xfs_da_state_blk *blk;
1246 struct xfs_da_blkinfo *info;
1247 xfs_dablk_t blkno;
1248 struct xfs_buf *bp;
1249 struct xfs_da3_icnode_hdr nodehdr;
1250 int count;
1251 int forward;
1252 int error;
1253 int retval;
1254 int i;
1255 struct xfs_inode *dp = state->args->dp;
1256
1257 trace_xfs_da_node_toosmall(state->args);
1258
1259 /*
1260 * Check for the degenerate case of the block being over 50% full.
1261 * If so, it's not worth even looking to see if we might be able
1262 * to coalesce with a sibling.
1263 */
1264 blk = &state->path.blk[ state->path.active-1 ];
1265 info = blk->bp->b_addr;
1266 node = (xfs_da_intnode_t *)info;
1267 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1268 if (nodehdr.count > (state->args->geo->node_ents >> 1)) {
1269 *action = 0; /* blk over 50%, don't try to join */
1270 return 0; /* blk over 50%, don't try to join */
1271 }
1272
1273 /*
1274 * Check for the degenerate case of the block being empty.
1275 * If the block is empty, we'll simply delete it, no need to
1276 * coalesce it with a sibling block. We choose (arbitrarily)
1277 * to merge with the forward block unless it is NULL.
1278 */
1279 if (nodehdr.count == 0) {
1280 /*
1281 * Make altpath point to the block we want to keep and
1282 * path point to the block we want to drop (this one).
1283 */
1284 forward = (info->forw != 0);
1285 memcpy(&state->altpath, &state->path, sizeof(state->path));
1286 error = xfs_da3_path_shift(state, &state->altpath, forward,
1287 0, &retval);
1288 if (error)
1289 return error;
1290 if (retval) {
1291 *action = 0;
1292 } else {
1293 *action = 2;
1294 }
1295 return 0;
1296 }
1297
1298 /*
1299 * Examine each sibling block to see if we can coalesce with
1300 * at least 25% free space to spare. We need to figure out
1301 * whether to merge with the forward or the backward block.
1302 * We prefer coalescing with the lower numbered sibling so as
1303 * to shrink a directory over time.
1304 */
1305 count = state->args->geo->node_ents;
1306 count -= state->args->geo->node_ents >> 2;
1307 count -= nodehdr.count;
1308
1309 /* start with smaller blk num */
1310 forward = nodehdr.forw < nodehdr.back;
1311 for (i = 0; i < 2; forward = !forward, i++) {
1312 struct xfs_da3_icnode_hdr thdr;
1313 if (forward)
1314 blkno = nodehdr.forw;
1315 else
1316 blkno = nodehdr.back;
1317 if (blkno == 0)
1318 continue;
1319 error = xfs_da3_node_read(state->args->trans, dp, blkno, &bp,
1320 state->args->whichfork);
1321 if (error)
1322 return error;
1323
1324 node = bp->b_addr;
1325 xfs_da3_node_hdr_from_disk(dp->i_mount, &thdr, node);
1326 xfs_trans_brelse(state->args->trans, bp);
1327
1328 if (count - thdr.count >= 0)
1329 break; /* fits with at least 25% to spare */
1330 }
1331 if (i >= 2) {
1332 *action = 0;
1333 return 0;
1334 }
1335
1336 /*
1337 * Make altpath point to the block we want to keep (the lower
1338 * numbered block) and path point to the block we want to drop.
1339 */
1340 memcpy(&state->altpath, &state->path, sizeof(state->path));
1341 if (blkno < blk->blkno) {
1342 error = xfs_da3_path_shift(state, &state->altpath, forward,
1343 0, &retval);
1344 } else {
1345 error = xfs_da3_path_shift(state, &state->path, forward,
1346 0, &retval);
1347 }
1348 if (error)
1349 return error;
1350 if (retval) {
1351 *action = 0;
1352 return 0;
1353 }
1354 *action = 1;
1355 return 0;
1356}
1357
1358/*
1359 * Pick up the last hashvalue from an intermediate node.
1360 */
1361STATIC uint
1362xfs_da3_node_lasthash(
1363 struct xfs_inode *dp,
1364 struct xfs_buf *bp,
1365 int *count)
1366{
1367 struct xfs_da3_icnode_hdr nodehdr;
1368
1369 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, bp->b_addr);
1370 if (count)
1371 *count = nodehdr.count;
1372 if (!nodehdr.count)
1373 return 0;
1374 return be32_to_cpu(nodehdr.btree[nodehdr.count - 1].hashval);
1375}
1376
1377/*
1378 * Walk back up the tree adjusting hash values as necessary,
1379 * when we stop making changes, return.
1380 */
1381void
1382xfs_da3_fixhashpath(
1383 struct xfs_da_state *state,
1384 struct xfs_da_state_path *path)
1385{
1386 struct xfs_da_state_blk *blk;
1387 struct xfs_da_intnode *node;
1388 struct xfs_da_node_entry *btree;
1389 xfs_dahash_t lasthash=0;
1390 int level;
1391 int count;
1392 struct xfs_inode *dp = state->args->dp;
1393
1394 trace_xfs_da_fixhashpath(state->args);
1395
1396 level = path->active-1;
1397 blk = &path->blk[ level ];
1398 switch (blk->magic) {
1399 case XFS_ATTR_LEAF_MAGIC:
1400 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
1401 if (count == 0)
1402 return;
1403 break;
1404 case XFS_DIR2_LEAFN_MAGIC:
1405 lasthash = xfs_dir2_leaf_lasthash(dp, blk->bp, &count);
1406 if (count == 0)
1407 return;
1408 break;
1409 case XFS_DA_NODE_MAGIC:
1410 lasthash = xfs_da3_node_lasthash(dp, blk->bp, &count);
1411 if (count == 0)
1412 return;
1413 break;
1414 }
1415 for (blk--, level--; level >= 0; blk--, level--) {
1416 struct xfs_da3_icnode_hdr nodehdr;
1417
1418 node = blk->bp->b_addr;
1419 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1420 btree = nodehdr.btree;
1421 if (be32_to_cpu(btree[blk->index].hashval) == lasthash)
1422 break;
1423 blk->hashval = lasthash;
1424 btree[blk->index].hashval = cpu_to_be32(lasthash);
1425 xfs_trans_log_buf(state->args->trans, blk->bp,
1426 XFS_DA_LOGRANGE(node, &btree[blk->index],
1427 sizeof(*btree)));
1428
1429 lasthash = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1430 }
1431}
1432
1433/*
1434 * Remove an entry from an intermediate node.
1435 */
1436STATIC void
1437xfs_da3_node_remove(
1438 struct xfs_da_state *state,
1439 struct xfs_da_state_blk *drop_blk)
1440{
1441 struct xfs_da_intnode *node;
1442 struct xfs_da3_icnode_hdr nodehdr;
1443 struct xfs_da_node_entry *btree;
1444 int index;
1445 int tmp;
1446 struct xfs_inode *dp = state->args->dp;
1447
1448 trace_xfs_da_node_remove(state->args);
1449
1450 node = drop_blk->bp->b_addr;
1451 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1452 ASSERT(drop_blk->index < nodehdr.count);
1453 ASSERT(drop_blk->index >= 0);
1454
1455 /*
1456 * Copy over the offending entry, or just zero it out.
1457 */
1458 index = drop_blk->index;
1459 btree = nodehdr.btree;
1460 if (index < nodehdr.count - 1) {
1461 tmp = nodehdr.count - index - 1;
1462 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1463 memmove(&btree[index], &btree[index + 1], tmp);
1464 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1465 XFS_DA_LOGRANGE(node, &btree[index], tmp));
1466 index = nodehdr.count - 1;
1467 }
1468 memset(&btree[index], 0, sizeof(xfs_da_node_entry_t));
1469 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1470 XFS_DA_LOGRANGE(node, &btree[index], sizeof(btree[index])));
1471 nodehdr.count -= 1;
1472 xfs_da3_node_hdr_to_disk(dp->i_mount, node, &nodehdr);
1473 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1474 XFS_DA_LOGRANGE(node, &node->hdr, state->args->geo->node_hdr_size));
1475
1476 /*
1477 * Copy the last hash value from the block to propagate upwards.
1478 */
1479 drop_blk->hashval = be32_to_cpu(btree[index - 1].hashval);
1480}
1481
1482/*
1483 * Unbalance the elements between two intermediate nodes,
1484 * move all Btree elements from one node into another.
1485 */
1486STATIC void
1487xfs_da3_node_unbalance(
1488 struct xfs_da_state *state,
1489 struct xfs_da_state_blk *drop_blk,
1490 struct xfs_da_state_blk *save_blk)
1491{
1492 struct xfs_da_intnode *drop_node;
1493 struct xfs_da_intnode *save_node;
1494 struct xfs_da_node_entry *drop_btree;
1495 struct xfs_da_node_entry *save_btree;
1496 struct xfs_da3_icnode_hdr drop_hdr;
1497 struct xfs_da3_icnode_hdr save_hdr;
1498 struct xfs_trans *tp;
1499 int sindex;
1500 int tmp;
1501 struct xfs_inode *dp = state->args->dp;
1502
1503 trace_xfs_da_node_unbalance(state->args);
1504
1505 drop_node = drop_blk->bp->b_addr;
1506 save_node = save_blk->bp->b_addr;
1507 xfs_da3_node_hdr_from_disk(dp->i_mount, &drop_hdr, drop_node);
1508 xfs_da3_node_hdr_from_disk(dp->i_mount, &save_hdr, save_node);
1509 drop_btree = drop_hdr.btree;
1510 save_btree = save_hdr.btree;
1511 tp = state->args->trans;
1512
1513 /*
1514 * If the dying block has lower hashvals, then move all the
1515 * elements in the remaining block up to make a hole.
1516 */
1517 if ((be32_to_cpu(drop_btree[0].hashval) <
1518 be32_to_cpu(save_btree[0].hashval)) ||
1519 (be32_to_cpu(drop_btree[drop_hdr.count - 1].hashval) <
1520 be32_to_cpu(save_btree[save_hdr.count - 1].hashval))) {
1521 /* XXX: check this - is memmove dst correct? */
1522 tmp = save_hdr.count * sizeof(xfs_da_node_entry_t);
1523 memmove(&save_btree[drop_hdr.count], &save_btree[0], tmp);
1524
1525 sindex = 0;
1526 xfs_trans_log_buf(tp, save_blk->bp,
1527 XFS_DA_LOGRANGE(save_node, &save_btree[0],
1528 (save_hdr.count + drop_hdr.count) *
1529 sizeof(xfs_da_node_entry_t)));
1530 } else {
1531 sindex = save_hdr.count;
1532 xfs_trans_log_buf(tp, save_blk->bp,
1533 XFS_DA_LOGRANGE(save_node, &save_btree[sindex],
1534 drop_hdr.count * sizeof(xfs_da_node_entry_t)));
1535 }
1536
1537 /*
1538 * Move all the B-tree elements from drop_blk to save_blk.
1539 */
1540 tmp = drop_hdr.count * (uint)sizeof(xfs_da_node_entry_t);
1541 memcpy(&save_btree[sindex], &drop_btree[0], tmp);
1542 save_hdr.count += drop_hdr.count;
1543
1544 xfs_da3_node_hdr_to_disk(dp->i_mount, save_node, &save_hdr);
1545 xfs_trans_log_buf(tp, save_blk->bp,
1546 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1547 state->args->geo->node_hdr_size));
1548
1549 /*
1550 * Save the last hashval in the remaining block for upward propagation.
1551 */
1552 save_blk->hashval = be32_to_cpu(save_btree[save_hdr.count - 1].hashval);
1553}
1554
1555/*========================================================================
1556 * Routines used for finding things in the Btree.
1557 *========================================================================*/
1558
1559/*
1560 * Walk down the Btree looking for a particular filename, filling
1561 * in the state structure as we go.
1562 *
1563 * We will set the state structure to point to each of the elements
1564 * in each of the nodes where either the hashval is or should be.
1565 *
1566 * We support duplicate hashval's so for each entry in the current
1567 * node that could contain the desired hashval, descend. This is a
1568 * pruned depth-first tree search.
1569 */
1570int /* error */
1571xfs_da3_node_lookup_int(
1572 struct xfs_da_state *state,
1573 int *result)
1574{
1575 struct xfs_da_state_blk *blk;
1576 struct xfs_da_blkinfo *curr;
1577 struct xfs_da_intnode *node;
1578 struct xfs_da_node_entry *btree;
1579 struct xfs_da3_icnode_hdr nodehdr;
1580 struct xfs_da_args *args;
1581 xfs_dablk_t blkno;
1582 xfs_dahash_t hashval;
1583 xfs_dahash_t btreehashval;
1584 int probe;
1585 int span;
1586 int max;
1587 int error;
1588 int retval;
1589 unsigned int expected_level = 0;
1590 uint16_t magic;
1591 struct xfs_inode *dp = state->args->dp;
1592
1593 args = state->args;
1594
1595 /*
1596 * Descend thru the B-tree searching each level for the right
1597 * node to use, until the right hashval is found.
1598 */
1599 blkno = args->geo->leafblk;
1600 for (blk = &state->path.blk[0], state->path.active = 1;
1601 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1602 blk++, state->path.active++) {
1603 /*
1604 * Read the next node down in the tree.
1605 */
1606 blk->blkno = blkno;
1607 error = xfs_da3_node_read(args->trans, args->dp, blkno,
1608 &blk->bp, args->whichfork);
1609 if (error) {
1610 blk->blkno = 0;
1611 state->path.active--;
1612 return error;
1613 }
1614 curr = blk->bp->b_addr;
1615 magic = be16_to_cpu(curr->magic);
1616
1617 if (magic == XFS_ATTR_LEAF_MAGIC ||
1618 magic == XFS_ATTR3_LEAF_MAGIC) {
1619 blk->magic = XFS_ATTR_LEAF_MAGIC;
1620 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1621 break;
1622 }
1623
1624 if (magic == XFS_DIR2_LEAFN_MAGIC ||
1625 magic == XFS_DIR3_LEAFN_MAGIC) {
1626 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1627 blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
1628 blk->bp, NULL);
1629 break;
1630 }
1631
1632 if (magic != XFS_DA_NODE_MAGIC && magic != XFS_DA3_NODE_MAGIC) {
1633 xfs_buf_mark_corrupt(blk->bp);
1634 return -EFSCORRUPTED;
1635 }
1636
1637 blk->magic = XFS_DA_NODE_MAGIC;
1638
1639 /*
1640 * Search an intermediate node for a match.
1641 */
1642 node = blk->bp->b_addr;
1643 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr, node);
1644 btree = nodehdr.btree;
1645
1646 /* Tree taller than we can handle; bail out! */
1647 if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH) {
1648 xfs_buf_mark_corrupt(blk->bp);
1649 return -EFSCORRUPTED;
1650 }
1651
1652 /* Check the level from the root. */
1653 if (blkno == args->geo->leafblk)
1654 expected_level = nodehdr.level - 1;
1655 else if (expected_level != nodehdr.level) {
1656 xfs_buf_mark_corrupt(blk->bp);
1657 return -EFSCORRUPTED;
1658 } else
1659 expected_level--;
1660
1661 max = nodehdr.count;
1662 blk->hashval = be32_to_cpu(btree[max - 1].hashval);
1663
1664 /*
1665 * Binary search. (note: small blocks will skip loop)
1666 */
1667 probe = span = max / 2;
1668 hashval = args->hashval;
1669 while (span > 4) {
1670 span /= 2;
1671 btreehashval = be32_to_cpu(btree[probe].hashval);
1672 if (btreehashval < hashval)
1673 probe += span;
1674 else if (btreehashval > hashval)
1675 probe -= span;
1676 else
1677 break;
1678 }
1679 ASSERT((probe >= 0) && (probe < max));
1680 ASSERT((span <= 4) ||
1681 (be32_to_cpu(btree[probe].hashval) == hashval));
1682
1683 /*
1684 * Since we may have duplicate hashval's, find the first
1685 * matching hashval in the node.
1686 */
1687 while (probe > 0 &&
1688 be32_to_cpu(btree[probe].hashval) >= hashval) {
1689 probe--;
1690 }
1691 while (probe < max &&
1692 be32_to_cpu(btree[probe].hashval) < hashval) {
1693 probe++;
1694 }
1695
1696 /*
1697 * Pick the right block to descend on.
1698 */
1699 if (probe == max) {
1700 blk->index = max - 1;
1701 blkno = be32_to_cpu(btree[max - 1].before);
1702 } else {
1703 blk->index = probe;
1704 blkno = be32_to_cpu(btree[probe].before);
1705 }
1706
1707 /* We can't point back to the root. */
1708 if (XFS_IS_CORRUPT(dp->i_mount, blkno == args->geo->leafblk))
1709 return -EFSCORRUPTED;
1710 }
1711
1712 if (XFS_IS_CORRUPT(dp->i_mount, expected_level != 0))
1713 return -EFSCORRUPTED;
1714
1715 /*
1716 * A leaf block that ends in the hashval that we are interested in
1717 * (final hashval == search hashval) means that the next block may
1718 * contain more entries with the same hashval, shift upward to the
1719 * next leaf and keep searching.
1720 */
1721 for (;;) {
1722 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1723 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1724 &blk->index, state);
1725 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1726 retval = xfs_attr3_leaf_lookup_int(blk->bp, args);
1727 blk->index = args->index;
1728 args->blkno = blk->blkno;
1729 } else {
1730 ASSERT(0);
1731 return -EFSCORRUPTED;
1732 }
1733 if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
1734 (blk->hashval == args->hashval)) {
1735 error = xfs_da3_path_shift(state, &state->path, 1, 1,
1736 &retval);
1737 if (error)
1738 return error;
1739 if (retval == 0) {
1740 continue;
1741 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1742 /* path_shift() gives ENOENT */
1743 retval = -ENOATTR;
1744 }
1745 }
1746 break;
1747 }
1748 *result = retval;
1749 return 0;
1750}
1751
1752/*========================================================================
1753 * Utility routines.
1754 *========================================================================*/
1755
1756/*
1757 * Compare two intermediate nodes for "order".
1758 */
1759STATIC int
1760xfs_da3_node_order(
1761 struct xfs_inode *dp,
1762 struct xfs_buf *node1_bp,
1763 struct xfs_buf *node2_bp)
1764{
1765 struct xfs_da_intnode *node1;
1766 struct xfs_da_intnode *node2;
1767 struct xfs_da_node_entry *btree1;
1768 struct xfs_da_node_entry *btree2;
1769 struct xfs_da3_icnode_hdr node1hdr;
1770 struct xfs_da3_icnode_hdr node2hdr;
1771
1772 node1 = node1_bp->b_addr;
1773 node2 = node2_bp->b_addr;
1774 xfs_da3_node_hdr_from_disk(dp->i_mount, &node1hdr, node1);
1775 xfs_da3_node_hdr_from_disk(dp->i_mount, &node2hdr, node2);
1776 btree1 = node1hdr.btree;
1777 btree2 = node2hdr.btree;
1778
1779 if (node1hdr.count > 0 && node2hdr.count > 0 &&
1780 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
1781 (be32_to_cpu(btree2[node2hdr.count - 1].hashval) <
1782 be32_to_cpu(btree1[node1hdr.count - 1].hashval)))) {
1783 return 1;
1784 }
1785 return 0;
1786}
1787
1788/*
1789 * Link a new block into a doubly linked list of blocks (of whatever type).
1790 */
1791int /* error */
1792xfs_da3_blk_link(
1793 struct xfs_da_state *state,
1794 struct xfs_da_state_blk *old_blk,
1795 struct xfs_da_state_blk *new_blk)
1796{
1797 struct xfs_da_blkinfo *old_info;
1798 struct xfs_da_blkinfo *new_info;
1799 struct xfs_da_blkinfo *tmp_info;
1800 struct xfs_da_args *args;
1801 struct xfs_buf *bp;
1802 int before = 0;
1803 int error;
1804 struct xfs_inode *dp = state->args->dp;
1805
1806 /*
1807 * Set up environment.
1808 */
1809 args = state->args;
1810 ASSERT(args != NULL);
1811 old_info = old_blk->bp->b_addr;
1812 new_info = new_blk->bp->b_addr;
1813 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1814 old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1815 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1816
1817 switch (old_blk->magic) {
1818 case XFS_ATTR_LEAF_MAGIC:
1819 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1820 break;
1821 case XFS_DIR2_LEAFN_MAGIC:
1822 before = xfs_dir2_leafn_order(dp, old_blk->bp, new_blk->bp);
1823 break;
1824 case XFS_DA_NODE_MAGIC:
1825 before = xfs_da3_node_order(dp, old_blk->bp, new_blk->bp);
1826 break;
1827 }
1828
1829 /*
1830 * Link blocks in appropriate order.
1831 */
1832 if (before) {
1833 /*
1834 * Link new block in before existing block.
1835 */
1836 trace_xfs_da_link_before(args);
1837 new_info->forw = cpu_to_be32(old_blk->blkno);
1838 new_info->back = old_info->back;
1839 if (old_info->back) {
1840 error = xfs_da3_node_read(args->trans, dp,
1841 be32_to_cpu(old_info->back),
1842 &bp, args->whichfork);
1843 if (error)
1844 return error;
1845 ASSERT(bp != NULL);
1846 tmp_info = bp->b_addr;
1847 ASSERT(tmp_info->magic == old_info->magic);
1848 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1849 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1850 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1851 }
1852 old_info->back = cpu_to_be32(new_blk->blkno);
1853 } else {
1854 /*
1855 * Link new block in after existing block.
1856 */
1857 trace_xfs_da_link_after(args);
1858 new_info->forw = old_info->forw;
1859 new_info->back = cpu_to_be32(old_blk->blkno);
1860 if (old_info->forw) {
1861 error = xfs_da3_node_read(args->trans, dp,
1862 be32_to_cpu(old_info->forw),
1863 &bp, args->whichfork);
1864 if (error)
1865 return error;
1866 ASSERT(bp != NULL);
1867 tmp_info = bp->b_addr;
1868 ASSERT(tmp_info->magic == old_info->magic);
1869 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1870 tmp_info->back = cpu_to_be32(new_blk->blkno);
1871 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1872 }
1873 old_info->forw = cpu_to_be32(new_blk->blkno);
1874 }
1875
1876 xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1877 xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1878 return 0;
1879}
1880
1881/*
1882 * Unlink a block from a doubly linked list of blocks.
1883 */
1884STATIC int /* error */
1885xfs_da3_blk_unlink(
1886 struct xfs_da_state *state,
1887 struct xfs_da_state_blk *drop_blk,
1888 struct xfs_da_state_blk *save_blk)
1889{
1890 struct xfs_da_blkinfo *drop_info;
1891 struct xfs_da_blkinfo *save_info;
1892 struct xfs_da_blkinfo *tmp_info;
1893 struct xfs_da_args *args;
1894 struct xfs_buf *bp;
1895 int error;
1896
1897 /*
1898 * Set up environment.
1899 */
1900 args = state->args;
1901 ASSERT(args != NULL);
1902 save_info = save_blk->bp->b_addr;
1903 drop_info = drop_blk->bp->b_addr;
1904 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1905 save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1906 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1907 ASSERT(save_blk->magic == drop_blk->magic);
1908 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1909 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1910 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1911 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1912
1913 /*
1914 * Unlink the leaf block from the doubly linked chain of leaves.
1915 */
1916 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1917 trace_xfs_da_unlink_back(args);
1918 save_info->back = drop_info->back;
1919 if (drop_info->back) {
1920 error = xfs_da3_node_read(args->trans, args->dp,
1921 be32_to_cpu(drop_info->back),
1922 &bp, args->whichfork);
1923 if (error)
1924 return error;
1925 ASSERT(bp != NULL);
1926 tmp_info = bp->b_addr;
1927 ASSERT(tmp_info->magic == save_info->magic);
1928 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1929 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1930 xfs_trans_log_buf(args->trans, bp, 0,
1931 sizeof(*tmp_info) - 1);
1932 }
1933 } else {
1934 trace_xfs_da_unlink_forward(args);
1935 save_info->forw = drop_info->forw;
1936 if (drop_info->forw) {
1937 error = xfs_da3_node_read(args->trans, args->dp,
1938 be32_to_cpu(drop_info->forw),
1939 &bp, args->whichfork);
1940 if (error)
1941 return error;
1942 ASSERT(bp != NULL);
1943 tmp_info = bp->b_addr;
1944 ASSERT(tmp_info->magic == save_info->magic);
1945 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1946 tmp_info->back = cpu_to_be32(save_blk->blkno);
1947 xfs_trans_log_buf(args->trans, bp, 0,
1948 sizeof(*tmp_info) - 1);
1949 }
1950 }
1951
1952 xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1953 return 0;
1954}
1955
1956/*
1957 * Move a path "forward" or "!forward" one block at the current level.
1958 *
1959 * This routine will adjust a "path" to point to the next block
1960 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1961 * Btree, including updating pointers to the intermediate nodes between
1962 * the new bottom and the root.
1963 */
1964int /* error */
1965xfs_da3_path_shift(
1966 struct xfs_da_state *state,
1967 struct xfs_da_state_path *path,
1968 int forward,
1969 int release,
1970 int *result)
1971{
1972 struct xfs_da_state_blk *blk;
1973 struct xfs_da_blkinfo *info;
1974 struct xfs_da_args *args;
1975 struct xfs_da_node_entry *btree;
1976 struct xfs_da3_icnode_hdr nodehdr;
1977 struct xfs_buf *bp;
1978 xfs_dablk_t blkno = 0;
1979 int level;
1980 int error;
1981 struct xfs_inode *dp = state->args->dp;
1982
1983 trace_xfs_da_path_shift(state->args);
1984
1985 /*
1986 * Roll up the Btree looking for the first block where our
1987 * current index is not at the edge of the block. Note that
1988 * we skip the bottom layer because we want the sibling block.
1989 */
1990 args = state->args;
1991 ASSERT(args != NULL);
1992 ASSERT(path != NULL);
1993 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1994 level = (path->active-1) - 1; /* skip bottom layer in path */
1995 for (; level >= 0; level--) {
1996 blk = &path->blk[level];
1997 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr,
1998 blk->bp->b_addr);
1999
2000 if (forward && (blk->index < nodehdr.count - 1)) {
2001 blk->index++;
2002 blkno = be32_to_cpu(nodehdr.btree[blk->index].before);
2003 break;
2004 } else if (!forward && (blk->index > 0)) {
2005 blk->index--;
2006 blkno = be32_to_cpu(nodehdr.btree[blk->index].before);
2007 break;
2008 }
2009 }
2010 if (level < 0) {
2011 *result = -ENOENT; /* we're out of our tree */
2012 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
2013 return 0;
2014 }
2015
2016 /*
2017 * Roll down the edge of the subtree until we reach the
2018 * same depth we were at originally.
2019 */
2020 for (blk++, level++; level < path->active; blk++, level++) {
2021 /*
2022 * Read the next child block into a local buffer.
2023 */
2024 error = xfs_da3_node_read(args->trans, dp, blkno, &bp,
2025 args->whichfork);
2026 if (error)
2027 return error;
2028
2029 /*
2030 * Release the old block (if it's dirty, the trans doesn't
2031 * actually let go) and swap the local buffer into the path
2032 * structure. This ensures failure of the above read doesn't set
2033 * a NULL buffer in an active slot in the path.
2034 */
2035 if (release)
2036 xfs_trans_brelse(args->trans, blk->bp);
2037 blk->blkno = blkno;
2038 blk->bp = bp;
2039
2040 info = blk->bp->b_addr;
2041 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
2042 info->magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
2043 info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2044 info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
2045 info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
2046 info->magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
2047
2048
2049 /*
2050 * Note: we flatten the magic number to a single type so we
2051 * don't have to compare against crc/non-crc types elsewhere.
2052 */
2053 switch (be16_to_cpu(info->magic)) {
2054 case XFS_DA_NODE_MAGIC:
2055 case XFS_DA3_NODE_MAGIC:
2056 blk->magic = XFS_DA_NODE_MAGIC;
2057 xfs_da3_node_hdr_from_disk(dp->i_mount, &nodehdr,
2058 bp->b_addr);
2059 btree = nodehdr.btree;
2060 blk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
2061 if (forward)
2062 blk->index = 0;
2063 else
2064 blk->index = nodehdr.count - 1;
2065 blkno = be32_to_cpu(btree[blk->index].before);
2066 break;
2067 case XFS_ATTR_LEAF_MAGIC:
2068 case XFS_ATTR3_LEAF_MAGIC:
2069 blk->magic = XFS_ATTR_LEAF_MAGIC;
2070 ASSERT(level == path->active-1);
2071 blk->index = 0;
2072 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
2073 break;
2074 case XFS_DIR2_LEAFN_MAGIC:
2075 case XFS_DIR3_LEAFN_MAGIC:
2076 blk->magic = XFS_DIR2_LEAFN_MAGIC;
2077 ASSERT(level == path->active-1);
2078 blk->index = 0;
2079 blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
2080 blk->bp, NULL);
2081 break;
2082 default:
2083 ASSERT(0);
2084 break;
2085 }
2086 }
2087 *result = 0;
2088 return 0;
2089}
2090
2091
2092/*========================================================================
2093 * Utility routines.
2094 *========================================================================*/
2095
2096/*
2097 * Implement a simple hash on a character string.
2098 * Rotate the hash value by 7 bits, then XOR each character in.
2099 * This is implemented with some source-level loop unrolling.
2100 */
2101xfs_dahash_t
2102xfs_da_hashname(const uint8_t *name, int namelen)
2103{
2104 xfs_dahash_t hash;
2105
2106 /*
2107 * Do four characters at a time as long as we can.
2108 */
2109 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
2110 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
2111 (name[3] << 0) ^ rol32(hash, 7 * 4);
2112
2113 /*
2114 * Now do the rest of the characters.
2115 */
2116 switch (namelen) {
2117 case 3:
2118 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
2119 rol32(hash, 7 * 3);
2120 case 2:
2121 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
2122 case 1:
2123 return (name[0] << 0) ^ rol32(hash, 7 * 1);
2124 default: /* case 0: */
2125 return hash;
2126 }
2127}
2128
2129enum xfs_dacmp
2130xfs_da_compname(
2131 struct xfs_da_args *args,
2132 const unsigned char *name,
2133 int len)
2134{
2135 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
2136 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
2137}
2138
2139int
2140xfs_da_grow_inode_int(
2141 struct xfs_da_args *args,
2142 xfs_fileoff_t *bno,
2143 int count)
2144{
2145 struct xfs_trans *tp = args->trans;
2146 struct xfs_inode *dp = args->dp;
2147 int w = args->whichfork;
2148 xfs_rfsblock_t nblks = dp->i_nblocks;
2149 struct xfs_bmbt_irec map, *mapp;
2150 int nmap, error, got, i, mapi;
2151
2152 /*
2153 * Find a spot in the file space to put the new block.
2154 */
2155 error = xfs_bmap_first_unused(tp, dp, count, bno, w);
2156 if (error)
2157 return error;
2158
2159 /*
2160 * Try mapping it in one filesystem block.
2161 */
2162 nmap = 1;
2163 error = xfs_bmapi_write(tp, dp, *bno, count,
2164 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
2165 args->total, &map, &nmap);
2166 if (error)
2167 return error;
2168
2169 ASSERT(nmap <= 1);
2170 if (nmap == 1) {
2171 mapp = ↦
2172 mapi = 1;
2173 } else if (nmap == 0 && count > 1) {
2174 xfs_fileoff_t b;
2175 int c;
2176
2177 /*
2178 * If we didn't get it and the block might work if fragmented,
2179 * try without the CONTIG flag. Loop until we get it all.
2180 */
2181 mapp = kmem_alloc(sizeof(*mapp) * count, 0);
2182 for (b = *bno, mapi = 0; b < *bno + count; ) {
2183 nmap = min(XFS_BMAP_MAX_NMAP, count);
2184 c = (int)(*bno + count - b);
2185 error = xfs_bmapi_write(tp, dp, b, c,
2186 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2187 args->total, &mapp[mapi], &nmap);
2188 if (error)
2189 goto out_free_map;
2190 if (nmap < 1)
2191 break;
2192 mapi += nmap;
2193 b = mapp[mapi - 1].br_startoff +
2194 mapp[mapi - 1].br_blockcount;
2195 }
2196 } else {
2197 mapi = 0;
2198 mapp = NULL;
2199 }
2200
2201 /*
2202 * Count the blocks we got, make sure it matches the total.
2203 */
2204 for (i = 0, got = 0; i < mapi; i++)
2205 got += mapp[i].br_blockcount;
2206 if (got != count || mapp[0].br_startoff != *bno ||
2207 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
2208 *bno + count) {
2209 error = -ENOSPC;
2210 goto out_free_map;
2211 }
2212
2213 /* account for newly allocated blocks in reserved blocks total */
2214 args->total -= dp->i_nblocks - nblks;
2215
2216out_free_map:
2217 if (mapp != &map)
2218 kmem_free(mapp);
2219 return error;
2220}
2221
2222/*
2223 * Add a block to the btree ahead of the file.
2224 * Return the new block number to the caller.
2225 */
2226int
2227xfs_da_grow_inode(
2228 struct xfs_da_args *args,
2229 xfs_dablk_t *new_blkno)
2230{
2231 xfs_fileoff_t bno;
2232 int error;
2233
2234 trace_xfs_da_grow_inode(args);
2235
2236 bno = args->geo->leafblk;
2237 error = xfs_da_grow_inode_int(args, &bno, args->geo->fsbcount);
2238 if (!error)
2239 *new_blkno = (xfs_dablk_t)bno;
2240 return error;
2241}
2242
2243/*
2244 * Ick. We need to always be able to remove a btree block, even
2245 * if there's no space reservation because the filesystem is full.
2246 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
2247 * It swaps the target block with the last block in the file. The
2248 * last block in the file can always be removed since it can't cause
2249 * a bmap btree split to do that.
2250 */
2251STATIC int
2252xfs_da3_swap_lastblock(
2253 struct xfs_da_args *args,
2254 xfs_dablk_t *dead_blknop,
2255 struct xfs_buf **dead_bufp)
2256{
2257 struct xfs_da_blkinfo *dead_info;
2258 struct xfs_da_blkinfo *sib_info;
2259 struct xfs_da_intnode *par_node;
2260 struct xfs_da_intnode *dead_node;
2261 struct xfs_dir2_leaf *dead_leaf2;
2262 struct xfs_da_node_entry *btree;
2263 struct xfs_da3_icnode_hdr par_hdr;
2264 struct xfs_inode *dp;
2265 struct xfs_trans *tp;
2266 struct xfs_mount *mp;
2267 struct xfs_buf *dead_buf;
2268 struct xfs_buf *last_buf;
2269 struct xfs_buf *sib_buf;
2270 struct xfs_buf *par_buf;
2271 xfs_dahash_t dead_hash;
2272 xfs_fileoff_t lastoff;
2273 xfs_dablk_t dead_blkno;
2274 xfs_dablk_t last_blkno;
2275 xfs_dablk_t sib_blkno;
2276 xfs_dablk_t par_blkno;
2277 int error;
2278 int w;
2279 int entno;
2280 int level;
2281 int dead_level;
2282
2283 trace_xfs_da_swap_lastblock(args);
2284
2285 dead_buf = *dead_bufp;
2286 dead_blkno = *dead_blknop;
2287 tp = args->trans;
2288 dp = args->dp;
2289 w = args->whichfork;
2290 ASSERT(w == XFS_DATA_FORK);
2291 mp = dp->i_mount;
2292 lastoff = args->geo->freeblk;
2293 error = xfs_bmap_last_before(tp, dp, &lastoff, w);
2294 if (error)
2295 return error;
2296 if (XFS_IS_CORRUPT(mp, lastoff == 0))
2297 return -EFSCORRUPTED;
2298 /*
2299 * Read the last block in the btree space.
2300 */
2301 last_blkno = (xfs_dablk_t)lastoff - args->geo->fsbcount;
2302 error = xfs_da3_node_read(tp, dp, last_blkno, &last_buf, w);
2303 if (error)
2304 return error;
2305 /*
2306 * Copy the last block into the dead buffer and log it.
2307 */
2308 memcpy(dead_buf->b_addr, last_buf->b_addr, args->geo->blksize);
2309 xfs_trans_log_buf(tp, dead_buf, 0, args->geo->blksize - 1);
2310 dead_info = dead_buf->b_addr;
2311 /*
2312 * Get values from the moved block.
2313 */
2314 if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2315 dead_info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
2316 struct xfs_dir3_icleaf_hdr leafhdr;
2317 struct xfs_dir2_leaf_entry *ents;
2318
2319 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
2320 xfs_dir2_leaf_hdr_from_disk(dp->i_mount, &leafhdr,
2321 dead_leaf2);
2322 ents = leafhdr.ents;
2323 dead_level = 0;
2324 dead_hash = be32_to_cpu(ents[leafhdr.count - 1].hashval);
2325 } else {
2326 struct xfs_da3_icnode_hdr deadhdr;
2327
2328 dead_node = (xfs_da_intnode_t *)dead_info;
2329 xfs_da3_node_hdr_from_disk(dp->i_mount, &deadhdr, dead_node);
2330 btree = deadhdr.btree;
2331 dead_level = deadhdr.level;
2332 dead_hash = be32_to_cpu(btree[deadhdr.count - 1].hashval);
2333 }
2334 sib_buf = par_buf = NULL;
2335 /*
2336 * If the moved block has a left sibling, fix up the pointers.
2337 */
2338 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
2339 error = xfs_da3_node_read(tp, dp, sib_blkno, &sib_buf, w);
2340 if (error)
2341 goto done;
2342 sib_info = sib_buf->b_addr;
2343 if (XFS_IS_CORRUPT(mp,
2344 be32_to_cpu(sib_info->forw) != last_blkno ||
2345 sib_info->magic != dead_info->magic)) {
2346 error = -EFSCORRUPTED;
2347 goto done;
2348 }
2349 sib_info->forw = cpu_to_be32(dead_blkno);
2350 xfs_trans_log_buf(tp, sib_buf,
2351 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
2352 sizeof(sib_info->forw)));
2353 sib_buf = NULL;
2354 }
2355 /*
2356 * If the moved block has a right sibling, fix up the pointers.
2357 */
2358 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
2359 error = xfs_da3_node_read(tp, dp, sib_blkno, &sib_buf, w);
2360 if (error)
2361 goto done;
2362 sib_info = sib_buf->b_addr;
2363 if (XFS_IS_CORRUPT(mp,
2364 be32_to_cpu(sib_info->back) != last_blkno ||
2365 sib_info->magic != dead_info->magic)) {
2366 error = -EFSCORRUPTED;
2367 goto done;
2368 }
2369 sib_info->back = cpu_to_be32(dead_blkno);
2370 xfs_trans_log_buf(tp, sib_buf,
2371 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
2372 sizeof(sib_info->back)));
2373 sib_buf = NULL;
2374 }
2375 par_blkno = args->geo->leafblk;
2376 level = -1;
2377 /*
2378 * Walk down the tree looking for the parent of the moved block.
2379 */
2380 for (;;) {
2381 error = xfs_da3_node_read(tp, dp, par_blkno, &par_buf, w);
2382 if (error)
2383 goto done;
2384 par_node = par_buf->b_addr;
2385 xfs_da3_node_hdr_from_disk(dp->i_mount, &par_hdr, par_node);
2386 if (XFS_IS_CORRUPT(mp,
2387 level >= 0 && level != par_hdr.level + 1)) {
2388 error = -EFSCORRUPTED;
2389 goto done;
2390 }
2391 level = par_hdr.level;
2392 btree = par_hdr.btree;
2393 for (entno = 0;
2394 entno < par_hdr.count &&
2395 be32_to_cpu(btree[entno].hashval) < dead_hash;
2396 entno++)
2397 continue;
2398 if (XFS_IS_CORRUPT(mp, entno == par_hdr.count)) {
2399 error = -EFSCORRUPTED;
2400 goto done;
2401 }
2402 par_blkno = be32_to_cpu(btree[entno].before);
2403 if (level == dead_level + 1)
2404 break;
2405 xfs_trans_brelse(tp, par_buf);
2406 par_buf = NULL;
2407 }
2408 /*
2409 * We're in the right parent block.
2410 * Look for the right entry.
2411 */
2412 for (;;) {
2413 for (;
2414 entno < par_hdr.count &&
2415 be32_to_cpu(btree[entno].before) != last_blkno;
2416 entno++)
2417 continue;
2418 if (entno < par_hdr.count)
2419 break;
2420 par_blkno = par_hdr.forw;
2421 xfs_trans_brelse(tp, par_buf);
2422 par_buf = NULL;
2423 if (XFS_IS_CORRUPT(mp, par_blkno == 0)) {
2424 error = -EFSCORRUPTED;
2425 goto done;
2426 }
2427 error = xfs_da3_node_read(tp, dp, par_blkno, &par_buf, w);
2428 if (error)
2429 goto done;
2430 par_node = par_buf->b_addr;
2431 xfs_da3_node_hdr_from_disk(dp->i_mount, &par_hdr, par_node);
2432 if (XFS_IS_CORRUPT(mp, par_hdr.level != level)) {
2433 error = -EFSCORRUPTED;
2434 goto done;
2435 }
2436 btree = par_hdr.btree;
2437 entno = 0;
2438 }
2439 /*
2440 * Update the parent entry pointing to the moved block.
2441 */
2442 btree[entno].before = cpu_to_be32(dead_blkno);
2443 xfs_trans_log_buf(tp, par_buf,
2444 XFS_DA_LOGRANGE(par_node, &btree[entno].before,
2445 sizeof(btree[entno].before)));
2446 *dead_blknop = last_blkno;
2447 *dead_bufp = last_buf;
2448 return 0;
2449done:
2450 if (par_buf)
2451 xfs_trans_brelse(tp, par_buf);
2452 if (sib_buf)
2453 xfs_trans_brelse(tp, sib_buf);
2454 xfs_trans_brelse(tp, last_buf);
2455 return error;
2456}
2457
2458/*
2459 * Remove a btree block from a directory or attribute.
2460 */
2461int
2462xfs_da_shrink_inode(
2463 struct xfs_da_args *args,
2464 xfs_dablk_t dead_blkno,
2465 struct xfs_buf *dead_buf)
2466{
2467 struct xfs_inode *dp;
2468 int done, error, w, count;
2469 struct xfs_trans *tp;
2470
2471 trace_xfs_da_shrink_inode(args);
2472
2473 dp = args->dp;
2474 w = args->whichfork;
2475 tp = args->trans;
2476 count = args->geo->fsbcount;
2477 for (;;) {
2478 /*
2479 * Remove extents. If we get ENOSPC for a dir we have to move
2480 * the last block to the place we want to kill.
2481 */
2482 error = xfs_bunmapi(tp, dp, dead_blkno, count,
2483 xfs_bmapi_aflag(w), 0, &done);
2484 if (error == -ENOSPC) {
2485 if (w != XFS_DATA_FORK)
2486 break;
2487 error = xfs_da3_swap_lastblock(args, &dead_blkno,
2488 &dead_buf);
2489 if (error)
2490 break;
2491 } else {
2492 break;
2493 }
2494 }
2495 xfs_trans_binval(tp, dead_buf);
2496 return error;
2497}
2498
2499static int
2500xfs_dabuf_map(
2501 struct xfs_inode *dp,
2502 xfs_dablk_t bno,
2503 unsigned int flags,
2504 int whichfork,
2505 struct xfs_buf_map **mapp,
2506 int *nmaps)
2507{
2508 struct xfs_mount *mp = dp->i_mount;
2509 int nfsb = xfs_dabuf_nfsb(mp, whichfork);
2510 struct xfs_bmbt_irec irec, *irecs = &irec;
2511 struct xfs_buf_map *map = *mapp;
2512 xfs_fileoff_t off = bno;
2513 int error = 0, nirecs, i;
2514
2515 if (nfsb > 1)
2516 irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_NOFS);
2517
2518 nirecs = nfsb;
2519 error = xfs_bmapi_read(dp, bno, nfsb, irecs, &nirecs,
2520 xfs_bmapi_aflag(whichfork));
2521 if (error)
2522 goto out_free_irecs;
2523
2524 /*
2525 * Use the caller provided map for the single map case, else allocate a
2526 * larger one that needs to be free by the caller.
2527 */
2528 if (nirecs > 1) {
2529 map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_NOFS);
2530 if (!map) {
2531 error = -ENOMEM;
2532 goto out_free_irecs;
2533 }
2534 *mapp = map;
2535 }
2536
2537 for (i = 0; i < nirecs; i++) {
2538 if (irecs[i].br_startblock == HOLESTARTBLOCK ||
2539 irecs[i].br_startblock == DELAYSTARTBLOCK)
2540 goto invalid_mapping;
2541 if (off != irecs[i].br_startoff)
2542 goto invalid_mapping;
2543
2544 map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
2545 map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
2546 off += irecs[i].br_blockcount;
2547 }
2548
2549 if (off != bno + nfsb)
2550 goto invalid_mapping;
2551
2552 *nmaps = nirecs;
2553out_free_irecs:
2554 if (irecs != &irec)
2555 kmem_free(irecs);
2556 return error;
2557
2558invalid_mapping:
2559 /* Caller ok with no mapping. */
2560 if (XFS_IS_CORRUPT(mp, !(flags & XFS_DABUF_MAP_HOLE_OK))) {
2561 error = -EFSCORRUPTED;
2562 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2563 xfs_alert(mp, "%s: bno %u inode %llu",
2564 __func__, bno, dp->i_ino);
2565
2566 for (i = 0; i < nirecs; i++) {
2567 xfs_alert(mp,
2568"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2569 i, irecs[i].br_startoff,
2570 irecs[i].br_startblock,
2571 irecs[i].br_blockcount,
2572 irecs[i].br_state);
2573 }
2574 }
2575 } else {
2576 *nmaps = 0;
2577 }
2578 goto out_free_irecs;
2579}
2580
2581/*
2582 * Get a buffer for the dir/attr block.
2583 */
2584int
2585xfs_da_get_buf(
2586 struct xfs_trans *tp,
2587 struct xfs_inode *dp,
2588 xfs_dablk_t bno,
2589 struct xfs_buf **bpp,
2590 int whichfork)
2591{
2592 struct xfs_mount *mp = dp->i_mount;
2593 struct xfs_buf *bp;
2594 struct xfs_buf_map map, *mapp = ↦
2595 int nmap = 1;
2596 int error;
2597
2598 *bpp = NULL;
2599 error = xfs_dabuf_map(dp, bno, 0, whichfork, &mapp, &nmap);
2600 if (error || nmap == 0)
2601 goto out_free;
2602
2603 error = xfs_trans_get_buf_map(tp, mp->m_ddev_targp, mapp, nmap, 0, &bp);
2604 if (error)
2605 goto out_free;
2606
2607 *bpp = bp;
2608
2609out_free:
2610 if (mapp != &map)
2611 kmem_free(mapp);
2612
2613 return error;
2614}
2615
2616/*
2617 * Get a buffer for the dir/attr block, fill in the contents.
2618 */
2619int
2620xfs_da_read_buf(
2621 struct xfs_trans *tp,
2622 struct xfs_inode *dp,
2623 xfs_dablk_t bno,
2624 unsigned int flags,
2625 struct xfs_buf **bpp,
2626 int whichfork,
2627 const struct xfs_buf_ops *ops)
2628{
2629 struct xfs_mount *mp = dp->i_mount;
2630 struct xfs_buf *bp;
2631 struct xfs_buf_map map, *mapp = ↦
2632 int nmap = 1;
2633 int error;
2634
2635 *bpp = NULL;
2636 error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap);
2637 if (error || !nmap)
2638 goto out_free;
2639
2640 error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0,
2641 &bp, ops);
2642 if (error)
2643 goto out_free;
2644
2645 if (whichfork == XFS_ATTR_FORK)
2646 xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2647 else
2648 xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2649 *bpp = bp;
2650out_free:
2651 if (mapp != &map)
2652 kmem_free(mapp);
2653
2654 return error;
2655}
2656
2657/*
2658 * Readahead the dir/attr block.
2659 */
2660int
2661xfs_da_reada_buf(
2662 struct xfs_inode *dp,
2663 xfs_dablk_t bno,
2664 unsigned int flags,
2665 int whichfork,
2666 const struct xfs_buf_ops *ops)
2667{
2668 struct xfs_buf_map map;
2669 struct xfs_buf_map *mapp;
2670 int nmap;
2671 int error;
2672
2673 mapp = ↦
2674 nmap = 1;
2675 error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap);
2676 if (error || !nmap)
2677 goto out_free;
2678
2679 xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
2680
2681out_free:
2682 if (mapp != &map)
2683 kmem_free(mapp);
2684
2685 return error;
2686}